Israel Medical Association Journal

Background: Heterotopic ossification is a common complication of hip surgery and musculoskeletal or brain traumas.

Objectives: To confirm by in vivo study that colchicine inhibits osteoblast cell proliferation with marked decrease in tissue mineralization.

Methods: Heterotopic ossification was induced in three groups of New Zealand white rabbits (females, 6 months old, weight 3–3.5 kg) by injecting 2 ml bone marrow drawn from the iliac crest into their right thigh muscle. To prevent heterotopic ossification, colchicine (0.25 mg/day) was administered orally for 4 weeks to two groups of adult rabbits: group A (preload group) – 1 week preceding bone marrow injection; group B – on day of injection; and group C – control group.

Results: After 4 weeks the rabbits were evaluated by radiographs and ultrasound for evidence of heterotopic ossification. At the end of the study histologic samples were taken from all the thighs. Imaging and histologic studies showed, with statistical significance, almost complete prevention of heterotopic ossification formation in group A (preload) and a marked decrease in group B, when compared with the controls in whom large new bone had formed at the injection site. These results indicated the inhibitory effects of colchicine on a bone-forming process in soft tissue such as heterotopic ossification.

Conclusions: The role of colchicine in preventing heterotopic ossification in other bone-forming conditions, such as hip arthroplasty or pelvic trauma, and after brain trauma, remains to be evaluated in a clinical setting.

Background: Many medical school curricula include training for ethical considerations, legal comprehension, implementation of patients' rights, awareness of cultural differences and communication skills (ELCE).

Objectives: To explore medical students' perceptions of their ELCE training during the clinical phase as well as the relationship between humanistic practice skills' experiences and the quality of clinical training.

Methods: A cross-sectional survey was carried out in two cohorts during their clinical year period at Tel Aviv University's Sackler Faculty of Medicine at the end of their internal medicine and surgery clerkships in the 2002 academic year. The research tool was an 18 item Likert-type questionnaire (ELCEQ), based on the literature of biomedical ethics, legal aspects and behavior of practice skills. The content validation of the questionnaire was established by consulting experts among the school's faculty. It was circulated among the students by representatives of the Unit of Medical Education.

Results: The response rate was 88%. Students reported only a few opportunities for gaining experience in humanistic practice skills. A weak correlation was found between students' assessment of the quality of clinical training and their experiences in humanistic practice skills.

Conclusions: A wider and more relevant range of active experiences in humanistic practice skills should be available to students during the clerkships. Correspondingly, there is a need for the clinical faculty to find innovative ways to internalize their task as role models and ensure that students acquire and are able to practice those skills.
 

Background: Food intake has an immediate effect on the cardiovascular system. However, the effect of a large meal as an immediate trigger for the acute coronary syndrome has not been assessed.

Objectives: To assess the relative risk for an ACS[1] within a few hours after the ingestion of a heavy meal.

Methods: In a case-crossover study 209 patients were interviewed a median of 2 days after an ACS. Ingestion of a large meal in the few hours immediately before the onset of ACS was compared with the comparable few hours the day before and with the usual frequency of large meals over the past year. Large meals were assessed by a 5 level scale.

Results: The relative risk of an acute coronary event during the first hour after a heavy meal ingestion was RR[2] = 7 (95% confidence interval 0.75–65.8) when the day before the ACS served as the control data and RR = 4 (95% CI[3] 1.9–8.6) when the usual frequency of heavy meals ingestion during the previous year served as the control data. 

Conclusions: The ingestion of heavy meals can trigger the onset of an ACS. Education of the population to avoid heavy meals, especially in people at high risk for coronary heart disease, should be included in the prevention of ACS. Research on specific nutrients that may act as potential triggers for ACS should be considered.

Background: Oral anticoagulation with warfarin can lead to life-threatening events as a result of either over-anticoagulation or undertreatment. One of the main contributors to an undesirable warfarin effect is the need to adjust its daily dose for a specific patient. The dose is adjusted empirically based on the experience of the clinician, a method that is often imprecise. There is currently no other well-accepted method for predicting the maintenance dose of warfarin.

Objective: To describe the application of an artificial neural network to the problem of warfarin maintenance dose prediction.

Methods: We designed a neural network that predicts the maintenance dose of warfarin. Data on 148 patients attending a large anticoagulant clinic were collected by file review. Using correlational analysis of the patients' data we selected the best input variables. The network was trained by using the back-propagation algorithm on a subset of our data and the results were validated against the rest of the data. We used a multivariate linear regression to create a comparable model.

Results: The neural network generated reasonable predictions of the maintenance dose (r = 0.823). The results of the linear regression model were similar (r = 0.800).

Conclusion: Neural networks can be applied successfully for warfarin maintenance dose prediction. The results are promising, but further investigation is needed.
 

Background: Hypertension is considered resistant if blood pressure cannot be reduced to <140/90 mmHg with an appropriate triple-drug regimen, including an oral diuretic, with all agents administered at maximal dosages. This definition has evolved with the development of new therapies and evidence-based data supporting treatment to lower BP[1] goals.

Objective: To assess whether vitamin C and atorvastatin improve endothelial function and blood pressure control in subjects with resistant arterial hypertension and dyslipidemia.

Methods: Forty-eight hyperlipidemic subjects with RH[2] (office systolic BP >140 mmHg and/or office diastolic BP >90 mm/Hg notwithstanding antihypertensive treatment with three medications in maximal doses) were randomized into three groups to receive additional medication for 8 weeks. Group VTC (n = 17) – mean 24 hour SBP[3] 150.6 ± 5.2 mmHg, DBP[4] 86.1 ± 3.3 mmHg, low density lipoprotein 158.1 ± 24.5 mg/dl) – received vitamin C 500 mg per day; Group ATR (n = 15) – mean 24 hour SBP 153.1 ± 4.8 mmHg, DBP 87.1 ± 6.7 mmHg, LDL[5] 162.6 ± 13.6 mg/dl) – received atorvastatin 20 mg/day; and Group PLA (n = 16) – mean 24 hour SBP 151.1 ± 7.4 mmHg, DBP 84.8 ± 5.9 mmHg, LDL 156.7 ± 26.1 mg/dl – received a placebo. High resolution ultrasound was used to calculate brachial artery flow-mediated dilation, and 24 hour ambulatory BP monitoring was performed at study entry and after 8 weeks.

Results: In the ATR group there were significant reductions of SBP (DSBP1-2: 13.7 ± 5.6 mmHg, P < 0.001), DBP (DDBP1-2: 7.8 ± 5.7 mmHg, P < 0.01), LDL (DLDL1-2: 67.7 ± 28.3 mg/dl, P < 0.001) and improvement of brachial artery FMD[6] (DFMD2-1: 4.2 ± 2.6%). No significant changes in BP, LDL and FMD were observed in the other two groups.

Conclusions: In subjects with RH and dyslipidemia, atorvastatin 20 mg/day compared to vitamin C 500 mg/day may help to achieve better BP control and improve endothelial function in a finite period. A larger trial is needed to assess the drug's efficacy in this population for longer periods.

Background: The physical properties of cancerous skin tissue have rarely been measured in either fresh or frozen skin specimens. Of interest are the elastic properties associated with the skin's ability to deform, i.e., to stretch and compress. Two constants – Young’s modulus and Poisson’s ratio – represent the basic elastic behavior pattern of any elastic material, including skin. The former relates the applied stress on a specimen to its deformation via Hooke’s law, while the latter is the ratio between the axial and lateral strains.

Objectives: To investigate the elastic properties of cancerous skin tissue. For this purpose 23 consecutive cancerous tissue specimens prepared during Mohs micrographic surgery were analyzed.

Methods: From these specimens we calculated the change in radial length (defined as the radial strain) and the change in tissue thickness (defined as axial strain).

Results: Based on the above two strains we determined a Poisson ratio of 0.43 ± 0.12 and an average Young modulus of 52 KPa.

Conclusions: Defining the elastic properties of cancerous skin may become the first step in turning elasticity into a clinical tool. Correlating these constants with the histopathologic features of a cancerous tissue can contribute an additional non-invasive, in vivo and in vitro diagnostic tool.

Background: Head lice move easily from head to head. The lack of safe, effective repellents leads to reinfestation.

Objectives: To test the efficacy of a slow-release citronella formulation as a repellent against the head louse.

Methods: During 4 months in 2003 a randomized, placebo-controlled double-blind clinical study was conducted in four elementary schools; 103 children were treated with the test formulation and 95 with a placebo.

Results: A significant difference was observed during the second examination 2 months later, when 12.0% of the children treated with the test repellent and 50.5% of those treated with placebo were infested with lice. A significant difference was also observed at the third examination 2 months later, when 12.4% of the children treated with the test repellent and 33.7% treated with placebo were infested. Overall, there were significant differences between those treated with the repellent and those treated with the placebo (15.4% and 55.1% respectively, P < 0.0001). Side effects were observed in 4.4% of children who disliked the odor of the formulation, and an additional 1.0% who complained of a slight itching and burning sensation.

Conclusions: Use of an effective repellent could significantly lower the incidence of reinfestations, which would lower expenditure on lice control, including pediculicides, combs and products for nit removal, and the time spent on treatment and removal of the nits.

The prevalence of obesity worldwide has risen sharply during the last four decades. The etiology of obesity is complex and includes a host of genetic influences in addition to the overconsumption of energy coupled with a sedentary lifestyle. Obesity is known to cause or exacerbate many co-morbid conditions such as diabetes, hypertension, dyslipidemia, coronary heart disease, stroke, certain cancers, arthritis and obstructive sleep apnea. Modest weight losses of 5–10% of actual weight are related to significant improvements in co-morbid conditions, but unfortunately the rate of recidivism with short-term therapy for obesity is high. The recent recognition of obesity as a chronic disease that should be treated with long-term programs and possibly with polypharmacy, and the alarming increase in its prevalence, have prompted extensive research and the development of new pharmacotherapy.