RESUMEN
AIM: To study the frequency of congenital cytomegalovirus (CMV) infection in newborns admitted to the Division of Neonatology, using nested polymerase chain reaction (PCR) and DNA to detect differences in blood and urine specimens. METHODS: The study was carried out for eight months. Newborns (n = 520) hospitalized in five hospitals in Campo Grande, Mato Grosso do Sul, Brazil, were checked for CMV by analysing blood and urine samples. RESULTS: Cytomegalovirus was PCR positive in 13 urine and 10 blood samples. Of the 13 positive urine patients, three (23%) had no clinical signs suggestive of CMV, and another three (23%) patients admitted to the neonatal intensive care unit (NICU) had no definite findings of bacterial infection, with negative blood culture and some clinical signs consistent with CMV as cholestasis, hepatomegaly and eosinophilia. Three patients were on mechanical ventilation and showed improvement after prescription of ganciclovir. One CMV positive child progressed to death. CONCLUSION: Cytomegalovirus detection in urine was slightly more efficient than in blood, and showed better sensitivity than in serological analysis (p < 0.01) therefore, boiled urine may be a better and easier specimen tool for CMV diagnosis in neonatal infection. The findings of the present research suggest that patients admitted to the NICU, especially premature infants, whose laboratory results are not compatible with bacterial infection, and exhibiting signs suggestive of CMV infection should have PCR done on urine for confirmation.
RESUMEN
Species of the genus Bothrops induce the vast majority of snakebite envenomings in Latin America. A preclinical study was performed in the context of a regional network of public laboratories involved in the production, quality control and development of antivenoms in Latin America. The ability of seven polyspecific antivenoms, produced in Argentina, Brazil, Peru, Bolivia, Colombia and Costa Rica, to neutralize lethal, hemorrhagic, coagulant, defibrinogenating and myotoxic activities of the venoms of Bothrops neuwiedi (diporus) (Argentina), Bothrops jararaca (Brazil), B. neuwiedi (mattogrossensis) (Bolivia), Bothrops atrox (Peru and Colombia) and Bothrops asper (Costa Rica) was assessed using standard laboratory tests. Despite differences in the venom mixtures used in the immunization of animals for the production of these antivenoms, a pattern of extensive cross-neutralization was observed between these antivenoms and all the venoms tested, with quantitative differences in the values of effective doses. This study reveals the capacity of these antivenoms to neutralize, in preclinical tests, homologous and heterologous Bothrops venoms in Central and South America, and also highlight quantitative differences in the values of Median Effective Doses (ED50s) between the various antivenoms.
Asunto(s)
Antivenenos/inmunología , Bothrops/fisiología , Venenos de Crotálidos/inmunología , Factores Inmunológicos/inmunología , Pruebas de Neutralización/métodos , Animales , Coagulación Sanguínea/efectos de los fármacos , Creatina Quinasa/sangre , Venenos de Crotálidos/efectos adversos , Evaluación Preclínica de Medicamentos , Femenino , Fibrinólisis/efectos de los fármacos , Hemorragia/inducido químicamente , América Latina , Dosificación Letal Mediana , Masculino , Ratones , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/enzimología , Miositis/inducido químicamenteRESUMEN
The receptors mediating guinea pig gall bladder (GPGB) contractions induced by endothelin-1 (ET-1) and related peptides were characterized using various ET receptor antagonists. As all ET-receptor agonists used, except sarafotoxin S6c (SRTX), failed to induce a clear-cut maximal response at the highest concentration tested (i.e. 100 nM), their potencies are expressed in terms of a CK50 (i.e. the concentration causing 50% of the response to 80 mM KCl). ET-1 (CK50 0.8 nM) was equipotent to ET-2 and SRTX (selective ET(B) receptor agonist), but more potent than ET-3 (5-fold) or IRL 1620 (selective ET(B) receptor agonist). BQ-123 (0.3 microM, peptidic ET(A) receptor antagonist) did not alter responses to ET-1, ET-3 or SRTX. BQ-788 (1 microM, peptidic ET(B) receptor antagonist) reduced the potency of ET-3 (9-fold at the CK50 level) and SRTX ( > 20-fold), but not ET-1. SRTX responses were unaffected by RES-701-1 (3 microM, peptidic ET(B) receptor antagonist). The combination BQ-123 (0.3 microM) plus BQ-788 (1 microM) did not modify responses to ET-1, inhibited SRTX responses similarly to BQ-788 alone and abolished ET-3 responses. Bosentan (1 microM, non-peptidic ET(A)/ET(B) receptor antagonist) reduced the potency of ET-1 (15-fold). ET-3 (9-fold) and SRTX (4-fold). In rat aorta, the antagonists blocked ET-1-induced contractions (BQ-123 and bosentan) or SRTX-induced endothelium-dependent relaxations (BQ-788, RES-701-1 and bosentan). Thus, the GPGB expresses both ET(A) and ET(B) receptors. As BQ-123 only blocked responses to ET-3 in the presence of BQ-788, there appears to be cross-talk between both receptor types. Also, the binding sites of ET-1 and ET-3 on the ET(A) receptor may not coincide entirely, as BQ-123, even in presence of BQ-788, did not affect ET-1-induced contractions.
Asunto(s)
Vesícula Biliar/metabolismo , Contracción Muscular , Receptores de Endotelina/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Antagonistas de los Receptores de Endotelina , Femenino , Vesícula Biliar/efectos de los fármacos , Cobayas , Masculino , Contracción Muscular/efectos de los fármacos , Oligopéptidos/administración & dosificación , Oligopéptidos/farmacología , Péptidos/farmacología , Péptidos Cíclicos/administración & dosificación , Péptidos Cíclicos/farmacología , Piperidinas/administración & dosificación , Piperidinas/farmacología , Ratas , Receptor de Endotelina A , Receptor de Endotelina BRESUMEN
The endothelin receptors controlling sympathetic neurotransmission and the presence of endothelin-converting enzyme were investigated in the mouse vas deferens. Endothelin-1 or endothelin-3 (0.01-100 nM) enhanced contractions evoked by field stimulation, yielding EC50 (geometric mean and 95% confidence limits) of 0.7 nM (0.4-1.6) and 13.7 nM (10.2-14.1) and Emax (mean +/- S.E.M. increase in twitch tension, in mg/10 mg wet tissue) of 473 +/- 35 and 520 +/- 51, respectively. The selective endothelin ETB receptor agonists IRL 1620 (Suc-[Glu9,Ala11,15]endothelin-1) and sarafotoxin S6c were inactive up to 100 nM. Responses to endothelin-3 were progressively inhibited by the selective endothelin ETA receptor antagonist BQ-123 (cyclo[D-Trp-D-Asp-Pro-D-Val-Leu]) (10, 30 and 100 nM). At 100 nM, BQ-123 almost abolished the response to endothelin-3 (100 nM). In contrast, at 100, 300 nM and 1 microM, BQ-123 shifted the curve to endothelin-1 to the right only 2-, 5- and 6-fold, respectively. The selective endothelin ETB receptor antagonist BQ-788 (N-cis-2,6-dimethylpiperidinocarbonyl-L-gamma-methyl-leucyl-D-1-++ +methoxycarbonyltryptophanyl-D-norleucine) (100 nM) did not modify responses to endothelin-1 or endothelin-3 (0.01-100 nM). Big-endothelin-1 (0.3-30 nM) was 10-fold less potent than endothelin-1 in increasing neurogenic responses (EC50 6.8 nM, 4.7-9.6; Emax 457 +/- 37 mg/10 mg wet tissue). Preincubation with phosphoramidon (100 microM) reduced responses to big-endothelin-1, but not endothelin-1.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Ácido Aspártico Endopeptidasas/metabolismo , Receptores de Endotelina/fisiología , Conducto Deferente/fisiología , Animales , Estimulación Eléctrica , Enzimas Convertidoras de Endotelina , Endotelinas/farmacología , Masculino , Metaloendopeptidasas , Ratones , Contracción Muscular , Oligopéptidos/farmacología , Péptidos Cíclicos/farmacología , Piperidinas/farmacología , Receptores de Endotelina/efectos de los fármacos , Conducto Deferente/efectos de los fármacos , Conducto Deferente/enzimologíaRESUMEN
1. The effect of propionate on lipid synthesis in lymphocytes cultured for 24 hr and incubated for 2 hr was investigated. 2. [1-14C]-propionate was incorporated mainly into phospholipids in both control and concanavalin A (Con A) stimulated cultured lymphocytes. 3. The content of free coenzyme A markedly decreased in 2 hr incubated lymphocytes when propionate was added to the medium at concentrations from 10 to 100 mmol/l. 4. Propionate at 40 mmol/l decreased the incorporation of [1-14C]-palmitate into phospholipids (86%), triacylglycerol (87%) and cholesterol ester (98%) and increased in cholesterol (133%) of cultured lymphocytes. 5. Addition of propionate into the culture medium at 2.5 and 5.0 mmol/l concentrations markedly increased the activity of hydrolases of various acylCoA derivatives. 6. The results suggest that propionate may reduce the content of acylCoA and so its esterification and this might be important for the regulation of lymphocytes proliferation.
Asunto(s)
Lípidos/biosíntesis , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Propionatos/farmacología , Animales , Radioisótopos de Carbono , Células Cultivadas , Coenzima A/metabolismo , Hidrolasas/metabolismo , Cuerpos Cetónicos/metabolismo , Activación de Linfocitos/fisiología , Linfocitos/enzimología , Masculino , Palmitatos/metabolismo , Ratas , Ratas WistarRESUMEN
Lipogenesis is essential for the rapid proliferation of cells and it is established that the biosynthesis of selected lipids precedes S-phase, DNA synthesis and the initiation of cell division. Pyruvate was previously shown to be an important lipid precursor for lymphocytes, macrophages and tumour cells. This study now reports the role of prostaglandins (PG) on the regulation of lipogenesis from [3-14C] pyruvate in 24-h cultured lymphocytes. It is shown that indomethacin (10 microM) and ibuprofen (10 microM), both inhibitors of PG biosynthesis, increased [3-14C] pyruvate incorporations into phospholipid and cholesterol fractions in resting lymphocytes but reduced its incorporation into these fractions in concanavalin A (Con A)-stimulated lymphocytes and tumour cells. These two agents also affected [2-14C] thymidine incorporation into the DNA of these cells in the same manner. Lipids produced from [3-14C] pyruvate and exported into the cell culture medium were also measured. The PG biosynthesis inhibitions reduced the transfer to culture medium of arachidonic acid, phospholipids, cholesterol and fatty acids higher than C20 by lymphocytes and tumour cells. Although macrophages are not proliferative cells, the cytoplasmic export measurement is important because these cells have a high capacity for lipid secretion. The results show that the PG biosynthesis inhibitors do not affect the export of phospholipids and cholesterol in macrophages. They do however markedly change the export of arachidonic acid and fatty acids higher than C20 produced from [3-14C] pyruvate in macrophages. It is also reported that a cell-stimulating response diminished the above fatty acid outcome in resting cells and augmented it in thioglycollate-stimulated macrophages. The findings suggest that PG modulation of lipogenesis may depend on cell cycle phase as well as the intrinsic lipid metabolic diversity and capacity.
Asunto(s)
Lípidos/biosíntesis , Linfocitos/metabolismo , Macrófagos Peritoneales/metabolismo , Neoplasias/metabolismo , Prostaglandinas/fisiología , Acetatos/metabolismo , Animales , Ácido Araquidónico/metabolismo , Radioisótopos de Carbono , Células Cultivadas , Concanavalina A/farmacología , ADN/metabolismo , ADN de Neoplasias/metabolismo , Células HeLa , Humanos , Ibuprofeno/farmacología , Indometacina/farmacología , Células KB , Activación de Linfocitos/efectos de los fármacos , Linfocitos/efectos de los fármacos , Neoplasias Experimentales/metabolismo , Prostaglandinas/biosíntesis , Piruvatos/metabolismo , Ácido Pirúvico , Ratas , Timidina/metabolismo , Células Tumorales CultivadasRESUMEN
Since acetyl-CoA produced through pyruvate dehydrogenase reaction is poorly oxidized by the Krebs cycle in rat lymphocytes, the fate of acetyl units was investigated in these cells. The results presented here show that 24-h cultured lymphocytes actively synthesize lipids from [3-14C]pyruvate. Furthermore, a considerable amount of these lipids have shown to be exported into the culture medium. Experiments with [1-14C] acetate as a lipid precursor showed a close similarity with the rates of incorporation of [3-14C] pyruvate into the same lipid fractions. Treatment of lymphocytes with the mitogen concanavalin A (Con A) markedly enhanced [1-14C] acetate incorporation into a variety of lipids, but the lectin did not affect [3-14C] pyruvate incorporation. The results suggest that lymphocytes convert pyruvate into lipids via the acetyl-CoA pathway and that Con A interferes in lymphocyte lipogenesis but does not seem to affect the pyruvate dehydrogenase reaction. The ability to incorporate pyruvate into certain lipids may have an important role for the rapidly dividing capacity of lymphocytes since the human cancer strain HeLa 155 (a quickly proliferating cell line) also exhibits this feature by converting much more [3-14C] pyruvate into lipids than do lymphocytes. In addition, comparative experiments with lymphocytes, peritoneal macrophages and HeLa cells indicate that pyruvate may provide precursors for cells with active lipid producing and exporting capacities.
Asunto(s)
Lípidos/biosíntesis , Linfocitos/metabolismo , Piruvatos/metabolismo , Acetatos/metabolismo , Acetilcoenzima A/metabolismo , Animales , Células Cultivadas , Concanavalina A/farmacología , Medios de Cultivo , Células HeLa , Humanos , Metabolismo de los Lípidos , Linfocitos/química , Linfocitos/efectos de los fármacos , Macrófagos Peritoneales/metabolismo , Masculino , Ácido Pirúvico , Ratas , Ratas WistarRESUMEN
Endothelin-1 (ET-1) and endothelin-3 (ET-3) induced a biphasic response (relaxation and contraction) in the guinea pig ileum. Short-term activation of protein kinase C (PKC) with phorbol 12,13-dibutyrate (PDBu) inhibited the contractile but not the relaxing component of the responses, as did H-7. Long-term pretreatment with PDBu reversed the short-term inhibition but did not affect the tachyphylaxis induced by ET-1. These results suggest that PKC contributes to ET-1 contraction but not to tachyphylaxis. The ETA antagonist BQ-123, at 34 nM, competitively inhibited ET-1 contraction, but at 340 nM the inhibition was noncompetitive. Dose-response curves for ET-1 relaxation were shifted to the left. For ET-3, BQ-123 (340 nM) only decreased the maximal contractile response of the dose-response curve without affecting the relaxation. We suggest that in this tissue there is one receptor for ET-1-induced contraction, which is competitively antagonized by BQ-123, and another one for ET-3-induced contraction, which is noncompetitively antagonized by BQ-123.