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Biomedical subjects

O Kobayashi

Publications and source records attributed to O Kobayashi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Overexpression of the OLE1 gene enhances ethanol fermentation by Saccharomyces cerevisiae.

The fermentation characteristics of Saccharomyces cerevisiae strains which overexpress a constitutive OLE1 gene were studied to clarify the relationship between the fatty acid composition of this yeast and its ethanol productivity. The growth yield and ethanol productivity of these strains in the medium containing 15% dextrose at 10 degrees C were greater than those of the control strains under both aerobic and anaerobic conditions but this difference was not observed under other culture conditions. During repeated-batch fermentation, moreover, the growth yield and ethanol productivity of the wild-type S. cerevisiae increased gradually and then were similar to those of the OLE1-overexpressing transformant in the last batch fermentation. However, the unsaturated fatty acid content (77.6%) of the wild-type cells was lower than that (86.2%) of the OLE1-recombinant cells. These results suggested that other phenomena caused by the overexpression of the OLE1 gene, rather than high unsaturated fatty acid content, are essential to ethanol fermentation by this yeast.

Culture Media↗
PubMed2000

The effects of intraoperative glucose infusion on portal blood insulin concentration and hepatic mitochondrial redox state during surgery: comparison of short-term and continuous infusions.

The relationships between the blood glucose level, portal blood immunoreactive insulin (IRI) concentration, ketogenesis, and hepatic mitochondrial redox state associated with intraoperative glucose administration were evaluated in patients undergoing total gastrectomy. A total of 26 patients were randomly allocated to two groups according to the type of infusion given; group 1 was given a short-term glucose infusion of 25 g in 30 min and group 2 was given a continuous glucose infusion of 10 g/h. The blood glucose concentration peaked 30 min after the glucose infusion was commenced, then decreased in group 1, despite a continuous rise in group 2. A temporary but significantly higher blood glucose level was observed in group 1 than in group 2, 30 and 60 min after the infusion was commenced. The portal blood IRI concentrations and arterial ketone body ratio (AKBR) continued to increase and the blood ketone body concentrations continued to decline after the start of the glucose infusion in both groups; however, after 60 and 120 min, the portal blood IRI and AKBR levels were significantly higher, and the blood ketone body levels significantly lower in group 1 than in group 2. These findings suggest that intraoperative glucose administration is beneficial for insulin secretion, ketogenesis, and the hepatic mitochondrial redox state, and that short-term infusion is superior to continuous infusion.

Aged↗
PubMed2000

A case of Walker-Warburg syndrome.

Walker-Warburg syndrome (WWS) is an autosomal recessive disorder characterized by type II lissencephaly, cerebellar and retinal anomalies, and congenital muscular dystrophy. We report a female diagnosed with WWS based on clinical criteria. This patient was found to have fetal hydrocephalus on ultrasonography at 29 weeks of gestation, and exhibited severe hypotonia, ocular malformations, and hydrocephalus at birth. MRI revealed type II lissencephaly, hydrocephalus, and other severe brain malformations. Genetic analysis was performed to distinguish WWS from severe Fukuyama-type congenital muscular dystrophy (FCMD), which has numerous findings in common. This revealed no expression of the founder haplotype or single-stranded conformation polymorphism (SSCP) abnormalities. Since the life expectancy of patients with FCMD is longer, differential diagnosis should be performed precisely.

Abnormalities, Multiple↗
PubMed2000

Insufficient diagnostic accuracy of imported serological kits for Helicobacter pylori infection in Japanese population.

Although there are many reports of the high diagnostic accuracy of commercially available serologic kits for Helicobacter pylori infection in Western countries, they rarely has been investigated in oriental population. Accordingly we examined their usefulness in 492 Japanese patients with dyspeptic symptoms. Diagnostic accuracy of 4 imported serologic kits (HEL-p TEST, HM CAP, G.A.P IgG, Helico G2) was investigated using the (13)C-urea breath test as the gold standard. When intermediate results were excluded, the sensitivity, specificity and accuracy of these serologic tests ranged from 88.6% to 97.8%, 67.9% to 85.9%, and 87.9% to 91.4%, respectively, which were comparable with reported median accuracy in the Western population. However, there were many intermediate results in these tests, ranging from 5.3% to 23.0%. Their usefulness seemed to be limited in our patient population because of the large number of intermediate results.

Adult↗
PubMed2000

Effect of age on the relationship between gastric cancer and Helicobacter pylori. Tokyo Research Group of Prevention for Gastric Cancer.

Helicobacter pylori is thought to be involved in the pathogenesis of gastric cancer, but the time point at which it produces its effects (critical time) is unknown. We measured the serum level of H. pylori antibody in 787 gastric cancer patients and 1007 controls aged 20 to 69. Odds ratios for different gastric cancer types and stages were determined for each 10-year age class. The overall odds ratio for gastric cancer decreased with age, being 7.0 for those aged 20 - 29, 14.5 for those aged 30 - 39, 9.1 for those aged 40 - 49, 3.5 for those aged 50 - 59, and 1.5 for those aged 60 - 69 (trend in odds ratios: P < 0.01). However, there was no such age-dependent trend for early diffuse-type cancer; the odds ratios were 12.6, 4.0, 7.2, 6.5, and 18.5 respectively (P = 0.29). Early cancer tended to show higher seroprevalence than advanced cancer, especially in older subjects. No significant difference in seroprevalence was observed between diffuse and intestinal cancers within each age-class. Seroreversion must have occurred in the time interval between the critical time and the diagnosis of the cancer, especially in older patients. The age-dependent relationship between H. pylori and gastric cancer may be due to seroreversion, which itself may be independent of age. This age-independence indicates that prolonged exposure to H. pylori does not increase the magnitude of its influence on gastric carcinogenesis. Possible mechanisms through which H. pylori exerts pathogenic effects are continuous inflammation in adulthood and / or irreversible damage to gastric mucosa in childhood or the teenage years.

Adult↗
PubMed2000

Necrotizing myopathy in a patient with chronic hepatitis C virus infection: a case report and a review of the literature.

We describe a 61-year-old man presenting with necrotizing myopathy associated with chronic active hepatitis due to hepatitis C virus (HCV) infection. Thirteen patients with HCV-associated myopathy have been reported previously. In most of these cases, varying degrees of inflammatory changes were observed in the muscle tissue. In 2 patients, myopathy developed after initiation of interferon therapy for chronic HCV hepatitis. Our case was unusual due to long-standing elevation of creatine kinase values which improved following interferon therapy and the non-inflammatory features of the muscle tissue where the HCV RNA minus strand, a marker for replicative intermediates of the virus, was undetectable. The association of myopathy with HCV infection might represent a unique clinical entity, although the underlying pathological mechanisms remain unknown.

Biopsy↗
PubMed2000

Cerebral function after aortic surgery using retrograde cerebral perfusion: report of three cases.

INTRODUCTION: The neurological analysis undertaken on three cases of aortic aneurysm treated surgically using retrograde cerebral perfusion (RCP) are reported herein. This is the first detailed analysis of postoperative neurological studies in such cases. METHODS: The oxygenation state of cerebral Hb and cytochrome aa3 levels were monitored by near-infrared spectroscopy (NIR) during RCP. Postoperative neurological scoring, computed tomography (CT), magnetic resonance imaging (MRI), and monitoring of local cerebral blood flow (LCBF) quantatively by N-isopropyl-p-[123I] iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) were performed for an extended follow-up period after surgery. RESULTS: The T2WI of MRI findings which consisted of many spotty high intensity areas in the striatum, cerebellum and hippocampus, may reflect the postoperative severe consciousness and mental disturbances (2-4 weeks). However, in all cases the neurological deficit gradually improved until they returned to their normal preoperative states. The improvement of LCBF correlated well with neurological recovery. CONCLUSION: The conditions of the conventional method of RCP must be improved to prevent transient severe consciousness and mental disturbances which occur after the operation in relationship with the appearance of the high intensity area on the MRI T2WI.

Adult↗
PubMed2000

Epithelial-mesenchymal interaction in gastric mucosal restoration.

In this review article we discuss the role of growth factors in gastric ulcer healing using an in vitro wound repair model with gastric epithelial and mesenchymal cells. Several growth factors accelerate gastric epithelial and mesenchymal wound healing in vitro with acceleration of cell migration and proliferation. Epidermal growth factor, transforming growth factor-alpha (TGFalpha), hepatocyte growth factor, and insulin accelerate predominantly gastric epithelial wound healing; and TGFbeta and basic fibroblast growth factor predominantly accelerate gastric mesenchymal wound healing. Platelet-derived growth factor-betabeta and insulin-like growth factor-1 (IGF-1) accelerate both significantly. Among these growth factors, IGF-1 produced from fibroblasts plays a key role in the gastric epithelial-mesenchymal interaction during the process of gastric wound healing.

Animals↗
PubMed1999

Mutations of calpain 3 gene in patients with sporadic limb-girdle muscular dystrophy in Japan.

Mutations of the calpain 3 gene, an intracellular calcium-activated neutral protease, is one of the causes of limb-girdle muscular dystrophy (LGMD). We examined 14 Japanese patients with sporadic LGMD for calpain 3 mutations, and found four mutations in five patients. Three (R461C, D707G and R147P) were novel missense mutations, and one was a splice-site mutation (801+1g-->a) resulting in skipping of exons 4 and 5. Of the five patients, three patients with homozygous missense mutations showed later onset and slower progression than the other two patients with an exon skipping or mRNA loss of unknown cause. It would appear that the occurrence of calpain 3 gene mutations in sporadic LGMD in Japan may be quite high since all five patients with mutations in this gene were among the 14 patients without apparent family history, an incidence of 36%. These findings also suggest that calpain 3 deficiency occurs in both sporadic and familial LGMD and that direct analysis of the calpain 3 gene may be useful in the definitive diagnosis not only of the 15q-linked familial but also of sporadic cases of LGMD.

Adolescent↗
PubMed1999

Tissue inhibitor of matrix metalloproteinase-1 in the plasma of patients with gastric carcinoma. A possible marker for serosal invasion and metastasis.

BACKGROUND: Expression of the tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in tumor tissue from patients with gastric carcinoma has been reported to be related to disease progression. However, to the authors' knowledge the clinical significance of plasma TIMP-1 concentrations in these patients has not been clarified. METHODS: Concentrations of TIMP-1 protein were examined by enzyme-linked immunoadsorbent assay in plasma samples from 149 patients who underwent resection of their primary tumors and from 18 patients with nonresected or recurrent disease. RESULTS: In the 149 patients whose primary tumors were resected, plasma TIMP-1 concentration was associated significantly with a variety of pathologic factors including macroscopic type, depth of invasion, lymph node and peritoneal metastases, vessel invasion, pattern of tumor infiltration into surround ing tissue, and disease stage. Plasma TIMP-1 concentration was significantly higher in patients with serosal invasion, lymph node metastasis, peritoneal dissemination, or liver metastasis than in those without these factors. Neither carcinoembryonic antigen (CEA) nor CA 19-9 concentrations appeared to be related to these measures of disease progression. In the 18 patients with nonresected or recurrent disease, TIMP-1, CEA, and CA 19-9 were similarly sensitive in predicting peritoneal, liver, and lymph node metastases. The combination of these three factors was able to detect 73.3% of patients with peritoneal metastasis, 83.3% of patients with liver metastasis, and 88.9% of patients with disease recurrence. CONCLUSIONS: In patients with gastric carcinoma, plasma concentration of TIMP-1 appears to correlate with both serosal invasion and metastasis.

CA-19-9 Antigen↗
PubMed1999

Molecular mechanism of the multiple regulation of the Saccharomyces cerevisiae ATF1 gene encoding alcohol acetyltransferase.

The ATF1 gene encodes an alcohol acetyl transferase (AATase), that catalyses the synthesis of acetate esters from acetyl CoA and several kinds of alcohols. ATF1 transcription is negatively regulated by unsaturated fatty acids and oxygen. A series of analyses of the ATF1 promoter identified an 18 bp element essential for transcriptional activation. Ligation of the 18 bp element into a plasmid carrying the CYC1 promoter deleted UAS-activated transcription and conferred transcriptional repression by unsaturated fatty acids. The 18 bp element contains a binding sequence for Rap1p, which is a transcriptional repressor and activator. In vitro binding studies showed that Rap1p binds to the 18 bp element essential for transcriptional activation. The results of internal deletion studies of the promoter region suggested that there was also a region responsible for ATF1 oxygen regulation. This region contained the consensus binding sequence for the hypoxic repressor Rox1p. In vitro binding studies showed that Rox1p binds to the region responsible for oxygen regulation. To investigate the effect of the hypoxic repressor complex on transcription, ATF1 expression was measured in rox1, tup1 and ssn6 disruptant strains. It was found that rox1, tup1 and ssn6 disruption caused elevated expression of ATF1 under aerobic conditions. Thus, the activation of ATF1 transcription is dependent on Rap1p, and the Rox1p-Tup1p-Ssn6p hypoxic repressor complex is responsible for repression by oxygen. Furthermore, a study of ATF1 expression in a sch9 null mutant suggested that the Sch9p protein kinase is involved in ATF1 trancriptional activation.

Acetyltransferases↗
PubMed1999

A case of McLeod syndrome with unusually severe myopathy.

A 51-year-old man developed weakness and muscle atrophy in the legs at the age of 41, later followed by choreiform involuntary movements. Neurological and laboratory examinations revealed severe muscle weakness and atrophy, and areflexia in all the extremities, acanthocytosis and an elevated serum creatine kinase level. Together with these findings, the weak expression of Kell blood group antigens and the absence of the Kx antigen led to a definite diagnosis of McLeod syndrome for his condition. Brain magnetic resonance imaging revealed marked atrophy of the head of the caudate nuclei. Although immunocytochemical analysis of dystrophin in muscle specimens from our patient revealed normal staining, we found prominent fiber size variability, central nuclei, and connective tissue proliferation as well as necrotic and regenerating fibers, which are as a whole compatible with the myopathology of muscular dystrophy. Moreover, muscle computerized tomography of the lower extremities revealed the 'selectivity pattern' characteristically reported in muscular dystrophies including Duchenne type muscular dystrophy. The muscular symptoms and pathology in McLeod syndrome have been reported to be mild, but the present case clearly shows that the muscular features in this condition may be much more severe than previously thought.

Acanthocytes↗
PubMed1999

Analysis of the genes activated by the FLO8 gene in Saccharomyces cerevisiae.

It is thought that the FLO8 gene encodes a transcriptional activator of the dominant flocculation gene FLO1 in Saccharomyces cerevisiae. To determine other genes which are regulated by FLO8, a detailed comparison of the transcripts from the FLO8 and Deltaflo8 strains was carried out. In addition to the FLO1 gene, it was found that transcription of the FLO11 and STA1 genes is positively regulated by FLO8. In flo8 strains, not only transcripts of the FLO11, STA1, and FLO1 genes but also invasive growth, extracellular glucoamylase production, and flocculation were undetected. From these results, it is suggested that FLO8 regulates these characteristics via the transcriptional regulation of the FLO11, STA1, and FLO1 genes.

Base Sequence↗
PubMed1999

Snowboarding injuries of the abdomen: comparison with skiing injuries.

A retrospective study was conducted to identify the characteristics of snowboarding injury of the abdomen in comparison with those of alpine skiing injuries. Between December 1988 and April 1997, 1579 patients were treated for snowboarding injuries and 9108 patients were treated after skiing accidents. 19 patients (1.2%) in snowboarding and 64 (0.7%) in skiing had abdominal injuries. The abdominal injury rate in snowboarders was significantly higher than that in skiers. Snowboarders with abdominal injuries were similar to skiers with respect to epidemiology but the patterns of injury in the two groups showed several distinct differences. Riding mistakes after jumping for the snowboarders (31.6%) was significantly higher than that for the skiers (0%). The main organs involved in snowboarding and skiing injuries were kidney, liver and spleen. The incidence of solitary renal injury in snowboarding (68.4%) was significantly higher than that in skiing (29.7%).

Abdominal Injuries↗
PubMed1999

Asymmetric reduction of hydroxyacetone to propanediol in immobilized halotolerant microalga Dunaliella parva.

Cells of the halotolerant microalga Dunaliella parva immobilized in calcium-alginate gel showed morphological characteristics and photosynthetic activity similar to those of free cells. The photosynthetic activity in immobilized cells fell only about 20% during 2 weeks incubation at 5 degrees C in the light. The asymmetric reduction of hydroxyacetone to (R)-propanediol was first examined in batch reactions with both free and immobilized cells. Since the activity of immobilized cells was as high as that of free cells, the optimum conditions for the column reactor were investigated using immobilized cells. The productivity of propanediol in immobilized cells increased in proportion to increases in the light intensity, suggesting that NADPH regenerated through photosynthesis was used for the asymmetric reduction. Electron microscopic observation of thin sections of immobilized cells after the reaction suggested that NADPH used for asymmetric reduction in the dark was produced through the metabolism of starch granules. The use of a CaCO3-free medium in the column reactor markedly prolonged the period of reductive activity and photosynthesis.

Journal Article↗
PubMed1999

Respiratory distress due to tracheal compression by the dilated innominate artery.

The case reported is of an 88 yr old female with hypertension and respiratory distress. A chest radiograph revealed a widening of the upper mediastinum. Computed tomographic scanning revealed tracheal compression by the innominate artery, which was elongated and curved. After intubation, she was treated with antihypertensive drugs. This resulted in the remarkable recovery of the patient from respiratory distress. To the authors' knowledge, this is the first reported case of respiratory distress owing to tracheal compression by elongation and curvature of the innominate artery.

Aged↗
PubMed1999

Thymidine phosphorylase/platelet-derived endothelial cell growth factor is upregulated in advanced solid types of gastric cancer.

Previous studies demonstrated that the immunohistochemical expression of thymidine phosphorylase (dThdPase) was related with distant metastasis and disease progression. In this study we investigated the production of dThdPase/platelet-derived endothelial cell growth factor in gastric cancer quantitatively. In a total of 75 tumour tissues and 60 normal gastric mucosa specimens, dThdPase protein concentrations were determined by ELISA. The amount of dThdPase was significantly higher in the tumour tissue than in the normal tissue. Intratumoural dThdPase concentrations were significantly higher in Borrmann types I and II macroscopically, in poorly differentiated and solid type histologically, in the medullary type of the tumour stroma, and in the tumour-invading serosa. In the medullary type of the amount of tumour stroma, protein levels of dThdPase were positively correlated with the vertical diameter of the tumour (r = 0.580, P = 0.019). By immunohistochemical study, dThdPase expression on tumour cells was observed in all seven specimens with high dThdPase protein levels, but not in all 14 cases with low dThdPase protein levels (P < 0.05). In summary, these data indicated that dThdPase is up-regulated in advanced solid types of gastric cancer, suggesting that dThdPase production in carcinoma cells might be induced by the microenvironment.

Analysis of Variance↗