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Biomedical subjects

M Ohara

Publications and source records attributed to M Ohara.

At least 145 records · Page 8Linked to original sources
PubMed1986

Real-time monitoring of the secretory function of cultured adrenal chromaffin cells.

A system to discriminate the real-time dynamics of the secretory function in cultured adrenal chromaffin cells, using a cell bed perfusion technique and an amperometric detector, was established. Examination of basal conditions revealed that the electrode potential and flow rate are crucial factors for monitoring precise dynamics of the secretory process. Stimulation of the cells either with acetylcholine (ACh) or with high K+ concentration caused a transient current response. The current responses showed concentration dependence for both stimuli, and also showed a high correlation with the amount of catecholamines (CA) in the respective peak fraction of perfusate. Either prolonged cholinergic stimulation or maintained depolarization produced a transient response, which is not attributable to a depletion of releasable storage of CA as indicated by double-stimulation experiments. Stimulation with high K+ concentration evoked an additional release of CA even after the cellular response to prolonged ACh was inactivated, whereas maintained depolarization with high K+ produced both facilitatory and inhibitory effects on the cell responsiveness to ACh. Most probably the transient natures of the secretory responses to ACh and to high K+ are mediated by different mechanisms. All the results suggest that the direct monitoring is profitable for studies on the regulatory mechanisms of the secretory function.

Acetylcholine↗
PubMed1986

[Surgical approach to abdominal aortic aneurysm with malignant alimentary tract tumor: report of three cases].

The clinical courses of three cases with various alimentary tract malignant lesions coincidental with abdominal aortic aneurysm were reported. Of those three patients, a simultaneous resection of the malignant lesion and aneurysm was carried out in two patients, while an secondary abdominal aneurysmectomy following the resection of the malignant lesion was done in one patient. A 70-year-old man with cancer of the cecum and an infra-renal abdominal aneurysm, was diagnosed preoperatively, and a simultaneous right hemicolectomy and aneurysmectomy were carried out. In the other patient, a 77-year-old man, presence of the gastric cancer was incidentally found at laparotomy and a 75 percent gastrectomy and an aneurysmectomy were carried out. In the third patient, both gastric cancer and an abdominal aneurysm were detected preoperatively. Distal partial gastrectomy was performed first because of severe epigastralgia and an asymptomatic aneurysm. The abdominal aneurysmectomy was carried out six months later. All patients were treated by daily administration of Cefazolin sodium or cefalotin sodium (4-10 g) and Dibekacin sulfate (200 mg) for seven to ten days postoperatively. In the case of second look operation, however, Fosfomycin 2-4 g/day was added to the above mentioned drug following the aneurysmectomy. All tolerated surgery well without any signs of infections. The first patient died on the 57th postoperative day from panperitonitis carcinomatosa following an episode of intestinal obstruction. Selection of the operative approaches for patients having both an alimentary tract malignant tumor and an abdominal aortic aneurysm was difficult, although the initial surgical intervention for the more life threatening lesion would be better justified.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1985

Aneurysms of the descending aorta: surgical experience with three methods of adjunct procedures.

Thirteen patients were surgically treated for the repair of aneurysms of the descending aorta, using three different types of adjunct procedures--an external temporary bypass with a vascular prosthesis, a tridodecylmethylammonium chloride (TDMAC) or a partial cardiopulmonary bypass. There was no operative death, though one patient died 73 days following surgery. Significant intraoperative morbidity occurred in 3 patients: one had ventricular fibrillation and the other two massive hemorrhages. There was no instance of paraplegia or renal failure. The only significant complication that developed was pulmonary insufficiency in two patients with a pump bypass. The mean operative time and the mean aortic occlusion time in patients with the TDMAC shunt were shorter than the times in patients with the vascular prosthetic shunt or the pump bypass. TDMAC shunt required no special equipment and cannulation was simpler and safer.

Adult↗
PubMed1984

The effects of the antirheumatic agents N-(2-carboxyphenyl)-4-chloroanthranilic acid disodium (CCA) and D-penicillamine on the NK and ADCC activities and interferon production of lymphocytes.

CCA and D-penicillamine enhanced the NK activity of human lymphocytes in vitro incubation. ADCC activity of the lymphocytes was increased slightly by D-penicillamine but not by CCA. CCA enhanced interferon production from lymphocytes but D-penicillamine did not.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1984

[A comparison with Dardik graft and Mindich graft on arterial bypass].

Arterial reconstruction using human umbilical cord vein graft as a vascular prosthesis was carried out in 24 patients, 26 legs, with arteriosclerosis obliterans. Dardik grafts were used in 13 legs and Mindich grafts in 13 legs. Twenty-six operations were divided into two groups; one with the proximal anastomosis above the femoral artery (proximal group) and the other with the proximal anastomosis below the femoral artery (distal group). Postoperative evaluation of all patients was performed at intervals of one to twenty-two months. To make the determination of graft patency, at least, it was required that the graft pulse was palpable. Cumulative patency rates were 54% and 69% in the Mindich grafts and Darkik grafts, respectively. In the proximal group, patency rates were 60% and 50% in Mindich grafts and Dardik grafts, respectively. While in the distal group, patency rates were 37.5% and 78% in Mindich grafts and Dardik grafts, respectively. The causes of the graft obstruction were as follows: 1) graft infection in 4 (2 with Mindich and 2 with Dardik grafts) 2) pseudointimal hyperplasia of the distal anastomosis in 4 with Mindich graft, 3) progression of atherosclerosis in one case with Dardik graft, and 4) substandard Dardik graft in one. It was concluded that Dardik graft should be used as first choice when compared with Mindich graft and these grafts should not be used easily, since these grafts were apt to be infected.

Aged↗
PubMed1983

Operative arteriography: an indicator for infrainguinal bypass.

Preceding infrainguinal artery bypass surgery, a complete arteriographic delineation of the recipient artery is not always feasible. For 13 out of 63 patients with occlusion of the infrainguinal arteries, distinct delineation could not be accomplished with preoperative angiography. However, prebypass operative arteriography was successful in 8 of the 13. In 5, we performed bypass surgery on vessels not visualized on the preoperative angiography. In the other 3, bypass was performed on vessels in which the status of the distal circulation had not been well defined, although the popliteal and infrapopliteal arteries were partially visualized on the preoperative angiography. Intraoperative arteriograms--a technique requiring operative exploration of the target vessel--can significantly improve the visualization of the recipient artery and the distal circulation. Therefore, prebypass operative arteriography may become another indicator for arterial bypass surgery.

Adult↗
PubMed1983

Natural and antibody-dependent cellular cytotoxicity of polymorphonuclear leukocytes.

Cytotoxic activity of polymorphonuclear leukocytes (PMN) in the peripheral blood of patients with various diseases was demonstrated to K562 cells (natural cytotoxicity, NC) and the antibody-coated P815 cells (antibody-dependent cellular cytotoxicity, ADCC), using a 51Cr-release method. The NC values of normal PMN were lower than those of normal lymphocytes with mean values of 5.0% and 30%, respectively. The NC values of patients' PMN were also lower in malignancy, chronic hepatitis and connective tissue diseases. The ADCC values of normal PMN were moderately high with a mean value of 16.0%, which was almost a half of normal lymphocytes. Higher ADCC values of PMN were found in patients with chronic hepatitis, SLE and Behcet's disease, and in these cases the ADCC values of their lymphocytes were extremely low. The supernatants of PMN mix-cultured with unlabeled K562 or the antibody-coated P815 cells were fairly cytotoxic to both cells, though the similar supernatants of lymphocytes were cytotoxic only to K562 cells, but not to the antibody-coated P815 cells.

Animals↗
PubMed1983

[Evaluation of surgical therapy for thromboangitis obliterans, with special reference to follow-up studies].

Out of sixty patients with thromboangitis obliterans from January 1966 to December 1981, 50 cases underwent such surgery as sympathetic ganglionectomy, thromboendarterectomy and arterial bypass. The remaining 10 cases received conservative therapies such as intravenous infusion of Prostaglandin E1 (60 micrograms in 5% glucose 500 ml) and epidural sympathetic ganglion block using 1% xylocaine. Good results were obtained in 29 operative cases and in 5 cases with non-surgical therapies. Among the operative cases, the subjective symptoms after discharge improved in forty-one patients (82%) unchanged in three (6%) and remained poor in six (12%). While, those of non-surgical group improved in eight and unchanged in two. In twelve of twenty-nine operative patients whose subjective symptoms improved immediately after discharge, their subjective distress turned worse again. However, the subjective symptoms of 5 patients in non-surgical group remained well in follow-up studies. Many patients who were diagnosed unchanged during follow-up period, had underwent the lumbar and/or thoracic sympathetic gangloinectomy. It is thus concluded that the effects of the sympathetic ganglionectomy are not permanent. The arterial reconstructive surgery is very effective for relief of peripheral ischemia in the follow-up studies if good function of the grafts was obtained in the early postoperative period.

Adult↗