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Biomedical subjects

R Levine

Publications and source records attributed to R Levine.

At least 145 records · Page 8Linked to original sources
PubMed1978

Synthesis of actin by cultured guinea pig megakaryocytes. Complex formation with fibrin.

Guinea pig megakaryocytes were isolated from femoral marrow and cultured in the presence of radioactive amino acids. Radioactivity was incorporated into several proteins including a 42 000 dalton polypeptide identified as actin by DNAase agarose affinity chromatography. Quantitative immunoelectrophoresis of megakaryocyte extract revealed that 3.0% of the total solubilized cellular protein was fibrinogen. Immunoabsorption studies using anti guinea pig fibrinogen beads failed to reveal the presence of newly synthesized radioactive fibrinogen in the cellular extract, however, radioactive actin was detected in the eluates obtained from the immune beads. When guinea pig fibrinogen was clotted with thrombin in the presence of radioactive megakaryocyte extract, a complex formed between a high molecular weight species of fibrin and actin. No actin fibrinogen complex was detected. The results suggest that actin synthesized by megakaryocytes complexes with fibrin formed from a relatively large pool of non-radioactive intracellular fibrinogen.

Actins↗
PubMed1978

Distinguishing between malignant and cirrhotic ascites by computerized step-wise discriminant functional analysis of its biochemistry.

This study was designed to evaluate the ability of a specifically programmed computer to select those biochemical substances most capable of distinguishing "cirrhotic ascites" from "malignant ascites". After simultaneously performing selected biochemical and electrophoretic studies on fresh unstored serum and ascites of 23 patients with documented cirrhosis and 18 patients with proven malignancies, computerized step-wise discriminant analysis of the multiple input revealed that the serum-to-ascites LDH ratio was able to distinguish "cirrhotic ascites" from "malignant ascites" with greater than 86% accuracy. Assignment to proper groups was increased to 89% with the addition of the ratio to serum total protein-to-ascites total protein. The predictive value of a positive result was 100%; specificity was 100%; the predictive value of a negative result was 85%. This type of computer analysis also permits incorporation of both additional cases and new substances thus increasing predictability and reducing type II statistical errors.

Albumins↗
PubMed1977

Regeneration of the retina in the adult newt, Triturus cristatus, following surgical division of the eye by a post-limbal incision.

An autoradiographic and histological study of retinal regeneration following a post-limbal ocular incision, in Triturus cristatus, is described. In these cases there is a major contribution to the regenerating retina from both the anterior complex (pars ciliaris retinae: ora serrata) and the retinal pigment epithelium. The tissue derived from the anterior complex can independently differentiate into retinal tissue if the anterior and posterior parts of the regenerate do not join. This contrasts with the situation following a limbal incision to the eye where the regenerative response of the anterior complex is inhibited. The significance of labelling patterns in the regenerating retina, following administration of 3H-thymidine, is discussed.

Animals↗
PubMed1977

Synthesis of factor VIII antigen by cultured guinea pig megakaryocytes.

Immunoprecipitates containing guinea pig Factor VIII antigen were prepared from guinea pig plasma with a cross-reacting rabbit anti-human Factor VIII. Monospecific antisera to guinea pig Factor VIII antigen were produced in rabbits by using these washed immunoprecipitates as immunogens. The resulting antisera to guinea pig Factor VIII antigen detected Factor VIII antigen in guinea pig plasma and inhibited the von Willebrand factor activity in guinea pig plasma. This antibody also detected Factor VIII antigen in a solubilized protein mixture prepared from isolated cultured guinea pig megakaryocytes. Cultured guinea pig megakaryocytes were labeled with radio-active leucine. By radioautography, 96.2% of the radio-activity was present in megakaryocytes. The radio-active Factor VIII antigen present in the solubilized cell protein mixture was isolated by immunoprecipitation and characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The results demonstrate that cultured guinea pig megakaryocytes synthesize Factor VIII antigen which contains the same polypeptide subunit (mol wt 200,000) present in guinea pig plasma Factor VIII antigen.

Animals↗
PubMed1976

Sliding colonic Maydl's hernia: report of a case.

An unusual variety of Maydl's hernia (hernia-in-W) in which all the herniated loops were colon is reported. The unusual anatomy of the hernia and its variations are described. It is important to examine the intraperitoneal intestine between the incarcerated loops in an effort to avoid leaving a nonviable segment of intraperitoneal intestine after repair of the hernia.

Aged↗
PubMed1975

Regeneration of the retina in the adult newt, Triturus cristatus, following surgical division of the eye by a limbal incision.

The regeneration of a retina in adult Triturus cristatus, following surgical division of the eye by a limbal incision, was studied. In agreement with recent reports, it was found that the regenerating retina is dervied from two sources; the retinal pigment epithelium and the pars ciliaris retinae. However, following a limbal incision, most of the retina appears to be derived from the retinal pigment epithelium in the posterior part of the eye. An unexpected finding of this study was that large cystlike spaces form in the fundal regions of the eye, between the regenerating retina and the retinalpigment epithelium. These spaces appear between five and eight days post-operative and persist long enough (25 to 30 days postoperative) to disrupt the fundal portion of the rengenerating retina and to cause it to lag behind the rest of the regenerate, in its development. The relationship of these observations to the genesis of positional markers in the regenerating retina is discussed.

Animals↗
PubMed1974

Hypoglycemia.

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Adult↗