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Biomedical subjects

Z Bentwich

Publications and source records attributed to Z Bentwich.

175 records · Page 10Linked to original sources
PubMedDate not supplied

Peripheral blood T and B lymphocyte subpopulations in Bell's palsy.

A prospective clinical, virological and immunological study was performed on 25 consecutive Bell's palsy (BP) patients. Multiple cranial nerve involvement was found in 15 patients. A significant decrease in the peripheral blood T lymphocyte percentage as well as an increase in B lymphocyte percentage (p less than 0.001) were found in 13 of the BP patients during the first 24 days from the clinical onset of the paralysis. No correlation was found between the peripheral blood lymphocyte subpopulations and the patient's age, sex, degree of paralysis or recovery rate. No changes were detected in the levels of immunoglobulins (IgG, IgM), complement (C3, C4) and antiviral antibodies to herpes simplex and zoster, EBV, cytomegalic virus, adenovirus, influenza and mumps. The clinical and immunological data of BP show a similar pattern to those of Guillain-Barre syndrome suggesting that BP may be an antoimmune demyelinating cranial polyneuritis which may be caused by a preceding viral infection.

Adolescent↗
PubMedDate not supplied

Increased CCR5 expression with decreased beta chemokine secretion in Ethiopians: relevance to AIDS in Africa.

OBJECTIVE: This study was undertaken to determine the contribution of HIV co-receptors and beta chemokine secretion to the increased susceptibility for human immunodeficiency virus (HIV) infection of peripheral blood mononuclear cells (PBMC) obtained from HIV-seronegative Ethiopian immigrants in Israel (ETH). STUDY DESIGN: Immune activation markers and HIV co-receptor expression on lymphocytes and monocytes, and beta chemokine secretion by CD8+ cells, were compared between ETH and non-Ethiopian Israeli (IS) HIV-negative individuals. RESULTS: The percentage of lymphocytes and monocytes expressing CCR5 was 1.6 and 3.0 times higher in ETH (n = 83) than in IS (n = 45), respectively (P < .001), whereas RANTES and MIP-1alpha secretion was 0.5 and 0.7 times lower (P < .01 and P < .05). The percentage of CCR5-expressing cells and RANTES secretion were inversely correlated (r = -0.7; P < .002). No differences were found in the proportion of CXCR4-expressing cells. No correlation between CCR5 expression and cell activation profile in the whole ETH population was found. However, in highly activated individuals (HLA-DR/CD3 > 7%), a significant decrease in CCR5 expression was observed. CONCLUSIONS: An increased proportion of CCR5-expressing cells with decreased beta chemokine secretion observed in ETH may account for the increased susceptibility to HIV infection of cells obtained from this group. These findings may partly explain the higher susceptibility for HIV infection in Africa and thus the rapid spread of acquired immunodeficiency syndrome (AIDS) in that continent.

Chemokine CCL3↗
PubMedDate not supplied

Surface markers and other characteristics of the lymphocyte in chronic lymphocytic leukemia.

The vast majority of leukemic cells bear surface Ig. The class restriction of this surface Ig and other characteristics described for chronic lymphocytic leukemia (CLL) are considered as evidence for the monoclonality of the neoplastic proliferation. Different CLL cases with various expressions of surface Ig represent various degrees of block in the maturation of the lymphocytes. Through the use of other cell markers, it has been shown that most cases of CLL represent B cell neoplasia. Variations in the expression of the various B cell markers on the leukemic cells were observed. One case in which the leukemic cells were clearly T cell in character, and a single case of mixed B and T CLL, are described. The significance of the sheep red blood cell rosette-forming cells in CLL is discussed. Scanning electron microscopy (SEM) can be a useful adjunct to the identification of B- and T-derived lymphocytes. According to these criteria, leukemic cells are mostly of the B type, although variations in their surface architecture were noted. It is concluded that SEM alone cannot consistently distinguish between leukemic B and T cells. Electron microscope studies of mitogen-transformed CLL lymphocytes suggest that there is a residual normal B and T population of cells in addition to the predominant, abnormally reacting cells, which are mostly of B origin. Antigenic changes on the surface of CLL lymphocytes are suggestive of normal antigens present on young normal lymphocytes, rather than of the emergence of truly "tumor-specific" antigens. These antigens are independent of the T or B origin of the leukemia. CLL lymphocytes are shown to be defective in their ability to form caps with concanavalin A and anti-HL-A sera, and in their osmotic regulatory capacity.

B-Lymphocytes↗
PubMedDate not supplied

[Antiviral strategies in the replication of human immunodeficiency virus].

The replication cycle of any virus involves a number of steps, beginning with specific attachment to a cell surface receptor leading eventually to production of progeny viruses by infected cells. In the case of the immunodeficiency virus type-1 (HIV-1), the first step involves a specific interaction between the gp120 viral envelope surface protein and specific CD4 receptor sites at the cell surface. This is followed by penetration of the virus into cells and the formation of proviral double-stranded DNA from single-stranded viral RNA, a process mediated through the action of the viral enzyme called reverse transcriptase. This, in turn, leads to the migration of proviral DNA into the nucleus of the cell and the integration of such DNA within the host cell genome. Finally both viral RNA and viral proteins are produced by the cell's genetic apparatus and new viruses are assembled at the cell surface. The fact that integration of viral DNA into host cell chromosomes occurs means that any cellular replication event will be accompanied by replication of viral DNA. Each of these steps represents a potential target for anti-viral chemotherapy. To date, most efforts to treat HIV-associated disease have focused on the reverse transcription step. In this respect, zidovudine (AZT) has been the most widely used anti-viral drug studied. However, the relative toxicity and lack of efficiency of this drug means that our efforts to develop new therapeutic strategies to combat HIV infection must continue.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Systemic lupus erythematosus in 49 Israeli males: a retrospective study.

Forty-nine male SLE patients, diagnosed and followed in seven medical centers in Israel between 1954 and 1983, were studied and analyzed retrospectively in order to determine whether the disease in males was clinically different from that reported in females both in Israel and in the world literature. The primary clinical and laboratory manifestations, the severity of the disease at the onset or at any time during the course of the disease, and the 1-15 year survival rates were not different from those described before in female SLE, although neurological involvement, nephritis, thrombocytopenia, vasculitis and hepatosplenomegaly were more prevalent in our series. However, more than half of the male patients (53%) had a benign course of disease characterized by long remissions requiring minimal or no medication. Long-term remission of serious renal involvement was observed completely in 14 and partially in 5 out of 33 patients. These results suggest that the male sex might alter the clinical course of SLE.

Adolescent↗
PubMedDate not supplied

The isolation of colon cancer organ specific neoantigen by the use of the leukocyte adherence inhibition assay and monoclonal antibodies.

The LAI reactivity of a colon organ specific neoantigen (OSN) was recovered from the urine of advanced colon cancer patients. In this study three physico-chemical steps were employed; precipitation by 80% ammonium sulfate, ion exchange, and molecular sieve chromatography. Each isolate was tested for activity and specificity by the direct tube leukocyte adherence inhibition (LAI) assay employing leukocytes from colon and breast cancer patients. The OSN enriched isolate was then used to generate monoclonal antibodies (Mab). Hybridomas were screened by ELISA. One hybridoma designated Bac 18.1 reacted preferentially with colon OSN and not with the urine from normals or patients with breast cancer. Affinity purification of colon OSN was achieved and it was shown to consist of a single band in SDS-PAGE with an apparent molecular weight of 30,000. The eluted polypeptide was specifically reactive in ELISA as well as in the LAI assay.

Antibodies, Monoclonal↗
PubMedDate not supplied

Antigen-specific human T-cell factors: T-cell helper and suppressor factors, immunochemical aspects.

Some immunochemical characteristics of a T-cell-derived ovalbumin (OA) antigen-specific helper (ThF120-OA) and a corresponding OA-specific suppressor effector factor (TsF120-OA) are described. These immunoregulatory molecules are retained by columns containing either the insolubilized antigen OA or the lectin ConA, or antibodies specific for the VH-region of immunoglobulins, for the beta 2-microglobulin or for Ia-framework determinants. Neither the helper factor nor the suppressor factor showed affinity for antisera specific for immunoglobulin isotypes. In search of a constant-region-like structure in factor molecules, antisera were raised in rabbits using ThF120-OA and TsF120-OA. The results show that antisera raised against ThF120-OA recognize one or more determinants of different antigenic specificities common to human ThF. This common structure is not species-specific since it is also recognized by rabbit antisera to mouse helper factor. It is absent, however, on human TsF120-OA. In the same way, human TsF120-OA was shown to interact with rabbit antisera to human (or murine) suppressor factors of different antigenic specificities, but not with anti-ThF.

Animals↗