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Biomedical subjects

E Benjamini

Publications and source records attributed to E Benjamini.

At least 55 records · Page 3Linked to original sources
PubMed1979

Mechanisms of resistance to infection with Coccidioides immitis in mice.

Serum from vaccinated mice was ineffective in neutralizing the infectivity of arthrospores of Coccidioides immitis for recipient mice. However, a T-cell-enriched lymphocyte population was effective in preventing a lethal infection. Spleen cells from immune mice were passaged through nylon wool columns resulting in a T-cell enriched, B-cell-depleted population as shown by the susceptibility of the cell population to anti-theta serum and the inability of the cells to transfer adoptively an immune response to ovalbumin. Whereas transfer of 5 x 10(7) unfractionated immune spleen cells was required to protect 100% of the recipients against a lethal infection with C. immitis, 7 x 10(6) T-cell-enriched immune spleen cells were sufficient for the same level of protection. Thus, transfer of resistance to infection was achieved with fewer cells after the removal of B cells from the transferred spleen cells. The results confirm that T cells are crucial in transferring resistance against infection with C. immitis in mice.

Animals↗
PubMed1978

Pharmacokinetics of fentanyl as determined by radioimmunoassay.

The pharmacokinetics of fentanyl were determined in human surgical patients using radioimmunoassay. Fentanyl was measured in the serum, cerebrospinal fluid (CSF), and urine of patients receiving 0.1, 0.5, or 1.0 mg/m2 of fentanyl intravenously. The kinetics of the disappearance of fentanyl from the serum were very similar at the three administered doses. At all doses, levels fell rapidly in the first five minutes to approximately 20% of the peak value. Thereafter, serum levels fell more slowly with an observed half-life (t 1/2) of approximately 10 to 20 min. depending on dose. By 2 hr serum levels had stabilized at low values (1, 5, and 8 ng/ml) and continued to decrease very slowly thereafter, with an observed t 1/2 of 1 to 2 hr at the low dose (0.1 mg/m2) and greater than 4 hr at 0.5 and 1.0 mg/m2. The serum elimination curves were dissected and described mathematically in terms of a three-compartment model. Urinary excretion of fentanyl accounted for 15% to 20% of the administered dose. Urinary excretion was very low during the first 2 hr, suggesting that this route of elimination is not important in terminating the actions of fentanyl in man. Fentanyl levels in the CSF of patients given terminating the actions of fentanyl in man. Fentanyl levels in the CSF of patients given the high dose (1 mg/m2) were low, and never exceeded 4 ng/ml. Peak levels of fentanyl in the CSF were not seen until at least 15 min after administration.

Adult↗
PubMed1978

Recognition of lysozyme by lymphocyte subsets.

Extensive studies with antisera from a variety of animals have failed to detect any cross-reactivity between egg white lysozyme and its reduced, S-carboxymethylated (CM-) derivative. In contrast, a number of studies addressing the specificity of T lymphocytes have revealed that these two forms of lysozyme cross-react rather extensively at that level. Preliminary attempts to eliminate this latter cross-reactivity by further denaturation and/or chemical modification have so far proven unsuccessful. In a second line of experimentation the response to CM-lysozyme of mice which are genetically unresponsive to native lysozyme was assessed and found deficient. The implications of these findings are discussed.

Animals↗
PubMed1978

Immunochemical studies on the tobacco mosaic virus protein.

The decapeptide having the amino acid sequence Thr-Thr-Ala-Glu-Thr-Leu-Asp-Ala-Thr-Arg has been shown to be a major antigenic determinant of the tobacco mosaic virus protein in rabbits, mice and guinea pigs. The antigenic specificity of the decapeptide is attributed to its C-terminal tripeptide Ala-Thr-Arg. Although this tripeptide has no demonstrable binding with antibodies to the protein, its N-octanoylated derivative exhibits specific binding with antibodies as well as the capacity to elicit delayed skin reactions in guinea pigs immunized with the protein. The latter results suggest that both B cells and T cells have antigen receptors of identical specificities. Although all mouse strains tested responded equally to TMVP, with the production of anti-protein, the response to the decapeptide was shown to be correlated (albeit not absolutely) with Ig allotype Iga exhibiting generally high responsiveness while Igb exhibiting generally low responsiveness. The low responsiveness could not be attributed to suppression of the secondary immune response.

Amino Acid Sequence↗
PubMed1977

Chemoimmunotherapy for canine lymphosarcoma.

A total of 157 dogs with lymphosarcoma were available for study; 67 were treated. All of the treated dogs were given 4 drug combinations and 20 of them also were given autogenous vaccine. Sixty (90%) of the dogs treated with multiple drugs improved clinically. Of the dogs with clinical improvement, 48 (80%) had either complete or partial remission; of these, 32 (67%) had complete remission. Clinical staging proved useful in increasing the accuracy of prognosis, whereby dogs in less advanced stages of disease responded better to therapy, with a higher percentage of complete clinical remissions and longer survival. The mean survival time of the 47 dogs treated with drugs alone was 138 days, which compared with a mean survival time of 30 days for 34 nontreated dogs. Dogs subjected to chemotherapy and immunotherapy had a mean survival time of 341 days. Dogs in complete remission at time of vaccination survived significantly (P less than 0.01) longer than did dogs treated with drugs and vaccinated while not incomplete remission.

Animals↗
PubMed1977

Antibody-dependent cell-mediated cytotoxicity in treated and nontreated cancer patients.

Antibody-dependent cell-mediated cytotoxicity (ADCC) exhibited by peripheral blood leukocytes was used as a criterion for assessing immune competence of groups of noncancerous individuals and of treated and untreated cancer patients. The results show that, as a group, leukocytes of nontreated cancer patients exhibited significantly lower ADCC than that exhibited by leukocytes of noncancerous individuals. However, the ADCC of leukocytes from cancer patients under treatment approximated that of normals. Thus, using ADCC as criterion, the results indicate that as a group, cancer patients under treatment tend to exhibit restored immune competence.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1977

Significance of T cells in resistance to experimental murine coccidioidomycosis.

The resistance of mice to coccidioidomycosis was found to be dependent on lymphoid cells. Thus, spleen cells from mice immunized with killed spherules of Coccidioides immitis, when transferred to irradiated (500 R) recipients, conferred upon the recipient mice resistance to infection with C. immitis. Prior incubation of these spleen cells with anti-theta serum in the presence of complement abrogated their capacity to protect the recipients from infection with C. immitis. Adult thymectomized mice, which had been irradiated (800 R) and reconstituted with bone marrow from normal mice, were more susceptible to infection with arthrospores than were nonthymectomized, irradiated bone marrow-reconstituted controls. Genetically homozygous athymic ("nude") mice died after infection with a dose of arthrospores that was sublethal for their heterozygote counterparts possessing a thymus, or for normal mice. The results indicate that a functioning T-cell population is an essential component for effective immunity to C. immitis.

Animals↗
PubMed1977

Opiate tolerance: independence from immunological mechanisms.

The possibility that immunological mechanisms are involved in the development of tolerance to the analgesic effect of morphine was investigated, focusing on several immunological parameters. The data indicate that transfer of spleen cells and bone marrow cells obtained from morphine-tolerant donors into nontolerant syngeneic recipient mice did not result in the transfer of tolerance to the analgesic activity of morphine. Furthermore, the data indicate that the thymus, which is essential for the immunological response to many antigens, was not involved in the induction of tolerance to the opiate since tolerance was induced in thymectomized mice as well as in genetically athymic mice. The results suggest that immunological factors do not seem to play a crucial role in the phenomenon of tolerance to the analgesic activity of morphine.

Analgesics↗
PubMed1977

Immunity to lymphoid tumors in syngeneic mice by immunization with mitomycin C-treated cells.

Immunization of mice with syngeneic mitomycin C-treated lymphoid tumor cells (EL-4 and S49A) conferred a high degree of immunity to transplantation with viable tumor cells in syngeneic animals. The development of this immunity was paralleled by the development of specific cell-mediated cytotoxicity; no anti-tumor antibodies could be detected in the immunized animals. In contrast to the high immunoprophylactic capacity of mitomycin C-treated cells, attempts to utilize these cells for immunotherapy were unsuccessful. Preliminary experiments did not reveal antigenic differences between mitomycin C-treated and untreated tumor cells.

Animals↗
PubMed1976

Synthetic hexapeptide substrates and inhibitors of 3':5'-cyclic AMP-dependent protein kinase.

The substrate specificity of the catalytic subunit of rabbit skeletal muscle 3': 5'-cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP: protein phosphotransferase) has been studied using the synthetic peptide Arg-Gly-Tyr-Ser-Leu-Gly corresponding to the sequence around serine 24, a phosphorylation site in reduced, carboxymethylated, maleylated (RCMM) chicken egg white lysozyme. This peptide served as a substrate for the enzyme and exhibited a 6-fold higher Vmax and a 100-fold higher Km than RCMM-lysozyme. Replacement of the arginine with glycine, histidine, or lysine resulted in a dramatic reduction in the Vmax. These results support the concept that arginine is an important residue in determining the substrate specificity of the protein kinase, predominantly influencing the Vmax of the phosphorylation reaction. Two synthetic peptides in which serine was replaced by an alanine acted as competitive inhibitors of phosphorylation of the synthetic peptide substrate and RCMM-lysozyme.

Amino Acid Sequence↗
PubMed1976

In vitro hemolysis of autologous erythrocytes caused by immune murine spleen cells and spherules of the fungus Coccidioides immitis.

This communication describes an in vitro system wherein mouse erythrocytes are lysed in the presence of spherules of the fungus Coccidioides immitis and spleen cells from syngeneic mice immunized with a variety of antigens. The antigens include: tobacco mosaic virus in complete Freund's adjuvant (CFA), CFA alone, separate components of CFA, sheep erythrocytes, and allogeneic tumor. Spleen cells from mice sublethally infected with C. immitis are also capable of participating in this response. The lytic phenomenon, which does not require complement, is dependent upon the number of spleen cells per culture, the number of spherules per culture, the time of culture incubation, the amount of antigen injected into the animal and the time after immunization at which spleen cells are recovered. Live spherules or spherules killed with heat, with dimethylsulfoxide, or with formalin were effective participants, together with immune spleen cells, in the lytic reaction.

Animals↗