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Biomedical subjects

H Ozasa

Publications and source records attributed to H Ozasa.

At least 37 records · Page 2Linked to original sources
PubMed1996

Successful percutaneous closure of a coronary artery fistula with a detachable balloon.

Percutaneous transcatheter closure technique of a coronary artery fistula with a detachable balloon was performed for a 14 year old male student. Complete closure of the fistula without any complications was confirmed by angiography after the procedure. When the patient underwent a second angiography 6 months after the closure, it was confirmed that the position of the balloon had not changed, that the interruption of the flow of the fistula had been maintained and that the diameter of the left coronary artery and the fistula were reduced. Percutaneous closure technique using a detachable balloon may become the primary treatment for a coronary artery fistula in place of surgical ligation.

Adolescent↗
PubMed1994

Extraction of serum proteins adsorbed on the surface of dialysis membranes.

Extraction of adsorbed proteins from dialysis membranes that had been used during actual hemodialysis procedures was performed. The condition of extraction with SDS plus 2-mercaptoethanol at 95 degrees C is more efficient than with only PBS or with SDS solution without 2-mercaptoethanol at 37 degrees C.

Adsorption↗
PubMed1994

[Induction and prevention of kidney injury induced by GSH depletion and vitamin E deficiency in rats].

Four-week-old Wistar male rats were fed a vitamin E (VE)-deficient diet for 8 weeks, followed by intraperitoneal injection of DL-buthionine- [S, R] -sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, at the dose of 1 mmol/kg body weight. As we reported previously, GSH depletion by administration of BSO induced acute tubular necrosis in the kidney of VE-deficient rats and was accompanied by decrease of renal TBA value and marked increase of renal lipofuscin content. In this study, we examined the effect of administration of AsA or Trolox C on these kidney injuries. AsA or Trolox C treatment increased renal GSH content and inhibited the increase of renal lipofuscin production. The increase of BUN and creatinine levels and LDH activity in the sera of rats administered BSO were inhibited by AsA or Trolox C treatment. AsA treatment completely protected the necrosis of epithelia of proximal renal tubules. These results suggest that GSH has an important role in preventing lipofuscin production through the reaction of lipid peroxides with amino acids. AsA spares GSH indicating that these compounds have similar antioxidant actions and that AsA can serve as an essential antioxidant in the presence of severe GSH deficiency.

Animals↗
PubMed1993

Immunohistochemical analysis of rat S-adenosylmethionine synthetase isozymes in developmental liver.

Mammalian S-adenosylmethionine (AdoMet) synthetase exists as two isozymes, liver-type and kidney(non-hepatic)-type enzymes. The developmental expression of these two isozymes proteins has been investigated in rat liver using immunohistochemical techniques. The liver-type AdoMet synthetase is expressed only in adult liver, but not in fetal liver. On the other hand, the kidney-type AdoMet synthetase is predominantly expressed in fetal liver and faintly detected in adult liver. It was also found that both isozymes were localized to the hepatocytes of rat liver. These results clearly show that AdoMet synthetase isozymes are developmentally regulated within hepatocytes. In addition, in rat kidney we have shown that the kidney-type AdoMet synthetase is predominantly localized to the distal tubule.

Amino Acid Sequence↗
PubMed1993

Medium-term results of percutaneous transluminal balloon aortic valvuloplasty with Inoue balloon catheter for congenital aortic stenosis.

Although percutaneous transluminal balloon aortic valvuloplasty (PTAV) has been performed for congenital aortic stenosis in infants and children for several years, its efficacy and the associated aortic regurgitation (AR) have not been widely discussed. Percutaneous transluminal balloon aortic valvuloplasty using an Inoue balloon catheter was performed for congenital aortic stenosis in 12 patients (4-16 years old) in this study. The systolic aortic valve pressure gradient ranged from 42 to 111 mmHg before PTAV and became < 50 mmHg immediately after PTAV in 10 cases (83%). Eight of these 10 patients had no increase in the gradient during subsequent observation for a period of 9-40 months. Aortic regurgitation increased immediately after PTAV in nine cases (75%). It increased from grade 1 to grade 2 in eight cases and from grade 1 to grade 3 in one patient; no significant enlargement of the left ventricular end-diastolic diameter and no significant change in the left ventricular end-diastolic pressure (LVEDP) or the cardiac index was observed during follow-up in these patients. There was a correlation between the diameter of the balloon and efficacy; an appropriate diameter was considered to be about 90% of the aortic annular diameter. Changes in the hemodynamic parameter after PTAV with an Inoue balloon were small in most patients and this procedure is considered to be a treatment that should be attempted prior to surgery for congenital aortic stenosis.

Adolescent↗
PubMed1993

Macromolecules that are colocalized with deposits of beta 2-microglobulin in hemodialysis-associated amyloidosis.

BACKGROUND: Common elements in many different types of amyloid may have important roles in amyloidogenesis. The proteinaceous tissue deposits have a common appearance in polarized light and other similar features. The present investigation describes for the first time the relation between beta 2-microglobulin (beta 2-M)-type amyloidosis and colocalized materials, as demonstrated using specific antibodies and hyaluronan-binding protein. EXPERIMENTAL DESIGN: Amyloid-rich carpal tunnel synovium was obtained surgically from 28 patients who were being treated by maintenance hemodialysis. Serial sections were examined using a hyaluronan (hyaluronic acid)-binding protein and antibodies against heparan sulfate-glycosaminoglycan, chondroitin sulfate-proteoglycan, dermatan sulfate-proteoglycan, alpha 1-antichymotrypsin, alpha 1-antitrypsin, inter-alpha-trypsin inhibitor, haptoglobin, and ubiquitin. RESULTS: Accumulation of hyaluronan was of three types, namely, localization around beta 2-M deposits, colocalization with deposition of beta 2-M itself and localization at a small distance from beta 2-M deposits. Immunostaining for heparan sulfate glycosaminoglycan was demonstrated at the sites of beta 2-M plaques. Chondroitin sulfate-proteoglycan did not show specific patterns of immunostaining, resembling hyaluronan rather than heparan sulfate. The other materials tested, alpha 1-antichymotrypsin, alpha 1-antitrypsin, inter-alpha-trypsin, haptoglobin and ubiquitin, were not immunostained at sites of beta 2-M plaques. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting revealed that the molecular weight of heparan sulfate-glycosaminoglycan was 16,000. CONCLUSIONS: These results suggest that HS has an important role in hemodialysis-associated amyloidosis as it does in other types of amyloidosis. Moreover, accumulation of hyaluronan may be an indication of inflammation of the carpal synovium.

Amyloidosis↗
PubMed1992

Relationship between plasma levels of hyaluronic acid and amyloid-associated osteoarthropathy in chronic hemodialysis patients.

Plasma levels of hyaluronic acid (HA) and acute-phase reactants were determined in chronic hemodialysis patients with or without carpal tunnel syndrome (CTS) and/or shoulder pain, which are characteristic symptoms of amyloid-associated osteoarthropathy. While levels of acute-phase reactants tended to be higher in the patients with CTS and/or shoulder pain than in patients without these symptoms, the difference was not significant. However, plasma levels of HA were significantly higher in the patients with these symptoms. Analysis of plasma levels of HA in age-matched patients also demonstrated a significant correlation between elevated levels of HA and the presence of CTS and/or shoulder pain. Among the patients with CTS and/or shoulder pain, those patients with bone cysts in the carpal bone or humeral head had significantly higher plasma levels of HA than patients without bone cysts. Thus, there appears to be a relationship between elevated plasma HA and amyloid-associated osteoarthropathy in chronic hemodialysis patients that is more specific than any correlation with levels of acute-phase reactants.

Acute-Phase Proteins↗
PubMed1992

Study of uterine prolapse by magnetic resonance imaging: topographical changes involving the levator ani muscle and the vagina.

Alternations of the pelvic structure with an emphasis on those of the levator ani muscle, associated with uterine prolapse, were studied using sagittal magnetic resonance images obtained from 19 subjects without and 14 with uterine or vaginal prolapse of varied degree and 3 patients with Rokitansky syndrome who had undergone a McIndoe operation. Two additional patients with a grade III uterine prolapse were also studied before and 2-3 months after corrective surgery consisting of vaginal hysterectomy combined with anterior colporrhaphy and posterior colpoperineorrhaphy. Absence or presence of prolapse, irrespective of its grade, was found to be related to whether or not a reference line extrapolated from the levator plate crossed the pubis on sagittal images. This was the case as well in patients with Rokitansky syndrome with a neovagina and loss of such crossings was restored in patients with prolapse after surgery. Backward bending of the upper vagina noted in nonprolapse conditions was usually absent in patients with uterine prolapse. These results document that topographical changes involving the levator ani muscle and the vagina occur in association with uterine prolapse.

Adult↗
PubMed1992

The effect of DHAS on steroidogenesis of the human corpus luteum.

To examine whether or not dehydroepiandrosterone sulfate (DHAS) is a substrate for steroidogenesis in the corpus luteum, we studied 17 women in the luteal phase, the follicular phase, and after castration. Following suppression of adrenal function with dexamethasone, DHAS was administered intravenously and the serum levels of DHAS, dehydroepiandrosterone (DHA), androstenedione (ADS), testosterone (T), 17 beta-estradiol (E2) and progesterone (P) were measured serially for 24 h. An obvious increase in the serum levels of all steroids except for E2 and P was observed in each subject for at least 8 h after DHAS administration. To evaluate the effect of DHAS on the serum levels of the steroid hormones, the integrated response area (IRA) was calculated for each hormone in all the subjects. The IRA values for ADS, T and E2 (at 2 and 4 h) in the luteal phase group were significantly higher than in the other DHAS treated groups, and the IRA values for DHA and P tended to be higher than in the other groups. These results suggest that the corpus luteum utilizes serum DHAS as a substrate for steroidogenesis.

Adult↗
PubMed1991

Chronic alpha 1 blockade in a patient with Eisenmenger syndrome.

In an 18-year-old male with Eisenmenger syndrome cyanosis and erythrocytosis were increasing. The erythrocytosis diminished following oral bunazosin and phlebotomy was not needed during the treatment. When bunazosin was stopped, the erythrocytosis increased, but when it was resumed, the erythrocytosis and general fatigue diminished.

Adolescent↗