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Biomedical subjects

R Cohen

Publications and source records attributed to R Cohen.

At least 181 records · Page 10Linked to original sources
PubMed1997

Laparascopic excision of pelvic kidney with single vaginal ectopic ureter.

An ectopic vaginal ureter is an uncommon cause of urinary incontinence. Most cases are associated with a duplex kidney where the orthotopic lower moiety ureter enters the bladder. The authors present a case of chronic, continuous low-grade urinary incontinence caused by the rare combination of a pelvic kidney and a single ectopic ureter draining into the vagina. This ectopic kidney was successfully removed laparoscopically. A review of the English-language literature showed this to be only the second reported case treated by laparoscopic nephrectomy.

Child↗
PubMed1997

A new assessment tool: the patient assessment and management examination.

BACKGROUND: The major goal of certification is to assure the public that the candidate is competent in all facets required of the position. The patient assessment and management examination (PAME) was developed to enable a more comprehensive assessment of competence in the practice of surgery. METHODS: A six-station, 3-hour, standardized-patient-based evaluation was developed. Each station was scored using a set of five-point global rating scales. PAME results were compared to the last two in training evaluation reports (ITER), the clinical knowledge component of the ITER (ITER-CK), an in-house oral examination (OE), and the Canadian Association of General Surgeons' multiple-choice examination (CAGS). RESULTS: Eighteen senior general surgery residents were evaluated. Overall reliability was 0.70 (Cronbach's alpha). Fifth-year residents scored significantly better than fourth-year residents (t = 3.062; p = 0.0074), with 1 year of training accounting for 37% of the variance in scores. Correlations between the PAME and each of the other measures were ITER, 0.24; ITER-CK, 0.38; OE, -0.13; and CAGS, 0.061, with the PAME demonstrating better reliability and stronger evidence of validity than any other. CONCLUSIONS: The PAME had better psychometric properties than other measures and assessed areas often not evaluated. This type of evaluation may be useful for feedback, remediation, or certification decisions.

Adult↗
PubMed1997

Efficacy and safety of loratadine plus pseudoephedrine in patients with seasonal allergic rhinitis and mild asthma.

BACKGROUND: Antihistamines have been shown to have a variety of therapeutic effects in asthma. Although nasal obstruction may play an important role in modulating lower airway function, no prior trial has used a decongestant in combination with an antihistamine in patients with allergic rhinitis and concomitant asthma. OBJECTIVE: We sought to determine the efficacy and safety of loratadine (5 mg) plus pseudoephedrine (120 mg) (L/P) twice daily in patients with seasonal allergic rhinitis and mild asthma. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of L/P in 193 subjects during the fall allergy season. Nasal and chest symptoms, albuterol use, and peak expiratory flow rates were recorded daily for 6 weeks. Spirometry was measured at baseline and after 1, 2, 4, and 6 weeks of therapy, and health-related quality of life was rated at the beginning and end of the study. RESULTS: Total rhinitis and asthma symptom severity scores were significantly reduced in patients receiving active therapy compared with those receiving placebo throughout the 6-week study. Peak expiratory flow rates improved significantly in patients treated with L/P during weeks 2 through 6 (peak effect [mean +/- SEM]: L/P, 26.23 +/- 4.64 L/min vs placebo, 8.52 +/- 3.53 L/min, p = 0.002) as did FEV1 (peak effect [mean +/- SEM]: L/P, 170 +/- 53 ml vs placebo, 20 +/- 40 ml, p = 0.01) at all clinic visits. In addition, select measures of asthma-specific quality of life improved significantly relative to placebo. CONCLUSIONS: L/P significantly improved nasal and asthma symptoms, pulmonary function, and quality of life in patients with seasonal allergic rhinitis and concomitant mild asthma.

Adolescent↗
PubMed1997

The postimperative negative variation following ambiguous matching of auditory stimuli.

Previous studies using the delayed-matching-to-sample paradigm with visual stimuli reliably induced a postimperative negative variation (PINV) in both schizophrenic patients and healthy controls. The PINV was found to be: (a) larger in schizophrenic patients than controls; (b) larger under conditions of ambiguous as compared to clear matching conditions; and (c) larger over right-hemispheric, fronto-temporal regions in controls, while a less asymmetrical distribution with a tendency for left-frontal predominance occurred in schizophrenic patients. The present study examined to what extent the development and scalp distribution of the PINV were modality-specific by applying the delayed-matching-to-sample design using auditory stimuli. Furthermore, the neurophysiological state during anticipatory negativity (CNV) and PINV was examined by presenting acoustic probe stimuli (one per trial on 50% of the trials) during baseline, CNV or PINV interval. Event-related slow and probe-evoked potentials were recorded in 13 patients with a chronic schizophrenic disorder (DSM-III-R) and 13 healthy control Ss from 15 electrode sites including midline and two sagittal rows over each hemisphere. Comparable group differences and effects of ambiguity on PINV amplitudes were found for both modalities, visual and auditory. The auditory stimuli produced a fronto-central distribution of the PINV in both groups. The probe-evoked vertexpotential was smaller in patients compared to controls, but exhibited comparable modulation with the largest amplitude during the CNV in both groups. Results suggest modality-non-specific cognitive determinants of the PINV. However, stimulus modality did affect the scalp distribution of the PINV. Probe-evoked responses point to different functional meaning of negativities prior to (CNV) and following (PINV) task-relevant stimuli.

Acoustic Stimulation↗
PubMed1997

Differences unrelated to clinical competence in the results of repeated multiple-station tests of clinical skills.

PURPOSE: To determine the extent to which systematic differences not related to group differences in clinical competence could be observed in the results of six administrations of the same multiple-station test of clinical skills. METHOD: The same 16 stations were administered as part of the Ontario International Medical Graduates Program clinical skills screening examination on three different occasions, and on each occasion in two sessions. The interval between the first (fall 1986) and second (March 1990) administrations was four years, and that between the second and third (July 1990) administrations, four months. International medical graduates were the candidates in the first two administrations; the third administration was to a combined sample of fourth-year clinical clerks and interns. A different item functioning (DIF) approach with sessions within administration as the grouping variable was used to describe the extent of differences unrelated to clinical competence in the results of the different test administrations. For the generalizability and DIF calculations the designs were balanced by sampling down to 33 cases in each session. RESULTS: Station DIF values varied considerably from station to station. DIF effects between sessions with administrations were less than those between administrations, and were less between the two administrations separated by four months than between the two administrations separated by four years. CONCLUSION: Hypotheses concerning the relative magnitudes of station DIF and total-test aggregated values of DIF, as a function of the time intervals between test occasions, were substantiated, demonstrating that the greater the time interval between test administrations, the greater the magnitude of DIF.

Clinical Competence↗
PubMed1997

Scorpion venom leads to gastrointestinal ischemia despite increased oxygen delivery in pigs.

OBJECTIVES: Scorpion envenomation may be accompanied by metabolic acidosis even in the absence of hypoxia and cardiovascular derangement. We tested the hypothesis that venom causes ischemia of the gastrointestinal tract rather than failure of delivery of oxygen to the periphery. DESIGN: Repeated measures, prospective study in experimental animals. SETTING: University-affiliated hospital research laboratory. INTERVENTIONS: In ten spontaneously breathing, intubated, sedated pigs, purified dried venom (Leiurus quinquestriatus), 0.05 mg/kg, was administered intravenously. Measurements were obtained before (baseline), and 5, 15, 30, 60, 120, 180, and 240 mins after injection. MEASUREMENTS AND MAIN RESULTS: Variables measured included: mean arterial pressure (MAP), heart rate (HR), mean pulmonary arterial pressure, pulmonary artery occlusion pressure, cardiac output, stroke volume, right ventricular ejection fraction (rapid thermistor), left ventricular dimensions (echocardiography), arterial gas tensions, lactate and catecholamine concentrations, gastric interstitial mucosal pH (tonometry), as well as systemic and pulmonary vascular resistances. Within 5 mins after venom injection, there was a hyperdynamic state accompanied by significantly increased MAP (97 +/- 18 to 136 +/- 47 mm Hg, p < .0003), HR (70 +/- 12 to 121 +/- 24 beats/min, p < .00006), and cardiac output (1.88 +/- 0.35 to 2.95 +/- 0.53 L/min, p < .0003), with no change in stroke volume, or pulmonary artery occlusion pressure. Right ventricular ejection fraction increased from 38.1 +/- 4.3 to 48.6 +/- 9.0% (p < .0009) by 15 mins. No change in left ventricular function was observed. There were significant decreases in systemic vascular resistance and pulmonary vascular resistance following envenomation. Arterial and gastric mucosal pH significantly decreased from 7.40 +/- 0.04 to 7.25 +/- 0.07 (p < .0001) for arterial pH, and 7.33 +/- 0.08 to 7.17 +/- 0.13 (p < .00001) for gastric mucosal pH by 30 mins after envenomation. The decrease in arterial pH was not sufficient to account for the change in gastric mucosal pH, indicating gastric mucosal ischemia. Arterial lactate increased from 2.6 +/- 1.4 to 7.4 +/- 1.9 (p < .05 x 10(-8)). There were significant increases in serum epinephrine and norepinephrine values by 5 mins. All hemodynamic variables and catecholamine concentrations returned to baseline by 4 hrs. However, there was persistent arterial and gastric mucosal acidosis and increased lactate concentrations even at 4 hrs. Oxygen delivery remained normal or supernormal for 4 hrs following envenomation. However, despite this finding, systemic and gastric mucosal pH changes indicate impaired gastrointestinal oxygen delivery. CONCLUSIONS: Despite increased peripheral oxygen delivery, scorpion envenomation was associated with evidence of ischemia of the gastrointestinal tract. This association could be due to shunting of blood from metabolically active areas, possibly associated with massive catecholamine release, or a direct toxic effect of the venom on regional oxygen transport at the cellular level.

Acidosis↗
PubMed1997

Change in nasopharyngeal carriage of Streptococcus pneumoniae resulting from antibiotic therapy for acute otitis media in children.

BACKGROUND: Acute otitis media is the leading reason for antibiotic prescriptions in childhood. The increase in antibiotic resistance of Streptococcus pneumoniae is generally attributed to the extensive use of antibiotics and the selective pressure on the bacterial strains of the nasopharyngeal flora. OBJECTIVE: To evaluate the change in nasopharyngeal carriage of S. pneumoniae during antibiotic therapy prescribed for acute otitis media. METHODS: Between October, 1993, and March, 1994, we conducted a clinical trial comparing cefpodoxime-proxetil and amoxicillin-clavulanate in acute otitis media. From 364 children, 4 months to 4.5 years old, a nasopharyngeal sample was obtained before and after treatment. Antibiotic susceptibility was established by determining minimal inhibitory concentrations by the agar dilution method. Serotype and randomly amplified polymorphic DNA analysis were used to compare pre- and posttreatment S. pneumoniae strains. RESULTS: The risk for a child to carry penicillin-resistant S. pneumoniae (MIC > or = 0.125 mg/l) did not increase after antibiotic treatment: 84 of 364 (23.1%) before, 70 of 364 (19.2%) after. There was a significant decrease of penicillin-susceptible S. pneumoniae carriage, 117 of 364 (32.1%) before treatment compared with 24 of 364 (6.6%) (P = 0.0001) after treatment. However, among the children carrying S. pneumoniae at the end of the treatment there was an increase in the percentage of penicillin-resistant pneumococci: 84 of 201 (41.8%) before treatment and 70 of 94 (74.5%) after treatment. Among the 94 children carrying S. pneumoniae at the end of the treatment, 22 did not harbor pneumococcus before, 16 carried another genotypically different serotype and 56 harbored the same serotype. Among these 56 children 2 patients harbored strains that had increased MICs for the tested beta-lactam antibiotics. The randomly amplified polymorphic DNA analysis showed that in one case, the strains were genetically different. CONCLUSIONS: These data illustrate that antibiotic therapy did not increase the rate at which children carried penicillin-resistant S. pneumoniae, but there was an increase in the rate of resistance among the children carrying pneumococci at the end of the treatment, mainly as a result of reduction of susceptible strains.

Acute Disease↗
PubMed1997

Correlation of basal menses CA-125 levels and 6 month pregnancy rates in women undergoing treatments for infertility without assisted reproductive methods.

PROBLEM: The objective of this study was to evaluate the correlation of menstrual CA-125 levels with pregnancy rates (PRs) after 6 months of treatment for infertility. METHOD: The sample consisted of a heterogenous group of 160 women who sought treatment for infertility. Treatments include progesterone supplementation, donor insemination, intrauterine insemination, and ovulation induction therapy. No laparoscopies were done during the study period. A baseline CA-125 level was drawn during menses before the initiation of therapy. Patients were followed for 6 months of treatment or until a pregnancy was achieved. RESULTS: There was no difference in the 6 month PR or viable PR by CA-125 level. CONCLUSIONS: Elevated CA-125 levels are not predictive of poor fertility potential at least during the first 6 months of infertility therapy. Even though these higher levels sometimes suggest that endometriosis is present, the data suggest that correction of male factor, cervical factor or ovulation factor provides effective PRs without the need for laparoscopic intervention.

Adult↗
PubMed1997

Bactericidal activity against intermediately cephalosporin-resistant Streptococcus pneumoniae in cerebrospinal fluid of children with bacterial meningitis treated with high doses of cefotaxime and vancomycin.

Cerebrospinal fluid (CSF) was taken from 19 children with bacterial meningitis treated with cefotaxime (300 mg/kg of body weight/day) and vancomycin (60 mg/kg/day). Median levels of drugs in CSF were smaller than expected, as follows: 4.4 microg/ml for cefotaxime, 3.2 microg/ml for desacetylcefotaxime, and 1.7 microg/ml for vancomycin. The median CSF bactericidal titer against an intermediately cefotaxime-resistant pneumococcus was 1:4. Our data suggest at least an additive interaction between the drugs used in this study.

Adolescent↗
PubMed1997

Neuropsychiatric factors in the illusion of visitors among geriatric patients: a case series.

The 'illusion of visitors' is a common phenomenon among geriatric patients presenting for psychiatric or neurologic evaluation and treatment. Although these illusory beliefs are etiologically diverse, patients may commonly have visual impairment and functional and/or structural disruption of frontal and right-hemisphere-mediated cognitive functioning. This article outlines eight cases of illusory beliefs among elderly patients, presenting psychiatric, neurologic, neuroimaging, and neuropsychological findings among these patients. Commonalities and differences among these cases are discussed, and a framework is provided for multidisciplinary assessment and treatment of patients presenting with illusory beliefs.

Aged↗
PubMed1997

Isoform variable action among thyroid hormone receptor mutants provides insight into pituitary resistance to thyroid hormone.

Resistance to thyroid hormone (RTH) is due to mutations in the beta-isoform of the thyroid hormone receptor (TR-beta). The mutant TR interferes with the action of normal TR to cause the clinical syndrome. Selective pituitary resistance to thyroid hormone (PRTH) results in inappropriate TSH secretion and peripheral sensitivity to elevated thyroid hormone levels. Association of the PRTH phenotype with in vitro behavior of the mutant TR has proved elusive. Alternative exon utilization results in two TR-beta isoforms, TR-beta 1 and TR-beta 2, which differ only in their amino termini. Although the TR-beta 1 isoform is ubiquitous, the TR-beta 2 isoform is found predominantly in the anterior pituitary and brain. To date, in vitro evaluation of RTH mutations has focused on the TR-beta 1 isoform. Site-directed mutagenesis was used to create several PRTH (R338L, R338W, V349M, R429Q, I431T) and generalized RTH (delta 337T, P453H) mutations in both TR-beta isoforms. The ability of mutant TRs to act as dominant negative inhibitors of wild type TR-beta function on positive and negative thyroid hormone response elements (pTREs and nTREs, respectively) was evaluated in transient transfection assays. PRTH mutants had no significant dominant negative activity as TR-beta 1 isoforms on pTREs found in peripheral tissues or on nTREs found on genes regulating TSH synthesis. PRTH mutants, in contrast, had strong dominant negative activity on these same nTREs as TR-beta 2 isoforms. Cotransfected retinoid X receptor-alpha was required for negative T3 regulation via the TR-beta 1 isoform but was not necessary for negative regulation via the TR-beta 2 isoform in CV-1 cells. The differing need for retinoid X receptor cotransfection demonstrates two distinct negative T3-regulatory pathways, one mediated by the TR-beta 1 and the other mediated by TR-beta 2. The selective effect of PRTH mutations on the TR-beta 2 isoform found in the hypothalamus and pituitary vs. the TR-beta 1 isoform found in peripheral tissues suggests a molecular mechanism for the PRTH disorder.

Alleles↗
PubMed1997

[Acute low digestive hemorrhage in testicular choriocarcinoma].

We report a case in which acute intestinal hemorrhage was the initial manifestation in the evolution of choriocarcinoma of the testis. The diagnosis of bleeding was difficult and required laparotomy. Metastatic lesion of the small bowel should be considered a possible cause of intestinal bleeding in patients with testicular choriocarcinoma.

Acute Disease↗
PubMed1996

[Causes of death in patients with medullary cancer of the thyroid. GETC. Groupe d'Etude des Tumeurs à Calcitonine].

OBJECTIVE: Medullary thyroid carcinoma (MTC) is characterized by different clinical forms and a possible prolonged survival, despite presence of metastases. In the present study, we have studied the clinical and biological characteristics of 119 decreased MTC patients. METHODS: Our data were retrieved retrospectively from the French medullary thyroid cancer study group (GETC). RESULTS: Our results showed that the cause of death was basically MTC (87%) but not exclusively, depending on the clinical forms and the age. Patients with type IIb multiple endocrine meoplasia (MEN) died earlier from their carcinoma. Patients with type IIa MEN died of causes other than MTC, especially pheochromocytoma. Two-thirds of the patients with sporadic forms of MTC, died with advanced metastases, usually from MTC. CONCLUSION: A significant number of deaths in patients with medullary thyroid carcinoma result from non-cancerous causes. This study established the clinical and biological characteristics of patients at risk of death.

Adolescent↗