Tuesday, May 18, 2021

The Mediating Role of Perceived Scholastic Competence in the Relationship between Motor Coordination and Academic Performanceioural Disturbance in People with Intellectual Disability - Juniper Publishers

 Intellectual & Developmental Disabilities - Juniper Publishers   

Introduction

The motor skill capabilities of a person are highly influenced by the motor learning they encounter across their lifespan through experience or specific practice [1]. However, there is a condition known as Developmental Coordination Disorder (DCD) that affects a small subset of children, resulting in attenuation of learning and compromised motor coordination when performing everyday tasks [2]. More specifically, children with DCD have motor coordination difficulties, and may have reached their motor related developmental milestones later than other healthy children. DCD can clinically present with difficulties in fine, as well as gross motor movements, which has consequences on their academic performance or activities of daily living. Importantly, these coordination difficulties are not a result of another pre-existing disease or pathology [3]. The incidence rate of DCD in children is believed to be relatively high, with 6-10% of the pediatric population having demonstrable obstacles with participation in physical activity [4-8]. In addition, it has been suggested that children who experience challenges with motor coordination as a result of DCD may not see improvements as they age [2,4]. The presence of DCD causes challenges in daily activities such as difficulty tying shoelaces, handwriting, and participating in physical activity [2,9]. Further, children affected by DCD may suffer ridicule from their classmates as their motor impairments are observable by others [2,10].

While the motor impairments associated with DCD have been shown to create difficulties for children in the classroom [11-13] recent evidence has revealed that the physical fitness of a child with poor motor proficiency is not a significant contributor to their academic performance [14]. Within the classroom, it is difficulties with handwriting that often limit scholastic participation in courses that require a significant amount of written work [11,15]. As a result, students affected by DCD are at risk of developing a poor sense of scholastic or cognitive competence because of lower grades [16]. Therefore, it is understandable that impairments in physical capabilities are thought to be associated with a child’s perceived cognitive and scholastic competence given age-specific environmental demands.

Importance of the problem and relevant research

Smits-Engelsman et al. [17] considered three primary hypotheses that might explain the motor difficulties observed in children with DCD: general slowness, limited capacity, and motor control mode. One common observation, with respect to general slowness, is that children with DCD are overall delayed in their performance of motor tasks [18]. Similarly, research has found that temporal processing impairment could account for some perceptual-motor and scholastic symptoms often associated with learning disorders [19]. Thus, children with DCD are likely to need more time to decide which movement is most appropriate for a given task [17]. Furthermore, the presence of motor coordination difficulties in children results in poorer performance on most measures of information processing, which would be a limiting factor in children with DCD [11,20]. With fewer resources available for parallel processing, planned movements could be compromised under high levels of cognitive load, which would support the limited capacity hypothesis. A third possibility is that the movement difficulties of children with learning disabilities reflect a reduced ability to automate motor skills [17]. This leads us to believe that children with DCD will demonstrate a reduced ability to transfer information from their minds to written words in a timely manner.

Within the last 20 years, graphonomic research has revealed important contributions to the understanding of fine motor control, motor development, and movement disorders [21]. In particular, the analysis of performance in handwriting and drawing tasks has been used to highlight neurological deficits affecting hand movements [22-24], as well as motor coordination difficulties in DCD [25-29]. Studies indicate that at least half of all children with a learning disability, or attention-deficit/ hyperactivity disorder are comorbid with DCD [18,30,31]. Thus, the difficulties in performing motor tasks experienced by individuals with DCD will only be exacerbated by the presence of a concomitant learning disability [18].

Relevant research to the study

Throughout their school years, children receive a great deal of comparative information about their capabilities from grading practices and teachers’ evaluations of their academic performances [32]. Ongoing comparative evaluations serve as an influence on a student’s sense of competence and self-efficacy with respect to academic performance. The amount of perceived self-efficacy has a significant impact not only on academic performance, but also on the student’s willingness to complete an academic task, as well as their self-motivation to improve where necessary. Prior literature demonstrates that children with a higher self-perceived sense of competence are more likely to attempt to perfect their cognitive abilities compared to those with the same level of cognitive skill, but a lower perceived sense of competence [33,34]. Cognitive development and function are largely dependent on a person’s writing literacy, which is mediated by their perception of selfefficacy. Enhancement of perceived writing efficacy by instruction has shown to increase levels of perceived self-efficacy for academic activities, personal standards for quality of writing, and academic goals [35]. Additionally, children with a high sense of self-efficacy behave more pro-socially, are more popular, and experience less rejection by their peers [36]. Thus, characteristics of children with DCD including poor self-efficacy, physical competence, and scholastic competence, would conceivably influence academic performance. To date, no research has examined the degree to which perceived scholastic competence influences academic performance in children with and without developmental coordination disorder. The primary objective of this study was to examine the mediating role of perceived scholastic competence in the relationship between motor coordination and academic performance in grade 6 children with and without developmental coordination disorder.

Materials and Methods

Research design

This nested case-control design was an ancillary study as part of a larger prospective cohort by the Physical Health Activity Study Team (PHAST); a 2-phase longitudinal investigation. Phase one was conducted between September 2004 and June 2007. During this phase, 2519 children from an original sample of 3030 grade four students (75 of 90 schools) agreed to participate in bi-annual school-based health assessments. Phase two was conducted between September 2007 and June 2010 on the same cohort of students. This research phase involved an annual school-based health assessment as well as a nested case-control laboratory based assessment that formed the design foundation for this study. Ethics approval for the study was obtained from Brock University and the District School Board of Niagara. All children were required to provide informed consent in order to participate in both school and laboratory-based assessments. Furthermore, PHAST required corresponding informed consent from the child’s parent or guardian to participate in both school and laboratory based assessments.

Participant selection

The original phase one of the PHAST longitudinal study included a surveillance sample of 2519 participants from September 2004 to June 2007. The second phase of the PHAST longitudinal study continued surveillance of 1785 of the original students (71% consent rate) from July 2007 to June 2010. Of these students, 963 (54% response rate) expressed interest in being contacted by telephone to participate in a laboratory-based component of the PHAST. A total of 124 grade 6 students were contacted by telephone who had previously been identified in phase one with suspected DCD by scoring in the lowest 10th percentile in motor coordination by the short form of the Bruininks-Oseretsky test of motor proficiency (BOTMP-SF) [37]. Exclusion criteria in this study included an individual’s intelligence quotient below average (SD=2) when compared to same age peers. A total of 67 of these children (31 females and 36 males) agreed to participate in the laboratory-based component of the PHAST (54% consent rate) and served as the cases for our study. Control subjects who scored above the 10th percentile on BOTMP-SF and matched for age (within 3 months), gender, and school proximity were contacted by telephone to provide assent to participate in this case-control study. Grade six students were chosen to control for course subjects being taught while completing the EQAO standardized test for a second time.

Measure of motor coordination

All subjects were evaluated for motor coordination by a certified pediatric occupational therapist using the Movement Assessment Battery for Children, 2nd Edition (mABC-2). The mABC-2 is the most frequently used standardized motor test to screen for children with DCD [38] and is considered both reliable and valid [39,40]. Regardless of each subject’s previous BOTMPSF score from phase one of the PHAST study, motor competence assessment of gross and fine motor coordination was evaluated in all subjects. The mABC-2 consists of eight task items grouped under three headings: Manual Dexterity, Aiming and Catching, and Balance. For each item, a standard score was provided. Parent or guardian were not present during the mABC-2 assessment. From each of these standard scores, a cumulative age adjusted score and percentile score was generated [41]. Children with a score at or below the 15th percentile were identified as having DCD. The pediatric occupational therapist was blinded to the child’s BOTMP-SF score. Nevertheless, a full assessment of all DSM-V criteria required to confirm a diagnosis of DCD was not possible. Specifically, the current study was not able to determine if the motor skills deficit significantly and persistently interferes with activities of daily living relative to the subject’s chronological age and influenced their academic productivity, prevocational activity, leisure, and play. Considering this limitation, the researchers of this study decided to use the term suspected DCD (s-DCD) to describe subjects below the 15th percentile for the mABC-2 score.

Measure of intellectual ability

Intellectual ability was assessed using the KBIT-2 [42] to verify that motor coordination was not discrepant with cognitive development [43]. The KBIT-2 is a brief and reliable measure of intelligence that does not require administration by psychologists and can be performed by a certified occupational therapist [42]. The test also provides a measure of the general level of a child’s intellectual ability.

Measure of scholastic competence

The PHAST administered Harter’s Perceived Competence Scale for Children in the participant’s homeroom class during the school-based assessment [44]. Research assistants explained the scale, guided students to completion, and verified the completeness of each questionnaire. The Harter scale contained 32 items representing six domains, including scholastic competence (6 items), social acceptance (6 items), athletic competence (5 items), physical appearance (5 items), behavioral conduct (5 items) and general domain of global self-worth (5 items). For the purpose of this investigation, a composite score ranging from 6-24 for scholastic competence using the following six questions was utilized.

1. (Harter Question 1): Some kids feel that they are very good at their schoolwork, but other kids worry about whether they can do the work assigned to them.

2. (Harter Question 7): Some kids feel like they are just as smart as other kids their age, but other kids aren’t so sure and wonder if they are as smart

3. (Harter Question 13): Some kids are pretty slow in finishing their schoolwork, but other kids can do their schoolwork quickly.

4. (Harter Question 19): Some kids often forget what they learn, but other kids can remember things easily.

5. (Harter Question 25): Some kids do very well at their class work, but other kids don’t do very well at their class work.

6. (Harter Question 31): Some kids have trouble figuring out the answer in school, but other kids almost always can figure out the answer.

Harter [44] previously verified the validity and reliability of the Harter scale through factor analysis of the six domains separately. Each domain demonstrated discriminating factors, indicating that the Harter scale is an effective tool in differentiating among the six domains in children [44].

Measure of academic performance

District School Board of Niagara provided the final grades for 10 grade 6 courses including, three English competencies (oral/ visual comprehension, reading, writing), Health and Physical Education, five Math operations (data/probabilities, numbers, patterns/algebra, geometry/spatial, measurement), Science and Technology, three Second Language competencies (oral, reading, writing), Social Studies, Visual Arts, Drama and Dance, Music, and three Education Quality and Accountability Office scores (math, reading, writing). Access to data for Geography, Design and Technology, Choices and Changes, and History were unavailable.

Statistical analyses

Independent t-tests and corresponding descriptive statistics were used to compare differences between s-DCD and control groups for subject age, mABC-2 score, K-BIT score, Harter total and sub-scale scores, and all final grades per academic subject. To address the study’s objective, multiple linear regression with a progressive adjustment strategy was incorporated using two models. Model one examined the main effect of motor coordination as measured by mABC-2 on academic performance using overall grade average. Model 2 determined if the relationship between mABC-2 score and academic performance was influenced by scholastic competence. More specifically, a reduction in the unstandardized b-coefficient in model 2 for mABC-2 score would suggest that diminished perceived scholastic competence mediates the initial relationship between motor coordination and academic performance. Both models controlled for age, gender, and intellectual ability. In the event of multicollinearity (variance inflation factor > 10), independent variables were zeroed. Level of significance for all statistical analyses was set at α=0.05.

Results

The study initially included 126 subjects: 63 children with s-DCD and 63 controls (non-DCD) matched for age within three months, gender, and school proximity. Due to incomplete data, the final sample for this study included 120 subjects (59 s-DCD cases, 61 healthy controls). Table 1 outlines the descriptive statistics for the s-DCD and control groups. Since cases and controls were matched on age, no significant difference existed. In accordance with DSM-V diagnostic criteria, children with s-DCD scored significantly lower on the mABC-2 assessment than non-DCD subjects. Children with s-DCD demonstrated significantly lower scores on the K-BIT scale of intelligence (p<0.01) and Harter Scale sub-component of ‘athletic competence’ (p<0.05) compared to matched controls. No significant differences were identified between groups within the other Harter Scale sub-components (i.e., scholastic, physical appearance, behavioral conduct, and global self-worth) or overall Harter Scale (p>0.05).

Academic performance

Table 2 outlines the comparative statistics of subjects with s-DCD versus matched control subjects for academic performance in each grade 6 course subject, overall grade average, and EQAO course grades in math, reading, and writing. Final grades were reported for all grade 6 course subjects except Geography, History, Choices and Changes, and Design and Technology. Students with s-DCD demonstrated significantly lower final course grades in all English components (oral communication, reading, writing), Health and Physical Education, Science and Technology, all Second Language components (oral communication, reading, writing), Social Studies, and two components of Math (patterning and algebra, measurement) compared to control subjects (p<0.05). Conversely, no significant differences in final course grades were demonstrated in three Math components (data management and probability, number sense and numeration, and geometry and spatial sense), Visual Arts, Drama & Dance, and Music (p>0.05). EQAO scores for math, reading, and writing were significantly lower in students with s-DCD compared to control subjects (p<0.01). Finally, overall grade average in all grade 6 courses was significantly lower in students with s-DCD (63.88 ±10.5) compared to non-DCD (70.81 ±11.4) matched control subjects (p<0.01).

Regression of academic performance on s-DCD and scholastic competence

Table 3 reports the results of the multiple linear regression analysis. The overall average for all courses served as our outcome measure of academic performance. All assumptions for independence of residuals, multicollinearity, and normality were met before continuing with analysis. In Model 1, after controlling for age, gender, and K-BIT score, the main effect of mABC-2 on the overall average was positive and significant (p<0.05). The mediating influence of perceived scholastic competence was tested in Model 2 and was statistically significant (p<0.01). The explained variance increased substantially from model 1 (R2=15%) to model 2 (R2=25.3%). The controlling variables of age, gender, and K-BIT were not significant in either models (p>0.05). Finally, the descending shift in the mABC-2 unstandardized b-coefficient from model 1 to model 2 indicated that perceived scholastic competence partially mediated the original relationship between mABC-2 and academic performance by 15%.

Discussion

This study evaluated the relationship between motor coordination, perceived scholastic competence, and academic performance in 120 grade six children with and without DCD. It was hypothesized that perceived scholastic competence would be a significant mediating factor in the relationship between motor coordination and academic performance. Theoretically, as the level of motor coordination in a child decreases, it leads to lower levels of perceived scholastic competence and increasingly poorer performance in school. However, independent t-testing revealed no significant difference between children with and without DCD on perceived scholastic competence while multiple linear regression analysis showed a significant mediating effect on academic performance. Several factors may explain these findings.

In a study investigating the psychosocial implications of impaired motor coordination in children and adolescents with and without DCD, Skinner and Piek [45] found that only younger children (8-10 years) with DCD demonstrated a lower perception of scholastic competence, and that perception of scholastic performance was not significantly different between adolescents aged 12-14 years with and without DCD [45]. The mean age of the s-DCD and non-DCD groups fell within this age range, which may explain why independent t-testing in our study revealed no significant difference in perceived scholastic competence between children with and without DCD.

Research on self-efficacy and expectancy beliefs has shown that the level of perceived scholastic competence in a child varies depending upon specific academic subject matter [46]. Studies have demonstrated that perceived competence can vary on whether a child is asked to solve a math problem [47,48] or perform a writing or reading assignment [47, 49]. Since the present study did not specify individual academic subject matter when measuring perceived scholastic competence, it is possible that a child’s overall academic versus course-specific perceived scholastic competence may vary.

Academic performance and developmental coordination disorder

In our study, children with s-DCD performed significantly worse than their healthy peers in the majority of course disciplines. The only course subjects that indicated no difference between study groups included the Arts (Music; Drama and Dance; Visual Arts) as well as three categories of Mathematics (Data Management and Probabilities; Number Sense and Numeration; Geometry and Spatial Sense).

These findings are consistent with previous research demonstrating that children with DCD have significantly greater challenges performing well in the classroom compared to children without impaired motor coordination [12,50]. While Dewey et al. [12] studied the effects of DCD on the attention, reading, writing, and spelling abilities of children, this is the first study to examine final grades in most of all course disciplines, as well as standardized provincial EQAO grades.

As expected, courses that require significant fine motor coordination for scripting (i.e., English, French, and Social Studies), or expect efficiency in gross motor coordination (i.e., Health & Physical Education), resulted in children with s-DCD performing significantly worse than their healthy peers. Research has shown that performing a large amount of script within a specific time frame is particularly difficult for children with motor coordination challenges as they take a significantly longer time per stroke compared to healthy controls [15]. This would explain why children with s-DCD in our study performed significantly worse in courses with large writing demands (English, French, Social Studies). Further, it has been found that 30-60% of a child’s school day is focused on fine motor activities with an emphasis on writing tasks [51], demonstrating the negative impact motor coordination difficulties can have on overall academic performance.

In addition to the writing deficiencies experienced by children with s-DCD within the language classes, our study also found that these children performed worse than their healthy peers in both the oral communication and reading components of these courses. It has been shown that scripting is very difficult for a child with DCD [52]. Due to these challenges with scripting, poor performance may result in negative feedback leading to children with DCD developing a low level of perceived competence in their ability to script. Therefore, it is possible that poor performance in the writing components of language classes leads to children with DCD developing poor perceived competence in their language skills as a whole.

Science & Technology course content does not require students to script large amounts of written material nearly as often as in the language courses. However, students are required to create sample drawings and/or diagrams to carry out course expectations with respect to experimental solution, as well as designing, building, and testing a device [53]. Nevertheless, drawing and building of experimental devices can be especially difficult for children with DCD as they exhibit diminished fine motor control [28]. Concerning mathematics specifically, our study found mixed results. Since significance was clear in some components (Measurement; Patterning & Algebra) and nearly significant in others (Number Sense & Numeration; Data Management & Probabilities), it was thought that children with s-DCD generally have greater challenges in most categories of Mathematics compared to their healthy peers. However, Smits- Engelsman et al. [17] suggested that children with DCD may not be completely disadvantaged in math activities that are discrete in nature such as measurements or drawing angles with protractors, as these fine motor activities do not pose as great of a challenge.

Children with s-DCD demonstrated comparable final grades relative to their healthy peers in Visual Arts and Music, as well as slightly better grades in Drama & Dance. The physical demands and coordination required for dancing and dramatic movement place a large emphasis on gross motor coordination, which should create significant difficulties for children with s-DCD. However, the Ontario Ministry of Education [53] emphasizes that student expectation in Dance & Drama is to develop personal movement vocabularies that communicate their feelings, ideas, and understandings of movement. The subjective evaluation of teachers on each student’s individual use of movement and elements of dance rather than rote repetition or learned choreographed movements may explain our findings in these courses. Further, subjective evaluation may allow children with coordination challenges greater freedom of personal expression rather than an emphasis on the need for comparison to their coordinated peers. This factor in addition to a lack of emphasis on a rigid pedagogical expectation by their teacher, may in combination result in better performance. The aforementioned phenomenon has been shown in previous research on the influence of social comparisons, demonstrating that individuals observing themselves as being surpassed by their peers results in a diminished sense of self-efficacy and a progressively impaired performance [54,55].

Subjective evaluation of students is not specific to Dance, as teachers of Visual Arts use their professional judgement to evaluate the course expectations that should be used to grade achievement of students [53]. While the involvement of fine motor tasks such as drawing, painting, sculpting, printmaking, and architecture in Visual Arts may be challenging for children with DCD, the lack of objective grading criteria, and the ability to evaluate student performance without comparison to their peers may foster a more non-threatening atmosphere that could motivate children with DCD in the discipline of fine and performing arts.

Final grades for Music class were considered the same for children with and without s-DCD. Music class is designed to teach students practical skills such as playing an instrument or singing, as well as the opportunity to explore music critically through emotion and reason [53]. The opportunity to respond to, analyze, and interpret music allows children to express their thoughts and feelings. Therefore, like Visual Arts and Dance, Music class is reflective of an environment that fosters free thinking and expression of feelings and emotions in response to musical pieces. Within the grade six arts, the potential exists for less emphasis on scripting or choreographed movements and greater emphasis on subjective evaluation by the teacher on expressive movement and creative thoughts by the student [53]. However, the degree in which these factors influence the academic success of a child with DCD is not well understood and requires further examination.

Limitations

Data missing for Geography, Design & Technology, Choices & Changes, and History limited our ability to evaluate scholastic performance for all course disciplines. Thus, the overall grade average is not entirely reflective of the academic performance differences between grade six students with and without s-DCD. Second, evaluation of perceived scholastic competence assessed belief and self-efficacy in all course disciplines in a general sense, rather than each individual course topic. Future investigations should consider accounting for class specific subject matter to provide a more accurate measurement of perceived scholastic competence. Third, validity of final grades may be limited due to teacher variation and bias during the evaluation process. Teacher evaluation tools are not as structured and standardized as the EQAO examinations and are therefore subject to disparity. Finally, the cross-sectional data for academic performance in grade six prohibited the researchers from establishing any level of causality. A longitudinal investigation of academic performance across several grades with corresponding measures of motor coordination and perceived scholastic competence would provide a greater understanding of any causal influence that may exist.

Conclusion

Perceived scholastic competence mediated the relationship between motor coordination and a child’s academic performance by 15%. Considering that children with DCD will have this condition through secondary and post-secondary education [4,56], it is expected that the impact of perceived scholastic competence on an individual with DCD will impede their scholastic performance throughout their academic careers. By applying differentiated instruction to children with DCD, such as adding an opportunity for the child to work through problems and assignments verbally while reducing the number of written requirements, teachers could prevent reductions in perceived scholastic competence in children with DCD. Due to their slower writing speed as a result of longer stroke times [15], a reduced written workload could limit the anxiety experienced by a child with DCD to complete an assigned task in the allotted time. Still, some course disciplines in the arts demonstrate promise in which children with DCD may experience scholastic success. Continued academic success in these courses may contribute to elevating the scholastic confidence in children with DCD despite fine and gross motor challenges.

Further, research on DCD and perceived scholastic competence could examine the influence of instructional feedback on a child’s self-efficacy. It is possible that teachers using strategies to encourage children through external feedback and verbal persuasion, rather than challenging them, could enhance performance within the classroom. Research has shown that strategies used by educators which include external feedback and verbal persuasion may have a significantly positive impact on a students’ motivation and perceived abilities in the subject matter [57].

Lastly, technological advancements in education could offer children with DCD the opportunity to express their knowledge using voice recognition software as an alternative to written work. While perceived scholastic competence plays a significant role in a child’s academic performance, research on the most effective methods to attenuate or prevent a child’s competence from suffering could provide teachers with the best methods of approaching the education of children with DCD. If children with DCD are provided with the necessary tools, they will discover a direct relationship between their effort and achievement.


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Monday, May 17, 2021

Recent Advances of Nanoparticle-Based Heterogeneous Catalysts forBiodiesel Production - Juniper Publishers

Recent Advances in Petrochemical Science - Juniper Publishers

Abstract

Biodiesel is a promising candidate fuel for traditional petroleum diesel fuel (derived from crude oil). The efficient production of biodiesel depends on various parameters which are involved in its preparation from its constituents, i.e., oil, methanol, catalyst and the total energy input (reaction time and temperature). This review highlights some recent developments in nanoparticles-based heterogeneous catalysts in biodiesel production. This involves the use of CaO-based catalysts derived from various sources. The operating conditions as well as the biodiesel yield are concisely highlighted.

Keywords: Biodiesel Renewable energy Heterogeneous catalysis Nanostructures

Background

Biodiesel is a promising alternative fuel for diesel vehicles and machines. Biodiesel is a renewable fuel which is characterized by low emission of the harmful nitrogen oxides and sulfur oxides gases, i.e., NOx and SOx compared to the traditional petroleum diesel. Thus, the use of biodiesel supports cleaner environment when it comes out the exhaust pipes and thus helps reduce global warming. Biodiesel production is growing world-wide due to the increasing desire for energy, and interest in environmentally friendly fuel production. It is gradually replacing petroleum diesel in several city buses, and some governmental fleets in the united states and elsewhere. It is basically the methyl ester of fatty acids which is prepared via the reaction between oil (triglyceride-fatty acid source) and methanol in such a way that methanol replaces the glycerol in what-is-called a trans-esterification process according to the following equation: Several parameters control the speed of the forward reaction towards the production of biodiesel. These include the amount of methanol, reaction temperature and time in addition to the presence of catalyst. Figure 1 above shows that a stoichiometric ratio of oil to methanol should be at least 1 to 3. Thus, a considerably sufficient amount of methanol should be added to the reaction mixture to ensure the high conversion of oil (triglyceride) to biodiesel. Also, each gallon of produced biodiesel requires at least one gallon of oil feedstock.

Keywords: Biodiesel Renewable energy Heterogeneous catalysis Nanostructures

Catalytic Aspect of Biodiesel Production

The kinetics of this un-catalyzed reaction (Figure 1) is slow. That is a catalyst should be used to push the forward reaction towards biodiesel production in a measurable rate. In this context, several catalysts were suggested including homogeneous catalysts (e.g., KOH and H2SO4) and heterogeneous catalysts (mainly basic oxides, e.g., CaO, MgO). The use of homogeneous catalysts furnishes the advantage of short reaction time and high reaction yield of biodiesel could be achieved [1-2]. But a major disadvantage is the corrosion of the reaction container, foaming (soap formation) together with the difficulty of separation of the homogeneous catalyst from the produced biodiesel and the huge amount of wastewater resulting from its washing, leading to a substantial increase in the overall cost of the process [3]. This is where heterogeneous catalysts show their superiority as a promising alternative particularly basic metal oxide (e.g., CaO, MgO, …. etc.). Thus, CaO-based catalysts showed a significant potential performance towards the forward direction of the trans-esterification process. CaO obtained from agricultural and industrial waste residues are introduced as commercial sources of CaO-based catalysts. The use of CaO solid based catalysts safes the environment, on the one hand, and high biodiesel production efficiency, on the other hand [4-5]. Recently the trans-esterification of vegetable oils to biodiesel has been successfullyachieved [6-9] using residues of paper mill industry [10], eggshell [5,11], sea creatures shell [12,13], animal bones [14-16] and plant ashes [17-19]. Recently, sugar beet agro-industrial waste showed superior activity towards biodiesel production via the transesterification reaction of sunflower oil with methanol [20]. The sole role of CaO is the acceleration of the replacement of glycerol by methanol via catalyzing the several elementary steps involved in the trans-esterification process [20].

The use of nanoparticle-based materials has been emerged as efficient catalysts in several chemical as well as electrochemical reactions. This is because of the high surface area associated with the use of materials in nanometer scale dimensions, e.g., nanoparticles, nanorods, nanospheres, nano cubes. Moreover, the electronic as well as the surface properties of materials are significantly differing in this tiny dimensions. For instance, gold nanoparticles based (AuNPs) catalysts showed a superb catalytic enhancement for low temperature oxidation of carbon monoxide as reported by Haruta et.al. [21]. Furthermore, AuNPs showed excellent electrocatalysis for the oxygen reduction reaction in alkaline, acidic and neutral media [22-24]. Using the virtues of nanoscale material, CaO-based catalysts were prepared in thistiny size dimension to catalysis the trans-esterification of oil to biodiesel (Figure 1). Abdelhady et. al. [20] prepared CaO-based nanocatalysts from sugar beet agro-industrial residue by thermal treatment. They showed that the calcination temperature plays a prominent role in determining the particle size, chemical composition as well as the surface area of the prepared catalyst. The optimum conditions for biodiesel production are shown using 1 wt% CaO nanoparticle-based catalyst (calcined at 800oC) after refluxing oil/methanol blend (molar ratio of 0.22) for 1 hour at 75oC. Whereas, Empikul et. al. [25] utilized 10 wt% of CaO-based catalyst (obtained from eggshell waste) for biodiesel production using palm olein oil and a high methanol to oil ratio (18:1) yielding ca. 94% in 2 hours and at 60°C. Similarly, Li. et. al. [11] utilized 6 wt% of CaO obtained from paper mill industry waste for transesterification of peanut oil into biodiesel (94%) under similar reaction conditions. Also, Correia et. al. [26] used crab shell residue as a source of CaO for the transesterification of sunflower oil in the presence of methanol with a biodiesel yiled of ca. 83% after reflux for 4 hours at 60°C. Additionally, Smith et. al. [17] used bovine bone as a source of CaO-based catalyst (with 8 wt% loading level) and a biodiesel yield of about 97% was obtained after 4 hours’ reflux at 65oC.

Recent Advances in Petrochemical Science

Concluding Remarks

This review highlights the significant advances in the use of Ca oxide-based catalysts derived from natural sources (e.g., wastes and residues from several agricultural and industrial activities) as promising heterogeneous catalysts for the production of biodiesel employing various oil feedstocks in the presence of methanol at acceptable reaction conditions expressed in reaction time and temperature. The suggested CaO-based heterogeneous catalysts showed superior activity towards biodiesel production compared to homogeneous catalysts (i.e., in solution phase) in terms of reusability, ease of separation, and milder aggressive corrosive effects on the reaction vessel and operating apparatus.


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Friday, May 14, 2021

Benign Phyllodes Tumor During Pregnancy: 2 Cases Report at the University Hospital of Angre, Abidjan - Juniper Publishers

Reproductive Medicine - Juniper Publishers 

Abstract

Phyllodes tumors are mammary tumors, consisting of both benign glandular epithelial cells and a proliferation of benign, borderline or malignant conjunctival cells that determine the type and histological grade of the tumor. Phyllode tumor is a rare fibroepithelial neoplasm representing less than 1% of all breast tumors. It occurs in adult women, most often between the ages of 35 and 55. We report 2 cases developed at the expense of the left breast associated with a gravid state, having as characters the rapid growth and the size exceeding the 20 cm of long axis. Based on micro-biopsies that enabled a pre-operative histological diagnosis of benignity, a lumpectomy with safety margins was performed. Histological diagnosis of benign certainty was made on the lumpectomy part, due to the heterogeneity of these tumors. Few cases have been reported during or just after a pregnancy. We followed these two patients, who were able to breastfeed with the right breast and, they did not have a recurrence after 2 years of follow-up.

Keywords: Phyllodes tumor; Benign breast tumor; Fibroadenoma; Pregnancy; Lumpectomy; Histology

Introduction

Breast phyllodes tumors are very rare tumors, accounting for less than 1% of all breast tumors. They are more common in women in genital activity than in postmenopausal women (Peak of frequency between 35 and 55 years). They are fibroepithelial tumors, close to fibroadenomas which represent the main differential diagnosis [1,2]. They are sometimes associated with non-specific signs such as dilatation of the skin veins, retraction of the nipple, skin ulcers, palpable axillary lymphadenopathy, or discoloration of the skin. They are most often benign (60-70%) and are considered a distinct group of neoplasia’s. The malignant forms “sarcomas phyllodes” are part of the primitive sarcomas of the breast [2,3]. The forms associated with pregnancy are very little described, hence the interest of the 2 cases we report.

Observations

Case n°1

We report the observation of a 35-year-old G3P1, with menstruation since the age of 14, which was followed for infertility for 3 years. She had no specific family pathological history. She consulted for a voluminous left breast mass on single progressive pregnancy in the second trimester. The onset of the symptom’s dates to a few months ago when a left breast mass was discovered during a self-examination of the breast. This mass was characterized by rapid growth, motivating consultation. The clinical examination of the breasts made it possible to objectify a voluminous mammary tumor of 22 cm long axis, of firm, painless, hypermobile consistency compared to the cutaneous plane and the deep plane, resulting in deformation of the breast with an orange-peel appearance on the breast surface with hyperpigmentation (Figure 1-3). Examination of the lymph nodes does not find axillary or supra-clavicular lymphadenopathy. The rest of the obstetric and somatic examination found no abnormality. A breast ultrasound was performed objectifying a lobulated hypoechoic mass with internal vascularization. A breast micro biopsy revealed a fibroepithelial lesion in favor of a phyllodes tumour. The patient underwent a large tumor resection, the anatomopathological analysis of which concluded to a grade 1 phyllode tumor (ductal hyperplasia without atypia) (Figure 4). The pregnancy continued normally until the end. The case was discussed in a multidisciplinary meeting, and the decision on exclusive supervision in the post-partum was retained. The patient was able to breastfeed with the right breast and did not relapse after 2 years of follow-up.

Case n°2

We report the observation of a 21-year-old nulliparous primigravida, puberty since the age of 13, without any personal or family pathological history, who consulted for a mass in the left breast during pregnancy. The onset of symptoms dates to the 6th month of pregnancy with the observation of a rapidly growing left breast mass, prompting a consultation. The clinical examination of the breasts found at the level of the lower quadrants of the left breast, a tumor of 20 cm of long axis, of firm consistency, painless, mobile in relation to the cutaneous plane and to the deep plane, without inflammatory signs or cutaneous lesions in look (Figure 6-8). Examination of the lymph node areas does not find axillary or supraclavicular lymphadenopathy. The rest of the somatic and obstetrical examination was unremarkable. A breast ultrasound was performed objectifying a hypoechoic tumor mass, measuring 20 cm, with regular contours. The diagnosis of an adenofibroma was then retained after a breast micro biopsy. The patient underwent a lumpectomy with excisional margin, the anatomopathological analysis of which concluded in a grade 1 phyllodes tumor (Figure 9 & 10). No adjuvant treatment was indicated, monitoring was carried out to detect a recurrence. The patient was able to breastfeed with the right breast and is in complete remission after 2 years of follow-up.

Discussion

Epidemiology

Often benign, phyllodes tumours are rare fibroepithelial stromal tumours of the breast [4,5] They are characterized by the proliferation of epithelial cells and connective tissue cells. They are most often diagnosed during the 4th and 5th decades of life.

Diagnostic

Breast tumors during pregnancy are often diagnosed in advanced stages due to the difficulty in distinguishing pathological changes, physiological changes. However, these tumors can be characterized by a malignant tumor with metastases in 10% of cases [6]. This case study is a presentation of benign phyllodes tumour occurring in pregnant women, very few cases of this association have been described in the literature [7,8]. Clinically, the phyllodes tumor during pregnancy is an extremely fastgrowing tumor causing a characteristic increase in breast volume. It manifests itself as a bulky, firm and elastic mass with a malignant potential [6,9]. In our 2 observations, the masses were unilateral, exceeding the 20cm long axis, which was much higher than the 3.75cm averages observed in the literature [1]. However, the literature finds a bilateral character in 16% of cases [9]. According to Sabban et al. [1], 15% of these tumors exceed 15cm in diameter [1]. The effect of gestational changes in hormone levels on this tumor has not been discussed in the literature, except for several case reports. Large size, rapid growth and bilaterality are often described in the literature [10]. Skin changes such as erythema, dilatation of the subcutaneous veins, stretch marks or inflammatory signs are present only in the case of large tumors as was the case in our first observation [11]. However, phyllodes tumors generally pose a problem of differential diagnosis with fibroadenomas. It is the histological aspect of the connective component that will make it possible to distinguish benign phyllodes tumors, malignant phyllodes tumors (phyllodes sarcomas) and border phyllodes tumors. These tumors must therefore be the subject of a precise preoperative diagnosis, by directed micro biopsy for histology, to provide for the correct surgical management. Ultrasound can show areas of heterogeneous echo structure with cystic anechoic areas [1,8,11]. Magnetic resonance imaging (MRI) when it is possible, also finds the semio logical criteria of a benign tumor. Thus, it does not make it possible to make the differential diagnosis between the phyllodes tumor and the adenofibroma. If macroscopically the benign phyllodes tumor seems well limited, it does not present a pseudo-capsule (consisting of compressive parenchyma) such as the adenofibroma and tends to diffuse into the adipose tissue in the form of small tumor clusters. Recurrence is therefore frequent if surgical excision is not sufficient. Although a few cases of metastases from a benign phyllodes tumor have been reported, they are linked to poor histological classification, probably due to an insufficient number of samples [1,8,10-12]. The histopronostic grade is established on the association of derogatory histological factors, in particular the number of mitoses per 10 fields, the severity of cellular atypias, the tumor / healthy parenchyma interface, the presence of tumor necrosis and stromal density [11].

Course of treatment

In therapeutic terms, surgery is the standard treatment [13]. Enlarged lumpectomy with a safety margin of 10mm is indicated for tumors of grade 1 and 2. And a simple mastectomy without lymph node dissection is indicated for tumors of grade 3, or for tumors larger than 5cm [1,5,6]. Adjuvant radiotherapy finds its place in the case of a grade 3 tumor, a third local recurrence, or a recurrence after a mastectomy [10,11]. Ultimately, phyllodes tumors behave relatively benign. However, we can have a local recurrence in 20 to 35% of cases and metastases appear in 10 to 20% of patients [1,5, 8, 10,12, 14] and after conservative treatment, hence the benefit of prolonged clinical monitoring over at least 5 years.

Conclusion

Phyllodes tumors in the period of gravido-puerperium are very rare clinical situations, it is necessary to think about it in front of a tissue nodule in rapid increase. Our observations testify to the voluminous character that these tumors can take during pregnancy, constituting a great semio logical value in comparison with adenofibromas. In the event of proven benignity, conservative treatment remains a benchmark provided that the tumor is removed extensively, followed by rigorous clinical and radiological monitoring.

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Thursday, May 13, 2021

Substance use Disorder: A Burning Issue - Juniper Publishers

 Addiction & Rehabilitation Medicine - Juniper Publishers

Abstract

Substance use disorder (SUD) has infiltrated all socio-cultural and economic strata causing loss of productivity. Mental and substance use disorders are a major public health concern everywhere and responding to the burden they cause is a challenge for health systems in both developed and developing regions. Treatment rates for people with mental and substance use disorders remain low, with treatment gaps of over 90% in developing countries. Developing countries are facing an escalating burden of non-communicable disease, with mental and substance use disorders among the most significant. Many developing countries spend less than 2% of their health budgets on mental health. Drug dependence produces significant and lasting changes in brain chemistry and function. Effective medications are available for treating nicotine, alcohol, and opiate dependence but not stimulant or marijuana dependence. Medication adherence and relapse rates are similar across these illnesses. Studies suggest that long-term care strategies of medication management and continued monitoring produce lasting benefits patients with substance use disorder. In this article, we will give a brief overview about substance use disorder.

Keywords: Substance use disorder; Alcohol; Nicotine

Introduction

Substance use disorders are important health concern worldwide. Substance use is a chronic disorder which is associated with significant mortality and morbidity. These disorders also account for significant health care utilization and medical costs. Substance use disorders occur when a person’s usage of alcohol, prescription drugs, or illegal drugs causes problems in his or her life and daily activity [1]. Treatment of substance use disorder involves detoxification and prevention of relapse. The major problem in treating patients with substance use disorders is relapse. Addiction is a chronic disorder that requires long-term treatment. Anticraving agents play the key role in the prevention of relapse. These medications generally reduce drug craving and reduce the likelihood of relapse to compulsive drug use. Anticraving agents along with other psychotropic drugs are used for management of the substance use disorders [2]. In India, substance abuse has infiltrated all socio-cultural and economic strata causing loss of productivity. Mental and substance use disorders are a major public health concern everywhere and responding to the burden they cause is a challenge for health systems in both developed and developing regions. Treatment rates for people with mental and substance use disorders remain low, with treatment gaps of over 90% in developing countries [3,4]. Developing countries are facing an escalating burden of non-communicable disease, with mental and substance use disorders among the most significant. Many developing countries spend less than 2% of their health budgets on mental health [5]. Drug dependence produces significant and lasting changes in brain chemistry and function. Effective medications are available for treating nicotine, alcohol, and opiate dependence but not stimulant or marijuana dependence. Medication adherence and relapse rates are similar across these illnesses. Studies suggest that long-term care strategies of medication management and continued monitoring produce lasting benefits patients with substance use disorder [6]. Substance abuse causes acute and chronic physical, psychological and social effects in varying amounts along with serious social problems in the form of crime, unemployment, family dysfunction and disproportionate use of medical care. Science has not yet explained fully the psychological processes leading to drug abuse. Substance abuse affects above 50 million people worldwide. Abuse of legally prescribed drugs is also increasing rapidly [7]. In India, the abuse of alcohol, cannabis and raw opium has been traditionally known. The abuse of synthetic narcotic drugs and psychotropic substances is comparatively new. Substance abuse has affected all socio-cultural and economic classes causing loss of productivity [8]. Family stress, lack of coping skills, peer pressure, personality disorder, co-morbid psychiatric illnesses, social stress and market forces act as risk factors [9].

Survey shows that around 20-30% of adult males and 5% of adult females use alcohol while 57% of the male and 10.8% of the female drug users consume opiates in some form or other. Rapid assessment survey on substance abuse shows that the primary abused drugs are heroin (36%), other opiates (29%) and cannabis (22%); 75% of addicts start drug abuse before 20 years of age; in urban areas heroin abuse is more while in other sites cannabis abuse is more [10,11]. The family remains the primary source of attachment, nurturing, and socialization for humans in our current society. Therefore, the impact of substance use disorders (SUDs) on the family and individual family members merits attention. Each family and each family member are uniquely affected by the individual using substances including but not limited to having unmet developmental needs, impaired attachment, economic hardship, legal problems, emotional distress, and sometimes violence being perpetrated against him or her. For children there is also an increased risk of developing a SUD themselves.

Thus, treating only the individual with the active disease of addiction is limited in effectiveness. The social work profession more than any other health care profession has historically recognized the importance of assessing the individual in the context of his or her family environment. Social work education and training emphasizes the significant impact the environment has on the individual and vice versa. This topic was chosen to illustrate how involving the family in the treatment of a SUD in an individual is an effective way to help the family and the individual. The utilization of evidence-based family approaches has demonstrated superiority over individual or group-based treatments [12]. Substance use disorder (SUD) is a disease whose social costs are high. The negative effects of drug abuse go well beyond the health and condition of the person who suffers from SUD. Research has shown a strong link between addiction and the disruption of family relationships, including severe psychosocial and physical effects on family members described as depression, anxiety, and stress. Parents’ depression when living with a partner suffering from SUD can contribute to the mental, physical, and social neglect of the family’s children, further aggravating the family’s anxiety and stress [13].

Management of substance use disorders

Substance use disorder (SUD) has been conceptualized as a chronic relapsing medical illness with relapses and remissions and a strong genetic component similar to diabetes type II and hypertension [6]. Risk for relapse is heightened because the neurobiological changes in brain pathways created by many years of alcohol and/or drug use do not completely revert to normal after the detoxification process. The intensity and nature of the behavioral intervention can influence the outcome of treatment for patients with SUDs. The use of medications in the treatment of SUD can also play a major role in preventing relapse and facilitating longer periods of abstinence. More effective medications have been developed over the past 30 years, and subsequently, pharmacotherapy has progressively played a more important role in the treatment of addictions. Medications are mostly used as adjuncts to psychosocial treatments and the role of pharmacotherapy in treatment depends on the specific type of SUD [14]. Pharmacological agents have three broad objectives: management of acute withdrawal syndromes through detoxification, attenuation of cravings and urges to use illicit drugs (initial recovery), and prevention of relapse to compulsive drug use [2].

Conclusion

Treatment of substance use disorder involves detoxification and prevention of relapse. The major problem in treating patients with substance use disorders is relapse. Addiction is a chronic disorder that requires long-term treatment. Anticraving agents play the key role in the prevention of relapse. These medications generally reduce drug craving and reduce the likelihood of relapse to compulsive drug use. Anticraving agents along with other psychotropic drugs are used for management of the substance use disorders.


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Tuesday, May 11, 2021

How can Plants help Fight COVID-19? - Juniper Publishers

Cell Science & Molecular Biology - Juniper Publishers   

Abstract

COVID-19 is a disease caused by SARS-CoV-2. The virus is highly contagious and is passed by human contact, and in severe cases it was found that COVID-19 was causing pneumonia and ultimately lung or multisystem organ failure. Vaccine development is a high priority for COVID-19. The main goal of vaccine development is to achieve herd immunity throughout the world. Various approaches are being utilized to accelerate vaccine development. One approach is called molecular pharming, which refers to the recombinant expression of pharmaceutically useful proteins in plants. Several unique steps have been followed for molecular pharming for vaccines in plants. These steps include expression of antigens in plant based systems, the creation of Virus Like Particles (VLPs), a VLP based vaccine in influenza, a SARS-COV vaccine using molecular pharming, and finally the creation of a COVID-19 vaccine from plant sources. Molecular pharming is advantageous and has an unprecedented opportunity for vaccine development for pandemic diseases because of rapid and low-cost production and recombinant technology.

Keywords: COVID-19; SARS-CoV-2; Molecular pharming; Vaccine; Plant-based vaccine; Virus; Virus-like-particles; Recombinant; Coronavirus

Abbreviations: COVID-19: Coronavirus; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2 of the genus betacoronavirus; VLP: Virus Like Particle; SARS-CoV: Severe acute respiratory syndrome coronavirus; MERS-CoV: Middle East respiratory syndrome-related coronavirus of the genus Betacoronavirus; RNA: Ribonucleic Acid; CoV-2: Coronavirus 2 of the genus betacoronavirus

Introduction

COVID-19 is a disease caused by SARS-CoV-2. In January of 2019, the disease was first identified in Wuhan, China, the capital of the Hubei Province. The virus is highly contagious and is passed by human contact. The outbreak of COVID-19, nicknamed coronavirus, has impacted every continent severely [1]. SARS-CoV-2 is an enveloped RNA virus that was first discovered in Wuhan, China, the capital of the Hubei Province. Like previous coronaviruses, SARS-CoV-2, now known as COVID-19 causes respiratory, hepatic, and neurological diseases [2]. Coronaviruses spread quickly, as seen with the 2002 outbreak of SARS-CoV in China or the 2012 MERS-CoV outbreak in the Middle East [3,4]. In most patients, COVID-19 will mimic common cold symptoms.

However, in severe cases, it was found that COVID-19 was causing pneumonia and ultimately lung or multisystem organ failure [2,5]. COVID-19 has been linked to the Huanan Seafood Wholesale Market in Wuhan, China. The market sells an array of live animals including bats, snakes and marmot. Most healthy people exposed to COVID-19 could range from being entirely asymptomatic to mild symptomatic. Mild symptoms include dry cough, sore throat, and most commonly fever. However, in older or high risk patients, symptoms can be severe including severe pneumonia, pulmonary edema, septic shock, or multisystem organ failure.

Males appear to be more susceptible to infection from COVID-19. Approximately 54.3% of infected people are male with an average age of 56 [6-8].

The Need for Vaccines for Covid-19

Vaccine development is a high priority for COVID-19 [9]. The main goal of vaccine development is to achieve herd immunity throughout the world. Various approaches are being utilized to accelerate vaccine development. Scientists have identified a protein known as the 3C protease that is necessary for all viral replication [10]. Spike protein of the COV-2 virus is a key antigen that is being utilized in gene based or protein based approaches for vaccine development [9]. The fastest approaches to develop vaccines are recombinant vaccines followed by inactivated or attenuated protein based vaccines [11]. Several challenges have been pointed out. Firstly, it is not clear what antigens will produce the most effective neutralizing antibodies. Secondly, there is a concern if the antibody titres are universally protective. Thirdly, there are instances where vaccines may paradoxically increase lung disease. And finally, vaccine development is an expensive and often commercially unviable process [9,11]. Several biotechnology companies including Moderna, CanSino and University of Oxford with AstraZeneca have entered clinical trials [12].

Molecular Pharming for Vaccines in Plants

Molecular pharming refers to the r ecombinant expression of pharmaceutically useful proteins in plants. In recent years, molecular pharming has been of particular interest because of the discovery that plants can be developed as bioreactors for the rapid production of candidate proteins through transient expression. Because plants can produce recombinant proteins at high levels and low cost, there is a large potential for this technology to be applied to development of recombinant vaccines [13]. Several unique steps have been followed for molecular pharming for SARS-COV-2 vaccine in plants:

1. Expression of antigens in plant based systems: The first challenge is to express the transgene for the antigen in plant cells. The time-tested method for this is to infect plant cells with genetically modified Agrobacterium [14,15]. This technology has been optimized to achieve large biomass and yield.

2. Virus Like Particles (VLPs): VLPs are attenuated plant viral particles that lack infectivity. They express viral coat proteins and can be modified to express candidate vaccine genes. A Canadian biopharmaceutical company Medicago studies plantbased technology that utilizes VLPs. A VLP is an easier system than Agrobacterium and has the potential to produce a large biomass of vaccines [16]. Amazingly, the virus like particles can form enveloped structures that bud off the intracellular membranes. These VLPs have a distinct advantage over isolated antigens because they present multivalent structures that mimic the original virus. This technology has been demonstrated to work for various viruses preclinically including Hepatitis B, Norwalk virus and Influenza [17-19].

3. VLP based vaccine in influenza: Using technology that included H5 strain Medicago scientists developed a preclinicaly active vaccine in three weeks [17]. A quadrivalent vaccine developed by this company is currently in Phase 3 clinical trials.

4. SARS-COV vaccine using Molecular Pharming: In preclinical studies, M and N structural proteins were utilized to develop vaccines during the Severe Acute Respiratory Syndrome (SARS) virus using potato virus and agroinfiltration systems [20]. Another study demonstrated expression of the S protein using agroinfiltration in tobacco plants [21].

5. COVID-19 vaccine from plant sources: Medicago has announced that the Canadian government has agreed to provide $ 7 million in funds to develop its COVID-19 vaccine, and VLPs have been produced in 20 days. A subsequent press release also claims that positive antibody responses have been seen in animal models.

Future Potential for Molecular Pharming for COVID-19

One of the potential advantages of the plant based approach is that robust expression of antigen in plants can be directly administered to humans without antigen purification. Such a technological revolution would have several advantages:

1. Possibility of administering plant based oral vaccines that could be rapidly produced at low cost and deployed rapidly esp. in developing countries.

2. Enhanced mucosal immunity that can be obtained by oral route that cannot be obtained by parenteral routes. This is especially important for respiratory pathogens like CoV-2 because they use respiratory epithelium as an entry point [22,23].

Conclusion

Molecular Pharming has an unprecedented opportunity for development of vaccines for pandemic diseases because of rapid and low-cost production and recombinant technology. In the future, advances in this area can lead to oral vaccines that may be convenient and easily deployable.

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Monday, May 10, 2021

After 180 Years, Is it Time for Something Better for Diagnosing UTI’s? - Juniper Publishers

 Urology & Nephrology - Juniper Publishers


Abstract

Urinary Tract Infections (UTI) are a common source of outpatient encounters for all ages of patients, along with emergency department visits and hospital admissions. Standard urine culture (SUC) has been the mainstay for diagnosis and treatment options for over 100 years, yet 25% of female patients develop recurrent, persistent urinary tract infections. New technologies are now available that quickly provide increased ability to detect organisms along with improved susceptibility information. We discuss the clinical validity and utility data available for Multiplex polymerase chain reaction (M-PCR) coupled with pooled antibiotic susceptibility testing (P-AST) for managing urinary tract infections.

Mini Review

Urinary Tract Infections (UTI) are a common source of outpatient encounters, emergency department visits, and hospital admissions [1,2]. Young and healthy people suffering from a UTI, while symptomatically aggravating, are unlikely to progress to serious complications [3]. However, older adults’ patients suffer from UTIs symptoms ranging from mild to severe, which may lead to delirium, sepsis, or mortality [4,5]. Effective treatment of UTI based on timely and accurate diagnosis is essential to keep elderly patients out of emergency rooms and hospitals. The Standard Urine Culture (SUC) has been the gold standard test for UTI diagnosis for over one hundred years, and has played a significant clinical role in managing patients with suspected UTI. Testing by SUC can often provide informative and actionable clinical information. However, SUC has limitations, particularly for providing complete information for the clinical management of older patients suffering from recurrent, persistent, or other complicated UTIs. These limitations include the inability to detect all relevant organisms causing the infection, producing results quickly enough to avoid empirical treatment and generating efficacious treatment recommendations [6-8]. Given the hospitalization and morbidity rates associated with UTIs in the elderly population, failure to identify a UTI, or adequately treat it, may have significant ramifications.

Novel advanced diagnostic testing methods such as multiplex polymerase chain reaction (M-PCR) coupled with pooled antibiotic sensitivity testing (P-AST) can provide clinically relevant microbiological data missed by SUC. Furthermore, the clinical need for these tests’ stems from the ability of these technologies to not only identify organisms but also provide optimal treatment options in a timely manner [9]. Four peer-reviewed published papers prospectively or retrospectively validated M-PCR/P-AST testing methods as a more useful diagnostic tool for managing complicated or recurrent UTI in the elderly [8,10-12]. A study by Wojno K et al. established the clinical value (or analytical validity) of using M-PCR to detect bacteria in urine. This study reported the results of 582 consecutive elderly patients with an average age of 77 years presenting to urologists with symptoms of a lower UTI. The authors compared the identification of bacterial organisms by M-PCR and SUC when tests were run in parallel on the same samples. The M-PCR detected uropathogens in 326 patients (56%, 326/582), while SUC detected uropathogens in 217 patients (37%, 217/582). M-PCR and SUC agreed in 74% of cases (431/582), and disagreed in 26% of cases (151/582): M-PCR was positive while SUC was negative in 22% of cases (130/582), and SUC was positive while PCR was negative in 4% of cases (21/582). The study identified polymicrobial infections, defined as 2 or more organisms present in a sample, in 175 patients (30%, 175/582), with M-PCR detecting 166 and SUC detecting only 39 (6.7%, 39/582). M-PCR identified polymicrobial infections in 67 cases (12%, 67/582) for which SUC results were negative. Additionally, M-PCR identified several microbes including Gram-positive bacterium, A. schaalii, A. omnicolens, C. riegelii, M. tuberculosis, M. hominis and Gram-negative bacterium, P. agglomerans, P. stuartii, and U. urealyticum missed by standard urine culture [8].

The publication concluded that SUC has limitations, including the inability to detect slow-growing, fastidious, or non-aerobic microorganisms, and SUC has a profound detection bias for fastgrowing Gram-negative aerobic organisms. Significantly, SUC had difficulty identifying most of the microorganisms that make up a polymicrobial infection. Similarly, the article by Vollstedt A. et al summarized results from a prospective trial comparing the detection levels of M-PCR and SUC of bacteria in UTI-symptomatic patients. The study enrolled 2,511 patients with UTI symptoms and an average age of 73 years from 37 urology clinics across the United States. M-PCR and SUC identified bacteria in 62.7% (1,575/2,511) and 43.7% (1,098/2,511) of cases, respectively. M-PCR detected 6 organisms which SUC failed to detect, including five Gram-positive bacteria A. schaalii, A. omnicolens, C. riegelii, M. tuberculosis, M. hominis and Gram-negative bacterium, P. agglomerans, P. stuartii, and U. urealyticum missed by standard urine culture and one Gram-negative bacterium (U. urealyticum), affecting 590 samples. Between the two testing methods, the study detected a total of 861 polymicrobial infections, with M-PCR detecting 834 (96.9%) and SUC detecting only 167 (19.5%). Polymicrobial detections made up 34.3% (861/2,511) of the total patients, and 53.0% of M-PCR positive cases (834/1575). SUC did not detect A. schaalii, which was the most common bacterium [53.0% (442/834)] detected in polymicrobial infections by M-PCR. The bacterial species detected by SUC but not detected by M-PCR, including Enterobacter species, the Enterococcus species, and several other rarely detected species, were detected in very small subsets of patients by SUC (0.9%, 0.2%, and 0.9%, of all patients, respectively). The M-PCR mix did not include primers for the missed species in the M-PCR assay at the time of the study [10].

This analysis has also showed the identity of microbes identified by M-PCR and the susceptibility results generated by P-AST takes an average of 29.7 hours (9 hours less than SUC) to provide physicians with urine pathogen and antibiotic susceptibility results. The difference in turnaround time improved a median of 19 hours (34.5 hours and 53.7 hours, for M-PCR/PAST and SUC, respectively) for patients with both positive pathogen identification and susceptibility results [10]. These two publications show the superior ability of M-PCR to quickly detect all relevant uropathogens in the sample, especially Gram-positive bacteria, along with more polymicrobial infections in patients with UTI symptoms [8,10].

A second paper by Vollstedt A. et al. focused on bacterial interactions in affecting susceptibility patterns. The study used a novel pooled antibiotic sensitivity testing method (P-AST) which assess the functional antibiotic sensitivity for a pooled sample. This assay measures optical density with a spectrophotometer, setting a threshold value to measure growth of organisms in a ‘pool’, or polymicrobial mixture. The benefit of the ‘pooled’ approach is that it allows real-world antibiotic sensitivity assessment of the polymicrobial community from the patient’s UTI. The average age of the patients were 74.9 years. This study analyzed 758 UTIsymptomatic patients with polymicrobial bacterial infections and antibiotic susceptibility results. By comparing results from these polymicrobial samples against monomicrobial bacterial samples from 594 UTI-symptomatic patients, the analyses revealed the odds of resistance to ampicillin (p = 0.005), amoxicillin/ clavulanate (p = 0.008), five different cephalosporins (p<0.05), vancomycin (p = <0.0001), and tetracycline (p = 0.010), increased with each additional bacterial species present. In contrast, the odds of resistance to piperacillin/tazobactam decreased by 75% for each additional species present (95% CI 0.61, 0.94, p = 0.010). Additionally, the comparison revealed 44 situations for which 13 pairs of bacterial species exhibited statistically significant interactions, which caused susceptibility patterns to change as measured by the Highest Single Agent Principle or Union Principle statistical analysis models [11]. These findings align with the results reported by De Vos et al, who examined the interactions between 72 bacterial isolates from elderly people with UTI symptoms. They measured the impact of species-to-species interactions on antibiotic efficacy. They assessed organism’s growth in response to two commonly used antibiotics for UTIs (trimethoprim-sulfamethoxazole and nitrofurantoin). Using media conditioned by donor isolates they observed that clinical isolates often protected each other from the antibiotics: 25% of tested species-to-species interactions showed greater than a 3.5- fold increase in tolerance for trimethoprim-sulfamethoxazole but decreases of the same magnitude only occurred in 12% of patient results [12].

Therefore, M-PCR is able to quickly detect all relevant uropathogens, especially Gram-positive bacteria, along with more polymicrobial infections in patients with UTI symptoms, [8,11] whereas the ‘pool’ approach used in the P-AST testing allows real-world antibiotic sensitivity assessment of the polymicrobial community from the patient’s UTI.

Does the improved performance of M-PCR/P-AST lead to better clinical outcomes? The study by Daly A. et al. addressed this question and shows the M-PCR/P-AST results are associated with better outcomes. The study used existing data from 66,381 patients seen for UTIs by primary care providers in the patient home or assisted living locations. The clinical outcomes measured in the study were numbers of hospital admission and/or emergency department utilization. Daly et al. divided patients into two non-overlapping cohorts. Physicians treated patients in cohort one (N=34,414) based upon the results from SUC. Physicians treated the other cohort (N=31,967) based upon the results from the M-PCR/P-AST assay. The patients in the two cohorts had similar demographics, comorbidities, Charlson/ Deyo Index Scores, number of provider visits, and enrollment locations. The analysis detected a 13.7% reduction in hospital admissions and/or emergency department utilization associated with the use of the M-PCR/P-AST assay compared with the use of traditional SUC. The 13.7% reduction in hospitalization when normalized to 34,414 patients in the SUC cohort would result in 156 fewer patients attending the ED/hospitalizations and/or ED utilization from a UTI [13]. Another study has shown that the savings of keeping patients out of the hospital for a UTI can be as high as $64,000 per patient when considering the dollars paid by the patient and insurance [14]. Thus, the cost avoidance for 156 patients is as high as $10,000,000. The cost of testing using M-PCR/P-AST for the target population suffering from UTI’s is well below the cost associated with adverse effects that result in ED or hospitalization.

For over a century, health care providers have accepted SUC as a tool to manage UTIs to identify both the bacteria and the appropriate treatment options. The diagnostic tool is well accepted, as is the notion that E. coli is the leading cause of UTI’s. Some may argue, therefore, that the pathogenic nature of bacteria uniquely identified by M-PCR is unknown as researchers have yet to perform Koch’s postulate studies on these species. Yet, though SUC has been accepted for over a century, 25% of UTI symptomatic women develop recurrent UTI’s despite SUC providing definitive bacterial identification and antibiotic recommendations [15- 17]. There is growing evidence of the pathogenic nature of the organisms uniquely identified by M-PCR. For example, A. schaalii, found to be involved in 53% of all M-PCR detected polymicrobial UTIs [10], was recently acknowledged as an uropathogen in older adults and young children [18]. Beyond missing critical pathogens, SUC fails to detect more than 2 organisms in an infection and does not consider bacterial interactions that impact susceptibility results. More than one in two patients (56.1%) who tested positive for UTIs were diagnosed with a polymicrobial infection based on M-PCR, and the odds of patients’ resistance to most antibiotics increased with each additional bacterial organism present, possibly due to bacterial interactions [11]. Additionally, specific combinations of bacteria either increase susceptibility or increase resistance, depending upon the specific pair of organisms and the antibiotic the pair is exposed to. Therefore, the P-AST methodology may detect the effects of these interactions, compared with the antibiotic susceptibility performed on isolates as in SUC [11].

What are the cumulative effects of SUC failure? Those with recurrent UTI’s are prophylactically prescribed antibiotics for recurrent UTI’s. As these patients age, the prophylactic use of antibiotic for UTI results in inappropriate antibiotic use, i.e. antibiotics being prescribed at a dose higher then recommended and for longer periods of time then recommended. In fact, some antibiotics are prescribed for life [19]. Indeed, studies show that 55% of antibiotics prescribed for UTI’s are inappropriate in the long-term home setting [20]. For older women, prophylactic antibiotic use was found to be associated with an increased risk of UTI related hospitalizations [21]. These patients may benefit from the M-PCR/P-AST test, which provide physicians with comprehensive and sensitive bacterial identification results from M-PCR along with susceptibility results from a pooled setting. As a result, therapeutic guidance may lead to more effective antibiotic selections. UTIs are a significant source of morbidity for the elderly. While conventional urine cultures remained the mainstay of diagnosing these patients for the last 180 years, evidence shows advanced diagnostic tests such as M-PCR/P-AST can identify pathogens not detected by SUCs, generates results more quickly, and provides antibiotic susceptibility results from real-world polymicrobial community [8,10-12]. Further evidence shows the detection and\treatment of these pathogens based on M-PCR/P-AST may lead to decreased hospital utilization as compared to patients who were managed using SUC [13].

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The Mediating Role of Perceived Scholastic Competence in the Relationship between Motor Coordination and Academic Performanceioural Disturbance in People with Intellectual Disability - Juniper Publishers

 Intellectual & Developmental Disabilities - Juniper Publishers    Introduction The motor skill capabilities of a person are highly i...