Blood coagulation studies during six day heparinless venoarterial bypass in sheep

Heparinless venoarterial bypass (HL-VAB) was carried out in 16 sheep for 6 days, by means of a closed circuit tubing coated with nonthrombogenic polyurethane-polyvinyl-graphite (PPG) and a roller pump. Nine experiments were completed uneventfully. Seven sheep died during bypass. The causes of death were pneumonia (2), caseous granulomatous lung abscess (3) or abdominal abscess (1), and thromboembolism (1). The last complication was caused by inadvertent trauma to the PPG coating at the time of tubing connection. In the animals in which HL-VAB was uneventful, no significant changes were noted in the hematologic studies including white blood counts, platelet counts, hematocrit, plasma fibrinogen levels, prothrombin time, thrombin time, activated partial thromboplastin time, Factors V and VIII, and free plasma hemoglobin levels. Inconsistant changes in the above parameters were noted in the animals which died of complications. In conclusion, prolonged HL-VAB has no adverse effects on blood coagulation mechanism.     

Aneurysm of the femoral artery occupationally exposed to a vibratory tool for more than 10 years

The first case of an aneurysm of the femoral artery occupationally exposed to a vibratory tool is described. A 72-year-old man with a right common femoral artery aneurysm had had an occupational history of putting a "breaker," which breaks concrete into pieces by means of powerful vibration, on the right groin for more than 10 years. The patient underwent aneurysmectomy and graft replacement, with reconstruction of the deep femoral artery. Pathologic examination of the resected aneurysm revealed fibrosis and lipid deposition in the intima, well-maintained elastic fibers without disruption in the media, and thickened adventitia, in place of the typical findings of atherosclerosis.     

Skim soy protein enhances GFR as much as beefsteak protein in healthy human subjects

Background It has been reported that an acute load of beefsteak (200g) significantly enhanced the glomerular filtration rate (GFR; inulin clearance and creatinine clearance) in healthy human subjects compared to that in the same subjects in the fasted state. However, no comparative study of the effects of the same amount of vegetable protein on GFR has been reported to date.Methods We attempted to compare changes in the GFR (inulin clearance and creatinine clearance) in six healthy male subjects following consumption of the same amount of beefsteak or baked skim soy with soy sauce (protein, 86.9g) after fasting. The clearance study was performed by conventional methods. Inulin was measured by the anthrone method. Creatinine was measured by the Jaffe rate assay method. Amino-acid analysis of the beefsteak and baked skim soy with soy sauce was done by acid or hydroxide hydrolysis and an amino-acid analyzer.Results A significant enhancement of the GFR (both inulin clearance and creatinine clearance) was observed following acute loading with beefsteak or baked skim soy with soy sauce, compared to the GFR in the fasted state. No significant difference was observed between the results with beefsteak and the results with baked skim soy with soy sauce. Amino-acid analysis revealed that the total amount of three amino acids (glycine, alanine, and arginine; or serine, alanine, and proline) was almost identical in beefsteak (animal protein) and baked skim soy with soy sauce (vegetable protein).Conclusions The present study demonstrated that vegetable protein with the same amino-acid composition could enhance the GFR in healthy subjects as much as animal protein.     

Cytoarchitecture and intercalated disks of the working myocardium and the conduction system in the mammalian heart

Working and specialized cardiac myocytes and their intercalated disks (ID) in the mammalian heart were examined by transmission and scanning electron microscopy. The NaOH/ultrasonication treatment of cardiac tissues resulted in the digestion of collagen fibers and separation of intercellular junctions. Auricular and ventricular myocytes were cylindrical in shape, bifurcated, and connected end-to-end at the ID. The ID in the working myocardium showed a stair-like profile, consisting of steps (plicate segments) and corresponding risers (interplicate segments). The ventricular myocytes had many steps and risers. The steps were filled with numerous finger-like microprojections, including desmosomes, fasciae adherentes, and small gap junctions. The risers showed the smooth surface, including desmosomes and large gap junctions. The cell strands of the sinoatrial node were oriented linearly, while those of the atrioventricular node formed a reticular network. The ID in both nodal cells was underdeveloped, having few microprojections. Myocytes in the His bundle and its branches were arranged in parallel, and Purkinje cell strands formed reticular networks. The ID in the His-Purkinje system was irregular in appearance, and the microprojections were larger in size and smaller in number than those of working myocytes. There were few microprojections in the sheep Purkinje cells. The gap junctions in the conduction system were few or small in size in the nodal tissue, but large in the His-Purkinje system.     

Glomerular calcification induced by bolus injection with dibasic sodium phosphate solution in Sprague-Dawley rats

To elucidate the nephrotoxicity of phosphate, dibasic sodium phosphate solution was given to Sprague-Dawley rats by daily bolus intravenous administration at concentrations of 0, 1, 25, 250, or 360 mM (0, 1, 28, 284, or 408 mg/kg Na2HPO4) for 14 days, and the kidneys were pathologically examined. There were no remarkable changes in blood chemistry values; however, urinalysis revealed mild to moderate proteinuria in the 250 and 360 mM groups. The kidneys from the 360 mM group were macroscopically pale. Histopathology revealed panglomerular deposition of basophilic dense granules, which were positive for von Kossa's staining, accompanied by dose-dependent degeneration of the glomerular epithelium and parietal epithelium in the 250 and 360 mM groups. Electron microscopic examination showed fusion of podocytes and increased microvilli, with large amounts of debris in the Bowman's space. Low-density lamellar structures were present not only in the glomerular epithelium, basement membrane, mesangial matrix and parietal epithelium but also within the Bowman's space depending on the severity of the glomerular lesion. Phosphorus and calcium were detected by X-ray microanalysis as fine particles admixed with lamellar structures. These results suggest that high-dose phosphate used in this study transiently overloads the glomerular epithelium during filtration through glomerular capillaries and produces insoluble calcium salt and glomerular lesions, resulting in proteinuria.