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J Soler

Publications and source records attributed to J Soler.

At least 145 records · Page 8Linked to original sources
PubMed1991

Mitochondrial F1-ATPase moiety from Phycomyces blakesleeanus: purification, characterization, and kinetic studies.

Mitochondrial F1-ATPase was purified from the mycelium of Phycomyces blakesleeanus NRRL 1555(-) and its kinetic characteristics were studied. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the enzyme reveals five bands (alpha, beta, gamma, delta, and epsilon) characteristic of the F1 portion with apparent molecular weights of 60,000, 53,000, 31,000, 25,000, and 21,000, respectively. The molecular weight of the native F1-ATPase from Phycomyces blakesleeanus was in agreement with the stoichiometry alpha 3 beta 3 gamma delta epsilon. The MgATP complex is the true substrate for ATPase activity which has a Km value of 0.15 mM. High concentrations of free ATP or free Mg2+ ions inhibit the ATPase activity. ADP appears to act as a negative allosteric effector with regard to MgATP hydrolysis, with the apparent Vmax remaining unchanged.

Adenosine Diphosphate↗
PubMed1991

Hysteretic behaviour and GSSG substrate inhibition shown by glutathione reductase from Phycomyces blakesleeanus.

Phycomyces blakesleeanus glutathione reductase shows hysteretic behaviour under experimental conditions, when GSSG substrate inhibition is observed. The progress curves for the reaction show an acceleration phase. The degree of hysteresis varied inversely as the enzyme concentration. It increased when GSSG or NADPH concentration increased, whereas the addition of GSH or NADP+ to the initial reaction mixture prevented it from occurring. In addition, hysteresis was dependent on pH, ionic strength and temperature, decreasing as any of these parameters increased. The parallel effects of pH and ionic strength on the GSSG substrate inhibition and hysteretic behaviour suggest a relationship between these two mechanisms. From the overall results reported in this paper, we propose that the hysteretic behaviour shown by Phycomyces glutathione reductase could be due to a process of time-dependent accumulation of reaction products rather than to a slow conformational change.

Glutathione↗
PubMed1991

Thyroid stimulating antibodies in patients with Graves' ophthalmopathy.

The possible pathogenetic role of thyroid stimulating antibodies (TSAb) was studied in 24 patients. The TSAb were measured by their ability to stimulate concentration of cAMP in human thyroid slices incubated in vitro with the immunoglobulins of these patients. The patients were divided in two groups: Group I, 16 patients with eye disease and hyperthyroidism and Group II, eight patients with eye disease but without hyperthyroidism. TSAb, were found to be high in 15 patients of the Group I (3.22 +/- 1.74 pmol cAMP/mg of wet tissue, mean +/- S.E.M.) whilst were normal in six patients of the Group II (0.98 +/- 0.53 pmol cAMP/mg of wet tissue, mean S.E.M.) (p < 0.001). These findings indicate that TSAb is not a marker of the Graves' ophthalmopathy and support the concept that hyperthyroidism and exophthalmos are two separate disorders.

Adolescent↗
PubMed1991

[Thyroid dysfunction induced by amiodarone in Catalonia. Prevalence and characteristics].

The purpose of this study was to review the epidemiological aspects and the characteristics of the thyroid disfunction produced by amiodarone in Catalonia, an area with type I endemic goiter. For this purpose, three groups of patients have been studied: 1) 102 patients with prolonged amiodarone treatment, out of whom 6 (5.9%) presented hyperthyroidism, and 2 (1.9%) hypothyroidism. 2) 909 patients with hyperthyroidism of any origin out of which 42 (4.6%) were produced by amiodarone. 3) 203 patients presenting primary hypothyroidism of any origin out of which 11 (3.8%) were induced by amiodarone. Out of the 48 patients with amiodarone induced hyperthyroidism, 16 presented multinodular goiter, 2 toxic thyroid goiter and 7 Graves Basedow disease. Thyroid uptake of 131I was studied in 10 cases being normal or increased in six of them, all with a underlaying thyroid pathology. Out of the 13 patients with amiodarone induced hypothyroidism, 3 presented diffuse goiter; thyroid uptake of 131I was studied in 5 patients, being normal or increased in 4 cases, 2 of which with thyroid pathology. Amiodarone administration very often produces thyroid disfunction, specially hyperthyroidism. These patients with hyperfunctional thyroids usually present underlying thyroid pathologies in which thyroid uptake of 131I are frequently not suppressed as well as in those patients in whide amiodarone induced hypothyroidism.

Adolescent↗
PubMed1991

Inhibition by excess of free ATP, and free Mg2+ ions of the mitochondrial F1-ATPase moiety from Phycomyces blakesleeanus.

High concentrations of either Mg-ATP complex, free ATP, or free Mg2+ ions were inhibitors of the mitochondrial F1-ATPase moiety from Phycomyces blakesleeanus. Free Mg2+ acts as a linear competitive inhibitor with regard to Mg-ATP hydrolysis with a Ki value of 2.8 mM. The inhibition by free ATP was markedly biphasic and thus simple competitive inhibition alone is not sufficient to explain the inhibitory effect. From these results conclusions were drawn about the binding of the substrate, Mg-ATP complex, to the enzyme.

Adenosine Triphosphate↗
PubMed1991

Allogeneic bone marrow transplantation in chronic lymphocytic leukemia: 17 cases. Report from the EBMTG.

Allogeneic bone marrow transplantation (BMT) was performed in 17 patients with chronic lymphocytic leukemia (CLL): 15 resistant and two untreated forms. There were 12 males and five females with a mean age of 40 years (32-49). The conditioning regimens and graft-versus-host disease (GVHD) prophylaxis varied. Successful engraftment was obtained in 15 evaluable cases. Lymphocytosis and clinical symptoms subsided in all but one case. All 15 evaluable patients developed acute GVHD. Among the 17 patients grafted, one early death was observed at the 15th day post-BMT, and one refractory patient died 2 months after BMT. Of the remaining 15 patients in complete remission (CR), four died from GVHD, hemorrhage and graft failure, and two relapsed at 7 and 54 months after BMT and died. Nine patients are alive in CR with a mean follow-up of 25.6 months (4-48). Chimerism was complete in eight patients and partial in the two T cell-depleted cases. In one case, an immunoglobulin gene rearrangement study showed no residual disease. These results suggest that allogenic BMT might be an alternative and possible curative therapy for refractory CLL in young patients when performed relatively early in the disease.

Adult↗
PubMed1990

Isocitrate lyase from Phycomyces blakesleeanus. The role of Mg2+ ions, kinetics and evidence for two classes of modifiable thiol groups.

Isocitrate lyase was purified from Phycomyces blakesleeanus N.R.R.L. 1555(-). The native enzyme has an Mr of 240,000. The enzyme appeared to be a tetramer with apparently identical subunits of Mr 62,000. The enzyme requires Mg2+ for activity, and the data suggest that the Mg2(+)-isocitrate complex is the true substrate and that Mg2+ ions act as a non-essential activator. The kinetic mechanism of the enzyme was investigated by using product and dead-end inhibitors of the cleavage and condensation reactions. The data indicated an ordered Uni Bi mechanism and the kinetic constants of the model were calculated. The spectrophotometric titration of thiol groups in Phycomyces isocitrate lyase with 5.5'-dithiobis-(2-nitrobenzoic acid) gave two free thiol groups per subunit of enzyme in the native state and three in the denatured state. The isocitrate lyase was completely inactivated by iodoacetate, with non-linear kinetics. The inactivation data suggest that the enzyme has two classes of modifiable thiol groups. The results are also in accord with the formation of a non-covalent enzyme-inhibitor complex before irreversible modification of the enzyme. Both the equilibrium constants for formation of the complex and the first-order rate constants for the irreversible modification step were determined. The partial protective effect of isocitrate and Mg2+ against iodoacetate inactivation was investigated in a preliminary form.

Ammonium Sulfate↗
PubMed1990

[Peripheral T-cell lymphoma. Morphologic, immunophenotypic and immunogenotypic studies of 10 cases].

We describe the histopathology, immunophenotype and immunogenotype of 10 cases of peripheral T-cell lymphoma. The majority of patients showed disseminated disease at the time of diagnosis. From a histopathological view point the cases were classified into 5 types: T zone lymphoma (4 cases); Lennert lymphoma (2 cases); pleomorphic lymphoma, small all type (2 cases); pleomorphic lymphoma of medium-sized cell type (1 case); pleomorphic lymphoma of large cell type (1 case). In most of them the neoplastic cells demonstrated a mature T-cell phenotype: CD3+, CD4+, CD8-, CD43+, CD45RO+, CD45RA-, CD20- and surface immunoglobulins. All cases studied displayed gene rearrangements for the T-cell receptor beta chain while the immunoglobulins genes remained in germinal configuration. Antibodies against the human T-cell lymphotropic virus type I were not found in the 9 samples studied.

Adult↗
PubMed1990

[Treatment of resistant or relapsing Hodgkin's disease with high doses of chemotherapy followed by autologous bone marrow transplant].

Eleven patients with Hodgkin's disease were treated with high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT). Four patients were resistant to initial therapy and 7 patients had relapsed but were progressing under second or third line therapy. The median time from initial diagnosis to transplantation was 44 months (range, 16 to 82). In 9 patients pre-ABMT consisted on high-dose CVB cyclophosphamide, etoposide and carmustine) chemotherapy, one patient was treated with BACT protocol (carmustine, cytosine arabinoside, cyclophosphamide and thioguanine) and other patient was treated with high-dose of busulfan and melphalan. In 8 patients complete remission (CR) was achieved, in one the remission was partial, one failed to respond and one case was not evaluable due to early death. Among CR patients, 2 died from late toxicity, and the other 6 remain in CR off therapy, one of them more than 33 months after ABMT. High-dose therapy produce severe myelosuppression in all patients. There were 3 treatment related death: one early death due to hemorrhagic myocarditis, one veno-occlusive disease of the liver and one due to cytomegalovirus sepsis. The high complete response rate in these heavily pretreated patients suggests that there may be an indication for high-dose therapy and ABMT in earlier resistant Hodgkin's disease. Moreover under such conditions, treatment related morbidity would be expected to be lower.

Adolescent↗
PubMed1990

Clinical and pathologic studies of twenty-six patients with penetrating foreign body injury to the joints, bursae, and tendon sheaths.

Foreign body synovitis has been neglected in the rheumatology literature. We describe 26 patients in whom arthritis, bursitis, or tenosynovitis appeared within 1 day to 7 years after an initial injury by a penetrating foreign body. Twenty-two patients presented with acute synovitis, which was followed by chronic or recurrent inflammation mimicking septic arthritis, osteomyelitis, monarticular juvenile rheumatoid arthritis, bone tumor, or apatite deposition disease. Foreign bodies were not seen in 5 inflammatory synovial fluids studied, but were seen in the synovium or periarticular tissues of 17 patients. Excisional biopsy was required in most patients for precise diagnosis and treatment.

Adolescent↗
PubMed1990

A study of the kinetic mechanism followed by glutathione reductase from mycelium of Phycomyces blakesleeanus.

An investigation of the reaction mechanism of glutathione reductase isolated from the mycelium of Phycomyces blakesleeanus NRRL 1555(-) was conducted. The enzyme showed GSSG concentration-dependent substrate inhibition by NADPH and pH-dependent substrate inhibition by GSSG. At pH 7.5, the kinetic data were consistent with a basic scheme corresponding to the branching mechanism, involving a ping-pong with formation of a dead-end F.NADPH complex and an ordered sequential mechanism. Both pathways have in common the step in which NADPH binds to the free oxidized form (E) of the glutathione reductase. At low concentrations of GSSG the ping-pong mechanism prevails, whereas at high concentrations the ordered mechanism appears to dominate. The data were analyzed on the basis of the limiting ping-pong mechanism with F.NADPH complex formation and of the hybrid mechanism, and the kinetic constants of the model were calculated. The data obtained at acidic pH values do not rule out the possibility that the kinetic model may be more complicated than the basic scheme studied.

Glutathione↗
PubMed1990

Immunophenotype of blast cells in acute myelofibrosis.

The immunophenotype of peripheral blood blast cells from six patients with acute myelofibrosis was studied using a panel of monoclonal antibodies directed against granulocytic, erythroid, megakaryocytic and lymphoid antigenic determinants. In all patients most of the blast cells were labeled with anti-HLA-DR and with the early myelomonocytic antibodies My7 (CD13), My9 (CD33) and B1-3C5 (CD34) (3/3). In three cases, platelet antibodies Edu3 (CD41) and GPIIIa (CD61) reacted with about 30% of blast cells. TdT was positive in two out of six samples studied. Lymphoid markers T3 (CD3), Leu9 (CD7), J5 (CD10), B4 (CD19) and B1 (CD20) were negative in all cases. These results suggest that blast cells are mainly of immature myelocytic origin. However, the coexistence of megakaryoblasts cannot be ruled out in the cases with a proportion of cells that are positive with Edu3 and GPIIIa antibodies.

Acute Disease↗
PubMed1990

Different lymphocyte activity in patients with polycythaemia vera versus secondary polycythaemia and healthy blood donors.

On comparing lymphocyte patterns in patients with polycythaemia vera (PV) versus healthy blood donors (NC) and patients with secondary polycythaemia (SP), we observed an altered CD4/CD8 ratio (p less than 0.01) mainly due to the decreased CD8 subpopulation in PV. We found an increased lymphocyte activity in PV patients when compared with both SP and NC: the interleukin 2 (IL-2) production was significantly higher (p less than 0.001) as was the lymphoproliferative response both to phytohaemagglutinin (p less than 0.001) and IL-2 (p less than 0.005). No significant differences were found between NC and SP. None of the PHA-stimulated PBMC samples from PV, SP or NC produced erythropoietin (EPO)-like or EPO-inhibitory activity. Our findings suggest an altered lymphoid lineage in PV patients.

Antibodies, Monoclonal↗