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Biomedical subjects

H Levine

Publications and source records attributed to H Levine.

At least 199 records · Page 11Linked to original sources
PubMed1978

Specificity and genetic restrictions of the guinea-pig immune response to dinitrophenyl-lysyl-alanyl octapeptides.

A series of 2,4-dinitrophenyl (DNP) octapeptides containing L-lysine and L-alanine were prepared to examine the specificity and genetic restrictions of both cellular and humoral immune responses in inbred guinea-pigs. Strains 2 and 13 guinea-pigs were therefore immunized with Lys4-Ala3-Lys(DNP), Lys3Ala4-Lys(DNP), Lys2-Ala5-Lys(DNP) and Lys-Ala6-Lys(DNP). Only Lys4-Ala3-Lys(DNP) was under Ir gene control and could induce both antibody and T-cell responses in strain 2 guinea-pigs. In contrast, Lys4-Ala3-Lys(DNP) injected in strain 13 guinea-pigs and the other DNP-octapeptides injected in strain 2 or 13 guinea-pigs elicited only antibody formation and no specific T-cell mediated response. Antibody formed in the absence of specific T-cell responsiveness in either strain 2 or 13 was hapten specific and lacked the capacity to discriminate the immunizing antigen from closely related DNP-peptides. Antibody produced by animals with specific T-cell responses, on the other hand, was exquisitely specific for the immunizing peptide and could discriminate it from closely related peptides.

Alanine↗
PubMed1977

The preoperative diagnosis of hepatic metastases in cases of colorectal carcinoma.

Preoperative LDH, CPK, alkaline phosphatase and liver scan results were compared with the presence or absence of hepatic metastases at operation in 124 laparotomies in 123 patients with colorectal carcinomas during a three-year period. The overall accurcy rates for the four tests ranged from 74 to 84 per cent. The false-negative rates were acceptably low (9-13 per cent) for all but the CPK determination. The false-positive rates were unacceptably high for all four tests (38 to 60 per cent). A 'metastatic score' for reducing the high false-positive rate is described. In view of the high false-positive rates of preoperative screening tests, laparotomy is presently the most accurate method of diagnosing hepatic metastases.

Adult↗
PubMed1977

Immune ascites in the guinea pig: specificity of cells and antibody in an induced peritoneal exudate.

Strain 2 guinea pigs, immunized with Lys10-Lys(Dnp) in CFA and repeatedly injected intraperitoneally with adjuvant, developed ascites. The fluid was harvested over 8 months in total amounts up to 2 liters per animal and contained substantial amounts of cells and antibody which reacted with the immunizing antigen and related peptides. The antibody was of the IgG and IgA classes and showed restricted heterogeneity. Among synthetic Dnp-oligopeptides, both the cells, studied by antigen-stimulated thymidine incorporation, and the purified antibody, studied by fluorescence quenching, demonstrated the same specificity for the immunizing antigen as has previously been noted in lymph node cells and in serum antibody. The technique offers a means for studying more cells and more antibody than has previously been possible from individual guinea pigs.

Animals↗
PubMed1976

A method for defining competency in Pediatrics.

In 1972 the American Board of Pediatrics (ABP) initiated studies leading to a report which identifies the important components of competency needed in the practice of pediatrics. The development of the report involved a group process engaging ABP board members and examiners. The outcome has been (a) the delineation of a process for establishing definitions of competency in a medical discipline; (b) the development of a framework for specifying the abilities needed to perform the tasks required of pediatricians; (c) an elaboration of samples of pediatric subjects to which these abilities and tasks are relevant; and (d) the development of a basis for choice of methods to use for purposes of certification.

Certification↗
PubMed1976

Transport of oxygen and carbon dioxide by hemoglobin-saline solution in the red cell-free primate.

This study was undertaken to investigate the respiratory properties of hemoglobin-saline solution. Eighteen baboons were exchange transfused with either 6 per cent dextran or 6 per cent hemoglobin-saline solution. All of the hemoglobin-saline solution treated baboons survived three hours at a zero hematocrit reading. All the dextran treated animals died when the hematocrit level fell below 6 per cent. Oxygen consumption and carbon dioxide production remained unchanged from base line during the zero hematocrit interval. It is concluded that the respiratory capability of hemoglobin-saline solution is sufficient to maintain life in the absence of erythrocytes.

Animals↗
PubMed1975

Relationship of posture and age to urinary protein excretion.

The influence of posture and age on urinary protein excretion was studied in 120 normal men volunteers. The supine excretion rate was less than 140 mug/min in all but two people (median value 38 mug/min) and tended to increase with age. The excretion rate decreased on quiet standing in 80% of people, which corresponded to a fall in creatinine-clearance. In the remaining 20% protein excretion increased on standing but generally remained within normal limits and was dissociated from changes in creatinine clearances. This increase was more prevalent in younger people and may represent a phenomenon analogous to orthostatic proteinuria, differing only quantitatively.

Adolescent↗
PubMed1975

Immunologic functions of isolated human lymphocyte subpopulations. VI. Further characterization of the surface Ig negative, E rosette negative (null cell) subset.

Sephadex G-200 anti-human Fab column chromatography and rosette depletion techniques were used to isolate three distinct subpopulations of human lymphocytes: 1) T cells which are surface Ig negative and E rosette positive, 2) B cells which are surface Ig positive and E rosette negative, and 3) a "Null" cell population which is both surface Ig negative and E rosette negative. All populations were analyzed for their capacity to develop surface Ig and synthesize Ig in vitro. Greater than 50% of cells in the Null cell population developed surface Ig by day 3 of cell culture. Furthermore, in vitro, the Ig content of the Null cell population, as well as their capacity to secrete Ig in culture, becomes comparable to that produced by B cells. In contrast, cultured T cells neither develop surface Ig nor secrete Ig in culture. These data strongly support the idea that the Null population contains a subset of Ig-producing B cells.

B-Lymphocytes↗
PubMed1974

Partners in dying.

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed1971

Antigen recognition and antibody specificity. Carrier specificity and genetic control of anti-dinitrophenyl-oligolysine antibody.

The exact specifiicity of anti-DNP antibody produced by Hartley guinea pigs immunized with a series of defined alpha,DNP and epsilon,DNP-oligolysines was studied by fluorescence quenching. All responder animals made anti-DNP antibody which recognized the precise chain length, +/- 1 lysyl residue, of the DNP-oligolysines used to induce the immune response as measured by an increase in binding energy (-DeltaF degrees ) for that antigen. The ability of the immune system to detect the smallest possible change in oligolysine chain length suggests that the anti-hapten antibody-forming cell possesses a highly specific recognition system for carrier conformation. When DNP-oligolysines are incorporated in an adjuvant containing M. tuberculosis H37Rv, both responder and nonresponder produce anti-DNP antibody, but only the responder develops delayed skin sensitivity. In addition to their failure to develop delayed hypersensitivity, nonresponders produced anti-DNP oligolysine antibody which did not show the increase in -DeltaF degrees for the immunizing antigen characteristic of responder antibody. These observations support a local environment hypothesis for antigen recognition at the level of the anti-hapten antibody-forming cell and suggest that the polylysine gene exerts its control at the same cell.

Animals↗