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Biomedical subjects

B Goldberg

Publications and source records attributed to B Goldberg.

At least 163 records · Page 9Linked to original sources
PubMed1979

The detection of superoxide anion from the reaction of oxyhemoglobin and phenylhydrazine using EPR spectroscopy.

The low temperature EPR spectrum of a quickly reacted mixture of oxyhemoglobin and phenylhydrazine was studied. With the use of a computer, the spectral contribution of methemoglobin in the region of g = 2 was subtracted. The remaining spectrum was that of an axial free radical (g perpendicular = 2.00, g parallel = 2.06) having the magnetic parameters of superoxide anion. In the presence of superoxide dismutase, this axial radical was not seen, confirming that superoxide anion is indeed generated by the reaction.

Chemical Phenomena↗
PubMed1979

Binding of soluble type I collagen molecules to the fibroblast plasma membrane.

Soluble 125I-labeled type I collagen binds to cultured fibroblasts but not to cultured epithelia. The binding of the ligand to fibroblasts is reversible, saturable and highly specific for sequences contained within the helical portions of the alpha1 and alpha2 chains. The amount of ligand bound is dependent upon cell number and ligand concentration. Binding is decreased but measurable at 4 degrees C. The steady state binding is greater at 26 degrees than at 37 degrees C due to a more rapid dissociation of the ligand-acceptor complex at 37 degrees C. The half-life of the complex is 46 min at 37 degrees C and approximately 2.5 hr at 26 degrees C. Scatchard plots of binding data indicate a single class of high affinity binding sites (KD = 1.2 X 10(-11) M) with each fibroblast binding approximately 500,000 molecules at saturation. Pretreatment of fibroblasts with bacterial collagenase, chondroitinase ABC or testicular hyaluronidase does not affect the binding reaction, whereas pretreatment of the cells with phospholipase C increases the amount of ligand bound. Ligand binding is decreased but not abolished after fibroblasts are treated with trypsin concentrations which remove surface fibronectin. Fibroblast monolayers treated with antiserum against fibronectin bind the radiolabeled ligand normally. In contrast to collagen, addition of excess fibronectin does not accelerate the dissociation of bound ligand from fibroblasts. Possible functions for surface-bound collagen are discussed.

Animals↗
PubMed1979

The pregnant Syrian hamster as a model to study intravascular trophoblasts and associated maternal blood vessel changes.

In pregnant Syrian hamsters (Mesocricetus auratus) used as an animal model for studying the migration of fetal trophoblasts and the associated changes in maternal blood vessels, intravascular trophoblasts migrated well beyond the blood vessels of the uterus and into the vessels of the mesometrium. They migrated beyond the decidua of the uterus, into the lumina of maternal uterine and mesometrial arteries, but not into veins. The arterial changes, which were often segmental, resembled those seen in the decidua and consisted of a replacement of normal smooth muscle cells by poorly differentiated stromal cells. Ultrastructurally, the trophoblasts were either above or below maternal endothelial cells. They occurred also as single or multiple layers within the lumina of arteries that lacked an endothelial lining. Apparent penetration of the elastic membrane by the fetal trophoblasts brought them into close apposition to maternal cells in the arterial wall. Histochemical studies showed heightened metabolic activity of the intravascular trophoblasts as suggested by strong histochemical reactions to nonspecific esterase, succinic dehydrogenase and the glycerophosphate dehydrogenase reactions. Thus, these metabolically active fetal trophoblasts actively migrate into the maternal arterial system, resulting in loss of endothelial cells and changes in the wall of the maternal arteries similar to those in the decidua at the uteroplacental junction.

Animals↗
PubMed1978

The role of ultrasonography in the diagnosis of certain neurologic disorders. A preliminary report.

Ultrasonography is the most innocuous and noninvasive procedure, ideally suited for screening patients suspected of having cerebrovascular insufficiency. The Doppler ultrasound and real-time techniques complement each other. The latter can actually display a two-dimensional dynamic image of the carotid artery. B-scan can also be used in fetuses, infants, and young children for precise assessment of the size of the ventricular system. It can be used for serial follow-up evaluation of hydrocephalus. Ultrasound can be utilized in determination of the depth and width of the lumbar spinal canal. Differentiation of cystic from solid masses in the spinal canal may also be made by this modality.

Brain Diseases↗
PubMed1977

South African multicentre study of metoprolol and propranolol in essential hypertension.

Ninety-three patients diagnosed as essential hypertensives, WHO stage I or II, entered this double-blind trial comparing 2 dose levels of CGP 2175-H 93/26 (metoprolol) with 2 doses of propranolol. Treatment on active medication was maintained for 6 weeks and was started after a 2-week washout and a 2-week placebo period. Twelve patients dropped out of the trial for reasons not related to the drugs and 1 patient was regarded as a therapeutic failure. Efficacy was assessed by measuring the diastolic and systolic blood pressure, pulse rate and by noting any significant ECG changes. All treatments reduced and maintained a lower blood pressure. However, a reduction with 360 mg propranolol per day was not statistically significant. Metoprolol 120 mg/d was significantly superior to propranolol 240 mg/d in holding the diastolic supine blood pressure at less than or equal to 90 mmHg. Metoprolol 120 mg/d and 210 mg/d pooled results were significantly superior to the propranolol 240 mg/d and 360 mg/d pooled data in maintaining a diastolic blood pressure of less than or equal to 90 mmHg. All treatments were well tolerated and in no case was it necessary to withdraw owing to adverse effects. No significant difference was detected between the treatments with respect to therapeutic emergent symptoms and signs. Laboratory results remained normal with all treatments.

Clinical Trials as Topic↗
PubMed1977

Collagen synthesis as a marker for cell type in mouse 3T3 lines.

Collagen synthesis was applied as a test of the fibroblastic or endothelial origin of the 3T3 mouse lines. Swiss/3T3 lines and Balb/3T3 (clone A31) were compared with respect to the amounts and types of collagen synthesized. All lines symthesized collagen at relatively high and similar rates. For all lines, 75-90% of the collagen synthesized was type I, and the remainder was type III. There was no evidence for synthesis of type IV collagen. By all these parameters, Swiss and Balb/3T3 lines resemble cultured fibroblasts rather than cultured vascular endothelia.

Animals↗
PubMed1977

Kinetics of processing of type I and type III procollagens in fibroblast cultures.

The rates of conversion of types I and III procollagens to their respective collagens were compared in seven fibroblast culture systems of murine or human origin. During 24 hr of radioactive labeling or after shorter pulses followed by chases of 20-48 hr, no evidence was obtained for conversion of radiolabeled type III procollagen to insoluble collagen. In the same cultures and under the same conditions, native collagen was generated from radiolabeled type I procollagen. There was no evidence for proteolytic degradation of type III procollagen during the chase experiments. The results are ascribed to a lack of availability of the enzymes required for processing of type III procollagen.

Cell Line↗
PubMed1977

Enzyme histochemistry of ovarina lipoid cell hyperplasia in a masculinized patient.

In an effort to better identify the specific steroids produced by histologically similar cells of certain ovarian tumors, a battery of histochemical assays was performed on a masculinizing tumor removed from a 21-year-old patient. Certain reactions were distinguished that seemed to be specific for the histologically classic luteinized stromal cell, and these reactions can be correlated with those obtained with Leydig and hilar cells. The apparent precursors of the interstitial cells (ISC) of this tumor, and to a lesser extent the immature ISC, possess unusually high cholinesterase activity, especially with the butyryl ester. The importance of the perivascular and neural elements in the process of steroidogenesis is suggested by the findings in this case.

Adenosine Triphosphatases↗
PubMed1977

Superoxide anion and drug-induced hemolysis.

Superoxide anion, either generated during the autooxidation of dihydroxyfumaria acid or by the interaction of 1,4-naphthoquinone-2-sulfonate and intracellular hemoglobin in red cells pretreated with the intracellular superoxide dismutase inhibitor, diethyldithiocarbamate, produces structural changes in red cells hemoglobin and hypotonic lysis. No evidence for lipid peroxidation was found in red cells exposed to either 1,4 naphthoquinone-2-sulfonate in the presence of diethyldithiocarbamate or to dihydroxyfumaric acid, although the membranes of these cells exposed to either 1,4 naphthoquinone-2-sulfonate in the presence of diethyldithiocarbamate or to dihydroxyfumaric acid, although the membranes of these cells retained a green pigment. These results suggest that superoxide anion reacts with cellular hemoglobin to form hemoglobin breakdown products which bind to the red cell membrane and thereby increase the osmotic fragility of the cell.

Catalase↗
PubMed1976

Superoxide anion as a mediator of drug-induced oxidative hemolysis.

The superoxide dismutase inhibitor diethyldithiocarbamate (DDC) was utilized to study the toxic effect of 1,4-naphthoquinone 2-sulfonate (NQ), a structural analog of the hemolytic drug, menadione, on red cells. NQ was shown to react with hemoglobin and result in the generation of superoxide anion (O2-). Red cells treated with NQ were found to undergo a gradual disappearance of their oxyhemoglobin and also hemolyze. Red cells pretreated with DDC to inhibit cellular superoxide dismutase were found to be markedly sensitive to oxyhemoglobin destruction and hemolysis in the presence of NQ. Superoxide dismutase-inhibited red cells were also found to undergo a slow autohemolysis in the absence of NQ. No evidence for lipid peroxidation was obtained for red cells treated with NQ either in the presence or the absence of DDC. Ghosts prepared from superoxide dismutase-inhibited red cells exposed to NQ were found to retain a green hemoglobin-derived pigment.

Binding Sites↗
PubMed1976

Angiography after renal homotransplantation.

The role of angiography in the investigation of problems encountered among 181 patients who received renal transplants at the Johannesburg General Hospital is analysed. In all, 23 patients underwent arteriography or venography after transplantation for the investigation of problems such as renal dysfunction, hypertension and suspected renal vein or iliofemoral venous thrombosis.

Diagnosis, Differential↗
PubMed1976

Production of superoxide anion during the oxidation of hemoglobin by menadione.

Menadione in the presence of oxyhemoglobin will accelerate the formation of methemoglobin and result in the generation of superoxide anion. Menadione appears to oxidize slowly ferrohemoglobin to ferrihemoglobin, while forming menadione semiquinone in the process. Menadione semiquinone is known to react with molecular oxygen to yield superoxide anion. The superoxide anion appears to be the source of hydrogen peroxide which accounts for most of the observed methemoglobin formation when hemoglobin is reacted with menadione.

Adult↗