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Biomedical subjects

R Cohen

Publications and source records attributed to R Cohen.

At least 235 records · Page 13Linked to original sources
PubMed1995

Radiocesium body burdens in immigrants to Israel from areas of the Ukraine, Belarus and Russia near Chernobyl.

Of the 500,000 immigrants from the former Soviet Union who came to Israel during 1990-1993, about 100,000 are estimated to have come from radiocontaminated areas near Chernobyl. These people were subject to chronic uptake of environmental radiocesium over protracted periods. During October-November 1991, a joint Israeli-Canadian investigation measured radiocesium body burdens in immigrants to Israel from the Ukraine, Belarus, and the southern Russian republic in order to provide factual information on radiocesium levels to concerned immigrants and to relate the body burdens to the geographic area of residence before coming to Israel. Assessments were made of 137Cs body burdens in 1,228 volunteer men, women, and children. These measurements were accompanied by medical assessments based on clinical histories and examinations. Radiocesium levels were strongly dependent on the duration of residence in Israel, with the highest levels being found in the most recent immigrants. The maximum level, extrapolated back to the time of leaving the former Soviet Union, was estimated to be about 0.83 kBq (10.3 Bq kg-1). Of the most recent immigrants from the Kiev region (< 101 days in Israel), only 15% had back extrapolated body burdens > 50 Bq, whereas 53% of those coming from Gomel and other towns in the contaminated zones (> 3.7 x 10(10) Bq km-2 of radiocesium) had detectable levels > 50 Bq. People coming from the latter region had significantly higher body burdens as compared to those from the former, in accordance with the higher degree of ground radiocesium contamination reported for the latter region. Women and children showed considerably lower total radiocesium content in comparison to men. All radiocesium body burdens at the time of measurement were too low to be of health concern.

Adolescent↗
PubMed1995

Demonstration of acquisition of trauma management skills by senior medical students completing the ATLS Program.

OBJECTIVE: To assess the teaching effectiveness of the Advanced Trauma Life Support (ATLS) Program among senior medical students. DESIGN, MATERIALS, AND METHODS: We used objective structured clinical examination (OSCE) and multiple choice question (MCQ) testing to assess 40 senior medical students (20 ATLS and 20 non-ATLS) at the University of Toronto. Pre- and post-ATLS, all students had four 15-minute OSCE stations and a 40-item MCQ test. The pre- and post-ATLS performance for the ATLS and non-ATLS group were compared. MEASUREMENTS AND MAIN RESULTS: Cronbach's reliability coefficients were 0.81 and 0.93 for the pre- and post-ATLS OSCEs. The mean (+/- SD) OSCE scores at the four pre-ATLS OSCE stations were 7.6 +/- 2.8, 7.4 +/- 2.3, 8.3 +/- 2.7, and 10.5 +/- 3.4 for the ATLS group and 6.5 +/- 2.1, 7.0 +/- 2.2, 7.6 +/- 2.5, and 9.6 +/- 3.1 for the non-ATLS group (p = NS). Post-ATLS scores for the four OSCE stations were: 15.5 +/- 1.6, 14.1 +/- 3.2, 12.3 +/- 2.9, and 18.3 +/- 1.0 (ATLS group) and 7.9 +/- 3.5, 6.3 +/- 2.8, 7.6 +/- 2.3, and 10.9 +/- 3.3 (non-ATLS group: p < 0.01). Pre-ATLS MCQ scores were 49 +/- 9 and 52 +/- 8% for the ATLS and non-ATLS groups respectively; the ATLS group increased MCQ scores to 83 +/- 5% and the non-ATLS group did not change (53 +/- 8%). Pre-ATLS scores for adherence to priorities were: 35 +/- 14% (ATLS) and 29 +/- 13% (non-ATLS: p = NS). Post-ATLS scores were 99 +/- 6% (ATLS) and 29 +/- 19% (non-ATLS; p < 0.01). The pre-ATLS organized approach to trauma ratings (range 1 to 5) were: 1.9 +/- 1.5 (ATLS) and 1.6 +/- 0.5 (non-ATLS; p = NS) compared to post-ATLS grades of 4.6 +/- 0.4 (ATLS) and 1.7 +/- 0.5 (non-ATLS: p < 0.01). All 20 students passed the ATLS course. CONCLUSION: Using highly reliable trauma OSCE stations we have demonstrated trauma management skills acquisition by senior medical students after the ATLS course.

Canada↗
PubMed1995

Clinical experience with cefpodoxime proxetil in acute otitis media.

Although it varies from country to country, there is a worrying worldwide increase in antibiotic resistance among pathogens causing otitis. This has led to a search for therapeutic alternatives to the reference treatment, which is still amoxicillin in many countries. Cefpodoxime proxetil is one such alternative. Six comparative randomized trials of cefpodoxime proxetil in childhood acute otitis media have been published or presented at international conferences. They involved a total of 1188 patients, 658 of whom received cefpodoxime proxetil and 530 of whom received the comparator drug (amoxicillin/clavulanic acid in 3 trials, cefaclor in 1, and cefixime in 2); duration of treatment varied from 5 days for cefpodoxime proxetil to 10 days for amoxicillin/clavulanic acid, and the age of the children included ranged from 2 months to 12 years. The clinical efficacy of cefpodoxime proxetil was at least equivalent to that of the comparators in 4 trials and significantly better in 2 trials. Firstly, in one study vs. amoxicillin/clavulanic acid, the superiority of cefpodoxime proxetil (8 mg/kg/day twice daily) in terms of healing at the end of treatment and in terms of the number of normal tympanograms at the follow-up visit was shown. Secondly, in a study performed by our group, vs. cefixime, cefpodoxime proxetil (8 mg/kg/day twice daily) showed a better healing rate at the end of treatment in febrile and painful acute otitis media. The microbiologic and pharmacokinetic data show that cefpodoxime proxetil is one of the most active compounds against Haemophilus influenzae and Streptococcus pneumoniae.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

A multicenter clinical trial of PerioGard in distinguishing between diseased and healthy periodontal sites. (I). Study design, methodology and therapeutic outcome.

We designed and performed a multicenter clinical trial to determine the relationship between measurements of the level of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) to other measures used to detect periodontal disease and monitor outcome of treatment, including pocket depth and gingival inflammation. 32 periodontitis patients were enrolled at the University of Washington, Seattle, 30 at the University of Florida, Gainesville, and 34 at the University of Illinois, Chicago. 10 periodontally normal control subjects were enrolled at each location. 8 diseased and 4 healthy sites were designated for study in each patient and 8 healthy sites designated in each control subject. Measures of disease included pocket depth, severity of gingival inflammation, and GCF volume. AST levels were measured using the PerioGard test kit. Clinical measurements were made and GCF samples harvested and tested 2x before and 2x after therapy consisting of scaling and root planing under local anesthetic. Specific design and other issues are discussed, including selection of patients and control subjects, sample size, selection of experimental test sites, methods for assessment of diseased and therapeutic improvement, harvesting of GCF and selection of appropriate biostatistical methods for data analysis. Demographics of the patient populations at the 3 locations are reported. As expected, therapy induced only negligible changes in the measures of disease at healthy sites in control subjects, and relatively minor improvement in healthy sites in patients. In contrast, statistically significant improvement relative to pretreatment baseline status in all 3 measures of disease was observed for diseased sites at all 3 study locations with all p-values less than 0.0002. The magnitude of improvement was comparable to that reported previously by others. The % of PerioGard-positive sites decreased significantly between the screening baseline and both post-treatment visits for patients at all 3 locations, with p values of 0.0001 to <0.0008.

Adult↗
PubMed1995

Health effects in a casual sample of immigrants to Israel from areas contaminated by the Chernobyl explosion.

We analyzed questionnaire and physician examination data for 1560 new immigrants from the former USSR divided into three groups by potential exposure to Chernobyl radiation. Two groups were chosen according to soil contamination by cesium-137 at former residences, as confirmed by our findings in a 137Cs body burden study. The third group consisted of "liquidators," persons who worked at the Chernobyl site after the disaster. Liquidators had greater self-reported incidences of symptoms commonly accepted as acute effects of radiation exposure, increases in prevalence of hypertension, and more health complaints. Excesses of bronchial asthma and health complaints were reported in children from the more exposed communities. Asthma prevalence in children potentially exposed in utero appears to be increased eightfold. Older adults from more exposed areas had more hypertension as assessed by history and measurements. These findings suggest the possible association of radiation exposure with several nonmalignant effects.

Adolescent↗
PubMed1995

Patterns of positive specimen margins and detectable prostate specific antigen after radical perineal prostatectomy.

Positive specimen margins and detectable postoperative prostate specific antigen (PSA) levels were analyzed after 200 consecutive radical perineal prostatectomies for clinical stages T1 and T2 adenocarcinoma of the prostate. Clinical parameters that correlated with lymph node metastases in concomitant pelvic lymphadenectomies were also noted. At a mean followup of 35 months 79% of the patients had undetectable PSA levels. Step-section pathological analysis of specimens obtained by either nerve sparing or extended radical modifications revealed that 41% of the tumors were organ confined and 56% had negative margins. Selective sacrifice of the posterolateral periprostatic fascia and the enclosed neurovascular bundle achieved negative margins and undetectable PSA levels despite capsular penetration in 15% of all patients. Of all positive margins with the perineal approach, solitary positive apical and posterolateral margins were infrequent (7% and 16%, respectively) but solitary positive anterior margins were more so (25%). Of those positive anterior margins 41% appeared to be artifactual and 45% might have been eliminated by avoiding avulsion of the puboprostatic ligaments. Pelvic lymphadenectomy could have been eliminated in 58% of the patients (clinical stage T2b or less, biopsy Gleason score 6 or less and PSA level 11 or less, for a node negative predictive value of 99%).

Adenocarcinoma↗
PubMed1995

Failure of focal prostate cancer on biopsy to predict focal prostate cancer: the importance of prevalence.

PURPOSE: We investigated whether the reported correlation between focal prostate cancer on biopsy and the presence of clinically insignificant cancer applies to men with an elevated serum prostate specific antigen level or a positive biopsy from an area of palpable abnormality. MATERIALS AND METHODS: A total of 33 men with these findings and focal cancer on biopsy underwent radical perineal prostatectomy, with step-section pathological analysis of all specimens and volume determination of all stage pT2a tumors. RESULTS: Pathological examination revealed that 17 tumors (52%) were stage T3, 10 (30%) stage T2b to c and 6 (18%) stage T2a, with 4 (12%) significant (volumes 0.8 to 1.2 ml.) and 2 (6%) insignificant (volumes 0.1 and 0.3 ml.) neoplasms. Thus, focal prostate cancer on biopsy correlated with significant cancer in 94% of the cases. CONCLUSIONS: In patients with another variable controlling for a high prevalence of significant prostate cancer, the focal nature of a positive biopsy probably reflects only sampling limitations and should not influence treatment. To restrict prostate biopsy to men with a high prevalence of significant cancer, targeted area biopsy alone must replace sextant biopsy in men with a palpable prostatic abnormality but a normal prostate specific antigen level.

Adult↗
PubMed1995

[Febrile syndrome: myocarditis and brucellosis].

A 20 year-old white man was admitted with fever and weight loss since 60 days previous to his admission and cardiac failure (functional class IV). The heart was enlarged in the echocardiographic examination without valvular involvement. Liver biopsy showed granulomatous hepatitis with a necrosis focus. The patient was treated with a combination of venous dilators and digital. Serum agglutination test for Brucella showed a titer of 1/250, and complement fixation 1/40. Seven days later, agglutination titer was 1/4000. He was treated with rifampin and trimethoprimsulfametoxazol. He got better; fever disappeared, and the signs of cardiac failure improved. Brucellosic myocarditis is an uncommon complication of brucellosis in the absence of endocarditis. In our knowledge, this case would be the first reported in Argentina and the third in adult patients out of the five cases reported worldwide.

Adult↗
PubMed1995

Metabolic and infectious disorders associated with emesis in infants.

Vomiting is associated with an endless array of medical and surgical conditions, including infectious and metabolic disorders. This article is designed to review the pathophysiological mechanism of vomiting in infants. There is tremendous overlap in the signs and symptoms associated with vomiting in infancy, and these will be described. Pertinent historical prospectives are examined including prenatal history, neonatal history, underlying conditions, recent or chronic medication usage, exposures to illnesses or toxin, and family history. Specific findings obtained during physical examination may help direct further assessment of the vomiting infant. Laboratory tests are essential to the evaluation of the infant with emesis. These studies serve not only to help assess the severity of illness in the vomiting infant, but also to aid in the appropriate collection and handling of specimens during the time of critical presentation that may be useful during what are often complex and confusing clinical courses. Therapeutic interventions including both specific and supportive modalities for infants with vomiting caused by infectious and metabolic disorders are discussed.

Diagnosis, Differential↗
PubMed1995

Breast lymphoma. A clinical and pathological review and 10-year treatment results.

Sixteen patients presenting with lymphoma involving the breast are described. Seven fulfilled the criteria for primary breast lymphoma, while the other 9 had evidence (sometimes only detected after extensive staging procedures) of concurrent lymphomatous involvement outside the breast. Histological diagnoses of the so-called primary breast lymphomas included 1 case of Hodgkin's disease and 6 of non-Hodgkin's lymphoma (including 2 with T-cell phenotypes). The patients with so-called secondary breast involvement included 8 with non-Hodgkin's lymphoma and 1 with a plasmacytoma of the breast with concomitant myelomatous involvement of bone marrow. Among the non-Hodgkin's lymphomas involving the breast the whole range of histological subtypes from low-grade to high-grade lesions were seen. There was no subtype of lymphoma with a specific predilection for breast involvement. Expression of oestrogen receptor protein as determined by immunocytochemical investigation using specific monoclonal antibodies was uniformly negative in lymphoid cells of 11 patients studied. Most of the patients in this series were treated by chemotherapy with uniformly good local control of lymphomatous involvement of the breast and an outcome similar to that of lymphomas presenting at other body sites. It is concluded that the approach to lymphomas of the breast should be similar to that of the equivalent types presenting elsewhere.

Adult↗
PubMed1995

Arteriovenous revascularization for lower limb salvage in unreconstructible arterial occlusive disease (long-term outcome).

Between February 1983 and June 1994 we attempted surgically to salvage twenty-six legs in twenty-five patients with insufficient distal run-off and severely ischemic feet; all of them had resting pain, and 23 had tissue necrosis. A saphenous venous graft was interposed between an artery of the lower extremity (femoral or popliteal) and the veins of the foot with obligatory end-to-side distal anastomosis. The patency of the venous circulation of the ischemic foot was ascertained by retrograde phlebography. Patients were followed from 3 months to 11 years (an average of 3 years and 5 months). In 19 legs (73%), surgery succeeded in preventing extensive gangrene of the foot, and allowed postponing or avoiding major amputation. The purpose of this paper is to analyze this experience, and stimulate further interest and study of the reversed microcirculation in critical ischemia.

Aged↗
PubMed1994

[Bacterial epidemiology of pharyngitis in pediatric private practice].

OBJECTIVES: While viruses are usually the causal agents of common sore throat in children, bacterial infections cannot be distinguished solely on the basis of clinical presentation. Thus most physicians in France prefer to prescribe antibiotics in order to prevent rheumatismal complications of group A streptococcal infections. We updated current epidemiological data on bacterial pharyngitis in paediatric out-patient clinics. METHODS: A prospective study was conducted from March 1 to June 1, 1992 by 9 physicians. Throat swabs were obtained from 102 controls and from 307 patients with acute pharyngitis. Samples were transferred to the same bacteriology laboratory for examination. RESULTS: The mean age of the children was 6.1 years for patients and 7.2 years for controls. Throat swabs were inoculated for culture within a mean delay of 22.6 hours. Cultures were performed on Columbia blood medium with nalidixic acid and colistin then incubated in CO2 enriched atmosphere and on trypticase blood soy medium + 3.5% NaCl. Group A streptococcal strains were identified by search for beta-haemolysis and latex characterisation of group A polyosides. Group A streptococcal strains were found in 8.8% of the controls and 36.8% of the patients. Groups B, C or G streptococci were found in 10.8 et 11.4% of the controls and patients respectively (NS). Arcanobacterium haemolyticum was never isolated. Clinical association of sore throat, erythematous pharyngitis, fever > 38 degrees C and cervical lymph nodes was found in only 33.63% of the sore throat cases with group A streptococcal infection and in 7.73% of those without group A streptococcal infection (p < 0.0001, sensitivity 33%, specificity 92%). CONCLUSION: These results emphasize the necessity either to treat all pharyngitis or to do throat swabs or rapid group A streptococcal tests for diagnosis.

Age Factors↗
PubMed1994

Prolonged circulation time and enhanced accumulation in malignant exudates of doxorubicin encapsulated in polyethylene-glycol coated liposomes.

In preclinical studies, a doxorubicin liposome formulation containing polyethylene-glycol (Doxil) shows a long circulation time in plasma, enhanced accumulation in murine tumors, and a superior therapeutic activity over free (unencapsulated) doxorubicin (DOX). The purpose of this study was to characterize the pharmacokinetics of Doxil in cancer patients in comparison with free DOX and examine its accumulation in malignant effusions. The pharmacokinetics of doxorubicin and/or liposome-associated doxorubicin were analyzed in seven patients after injections of equivalent doses of free DOX and Doxil and in an additional group of nine patients after injection of Doxil only. Two dose levels were examined, 25 and 50 mg/m2. When possible, drug levels were also measured in malignant effusions. The plasma elimination of Doxil followed a biexponential curve with half-lives of 2 and 45 h (median values), most of the dose being cleared from plasma under the longer half-life. Nearly 100% of the drug detected in plasma after Doxil injection was in liposome-encapsulated form. A slow plasma clearance (0.1 liter/h for Doxil versus 45 liters/h for free DOX) and a small volume of distribution (4 liters for Doxil versus 254 liters for free DOX) are characteristic of Doxil. Doxorubicin metabolites were detected in the urine of Doxil-treated patients with a pattern similar to that reported for free DOX, although the overall urinary excretion of drug and metabolites was significantly reduced. Doxil treatment resulted in a 4- to 16-fold enhancement of drug levels in malignant effusions, peaking between 3 to 7 days after injection. Stomatitis related to Doxil occurred in 5 of 15 evaluable patients and appears to be the most significant side effect in heavily pretreated patients. The results of this study are consistent with preclinical findings indicating that the pharmacokinetics of doxorubicin are drastically altered using Doxil and follow a pattern dictated by the liposome carrier. The enhanced drug accumulation in malignant effusions is apparently related to liposome longevity in circulation. Further clinical investigation is needed to establish the relevance of these findings with regard to the ability of liposomes to modify the delivery of doxorubicin to solid tumors and its pattern of antitumor activity.

Adult↗