Type II retrocaval ureter causing hydronephrosis in a cat: case report / Ureter retrocava tipo II causando hidronefrose em um gato: relato de caso

Retrocaval ureter (RU) is an abnormal embryonic development of the caudal vena cava (CVC) that leads the ureter to be entrapped dorsal to the CVC. In most cases there is no clinical impact; however, it can cause hydronephrosis. We report a rare case of type II symptomatic retrocaval ureter in a feline treated with nephroureterectomy. A 4-year-old, intact male, mixed breed cat was submitted to abdominal ultrasound and severe right hydronephrosis was diagnosed, with no signs of obstruction. We performed an exploratory celiotomy, in which a displacement of the right ureter dorsal to the CVC was observed. The animal was treated with ureteronephrectomy and recovered well. No intraluminal cause was found, and a urethral catheter could be easily inserted across the ureter length. The real clinical relevance of the RU is unknown, since it is a common find in post-mortem examination without kidney impact and, when significant, is often associated to other causes of ureteral obstructions, such as calculi and strictures. Additionally, in humans, type II RU seldom develops obstruction and hydronephrosis. In our case, due to absence of other causes of obstruction, probably mechanical compression of the CVC against the psoas muscle caused the hydronephrosis.(AU)

O ureter retrocava (UR) é originado por uma falha na formação embriológica da veia cava caudal (VCC), que leva ao aprisionamento do ureter dorsal à VCC. Na maioria dos casos, não há impacto clínico; entretanto, essa anomalia pode causar hidronefrose. Relata-se um raro caso de UR tipo II sintomático em um felino, tratado com nefroureterectomia. O referido animal, sem raça definida, macho intacto de quatro anos de idade, foi submetido à ultrassonografia abdominal, que revelou acentuada hidronefrose direita, sem sinais de obstrução. Realizou-se celiotomia exploratória, na qual foi possível observar o ureter direito dorsal à VCC. O animal foi tratado com nefroureterectomia e se recuperou satisfatoriamente. Nenhuma causa intraluminal foi encontrada e um cateter uretral pôde ser facilmente inserido por todo o comprimento do ureter. A real relevância clínica do UR é desconhecida, visto que é um achado comum em exames post mortem, sem impacto aos rins e, quando significante, frequentemente está associado a outras causas de obstrução ureteral, como cálculos e estenoses. Adicionalmente, em humanos, o UR tipo II raramente desenvolve obstrução e hidronefrose. Neste caso, devido à ausência de outros motivos de obstrução, acredita-se que a compressão mecânica da VCC contra o músculo psoas foi a causa da hidronefrose.(AU)

Development and validation of an LC-MS/MS method for tyrphostin A9 / 药物分析学报

Here we have presented a sensitive and selective LC-MS/MS method for the quantification of tyrphostin A9, which is a selective inhibitor for platelet derived growth factor receptor tyrosine kinase and has been investigated in vitro as a potent oxidative phosphorylation uncoupler. The murine analytical method was developed for three biological matrices: cell culture media, 3T3-L1 cell lysate, and murine plasma. For each matrix the limit of detection and the limit of quantification were found to be 0.5 ng/mL and 1.0 ng/mL, respectively. The range of standard curve for each matrix was 1.0-100 ng/mL, linearity was >0.99, and the precision and accuracy were within 20％. 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoic acid was found to be the most suitable internal standard. The validated LC-MS/MS method was used to investigate stability and in vitro pharmacokinetics of tyrphostin A9. It was found that tyrphostin A9 is susceptible to hydrolysis, and the degradation product was identified as 3,5-di-tert-butyl-4-hydroxybenzaldehyde. Tyrphostin A9 was not stable in biological matrices, and the rate of its degra-dation in murine plasma was faster than that in cell culture media. In vitro pharmacokinetic studies revealed that tyrphostin A9 concentrations in the cell culture media declined in a bi-exponential manner and the concentrations inside the adipocytes remained constant, suggesting tyrphostin A9 has an intracellular binding site and is retained within the cell. The LC-MS/MS method presented here paves the way for further quantitative investigations involving tyrphostin A9.

Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

The dependence of sweat composition and acidity on sweating rate (SR) suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac-) and ammonia (NH3) and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men) cycled in the heat (42°C, 20 percent relative humidity) at 50 percent VO2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject's lower back. During bout 1, sweat from girls and boys had higher Lac- concentrations (23.6 ± 1.2 and 21.2 ± 1.7 mM; P < 0.05) than sweat from women and men (18.2 ± 1.9 and 14.8 ± 1.6 mM, respectively), but Lac- was weakly associated with SR (P > 0.05; r = -0.27). Sweat Lac- concentration dropped during exercise bout 2, reaching similar levels among all groups (overall mean = 13.7 ± 0.4 mM). Children had a higher sweat NH3 than adults during bout 1 (girls = 4.2 ± 0.4, boys = 4.6 ± 0.6, women = 2.7 ± 0.2, and men = 3.0 ± 0.2 mM; P < 0.05). This difference persisted through bout 2 only in females. On average, children's sweat pH was lower than that of adults (mean ± SEM, girls = 5.4 ± 0.2, boys = 5.0 ± 0.1, women = 6.2 ± 0.5, and men = 6.2 ± 0.4 for bout 1, and girls = 5.4 ± 0.2, boys = 6.5 ± 0.5, women = 5.2 ± 0.2, and men = 6.9 ± 0.4 for bout 2). This may have favored NH3 transport from plasma to sweat as accounted for by a significant correlation between sweat NH3 and H+ (r = 0.56). Blood pH increased from rest (mean ± SEM; 7.3 ± 0.02) to the end of exercise (7.4 ± 0.01) without differences among groups. These results, however, are representative of sweat induced by moderate exercise in the absence of acidosis.

Parasitoses intestinais. / Intestinal parasitosis

Os autores pretendem desenvolver o estudo de parasitoses intestinais a partir da observacao conjunta dessas enfermidades, destacando seus aspectos comuns de sintomatologia, epidemiologia, metodos de investigacao e controle