Effect of problem-based, self-directed undergraduate education on life-long learning

OBJECTIVE

To compare how well graduates of a self-directed, problem-based undergraduate curriculum (at McMaster University [MU], Hamilton, Ont.) and those of a traditional curriculum (at the University of Toronto [UT]) who go on to primary care careers keep up to date with current clinical practice guidelines.

DESIGN

Analytic survey. Management of hypertension was chosen as an appropriate topic to assess guideline adherence. An updated version of a previously validated questionnaire was mailed to the participants for self-completion.

SETTING

Private primary care practices in southern Ontario.

PARTICIPANTS

A random sample of 48 MU graduates and 48 UT graduates, stratified for year of graduation (1974 to 1985) and sex, who were in family or general practice in Ontario; 87% of the eligible subjects in each group responded.

MAIN OUTCOME MEASURES

Overall and component-specific scores; analysis was blind to study group.

RESULTS

The overall mean scores were 56 (68%) of a possible 82 for the MU graduates and 51 (62%) for the UT graduates (difference between the means 5, 95% confidence interval 1.9 to 8.2; p < 0.01). Multivariate linear regression analysis of seven factors that might affect questionnaire scores revealed that only the medical school was statistically significant (p < 0.01). The MU graduates had significantly higher mean scores than the UT graduates for two components of the questionnaire: knowledge of recommended blood pressures for treatment (p < 0.05) and successful approaches to enhance compliance (p < 0.005). The trends were similar for the other components but but were not significant.

CONCLUSIONS

The graduates of a problem-based, self-directed undergraduate curriculum are more up to date in knowledge of the management of hypertension than graduates of a traditional curriculum.

Depression, problem-solving ability, and problem-solving appraisals

Behavioral analytic methods were used to create a college student version of the Means Ends Problem Solving Procedure (MEPS). This instrument then was administered with measures of perceived problem-solving ability to depressed and nondepressed students to determine whether differences exist in both problem-solving ability and problem-solving appraisal. Analyses revealed that depressed subjects had more negative expectations and lower appraisals of their problem-solving ability. However, the groups did not differ in terms of the actual quality of their behavioral solutions to interpersonal, intrapersonal, and emotional problem situations. The results are interpreted as support for the role of cognitive factors in depression and problem-solving across a range of problem-solving situations.

Increases in knowledge and use of information technology by entering medical students at McMaster University in successive annual surveys

OBJECTIVE

To determine self-reported microcomputer and information technology competency, access, and usage by entering medical students and their perceptions of the need for training in additional applications.

DESIGN

Cross-sectional surveys of successive classes.

SETTING

McMaster University Faculty of Health Sciences Medical Undergraduate Program, which has a 33-month, problem-based, self-directed learning curriculum and a high applicant-to-student ratio.

PARTICIPANTS

Medical school classes entering in 1987, 1988, and 1989. Response rates were 80%, 90%, and 86% respectively.

MEASURES

A self-report questionnaire was sent to each student, with up to two follow-up letters to prompt a response.

RESULTS

There was a progressive rise in reported information technology access and use for the three years. For the classes starting in 1987, '88, and '89 respectively, computer access was 29%, 49%, and 49% (P < 0.002 for linear trend), and, among those with computer access, modem access was 17%, 29% and 50% (P = 0.012). Self-service MEDLINE use on CD-ROM at the Health Sciences Library was 65%, 75%, and 89% respectively (P < 0.001) for all respondents within the first few months of starting medical school. Over 50% of each class stated they would take courses, if available, on clinical applications software, office management, online searching, filing, and CD-ROM searching.

CONCLUSIONS

Half of the most recent entering students already had access to a personal computer and most wished to learn computer applications that would assist them with patient management, and with information access and organization. Medical schools need to address which applications they will teach or make available and how to bring all students to acceptable competency in their use.

Performance appraisal of online MEDLINE access routes

OBJECTIVE

To compare the performance and cost of 11 online MEDLINE systems with MEDLINE at Elhill.

DESIGN

Comparative study. SYSTEMS: Eleven online daytime systems commercially available in North America offering the MEDLINE database.

MEASURES

Number of relevant citations, number of irrelevant citations, proportion of searches producing no relevant citations and cost per relevant citation were analyzed for each system. Relevance and cost for each system were compared with direct searching of MEDLINE through NLM for librarian and clinician search strategies for 18 clinical questions. The citations retrieved by both strategies were pooled and rated for relevance on a 7-point scale.

RESULTS

Numbers of relevant and irrelevant citations and cost per relevant citation were higher for clinician searches than librarian searches, reflecting the higher total number of citations retrieved by the clinician approaches. A lower proportion of clinician searches produced no relevant citations than librarian searches.

CONCLUSIONS

Eleven daytime MEDLINE systems performed similarly in terms of retrieval and cost within similar searching groups. Clinicians, however, tended to capture larger overall retrievals resulting in higher numbers of relevant and irrelevant citations than librarians.

A study to enhance clinical end-user MEDLINE search skills: design and baseline findings

OBJECTIVE

To determine if a preceptor and timely, individualized feedback improves the performance of physicians in searching MEDLINE using GRATEFUL MED in clinical settings.

DESIGN

Randomized controlled trial.

SETTING

A 300 bed primary to tertiary care teaching hospital. Computers were installed in wards and clinics of 6 major clinical services, and the emergency room, intensive care and neonatal intensive care units.

SUBJECTS

All physicians and physicians-in-training from the departments of Medicine, Family Medicine, Surgery, Psychiatry, Pediatrics, and Obstetrics and Gynecology were included if they made patient care decisions for at least 8 weeks during the study period.

INTERVENTION

All participants were given a 1-hour training class and 1 hour of individualized searching with 1 of the 2 study librarians. After training, participants were randomized to a control group who received no further intervention or to an intervention group in which each person chose a clinical preceptor experienced in MEDLINE searching and received individualized feedback by a study librarian on their first 10 searches, indicating search quality and providing suggestions for improvement. Feedback was mailed the first week day after the search was done.

MAIN MEASURES

Baseline characteristics by study group, department and level of training, study participation rates, and searching rates.

MAIN RESULTS

308 of 392 eligible physicians joined the study. Participation was almost 80% with some variation by department and level of training. Excellent balance in the baseline characteristics was achieved for the 2 groups, as well as for the number who did first searches. Intervention group participants searched MEDLINE more often than did controls (3.5 searches per month vs 2.5 per month for controls, P = 0.046). The recall and precision for first searches for both groups was significantly less than that of librarians. The analysis of study data will be completed by September 1991.

CONCLUSIONS

Clinicians are willing to do self-service searching of MEDLINE in clinical settings but their precision and recall are less than a trained librarian at baseline. Search skills enhancements are needed and the effect of feedback and preceptors is being tested.

SOURCE OF FUNDING

U.S. National Library of Medicine and Ontario Ministry of Health.

Effect of select menhaden fish meal in starter diets for pigs

Two trials were conducted to evaluate a select menhaden fish meal (SMFM) as a protein source in starter diets for 390, 3-wk-old weaned pigs. Initial weights averaged 4.8 and 5.5 kg in Trials 1 and 2, and trials were conducted for 5 and 4 wk, respectively. Diets in Trial 1 were formulated by substituting levels of 0, 4, 8, 12, 16 or 20% SMFM for soybean meal plus corn on a protein basis. The 20% fish meal diet contained no soybean meal; all diets contained between 19.8 and 20.2% CP, between 1.34 and 1.40% lysine and 25% dried whey. Replacement of soy protein with fish meal elicited a quadratic improvement (P = .01) in cumulative ADG and average daily feed intake (ADFI) by the end of wk 5. The diet containing 8% SMFM resulted in the maximum observed ADG; however, the maximum ADFI occurred in pigs fed the diet containing 12% SMFM. Breakpoint analysis indicated that 4.5 and 9.3% SMFM maximized ADG and ADFI, respectively. Addition of SMFM did not affect efficiency of feed utilization (F/G). In Trial 2, a 2 X 3 factorial with two levels of dried whey (10 or 20%) and three levels of SMFM (0, 4 or 8%), a SMFM X dried whey interaction (P less than .05) was observed for cumulative ADG and F/G by the of wk 4 with greater benefit from SMFM with 10% than with 20% dried whey.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine transport systems on dissociated brain cells from mouse, guinea-pig, and rat

The kinetics and sodium dependence of adenosine transport were determined using an inhibitor-stop method on dissociated cell body preparations obtained from mouse, guinea-pig and rat brain. Transport affinity (KT) values for the high affinity adenosine transport systems (KT(H] were significantly different between these three species; mean +/- SEM values were 0.34 +/- 0.1 in mouse, 0.9 +/- 0.2 in rat, and 1.5 +/- 0.5 microM in guinea-pig. The KT values for the low affinity transport system (KT(L) were not different between the three species. Brain cells from rat displayed a significantly greater maximal capacity to accumulate [3H]adenosine (Vmax) than did mouse or guinea-pig for the high affinity system, or than did mouse for the low affinity system. When sodium chloride was replaced in the transport medium with choline chloride, the KT(H) values for guinea-pig and rat were both increased by approximately 100%; only in rat did the change reach statistical significance. The sodium-dependence of adenosine transport in mouse brain was clearly absent. The differences between KT(H) values in mouse and those in guinea-pig or rat were accentuated in the absence of sodium. The differences in kinetic values, ionic requirements, and pharmacological characteristics between adenosine transporters in CNS tissues of mouse, guinea-pig and rat may help account for some of the variability noted among species in terms of their physiological responses to adenosine.

HLA class I-related impairment in IL-2 production and lymphocyte response to microbial antigens in reactive arthritis

The contribution of certain Gram-negative bacteria and host HLA class I Ag to the development of reactive arthritis (ReA)3 has strong epidemiologic support but the pathogenesis of the arthritis is unknown. An outbreak of Salmonella typhimurium afforded the opportunity to compare the immune response to the organism between those who developed ReA (ReA+, n = 11) with those who did not (ReA-, n = 12). Of the 11 ReA+ patients, 4 were B27-positive and 6 were B7-positive; of the ReA- patients none was B27- or B7-positive. The causative pathogen S. typhimurium phage 22 was used to examine PBL proliferation by [3H]thymidine incorporation. Impairment in lymphocyte response to S. typhimurium in ReA+ compared with ReA- was demonstrated by: i) lower stimulation index (1.9 +/- 0.3 for ReA+, 5.7 +/- 0.6 for ReA-, p less than 0.01); ii) lower in vitro Ig production; and iii) lower Ag-induced IL-2 production. Mixing experiments did not demonstrate a soluble suppressor factor in ReA+ supernatants. Thus, after infection with S. typhimurium there is an impairment in cellular immunity that has correlates in immunogenetic and clinical features of the infected population.

HLA class I-related impairment in IL-2 production and lymphocyte response to microbial antigens in reactive arthritis

The contribution of certain Gram-negative bacteria and host HLA class I Ag to the development of reactive arthritis (ReA)3 has strong epidemiologic support but the pathogenesis of the arthritis is unknown. An outbreak of Salmonella typhimurium afforded the opportunity to compare the immune response to the organism between those who developed ReA (ReA+, n = 11) with those who did not (ReA-, n = 12). Of the 11 ReA+ patients, 4 were B27-positive and 6 were B7-positive; of the ReA- patients none was B27- or B7-positive. The causative pathogen S. typhimurium phage 22 was used to examine PBL proliferation by [3H]thymidine incorporation. Impairment in lymphocyte response to S. typhimurium in ReA+ compared with ReA- was demonstrated by: i) lower stimulation index (1.9 +/- 0.3 for ReA+, 5.7 +/- 0.6 for ReA-, p less than 0.01); ii) lower in vitro Ig production; and iii) lower Ag-induced IL-2 production. Mixing experiments did not demonstrate a soluble suppressor factor in ReA+ supernatants. Thus, after infection with S. typhimurium there is an impairment in cellular immunity that has correlates in immunogenetic and clinical features of the infected population.

Sodium-dependent uptake of nucleosides by dissociated brain cells from the rat

Sodium-dependent 3H-labeled nucleoside transport was studied using a mixed population of dissociated brain cells from adult rats. The accumulation of [3H]adenosine during brief (15-s) incubation periods was significantly greater in the presence of 110 mM Na+ than in its absence. This occurred at substrate concentrations that ranged from 0.25 to 100 microM. Similar findings were observed for the rapid accumulation of [3H]uridine. Kinetically, the rapid accumulation of [3H]adenosine in both the absence and the presence of Na+ was best described by a two-component system. In the presence of Na+, the KT and Vmax values for the high-affinity affinity component were 0.9 microM and 8.9 pmol/mg of protein/15 s, and those for the low-affinity component were 313 microM and 3,428 pmol/mg of protein/15 s, respectively. In the absence of Na+, the KT value for the high-affinity component was significantly higher (1.8 microM). [3H]Uridine accumulation was best described kinetically by a one-component system that in the presence of Na+ had KT and Vmax values of 1.0 mM and 2.6 nmol/mg of protein/15 s, respectively. As was found for [3H]adenosine, in the absence of Na+, the KT value was significantly higher (1.8 mM). The sodium-dependent transport of [3H]adenosine was inhibitable by ouabain and 2,4-dinitrophenol. Of the three nucleoside transport inhibitors tested, only nitrobenzylthioninosine demonstrated high affinity and selectivity in blocking the sodium component. Thus, high-affinity sodium-dependent nucleoside transport systems, in addition to facilitated diffusion systems, exist on brain cells from adult rats.

Postdysenteric reactive arthritis. A clinical and immunogenetic study following an outbreak of salmonellosis

Following an outbreak of foodborne gastroenteritis caused by Salmonella typhimurium, questionnaires were sent to affected individuals and then to the family physicians of any who experienced extra-enteric complications. Of 260 individuals infected with S typhimurium for whom adequate data were obtained, 19 patients developed joint disease (7.3%). All were men; the mean age +/- SD was 39.3 +/- 1.6 years. Among the 16 patients for whom this information was available, the interval from the onset of diarrhea to the onset of joint pain was less than 7 days in 7, 8-21 days in 2, and greater than 21 days in 7. There was a significantly longer duration of diarrhea in those patients with joint disease (mean +/- SEM 15.2 +/- 2.6 days) than in those without complications (10.0 +/- 1.1 days) (P less than 0.01). The joint disease was monarticular in 3 patients and polyarticular in 16. The joints most commonly affected were the elbow (47%), wrist (47%), knee (42%), low back (32%), and shoulder (32%). Six of the 19 patients had at least 1 extraarticular feature: ocular (5 patients), mucosal (1 patient), urethral (2 patients), or cutaneous (1 patient). Of these 19 patients, 11 were located and agreed to HLA typing. Four were positive for HLA-B27, 6 were HLA-B7 positive, and 1 had HLA-Bw60. Of the 4 B27 positive patients, 3 were DR1 positive; of the 6 B7 positive patients, 5 were DR2 positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological characterization of rapidly accumulated adenosine by dissociated brain cells from adult rat

Mechanically dissociated brain cells from adult rats were used to study biochemically and pharmacologically their capacity to accumulate rapidly [3H]adenosine. The assay, which used an inhibitor-stop method to prevent further uptake into cells, was characterized with respect to protein and optimal substrate concentrations, and incubation times that ranged from 5 to 180 s. The accumulation of [3H]adenosine using 15-s incubation periods, conditions under which less than 10% of accumulated [3H]adenosine was metabolized, was best described kinetically by a two-component system with Km and Vmax values for the high-affinity component of 0.8 microM and 6.2 pmol/mg protein/15 s and for the low-affinity component 259 microM and 2,217 pmol/mg protein/15 s, respectively. The potencies with which nucleosides, adenosine deaminase resistant adenosine receptor agonists, and nucleoside uptake inhibitors competed for these uptake components were determined. Of the nucleosides examined, adenosine was the "preferred" substrate for the uptake site. The Ki value of adenosine for the high-affinity component was 10.7 microM. Inosine and uridine competed for a single lower affinity uptake system: Ki values were 142 and 696 microM, respectively. Nucleoside uptake inhibitors--nitrobenzylthioinosine, dipyridamole, and dilazep--were the most potent inhibitors of [3H]adenosine accumulation tested: the Ki values for the high-affinity system were 0.11, 1.3, and 570 nM, respectively. The adenosine analogs S-phenylisopropyladenosine, R-phenylisopropyladenosine, and cyclohexyladenosine inhibited the high-affinity component with Ki values of 2.3, 9.3, and 14.5 microM, respectively. N-Ethylcarboxamidoadenosine competed for a single lower affinity uptake system: Ki, 292 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical significance of common eye changes in older patients

The limbus is often affected by degenerative lesions, many associated with the aging process. Some degenerations may cause irritation, discomfort, and poor vision, thus requiring ophthalmological treatment, while a few require systemic evaluation and treatment. As the limbus is also subject to neoplasms and inflammatory processes, any limbal lesion whose identity is less than obvious should prompt an ophthalmologic consultation.

Successful treatment of the ocular ischemic syndrome with panretinal photocoagulation and cerebrovascular surgery

The ocular ischemic syndrome is a manifestation of chronic vascular insufficiency. The natural history is for progressive visual loss. The authors describe 12 patients (13 eyes) who presented with at least one asymmetric ocular finding, including midperipheral dot and blot hemorrhages (hypoperfusion retinopathy) (in 8), iris neovascularization (in 7), neovascular glaucoma (in 3) and vitreous hemorrhage (in 1). Cerebral angiography revealed stenosis or occlusion of the ipsilateral carotid artery in all cases. The treatment was panretinal photocoagulation (in four cases), cerebrovascular surgery (in three) or both (in six). All but one patient showed stabilization of visual acuity (20/60 or better in nine cases) and regression of proliferative retinopathy and of iris neovascularization. The results underline the importance of early recognition and treatment of the ocular ischemic syndrome.

Immunochemical analysis of immune response to Chlamydia trachomatis in Reiter's syndrome and nonspecific urethritis

Chlamydia trachomatis (Ct) has been proposed as a causative agent in Reiter's syndrome (RS) when an infection occurs in a susceptible host. To assess whether this susceptibility is reflected in a characteristic humoral immune response we compared patients with complicated (RS) and uncomplicated courses of nonspecific urethritis (NSU). Geometric mean titres of antibodies to C. trachomatis by immunofluorescence were 89.6 for RS, 80.0 for NSU and 16.0 for normals. 125I-Protein A probing of immunoblotted antigens of C. trachomatis revealed no band unique to RS. 125I-anti-IgA probing of immunoblots demonstrated reactivity with the 59,000 dalton antigen in 11/11 RS and 2/6 NSU. The major outer membrane protein of C. trachomatis (40,000 daltons) bound immunoglobulin nonspecifically. There was no clearly differentiating feature between HLA-B27-positive and B27-negative RS. One sequentially studied patient revealed an augmentation in synovial fluid IgA reactivity during the course of disease. No pattern of humoral immune response to C. trachomatis could be regarded as specific for RS nor for HLA B27-positivity. The study did not identify a Reiter's-specific antigen in C. trachomatis but demonstrates the usefulness of applying blotting techniques to population studies of HLA modulation of immune response to infectious agents.

Analysis of serum and synovial fluid IgA in Reiter's syndrome and reactive arthritis

The presumed antecedent infection which precedes Reiter's syndrome and reactive arthritis is frequently across a mucosal surface, and IgA immune responses may play a role in this process. Twelve of 29 patients with these conditions demonstrated elevation in serum IgA levels, and serum IgA levels in the postdysentery group (mean 3.21 g/liter +/- 1.27) were higher (P less than 0.01) than those in the posturethritis group (mean 2.40 g/liter +/- 0.80). In 10 of the 12 patients, IgA was the only immunoglobulin increased. There was no evidence of activation of complement in serum or synovial fluid. Using a complement-dependent assay, we were unable to demonstrate circulating IgA immune complexes. Sucrose density gradient ultracentrifugation analysis was used to assess IgA immune complexes in a non-complement-dependent manner. IgA of 11s was in fact demonstrated by this technique but appeared to be polymeric IgA on the basis of specific binding of secretory component and resistance to acid dissociation. IgA rheumatoid factor was not present. Synovial fluid revealed levels of polymeric IgA higher (mean 56.7% +/- 12.9) than did serum (23.7% +/- 13.9, P less than 0.001) despite higher levels of total IgA in serum than in synovial fluid (synovial fluid:serum ratio of IgA, mean 0.53 +/- 0.11). Although elevation in serum IgA in postdysenteric arthropathies suggests mucosal acquisition of antigen, the study does not implicate IgA circulating immune complexes in the pathogenesis of these diseases.

Arthritis, vasculitis, and cryoglobulinemia associated with relapsing hepatitis A virus infection

Hepatitis A virus, unlike hepatitis B virus, has rarely been associated with extrahepatic features. Two patients developed relapsing hepatitis A complicated by arthritis in both cases and cutaneous vasculitis in one. Both patients had cryoglobulinemia, with cryocrit values of 4.3% and 8.6%. Serologic studies showed that the cryoglobulin consisted of polyclonal IgM and IgG. The washed cryoglobulin was analyzed by sucrose density gradient ultracentrifugation under neutral (pH 7.4) and acidic (pH 2.8) conditions. Enzyme-linked immunosorbent assay techniques were used to characterize the native and dissociated cryoglobulin. The cryoglobulin contained acid-dissociable IgG complexes greater than 19S, and high molecular weight rheumatoid factors of both IgG and IgM isotypes that could be dissociated to 7S and 19S forms, respectively. Dissociation of the cryoglobulin augmented 7S anti-hepatitis A virus IgG 2.27-fold, but augmented total 7S IgG only 1.12-fold, suggesting enrichment of antiviral antibody in the cryoglobulin.

Molecular mimicry in Reiter's syndrome: cytotoxicity and ELISA studies of HLA-microbial relationships

The pathogenic links between HLA antigens, certain bacterial infections and arthritis have not yet been characterized. The hypothesis of cross-reactivity between HLA B27, the marker of disease susceptibility for these disorders, and the provocative microorganism has been suggested by studies of Klebsiella and ankylosing spondylitis. The present study examines the possibility of molecular mimicry between HLA B27 and two organisms implicated more directly in reactive arthritis, Yersinia enterocolitica and Chlamydia trachomatis. Antibodies against these organisms were obtained both from patients and from antisera raised in rabbits. Neither source of antibacterial antibody was specifically cytotoxic for HLA B27-positive lymphocytes, even when the target cells were derived from patients with recent infections due to these organisms. In addition, monoclonal antibodies against HLA B27 (M1 and M2) showed no reactivity with antigens from these organisms in an ELISA system. These data do not support the notion of molecular mimicry as being the basis of immunogenetic susceptibility to reactive arthritis and Reiter's syndrome following infections with Y. enterocolitica and C. trachomatis.

Hypertension control in two Canadian communities: evidence for better treatment and overlabelling

We evaluated the prevalence and control of hypertension in two Canadian cities without university medical centre facilities. A stratified multistage probability sample was selected, and we interviewed 6258 adults between the ages of 30 and 69 inclusive. Blood pressure measurements were obtained during home interviews. Up to two further visits were made to people with untreated blood pressure elevation. By a diagnostic criterion of 90 mmHg, the hypertension prevalence was 114/1000. Six per cent of the hypertensives were undetected, 6% detected but untreated, 17% treated but uncontrolled and 70% were being treated and controlled. Control was better in females and older subjects. These findings show no disadvantages to hypertensives living away from university medical centres. We found a hypertension prevalence of 143/1000 among people who reported being diagnosed as hypertensive but who had normal blood pressure while not on medication. These results suggest a problem with over-labelling of hypertensives.

Does a mailed continuing education program improve physician performance? Results of a randomized trial in antihypertensive care

Evidence is sparse concerning the value of the "educational" materials that physicians receive in the mail. We conducted a randomized trial of a mailed continuing education program on hypertension for primary care physicians. Although formal pretesting documented that the program led to significant improvements in physician knowledge over the short term, the current study showed no lasting effect on physician knowledge (mean scores on an end-of-study questionnaire were 50% and 52% for study and control physicians, respectively) and no influence on performance in lowering the blood pressures of patients referred from screening (mean blood pressure drop for study patients, 12.2/10.4 mm Hg vs 13.0/10.6 mm Hg for control patients). The chance that we missed a difference in diastolic blood pressure as great as 3 mm Hg is less than 5%. Resources spent on instructional materials mailed to physicians may be wasted.

Temporal desensitization of rat uteri for the decidual cell reaction is abolished by cholera toxin acting by a mechanism apparently not involving adenosine 3':5'-cyclic monophosphate

To determine if increased endometrial vascular permeability (a response which precedes decidualization) could be obtained in temporally nonsensitized uteri by treatments designed to increase endometrial adenosine 3':5'-cyclic monophosphate (cAMP) concentrations, cholera toxin (an activator of adenylate cyclase) was injected into the uterine lumen of immature rats treated to be at the equivalent of day 4, 5, or 6 of pseudopregnancy. In all experiments, the rats were pretreated with indomethacin to inhibit endogenous prostaglandin (PG) synthesis. Endometrial vascular permeability, determined using 125I-labeled bovine serum albumin, was assessed 8 h later. Cholera toxin increased endometrial vascular permeability to the same level in all groups. As determined by uterine weights 5 days after the intrauterine administration of cholera toxin or its vehicle, the toxin produced the same extent of decidualization in all groups. Cholera toxin had no detectable effect on uterine cAMP concentrations in rats sacrificed 15 min after intrauterine treatment. In contrast, intrauterine administration of PGE2 increased uterine cAMP concentrations at 15 min in all groups. These data suggest that the effects of cholera toxin and of PGE2 on endometrial vascular permeability and decidualization are not mediated by cAMP.

Giant retinal tears, retinal detachment and retinitis pigmentosa

A patient with retinitis pigmentosa and sensorineural deafness presented with bilateral giant retinal tears and a unilateral retinal detachment. The peripheral visual field loss could have been erroneously ascribed to the primary retinal dystrophy. A retinal detachment must be considered in patients with a sudden loss of visual acuity or field even if they have a primary retinal dystrophy.

Estrogen and uterine sensitization for the decidual cell reaction in the rat: role of prostaglandin E2 and adenosine 3':5'-cyclic monophosphate

The possibility that estrogen affects uterine sensitization for decidualization by altering the ability of E-series prostaglandins (PGs) to increase adenosine 3':5'-cyclic monophosphate (cAMP) concentrations was investigated. To determine if increased endometrial vascular permeability, a response which precedes decidualization, could be obtained in nonsensitized uteri by treatments designed to increase endometrial intracellular cAMP concentrations, cholera toxin, an activator of adenylate cyclase, was injected into the uterine lumen of immature rats pretreated with progesterone and either 0, 0.5 or 10 micrograms estrone with indomethacin to inhibit endogenous PG synthesis. Endometrial vascular permeability, determined using 125I-labeled bovine serum albumin, was assessed 8 h later. Cholera toxin produced a dose-dependent increase in endometrial vascular permeability in all groups; the uteri of rats pretreated with the optimal hormone regimen (0.5 micrograms estrone plus 2 mg progesterone) responded to a lower dose of the toxin. As determined by uterine weights and histologic examination 5 days after the intrauterine administration of cholera toxin or its vehicle, the toxin induced decidualization in rats pretreated with progesterone and 0 or 0.5 micrograms estrone, but not in those receiving 10 micrograms estrone. Cholera toxin had no detectable effect on uterine cAMP concentrations in animals sacrificed 15 min or 3 h after intrauterine treatment. The intrauterine injection of 8-Br-cAMP, with or without 3-isobutyl-1-methyl-xanthine, did not increase endometrial vascular permeability in indomethacin-treated animals pretreated with the different hormone regimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Sexual behavior of group-housed stumptail macaques (Macaca arctoides): temporal, demographic and sociosexual relationships

A detailed quantitative analysis of sexual behavior in a social group of captive stumptail macaques was conducted. The distribution of copulations both over days and among animals, and the relationships between copulation and various sociosexual patterns were investigated. Copulations occurred erratically over days and were preferentially directed to a small minority of females. Most patterns of sociosexual behavior were at their highest rates during actual copulatory episodes, others occurred independent of ejaculation. It is suggested that the relationships between variables such as social rank, age and parity and sociosexual patterns are quite flexible and probably vary with the species, testing conditions and demographic make-up of the group.

Effects of labelling on income, work and social function among hypertensive employees

Two hundred and thirty hypertensive Canadian steelworkers were followed for 5 years after screening and referral. Data on income, absenteeism and measures of work and social function were collected on these men and on a matched group of 230 normotensive employees. In the fifth year after screening, hypertensive employees earned an average of Can. $1093 less than normotensive employees despite similar incomes in the year before screening. This adverse effect on income was observed regardless of awareness of hypertension at the time of screening or compliance with treatment. Illness-related absenteeism among hypertensives rose in the year following screening and remained elevated for 4 years after screening. Normotensive and hypertensive employees reported similar levels of physical ability and psychological well-being. These findings need verification in other settings before inclusion in cost-effectiveness analyses of the management of hypertension.