Tear buffering in contact lens wearers

The buffering capacity of tears collected from contact lens wearers was compared to that from non-contact lens wearers. Three groups of subjects were investigated: 6 subjects not wearing contact lenses, 3 subjects wearing rigid contact lenses, and 3 subjects wearing hydrogel contact lenses. Each of the 12 subjects provided, on 6 separate occasions, 100 microliters of tears. The pH of the tears was measured with a closed chamber, temperature stabilized micro-electrode system firstly on collection and then after titration with acid and base. In all, 28 titration steps across the acid-base spectrum were completed for each subject's tears on each occasion. These tear pH responses to acid-base challenge were compared to that of unbuffered distilled water for the same titration procedure. There was no statistically significant effect of contact lens wear on tear buffering capacity, but considerable inter-subject variability was noted.     

Diet and insulinlike growth factor I in relation to body composition in women with exercise-induced hypothalamic amenorrhea

To assess the potential influence of diet and endogenous peptide anabolic hormone secretion on exercise-related differences in body composition, we compared levels of macronutrient intake, insulinlike growth factor I (IGF-I), and fat-free mass (FFM) and fat mass (FM) in matched groups of exercising women with and without secondary hypothalamic amenorrhea. Women were tightly matched according to somatotype and grouped into those with exercise amenorrhea (EXam, n = 6), exercise eumennorhea (EXeu, n = 5), and sedentary eumennorheic controls (SED, n = 5). Although no between-group difference was observed in FFM, the EXeu subjects had a significantly lower fat fraction and a significantly elevated FFM/FM ratio. Kilocaloric and protein intakes did not differ between groups, but dietary fat intake was lowest and carbohydrate intake highest in the EXam subjects. Dietary macronutrients were not correlated with the FFM/FM ratio. However, levels of insulinlike growth factor I were significantly correlated to the FFM/FM ratio and there was a clear trend for the hormone to be highest in the EXeu subjects. We conclude that differences in body composition between exercising women with and without exercise-induced hypothalamic-pituitary dysfunction were related to an alteration in IGF-I secretion, although differences in macronutrient intake might also be a factor. Further studies are warranted to elaborate upon the dietary and hormonal factors regulating the body composition response to exercise.     

Regulation of G proteins by chronic antidepressant drug treatment in rat brain: tricyclics but not clorgyline increase Go alpha subunits.

The effect of long-term (3-week) administration of various antidepressant drugs on the steady-state concentrations of G protein alpha subunits, Gs alpha, Gi alpha, and Go alpha, has been investigated in rat brain using an enzyme-linked immunosorbent assay. Tricyclic antidepressants and clorgyline decreased Gs alpha and, to a lesser extent, Gi alpha in several brain regions, while Go alpha was increased by tricyclics but not clorgyline. We conclude that long-term treatment with antidepressant drugs exerts differential effects on G protein alpha subunits, and that antidepressant efficacy may potentially be based on functional modifications of signal transduction.     

A systematic review of resident‐as‐teacher programmes

Context Residents in all disciplines serve as clinical teachers for medical students. Since the 1970s, there has been increasing evidence to demonstrate that residents wish to teach and that they respond positively to formal teacher training. Effective resident‐as‐teacher (RaT) programmes have resulted in improved resident teaching skills. Current evidence, however, is not clear about the specific features of an effective RaT programme. Objectives This study was performed in order to investigate the effectiveness of RaT programmes on resident teaching abilities and to identify the features that ensure success. Methods of assessment used to ascertain the effectiveness of RaT programmes are also explored. Methods The literature search covered the period between 1971 and 2008. Articles focusing on improving resident teaching skills were included. Each study was reviewed by two reviewers and data were collected using a standard abstraction summary sheet. Study outcomes were graded according to a modified Kirkpatrick's model of educational outcomes. Results Twenty‐nine studies met review inclusion criteria. Interventions included workshops, seminars, lectures and teaching retreats. Twenty‐six studies used a pre‐ and post‐intervention outcome comparison method. Subjective outcome measures included resident self‐evaluation of teaching skills or evaluation by medical students, peers and faculty members. Objective outcome measures included written tests, evaluation of teaching performance by independent raters and utilisation of objective structured teaching examinations. One study objectively measured learning outcomes at the level of medical students, utilising the results of an objective structured clinical examination. Overall resident satisfaction with RaT programmes was high. Participants reported positive changes in attitudes towards teaching. Participant knowledge of educational principles improved. Study methodologies allowed for significant risks of bias. Conclusions More rigorous study designs and the use of objective outcome measures are needed to ascertain the true effectiveness of RaT programmes. Future research should focus on determining the impact of RaT programmes on learning achievement at the level of medical students.     

State dental boards and mandatory HIV testing.

Public and professional debate over what, if any, action should be taken by state regulatory agencies regarding AIDS and the HIV status of dentists has increased in recent months. To determine if state boards had workable policies in place or were considering such policies, a telephone survey of all state boards was undertaken. All boards participated, although three provided only limited information. As of early 1992, only two boards required evidence of immunity to HVB for relicensure and none require evidence of seronegativity to HIV for relicensure. Twelve percent of the boards anticipate such requirements within two years. None have mandatory HIV testing, but 13 percent anticipate such requirements in the near future. The authors conclude that while few agencies have taken more than tentative steps toward rigorous HIV testing or restrictions, most are aware of much closer public scrutiny. More restrictions seem likely as these agencies attempt to balance public and professional rights and responsibilities.