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Biomedical subjects

S Weitzman

Publications and source records attributed to S Weitzman.

At least 145 records · Page 8Linked to original sources
PubMed1976

Maintenance of hyporesponsiveness to antigen by a distinct subclass of T lymphocytes.

Immunization with increasing doses of SRBC, in excess of 10(8), results in a progressive decline in the anti-SRBC PFC response. This hyporesponsive state is antigen specific and is reflected in a decrease of both T helper and B antibody-forming activity. We asked whether the apparent defect of T helper activity reflected a) an absence of alphaSRBC helper T cell activity, or b) the presence of SRBC-specific suppressor T cells within the hyporesponsive population. Our results indicate that at least a portion of hyporesponsiveness noted after antigen exposure to large doses of antigen can be ascribed to specific suppressor T cell activation. Fractionation of the suppressive T cell population using Ly antiserum showed that specific suppressive activity was mediated by a subclass of T cells (Ly2+), distinct from that committed to express helper function (Ly1).

Animals↗
PubMedDate not supplied

Telomerase activity as a prognostic factor in neuroblastomas.

Neuroblastoma is the most common extracranial solid tumor of early childhood. This tumor demonstrates significant heterogeneity with respect to pathologic, genetic, and clinical features. The outcome varies from spontaneous regression or maturation to rapid progression, despite aggressive therapy. Prognostic factors have been found that identify those tumors which have a high probability of aggressive behavior; these factors include unfavorable histology, MYCN copy number, deletions of the short arm of chromosome 1, DNA content, and TRK-A (high-affinity receptor protein for nerve growth factor) expression. Recent studies have suggested that high levels of telomerase activity also correlate with poor clinical outcome. We investigated this relationship in 40 patients with untreated neuroblastoma, using a PCR-ELISA assay for telomerase activity. In these patients, 23 tumors had no or minimal telomerase activity whereas 15 had high levels of activity. In two tumors, telomerase activity was not assessable. There was significant correlation between the telomerase activity and MYCN copy number, 1p deletions, and TRK-A expression, as well as patient age, clinical stage, and outcome. The histological classification of the tumors was not significantly different between the two groups, being predominantly unfavorable by the Shimada classification. In addition, for 17 patients tumor tissue was assessed for telomerase activity post-chemotherapy. In those cases where the tumor was negative for telomerase activity before and after chemotherapy, the patients uniformly did well. In cases where the tumor was positive before and negative or weakly positive after treatment, two of the seven patients did well clinically. However, in cases that were positive after chemotherapy, all had recurrence or died. In conclusion, telomerase activity appears to be a prognostic factor for neuroblastomas. In addition, assessment of tumors post-chemotherapy may be a further indicator of clinical outcome.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

A population-based study of the usefulness of screening for neuroblastoma.

BACKGROUND: Neuroblastoma has many characteristics which suggest that preclinical detection might improve outcome. The Quebec Neuroblastoma Screening Project was initiated to determine whether mass screening could reduce mortality in a large cohort of infants. As an early endpoint, we report whether screening could reduce the incidence of poor-prognosis neuroblastoma in children with advanced-stage disease over 1 year of age. METHODS: All 476,603 children born in the province of Quebec during the 5-year period of May 1, 1989, to April 30, 1994, were eligible for urinary assay of homovanillic acid and vanillylmandelic acid at 3 weeks and 6 months of age. Children with a positive screen were referred to one of four paediatric cancer centres in the province for uniform evaluation and treatment if necessary. Standardised incidence ratios (SIRs) were calculated for neuroblastoma in the province and two similar population-based controls, the state of Minnesota and the province of Ontario, during the same period of time and with similar ascertainment procedures. FINDINGS: Compliance with screening in Quebec province was 91% at 3 weeks (n = 425,816) and 74% at 6 months (n = 349,706). Through July 31, 1995, with a follow-up of the birth cohort of 15-75 months, 118 cases of neuroblastoma were diagnosed, 43 detected preclinically by screening, 20 detected clinically before screening at 3 weeks of age, and 55 detected clinically after 3 weeks of age having normal screens (52) or never screened (3). Retrospective analysis of stored samples confirmed that 49 of 52 patients missed by screening had levels of catecholamine metabolites that were too low to be detected at 6 months or earlier. Based on US Surveillance, Epidemiology and End Results data, 54.5 cases of neuroblastoma would have been expected in Quebec province during the study period, for an SIR of 2.17 (95% CI 1.79-2.57, p < 0.0001). For the two control groups, 43 and 80 cases of neuroblastoma were detected, respectively, compared with 37.9 and 85.4 expected, overall SIR 1.00 (not significant). SIRs for Quebec province by age at diagnosis in yearly intervals show a marked increased incidence under 1 year of age (SIR 2.85, 2.26-3.50), with no reduction in incidence in subsequent years. Limiting analysis to only patients diagnosed over 1 year of age with advanced-stage disease, 22 cases were detected in Quebec province versus 14.4 expected (SIR 1.52, 0.95-2.23). Data in the two control groups show no significant increase or decrease in any-stage disease in children under or over the age of 1 year, except for an increase in early-stage disease in Minnesota children over 1 year: 10 versus 3.8 expected (SIR 2.67, 1.27-4.58). INTERPRETATION: Screening for neuroblastoma increases the incidence in infants without decreasing the incidence of unfavourable advanced-stage disease in older children. It is unlikely that screening for neuroblastoma in infants will reduce mortality for this disease.

Chromatography, Thin Layer↗
PubMedDate not supplied

Pituitary stalk thickening and primary central nervous system lymphoma.

We report a 14-year-old girl in whom a diagnosis of primary central nervous system lymphoma was confirmed while receiving growth hormone (GH) for GH deficiency, detected after presenting with short stature. MRI revealed an enhancing and thickened pituitary stalk with absence of the normal bright signal in the posterior pituitary. Regular MRI surveillance detected progression of the neurohypophyseal changes 13 months into GH treatment. Biopsy confirmed this to be B-cell large cell lymphoma. This case highlights the diagnostic and management challenges inherent in treating such children.

Central Nervous System Neoplasms↗
PubMedDate not supplied

Case report. Simultaneous fungal and viral infection of the central nervous system.

A patient with lymphoma developed central nervous system dysfunction and the diagnosis of cryptococcal meningitis was made. Because of discordant clinical and laboratory responses to appropriate treatment, further investigations were performed and the additional diagnosis of progressive multifocal leukoencephalopathy (PML) was established. Computerized axial tomography (CT scanning) proved helpful in pointing toward the latter disorder. Clinical, neuropathological, and microbiologic features are presented. The diagnostic approach to central nervous system illness in patients with impaired immunocompetence should include consideration of simultaneous infection with multiple agents.

Central Nervous System Diseases↗
PubMedDate not supplied

Hospice and palliative care: attitudes and practices of the physician faculty of an academic hospital.

It has been suggested that physicians, particularly in academic hospitals, are resistant to the hospice approach to palliative care for terminally ill patients. It is of interest, therefore, to assess the attitudes and practices of the physician faculty of an academic hospital where a hospice program has been in existence for more than 10 years. This was assessed with two faculty surveys. All 966 physician faculty that were on staff at Northwestern Memorial Hospital in the fall of 1993 were sent a survey about their opinion of hospice care (Survey A). Then, all physicians who had referred patients to the hospice program between September 1993 and September 1994 at Northwestern Memorial Hospital received a survey letter after the death of their patient (Survey B). Seventy-seven percent of faculty physician respondents to Survey A had either referred patients, or knew of colleagues who had referred patients to a hospice program. Ninety-four percent of those who answered "yes" to the question about referrals reported satisfaction with their care. Ninety-four percent would refer patients in the future and 96 percent thought the hospice program was a valuable resource to the medical center. Of the respondents to Survey B, nearly 100 percent thought the referral had been handled in an "excellent" or "good" fashion, that communication with hospice staff was "excellent" or "good," that symptom control was "excellent" or "good," that their patients and families had received "excellent" or "good" psychosocial support, and that their patients and families were satisfied with the hospice care they received.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗
PubMedDate not supplied

Myocardial infarction site and mortality in diabetes.

Survival after a first myocardial infarction (MI) was examined in 54 diabetic and 270 nondiabetic subjects according to anatomic site of MI. Complete survival status information was obtained during a 12-yr follow-up. Compared with nondiabetic subjects, diabetics had a higher proportion of anterior site of MI below the age of 60 in both sexes. A significantly higher mortality was experienced in both sexes by patients with anterior MIs compared with other infarction sites (47% vs. 13% respectively, over 12 yr of follow-up). This excess fatality was differentially distributed by diabetic status. The 60-day mortality following admission with an anterior MI was significantly higher in diabetic (55%) than in nondiabetic subjects (31%). No differences in 60-day survival were found between diabetic and nondiabetic subjects with other infarction sites. Thus, anterior size and diabetic status each convey an increased risk of early postinfarct mortality. The findings from this study suggest that the presence of both is synergistic with regard to the 60-day mortality rate.

Diabetes Complications↗
PubMedDate not supplied

Regional differences in appropriateness of cholecystectomy in a prepaid health insurance system.

BACKGROUND: Previous studies have reported variation in the population-based use rate of diagnostic and therapeutic procedures. Cholecystectomy is one of the most common surgical procedures, and we conducted this study to assess whether in Israel the use of this procedure varied by region and whether differences in use can be related to differences in appropriateness of use. In Israel, there is a pre-paid health insurance system and all surgeons are salaried. METHODS: Age-adjusted rates of cholecystectomy in four hospitals, each serving a defined population in Israel, were calculated. Two hundred and sixty-six potential clinical indications for performing cholecystectomy were rated as to their appropriateness by a panel of 9 expert physicians. A trained team abstracted the medical records of all patients who underwent the operation in the four Israeli hospitals in 1986 (n = 702) and recorded the clinical indication for the surgery. RESULTS: The population-based age-adjusted rates of cholecystectomy varied over threefold among the four hospitals. 29% of the cholecystectomies were performed for less than appropriate reasons, and this figure varied by hospital from 36% to 17% (p = 0.002). However, appropriateness did not vary systematically with the population-based use rate. CONCLUSION: Cholecystectomy was performed frequently for inappropriate or equivocal reasons, even in a country in which resources are limited, and physicians are salaried. Efforts to improve surgical decision making should be undertaken.

Adult↗
PubMedDate not supplied

Estimation of the prevalence of diabetes mellitus in Israel based on hypoglycemic drug supply and consumption.

In recent years, the estimation of drug utilization has become an efficient instrument for the evaluation of health services. The Defined Daily Dose (DDD) method, standardized by the WHO, using consumption data, provides a basis for comparison of morbidity between different places and over different periods of time. The aim of this study was to validate the estimated prevalence of Diabetes Mellitus in Israel obtained by the DDD method. We compared this estimate with data from medical records and from medication cards for the chronically ill. The study focused on Kupat Holim insurees, aged 30 years and older, registered in three Beer Sheva primary care clinics in 1985. By the DDD method we predicted 319 cases of diabetes; record review and medication cards disclosed 353 and 379 cases respectively. Most of this discrepancy was due to oral treated cases of diabetes by the DDD approach. For insulin treated, diabetes the DDD method predicted 108 cases as compared to 102 and 125 by chart and medication review. Because the review of medical records is expensive and medication cards for chronic patients are not always available, the DDD approach is a cheap, efficient and simple way to estimate prevalence of diabetes. Improved knowledge of prevalence may serve as a basis for monitoring therapeutic practices and therefore improving the quality of health services.

Adult↗