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Biomedical subjects

B Klein

Publications and source records attributed to B Klein.

At least 325 records · Page 18Linked to original sources
PubMed1983

Myeloproliferative Sarcoma Virus stimulates pluripotent hematopoietic stem cells and provokes tumoral transformation of the hematopoietic microenvironment in vitro.

The Myeloproliferative Sarcoma Virus (MPSV) induces an increase in the number and concentration of pluripotent stem cells in long-term murine bone marrow cultures. This is followed by an increased number of precursor cells of the granulocyte and macrophage lines (GM-CFC). This increase is comparable to that observed in DBA/2 mouse spleens in vivo two to three weeks after viral infection. Proliferation of CFUs and GM-CFC decreases five weeks after infection with MPSV, in parallel to the gradual decline of reverse transcriptase activity in the culture medium. GM-CFC which can proliferate in the absence of added colony stimulating factor (CSF) were detected at week 6 post MPSV infection. Adherent tumor cells were observed nine weeks after infection. These fibroblast type cells gave rise to a permanent line which produced a CSF-like activity. Our results show that MPSV causes the tumoral transformation of fibroblast-like cells of the bone-marrow hematopoietic microenvironment. In addition, MPSV also strongly stimulates the proliferation of hematopoietic stem cells. MPSV is, until now, the first murine retrovirus which exhibits such properties.

Animals↗
PubMed1983

Diminished interleukin-2 activity production in cancer patients bearing solid tumors and its relationship with natural killer cells.

Interleukin-2 (IL-2) activity production by stimulated peripheral blood lymphocytes (PBL) from solid tumor bearing cancer patients was lower than in normal subjects. Natural-killer (NK) cell activity in the PBL of cancer patients was very significantly correlated to IL-2 activity production (P less than 0.001). These results might suggest a central role for IL-2 in the immune dysfunctions in cancer patients, and the possible use of IL-2 as an immunological response modifier in these patients.

Adult↗
PubMed1983

Analysis of virus-specific mRNAs present in cells transformed with restriction fragments of adenovirus type 5 DNA.

Adenovirus type 5 (Ad5) mRNAs present in cells transformed with left-terminal Ad5 DNA fragments (XhoI-C, 0 to 15.5%; HindIII-G, 0 to 7.7%; HpaI-E, 0 to 4.3% were characterized by 'Northern blotting' and S1 nuclease analysis. They were compared with the mRNAs transcribed from the Ad5 E1 region in the early and late stages of lytic infection. It is shown that in XhoI-C-transformed cells the same mRNAs were transcribed as early during lytic infection: two co-terminal mRNAs from region E1a, differing only in their splicing, and one major E1b transcript. In HindIII-G-transformed cells additional E1a mRNAs were detected with a novel 5' terminus, but with the normal splicing pattern. Instead of the normal E1b mRNA, HindIII-G-transformed cells were found to contain mRNAs consisting of a viral E1b segment and a non-viral segment. This E1b-encoded segment was shown not to be involved in RNA splicing. The mRNAs in cells transformed with Ad5 HpaI-E were similar to the E1a mRNAs found in XhoI-C- and HindIII-G-transformed, and in lytically infected cells but had aberrant 3' termini. These results are discussed in the light of the Ad5 E1 DNA and RNA sequences, and protein mapping data.

Adenoviruses, Human↗
PubMed1983

Induction of human T colony formation by phorbol myristate acetate.

Phorbol myristate acetate (PMA) is a potent inducer of T colony formation by peripheral blood lymphocytes. A mean cloning efficiency of 0.3% (0.05-0.5%) is obtained with PMA concentrations of 100-1000 ng/ml. PMA-induced T colony formation does not require the presence of monocytes and therefore differs from other mitogens in this respect. Purified T-colony-promoting activity (TCPA) (devoid of phytohaemagglutinin (PHA)) increases PMA-induced T colony numbers and induces T colony formation at low PMA doses (0.01 to 1 ng), concentrations at which no T colonies are detected in the absence of added TCPA. PMA-induced colonies are mainly composed of cells bearing Fc receptors for IgM (54%), which is not the case for colonies obtained with PHA (11%). PMA-induced colony cells do not bind OKT3 and OKT4 monoclonal antibodies, whereas 23% are able to bind OKT8 antibody. These results demonstrate that PMA is a potent inducer of T colony formation and may therefore serve as a useful tool for the study of T-cell differentiation.

Antigens, Surface↗
PubMed1983

Osteomyelitis of both clavicles as a complication of subclavian venipuncture.

Complications of subclavian vein catheterization are common and include pneumothorax, hemothorax, and sepsis. Osteomyelitis is a rare complication. The present report describes a patient with osteomyelitis of both clavicles due to subclavian vein venipuncture, in whom fever and chills were absent and the sole clinical finding was local pain and tenderness in the involved area.

Aged↗
PubMed1983

Myeloproliferative syndrome induced by MPSV in DBA/2 mice: presence of a mixed-colonies promoting activity (MPA) in the spleen.

The myeloproliferative syndrome induced by the myeloproliferative sarcoma virus (MPSV) in DBA/2 mice stimulates the proliferation of pluripotent hemopoietic stem cells (HSC) and of progenitors committed toward granulomacrophagic and erythroid cell lines. This stimulation may result from a direct effect of the MPSV on HSC or from an indirect effect via locally secreted factors. Normal isogenic bone marrow cells were incubated in the mixed colony-forming unit system in semisolid medium supplemented with conditioned media obtained after incubating neoplastic spleen cells for 3 days at 37 degrees C. These spleen conditioned media contain an activity that is physically separable from MPSV by ultracentrifugation and which, in the presence of a very low quantity of erythropoietin, can induce in vitro the proliferation and differentiation of pluripotent HSC, detected by this Mix-CFU technique. We termed this activity mixed-colonies promoting activity (MPA). These results suggest that the hyperplasia of the nonlymphoid hematopoietic system in the neoplastic spleen results from an indirect effect of the MPSV on pluripotent HSC via locally secreted factors.

Animals↗
PubMed1983

Hematopoietic precursors in disease induced by the myeloproliferative sarcoma virus.

Granulocyte and macrophage precursors (GM-CFU-C-), which differentiate in vitro without added granulocyte and macrophage colony stimulating factor (GM-CSF), can be detected in the hematopoietic organs of mice infected with myeloproliferative sarcoma virus (MPSV). Retransplantation experiments have shown that the GM-CFU-C- are incapable of autonomous growth and depend on a factor present in medium conditioned by MPSV spleen cells (MPSV-CM). This factor is not MPSV and is not produced by spleen cells of noninfected mice. Two classical sources of GM-CSF, lung GM-CSF and GM-CSF contained in the plasma of endotoxin-treated mice, cannot replace the MPSV factor. Inversely, MPSV-CM does not stimulate the growth of retransplanted clusters induced in normal bone marrow with lung GM-CSF, whereas lung GM-CSF does. Two conditioned media containing activity promoting the in vitro proliferation and differentiation of hematopoietic stem cells in the mixed colony assay stimulate the growth of MPSV clusters: one medium was conditioned by pokeweed-mitogen-stimulated spleen cells, the other by the WEHI 3 cell line. The implication of the results in the comprehension of MPSV disease is discussed.

Animals↗
PubMed1983

Suppressor effect of prostaglandins on T colony formation.

This study evaluated the action of prostaglandins on T colony formation. A single step culture process was used which involved direct seeding of freshly isolated peripheral blood mononuclear cells (MC) in semi-solid agar culture medium containing phytohaemagglutinin (PHA). Suppression of endogenous production of prostaglandins with 10(-6) M indomethacin increased T colony formation by up to 100%. Similarly, addition of synthetic prostaglandin E (PGE) to the culture system demonstrated a dose-dependent reduction of T colony formation by PHA-stimulated non-adherent cells. The 50% inhibitory dose (ID 50) was 10(-7) M for PGE2 and 1.3 x 10(-7) M for PGE1. Prostaglandin F had no effect on T colony formation. The synthesis of PGE by adherent cells can be increased two- to three-fold in the presence of T colony promoting activity released by PHA-stimulated lymphocytes. We conclude that monocyte produced PGE is responsible for the suppressor effect exerted by these cells on T colony formation. The PGE inhibitory role is interpreted as a feedback mechanism, modulated by lymphokines released by PHA-activated lymphocytes.

Clone Cells↗
PubMed1983

Modulation of PHA-induced T colony formation by phorbol myristic acetate.

PMA (10 ng/ml), induced a four-fold increase in PHA-induced T colony formation by peripheral blood lymphocytes (PBL). At lower (0.1-1 ng/ml) and higher concentrations (100-1,000 ng/ml), PMA had an inhibitory effect. The potent co-mitogen effect observed at 10 ng/ml PMA was associated with a strong increase in T colony promoting activity (TCPA) released by PHA stimulated PBL cultured in the presence of PMA (10 ng/ml). PMA at all concentrations exerted an inhibitory effect on T colony formation when PBL were cultured in the presence of PHA and an optimal concentration of exogenous TCPA. PMA was also capable of assuming the essential role played by monocytes in T colony formation. Thus, PMA can fulfil both co-mitogen and monocyte like roles in T colony formation. These activities closely resemble those previously described for interleukin 2 (IL2) production.

Clone Cells↗
PubMed1982

[An experimental model of osteosarcomas in rats ].

Satisfactory experimental models for preclinical prediction in cancerology must answer the following criteria: reproducibility of the method used for inducing tumors; clinical, pathological and kinetic similarity with the corresponding human tumors. We have developed a model of osteosarcoma locally induced by insoluble radioactive cerium chloride (144Ce CI3) in Sprague Dawley rats. This method yields over 80% of bone tumors at the injection site, of which approximately half are histologically similar to human tumors. These tumors double their volume fairly slowly (in approximately 20 days); lung metastases occur both early and frequently (80% of animals). A transplantable tumor was developed from an induced osteosarcoma and adapted to the Curie strain. Transplantation in the bone, next to the bone, or under the skin is followed by widespread metastatic dissemination. The kinetics and histological features of the primary tumor are maintained. Tumor 85 strontium uptake is similar to that seen in human osteosarcomas. These new models of osteosarcomas are being used for evaluating new cancer chemotherapeutic agents and interferon, etc.

Animals↗
PubMed1982

Production of high titers of interferon-gamma by prestimulated murine spleen cells.

Concanavalin A (Con A)-induced interferon-gamma (IFN-gamma) production by murine spleen cells prestimulated with Con A for different periods of time has been studied. Highest titers of antiviral activity were obtained by restimulation of cells that had been prestimulated with Con A for 3 days. These cells produced up to 30 times more IFN than freshly isolated spleen cells stimulated under the same conditions. In an effort to explain this rise in the capacity to produce IFN-gamma, the possibility that it was due to the inactivation of a suppressor cell was excluded. The addition of freshly isolated spleen cells at different concentrations to prestimulated cells did not affect subsequent Con A-induced IFN-gamma production. Separation of freshly isolated or prestimulated spleen cells by velocity sedimentation at unit gravity showed that in the latter case most of the IFN-gamma was produced by a population of large-sized cells not present in the former population. It was concluded from these experiments that prestimulation of spleen cells with Con A gives rise to a population of large-sized cells that produce, upon restimulation with the same mitogen, much higher titers of IFN-gamma than those obtained upon primary stimulation of small resting lymphocytes.

Animals↗
PubMed1982

Cellular proliferation kinetics of the murine sarcoma induced by the Moloney sarcoma virus.

Cell proliferation kinetics of the sarcoma induced by Moloney virus was studied in newborn Swiss OF1 mice. After in vivo injection of tritiated thymidine, followed by autoradiography, it was shown that the majority of cells were actively proliferating (labelling index; 31%, growth fraction 78%). The mean cell cycle was 16 hr and cell loss was relatively low (cell loss factor 48%). The study of tumour specific activity with time after a single [in vivo] injection of [3H]dR or [125I]UdR did not demonstrate the same degree of cell loss as that calculated by autoradiography. This result is consistent with a massive reutilization of radioactivity released by normal tissues.

Animals↗
PubMed1982

[Studies on determination of alpha-amylase with p-nitrophenyl-alpha-D-maltotetraoside].

Nitrophenylmaltodextrins are alpha-amylase substrates which allow a continuous determination with a zero order kinetics over a period of at least 10 min, without deviations from linearity. Only one auxiliary enzyme is necessary. Practicability and clinical evidence of alpha-amylase determinations by means of p-nitrophenyl-alpha-D-maltotetraoside are demonstrated. The interserial precision of 0.84% cannot conceal an only moderate correlation with previous methods. This fact, however, does not negate the advantages.

Amylases↗
PubMed1982

[A new procedure for the revision and reposition of functionless peritoneal dialysis catheters].

The most important requirement for satisfactory transperitoneal dialysis is faultless functioning of the Tenckhoff catheter. Suddenly occurring functional disturbances are often caused by wrong positioning and by envelopment of the catheter by tissue, which require surgical correction. A technique for successfully locating and replacing a transperitoneal catheter by means of an operation laparoscope is described.

Adult↗
PubMed1982

A study of added GM-CSF independent granulocyte and macrophage precursors in mouse spleen infected with myeloproliferative sarcoma virus (MPSV).

A subpopulation of granulocyte and macrophage precursors (GM-CFUc) differentiating in the agar colony technique of Bradley and Metcalf into mature granulocytes and macrophages, without the addition of granulocyte and macrophage colony stimulating factor (GM-CSF), can be detected in MPSV infected mice. These precursors were detected 5 days after virus infection, reaching a maximal concentration of 1/10,000 spleen or bone marrow cells, 25 days after viral infection. The number of the added GM-CSF independent GM-CFUc was linearly correlated with the number of seeded MPSV hematopoietic cells. No GM-CSF producing cells could be detected in the MPSV spleen using normal bone marrow GM-CFUc as responder cells. Study of the GM-CSF sensitivity of the GM precursors has demonstrated the existence of two GM-CFUc populations in the MPSV spleen: a) a GM-CSF dependent population with a GM-CSF sensitivity similar to that of normal GM-CFUc b) a GM-CFUc population which differentiated in the absence of detectable amount of GM-CSF and of which differentiation was not affected by the addition of progressive amounts of GM-CSF. A possible model explaining these results is proposed.

Animals↗
PubMed1982

Carprofen in osteoarthrosis.

Two randomized double-blind trials with carprofen in osteoarthrosis were performed. The first compared carprofen with ibuprofen in 2 groups of 10 patients for 8 weeks and the second compared carprofen administered in two different schedules (100 mg in the morning plus 200 mg in the evening versus 100 mg 3 times daily) for 4 weeks, also in 2 groups of 10 cases. The trials indicate that carprofen is effective and well tolerated. In the first trial efficacy shows a small trend in favour of carprofen and in the second a slight superiority of the b.i.d. schedule as compared to t.i.d.

Adult↗