Biomedical subjects
Publications and source records attributed to Y Hosoda.
A simple approach for exposing a difficult mitral valve within a small left atrium is described herein through the report of case. Mobilization of the superior vena cava with direct venous cannulation and extended dissection of the interatrial groove provide excellent mitral valve exposure, even in patients with a small left atrium.
Transesophageal echocardiography (TEE) is a valuable diagnostic tool for providing clear images of the proximal coronary arteries. We describe herein the case of an elderly man in whom dissection and an atherosclerotic plaque in the proximal coronary arteries were demonstrated by TEE during combined coronary artery bypass grafting and aortic valve replacement. Thus, retrograde cardioplegia was employed, whereby trauma to the coronary ostia was avoided.
A new method for allowing stool passage into the pelvic pouch before ileostomy closure to verify the defecation state and diminish stool frequency is reported herein. This was accomplished by fitting an ileostomy connector connecting the proximal and distal openings of the diverting loop stoma. The ileostomy connector was initially in place for 6 h a day, the length of time being gradually increased until it was able to be left in for 24 h a day over a 3-month period. The calculated daily frequency of stools decreased from 24 to 6 or 7 times, and the mean daily frequency immediately after ileostomy closure was 6.5 times. Physiological study also showed an improvement, with squeeze pressure increasing from 35 cmH2O to 116 cmH2O and the maximum tolerated volume increasing from 35 ml before, to 90 ml 3 months following the use of an ileostomy connector. Thus, we conclude that an ileostomy connector may be useful to predict postoperative functional outcome and its complications, and to diminish the frequency of defecation before ileostomy closure in patients with a covering loop stoma.
The changes in myosin light chain I (MLC I) following aortocoronary bypass were studied in 31 patients and the curves of these changes were classified into three different patterns. A peak level of 14.7 +/- 1.54 ng/ml was seen in seven patients on postoperative day (POD) 2 which decreased suddenly to less than twice the normal value by POD 7 (group 1). Another 19 patients showed a peak level of 20.7 +/- 16.5 ng/ml on POD 5, which decreased slowly and was still high even by POD 7 (group 2). The remaining five patients developed only a slight increase in the MLC I level after the operation, with a peak value of 5.5 +/- 0.8 ng/ml (group 3). Creatine kinase myocardial band and glutamic oxaloacetic transaminase also remained low in this group. No correlation existed between the peak value of MLC I and the aortic cross-clamping time, or between the peak value of MLC I and the cardiopulmonary bypass time. Furthermore, the difference in cardiac output before and after the operation did not significantly differ among the three groups. These findings indicate that the measurement of MLC I is useful for diagnosing perioperative myocardial damage and may also be useful in the study of myocardial protection.
Fifteen patients were examined before and immediately after balloon angioplasty with a 4.3F, 30 MHz rotational tip intravascular ultrasound system. In 12 (80%) patients, 13 procedures could be analyzed because of sufficient image quality. The lesions for intravascular ultrasound (IVUS) study consisted of pulmonary arterial stenosis in 4 patients, Blalock-Taussig shunt stenosis in 3, coarctation of the aorta in 2, subclavian artery stenosis in 1, renal artery stenosis in 1, and ductus arteriosus in 1. Three distinctive morphologic types were identified: Group I had arterial stretching (3 patients); group IIa had superficial tearing (3); group IIb had deep intimal-medial tearing (5); group III had dissection (2). In the narrowest site, minimal and maximal luminal diameters, luminal area before and after balloon angioplasty were 3.5 +/- 1.8 mm vs 4.5 +/- 2.5 mm, 4.1 +/- 2.1 mm vs 5.4 +/- 3.5 mm, and 49.8 +/- 30.2 mm vs 88.3 +/- 45.2 mm2, respectively. The recoil value of group IIb with appropriate balloon angioplasty was approximately 0.3. IVUS may be an useful modality for evaluating the morphologic mechanism of dilatation after balloon angioplasty.
A 1-month-old boy with respiratory distress underwent pulmonary artery banding after diagnosis of d-loop transposition of the great arteries and ventricular septal defect. Respiratory distress recurred after surgery. Angiography, esophagography, and magnetic resonance imaging showed left aortic arch, retroesophageal aorta, and right descending aorta. Surgery at 9 months of age showed a right-sided ligamentum arteriosum. Division of the ligamentum relieved the constriction of the esophagus and trachea caused by this rare form of vascular ring.
OBJECTIVES: To determine the potential of lipid-lowering therapy to reduce saphenous vein graft obstruction, we retrospectively studied the association between graft obstruction and serum cholesterol levels. BACKGROUND: Atherosclerosis is the major cause of vein graft obstruction. Approximately 50% of grafts are occluded by 10 years after operation. It remains to be established whether lipid control affects long-term graft survival. METHODS: We carried out a retrospective review of all 284 patients who had undergone coronary artery bypass graft surgery at Juntendo University Hospital between 1976 and 1991 and met the following additional criteria: at least one saphenous vein graft, repeat coronary arteriography at some point after coronary artery bypass graft surgery and a serum cholesterol level > or = 200 mg/dl before operation. Saphenous vein graft obstruction rates were compared among three groups classified by serum cholesterol levels at follow-up arteriography: group I < 200 mg/dl; group II 200 to 239 mg/dl; group III > or = 240 mg/dl. A vein graft was considered obstructed if it was narrowed by > or = 70%. RESULTS: In group I, 88% of grafts were not obstructed 7 years after operation. The respective rates were 61% in group II and 57% in group III (p < 0.005). This relation was true for vein grafts to the left anterior descending and other coronary arteries. CONCLUSIONS: Lower serum cholesterol levels are associated with lower rates of vein graft obstruction for up to 7 years. This suggests that cholesterol-lowering therapy may improve long-term saphenous vein graft survival after coronary artery bypass surgery.
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The transitional region of the eighth cranial nerve, where the central and peripheral nervous tissues are contiguous, was studied by electron microscopy using surgically resected specimens of the human eighth cranial nerve root. The astrocytic glial dome was sharply demarcated by a basement membrane from the peripheral portion of the nerve. Half-desmosomes were found on the edge of the astrocytic glial dome and at the luminal surface of the perivascular glial limiting membrane. Desmosomes and gap junctions were found between the astrocytic processes. These ultrastructural features suggest a weak link between the central and peripheral portions of the nerve which might predispose the transitional region to injury, although the peripheral and central portions have sufficient resistance to external stresses independently.
By using surgical materials obtained from 7 cases of vestibular schwannoma, the ultrastructure of melanocytes in the dark cell area of human vestibular organs was examined by light microscopy and electron microscopy. Paraffin sections were stained with hematoxylin and eosin. Glutaraldehyde-fixed specimens were observed by electron microscopy. Melanocytes were found in the subepithelial layer of the dark cell area. Melanocytes had round or spindle-shaped nuclei and clear cytoplasm with brown pigment granules which were thought to be melanin granules. Besides melanocytes, there were fibroblasts and small blood vessels. By electron microscopy we found melanocytes with round shaped melanosomes in various stages of pigmentation, well-developed Golgi apparatus and endoplasmic reticulum in the cytoplasm, and many cytoplasmic processes. There were pinocytotic vesicles just under the limiting membrane of the melanocytes, and intermediate filaments were abundant in the cytoplasm. On the other hand long-spacing collagen was found in the connective tissue area around melanocytes.
The infralabyrinthine approach to vestibular neurectomy was performed in 9 patients with unilateral Menière's disease. According to the AAOO (1972) criteria, 7 of 9 cases were graded as class B and the remaining 2 cases as class C. Otherwise, according to the AAO-HNS (1985) criteria, 6 patients who could be followed over 2 years were all graded as 'complete' at the vertigo control. The compensation of the spontaneous vestibular signs was rapid in the first 2 postoperative weeks, though an occasional imbalance on movement persisted even 3 years after the operation. No specific caloric reaction was elicited in any patient after warm or cold water irrigation of the operated side in any postoperative period. There have been no serious complications except a delayed facial palsy that appeared in one case one week after surgery. This approach offers access to the vestibular nerve with minimal risk and morbidity.
Finland and Hokkaido resemble each other; the four season climate with cold winters and cool summers is the same as is the frequency of tuberculosis. The size of the population is almost the same. From the 1984 Japanese nationwide sarcoidosis survey we got the data from Hokkaido (288 patients) in order to compare the information with similarly collected data in Finland from 1984 (1,378 patients). The crude prevalence of sarcoidosis was 28.2 per 100,000 in Finland and 3.7 per 100,000 in Hokkaido. The annual incidence was 11.4 per 100,000 in Finland and 1.0 per 100,000 in Hokkaido. The sex distribution was similar; 63% vs 67% women in Finland and Hokkaido, respectively. At diagnosis the Hokkaidoan patients were significantly younger. In Hokkaido more cases were detected via mass X-ray survey (43% vs 34%). Among symptomatic patients eye symptoms were more frequent in Hokkaido, whereas respiratory and joint symptoms and erythema nodosum were more frequent in Finland. Bilateral hilar lymphadenopathy (BHL) was equally distributed (82% vs 84% whereas parenchymal lesions were seen more often in Finland (49% vs 25%) as well as peripheral lymphadenopathy (16% vs 8%).
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A 30-year-old man was admitted to the hospital because of type A aortic dissection associated with annuloaortic ectasia (AAE). A magnetic resonance image (MRI), computed tomography of the aorta demonstrated aortic enlargement with dissection, but revealed no evidence of dissection of the aortic arch. A transesophageal echocardiography demonstrated dissection of the aortic arch. A graft replacement of the total aortic root were performed using hypothermic circulatory arrest with retrograde cerebral perfusion and open distal anastomosis. We reconstructed coronary ostiums with carrel patch, and discontinued the operation without major bleeding. No neurological deficit was found postoperatively.
Pericardial cyst and diverticulum are commonly found in areas of cardiophrenic angles. In this article, we reported on two operated cases (54-year-old female, 43-year-old male) with pericardial diverticula in upper mediastinum. On their chest CT films, well circumscribed cystic lesions were seen in the right (case 1) and left (case 2) upper mediastinum. Based on findings of imaging modalities such as CT, MRI and transesophageal ultrasonography, the lesions were suspected of benign cystic tumors such as bronchogenic cyst, lymphatic cyst, esophageal cyst and pericardial cyst. However, definite diagnoses were made by thoracotomy. Even though the cystic lesion is recognized in the upper mediastinum, pericardial diverticulum should be considered as its diagnosis as well as bronchogenic cyst, lymphatic cyst, esophageal cyst.
In 1986, familial medullary thyroid carcinoma (FMTC) was recognized clinically as a distinct entity, clearly distinguished from multiple endocrine neoplasia (MEN), being characterized by the development of MTC in the absence of any additional neoplasms. Ret proto-oncogene was first identified in 1985 using transformation assay. The gene was mapped to the chromosome 10, similar to MEN and FMTC, and was expressed at high levels in MTC. In 1993, ret mutations were identified in patients with MEN2A and FMTC, and many other mutations has been clarified up to today. What is the normal function of RET and how ret mutations lead to tumor formation in MEN and FMTC are focus of intensive studies at present.
To analyze the nature of intestinal mucosal lymphocytes in Crohn's disease, we established T cell lines of patients' intraepithelial lymphocytes. T cell lines from the affected terminal ileum of the patients showed an increased proportion of CD4+V beta 5.2/5.3+ T cells. These cells were increased in number after stimulation with staphylococcal enterotoxins C1 and D, showed an increase in cytolytic activity, and produced a large amount of interferon-gamma. To clarify the role of CD4+ mucosal lymphocytes in the intestinal inflammation, we then developed a novel colitis model by immunizing a rat with trinitrobenzenesulfonic acid (TNB) emulsion with adjuvant. Deep ulceration and granuloma formation in this colitis model resembled the histopathological findings of human Crohn's disease. Immunohistochemical and flow cytometric analysis demonstrated that the number of CD45RC(high)CD4+ mucosal lymphocytes was increased. Interestingly, the administration of anti-CD4 Abs prevented severe inflammation in the model. After treatment with anti-CD4 Abs, the anti-TNB Ab titer, the number of CD45RC(high)CD4+ cells, and interferon-gamma mRNA expression were significantly decreased in the mucosa of the model. These results suggest that some subsets of CD4+ mucosal lymphocytes play an important role in the triggering and progression of inflammation in Crohn's disease.
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