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Biomedical subjects

A Oshima

Publications and source records attributed to A Oshima.

At least 37 records · Page 2Linked to original sources
PubMed2001

Structural analyses of the deduced amino acid sequences of a novel type heme-copper terminal oxidase, cytochrome aco3, from alkalophilic Bacillus YN-2000.

Cytochrome aco3 from a facultatively alkalophilic bacterium, Bacillus YN-2000, was found to be alkaline- and heat-tolerant. To better understand the structural features of Bacillus YN-2000 cytochrome aco3, the gene encoding this enzyme was cloned and sequenced. Nucleotide sequence analyses of the region neighboring the acoI (subunit I) gene revealed that the acoII (subunit II) and acoIII (subunit III) genes were concomitantly clustered upstream and downstream of the acoI gene, respectively, forming an operon with transcriptional polarity. The deduced amino acid sequence of subunit I was highly similar to that of cytochrome caa3 from thermophilic bacterium Bacillus PS3 in which the heme a3 could be replaced with heme o. Furthermore, a marked paucity of basic amino acid residues was found in the cytochrome c-binding subunit II, which might be a result of the adaptation to a highly alkaline external milieu.

Amino Acid Sequence↗
PubMed2000

Effect of interferon therapy on the incidence of hepatocellular carcinoma and mortality of patients with chronic hepatitis C: a retrospective cohort study of 738 patients.

The effect of interferon on the long-term clinical outcome of patients with chronic hepatitis C remains unclear. This study included 594 patients with chronic hepatitis C who received interferon-alpha therapy (Interferon group) and 144 patients with chronic hepatitis C who did not receive interferon (Control group). The patients in the Interferon group were classified into the following three groups based on the response of the serum aminotransaminase level of the patient during and after completion of the therapy protocol: sustained responders (n = 175), transient responders (n = 165), and non-responders (n = 254). The age, sex, serum aminotransaminase level, platelet count, histological staging, hepatitis C virus (HCV) subtype, and HCV concentration at baseline were adjusted with the Cox proportional hazards model. The length of follow-up for assessment of the risk for developing hepatocellular carcinoma (HCC) was 57.2 +/- 13.9 months in the Interferon group and 67.7 +/- 28.7 months in the Control group. Multivariate analysis showed that interferon therapy decreased the risk for developing HCC by 48% compared with that in the Control group (P = 0.064). The older the age, being male, having a low platelet count, and higher histological stage were independent factors associated with the development of HCC. The hazard rate ratio for development of HCC in the sustained responders, transient responders, and non-responders was 0.16 (95% confidence interval [CI]: 0.04-0.62), 0.27 (95% CI: 0. 09-0.79), and 0.74 (95% CI: 0.37-1.48), respectively. During follow-up, 18 patients in the Interferon group died (10 from liver-related diseases) and 17 patients in the Control group died (10 from liver-related diseases). No sustained responder or transient responder in the Interferon group died of liver-related disease. The cumulative survival rates of the Interferon and Control groups were nearly identical during the first 5 years following diagnosis. Thereafter, the cumulative survival rate of the Control group declined, resulting in an 8-year survival rate in the Interferon and Control groups of 97% and 81%, respectively (P = 0. 061). Similar trends were seen in the survival analysis of those who had died of liver disease: the 8-year survival rates of the Interferon and Control groups were 98% and 88%, respectively (P = 0. 32). Our study demonstrated that interferon therapy significantly lowered the incidence of HCC among patients with chronic hepatitis C who showed sustained normalization and among patients who showed transient normalization of the serum aminotransferase level after completion of interferon therapy. The survival analyses and determination of cause of death suggested that interferon therapy improves the long-term survival of chronic hepatitis C patients who respond to this therapy, possibly by decreasing mortality from liver-related diseases.

Antiviral Agents↗
PubMed2000

Final results of the Can Routine Ultrasound Influence Stent Expansion (CRUISE) study.

BACKGROUND: Intravascular ultrasound (IVUS) can assess stent geometry more accurately than angiography. Several studies have demonstrated that the degree of stent expansion as measured by IVUS directly correlated to clinical outcome. However, it is unclear if routine ultrasound guidance of stent implantation improves clinical outcome as compared with angiographic guidance alone. METHODS AND RESULTS: The CRUISE (Can Routine Ultrasound Influence Stent Expansion) study, a multicenter study IVUS substudy of the Stent Anti-thrombotic Regimen Study, was designed to assess the impact of IVUS on stent deployment in the high-pressure era. Nine centers were prospectively assigned to stent deployment with the use of ultrasound guidance and 7 centers to angiographic guidance alone with documentary (blinded) IVUS at the conclusion of the procedure. A total of 525 patients were enrolled with completed quantitative coronary angiography, quantitative coronary ultrasound, and clinical events adjudicated at 9 months for 499 patients. The IVUS-guided group had a larger minimal lumen diameter (2.9+/-0.4 versus 2.7+/-0. 5 mm, P<0.001) by quantitative coronary angiography and a larger minimal stent area (7.78+/-1.72 versus 7.06+/-2.13 mm(2), P<0.001) by quantitative coronary ultrasound. Target vessel revascularization, defined as clinically driven repeat interventional or surgical therapy of the index vessel at 9 month-follow-up, occurred significantly less frequently in the IVUS-guided group (8.5% versus 15.3%, P<0.05; relative reduction of 44%). CONCLUSIONS: These data suggest that ultrasound guidance of stent implantation may result in more effective stent expansion compared with angiographic guidance alone.

Aspirin↗
PubMed2000

Tissue characterization of atherosclerotic plaques by intravascular ultrasound radiofrequency signal analysis: an in vitro study of human coronary arteries.

BACKGROUND: Conventional gray-scale images of intravascular ultrasound (IVUS) cannot accurately differentiate histologic subtypes of sonolucent coronary plaques with or without a lipid core. METHODS: We analyzed radiofrequency signals obtained in vitro from 24 regions of interest (ROI) of noncalcified (sonolucent) plaques in 10 atherosclerotic coronary artery specimens pressure-fixed by formalin. Radiofrequency signals were sampled with a 30-MHz IVUS catheter and digitized at 500 MHz in 8-bit resolution. The ROIs were histologically categorized into 12 plaques with a lipid core and 12 plaques without it. Integrated backscatter and statistical parameters of the radiofrequency envelope (mean/SD ratio [MSR], skewness, and kurtosis) within the ROI were calculated offline, and their ability to detect a lipid core was compared with visual analysis of the IVUS video images. In the group with lipid cores, percent area of a lipid core in each ROI was measured in a digitized histologic image by a computerized planimeter. RESULTS: Sensitivity and specificity of MSR, skewness, and kurtosis for lipid core detection were substantially greater than visual video image analysis (83.3% and 91.7%, 100% and 91.7%, 100% and 91.7% vs 53.3% and 71.7%). Furthermore, the parameters of integrated backscatter, MSR, skewness, and kurtosis were significantly correlated to percent of core area (r = -0.64, -0.73, 0.78, and 0.63, respectively; P<.05). CONCLUSIONS: Compared with IVUS video images, the parameters of radiofrequency signal analysis may be used to aid in more accurate detection and quantitative evaluation of a lipid core, which is one of the major factors of a vulnerable coronary plaque.

Coronary Artery Disease↗
PubMed2000

The 11 A resolution projection map of Na+/K+-ATPase calculated by application of single particle analysis to two-dimensional crystal images.

Two-dimensional (2D) crystals of Na+/K+-ATPase were vitrified and observed with an electron cryo-microscope that allowed specimen observation at liquid helium temperature. Images showing 19 A spots on the optical diffraction patterns were digitized and processed by a crystallographic method. After optimization of parameters for the image processing, the locally averaged images revealed that each 2D crystal contained heterogeneous molecules. Single particle analysis was therefore applied to the 2D crystal images to select homogeneous molecule images, and averaging the selected images significantly improved map quality. Five major peak densities were clearly resolved in the new projection map, while two were found previously.

Animals↗
PubMed2000

Reproducibility of diagnosis and its influence on the distribution of lung cancer by histologic type in Osaka, Japan.

The histologic types of lung cancer cases diagnosed in 1979-1980 (n=799) and 1987 (n=587) were independently reviewed by two pathologists in order to investigate the reproducibility of the diagnosis of the histologic type when the WHO classification (1981) was used. The specimens from 354 surgical cases and biopsy or cytology specimens from 1032 non-surgical cases were reviewed. The inter-observer agreement was 87.9% (kappa=0.79) for surgical cases and 81.4% (kappa=0.72) for non-surgical cases. When compared to the original diagnosis, the agreement was 86.8% (kappa=0.78) for surgical and 86.4% (kappa=0.79) for non-surgical cases in 1979-1980 and the agreement was 92.8% (kappa=0.87) for surgical and 89.1% (kappa=0.83) for non-surgical cases in 1987. By histologic type, no difference in the agreement was observed except for large cell carcinoma. The distribution of histologic types after the review differed only slightly (less than 6%) from the original distribution. This suggests that in Osaka, Japan, the diagnosis based on the WHO classification (1981) had only a limited influence on the distribution of histologic types, and is not a major reason for the changing trends in lung cancer incidence by histologic type.

Diagnosis, Differential↗
PubMed2000

Effects of calcium and calcium chelators on growth and morphology of Escherichia coli L-form NC-7.

Growth of a wall-less, L-form of Escherichia coli specifically requires calcium, and in its absence, cells ceased dividing, became spherical, swelled, developed large vacuoles, and eventually lysed. The key cell division protein, FtsZ, was present in the L-form at a concentration five times less than that in the parental strain. One interpretation of these results is that the L-form possesses an enzoskeleton partly regulated by calcium.

Bacterial Proteins↗
PubMed2000

Natural history of early gastric cancer: a non-concurrent, long term, follow up study.

BACKGROUND: Controversy has arisen on the natural history of early gastric cancer (EGC). While some emphasise the effectiveness of early detection in reducing mortality from gastric cancer, others insist that EGC is a pseudo-cancer. AIMS/PATIENTS/METHODS: To elucidate the natural history of EGC, a non-concurrent, long term, follow up study was conducted in 71 patients who were diagnosed endoscopically as having EGC, which was confirmed as cancer on biopsy, but in whom surgical resection was not conducted or delayed by more than six months. RESULTS: The natural course of EGC was observed in 56 cases. Over a period of 6-137 months, 20 remained in the early stage while 36 progressed to the advanced stage. The proportion remaining in the early stage consistently decreased with time. Median duration of those who remained in the early stage was estimated as 44 months. The cumulative five year risk for progressing to the advanced stage was 63.0%. In 38 cases there was no evidence for undergoing surgical resection for gastric cancer. The cumulative five year corrected survival was estimated as 62.8% among those unresected. Hazard rate ratio for gastric cancer mortality was 0.65 (p=0.34) for screening detected versus non-screening detected. Hazard rate ratio for gastric cancer mortality was 0.51, significantly lower for patients whose operations were delayed compared with those unresected. CONCLUSIONS: Although EGC showed a relatively long natural history in general, it progressed to the advanced stage with time and led to death from gastric cancer for the most part if left untreated.

Adenocarcinoma↗
PubMed2000

Effectiveness of interferon therapy for reducing the incidence of hepatocellular carcinoma among patients with type C chronic hepatitis.

STUDY PURPOSE: To evaluate the effect of interferon treatment for reducing the incidence of hepatocellular carcinoma among patients with type C chronic hepatitis. METHODS: Retrospective cohort study was conducted on 923 patients with type C chronic hepatitis, who were identified through databases of Osaka Medical Center for Cancer and Cardiovascular Diseases. Two hundred and twenty-four of those had undergone interferon treatment, while the other 699 patients had not. Kaplan-Meier method and the proportional hazards model were used for statistical analysis. RESULTS: Five-years' cumulative incidence of hepatocellular carcinoma was 2.2% among the interferon treated patients, while 9.5% among the interferon untreated. Difference between the 2 curves of the cumulative incidence was statistically significant (p=0.0015). After adjustment for possible confounders, hazard rate ratio of hepatocellular carcinoma was 0.31 in the interferon treated group, significantly lower than that in the untreated (p=0.015). Hazard rate ratio for death from causes other than hepatocellular carcinoma and liver diseases was also lower among the interferon treated group than that among the untreated, although not significant. CONCLUSIONS: Interferon treatment is suggested to reduce the risk of hepatocellular carcinoma among patients with type C chronic hepatitis, and not to increase the risk for death from causes other than hepatocellular carcinoma and liver diseases.

Antiviral Agents↗
PubMed2000

The risk for second primaries in gastric cancer patients: adjuvant therapy and habitual smoking and drinking.

STUDY PURPOSE: To examine whether adjuvant therapy for gastric cancer increases the risk for second primaries, and whether smoking and drinking increase the risk. SUBJECTS AND METHODS: 1,631 patients who were newly diagnosed with gastric cancer and underwent curative operation at Osaka Medical Center for Cancer and Cardiovascular Diseases during 1978-92. Incidence of second primaries were examined through linkage to Osaka Cancer Registry as of the end of December 1995. Observed number of second primaries (O) was compared with the expected according to the incidence in general population (E). Proportional hazards model was used to estimate hazard rate ratio (HR) for second primaries. RESULTS: 149 second primaries were observed. Seventeen cases, detected within 2 months after diagnosis of gastric cancer, were excluded. O/E ratio was 1.13 for adjuvant chemotherapy, 0.93 for immuno-chemotherapy, and 0.78 for immunotherapy, while 1.14 for operation only (not significant). Age-, sex-, and stage-adjusted HR was 1.02 (95% C.I. 0.69-1.50) for chemotherapy, 0.80 (0.41-1.57) for immuno-chemotherapy, and 0.60 (0.08-4.34) for immunotherapy, as compared with the risk for operation only. Among males, HR for current smokers vs. never smokers was 1.82 (1.02-3.26). CONCLUSIONS: Adjuvant therapy for gastric cancer did not significantly increase the risk for second primaries, while smoking elevated it.

Adolescent↗
PubMed2000

[Dermatophytosis of the external auditory meatus].

Dermatophytosis of the external auditory meatus is believed to be a fairly rare disease. In the past three and a half years we have had seven cases of dermatophytosis in the external auditory meatus. All cases except one were associated with tinea of other lesions. Case 1: A 44-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 2: A 14-year-old boy, the son of case 1 had no tinea elsewhere on his body, including the auricle. He scratched the auditory meatus with an earpick which his father had used. Case 3: A 62-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 4: A 50-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 5: A 36-year-old man had tinea of the auricle, tinea pedis, tinea unguium and tinea cruris. Case 6: A 30-year-old woman had tinea of the auricle. Case 7: A 68-year-old man had tinea of the auricle, tinea pedis, tinea unguium and tinea manuum. Endoscopic examination (except for cases 4 and 7) revealed dry cerumen from cartilaginous to bony region of the external auditory meatus. Direct examination using KOH method of the cerumen in all cases demonstrated numerous fungal elements. Fungal cultures identified Trichophyton rubrum except for cases 3 and 6. All cases were successfully treated with oral itraconazole or terbinafine. We suggest that tinea of the external auditory meatus is frequently associated with that of the auricle.

Adolescent↗
PubMed2000

Regional cerebral blood flow in the patients with depressive disorders.

Regional Cerebral blood flow (rCBF) and metabolism in major depression have been studied intently. Those studies are expected to reveal the mechanisms of the mood disorders, and also to give us valuable informations that the specific brain regions participating mood regulation. However, the data still have been inconsistent. In the present study we measured rCBF in patients with major depression and depressive state using xenon-CT CBF method. There is a tendencies that the rCBF values of normal control is the highest, and those of major depression is the lowest in most of the regions. The rCBF values in the patients with major depression are significantly lower than those in normal control in the right anterior frontal cortex, temporal cortex, putamen and thalamus. We also measured rCBF before and 90 minutes after giving calcium antagonist nilvadipine (4 mg, p.o.) in those subject. There is a tendency that nilvadipine increased in rCBF in normal control, however, it decreased in rCBF in major depression.

Adult↗
PubMed2000

[The relationship between stages and biochemical markers of smoking. Workplace-based cross-sectional and longitudinal studies].

In order to clarify smokers' characteristics by "Stages of Change" based on Prochaska's transtheoretical model, we conducted cross-sectional and logitudinal studies with biochemical markers of smoking and smoking habits. In a workplace-based sample of 277 male smokers, we examined cross-sectionally the relationships between stages and biochemical markers of smoking which include expired carbon monoxide concentrations and urinary nicotine metabolite concentrations, and smoking habits which include the number of cigarettes smoked per day, yields of cigarettes, inhalation patterns, time to first morning cigarette, and quit attempts in the past. Additionally we examined longitudinally the relationship between stages and expired carbon monoxide concentrations, the number of cigarettes, and yields of cigarettes. In the cross-sectional study there were significant differences among stages on expired carbon monoxide concentrations (P = 0.006), urinary nicotine metabolite concentrations (P = 0.049), the number of cigarettes smoked per day (P = 0.001), and yields of cigarettes (P = 0.042) using analyses of variance. There were also significant differences among stages on time to first morning cigarette (P = 0.018) and quit attempts in the past (P < 0.001) using chi-square tests. In the longitudinal study for each level of elevation in stage during a one-year period, expired carbon monoxide concentrations decreased on an average of 2.3 ppm (P = 0.125) and the number of cigarettes smoked per day decreased on an average of 2.8 cigarettes per day (P = 0.07). However, the yields of cigarettes did not change during the one-year period.

Adult↗
PubMed1999

Feasibility of in vivo intravascular ultrasound tissue characterization in the detection of early vascular transplant rejection.

BACKGROUND: Unprocessed ultrasound radiofrequency (RF) signal analysis has been shown to distinguish different tissue structures more reliably than gray-scale interpretation of conventional ultrasound images. METHODS AND RESULTS: The objective of this study was to test the feasibility of in vivo intravascular ultrasound (IVUS) RF signal analysis in an animal model of allograft rejection. Six cynomolgus monkeys underwent transplantation of 3-cm aortic allograft segments distal to the renal arteries from immunologically mismatched donors. IVUS imaging with a 30-MHz system was performed 84 to 105 days after the operation. RF signals were acquired from cross sections of the recipient and the allograft aortas in real time with a digitizer at 500 MHz with 8-bit resolution. Sixty-five cross sections and 68 regions of interest (31 in host aorta and 37 in allograft) were analyzed in the adventitial layer with a total number of 8568 vectors processed. For each region of interest, a weighted-average attenuation was calculated on the basis of the attenuation and length for each individual vector. Histological examination was performed at every cross section imaged by IVUS. When the gray-scale images of conventional IVUS scored by an independent observer were compared, no distinction between adventitia of the native aorta and allograft was possible. Analysis of the average RF backscatter power also showed no significant difference (70.32+/-3.55 versus 70.72+/-3.38 dB). However, the average attenuation of allografts was significantly lower than that of the host aortas (2.64+/-1.38 versus 4.02+/-1.16 dB/mm, P<0.001). Histology demonstrated a marked adventitial inflammatory response in all allografts, with no inflammation observed in the host aortas. CONCLUSIONS: In vivo IVUS tissue characterization can be performed during routine imaging. In this model of transplant vasculopathy, RF attenuation measurements were more sensitive than visual or quantitative gray-scale analysis.

Animals↗
PubMed1999

Impact of cilostazol on clinical and angiographic outcome after primary stenting for acute myocardial infarction.

Cilostazol, an antiplatelet drug that also may inhibit smooth muscle proliferation, was given together with aspirin after primary stenting to treat patients with acute myocardial infarction. In a randomized controlled trials of 50 patients, clinical and angiographic outcome at 6 months was significantly improved with cilostazol, depicting a significantly smaller late loss and/or loss index.

Adult↗
PubMed1999

Risk factors for breast cancer in Japan, with special attention to anthropometric measurements and reproductive history.

BACKGROUND: Breast cancer incidence has increased rapidly in Japan recently, but there have been only a few studies on the risk factors for breast cancer in Japan. A case-control study was conducted to evaluate the roles of anthropometric and reproductive factors in the etiology of breast cancer in Osaka. METHODS: Based on information from a self-administered questionnaire at Osaka Medical Center for Cancer and Cardiovascular Diseases, body mass index, body weight and height were compared between 376 cases and 430 controls, together with other factors such as age at menarche, age at first delivery and family history of breast cancer by menopausal status. Logistic regression analysis was employed for adjusting confounding factors and estimating odds ratios with their 95% confidence interval for breast cancer. RESULTS: A body mass index of >25 was significantly associated with the risk among post-menopausal women (age-adjusted odds ratio: 1.90, 95% confidence interval: 1.10-3.24) as compared with the risk for a body mass index of < or = 20. A weight of > or =58 kg showed significantly increased risk compared with a weight of < or = 47 kg among post-menopausal women (1.83, 1.10-3.01), while height of > or = 159 cm showed a significantly elevated risk than height of < or = 149 cm among pre-menopausal women (2.51, 1.17-5.39). Age at menarche of < or = 13 years resulted in a higher risk of breast cancer among post-menopausal women, while age at first delivery of > or = 28 years was associated with the risk among pre-menopausal women. Family history of breast cancer was associated with the risk for breast cancer. CONCLUSIONS: These results were all very consistent with findings observed in western countries.

Adult↗