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Biomedical subjects

M Yamauchi

Publications and source records attributed to M Yamauchi.

At least 217 records · Page 12Linked to original sources
PubMed1995

Genotype distribution in Nagoya and new genotype (genotype 3a) in Japanese patients with hepatitis C virus.

We evaluated hepatitis C virus (HCV) genotype distribution among Japanese patients in the city of Nagoya and the possible existence of any other genotype not determined by Okamoto's method. Eighty-five of 93 (91.4%) anti-HCV-positive patients had detectable HCV RNA. The genotype of the HCV isolate was determined in 84 of 85 (98.8%) of these HCV RNA-positive patients by Okamoto's method but determination was not possible in one (1.2%). Genotype 1b was detected in 58 of the 85 patients (68.2%), genotype 2a in 20 (23.5%), genotype 2b in 3 (3.5%), and genotype 1b + 2a in 3 (3.5%). In the remaining 1 patient in whom the genotype could not be determined, we determined the nucleotide sequence of the core region in HCV RNA extracted from this patient and evaluated it by molecular evolutionary analysis. This HCV isolate was then classified as genotype 3a. These results suggest that genotype 3a is rare among Japanese patients with HCV; thus, when classifying Japanese isolates, we should take more care because genotype 3a is not determined by current typing systems.

Amino Acid Sequence↗
PubMed1995

The effects of extracellular pH on intracellular pH, Ca2+ and tension of canine tracheal smooth muscle strips.

The effects of changes in extracellular pH (pHo) on intracellular Ca2+ concentration ([Ca2+]i) or intracellular pH (pHi) were measured simultaneously with muscle tension in canine tracheal smooth muscle strips. [Ca2+]i and pHi were measured using the fluorescent dyes fura-2 and BCECF, respectively. During high K(+)-induced contractions (24.2, 36.4 or 72.7 mM) at pH 7.4, pHo was changed to 7.8 or 7.0 with NaOH or HCl, respectively. Induced changes in pHi were equal to approximately 50% of the changes in pHo. Alkalinization significantly increased [Ca2+]i and enhanced muscle contraction at all concentrations of K+ but did not alter the relationship between muscle tension and [Ca2+]i. Acidification significantly decreased [Ca2+]i without changing muscle tone; hence, the muscle tension-[Ca2+]i relationship was shifted to the left. These results suggest that changes in pHo can alter airway smooth muscle tone by changing [Ca2+]i and pHi.

Animals↗
PubMed1995

Association of a restriction fragment length polymorphism in the alcohol dehydrogenase 2 gene with Japanese alcoholic liver cirrhosis.

BACKGROUND/AIMS: The association of ADH2 polymorphisms with alcoholic liver cirrhosis has not been clearly demonstrated. METHODS: We investigated the association of two alleles in the ADH2 gene marked by restriction fragment length polymorphisms in patients with alcoholic liver cirrhosis. The ADH2 restriction fragment polymorphisms with Mae III were determined using the polymerase chain reaction on lymphocytes from 76 male Japanese alcoholics (non-cirrhotic patients; 34 cases, cirrhotic patients; 42 cases) and 60 healthy male subjects. RESULTS: The frequency of the ADH2(1)/ADH2(1) genotype was significantly higher in the alcoholics than in the healthy subjects p < 0.001). In the alcoholics, the genotype ADH2(2)/ADH2(2) was significantly more prevalent in the cirrhotic group than in the non-cirrhotic group (p < 0.05). CONCLUSIONS: These results suggest that the Mae III polymorphisms of the ADH2 gene may be associated not only with susceptibility to alcoholic liver cirrhosis, but also with the development of alcoholism in Japanese patients.

Adult↗
PubMed1995

Polymorphisms in alcohol metabolizing enzyme genes and alcoholic cirrhosis in Japanese patients: a multivariate analysis.

Alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), and P450IIE1 are the primary enzymes that catalyze the conversion of ethanol to acetaldehyde and then to acetate. Genetic polymorphisms have been reported in ADH2, ADH3, ALDH2, and the 5'-flanking region of P450IIEI. In this study, we used multivariate analysis to determine which genetic polymorphisms in alcohol metabolizing enzymes were independently associated with the development of alcoholic cirrhosis. Thirty-four noncirrhotic alcoholic patients, including 27 with fatty liver and 7 with nonspecific changes, and 46 patients with alcoholic liver cirrhosis were studied. Restriction fragment length polymorphisms (RFLPs) in the ADH2 and P450IIE1 genes were detected by digestion of polymerase chain reaction (PCR)-amplified DNA with MaeIII and RsaI, respectively. In the ALDH2 gene, RFLPs were detected by differences in the MboII site after PCR amplification. By multivariate analysis of four significant factors including total alcohol intake, ADH, ALDH, and P450IIE1 using the multiple logistic regression model, genotype ADH2(2)/ADH2(2) (P = .029) and genotype c1/c1 of P450IIE1 (P = .013) were found to be independently associated with alcoholic cirrhosis. The odds ratios for ADH2(2)/ADH2(2) genotype and the type A genotype of P450IIE1 (c1/c1) were 4.600 and 4.006, respectively. These results suggest that ADH2 and P450IIE1 gene polymorphisms may be independently associated with the development of alcoholic liver cirrhosis in Japan.

Adult↗
PubMed1995

Connective tissue integrity is lost in vitamin B-6-deficient chicks.

The objective of the present investigation was to characterize further the connective tissue disorder produced by pyridoxine (vitamin B-6) deficiency, as previously evidenced by electron microscopy. Following the second post-natal week, fast growing male chicks were deprived of pyridoxine for a 1-mo period. Six weeks post-natally, blood concentrations in the experimental deficiency group had declined to deficiency levels as registered by low concentrations of pyridoxal phosphate (coenzyme form) in erythrocytes, but did not reach levels associated with neurological symptoms. Light microscopic study showed abnormalities in the extracellular matrix of the connective tissues. Collagen cross-links and the aldehyde contents were not significantly lower in cartilage and tendon collagens of vitamin B-6-deficient animals than in age-matched controls; also, their proteoglycan degrading protease and collagenase activities measured in articular cartilages were not greater. Thus, proteolysis was an unlikely alternative mechanism to account for the loss of connective tissue integrity. These results point to the need for further investigation into adhesive properties of collagen associated proteoglycans or other proteins in vitamin B-6-deficient connective tissue.

Animals↗
PubMed1995

The effect of cardiac output on the onset of neuromuscular block by vecuronium.

A relationship between cardiac output and the onset time of neuromuscular blockade administered into a peripheral vein was evaluated in 41 adult patients. Anaesthesia was induced with midazolam and fentanyl and maintained with intermittent doses of fentanyl and 66% nitrous oxide in oxygen. After immobilisation of the forearm in a splint, the ulnar nerve in the other arm was stimulated supramaximally every 10 s and the adduction force of the thumb was recorded. The times from administration of vecuronium 0.08 mg.kg-1 to first and 95% depression of twitch response was 82.4 (18.0) s and 191.7 (33.5) s (mean, SD), respectively. A significant correlation between cardiac index and the onset time of blockade was observed. This study demonstrated that the rapidity of the onset of paralysis in the adductor pollicis muscle after vecuronium injection into a peripheral vein is clearly related to cardiac output.

Adolescent↗
PubMed1995

Alcohol-metabolizing enzyme polymorphisms and alcoholism in Japan.

The liver enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), which are responsible for the oxidative metabolism of ethanol, are polymorphic in humans. Cytochrome P450IIE1, an ethanol-inducible isozyme of liver microsomal P450, is also important in ethanol metabolism. Genetic polymorphisms in the 5'-flanking region of the human cytochrome P450IIE1 gene have recently been reported. We hypothesized that the polymorphisms of ADH, ALDH, and P450IIE1 modify the susceptibility to development of alcoholism. We determined the genotypes of the ADH2, ALDH2, and P450IIE1 loci of 96 Japanese alcoholics and 60 healthy male subjects, using leukocyte DNA by the restriction fragment-length polymorphism by polymerase chain reaction. The alcoholics had significantly higher frequencies of the ADH2(1) and ALDH2(1) alleles than did the healthy subjects. No significant difference in the frequency of the P450IIE1 genotype was observed between the alcoholics and the healthy subjects. In conclusion, genetic polymorphisms of the ADH and ALDH genes, but not of the P450IIE1 gene, influence the risk of developing alcoholism in Japanese.

Adult↗
PubMed1995

Stem cell factor binding to retrovirus primer binding site silencers.

Using modified nuclear lysis and binding conditions, we have examined the binding of an embryonal carcinoma (EC) cell factor, binding factor A, to a stem cell-specific silencer which acts at the DNA level and overlaps the Moloney murine leukemia virus (M-MuLV) proline primer binding site (PBS). Following our protocol, we found that in vitro binding of factor A correlated with the in vivo activity of the M-MuLV silencer. Factor A bound specifically to the wild-type silencer element at room temperature and 30 degrees C, but not at 4 degrees C, and bound 10-fold better to the full-length silencer than to a minimal silencer core element. The factor was enriched in nuclear compared with cytosolic extracts and in undifferentiated EC cells compared with differentiated cells in which the silencer is nonfunctional. Salt and ion requirements for factor A binding were investigated, and partial purification steps indicated the factor to be a heparin-Sepharose-binding moiety of greater than 100 kDa. To examine possible relationships between silencer and PBS activities, sequences representing phenylalanine, isoleucine, lysine-1,2, lysine-3, methionine, and tryptophan PBS DNA fragments were tested in vivo for stem cell-specific repression of M-MuLV expression and in vitro in DNA binding assays. Of these PBS elements, only the lysine-1,2 PBS DNA fragment showed consistently high levels of repression. Interestingly, the lysine-1,2 PBS DNA fragment also formed a complex with an EC cell factor with characteristics similar to those of factor A. However, the two factors did not cross-compete in binding studies, suggesting that they may be different but related factors. Our results suggest that expression of Mason-Pfizer monkey virus, visna virus, and spumavirus, which use the lysine-1,2 PBS, may be inhibited in undifferentiated stem cells.

Base Sequence↗
PubMed1995

Comparison of dopamine contents in lung vasculature of several species.

Catecholamine contents of human, rabbit and rat pulmonary vasculature were surveyed. Human pulmonary vasculature was obtained from lobectomized specimens of lung tumors. Catecholamines were measured by high performance liquid chromatography after aluminum extraction. High dopamine (DA) content (1.4 nmol/g wet weight) and high DA/noradrenaline (NA) ratio (17.9%) were observed in rabbit pulmonary arterial trunks. In rabbit pulmonary arterial branches, DA content was 0.26 nmol/g wet weight and DA/NA ratio was 4.2%. In rat, NA contents were less in intra- and extra-pulmonary arteries (1.5 and 4.0 nmol/g wet weight, respectively) compared with pulmonary vasculature of rabbit or with the other vasculatures of the same animals. DA contents were 1.9 and 1.8 nmol/g wet weight in intra- and extra-pulmonary arteries, respectively, and DA/NA ratios were markedly high (218 and 48%, respectively). On the other hand, DA/NA ratios were around 1% in human intrapulmonary arteries and that for large-sized (more than 2 mm in diameter) intrapulmonary vein was 8.5%. Species difference and regional difference among pulmonary vascular beds are evident and at least in human pulmonary artery, DA/NA ratio is not as high as rabbit and rat pulmonary arteries.

Animals↗
PubMed1995

Regulation of bone sialoprotein gene transcription by steroid hormones.

During the initial formation of bone, dentine and cementum in tooth morphogenesis, fully differentiated osteoblasts, odontoblasts and cementoblasts express bone sialoprotein (BSP), a mineralized tissue-specific acidic glycoprotein that has been implicated in the nucleation of hydroxyapatite crystal growth. The expression of BSP is regulated by steroid hormones that modulate mineralized tissue formation. Thus, the transcription of the BSP gene is induced by glucocorticoids in association with osteoblast differentiation and glucocorticoids also stimulate the expression of BSP in differentiated osteoblasts. In contrast, however, vitamin D3 suppresses bone formation and abrogates the expression of BSP. Our studies, using the osteoblastic cell lines ROS 17/2.8 and UMR 106-06, have revealed that the glucocorticoid (10(-8) M dexamethasone; dex) effect on BSP mRNA involves both direct and indirect pathways. To determine the molecular basis of the direct pathway on transcriptional regulation of the BSP we have isolated and characterized the promoter regions of both the human and rat BSP genes. The promoters are characterized by a highly conserved region (BSP box) encompassing the immediate promoter region, which includes a unique inverted TATA box overlapped by a putative (DR3) vitamin D3 response element (VDRE). Possible glucocorticoid response elements are present approximately 1 kb and approximately 1.4 kb further upstream. Transient transfection analysis of chimeric constructs linked to a luciferase reporter gene have shown Dex-stimulated expression in constructs that include one or both GREs, whereas vit D3 suppresses expression in a short construct that includes the VDRE.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

The mineral and protein content of enamel in amelogenesis imperfecta.

The purpose of this investigation was to characterize the enamel composition of teeth affected with the hereditary enamel disorders known as amelogenesis imperfecta. Teeth from 10 individuals representing all 3 major AI types (hypocalcified, n = 3; hypomaturation, n = 3; hypoplastic, n = 4) and 10 normal teeth were studied. Half of each tooth was used for histological and biochemical studies. The enamel protein content was estimated by amino acid analysis. The enamel mineral content (volume %) was determined from the calcium and/or phosphorus content. Calcium was measured using atomic absorption and phosphorus was determined colorimetrically. The mean enamel mineral content was reduced for all hypomaturation and hypocalcified AI teeth while hypoplastic AI enamel varied from normal to reduced compared with normal enamel. The enamel protein content was increased in all but one AI case (7 cases were examined for protein) compared with the normal enamel. The mineral and protein content in AI enamel showed a significant inverse relationship (R = -0.939, P = 0.001). This study shows that all three of the major AI groups can have subtypes associated with substantial decreases in the enamel mineral content, although hypomineralization appears most severe in the hypomaturation and hypocalcified AI types. The decreased mineral content was associated with an increased protein content in AI enamel. These findings provide further evidence that altered enamel mineralization in AI teeth likely involves abnormal post-secretory processing of the enamel proteins.

Amelogenesis Imperfecta↗
PubMed1995

[The utility of thermistor attached tracheal tube for pediatric patients in cardiac surgery].

During cardiac surgery, esophageal, rectal, or bladder temperature is usually monitored as an index of core temperature; however, these methods are invasive, and often inconsistently reflect the central body temperature, especially in pediatric patients. The purpose of this study was to evaluate the utility of tracheal temperature monitoring during cardiac surgery in pediatric patients. Fifteen children (ages; 8 m.-7 yr.) undergoing cardiac surgery with cardio-pulmonary bypass (CPB) were studied. Anesthesia was induced and maintained with high doses of fentanyl and intermittent doses of midazolam. After anesthetic induction, esophageal, rectal, bladder, tympanic, and forehead deep temperatures were monitored with a Core Temp Monitor (CTM-205, Terumo Co.). Simultaneously, the tracheal temperature was monitored with a specially made tracheal tube. A thermistor was attached by medical glue (Loctite Prism, Loctite Co.) at the anterior surface of a tracheal tube (Trachelon, Terumo Co.) without cuff (inside diameter 4.0-6.0 mm) where the tracheal tube tightly fits against the trachea. The inspired gas was warmed to 35 degrees C and humidified. During CPB, the blood temperature at the inlet to the patients was also recorded simultaneously. All indicated temperatures (Y) during CPB were analyzed for correlation with the blood temperature to the patients (X). The tracheal temperature had the highest correlation with the blood temperature from the patients (Y = 0.68X + 10.60, r = 0.89). There were also good correlations of the esophageal as well as bladder temperatures with blood temperature. There were no patients who suffered tracheal inflammation or laryngeal edema from the thermistor. Monitoring tracheal temperature is not only valuable for monitoring the core temperature, but also is convenient for pediatric patients in cardiac surgery.

Anesthesia, General↗
PubMed1995

[A successful operation for left atrial myxoma and mitral valve regurgitation with giant LA].

A 78-year-old woman was introduced to our clinic, complaining of orthopnea and severe appetite loss, and her performance status was evaluated as NYHA IV. Computed tomogram revealed a myxoma in left atrium (LA) as a low density area and MRI demonstrated a high intensity shadow. Left ventriculogram and color Doppler echocardiogram showed severe mitral valve regurgitation (MR) with giant LA. LA myxoma was completely resected through both LA-tomy and RA-tomy. The LA was plicated according to the method reported by Kawazoe, followed by a mitral valve replacement with SJM 25 mm, and a tricuspid annuloplasty according to the DeVega's method. The postoperative course was uneventful and her performance status improved to NYHA II at discharge. LA myxoma frequently causes secondary MR. In this case, however, the LA myxoma did not affect the function of mitral valve, judging from its size and position. There were a few reports about LA myxoma complicated with primary MR. We also confirmed that a LA plication was very useful for the treatment of giant LA to improve a respiratory failure.

Aged↗
PubMed1995

[A case of lung scar cancer with special pathohistological feature and high CA 19-9 level].

A 58-year-old woman complained of cough and fever. CX-P and chest CT revealed pneumonic shadow and serum CA 19-9 level was high. Since the malignant cells were found in the bronchial lavage fluid, the lower lobectomy of the left lung was done. Both macroscopically and microscopically, adenocarcinoma only existed in 2-3 mm width at the peripheral site of the scar lesion. The postoperative CA 19-9 values continued to be high, suggesting the recurrence of the cancer. After 23 months from the first operation, the upper lobe of the left lung was resected on the base of the similar findings in CX-P and chest CT. The histological finding of the specimen was compatible with the scar cancer described above. After the second operation, the serum CA 19-9 value decreased to normal. We reported a case of the lung scar cancer with special pathohistological feature.

Adenocarcinoma, Papillary↗
PubMed1995

[Chemosensitivity test with endoscopic biopsy specimens].

In SDI test using tetrazolium salt, we compared MTT with XTT, which has been recently developed and is more sensitive than MTT. Further, a chemosensitivity test with endoscopic biopsy specimens using XTT was conducted. The reproducibility of the MTT assay was assessed under various conditions. The I.I of MTT assay did not vary according to type or concentration of anticancer drugs and the biopsy site of specimens. Then MTT and XTT assay were compared, revealing the results of these 2 assays were significantly correlated. Thus, XTT assay was performed with tissues from surgical specimens using biotome. Of the 16 specimens subjected to XTT assay, 6 showed an OD value of 0.100 or more, which was well within assessment. XTT assay was also performed in biopsy specimens from patients using a biotome manipulated under endoscopic guidance before operation. Three among 6 specimens showed an OD value of 0.100 or more. Our findings have demonstrated that the SDI test using XTT can be used for the chemosensitivity test, even when these specimens contain a relatively small number of cells collected using a biotome.

Animals↗
PubMed1995

[Acute thrombosed aortic dissection--its clinical manifestation and treatment for Stanford A type].

Ten patients (mean age of 63 years old) with acute thrombosed aortic dissection (ATAD) have been evaluated among 31 aortic dissections during past 10 years (from 1985 to 1995). The six cases are Stanford A type and others are Stanford B type. The mean maximal diameter of aorta was 52 +/- 6 mm in Stanford A type and 41 +/- 4 mm in Stanford B type. The ratio of true lumen was 78 +/- 14% to that of whole horizontal section area in thrombosed type and 34 +/- 19% in opacified type dissection. We had chosen conservative treatment for all ATAD. However, five patients with Stanford A type dissection needed to be operated on in short term periods. Three patients were operated upon within three days from onset, and another two patients were operated on 34th and 37th day from onset, respectively. ATAD is firstly treated medically and its prognosis is generally well. However, we proposed here that the conservative treatment for ATAD, especially Stanford A type dissection, must be reconsidered because of our many operations for ATAD in the follow-up periods.

Acute Disease↗