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Biomedical subjects

M Shaklai

Publications and source records attributed to M Shaklai.

At least 55 records · Page 3Linked to original sources
PubMed1992

The inheritance of type I and type III von Willebrand's disease in Israel: linkage analysis, carrier detection and prenatal diagnosis using three intragenic restriction fragment length polymorphisms.

Three intragenic restriction fragment length polymorphisms (RFLPs) were used to study linkage and analyse the mode of inheritance in type I and type III von Willebrand's disease (vWD). In two families linkage was established between Sac I RFLPs and the inheritance of type I vWD. RFLP analysis of amniocyte DNA from a potentially affected foetus enabled us to establish a prenatal diagnosis of vWD in a third family with type I vWD. Linkage was also established in four families between the Sac I and two Taq I RFLPs and the inheritance of type III vWD. All type III probands were homozygotes and inherited the same mutant vWF allele from both parents. Heterozygous carriers from one type III family were phenotypically normal and could be detected only by linkage analysis, whereas carriers from the remaining three type III families were asymptomatic but had decreased values of vWF antigen and activity. RFLP-based linkage analysis of vWD alleles provides a way to improve the diagnostic precision, detect carriers, and may be useful for prenatal diagnosis of type III vWD.

Female↗
PubMed1991

Derivatives of butyric acid as potential anti-neoplastic agents.

A novel derivative of butyric acid, pivalyloxymethyl butyrate (AN-9) has been shown, in vitro, to: (a) induce cytodifferentiation and inhibit the proliferation of leukemic cells; (b) inhibit the growth and formation of Lewis lung carcinoma colonies in semi-solid agar. AN-9 affect cells at about 10-fold lower concentration and at a faster rate than does butyric acid. The pivalyloxymethyl esters of propionic, isobutyric and valeric acids do not elicit effects similar to those of AN-9, while the isobutyryloxymethyl butyrate does, which strongly suggests that the activity of AN-9 stems from intracellular metabolic degradation of the pro-drug to butyric acid. In vivo, AN-9, increased the survival of mice in Lewis lung carcinoma primary cancer model and significantly decreased the number of lung lesions of the animals inoculated with highly metastatic cells, but did not affect their life span. Acute LD50 studies have shown that AN-9 possesses low toxicity. These results suggest that AN-9 is a potential anti-neoplastic agent as well as a tool for investigation of the differentiation induction mechanism.

Animals↗
PubMed1991

Nutritional zinc increases platelet reactivity.

After ingestion of 220 mg zinc sulfate, platelet aggregation was evaluated at various time intervals (i.e., T = 0, 1, and 3 hr) and the autologous plasma analyzed by atomic absorption analysis. The zinc levels increased maximally some 0.4 +/- 0.2 microgram/ml within 3 hr after ingestion, which for the entire blood pool corresponds to only 5% of the ingested zinc. Aggregation responses of platelet rich plasma (PRP), instigated with suboptimal levels of thrombin (less than 0.2 U/ml), ADP (less than 2 microM), epinephrine (less than 2 microM), collagen (less than 2 micrograms/ml), or PAF (less than 50 ng/ml), show significant improvement to at least one aggregant. Mean +/- SEM values for delta % aggregation increase are as follows: thrombin, 51 +/- 10%; epinephrine, 21 +/- 6%; ADP, 31 +/- 6%; collagen 23 +/- 6%; and platelet aggregating factor (PAF), 56 +/- 6%. For controls, the platelets from one individual with Glanzmann thrombasthenia as well as four undosed volunteers exhibited no significant changes in platelet responsiveness. Increased platelet responsiveness to agonists after zinc sulfate ingestion was observed in PRP from blood collected in either citrate or heparin. We demonstrate that within a relatively short time period, single bolus of nutritional zinc intake can significantly increase platelet reactivity. These findings show that nutritional zinc availability is relevant to hemostasis and may pertain to the viability of platelet concentrates in blood banks.

Adenosine Diphosphate↗
PubMed1991

Haemarthrosis in patients with mild coagulation factor deficiency.

While haemarthrosis is a common finding in severe factor VIII or IX deficiency, it is unusual in mild coagulation factor deficiencies. We describe three patients with mild factor IX, X or XI deficiency who presented with spontaneous haemarthrosis. All underwent joint puncture with subsequent worsening of the haemarthrosis in the affected joint. This report indicates that: (i) even mild coagulation factor deficiency may be associated with haemarthrosis; (ii) patients with suspected haemarthrosis should undergo routine screening coagulation tests before joint puncture; and (iii) any abnormalities in the screening tests indicate a need for further evaluation of the coagulation status. In such cases puncture of the joint should be deferred and specific therapy started immediately.

Adult↗
PubMed1990

Proliferation-associated changes of Ca2+ transport in myeloid leukemic cell lines.

Proliferation-associated changes in calcium metabolism were investigated employing the promyelocytic HL-60 and monoblastic U-937 cell lines. The cells were stimulated to proliferate employing mitogenic factors as follows. 1) Transferrin or insulin: HL-60 cells were adjusted for growth in serum-free medium, and 24 h prior to the experiment, the cells were deprived of transferrin or insulin. The re-addition of either one of them stimulated cell proliferation as was evident by increased [3H]-tymidine incorporation activity. Cell proliferation was associated with an enhanced Ca2+ influx rate, measured by 45Ca2+ uptake activity. 2) Granulocyte-monocyte colony-stimulating factor (GM-CSF): addition of GM-CSF to proliferating or quiescent HL-60 cells resulted in increased cell proliferation, which was also accompanied by increased rate of Ca2+ influx. 3) Serum: HL-60 and U-937 were grown for 24 h in serum-depleted medium. Re-addition of serum to the cells was not associated with immediate or delayed change in calcium influx rate but rather with an immediate increase in the cytosolic free calcium concentration, measured employing the fluorescent probe, fura-2AM. This increase was independent of extracellular calcium, unaffected by verapamil, diltiazem, and lanthanum, and associated with enhanced 45Ca2+ efflux. Thus, in all three cases evoked cell proliferation was accompanied by quantitative changes in Ca2+ metabolism. While the transferrin-, insulin-, and GM-CSF-stimulated cell proliferation was accompanied by delayed increases in 45Ca2+ influx, the serum-stimulated cell proliferation was accompanied by an immediate elevation of free cytosolic Ca2+.

Biological Transport↗
PubMed1990

The role of increased calcium influx rate in receptor mediated function of differentiating HL-60 cells.

In this study we have investigated the link between increased Ca2+ influx rate, acquired upon the differentiation of HL-60 cells, to changes in cytosolic free Ca2+ ([Ca2+]i], evoked by the chemotactic peptide-FMLP and the mitogen Con-A. Although differentiating and undifferentiated HL-60 cells exhibited similar steady-state levels of [Ca2+]i, cells induced to differentiate by dibutyryl-cAMP, at 48 h, exhibited enhanced Ca2+ influx rate, measured by non-steady state 45Ca2+ uptake, and augmentation of FMLP-stimulated Ca2+ influx. At 120 h the above cells responded to FMLP but not to Con-A, by a marked augmentation of Ca2+ influx, and elevated levels of [Ca2+]i. On the other hand HL-60 cells induced to differentiate by retinoic acid responded, as described above, to Con-A but not to FMLP. HL-60 cells grown in the presence of cholera-toxin, were reported to express high levels of FMLP-receptors without expressing cell differentiation. We have demonstrated that, in these cells the Ca2+ influx rate was unchanged, moreover, FMLP-stimulated Ca2+ influx and [Ca2+]i rise were low. These findings strongly suggest that the presence of receptor is not sufficient for FMLP-mediated changes in [Ca2+]i. A link between increased Ca2+ influx rate, acquired upon induction of differentiation, and receptor mediated response in these cells is proposed.

Bucladesine↗
PubMed1990

The role of calcium in differentiation of leukemic cell lines.

Increased calcium influx associated with differentiation of four human myeloid leukemic cell lines: HL-60, KG-1, U-937 and K-562, to either monocytic or granulocytic direction was demonstrated. Calcium influx was measured employing two methods; measurement of radioactive calcium influx rate at 4 degrees C and employing the fluorescent probe, fura-2 acetoxymethyl ester. The increase in Ca2+ influx was demonstrated with three chemically unrelated differentiation inducers: retinoic acid, 1 alpha, 25 dihydroxy vitamin D3 and dimethyl sulfoxide. Inhibitors of calcium uptake such as verapamil diltiazem and cromolyn, partially reduced differentiation, suggesting that differentiation of myeloid leukemic cell lines is dependent on the availability of extracellular calcium.

Calcitriol↗
PubMed1989

Long-term proliferation of human leukemia cells induced by mouse stroma.

Acute lymphocytic leukemias (ALL) of infants and children were found to preferentially survive in coculture with a cloned cell line of endothelial adipose cells (14F1.1) from mouse bone marrow. One of these ALLs expressed a phenotype compatible with an early stage of differentiation (HLA-DR+, CD19+, and CD34+) and exhibited extensive growth in the presence of the mouse stromal cells during a period greater than 25 weeks following seeding. These ALL cells were strictly dependent upon the mouse stromal clone 14F1.1 and failed to proliferate in the absence of the endothelial adipocytes or with a variety of "feeder cells." Throughout the culture period the cells died if removed from the stroma. No similarly proliferative cell population with strict dependence upon stromal cells was found among a variety of other leukemias including hairy cell, acute myeloid, and chronic lymphocytic leukemia. The 14F1.1 clone has been previously found to promote the renewal of mouse and human stem cells. It is therefore possible that leukemias with a stem cell-like phenotype depend upon stromal cell factors similar to those affecting the growth of normal stem cells. These factors appear to operate across genetic barriers.

Antibodies, Monoclonal↗
PubMed1988

The heme biosynthetic pathway in lymphocytes of patients with malignant lymphoproliferative disorders.

The metabolism of heme is impaired in lymphocytes of patients with malignant lymphoproliferative disorders (MLPO). Two of the enzymes of the heme biosynthetic pathway, delta-aminolevulinic acid dehydrase (ALAD) (EC 4.2.1.24) and ferrochelatase (FC) (EC 4.99.1.1) are markedly reduced. The activity of porphobilinogen deaminase (PBGD) (EC 4.3.1.8) is increased. The rate-limiting enzyme of heme biosynthesis in the liver, aminolevulinate synthase (ALAS) (EC 2.3.1.37) remains unchanged although the concentration of total heme in the lymphocytes is markedly reduced. This might reflect a lack of negative feedback inhibition by heme on ALAS activity in this system.

5-Aminolevulinate Synthetase↗
PubMed1988

Differentiation-associated changes of cation-transport activities in myeloid leukemic cell lines.

Induction of differentiation in HL-60 and U-937 leukemic cell lines, resulted in 1.5-10-fold increase in 45Ca2+ uptake. The increased 45Ca2+ uptake in the differentiating cells was inhibited by verapamil, cromolyn and amiloride. Elevation in Ca2+ uptake in differentiating cells was also demonstrated using the fluorescent probe, fura-2 acetoxymethyl ester. The increased 45Ca2+ uptake was accompanied by a decrease in ouabain-insensitive and -sensitive 86Rb+ uptake. Furthermore, correlation between the changes in these activities was observed. Modulation of extracellular pH affected differentiation: higher pH increased the extent of differentiation.

Amiloride↗
PubMed1988

Recombinant interferon alpha-C for advanced hairy cell leukemia. An Israeli multicenter study.

Thirteen patients with advanced hairy cell leukemia were treated with a new subspecies of interferon (IFN): recombinant IFN (rIFN)-alpha-C. The timing of the peripheral hematologic remission of individual blood elements was similar to that reported for other interferons, and 60% of patients attained a complete peripheral hematologic remission at 9 months. Two patients relapsed despite a good initial response to IFN. No anti-IFN antibodies could be detected in their sera. In vitro studies of colony formation from the peripheral blood of all responding patients showed that rIFN-alpha-C did not inhibit the growth of colonies but favorably affected the maturation of their elements towards monocytes, granulocytes, and erythroid elements. The relapsing patient examined initially experienced a similar beneficial in vitro response which paralleled his in vivo improvement. During relapse, rIFN-alpha-C inhibited both the colony formation and the myelomonocytic differentiation in the in vitro cultures. These findings may suggest that the acquired resistance to IFN in our patient could be due either to an acquired stem cell maturation arrest in response to IFN or to emergence of a new clone indifferent to IFN-alpha-C differentiation effect.

Age Factors↗
PubMed1988

Butyric acid: inhibition of non-leukemic and chronic myeloid leukemia granulocyte macrophage clonal growth.

Butyric acid has been shown to inhibit the growth of several established tumor cell lines and to induce either granulocytic or erythroid differentiation in different human and murine leukemic cell lines. The dose-dependent effect of butyric acid was tested in vitro on the clonal growth of granulocyte macrophage progenitors in 13 patients with chronic myeloid leukemia (CML) and compared with control bone marrow and peripheral blood responses. The growth of myeloid progenitors from both healthy donors and non-leukemic and leukemic patients was almost completely inhibited by 1.0 mM butyric acid. At 0.5 mM butyric acid, inhibition of CML progenitors, both from chronic phase and blastic phase patients, was significantly greater (P less than 0.01) than bone marrow from non-leukemic patients and peripheral blood controls. Butyric acid, a 4-carbon compound, was the most potent inhibitor of six short chain fatty acids tested on CML myeloid progenitors.

Adult↗
PubMed1988

Autoimmunity in chronic lymphocytic leukaemia.

Seventy-nine patients with chronic lymphocytic leukaemia were evaluated for the presence of autoimmune diseases and autoantibodies. One patient has polymyositis and two additional patients presented with features suggestive of pernicious anaemia and chronic active hepatitis. The Coombs' direct test was positive in 7% and immune thrombocytopenia was present in 8.1% of patients. Five (7%) patients had M-protein in the serum. No increased frequency of other autoantibodies was noted in our study group. We conclude that the propensity to develop antibodies is restricted only to the haematopoietic system and that there is no increased frequency of non-haematological autoimmune diseases in chronic lymphatic leukaemia.

Aged↗