Biomedical subjects

B Shohat

Publications and source records attributed to B Shohat.

133 records · Page 8Linked to original sources

PubMedDate not supplied

Oxidation of polyamines in human seminal plasma: a possible role in immunological infertility.

Sixty-two specimens of seminal plasma obtained from normozoospermic, oligozoospermic, azoospermic, and immunologically infertile males were investigated. The levels of spermine, basal aldehyde, and aldehyde oxidation products were measured, as was the immunosuppressive activity of seminal plasma. No immunosuppressive activity was found in the immunologically infertile group; all other groups showed immunosuppressive activity. The immunologically infertile males showed low aldehyde oxidation products.

Autoantibodies↗

PubMedDate not supplied

Lymphocyte subpopulation before and after operation in patients with benign vs malignant breast disease.

Multiple parameters of immune function were measured serially before and one and five weeks following operation in 14 patients with fibrocystic disease of the breast (Group A) and in 20 patients with stage 1-2 infiltrating duct carcinoma (Group B). These parameters included the following: WBC, total number and percentage of lymphocytes, numbers of B cells, T cells, T-active, T-helper and T-suppressor cells and the ratio between the latter as well as spontaneous suppressor or helper activity and the graft-versus-host reaction. Prior to operation no statistically significant difference was found between the two groups except for the number of T-helper cells, which was higher in Group B (p less than 0.05), and the spontaneous suppressor activity, which was higher in Group B (p less than 0.05). The finding of such a high percentage (80%) of negative graft-versus-host reactions five weeks after operation together with the high suppressor activity may indicate the presence of tumor micrometastases. The burden of surgery and general anesthesia was stronger in Group B, with a pronounced difference found between the groups (p = 0.0005), but the interaction between the influence of time (surgery and anesthesia) and the groups was not as great (p = 0.4864) and was found to be different for each group.

Breast Neoplasms↗

PubMedDate not supplied

The influence of perioperative transfusions on the immunological profile of patients with colorectal adenocarcinoma.

Seventy patients with Duke's C adenocarcinoma scheduled to undergo operation were divided into two groups, those who received no perioperative transfusion (Group I, 26 patients) and those who received an average of 2.1 units per person of packed red blood cells perioperatively (Group II, 44 patients). Immunological parameters were tested before and one and five weeks after the operation in order to determine the influence of the transfusion on these parameters as well as that of the site of the tumor, whether right colon, left colon or rectum. Comparison of the mean values obtained before operation with those obtained one week post-operatively revealed a significant change in the number of B cells (p = 0.014), with a decrease in Group I and a rise in Group II, which was seen to persist for the mean values obtained five weeks after operation. The higher rates of recurrency and lower rates of survival reported in patients who received transfusion may be related to an as yet unidentified role of B cells or a subpopulation in the immune system, manifested in the suppression of activity of those components responsible for destroying micrometastases. In relation to the site of the tumor no definite conclusions can yet be drawn as to the prognostic importance of our findings concerning the immunological parameters.

Adenocarcinoma↗

PubMedDate not supplied

Immunosuppressive activity of two plant steroidal lactones withaferin A and withanolide E.

Withaferin A and withanolide E, two steroidal lactones of plant origin were demonstrated to have specific immunosuppressive effects on human B and T lymphocytes as well as on mice thymocytes. E rosettes and EAC rosette formation by normal human T and B lymphocytes were inhibited by the two compounds at very low concentrations. The formation of mouse red blood rosettes by chronic lymphatic leukemic cells were only inhibited by withaferin A. The functional activity of normal human T lymphocytes as assessed by a local xenogeneic graft versus host reaction was also affected by these two plant steroidal lactones. These experiments demonstrate a specific action of the compound on antigen recognition as well as proliferative capacity of T lymphocytes as well as B lymphocytes.

Animals↗

PubMedDate not supplied

Immunosuppressive activity of human amniotic fluid of normal and abnormal pregnancies.

Twenty specimens of amniotic fluid (AF) obtained between week 16 and 18 of gestation from normal pregnant women and six specimens from pregnant women in which trisomia of chromosome 21 was found were tested for immunosuppressive activity. Incubation of normal human donor lymphocytes with 0.2-1 mL of AF from normal pregnant women for one hour at 37 degrees C was sufficient for induction of significant inhibition of the ability of these cells to induce a local xenogeneic graft-versus-host reaction (GVHR) as well as inhibition of E and E-active rosette formation, the GVHR being the most sensitive test. On the other hand, amniotic fluid obtained from the six pregnant women in which trisomia of chromosome 21 was found showed no inhibitory activity in either the E or E-active rosette formation, nor in the local xenogeneic graft-versus-host reaction. AF from all the women tested was found to have no effect on phenotype expression of the lymphocytes, as tested by the monoclonal antibodies OKT4+ and OKT8+, nor on B-lymphocytes, as tested by surface immunoglobulins. No correlation was found between the alpha-fetoprotein levels in the sera of those women and the immunosuppressive activity. These findings indicate that genetic defects of the conceptus are not limited to the embryo but may affect the composition of immunosuppressive components present in normal amniotic fluid.

Amniotic Fluid↗

PubMedDate not supplied

Cell-mediated immunity in uremic patients prior to and after 6 months' treatment with continuous ambulatory peritoneal dialysis.

The number of circulating T-lymphocytes and their functional activity were studied in a group of 14 uremic patients prior to and after 6 to 9 months of treatment with continuous ambulatory peritoneal dialysis (CAPD). Low absolute T cell counts were found on initial examination in five of eight patients tested. There was no change in T cell counts after CAPD. The functional activity of T cells was tested by the local xenogeneic graft vs. host reaction (GVHR). Of the 14 patients tested with this technique, 10 initially showed impaired T cell functional activity. After CAPD a clear improvement in functional activity of the T cells was found in 4 of 10 patients with impaired GVHR. In three of these four patients, an inhibitory factor that had been present in the serum disappeared after CAPD.

Aged↗

PubMedDate not supplied

Effect of UVB and AS101 on interleukin-2 production and helper activity in psoriatic patients.

Peripheral blood lymphocytes were obtained from eight untreated patients suffering from long-standing plaque-type psoriasis 1 h following UVB treatment and at the end of 15 UVB treatments. Before treatment and following in vivo treatment with 0.01-0.3 J/cm2, the patients' lymphocytes were tested for interleukin-2 (IL-2) production, and helper activity with and without addition of the immunomodulator AS101. AS101 is a synthetic organotellurium compound, ammonium trichloro-(O,O'-dioxyethylene) tellurate. UVB at a flow of 0.01 J/cm2 did not affect any of these functions. However, after 15 UVB treatments, when the dose given had reached 0.3 J/cm2, a complete inhibition of IL-2 production and helper activity was observed. In vitro addition of AS101 at 0.1 micrograms/ml to the in vivo UVB-treated lymphocytes raised IL-2 production to approximately double the initial level, and improved the helper activity of CD4 cells.

Adjuvants, Immunologic↗