Search PubMed⌕ Search

Biomedical subjects

S Argov

Publications and source records attributed to S Argov.

At least 55 records · Page 3Linked to original sources
PubMed1986

Cytolysis of actinomycin D-treated target cells by cell-free supernatants from human monocytes.

The lytic mechanism of human peripheral blood monocytes was studied by using as targets actinomycin D-treated WEHI-164, an NK-insensitive murine fibrosarcoma cell line. Monocytes, but not lymphocytes, lysed WEHI-164 target cells pre-treated with actinomycin D within 6 h in 51Cr-release assays. Because cytolysis could not be inhibited competitively by unlabeled WEHI/D target cells, contact-independent mechanisms of cytolysis were investigated. Cell-free supernatants collected from monocytes cultured for 4-6 h at 37 degrees C lysed target cells as effectively as effector cell preparations of monocytes. Supernatants from lymphocytes cultured in parallel were not cytolytic. Cytolytic activity was not detected in supernatants from preparations of monocytes that were held on ice. However, monocytes produced cytolytic activity whether they were isolated by adherence or remained unseparated in suspensions of mononuclear cells. The cytolytic activity in cell-free supernatants (CFS) from monocytes was unaffected by incubation with protease inhibitors. CFS activity was destroyed by heat. Storage of CFS at 37 degrees, 22 degrees, 4 degrees, or -20 degrees C for 24 h decreased cytolytic activity; however, loss of cytotoxicity was minimized by storage at 4 degrees C. The cytolytic substance detected in 4-h CFS from monocytes appeared to be a protein(s) based on the sensitivity of the cytolytic activity to proteases. Cytolytic activity of CFS eluted from Sephacryl 200 in a single peak with an apparent molecular weight between 25,000 and 45,000 daltons.

Animals↗
PubMed1986

Postsplenectomy pericardial effusion in two patients with myeloid metaplasia.

Self-limited sympathetic pleural effusion is a well-known nonspecific sequela following any upper abdominal surgery, including splenectomy. However, to our knowledge, there is no report in the literature on sympathetic pericardial effusion immediately following splenectomy. We describe two patients with agnogenic myeloid metaplasia and refractory hemolytic anemia in whom pericardial effusion appeared a few days after splenectomy. The possible pathophysiologic mechanism is discussed.

Female↗
PubMed1985

Phorbol ester-induced lymphocyte adherence: selective action on NK cells.

Treatment of human peripheral blood lymphocytes (PBL) with phorbol dibutyrate (PDBU) for 20 to 45 min at 37 degrees C induces adherence of 5 to 30% of the cells to plastic. The adherent cells (pAd) were highly enriched in NK cells on the basis of the following findings: 1) they exhibit high NK and ADCC activity but do not lyse the NK-resistant cell line, Daudi; 2) cytotoxic activity is enhanced by pretreatment with interferon-alpha (IFN-alpha); 3) the surface markers of these cells, as determined with monoclonal antibodies, are consistent with NK cells; and 4) they are enriched with cells morphologically similar to large granular lymphocytes. Conversely, the PDBU-nonadherent cells were substantially depleted of NK cells. The fact that the pAd cells do not lyse the Daudi line and that their NK activity can be further augmented by IFN-alpha would suggest that the pAd are enriched for NK cells rather than changed in their characteristics as a result of the separation procedure. Moreover, no consistent and appreciable modulation of NK activity induced by PDBU was observed. This report therefore demonstrates that PDBU selectively induces NK adherence of NK cells, which may have practical as well as biological implications.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1985

Hydatid cyst of the liver rupturing into the biliary tract--mimicking acute cholecystitis on hepatobiliary scanning.

Two patients presenting with right upper abdominal colicky pain, jaundice, and fever had a hepatobiliary scan using Tc 99m HIDA. The scan was suggestive of acute cholecystitis and a space occupying lesion in the liver. On operation, liver echinococcosis, located in the right lobe rupturing into the biliary ductal system, was found. Intraoperative cholangiography revealed filling defects in the main biliary ducts. Exploration of the common bile duct disclosed daughter cysts and cystic debris. Acute cholecystitis or stones were not found. We conclude that in patients with a clinical picture and HIDA scanning compatible with acute cholecystitis and a space occupying lesion in the liver, the diagnosis of hydatid cyst of the liver which has ruptured into the biliary tract should be considered.

Acute Disease↗
PubMed1984

The major role of the operative cholangiogram within the indications for common bile duct exploration.

The accuracy of the clinical indications for common bile duct exploration was studied in a group of 495 patients. The patients were divided into two groups: operative cholangiography was performed in 5 per cent of cases in Group A and 62 per cent of cases in Group B. The results demonstrate the high efficiency of this procedure, its safety, accuracy (82%), and its effectiveness in the discovery of unexpected stones and in shortening of hospitalization. Analysis of the results point out the indications for intraoperative cholangiography: It should be carried out in all biliary tract operations, except for those in which other clinical indications for exploration already exist (palpable stones in the common bile duct or the combination of dilated common bile duct either with jaundice at the time of operation or with history of severe jaundice in the past). Under all other circumstances an operative cholangiogram should be performed.

Acute Disease↗
PubMed1983

Immune interferon (IFN-gamma) production in autologous mixed cultures.

T cells were exposed in vitro to autologous B cells or monocytes. Tested on the seventh day, the cultured lymphocytes lysed K562, Daudi, autologous, and allogeneic phytohemagglutinin (PHA) blasts. Autologous B blasts were not affected. The supernatants contained gamma interferon (IFN-gamma). The quantity of IFN did not correlate with the strength of the proliferative response nor with the strength of the cytotoxic potential.

Cell Division↗
PubMed1983

Effect of interferon on cell proliferation and generation of cytotoxic potential in mixed autologous and allogeneic lymphocyte cultures.

Autologous and allogeneic mixed lymphocyte cultures (AMC and MLC) were assayed for blastogenesis, generation of cytotoxic potential, and the effect of interferon (IFN-alpha) on these features. The cells of the mixed cultures lysed K562, Daudi, and autologous and allogeneic phytohaemagglutinin blasts. Stimulator-specific cytotoxicity was observed only in MLC. B blasts induced with Staphylococcus aureus were only affected in a stimulator-specific manner. Short-term IFN treatment of the MLC-derived effectors before the lytic assay enhanced the nonspecific component of cytotoxicity. Cell proliferation was considerably lower in AMC than in MLC. This was decreased when IFN-alpha was added at the initiation of the cultures. The presence of IFN influenced the generation of lytic potential. Comparison of the lysis of the different targets exerted by MLC-activated cells suggested that the specific component was more substantially elevated than the nonspecific one. It is likely that the IFN induced such modifications in the culture conditions that favoured the proliferation of the specific clone. Re-exposure of lymphocytes cultured in the presence of IFN to another dose of IFN before the assay had no influence on their lytic potential.

B-Lymphocytes↗
PubMed1982

IFN-alpha-induced modulations of the events in human mixed lymphocyte cultures.

Autologous mixed lymphocyte cultures (AMC) with T-enriched subset of human blood lymphocytes as responders and B-cells or plastic adherent cells as stimulators and allogeneic mixed lymphocyte cultures (MLC) were assayed for blastogenesis and generation of cytotoxic potential. The activated cells lyzed K562 and Daudi, autologous and allogeneic PHA-blasts. The AMC population affected the autologous and allogeneic blasts at a similar strength and there was no indication for selective effects. B-Blasts induced with Staphylococcus aureus were not lyzed. The MLC populations had a stimulation-specific cytotoxic component. This was revealed by the stronger effect against the stimulator PHA-blasts and by the lysis of the stimulator B-blasts. Short-time interferon (IFN) treatment prior to the lytic assay enhanced the anti-Daudi and anti-K562 lytic activity of the AMC and MLC populations. With AMC the lytic efficiency against the autologous and allogeneic PHA-blasts were not changed while with MLC they were also elevated. This increase was confined to the non-specific component of the cytoxicity. The proliferation of lymphocytes was suppressed when interferon was added at the initiation of the mixed cultures. On a per-cell basis the cytotoxic potential of these cultures were stronger. In the MLC the stimulation-specific component increased more substantially than the effect against the non-specific targets. It is possible that the IFN-induced modification of the culture conditions such as suppression of the initial proliferation favored the growth of the specific clone. Re-exposure of these cells to another dose of interferon prior to the lytic assay had no effect on the lytic potential.

Cell Line↗