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T Kurosawa

Publications and source records attributed to T Kurosawa.

At least 55 records · Page 3Linked to original sources
PubMed1999

Bilirubin pigmentation of human teeth caused by hyperbilirubinemia.

This study was conducted to identify bilirubin in deciduous teeth obtained from two patients with a history of severe liver dysfunction. Teeth were histologically analyzed and bilirubin was extracted and quantified spectrophotometrically. Histological analysis revealed a green line in the dentine running parallel to the incremental lines. A chloroform/methanol/acetic acid (30:10:0.5, v/v) extract of the teeth was evaporated and the residue dissolved in chloroform. Absorption spectra were prepared before and after the diazo reaction. The absorption maximum shifted from 450 nm before to 540 nm after the diazo reaction and was higher than that of normal deciduous teeth. These results indicate that the discolouration of teeth in patients with severe liver dysfunction is due to bilirubin deposition.

Bilirubin↗
PubMed1999

Nephrotic mice (ICGN strain): a model of diffuse mesangial sclerosis in infantile nephrotic syndrome.

The ICGN mouse strain is a unique model for naturally occurring nephrotic syndrome. In the present study, we examined the onset of the clinical manifestation of nephrotic syndrome and determined the sequence of intraglomerular events associated with progression of nephrotic conditions. Laboratory analysis revealed that homozygous (nep/nep) mice showed urinary albumin excretion during the suckling stage, rapidly leading to hypoalbuminemia accompanied by body growth failure. Renal pathology demonstrated that an initial intraglomerular event in the nephrotic mice was observed 3 weeks after birth in the form of mesangiolytic lesions, characterized by microaneurysm, platelet accumulation and capillary ballooning. In 6-week-old homozygous mice, mesangial sclerosis, characterized by mesangial expansion and glomerular hypertrophy, was observed in a diffuse fashion. Immunohistochemistry revealed that the glomerular cells in the 3-week-old homozygous suckling mice were positive for alpha-smooth muscle actin, suggesting a phenotypic change in the mesangial cells. Mesangial expansion, confirmed by the over-deposition of type I collagen, was evident until 6 weeks after weaning, while it was of interest that fibrogenic cytokines such as platelet-derived growth factor and transforming growth factor-beta were not detected in the sclerotic glomeruli throughout the observations. Furthermore, the nephrotic features were shown to be resistant to steroid therapy with a high dose of prednisolone. Our results suggest that diffuse mesangial sclerosis, a hereditary glomerular disease, may be genetically generated through early myofibroblast formation, which occurs and develops probably independently of up-regulation of these fibrogenic cytokines. In conclusion, the homozygous nephrotic mouse (ICGN strain) is believed to be a good model for investigating not only nephrotic conditions but also cellular and molecular pathogenesis of diffuse mesangial sclerosis in steroid-resistant infantile nephrotic syndrome.

Albuminuria↗
PubMed1999

Profile of urinary bile acids in infants and children: developmental pattern of excretion of unsaturated ketonic bile acids and 7beta-hydroxylated bile acids.

Unusual bile acids, such as unsaturated ketonic and 7beta-hydroxylated bile acids, have been detected in urine early in life. To elucidate the normal profiles of usual and unusual urinary bile acids in the neonatal and pediatric periods, we measured the concentrations of 28 kinds in urine from normal newborns, infants, and children by gas chromatography-mass spectrometry. The mean total bile acid/Cr ratio in 7-d-old infants was significantly higher than in subjects of other age groups (birth, 2-4 mo, 5-7 mo, 11-12 mo, 2-3 y, 9-14 y, and adult) (p < 0.05). Relatively large amounts of unusual bile acids were detected during infancy, especially during the period up to 1 mo of age. At that time, 1beta,3alpha,7alpha,12alpha-tetrahydroxy-5bet a-cholan-24-oic, 7alpha, 12alpha-dihydroxy-3-oxo-5beta-chol-1-en-24-oic, and 7alpha,12alpha-dihydroxy-3-oxo-4-cholen-24-oic acids were predominant among the unusual urinary bile acids present. Moreover, the levels of 3alpha,7beta,12alpha-trihydroxy-5beta-cholan+ ++-24-oic acid increased significantly after 2-4 mo of age. These results indicate that bile acid synthesis and metabolism in the liver of developing infants are significantly different from that occurring in the liver of adults. Significant amounts of urinary isomerized 7beta-hydroxylated bile acids were detected after late infancy, probably because of changes in the intestinal bacterial flora response to a change in nutrition. We describe, for the first time, evidence of the epimerization of the 7alpha-hydroxyl group of cholic acid, which may be unique to human development.

Adolescent↗
PubMed1999

Histopathological and immunohistochemical analysis of the endocrine and exocrine pancreas in twelve cattle with insulin-dependent diabetes mellitus (IDDM).

Histological and immunohistochemical studies were carried out on the pancreas of twelve cattle of insulin-dependent diabetes mellitus (IDDM). They showed clinical signs such as persistent hyperglycemia, glycosuria and decreased glucose tolerance, and some cases accompanied with or without ketonuria. Histopathologically, eight cattle were diagnosed as chronic IDDM, while others were acute IDDM. The most characteristic lesions of the pancreas in chronic IDDM showed a decrease in the size and number of pancreatic islets, interlobular and interacinar fibrosis, mild lymphocytic insulitis, and vacuolation of a few islets. Almost all cells in the atrophied islets had a small amount of ungranulated cytoplasm. Immunohistochemical examination revealed that the atrophied islet cells did not react to anti-insulin antibody, but occasionally reacted to anti-glucagon or somatostatin antibodies. A few solitary islets with mild lymphocytic infiltration, necrotic islets with occasional calcification, and atrophied islets with mild fibrosis were also observed. A few islets consisted of many islet cells with vacuolated cytoplasm including a small number of insulin-positive granules. Accumulation of glycogen granules was occasionally observed in these islets. Islet fibrosis was due to the proliferation of collagen fibers reactive to both anti-collagen type I and type III antibodies. In acute IDDM, the major islets consisted of the cells with vacuolated cytoplasm indicating the degranulation of islet cells. These islets contained many islet cells with shrunken cytoplasm and karyorrhectic nuclei. Lymphocytic infiltration was frequently observed in the islets which consisted of many islet cells having karyorrhectic nuclei and vacuolated and severely degranulated cytoplasm. Immunohistochemically, islet cells with vacuolated cytoplasm had a small amount of insulin-positive granules, suggesting severe degranulation of beta-cells. An increase in acinar islet-cells and proliferation of ductal epithelial cells showing insulin-immunoreactivity were observed. Bovine IgG-immunoreactive islet cells were frequently seen in the vacuolated islets. In summary, pathological observations suggested that beta-cells were being destroyed by an inflammatory process which selectively affected the pancreatic islets. Lymphocytic insulitis and anti-bovine immunoreactive islet cells were thought to be the most significant changes in determining the etiology and pathogenesis of bovine IDDM, and suggested their role in anti-islet autoimmunity in this form of diabetes.

Animals↗
PubMed1999

Immunohistochemical detection of the enzyme glutamic acid decarboxylase and hormones of the islets of Langerhans in spontaneous insulin-dependent diabetes mellitus in cattle.

Immunohistochemical expression of glutamic acid decarboxylase (GAD) enzyme was detected in the pancreatic islets of 12 cattle with spontaneous insulin-dependent diabetes mellitus (IDDM). The most characteristic changes were atrophy and decreased number of pancreatic islets, enlarged islets with vacuolated beta cells, and lymphocytic islet adenitis. Atrophied islets were composed of small islet cells without cytoplasmic insulin-positive granules. Immunohistochemically, GAD was not found in the cytoplasm of atrophied islet cells. Furthermore, enlarged islets consisting of islet cells with vacuolated cytoplasm were frequently observed. The cytoplasm of vacuolated cells contained very few GAD- and insulin-positive granules, indicating beta cell destruction. Enlarged islets with mild lymphocytic infiltrates were frequently observed. These findings suggest that islet cells in cattle with IDDM lose their insulin synthesis function and their ability to regulate hormonal secretion of alpha and delta cells.

Animals↗
PubMed1998

Hepatocyte growth factor prevents renal fibrosis and dysfunction in a mouse model of chronic renal disease.

Chronic renal disease (CRD) is generally thought to be incurable, except through renal transplantation, and the number of patients with CRD is on the increase. Glomerulosclerosis and tubulointerstitial fibrosis represent the morphological equivalent of end-stage CRD. In this study, we demonstrated the preventive effect of hepatocyte growth factor (HGF) on the progression of renal dysfunction and fibrosis, using a spontaneous mouse model for CRD (ICGN strain). The mice progressively developed glomerular sclerotic injury, tubular atrophy, and renal dysfunction until they were 17 wk of age. When recombinant HGF was injected into these mice during a 4-wk-period (from weeks 14-17 after birth), DNA synthesis of tubular epithelial cells was found to be 4.4-fold higher than in mice without HGF injection, thereby suggesting tubular parenchymal expansion promoted by HGF. Notably, HGF suppressed the expression of transforming growth factor-beta and of platelet-derived growth factor as well as myofibroblast formation in the affected kidney. Consequently, the onset of tubulointerstitial fibrosis was almost completely inhibited by HGF, while HGF attenuated the progression of glomerulosclerosis, both leading to preventing manifestation of renal dysfunction. From our results, supplement therapy with HGF may be taken into consideration as a novel option for prevention and treatment of CRD.

Animals↗
PubMed1998

Dentatorubropallidoluysian atrophy: clinicopathological study of dementia and involvement of the nucleus basalis of Meynert in seven autopsy cases.

This report concerns a clinicopathological study including a quantitative pathological study on the nucleus basalis of Meynert (nbM) of seven Japanese autopsy cases (four male, three female) of dentatorubropallidoluysian atrophy (DRPLA) with special reference to the clinicopathological correlation of dementia in DRPLA. In each case the pattern of the inheritance was consistent with that of an autosomal dominant trait. The neurological examination revealed that all seven individuals had cerebellar signs. Six patients had epilepsy and choreoathetoid involuntary movement; myoclonus was evident in five patients. Dementia was noted in all seven patients. Degeneration of the globus pallidus (particularly the lateral segment) and of the dentate nucleus was the principal pathological feature. Brain weights at autopsy ranged from 1020 to 1400 g (average 1241 g: male 1320 g, female 1135 g). The quantitative evaluation revealed no significant loss of neurons in the nbM as compared with a control group. There was no clinicopathological correlation between dementia and involvement of the nbM. We suggest that the dementia of DRPLA is due not to the involvement of the nbM, but to - as yet - unidentified pathology elsewhere.

Adolescent↗
PubMed1998

Diagnosis of the first Japanese patient with 3-oxo-delta4-steroid 5beta-reductase deficiency by use of immunoblot analysis.

UNLABELLED: A 3-oxo-delta4-steroid 5beta-reductase (5beta-reductase) deficiency is difficult to diagnose because severe liver damage can result in a similar pattern of metabolite excretion. We investigated the usefulness of immunoblot analysis for diagnosis of 5beta-reductase deficiency and quantitatively analysed urinary bile acids by gas chromatography-mass spectrometry in a 5-month-old Japanese boy with severe neonatal cholestasis associated with hypertyrosinaemia. A liver sample was examined by immunoblot analysis using monoclonal antibodies against 5beta-reductase. Urinary 3-oxo-delta4 bile acids accounted for 88.3% of total bile acids, 5alpha-bile acids for 0.9%, and primary bile acids for 9.1%. Immunoblot analysis of the liver tissue showed an indistinct band of 5beta-reductase. CONCLUSIONS: These findings suggest that this patient had a secondary 5beta-reductase deficiency due to severe liver damage, even though 3-oxo-delta4 bile acids constituted more than 70% of total urinary bile acids. However, the patient may possibly have had an inherited 5beta-reductase deficiency.

Amino Acid Metabolism, Inborn Errors↗
PubMed1998

Urinary 7alpha-hydroxy-3-oxochol-4-en-24-oic and 3-oxochola-4,6-dien-24-oic acids in infants with cholestasis.

BACKGROUND/AIMS: Urinary 3-oxo-delta4 bile acids have been detected in infants who ultimately died of liver disease. We used qualitative and quantitative methods to compare urinary 3-oxo-delta4 bile acids in liver disease, determining their composition and evaluating the prognostic implication in patients of various ages with various liver diseases. METHODS: Gas chromatography-mass spectrometry was used to measure 3-oxo-delta4 bile acids in the urine of patients and healthy controls. RESULTS: Patients with a deficiency of 3-oxo-delta4-steroid 5beta-reductase and acute hepatic failure exhibited a significantly higher percentage of 3-oxo-delta4 bile acids in total bile acids in urine than the healthy controls or other patient groups, including those with neonatal cholestasis or biliary atresia (p<0.0001). The urinary 3-oxo-delta4 bile acids in patients with 3-oxo-delta4-steroid 5beta-reductase deficiency who had a poor prognosis were mainly 7alpha-hydroxy-3-oxochol-4-en-24-oic acid and 3-oxochola-4,6-dien-24-oic acid. CONCLUSIONS: Our results indicate that an increase in the 7alpha-hydroxy-3-oxochol-4-en-24-oic acid and 3-oxochola-4,6-dien-24-oic acid in the urine of patients with hepatobiliary disease indicates a poor prognosis.

Adolescent↗
PubMed1998

Thiolase involved in bile acid formation.

The formation of cholic acid and chenodeoxycholic acid through cleavage of the side chains of CoA esters of 3alpha,7alpha,12alpha-trihydroxy-5beta-choles tan-26-oic acid and 3alpha,7alpha-dihydroxy-5beta-cholestan-26-oic acid is believed to occur in peroxisomes. Recently, we found a new peroxisomal enzyme, D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein, and suggested that this bifunctional protein is responsible for the conversion of 3alpha,7alpha,12alpha-trihydroxy-5beta-cholest-2 4-en-26-oyl-CoA and 3alpha,7alpha-dihydroxy-5beta-cholest-24-en-26-oyl-CoA to their 24-oxo-forms. In the present study, the products of this bifunctional protein reaction were analyzed by gas chromatography-mass spectrometry, and the formation of 24-oxo-27-nor-cholestanes was confirmed. Previously, we found a new thiolase in Caenorhabditis elegans, P-44, and suggested that P-44 and sterol carrier protein x, a peroxisomal protein, constitute a second group of 3-oxoacyl-CoA thiolases. The production of cholic acid and chenodeoxycholic acid from the precursors on incubation with the bifunctional protein and sterol carrier protein x or P-44 was confirmed by gas chromatography.

17-Hydroxysteroid Dehydrogenases↗
PubMed1998

Evaluation of potential fat emboli during placement of intramedullary nails after orthopedic fractures.

STUDY OBJECTIVE: To evaluate material with high echogenicity demonstrated by transesophageal echocardiography (TEE) during the reamed intramedullary nailing procedure in long-bone fracture patients, and to analyze BAL fluid (BALF) in these patients as well as in those with the fat embolism syndrome (FES). DESIGN: Prospective cohort study. SETTING: Emergency and critical care center of a university hospital. PATIENTS: Fifteen patients with long-bone fractures in whom reamed intramedullary nailing was performed, and five patients diagnosed with FES. MEASUREMENTS: During reamed nailing procedures, TEE was performed. We measured the differential cell counts, percentage of lipid-laden cells, and albumin concentration in BALF after the operation. We compared TEE findings and BALF analysis in the surgical patients. In addition, we compared BALF findings in the surgical patients and in the FES patients. RESULTS: We divided 15 patients who underwent TEE into three subtypes based on the appearance of embolic material within the chambers of the right heart. The lipid-laden cells in BALF increased significantly in those patients with highly echogenic material by TEE (p < 0.05). The percentage of the lipid-laden cells in BALF was not significantly different between the TEE patients and those with FES. On the other hand, FES patients showed a statistically significant increase in leukocyte counts and albumin concentration (p < 0.05). CONCLUSIONS: The highly echogenic material seen in TEE during reamed intramedullary nailing could be fat globules on the basis of BALF analysis. However, all patients with large emboli by TEE do not develop FES. A factor other than mechanical obstruction by fat globules may be necessary for the development of FES.

Adolescent↗
PubMed1998

Preventive effect of ACE inhibitor on interstitial myofibroblast formation and matrix deposition in a nephrotic model.

The nephrotic mouse (ICGN strain) is a useful model for progressive nephrotic syndrome (NS). In the present study, we demonstrated the preventive effects of enalapril, an angiotensin converting enzyme (ACE) inhibitor, on the progression of renal dysfunction and tubulo-interstitial fibrosis in the NS mice. Administration of enalapril (5 mg/dL in drinking water) to the 4-week-old NS mice for a 4-week-period did not improve their nephrotic symptoms such as albuminuria and hypoalbuminemia, but significantly suppressed the increases in blood urea nitrogen and serum creatinine levels. Renal histopathology demonstrated that the administration of the ACE inhibitor significantly attenuated the progression of the tubular and interstitial lesions (tubular dilatation, luminal cast accumulation and interstitial expansion) rather than the glomerular sclerotic changes. The suppression of the increase in blood urea nitrogen level by enalapril depended on the attenuated tubular injury rather than on the unchanged glomerular matrix deposition. Immunohistochemical examination revealed that the administration of the ACE inhibitor suppressed the formation of myofibroblasts, identified by the alpha-smooth muscle actin-positive cells, in the interstitial spaces. Consequently, interstitial matrix deposition was significantly reduced in the NS mice treated with enalapril. From the results obtained with the spontaneous nephrotic model, we emphasize a possibility that ACE inhibitor may be effective for attenuating progression of renal dysfunction and fibrosis in human NS, even if the ACE inhibitor fails to improve nephrotic symptoms such as albuminuria and hypoalbuminemia.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Tyrosinemia type I-like disease: a possible manifestation of 3-oxo-delta 4-steroid 5 beta-reductase deficiency.

BACKGROUND: It has been suggested that quantitative analysis of urinary bile acids may help to distinguish primary 3-oxo-delta 4-steroid 5 beta-reductase deficiency from the excretion of 3-oxo-delta 4 bile acids that occurs as a result of liver damage. METHODS: Urinary bile acids were quantitatively analyzed by gas chromatography-mass spectrometry in four Japanese patients with severe neonatal cholestasis associated with hypertyrosinemia without urinary succinylacetone (i.e. tyrosinemia type I-like disease). These four patients represented sporadic cases. RESULTS: Large amounts of 3-oxo-delta 4 bile acids were detected, which comprised greater than 80% of the total urinary bile acids. Small amounts of allo-bile acids and primary bile acids were also detected, comprising less than 1% and 15% of the total urinary bile acids, respectively. CONCLUSIONS: It was suspected that these four patients had a primary 3-oxo-delta 4-steroid 5 beta-reductase deficiency. However, it is possible that some patients in this study may have had a secondary 3-oxo-delta 4-steroid 5 beta-reductase deficiency, caused by idiopathic neonatal cholestatic liver failure.

Amino Acid Metabolism, Inborn Errors↗
PubMed1997

Determination of 3-oxo-delta4- and 3-oxo-delta4,6-bile acids and related compounds in biological fluids of infants with cholestasis by gas chromatography-mass spectrometry.

A method has been developed for the determination of 3-oxo-delta4- and 3-oxo-delta4,6-bile acids and related bile acids in biological fluids of infants by gas chromatography-mass spectrometry (GC-MS) of the methyl ester-dimethylethylsilyl ether-methoxime derivatives. The 7alpha-hydroxylated 3-oxo-delta4-bile acids were partially dehydrated to give the 3-oxo-delta4,6-bile acids by trimethylsilyl or dimethylethylsilyl derivatization and other pretreatments under acidic or alkaline conditions for GC-MS analysis. To prevent dehydration, the 3-oxo-delta4-bile acids were derivatized to the oximes by treatment with O-methylhydroxylamine prior to pretreatments such as solid-phase extraction, enzymatic solvolysis and hydrolysis of the conjugates, and silylation with dimethylethylsilylimidazole. Calibration curves for the bile acids were linear over a range of 5-250 ng and the detection limit was 100 pg for each 3-oxo-delta4-bile acid. Recoveries of the bile acids and their glycine and taurine conjugates from bile acid-free urine and serum ranged from 94.2 to 105.9% of their added amounts. The bile acids in urine and serum of four patients with severe cholestatic liver disease were measured by the analytical method, and the 3-oxo-delta4-bile acids were determined to be the major bile acids (59-68%) in the urines associated with 3-oxo-delta4-steroid 5beta-reductase deficiency or dysfunction.

Bile Acids and Salts↗
PubMed1997

Determination of fetal bile acids in biological fluids from neonates by gas chromatography-negative ion chemical ionization mass spectrometry.

A method has been developed for microanalysis of fetal bile acids in biological fluids from neonates by capillary gas chromatography-mass spectrometry using negative-ion chemical ionization of pentafluorobenzyl ester-dimethylethylsilyl ether derivatives of bile acids. Calibration curves for the bile acid derivatives are useful over the range 0.1-100 pg and the detection limit for bile acids was 1 fg (S/N = 5) using isobutane as a reagent gas. Recoveries of the bile acids and their glycine and taurine conjugates from bile acid-free serum and dried blood discs ranged from 92 to 101% and from 93 to 108%, respectively, of the added amounts of their standard samples. The analysis of bile acids on a dried blood disc, meconium and urine from infants, exhibited significant hydroxylation at the 1 beta-, 2 beta-, 4 beta- and 6 alpha-positions of the usual bile acids, cholic and chenodeoxycholic acids, for the urinary or fecal excretion of bile acids in the fetal and neonatal periods. The present method was applied clinically to analyze bile acids on a dried blood disc from neonatal patients with congenital biliary atresia and hyper-bile-acidemia.

Bile Acids and Salts↗
PubMed1997

Temperature-induced differential kinetic properties between an initial burst and the following steady state in membrane-bound enzymes: studies on lathosterol 5-desaturase.

The NADH-dependent lathosterol 5-desaturation reaction that forms 7-dehydrocholesterol is biphasic, an initial burst followed by steady state. The steady-state phase is slower than the burst phase, because the latter diffusion of the lathosterol substrate within the microsomal membrane must occur before the next reaction can take place [Y. Takakuwa, H. Nishino, Y. Ishibe, and T. Ishibashi (1994) J. Biol. Chem. 269, 27889-27893]. In the present study, changes in the structure and function of the membrane were examined by measurement of the Arrhenius activation energy of lathosterol 5-desaturase at various temperatures between 2 and 45 degrees C. At the burst phase, there was a lack of discontinuity in the Arrhenius plots at the presumed phase transition temperature for the microsomal membrane. However, the plots of the activities of the steady state showed breaks at around 17 and 32 degrees C. It was concluded that phospholipid phase transition affects the steady-state phase but not the burst phase. Furthermore, treatment of microsomes with low concentrations of deoxycholate, known to perturb the membrane integrity, resulted in a break of the activation energy of the burst phase. These results have revealed further evidence for our previous model suggesting interaction between the substrate and enzyme within the microsomal membrane via lateral diffusion.

Animals↗