Biomedical subjects
B Granger
Publications and source records attributed to B Granger.
[The concept of psychiatric threshold in hemodialysis and kidney transplantation].
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[Carbamazepine: a new perspective in the treatment of affective diseases].
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Some factors inducing formation of metacyclic stages of Trypanosoma cruzi.
Epimastigotes of Trypanosoma cruzi, Peru strain, incubated in Contreras' artificial triatomine urine transformed into metacyclic trypomastigotes within 48 h at 28 degrees C when 10 mM L-proline or L-glutamate was added to the medium. Smaller numbers of metacyclic stages were induced in the presence of glucose or L-alanine. The L-leucine and L-isoleucine, 2 amino acids known to inhibit proline catabolism, inhibited proline-induced metacyclogenesis. Cells gassed with 5% CO2 showed significantly faster rates and higher levels of transformation than those not gassed, therefore indicating the additional importance of CO2 for transformation.
Further studies on substrates inducing metacyclogenesis in Trypanosoma cruzi.
Epimastigotes of Trypanosoma cruzi, Peru strain, incubated in Contreras' artificial triatomine urine transformed into metacyclic trypomastigotes when 10 mM L-glutamine, L-asparagine or D-fructose was added to the medium. Metacyclogenesis with these substrates was comparable to the percent metacyclic morphotype formation induced by L-proline and significantly greater than that stimulated by 10 mM D-glucose. Sodium acetate (10 mM) increased transformation induced by L-proline, and L-hydroxyproline (10 mM) increased transformation induced by D-fructose. Phosphoenolpyruvate (10 mM) inhibited L-proline-induced metacyclic trypomastigote stage formation. Three antimetabolites, azetidine 2-carboxylate (5 mM), malonic acid (1 mM), and desthiobiotin (5 mM), completely inhibited D-fructose-induced but not L-proline-induced transformation. The Costa Rica, Y, and CL strains of T. cruzi showed different patterns of percent metacyclogenesis with substrates that induce transformation in the Peru strain.
Hepatitis C virus in patients with polyarteritis nodosa. Prevalence in 38 patients.
In order to assess the prevalence of hepatitis C virus (HCV) in polyarteritis nodosa (PN), 38 patients with systemic necrotizing angiitis were retrospectively tested for the presence of anti-HCV antibodies (Ab). Twenty-one patients were hepatitis B virus (HBV) positive, comprising group A, and 17 were HBV negative, comprising group B. Two patients from group A had anti-HCV Ab (2/21: 9.5%). One was treated unsuccessfully with corticosteroids, then with vidarabine and plasma exchanges; HBe/anti-HBe seroconversion was not observed and anti-HCV Ab disappeared 8 months after the onset of PN. The second patient was successfully treated with corticosteroids, then vidarabine and plasma exchanges; he recovered from PN, HBV seroconversion occurred, and the anti HCV Ab remained detectable. These results show that: 1) the prevalence of anti HCV Ab in PN related to HBV is nearly the same (9.5%) as the prevalence of HCV Ab observed in patients with chronic hepatitis related to HBV infection; 2) the course of these two viral infections can be different and the role of HCV as an etiologic factor in PN has not been established.
Action of exogenous potassium and calcium ions on in vitro metacyclogenesis in Trypanosoma cruzi.
The cations Ca2+ and K+ and the anions Cl-, HCO3-, and PO4- were studied for their contribution to metacyclic trypomastigote formation of Trypanosoma cruzi in starvation media consisting of phosphate-buffered saline (PBS) + 10 mM proline + 10 mM sodium acetate as well as one of the following salts: 0.035% NaHCO3 (PBSNPA), 0.035% K2CO3 (PBSKPA) or 0.035% K2HPO4 (PBSPPA). Isolates CL and DM28c were activated to transform with 5% CO2 and the percent metacyclogenesis determined after incubation for 96 h in PBS starvation media. Maximal metacyclogenesis was found with CaCl2 and KCl. In the presence of K+, the percent transformation was highest with the phosphate salt, followed by the carbonate and the chloride salts. Cells incubated in PBSNPA and the cationic ionophores A23187 (5 x 10(-6) M), lasalocid (5 x 10(-6) M), and valinomycin (10(-8) M) do not survive; addition of 2 mM CaCl2 or 17 mM KCl to DM28c cells, reversed the lethal action of the ionophores permitting differentiation into metacyclic forms. The addition of CaCl2 to CL cells incubated in ionophores abrogated the lethal effect of the ionophores but transformation was significantly different than in control preparations. Adding KCl to ionophore incubated cells resulted in normal levels of transformation except in the case of valinomycin. DM28c and CL cells incubated in PBSKPA show significantly greater metacyclogenesis in the presence of 5 mM EGTA. These results indicate that exogenous concentrations of several cations and anions significantly influence T. cruzi metacyclogenesis and that the degree of response by the parasite to free ion levels may be strain dependent.
[Lithium poisoning. 2 unpublished interactions: acetazolamide and niflumic acid].
Two lithium intoxication cases due to an association with acetazolamide and niflumic acid are reported. They confirm the necessity of plasma lithium monitoring when a new drug is added.