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T Urakami

Publications and source records attributed to T Urakami.

At least 37 records · Page 2Linked to original sources
PubMed1996

Synthesis and aldose reductase-inhibitory activity of imidazopyrroloquinoline esters.

Derivatives of imidazopyrroloquinoline (IPQ) and its esters were synthesized. Some of these compounds potently inhibited aldose reductases of rabbit lens and dog kidney, as well as the human recombinant enzyme, though the coenzyme pyrroloquinoline quinone (PQQ) was a relatively poor inhibitor. The IPQ esters with a methyl substituent at the C-3 carboxyl group were less potent inhibitors than the analogs without esterification at this position. An IPQ ester with the free carboxyl group at C-3 inhibited sorbitol accumulation in rat red blood cells.

Aldehyde Reductase↗
PubMed1995

Serial changes in the prevalence of islet cell antibodies and islet cell antibody titer in children with IDDM of abrupt or slow onset.

OBJECTIVE: To elucidate the significance of clinical and immunogenic heterogeneity in Japanese children with insulin-dependent diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: Serial changes in the prevalence of islet cell antibodies (ICAs) and in ICA titer were monitored for 10 years after diagnosis in 34 IDDM children, 17 with abrupt onset and 17 with slow onset, whose durations of disease were > 5 years. RESULTS: In slow-onset IDDM children, enough beta-cell function was maintained in the early phase of the disease within 2 years after diagnosis. There was a high prevalence of ICAs in children with both forms of IDDM at the time of diagnosis (abrupt onset 94%; slow onset 82%). However, the decline in the frequency of ICAs in slow-onset IDDM seemed less marked than in abrupt-onset IDDM after a duration of > or = 1 year (47 vs. 82%, 1-3 years; 24 vs. 47%, 3-5 years; 24 vs. 47%, 5-7 years; 18 vs. 53%, 7-10 years, P < 0.05). In terms of changes in ICA titer, abrupt-onset IDDM children initially had high ICA levels of 160-320 Juvenile Diabetes Foundation units (JDF U), but these titers decreased rapidly after the 1st year. On the other hand, slow-onset IDDM children tended to continue to be ICA+ for a relatively long period with low titers of 20-40 JDF U. Among 12 children who remained ICA+ for > 5 years, slow onset was noted in 67% while abrupt onset was seen in only 33%. CONCLUSIONS: From these results, we speculated that changes in ICA titer reflect the slow autoimmune destruction of pancreatic beta-cells. It may be probable that immunogenic factors as well as environmental factors could affect the clinical features in the early phase of IDDM in children.

Age of Onset↗
PubMed1994

Association of polymorphism in the interferon gamma gene with IDDM.

Cytokines may play important roles in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). We analysed a dinucleotide repeat polymorphism within the first intron of the interferon gamma (IFN-gamma) gene in Japanese diabetic patients (175 IDDM and 145 non-insulin-dependent diabetes mellitus) and 267 control subjects. A significant difference was observed in the global allele distribution of the polymorphism between the IDDM and control groups (p = 0.039). The difference from the control group was more evident in the patients whose insulin therapy started within 1 year from onset (p = 0.006) or in the young-onset (< 10 years) patients (p = 0.0006). The alleles "3" and "6" were increased in the IDDM patients, and a significant increase in the frequency of the "3/6" genotype was observed in the IDDM patient group (9.1%, RR 2.9, p = 0.010), in the patients with initial insulin therapy less than 1 year from onset (10.6%, RR 3.4, p = 0.004), or in the young-onset patients (16.7%, RR 5.7, p = 0.0003) in comparison to the control subjects (3.4%). There was a tendency towards frequent occurrence of clinical characteristics which reflect young or abrupt onset of diabetes or both, and depletion of insulin secretion capacity in the patients with "3/6" or "6/6" in comparison to the patients with other genotypes. These results suggest that the IFN-gamma gene region may contribute to the pathogenesis of IDDM and could be a genetic marker for IDDM.

Adult↗
PubMed1994

Epidemiology of type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus in Japanese children.

The overall annual IDDM incidence rates by area in Japan for 1985-1989 for children 0-14 years of age at diagnosis were from 1.65 to 2.07 per 100,000. The incidence in males and females did not show any temporal trends during the period between 1980 and 1989. The prevalence of IDDM was about 1 per 10,000. The clinical features at diagnosis among Japanese IDDM children identified during the 2-year period between 1979 and 1980 were as follows. Fourteen percent of the cases were in coma and 12% of the cases were asymptomatic at diagnosis. There is a suggestion that slow onset IDDM is often seen in Japan. In these children, the decline of serum CPR levels and the prevalence of ICA (islet cell antibodies) over the course of diabetes was slower than in those with an abrupt onset classical IDDM. During the period from 1975 through 1990 the incidence rates of NIDDM in school children showed as much as an approximate 1.5-fold increase along with a similar increase in the prevalence of obesity. About eighty percent of these NIDDM children were obese. A predominance of female children developing diabetes was seen in both type of diabetes, IDDM and NIDDM, in Japan. Non-obese type NIDDM in children was more common in females than in males. It is interesting to note that the mean height of Japanese children with IDDM was not different from the national average, but children with NIDDM were significantly taller than the national average.

Adolescent↗
PubMed1994

Enzyme immunoassay for erythrocyte aldose reductase.

This two-site immunoassay measures erythrocyte aldose reductase by using monoclonal and polyclonal antibodies to recombinant human enzyme. Total incubation time is 2.5 h, and the limit of detection is < 0.05 microgram/L. Analytical recovery tested with blood samples from healthy and diabetic individuals was 101-106%. Average CVs within and between assays were 3.7% and 4.8%, respectively. The enzyme content determined by this system correlated well with the activity of aldose reductase isolated from the same erythrocyte preparations. The amount of erythrocyte aldose reductase per milligram of hemoglobin was higher in women than in men (P < 0.001), but no significant correlation was observed between the amount of enzyme and the age of the individuals. This assay method should provide useful clinical information to optimize administration of aldose reductase inhibitors for effective prevention and treatment of diabetic complications.

Adult↗
PubMed1993

Recombinant human granulocyte colony-stimulating factor therapy for cyclic neutropenia associated with common variable immunodeficiency.

A 14 year old boy with common variable immunodeficiency (CVID) had regularly recurring episodes of severe infections independently of the serum gamma-globulin level. Serial blood counts revealed that this patient also had cyclic neutropenia. Recently, recombinant human granulocyte colony-stimulating factor (rhG-CSF) was reported to be an effective treatment for this disease. We tried rhG-CSF therapy for this patient and a prompt increase in the neutrophil count was noted. However, the cyclic alterations and duration of the nadir of the neutrophil count were not altered, which suggested that rhG-CSF has a variable efficacy in at least some patients with cyclic neutropenia.

Adolescent↗
PubMed1992

Trace levels of pyrroloquinoline quinone in human and rat samples detected by gas chromatography/mass spectrometry.

A detailed procedure for the assay of free pyrroloquinoline quinone (PQQ) in human and rat samples by gas chromatography/mass spectrometry (GC/MS) has been established with stable-isotopic PQQ as internal standard. PQQ was extracted from the samples, after addition of the internal standard, with butanol under acid conditions and with Sep-Pak C18 cartridges. After derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ by selected ion monitoring, respectively. Trace amounts of free PQQ were detected in eight organs, plasma and urine of the human, and in three organs of the rat. The PQQ level was highest in the human spleen (5.9 +/- 3.4 ng/g tissue, followed by the pancreas and lung, and it was below detection limits for human brain and heart. Trace levels of PQQ were also found in rat small intestine, liver and testis. Our data are far below those measured by the redox cycling method of Gallop's group for human plasma, adrenal and urine.

Animals↗
PubMed1992

Production of pyrroloquinoline quinone by using methanol-utilizing bacteria.

A large number of methanol-utilizing bacteria were screened for extracellular production of pyrroloquinoline quinone (PQQ) by using methanol as the carbon and energy sources. Of the bacteria selected, Hyphomicrobium sp. strain TK 0441 was examined for PQQ production by using a jar fermentor. The amount of PQQ in the broth and the level of methanol dehydrogenase activity in the cells were increased by simply decreasing the amount of Fe added to the medium. On the other hand, extracellularly produced protein which interfered with the purification of PQQ was decreased by simply increasing the amount of Mg added to the medium. A suitable medium that contained 1 mug of Fe per ml, 150 mug of Mg per ml, and trace elements was developed. In this medium, the production of PQQ reached approximately 1 mg/ml and protein formation was low.

Journal Article↗
PubMed1990

Failure to verify the presence of pyrroloquinoline quinone (PQQ) in bovine plasma amine oxidase by gas chromatography/mass spectrometry.

The presence of covalently bound pyrroloquinoline quinone (PQQ) in bovine plasma amine oxidase (BPAO) was examined by the use of gas chromatography/mass spectrometry. The enzyme was subjected to proteolysis with proteinase in the presence of [U-13C]PQQ as an internal standard. After isolation and derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ, respectively, by selected ion monitoring (SIM). In the SIM profile, although the sample extract obtained from BPAO treated with proteinase clearly showed the peak at m/z 462 for the internal standard, there were no peaks detectable at m/z 448, showing the absence of PQQ in the proteolysis digest of BPAO. Thus, our results do not support the claim that BPAO contains covalently bound PQQ in its structure.

Amine Oxidase (Copper-Containing)↗
PubMed1990

Extractions of pyrroloquinoline quinone from crude biological samples.

The best conditions for extractions of free pyrroloquinoline quinone (PQQ) from crude biological samples were investigated with various organic solvents and Sep-Pak C18 cartridges. PQQ was measured with use of its native fluorescence in aqueous solution. PQQ was well extracted into n-butanol under acid conditions, and addition of NaCl did not improve the solvent extraction. PQQ, which had been extracted into n-butanol, could be re-extracted into an aqueous phase by addition of either n-heptane or pyridine, or combination of them. PQQ, which had been adsorbed to Sep-Pak C18 cartridges, could be eluted with a mixture of pyridine and water with very excellent recovery. The recovery of 1 micrograms PQQ, which had been added to 1 g human liver, brain and 1 ml plasma and had undergone the n-butanol and the Sep-Pak extractions, was 50, 75 and 105%, respectively. From the blank fluorescence, endogenous levels of free PQQ in human liver, brain and plasma were found not greater than 0.41, 0.08 and 0.13 micrograms/g or ml, respectively, if present.

Brain Chemistry↗
PubMed1990

Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov., which utilize N,N-dimethylformamide.

Two methylamine- and N,N-dimethylformamide-utilizing Paracoccus spp. are described. These bacteria are gram-negative, nonsporeforming, nonmotile, coccoid or short rod-shaped organisms. Their DNA base composition is 62 to 68 mol% G + C. Their cellular fatty acids include large amounts of C18:1 acid. Their major hydroxy acids are 3-OH C10:0 and 3-OH C14:0 acids. The major ubiquinone is Q-10. These bacteria are distinguished from Paracoccus denitrificans and Paracoccus alcaliphilus by physiological characteristics and by DNA-DNA-homology. Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov. are proposed. The type strain of P. aminophilus is DM-15 (= JCM 7686), and the type strain of P. aminovorans is DM-82 (= JCM 7685). Paracoccus halodenitrificans is distinguished from other Paracoccus species on the basis of cellular fatty acid composition, hydroxy fatty acid composition, and DNA-DNA homology. It may not be a valid member of the genus Paracoccus.

Base Composition↗
PubMed1989

Type 1 (insulin-dependent) diabetes in Japanese children is not a uniform disease.

The initial course of Type 1 (insulin-dependent) diabetes mellitus was studied in two groups of Japanese children, i.e. 21 patients with abrupt onset (Group A) and 19 patients detected by urine glucose screening at school with minimal or no symptoms (Group B). There was no statistical difference in mean age at diagnosis between Group A and B (11 +/- 3 years vs 11 +/- 3 years). Group A patients revealed a rapid deterioration of pancreatic B-cell function, but there was evident recovery of the B-cell function from 3 to 9 months following initial treatment. The B-cell capacity in Group B was self maintained until 24 months after diagnosis. Thereafter, even these patients exhibited a progressive decline in the B-cell function. The two groups had a similar incidence of islet cell antibodies at diagnosis (58% vs 69%). However, human leukocyte antigen studies revealed that patients in Group A had a significantly higher prevalence of DR4 and DRW9 than those in Group B (p less than 0.01). These results suggest that in Japanese children there are two forms of diabetes, an abrupt and a slow onset form, which are clinically different and which also seemed to be genetically independent types, or possibly the same disease diagnosed at different stages.

Adolescent↗
PubMedDate not supplied

Initial signs and diagnosis of diabetes--special considerations of Oriental patients.

Hyperglycemia and other metabolic derangements resulting from absolute or functional deficiency of insulin are accompanied by typical signs and symptoms of diabetes. The clinical signs and the findings of hyperglycemia over 200 mg/dl should establish a diagnosis of diabetes mellitus. An oral glucose tolerance test (O-GTT) is rarely necessary for diagnosis of diabetes in a child. A small proportion of children, however, present less severe symptoms, and may require an O-GTT. Approximately 14% of IDDM children were in coma at diagnosis in Tokyo, and 11 onset deaths (0.94%) were observed among the 1172 newly diagnosed IDDM cases in Japan. A significant decline in the onset mortality, however, has been observed in the past 20 years in Japan in association with the improvement of early management of childhood diabetes. The clinical distinction of IDDM from NIDDM is often difficult in diabetic children of Oriental origin without obesity. Japanese IDDM can be divided into two forms, abrupt and slow onset forms, but they may be essentially the same disease. There was no difference in the frequency of being tested positive for circulating ICA between the two groups of the patients. But a difference in the frequency of HLA DR4 and DRW9 was noticed between the two groups. Clinical features of 107 children with NIDDM were studied and about 75% of these cases were obese. All of them can be detected by routine urinalysis for glucose. Diet and exercise therapy in most of the newly diagnosed patients resulted in remission but some of them may require insulin or an oral hypoglycemic agent to get better glycemic control.

Child↗