Determination of acute toxicity of ammonium in juvenile Patagonian blenny (Eleginops maclovinus) / Determinação da toxicidade aguda do amônio em Babosas-da-Patagônia (Eleginops maclovinus) juvenis

Abstract Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.

Resumo A toxicidade aguda (LC50-96h) de amônia deionizada (NH3 ) em Babosas-da-Patagônia (Eleginops maclovinus) juvenis foi avaliada. As concentrações de sal de amônia deionizada em água foram preparados com 24,09 ± 2,1 g de cloreto de amônio (NH4Cl). Os peixes foram expostos em triplicata a diferentes concentrações de amônia: 0,05; 0,094; 0,175; 0,325 e 0,605 mg L-1 de NH3. Além disso, um grupo de controle foi incluído. Peixes experimentais foram mantidos em fotoperíodo de 16: 8h. As temperaturas médias foram 16,24 + 1,40 °C. A concentração de oxigênio foi 16.24 +1.40°C mg L-1 . O pH da água foi de 7,89 + 0,2. h LC50-96h, foi estimada usando o método estatístico de Probit (intervalos de 95%) usando o software EPA (1993). E. maclovinus juvenis apresentaram uma LC 50-96h de 0.413mg NH3 L-1 valor diferente da maioria das espécies marinhas. Este estudo apresenta o primeiro registro de toxicidade amónio em espécies marinhas do Chile.

Determination of acute toxicity of ammonium in juvenile Patagonian blenny (Eleginops maclovinus).

Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.

Determination of acute toxicity of ammonium in juvenile Patagonian blenny (Eleginops maclovinus)

Abstract Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.

Resumo A toxicidade aguda (LC50-96h) de amônia deionizada (NH3 ) em Babosas-da-Patagônia (Eleginops maclovinus) juvenis foi avaliada. As concentrações de sal de amônia deionizada em água foram preparados com 24,09 ± 2,1 g de cloreto de amônio (NH4Cl). Os peixes foram expostos em triplicata a diferentes concentrações de amônia: 0,05; 0,094; 0,175; 0,325 e 0,605 mg L-1 de NH3. Além disso, um grupo de controle foi incluído. Peixes experimentais foram mantidos em fotoperíodo de 16: 8h. As temperaturas médias foram 16,24 + 1,40 °C. A concentração de oxigênio foi 16.24 +1.40°C mg L-1 . O pH da água foi de 7,89 + 0,2. h LC50-96h, foi estimada usando o método estatístico de Probit (intervalos de 95%) usando o software EPA (1993). E. maclovinus juvenis apresentaram uma LC 50-96h de 0.413mg NH3 L-1 valor diferente da maioria das espécies marinhas. Este estudo apresenta o primeiro registro de toxicidade amónio em espécies marinhas do Chile.

Modulation of the transient outward current (Ito) in rat cardiac myocytes and human Kv4.3 channels by mefloquine.

The antimalarial drug mefloquine, is known to be a potassium channel blocker, although its mechanism of action has not being elucidated and its effects on the transient outward current (Ito) and the molecular correlate, the Kv4.3 channel has not being studied. Here, we describe the mefloquine-induced inhibition of the rat ventricular Ito and of CHO cells co-transfected with human Kv4.3 and its accessory subunit hKChIP2C by whole-cell voltage-clamp. Mefloquine inhibited rat Ito and hKv4.3+KChIP2C currents in a concentration-dependent manner with a limited voltage dependence and similar potencies (IC50=8.9µM and 10.5µM for cardiac myocytes and Kv4.3 channels, respectively). In addition, mefloquine did not affect the activation of either current but significantly modified the hKv4.3 steady-state inactivation and recovery from inactivation. The effects of this drug was compared with that of 4-aminopyridine (4-AP), a well-known potassium channel blocker and its binding site does not seem to overlap with that of 4-AP.

[Intestinal obstruction for malrotation in an adult patient. Report of a case]. / Obstrución intestinal por malrotación en el adulto: A propósito de un caso.

We present a case of a 78 year-old man with the pathological antecedent of chronic constipation that comes to our emergency room at the Victor Lazarte Echegaray Hospital. He presented abdominal pain and progressive abdominal distension, nausea and bilious vomits of two days of evolution. The clinical examination showed an evident abdominal distension, and some metallic intestinal noises. A frontal and lateral simple abdominal x- ray showed a considerable distension of the gastric camera and intestinal loops and free fluid all over the abdominal cavity, all of which was compatible with the diagnosis of intestinal obstruction. At the operating room we proceeded with a exploration and we founded an intestinal obstruction at the ascending colon (Ladd's Bands) of high location with bloody fluid in the abdominal cavity, multiple fecalomas in the descending colon, and intestinal ischemia in the distal small bowel, the color, tone and coiling of the intestine recovered after section of the Ladd's bands. The patient evolved favorably.

Histomorphometric analysis in the ovary of newly hatched chicks treated with follicle-stimulating hormone during embryonic development.

We studied the histomorphometric changes induced in the left ovary of newly hatched chicks treated with follicle stimulating hormone (FSH) during embryonic development. After FSH treatment the thickness of the ovarian cortex, the number per unit of area and total mass per ovary of germ and pregranulosa cells increased, accompanied by hypertrophy of the pregranulosa cells. The volume of interstitial cell cords, lacunar system, and blood capillaries was increased and modifications in poorly differentiated cells were also observed. The number of interstitial cells and the average volume of interstitial cells also increased, from which we can deduce that these two last events are important in the enlargement of the interstitial cell cords. These findings suggest that the prefollicular ovary is able to respond to FSH, inducing structural changes both in the ovarian cortex as well as in the subcortical medulla.

Ira con neumonia en menores de dos meses: Reviciòn de 6 años / Acute respiratory infections pneumonia in children less of two months: review of 6 years

Se realizo un estudio retrospectivo en el Hospital del Niño Dr. Ovidio Aliaga Uria de la ciudad de La Paz, analizando los casos de IRA con neumonia en menores de dos meses desde enero de 1990 a diciembre de 1995. Se encontro que el 24,3 porciento de los casos de neumonia en menores de cinco años correspondiò al grupo etareo analizado. En este grupo el sexo masculino fue el màs suceptible, màs frecuente entre los 31 a 60 dìas de edad y durante los meses de abril a septiembre. La mortalidad encontrada fue del 8,9 porciento afectando principalmente a los niños entre 8 a 30 dìas de edad. El seguro de Maternidad y Ninez que esta vigente desde junio de 1996, mejorarà la cobertura de atenciòn a la madre y el niño menor de 5 años y creemos que mejorarà tanto la morbilidad materna como infantil