Introduction of a simulation laboratory to preclinical students at St. George's University in Grenada

OBJECTIVE: To investigate the use of high fidelity simulation mannequins in improving competence and confidence levels of medical students to recognize cardiac and lung sounds. Study design: Observational study. SUBJECTS and METHODS: The students took a pre-test evaluating their ability to recognize cardiac and respiratory sounds. They then rotated through three clinical scenarios using simulation mannequins. They were then given a post-test. Both prior to, and following the session the students completed a Likert scale on their comfort in recognizing the sounds. The pre- and post-test scores were compared. RESULTS: There was a significant improvement in the students' ability to recognize cardiac and respiratory sounds (p<0.0001), as well as in their comfort levels (p<0.0001). Overall, 80% of the studnets felt more comfortable in their ability to recognize the sounds, 17% felt the same and 3% felt less comfortable. CONCLUSION: Use of simulation mannequins improves medical students' abilities, as well as comfort in recognizing cardiac and respiratory sounds.

Examining HIV/AIDS provider stigma: assessing regional concerns in the islands of the Eastern Caribbean.

HIV/AIDS provider stigma has been understudied in the context of prevention, testing, and treatment. Results of a survey of persons associated with HIV/AIDS education, health care, and social service delivery in the Eastern Caribbean are described. Reliable constructs were observed for warmth towards PLHA, comfort in association with them, tendencies to distance from or condemn them, beliefs in viral transmission myths, and perceived capacity to counsel effectively. Most discrimination was directed towards MSM and IDUs. Providers whose roles were likely to involve touch felt less comfortable around PLHA and more likely to distance from and condemn them than providers whose roles were not. Implications for improved measurement and incorporation of mindfulness techniques in stigma intervention are discussed.

Cancer incidence and mortality in Grenada 1990-2000.

This paper summarizes and discusses the available cancer incidence (1996-2000) and mortality data (1990-2000) for the tri-island Caribbean nation of Grenada, Carriacou and Petit Martinique. Data for the analysis came from three sources: the Grenada Department of Statistics, the histopathology specimen books from St George's General Hospital and the Death Registry of the Ministry of Health, Grenada. The age-standardized rates (ASR) per 100 000 for all cancer sites combined were 170.2 in females and 158.2 in males. The four most frequent diagnoses (ASR) by cancer site in females were cervix (60.7), breast (49.1), uterus (28.4) and skin (13.3); and among males, prostate (61.4), bladder (16.3), skin (19.3) and stomach (10). Age-standardized mortality rates per 100 000 for all cancer sites combined were 105.4 in females and 165 in males. The four most frequent cancer associated mortalities (ASR) in females were breast (17.9), uterus (11.2), colon (10.3) and cervix (9.7); and among males, prostate (53.6), lung (18.7), stomach (14.5) and colon (10.9). This study found statistically significant spatial trends for overall cancer mortality and temporal trends in incidence and mortality rates for prostate and for incidence rates of stomach cancer. These rates are compared with those from other areas in the Caribbean and the United States of America and encourage efforts to establish a cancer registry in Grenada.

Six-month patient outcomes in a preventive cardiology center.

More effective ways to improve lifestyle behaviors need to be developed. Two hundred forty adult patients at a preventive cardiology clinic were randomly assigned to receive either one or five sessions of behavioral instruction to improve cardiovascular risk behaviors. Results for 102 patients from 6-month follow-up data revealed few significant differences between the two groups. However, in the two groups combined, there were significant reductions in total calories, percent of calories from total fat, percent of calories from saturated and monounsaturated fat, and dietary cholesterol. Reductions were also found in systolic blood pressure, triglycerides, body mass index, and weight. In multiple regression analyses, changes in physiologic variables were primarily associated with baseline and demographic characteristics. Changes in total calories, percent of calories from polyunsaturated fat, and walking were predicted by changes in social support or knowledge. Although most patients improved, the intensity of behavior change instruction was not related to the amount of change in cardiovascular risk factors. (c) 2001 by CHF, Inc.

An analysis of Ca2+ release by DGEA: mobilization of two functionally distinct internal stores in Saos-2 cells.

Osteoblasts can be activated by their collagen matrix and in particular the DGEA peptide motif. We have reported that DGEA is able to activate Ca2+ signaling pathways in the human osteoblast-like cell line, Saos-2, by a tyrosine kinase-dependent pathway (T. J. McCann, W. T. Mason, M. C. Meikle, and F. McDonald. Matrix Biol. 16: 271-280, 1997). In the present study, we show that this activity is due to coupling of the signal to intracellular Ca2+ stores, since the DGEA action is not blocked by La3+ but is lost when Ca2+ stores are depleted with 2 microM and blocked by 10 microM ryanodine. The activated stores also differ functionally from those activated by thrombin, as blockade with U-73122 obstructs only thrombin-activated Ca2+ release. We have shown that the DGEA activity was not due to its high-charge density, since the two acidic residues can be substituted with their uncharged homologues (asparagine and glutamine) without significant loss of activity. This was in turn measured by an adhesion assay that also demonstrated this level of specificity. Furthermore, by constructing DGEA bound to FITC, we have shown that DGEA binding was dependent on divalent cations. We have also demonstrated that an intact actin cytoskeleton is not required for Ca2+ activation by inhibiting actin polymerization with the addition of cytochalasin B. These data strengthen the argument that collagen has a significant role in regulating osteoblast function via this peptide motif.

A randomized trial of cardiovascular risk factor reduction: patterns of attrition after randomization and during follow-up.

BACKGROUND: The Preventive Cardiology Center compared two intensities of behavior modification for cardiovascular disease (CVD) risk factors in persons at risk and their families. Characteristics of drop-outs both before and after intervention were compared with subjects who completed the 6-month trial. METHODS: A total of 333 individuals of all ages were enrolled in the study and randomly assigned by family to a single-session ('skills' group-low-intensity) or a five-session ('practice' group-high intensity) intervention. Baseline and follow-up assessments included a personal and family health questionnaire, nutritional intake survey, and clinic visit to obtain blood pressure, lipids, and height and weight data. RESULTS: Two hundred and forty adults over 18 years of age were randomly assigned to one of the two intervention groups. Of these, 68 subjects (28.3%) did not participate in the intervention. Multivariate analysis revealed that these 'early drop-outs' were significantly more likely to be non-white and to have had a lower LDL cholesterol. Of the 172 subjects attending the intervention, 70 (40.7%) did not attend the 6-month follow-up ('late drop-outs'). Multivariate analysis revealed that, compared with follow-up attendees, non-attendees were significantly more likely to be white and to be current smokers. CONCLUSIONS: Both early and late drop-outs in a randomized trial of CVD risk reduction were significantly different than continuing participants in several key factors. These differences suggest the use of caution in both interpreting and making generalizations about behavioral trials of risk factor reduction when attrition is high.

A collagen peptide motif activates tyrosine kinase-dependent calcium signalling pathways in human osteoblast-like cells.

A collagen peptide motif (DGEA) which is a putative alpha 2 beta 1 integrin binding site was examined for its ability to activate Ca2+ signalling pathways in the human osteoblast-like cell line SaOS-2. We show that these cells express both alpha 2 beta 1 integrin subunits (by immunocytochemistry) and that an anti-beta 1 monoclonal antibody (DF5) mobilizes Ca2+ in these cells. DGEA elevated intracellular Ca2+ in fura-2-loaded cells, in a concentration- and sequence-dependent fashion, with an EC50 of 250 microM. The tyrosine kinase inhibitor herbimycin A reduced the number of cells responding to DGEA and to transforming growth factor alpha. Thrombin also stimulated a rise in intracellular Ca2+, but the number of cells responding was not reduced by herbimycin A. The DGEA response was dependent on extracellular Ca2+, but was not due to Ca2+ influx, since it was blocked by thapsigargin and not by lanthanum. Using three different anti-alpha 2 monoclonal antibodies, we were unable to show that the DGEA-induced Ca2+ signal was mediated by the alpha 2 beta 1 integrin. In summary, the DGEA collagen motif does appear to activate receptor-mediated Ca2+ signalling events in SaOS-2 cells, in a divalent cation-dependent manner, but we were unable to demonstrate a role for alpha 2 beta 1 integrin in this response.

Calcium waves in fluid flow stimulated osteoblasts are G protein mediated.

Calcium (Ca2+) entry upon cell perturbation has been examined in transformed human osteoblast cells (U-2/OS). The cells were deformed by fluid flow from a patch pipette held in proximity to the cell by applying a positive pressure (+50 mm Hg) for the passage of saline over the membrane. Intracellular calcium [Ca2+]i was examined following loading with 5 microM Fura-2 AM. The changes in ratio were determined at 330-ms intervals. Waves of [Ca2+]i were seen spreading along the length of the individual cell following stimulation (n = 30). The initial change in Ca2+ at the site of stimulation occurred within 660 ms after applying the stimulus. Following 1.3 (+/- 0.33) s of raised [Ca2+]i, the values returned to those of predeformation. The Ca2+ response following fluid flow stimulation was blocked by 300 microM Cd2+, a specific blocker of Ca2+ channels, demonstrating an extracellular source of Ca2+. Preincubation with cholera toxin (250 ng/ml for 6 h) prolonged the elevation of Ca2+ induced by fluid flow stimulation (n = 20). In contrast, pertussis toxin (250 ng/ml for 6 h) completely eliminated the Ca2+ response to fluid flow stimulation (n = 20). Cells maintained in solutions free of Ca2+ demonstrated no change in [Ca2+]i. Tetraethylammonium (6 mM) had no effect on the response (n = 10). In addition pretreatment with ryanodine (2 and 10 microM; each group n = 10) in media showed a reduced wave of Ca2+ in response to mechanical deformation. The response to a phospholipase C inhibitor also eliminated the response to the mechanical deformation (n = 10). In addition cells that demonstrated changes in Ca(2+)-containing media lost the ability to respond when EGTA was added to the media. Following this, 2 microM ryanodine was added to the cells, demonstrating a response too small to replicate the fluid flow stimulated wave, but supporting the view that the cells were vital following preincubation.

IgE predicts future nonfatal myocardial infarction in men.

Established risk factors cannot explain all the variance in coronary heart disease (CHD). Immunoglobin E (IgE), a mediator of allergy, can affect platelets and arterial smooth muscle. We previously demonstrated a cross-sectional association between IgE and cardiovascular disease (CVD) in men. The present study evaluated this relationship prospectively in 278 men and 343 women followed for a mean of 8.9 years. There was an association between IgE and coronary disease in men, but not in women. There was no association for CVD, stroke, or all-cause mortality. The age-adjusted relative risk (RR) for coronary mortality in men with baseline IgE > or = 200 kU/L was 1.66 (p < or = 0.66), but for nonfatal myocardial infarction (MI) it was 6.46 (p < or = 0.01). This association was independent of smoking and other risk factors, and unrelated to allergy. Thus, elevated IgE was a strong independent prospective risk factor for nonfatal, but not fatal, MI in men.

Effects of a preventive cardiology curriculum on behavioral cardiovascular risk factors and knowledge of medical students.

We evaluated a Preventive Cardiology Academic Award (PCAA) program designed to integrate preventive cardiology concepts into the medical school curriculum. Diet, preventive cardiology knowledge, preventive cardiology attitudes, exercise behavior, and body mass index were compared at entrance to medical school and during the graduation year. Complete data were available on 94 students (65 men and 29 women). Similar data from students who graduated in 1987, prior to the introduction of the PCAA curriculum, served as a control. Women showed a significant enhancement in attitude towards cardiovascular disease (CVD) prevention, while both men and women significantly increased their knowledge about CVD prevention. The frequency of planned physical activity decreased significantly in both sexes and men showed a significant increase in body mass index. Men significantly reduced total calories, percent of calories from fat and saturated fat and dietary cholesterol and increased fiber intake. In women, the only significant reduction was in total calories. In comparison to the control class that did not have the program, men receiving the PCAA curriculum reduced dietary cholesterol, dietary fat, saturated fat and monounsaturated fat. Changes in these dietary parameters were nonsignificant for women in comparison to the control class women. Additional analyses showed no systematic secular trends in dietary or other variables in classes entering from 1986 to 1990. We conclude that the PCAA curriculum changes have favorably affected the preventive cardiology knowledge, attitudes and diet of medical students.

Use of pertussis toxin to investigate the mechanism of action of prostaglandin F2 alpha on the corpus luteum in sheep.

Pertussis toxin catalysed the ADP-ribosylation of a protein of M(r) 40,000 in ovine luteal tissue. Ribosylation of 45% of this protein in whole cell incubations (as judged by subsequent ribosylation of cell-free preparations in the presence of [32P]NAD) attenuated the prostaglandin (PG)F2 alpha-stimulated hydrolysis of [3H]inositol-labelled phosphatidylinositol-4,5-bisphosphate into inositol trisphosphate by 60%, but did not affect the inhibition by PGF2 alpha of LH-stimulated accumulation of cyclic AMP. It is concluded that activation of phospholipase C by PGF2 alpha involves a pertussis toxin-sensitive protein, probably a G protein, and that the inhibitory effect of PGF2 alpha on LH-stimulated adenylate cyclase is unlikely to be directly mediated by such a protein.

Mortality over a period of 10 years in patients with peripheral arterial disease.

BACKGROUND: Previous investigators have observed a doubling of the mortality rate among patients with intermittent claudication, and we have reported a fourfold increase in the overall mortality rate among subjects with large-vessel peripheral arterial disease, as diagnosed by noninvasive testing. In this study, we investigated the association of large-vessel peripheral arterial disease with rates of mortality from all cardiovascular diseases and from coronary heart disease. METHODS: We examined 565 men and women (average age, 66 years) for the presence of large-vessel peripheral arterial disease by means of two noninvasive techniques--measurement of segmental blood pressure and determination of flow velocity by Doppler ultrasound. We identified 67 subjects with the disease (11.9 percent), whom we followed prospectively for 10 years. RESULTS: Twenty-one of the 34 men (61.8 percent) and 11 of the 33 women (33.3 percent) with large-vessel peripheral arterial disease died during follow-up, as compared with 31 of the 183 men (16.9 percent) and 26 of the 225 women (11.6 percent) without evidence of peripheral arterial disease. After multivariate adjustment for age, sex, and other risk factors for cardiovascular disease, the relative risk of dying among subjects with large-vessel peripheral arterial disease as compared with those with no evidence of such disease was 3.1 (95 percent confidence interval, 1.9 to 4.9) for deaths from all causes, 5.9 (95 percent confidence interval, 3.0 to 11.4) for all deaths from cardiovascular disease, and 6.6 (95 percent confidence interval, 2.9 to 14.9) for deaths from coronary heart disease. The relative risk of death from causes other than cardiovascular disease was not significantly increased among the subjects with large-vessel peripheral arterial disease. After the exclusion of subjects who had a history of cardiovascular disease at base line, the relative risks among those with large-vessel peripheral arterial disease remained significantly elevated. Additional analyses revealed a 15-fold increase in rates of mortality due to cardiovascular disease and coronary heart disease among subjects with large-vessel peripheral arterial disease that was both severe and symptomatic. CONCLUSIONS: Patients with large-vessel peripheral arterial disease have a high risk of death from cardiovascular causes.

Prostaglandin-induced secretion of oxytocin and prolactin in red (Cervus elaphus) and Pere David's (Elaphurus davidianus) deer hinds: evidence for oxytocin of luteal origin.

Peripheral plasma concentrations of oxytocin in female red deer during the luteal phase of the oestrous cycle (9.3 +/- 2.1 fmol/ml) exceeded those in the follicular phase (3.1 +/- 1.4) or during seasonal anoestrus (3.2 +/- 1.3). In both red and Père David's deer hinds during the mid-luteal phase of the cycle, systemic administration of a luteolytic dose of the prostaglandin F2 alpha analogue, cloprostenol, caused the concentration of oxytocin in the peripheral circulation to rise. Mean (+/- SEM) concentrations increased from 8.1 +/- 0.7 to 97 +/- 8 fmol/ml in red and from 6.2 +/- 0.7 to 153 +/- 30 fmol/ml in Père David's hinds within 5 min of treatment. During seasonal anoestrus oxytocin secretion in response to cloprostenol was reduced to less than 10% of that during the breeding season, in both species. Cloprostenol treatment raised circulating concentrations of prolactin in both species during the breeding season, and during anoestrus in red deer only. The concentration of oxytocin in a single corpus luteum removed at laparotomy from one red deer hind at the mid-luteal phase of the cycle was 66 nmol/g wet wt; identification was authenticated by HPLC. These results suggest that the corpus luteum secretes oxytocin in the Cervidae, as established previously in the Bovidae, and that luteal oxytocin secretion is stimulated by prostaglandin.

Effects of prostaglandin F2 alpha and other potential secretagogues on oxytocin secretion and second messenger metabolism in the ovine corpus luteum in vitro.

Release of oxytocin by sliced or minced sheep luteal tissue in vitro was stimulated up to 1.6- and 2.3-fold by arachidonic acid and the calcium ionophore A23187 respectively. Prostaglandin (PG) F2 alpha and the PGF2 alpha analogue cloprostenol, and other potential agonists known to be active in vivo, including noradrenaline and acetylcholine, were ineffective, as was the phorbol ester tetradecanoylphorbol acetate (TPA). The ineffectiveness of PGF2 alpha was not due to a general unresponsiveness of the tissue in vitro, as PGF2 alpha reduced LH stimulation of tissue concentrations of cyclic AMP and activated inositol lipid hydrolysis. The effect of arachidonic acid was accompanied by release from the tissue of the cytosolic enzyme lactate dehydrogenase (at arachidonic acid concentrations below those required to release oxytocin) and its effect on oxytocin and lactate dehydrogenase release was mimicked by oleic and linolenic acids; arachidonic acid was concluded to act by a non-physiological physicochemical effect without conversion to an eicosanoid. As PGF2 alpha in vitro is known to raise intracellular Ca2+ concentrations in the large luteal cells that secrete oxytocin, and as A23187 stimulates oxytocin release in vitro in the presence and absence of TPA, it is concluded that in-vitro incubation results in an artifactual blockade of the oxytocin-releasing action of PGF2 alpha at an unidentified point distal to the effect on intracellular Ca2+.

Rehabilitation of stroke patients in a day hospital.

A comprehensive rehabilitation program for stroke patients strives to rectify deficits in communication, cognition, sensation and motor function. Day hospitals can provide diagnostic and remedial therapy services daily or for several hours a week. At the same time, patients can live at home, maintaining their place in the family and community. Day hospitals can also benefit patients who were not introduced to a rehabilitation program soon after suffering a stroke, and provide intermittent upgrading and maintenance therapy for those with recurrent or remote strokes. The day hospital can help the family physician to assess patients' functional status, and assist with caregiving. The experience of a Toronto day hospital is described.

Isolation of bacterial pathogens from table eggs in Grenada

To investigate whether table eggs in Grenada were contaminated with bacterial pathogens, 30 eggs were bought from supermarkets, 70 from vendors and 60 from poultry farms. Depending on source, shell membranes and yolks were separately pooled and cultured for the isolation of bacteria. A total of 76 positive bacterial cultures were obtained from the various samples, with a higher proportion from shell membrane yolk samples. Supermarket eggs had the lowest percentage of bacterial pathogens (11.8 percent), followed by those from farms (29 percent), while eggs bought from vendors had the highest bacterial contamination (59.2 percent). Organisms of the family Enterobacteriaceae were the most frequent contaminants, which included Escheria coli, Shigella, Salmonella, Klebsiella, Proteus, Serratia and Enterobacter. E. coli and salmonella isolates tested for sensitivity to eight antimicrobial agents. This small yet sugestive study indicated the need for marketing improvements of eggs in Grenada (AU)