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Biomedical subjects

S Argov

Publications and source records attributed to S Argov.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Radical ambulatory hemorrhoidectomy].

Internal hemorrhoids is one of the most common diseases, affecting about 4% in western populations. Treatments include coagulation, freezing, rubber-band ligation, and sclerosing agents, which indicates that there is no ideal method. Surgical hemorrhoidectomy is considered radical as it usually involves general or regional anesthesia and hospitalization for 1-2 days. 1519 hemorrhoidectomies were performed by the author in 17 years, all under local anesthesia on an ambulatory basis. With this method hemorrhoidectomy can be relatively simple and inexpensive.

Adult↗
PubMed1994

Human peritoneal mesothelial cells synthesize IL-1 alpha and beta.

We studied the ability of human peritoneal mesothelial cells (HPMC) to produce the major pro-inflammatory cytokines interleukin-1 alpha (IL-1 alpha) and -beta when stimulated by lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF alpha) or IL-1 alpha, or combinations of these three factors. Biological activity of IL-1 was measured by bioassay, and levels of IL-1 alpha and beta were determined using specific radioimmunoassays. We found that HPMC are capable of secreting IL-1 alpha and -beta in response to stimulation by these substances, but stimulation with a combination of LPS + TNF alpha, LPS + IL-1 alpha, or TNF alpha + IL-1 alpha, had a marked synergistic effect on cytokine production. A combination of all three substances together had a significantly enhanced synergistic effect. Using reverse transcription PCR, we found a peak in IL-1 alpha and beta mRNA levels three hours after stimulation. We found that LPS, TNF alpha and IL-1 alpha alone, or in combination, caused an increase in IL-1 alpha and -beta mRNA levels. Cycloheximide and actinomycin D blocked the production of IL-1 alpha and -beta protein, showing that de novo production of IL-1 or synthesis of mRNA stabilizing proteins are needed after stimulation. We thus conclude that HPMC play an important role in the amplification of the initial peritoneal inflammatory response which originates in the peritoneal macrophages, and these findings are of importance in understanding the peritoneal response to infection in continuous ambulatory peritoneal dialysis (CAPD) patients.

Base Sequence↗
PubMed1994

Gamma/delta T-cell lymphoma involving the subcutaneous tissue and associated with a hemophagocytic syndrome.

A case of gamma/delta-positive T-cell lymphoma localized primarily in the subcutaneous adipose tissue and associated with an extensive hemophagocytic syndrome and a rapid, fatal outcome is presented. Previous reports of gamma/delta cutaneous and subcutaneous T-cell lymphomas are reviewed. To define the characteristics of a T-cell subset of neoplastic cells bearing the gamma/delta receptor in a subcutaneous lymphoma, we undertook clinical and laboratory examinations, morphological evaluation of biopsies, electron microscopy, and extensive immunohistochemical studies. Immunohistochemical studies showed that the neoplastic cells expressed the gamma/delta T-cell receptor (CD3+, C gamma M1+) and were CD2+, CD43+, CD45+, CD45RO+, PCNA+, but were beta F1-, CD1-, CD4-, CD8-, CD15-, CD20-, CD25-, CD30-, CD45R-, CD57-, CD68-, Mac 387-, and HLA Dr-. To the best of our knowledge, this is the first report of a subcutaneous T-cell lymphoma of gamma/delta type involving the subcutaneous tissue and associated with a hemophagocytic syndrome.

Adipose Tissue↗
PubMed1991

Autoantibodies in male homosexuals and HIV infection.

We have used ELISA to study the frequency of autoantibodies to several antigens in the serum of 17 male homosexuals (MHS) negative for HIV (HIV-), 11 asymptomatic HIV seropositive MHS (HIV+) and patients with ARC (N = 15) or AIDS (N = 13), and compared them to 20 matched healthy heterosexual controls. Serum antibody binding to histones, cardiolipin, ss-A, ss-B and Sm was found to be significantly higher in each of the MHS groups studied as compared to controls (P less than 0.001), and was also increased in the HIV+ patients vs. the HIV- group (P less than 0.05). In contrast, no increase in autoantibodies to ss-DNA, ds-DNA, poly(I), poly(G) or RNP were found in any of the groups tested. These results enlarge the spectrum of autoimmunity previously reported in HIV infection and identify a similar pattern to a lesser degree, already present in HIV- MHS, suggesting a role for HIV or concomitant virus infections in its pathogenesis.

AIDS-Related Complex↗
PubMed1990

Burkitt's lymphoma of the tonsil.

A case of Burkitt's lymphoma involving the tonsil in a 10-year-old Bedouin boy, is presented. The biological behaviour and the clinical presentation of this unusual neoplasm are discussed and the English language literature is reviewed. The diagnosis was made by histological examination, electron microscopy and confirmed by immunohistochemistry. The patient showed an excellent symptomatic response to surgery and chemotherapy.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

The detection of anti-Sm-RNP activity in sera of patients with monoclonal gammopathies.

The sera of 141 patients with monoclonal gammopathies were examined for the presence of anti-RNP and anti-Sm activities. An enzyme-linked immunosorbent assay (ELISA) was employed. Thirty-two sera were found to bind RNP while 16 bound to Sm. The anti-Sm and anti-RNP antibodies were found in sera of patients with IgG, IgM and IgA gammopathies. The activity against RNP and/or Sm was confirmed further by using purified immunoglobulins, employing competition assays and immunoblotting. Anti-Sm antibodies are regarded as being highly specific for SLE, yet none of the patients whose serum was found to contain high titres of anti-Sm/anti-RNP antibodies presented with symptoms related to SLE or other rheumatic diseases. Our results of a high incidence of anti-ribonucleoproteins activity in the serum of patients with monoclonal gammopathies support previous reports of autoantibody properties characteristic of these immunoglobulins.

Antibodies, Antinuclear↗
PubMed1989

Autoantibody production by patients infected with Leishmania.

Sera from 29 patients with visceral leishmaniasis and 14 patients with cutaneous leishmaniasis were tested against a panel of nine nuclear antigens employing an enzyme-linked immunosorbent assay (ELISA). Anti- Sm, RNP, SS-A and SS-B antibodies were present in high titres in 83, 86, 36 and 73 per cent of the patients with visceral leishmaniasis and in 7, 14, 25 and 25 per cent of the patients with cutaneous leishmaniasis. One serum from a patient with visceral leishmaniasis which reacted strongly with Sm, RNP, SS-A and SS-B was examined by immunoblotting on extractable nuclear antigen from Hela cells. This serum binds to nine different antigenic bands (16, 23, 29, 30, 40, 50, 58, 100 and 115 kD). These same antigens were recognized by serum from a patient with systemic lupus erythematosus. The binding of visceral leishmaniasis serum antibodies to ribonucleoproteins was inhibited by prior incubation of serum with either leishmanial membrane antigens, from four different species of Leishmania, or intact cells of Leishmania donovani, implying molecular resemblance between common leishmanial antigens and ribonuclear antigens. It seems that appearance of autoantibodies to ribonucleoproteins in sera of patients infected with Leishmania is not only due to simply polyclonal activation of lymphocytes, but is also the result of a molecular mimicry between leishmanial antigens and ribonucleoproteins.

Antibodies, Antinuclear↗
PubMed1988

Naturally-occurring tumor-reactive autoantibodies: a monoclonal antibody from normal mice reacts with tumor cells and with DNA.

A natural IgM monoclonal antibody, 1.67, was generated from apparently healthy unstimulated BALB/c mice. This antibody reacted with L5178Y murine T cell lymphoma, with human Raji cells, and with several normal cells. Further analysis of its ligand binding capacity disclosed strong binding to single-stranded DNA (ssDNA). However, this naturally-occurring monoclonal antibody binds to different epitopes on cell membranes and on DNA than another anti-DNA monoclonal antibody (18/103/1) from human origin. This conclusion was based on competition assays. Furthermore, NOA 1.67 lacks the 16/6 idiotype expressed on the 18/103/1 antibody. The 16/6 idiotype is shared by human and mouse lupus monoclonal autoantibodies that bind simultaneously to lymphoid cells and DNA. This is a first report on a natural autoantibody that binds to malignant and to normal cell membrane(s) as well as to ssDNA. It may have regulatory functions controlling malignancy and or autoimmunity.

Animals↗
PubMed1988

A human monoclonal anti-DNA antibody derived from a patient with polymyositis having the common lupus 16/6 idiotype.

A human IgM monoclonal antibody (Pol-1, SA-1) was generated by the human hybridoma technique from the peripheral blood lymphocytes (PBL) of a patient with active polymyositis. The antibody was found to bind to ssDNA, dsDNA, poly(I) and poly(G) and to carry the common lupus anti-DNA antibody idiotype (16/6 Id). Another human IgM monoclonal antibody (Pol-2, SA-2) produced by similar methods from the PBL of the same patient while in remission lacked the ligand-binding capacities of Pol-1 SA-1 and did not have the 16/6 Id. Analyses of 19 sera samples from patients with polymyositis showed no antinuclear antibodies, excluding a 40% prevalence of the 16/6 Id. The serum of the patient whose lymphocytes were employed to generate the hybridoma was negative for anti-DNA activity as well as for the 16/6 Id. This study suggests that the hybridoma technique may enable expression of dormant idiotypic affinities which do not normally appear in sera.

Antibodies, Antinuclear↗
PubMed1987

Inhibition of human natural killer cell activity by a synthetic peptide homologous to a conserved region in the retroviral protein, p15E.

It has been shown previously that the retroviral envelope protein p15E suppresses certain monocyte and lymphocyte functions. In this paper, we describe the effects on natural killer (NK) activity of a synthetic peptide (CKS-17) with homology to a region of p15E conserved among numerous retroviruses. Enriched human NK cells were assayed against K562 tumor target cells in a 51Cr-release cytotoxicity assay. Pretreatment of NK cells with CKS-17 at concentrations as low as 1.5 microM, but not with equivalent concentrations of control materials, markedly and reproducibly suppressed NK lytic activity. Prior exposure of NK cells to interferon-alpha (IFN-alpha) at 1000 U/ml did not alter their sensitivity to CKS-17-induced inhibition. Pretreating NK cells with CKS-17 almost entirely diminished their responsiveness to IFN-alpha and IFN-gamma, but not to interleukin 2 (IL 2). Kinetics experiments demonstrated that CKS-17-mediated suppression of both endogenous and activated NK cells was reversible after 18 hr at 37 degrees C. Experiments designed to examine the CKS-17 mechanism of action revealed that the peptide bound to all Leu-11+ lymphocytes, as shown by two-color flow cytometry. CKS-17 did not, however, inhibit effector cell/target cell conjugate formation. These data suggest a new mechanism for immune suppression mediated by retroviruses; inhibition of NK function. They moreover imply that the CKS-17 peptide interferes with the lytic phase of NK cytolysis.

Adolescent↗
PubMed1987

Heterogeneity of human natural killer (NK) cells: enrichment of NK by negative-selection with the lectin from Erythrina cristagalli.

A novel technique for the isolation and enrichment of human natural killer (NK) cells from peripheral blood mononuclear cells (MNC) is described. Negative selection of MNC with the lectin from Erythrina cristagalli (ECA), whether by panning or agglutination in solution, resulted in a population of lymphocytes (5-20% of original MNC) highly enriched in cells exhibiting NK function. This enrichment was evident by a significant increase (range of 3-50-fold) in cells with large granular lymphocyte (LGL) morphology, K562 tumor-binding cells, cytotoxic activity, and cells expressing NK phenotypic markers (Leu 11+, OKM1+). Analysis of the cytolytic specificity of the cells demonstrated that the lytic spectrum was typical of endogenous NK. The effector cells were responsive to augmentation of cytotoxic potential by lymphokines (IL-2, IFN alpha, and IFN gamma) and capable of antibody-dependent cell-mediated cytotoxicity (ADCC). ECA-negative [ECA(-)] cells were equivalent to NK isolated by Percoll gradient fractionation. NK heterogeneity was demonstrated by the observation of a small percentage (1-5% of MNC) of NK in the ECA(+) population. This technique was found to be advantageous for the study of NK heterogeneity and NK biology.

Adolescent↗
PubMed1987

Human monoclonal antibodies derived from pleural effusion lymphocytes of a patient with breast carcinoma react with human breast cancer-associated antigens and mouse mammary tumor virus polypeptides.

Four human hybridoma cell lines (PEB1-4) were established from a fusion of pleural effusion lymphocytes isolated from a breast cancer patient with metastatic disease, 6 years postmastectomy. The hybridomas secreted IgG-k (3 micrograms/ml/10(6) cells). These monoclonal antibodies (PEB1-4) reacted to different degrees with mouse mammary tumor virus (MMTV) and T47D particles (HuMTV). Immunological cross-reaction was also detected with antigens isolated from body fluids of breast cancer patients (BF-Ag). The binding capacity of the monoclonal antibodies (MAbs) PEB1-4 to the above-mentioned antigens was measured by RIA. The specificity of these antibodies was further demonstrated by radioimmunoprecipitation of MMTV, T47D (HuMTV) and BF-Ag. The binding of PEB1-4 to surface antigens of intact cells grown in culture was measured by RIA. Some of the MAbs were shown to bind more avidly to breast cancer cells than to nonbreast cancer cells or nonmalignant cells. The PEB1-4 human monoclonal antibodies may be found useful in analyzing the virus-breast cancer relationship.

Aged↗
PubMed1987

Low serum antimycobacterial glycolipid antibody titers in the sera of patients with systemic lupus erythematosus associated with central nervous system involvement.

Antibodies which bind to glycolipids derived from Mycobacterium tuberculosis were sought in the sera of patients with systemic lupus erythematosus (SLE), with and without neurological disease, patients with active tuberculosis and normal controls. A significantly lower activity against the mycobacterial glycolipids was detected in the sera of patients with SLE with neurological involvement compared to other patients with SLE or controls. We suggest that low antibody levels against mycobacterial glycolipids may be useful in the diagnosis of patients with SLE in whom involvement of the central nervous system is suspected.

Antibodies, Bacterial↗
PubMed1986

Defective natural killing activity but retention of lymphocyte-mediated antibody-dependent cellular cytotoxicity in patients with the X-linked lymphoproliferative syndrome.

Cellular mediated immune responses in vitro of six males with X-linked lymphoproliferative syndrome (XLP) were investigated. Impaired natural killing (NK) activity compared to seven controls (P less than 0.001) and interferon-alpha activation (P less than 0.011) were detected. However, normal numbers of lymphocytes expressing NK-associated antigens (Leu-7 and MO1) and large granular lymphocytes (LGL) were observed in all patients. Normal lymphocyte-mediated antibody-dependent cellular cytotoxicity (ADCC) (P less than 0.531) was found. NK and ADCC activities have been regarded as being mediated by the same subsets of lymphocytes, however, results of this study do not support this hypothesis: lymphocytes with impaired NK but normal ADCC functions (NK-/K+) were found in males with XLP.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1986

Crohn's disease isolated to the appendix: truths and fallacies.

Twenty-five cases of Crohn's disease confined to the appendix were reported in eight hospitals in Israel during a 15-year period. Review of the histologic slides confirmed the diagnosis in 22 cases. Re-evaluation of these 22 patients included physical examination and radiologic studies of the small and large bowel. Rectosigmoidoscopy was performed in 16 patients. Signs and symptoms of Crohn's disease at other sites in the gastrointestinal tract did not occur during follow-up periods of two to 15 years (mean, 6.4 years) after appendectomy. This study and a review of the literature indicate that in most cases (93 per cent) Crohn's disease initially limited to the appendix is not a predictor of subsequent involvement of another portion of the bowel. It is concluded that the so-called Crohn's disease isolated to the appendix is a form of chronic granulomatous and follicular appendicitis of unknown etiology that is unrelated nosologically in the majority of the cases to Crohn's disease proper.

Adolescent↗