Search PubMed⌕ Search

Biomedical subjects

T Murai

Publications and source records attributed to T Murai.

At least 127 records · Page 7Linked to original sources
PubMed1997

Effect of fasting subjects' posture on 13C-urea breath test for detection of Helicobacter pylori infection.

BACKGROUND: Although many factors that may affect the 13C-urea value have been verified, no literature is available regarding the effect of the posture of the patient on the shape of the delta 13C excretion curve. In an effort to contribute to the development of a simple and standard procedure for the 13C-urea breath test, we investigated whether either the posture of the patient during the procedure or the mouthwash after dosing affects the shape of the delta 13C excretion curve. MATERIALS AND METHODS: Seventy-two Helicobacter pylori-infected subjects were divided into four groups according to the position during procedure and the mouthwash after dosing: group A, in the supine position with mouthwash; group B, in the sitting position with mouthwash; group C, changed position by rolling with mouthwash; and group D, changed position (as did group C) without mouthwash. Absolute values of delta 13C at each sampling point were compared in the four groups. RESULTS: delta 13C values in group A gradually increased until the 15-minute point; those in group B were almost stable from 5 to 30 minutes, and those in group C peaked at the 5-minute point, then decreased until 30 minutes, the values becoming similar at the 20-minute point. Significant differences were seen between groups A, B, C, and D at the 5- and 10-minute points. CONCLUSION: These results suggest that posture and mouthwash affect delta 13C value at the 5- and 10-minute points. Sampling at 20 (maybe 15 or 30) minutes for fasting patients in a sitting position is considered to be appropriate for detection of H. pylori infection in a standard two-sampling-point 13C-urea breath test.

Breath Tests↗
PubMed1997

Construction of a starch-utilizing yeast by cell surface engineering.

We have engineered the cell surface of the yeast Saccharomyces cerevisiae by anchoring active glucoamylase protein on the cell wall, and we have endowed the yeast cells with the ability to utilize starch directly as the sole carbon source. The gene encoding Rhizopus oryzae glucoamylase with its secretion signal peptide was fused with the gene encoding the C-terminal half (320 amino acid residues from the C terminus) of yeast alpha-agglutinin, a protein involved in mating and covalently anchored to the cell wall. The constructed plasmid containing this fusion gene was introduced into S. cerevisiae and expressed under the control of the glyceraldehyde-3-phosphate dehydrogenase promoter from S. cerevisiae. The glucoamylase activity as not detected in the culture medium, but it was detected in the cell pellet fraction. The glucoamylase protein transferred to the soluble fraction from the cell wall fraction after glucanase treatment but not after sodium dodecyl sulfate treatment, indicating the covalent binding of the fusion protein to the cell wall. Display of the fused protein was further confirmed by immunofluorescence microscopy and immunoelectron microscopy. The transformant cells could surely grow on starch as the sole carbon source. These results showed that the glucoamylase was anchored on the cell wall and displayed as its active form. This is the first example of an application of cell surface engineering to utilize and improve the metabolic ability of cells.

Cell Membrane↗
PubMed1997

Idiopathic restrictive cardiomyopathy with diffuse perimyocytic fibrosis--a rare observation.

Idiopathic restrictive cardiomyopathy (RCM) is rare. Even today little is understood of its etiology or underlying mechanisms, and definitive diagnostic criteria are lacking. In this report, we describe a case of idiopathic RCM in a young Japanese woman who died while awaiting cardiac transplantation during the 5-year course of the disease. Rare pathologic findings of diffuse perimyocytic fibrosis were revealed at autopsy.

Adult↗
PubMed1997

Panhypopituitarism due to Rathke's cleft cyst associated with pituitary oncocytoma.

A 38-year-old male with panhypopituitarism due to Rathke's cleft cyst associated with a pituitary oncocytoma is reported. The presenting signs were general myalgia and slight fatigue. Endocrine examinations revealed panhypopituitarism. Magnetic resonance imaging disclosed a suprasellar cystic lesion of the pituitary gland. Cytological examination demonstrated ciliated cells in the mucinous fluid flowing from the cyst during the pituitary operation. A pituitary oncocytoma with randomly scattered S-100 immunoreactive cells was found upon histologic examination of the nodular tissue curettaged from the internal wall of the cyst. These results suggest that the pituitary adenoma was derived from folliculostellate cells included in the Rathke's cleft wall.

Adenoma, Oxyphilic↗
PubMed1997

Adrenocorticotropin-independent macronodular adrenocortical hyperplasia associated with multiple colon adenomas/carcinomas which showed a point mutation in the APC gene.

We report a male Japanese with corticotropin (ACTH)-independent macronodular adrenocortical hyperplasia (AIMAH) associated with multiple colon adenomas/carcinomas. The plasma cortisol level was elevated with no diurnal rhythm and was not suppressed with dexamethasone. Basal plasma ACTH was unmeasurable but subnormally increased after administration of metyrapone or corticotropin releasing hormone. Both adrenals were resected and weighed 90g; the histopathologic findings were similar to those of AIMAH as previously reported. At least 21 colon lesions which were adenomas or carcinomas, were resected endoscopically or surgically. This is the second reported case of the association of AIMAH with multiple colon polyps. An APC gene point mutation was detected in the colon cancer tissue by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP)/direct sequencing analysis at the putative splice acceptor site consensus sequence. However, no abnormality of APC gene was detected in the adrenocortical hyperplastic tissue. The possible etiological coexistence of these two diseases is discussed.

Adenoma↗
PubMed1997

[Mechanism of silent myocardial ischemia in elderly patients with coronary artery disease--assessment by dipyridamole thallium scintigraphy].

To evaluate the clinical significance of silent myocardial ischemia in elderly patients with coronary artery disease, 147 patients (aged 65 years and older) underwent coronary angiography and dipyridamole thallium scintigraphy. Seventy-four patients (44 men, 30 women) who showed reversible defects (RD) and ischemic ST depression during scintigraphy were divided into two groups: 13 with silent RD (18%, 12 men, 1 woman), and 61 with painful RD (82%, 32 men, 29 women). Most patients with silent RD were men. The prevalence of myocardial infarction was similar in patients with silent RD (62%) and in patients with painful RD (49%). The prevalence of multivessel disease was also similar in the two groups: 85% in patients with silent RD and 82% in patients with painful RD. Among 38 patients with infarction, 8 had silent RD and 30 had painful RD. The prevalence of RD in the area of infarction was greater in patients with silent RD (63%) than in patients with painful RD (47%), but the difference was not statistically significant. The prevalence of extensive infarction (fixed defects) was greater in patients with silent RD (75%) than in patients with painful RD (30%, p < 0.05). Among 36 patients without infarction, there was no scintigraphic parameter which showed significant difference. Bypass grafting and angioplasty were initially performed in 23% of the patients with silent RD and in 36% of the patients with painful RD (ns). When the two groups were treated medically during the follow-up period of 29 +/- 22 months, the incidences of cardiac events were similar: 10% in patients with silent RD and 13% in patients with painful RD. The prevalence of silent RD is not high in elderly patients with significant coronary artery disease. Compared with the patients with painful RD, those with silent RD were more likely to have an old and extensive myocardial infarction, and they tended to have RD in the area of the infarct.

Aged↗
PubMed1997

Beta-blockade does not improve orthostatic intolerance induced by 20 days bed rest.

To assess if propranolol influences orthostatic intolerance induced by prolonged bed rest (BR), a lower body negative pressure test (LBNP) and left ventricular (LV) echocardiography before and during -40mmHg of LBNP were performed with and without intravenous propranolol administration (0.04mg/kg) in 9 healthy volunteers (mean age: 21 years) before and after 20 days BR. LBNP tolerance time (LBNP-T), endpoint heart rate(HR), and percentage changes from 0 to -40mmHg LBNP in HR, LV diastolic dimension(LVDd), stroke volume (SV), cardiac output (CO), and systemic vascular resistance(SVR) were measured. After BR, percentage changes in CO during LBNP was not altered by propranolol (-12+/-21% vs. -24+/-24%; with and without propranolol; p>0.05) because the effect on percentage changes in HR (18+/-11% vs. 26+/-12%; p<0.05) cancelled out the effects of percentage changes in LVDd (-9+/-6% vs. -15+/-10%; p<0.05) and percentage changes in SV (-26+/-16% vs. -39+/-22%; p<0.05). In addition, propranolol decreased end-point HR (85+/-15bpm vs. 119+/-l4bpm; p<0.05) and percentage changes in SVR (25+/-32% vs. 53+/-57%; p<0.05). As a result, LBNP-T after BR was unchanged by propranolol (8.8+/-3.3min vs. 10.8+/-5.0min; p>0.05). In conclusion, propranolol failed to change orthostatic intolerance induced by BR.

Adrenergic beta-Antagonists↗
PubMed1997

Effect of bed rest immobilization on metabolic turnover of bone and bone mineral density.

Immobilization induces abnormal bone metabolism and severe decalcification of bone. To investigate the effect of middle-term immobilization on bone metabolism, we studied 10 young healthy males and females during bed rest for 20 days. Bone mineral density (BMD) rapidly decreased in both lumbar and metacarpal bones. No bone showed consistent BMD alterations, partial increase and partial decrease, and both lumbar and metacarpal bone showed similar rapid BMD change. Urinary excretion of pyridinoline tended to slightly increase by day 10, and to decline by day 20 (mean +/-SE: 34.2 +/-7.4, 26.3+/-4.6 nmol day-1, respectively). Neither alkaline phosphatase (isoform III) nor tartrate-resistant acid phosphatase, changed, suggesting that in the early stage of immobilization bone matrix in some part might increase or be resorbed without any activation of osteoblast or osteoclast, resulting in rapid calcification or decalcification, respectively.

Absorptiometry, Photon↗
PubMed1997

ABR findings, electrocochleograms and caloric tests in vertebrobasilar ischemic rats.

In rats with ischemia induced by occlusion of the anterior inferior cerebellar artery (AICA) or vertebral artery (VA), we investigated the auditory brainstem response (ABR), electrocochleogram and caloric test result. Upon occlusion of the VA, there was no change of the ABR, whereas in the caloric test the duration of nystagmus upon stimulation of both ears shortened. Upon occlusion of the AICA, the cochlear blood flow (CoBF) showed one of three patterns of change no change: n = 5; decrease: n = 10; and transient decrease with recovery: n = 5. The cochlear potentials were dependent on the residual CoBF. In the caloric test, when the left AICA was occluded, the duration of nystagmus induced by stimulation of the left (ipsilateral) ear was shorter than that induced by the right (contralateral) ear. Based on the functional test results, we conclude that in this model of ischemia the function of the vestibular structures including the semicircular canals is more severely affected than is the hearing function.

Action Potentials↗
PubMed1997

Reduplicative paramnesia in patients with focal brain damage.

Reduplicative paramnesia (RP) has drawn attention as a distinct behavioral syndrome caused by focal brain damage. To elucidate the pathogenesis of RP, we assessed its prevalence among patients with focal brain damage and followed those patients with typical RP. Seventy-seven patients with focal brain damage (47 with left hemispheric, 21 with right hemispheric, and 9 with bilateral damage) were assessed for the presence of RP using a questionnaire intended to elucidate this condition. Two patients showed typical RP for place, and four patients showed atypical RP (three for place and one for person); altogether, these six patients constituted 7.8% of the sample. In three patients, the lesions were situated in the right hemisphere; in two, the lesions were bilateral (right dominant); and in one, the lesions were in the left hemisphere, indicating the relative importance of right hemispheric damage and a possible contributory role of additional left hemispheric damage in RP. The case studies of patients with typical RP suggest the heterogeneity of the underlying cognitive factors in RP.

Adolescent↗
PubMed1997

Suicide by self-stabbing in the city of Tokyo--a review of accumulated data from 1976 to 1995.

Accumulated data of suicide by self-stabbing in the city of Tokyo (population: approx. 8.1 million. 1994) between 1976 and 1995 was reviewed. The overall numbers of suicides for each year were similar (min.: 1178, max.: 1620, 1346.9 on average), while the annual number of unusual death cases increased gradually (5399 in 1976 to 9226 in 1995). The annual number of suicides by self-stabbing fluctuated irregularly, but was generally low (2.3-4.7%) among modes of suicide. A significant difference was observed between the sex ratio in suicidal self-stabbing and that for all suicide; the male/female ratio is higher in suicidal self-stabbing than in suicides overall. The majority of fatally wounded body sites were in the neck, chest, abdomen, wrists and forearms. Marked differences according to sex were observed in terms of the implements employed for self-stabbing; craft knives, swords and recreational knives, fragments of glass, carpenter's tools and surgical knives were used almost exclusively by men, while more than 80% of women used kitchen knives or razors. No influence of psychiatric history on suicide by self-stabbing was proved.

Adolescent↗
PubMed1997

Perinatal bile acid metabolism: analysis of urinary bile acids in pregnant women and newborns.

The metabolism of bile acids in 30 pregnant women was evaluated by analyzing the urinary composition of bile acids during late gestation (weeks 30-41) and again in these women and their newborn infants during the first week after delivery. The levels of individual bile acids were determined by gas chromatography-mass spectrometry after solvolysis and hydrolysis of bile acid conjugates. The mean total bile acid/creatinine ratio in pregnant women decreased from 1.22 micromol/mmol creatinine at 30-32 weeks of gestation to 0.15 micromol/mmol creatinine at 6-7 days after delivery. The mean percentage of 1beta-hydroxylated bile acids peaked at 27% at 3-4 days after delivery. In newborn infants, the mean total bile acid/creatinine ratio rapidly increased from 3.39 micromol/mmol creatinine at birth to 54.33 micromol/mmol creatinine at 7 days. During this period, large amounts (40-50%) of unsaturated ketonic bile acids, especially 7alpha,12alpha-dihydroxy-3-oxo-5beta-chol-1-en-24-oic acid and 7alpha,12alpha-dihydroxy-3-oxo-4-cholen-24-oic acid, were observed in the infants' urine. These data suggest that, during the perinatal period, the formation of polyhydroxylated and unsaturated ketonic bile acids probably represents a mechanism for the excretion of bile salts, and that the metabolism of bile acids in both the mother and the infant changes significantly after birth.

Adult↗
PubMed1997

[The Endotoxin Reference Standard of the National Institute of Health Sciences (the Japanese Pharmacopoeia Endotoxin Reference Standard) (Control 971)].

The third lot (Control 971) of the Endotoxin Reference Standard of the National Institute of Health Sciences (the Japanese Pharmacopoeia Endotoxin Reference Standard) was prepared. The potency of the new lot was assayed against USP Endotoxin Reference Standard (EC-6) and defined as containing 13,000 endotoxin units (EU) per vial by a collaborative study of 7 laboratories.

Endotoxins↗
PubMed1996

Brainstem ischemic damage following occlusion of the blood vessels in the rat's posterior cerebral circulation.

Progression of ischemic damage was investigated immunohistochemically in neural dendrites using microtubule-associated protein 2 (MAP2) as a dendritic marker in the rat's brainstem. Neuronal soma and dendrites were clearly stained by this protein but some structures such as axonal bundles, glia and endothelial cells were not visualized. When the anterior inferior cerebellar artery (AICA) was occluded unilaterally for 30 min, a wide ischemic lesion was detected in the occluded side of the brainstem and was observed as a loss of reaction to MAP2. After ischemia for 2 h, loss of reaction in the perikarya and dendrites was seen to expand to the ipsilateral (occluded side) cochlear nucleus. When the basilar artery was blocked, ischemic damage in the vestibular nucleus was more intense than that in the cochlear nucleus. In all specimens studied, differences in anatomical blood supply demonstrated selective tissue vulnerability for ischemic damage.

Animals↗
PubMed1996

Ethanol retards gastric epithelial restoration in monolayer cultures.

The purpose of this study was to clarify the effect of ethanol on confluent monolayer gastric epithelial cells that had a round cell-free area in the center of the culture dish. Restoration of such "wounding" was evaluated quantitatively every 12 hr using a computer image analyzer with and without ethanol. Without ethanol, restoration was achieved within 48 hr. Exposure to ethanol retarded cellular restoration significantly. Staining for actin and myosin in the control group revealed the presence of lamellipodia and stress fibers. However, in the ethanol group narrowed lamellipodia and few stress fibers were observed. In conclusion, ethanol retarded the migration and proliferation of cultured gastric mucosal cells after in vitro wounding, possibly by damaging the cytoskeletal system.

Actins↗
PubMed1996

Identification and characterization of ispA, a Shigella flexneri chromosomal gene essential for normal in vivo cell division and intracellular spreading.

The virulent phenotype of Shigella requires loci on the chromosome as well as on the large virulence plasmid, and is regulated via a complex web of interactions amongst various chromosomal and large plasmid genes. To further investigate the role of chromosomal loci in virulence, we performed random Tn10 mutagenesis in Shigella flexneri YSH6000T, and isolated an avirulent mutant (V3404) incapable of spreading throughout an epithelial cell monolayer. Although V3404 initially spread intercellularly at the same rate as the wild-type, it gradually slowed down and ceased spreading as a result of increasing defects in cell division, leading to the formation of long filamentous bacteria lacking septa, trapped within cells. In addition, the mutation affected the ability of V3404 to polymerize actin, a prerequisite for intra- and inter-cellular spreading ability. Sequencing of Tn10-flanking DNA revealed that the mutated gene, designated ispA (intracellular septation), was equivalent to a previously sequenced but uncharacterised gene of Escherichia coli located between trp and tonB. Using E. coli sequence data, we cloned the ispA gene from the YSH6000T chromosome and found that it complemented the V3404 mutation. Nucleotide sequencing and in vitro expression experiments revealed that ispA coded for a small (21 kDa), very hydrophobic protein. These results thus show that ispA is an essential virulence gene affecting several functions of the virulence process.

Actins↗
PubMed1996

Enzyme immunoassay for conjugated cholic and 1 beta-hydroxycholic acids in urine of early infancy.

A direct competitive heterologous enzyme immunoassay (EIA) for conjugated cholic acid (CA) was developed using horseradish peroxidase labeled antigen having a shorter bridge length than that of the immunogen. An appropriate dose-response curve for conjugated CA was obtained in the range of 0.05-50 ng/well. Specificity of the EIA proved satisfactory in terms of cross-reactivities to 23 kinds of related bile acids. The proposed method was evaluated to be useful for the determination of conjugated CA in urine with acceptable accuracy and inter- and intra-assay precision. The results of analysis showed a reverse relationship between age and urinary excretion ratio of conjugated 1 beta-hydroxy-CA to conjugated CA in the first 9 months after birth.

Bile Acids and Salts↗