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Biomedical subjects

M Honda

Publications and source records attributed to M Honda.

At least 343 records · Page 19Linked to original sources
PubMed1996

Regulation of the last two enzymatic reactions in cholesterol biosynthesis in rats: effects of BM 15.766, cholesterol, cholic acid, lovastatin, and their combinations.

The Smith-Lemli-Opitz syndrome is a common inherited birth disorder caused by markedly reduced 7-dehydrocholesterol delta 7-reductase activity, the final enzyme in the cholesterol biosynthetic pathway. BM 15.766 (4-[2-[1-(4-chlorocinnamyl)piperazin-4-yl]ethyl]-benzoic acid) inhibits 7-dehydrocholesterol delta 7-reductase activity, reduces plasma cholesterol levels, and increases 7-dehydrocholesterol levels to reproduce the biochemical abnormalities of the syndrome in rats. Cholesterol, cholic acid, and lovastatin, alone or in combinations, were fed to rats given BM 15.766, and hepatic activities of the last two enzymes in the cholesterol biosynthetic pathway, lathosterol 5-dehydrogenase and 7-dehydrocholesterol delta 7-reductase, were measured. After feeding BM 15.766, hepatic 7-dehydrocholesterol delta 7-reductase activity decreased by 77% while lathosterol 5-dehydrogenase activity tended to increase, so that the ratio of 5-dehydrogenase to delta 7-reductase activities increased from 0.33 to 2.8. In BM 15.766-fed rats, treatment with cholesterol suppressed both 5-dehydrogenase and delta 7-reductase activities by 76% and 66%, respectively, and decreased the 5-dehydrogenase: delta 7-reductase activities ratio from 2.8 to 2.2. In contrast, treatment with cholic acid and BM 15.766 further inhibited delta 7-reductase activity by 67% without changing significantly the 5-dehydrogenase activity that had increased the ratio to 5.5. Combining BM 15.766 with lovastatin increased 5-dehydrogenase activity fivefold but did not change delta 7-reductase activity, raising the ratio to 14.3. In BM 15.766-treated rats, the first and last two enzymatic reactions in the cholesterol biosynthetic pathway catalyzed by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, lathosterol 5-dehydrogenase, and 7-dehydrocholesterol delta 7-reductase are down-regulated by cholesterol. Thus, only cholesterol and not cholic acid or lovastatin could reduce elevated plasma 7-dehydrocholesterol levels induced by BM 15.766.

Animals↗
PubMed1996

Abnormal sensorimotor integration in writer's cramp: study of contingent negative variation.

To investigate the pathophysiology of idiopathic focal dystonia, we recorded contingent negative variation (CNV) as a physiological index of sensorimotor integration in 14 right-handed patients with writer's cramp and compared it with normative data. CNV was recorded in the S2 choice reaction time paradigm: Two kinds of auditory S2 (Go or No-Go) were given 2 s after the auditory S1, and the subject reacted only to the Go signal by extending the wrist. In normal subjects, the late CNV amplitude had no difference at Cz between left- and right-hand tasks and was symmetric without significant amplitude laterality irrespective of the side of hand movement. In patients with writer's cramp, the late CNV amplitude at Cz was relatively larger for the left-hand task than the right-hand task (p < 0.03), and a significant amplitude laterality of the late CNV (larger on the right) was present especially at the central area for the right-hand task (p < 0.03). Since the late CNV is known to be generated, at least in part, from primary and supplementary motor cortices, the significant laterality of the late CNV seen with the right-hand task in patients with writer's cramp might represent functional abnormality of motor cortices possibly as the result of basal ganglia function.

Adult↗
PubMed1996

Quantitative capillary reversed passive latex agglutination test for C-reactive protein (CRP) in the dog.

A capillary reversed passive latex agglutination test (capillary RPLA) was developed which allows quantification of serum C-reactive protein (CRP) within approximately 15 min. The logarithmic regression line (calibration curve) obtained after measuring each CRP concentration three times in twofold dilutions of a standard canine serum containing 222 micrograms/ml of CRP was y = 6.394 + 0.030x (r = 0.995). Capillary RPLA permitted quantification of CRP in the range 6.9-222 micrograms/ml. The coefficients of variation ranged from 10.28% to 12.40%. The recovery rates (percentage recovery) of CRP by capillary RPLA were within the range 87% to 106%. On measuring the CRP concentrations in sera from 78 dogs by capillary RPLA, single radial immunodiffusion (SRID) and enzyme-linked immunosorbent assay (ELISA), close correlations were demonstrated between SRID and capillary RPLA (y = 7.250 + 1.109x, r = 0.978), between SRID and ELISA (y = 3.042 + 1.059x, r = 0.967), and between capillary RPLA and ELISA (y = 1.778 + 0.929x, r = 0.962). Capillary RPLA may be considered useful as a routine biochemical technique for measurement of serum CRP concentration in the dog.

Animals↗
PubMed1996

Coarctation of the aorta and renal hypoplasia in a boy with Turner/Noonan surface anomalies and a 46,XY karyotype: a clinical model for the possible impairment of a putative lymphogenic gene(s) for Turner somatic stigmata.

This paper describes a 12-year-old Japanese boy with coarctation of the aorta, renal hypoplasia, Turner/Noonan surface anomalies, and a 46,XY karyotype. Although the patient might represent an exceptional case of Noonan syndrome, the combination of the somatic stigmata appears to be consistent with a mutation of the putative lymphogenic gene(s) for Turner somatic stigmata.

Aortic Coarctation↗
PubMed1996

Morphological analysis of pancreatic endocrine cells in newborn animals delivered by experimental diabetic rats.

Rats with mildly impaired glucose tolerance (MIGT) were prepared by the administration of streptozotocin and subsequent islet-isotransplantation. Of pups born to these rats, 65% exhibited macrosomia that weighed over 6.8 g (average weight of control pups was 5.96 g). The morphological changes in the endocrine pancreas in pups born of MIGT and normal control rats were studied using immunohistochemical methods and quantitative morphological analysis. In macrosomic pups, the percentages of pancreatic tissue devoted to islet areas and B cell areas were significantly higher than in control pups. The percentage of pancreas devoted to A cell areas was also higher in macrosomic than normal pups, while the ratio of A/B cell areas was in normal range. In non-macrosomic pups born to MIGT rats, the percentages of pancreas devoted to islet tissues, B cell, and A cell areas were each lower than these in macrosomic pups. Moreover, increase in the proportions of islet and B cell areas in the pancreatic tissue in pups born of MIGT mothers was linearly correlated with increase in birthright. There were no significant differences in D cell area as a proportion of pancreas among macrosomic, non-macrosomic and control pups. These findings suggest that insulin secreted from B cells play important roles in the control of fetal growth.

Animals↗
PubMed1996

Electrocardiographic abnormalities in patients receiving hemodialysis.

We assessed standard 12-lead and Holter electrocardiographic (ECG) abnormalities in maintenance hemodialysis (HD) patients. Of 221 outpatients receiving HD, 143 (65%) had ECG abnormalities. Rates were higher in male, elderly, hypertensive, and diabetic patients than in female, younger, normotensive, and nondiabetic patients. The prevalence of ECG changes correlated inversely with HD duration. Serial ECGs were compared in 87 patients whose average HD duration was 7.5 +/- 2.5 years. Thirty-four patients (39%) showed normal ECGs throughout, 27 (31%) relatively stable abnormalities, 22 (25%) worsening, and 4 (5%) reversion to normal. Age, hypertension, and diabetes are factors related to abnormal ECG findings. Among the 142 Holter recordings from 72 patients, 70 (97%) were basically in sinus rhythm, and 2 (3%) were in atrial fibrillation. The average frequency of supraventricular premature contractions (SVPCs) was 1597 +/- 9725 per 24 hours, and that of ventricular premature contractions (VPCs), 556 +/- 1415. VPCs were multifocal in 9%, in runs in 25%, and early in 1%. In 29 (40%) of recordings, VPCs appeared mainly during and for several hours after HD. ST-T changes were seen in 43 (60%). In 11, ST depression occurred during and a few hours after HD. Patients receiving HD showed diverse ECG abnormalities. Holter ECGs revealed a high incidence of arrhythmias and ST-T changes, which frequently appeared in relation to HD timing.

Adolescent↗
PubMed1996

Effect of YM 9429, a potent teratogen, on cholesterol biosynthesis in cultured cells and rat liver microsomes.

YM 9429 (cis-1-[4-(p-menthan-8-yloxy)phenyl]piperidine) is a hypolipidemic agent with a potent and specific teratogenicity, inducing cleft palate and skeletal variations in rats. Since cleft palate is generally observed in the Smith-Lemli-Opitz syndrome, a common syndrome of multiple congenital anomalies caused by reduced activity of 7-dehydrocholesterol delta 7-reductase (3 beta-hydroxysteroid delta 7-reductase), the final enzyme in the cholesterol biosynthetic pathway, YM 9429 was suspected of being an inhibitor of this enzyme. To prove this hypothesis, YM 9429 was added to cultured human skin fibroblasts and to cultured Morris hepatoma cells and incubated with [5-3H]mevalonolactone. After 24 h, radiolabeled 7-dehydrocholesterol accumulated in the cells, whereas the formation of radiolabeled cholesterol was markedly reduced. The results indicate that YM 9429 inhibits the conversion of 7-dehydrocholesterol to cholesterol catalyzed by the microsomal enzyme 7-dehydrocholesterol delta 7-reductase. In rat liver microsomes, the mode of inhibition was found to be noncompetitive, with a Ki of 40 microM. These results suggest that YM 9429 induced developmental abnormalities in rats by the same mechanism as the Smith-Lemli-Opitz syndrome. This compound might be useful for studying the pathogenesis of anomalies in animal models of the Smith-Lemli-Opitz syndrome.

Animals↗
PubMed1996

Localization of HIV-1 in human thymic implant in SCID-hu mice after intravenous inoculation.

Human immunodeficiency virus type 1 (HIV-1) was immunohistochemically and ultrastructurally localized in human thymus implants in SCID-hu mice 3 weeks after intravenous (i.v.) inoculation of the virus. A viral antigen (gp120) was predominantly distributed in and around the epithelial cells in Hassall's corpuscles as demonstrated by fluorescence immunohistochemistry. Occasional solitary round cells positive for the viral antigen but negative for cytokeratin were detected in the perivascular areas. Ultrastructural examinations clearly revealed a number of mature viral particles in the intercellular spaces of the Hassall's corpuscles. Thus the present study indicates the possibility that thymic epithelial cells in Hassall's corpuscles act as a target and/or reservoir in an early stage of HIV infection.

Animals↗
PubMed1996

No proof of HTLV-I/II in intravenous drug abusers with a high rate of HIV-1 infection in central Thailand.

Serum specimens of 1,074 intravenous drug abusers (IVDA) were examined for infection with HIV-1, HTLV-I and HTLV-II in central Thailand. Three hundred and sixty-two of the specimens were seropositive for HIV-1 (33.7%). The HIV-1 seropositive IVDAs exhibited increased seropositivity with age through group 40-44 and significantly decreased seropositivity over the age of 45. In contrast, no seropositivity to either HTLV-I or -II was detected in the samples tested by a particle-agglutination assay for HTLV followed by type-specific Western blotting for HTLV. Reference to previous reports suggested that the rate of HIV infection in IVDAs has decreased with no HTLV-I or HTLV-II in Thailand when compared with that of the HIV infection in 1992.

Adolescent↗
PubMed1996

Human T-lymphotropic virus type II in Japan.

Serum specimens were assayed for human T-lymphotropic virus type II(HTLV-II) infection in 1,500 individuals known to be seropositive for HTLV-I and 30,000 blood donors in Japan. All HTLV-I-positive individuals were negative for HTLV-II. However, one of the blood donors was clearly seropositive for HTLV-II. Further, the donor was shown to be positive for HTLV-IIb. Here we report at least one case with HTLV-II in Japan and discuss the origin of the infection.

Adult↗
PubMed1996

Effects of ACE inhibition and beta-blockade on collagen remodelling in the heart of Bio 14.6 hamsters.

1. The effects of angiotensin converting enzyme (ACE) inhibition and beta-blockade on collagen in the heart and on plasma catecholamines and tissue angiotensin (Ang) I and II were examined in Bio 14.6 Syrian hamsters. Male hamsters (76-79 days old) were given low-dose enalapril (3 mg/kg per day), high-dose enalapril (30 mg/kg per day), atenolol (50 mg/kg per day) or vehicle for 65 days. Age and sex matched healthy F1b hamsters were used as controls. Collagen concentration was determined by measuring hydroxyproline content and the relative proportion of type I, III, and V collagens was obtained by non-interrupted sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE). Per cent collagen area (PCA) was measured by pixel counting in myocardial tissue by a personal computer. 2. Although heartweight (HW) and bodyweight (BW) in F1b controls were significantly higher compared with drug-treated groups and vehicles, the HW/BW ratio in cardiomyopathic Bio 14.6 hamsters tended to be high compared with F1b controls and was decreased by each drug treatment. 3. Collagen concentration, total collagen content and PCA in the heart of Bio 14.6 hamsters were significantly higher than F1b controls. Collagen concentration and total collagen content were significantly decreased in all drug-treated groups compared with vehicles. 4. The proportion of type I collagen tended to decrease while that of type III collagen tended to increase in all drug-treated groups compared with vehicles. Type V collagen in vehicle-treated group was significantly higher than in F1b controls, while it tended to decrease in all drug-treated groups compared with vehicles. 5. Plasma concentrations of catecholamines (adrenaline and noradrenaline) were decreased significantly by atenolol and high-dose enalapril, but not by low-dose enalapril. Tissue AngI remained unaltered in any of the drug-treated hamsters. Tissue AngII was decreased by the high-dose enalapril and beta-blockade, and tended to be decreased by low-dose enalapril treatment. 6. These results reveal that enalapril and atenolol produced similar beneficial effects on collagen remodelling in Bio 14.6 hamsters by decreasing the total amount of collagen, and also by changing collagen phenotypes through the inhibition of the renin-angiotensin system. Both drugs also improved myocardial morphological integrity.

Adrenergic beta-Antagonists↗
PubMed1996

Case report: intrahepatic cholangiocarcinoma with rhabdoid transformation.

Sarcomatous transformation is found in approximately 5% of patients with intrahepatic cholangiocarcinoma. According to previous reports, sarcomatous cholangiocarcinomas are composed of spindle-shaped cells and/or multinucleated giant cells. Usually, vimentin is expressed by these sarcomatoid cells. We report a case of intrahepatic cholangiocarcinoma with an element of rhabdoid cells that occurred in a 61-year-old woman admitted for back pain. Various imaging techniques demonstrated multiple liver masses. Histologically, these tumours formed in both sarcomatous and ordinary tubular adenocarcinomatous areas. The sarcomatoid areas were occupied mainly by loosely arranged, eosinophilic rhabdoid cells, which expressed both keratin and vimentin. These findings suggest that rhabdoid cells may occur in an undifferentiated stage of cholangiocarcinoma and possess a strong tendency to metastasize.

Bile Duct Neoplasms↗
PubMed1996

Novel Metabolic Transformation Pathway for Cyclic Imides in Blastobacter sp. Strain A17p-4.

The metabolic transformation pathway for cyclic imides in microorganisms was studied in Blastobacter sp. strain A17p-4. This novel pathway involves, in turn, hydrolytic ring opening of a cyclic imide to yield a monoamidated dicarboxylate, hydrolytic deamidation of the monoamidated dicarboxylate to yield a dicarboxylate, and dicarboxylate transformation similar to that in the tricarboxylic acid cycle. The initial step is catalyzed by a novel enzyme, imidase. Imidase and subsequent enzymes involved in this metabolic pathway are induced by some cyclic imides, such as succinimide and glutarimide. Induced cells metabolize various cyclic imides.

Journal Article↗
PubMed1996

Mutations within the 5' nontranslated RNA of cell culture-adapted hepatitis A virus which enhance cap-independent translation in cultured African green monkey kidney cells.

Mutations in the 5' nontranslated RNA (5'NTR) of an attenuated, cell culture-adapted hepatitis A virus (HAV), HM175/P16, enhance growth in cultured African green monkey kidney (BS-C-1) cells but not in fetal rhesus monkey kidney (FRhK-4) cells (S. P. Day, P. Murphy, E. A. Brown, and S. M. Lemon, J. Virol. 66: 6533-6540, 1992). To determine whether these mutations enhance cap-independent translation directed by the HAV internal ribosomal entry site (IRES), we compared the translational activities of the 5'NTRs of wild-type and HM175/P16 viruses in two stably transformed cell lines (BT7-H and FRhK-T7) which constitutively express cytoplasmic bacteriophage T7 RNA polymerase and which are derived from BS-C-1 and FRhK-4 cells, respectively. Translational activity was assessed by monitoring expression of a reporter protein, chloramphenicol acetyltransferase (CAT), following transfection with plasmid DNAs containing bicistronic T7 transcriptional units of the form luciferase-5'NTR-CAT. In both cell types, transcripts containing the 5'NTR of HM175/P16 expressed CAT at levels that were 50- to 100-fold lower than transcripts containing the IRES elements of Sabin type 1 poliovirus or encephalomyocarditis virus, confirming the low activity of the HAV IRES. However, in BT7-H cells, transcripts containing the 5'NTR of wild-type virus. This translational enhancement was due to additive effects of a UU deletion at nucleotides 203 and 204 and a U-to-G substitution at nucleotide 687 of HM175/P16. These mutations did not enhance translation in FRhK-T7 or Huh-T7 cells (a T7 polymerase-expressing cell line derived from human hepatoblastoma cells) or in vitro in rabbit reticulocyte lysates. These results demonstrate that mutations in the 5'NTR of a cell culture-adapted HAV enhance viral replication by facilitating cap-independent translation in a cell-type-specific fashion and support the concept that picornaviral host range is determined in part by differences in cellular translation initiation factors.

Animals↗
PubMed1996

Matrix metalloproteinase-7 expression in gastric carcinoma.

BACKGROUND/AIMS: Matrix metalloproteinase-7 (MMP-7) belongs to the same family as matrix degrading metalloproteinase (MMPs) that may play an important part in cancer cell invasion and metastasis. This study reports on the MMP-7 mRNA expression level both in human gastric carcinomas and the normal gastric mucosa. METHODS: From fresh specimens of 47 surgical pairs of primary gastric carcinomas and corresponding normal tissue specimens, cDNA was obtained by reverse transcription (RT) and thereafter MMP-7 mRNAs were detected by means of a polymerase chain reaction. The tumour/normal (T/N) ratio of MMP-7 expression was calculated after correcting for glyceraldehyde-3-phosphate dehydrogenase as an internal control. RESULTS: The expression corrected levels of MMP-7 mRNA of the tumour was greater than that of the normal mucosa in 41 of 47 cases (87%). The 13 cases whose T/N ratio was more than 2.1 showed a deeper invasion of the gastric wall, and more frequent lymphatic or vascular permeations than the 34 cases whose T/N ratio was less than 2.0. An immunohistochemical study showed that MMP-7 was predominantly expressed in the cancer cells, weakly expressed in normal epithelial cells, and not expressed in the surrounding stromal cells. CONCLUSIONS: These findings suggest that the overexpression of MMP-7 may thus play an important part in tumour invasion in gastric carcinomas while, in addition, MMP-7 may also prove to be a useful marker for determining the biological aggressiveness of gastric carcinoma.

Aged↗
PubMed1996

Increased activity of plasma cholesteryl ester transfer protein in children with end-stage renal disease receiving continuous ambulatory peritoneal dialysis.

The activity of cholesteryl ester transfer protein (CETP) was assayed in sera of children and adolescents on continuous ambulatory peritoneal dialysis (CAPD) by coincubating lipoprotein-deficient samples with exogenous donor and acceptor lipoproteins. Serum levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B and apolipoprotein B/apolipoprotein A1 ratio were increased, while the high-density lipoprotein cholesterol level was decreased. The CETP activity in children on CAPD exceeded that in either adults or control children, and was correlated with low-density lipoprotein cholesterol, apolipoprotein B, and total cholesterol/high-density lipoprotein cholesterol, low-density lipoprotein cholesterol/high-density lipoprotein cholesterol, and apolipoprotein B/apolipoprotein A1 ratios. The CETP activity in CAPD patients may be due to increased synthesis in response to a protein loss in the dialysis fluid and may exacerbate atherosclerosis.

Adolescent↗
PubMed1996

Results of surgery for paralytic exotropia due to oculomotor palsy.

In 138 cases of paralytic exotropia due to oculomotor palsy, transposition of the superior oblique muscle and resection of the medial rectus muscle were carried out. Surgery was performed with or without recession of the lateral rectus muscle. The long-term prognosis for 4 years or more was observed in 35 cases. We found that the same results could be obtained by selecting transposition of the superior oblique muscle in cases of complete palsy and resection of the medical rectus muscle in cases of incomplete palsy. There was no benefit in combining resection of the medial rectus muscle when performing the transposition of the superior oblique muscle. Regardless of which method was used, a combination with recession of the lateral rectus muscle greatly improved the effectiveness of the procedure.

Adolescent↗