Biomedical subjects

S Oshima

Publications and source records attributed to S Oshima.

At least 73 records · Page 4Linked to original sources

PubMed1999

Altered expression of CD45 isoforms in differentiation of acute myeloid leukemia.

Specific expression of different CD45 isoforms can be seen in various stages of differentiation of normal nucleated hematopoietic cells. Association of membrane expression of CD45 isoforms and differential levels of leukemia cells was studied in 91 cases with de novo acute myeloid leukemia (AML). Membrane expression of CD45RA and CD45RO was analyzed by flow cytometry and their expression patterns were compared with AML subtypes classified according to the French-American-British (FAB) classification. CD45RA was essentially expressed in all of the FAB myelocytic subtypes (M0-M3). Its expression in percentage was lower in the most differentiated subtype of AML (M3) when compared with other myelocytic subtypes. CD45RO expression was rarely observed in cases with myelocytic subtypes (1/56 cases of M0, M1, M2, and M3) except for the minimally differentiated myelocytic subtype (M0) or those with potential for differentiation to T-cell lineage where three of 12 cases showed CD45RO expression. When leukemia cells of an M3 case were differentiated to mature granulocytes by treatment of all-trans-retinoic acid, they showed increasing expression of CD45RO. In subtypes with a monocytic component (M4 and M5), both of CD45RA and CD45RO expression were observed and mutually exclusive. When 10 cases of M5 were subdivided by the differential level into undifferentiated (M5a) and differentiated monocytic leukemia (M5b), expression of CD45RA and CD45RO was strictly restricted to cases with M5a and M5b, respectively. These results suggest that CD45 isoform expression in AML characterizes differential levels both in myelocytic and monocytic lineages and specifically disturbed in each subtype. The assessment of CD45 isoform expression appears to provide an insight on biological characteristics and a useful supplementary test for differential diagnosis of AML subtypes.

Acute Disease↗

PubMed1999

Changes in number of serotonin-containing cells and serotonin levels in the intestinal mucosa of rats with colitis induced by dextran sodium sulfate.

The role of serotonin in the pathogenesis of inflammatory bowel disease has not been fully studied. We examined the changes in the serotonin level and the density of serotonin-containing enterochromaffin (EC) and mast cells in the intestinal mucosa of dextran sodium sulfate (DSS)-induced colitis in rats. Rats were treated with 1.5% DSS for 1 month. Serotonin levels were biochemically measured and the density of epithelial EC cells and mucosal mast cells was quantified by serotonin immunohistochemistry. DSS caused malnutrition due to chronic diarrhea. Infiltrated inflammatory cells were microscopically observed in the colonic wall with intact epithelium. The serotonin content in the mucosa/submucosa tissue was increased in the proximal and distal colon in DSS-treated rats, compared to that in control rats. The density of EC cells in the epithelium also increased in the proximal and distal colon in DSS-treated rats. In contrast, the density of mast cells in the lamina propria dramatically increased in the distal, but not in the proximal colon in DSS-treated rats. This discrepancy implies the serotonin released from EC cells and from mast cells may play different roles in the pathogenesis of DSS-induced colitis.

Animals↗

PubMed1999

Evaluation of preoperative and intraoperative arterial stimulation and venous sampling for diagnosis and surgical resection of insulinoma.

BACKGROUND: The precise intraoperative localization of insulinoma is essential for successful surgical treatment. In addition to various imaging modalities developed recently, arterial stimulation and venous sampling (ASVS) has also been used for tumor localization. METHODS: Preoperative and intraoperative ASVS procedures were performed in 6 patients with insulinoma. Intraoperative ASVS was performed before and after tumor resection. Immunoreactive insulin (IRI) concentrations and the IRI ratio (IRI concentration at each time interval after calcium injection/baseline IRI concentration) were determined by the conventional or a quick IRI method. RESULTS: The site of the tumor was identified preoperatively in all patients. The peak of the IRI ratio varied widely, but setting the cutoff value at 3.0 clearly differentiated peak IRA ratios in feeding arteries from those of nonfeeding arteries. Intraoperative ASVS showed a similar elevation of IRI levels, but the elevation disappeared after tumor resection in all but 1 patient. In 2 patients, resection of the tumor was confirmed during surgery by measuring IRI levels by the quick IRI method. CONCLUSIONS: A combination of ASVS and conventional imaging modalities is useful for precise localization of insulinoma. Resection of the tumor can be confirmed intraoperatively by comparing IRI levels associated with preoperative and postresective ASVS.

Adult↗

PubMed1999

Chemoprevention by the oxygenated carotenoid beta-cryptoxanthin of N-methylnitrosourea-induced colon carcinogenesis in F344 rats.

Beta-cryptoxanthin (betaCx), one of 4 major carotenoids in the blood, was investigated for anticarcinogenic activity in F344 rats. Four groups of 25 rats each received an intrarectal dose of 2 mg of N-methylnitrosourea 3 times a week for 5 weeks, and were fed the diet supplemented with 0 ppm (control), 25 ppm, 5 ppm or 1 ppm betaCx throughout the experiment. The colon cancer incidence at week 30 was significantly lower in the betaCx (25 ppm) diet group, but not in the betaCx (5 ppm) and betaCx (1 ppm) diet groups, than in the control diet group: 68%, 84%, 80% vs. 96%. The results suggested that dietary betaCx may affect colon carcinogenesis after accumulation in the colonic mucosa, perhaps due to absorption from the colon as well as the small intestine.

Animals↗

PubMed1999

Left posteroseptal Mahaim fiber associated with marked longitudinal dissociation.

We report a patient who underwent radiofrequency catheter ablation of a left posteroseptal atrioventricular (AV) Mahaim fiber with a marked longitudinal dissociation. During atrial pacing, Wenckebach-type atrioventricular block over the accessory pathway was observed with progressive preexcitation and no change in polarity of the delta waves. The AV conduction curve was discontinuous, with a distinct "jump-up" in local AV conduction time of 84 ms. The earliest ventricular activation was recorded from the posteroseptal portion of the mitral annulus, and the unipolar electrogram from a distal electrode had a high, steep deflection with uniphasic QS-like activity with 62 ms of local AV conduction time.

Adult↗

PubMed1999

Quantitative analysis of surface P-wave morphology in isthmus ablation for type 1 atrial flutter: differentiation between complete isthmus block and slow isthmus conduction.

Changes in P-wave morphology in inferior leads during atrial pacing at the margins of the carvo-tricuspid isthmus have been reported to be useful for predicting the creation of isthmus block in radiofrequency (RF) ablation of type I atrial flutter (AFL). However, it is not known whether these changes in P-wave morphology allow the clinician to differentiate between complete isthmus block and slow isthmus conduction. P-wave morphology during low lateral right atrial (LLRA) pacing, as well as during coronary sinus ostium (PCS) pacing, was evaluated prior to ablation, during slow isthmus conduction, and after complete isthmus block in 30 patients with AFL. Changes in P-wave morphology during LLRA pacing were not sufficient to differentiate between complete isthmus block and slow isthmus conduction. While changes in P-wave morphology in lead II from inverted to biphasic during PCS pacing were observed in both slow isthmus conduction and complete isthmus block, the ratio of the positive component to the total P-wave amplitude (P-wave ratio) was significantly different between slow isthmus conduction (20+/-17%) and complete isthmus block (40+/-11%) (P<0.0001). When the P-wave ratio in lead II during PCS pacing was more than 75% of the F-wave ratio in lead II during AFL, bilateral complete isthmus block was predicted with a sensitivity of 88%, a specificity of 71%, a positive predictive value of 75%, and a negative predictive value of 85%. These results indicate that a P-wave ratio greater than 20% or a P-wave ratio during PCS pacing greater than 75% of the F-wave ratio during AFL may predict a bidirectional complete isthmus block.

Aged↗

PubMed1999

The time from anaerobic threshold (AT) to respiratory compensation point reflects the rate of aerobic and anaerobic metabolism after the AT in chronic heart failure patients.

The significance of the time from anaerobic threshold to respiratory compensation point (RCP-AT time) in patients with chronic heart failure was investigated. Thirty-seven patients with chronic heart failure (New York Heart Association class II or III) were enrolled into the study. Cardiopulmonary exercise testing was performed using breath-by-breath gas sampling. A bicycle ergometer was used, and incremental exercise testing was carried out. Anaerobic threshold, respiratory compensation point (RCP), and the slope of oxygen uptake (VO2) as a function of work rate (deltaVO2/deltaWR) were measured. A positive correlation (r=0.53) between RCP-AT time and deltaVO2/deltaWR was found. RCP-AT time was corrected for the whole exercise period (ramp exercise-RCP point), and the correlation between corrected RCP-AT time and deltaVO2/deltaWR was still present (r=0.46). There was no correlation between RCP-AT time and anaerobic threshold. These findings suggest that RCP-AT time is a new parameter that reflects the rate of the aerobic and anaerobic metabolism after AT.

Anaerobic Threshold↗

PubMed1999

Right ventricular infarction with cardiogenic shock treated with percutaneous cardiopulmonary support: a case report.

A patient with a right ventricular infarction was resuscitated with percutaneous cardiopulmonary support (PCPS), after attempts at reperfusion, high-dose inotropic support and intra-aortic balloon counterpulsation failed to improve the hemodynamic compromise. Emergency PCPS improved the cardiogenic shock and the reduced right ventricular load, allowing the ischemic right ventricle to recover in the setting of unsuccessful reperfusion. This case demonstrates the use of PCPS as a hemodynamic support device for spontaneous recovery of the ischemic right ventricle. PCPS may be a potential therapy for patients with right ventricular infarction.

Angioplasty, Balloon, Coronary↗

PubMed1999

Relation between coronary thrombus and angiographic no-flow during primary angioplasty in patients with acute myocardial infarction.

No flow is an unsolved issue in primary percutaneous transluminal coronary angioplasty (PTCA) for patients with acute myocardial infarction (AMI), and the pathophysiology of no-flow is undetermined. To evaluate the potential participation of coronary thromboembolism in no-flow during primary PTCA, the present study reviewed cinefilms of 256 consecutive patients who underwent primary PTCA for AMI within 24h after the onset of chest pain between January 1992 and June 1998, focusing on the thrombus size. Angiographic no-flow was defined as the cessation of flow into the distal coronary circulation of the treated vessel with a to-and-fro contrast movement, not attributable to high-grade stenosis or spasm of the original target lesion. The coronary thrombus size was determined by using the 2-cm balloon catheter as a reference after crossing the infarct-related occluded artery with a guide wire. Angiographic no-flow was observed in 37 patients (37/256, 14%): 14 of 29 cases (48%) with a large thrombus (> or =2cm) versus 23 of 227 cases (9%) with a small thrombus (<2cm, 14/29 vs 23/227, p<0.01). Among 37 patients who experienced angiographic no-flow, overt distal emboli were observed in 14 patients. A thrombolytic agent was used through a guiding catheter in 102 cases prior to or after balloon dilatation to prevent or attenuate distal embolism, particularly in all those cases with a large thrombus (29/29 100%), and angiographic no-flow was seen in 27 cases of this subgroup (27/102, 26%). It is suggested that distal thromboembolism plays an important role in the mechanism of angiographic no-flow during primary PTCA performed for AMI.

Aged↗

PubMed1999

Percutaneous transluminal coronary angioplasty, alone or in combination with urokinase therapy, during acute myocardial infarction.

To investigate the effect of pre-treatment of a thrombus with a low dose of urokinase on establishing patency in a persistent infarct-related artery (IRA) during direct percutaneous coronary angioplasty (PTCA), the frequency of acute restenosis during direct PTCA, alone, or in combination with the intracoronary administration of urokinase, was examined in a consecutive nonrandomized series of patients with acute myocardial infarction (AMI). Two hundred and seventy-two successful PTCA patients (residual stenosis <50%) were divided into 2 groups: 88 patients received pre-treatment with intracoronary urokinase following PTCA (combination group); 184 received only direct PTCA without thrombolytic therapy (PTCA group). In the present study, after achievement of a residual stenosis of less than 50%, IRA was visualized every 15 min to assess the frequency of acute restenosis, which was defined as an acute progression of IRA with more than 75% restenosis after initially successful PTCA. In the patients with a large coronary thrombus, the frequency (times) of acute restenosis was significantly lower in the combination group than in the PTCA group (0.98+/-0.19 vs 2.92+/-0.32, p<0.0001). On the other hand, in the patients with a small coronary thrombus, the frequency of acute restenosis showed no difference in either group. The present study indicates that in patients with AMI, PTCA combined with pre-treatment of a low dose of urokinase is much more effective than PTCA alone, especially for those patients who have a large coronary thrombus.

Angioplasty, Balloon, Coronary↗

PubMed1999

Absorption and distribution of lycopene in rat colon.

Colonic absorption and distribution of lycopene, which inhibited rat colon carcinogenesis in our previous studies, were investigated in Sprague-Dawley rats. Three groups of six rats each with or without a single-barreled colostomy at the mid colon were given a single intragastric or intracolonic dose of 0.2 mL of corn oil containing 12 mg of lycopene. Twenty-four hours later, all rats were sacrificed and the blood and some tissues were collected. The contents of lycopene in the samples were assayed by HPLC. Lycopene was detected in an appreciable amount in the liver, but only in trace amount in the serum of all rats treated with an intracolonic dose of lycopene and in rats with an intragastric dose. After an intragastric lycopene treatment, lycopene was detected in the mucosa of the proximal colon and of the distal colon of the colostomized rats, whose distal colon had been excluded from the fecal stream. A large amount of lycopene was recovered in the feces. None was detected in any sample from the control rats treated with an intragastric or intracolonic dose of plain corn oil. The results suggest that lycopene is absorbed from the colon and also from the small intestine. It might be concluded that both ways of absorption contribute to a comparative amount of lycopene accumulation in the colon mucosa after ingestion of this carotenoid.

Animals↗

PubMed1999

Cardiac sympathetic activity estimated by 123I-MIBG myocardial imaging in patients with dilated cardiomyopathy after beta-blocker or angiotensin-converting enzyme inhibitor therapy.

UNLABELLED: Impaired cardiac sympathetic activity can be evaluated by 123I-metaiodobenzylguanidine (MIBG) imaging. METHODS: We studied the significance of MIBG imaging for 24 patients (age 58+/-12 y) with dilated cardiomyopathy (DCM). We compared 12 patients (group A) treated with metoprolol (dose from 30-60 mg/d) with 12 patients treated with angiotensin-converting enzyme (ACE) inhibitors. Patients were studied before treatment, after 5 mo of treatment (only in group A) and after 1 y of treatment. Cardiac MIBG uptake was assessed as the heart-to-mediastinum activity ratio (H/M) and total defect score (TDS) from anterior planar and SPECT MIBG images, which were acquired in 4 h after tracer injection. New York Heart Association (NYHA) class and left ventricular ejection fraction (LVEF) calculated by echocardiography were also assessed. RESULTS: TDS decreased in both groups (in group A, from 30+/-7 through 23+/-9 to 18+/-10; P < 0.01, in group B, from 30+/-6 to 24+/-8; P < 0.01) and H/M was increased in both groups (in group A, from 1.87+/-0.31 through 2.03+/-0.28 to 2.14+/-0.29; P < 0.01, in group B, from 1.82+/-0.28 to 1.94+/-0.26; P < 0.05). But TDS and H/M were more improved in group A than in group B (P < 0.05). LVEF was significantly increased in only group A (from 38+/-6 through 43+/-8 to 49%+/-9%; P < 0.01). NYHA improved in both groups (in group A, from mean 2.5 through 2.1 to 1.8; P < 0.01, in group B, from mean 2.6 to 2.1; P < 0.05) but was more improved in group A than in group B (P < 0.05). CONCLUSION: Cardiac function, symptom and cardiac sympathetic activity evaluated by MIBG images improved after the beta-blocker therapy more than with the treatment that used ACE inhibitors.

3-Iodobenzylguanidine↗

PubMed1999

Overexpression of cyclooxygenase-2 in carcinoma of the pancreas.

The level of cyclooxygenase (COX)-2 has been investigated recently in various human carcinomas. In the present study, we examined the distribution and extent of COX-2 protein in human pancreatic tumors using immunohistochemistry. A strong expression of COX-2 protein was present in 23 of 52 (44%) pancreatic carcinomas, a moderate expression was present in 24 of 52 (46%) pancreatic carcinomas, and a weak expression was present in 5 of 52 (10%) pancreatic carcinomas. In contrast, benign tumors showed weak expression or no expression of COX-2, and only islet cells displayed COX-2 expression in normal pancreatic tissues. Overexpression of COX-2 in carcinoma tissues was also confirmed by Western blot analysis. Furthermore, consistent with the results at protein levels, reverse transcription-PCR analyses indicated that COX-2 mRNA was overexpressed in 7 of 13 (54%) carcinomas, but in none of 3 benign tumors. Our findings suggest that COX-2 inhibitors might be potentially effective against pancreatic carcinomas and that COX-2 may be involved in certain biological processes in pancreatic islets.

Adenocarcinoma↗

PubMed1999

[The characteristics of myocardial fatty acid metabolism in patients with left ventricular hypertrophy].

We evaluated the characteristics of myocardial fatty acid metabolism in patients with left ventricular hypertrophy (LVH). Myocardial imaging with 123I-beta-methyl iodophenyl pentadecanoic acid (BMIPP) was performed in 28 patients with hypertrophic cardiomyopathy (HCM), 15 patients with hypertensive heart disease (HHD), 13 patients with aortic stenosis (AS) and 8 normal controls (NC). The patients with HCM consisted of 13 patients of asymmetric septal hypertrophy (ASH), 7 patients of diffuse hypertrophy (Diffuse-HCM) and 8 patients of apical hypertrophy (APH). Planar and SPECT images of BMIPP were acquired 15 minutes and 4 hours after tracer injection. Resting 201Tl SPECT images and echocardiography were also performed on other days. We calculated heart/mediastinum count ratio and washout rate of BMIPP by using planar image. In patients with LVH, the incidence of reduced BMIPP uptake was more frequent than that of reduced 201Tl uptake. In delayed images, more than 60% of patients with LVH reduced BMIPP uptake, especially remarkable for patients with ASH and APH. The washout rate of all cardiac hypertrophic disorders was tended to be higher than that of normal subjects. Reduced BMIPP uptake was frequently found in septal portion of anterior and inferior wall in patients with ASH, in inferior wall in patients with Diffuse-HCM and HHD, in apex in patients with APH and AS. These results suggest that BMIPP scintigraphy can differentiate three types of cardiac hypertrophy.

Aged↗

PubMed1999

[Effect of exercise therapy on oxygen consumption in patients with chronic heart failure].

The effect of exercise training on delta Vo2/delta WR was studied in 12 patients(11 men, one woman, mean age 62 +/- 9 yr)with chronic heart failure(old myocardial infarction, dilated cardiomyopathy, patients after coronary arterial bypass graft surgery and patients after aortic valve replacement). Cardiopulmonary exercise testing was performed to decide the exercise tolerance and assess the delta Vo2/delta WR. Patients underwent physical training at the anaerobic threshold for 3 months. Cardiopulmonary exercise testing was performed after the second week and after the third month. The anaerobic threshold increased at the third month compared with before exercise testing and the second week(p < 0.05, respectively) (before exercise testing: 13.6 +/- 2.0 ml/min/kg, the second week: 14.7 +/- 2.5 ml/min/kg, the third month: 16.2 +/- 2.1 ml/min/kg). The delta Vo2/delta WR increased at the second week compared with before exercise testing(before exercise testing: 8.9 +/- 1.9 ml/min/W, the second week: 10.6 +/- 1.9 ml/min/W, p < 0.05), but significantly decreased at the third month compared with the second week(the third month: 9.4 +/- 1.7 ml/min/W, p < 0.05). Serial increase of the anaerobic threshold and the peak Vo2/heart rate suggests that the exercise tolerance and cardiac function of the patients improved significantly. The increase of the delta Vo2/delta WR after the first 2 weeks seemed to depend on the luxury blood supply to both working and non-working muscles. The decrease of delta Vo2/delta WR at the third month may be due to the redistribution of the blood flow to the working muscles.

Chronic Disease↗

PubMed1999

Evaluation of new 4 French catheters by comparison to 6 French coronary artery images.

The use of 4 Fr catheters for diagnostic coronary arteriography improves patient comfort and could potentially reduce costs by decreasing arterial complications and encouraging outpatient examination. We examined the performance of recently developed 4 Fr catheters (100 cm long, 0.042 inch internal diameter) through in vitro flow rate patterns and in vivo image quality. Flow patterns (flow rate calculated from pressure with the Hagen Poiseuille relation) were obtained by hand (10 ml volume; maximal effort, one-handed full injection) and power injection (10 ml volume; 5 ml/sec) in the 4 Fr catheters were compared to 5 Fr (0.047 inch) and 6 Fr (0.057 inch) catheters. In 20 patients, coronary arteriograms were obtained from 4 Fr hand injection (4 HI), 4 Fr power injection (4 PI), 6 Fr hand injection (6 HI ), and 6 Fr power injection (6 PI) were compared after being scored into 5 grades. Coronary diameter was assessed at two sites for all injections in the same group of patients. In power injections, peak flow rates were consistently 5.5 ml/sec in all catheters. Hand injections were much more variable; peak flow rate ranges for 5 different physicians were 3.5-6.0 ml/sec. in 6 Fr, 1.8-3.0 ml/sec. in 5 Fr and 1.4-2.0 ml/sec in 4 Fr catheters. Mean image scores of left arteriograms were significantly higher for 4 PI versus 4 HI and for 6 Fr images compared to 4 PI (p < 0.001). In right arteriograms, 4 HI scored significantly lower than other methods (4 PI, 6 HI and 6 PI; p < 0.001). In 4 HI left coronary arteriograms, the frequency of grade > 2 was 96% and > 3 was 82%. Power injection improved 4 Fr imaging to 99% greater than grade 2 and 93% greater than grade 3. There were no differences in the frequency of images above grade 3 in right coronary arteriograms. Measured coronary artery diameters at 40 normal and 17 stenotic sites by QCA analysis (Acom, Siemens AZ, Erlangen, Germany) did not influence the study data. We concluded that coronary arteriograms by hand injection with 4 Fr catheters were inferior compared to 6 Fr images. Power injection and/or larger catheters may be necessary to ensure the highest quality images are obtained.

Blood Flow Velocity↗

PubMed1998

Time-domain and spectral turbulence analyses of the signal-averaged electrocardiogram have different predictive values for sustained ventricular tachycardia in patients with myocardial infarction.

We performed signal-averaged ECG and programmed stimulation in 15 patients after myocardial infarction with ventricular tachycardia and 49 patients after myocardial infarction without ventricular tachycardia to compare the spectral turbulence analysis and time-domain analysis of signal-averaged ECG for prediction of clinical and induced ventricular tachycardia. Sustained monomorphic ventricular tachycardia was inducible in all 15 patients with clinical sustained monomorphic ventricular tachycardia (group 1) and in 9 patients without clinical sustained monomorphic ventricular tachycardia (group 2). Sustained monomorphic ventricular tachycardia was not inducible in 40 patients without clinical sustained monomorphic ventricular tachycardia (group 3). While there was no difference in time-domain variables between groups 1 and 2, there were significant differences between groups 2 and 3. Values obtained by spectral turbulence analysis differed significantly between groups 1 and 2, but not between groups 2 and 3. Time-domain analysis showed abnormal values in 87% of group 1 patients, 78% of group 2, and 35% of group 3. Spectral turbulence analysis showed abnormal values in 93% of group 1, 11% of group 2, and 30% of group 3. In conclusion, frequency-domain spectral turbulence analysis of signal-averaged ECG is more useful than the time-domain analysis in predicting the spontaneous occurrence of sustained monomorphic ventricular tachycardia in patients after myocardial infarction.

Aged↗

PubMed1998

Rapid diagnosis of red sea bream iridovirus infection using the polymerase chain reaction.

A simple and sensitive polymerase chain reaction (PCR) based assay is described for detection of the red sea bream iridovirus (RSIV) in infected fish. The assay involves amplification of a portion of the ribonucleotide reductase small subunit (RNRS) gene of the virus from DNA isolated from the spleen. The system was tested on red sea bream following an experimental infection. In our infection model, disease signs first became apparent 5 to 6 d post-infection, and mortality commenced at Day 6 and reached 90% by Day 9. No amplified product was detected from fish at 1 or 2 d post-infection, but 3 of 5 fish tested positive at Day 3, and all fish tested positive at Days 5 and 8. Thus, infection could be detected prior to the appearance of overt symptoms. This PCR method should be of considerable value for aquaculture to detect RSIV infection.

Animals↗