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C Legoff

Publications and source records attributed to C Legoff.

4 recordsLinked to original sources
PubMed1996

Na(+)-K+(NH4+)-2Cl- cotransport in medullary thick ascending limb: control by PKA, PKC, and 20-HETE.

Cell pH was monitored in suspensions of medullary thick ascending limbs (MTALs) of rat kidney to determine possible effects of various transduction pathways on apical Na(+)-K+ (NH4+)-2Cl- cotransport, the activity of which was measured as the bumetanide-sensitive component of cell acidification caused by abrupt exposure to 4 mM NH4Cl. 8-Bromoadenosine 3',5'-cyclic monophosphate stimulated cotransport activity through activation of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA), since the cAMP effect was abolished by N-[2-(p- bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89); stimulation by cAMP (P < 0.02) was observed even when other Na+, Cl-, and K+ carriers were blocked by ouabain, diphenylamine-2-carboxylate, and barium, which indicates that cotransport was directly affected by PKA. Phorbol 12,13-dibutyrate also stimulated cotransport activity (P < 0.03), which was abolished by protein kinase C (PKC) blockade by staurosporine. In contrast, cotransport activity was reduced (P < 0.001) by arachidonic acid or 20-hydroxyeicosatetraenoic acid (20-HETE), as well as by an ionomycin-induced rise in cytosolic Ca2+ ([Ca2+]i). Inhibition by arachidonic acid or ionomycin was abolished by econazole and SKF-525A that inhibit cytochrome P-450-dependent monoxygenase, which produces 20-HETE from arachidonic acid in the MTAL, and the ionomycin effect was prevented when phospholipase A2 (PLA2) was blocked by 4-bromophenacyl bromide or oleyloxyethyl phosphorylcholine. The results demonstrate that MTAL apical Na(+)-K+(NH4+)-2Cl- cotransport is stimulated by PKA and PKC and inhibited by 20-HETE that may be produced after a rise in [Ca2+]i through PLA2 activation.

Ammonia↗
PubMed1994

Comparison of nested PCR for detection of DNA in plasma with pp65 leukocytic antigenemia procedure for diagnosis of human cytomegalovirus infection.

A nested PCR was used for the detection of human cytomegalovirus (HCMV) DNA in plasma. The presence of HCMV DNA and its correlation to pp65 leukocytic antigenemia were investigated with 299 blood samples from 45 organ transplant recipients and 63 AIDS patients. Of the 53 samples positive by nested PCR, 52 (98%) were also positive for leukocytic antigenemia and 23 had high levels of antigenemia (> 50 positive cells per 2 x 10(5) leukocytes). Of the 246 samples negative in PCR, only 3 (1.2%) had highly positive antigenemia. For 15 patients having a high antigenemia level in the course of their disease, consecutive blood samples were studied and also assessed for viremia in culture. The extent to which HCMV DNA, detected by PCR, was present in plasma correlated with increased levels of HCMV leukocytic antigenemia for six of the eight AIDS patients and for all the organ transplant recipients. Positivity for HCMV DNA in PCR and for viremia in cell culture was usually restricted to the highest antigenemia levels. From a total of 69 blood samples, PCR and culture gave positive results, respectively, for 17 of 32 samples (53%) and 14 of 32 samples (43%) from transplant recipients and for 15 of 37 samples (40%) and 9 of 37 samples (24%) from AIDS patients. Our findings have shown a strong correlation between high levels of leukocytic antigenemia and HCMV DNA in plasma. The detection of HCMV DNA in plasma by this nested PCR can prove HCMV dissemination in blood, but it lacks the rapidity and simplicity of the leukocytic pp65 antigenemia procedure.

AIDS-Related Opportunistic Infections↗
PubMed1987

Specific antibody response to Pasteurella multocida.

Six patients with culturally proven Pasteurella multocida infection were evaluated serologically. The infections were 1 foot abscess, 1 septicemia, 3 bronchitis and 1 bronchopneumonia. Most of them were elderly women closely exposed to pets or domestic animals. The serotypes of the strains were determined in 5 cases (3 A3, 2 A7). Specific antibodies against capsular and somatic antigens of P. multocida were determined by indirect hemagglutination and agglutination respectively. The antibodies were strictly directed against the capsular and somatic specificities of the isolated strain. The range of the serum antibody titers were 20 to 2,560 to capsular antigens and 5 to 640 to somatic antigens within 2 weeks after the first clinical signs of infection. Several months after successful treatment, the capsular antibodies were lower while the somatic antibodies had almost disappeared. These findings suggest a good sensitivity for these serologic methods in active cases. Declining antibody titers follow healing. Cross-reactivity of the serologic tests with other bacteria was not observed. Serologic diagnosis of P. multocida infections is a possible alternative to direct diagnosis when cultures are negative or when unusual localizations must be confirmed.

Adult↗