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Biomedical subjects

J Wetherell

Publications and source records attributed to J Wetherell.

8 recordsLinked to original sources
PubMed2003

Guinea-pig heart acetylcholinesterase after continuous physostigmine administration.

G1 and G4 acetylcholinesterase (AChE) molecular forms were separated in different regions of guinea-pig heart. The activities of both were highest in the left side of the left ventricle (LV(L)). The reversible anticholinesterase physostigmine, or saline, was administered continuously for six days. In saline-treated animals the activity of both molecular forms was markedly increased in both atria, G1 activity was increased on the left side of the right ventricle (LV(R)), and G4 activity was increased on both sides of the right ventricle compared to untreated animals. However, G1 activity was significantly decreased on the left side of the left ventricle. Physostigmine administration caused a significant reduction in G4 activity in the left atrium (LA), the left side of the right ventricle, and the left side of the left ventricle, and a significant increase in G1 activity on the right side of the right ventricle compared to saline-treated animals. The distribution of AChE indicates a role for parasympathetic nerves in the control of both ventricles and atria. The changes in AChE in saline-treated animals could have been due to the anaesthesia or stress of the surgical procedures. Physostigmine caused delayed changes in the enzyme in some regions, consistent with an effect on its expression.

Acetylcholinesterase↗
PubMed1999

Introducing Adelaide dental students to a problem-based learning curriculum.

A course designed to introduce new students to a problem-based learning (PBL) curriculum in dentistry at the University of Adelaide is described. Australian students are admitted to the Adelaide dental course either directly from school (SL) or after one or more years of tertiary education (TT). The admissions process is designed to select academically able students who will flourish in a problem-based environment. Some international students (INT) are also selected through a modified admissions process. A 9-item questionnaire derived from frequently-asked questions from previous years was administered to the new students at the beginning and at the end of the introductory course, and each individual's responses before and after the course were compared. There was an increased number of positive responses (significant at P < 0.05 to 7 of the 9 items) after the course. Although the course appeared to be effective in familiarising new students with a PBL curriculum, many students were still uncertain about two items which commonly provoke anxiety, namely how to decide when to stop researching a topic, and how to balance group and solo learning.

Attitude of Health Personnel↗
PubMed1999

Self-assessment in a problem-based learning curriculum in dentistry.

The creation of sound self-judgement for students is an integral goal in any educational sphere. Student clinicians in dentistry must learn sufficient skills to be able to self-assess their performance very accurately, because after graduation, the nature of dental procedures means that others are seldom in a position to evaluate the quality of their work. Over recent years, the Department of Dentistry at the University of Adelaide has been developing a self-assessment procedure, initially as a pilot study in the subject oral diagnosis, and currently in all years of the course. This paper describes how self-assessment has been demonstrated to work initially in the pilot subject, and currently across the whole course. The paper also describes how the criteria for assessment and the levels of performance expected for each grade are established and how student performance is monitored. Finally, evidence is presented to indicate acceptance by the students of self-assessment as a valuable and integral part of their learning in dentistry.

Curriculum↗
PubMed1997

Effects of excitatory amino acid antagonists on dendrotoxin-induced increases in neurotransmitter release and epileptiform bursting in rat hippocampus in vitro.

Alpha-dendrotoxin (alpha-DTx), a snake venom toxin which blocks several types of fast-activating voltage-dependent potassium channels, induces limbic seizures and neuronal damage when injected into the brain. The mechanisms underlying these convulsant and neuropathological actions are not fully understood. We have studied the effects of alpha-DTx on neurotransmitter release and electrical activity in rat hippocampal brain slices and the role of excitatory amino acid receptors in mediating these actions of the toxin. alpha-DTx increased the basal release of acetylcholine, glutamate, aspartate, and GABA in a concentration-dependent manner and induced epileptiform bursting in the CA1 and CA3 regions of the slice. The increase in neurotransmitter release was evident during the first 4 min after toxin addition, whereas the bursting appeared after a concentration-dependent delay (20-40 min with 250 nM toxin). The N-methyl-D-aspartate (NMDA) receptor antagonists AP5 and MK-801 had no effect on the frequency or amplitude of dendrotoxin-induced epileptiform bursts, but the non-NMDA antagonists CNQX and DNQX abolished bursting in both CA1 and CA3 within 4-6 min. In contrast, the toxin-induced increases in neurotransmitter release were not blocked by DNQX. This study has demonstrated that, following exposure to alpha-DTx, there is a rapid increase in the release of neurotransmitters which precedes the onset of epileptiform bursting in the hippocampus. Since DNQX abolished the bursting but had no effect on the increase in neurotransmitter release, these results suggest that DNQX blocks alpha-DTx-induced epileptiform activity by antagonism of postsynaptic non-NMDA receptors.

2-Amino-5-phosphonovalerate↗
PubMed1996

The use of student journals in problem-based learning.

This paper describes several examples of the use of journals in a Bachelor of Dental Surgery course. The examples cover: the use of journals in first year subjects and in later-year clinical subjects; the effect of changes in policy and practise as a result of experience with journals; and student views on their experiences with journals. The use of journals offers a means of achieving some of the more important goals of problem-based learning (PBL), particularly those requiring students to reflect upon and evaluate their experiences. When effectively integrated in a PBL course, journals have several functions: to formalize reflection; an outlet for personal feeling; an opportunity for feedback about a student's progress and about the course; to provide the student with a summary of the year's work; and a means whereby students and teachers gain insight into the learning process. However, our experience in Dentistry raises several contentious issues, especially with regard to confidentiality and assessment. We make several recommendations for the effective use of journals based on the need for frequent communication between students and staff, the development of an environment of trust, and the need for staff and student education in journal use.

Adult↗
PubMed1996

First-year responses to a new problem-based curriculum in dentistry.

The first year of a new Bachelor of Dental Surgery curriculum was introduced at the University of Adelaide in 1993. Four integrated streams replaced the previous large number of separate subjects, with an overall reduction in formal contact hours, more exposure to clinical practise, and an emphasis on problem-based learning and student self-directed learning. This report compares students attitudes to the new programme with their attitudes to the previous course. Evaluation forms were completed by 30 of 53 first-year students in 1992 and 38 of 47 first-year students in 1993. Comparisons between years, made using the Student's that, indicated significant differences for several questions. For example, the workload in the previous course was considered to be significantly heavier, with too much theory and too many topics. It was felt that the aims and objectives of the new course were significantly clearer; there was more time to understand material; more opportunities to choose areas to study; students were encouraged more to think for themselves; and staff were more understanding and supportive. The authors conclude that the new problem-based Adelaide dental curriculum has facilitated a more contextual and better-balanced learning environment for students.

Attitude↗
PubMed1994

A problem-based approach to a course in oral diagnosis.

This paper describes the first two years of an attempt to introduce a problem-based approach into the teaching of oral diagnosis. The most significant features of this approach were the involvement of the students in setting course goals, the use of student journals to encourage reflection on learning, the encouragement of self-assessment, and an attempt to relate clinical practice to problem-solving seminars. The paper reports on student reactions to the course and discusses further developments in the course, in particular attempts to develop a more explicit understanding in students of their own learning processes, and more attention to factors in the learning environment which engender confidence, reflection and self-evaluation.

Diagnosis, Oral↗