Pressão venosa central em bezerros neonatos hígidos / Central venous pressure in healthy newborn calves

Com o propósito de estabelecer valores-padrão da pressão venosa central (PVC), utilizaram-se 24 bezerros sadios, da raça Holandesa, com idade entre oito e 30 dias, e peso entre 37 e 50kg. A PVC foi medida, no átrio direito, com uso de cateter intravenoso e equipo próprio usando-se como via de acesso a veia jugular esquerda. O átrio direito foi considerado o ponto zero de referência para as leituras, estando topograficamente em correspondência externa à articulação escapuloumeral no animal em estação e à região do esterno, quando em decúbito lateral direito. Estabeleceram-se os valores médios da PVC, em centímetros de água, de 0,81±1,40 e 0,88±1,76, respectivamente, nos animais em estação e em decúbito lateral, e não houve diferença estatística entre os valores. A metodologia empregada para mensurar a PVC de bezerros revelou-se segura e exeqüível, não necessitando de aparelhagem sofisticada para a sua determinação.

With the aim of determining the central venous pressure (CVP) standard values, twenty-four healthy Holstein calves, aging 8-to-30 days and weighing from 37 to 50kg, were studied. To measure CVP, a specific intravenous catheter was inserted in the right atrium through the left jugular vein. The right atrium was the reference mark (zero) for the measurements, topographically in external correspondence to the scapulohumeral joint, when the animal was standing; and to the sternum region, when the animal was in right lateral recumbency. It was measured a mean CVP, in centimetres of H2O - 0.81±1.40 for animals in standing position, and 0.88±1.76 for animals in lateral recumbency - with no statistical difference between those values. The technique used for measuring CVP in calves was determined to be feasible and do not require sophisticated devices.

Cell cycle regulators during human atrial development

OBJECTIVES: The molecular mechanisms that regulate cardiomyocyte cell cycle and terminal differentiation in humans remain largely unknown. To determine which cyclins, cyclin dependent kinases (CDKs) and cyclin kinase inhibitors (CKIs) are important for cardiomyocyte proliferation, we have examined protein levels of cyclins, CDKs and CKIs during normal atrial development in humans. METHODS: Atrial tissues were obtained in the fetus from inevitable abortion and in the adult during surgery. Cyclin and CDK proteins were determined by Western blot analysis. CDK activities were determined by phosphorylation amount using specific substrate. RESULTS: Most cyclins and CDKs were high during the fetal period and their levels decreased at different rates during the adult period. While the protein levels of cyclin D1, cyclin D3, CDK4, CDK6 and CDK2 were still detectable in adult atria, the protein levels of cyclin E, cyclin A, cyclin B, cdc2 and PCNA were not detectable. Interestingly, p27KIP1 protein increased markedly in the adult period, while p21CIP1 protein in atria was detectable only in the fetal period. While the activities of CDK6, CDK2 and cdc2 decreased markedly, the activity of CDK4 did not change from the fetal period to the adult period. CONCLUSION: These findings indicate that marked reduction of protein levels and activities of cyclins and CDKs, and marked induction of p27KIP1 in atria, are associated with the withdrawal of cardiac cell cycle in adult humans.