Electromyographic analysis of the gait cycle phases of boxer dogs / Análise eletromiográfica do ciclo de marcha em cães da raça boxer

Systematic studies involving technologies such as surface electromyography (sEMG) may provide important data that enable veterinarians to recognize musculoskeletal, ligamentous, and neurological alterations. The aim of this study was to describe the gait cycle phases and the timing of muscle activation in healthy Boxer dogs during gait by means of sEMG. The gait cycle of seven Boxer dogs was evaluated and sEMG was recorded from the biceps brachii, triceps brachii, brachiocephalic, rectus femoris, semitendinosus, semimembranosus, and superficial gluteal muscles of the right hemibody. Circular monopolar Ag/AgCl electrodes were attached to the mean point between the motor point and the muscle insertion. The electromyographic signals were collected by an active interface with 20-fold gain in a bipolar differential configuration using a 16-channel signal conditioner (EMG Systems Brasil), while the dogs walked on a treadmill at a speed of 2m/s. Pearson's correlation was used for the statistical analysis. A positive correlation was found between the rectus femoris and biceps brachii (r= 0.81); superficial gluteal and triceps brachii (r= 0.69); semitendinosus-semimembranosus and biceps brachii (r= 0.76); and rectus femoris and semitendinosus and semimembranosus muscle groups (r=0.99). The biceps brachii and brachiocephalic muscles work in tandem to position the thoracic limb during the gait cycle, while the semitendinosus-semimembranosus group flexes the knee and, simultaneously with the quadriceps that flexes the hip, prevents the contact of the pelvic limb with the ground during the swing phase. The body is propelled forward by the triceps brachii muscle, which extends the elbow and flexes the shoulder at the final contact, while the superficial gluteal muscle extends the hip.(AU)

Estudos sistemáticos que envolvem uso de tecnologias, como a eletromiografia de superfície (EMGs), podem fornecer dados importantes que capacitam os clínicos a diferenciar as alterações musculoesqueléticas, ligamentares ou neurológicas. Objetiva-se com este trabalho descrever as fases da marcha canina e o momento de ativação dos músculos de cães saudáveis da raça Boxer durante a marcha, por meio da eletromiografia de superfície. Avaliou-se a marcha de sete cães da raça Boxer, e o sinal elétrico da eletromiografia de superfície foi coletado do bíceps braquial, do tríceps braquial, do braquiocefálico, do reto femoral, do semitendinoso/semimembranoso e do glúteo superficial do hemicorpo direito. Os eletrodos monopolares circulares de prata com cloreto de prata (Ag/AgCl) foram posicionados no ponto médio entre a placa motora e a inserção desses músculos. Os sinais eletromiográficos foram capturados e adquiridos por uma interface ativa com ganho de 20x em configuração diferencial bipolar e por um condicionador de sinais (EMG Systems Brasil) de 16 canais, enquanto os cães caminharam em esteira com velocidade de 2m/s. Para análise estatística, foi aplicado teste de correlação de Pearson. Verificou-se correlação positiva entre os músculos retofemoral e bíceps braquial (r= 0,81); glúteo superficial e tríceps braquial (r= 0,69); semitendinoso/semimembranoso e bíceps braquial (r= 0,76); e entre o músculo reto femoral e o grupo muscular semitendinoso e semimembranoso (r=0,99). Os músculos bíceps braquial e braquiocefálico do mesmo membro trabalham em sinergia para posicionar o membro torácico durante o ciclo de marcha, enquanto o grupo muscular semitendinoso/semimembranoso flexiona o joelho e, simultaneamente com o quadríceps, que flexiona o quadril, impede que o membro pélvico entre em contato com o solo no balanço. Para impulsionar o corpo à frente, o músculo tríceps braquial estende o cotovelo e flexiona o ombro no contato final e o glúteo superficial estende o quadril.(AU)

Fracture resistance of root filled molar teeth restored with glass fibre bundles.

AIM: To evaluate the effect of unidirectional or woven glass fibre tapes inserted into MOD cavity preparations on the fracture resistance of root filled molar teeth. METHODOLOGY: Extracted human molar teeth were randomly divided into six groups (n = 15) : G1 - sound teeth, control; G2 - MOD cavity preparation; G3 - MOD + root canal treatment (Endo); G4 - MOD + Endo + composite resin restoration (Resin); G5 - MOD + Endo + unidirectional fibre (UF) + Resin; G6 - MOD + ;Endo + woven fibre (WF) + Resin. The teeth were subjected to a compressive fracture test in a universal testing machine. After testing, two failure modes were classified: pulp chamber floor or cusp. RESULTS: The highest and the lowest mean fracture strengths were found in sound teeth (G1) (4960N) and MOD + root canal treatment (G3) (612.84N), respectively, with significant differences from the other groups (P < 0.05). The remaining groups had statistically similar means. In G5 and G6, there was a tendency for fracture to occur in the pulp chamber floor compromising tooth integrity. CONCLUSIONS: The insertion of glass fibres into MOD cavity preparations and restoring them with composite resin was not different than molar teeth filled with composite resin only in terms of fracture resistance. Fibres placed into MOD cavities do not reinforce teeth.

Pregnancy restores insulin secretion from pancreatic islets in cafeteria diet-induced obese rats.

Insulin resistance during pregnancy is counteracted by enhanced insulin secretion. This condition is aggravated by obesity, which increases the risk of gestational diabetes. Therefore, pancreatic islet functionality was investigated in control nonpregnant (C) and pregnant (CP), and cafeteria diet-fed nonpregnant (Caf), and pregnant (CafP) obese rats. Isolated islets were used for measurements of insulin secretion (RIA), NAD(P)H production (MTS), glucose oxidation ((14)CO(2) production), intracellular Ca(2+) levels (fura-2 AM), and gene expression (real-time PCR). Impaired glucose tolerance was clearly established in Caf and CafP rats at the 14th wk on a diet. Insulin secretion induced by direct depolarizing agents such as KCl and tolbutamide and increasing concentrations of glucose was significantly reduced in Caf, compared with C islets. This reduction was not observed in islets from CP and CafP rats. Accordingly, the glucose oxidation and production of reduced equivalents were increased in CafP islets. The glucose-induced Ca(2+) increase was significantly lower in Caf and higher in CafP, compared with all other groups. CP and CafP islets demonstrated an increased Ca(2+) oscillation frequency, compared with both C and Caf islets, and the amplitude of oscillations was augmented in CafP, compared with Caf islets. In addition, Ca(v)alpha1.2 and SERCA2a mRNA levels were reduced in Caf islets. Ca(v)alpha1.2, but not SERCA2a, mRNA was normalized in CafP islets. In conclusion, cafeteria diet-induced obesity impairs insulin secretion. This alteration is related to the impairment of Ca(2+) handling in pancreatic islets, in especial Ca(2+) influx, a defect that is reversed during pregnancy allowing normalization of insulin secretion.

[Hantavirus pulmonary and cardiovascular syndrome: epidemiology, clinical presentation, laboratory diagnosis and treatment]. / Síndrome pulmonar e cardiovascular por Hantavirus: aspectos epidemiológicos, clínicos, do diagnóstico laboratorial e do tratamento.

The Hantavirus pulmonary and cardiovascular syndrome (HPCVS) is an emerging disease in Brazil. In this study, eight confirmed cases of HPCVS were studied. All the patients presented fever and dyspnea as well as thrombocytopenia and hypoxemia. Tachycardia, malaise, hypotension and lung rales occurred in 75 to 87.5% of the cases. Hemoconcentration, blood cell count increased and immature neutrophils, and high levels of creatinine were observed in 75 to 87.5%. Intravenous liquid infusion, the use of drugs for increasing systemic vascular resistance and inotropism, and mechanic ventilation were used for the patients. Mechanical ventilation and volume administration should be started precociously, preferable in intensive care units employing recommended universal and respiratory precautions. Careful volume administration should be limited if signs of pulmonary edema develop. Mortality (50%) is high and probably related to the severity of the disease as well as to a delayed attending of the patients for intensive management. It is important to report hantaviruses and HPCVS to the Brazilian medical community considering that many cases could be undiagnosed.

Síndrome pulmonar e cardiovascular por Hantavirus: aspectos epidemiológicos, clínicos, do diagnóstico laboratorial e do tratamento / Hantavirus pulmonary and cardiovascular syndrome: epidemiology, clinical presentation, laboratory diagnosis and treatment

The Hantavirus pulmonary and cardiovascular syndrome (HPCVS) is an emerging disease in Brazil. In this study, eight confirmed cases of HPCVS were studied. All the patients presented fever and dyspnea as well as thrombocytopenia and hypoxemia. Tachycardia, malaise, hypotension and lung rales occurred in 75 to 87.5% of the cases. Hemoconcentration, blood cell count increased and immature neutrophils, and high levels of creatinine were observed in 75 to 87.5%. Intravenous liquid infusion, the use of drugs for increasing systemic vascular resistance and inotropism, and mechanic ventilation were used for the patients. Mechanical ventilation and volume administration should be started precociously, preferable in intensive care units employing recommended universal and respiratory precautions. Careful volume administration should be limited if signs of pulmonary edema develop. Mortality (50%) is high and probably related to the severity of the disease as well as to a delayed attending of the patients for intensive management. It is important to report hantaviruses and HPCVS to the Brazilian medical community considering that many cases could be undiagnosed.

A síndrome pulmonar e cardiovascular por Hantavirus (SPCVH), é doença emergente com descrição crescente de casos no Brasil. Neste trabalho, estudou-se 8 casos confirmados da doença. Todos apresentaram febre e dispnéia. Taquicardia, astenia, hipotensão e estertoração pulmonar ocorreram em 75 a 87,5% dos casos. Plaquetopenia e hipoxemia ocorreram em 100% dos casos, hemoconcentração, leucocitose com desvio à esquerda e elevação de uréia e creatinina séricas em 75 a 87,5%. Assistência respiratória, hidratação endovenosa e utilização de aminas vasoativas foram as medidas utilizadas nos pacientes. Ressalta-se que o suporte ventilatório e cardiovascular deve ser precocemente instituído, preferencialmente em unidades de terapia intensiva, com precauções universais e respiratórias de isolamento. Deve-se ter cuidados com infusão excessiva de líquidos para não agravar o edema pulmonar. A mortalidade observada, de 50%, é elevada, deveu-se à gravidade da doença e ao comparecimento tardio para tratamento intensivo. Deve-se informar sobre a SPCVH aos profissionais de saúde, considerando que casos de SPCVH, provavelmente, vêm passando desapercebidos.

Post-exercise changes in blood pressure, heart rate and rate pressure product at different exercise intensities in normotensive humans

To evaluate the effect of exercise intensity on post-exercise cardiovascular responses, 12 young normotensive subjects performed in a randomized order three cycle ergometer exercise bouts of 45 min at 30, 50 and 80 per cent of VO2peak, and 12 subjects rested for 45 min in a non-exercise control trial. Blood pressure (BP) and heart rate (HR) were measured for 20 min prior to exercise (baseline) and at intervals of 5 to 30 (R5-30), 35 to 60 (R35-60) and 65 to 90 (R65-90) min after exercise. Systolic, mean, and diastolic BP after exercise were significantly lower than baseline, and there was no difference between the three exercise intensities. After exercise at 30 per cent of VO2peak, HR was significantly decreased at R35-60 and R65-90. In contrast, after exercise at 50 and 80 per cent of VO2peak, HR was significantly increased at R5-30 and R35-60, respectively. Exercise at 30 per cent of VO2peak significantly decreased rate pressure (RP) product (RP = HR x systolic BP) during the entire recovery period (baseline = 7930 ñ 314 vs R5-30 = 7150 ñ 326, R35-60 = 6794 ñ 349, and R65-90 = 6628 ñ 311, P<0.05), while exercise at 50 per cent of VO2peak caused no change, and exercise at 80 per cent of VO2peak produced a significant increase at R5-30 (7468 ñ 267 vs 9818 ñ 366, P<0.05) and no change at R35-60 or R65-90. Cardiovascular responses were not altered during the control trial. In conclusion, varying exercise intensity from 30 to 80 per cent of VO2peak in young normotensive humans did not influence the magnitude of post-exercise hypotension. However, in contrast to exercise at 50 and 80 per cent of VO2peak, exercise at 30 per cent of VO2peak decreased post-exercise HR and RP.

Post-exercise changes in blood pressure, heart rate and rate pressure product at different exercise intensities in normotensive humans.

To evaluate the effect of exercise intensity on post-exercise cardiovascular responses, 12 young normotensive subjects performed in a randomized order three cycle ergometer exercise bouts of 45 min at 30, 50 and 80% of VO2peak, and 12 subjects rested for 45 min in a non-exercise control trial. Blood pressure (BP) and heart rate (HR) were measured for 20 min prior to exercise (baseline) and at intervals of 5 to 30 (R5-30), 35 to 60 (R35-60) and 65 to 90 (R65-90) min after exercise. Systolic, mean, and diastolic BP after exercise were significantly lower than baseline, and there was no difference between the three exercise intensities. After exercise at 30% of VO2peak, HR was significantly decreased at R35-60 and R65-90. In contrast, after exercise at 50 and 80% of VO2peak, HR was significantly increased at R5-30 and R35-60, respectively. Exercise at 30% of VO2peak significantly decreased rate pressure (RP) product (RP = HR x systolic BP) during the entire recovery period (baseline = 7930 +/- 314 vs R5-30 = 7150 +/- 326, R35-60 = 6794 +/- 349, and R65-90 = 6628 +/- 311, P < 0.05), while exercise at 50% of VO2peak caused no change, and exercise at 80% of VO2peak produced a significant increase at R5-30 (7468 +/- 267 vs 9818 +/- 366, P < 0.05) and no change at R35-60 or R65-90. Cardiovascular responses were not altered during the control trial. In conclusion, varying exercise intensity from 30 to 80% of VO2peak in young normotensive humans did not influence the magnitude of post-exercise hypotension. However, in contrast to exercise at 50 and 80% of VO2peak, exercise at 30% of VO2peak decreased post-exercise HR and RP.