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Biomedical subjects

F Watanabe

Publications and source records attributed to F Watanabe.

At least 145 records · Page 8Linked to original sources
PubMed1994

A new method of quantitating serum and urinary levels of 1,5-anhydroglucitol in insulin-dependent diabetes mellitus.

A new method was developed for quantitating the serum and urinary levels of 1,5-anhydroglucitol (AG), a sensitive and informative marker of glycemic control. This method utilized a combination of ODS and pyranose oxidase-immobilized columns for HPLC, and monitored hydrogen peroxide production with an electrochemical detector. We applied this method to determine the serum and urinary AG levels in 15 patients with insulin-dependent diabetes mellitus (IDDM) as well as in control subjects. Baseline separation of AG from other sugars such as glucose and myoinositol was achieved. Quantitation of AG was achieved over the range from 0.2 ng to 0.3 micrograms based upon peak heights. The serum and urinary AG levels in the IDDM patients were 4.4 +/- 8.3 mg/l and 5.1 +/- 4.3 mg/day, respectively. We found that the urinary AG to serum AG ratio showed a linear correlation with the urinary glucose level in the IDDM patients (urinary glucose (y) vs. urinary AG to serum AG ratio (x): y = 9.071x-0.991; r = 0.968, P < 0.001). This method proved efficient and reliable for quantitating urinary AG. Since determination of both the AG and glucose levels in urine gives equivalent clinical information to the serum AG level, urinary monitoring could provide a valuable addition to the available methods for assessing the glycemic status of IDDM patients.

Adolescent↗
PubMed1994

Cytochrome b5-like hemoprotein/cytochrome b5 reductase complex in rat liver mitochondria has NADH-linked aquacobalamin reductase activity.

Rat liver mitochondrial NADH-linked aquacobalamin reductase was characterized to clarify its enzymological properties. Most of the enzyme was solubilized with 10 g/L Triton X-100 from rat liver mitochondrial membranes. The elution behavior of the solubilized enzyme was identical to that of NADH-cytochrome c reductase (b-type cytochromes/cytochrome b5 reductase complex) during DEAE-Sepharose Fast Flow column chromatography. By mixing both purified cytochrome b5-like hemoprotein (outer membrane-cytochrome b) and cytochrome b5 reductase, cob(II)alamin was formed from aquacobalamin and NADH. These results provide evidence that the outer membrane-cytochrome b/cytochrome b5 reductase complex has the activity of the NADH-linked aquacobalamin reductase in rat liver mitochondria. Some properties of the NADH-linked aquacobalamin reductase were studied using the function of rat liver mitochondrial membranes. The specific activity (109.5 +/- 14.3 nmol.min-1.mg protein-1) of the enzyme was shown under physiological conditions (pH 7.1 at 40 degrees C). The optimal pH and temperature for activity were 7.1 and 40 degrees C, respectively. The apparent Km values were 41.9 mumol/L for aquacobalamin in the presence of 0.2 mmol/L NADH and 14.4 mumol/L for NADH in the presence of 0.1 mmol/L aquacobalamin. The enzyme was specific for aquacobalamin, because cyanocobalamin could not be reduced by the enzyme.

Animals↗
PubMed1994

HCV-marker-positive autoimmune-type chronic active hepatitis: a possible relation between HCV infection and liver autoreaction.

This study focused on 32 patients who were diagnosed as having autoimmune hepatitis based upon clinical and histological factors. Fifteen of these patients were positive for HCV-RNA and for one of the HCV-related markers tested, including anti-C100, ELISA II, and RIBA 2 (Group 2). The remaining 17 patients were negative for all HCV-related markers (Group 1). Clinical factors in the two groups, including the frequency of autoantibodies, serum levels of aminotransferase and gammaglobulin, HLA phenotypes, and the response to corticosteroid treatments, were compared. The titer of serum anti-nuclear antibodies and the level of serum aminotransferase at initial diagnosis were significantly higher in Group 1 than in Group 2. Furthermore, the genetic background of the two groups, as indicated by HLA phenotypes, differed. All cases in Group 1 were HLA-DR4-positive, whereas only 60% of those in Group 2 cases had HLA-DR4. Also, all cases in Group 1 but only 66.7% of the cases in Group 2 showed good clinical responses to corticosteroid treatment. Finally, no cases of HCV-related-marker-positive autoimmune hepatitis (Group 2) had antibodies for LKM, suggesting that these cases were clinically different from type II autoimmune hepatitis. These data indicated that immunosuppressive treatment might be the preferred initial treatment in patients who either satisfy the criteria for AIH or who are sero-positive for an HCV-marker.

Autoantibodies↗
PubMed1994

Studies on steroids in fetuses and neonates: identification of 16-dehydropregnenolone in the circulation of pre-term neonates.

Unconjugated steroids were extracted with dichloromethane from the serum of pre-term neonates. Conjugated steroid fraction in the residue was separated and purified by high performance liquid chromatography. The purified steroid fraction was subjected to enzyme (arylsulfatase from Helix pomatia) or acid hydrolysis. Liberated steroid was analyzed by gas chromatography-mass spectrometry (GC/MS) and gas chromatography-Fourier transformation infrared spectroscopy (GC/FT-IR). All of the results obtained from GC/MS and GC/FT-IR analysis were identical with those of authentic 16-dehydropregnenolone (3 beta-hydroxy-5,16-pregnadien-20-one, 16-DHP). This is the first report to demonstrate the presence of 16-DHP in human blood.

Arylsulfatases↗
PubMed1994

Cardiovascular effects of 20 days bed rest in healthy young subjects.

To evaluate the effects of inactivity on the cardiovascular system in normal subjects, left ventricular echocardiography and vascular ultrasound of the common carotid artery, abdominal aorta and femoral artery, and lower body negative pressure tests were performed in 14 healthy volunteers (mean age: 22 years) before and after 20 days of strict bed rest. Cardiac output was calculated from echocardiographic measurements and peripheral arterial flows by multiplying cross-sectional area of an artery by heart rate and time-velocity integral measured by pulsed Doppler ultrasound with angle correction. Systemic vascular resistance, lower body vascular resistance, leg vascular resistance and head vascular resistance were also calculated. After bed rest, heart rate increased (69 +/- 2 to 79 +/- 3 bpm), while left ventricular diastolic dimension (49 +/- 1 to 45 +/- 1 mm), systolic blood pressure (137 +/- 5 to 116 +/- 4 mmHg), cardiac output (6.2 +/- 0.3 to 5.4 +/- 0.3 1.min-1), abdominal aortic flow (4.1 +/- 0.4 to 3.1 +/- 0.3 1.min-1), femoral artery flow (0.66 +/- 0.07 to 0.33 +/- 0.04 1-min-1), and lower body negative pressure test tolerance time (750 +/- 71 to 582 +/- 48 s) decreased significantly (p < 0.05). However, common carotid artery flow (0.97 +/- 0.09 to 1.03 +/- 0.08 1.min-1) did not change. Although no significant changes in systemic vascular resistance, lower body vascular resistance or head vascular resistance were observed, leg vascular resistance increased significantly after 20 days of bed rest (6933 +/- 2905 to 13221 +/- 2606 dyn.s.cm-1) (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Immunoassay of synthetic corticosteroids].

Synthetic corticosteroids, such as betamethasone and dexamethasone, have been widely used for diagnosis and therapy of various diseases in the area of clinical medicine. When synthetic corticosteroids are to be administered over long periods, the dose must be the smallest one that will achieve the desired effect. This dose must be determined by blood levels of these steroids. We have investigated the application of enzyme immunoassay (EIA) for the measurement of blood levels of synthetic corticosteroids. In this section, the development and application of EIA for betamethasone and dexamethasone are described.

Betamethasone↗
PubMed1994

[Clinical significance of flow cytometric DNA analysis in metastatic lymph node of colorectal cancer].

Significance of flow cytometric DNA analysis in metastatic lymph nodes for assessing malignant potential of colorectal cancer was investigated using paraffin-embedded materials of primary lesions and metastatic lymph nodes from 65 patients who had been treated between 1975 and 1990. The DNA ploidy patterns of metastatic nodes were identical in 61.5% with those of primary lesions. Diploid cancers were significantly more frequent in metastatic nodes than in primary lesions. There were significantly more aneuploid cancers in proximal nodes than in distant nodes. There was no relation between ploidy patterns in primary lesions and survival. However, a significant relation was found between ploidy patterns in metastatic nodes and survival. Diploid cancer in metastatic nodes had a significantly better survival than aneuploid cancer, in all patients as well as those with curative resection. In patients with stage III and in those with the same depth of invasion, the survival rate of diploid cancer in metastatic nodes was significantly higher. There was no correlation between ploidy patterns in metastatic nodes and clinicopathological variables in primary lesions, such as histological type, depth of invasion, nodal involvement, peritoneal or hepatic involvement and stage. These results suggest that nuclear DNA content in metastatic lymph nodes may be a prognostic indicator in colorectal cancer with nodal involvement.

Colorectal Neoplasms↗
PubMed1993

Characterization of aquacobalamin reductase (NADPH) from Euglena gracilis.

Aquacobalamin reductase (NADPH), which catalyzes the reduction of aquacobalamin to cob(II)alamin in the synthesis of cobalamin coenzymes, has already been purified from mitochondria of Euglena gracilis and partly characterized. Here, the enzyme was further characterized to clarify its enzymatic properties. The enzyme reduced 2 mol of aquacobalamin per mole of NADPH and had NADPH diaphorase-like activity. The 16 amino acid residues at the NH2-terminal of the enzyme were identical with those of the NADPH diaphorase domain of pyruvate: NADP+ oxidoreductase, which is involved in Euglena wax ester fermentation. Peptide mapping of the aquacobalamin reductase showed that elution during C-18 reversed-phase high-performance liquid chromatography was identical to that of the NADPH diaphorase domain. Immunoblotting indicated that the Euglena aquacobalamin reductase had a higher molecular weight (166,000) in the intact mitochondria than the purified enzyme (65,000), and that the molecular weights of the native and purified enzyme were identical with those of the subunit and the NADPH diaphorase domain, respectively. These results showed that the aquacobalamin reductase isolated earlier was the NADPH diaphorase domain, cleaved by trypsin during preparation of the mitochondrial homogenate from the native enzyme. Purified pyruvate:NADP+ oxidoreductase also had the activity of aquacobalamin reductase, which suggests that the enzyme in Euglena mitochondria has more than one function in the synthesis of cobalamin co-enzymes.

Animals↗
PubMed1993

A case of Sjögren's syndrome complicating immune-mediated aplastic anaemia.

A 78-year-old Japanese woman with Sjögren's syndrome complicating immune-mediated aplastic anaemia is described. A diagnosis of aplastic anaemia was made from severe pancytopenia with hypoplastic marrow. Laboratory studies suggested an association of bone marrow suppressive T-lymphocytes with the pathogenesis of aplastic anaemia. Following the administration of mepithiostan and prednisolone, pancytopenia improved gradually. Two years after the onset of aplastic anaemia, Raynaud's phenomenon developed and examinations revealed the existence of keratoconjunctivitis sicca and anti-SSA/Ro and anti-SSB/La antibodies.

Aged↗
PubMed1993

Chronic destructive monoarthritis of the wrist in patients with anti-SSA/Ro antibodies: report of two cases.

Among 340 patients with rheumatic diseases, two cases of chronic destructive monoarthritis of the wrist with anti-SSA/Ro antibodies and rheumatoid factor, were observed for over three years. It is not clear whether these cases represent a specific subset of rheumatoid arthritis (RA) or whether they may progress to diffuse symmetrical destructive polyarthritis typical of RA. Long-term follow-up studies including analysis of autoantibodies will be needed to clarify the characteristics and course of chronic monoarthritis.

Antibodies, Antinuclear↗
PubMed1993

Marked thrombocytosis with chromosomal abnormalities in a patient with rheumatoid arthritis.

An 80 year-old Japanese woman with rheumatoid arthritis (RA), complicated with thrombocytosis is described. Mild to moderate thrombocytosis is commonly observed in patients with RA, but she had marked thrombocytosis of over 1000 x 10(3)/mm3 and monosomy 22 with marker chromosome. This case suggests that thrombocytosis unusual with disease activity of RA might occur, and that careful evaluation of the thrombocytosis is required.

Aged↗
PubMed1993

Immunogenetic background of hepatitis B virus infection and autoimmune hepatitis in Japan.

Human leucocyte antigen (HLA)-typing was studied in 82 hepatitis B carriers and 15 cases of autoimmune hepatitis (AIH) to elucidate the genetic factors which may associated with the etio-pathogenesis of chronic hepatitis in Japan. There were two types of HLA phenotypes: HLA A2 was associated with the progression of the disease induced by HBV infection, and HLA A26 and DR5 were related to the retardation of the disease. A family study confirmed the strong association of these HLA phenotypes with the disease induced by HBV infection. In the analysis of AIH, HLA DR4 is a risk factor related to susceptibility of Japanese AIH which shows different clinical manifestations compared to HLA-DR3-positive AIH, dominantly observed in Western countries. These results suggest that genetic background as expressed by HLA, is an important factor in restricting the development of type B hepatitis and AIH, and can explain racial differences of disease susceptibility.

Autoimmune Diseases↗
PubMed1993

New subtype of apical hypertrophic cardiomyopathy identified with nuclear magnetic resonance imaging as an underlying cause of markedly inverted T waves.

OBJECTIVES: The aim of this study was to elucidate the clinical importance of a new subtype of apical hypertrophic cardiomyopathy that could not be diagnosed with the classical diagnostic criteria. BACKGROUND: Apical hypertrophic cardiomyopathy is recognized by a characteristic spade-shaped intraventricular cavity on the end-diastolic left ventriculogram in the right anterior oblique projection, often associated with giant negative T waves [negativity > or = 1.0 mV (10 mm)]. As an underlying cause of giant negative T waves, an additional new subtype of apical hypertrophic cardiomyopathy has been identified. METHODS: In 40 patients with inverted T waves (negativity > or = 0.5 mV), including 26 patients with giant negative T waves, nuclear magnetic resonance (NMR) long-axis images corresponding to the left ventriculogram in the right anterior oblique projection and short-axis images at various levels, including the apical level, were obtained to define the site of hypertrophied myocardium. RESULTS: Long-axis images indicated a spadelike configuration in 17 patients, whereas this diagnostic configuration was not present in the other 23 patients. Nine of these 23 patients had significantly hypertrophied myocardium at the basal level. In the 14 remaining patients, short-axis images indicated no hypertrophy at the basal level and proved that the area of hypertrophied myocardium was confined to a narrow region of the septum or the anterior or lateral wall at the apical level (nonspade apical hypertrophic cardiomyopathy). The hypertrophied myocardium of the nonspade type was so narrowly confined that the mass did not form a spadelike configuration or could not be detected on the long-axis image. CONCLUSIONS: Nonspade apical hypertrophic cardiomyopathy was newly identified on NMR short-axis images, and this could be an additional, important underlying cause of moderately to severely inverted T waves.

Aged↗
PubMed1993

Relationship between distribution of hypertrophy and electrocardiographic changes in hypertrophic cardiomyopathy.

To assess the relationship between the distribution of hypertrophy and electrocardiographic changes in patients with hypertrophic cardiomyopathy, magnetic resonance imaging and ECG findings were correlated in 25 patients with apical hypertrophy (group I), 15 patients with both apical and basal hypertrophy (group II), and 11 patients with hypertrophy localized to the basal left ventricle (group III). The number of precordial leads with negative T waves (-0.5 mV or more) was greater in group I than in groups II and III (I = 3.0 +/- 1.5, II = 1.7 +/- 1.5, III = 0.3 +/- 0.6; p < 0.01). Giant negative T waves (-1.0 mV or more) in precordial leads were found in 13 patients (52%) in group I and five patients (33%) in group II but were not found in group III. In contrast, tall positive T waves (> or = 1.0 mV) in precordial leads were found in two patients (13%) in group II and five (45%) in group III but were not found in group I. These results suggest that the distribution of hypertrophy in patients with hypertrophic cardiomyopathy produces a particular T wave polarity in precordial leads.

Adult↗
PubMed1993

Mitochondrial NADPH-linked aquacobalamin reductase is distinct from the NADPH-linked enzyme from microsomal membranes in rat liver.

Mitochondrial NADPH-linked aquacobalamin reductase was purified and characterized to clarify its enzymatic properties. The enzyme was purified about 360-fold over rat liver mitochondrial membranes in a yield of 7.5%. The purified enzyme was homogenous in SDS-PAGE. The molecular mass (M(r)) of the enzyme was calculated to be 65 kDa by SDS-PAGE and by Toyopearl HW55 gel filtration, indicating that the enzyme is a monomeric polypeptide with M(r) of 65 kDa. The enzyme was a flavoprotein containing 1 mol of FAD and FMN per mole of the enzyme. The enzyme was specific for NADPH as electron donor and had the ability to reduce cytochrome c (15.4 mumol.min-1 x mg protein-1), potassium ferricyanide (4.9 mumol.min-1 x mg protein-1) and 2,6-dichlorophenolindophenol (16.8 mumol.min-1.mg protein-1) as well as aquacobalamin (6.4 mumol.min-1 x mg protein-1). Although the enzyme immunoreacted with an antibody against NADPH-cytochrome P-450 reductase, which had the activity of the NADPH-linked aquacobalamin reductase in rat liver microsomes, the mitochondrial enzyme and the microsomal enzyme had different enzymological properties.

Animals↗