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Biomedical subjects

J Soler

Publications and source records attributed to J Soler.

At least 199 records · Page 11Linked to original sources
PubMed1986

Coincident multiple myeloma and non-Hodgkin's lymphoma with 2 serum monoclonal immunoglobulins.

A case with features of both multiple myeloma and non-Hodgkin's lymphoma at the moment of diagnosis is presented. The patient had lytic bone lesions and biclonal gammopathy, IgM kappa and IgA kappa. In the bone marrow biopsy, there was a diffuse infiltration by atypical plasma cells coexisting with an interstitial and nodular infiltration by poorly differentiated lymphoid cells. Immunofluorescence studies showed positive staining with alpha and kappa antisera in the cytoplasm of plasma cells and with mu and kappa antisera on the surface of lymphoid cells. After the beginning of chemotherapy, the IgA kappa monoclonal protein disappeared and the IgM kappa monoclonal protein remained constant.

Aged↗
PubMed1986

Partial purification and some kinetic properties of glucose-6-phosphate dehydrogenase from Phycomyces blakesleeanus.

Glucose-6-phosphate dehydrogenase from sporangiophores of Phycomyces blakesleeanus NRRL 1555 (-) was partially purified. The enzyme showed a molecular weight of 85 700 as determined by gel-filtration. NADP+ protected the enzyme from inactivation. Magnesium ions did not affect the enzyme activity. Glucose-6-phosphate dehydrogenase was specific for NADP+ as coenzyme. The reaction rates were hyperbolic functions of substrate and coenzyme concentrations. The Km values for NADP+ and glucose 6-phosphate were 39.8 and 154.4 microM, respectively. The kinetic patterns, with respect to coenzyme and substrate, indicated a sequential mechanism. NADPH was a competitive inhibitor with respect to NADP+ (Ki = 45.5 microM) and a non-competitive inhibitor with respect to glucose 6-phosphate. ATP inhibited the activity of glucose-6-phosphate dehydrogenase. The inhibition was of the linear-mixed type with respect to NADP+, the dissociation constant of the enzyme-ATP complex being 2.6 mM, and the enzyme-NADP+-ATP dissociation constant 12.8 mM.

Adenosine Triphosphate↗
PubMed1985

Blast crisis of chronic granulocytic leukemia with mast cell and basophilic precursors.

The authors report a patient with Ph1-positive chronic granulocytic leukemia (CGL) who developed "blast crisis" after six years of chronic phase. The presence of mast cell precursors and basophil blasts was demonstrated by ultrastructural morphology and cytochemistry. Membrane phenotype studies with monoclonal antibodies helped in the further characterization of these cells. The possible implication of these findings in the origin of mast cells and the relationship of these cells with basophils are discussed.

Adult↗
PubMed1985

Cytoplasmic malate dehydrogenase from Phycomyces blakesleeanus: kinetics and mechanism.

The kinetics and reaction mechanism of cytoplasmic malate dehydrogenase (L-malate:NAD+ oxidoreductase, EC 1.1.1.37) from mycelium of Phycomyces blakesleeanus NRRL 1555 (-) in 0.1 M potassium phosphate buffer (pH 7.5) at 30 degrees C have been investigated. The initial rate and product inhibition studies were consistent with an ordered bi-bi mechanism that involved more than one kinetically significant ternary complex and also with the coenzyme binding first. The dissociation of the coenzyme from the enzyme-coenzyme complex appeared to be the slowest step in either direction of the reaction. The kinetic and rate constants for the individual steps of the reaction were determined.

Cytoplasm↗
PubMed1984

In situ behaviour of D(-)-lactate dehydrogenase from Escherichia coli.

Some kinetic properties of the D(-)-lactate dehydrogenase (EC 1.1.1.28) of Escherichia coli have been investigated. There were marked differences between the kinetic properties of the enzyme studied in situ compared with the in vitro D(-)-lactate dehydrogenase. D(-)-Lactate dehydrogenase in situ showed high substrate inhibition with pyruvate over the pH range 6.0-7.0, whereas the enzyme in vitro did not. The pH optimum for pyruvate reduction by the in situ D(-)-lactate dehydrogenase ranged between pH 7.5 and 7.8, whereas the in vitro enzyme showed its pH optimum between pH 6.8 and 7.0. The pK values of the prototropic groups that controlled the enzymatic activity shift to the acidic region for the in vitro enzyme with respect to the in situ enzyme. In vitro D(-)-lactate dehydrogenase exhibits homotropic interactions with its substrate, pyruvate and its coenzyme, NADH, at pH values ranging between pH 6.0 and 8.5, but the in situ enzyme showed homotropic interactions neither with pyruvate nor with NADH at all pH values studied.

Escherichia coli↗
PubMed1984

The kinetic mechanism of pyruvate reduction by lactate dehydrogenase from Phycomyces blakesleeanus.

The kinetics of pyruvate reduction by lactate dehydrogenase from Phycomyces blakesleeanus NRRL 1555 (-) have been determined at pH 6.0. Initial rate studies performed in the pyruvate reduction direction suggest that a sequential mechanism is operating. Product inhibition studies with NAD+ and L(+)-lactate are consistent with an ordered sequential mechanism if we considered that NAD+ mimics the NADH that binds cooperatively on the enzyme and also the existence of dead-end complex responsible for substrate inhibition by pyruvate at this pH value.

Fungi↗