Translocation yield from the mouse spermatogonial stem cell following fractionated X-ray treatments: influence of unequal fraction size and of increasing fractionation interval.

(1) The genetic response of the mouse spermatogonial stem cell to a high dose of X-rays given in two unequal fractions 24 h apart can be dependent upon the order in which the two fractions are given. When 1000 R was administered as 100 R followed by 900 R the recovered translocation yield (22%) was similar to that which can be obtained by extrapolation from lower doses and also to that of a 500 + 500 R 24 h fractionation. By contrast, when the 900 R preceded the 100 R the response was much lower (7.4%), yet still greater than that produced by a single 1000 R treatment (4.5%). The same order of effectiveness was observed for length of sterile period. (2) The sub-additive translocation yields previously obtained with 800 R treatments given in fractions of 500 R and 300 R at intervals of 3-12 days were found to be maintained with intervals up to at least 15 days but additivity was regained by the end of the third week. Sterile period data indicated that with these intervals the germinal epithelium had recovered sufficiently from the first fraction for spermatogenesis to restart before the second fraction was given. (3) It is concluded from the two experiments that (a) 24 h after a radiation exposure the surviving stem cells are more sensitive than formerly both to killing and genetic damage, (b) at this time they are no longer heterogeneous in their radiosensitivities, so that increasing yields of genetic damage may be obtained with increasing dose i.e. there is no fall in yield at higher doses, (c) the change in sensitivity could be a consequence of a synchronization to a sensitive stage in a cell cycle, or to a transitional phase preparatory to entering a different cell cycle. (d) to achieve rapid repopulation of the germinal epithelium the surviving stem cells are stimulated to enter a shorter cell cycle and this is the cause of the sub-additive translocation yields with fractionation intervals of 3-15 days, (e) the recommencement of spermatogenesis is associated with the reestablishment of the heterogeneity in radiosensitivity among the stem cells. At this time additive translocation yields can again be recovered.

Peer review. Part 2: The influence of internal and external standards on outcome.

Two peer review groups of ten general practitioners each reviewed their management of two conditions, headache and fatigue. Each group used internal standards which they had set for the review of one condition and external standards set by the other group for the other condition. Data for the review were collected from the general practitioners' case notes and presented to them. The following year their management was again reviewed. Group 1 improved their management of both conditions by 15%. Group 2 improved their management of the condition where internal standards were used by 12% and the condition where external standards were used by 9%. This difference was not statistically significant. Although there was a significant improvement in the management of both conditions in each group, the use of internal versus external standards made no difference to the degree of improvement following peer review.

Peer review. Part 1: Attitudes to internal and external standards.

Two peer review groups of ten general practitioners each reviewed their management of headache and fatigue. Each group used internal standards which they had set for the review of one condition and external standards set by the other group for the other condition. Data for the review was collected from the general practitioners' case notes and presented to them. The following year their management was again reviewed. The attitudes of the general practitioners to the use of both internal and external standards in peer review were measured using written questionnaire. There was no statistically significant difference in attitude to the two different types of standards. The attitudes of the general practitioners to external standards from a variety of sources were also measured. External standards developed by other peer review groups of general practitioners were significantly more acceptable (p less than 0.05) than standards developed by hospital specialists or the Department of Health.

Women in general practice in New Zealand.

AIM: To investigate the role of women general practitioners (GPs) in New Zealand. METHOD: A five-page questionnaire was posted to 200 randomly selected women GPs from throughout New Zealand. One follow-up mailing was sent. RESULTS: A response rate of 79% was achieved. Twenty-four percent of women GPs work less than 5/10 but 46% earn less than $40000. Forty-eight percent of women GPs' partners also earn less than $40000. The most common reason for working part-time was parenting responsibilities. Eighty-seven percent are married or live with a partner, 77% have children, 48% have preschool-aged children. Only 15% have Membership of the RNZCGP and 57% are owner or partner in their practice. CONCLUSION: Women GPs suffer both professional and financial difficulties because of their dual motherhood/professional roles.

Learning by distance for general practitioners: students' experiences of Goodfellow Unit diplomas.

AIM: To examine students' reasons for studying and their learning experiences in the Goodfellow Unit postgraduate distance learning diplomas. METHOD: A survey was sent to all students currently enrolled in the Goodfellow Unit diplomas in emergency, sports and geriatric medicine. RESULTS: The response rate was 63%. Students had enrolled to gain more skills on their present job for personal satisfaction or for personal interest. Students reported difficulties in fitting study into already busy lives, but general satisfaction with the learning format of videotaped lecture sessions plus written study guides. They also reported having to develop a different method of learning from their undergraduate study methods. Students predicted a number of ways of improving learning outcomes. CONCLUSION: Distance learning is a viable option for busy general practitioners, as long as it can be self paced, practical and relevant to the work situation.

Changes in CME uptake caused by reaccreditation.

AIM: To determine whether the requirements of the reaccreditation programme of the Royal New Zealand College of General Practitioners (RNZCGP) have changed the amount and type of continuing medical education (CME) done by the participating general practitioners. METHOD: A written questionnaire was sent to 200 randomly selected general practitioners doing the RNZCGP reaccreditation programme. RESULTS: The response rate was 82%. Although almost half the general practitioners had been motivated to spend more time on CME by the reaccreditation programme, for most this was a small increase. However, there was a trend towards selection of higher quality courses and towards increasing the time spent on educational activities more likely to result in changed behaviour. CONCLUSION: The RNZCGP reaccreditation programme is having beneficial effects on the CME activities of many of the participating general practitioners.

The validity of general practitioners' self assessment of knowledge: cross sectional study.

OBJECTIVE: To determine whether general practitioners can make accurate self assessments of their knowledge in specific areas. DESIGN: 67 general practitioners completed a self assessment of their level of knowledge over a variety of topics using a nine point semantic differential scale. An objective assessment of their knowledge was then made by administering true-false tests on two of the topics: thyroid disorders and non-insulin dependent diabetes. The study was repeated with another group of 60 general practitioners, using sexually transmitted diseases as the topic. SETTING: General practices in New Zealand. SUBJECTS: Random sample of 67 general practitioners in Auckland. MAIN OUTCOME MEASURE: Test scores for self assessment and for actual knowledge. RESULTS: Correlations between self assessments and test scores were poor for all three topics studied (r = 0.19 for thyroid disorders, 0.21 for non-insulin dependent diabetes, 0.19 for sexually transmitted diseases). CONCLUSIONS: As general practitioners cannot accurately assess their own level of knowledge on a given topic, professional development programmes that rely on the doctors' self perceptions to assess their needs are likely to be seriously flawed.

Partial reversal by sodium ascorbate of hyperoxia-induced damage to HEp-2 cell cultures.

Hyperoxia induced cellular damage was used as an experimental model system for examining the ameliorative role of antioxidants. Multiplication of HEp-2 cells in monolayer culture was inhibited after exposure to 100% O2 either hyperbarically at 3 atm absolute (atma) or normobarically at 1 atma for periods from 15 s to 4 h. The inhibition was characterized by a slower rate of replication for a period from 1 to 3 d after exposure than in unexposed cultures, and then massive cellular death. Less killing followed exposure to normobaric O2 than to hyperbaric O2, and the shorter the period of exposure to hyperoxia the less killing. Addition of 100 micrograms/ml of sodium L-ascorbate to unexposed cultures enhanced growth (cell number at 6 d) almost twofold. When added ascorbate was present only during hyperoxic exposure (but not afterward), subsequent growth in air was enhanced 1.6-fold. However, when cells were exposed without added ascorbate, there was from 2 to 12-fold greater growth in air in the presence of the added ascorbate (as compared to exposed controls). This greater growth was always only a partial reversal of the lethal effect resulting from hyperoxia. Addition of 25 micrograms/ml catalase did not affect control or exposed cultures. Addition of ascorbate plus catalase was not as effective as ascorbate alone in promoting growth; the catalase moiety antagonized some of the growth enhancing influence of ascorbate. This suggests that extracellular H2O2 was not a factor in the lethal effect resulting from hyperoxia.

Attitudes to recertification measured over time using a validated semantic differential scale.

OBJECTIVES: This study was designed to measure the acceptability of the Royal New Zealand College of GPs' Recertification programme to the GPs in the programme. DESIGN: Questionnaire study of a stratified random sample of members of the RNZCGP. METHOD: A semantic differential attitude scale was developed and validated. The scale was administered to 300 GPs before the Recertification programme began and repeated with 100 of these GPs 18 months later. After 3 years of the programme the questionnaire was administered to the original 300 GPs. RESULTS: Baseline data showed reasonable acceptance of the concept of recertification but by 18 months there was a significant deterioration in the way the programme was perceived and this did not change over 3 years. Many GPs were not convinced of the value of the programme.