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Biomedical subjects

K Toyoda

Publications and source records attributed to K Toyoda.

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

The relationship between decrease in Cx32 and induction of P450 isozymes in the early phase of clofibrate hepatocarcinogenesis in the rat.

To examine the relationship between the decrease in connexin 32 (Cx32) and induction of P450 isozymes in the early phase of clofibrate hepatocarcinogenesis, a total of 20 male F344 rats were initiated with a single intraperitoneal injection of 150 mg/kg of diethylnitrosamine (DEN) or given the saline vehicle alone and starting 2 weeks later given diet containing 0.18, 0.09, and 0% clofibrate for 6 weeks. All animals were subjected to two-thirds partial hepatectomy at week 3 and killed at week 8. Absolute and relative (ratios to body weight) liver weights were significantly increased in the DEN + clofibrate groups compared with the DEN-alone group. Diffuse hepatocellular hypertrophy with granular cytoplasmic eosinophilia characterized by a marked increase in peroxisomes and smooth endoplasmic reticulum, was observed in the clofibrate treated rats. Induction of cytochrome P450 (CYP) 4A1 and 2B1/2 was noted in the DEN + clofibrate groups, this being most marked in the CYP 2B1 case. Immunohistochemically, positive immunostaining for anti-CYP 4A1 and CYP 2B1 were observed diffusely and centrilobularly, respectively. The numbers and areas of Cx32-positive spots per hepatocyte in the centrilobular areas in the treated rats were significantly decreased in an essentially dose-dependent manner, but no changes were observed in periportal areas. The numbers and areas of foci positive for glutathione S-transferase placental form (GST-P) were decreased in a dose dependent manner in the clofibrate treated groups. These results suggest that the CYP 2B1/2 induction and Cx32 decrease in centrilobular hepatocytes, similarly to those thought to be involved in the hepatic promotion mechanism of phenobarbital, may also play important roles in clofibrate actions in the liver, in addition to its causation of oxidative DNA injury.

Animals↗
PubMed1999

Induction of defense responses by synthetic glycopeptides that have a partial structure of the elicitor in the spore germination fluid of Mycosphaerella pinodes.

A high molecular weight elicitor (> 70 kDa) from spore germination fluid of a pea pathogen, Mycosphaerella pinodes, has a partial structure of beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man, which is O-glycosidically attached to serine in the protein moiety. To elucidate the minimum structure for the elicitor activity to pea plants, the effects of nine glycopeptides including beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man-O-Ser (No. 1) to [beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man]3-O-Ser3-Pro3 (No. 9) on the infection by M. pinodes, superoxide generation and ATPase activity were measured. The glycopeptides [beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man]-O-Ser2-Pro2 (No. 3) to No. 9 induced rejection reaction of pea tissue against M. pinodes. The glycopeptides No. 3 to No. 9 also induced superoxide generation on uninjured pea leaves. Moreover, the glycopeptides No. 3 to No. 9 induced in vitro the activation of cell wall-bound ATPase and superoxide generation system in the protein fraction solubilized from pea cell wall. The results indicate that the synthetic glycopeptides, No. 3 to No. 9, are available to analyze the signal transduction cascade leading to defense responses and the receptor for the elicitor.

Amino Acid Sequence↗
PubMed1999

Duodenal ulceration into the cystic artery with massive hemorrhage.

This is a case presentation of a unique cause of intestinal bleeding. A duodenal ulcer eroded into the superficial branch of the cystic artery, causing massive intestinal hemorrhage. The patient, a 76-year-old woman, presented with left upper abdominal and left back pain secondary to cystic lesions in the pancreas body and tail. Stress after operation and complication of leakage of pancreatic juice after distal pancreatectomy with splenectomy and diclofenac sodium administration may have caused a deep peptic ulcer to erode the cystic artery. We performed a transfixing ligation of the bleeding vessel, serosal suture of ulcer of the gallbladder, and simple closure of the duodenal ulcer with covering greater omentum. There were no serious complications after the operation, and the patient made an uneventful recovery.

Aged↗
PubMed1999

Near-infrared spectroscopy for dairy management: measurement of unhomogenized milk composition.

The potential of near-infrared spectroscopy to measure fat, total protein, and lactose contents of unhomogenized milk was studied for use in dairy management, as a new tool for on-line milk analysis in the process of milking. Influence of the spectral region, sample thickness, and spectral data treatment on the accuracy of determination was investigated. Transmittance spectra of 258 milk samples, collected at different stages of the milking process, were obtained with a spectrophotometer (NIRSystems 6500; FOSS-NIRSystems, Silver Spring, MD) in the wavelength range from 400 to 2500 nm with sample thicknesses of 1 mm, 4 mm, and 10 mm. The spectral region and sample thickness were found to be significant factors for milk fat and total protein determination but not the lactose determination. The best accuracy was obtained with the 1100 to 2400 nm region, 1-mm sample thickness, and the first derivative data transformation. For the spectral region from 700 to 1100 nm, close accuracy was obtained for fat with a 10-mm sample and for total protein with a 1-mm sample thickness. The sample thickness did not change significantly the accuracy of lactose determination. Different treatments of spectral data did not improve the calibrations for fat and protein. For the region from 700 to 1100 nm, where inexpensive on-line sensors could be used, the highest positive coefficients for fat were at 930, 968, 990, 1026, 1076, and 1092 nm; for lactose were at 734, 750, 786, 812, 908, 974, 982, and 1064 nm; and for total protein were at 776, 880, 902, 952, and 1034 nm.

Animals↗
PubMed1999

[Prognostic factors in a patients with renal cell carcinoma].

PURPOSE: The purpose of this study is to evaluate prognostic factors of renal cell carcinoma using univariate statistics. MATERIALS AND METHODS: Materials are 182 patients treated from 1976 to 1992. Kaplan-Meier method and generalized wilcoxon test were used for statistical analysis. RESULTS: Seventy cases were found incidentally without any symptoms. The overall 5- and 10-year survival rates by Kaplan-Meier method were 73.8% and 66.2%, respectively. In the univariate analysis, sex, chief complaints, tumor sizes, T-Stages, venous invasions and grades were statistically significant prognostic factors. The prognosis of males more than 60 years of age was significantly poor. The prognosis of patients with incidentalomas was far better than that of symptomatic patients. CONCLUSION: Sex and chief complaints were pointed out as significant prognostic factors for renal cell carcinoma.

Adult↗
PubMed1999

[Primary intestinal type adenocarcinoma of the urinary bladder: a case report].

A 43-year-old man was referred to our hospital with complaints of macroscopic hematuria, micturition pain, and pollakisuria. Cystoscopy revealed a papillary broad-based tumor of 4 cm in diameter at the posterior wall and trigone of the urinary bladder. A punch biopsy specimen was diagnosed histopathologically as adenocarcinoma mimicking colorectal cancer. Computed tomographic (CT) scan demonstrated a large tumor involving both the urinary bladder and the rectum. Total cystoprostatectomy and low anterior resection following colorectal anastomosis, double barreled colostomy, and ileal conduit urinary diversion were performed. The tumor was diagnosed histopathologically as primary intestinal type adenocarcinoma of the urinary bladder infiltrating the sigmoid colon and the small intestine. The patient died 12 months after the operation due to peritonitis carcinomatosa.

Adenocarcinoma↗
PubMed1999

[A 13-week subchronic toxicity study of chitin in F344 rats].

A subchronic toxicity study of chitin, a natural structural component of crustacean shells, was performed in F344 rats by feeding of the powdered diet containing 5%, 1.7%, 0.6%, 0.2%, and 0% concentrations of the substance. Each group consisted of 10 males and 10 females. All animals survived until the end of the experiment. There were no changes indicating obvious toxicity of chitin in the clinical signs, body weight, food intake, hematology, serum biochemistry, or histopathological findings, except a slight decrease in body weight gain in the 5% chitin-treated males. Although the mechanism is unclear, the suppression of body weight gain may be due to the slight decrease in caloric content of the food in the 5% chitin-treated animals, a change unrelated to toxicity. Thus, there was no obvious toxicity of chitin in F344 rats at concentrations up to 5% in the diet for 13 weeks.

Administration, Oral↗
PubMed1998

5-fluorouracil and low-dose recombinant interferon-alpha-2a in patients with hormone-refractory adenocarcinoma of the prostate.

BACKGROUND: The effectiveness of a chemotherapy regimen including 5-fluorouracil (5-FU) and recombinant interferon-alpha-2a (rIFN-alpha-2a) was evaluated in hormone-refractory prostate cancer patients. METHODS: Patients received a continuous intravenous infusion of 5-FU at 600 mg/m2/day for 5 days (D1-D5), followed by a bolus injection of 5-FU on D15 and D22. Patients received intramuscular injection of rIFN-alpha-2a at 3 million IU on D1, D3, D5, D15, and D22. This schedule was repeated every 4 weeks. RESULTS: Between 1993 and 1995, 23 patients with hormone refractory prostate cancer were enrolled in this study. Two of five patients with nodal disease exhibited partial responses according to the NPCP criteria. Fourteen of 17 patients with bone disease showed stable disease. Of 21 patients assessible for response, 9 patients had a decrease in the PSA level greater than 50% of baseline. Bone pain disappeared partially or completely in 8 of 14 patients with this symptom at entry. The median overall survival was 18 months. The associate toxicity was well tolerable. CONCLUSIONS: Combination chemotherapy of 5-FU and low dose rIFN-alpha-2a in patients with hormone-refractory prostate cancer proved feasible, and with acceptable toxicity.

Adenocarcinoma↗
PubMed1998

Tuberculous bursitis of the greater trochanter.

A patient with tuberculous bursitis of the greater trochanter is reported. A 37-year-old woman had experienced persistent dull hip pain and noticed diffuse swelling over the greater trochanteric region. Plain radiograph revealed unremarkable osteopenic changes in the greater trochanter and faint mineralization in the vicinity of the trochanter. Computed tomogram showed erosion of the trochanter and a large soft tissue mass. Magnetic resonance imaging demonstrated a large multicystic mass. Histology of the cyst wall, showing chronic granulomatous tissue, and a positive culture of Mycobacterium tuberculosis confirmed the diagnosis of musculoskeletal tuberculosis. Complete excision of the lesion, followed by 6 months of antituberculous chemotherapy with rifampicin and isoniazid, cured the disease. There has been no sign of recurrent disease in 30 months of follow-up. Correct diagnosis was difficult because of its rarity, but modern imaging technology, magnetic resonance imaging, in particular, was extremely useful for showing the extent of the disease. Tuberculous infection should be considered as a differential diagnosis in patients with persistent hip pain.

Adult↗
PubMed1998

Standardization and security for the EMR.

The Ministry of Health and Welfare of Japan announced 'Healthcare Information Strategy 21' in 1994. This report shows that the Healthcare Information System is the key to improving the quality and efficiency of healthcare. One of the elements for realizing the new Healthcare Information System is the Electronic Medical Record (EMR). Following the publication of this report, work began with the aim of discovering a way to recognize the EMR as formal documentation and four national projects of research and development have been started. The themes of these projects are: 'Interoperability of EMR', 'Standardization of EMR', 'Modeling of the Clinical Process' and 'Security for EMR'. The Japanese Association of the Healthcare Information Systems Industry (JAHIS) is in charge of 'Security for EMR'. There are many discussions in relation to the security for EMR. However, many of these discussions relate to information technology, while there are few discussions regarding definitions of security. Therefore, there are many different theories about security itself, which will be an obstacle to standardization. To design the security system for EMR, JAHIS has defined 'Security for EMR' as the first step. The present study was conducted with medical informatics and security specialists. It has designed 'Requirement Definitions', 'Goals of Security', 'Estimation of threats to security', 'Necessity conditions' and a 'Security Model'. This paper covers these definitions and our security design concept.

Computer Security↗
PubMed1998

Attenuation and recovery of brain stem autoregulation in spontaneously hypertensive rats.

Cerebral large arteries dilate actively around the lower limits of CBF autoregulation, mediated at least partly by nitric oxide, and maintain CBF during severe hypotension. We tested the hypothesis that this autoregulatory response of large arteries, as well as the response of arterioles, is altered in spontaneously hypertensive rats (SHR) and that the altered response reverts to normal during long-term antihypertensive treatment with cilazapril, an angiotensin-converting enzyme inhibitor. In anesthetized 6- to 7-month-old normotensive Wistar-Kyoto rats (WKY), 4- and 6- to 7-month-old SHR without antihypertensive treatment, and 6- to 7-month-old SHR treated with cilazapril for 10 weeks, local CBF to the brain stem was determined with laser-Doppler flowmetry and diameters of the basilar artery and its branches were measured through a cranial window during stepwise hemorrhagic hypotension. The lower limit of CBF autoregulation shifted upward in untreated SHR to 90 to 105 mm Hg from 30 to 45 mm Hg in WKY, and it reverted to 30 to 45 mm Hg in treated SHR. In response to severe hypotension, the basilar artery dilated by 21 +/- 6% (mean +/- SD) of the baseline internal diameter in WKY. The vasodilation was impaired in untreated SHR (10 +/- 8% in 4-mo-old SHR and 4 +/- 5% in 6- to 7-month-old SHR), and was restored to 22 +/- 10% by treatment with cilazapril (P < 0.005). Dilator responses of branch arterioles to hypotension showed similar attenuation and recovery as that of the basilar artery. The data indicate that chronic hypertension impairs the autoregulatory dilation of the basilar artery as well as branch arterioles and that antihypertensive treatment with cilazapril restores the diminished dilation toward normal.

Animals↗
PubMed1998

Auditory evoked neuromagnetic response in cerebrovascular diseases: a preliminary study.

OBJECTIVES: Magnetoencephalography (MEG) measures aspects of the function of the auditory cortex of the human brain with high spatial resolution. The objective was to determine whether MEG also accurately identifies the auditory cortex of the brain in patients with ischaemic stroke. METHODS: The auditory evoked magnetic field (AEF) was examined after stimuli of 1 kHz tone bursts in 24 stroke patients without apparent infarcts in the auditory cortex, and compared the topography of sources of 50 ms (P50m) and 100 ms latency deflections (N100m), the most prominent components of middle and long latency AEFs, with that of 12 normal subjects. Cerebral haemodynamics in and around the auditory cortex were evaluated using PET. RESULTS: In nine of 24 stroke patients, the accurate magnetic sources of P50m or N100m were not identified. The distribution of P50m sources varied more widely than N100m. Eight of these nine patients had severe stenotic lesions in the carotid or middle cerebral arterial trunks. Patients with abnormal P50m responses had decreased supratemporal and hemispheric blood flow compared with patients with normal P50m responses. CONCLUSIONS: These findings suggest that large vessel disease with disturbed cerebral haemodynamics in and near the auditory cortex tend to affect AEFs, especially the middle latency components. This is the first combined study of MEG and PET to show a significant correlation between AEF responses in stroke patients and their PET indices.

Adult↗
PubMed1998

Improvement of relaxation in an atherosclerotic artery by gene transfer of endothelial nitric oxide synthase.

Gene transfer with replication-deficient adenovirus is a useful tool to study vascular biology. We have reported that overexpression of endothelial nitric oxide (NO) in carotid arteries from normal rabbits augments vasorelaxation mediated by NO. In this study, we tested the hypothesis that adenovirus-mediated gene transfer of endothelial nitric oxide synthase (eNOS) improves impaired relaxation of atherosclerotic vessels. We used 2 replication-deficient adenoviruses: AdeNOS, which carries cDNA for eNOS, and Adbetagal, which expresses beta-galactosidase. Common carotid arteries from 10 New Zealand White (NZW; plasma cholesterol, 79+/-13 mg/dL) and 10 Watanabe heritable hyperlipidemic (WHHL; plasma cholesterol, 452+/-39 mg/dL) rabbits were incubated in organ culture with AdeNOS, Adbetagal, or vehicle alone. Carotid arteries from WHHL rabbits had mild to moderate atherosclerotic lesions. Histochemical staining for beta-galactosidase and immunohistochemistry for eNOS indicated transgene expression in the endothelium and adventitia in both NZW and WHHL rabbits. Expression of eNOS determined with Western blot analysis after incubation with AdeNOS tended to be higher in vessels from WHHL rabbits than NZW rabbits. Effects of transgene expression on vascular function were examined by recording isometric tension 1 day after transduction. After precontraction with phenylephrine, acetylcholine produced significantly less relaxation in vessels from WHHL rabbits than in vessels from NZW rabbits. Relaxation in response to acetylcholine was greater in carotid arteries from both NZW and WHHL rabbits that were transfected with AdeNOS than in vessels treated with vehicle or Adbetagal. Vasorelaxation in response to acetylcholine was inhibited by Nomega-nitro-L-arginine. Responses to sodium nitroprusside were similar after treatment with vehicle alone, Adbetagal, or AdeNOS in both groups of rabbits. Thus, overexpression of eNOS with an adenoviral vector improves impaired NO-mediated relaxation in atherosclerotic arteries.

Adenoviridae↗
PubMed1998

Cationic polymer and lipids enhance adenovirus-mediated gene transfer to rabbit carotid artery.

BACKGROUND AND PURPOSE: Improvement of efficiency of gene transfer to endothelium could be useful for several applications. We tested the hypothesis that cationic nonviral molecules augment adenovirus-mediated gene transfer to blood vessels, perhaps by alteration of the surface charge of adenovirus and facilitation of binding to endothelium. METHODS: Carotid arteries from rabbits were incubated in vitro for 0.5 to 2 hours with an adenoviral vector alone or noncovalent complexes of adenovirus with poly-L-lysine (a cationic polymer) or lipofectin (a cationic lipid). Binding of adenovirus to the vessels was evaluated immediately after incubation with virus, and assay of transgene (ss-galactosidase) activity and histochemistry were performed 24 hours after gene transfer. To determine whether cationic molecules can be used to augment alteration of vascular function by adenovirus-mediated gene transfer, we also examined effects on gene transfer of endothelial nitric oxide synthase. RESULTS: Assay of ss-galactosidase activity indicated that both cationic molecules increased transgene expression in vessels by approximately 5- to 6-fold. In contrast, when endothelium was removed from the vessels after gene transfer, poly-L-lysine and lipofectin did not significantly increase transgene activity. Histochemistry for ss-galactosidase also suggested that the adenovirus-cationic molecule complexes augmented transgene expression mainly in the endothelium. In addition, we found that complexing adenovirus with cationic molecules increased binding of adenovirus to the vessels. After gene transfer with recombinant adenovirus containing endothelial nitric oxide synthase, calcium ionophore (A23187) produced greater relaxation of vessels treated with adenovirus complexed with poly-L-lysine or lipofectin than those treated with adenovirus alone. CONCLUSIONS: Cationic molecules improve the efficiency of adenovirus-mediated gene transfer to blood vessels.

Adenoviridae↗
PubMed1998

NK-104, a newly developed HMG-CoA reductase inhibitor, suppresses neointimal thickening by inhibiting smooth muscle cell growth and fibronectin production in balloon-injured rabbit carotid artery.

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been reported to suppress smooth muscle cell growth and arterial neointimal thickening. In this study, to elucidate the potency and mechanisms of NK-104 ((+)-monocalcium bis[(3R,5S,6E)-7-[2-cyclopropyl-4-(4-fluorophenyl)-3-quinolyl]-3,5-dihydroxy-6-heptenoate], CAS 147526-32-7) in neointimal thickening, the effect of NK-104 on the neointimal thickening, Br-dU-labeled cell number and extracellular matrix immunohistochemistry were examined in balloon-injured rabbit carotid artery. NK-104 suppressed the neointimal thickening dose-dependently, and the suppression was 69.5% at 1.0 mg/kg. NK-104 suppressed the intimal total and Br-dU-labeled cell number. Fibronectin and type I collagen were observed in 81% and 38% of the total intimal area in the control arteries, respectively, and the areas occupied by fibronectin and type I collagen were significantly decreased by 1.0 mg/kg NK-104 to 39% and 22%, respectively. The decrease in fibronectin per cell was more potently demonstrated. Aortic total and activated TGF-beta contents that were markedly increased in the injured artery were increased further by NK-104. NK-104 concentration-dependently suppressed fibronectin content of the basement lesion in rabbit primary cultured smooth muscle cells. These findings suggest that NK-104 suppresses balloon-injury-induced neointimal thickening through inhibition of intimal smooth muscle cell growth and extracellular matrix accumulation.

Animals↗
PubMed1998

[A case of prostatic tuberculosis: usefulness of transrectal ultrasound in diagnosis].

A case of prostatic tuberculosis is reported. A 61-year-old male visited our clinic complaining of urinary retention. On digital rectal examination, the prostate was found to be enlarged, hard, and uneven. Transrectal ultrasound revealed a large hypoechoic lesion in the posterior aspect of the prostate. Transrectal ultrasound guided systematic biopsies of the prostate were performed. The specimens obtained from the hypoechoic lesion, were diagnosed histopathologically as prostatitis with epithelioid granuloma, Langhans' type giant cells, and caseous necrosis. Mycobacterium tuberculosis was detected in the physiological saline solution injected into the urethra after prostatic massage. The patient was diagnosed as having prostatic tuberculosis and underwent antituberculotic therapy with INH and RFP. Transrectal ultrasound seemed to be useful in detecting histopathological changes associated with tuberculosis in the prostate.

Anemia, Refractory, with Excess of Blasts↗
PubMed1998

[Determination of pyrazinamide susceptibility for Mycobacterium tuberculosis by use of Middlebrook culture media and comparison with results of pyrazinamidase test].

We developed a new test method to determine pyrazinamide (PZA) susceptibility for Mycobacterium tuberculosis in an acidified Middlebrook 7H9 broth (pH6.0), and evaluated in comparison with the agar proportion method of the National Committee for Clinical Laboratory Standards (NCCLS) M24-T and with pyrazinamidase assay. The test method is based on a culture in 4 ml of the modified Middlebrook 7H9 broth containing 100, 200 and 400 micrograms PZA/ml, respectively. First, the cell suspension was adjusted to a McFarland #1 turbidity, and then diluted 1:10. After mixing, 0.1 ml of the diluted cell suspension was inoculated and incubated at 36 +/- 1 degrees C in an ambient air. After 7 day-incubation, the test broth was read in comparison with the growth control. When a significant growth at 100 micrograms PZA/ml or an attenuated growth at 100 micrograms PZA/ml but a significant growth at 400 micrograms PZA/ml were observed, the test isolate was interpreted as being PZA-resistant. When PZA-susceptible and PZA-resistant ATCC reference strains were repeatedly tested, the results obtained were highly precise and accurate. A total of 65 clinical isolates were tested, the results indicating 95.4% of agreements with the agar proportion method and 90.8% with pyrazinamidase assay. There found six discrepant results of 13 resistant isolates; three were susceptible by the agar proportion and all the six were positive by pyrazinamidase assay. Accordingly, we can conclude that, in place of radiometric Bactec System, our newly developed test method is an accurate, practical, rapid and nonradiometric alternative to determine PZA susceptibility for M. tuberculosis in clinical mycobacteriology laboratories.

Amidohydrolases↗