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Biomedical subjects

S Becker

Publications and source records attributed to S Becker.

At least 397 records · Page 22Linked to original sources
PubMed1982

Flow cytometric analysis of macrophage heterogeneity and differentiation: utilization of electronic cell volume and fluorescent substrates corresponding to common macrophage markers.

We have utilized electronic cell volume (ECV) and several fluorescent analogues of traditional macrophage markers in a flow cytometric characterization of macrophage heterogeneity. With this technique, various features of macrophage differentiation and activation can be determined on as few as 10,000 cells per assay. Quantitations of cell volume, phagocytosis, RNA, myeloperoxidase, acid phosphatase, and the ectoenzyme leucine aminopeptidase have been carried out on cultured human monocytes and peritoneal macrophages. Quantitations of the amount of a particular marker on a per cell basis, as well as population distributions, are of particular value in characterizing the heterogeneity in resident and inflammatory macrophages and the temporal relationships between different markers during macrophage activation and differentiation. This technique will facilitate a sophisticated analysis of monocyte-macrophage development by permitting the simultaneous analysis of a number of these features. In this way the interrelationships between different macrophage markers can be quantitated at the single cell level.

Acid Phosphatase↗
PubMed1982

Seasonal changes in nutritional status and the prevalence of malnutrition in a longitudinal study of young children in rural Bangladesh.

During longitudinal field studies of the growth, dietary intake, and morbidity from infectious diseases of children between 6 and 60 months of age in two rural villages of Bangladesh, seasonal fluctuations in growth, nutritional status, and the prevalence of malnutrition were observed. The weight, length, arm circumference, and triceps skinfold thickness of 197 children were measured monthly for 15 months and compared with sex-specific local village norms and international reference populations. The percentages of expected weight for length, arm circumference for age, triceps skinfold thickness for age, and the percentages of expected monthly increments of weight and length for age were the indicators most sensitive to seasonal changes. The percentages of expected weight for age and length for age also changed significantly by month of year, but were less responsive to seasonal variation. The periods of greatest nutritional deficit depended on which anthrometric indicator was used to define nutritional status, but generally occurred during the monsoon and persisted until the subsequent harvest period. However, the fall in mean percentage of expected length for age and the increase in the prevalence of stunting occurred several months after the periods of greatest malnutrition identified by the other measurements. The importance of selecting the appropriate anthropometric techniques to detect seasonal changes and the implications of such changes are discussed.

Bangladesh↗
PubMed1982

Lack of effect of luteinizing hormone-releasing hormone on pancreatic exocrine secretion and release of gastrin and pancreatic polypeptide in dog.

In 7 conscious dogs with gastric and duodenal Thomas fistulas we studied the effect of an intravenous bolus injection of luteinizing hormone-releasing hormone (LHRH, 100 microgram) on pancreatic bicarbonate and protein secretion stimulated by an intravenous infusion of secretin (500 ng kg-1 hr-1) and on plasma concentrations of pancreatic polypeptide (PP) and gastrin. LHRH did not significantly alter pancreatic bicarbonate and protein output in response to secretion and plasma levels of gastrin and PP as measured by radioimmunoassay. The lack of any significant influences of intravenous LHRH on exocrine pancreatic secretion does not exclude an effect of LHRH on pancreatic bicarbonate and enzyme secretion via paracrine delivery.

Animals↗
PubMed1981

Stomal recurrence. A critical analysis of risk factors.

Stomal recurrence developed in 5% of the 507 patients who underwent total laryngectomy for a squamous cell carcinoma. The most common site of the primary tumor was the glottis, followed by the supraglottic and pyriform sinus regions. Initial subglottic extension of the tumor and metastatic lymphadenopathy were the most significant risk factors. The primary tumor size, prior emergency tracheostomy, and conservation surgical procedures had no effect on the incidence of stomal recurrence. The median survival in patients with stomal malignant neoplasms was only five months. In high-risk patients, extended dissection or elective postoperative radiotherapy is recommended.

Carcinoma, Squamous Cell↗
PubMed1981

Effects of truncal vagotomy and antrectomy on bombesin-stimulated pancreatic secretion, release of gastrin, and pancreatic polypeptide in the anesthetized dog.

The short-term effects of truncal vagotomy and antrectomy on bombesin-stimulated pancreatic secretion and release of gastrin and pancreatic polypeptide (PP) were studied in 18 anesthetized dogs. Together with an intravenous infusion of secretin (250 ng/kg/hr) bombesin (500 ng/kg/hr) was given before and after truncal vagotomy, antrectomy, and sham operation (N = 6 dogs per group). Peak incremental pancreatic protein output in response to bombesin was about 2-3 times higher before than after the different surgical procedures (tachyphylaxis). Neither truncal vagotomy nor antrectomy significantly altered the pancreatic protein response to bombesin when compared with sham operation. Bombesin produced a mean 1-hr increase over basal of 196 pM for gastrin, which was abolished by antrectomy but not appreciably affected by truncal vagotomy and sham operation. The mean 1-hr increment (207 pM) for PP in response to bombesin was not changed by truncal vagotomy, antrectomy, and sham operation. This study shows in the anesthetized dog that exogenous bombesin stimulates release of PP as well as gastrin; that the release of gastrin by bombesin is not vagally dependent; that neither truncal vagotomy nor antrectomy alter the release of PP by bombesin; and that the action of bombesin on pancreatic protein secretion does not depend on release of gastrin or on intact vagal nerves.

Animals↗
PubMed1981

Listeria and gram-negative bacillary meningitis in New York City, 1972-1979. Frequent causes of meningitis in adults.

In an eight year period (1972-1979), 158 cases of enteric gram-negative bacillary meningitis and 53 cases of Listeria meningitis were reported to the New York City Health Department. These two forms of bacterial meningitis were the fourth and fifth most common ones reported to the Department, respectively. The cumulative total of reported cases of gram-negative rod meningitis over this less than the reported cases due to Neisseria meningitis over this period. In contrast to most previous studies of Listeria and enteric gram-negative meningitides, the majority of cases occurred in adults. Listeria meningitis occurred more often in immunosuppressed hosts and the elderly than in the newborn; gram-negative bacillary meningitides were seen more often in elderly septic patients and in patients with traumatic skull fracture than in infants during the first months of life. The over-all mortality of Listeria meningitis was 62 percent; that of the combined gram-negative meningitides 71.3 percent. The mortality in adults with Escherichia coli and Klebsiella meningitis who were treated with chloramphenicol as the major antibiotic was 83 percent. In comparison, the only appreciable survival rates noted were in those with Listeria, Escherichia coli, Proteus mirabilis and Salmonella meningitis who were treated with ampicillin alone in whom the over-all mortality was 51 percent.

Adolescent↗
PubMed1981

In vitro demonstration of in situ autologous tumour-cell cytotoxicity in MSV-induced tumours in A/SN mice.

Moloney sarcoma-virus (MSV)-induced tumours in A/Sn mice have been dispersed with collagenase and DNase 8-15 days after virus inoculation, and both "sarcoma" and inflammatory cells separated by sedimentation velocity and adherence techniques. The isolated "sarcoma" cells had the morphological characteristics of atypical cells (i.e. cytoplasmic blebbing, vacuolization and prominent nucleoli) and were easily adapted to in vitro growth. As few as 2 x 10(3) of these cells inoculated i.m. produced new tumours within 8 days of injection in both syngeneic and allogeneic mice. Also, cell-free supernatant from "sarcoma"-cell cultures produced tumours, indicating that the successful transplantation of the "sarcoma" cells was probably due to production of infective virus. Cells cytotoxic in vitro against the "sarcoma" cells were present within both spleen and tumour of the tumour donors, but not in the spleens of normal mice. The cytotoxicity was specific against virus-infected cells, since in a mixture of virus-positive (gp 70) and virus-negative cells, positive cells were removed while negative cells were not affected, as measured by a visual cytotoxicity assay using immunostaining. Although T cells could be isolated from the MSV-induced tumours, these cells did not appear to mediate the cytotoxicity detected against the MSV "sarcoma" cells. These results suggest that early MSV infections might be sensitive to cytotoxic mechanisms distinct from those reported with established MLV- or MSV-induced tumour lines.

Animals↗
PubMed1981

Seasonality of deaths in Matlab, Bangladesh.

Deaths registered between 1972 and 1974 in a population of 260 000 in a rural area of Bangladesh were analysed for seasonal patterns. Age and cause of death groups were considered. The findings include: (1) The number of neonatal deaths has a peak in October but after adjustment for the seasonal pattern of births, the actual risk of neonatal morality is found to peak 2 months earlier. (2) Postneonatal deaths peak in April with above average proportions of deaths in the peak month attributed to dysentery. (3) Deaths of persons above age 45 peak in the cool season. (4) Dysentery and chronic diarrhoea deaths are highest in December. This coincides with the maximum incidence of shigella dysentery. (5) Accidental deaths are maximum in July due to increased drownings during the monsoon. The age and cause of death groups which contribute the largest proportions of total deaths are also the groups which show seasonal patterns.

Adolescent↗
PubMed1981

Effect of adding albumin to solutions of secretin on pancreatic volume and bicarbonate response.

In six conscious dogs with gastric and pancreatic Thomas fistulas, we studied the pancreatic bicarbonate response to intravenous bolus injections of synthetic secretin dissolved either in 5 ml of 0.15 M NaCl alone or in the same amount of NaCl to which dog albumin had been added, to give a 0.1% solution. The pancreatic bicarbonate (micromol . 10 min-1) response to the four lowest doses of secretin (12.5, 25, 50, 100 ng . kg-1) used was significantly (p less than 0.05) higher when secretin was dissolved in NaCl plus albumin than in NaCl alone. The pancreatic response to higher doses of secretin (200, 400, 800, 1600 ng . kg-1) was not significantly altered by the addition of albumin. The D50 of secretin was about 2.6 times greater in the absence than in the presence of albumin. This study suggests that albumin should be added to dilute solutions of secretin to preserve biological activity.

Albumins↗
PubMed1980

Non-T-cell-mediated cytotoxicity in MSV tumor-bearing mice. III. Macrophage-mediated cytotoxicity against autochthonous MSV tumor-isolated target cells.

Cytotoxic macrophages have been isolated from Moloney sarcoma virus (MSV) tumors induced in uncompromised, immunosuppressed and athymic nude mice. Macrophages from compromised mice were at least as active as those from uncompromised mice when tested against the autochthonous MSV target cells. Although both cytolytic and cytostatic activity could be demonstrated with all tumor-derived macrophages, cytostatic and cytolytic effects could be distinguished from each other only at high effector target-cell ratios. A variety of target cells were compared for sensitivity to the various tumor-associated macrophages. The autochthonous virus-infected MSV-target cells appeared to be more sensitive to the macrophage effects than fastgrowing, established cell lines. Normal embryo fibroblasts were only slightly affected. Peritoneal exudate cells from tumor-bearers were much less active than either the tumor-isolated macrophages or bone-marrow culture-derived macrophages. Both were more active than control peritoneal cells. Although no quantitative or qualitative differences in macrophage activity could be detected in mice with regressing lesions and immuno-compromised mice with progressing lesions, the ratio of macrophages to "sarcoma" cells was three to five times higher in regressing tumors.

Animals↗
PubMed1980

Characterization of the presumptive sarcoma cells in primary MSV tumors.

Presumptive sarcoma cells have been isolated from primary MSV tumors induced in normal, immunosuppressed (ALG) and athymic nude mice. These cells were atypical in appearance, induced tumors in secondary hosts and expressed the viral antigens gp70, p30 and p12. In vitro growth characteristics of the MSV cells were tested in a variety of assays defining cell transformation. None of these indicated that the virus-positive cells were transformed. Sex chromosome marker studies were carried out to determine if secondary tumor arose solely from proliferation of donor cells or through infection of host tissue. Tumors from female irradiated mice induced by injections of tumor cells derived from male mice contained a high proportion of metaphases of non-donor origin, indicating that infection is an important but not the sole mechanism involved in tumor transfer. These data also demonstrated that many of the sarcoma cells are damaged as a result of infection as shown by the presence of chromosome breaks and aneuploid metaphases. Histologic sections of both regressor and progressor tumors showed that the virus-positive cells were scattered as single cells surrounded by inflammatory cells, rather than as masses of dividing virus-positive cells found in the MSV-induced transplanted tumor. Collectively, these data support the contention that the MSV tumor is the manifestation of a response to a highly noxious virus infection rather than a tumor of dividing, transformed malignant cells.

Animals↗