Effects of heparin on the vasodilator action of protamine in the rabbit mesenteric artery.

1. The effects of protamine on the rabbit isolated small mesenteric artery were investigated both in the presence and in the absence of heparin, by the isometric tension-recording method. 2. The dissociation constant for the binding of heparin to protamine has never been previously reported, so in order to minimize the effects of protamine, known to have a vasodilator action, and to examine only the effects of a heparin-protamine complex, the experiments with heparin were performed in the presence of high concentrations of heparin (21-700 u ml-1), concentrations at which heparin itself does not affect the vascular tone. 3. Protamine (15-500 micrograms ml-1), in the absence of heparin, was found to inhibit (P < 0.05) noradrenaline (1 microM)-induced contractions both in endothelium-intact and in endothelium-denuded tissues. 4. Such vasodilator action of protamine in either endothelium-intact or -denuded tissues continued, even in the presence of excess heparin at a heparin/protamine (H/P) ratio of 1.4 u micrograms -1, but was almost completely blocked in the presence of a much greater excess of heparin (H/P ratio > or = 4.7 u micrograms -1): heparin was present both before and during the application of protamine. 5. The vasodilator action of protamine in the absence of heparin was prolonged both in the endothelium-intact and -denuded tissues after protamine had been washed out from the bath with Krebs solution.(ABSTRACT TRUNCATED AT 250 WORDS)     

A case of mediastinal neurinoma originating from right intrathoracic vagal nerve

A 34-year-old woman was admitted with an abnormal shadow on a chest X-ray film. Under a preoperative diagnosis of benign bronchogenic cyst, operation was carried out and the tumor was found to be originating from the right main vagal nerve in the mid-superior mediastinum. The vagal nerve was transected to remove the tumor. Pathological diagnosis was a neurinoma. Postoperative complication was chylothorax which was successfully treated with thoracic drainage and intravenous hyperalimentation.     

A case of aneurysm of the inferior left ventricular wall

Aneurysms of the inferior left ventricular wall represent only a small fraction of all aneurysms that have been reported in surgical series. And in comparison to anterior left ventricular aneurysms, a comparatively higher percentage of reported inferior wall aneurysms was classified as false. A 73-year-old male was admitted for acute inferior myocardial infarction. Three weeks after admission, cardiac catheterization was carried out. Coronary arteriography revealed triple vessel disease and left ventriculography showed an aneurysm of the inferior left ventricular wall, whose feature near the mitral annulus was multiple fenestrations. Left ventricular aneurysmectomy and aortocoronary bypass grafting to the left anterior descending artery were simultaneously performed under cardiopulmonary bypass with moderate hypothermia. The pathological feature was a true aneurysm. The postoperative course was uneventful.     

Direct determination of benzalkonium chloride in ophthalmic systems by reversed-phase high-performance liquid chromatography

High-performance liquid chromatography has been used to quantitate benzalkonium chloride (alkylbenzyldimethylammonium chloride) in complex ophthalmic formulations at or below concentration levels of 50 ppm. The method involves a one-step dilution for sample preparation and direct injection; therefore, recovery and/or conversion problems are nonexistent. The assay is quick, specific, reproducible, and simple. This new approach makes routine determinations far simpler than previous methods and is especially useful for product stability studies and quality control procedures.     

Factor VIII lability, protein C and other vitamin K-dependent proteins

The stability of factor VIII was studied in plasmas from patients on long-term warfarin therapy. The percent residual factor VIII activity (F.VIII:C) after incubation at 37 degrees C for 4 hr was higher in warfarinized patients than in normal subjects; 76.9 +/- 10.8% (mean +/- SD) of the initial F.VIII:C in the patients versus 61.6 +/- 5.8% in normal subjects (p less than 0.001). On the whole, neither protein C nor vitamin K-dependent coagulation factors except factor VII activity (F.VII:C) correlated with the residual F.VIII:C. There was a negative and weak correlation between the residual F.VIII:C at 4 hr and either the initial F.VIII:C or F.VII:C. Another experiment using protein C depleted plasma showed a relatively enhanced stability of F.VIII:C in the protein C deficiency. These results indicate that factor VIII is more stable in warfarinized plasma, and that protein C and vitamin K-dependent coagulation factors are not the sole, main factor responsible for such a phenomenon.     

Lp(a) lipoprotein in cerebrovascular disease and dementia

Lp(a) lipoprotein has been considered an independent risk factor in the development of coronary heart disease (CHD). We examined the role of Lp(a) in patients with cerebrovascular disease (CVD) and those with dementia. The Lp(a) concentration in patients with CHD, those with cerebral infarction due to a large artery occlusion and those with vascular dementia (VD) was significantly higher than that of age-matched control subjects. However, the Lp(a) concentration was not high in cerebral infarction due to a small artery occlusion, intracerebral hemorrhage and dementia of the Alzheimer type (DAT). The present results suggest that Lp(a) should cause VD as well as CVD, and that Lp(a) should be one of the indicators that distinguish VD from DAT.     

Oxygen-assisted breath-holding in computed tomography

To achieve prolonged breath-holding, oxygen was administered just before dynamic CT and high resolution lung CT. Oxygen administration has proved to be a supportive means to improve the quality of CT studies.