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Biomedical subjects

M Ochiai

Publications and source records attributed to M Ochiai.

At least 109 records · Page 6Linked to original sources
PubMed1996

ST reelevation at reperfusion is associated with the occurrence of late potentials in patients with acute anterior infarction.

The relationship between ST reelevation at reperfusion and the occurrence of late potentials (LPS) in 35 patients with a first anterior infarction who had single vessel disease was investigated. All patients underwent a successful primary angioplasty and had a patent infarct related artery confirmed angiographically 4 weeks later. Patients were classified into groups based on changes in the ST level at reperfusion: patients with ST reelevation (group A, n = 22) and patients without ST reelevation (group B, n = 13). Signal-averaged ECG was performed 4 weeks after primary angioplasty to detect LPS. Cineventriculography was performed to measure left ventricular ejection fraction (LVEF) and evaluate regional wall motion of the infarct area (SD/chords). LPS were present in eight of the 22 group A patients (36%) and in none of the 13 group B patients (P < 0.05). Left ventricular function was impaired in patients in group A compared with patients in group B (LVEF: 5 1 +/- 12 vs 63 +/- 10, P < 0.01; SD/chords: -2.7 +/- 0.9 vs -1.9 +/- 1.1, P < 0.05). These data suggest that ST reelevation and myocardial damage at reperfusion are associated with the occurrence of LPS in patients with successfully recanalized infarct related arteries after acute anterior infarction.

Action Potentials↗
PubMed1996

Angiographic and coronary risk factor analyses of Japanese patients with ischemic heart disease before age 40--a multicenter cooperative study.

Coronary angiographic and risk factor (RF) characteristics were analyzed in 133 Japanese patients with ischemic heart disease (IHD) who were less than 40 years old and who had undergone coronary angiography (CAG) during the past 10 years at six university hospitals in the Tokyo area. We compared the coronary angiographic characteristics of the subject group with those of 216 controls with coronary sclerosis detected by CAG who were more than 40 years old (older control group) and the RF characteristics with those of 133 sex- and age-matched volunteers (younger control group). Sixty seven percent of the subjects (89 cases) were diagnosed as having myocardial infarction (MI) and 33% (44 cases) had angina pectoris (AP). Coronary artery disorders in this group consisted of 103 (77%) cases of coronary sclerosis, 20 (15%) cases of coronary spasm and 10 (8%) cases of miscellaneous diseases, eg, possible vasculitis with connective tissue disease, congenital anomalies, etc. The incidences of significant (> or = 75%) sclerotic narrowing in 0 vessels (31%) and 1 vessel (49%) in the subject group were significantly (p < 0.01) higher than those in the older control group, while the incidence of multivessel disease was significantly (p < 0.05) less in the subject group than in the older control group. The incidences of the following coronary risk factors were significantly (p < 0.05) higher in the subjects than in the younger controls: smoking (83% vs 35%), hypercholesteremia (44% vs 10%), obesity (31% vs 9%), hypertension (29% vs 3%), familial IHD (28% vs 7%) and diabetes mellitus (19% vs 2%). Thus, zero- or single-vessel disease predominated in the younger subject group and the prevalence of coronary risk factors was significantly higher in the subject.

Adult↗
PubMed1996

[Symptoms, diagnosis and treatment of pancreaticobiliary maljunction associated with congenital cystic dilatation of bile duct].

The concept of congenital biliary dilatation (CBD) was established by Alonso-Lej whose classification has been widely accepted and become a standard. Todani, Komi and several investigators then added additional subclassifications and/or made a proposal of new classification. The trias, abdominal pain, abdominal mass and jaundice, had been characteristically found in these cases, but recently asymptomatic cases are often found. Many reports have shown that the cases with cystic dilation of the biliary duct frequently associated with biliary carcinoma and pancreaticobiliary maljunction (PBM), an anomalous union of pancreatic duct with biliary tree since the Rabbit's first report. Whereas extracorporeal ultrasound and CT scan are minimally invasive diagnostic procedures for these cases, a direct cholangiography, ERCP and PTC are the diagnostic procedures that make a definite diagnosis for the appropriate treatment. Recently, endoscopic ultrasound (EUS), helical CT and magnetic resonance cholangiopan-creatography (MRCP) have drawn an attention since these methods are less invasive than those ever being used. In particular, MRCP will be suitable for the screening of preoperative examination. Whereas cystoduodenostomy used to be performed in the past for these cases, the resection of dilatted bule duct along with the diversion of bile from pancreatic juice should be performed to prevent biliary carcinoma. Cholecystectomy along with the resection of bile duct and the biliary diversion from pancreatic juice should also be performed for cases of PBM without CBD because mutagenicity of bile mixed with pancreatic juice and K-ras point mutation in noncancerous bile duct epithelium in cases of PBM without CBD were demonstrated.

Bile Ducts↗
PubMed1995

Molecular cloning of insect pro-phenol oxidase: a copper-containing protein homologous to arthropod hemocyanin.

Pro-phenol oxidase [pro-PO; zymogen of phenol oxidase (monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1)] is present in the hemolymph plasma of the silkworm Bombyx mori. Pro-PO is a heterodimeric protein synthesized by hemocytes. A specific serine proteinase activates both subunits through a limited proteolysis. The amino acid sequences of both subunits were deduced from their respective cDNAs; amino acid sequence homology between the subunits was 51%. The deduced amino acid sequences revealed domains highly homologous to the copper-binding site sequences (copper-binding sites A and B) of arthropod hemocyanins. The overall sequence homology between silkworm pro-PO and arthropod hemocyanins ranged from 29 to 39%. Phenol oxidases from prokaryotes, fungi, and vertebrates have sequences homologous to only the copper-binding site B of arthropod hemocyanins. Thus, silkworm pro-PO DNA described here appears distinctive and more closely related to arthropod hemocyanins. The pro-PO-activating serine proteinase was shown to hydrolyze peptide bonds at the carboxyl side of arginine in the sequence-Asn-49-Arg-50-Phe-51-Gly-52- of both subunits. Amino groups of N termini of both subunits were indicated to be N-acetylated. The cDNAs of both pro-PO subunits lacked signal peptide sequences. This result supports our contention that mature pro-PO accumulates in the cytoplasm of hemocytes and is released by cell rupture, as for arthropod hemocyanins.

Amino Acid Sequence↗
PubMed1995

A serine protease zymogen in insect plasma. Purification and activation by microbial cell wall components.

A protease zymogen present in the plasma fraction of the hemolymph of silkworm, Bombyx mori, was purified to homogeneity as judged by SDS/PAGE and IEF/PAGE. An activating system for the zymogen was also isolated from the plasma fraction and was shown to be triggered by zymosan (yeast cell wall polysaccharide containing beta-1,3-glucan) or peptidoglycan. Using this system, the purified zymogen was activated and the active enzyme was purified to homogeneity. The physiological function of the zymogen or its active form is not yet known, but the active form was shown to have narrower substrate specificity than trypsin. Among 33 peptide derivatives examined, Boc-Gln-Arg-Arg-NH-Mec and Boc-Val-Pro-Arg-NH-Mec (Boc = tert-butoxycarbonyl, NH-Mec = 4-methylcoumaryl-7-amide) were the best and the second best substrates, respectively. The purified zymogen was determined to be a 39-kDa protein consisting of a single polypeptide. The active form of the zymogen was labeled with [3H]diisopropylfluorophosphate and was completely inactivated by (p-amidinophenyl)methanesulfonyl fluoride. The molecular mass of the [3H]-labeled enzyme was determined to be 38 kDa in SDS/PAGE under reducing conditions. These results indicate that the 39-kDa protein purified in the present study is a zymogen of a serine-type protease and that the activation of the zymogen occurs by limited proteolysis.

Amino Acid Sequence↗
PubMed1995

Myocardial damage after successful thrombolysis is associated with the duration of ST re-elevation at reperfusion.

The purpose of this study was to investigate the significance of ST re-elevation at reperfusion using strict criteria for patient inclusion and exclusion. Twenty-nine patients who had a first anterior infarction with single-vessel disease, successful recanalization by intracoronary thrombolysis (ICT) with urokinase, and an angiographically confirmed patent infarct-related artery after 4 weeks, were divided into three groups according to the deviation of the ST segment at reperfusion: Group A, 10 patients with sustained ST re-elevation; Group B, 10 patients with transient ST re-elevation; and Group C, 9 patients with ST reduction. Left ventricular (LV) function was evaluated from cineventriculograms performed in the 30 degrees right anterior projection 4 weeks after ICT. LV ejection fraction and regional wall motion of the infarct area, evaluated by the centerline method (SD/chords), were significantly lower in Group A (44 +/- 10%, -3.2 +/- 0.4) than in Group B (61 +/- 9%, -1.9 +/- 0.7) and Group C (60 +/- 5%, -2.0 +/- 0.4) (p < 0.01). Peak creatine kinase (CK) activity was significantly higher in Group A (5848 +/- 2112 IU) than in Group B (2485 +/- 1254 IU) and Group C (1889 +/- 1525 IU) (p < 0.05). These data suggest that a sustained ST re-elevation at reperfusion was strongly associated with marked LV dysfunction and higher peak CK activity. It was concluded that sustained, not transient, ST re-elevation associated with successful reperfusion indicates extensive myocardial damage.

Aged↗
PubMed1995

In vitro effects of ACTH on interrenal corticosteroidogenesis during early larval development in rainbow trout.

Interrenal tissue from embryonic and larval rainbow trout (Oncorhynchus mykiss) was cultured in vitro and exposed to various doses of adrenocorticotropin (ACTH) to document the ontogeny of interrenal responsiveness to tropic stimulation. Resting and acute stress-induced changes in whole-body cortisol levels in vivo were also measured to determine if the corticosteroid stress response first develops with the onset of interrenal responsiveness to ACTH. No evidence was found that the hypothalamic-pituitary-interrenal (HPI) axis of rainbow trout is transiently activated prior to hatching. In vivo, a corticosteroid stress response was first observed 2 weeks after hatching, and stress-induced cortisol levels (at 1 hr poststress) were significantly higher 3 weeks after hatching than they were at 2 or 4 weeks after hatching. In contrast, cultured interrenal tissue produced significant levels of cortisol in response to ACTH at the time of hatching, and in vitro cortisol production by the interrenal increased significantly between 3 and 4 weeks after hatching. Interrenal sensitivity to ACTH did not change appreciably with development. We conclude that (1) the final maturation of the corticosteroid stress response in rainbow trout occurs at the level of the brain and/or sensory inputs and not at the level of the interrenal cell; (2) negative feedback mechanisms within the HPI axis develop 3 to 4 weeks after hatching; and (3) the period between 3 and 4 weeks after hatching may be homologous to the stress hyporesponsive period after birth in mammals and thus could be a stage when environmental influences can permanently alter the development of the corticosteroid stress response in rainbow trout.

Adrenocorticotropic Hormone↗
PubMed1995

Intrahepatic sarcomatous cholangiocarcinoma.

A 77-year-old man, diagnosed with a liver tumor, was referred to our hospital. Abdominal ultrasonography demonstrated a low echoic mass in the liver S2 region, and abdominal CT confirmed the presence of a round low-density mass 7 cm in diameter. Enhanced angio-computed tomography (CT) showed a ring-like form with a pale periphery. In the delayed phase of angio-CT, the inside of the mass was enhanced, showing septal stricture. Abdominal magnetic resonance imaging (MRI) revealed a heterogenous low intensity area in T1-weighted images, with a clear high intensity border becoming apparent in T2-weighted images. Stretching of the hepatic artery was evident on the arterial phase of angiography, while an avascular area was apparent in the lateral segment of the liver in the portal phase. Lateral segmentectomy was performed. The size of the tumor was 6 x 6 x 5 cm. On macroscopic cross section, it was white and clearly demarcated from the surrounding tissue. Microscopic observation of H&E-stained specimens did not show any glandular formation. The tumor consisted of an irregular fascicular arrangement of spindle-shaped and round cells with poor intercellular adhesion. While there was no region containing differentiated epithelial components, silver impregnation staining revealed structures resembling regenerating bile ducts. The tumor cells were positive for wide-keratin, and for vimentin staining. Tumor cells were carcinoembryonic antigen (CEA)-positive and alpha-feto protein (AFP)-negative. From the above findings, the tumor was judged to have originated from epithelium rather than from mesenchymal elements. The final diagnosis was intrahepatic cholangiocarcinoma with secondary sarcomatous transformation, rather than hepatocellular carcinoma.

Aged↗
PubMed1995

Formation and removal of DNA adducts in the liver of rats chronically fed the food-borne carcinogen, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline.

Effects of chronic administration of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) at 0.4, 8 and 400 ppm in the diet on DNA adduct formation and removal in the rat liver were examined by the 32P-postlabeling method. The 0.4 and 8 ppm doses for 40 weeks resulted in time-dependent increases in MeIQx-DNA adduct levels until 16 and 8 weeks, respectively, with constant values being maintained thereafter. In the case of a carcinogenic dose (400 ppm) of MeIQx, the adduct levels reached a maximum at week 12, and then gradually decreased. Alteration of metabolism of MeIQx during liver carcinogensis might be related to this decrease in DNA adduct levels. When MeIQx administration was stopped at week 20, 60-90% of the MeIQx-DNA adducts formed with the three doses (0.4, 8 and 400 ppm) of MeIQx were removed in a biphasic manner after return to a basal diet, with initial rapid removal followed by a slow change. No difference in the pattern of MeIQx-DNA adducts was detected on thin layer chromatography at any dose at any time point. Thus, it is suggested that there may be at least two types of damaged DNA, susceptible and resistant to removal of MeIQx-DNA adducts, after chronic administration of MeIQx.

Adenoma↗
PubMed1995

[Current occurrence and infection control of MRSA enteritis for surgical patients in Japan (first report)].

We investigated the current occurrence and the infection control of MRSA enteritis in the surgical facilities in Japan from July 1990 to June 1992. In this two years, MRSA enteritis was encountered in 831 cases in 144 of 279 facilities (51.6%) which had replied to our survey. Frequency of onset of MRSA enteritis in the surgical specialty was 95% in abdominal surgery and general surgery. Nosocomial infection controls for MRSA infection were done in 92.1% of 261 facilities who replied to our questionnaire. Preventive control in the preoperative and postoperative periods were performed in 23.8%. Various controls for MRSA enteritis were recognized and enforced in 56.7% with restriction of postoperative antibiotics, 65.5% with environmental controls, 70.5% with preventive control for the medical staff and 42.9% with the control for the expansion of nosocomial MRSA infections.

Cross Infection↗
PubMed1995

[Local spread of carcinoma of the esophagus by perineural invasion].

For clarification of the clinico-pathological features of carcinoma of the esophagus by perineural invasion (pni), 107 resected specimens were histologically examined. A correlation between pni and other findings, including clinical results, was sought. Pni was found in 31 patients (29.0%). It was found in no cases without adventitial cancerous invasion, at 26.3% in a1, 36.5% in a2 and 66.7% in a3. Pni would thus appear to be closely correlated with the depth of invasion. It also showed correlation with lymph-canal invasion but not with venous invasion or lymph node metastasis. Pni positivity was the same regardless of patient's age and sex, as well as tumor size, location and histological differentiation. In patients who had undergone preoperative radiotherapy, lymph-canal and venous invasion were noted to have markedly decreased but not pni. Curative resection was carried out in 57.9% of the pni negative patients and in 32.3% of the pni positive. Local recurrence was observed in 30.0% of pni positive and only 4.5% of negative cases. The cumulative survival rate was not significantly less in positive compared to negative patients.

Adult↗
PubMed1995

[The characteristic feature of myocardial imaging with 123I-labeled 15-(p-iodophenyl)-3R,S-methylpentadecanoic acid in hypertrophic cardiomyopathy with asymmetric septal hypertrophy].

The aim of this study was to elucidate the characteristic feature of myocardial imaging with 123I-labeled 15-(p-iodophenyl)-3R,S-methylpentadecanoic acid (BMIPP) in the patients with hypertrophic cardiomyopathy (HCM). In 26 patients with asymmetric septal hypertrophy (ASH), the imaging data were acquired for 15 minutes after the injection of 123I-BMIPP by the emission computed tomography (ECT). ECT image was divided into 17 segments to score the severity of the defect in each segment using a 5-point grading system from score 3 to score -1; score 3 = severely decreased tracer uptake, score 2 = moderately decreased tracer uptake, score 1 = mildly decreased tracer uptake, score 0 = normal and score -1 = increased tracer uptake. Reduced uptake (Defect Score > or = 2) was frequently observed in septal portion of anterior wall (65%), septal portion of posterior wall (62%) and apical wall (73%). Defect score was higher in septal portion of anterior wall (p < 0.001), septal portion of posterior wall (p < 0.01) and apical wall (p < 0.01) than in the ventricular septum. This result indicates that in hearts with ASH, 123I-BMIPP image reveals severely impaired fatty acid metabolism in these regions. With the reference of the previous report about histologic features in necropsy hearts with HCM, myocardial fatty acid metabolic disorder shown by reduced 123I-BMIPP uptake is closely related to the histological abnormalities in hearts with HCM.

Adult↗
PubMed1994

Dietary carcinogens and mammary carcinogenesis. Induction of rat mammary carcinomas by administration of heterocyclic amines in cooked foods.

Grilled or fried meat and fish contain various mutagenic heterocyclic amines, and structures of at least 19 compounds have already been determined. Among these, 10 have been examined for long term carcinogenicity, all proving to be positive. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), for example, preferentially induced mammary adenocarcinomas in 47% of Fischer 344 female rats when supplemented into the diet at a concentration of 400 parts per million (ppm) for 52 weeks. Moreover, 100 ppm of PhIP for 104 weeks yielded the same incidence. PhIP in the diet for 48 weeks also induced mammary cancer in Sprague-Dawley female rats with incidences of 72 and 25% at 200 ppm and 100 ppm. 2-Amino-3,4-dimethylimidazo[4,5-f]quinoline in the diet at 300 ppm also induced a 25% incidence of mammary adenocarcinomas within 40 weeks. Analysis of PhIP-induced rat mammary carcinomas for ras mutations by polymerase chain reaction-single-strand conformation polymorphism and direct sequencing revealed Ha-ras activation in 3 of 17 carcinomas; all were G-->A transitions at the second letter of codon 12 replacing glycine by glutamic acid. A p53 gene mutation was also found in 1 of 10 carcinomas examined; a G-->T transversion was detected at the third letter of codon 130, with a substitution of asparagine for lysine. PhIP is the most abundant mutagenic and carcinogenic heterocyclic amine in grilled meat, and, therefore, a role for this compound in human carcinogenesis is strongly implied.

Adenocarcinoma↗
PubMed1994

Tissue-specific mutational spectra of 2-amino-3,4-dimethylimidazo[4,5-f]quinoline in the liver and bone marrow of lacI transgenic mice.

2-Amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) is a food-borne heterocyclic amine, so clarification of its mutational spectrum is important for evaluation of its carcinogenic risk to humans. The mutational spectrum of MeIQ was investigated in the liver and bone marrow of transgenic mice carrying the lacI gene. By PCR--single-strand conformation polymorphism analysis and sequencing of the lacI gene, 81 and 61 mutations were identified in 80 and 59 mutants obtained from the liver and bone marrow respectively of three transgenic mice given food containing 300 p.p.m. MeIQ. In the liver, G-->T transversions were the most frequent, accounting for 46% of the total mutations, followed by G-->A transitions (25%). In the bone marrow, four types of mutations, G-->T transversions, G-->A transitions, complex mutations and one base deletions, each accounted for 21-23% of the total mutations. Of the total mutations, 10% were found at nucleotide 92 in the liver and at nucleotide 222 in the bone marrow. Analysis of 27 and 13 mutants from the liver and bone marrow respectively of control mice showed frequent G-->A transitions at CpG sites. These findings suggest a tissue-specific mechanism of mutagenesis.

Animals↗
PubMed1994

Identification of N-(deoxyguanosin-8-yl)-2-amino-3,4-dimethylimidazo[4,5-f]quinoline (dG-C8-MeIQ) as a major adduct formed by MeIQ with nucleotides in vitro with DNA in vivo.

The N-hydroxylamine of a carcinogenic heterocyclic amine, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), was reacted with four 2'-deoxynucleoside 3'-monophosphates after O-acetylation. 32P-Postlabeling analysis demonstrated that the adduct was formed with only the guanine nucleotide, and the structure of the compound in the obtained adduct spot was determined to be N-(deoxyguanosin-8-yl)-MeIQ 3',5'-diphosphate (3',5'-pdGp-C8-MeIQ). DNA samples from livers of mice fed MeIQ were also 32P labeled under standard conditions and additionally treated with nuclease P1 and phosphodiesterase I. A single adduct spot was obtained and the structure of the adduct was identified as 5'-pdG-C8-MeIQ. Thus, MeIQ binds at the C-8 position of guanine in vitro and in vivo, like other heterocyclic amines.

Animals↗
PubMed1994

Morphologic changes in the pancreas detected by screening ultrasonography in a mass survey, with special reference to main duct dilatation, cyst formation, and calcification.

Subclinical morphologic changes in the pancreas detected by screening ultrasonography of 130,951 subjects were analyzed in relation to their incidence and background factors. Main pancreatic duct (MPD) dilatation, cystic lesion, and calcification were found in 644 (0.49%), 271 (0.21%) and 65 (0.05%) patients, respectively. The incidence of MPD dilatation and calcification was significantly higher in men (p < 0.0001), whereas cystic lesion was significantly more frequent in women (p < 0.01). Age-dependent increase in the incidence of MPD dilatation and cystic lesion was observed in both sexes whereas that of calcification was observed only in men. Further detailed examinations for 312 randomly selected patients with these findings revealed that 97% of MPD dilatation, 95% of cystic lesion, and 86% of calcification were correctly identified by ultrasonography. Finally, 18 (5.8%) patients with chronic pancreatitis, 16 (5.1%) with neoplastic cysts, 3 with mucin-producing tumors, and 3 with carcinomas (0.96%, respectively) were detected. On the other hand, in 84.0% of MPD dilatation, 87.4% of cystic lesion, and 50.0% of calcification, we could not attribute their etiology to any known pancreatic disease. It is indicated that aging and gender are major clinically related factors of these changes.

Adult↗