Clock genes expression and locomotor activity are altered along the light-dark cycle in transgenic zebrafish overexpressing growth hormone.

In the present work it was demonstrated that transgenic Danio rerio overexpressing growth hormone (GH-transgenic) present either altered gene expression at a determined time point, or different expression pattern along the LD cycle, when compared with non-transgenic (NT) animals, in the positive and negative loops of the circadian system. Gene expression of clock paralogs was reduced in GH fish at the beginning of the dark phase, leading to diminished expression amplitude along the LD cycle. Furthermore, although no differences were observed between NT and GH animals for bmal1a and cry2b expression at each time point, only GH fish presented amplitude along the LD cycle. Also, the locomotor activity behavior was evaluated for both groups. GH-transgenic animals presented higher locomotor activity along the whole LD cycle when compared with NT animals. These data suggest that alterations in the gene expression patterns along the LD cycle of the positive and negative loops of the circadian system, could lead to altered locomotor activity behavior in GH-transgenic fish, and GH overexpression could be responsible for these alterations, either affecting the pathways involved in the expression of genes from the circadian system or altering the metabolism.

Mr flow measurement in the internal mammary artery-to-coronary artery bypass graft: comparison with graft stenosis at radiographic angiography.

PURPOSE: To evaluate the sensitivity and specificity of breath-hold magnetic resonance (MR) flow measurement for detection of significant stenosis in internal mammary artery bypass grafts. MATERIALS AND METHODS: Twenty-six consecutive patients who had undergone coronary artery bypass surgery were examined. Breath-hold velocity-encoded cine MR images were obtained at the midpoint of the internal mammary artery between its origin from the subclavian artery and the distal anastomosis to the left anterior descending artery. RESULTS: MR images were obtained successfully in 24 patients. At conventional angiography, no significant stenosis was observed in 17 patients (group A), and significant stenosis (diameter > 70%) was observed in seven patients (group B). The mean diastolic-to-systolic peak velocity ratio in group B (0.61 +/- 0.44 [SD]) was significantly lower than that in group A (1.88 +/- 0.96; P <.01). Evaluation of graft stenosis with the diastolic-to-systolic peak velocity ratio revealed a sensitivity of 86% and a specificity of 88%. The mean blood flow rate at baseline in group B (16.9 mL/min +/- 5.5) was significantly lower than that in group A (79.8 mL/min +/- 38.2; P <.01). The sensitivity and specificity of MR blood flow measurement in predicting significant stenosis were 86% and 94%, respectively. The mean pharmacologic flow reserve ratios were 2.00 +/- 1.43 in group A and 1.39 +/- 1.46 in group B (P >.05). CONCLUSION: Fast MR blood flow measurement at baseline is highly useful for predicting significant stenosis in internal mammary arterial grafts.

[The effects of intravenous milrinone for the patient undergoing CABG].

The hemodynamic effects of intravenous infusion of milrinone were evaluated in 25 patients undergoing CABG using an internal mammary artery graft. Milrinone was administered to 9 patients at the time of weaning from cardiopulmonary bypass, at a dosage of 3 to 5 micrograms/kg/min. Postoperative cardiac function was compared in this group versus the other 17 patients who were treated without milrinone. We determined such parameters as cardiac index, wedge pressure and mean pulmonary pressure. Our findings did not show any significant difference between the 2 groups. We also studied a subject of low-output patients (EF < 0.5). In the patients with low-cardiac output, the use of milrinone in addition to standard postoperative administration of low-dose dopamine reduced mean pulmonary pressure and wedge pressure. Thus, milrinone not only improved the left ventricular function, but also expanded the pulmonary vascular bed.

[Completion pneumonectomy combined with graft replacement of thoracic aortic aneurysm by simple clamping].

A 59-years-old male patient who had left upper lobe partial resection 30 years ago. He was seen at the family physician because of cough. A chest X-ray was showing an abnormal mass shadow measuring 3 x 4 cm in left lower lobe like honey comb. And squamous cell carcinoma (SCC) was detected in his sputum. He was diagnosed as primary lung cancer and introduced to our department to have operation. Chest CT-scan was showing lung tumor suspected SCC measuring 4.3 x 2.6 cm in segment 8 faced chest wall. At the same time, we detected thoracic aortic aneurysm and subcarinal lymph node, but could not see where the boundary is, so it was hard to distinguish between parietal thrombus with thoracic aortic aneurysm and swelling subcarinal lymph node. We decided it swelling subcarinal lymph node by three-dimensional treated CT-scan. Aortic angiography was showing proximal descending aortic aneurysm measuring diameter was 4.5 cm. Abdominal CT-scan was showing infrarenal abdominal aortic aneurysm measuring diameter was 5.5 cm. He was diagnosed as primary lung cancer (It. S8, SCC) (cT2N2M0, Stage IIIB), thoracic aortic aneurysm, abdominal aortic aneurysm, and idiopathic pulmonary fibrosis, and had completion pneumonectomy (R 2 b) for primary lung cancer and graft replacement with aneurysm dissection for thoracic aortic aneurysm without extracorporeal circulation. In this operation, we could find swelling subcarinal lymph node measuring 5 x 3 cm instead of parietal thrombus with thoracic aortic aneurysm. Pathological examination diagnosed middle differential SCC and no metastasis from dissected lymph node (PT2N0M0, Stage I A).

Comparative studies of glycoprotein Ib in heparin coated and nonheparin coated extracorporeal circulation circuits.

Contact between blood and artificial materials has various effects on blood. Impairment of platelet function is an especially important and well known effect, but its precise mechanism is not clearly understood. The authors constructed a circulation model to investigate the effect of extracorporeal circulation on platelet membrane glycoproteins (GPs), especially GP Ib, and to compare the changes in GP Ib in heparin coated (group C) and nonheparin coated (group N) circuits. As determined by flow cytometry, GP Ib in both groups decreased on initiating circulation, but the decrease in group N was significantly larger than that in group C. There was no observed change in GP IIb/IIIa levels in either group. The extent of shear stress induced platelet aggregation significantly decreased during circulation in both groups. Decreases in the extent of shear stress induced platelet aggregation were significantly less with the use of heparin coated circuits. In addition, the amount of GP Ib in the high speed pellet decreased progressively during circulation in both groups. In contrast, the amount of GP Ib in the Triton insoluble (low speed) pellet increased dramatically during circulation. However, expression of GP Ib in the Triton soluble platelet fraction was low in both groups. From the results, it was concluded that the cause of the decrease in platelet function during extracorporeal circulation is attributable to the internalization of GP Ib from the platelet surface inside the platelet. It also can be said that a heparin coated circuit is one effective means of controlling this change.