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Biomedical subjects

S Ohtsuka

Publications and source records attributed to S Ohtsuka.

At least 19 recordsLinked to original sources
PubMed1997

Relation of a decrease in arterial compliance to ST segment depression on exercise electrocardiograms in patients with hypertension.

Decreased arterial compliance (ACo) and increased arterial resistance are the major alterations of arterial function in patients with hypertension. The influence of decreased ACo on the heart was investigated in patients with hypertension. Patients with a systolic blood pressure of > 140 mmHg, a diastolic blood pressure of > 90 mmHg, or both, who had normal coronary arteriograms were enrolled. These patients were divided into two groups according to the value of ACo: Group I, patients with ACo > or = 0.9 ml/mmHg (n = 15); and Group II, patients with ACo < 0.9 ml/mmHg (n = 13). There were no significant differences in arterial resistance, age, gender, and body surface area between the groups. Echocardiographic, hemodynamic, and exercise stress test variables were compared between the groups. There were no differences between the groups in left ventricular (LV) wall thickness and volume, cardiac output, LV end-diastolic pressure, and LV ejection fraction. However, pulse pressure was higher in Group II than in Group I. Ergometer exercise stress testing revealed that, although exercise duration and the peak rate-pressure product were similar in the two groups, ST segment depression of > or = 1.0 mm on the exercise electrocardiograms was induced more frequently in Group II than in Group I (92% vs. 27%, p < 0.001). Thus, the decrease in ACo in patients with hypertension may not significantly affect LV wall thickness, volume, or ejection fraction; however, it may increase pulse pressure and may adversely affect coronary circulation, as suggested by the ST segment depression on exercise electrocardiograms.

Arteries↗
PubMed1997

Evaluation of tetrahydropyranyladriamycin as an immunosuppressant in concordant xenotransplantation.

BACKGROUND: Tetrahydropyranyladriamycin (THP), a derivative of anthracycline, exhibits a stronger antiproliferative activity and a lower cardiotoxicity than the other anthracyclines. The value of THP as an immunosuppressant has not been examined yet, whereas cyclophosphamide, which is another antiproliferative drug, has shown promise as an immunosuppressant in concordant xenotransplantation. METHODS: The effect of THP on the marginal zone in the spleen and anti-species antibody production was evaluated and was compared with that of cyclophosphamide in a concordant xenogeneic splenocyte injection model (hamster-to-rat). Next, THP was used as monotherapy for hamster-to-rat heart transplantation to substantiate the potency of its immunosuppressive activity in concordant xenotransplantation. Finally, combination therapy with THP plus FK506 was tried. RESULTS: THP (5 mg/kg) suppressed the expansion of the marginal zone more than did cyclophosphamide (40 mg/kg) and inhibited the production of antispecies antibody as much as did cyclophosphamide (40 mg/kg) in the splenocyte injection model. THP monotherapy could prolong the survival of hamster-to-rat heart grafts up to 14.5 +/- 3.2 days (n = 21). The rejected grafts in the THP-treated animals did not show any histologic evidence of vascular endothelial damage but did exhibit a mononuclear cell infiltration. Combination therapy with THP plus FK506 provided excellent graft survival. CONCLUSIONS: THP can prevent early phase humoral rejection in concordant xenotransplantation.

Animals↗
PubMed1996

Expandable metallic stents for tracheobronchial stenoses in esophageal cancer.

BACKGROUND: Tracheobronchial stenosis in patients with esophageal cancer can be life threatening. Few reports have discussed use of expandable metallic stents for central airway stenoses in patients with esophageal cancer. METHODS: Twelve patients with esophageal cancer underwent placement of expandable metallic stents for respiratory distress caused by tracheobronchial stricture. Single or double metallic stents were placed in the stenotic airways under fluoroscopic guidance. Improvement in respiratory symptoms and clinical outcome were assessed. RESULTS: Most stenoses were located in the trachea or the left main bronchus. From one to four expandable metallic stents were placed in each stricture site, with immediate relief of respiratory symptoms in 8 patients. One patient with tracheomalacia in alive 3 years after stent placement and another is alive 6 months after stent insertion. The other 10 patients lived from 10 to 70 days (mean; survival, 35 days) after stent placement. Death was due to progression of disease. CONCLUSIONS: Although metallic stents are useful for relieving respiratory distress in patients with advanced esophageal cancer, additional therapies should be considered.

Aged↗
PubMed1996

Alterations in left ventricular wall stress and coronary circulation in patients with isolated systolic hypertension.

OBJECTIVES: To study the alterations in cardiac function and coronary circulation in patients with isolated systolic hypertension (ISH). PATIENTS: Ten patients with a history of ISH were studied and findings were compared with those of seven normotensive subjects. All of the patients had angiographically normal coronary arteries. They underwent cardiac catheterization, and haemodynamic variables and coronary flow velocity were measured. All of the patients also underwent treadmill exercise testing. MAIN OUTCOME MEASURES: Left ventricular mass was evaluated by echocardiography. The coronary flow velocity data were obtained by using the intracoronary Doppler catheter technique. ST-segment depression was observed on the exercise electrocardiogram. RESULTS: Systemic vascular resistance did not differ, whereas total arterial compliance was decreased in the ISH patients versus the controls (P < 0.001). The left ventricular mass of the ISH patients was increased slightly, but their left ventricular systolic wall stress was greater than that of the controls (P < 0.01). The coronary flow reserve ratio and the ratio of diastolic to total coronary flow were decreased in the ISH patients versus the controls (P < 0.01). ST-segment depression on the exercise electrocardiogram was frequently observed in the hypertensive patients (80 versus 0% in control subjects, P < 0.01). CONCLUSIONS: Patients with ISH were characterized haemodynamically by a decrease in arterial compliance. They showed an increase in left ventricular systolic wall stress and also showed decreases in coronary flow reserve ratio and in the relative diastolic coronary flow. Such alterations observed in patients with ISH are detrimental to the heart and may contribute to a reduced exercise capacity and the induction of subendocardial ischaemia during exercise.

Adult↗
PubMed1996

The evaluation of masticatory function with low adhesive colour-developing chewing gum.

Many objective methods have been described to evaluate masticatory function. Recently, a new chewing gum system has been reported that utilizes a phloxine-sodium bicarbonate reaction and measures a chromatic coordinate as a functional indicator. A low-adhesive colour-developing chewing gum has been developed by selecting an appropriate gum base. This study examined the applicability of the system and reproducibility of results in subjects with different dental states. Tests were performed on 15 natural dentate subjects and 15 complete denture wearers after determination of germane test conditions through a pilot study. The colour was measured by a*, one of the coordinates in the L*a*b* colour system. All subjects could perform the test. The coefficient of variation ranged from 1.87% to 7.90%, averaging 5.15% in the natural dentate subjects and from 1.5% to 17.9%, averaging 9.75% in the complete denture wearers. The 95% confidence interval of a* was 28.76 +/- 1.76 in the natural dentate subjects and 10.05 +/- 2.58 in the complete denture wearers. The results indicated that this material can be useful for both complete denture wearers and subjects with a natural dentition with adequate reproducibility.

Adhesives↗
PubMed1996

Changes of vasoactive peptides and effects of inhaled nitric oxide after pneumonectomy.

To clarify the role of vasoactive peptides in the physiologic response to pneumonectomy, we investigated the changes of atrial (A-type) natriuretic peptide (ANP). C-type natriuretic peptide (CNP), and endothelin-1 (ET-1) levels in the lung and blood after pneumonectomy and the effects of inhaled nitric oxide (NO; 5 ppm) after pneumonectomy in beagle dogs. The concentrations of these peptides in the lung and blood were measured by radioimmunoassay. The dogs in group A (n = 10) were observed without NO inhaling after right pneumonectomy, and the dogs in group B (n = 5) were observed with NO inhaling from 120 to 180 min after right pneumonectomy. After the thoracotomy, right lung tissue was resected for the pre-operative histological control. Tissue from the left lung was obtained at 120 min (5 dogs in group A), at 180 min (5 dogs in group A), and after 60 min of NO inhalation (group B) for the post-operative histological material. Peripheral blood was collected from the femoral artery. The pulmonary arterial pressure (PAP) was significantly increased after pneumonectomy, but rapidly decreased to the same level as the pre-operative stage after NO inhalation. Increases of plasma ANP, lung ANP and lung CNP levels occurred after pneumonectomy, while the ET-1 level was unchanged. Inhaled NO rapidly reduced the plasma ANP, lung ANP and lung CNP. These results indicate that both ANP and CNP act to maintain normotensive homeostatic balance in the pulmonary circulation.

Administration, Inhalation↗
PubMed1995

Localization of three fragments of connectin in chicken breast muscle sarcomeres.

Connectin (titin) links the Z line to the myosin filament in sarcomeres of vertebrate skeletal muscle. An 800 kDa fragment of alpha-connectin runs from the Z line up to the N2 line region in the I band, and the following beta-connectin portion runs up to the edge of the M line on the myosin filament in chicken breast muscle sarcomeres. Immunoelectron microscopy showed that a 400 kDa fragment following the 800 kDa fragment reaches the edge of the myosin filament and, thereafter a 1,700 kDa fragment runs to the M line on the myosin filament in chicken breast muscle sarcomeres. When stretched, the epitopes to anti-400 kDa fragment antibodies outside the myosin filament moved toward the inside of the I band.

Animals↗
PubMed1995

[Multiparametric cytometric analysis of hepatocellular carcinoma and its allied lesions combining DNA ploidy analysis with morphometry using DAPI/HP double staining].

Hepatocellular carcinomas (HCC) of various differentiation, Edmondson (Edm) grade I-IV, often based upon viral infectious hepatitis transformed through regeneration, nodular and/or dysplastic adenomatous hyperplasia. Aspiration cytology, even needle biopsy for such lesions, is very difficult to interpret. We have been studying multiparametric cytologic analysis using DAPI/Hematoporphyrin (HP) staining for the cece samples provided from exactly trimmed 50-microns thick paraffin sections, employing a new software program which we developed, combining DNA ploidy and cell protein content analysis with morphometry. DAPI indicates DNA content and nuclear size and HP indicates cell protein content and cell size. From 21 cases of HCC, 43 nodules or masses including multiple lesions and nodule in nodule were analyzed. Surrounding non-neoplastic hepatic tissues were examined as the control specimens. On DNA histogram, cases with the peak over 2.4 c are identified as aneuploid (Aneupl). Cases of Edm I, or II, 6 of 8 samples showed Aneupl., all of 11 cases of Edm II, 11 cases of Edm III, and one of Edm IV showed Aneupl. Multinodular foci in the same cases and also nodule in nodule often showed different modes of Aneupl. This suggested heterogenetic carcinogeneity. Noncarcinomatous foci often showed Aneupl. modes, which may indicate malignant transformation or malignant potential.

Carcinoma, Hepatocellular↗
PubMed1995

[Evaluation of the peripheral skin sympathetic function by cooling thermography in women with climacteric complaints].

To evaluate the peripheral skin sympathetic function, cooling thermography was performed on women with climacteric complaints (CG) and without them (NG). Both hands were immersed into 4 degree C water for 1 minute ant the nail temperature of the right second finger was measured before and after the stress every 1 minute for 7 minutes. And the recovery rate was calculated. By dividing the CG groups by the 5 minute recovery rate minus the 2SD of the NG groups, there was seen to be a significant difference between the recovery patterns. One is a good recovery group (GR, N = 26) and the other is a poor recovery group (PR, N = 28). The significant difference between GR and PR groups was only recognized in the pre-cooling nail temperature. No significant difference was seen in age, Body Mass Index, Kupperman Index, symptoms, serum estradiol or serum testosterone levels. These results indicate that in about half of women with climacteric symptoms, peripheral skin sympathetic nerve function is continuously hypertensioned and the response to cooling stress is decreased. Although the reason for these results is not clear, sympathetic nerve dysfunction is supposed to be the main cause. This test is useful for evaluating peripheral skin sympathetic function.

Adult↗
PubMed1994

Chronically decreased aortic distensibility causes deterioration of coronary perfusion during increased left ventricular contraction.

OBJECTIVES: This study investigated the long-term effects of decreased aortic distensibility on the heart in relation to coronary perfusion. BACKGROUND: Aortic distensibility is decreased in patients with atherosclerosis and hypertension and in the elderly. However, the effect of a long-term decrease in aortic distensibility on coronary perfusion has not been fully investigated. METHODS: Twelve anesthetized dogs underwent thoracotomy and were allocated to two groups: Group I included six control dogs with a normal aorta; Group II included six dogs with decreased aortic distensibility produced by banding the descending aorta. After 4 to 6 weeks, the dogs had a second operation to measure coronary artery flow and transmural flow distribution. Because the effect of decreased aortic distensibility on coronary perfusion may be affected by ventricular contractility, measurements were performed at baseline and during increased ventricular contraction induced by isoproterenol infusion. RESULTS: At baseline, arterial compliance was reduced by 35% in Group II, but there was no change in total mean arterial resistance. Hemodynamic variables, regional wall motion and coronary flow were also similar in both groups. However, during isoproterenol infusion, coronary flow increased more in Group II than in Group I (p < 0.01), and the coronary flow reserve ratio (maximal peak hyperemic flow divided by rest flow) decreased more in Group II than in Group I (mean [+/- SD] 1.9 +/- 0.4 vs. 2.4 +/- 0.3, p < 0.05). Moreover, although the transmural flow distribution was similar in the two groups at baseline, during isoproterenol infusion the endocardial flow increased less in Group II than in Group I (p < 0.05), and the endocardial/epicardial flow ratio was significantly decreased in Group II compared with Group I (mean [+/- SD] 0.70 +/- 0.18 vs. 0.99 +/- 0.22, p < 0.05). The subendocardial electrocardiogram showed ST segment elevation during isoproterenol infusion in Group II (p < 0.05) but not in Group I. CONCLUSIONS: These results demonstrate that during increased ventricular contraction, chronically decreased aortic distensibility contributes to a further decrease in the coronary flow reserve ratio, impairs endocardial blood flow and may induce subendocardial ischemia even in the absence of coronary artery stenosis.

Animals↗
PubMed1994

Experimental rat pancreas transplant: surgical technique and immunological considerations.

Vascularized whole pancreas transplantation in the rat was performed on the abdomen using a cuff technique for vascular anastomoses. Two different exocrine drainage procedures, either intestinal or ureter drainage, were used. In the isograft transplant models, hyperglycemia was ameliorated immediately after transplantation and all of the grafts functioned during the observation period. In the allograft transplant models without immunosuppression, graft rejection, as defined by recurrence of hyperglycemia (blood glucose > 200 mg/dl) occurred 6-9 days post-transplant. Allograft rejection could be delayed approximately 1 month after transplant with short-term use of FK506. These different models, using either intestinal or ureter exocrine drainage, are similar to dominant clinical pancreas transplantation with enteric exocrine drainage or urinary tract drainage, respectively. It is thus concluded that whole pancreas transplant with either intestinal or ureter exocrine drainage is an ideal model for physiological and immunological experimental studies in pancreas transplantation.

Animals↗
PubMed1994

Post-infantile giant cell hepatitis in an elderly female patient with systemic lupus erythematosus.

A 69-year-old Japanese female was admitted because of general fatigue. Laboratory data showed elevation of serum total bilirubin, transaminase, gamma-glutamyl transpeptidase, and creatinine levels. An immunological study revealed hypergammaglobulinemia, low titer of complement, and high titers of antinuclear antibody, anti-DNA antibody, and circulating immune complexes. Antibodies to parainfluenza virus 3 were positive. Histology of the liver disclosed numerous giant cell hepatocyte transformations with the lobular architecture being slightly distorted by portal inflammation and fibrosis. These findings led us to make a diagnosis of giant cell hepatitis associated with systemic lupus erythematosus. Prednisolone was effective in improving the anemia and the serum immunoglobulin, immune complex, and antinuclear antibody levels. The addition of cyclosporine to the initial corticosteroid therapy was also beneficial in decreasing the transaminase level and in improving liver histology. The patient died of acute pneumonitis and renal failure on the 166th day after admission. Parainfluenza virus 3 and autoimmune mechanisms were thus considered to be the causes of the giant cell hepatitis.

Aged↗
PubMed1994

The hypothalamic-pituitary-ovarian axis in patients with endometriosis is suppressed by leuprolide acetate but not by danazol.

OBJECTIVE: To investigate the effects of leuprolide acetate (LA), a GnRH agonist (GnRH-a), and of danazol on the hypothalamic-pituitary-ovarian axis in patients with endometriosis. DESIGN: Ten patients were divided into LA and danazol treatment groups. MEASURES: Serum levels of E2, immunoreactive and bioactive LH, pulsatility of LH, and gonadotropins release by GnRH. Changes in serum E2 levels by hMG administration during LA treatment. RESULTS: Serum E2 level decreased to near castrated levels during the LA treatment, while it remained unchanged during the danazol treatment. Leuprolide acetate administration resulted in a significant suppression of the serum level of bioactive LH, of the pulsatility of LH release, of the pituitary response to GnRH injection, and of the elevation in the serum E2 level by hMG administration, but danazol treatment did not show these suppressive effects. CONCLUSION: Our results suggest that the hormonal actions of LA and danazol on endometriosis are different from each other, especially in the suppression of serum E2 level.

Adult↗