Effect of the bileaflet inlet valve angle on the flow of a pediatric ventricular assist device: Experimental analysis.

BACKGROUND: Mechanical heart valves (MHV) and its fluid dynamics inside a pulsatile pediatric ventricular assist device (PVAD) can be associated with blood degradation. In this article, flow structures are analyzed and compared by an experimental investigation on the effect of bileaflet MHV positioned at varying angles in the inlet port orifice of a PVAD. METHODS: Time-resolved particle image velocimetry was applied to characterize the internal flow of the device. St Jude Medical bileaftlet valves were used on the inlet orifice and positioned at 0°, 15°, 30°, 45°, 60°, and 90° in relation to the centerline of the device. Three planes with bidimensional velocity magnitude fields were considered in the analysis with visualization of diastolic jets, device wall washing patterns and flow circulation during emptying or systole of the pump. Also, the washing vortex area, and vertical velocity probabilities of regurgitant flows in the inlet valve were evaluated. RESULTS: The results show that a variation in the angle of the MHV at the inlet port produced distinct velocities, fluid structures, and regurgitant flow probabilities within the device. MHV positioned at an angle of 0° generated the strongest inlet jet, larger vortex area during filling, more prominent outgoing flow, and less regurgitation compared to the angles studied. The presence of unfavorable fluid structures, such as small vortices, and/or sudden flow structure interruption, and/or regurgitation, were identified at 45° and 90° angles. CONCLUSIONS: The 0° inlet angle had better outcomes than other angles due to its consistency in the multiple parameters analyzed.

Utilização de medidas osteológicas para estimativa de comprimento corporal em peixe-boi da Amazônia / Using osteological measurements to estimate body length in Amazonian manatees

O comprimento corporal é um importante parâmetro em estudos morfológicos, ecológicos e comportamentais de uma espécie e contribui para o entendimento da condição corporal de um indivíduo. Este parâmetro é essencial para estratégias de conservação e manejo, informando estudos que avaliam taxas de crescimento, maturidade física e classificação dos indivíduos em grupos de idade, promovendo uma melhor precisão aos parâmetros biológicos de uma espécie. O objetivo desse trabalho foi identificar preditores de comprimento corporal para o peixe-boi da Amazônia (Trichechus inunguis) utilizando caracteres métricos de material osteológico. Onze medidas lineares do crânio, mandíbula, escápula e úmero foram coletadas de 41 esqueletos de peixe-boi da Amazônia de diferentes classes de idade (filhote, juvenil e adulto). Os dados foram analisados por regressão linear simples. O comprimento côndilobasal foi o melhor preditor de comprimento corporal para a espécie (R = 0,943), entretanto, todos os ossos avaliados mostraram pelo menos um caractere com capacidade de predizer o comprimento corporal (R2 > 0,9). Os resultados deste estudo são úteis para inferir o comprimento corporal de peixes-boi da Amazônia a partir de ossos depositados em museus e coleções biológicas, expandindo o potencial informativo destes materiais. (AU)

Cryptosporidium spp. and Giardia sp. in aquatic mammals in northern and northeastern Brazil.

Cryptosporidium and Giardia are protozoans that can infect humans and wild and domestic animals. Due to the growing importance of diseases caused by protozoan parasites in aquatic species, we aimed to evaluate the frequency of infection by Cryptosporidium spp. and Giardia sp. in aquatic and marine mammals in the northern and northeastern regions of Brazil. We collected 553 fecal samples from 15 species of wild-ranging and captive aquatic mammals in northern and northeastern Brazil. All samples were analyzed by the Kinyoun technique for identification of Cryptosporidium spp. oocysts. Giardia sp. cysts were identified by means of the centrifugal-flotation technique in zinc sulfate solution. Subsequently, all samples were submitted for direct immunofluorescence testing. The overall frequency of infection was 15.55% (86/553) for Cryptosporidium spp. and 9.04% (50/553) for Giardia sp. The presence of Cryptosporidium spp. was detected in samples from 5 species: neotropical river otter Lontra longicaudis (15.28%), giant otter Pteronura brasiliensis (41.66%), Guiana dolphin Sotalia guianensis (9.67%), Amazonian manatee Trichechus inunguis (16.03%), and Antillean manatee T. manatus (13.79%). Giardia sp. was identified in L. longicaudis (9.23%), P. brasiliensis (29.16%), pygmy sperm whale Kogia breviceps (100%), dwarf sperm whale K. sima (25%), S. guianensis (9.67%), T. inunguis (3.81%), and T. manatus (10.34%). This is the first report of Cryptosporidium spp. in L. longicaudis, P. brasiliensis, and S. guianensis, while the occurrence of Giardia sp., in addition to the 2 otter species, was also identified in manatees, thus extending the number of hosts susceptible to these parasitic agents.

Changes in the blood parameters of the Amazonian manatee (Trichechus inunguis) after long-distance transportation / Alterações nos padrões sanguíneos do peixe-boi da Amazônia (Trichechus inunguis) após transporte de longa distância

In this study we report the hematological, biochemical and hormonal parameters in a juvenile male Amazonian manatee measured before transport, immediately after transport, and during adaptation to a new facility. The animal was transported from Manaus, Amazonas State, Brazil, to São Paulo, São Paulo State, Brazil, (2,733 km) within 6 hours. Among all blood parameters analyzed, we observed obvious neutrophilia, lymphopenia, and increases in the neutrophil/lymphocyte ratio and serum glucose and aspartate aminotransferase (AST) levels, but these parameters subsequently returned to normal. These results suggest that transport and changes in the environment are temporary stressful events for Amazonian manatees. We, therefore, recommend monitoring the hematological and biochemical parameters before and after translocation to minimize the effects of handling stressors in this species.

Neste estudo, são relatados os parâmetros hematológicos, bioquímicos e hormonais em um peixe-boi da Amazônia macho jovem, medidos antes do transporte, imediatamente depois, e durante a sua adaptação a um novo recinto. O animal foi transportado de Manaus, Estado do Amazonas, Brasil, para São Paulo, Estado de São Paulo, Brasil, (2.733 km) durante 6h de viagem. Entre os parâmetros sanguíneos analisados, foi observada clara neutrofilia, linfopenia e aumento na relação neutrófilo/linfócito e nos níveis de glicose e aspartato aminotransferase (AST), mas estes parâmetros posteriormente voltaram aos valores normais. Estes resultados sugerem que o transporte e as mudanças no ambiente são eventos estressantes para o peixe-boi da Amazônia. Desta forma, é recomendável o monitoramento dos parâmetros hematológicos e bioquímicos antes e após a translocação para minimizar os efeitos de agentes estressores nesta espécie.

Morphological analysis of testes from post-hatch chicks submitted to temperature variation during incubation / Análise morfológica dos testículos de pintainhos recém-eclodidos submetidos à variação de temperatura durante a incubação

This study aimed to evaluate the effects of temperature variation during incubation on testicular morphology of post-hatch chicks. We utilized 60 eggs incubated under different temperatures: Group 1 ­ 37.5°C; Group 2 ­ 39.5°C; and Group 3 ­ 34°C. Chicks were weighted and the testes were histologically analyzed. All eggs from Group 3 showed embryonic death. There were no significant differences in body weight and testicular morphology between Groups 1 and 2; however, there was a difference in the diameter of the seminiferous tubules (p < 0.001). The increase in temperature to 39.5°C during incubation causes a decrease in diameter of the seminiferous tubules.

Este estudo objetivou avaliar os efeitos da variação de temperatura durante a incubação na morfologia testicular de pintainhos recém-eclodidos. Foram utilizados 60 ovos incubados em diferentes temperaturas: Grupo 1 ­ 37,5°C; Grupo 2 ­ 39,5°C; e Grupo 3 ­ 34°C. Os pintainhos foram pesados e seus testículos analisados histologicamente. Todos os ovos do Grupo 3 apresentaram morte embrionária. Não houve diferenças significativas no peso e na morfologia testicular entre os Grupos 1 e 2, porém, houve diferença no diâmetro dos túbulos seminíferos (p < 0,001). A elevação da temperatura para 39,5°C durante a incubação causa a redução do diâmetro dos túbulos seminíferos.

Noninvasive monitoring of androgens in male Amazonian manatee (Trichechus inunguis): biologic validation.

The Amazonian manatee (Trichechus inunguis) is endemic in the Amazonian basin and is the only exclusively fresh water sirenian. Historically hunted on a large scale, this species is now considered endangered, and studies on the reproductive physiology are critical for the improvement of reproductive management of captive and wild populations of manatees. The aim of this study was to verify the viability of androgen measurement in saliva, lacrimal, urine, and fecal samples of the Amazonian manatee by conducting a hormone challenge. Two adult male manatees (A-1 and A-2) were submitted to an experimentation protocol of 12 day (D1 to D10). On D0, the animals received an intramuscular injection of gonadotropin-releasing hormone (GnRH)-analogue. Salivary, lacrimal, urinary, and fecal samples were collected daily (between 0800 hours and 0900 hours) and frozen at -20 degrees C until assayed. Fecal samples were lyophilized, extracted with 80% methanol, and diluted in buffer before the radioimmunoassay (RIA). Urine samples underwent acid hydrolysis and were diluted in depleted bovine serum. Salivary and lacrimal samples were assayed without the extraction step. Hormonal assays were conducted with a commercial testosterone RIA kit. An androgen peak (> median + 2 interquartile range [IQR]) was observed in all matrices of both animals, although it was less prominent in the lacrimal samples of A-2. However, the fecal androgen peak (A-1 peak = 293.78 ng/g dry feces, median [IQR] = 143.58 [32.38] ng/g dry feces; A-2 peak = 686.72 ng/g dry feces, median [IQR] = 243.82 [193.16] ng/g dry feces) occurred later than urinary (A-1 peak = 648.16 ng/mg creatinine [Cr], median [IQR] = 23.88 [30.44] ng/mg Cr; A-2 peak = 370.44 ng/mg Cr, median [IQR] = 113.87 [117.73] ng/mg Cr) and salivary (A-1 peak = 678.89 pg/ml, median [IQR] = 103.69 [119.86] pg/ml; A-2 peak = 733.71 pg/ml, median [IQR] = 262.92 [211.44] pg/ml) androgen peaks. These intervals appear to be correlated with the long digesta passage time in this species. The salivary and urinary peaks were closely associated. These results demonstrate that androgen concentrations in saliva, urine, or feces samples reflect reliably physiologic events and are a powerful tool for noninvasive reproductive monitoring of Amazonian manatees.