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Biomedical subjects

D Bernstein

Publications and source records attributed to D Bernstein.

At least 181 records · Page 10Linked to original sources
PubMed1978

Effects of acute alcohol administration on reproductive endocrinology in the male rat.

The results of the current studies further document that acute alcohol administration markedly disrupts the function of the HPG in the male. Our results indicate that alcohol depresses serum testosterone levels and, thereby, produces clinical symptoms associated with hypoandrogenization. Moreover, our studies suggest that acute alcohol administration also affects the hypothalamic-pituitary axis by reducing serum LH levels--an effect that may represent the primary action of alcohol on the HPG.

Animals↗
PubMed1978

Lateral ventral (spigelian) hernias in infants and children.

Lateral ventral hernias are found in the spigelian fascia lateral to the junction of the arcuate and semilunar lines and below the level of the umbilicus. Three cases are reported in infants and children. Diagnosis depends on finding an unusual mass on the anterior abdominal wall and palpation of the rim of the hernia defect upon reduction of the mass. A spigelian hernia may be misdiagnosed easily if the examiner is unaware that it can occur in childhood. The edge of the defect must be outlined while the child is straining, prior to induction of anesthesia, as the rim may be difficult to find when the patient is asleep.

Abdominal Muscles↗
PubMed1975

Use of radioimmunoassays to determine the concentration of streptococcal group-specific antibodies in rabbit antisera.

A radioimmunoassay was developed for the quantitation of antibodies to the Group A, A-variant, and C carbohydrates in rabbit streptococcal antisera. The assay employs radiolabeled purified Group carbohydrate which has been tyrosylated to allow for incorporation of 125-I. This assay has an advantage over the intitative precipitin test because it measures non-precipitating antibody in addition to precipitating antibody. Furthermore, 7S anti-IgG in rabbit antisera give a falsely elevated value for the antibody concentration in the quantitative precipitin test. This did not occur with the radioimmunoassay. The assay described is reproducible, sensitive, and uses little antisera.

Adsorption↗
PubMed1975

A radioactive hapten-binding assay for measuring antibodies to the pentapeptide determinant of peptidoglycan.

A major portion of the humoral immune response to peptidoglycans is directed against the non-cross-linked pentapeptide side chains of these ubiquitous bacterial antigens. At present, no specific and sensitive assay for pentapeptide antibody determination is available. Therefore, a radioimmunoassay has been developed which employs the synthetic pentapeptide hapten L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala, labeled by the active ester method of Bolton and Hunter to high specific activities (6.74 to 18.18 muCi/mug) with 125I, and used as a reagent for measuring pentapeptide antibody. A-variant streptococcal antisera, known to contain pentapeptide antibodies as shown by quantitative precipitation, would bind more than 95% of the radiolabeled hapten in contrast to 2 to 3% by preimmune rabbit sera. Specificity of the binding reaction was demonstrated by inhibition experiments imploying various synthetic oligopeptides related or unrelated to the pentapeptide in the radioimmunoassay. Binding curves established with serial dilutions of peptidoglycan antiserum were linear from 15 to 500 mug/ml of antibody permitting pentapeptide antibody measurement within this range. Comparative data on pentapeptide antibody determinations by quantitative precipitation and radioimmunoassay are given and the time course of the production of this antibody in 14 rabbits hyperimmunized with A-variant streptococcal vaccine is reported.

Ammonium Sulfate↗
PubMed1975

Measurement of peptidoglycan antibodies by a radioimmunoassay.

Staphylococcus epidermidis peptidoglycans solubilized by sonication or lysozyme digestion, and synthetic peptidoglycan analogs such as HSA-carboxymethyl-Gly-L-Ala-L-Ala-D-Ala-D-Ala (HSA-pentapeptide) or L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala (pentapeptide) have been labeled with 125I and tested for their applicability in the radioactive antigen binding assay. Use of radioiodinated Staph. epidermidis peptidoglycans was found to be considerably impeded by the presence of at least 2 different antigenic sites on such molecules, the pentapeptide and the glycan determinant. Application of labeled HSA-pentapeptide was limited by the necessity to use PEG for precipitation of Ag-Ab-complexes and by short linear potions of binding curves. However, the synthetic pentapeptide hapten, radioiodinated by the active ester method of BOLTON and HUNTER, proved to be a most useful regent for the selective measurement of pentapeptide antibody. Inhibition studies indicated that the immunological specificity of the labeled hapten was retained. Pentapeptide binding curves were linear from 15-500 g/ml of antibody. Generally, there was good agreement between pentapeptide antibody concentrations measured by radioimmunoassay and quantitative precipitation.

Antibodies↗
PubMed1973

Homogenous rabbit 7S anti-IgG with antibody specificity for peptidoglycan.

The relationship between 7S anti-IgG and antibodies to streptococcal cell wall peptidoglycan was examined for four streptococcal Group C antisera. Homogeneous 7S anti-IgG components in these sera were isolated by means of an IgG immunoadsorbent column. For two of the four antisera, the anti-peptidoglycan activity of the 7S anti-IgG had specificity for the pentapeptide, L-Ala-D-Glu-gamma-L-Lys-D-Ala-D-Ala, the antigenic determinant of peptidoglycan, as well as for the Fc of IgG. Detailed studies on the 7S anti-IgG from one of the antisera revealed that the pentapeptide inhibited the coprecipitation reaction of 7S anti-IgG R3387 with antigen-antibody complexes and the precipitin reaction between 7S anti-IgG R3387 and its anti-idiotype serum.

Animals↗
PubMed1973

Isolation and immunochemical characterization of rabbit 7S anti-IgG with restricted heterogeneity.

7S anti-IgGs were isolated from four rabbit antistreptococcal antisera by the use of immunoabsorbent columns. The isolated proteins were of restricted molecular heterogeneity; they formed a monodisperse band on microzone electrophoresis and had a limited number of light chain bands when analyzed on urea polyacrylamide gel. The binding site of the 7S anti-IgGs was detected in the F(ab')(2) portion of the molecule. The binding site has antibody specificity for the Fc portion of IgG. For one 7S anti-IgG the combining site on the Fc portion could further be defined. A pepsin fragment of Fc, described as Pep-III', was a potent inhibitor of the coprecipitation of 7S anti-IgG with antigen-antibody complexes. An idiotypic cross-reaction was detected between the 7S and 19S anti-IgGs isolated from the same rabbit with anti-idiotype sera prepared in guinea pigs. This idiotypic specificity was not detected in the 7S anti-IgGs of 20 other rabbits.

Animals↗
PubMed1972

Occurrence of 19S and 7S anti-IgGs during hyperimmunization of rabbits with streptococci.

All 110 rabbits immunized with Group A, A-variant, and C streptococcal vaccines produced 19S anti-IgG in addition to antibodies to the streptococcal carbohydrates. 19S anti-IgG was detected by hemagglutination of rabbit red blood cells coated with rabbit anti-blood group F antibody. Antisera of 88 of these animals were also tested for 7S anti-IgG with a coprecipitation assay. This assay is based on the coprecipitation of 7S anti-IgG with complexes of streptococcal carbohydrate and anti-carbohydrate antibody. 50 of the 88 anti-Group C streptococcal antisera contained 7S anti-IgGs. In eight antisera the concentration was greater than 5 mg/ml. The data suggest a genetic influence on the occurrence of 7S anti-IgG. The eight rabbits which produced more than 5 mg/ml of 7S anti-IgG belonged to three related families. Moreover, there were families in which almost every member produced 7S anti-IgG and other families in which only 30% of the members manufactured 7S anti-IgG. The streptococcal vaccine was an especially efficient stimulus for the production of 19S anti-IgG, whereas the pneumococcal vaccine was much less effective in this respect. Furthermore, 7S anti-IgGs were not detected in antipneumococcal antisera, although the concentration of anti-capsular antibodies was similar to that of anti-carbohydrate antibodies in antistreptococcal antisera.

Animals↗