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Biomedical subjects

J Hakim

Publications and source records attributed to J Hakim.

At least 163 records · Page 9Linked to original sources
PubMed1978

Cyanide-insensitive NADH oxidation by subcellular fractions isolated from human polymorphonuclear blood cells.

The biochemical triad, NADH oxidation, oxygen (O2) uptake and hydrogen peroxide (H2O2) formation, by subcellular fractions of human blood polymorphonuclears (PMNs) was investigated. It was found that this biochemical triad (1) was under the control of the granule-rich fraction (GRF) only; (2) was not inhibited by cyanide; (3) occurred stoichiometrically for its three components, and (4) accounted quantitatively for the respiratory burst of the stimulated PMN. It was also shown that the above biochemical triad (1) involved an enzymatic step; (2) was enhanced by acidic pH (0.5) and Mg++; (3) was inhibited by Cu++ or low concentration of Mn++; (4) was dependent on H2O2, perhydroxyl radical (HO2) and hydroxyl radical (HO) since either catalase or superoxide dismutase or scavengers of HO2 or HO were inhibitor, and (5) involved multistep reactions. Evidence is provided that the sequence of the reactions is first a generation of H2O2, (spontaneously from NADH in our incubation medium), secondly the production of HO from H2O2, thirdly the oxidation of NADH with further production of HO2,O2 uptake and H2O2 formation, probably through a chain reaction. The identification of the enzyme(s) involved in these multistep reactions needs further studies.

Cyanides↗
PubMed1978

[The development of urogenital organs after lateral mesoblast heterotopic graft in the toad (Bufo bufo) neurula. I. Distinct inversions of anteroposterior and dorsoventral axis of the lateral plate (author's transl)].

Anteroposterior inversion of lateral mesoblast of early toad neurula is followed by differentiation of diverse urogenital blastema, according to the transplant position before the graft. Anteroposterior polarity of lateral mesoderm is thus perfectly determined in young neurula. On the contrary, dorsoventral inversion of lateral mesoblast leads to mesodermic blastema formation according to the transplant position after the graft. Particularly, the dorsal region of the lateral plates displaced to ventral position does not form blastema. On the other hand, the ventral region which shows a dorsal position after the graft develops and produces a typical blastema. Thus, in the young neurula, the dorsoventral polarity is not yet determined in the lateral plate of the mesoblast. Such a result shows also that the ventral and posterior regions of the lateral mesoblast are competent to form blastema. Moreover, factors from dorsal origin and external to lateral mesoblast take part in urogenital organ anlagen formation.

Animals↗
PubMed1978

[The development of urogenital organs after lateral mesoblast heterotopic graft in the toad (Bufo bufo) neurula. II. Simultaneous inversion of anteroposterior and dorsoventral axis of the lateral plate].

Simultaneous inversion of the anteroposterior and dorsoventral axes of the lateral mesoblast in the early toad neurula leads to the total agenesis of the urogenital organs. The experimental results show that the lateral mesoblast is unable to undergo self-differentiation, and that three factors at least are required for the formation of the urogenital blastemata. The mesoblast must be competent: only the posterior (dorsal, but also ventral) part of the lateral mesoderm is endowed with this competence. It must receive two stimulating influences, from the cordomesoblast on the one hand, and from the dorsocaudal endoblast on the other hand.

Animals↗
PubMed1977

Blood polymorphonuclear dysfunction in patients with alcoholic cirrhosis.

Polymorphonuclear leucocyte function was investigated in twenty patients with alcoholic cirrhosis and three patients with cryptogenic cirrhosis. Bacterial ingestion, oxygen-dependent bactericidal capacity, and chemotactic response were measured. Serum dependent abnormalities were common; they included deficiencies of ingestion and of all subsequent oxygen-dependent metabolic events (three patients), all oxygen-dependent metabolic events (one patient), cytochrome c reduction and iodination deficiencies (six patients), isolated cytochrome c reduction deficiency (ten patients), and chemotactic deficiencies (fourteen out of eighteen patients). Serum-independent abnormalities were much less common; they included increased ingestion rate (four patients), decreased stimulated reduction of nitroblue tetrazolium (three patients), and decreased myeloperoxidase content (eight patients). Polymorphonuclear leucocyte abnormalities are frequent in cirrhosis and may account in part for increased susceptibility to infection in that disease.

Adult↗
PubMed1977

Metabolic activity of phagocytosing granulocytes in chronic granulocytic leukemia: ultrastructural observation of a degranulation defect.

The functional capacities of granulocytes in patients with chronic granulocytic leukemia are still a subject of controversy, probably due to the heterogeneity of the abnormalities observed from patient to patient. For a better definition of these abnormalities, 14 patients with untreated chronic granulocytic leukemia were studied. The patients were divided into three groups on the basis of the functional activities of their phagocytosing granulocytes. In four patients (group I), the granulocytes were normal in respect to particle ingestion, nitroblue tetrazolium (NBT)-stimulated reduction, cyanide-insensitive oxygen (O2) consumption, superoxide anion (O2-)-stimulated production, hydrogen peroxide (H2O2) production, and iodination. They also had a normal myeloperoxidase (MPO) content. In four patients (group III), the granulocytes were significantly defective in all of these activities. In the six remaining patients (group II), all the initial metabolic steps of the phagocytosing granulocytes (ingestion, NBT reduction, O2 consumption, O2-production, H2O2 production) were normal, as were the MPO content of the granulocytes, while iodination was strikingly decreased. These metabolic features suggested a degranulation defect which was observed ultrastructurally in the only patient studied among these six. The phagocytosing granulocytes of this patient did not degranulate and no deposits of MPO activity were seen in the phagosomes.

Cytoplasmic Granules↗
PubMed1976

Bilirubin and paranitrophenol glucuronyl transferase activities and ultrastructural aspect of the liver in patients with chronic hemolytic anemias.

The hepatic ultrastructural aspect and the hepatic bilirubin (Bil-GT) and paranitrophenol (PNP-GT) glucuronyl transferase activities were studied in twenty subjects with a chronic hemolytic anemia (HA) and five subjects with an aplastic anemia. In chronic HA: the hepatic ultrastructural aspect showed mitochondrial abnormalities affecting structure (paracrystalline inclusions), size (giant mitochondria) and shape (irregular mitochondria); there was a decrease of Bil-GT activity in 80 percent of the patients. No connection could be shown between the HA etiology and the degree of the enzymatic activity decrease. The physiopathological mechanism of this enzymatic activity decrease is unknown; no deficiency of PNP-GT was observed; in chronic aplastic anemias there does not seem to be any modification, either of Bil-GT activity, or of hepatic PNP-GT activity. It is concluded that Bil-GT is often decreased in HA and that neither Bil-GT measurement nor the ultrastructural aspect of the liver distinguish chronic HA from Gilbert's syndrome.

Anemia, Aplastic↗
PubMed1976

Studies on the mechanism of NADPH oxidation by the granule fraction isolated from human resting polymorphonuclear blood cells.

Various factor affecting NADPH-oxidation by resting human leucocyte granules (LG) at acid pH, have been investigated. It was found that: 1) oxidation of NADPH by LG was increasingly inhibited by increased cyanide concentrations in the medium and was abolished by 4 mM cyanide. 2) with or without cyanide in the incubation medium, LG omitted, Mn++ in the presence of NADPH induced superoxide anion (O- WITH 2) production, as evidenced by oxygen consumption and H2O2 production, which were abolished (in the absence of cyanide) by cytochrome C (a potent O- with 2 scavenger). 3) Both NADPH oxidation in the presence of 2 mM cyanide (cyanide-resistant) and in its absence (cyanide-sensitive) by LG occurred only in the presence of Mn++, and both were inhibited by superoxide dismutase. 4) Cyanide-resistant NADPH oxidation by LG generated H2O2, was inhibited by H2O2 and was not modified by "active" catalase. The ratio of cyanide-resistant NADPH oxidation/O2 uptake was 1 up to 1.25 mM NADPH, and increased above this concentration. 5) Cyanide-sensitive NADPH oxidation was inhibited by catalase and increased upon addition of H2O2. The ratio of cyanide-sensitive NADPH oxidation/O2 uptake was 2. It was concluded that after initiation by O - with 2, produced independently of LG, two sequential types of LG dependent NADPH oxidations occur. First, an O - with 2-dependent protein mediated NADPH oxidation (cyanide-resistant) which generates H2O2 and O - with 2 occurs. Second, NADPH peroxidation (cyanide-sensitive) which utilizes H2O2 takes place.

Cyanides↗
PubMed1976

Bilirubin and paranitrophenol glucuronyl transferase activities of the liver in patients with Gilbert's syndrome An attempt at a biochemical breakdown of the Gilbert's syndrome.

Hepatic bilirubin (Bil-GT) and paranitrophenol glucuronyl transferase (PNP-GT) activities were measured in 26 subjects with Gilbert's syndrome (GS) and in one subject with a Crigler-Najjar type 2. Firstly, the results allowed us to distinguish three groups of patients in GS. In the first group, Bil-GT activity decreased by 25% of that of the controls and PNP-GT activity was normal. In the second group, Bil-GT decreased by 25% of that of the controls and PNP-GT decreased by 50% of that of the controls. In the third group, Bil-GT decreased by 50% of that of the controls and PNP-GT activity was normal. Secondly, the results showed in the Crigler-Najjar type 2 that Bil-GT activity was 25% of that of the controls and PNP-GT was 10% of that of the controls. From these results the following hypothesis has been raised: (1) the subjects of the third GS group were probably heterozygous to the homozygous disease which affected the subjects of the first GS group, and (2) the subjects of the second GS group were most likely heterozygous to the homozygous disease which affected our Crigler-Najjar type 2. However, in the present state of our knowledge, the scheme of GS classification which we propose requires confirmation.

Bilirubin↗
PubMed1975

[Conseqquences of dorso-ventral and anterior-posterior reversion of early neurula lateral mesoblast on development of urogenital system in common toad, Bufo bufo. (Amphibia anura)].

At early neurula stage of the toad, cranio-caudal and dorso-ventral reversal of lateral mesoblast is performed. The genito-urinary system is therefore missing after this intervention. The three following factors of the formation of this system anlage are anlyzed: lateral mesoderm competence, stimulative activites of dorso-caudal endoblast on the one hand, of chordo-mesoderm on the other hand.

Animals↗
PubMed1975

[The effects of anterio-posterior and dorso-ventral inversions of the lateral mesoblast of the neurula on the formation of the mesonephric, medullary, and adrenal anlage of the common toad, Bufo bufo L. (Amphibia, Anoura)].

The experimental results of cranio-caudal reversal and dorso-ventral reversal of the lateral mesoblast of the toad early neurula prove that, at this stage, the cranio-caudal polarity of this tissue is fixed but not the dorso-ventral one. External factors are responsible for the formation of mesonephric, adrenal and gonadal medullary anlage by the lateral mesoblast.

Adrenal Glands↗
PubMed1975

Quantitative iodination of human blood polymorphonuclear leukocytes.

It was shown by Pincus and Klebanoff that a correlation existed between leukocytic iodination measured in vivo and microbicidal leukocytic activity. We have analyzed the results of this test in relation to time and in the presence of variable quantities of polymorphonuclear leukocytes (PMN). The values observed per time and PMN unit proved to be equivalent in the presence of 2.5 X 105 PMN or 5.0 x 105 PMN per 0.5 ml of incubation medium, measured after 10, 20 and 30 minutes or in the presence of 1.0 x 106 PMN, measured after 10 minutes. That is to say iodination is proportional to leukocyte concentration and incubation time. Increase of either the quantity of cells or the incubation time, beyond the area we defined, reduced iodination per cell and per unit of time. Concerning the patients with an insufficient iodination, we have studied 2 parameters in the presence of 5.0 x 105 PMN: 1) initial iodination measured after 10 and 20 minutes and 2) stability of iodination measured after 60 minutes. These two parameters were equally affected in two cases with myelofi-rosis, 3 patients with acquired refractory anaemia, one with chronic lymphoid leukaemia, one with erythroleukaemia, one with hairy cell leukaemia, one with systemic mastocytosis and almost complete myeloperoxidase dificiency, one with sickle cell disease, two with liver diseases and two with chronic myeloid leukaemia. The iodination at the 60th minute was more affected than at the 10th minute with a patient with myelofibrosis and 4 other patients with acquired refractory anaemias. The significance of these differences is not well understood; however the meaning of the decrease in the iodination of whatever type is that a PMN anomaly exists directly related to the myeloperoxidase H2O2 halogenation system, or to one of the stages of engulfment and/or metabolic events preceeding it and leading to the production of H2O2. This test, with the alterations we introduced, is suggested as a test for detection of functional PMN abnormalities.

Blood Bactericidal Activity↗
PubMed1975

Gd(minus)Matam, an African glucose-6-phosphate dehydrogenase variant with enzyme deficiency. Biochemical and immunological properties in various hemopoietic tissues.

Two unrelated Senegalese patients, both native of the Matam province, were found to have the same deficient G6PD variant. One has no hematological history, the other had several induced acute hemolytic episodes. The deficiency was almost complete in red blood cells and 20-30 percent of the normal level in leukocytes and platelets; in leukocytes the deficiency was due to a decrease in the molecular specific activity of the enzyme to which a molecular instability was added, explaining the greater deficiency in red blood cells. The electrophoretic mobility was slightly fast in leukocytes and platelets but normal in red blood cells. This pattern was confirmed by electrofocusing in ampholine-acrylamide gel. From a kinetic point of view, these enzymes were characterized by a lowered Km (G6P) (13 to 20 muM) a normal Km (NADP+), a Ki (NADPH) increased about twice, a thermal instability, a biphasic pH curve and an increased activation energy (15 kcal/mole). The polymorphonuclear cells were functionally strictly normal: engulfment, nitroblue tetrazolium (NBT) reduction test, induced iodination, and oxygen consumption were normal. The authors discuss the importance of post-synthetic modifications of the muted enzymes and their repercussions on the enzyme characteristics.

Blood Platelets↗
PubMed1975

Acquired erythroenzymopathies in blood disorders: study of 200 cases.

Enzyme abnormalities are frequently found in the red cells of patients with various acquired blood disorders. In leukaemias, preleukaemic states and bone marrow insufficiencies with or without sideroblastosis, changes in enzyme activity are usually characterized by the coexistence of deficiency of some enzymes and an increased activity of others. The most frequently decreased activities are those of pyruvate kinase, phosphofructokinase,2,3-diphosphoglycerate mutase and adenylate kinase; the most frequently increased activities are those of hexokinase, aldolase, enolase, 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase. In primary myelofibrosis and in polycythaemia rubra vera, enzyme deficiencies are infrequent and differ from those observed in leukaemias and related disorders. Phosphohexose isomerase and phosphoglucomutase deficiencies seem relatively specific for polycythaemia rubra vera. Explanations for the acquired enzymopathies are still at the stage of hypothesis. The theory of multiple genetic damage may explain some findings but has not yet been proved right. The possibility of post-translational molecular modification is suggested as a working hypothesis.

Anemia, Aplastic↗
PubMed1975

Acquired red cell pyruvate kinase deficiency in leukemias and related disorders.

The authors studied red blood cell pyruvate kinase activity of 202 patients with various hemopathies. A PK deficiency of moderate grade was found in 39% of patients with acute myeloblastic leukemias, in 57% of those with primary medullary insufficiency without aplasia, in 61% of those with refractory sideroblastic anemia. The PK deficiency was often associated with deficiencies of other red cell enzymes. The mechanism of such enzyme abnormalities was discussed with the hypothesis of a post-translational molecular alteration.

Anemia↗