Chronotropic action of 5-hydroxytryptamine (5-HT) on colonic migrating motor complexes (CMMCs) in the isolated mouse colon

The effects of 5-hydroxytryptamine (5-HT) and related drugs on colonic migrating motor complexes (CMMCs) were evaluated in isolated colons from the heterozygotes of pie-bald lethal mice. 5-HT produced a dose-related increase in the frequency of CMMCs without any change in the amplitude or duration of the CMMC contractions themselves. The 5-HT(2) agonist, alpha-methyl 5-HT, (100 nM-1 microM) increased the frequency of CMMCs whilst the 5-HT(3) agonist, 2-methyl 5-HT, did so at 10 microM. The 5-HT(4) agonist, 5-methoxy dimethyl tryptamine oxalate did not alter the frequency of CMMCs in the concentration range 1 nM-10 microM. The 5-HT(3) receptor antagonist, ondansetron, increased the interval between CMMCs in the concentration range 100 nM-1 microM, whilst the 5-HT(1) receptor antagonist, methiothepin, the 5-HT(2) receptor antagonist, cyproheptadine and the 5-HT(4) receptor antagonist, SDZ 205 557, had no significant effects on the interval between CMMCs in the concentration range 1 nM-10 microM. The effects of 5-HT did not appear to be altered by the presence of ondansetron (1 microM) or cyproheptadine (1 microM). However, in the presence of ondansetron (1 microM), the further addition of cyproheptadine (1 microM) effectively abolished CMMCs. Furthermore, in the combined presence of these antagonists the effects of 5-HT were severely diminished. It is suggested that the frequency of CMMCs may be under the influence of endogenously released 5-HT in this preparation     

Antibodies to diabetes-associated autoantigens in Indian patients with Type 1 diabetes: prevalence of anti-ICA512/IA2 and anti-SOX13

We ascertained frequencies of autoantibodies to a suite of islet cell antigens including ICA512/IA2 and SOX13 in Asian Indians with Type 1 diabetes and in other forms of diabetes. Autoantibodies to ICA512/IA2 and SOX13 were tested by radioimmunoprecipitation assay, and results were amalgamated with previous data on antibodies to glutamic acid decarboxylase (GAD) and to islet cell cytoplasmic antigens (ICA). The frequency of anti-SOX13 was higher in Asian Indians than in Europids. Overall, the combined frequency for all autoantibodies to diabetes-associated antigens in Type 1 diabetes in Indians approached the frequency reported for Europids. There was an unexpectedly high frequency of autoantibody reactions to any one of the autoantigens tested (24%) in fibrocalculous pancreatic diabetes, however, individual autoantibody frequencies were relatively low. Our data indicate that, whatever the population studied, testing for multiple autoantigenic reactivities is more informative than more limited testing, and that there may be regional (presumably ethnically based) differences in levels of particular autoantibodies in cases of Type 1 diabetes.     

Matrix Structure Evolution and Nanoreinforcement Distribution in Mechanically Milled and Spark Plasma Sintered Al-SiC Nanocomposites

Development of homogenous metal matrix nanocomposites with uniform distribution of nanoreinforcement, preserved matrix nanostructure features, and improved properties, was possible by means of innovative processing techniques. In this work, Al-SiC nanocomposites were synthesized by mechanical milling and consolidated through spark plasma sintering. Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X-ray Spectroscopy (EDS) facility was used for the characterization of the extent of SiC particles’ distribution in the mechanically milled powders and spark plasma sintered samples. The change of the matrix crystallite size and lattice strain during milling and sintering was followed through X-ray diffraction (XRD). The density and hardness of the developed materials were evaluated as function of SiC content at fixed sintering conditions using a densimeter and a digital microhardness tester, respectively. It was found that milling for 24 h led to uniform distribution of SiC nanoreinforcement, reduced particle size and crystallite size of the aluminum matrix, and increased lattice strain. The presence and amount of SiC reinforcement enhanced the milling effect. The uniform distribution of SiC achieved by mechanical milling was maintained in sintered samples. Sintering led to the increase in the crystallite size of the aluminum matrix; however, it remained less than 100 nm in the composite containing 10 wt.% SiC. Density and hardness of sintered nanocomposites were reported and compared with those published in the literature.     

Development of a prediction equation for the estimation of mandibular canine and premolar widths from mandibular first permanent molar and incisor widths

The aim of this study was to develop a prediction equation for estimating the total widths of the mandibular permanent canines and premolars (TCPW) using the total widths of the mandibular first permanent molars and incisors (TWFMI). The sample comprised 288 mandibular dental casts of orthodontic patients (106 males and 182 females, average age 13.8 and 14.4 years, respectively). A digital vernier calliper was used to measure the mesiodistal tooth widths from the mandibular right to the left first permanent molar. An independent t-test was used to determine any gender difference and a multiple linear regression equation to predict TCPW using TWFMI. A paired t-test was used to compare the actual and predicted values of the canines and premolars. The results showed a statistically significant difference (P < 0.01) between the mesiodistal tooth widths of males and females. A moderate correlation and determination coefficient between TCPW and TWFMI was found (r = 0.64 to r = 0.67 and r(2) = 0.41 to r(2) = 0.44, respectively). There was no significant difference between actual and predicted values for males and females. The regression equations proposed are a good prediction method to determine TCPW.     

Portfolios in Saudi medical colleges: Why and how?

Over recent decades, the use of portfolios in medical education has evolved, and is being applied in undergraduate and postgraduate programs worldwide. Portfolios, as a learning process and method of documenting and assessing learning, is supported as a valuable tool by adult learning theories that stress the need for learners to be self-directed and to engage in experiential learning. Thoughtfully implemented, a portfolio provides learning experiences unequaled by any single learning tool. The credibility (validity) and dependability (reliability) of assessment through portfolios have been questioned owing to its subjective nature; however, methods to safeguard these features have been described in the literature. This paper discusses some of this literature, with particular attention to the role of portfolios in relation to self-reflective learning, provides an overview of current use of portfolios in undergraduate medical education in Saudi Arabia, and proposes research-based guidelines for its implementation and other similar contexts.A portfolio in education is a collection of evidence that learning, or more generally, an effort to the achievement of a goal, has taken place. In medical education, the concept and practical uses of portfolio have evolved over the last 2 decades, under the influence of various theories of adult and experiential education.1 This evolution has encompassed workbooks, log books, reflective learning and competence based learning tools, typically with feedback and reflective writing as essential parts of the collection and process that a portfolio both represent and derives from. Currently, portfolios are used in various forms and for diverse purposes in medical education in many parts of the world, and their uses are widely accepted as complementary to other conventional methods of learning and assessment.2,3 This paper is a part of Ministry-funded project for development and implementation of portfolio in undergraduate medical education. The purpose of this paper is to highlight the strengths and limitations of portfolios as learning and assessment tool in this context, to provide an account of its current use in King Abdulaziz University (KAU), Saudi Arabia, and to propose evidence-based guidelines for its implementation and other similar contexts.

Portfolios and adult learning theory

Portfolio-based learning has shown to be consistent with the principles of andragogy, which was developed by Malcom Knowles beginning in the 1990’s4 as a theory of adult learning with mature learners as the primary target. The theory suggests on the notion that adult learners have to discover why they should be learning something and on the belief that, for these learners, understanding the relevance of material and concepts is essential. Also, central to andragogy are the notions that adult learners are self-directed individuals who are capable of taking responsibility for their learning experientially, and through problem solving is key to success.5

The role of portfolios in learning and teaching

A portfolio is widely regarded as a multipurpose tool that can positively impact learners’ and educators’ attitudes to learning, teaching, and assessment, as well as increasing their sense of hands-on connection to their work.6,7 Indeed, portfolio-based learning provides a combination of processes that function interactively to enhance learning, a benefit that may not be achieved through any other single learning tool. These processes include, and contribute to the learner’s capacity for, autonomous learning and reflective practice.Reflection is a metacognitive procedure that creates a better understanding of the self as well on the situation so that future actions can be informed by this understanding. Self-regulated and lifelong learning depend on reflection as an important aspect. Self-reflection, moreover, is also key to developing both a therapeutic relationship and professional expertise.8 Developing reflective practice, which is an essential feature of portfolio based education, encourages students to think on their experiences, actions, performance, and shortcomings; thereby, preparing them to become independent professionals and to use their learning abilities effectively in postgraduate studies.9 The benefits of portfolio; however, are not limited to student learning. Student feedback on the learning process provides educators with a basis upon which to reflect on and improve their teaching methods and their methods of discharging their professional responsibilities. This process can improve student-teacher relationships and can provide support for students as they face personal, emotional, and educational challenges of completing their medical education.10

The role of portfolios in assessment

The commonly heard phrase “assessment drives learning” refers to the phenomenon by which students tend to learn in ways that are influenced or determined by how their assessment is planned and implemented.11 In light of this expectation, assessment by portfolio is necessary in order to validate portfolios as a learning tool. Nonetheless, portfolios can add distinctive elements to the overall evaluation of medical students’ progress. In particular, assessment by portfolio adds a subjective element of evaluation of students’ learning through experience and reflection. Moreover, as an assessment tool, portfolio can be broad-based, encompassing material that is formative and summative, qualitative, and quantitative as well as considered highly individualized.12,13Although subjective in nature, the credibility (validity) and dependability (reliability) of the portfolio-based assessment process can be safeguarded using established methods.5 The benefits of portfolio-based assessment build on the value that it adds to the learning process through student-centered, self-directed, thought provoking, responsibility-building approach to professional development.

Importance of portfolios in Saudi Arabian medical education

In 2010, the competence framework for medical graduates in Saudi Arabia known as the Saudi-Meds was established to guide curriculum development and assessment, as well as to ensure that Saudi medical education adapts to the changing needs of current times. These competencies were organized into 7 broad fields and subdivided into 30 areas.14 The Phase II consultation document consolidated the framework into 6 fields, which are further subdivided into 16 competencies. The National Commission for Academic Accreditation and Assessment (NCAAA),15 in order to achieve accreditation and quality assurance, requires these to be further classified into 5 domains: knowledge, cognitive skills, interpersonal skills, communication skills, and psychomotor skills, which are known collectively as the National Qualification Framework.15Although traditional tools of learning and assessment can account for most of these domains and competencies, the current trend in Saudi medical colleges to teach subjects such as medical ethics and professionalism primarily through didactic lectures does not provide an effective means of modifying students’ behavior in ways that promote patient care and professionalism.16 Promoting such change requires thoughtful reflection on clinical and other encounters during students’ hospital learning experience, with supervised discourse involving peers and effective feedback from faculty. Portfolios, in this scenario, can be an effective tool in tracking, demonstrating, and assessing reflective learning experiences. The portfolio process, moreover, can provide opportunities for students to collect evidence of their leadership roles and their involvement in patient and peer education, as well as to improve their writing skills, all of which are fields that have been emphasized by the Saudi-Meds and by The National Commission for Academic Accreditation and Assessment (NCAAA), but that are nevertheless largely overlooked in the course of traditional methods of teaching and assessment.

Guidelines for implementing portfolio-based learning and assessment in medical colleges in Saudi Arabia

The Association of Medical Education in Europe (AMEE) has published explicit guidelines for implementing portfolios in learning and in assessment for medical students.1 The following guidelines were developed in accordance with the 6-point schema (Figure 1), which represents a modification of the Association of Medical Education in Europe (AMEE) guidelines, which is designed to fit with current Saudi educational needs and practices.Open in a separate windowFigure 1Guidelines for implementing portfolio-based learning and assessment in medical colleges in Saudi Arabia.

Develop a general consensus

Portfolios and reflective learning may be completely novel concepts for most stakeholders in Saudi medical education; therefore, before implementing these practices, it is necessary to develop a consensus among administrators and faculty regarding the need to include them along with tools currently in use. Doing so may require presentations, workshops, and the piloting of portfolio use on an experimental basis. At King Abdulaziz University (KAU), Jeddah, Saudi Arabia, a planned awareness was created among faculty members by portfolio working group, which discussed their experiences with implementation of portfolios formatively within their modules, in different faculty meetings and seminars.

Select an appropriate place in the curriculum

In order to gain the maximum benefit from portfolios, the competencies, and learning objectives to be achieved through this method must be selected with care. Decisions will therefore need to be made regarding the placement of portfolio in the curriculum map. Introduction of portfolios in early years of medical school can prepare the students’ for later years when they have more clinical experience to reflect upon, and maximize their learning through reflection and feedback. Another consideration to be kept in mind is that Saudi students may initially have difficulty in writing their thoughts due to limitations of writing skills in English language. Therefore, students at KAU were initially given the option to write in their native (Arabic) language, if they had difficulty in explaining themselves in English. Students’ writing skills and language improved with time and so did their reflections.

Select an appropriate support group

Motivated faculty members, who are willing to put in the time and effort needed to develop students’ learning competencies in ways that will ultimately help them to become better professionals, will be indispensable in the process of implementing portfolio-based learning and assessment. Faculty enthusiasm can be enhanced by rewarding innovative and progressive activities. In our experience, selecting the initial group to initiate the process is most difficult; however, once the “ball starts to roll” many faculty members get motivated to join the group.

Develop the portfolio

Once the appropriate competencies and other objectives are set, the team can determine the material that can be used to gather proper evidence of student learning. There is almost no limit on creativity while choosing the modalities that can be used in a portfolio. From feedback, reports, reflective write ups on incidents to pictures and video recordings, all can be a part of the portfolio. The availability of resources and feasibility of their use will guide the faculty in deciding on the right directions in which to develop portfolio as an effective tool for promoting positive behavior change in Saudi medical students. A plan for how the collected material will be used for students’ assessment should also be developed at this point. In our opinion, limitations of time, and human resource required for assessment process often become a factor in limiting the collectables in portfolios.

Orientation of students

Students must be informed, from the outset, regarding the methods to be used in portfolio-based learning and assessment. They should also receive written guidelines that explain the learning methods, content, assessment process, marking system, and benefits that pertain to the use of portfolio. If they are well informed on what to expect, students are less likely to feel anxious or threatened; thereby, increasing the likelihood of a successful and enjoyable learning experience.

Designing the assessment plan and evaluation process

This process must encompass decisions regarding the nature of assessment (formative or summative) for students at various levels as well as regarding marking criteria for the content of portfolios, training for examiners, and the time, place and methods to be used for assessment. The process of evaluation for improvement and quality assurance in place at the start of implementation not only secures a smooth-running process, it also instills stakeholders, and observers with confidence.

Limitations of portfolios

A number of limitations with the use of portfolios have been reported including students and faculty finding it time-consuming, less important or distractive from other forms of learning, and, at times, inability of students to understand the purpose of the whole exercise.12 These limitations can be tackled with a thoughtfully prepared plan for development and implementation of the process.The authors acknowledge that there still are unanswered questions regarding the use of portfolios in Saudi Arabian culture of medical education, implementation process details, assessment criteria, and standard setting. We are hopeful that these issues will be better understood once we have the results of local implementation of the portfolios, the KAU portfolio project.In conclusion, we believe implementation of portfolios as a method for learning and assessment requires careful consideration and understanding of the tool, careful selection of the topics and competencies that can maximally benefit from this relatively complex modality, and buy-in of the involved stakeholders for the painstaking process of change. We recommend that portfolios, at least in the initial phase of implementation, should only be used to achieve selected competencies, particularly those that are not typically achievable through other, less multi-faceted, and more easily implemented means of education.