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Biomedical subjects

T Ishihara

Publications and source records attributed to T Ishihara.

At least 217 records · Page 12Linked to original sources
PubMed1997

Prolyl 4-hydroxylase inhibitor (HOE 077) inhibits pig serum-induced rat liver fibrosis by preventing stellate cell activation.

BACKGROUND/AIMS: The aim of this study was to investigate the effect and mechanism of fibrosuppression by a newly synthesized prolyl 4-hydroxylase inhibitor [HOE 077, 2, 4-pyridine dicarboxylic acid bis [(2-methoxyethyl) amide]] on pig serum-induced liver fibrosis in the rat. METHODS: Male Wistar rats received 0.5 ml of pig serum twice a week for 10 weeks with 0, 100 or 200 ppm of HOE 077. At the end of the experiment, the hydroxyproline content of the liver, and alanine aminotransferase were measured. Histological stains used were HE, azan and a stain for alpha-smooth muscle actin (alpha-SMA). Electron microscopy was also performed. Messenger RNA expressions of type I and III procollagen were examined by Northern blot analysis. alpha-SMA positive cells and fibers with azan staining were assessed as percent area of the tissue specimen, using an image analysis system. RESULTS: Rats that received pig serum for 10 weeks showed an increased liver hydroxyproline content of 318+/-39 microg/g wet weight (n=15). HOE 077 at doses up to 200 ppm significantly (p<0.01) reduced this increase of liver hydroxyproline content (181+/-39 microg/g wet weight, n=15) in accordance with improved histological findings. 200 ppm of HOE 077 significantly reduced mRNA expressions of alpha2(I) (486+/-102 vs 151+/-36, p<0.01) and alpha1(III) (276+/-127 vs 160+/-67, p<0.05) procollagen and percent area of alpha-SMA positive cells (2.94+/-2.14 vs 1.17+/-0.88%). Electron microscopy revealed that 200 ppm of HOE 077 prevented the loss of fat droplets. CONCLUSIONS: A prolyl 4-hydroxylase inhibitor (HOE 077) prevented pig serum-induced rat liver fibrosis by inhibiting stellate cell activation.

Animals↗
PubMed1997

Purification and characterization of myofibril-bound serine proteinase from carp Cyprinus carpio ordinary muscle.

1. A novel myofibril-bound serine proteinase (MBP) has been purified from ordinary muscle of the carp Cyprinus carpio. 2. It was solubilized from the myofibril fraction with acid treatment (under the conditions of 0.6 M KCl, pH 4.0), then purified by column chromatographic steps on Ultrogel AcA 54, and Arginine-Sepharose 4B. 3. The purified enzyme revealed a single protein band on SDS-PAGE, and its molecular mass was estimated to be 30 kDa by SDS-PAGE and gel filtration. 4. The optimum pH and temperature of the enzyme were 8.0 and 55 degrees C, respectively, when Boc-Phe-Ser-Arg-MCA and casein were used as substrates. 5. The enzyme hydrolyzed Boc-Gln-Arg-Arg-MCA most rapidly, and also hydrolyzed the substrates for trypsin-type proteinase, but not for chymotrypsin. The enzyme was inhibited by serine proteinase inhibitors such as DFP, STI and leupeptin. These results suggested that the enzyme was a trypsin-type serine proteinase. 6. Boc-Phe-Ser-Arg-MCA hydrolyzing activity of the purified enzyme was reduced by addition of NaCl, but the caseinolytic activity and Boc-Phe-Ser-Arg-MCA hydrolyzing activity of the partially purified enzyme were activated by NaCl.

Amino Acid Sequence↗
PubMed1997

Substrate specificity of carp Cyprinus carpio cathepsin H with methylcoumarylamide substrates.

Cathepsin H was purified from the crude extract of carp (Cyprinus carpio) hepatopancreas by a reformed method involving six stages, and the specific activity increased about 11,500-fold with a 23% recovery. Of varying fluorescent synthetic substrates tested, carp cathepsin H possessed an ability to hydrolyze four N-terminal unblocked substrates those are composed of a single amino acid bound to 4-methylcoumaryl-7-amide (MCA), namely Leu-MCA, Arg-MCA, Lys-MCA and Ala-MCA. In contrast the enzyme was only marginally able to hydrolyze an unblocked substrate such as Pro-Phe-Arg-MCA and totally unable to degrade all blocked derivative employed. From the kinetic constants with four unblocked substrates, car cathepsin H had the highest affinity toward Leu-MCA with a Km value of 35.4 microM. Besides both the hydrolytic rates and molecular activities of the enzyme decreased from Lys-MCA > Arg-MCA > Ala-MCA > Leu MCA as judged by their Vmax and Kcat values, respectively. Otherwise, optimal pHs for hydrolysis of cathepsin H were different for four substrates. The enzyme exhibited maximum level of the activity at pH 6.5 for Arg-MCA and Lys-MCA and at pH 7.0 for Leu-MCA and Ala-MCA.

Animals↗
PubMed1997

Purification and characterization of cathepsin L from hepatopancreas of carp Cyprinus carpio.

Cathepsin L was purified from carp hepatopancreas by a method involving ammonium sulfate precipitation and a series of column chromatographies, in which the enzyme had an affinity toward Concanavalin A and Cibacron Blue F3GA. Its homogeneity was established by Native-PAGE, but two protein bands corresponding to molecular masses of 30,000 (single chain) and 24,000 (heavy chain) migrated on SDS-PAGE. The enzyme exhibited a maximum activity for carbobenzoxy-L-phenylalanyl-L-arginyl-4-methylcoumaryl-7-amide (Z-Phe-Arg-MCA) at pH 5.5-6.0 and 50 degrees C and the remarkable stability at pH 5.0-6.5 and below 40 degrees C. All tested cysteine protease inhibitors and TLCK and chymostatin markedly inhibited its activity, whereas the other serine protease inhibitors and a metalloprotease inhibitor negligibly affected it. In addition, several metal compounds reduced either its activity or stability to differing extents. Although EDTA alone caused an only marginal activation of the enzyme, its maximum activation required both 2 mM cysteine and 1 mM EDTA. The enzyme had an ability to hydrolyze three peptidyl-MCA substrates including Z-Phe-Arg-MCA, but all kinetic constants indicate that Z-Phe-Arg-MCA is the optical substrate to the enzyme.

Animals↗
PubMed1997

Temporal pattern of AP-1 DNA-binding activity in the rat hippocampus following a kindled seizure.

DNA binding by transcripton factor AP-1 was enhanced remarkably following kindling stimulation in rat amygdala. Maximum increase occurred 2 h after stimulation with return to baseline within 24 h. Supershift and western analyses revealed that 38,000 mol. wt Fos-related antigen and JunD were the main components of the evoked AP-1 complexes at the time their induction reached maximum. AP-1 induction 2 h after the last kindling stimulation was more prominent in samples from previously kindled rats than in those from non-kindled rats. This study sought to establish the role of AP-1 in plastic changes of the hippocampus associated with kindling. Male Sprague-Dawley rats were kindled from the left amygdala until they exhibited Racine15 class 5 generalized seizures. Nuclear proteins were extracted from dorsal hippocampi obtained from 0 to 24 h after final stimulations. From these, we evaluated the temporal pattern of DNA binding by AP-1 using a gel mobility-shift assay with a 32P-labelled AP-1 probe. Supershift and western analyses were added to investigate components of the seizure-evoked AP-1 complexes. Our results suggest that the basal level of AP-1 complexes is not associated with the seizure susceptibility in kindling. However, development of kindling appears to facilitate stimulus-evoked AP-1 induction, probably via plastic changes in the central nervous system. AP-1 may mediate such changes by regulating expression of certain genes.

Analysis of Variance↗
PubMed1997

Polymorphism analysis of Fukuyama type congenital muscular dystrophy (FCMD) siblings with different phenotypes.

Peak motor function in Fukuyama type congenital muscular dystrophy (FCMD) is generally considered to be no better than sitting without help or sliding on the buttocks. There are a few patients who acquire the ability to stand and a small fraction of our total congenital muscular dystrophy (CMD) population are able to walk at some point. These ambulant cases may reflect a broad spectrum of motor disabilities in the category of FCMD, or may represent another CMD entity, which closely resembles but is distinct from FCMD. Since the localization of the FCMD gene to chromosome 9q3 1 by Toda et al. in 1993 and 1994, polymorphism analysis of this disease has become possible. We describe correlations between clinical features and genetic analysis using microsatellite markers flanking the FCMD locus in two FCMD families each having two affected children with distinctly different motor abilities. The results demonstrate that two sets of FCMD siblings share exactly the same haplotype at nine marker loci spanning 23.3 cM, surrounding the FCMD locus. Our results provide genetic confirmation that some FCMD cases may acquire the ability to walk.

Adolescent↗
PubMed1997

Early experience of retrograde cerebral perfusion.

Since 1990, retrograde cerebral perfusion has been applied in aortic arch surgery in the Nagoya University group to protect the brain. This study reviews the group's early clinical results, and especially of neurological outcome in patients undergoing aortic arch surgery via mid sternotomy by using retrograde cerebral perfusion only via the superior vena cava. Seventy-three cases (47 men, 26 women; mean age 62.3 (range 26-82 years)) participated in the study. True aneurysm was diagnosed in 17 cases and aortic dissection in 56. Emergency operations were performed in 49 cases (67%). The proximal aortic arch was replaced in 38 cases, the total aortic arch in 21, the distal arch in six, and the aortic root in two. Mean (s.d.) retrograde cerebral perfusion duration was 55(23) (range 12-115) min and superior vena cava flow rate 350(143) ml/min. Excluding four cases of early surgical death, a total of 10 patients (14.5%) showed neurological dysfunction. Symptoms were coma in eight cases and motor paralysis in two. Three of these 10 cases were recovered without symptoms and six died. The early mortality rate was 19.2%. Significant differences in retrograde cerebral perfusion duration (49(20) versus 83(18) minutes, P < 0.001), superior vena cava pressure (23.2(7.2) versus 28.2(7.4) mmHg, P = 0.046), and preoperative cardiac arrest P < 0.05) were evident between groups with and without neurological dysfunction. There were no neurological dysfunctions in patients undergoing retrograde cerebral perfusion for < 60 minutes at under 30 mmHg of superior vena cava pressure. In conclusion, retrograde cerebral perfusion may be used to extend the duration of safe cerebral circulatory arrest.

Aortic Dissection↗
PubMed1997

Purification and characterization of polyamine aminotransferase of Arthrobacter sp. TMP-1.

Polyamine aminotransferase of Arthrobacter sp. TMP-1 was induced by 1,3-diaminopropane (DAP), N-3-aminopropyl-1,3-diaminopropane (norspermidine), spermidine, and spermine, but not by putrescine. The enzyme was purified to homogeneity. Its molecular weight and subunit size were 129,000 and 64,000, respectively. Its absorption spectrum had maxima at 280 and 420 nm and a shoulder at about 350 nm, and changes were observed upon the addition of DAP, putrescine, and sodium borohydride. The spectrum and its changes indicated that the enzyme contained pyridoxal-5'-phosphate as the coenzyme. The coenzyme content was found to be 1 mol per mol of subunit. DAP, putrescine, norspermidine, spermidine, and spermine were active amino donors and gave relative rates of 100, 73, 24, 30, and 23%, respectively. Pyruvate was the most active amino acceptor, while 2-ketoglutarate and oxaloacetate were inert. The equilibrium constant of the DAP-pyruvate transamination was 0.34. DAP was suggested to be a minor product of the norspermidine-pyruvate reaction.

Arthrobacter↗
PubMed1997

Action of polyamine aminotransferase on norspermidine.

The norspermidine-pyruvate reaction catalyzed by polyamine aminotransferase from Arthrobacter sp. TMP-1 formed N-3-aminopropyl-3-aminopropionaldehyde (APAPAL), L-alanine, 1,3-diaminopropane (DAP), allylamine, and acrolein, and the relative rates of formation of the latter four products were 24, 3.3, 2.3, and 1.2%, respectively, of the rate of the DAP-pyruvate transamination. The identification of APAPAL was done by 13C-NMR after it had been enzymatically oxidized to N-3-aminopropyl-beta-alanine followed by isolation of the oxidized product. The DAP was also isolated and identified by 13C-NMR. The allylamine and acrolein were identified by HPLC and a specific color reaction with m-aminophenol, respectively. In the absence of pyruvate, the enzyme catalyzed the elimination of DAP from norspermidine to yield allylamine, and the addition of DAP to allylamine to yield norspermidine with relative rates of 0.007 and 0.095%, respectively. When allylamine was incubated with the enzyme as the sole substrate, it was converted to N-allyl-1,3-diaminopropane and an unidentified product.

Acrolein↗
PubMed1997

Arteriovenous malformation in the buttock: treatment with a combination of selective embolization and excision.

Arteriovenous malformation (AVM) in a 22-year-old Japanese female is reported. The malformation presented as a nontender, pulsating tumor. An area of marked hypervascularity was revealed in the dermis and muscles of the right buttock by arteriography. The tumor was removed after embolizing the right superior and inferior gluteal arteries, which were the main feeding arteries. Histological examination revealed a number of artery-like vessels, encircled by proliferating capillaries. Follow-up three years after excision showed no clinically remarkable changes. Selective embolization was useful for the excision.

Adult↗
PubMed1997

An autopsy case of diffuse malignant mesothelioma of the pericardium.

A report is presented of an autopsy case of a 71-year-old Japanese man with a diffuse malignant epithelial mesothelioma of the pericardium with massive pericardial effusion and a thickened pericardium. He had no history of exposure to asbestos. He suffered severe heart failure and later died. Autopsy revealed that the tumor had developed over the pericardium. Microscopically, the tumor cells were arranged in an epithelial form, and histochemically, the cytoplasm of these cells contained glycogen and hyaluronic acid. The tumor tissue showed immunohistochemical positivity for cytokeratin, epithelial membrane antigen, vimentin, cancer antigen 125, thrombomodulin, mesothelial antigen, muscle actin and human milk fat globule. In contrast, all the tumor cells were negative for human carcinoembryonic antigen and epithelial antigen. Ultrastructurally, the tumor cells had long, thin microvilli, abundant intermediate filaments, intracytoplasmic lumina and long desmosomes. It is considered that the patient had a typical malignant epithelial mesothelioma of the pericardium.

Aged↗
PubMed1997

A case of lymphoid interstitial pneumonia in a 3-month-old boy not associated with HIV infection: immunohistochemistry of lung biopsy specimens and serum transforming growth factor-beta 1 assay.

The case of a 3-month-old boy with lymphoid interstitial pneumonia (LIP) is reported. He had cough and tachypnea, his weight gain was poor and a chest radiograph showed microgranular shadows in almost all lung areas. Histological investigations revealed severe cellular infiltration by a variety of lymphoid and plasma cells with lymphoid follicle formation in the alveolar walls and also around the bronchioles. Foamy macrophages, a few lymphocytes and exudate filled the alveolar spaces. Epithelial cells lining the air spaces expressed human leukocyte antigen (HLA)-DR. Lymphocytes and macrophages in the alveolar spaces expressed transforming growth factor (TGF)-beta strongly. Serum TGF-beta 1 concentrations were measured eight times during the course of his illness. They exceeded the upper end of the normal range in four samples and were within it in the others. These results suggested that dysfunction of the immune system, especially abnormal expression of HLA-DR in non-immune cells and exaggerated production of TGF-beta played important roles in the pathogenesis of LIP in this patient.

Antigens, CD↗
PubMed1997

Cystic pulmonary metastases of endometrial stromal sarcoma of the uterus, mimicking lymphangiomyomatosis: a case report with immunohistochemistry of HMB45.

A case of endometrial stromal sarcoma (ESS) showed cystic pulmonary metastases mimicking lymphangiomyomatosis (LAM). A 58-year-old female, who had undergone total hysterectomy for low-grade ESS 16 years previously, had repeated bouts of pneumothorax. Multiple thin-walled cysts in the peripheral lung were revealed by radiological examinations. In an open-lung biopsy specimen, cystic lesions were surrounded by layers of spindle-shaped cells of varying thickness that resembled LAM. However, in addition to subtle histologic differences from LAM, HMB45 (antimelanoma antibody) showed positive in LAM (n = 3), but was negative in ESS (n = 2) and the cystic lesions of this case. Using myogenic markers (desmin and alpha-smooth muscle actin), metastatic ESS could be immunohistochemically differentiated from mesenchymal cystic hamartoma (n = 1). HMB45 immunohistochemistry is useful in the differential diagnosis of cystic pulmonary lesions.

Actins↗
PubMed1997

2-Arylmethyl-1,4-benzoquinones. II. Novel inhibitors of platelet aggregation: synthesis and pharmacological evaluation.

Two new series of 2-arylmethyl-1,4-benzoquinones (2 and 3) were synthesized for evaluation of their pharmacological activities. These compounds showed significant inhibition of platelet aggregation and some of them possessed a protective against endothelial cell injury. Structure-activity relationship studies indicated that 2b, 2d and 3b are potent inhibitors of platelet aggregation induced by arachidonic acid (AA) with an IC50 in the range of 1-10 micrograms/ml. Among them, 3b showed a significant inhibitory activity against endothelial cell injury caused by hydrogen peroxide (H2O2) at 1 microM.

Animals↗
PubMed1997

Autoantibody against IA-2 improves the test sensitivity for insulin-dependent diabetes mellitus in Japanese patients of child onset.

We previously reported that IA-2 autoantibodies (Ab) facilitated the diagnosis of Japanese insulin-dependent diabetes mellitus (IDDM), but the number tested was not large enough to investigate whether IA-2Ab can improve the diagnostic accuracy. In this report, sera from 78 patients with less than 2 year-disease duration (the mean (range) ages were 19.2 (6-52) years old) were tested in order to clarify that the combination of IA-2Ab and glutamic acid decarboxylase 65 (GAD65)Ab would improve the test sensitivity for IDDM. Both of the autoantibodies were frequently detected in Japanese abrupt-onset IDDM but the frequency of GAD65Ab was higher than that of IA-2Ab (69% and 47%, respectively, P = 0.024). The two autoantibodies were discordant in respect to both positivity and titer. The positivity for IA-2Ab decreased with the increasing onset-age of the patients (76, 47, 37, 21% for each quartile of age tested), but the frequency of GAD65Ab was unaffected. Among the youngest quartile (< or = 12 years old), IA-2Ab, in combination with GAD65Ab, significantly improved sensitivity (68% to 92%, P < 0.05), but when we tested patients over 12 years old, IA-2Ab caused little, if any, improvement in sensitivity. We confirmed that IA-2 antibody was detected in IDDM among Japanese, as seen in Caucasians, but the test sensitivity was improved only in young IDDM patients among Japanese.

Adolescent↗
PubMed1997

Role of IGF binding protein-1 in the dawn phenomenon and glycemic control in children and adolescents with IDDM.

OBJECTIVE: To clarify the involvement of IGF binding protein (IGFBP)-1 in the dawn rise in plasma glucose and in the overall glycemic control in patients with IDDM. RESEARCH DESIGN AND METHODS: Seventy patients with IDDM were divided into three groups according to pubertal development. Blood samples were obtained for measuring plasma glucose, IGFBP-1, and free insulin at 2200, 0500, and 0700 over a 2-day period. Levels of HbA1c, IGF-1, and IGFBP-3 were determined at 0700. Urinary growth hormone (GH) was collected overnight. To examine its frequency, the dawn phenomenon was defined on the basis of the following: 1) change in plasma glucose from 0500 to 0700, 2) plasma glucose level at 0700, and 3) no antecedent hypoglycemia. RESULTS: There was a statistically significant link between the dawn changes in plasma glucose and IGFBP-1 (r = 0.37, P < 0.01). The former was not related to the change in free insulin or to the overnight urinary GH level. In stepwise regression analyses, plasma glucose at 0700 = 0.03 IGFBP-1 (P < 0.01) + 0.525 HbA1c (P < 0.01) + 3.696 (R2 = 51%). Approximately half of the patients in each group exhibited the dawn phenomenon; 38% of patients with HbA1c < 8% also showed the dawn phenomenon. CONCLUSIONS: We have demonstrated a statistically significant link between the morning risk in IGFBP-1 and plasma glucose. The free fraction of IGF-1 modulated by acute changes in IGFBP-1 may play a direct role. The dawn phenomenon may occur regardless of pubertal stage or glycemic control in children and adolescents with IDDM.

Adolescent↗