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Biomedical subjects

Y Kahn

Publications and source records attributed to Y Kahn.

13 recordsLinked to original sources
PubMed1993

Interleukin-6 inhibits the proliferation of B-chronic lymphocytic leukemia cells that is induced by tumor necrosis factor-alpha or -beta.

Tumor necrosis factor (TNF-alpha) acts as a growth stimulatory factor on leukemic B lymphocytes from many patients with chronic lymphocytic leukemia (CLL). Because TNF induces production of interleukin-6 (IL-6), which has been shown to be a growth factor for myeloma and other transformed B cells, we examined the possibility that IL-6 mediates the growth-stimulatory effect of TNF on B-CLL cells. In fact, we found that IL-6 is an inhibitor of B-CLL growth. The addition of recombinant human IL-6 markedly decreased the TNF-induced B-CLL growth, and this decrease was even greater when soluble IL-6 receptor, known to act as IL-6 agonist, was added with recombinant IL-6. Conversely, neutralizing monoclonal antibodies to IL-6 and to the IL-6 receptor potentiated the growth stimulation of TNF on B-CLL cells, in line with the possibility that IL-6 functions as a negative feedback regulator of an autocrine TNF action on these B-leukemic cells. Evidence is presented that production of IL-6 by monocytes and B cells of CLL patients is low, suggesting that administration of IL-6 may be beneficial in CLL to reduce the eventual growth stimulation by TNF and, possibly, also the deficiency in platelets and Ig production in this disease.

Animals↗
PubMed1991

Heterotypic leukocyte aggregation in the peripheral blood of patients with leukemia, inflammation and stress.

This study deals with the question of whether the aggregates of leukocytes in the peripheral blood are homo- or heterotypic. One hundred-fifty individuals with leukemia, inflammation, and physical and mental stress, were examined. It was found that the various cell populations of the peripheral blood are represented in the aggregates and that aggregates are generally heterotypic. Normal and malignant leukocytes were noted in aggregates of patients with leukemia, suggesting that adhesive mechanisms are similar for both normal and malignant leukocytes. This was also supported in two animal models, one with leukocytosis of normal cells and the other with leukocytosis of leukemic cells, in which the state of leukocyte adhesiveness/aggregation in the peripheral blood correlated with tissue leukostasis. The possibility exists that "non specific stickers", present in the peripheral blood, promote interactions between the white blood cells, normal and malignant, and between these cells and the endothelium.

Adolescent↗
PubMed1989

Rearrangements in the p53 gene in Philadelphia chromosome positive chronic myelogenous leukemia.

Molecular structural analysis of the p53 gene in patients with Philadelphia chromosome-positive chronic myelogenous leukemia (CML) indicates a significant incidence of gene rearrangements in patients at either accelerated phase or blastic crisis. Southern blot analysis of genomic DNA hybridizing with either genomic or cDNA p53 specific probes indicated that 30% of the CML patients at blastic crisis phase exhibited rearrangements, mostly mapping downstream to the first non-coding exon. This is compatible with the observation that the progression of CML from the chronic to the acute phase involves frequent aberrations in chromosome 17, to which the p53 oncogene has been mapped. Therefore, we suggest that one of the pathways of development of CML to the acute phase is associated with aberrations in the p53 nuclear oncogene.

Blast Crisis↗
PubMed1986

Influence of patient hemogram on growth index values generated from a radiometric detection device.

Blood samples from 20 patients with widely varying concentrations of erythrocytes and leukocyte subtypes were inoculated into BACTEC 6B bottles (Johnston Laboratories, Inc., Towson, Md.). There was no relationship between growth index value and hemogram. Although sterile blood is capable of generating small amounts of 14CO2, the mechanism for this phenomenon is not related to the concentration of a specific type of blood cell.

Adult↗
PubMed1986

Purpura fulminans in an adult.

Purpura fulminans is a rare disease of childhood, manifested by massive hemorrhage into the skin, widespread thrombosis of venules and arterioles and a hematologic picture of disseminated intravascular coagulation. An unusual case in a 68-year-old man is presented and the mode of therapy discussed.

Aged↗
PubMed1981

Leukaemic infiltration of the prostate.

A biopsy of the prostate should be done in lymphoma/leukaemic patients suffering from urinary obstruction. Patients with a lymphomatous infiltration of the prostate should be irradiated and not subjected to surgery. Two such cases successfully irradiated are described and the present literature is reviewed.

Aged↗
PubMed1979

Subendocardial infarction and thrombocytopenia.

Two female patients who suffered from drug-induced thrombocytopenic purpura and subendocardial myocardial infarction are presented. One of them died from cerebral haemorrhage and diffuse subendocardial punctate haemorrhages were found at post-mortem. The abnormal haemostasis which is associated with thrombocytopenia might induce diffuse damage of the myocardium and might impair heart performance. This finding may be more frequent than hitherto appreciated and calls for serial electrographic tracings in thrombocytopenic patients.

Anti-Inflammatory Agents↗
PubMed1978

Increase in platelet aggregation following a rise in plasma free fatty acids.

Platelet aggregation was studied following intravenous injection of heparin to nine healthy adults. Heparin is known to produce an increase in the concentration of free fatty acids (FFA) within 10 minutes of intravenous injection. A significant correlation was found between the intensity of primary platelet aggregation and changes in plasma FFA levels. No correlation was found between plasma FFA levels and the intensity of secondary platelet aggregation.

Fatty Acids, Nonesterified↗
PubMed1976

Aplastic anemia followed by leukemia in congenital trisomy 8 mosaicism. Ultrastructural studies of polymorphonuclear cells in peripheral blood.

The case of a 40-year-old patient with congenital trisomy 8 and sex chromosome mosaicism is discussed. The main clinical features were: mental retardation, thick and darkly pigmented skin, prominent forehead, convergent strabismus, high arched palate, flexion contractures of the extremities, and numerous skeletal abnormalities. The patient developed severe aplastic anemia followed by an interim period of preleukemia which developed into acute leukemia. Electron microscope examination of the white blood cells at the stage of the aplastic anemia showed ultrastructural abnormalities similar to those observed in other genetic disorders with a predisposition to leukemia, as well as in leukemia.

Acute Disease↗