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Biomedical subjects

T Yabe

Publications and source records attributed to T Yabe.

At least 91 records · Page 5Linked to original sources
PubMed1996

HKR1 encodes a cell surface protein that regulates both cell wall beta-glucan synthesis and budding pattern in the yeast Saccharomyces cerevisiae.

We previously isolated the Saccharomyces cerevisiae HKR1 gene that confers on S. cerevisiae cells resistance to HM-1 killer toxin secreted by Hansenula mrakii (S. Kasahara, H. Yamada, T. Mio, Y. Shiratori, C. Miyamoto, T. Yabe, T. Nakajima, E. Ichishima, and Y. Furuichi, J. Bacteriol. 176:1488-1499, 1994). HKR1 encodes a type 1 membrane protein that contains a calcium-binding consensus sequence (EF hand motif) in the cytoplasmic domain. Although the null mutation of HKR1 is lethal, disruption of the 3' part of the coding region, which would result in deletion of the cytoplasmic domain of Hkr1p, did not affect the viability of yeast cells. This partial disruption of HKR1 significantly reduced beta-1,3-glucan synthase activity and the amount of beta-1,3-glucan in the cell wall and altered the axial budding pattern of haploid cells. Neither chitin synthase activity nor chitin content was significantly affected in the cells harboring the partially disrupted HKR1 allele. Immunofluorescence microscopy with an antibody raised against Hkr1p expressed in Escherichia coli revealed that Hkr1p was predominantly localized on the cell surface. The cell surface localization of Hkr1p required the N-terminal signal sequence because the C-terminal half of Hkr1p was detected uniformly in the cells. These results demonstrate that HKR1 encodes a cell surface protein that regulates both cell wall beta-glucan synthesis and budding pattern and suggest that bud site assembly is somehow related to beta-glucan synthesis in S. cerevisiae.

Bacterial Outer Membrane Proteins↗
PubMed1996

Role of three chitin synthase genes in the growth of Candida albicans.

The CHS2 and CHS3 genes of Candida albicans were disrupted. The double disruptant was still viable. Assessment of chitin and of calcofluor white resistance shows that CHS1 is responsible for septum formation and CHS3 is responsible for overall chitin synthesis otherwise. There were only small differences in virulence to immunocompromised mice of homozygous chs2 delta amd chs3 delta null mutants.

Animals↗
PubMed1996

Study design and statistical analysis of toxicokinetics: a report of JPMA investigation of case studies.

In 1994, the Japanese Pharmaceutical Manufacturers Association (JPMA) conducted a questionnaire survey on case studies of toxicokinetics which were recently conducted its member companies. The present paper summarizes study designs and results of data analysis of 102 cases of repeated oral dose toxicity studies with dogs, monkeys, rats or mice. The statistical analysis of toxicokinetic data introduced in this paper, e.g. log-transformation of concentration data, analysis of variance and regression analysis, may be useful in clarifying the comprehensive effects of test doses, duration of repeated dosing, and sex of test animal on the systemic exposure. Suggestions are made on how experimental design can aid the efficient conduct of toxicokinetic studies in the face of limits on the number of animals.

Animals↗
PubMed1996

[Two cases of Candida endocarditis associated with abdominal disease].

Two cases of Candida endocarditis are reported. The first case was of a 63-year-old man who had a positive blood culture for Candida albicans during treatment for liver abscess and early gastric cancer. He was transferred to our department, and aortic and tricuspid regurgitation due to Candida endocarditis was diagnosed. The patient was successfully treated with aortic valve replacement, tricuspid valve plasty and anti-fungal agents. The second case was of a 65-year-old man who complained of fever. Despite a diagnosis of common bile duct cancer and resection of the tumor, the fever persisted. He was transferred to our department and was diagnosed having aortic regurgitation due to Candida endocarditis, complicated by heart failure. Although intense medical therapy including antifungal agents, diuretics, catecholamines and digoxin was initiated, the patient died from multiple embolisms 9 days later. In the treatment of Candida endocarditis, early diagnosis and early decision-making for either surgical or medical therapy is indispensable. Although the prevalence of Candida endocarditis is low, the differentiation of this disease should be taken into account in febrile elderly patients with long-standing therapy with antibiotics.

Aged↗
PubMed1996

[An elderly patient with Leriche syndrome complicated by congestive heart failure and rhabdomyolysis].

A 64-year-old man, who had had bilateral intermittent claudication and leg pain for five years, was admitted because of sudden onset of severe leg pain, and acute respiratory failure. Laboratory data showed markedly elevated serum CK of 73,050 IU/L, and urinary myoglobin of 430,000 ng/ml. A diagnosis of rhabdomyolysis was made. Renal dialysis was required for the next two days because of acute renal failure. The aortogram was performed on the 32nd day and disclosed complete obstruction of the abdominal aorta immediately distal to the bilateral renal arteries. Good collateral flow was noted to the popliteal arteries. On the 49th day, the patient successfully underwent extra-anatomical bypass surgery (axillo-bifemoral bypass). The mechanism of rhabdomyolysis in this elderly patient was discussed.

Heart Failure↗
PubMed1996

[Clinical investigations of five patients with intracranial lesions presenting tinnitus].

We investigated 5 patients with intracranial lesions. The initial complaint was tinnitus with normal hearing or sight sensorineural hearing loss. The lesions were 2 cerebello-pontine angle meningiomas, 1 cerebello-pontine angle epidermoid cyst, 1 supratentorial falx meningioma and 1 dural arteriovenous malformation at the temporal bone. Because of pulsatile or severe persistent tinnitus, we performed CT and MRI to determine the presence of intracranial lesions. Some patients had an episode of cerebral infarction and the complaint of headache or head heaviness. Quantitative measurement of tinnitus showed a low-frequency character in a pitch-match examination and moderate loudness in loudness balance. In the patients with falx meningioma and dural arteriovenous malformation, the tinnitus character was pulsatile and abnormal blood flow might have affected the peripheral auditory system. On the other hand, in the patients with a cerebello-pontine angle tumor, the tinnitus character was non-pulsatile and compression on the central auditory system by the tumor might have caused the tinnitus.

Adult↗
PubMed1996

[Infective endocarditis associated with vertebral osteomyelitis: report of two cases].

A 42-year-old man and a 65-year-old woman with infective endocarditis suffered onset of severe back pain. Magnetic resonance imaging and technetium-99 m bone scanning demonstrated osteomyelitis in the lumbar spine which is an unusual complication of infective endocarditis. The man was treated by antibiotics and finally aortic valve replacement and laminectomy with bone grafting. The woman had small patent ductus arteriosus and developed aortic regurgitation, but was treated by antibiotics and corset application with good result. The possibility of osteomyelitis in the lumbar spine should be considered in a patient with endocarditis complaining of severe back pain. The appropriate antibiotic therapy over a prolonged period is recommended.

Adult↗
PubMed1995

Quantitative measurements of cardiac phosphorus metabolites in coronary artery disease by 31P magnetic resonance spectroscopy.

BACKGROUND: 31P metabolite measurements in the human heart by magnetic resonance spectroscopy (MRS) have been reported previously. By use of a method in which metabolite content was quantified with reference to a standard located outside the chest, it has become possible to measure the content of phosphocreatine (PCr) and ATP in vivo in the human heart. In this study, PCr and ATP contents were measured by 31P MRS and compared in human myocardium with reversible ischemia or scar diagnosed by exercise thallium scintigraphy. METHODS AND RESULTS: Forty-one subjects with stenosis of the left anterior descending coronary artery (> 50%) and 11 healthy control subjects (C) composed the present study group. Patients were divided into two groups on the basis of exercise 201Tl scintigraphy: a reversible 201Tl defect group (RD[+], n = 29) who demonstrated redistribution at late image and a fixed 201Tl defect group (RD[-], n = 12). While the subjects lay supine within the magnet, 31P MR spectra were obtained from the anterior and apical regions of the left ventricle by slice-selected one-dimensional chemical shift imaging. For metabolite quantification, a standard was placed at the center of the surface coil. ANOVA revealed significant differences among the three groups with respect to the mean (+/- SD) PCr at rest (C, 12.14 +/- 4.25 > RD[+], 7.64 +/- 3.00 > RD[-], 3.94 +/- 2.21 mumol/g wet heart tissue, P < .05) as well as a significant decrease in ATP in the RD(-) group (C, 7.72 +/- 2.97; RD[+], 6.35 +/- 3.17 > RD[-], 4.35 +/- 1.52 mumol/g wet heart tissue, P < .05). CONCLUSIONS: Compared with healthy control subjects, PCr content decreased significantly in patients with both reversible and fixed 201Tl defects, and ATP content decreased significantly in subjects with fixed thallium defects. These results suggest that the measurement of ATP content in the human heart by 31P MRS is a clinically important method for the evaluation of myocardial viability.

Adenosine Triphosphate↗
PubMed1995

The origin of pilonidal sinus: a case report.

The etiology of pilonidal sinus remains controversial. Some think it is congenital, and others think it is acquired. It is difficult to distinguish acquired pilonidal sinus from congenital, because infection almost always complicates both. We report here one case of acquired pilonidal sinus unaccompanied by infection. Histological examination showed that no epidermis or hair follicle was present in the inner wall of the sinus. This case shows that acquired pilonidal sinus is due to invasion of external hairs and that this condition needs to be distinguished from congenital pilonidal sinus.

Adult↗
PubMed1995

Determinants of exercise capacity in the hypertensive elderly--a study based on the assessment of cardiac reserve by dipyridamole radionuclide angiography.

To evaluate the determinants of exercise capacity in the hypertensive elderly with an assessment of cardiac reserve by dipyridamole radionuclide angiography, 31 elderly subjects (aged 62 to 78 years, 15 hypertensive and 16 normotensive) underwent symptom-limited maximum treadmill exercise with measurement of maximal oxygen consumption along with radionuclide angiography in list mode at rest and after dipyridamole infusion. In the normotensive elderly, maximal oxygen consumption correlated with relative filling volume during the rapid filling period at rest (r = 0.58; p < 0.05), and correlated inversely with the percent change in the peak ejection rate with dipyridamole (r = -0.63; p < 0.01). In contrast, maximal oxygen consumption correlated with atrial contribution at rest (r = 0.69; p < 0.005), and correlated inversely with the percent change in atrial contribution with dipyridamole (r = -0.87; p < 0.0001) in the hypertensive elderly. These results indicate that the mechanisms for maintaining exercise capacity are different in elderly subjects with or without hypertension.

Aged↗
PubMed1995

[Diagnosis and prognosis of elderly patients with coronary artery disease: assessment with dipyridamole thallium imaging].

Noninvasive evaluation of coronary artery disease is difficult in elderly patients because of their limited exercise-capacity. The diagnostic and prognostic value of dipyridamole perfusion scintigraphy was assessed in 147 patients aged 65 years and older. All patients underwent coronary angiography. Initially, 32 patients had percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). The other 115 patients were first treated medically and followed for a mean of 29 +/- 22 months. Nine patients (7.9%) had cardiac events including cardiac death and coronary intervention (PTCA or CABG) during the follow-up. Dipyridamole perfusion scintigraphy was performed safely in all patients, whereas treadmill exercise testing could not be adequately performed in 24 patients, 18 of whom had multivessel disease. Multiple regression analysis showed that: fixed defect and reversible defect were powerful detectors of coronary lesions (p = 0.0001, p = 0.0027, respectively), all patients with fixed disease and 94% of patients with only reversible defect had significant coronary lesion; Diffuse slow washout and ST depression were statistically significant for detecting multivessel coronary lesions in patients with fixed disease (p = 0.0001, p = 0.017, respectively), the sensitivity and specificity of diffuse slow washout and/or ST depression for detecting multivessel coronary lesions ware 85% and 74%, respectively, and ST depression was statistically significant for detecting multivessel coronary lesions (p = 0.0002) in patients with only reversible defect, the sensitivity and specificity of ST depression were 88% and 64%, respectively. Cox survival analysis identified diffuse slow washout as the best predictor of future cardiac events among the scintigraphic variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

Partially implantable piezoelectric middle ear hearing device. Long-term results.

In accordance with the 1992-1993 Japanese government approval of production and implementation in the health insurance system of the partially implantable piezoelectric middle ear device (P-MEI), we are conducting follow-up studies on the implanted patients. This article reports the results of the 16 cases, which are regarded as successful implantations because these patients are using the device every day as long as they are awake. A successful case is presented to illustrate the efficacy of the device.

Adult↗