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Biomedical subjects

B Rosenbaum

Publications and source records attributed to B Rosenbaum.

48 records · Page 3Linked to original sources
PubMed1983

Interaction of specifically purified isotypes of bovine antibody to Brucella abortus in the haemolysis in gel test and enzyme-linked immunosorbent assay.

The detection limits for purified bovine IgM, IgG1 and IgG2 antibody to Brucella abortus in the haemolysis in gel test and in an enzyme-linked immunosorbent assay (ELISA) were established. The limits for IgM, IgG1 and IgG2, respectively, were: 5500, 60 and 4850 ng of antibody in the lytic test and 2750, 3.5 and 16 ng in the ELISA test. Bovine IgG2 produced lysis only in the presence of fresh, whole bovine serum.

Animals↗
PubMed1983

Failure of bovine complement levels measured by radial hemolysis to correlate with tube titration.

Hemolytic complement levels in 30 duplicate samples of normal bovine sera were determined by a tube titration method (CH50) and by a radial hemolysis in gel assay. Significant correlation was not observed between the values obtained by the 2 tests. This lack of correlation could be a result of considerable error observed in values obtained for duplicate samples in the CH50 method or to the relative insensitivity of the hemolysis in gel test. The hemolytic reaction in gel was found to depend on Mg2+, thus raising questions (i) about its validity in determining total hemolytic complement or (ii) about bovine C1q depending on Mg2+ rather than Ca2+ for binding to immune complexes.

Animals↗
PubMed1982

Effect of hydrostatic pressure on ADH induced osmotic water flow in toad bladder.

The effect of hydrostatic pressure (HP) on antidiuretic hormone (ADH) stimulated osmotic water flow (Jv) across the toad urinary bladder was evaluated. Jv for ADH-stimulated bladders was significantly reduced by an elevation of the serosal HP gradient to 1 cm H2O. Subsequent elimination of the HP gradient resulted in a recovery of Jv. Serosal HP also caused a reversible increase in sucrose permeability (P sucrose). For ADH-treated bladders fixed with glutaraldehyde during serosal HP exposure, subsequent exposure to a mucosal or serosal HP gradient caused acceleration or inhibition of Jv, respectively. The reduction in ADH-associated Jv with serosal HP was apparently caused by a back-flux of water through a paracellular pathway. Jv and P sucrose were not affected by mucosal HP during ADH stimulation. The results suggest a specific sensitivity of a paracellular pathway to a small serosal HP gradient in bladders with ADH-stimulated water flow. The reversibility of this effect on P sucrose suggests that the elements comprising the apical junctions are dynamic structures capable of recovering at least some of their permeability properties.

Animals↗
PubMed1982

Renal tubular sodium reabsorption and oxygen consumption in the hypothyroid dog.

The degree to which an insufficiency of thyroid hormone (TH) affects renal tubular sodium reabsorption (RNa) and oxygen consumption (QO2) in vivo, was investigated in a mature mammalian kidney. The results suggest that TH influences renal QO2 as a result of alterations in renal hemodynamics and the renal tubular handling of sodium. Changes in GFR played a major role in the regulation of RNa and QO2. This is suggested by the comparison of hypothyroid animals with and without renal compensatory hypertrophy. In the latter group a twofold lower GFR was associated with parallel changes in RNa and QO2. However, in going from euthyroid (E) to hypothyroid (H) conditions, the decrease in RNa of 31 +/- 4% was greater than the reduction in GFR of 25 +/- 3% (p less than .05). Thus, a decrease in RNa of 6 +- 2% under hypothyroid conditions could not be attributed to the changes in GFR. The normal renal stoichiometry between RNa and QO2 in hypothyroid animals indicates that the above changes in RNa were accompanied by comparable changes in QO2. The decrease in RNa in hypothyroid animals was not associated with a significant change in kidney weight (E:48.2 +/- 4.0gm., n = 5 and H:45.4 +/- 1.4gm, n = 5; pN.S.) The results suggest that an adaptive response to changes in GFR is the predominant cause of the decrease in RNa and renal QO2 under hypothyroid conditions. A modest reduction in renal tubular sodium reabsorptive capacity in hypothyroid animals is probably secondary to a direct effect of TH on active sodium transport.

Animals↗
PubMed1982

Effect of systemic antimicrobial prophylaxis on microbial flora.

Fifteen patients undergoing intensive chemotherapy for oat cell carcinoma of the lung in a protected environmental unit received antimicrobial prophylaxis with oral trimethoprim-sulfamethoxazole and short courses of parenteral ticarcillin, tobramycin, and miconazole. Altogether, 58 (65%) of 89 strains of aerobic bacteria and 28 (60%) of 47 strains of anaerobic bacteria present before prophylaxis were no longer cultured from stool specimens during prophylaxis. Ten strains of bacteria and four fungi were acquired in the stools during prophylaxis. Most fungi persisted in the throat and stools during prophylaxis. Bacterial infections occurred infrequently, but three patients developed Candida esophagitis. The regimen was well tolerated with minimal side effects.

Adult↗
PubMed1981

Protected environments in cancer chemotherapy: design and function of a large unit.

The construction of a new hospital building permitted the design of a new protected environment unit. The design and operating procedures of this unit are described. Microbiological monitoring has been conducted using air sampling, floor sampling, and settling plates. Microbial contamination is substantially lower in the protected environment unit than in comparable locations elsewhere in the hospital.

Air Microbiology↗
PubMed1981

Patterns of oropharyngeal and fecal flora in patients with acute leukemia.

The oropharyngeal and fecal flora in 33 patients hospitalized with acute leukemia was examined. Normal flora predominated on admission. All patients received chemotherapy during the 48 hr after admission and at least one course of antibiotics during hospitalization. By the end of the study, 68% of the initial normal throat flora and 57% of the fecal flora had disappeared. The shift in flora was mainly due to the persistence or acquisition of aerobic gram-negative bacilli. Before antibiotics were given, the normal flora in both sites had already decreased in quantity, and increased numbers of aerobic gram-negative bacilli were found. After the first course of antibiotics, a further decrease in the total number of normal strains was observed. Information obtained from surveillance cultures was helpful for understanding the changes in flora but did not correlate with the microbiology of the infectious processes and could not be used to predict infection.

Acute Disease↗
PubMedDate not supplied

Ex vivo evaluation of the NASA/DeBakey axial flow ventricular assist device. Results of a 2 week screening test.

The authors investigated the antithombogenicity of the NASA/DeBakey axial flow ventricular assist device in an ex vivo calf model. The device is 3 inches in length and 1 inch in largest diameter. The pump weighs 53 g and displaces 15 ml. The unit consists of three major components: a flow straightener, a spinning inducer/impeller, and a diffuser. The impeller has rod shaped permanent magnets embedded within the six blades and is activated magnetically by a motor stator that is positioned outside the flow tube. Previous 2 day screening tests demonstrated an antithrombogenic configuration in short-term implantation. Based on the results of these 2 day screening tests, five pumps with the best configuration were implanted into a calf for 2 weeks for anti thrombogenicity confirmation. Pumps were implanted paracorporeally, and heparin was used to maintain activated clotting time to approximately 250 sec. Each pump was changed every 2 weeks as planned. During the experiment, all pumps demonstrated stable pumping. The required electric power was 7 to 8 watts and pump flow was maintained at 4 L/min. The calf was in excellent condition. Liver and renal function were maintained, plasma free hemoglobin was kept at less than 4 mg/dl (3.3 +/- 0.3 mg/dl), and lactate dehydrogenase was 1043 +/- 36 units/L. In this experimental series, all five pumps passed the 2 week implantation. Two week ex vivo test results indicated very slight thrombus in the hub areas of some pumps. For the next phase of the implantation study, minor design optimization is necessary to completely eliminate thrombus formation. According to our step by step approach, the in vivo test aiming for long-term implantation is ongoing.

Animals↗