Testicular thermoregulation in Bos indicus, crossbred and Bos taurus bulls: relationship with scrotal, testicular vascular cone and testicular morphology, and effects on semen quality and sperm production

Mechanisms of testicular thermoregulation, the relationship of scrotal, testicular vascular cone (TVC), and testicular morphology with thermoregulatory capability, and their effects on semen quality and sperm production were studied in 20 Bos indicus, 28 crossbred, and 26 Bos taurus bulls. The ratio of testicular artery length and volume to testicular volume were larger (P < 0.05) in B. indicus and crossbred bulls than in B. taurus bulls (1.03 and 0.94 cm/cm(2). versus 0.48 cm/cm(3); 0.034 and 0.047 ml/cm(3) versus 0.017 ml/cm(3), respectively). Testicular artery wall thickness (average 192.5, 229.0, and 290.0 mum, respectively) and arterial-venous blood distance in the TVC (average 330.5, 373.7, and 609.4 pm, respectively) were smallest in B. indicus, intermediary in crossbred, and greatest in B. taurus bulls (P < 0.05); the proximity between arterial and venous blood was consistent with the estimated decrease in arterial blood temperature after passage through the TVC (5.9, 5.0, and 2.9 degreesC, in B. indicus, crossbred, and B. taurus bulls, respectively). In crossbred and B. taurus bulls, there was a positive top-to-bottom scrotal temperature gradient and a negative testicular subtunic temperature gradient. However, in B. indicus bulls, both scrotal and testicular subtunic temperatures gradients were positive. Differences in the vascular arrangement, characteristics of the artery (e.g. wall thickness) or thickness of the tunica albuginea may have affected the testicular arterial blood and subtunic temperatures in B. indicus bulls. Better testicular thermoregulatory capability was associated with increased scrotal shape (pendulosity), testicular artery length and volume, and top-to-bottom gradient of the distance between the artery wall and the veins in the TVC. Increased semen quality was associated with increased testicular volume and scrotal subcutaneous (SQT) temperature gradient, and with decreased scrotal surface and testicular temperatures. Increased sperm production was associated with increased testicular artery volume, testicular volume, and SQT temperature gradient, and with decreased testicular artery wall thickness, scrotal circumference (SC), and scrotal surface, testicular subtunic, and epididymal temperatures. In conclusion, morphology of the TVC may contribute to the greater resistance of B. indicus bulls to high ambient temperatures by conferring a better testicular blood supply and by facilitating heat transfer between the testicular artery and veins. Testicular thermoregulation was associated with opposing scrotal and testicular subtunic temperatures gradients only in crossbred and B. taurus bulls. Scrotal, TVC, and testicular morphology influence testicular thermoregulatory capability and were associated with differences in semen quality and sperm production. (C) 2003 Elsevier B.V. All rights reserved.

Hemodynamic effects of butorphanol in desflurane-anesthetized dogs

Objective To evaluate the effects of butorphanol on cardiopulmonary parameters in dogs anesthetized with desflurane and breathing spontaneously.Study design Prospective, randomized experimental trial.Animals Twenty dogs weighing 12 +/- 3 kg.Methods Animals were distributed into two groups: a control group (CG) and butorphanol group (BG). Propofol was used for induction and anesthesia was maintained with desflurane (10%). Forty minutes after induction, the dogs in the CG received sodium chloride 0.9% (0.05 mL kg(-1) IM), and dogs in the BG received butorphanol (0.4 mg kg(-1) IM). The first measurements of body temperature (BT), heart rate (HR), arterial pressures (AP), cardiac output (CO), cardiac index (CI), central venous pressure (CVP), stroke volume index (SVI), pulmonary arterial occlusion pressure (PAOP), mean pulmonary arterial pressure (mPAP), left ventricular stroke work (LVSW), systemic (SVR) and pulmonary (PVR) vascular resistances, respiratory rate (fR), and arterial oxygen (PaO(2)) and carbon dioxide (PaCO(2)) partial pressures were taken immediately before the administration of butorphanol or sodium chloride solution (T0) and then at 15-minute intervals (T15-T75).Results In the BG, HR, AP, mPAP and SVR decreased significantly from T15 to T75 compared to baseline. fR was lower at T30 than at T0 in the BG. AP and fR were significantly lower than in the CG from T15 to T75. PVR was lower in the BG than in the CG at T30, while PaCO(2) was higher compared with T0 from T30 to T75 in the BG and significantly higher than in the CG at T30 to T75.Conclusions and clinical relevance At the studied dose, butorphanol caused hypotension and decreased ventilation during desflurane anesthesia in dogs. The hypotension (from 86 +/- 10 to 64 +/- 10 mmHg) is clinically relevant, despite the maintenance of cardiac index.

Ablation of NK1 receptor bearing neurons in the nucleus of the solitary tract blunts cardiovascular reflexes in awake rats

The nucleus of the solitary tract (NTS) receives primary afferents involved in cardiovascular regulation. We investigated the role of NK1-receptor bearing neurons in the NTS on cardiovascular reflexes in awake rats fitted with chronic venous and arterial cannulae. These neurons were lesioned selectively with saporin conjugated with substance P (SP-SAP, 2 mu M, bilateral injections of 20 nL in the subpostremal NTS, or 200 nL in both the subpostremal and the commissural NTS). Before, and 7 and 14 days after injection of SP-SAP, we measured changes in blood pressure and heart rate induced by i.v. injection of phenylephrine and nitroprusside (baroreceptor reflex), cyanide (arterial chemoreceptor reflex), and phenylbiguanide (Bezold-Jarisch reflex). The smaller injections with SP-SAP completely abolished NK1 receptor staining in the subpostremal NTS. The larger injections abolished NK1 receptor immunoreactivity in an area that extended from the commissural NTS to the rostral end of the subpostremal NTS. The lesions seemed to affect only a limited number of neurons, since neutral red stained sections did not show any obvious reduction in cell number. The smaller lesions reduced the gain of baroreflex bradycardia and the hypotension induced by phenylbiguanide. The larger lesions completely abolished the response to phenylbiguanide, blocked the baroreflex bradycardia induced by phenylephrine, severely blunted the baroreflex tachycardia, and blocked the bradycardia and reduced the hypertension induced by cyanide. Thus, these responses depend critically on NK1-receptor bearing neurons in the NTS. (c) 2006 Elsevier B.V. All rights reserved.

Candidemia in a Brazilian tertiary hospital: microbiological and clinical features over a six-year period

Yeasts are becoming a common cause of nosocomial fungal infections in immunocompromised patients. Such infections often develop into sepsis with high mortality rates. The aim of this study was to evaluate some of the numerous factors associated with the development of candidemia. Medical records were retrospectively analyzed of 98 Candida spp. patients. Results showed that the most prevalent risk factors for developing candidemia were: antibiotics and antifungal agents (93.9% and 79.6%, respectively); the use of central venous catheter (93.9%); mechanical ventilation (73.5%); and parenteral nutrition (60.2%). The main species of Candida found were: C. parapsilosis (37.76%), C. albicans (33.67%); and others (28.57%). C. glabrata showed the highest mortality rate (75%), followed by C. tropicalis (57.1%) and C. albicans (54.5%). The elevated mortality rate found in this study indicates that preventive measures against candidemia must be emphasized in hospitals.

The Importance of Bees for Eggplant Cultivations (Hymenoptera: Apidae, Andrenidae, Halictidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito do exercício físico e do polimorfismo T-786C na pressão arterial e no fluxo sanguíneo de idosas

FUNDAMENTO: O polimorfismo T-786C do gene da sintetase do óxido nítrico endotelial (eNOS) e a produção de ânion superóxido podem diminuir a produção e biodisponibilidade do óxido nítrico, comprometendo o grau de vasodilatação, podendo este efeito ser revertido pelo exercício físico. OBJETIVO: Investigar a influência do treinamento aeróbico e do polimorfismo T-786C nas concentrações dos metabólitos do óxido nítrico (NOx), no fluxo sanguíneo (FS) e na pressão arterial (PA). MÉTODOS: Trinta e duas idosas pré-hipertensas (59 ± 6 anos) foram separadas em dois grupos de acordo com o polimorfismo T-786C (TT e TC+CC). Foram analisadas as concentrações de NOx (plasma) e fluxo sanguíneo por pletismografia de oclusão venosa em repouso, 1, 2 e 3 minutos pós-oclusão (FS-0, FS-1, FS-2, FS-3, respectivamente). As avaliações foram realizadas antes e após 6 meses de um programa de exercício aeróbico. RESULTADOS: Nas avaliações pré-treinamento, os níveis de NOx foram menores no grupo TC+CC em relação ao grupo TT. O grupo TT apresentou correlações entre NOx e FS-0 (r = 0,6) e pressão arterial diastólica (PAD) e FS-0 (r = -0,7), porém nenhuma correlação foi encontrada no grupo TC+CC. Nas avaliações pós-treinamento, ocorreram correlações entre NOx e FS-0 (r = 0,6) e nas mudanças do NOx e PAD (r = -0,6) no grupo TT. Também foram obtidas correlações entre PAD e FS-1 (r = -0,8), PAD e FS-2 (r = -0,6), PAD e FS-3 (r = -0,6), nas mudanças entre NOx e FS-1 (r = 0,8) e mudanças do NOx e PAD (r = -0,7) no grupo TC+CC. CONCLUSÃO: Conclui-se que 6 meses de exercício aeróbico podem contribuir para aumentar as relações existentes entre NO, PA e FS em idosas portadores do alelo C.

Effects of temperature on lung and blood gases in the South American rattlesnake Crotalus durissus terrificus

The effects of temperature on lung and blood gases were measured in the South American rattlesnake (Crotalus durissus terrificus). Arterial blood and lung gas samples were obtained from chronically cannulated animals at 15, 25, and 35 degrees C. As expected for reptiles, arterial pH fell with increased temperature (0.018 U degrees C-1 between 15 and 25 degrees C and 0.011 U degrees C-1 between 25 and 35 degrees C) while lung gas PCO2 rose from 5.8 mmHg at 15 degrees C to 13.2 mmHg at 35 degrees C. Concurrently, lung gas PO2 declined from 132 mmHg at 15 degrees C to 120 mmHg at 35 degrees C, and arterial PO2 increased from 33 to 76 mmHg in that temperature range. Arterial haemoglobin O-2 saturation rose from 0.53 at 15 degrees C to 0.83 at 25 degrees C but became slightly reduced (0.77) with a further elevation of temperature to 35 degrees C. Arterial haemoglobin concentration increased from 1.96 to 2.53 mM between 15 and 35 degrees C, consistent with higher demands on oxygen delivery to tissues at elevated temperatures. Moreover, the substantial increase of haemoglobin O-2 saturation between 15 and 25 degrees C conforms to the idea that reduction of the central vascular right-to-left shunt (pulmonary bypass of systemic venous return) is associated with high metabolic demands. (C) 1998 Elsevier B.V. All rights reserved.

Freqüência da mutação 844ins68 do gene da cistationina beta-sintetase em pacientes com trombose venosa profunda

A hiper-homocisteinemia, resultante da deficiência na conversão da homocisteína em cistationina, constitui em fator de risco isolado para doenças vasculares. A mutação 844ins68 do gene da cistationina beta-sintetase é um fator adicional de risco para a trombose venosa profunda. O objetivo deste estudo foi avaliar a freqüência da mutação 844ins68 do gene da cistationina beta-sintetase em pacientes com trombose venosa profunda. Foram avaliados em estudo caso-controle 95 pacientes com trombose venosa profunda, a presença da mutação 844ins68 no éxon 8 do gene da cistationina beta-sintetase. Como critério de inclusão foi adotada a presença de trombose venosa profunda confirmada pelo dúplex ou flebografia. O grupo controle constituiu-se de 95 doadores de sangue, sem história familiar prévia de trombose venosa, com sexo, grupo étnico e idades pareados aos do grupo de estudo. Foram coletados 5 mL de sangue venoso com o uso de anticoagulante EDTA de cada participante. O DNA foi extraído dos leucócitos pelo método DTAB e CTAB. A detecção da mutação do gene foi realizada por amplificação de um segmento gênico por PCR, com iniciadores que flanqueiam a região de inserção e com revelação em gel de agarose a 2%, corado com brometo de etídio, sob luz UV. O fragmento correspondente ao alelo normal contém 184 pares de base e o correspondente ao alelo mutante, 252 pares de base. O teste exato de Fisher foi utilizado na análise dos resultados. A condição heterozigota para a mutação foi encontrada em 14,73% dos pacientes e em 3,1% dos indivíduos do grupo controle (p = 0,009). A freqüência do alelo mutante mostrou diferença significativa (p = 0,01), sendo 0,074 para os pacientes versus 0,016 para o grupo controle. Não foram encontrados casos de homozigose.

Avaliação de Hb A2 e Hb F em doadores de sangue de região malarígena da Amazônia Oriental brasileira por HPLC

In malaria endemic regions of Africa, resistance to infection by Plasmodium has been observed in under 6-month-old children, when there are higher fetal hemoglobin (Hb F) levels. Research performed in the São José do Rio Preto region, central-east Brazil, reported increased levels of Hb F in blood donors. The purpose of this work was to evaluate the A2 hemoglobin (Hb A2) and Hb F concentrations in blood donors deriving from the Brazilian malaria endemic region. Forty-five blood donor samples from Macapá, from patients with varying genders, ages and ethnic origins, were collected by venous puncture after informed consent was obtained. The samples were analyzed by High Performance Liquid Chromatography (HPLC) - System Variant (Bio-Rad). The HPLC demonstrated sensitivity and rapidity in the identification and measurement of the hemoglobins and gave precise results. Moreover, it provided measurement of hemoglobin variants, even when they were present in small amounts, providing a diagnosis of hemoglobinopathies. Hb F levels above the normal were observed in 33.3% of the analyzed samples. The presence of increased Hb F can suggest resistance to infection by Plasmodium falciparum, as there have been reports that infected red blood cells interfere in the development of the parasite.

Rastreamento familiar do fator V de Leiden: a importância da detecção de portadores heterozigotos

O fator de Leiden é uma mutação genética que predispõe seus portadores ao tromboembolismo venoso. O objetivo do estudo foi investigar a distribuição dos alelos em 21 membros da família de três pacientes portadores de trombose com a presença da mutação do fator V de Leiden. A detecção da mutação no gene do fator V foi realizada entre portadores da mutação no estado heterozigoto. Este estudo foi realizado no Centro de Hematologia e Hemoterapia do Ceará - Hemoce. Observou-se a presença da mutação no estado heterozigoto na família 1 (83,3%), na família 2 (40%) e na família 3 (50%). No total de 24 membros (pacientes e familiares) analisados, 50% (12/24) apresentaram a mutação, todos no estado heterozigoto, 66,7% (8/12) não apresentaram trombose. A detecção do fator V de Leiden em pacientes portadores de eventos trombóticos é recomendado para esclarecimento das causas e para efetuar o rastreamento em membros de sua família, ainda sem o aparecimento de eventos trombóticos, de forma a avaliar os riscos associados e assim determinar um acompanhamento médico preventivo.

Tromboflebite superficial: epidemiologia, fisiopatologia, diagnóstico e tratamento

A tromboflebite superficial de membros inferiores é doença de ocorrência comum, estando associada a diversas condições clínicas e cirúrgicas. Historicamente considerada doença benigna, devido à sua localização superficial e ao fácil diagnóstico, o tratamento foi conservador durante muito tempo, na maioria dos casos. Entretanto, relatos recentes de freqüências altas de complicações tromboembólicas associadas - 22 a 37% para trombose venosa profunda e até 33% para embolia pulmonar - alertaram para a necessidade de abordagens diagnósticas e terapêuticas mais amplas, visando diagnosticar e tratar essas possíveis complicações. A possibilidade da coexistência dessas e de outras desordens sistêmicas (colagenoses, neoplasias, trombofilias) interfere na avaliação e influencia a conduta terapêutica, que pode ser clínica, cirúrgica ou combinada. No entanto, devido à falta de ensaios clínicos controlados e às incertezas quanto a sua história natural, o diagnóstico e o tratamento da tromboflebite superficial continuam indefinidos. Neste trabalho, foi feita uma revisão da literatura analisando-se a epidemiologia, fisiopatologia e estado atual do diagnóstico e tratamento da tromboflebite superficial.

Novos anticoagulantes para a profilaxia do tromboembolismo venoso em cirurgias ortopédicas de grande porte

Após cerca de 50 anos de experiência com a heparina e antagonistas da vitamina K (AVK), pesquisas e estudos com novos anticoagulantes vêm evoluindo de forma crescente nos últimos anos. Embora consagrados pelo uso, os anticoagulantes tradicionais têm limitações importantes em termos de controle laboratorial, complicações, efeitos colaterais, interações com medicamentos e dieta. A heparina não fracionada (HNF) tem interação com proteínas plasmáticas e parede vascular, pode desencadear trombocitopenia induzida pela heparina (TIH), só pode ser administrada por via parenteral, exige controle laboratorial pelo teste da tromboplastina parcial ativada (TTPa), pode provocar osteoporose e alopecia quando usada por períodos prolongados e sua produção tem origem biológica. A AVK tem a vantagem de poder ser ministrada por via oral, mas o controle (feito pela razão normatizada internacional) pode ser difícil em alguns casos, já que tem início de ação demorado, janela terapêutica estreita, interação com dieta e grande número de medicamentos, pode provocar necrose de pele em portadores de deficiência de antitrombina e de proteínas C e S, e pode induzir alterações fetais quando usada na gravidez. Na década de 1980, surgiram as heparinas de baixo peso molecular, que foram uma evolução da heparina não fracionada, pois apresentaram maior biodisponibilidade, dosagem por peso corporal, sem necessidade de controle laboratorial, administração por via subcutânea, menor risco de trombocitopenia induzida pela heparina, e eficácia e segurança similares à heparina não fracionada. Na última década surgiram, então, uma série de novos anticoagulantes no mercado, os quais têm apresentado resultados promissores em várias situações de profilaxia e tratamento do tromboembolismo venoso. Nesta revisão, são apresentados as novas heparinas de baixo peso molecular, as heparinas de ultrabaixo peso molecular, os pentassacarídeos, os novos inibidores diretos do fator Xa e inibidores do fator IIa.

Plasma cortisol levels in captive wild felines after chemical restraint

Eight Panthera onca (Po), 13 Felis concolor (Fc), 7 Felis yagouaroundi (Fy), 7 Felis tigrina (Ft) and 5 Felis pardalis (Fp) specimens from São Paulo State zoos were used. All animals were restrained with darts containing 10 mg/kg ketamine and 1 mg/kg xylazine. Venous blood samples were collected as soon as possible (within 15-20 min) and serum was frozen until the time for cortisol quantification. Cortisol was determined using a solid phase radioimmunoassay with an intra-assay coefficient of 8.51%. Data were analyzed statistically by the Kruskal-Wallis test, followed by Dunn's multiple comparisons test, and the one-sample t-test, with the level of significance set at P<0.05. Data are reported as means ± SEM. Cortisol levels differed among the captive felines: Po = 166 ± 33a, Fc = 670 ± 118b, Fy = 480 ± 83b, Ft = 237 ± 42ab, Fp = 97 ± 12a nmol/l (values followed by different superscript letters were significantly different (P<0.001)). Since most of the veterinary procedures on these species involve chemical restraint, these results show the necessity of preventive measures in order to minimize the effect of restraint stress on more susceptible species

Effects of caffeine on time to exhaustion in exercise performed below and above the anaerobic threshold

Controversy still exists concerning the potential ergogenic benefit of caffeine (CAF) for exercise performance. The purpose of this study was to compare the effects of CAF ingestion on endurance performance during exercise on a bicycle ergometer at two different intensities, i.e., approximately 10% below and 10% above the anaerobic threshold (AT). Eight untrained males, non-regular consumers of CAF, participated in this study. AT, defined as the intensity (watts) corresponding to a lactate concentration of 4 mM, was determined during an incremental exercise test from rest to exhaustion on an electrically braked cycle ergometer. on the basis of these measurements, the subjects were asked to cycle until exhaustion at two different intensities, i.e., approximately 10% below and 10% above AT. Each intensity was performed twice in a double-blind randomized order by ingesting either CAF (5 mg/kg) or a placebo (PLA) 60 min prior to the test. Venous blood was analyzed for free fatty acid, glucose, and lactate, before, during, and immediately after exercise. Rating of perceived exertion and time to exhaustion were also measured during each trial. There were no differences in free fatty acids or lactate levels between CAF and PLA during and immediately after exercise for either intensity. Immediately after exercise glucose increased in the CAF trial at both intensities. Rating of perceived exertion was significantly lower (CAF = 14.1 ± 2.5 vs PLA = 16.6 ± 2.4) and time to exhaustion was significantly higher (CAF = 46.54 ± 8.05 min vs PLA = 32.42 ± 14.81 min) during exercise below AT with CAF. However, there was no effect of CAF treatment on rating of perceived exertion (CAF = 18.0 ± 2.7 vs PLA = 17.6 ± 2.3) and time to exhaustion (CAF = 18.45 ± 7.28 min vs PLA = 19.17 ± 4.37 min) during exercise above AT. We conclude that in untrained subjects caffeine can improve endurance performance during prolonged exercise performed below AT and that the decrease of perceived exertion can be involved in this process

Experimental ischemia and reperfusion in equine small colon

Sob anestesia geral, com constante controle sobre a pressão arterial e a saturação de oxigênio da hemoglobina arterial, realizou-se celiotomia em 12 eqüinos. No cólon menor exposto foram demarcados três segmentos de 25cm, separados entre si por igual distância. Dois desses segmentos foram submetidos à isquemia arteriovenosa completa por 90 (grupo A) ou 180 minutos (grupo B). O terceiro segmento foi o grupo-controle. Amostras para histopatologia foram colhidas ao final dos períodos de isquemia e após 90 e 180 minutos de reperfusão no grupo A e após 90 minutos de reperfusão no grupo B. No controle, colheram-se amostras no início e final do procedimento. Avaliaram-se as lesões produzidas na mucosa e na submucosa pelos métodos semiquantitativos-escores para desprendimento de epitélio, edema, hemorragia e infiltrado de neutrófilos, e pelos quantitativos-porcentagem de perda de mucosa (PM) e razão cripta:interstício (C:I). As lesões isquêmicas foram mais intensas no grupo B do que no A para PM, C:I, desprendimento de epitélio e edema de mucosa. As amostras obtidas após a reperfusão revelaram que houve agravamento na PM, C:I, desprendimento de epitélio e edema de submucosa em ambos os grupos. Concluiu-se que a reperfusão agravou as lesões isquêmicas no cólon menor e que o modelo proposto é viável para produção dessas lesões.