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Biomedical subjects

M R Stein

Publications and source records attributed to M R Stein.

14 recordsLinked to original sources

SV-40 transformation: effect on GM2 ganglioside in cultured cell lines.

In previous work, we observed the presence of substantially elevated levels of GM2 after Simian Virus 40 (SV-40) transformation of human fetal brain cells. This elevated level of GM2 contrasted with the reports of many other investigators who had often observed decreased levels of GM2 and a simplification of ganglioside pattern in various non-neural rodent cell lines. In order to determine if the increase in GM2 in the transformed human brain cells would also be found in transformed rodent brain cells, we analyzed ganglioside changes after transformation in mouse brain cell lines and observed the increase in GM3 and low levels or lack of GM2 usually noted in rodent SV-40 transformed cell lines. In addition, we analyzed changes after SV-40 transformation in three human fibroblast lines and found that all three lines contained substantially elevated levels of GM2 after SV-40 transformation. As a result of this study, our earlier work on SV-40 transformed human brain cells, and occasional other reports of high levels of GM2 in human SV-40 transformed cell lines, elevated levels of GM2 may be considered a marker for SV-40 transformed human cells of both fibroblastic and neural origin.

Animals

Comparison of severity of illness indicators in an intensive care unit.

Meaningful comparison of patient outcomes requires an assessment of the severity of illness for the patients being compared. The more severe the underlying illness, the worse the expected outcome. We studied several severity of illness indicators derived from different methodologies in a medical intensive care unit. We compared the Acute Physiologic and Chronic Health Evaluation II, the accepted benchmark indicator for intensive care units, with one complex indicator, Computerized Severity Score, and three simpler indicators, Comorbidity, McCabe-Jackson, and American Society of Anesthesiologists. We found that all correlated well with a comorbidity index. We conclude that the Acute Physiologic and Chronic Health Evaluation II, the Computerized Severity Score, and the McCabe-Jackson scoring systems appear to be comparable predictors of comorbidity in a medical intensive care unit. Selection of a severity indicator will depend on the resources available and the intended uses.

Aged

Gangliosides in SV-40-transformed cells derived from Tay-Sachs disease fetal brain.

A human glial brain cell line derived from a Tay-Sachs disease fetal cerebellum was transformed with SV-40 virus in order to obtain a transformed brain cell line which reflected the characteristics of the disease. It was shown that the transformed TSD cell line maintained an elevated level of GM2 which was similar to that shown by the nontransformed precursor. In addition, the TSD transformed line lacked hexosaminidase A.

Cerebellum

Fatal Portuguese man-o'-war (Physalia physalis) envenomation.

A fatal case of Physalia physalis (Portuguese man-o'-war) envenomation occurred on the Florida Atlantic coast in 1987. Despite appropriate beachside first aid, the patient was conscious only several minutes before having primary respiratory arrest and, later, cardiovascular collapse that resulted in death. Discharged nematocysts were still visible on the injured stratum corneum five days after envenomation. Additional treatment maneuvers suggested by this case include testing the tentacle fragments found on the victim's skin before their removal to ensure that nematocyst firing has been counteracted. We document the first human fatality caused by P physalis envenomation.

Aged

Induction of lymphomas and fibrosarcomas in nude mice after implantation of simian virus 40-transformed human meningioma.

Human cells transformed by Simian virus 40 (SV40) usually show little or no tumor formation after implantation in nude mice. In long-term studies, however, we have observed that 127 to 366 days after subcutaneous injection of SV40-transformed human meningioma cells (KJ-M2-T) into nude mice (Nu/Cox), 6 of 15 animals developed lymphomas or fibrosarcomas, usually at the site of inoculation. The induced tumors were of murine origin and were positive for SV40-T antigen. Chromosome analysis and G11 staining revealed no evidence of hybridization between human and mouse cells. No spontaneous shedding of SV40 was noted with KJ-M2-T cells in vitro; however, SV40 could be rescued after fusion of KJ-M2-T with BS-C-1 monkey kidney cells, but not with L929 mouse fibroblasts. A parallel study using SV40-transformed human fetal brain cells failed to induce tumors in nude mice despite the demonstration that infectious SV40 could also be rescued from this line after fusion with BS-C-1 but not with L-929. Subcutaneous injection of 5 X 10(3) TCID's of SV40 (strain J436) into nude mice resulted in the induction of fibrosarcomas at the injection site in 6 of 15 mice after 273 to 396 days. The induction of malignant lymphomas after implantation of SV40 transformed cells contrasted with the development of fibrosarcomas after injection of free virus. This study suggests that after subcutaneous implantation into nude mice, some SV40-transformed human tumor cell lines can serve as vectors for transmitting SV40 to murine cells causing transformation and tumor development in the host animal.

Animals

Assessment of a technique for scintigraphic monitoring of pulmonary aspiration of gastric contents in asthmatics with gastroesophageal reflux.

Ten asthmatics with gastroesophageal reflux had scintigraphic evaluation of gastropulmonary aspiration. Five mCi of Tc99m sulfur colloid diluted in 50 ml of isotonic saline were administered by nasogastric tube at bed time and the lungs were imaged the following morning. Imaging in 20 studies yielded no evidence of gastropulmonary aspiration. Scintigraphic evaluation has previously been reported to demonstrate gastropulmonary aspiration in some patients with gastroesophageal reflux and pulmonary disease. This study indicates that the technique may lack adequate sensitivity or that gastropulmonary aspiration in asthmatics with gastroesophageal reflux occurs in only a small subgroup of these patients or at infrequent intervals and is difficult to detect.

Adult

A laboratory evaluation of immune complexes in patients on inhalant immunotherapy.

Patients with allergic rhinitis receiving maintenance inhalant immunotherapy and two control groups were studied for evidence of circulating immune complexes. The first control group contained patients with allergic rhinitis who had never received immunotherapy. The second control group contained normal volunteers. Patients in the treatment group had no proteinuria. When compared with the control group, the treatment group had no statistically significant differences in incidence of Clq binding immune complexes, cryoglobulinemia, rheumatoid factor, or complement depletion. This initial study suggests that maintenance immunotherapy does not result in an increase of circulating immune complexes.

Antigen-Antibody Complex

Gastroesophageal reflux and asthma: a possible reflex mechanism.

Fifteen asthmatic patients with gastroesophageal reflux underwent an intraesophageal acid provocation test. Pulmonary function measurements demonstrated increased flow resistance when reflux symptoms occurred. After relief of symptoms, these changes tended to rapidly reverse. The technique employed and the prompt reversal of pulmonary functions suggest reflex mechanisms may be producing the observed bronchoconstriction.

Adolescent

Ineffectiveness of human chorionic gonadotropin in weight reduction: a double-blind study.

Our investigation was designed to retest the hypothesis of the efficacy of human chorionic gonadotropin (HCG) on weight reduction in obese women in a clinic setting. We sought to duplicate the Asher-Harper study (1973) which had found that the combination of 500 cal diet and HCG had a statistically significant benefit over the diet and placebo combination as evidenced by greater weight loss and decrease in hunger. Fifty-one women between the ages of 18 and 60 participated in our 32-day prospective, randomized, double-blind comparison of HCG versus placebo. Each patient was given the same diet (the one prescribed in the Asher-Harper study), was weighed daily Monday through Saturday and was counselled by one of the investigators who administered the injections. Laboratory studies were performed at the time of initial physical examinations and at the end of the study. Twenty of 25 in the HCG and 21 of 26 patients in the placebo groups completed 28 injections. There was no statistically significant difference in the means of the two groups in number of injections received, weight loss, percent of weight loss, hip and waist circumference, weight loss per injections, or in hunger ratings. HCG does not appear to enhance the effectiveness of a rigidly imposed regimen for weight reduction.

Adult