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Biomedical subjects

H Sakurai

Publications and source records attributed to H Sakurai.

At least 361 records · Page 20Linked to original sources
PubMed1994

Effect of growth hormone on wound healing in protein-malnourished rats treated with corticosteroids.

This study was designed to evaluate the efficacy of human growth hormone (GH) in improving the tensile strength of wounds weakened by chronic protein malnourishment and corticosteroid (CS) administration. Eighty-six female Sprague-Dawley rats, weighing 80 to 100 g, were divided into five groups. Group 1 (control) received 23.4% protein chow for 8 weeks before surgery. Groups 2, 3, 4, and 5 received nonprotein chow on alternate days for the same duration. Groups 3 and 5 received prednisolone (2 mg/kg/d intramuscularly) for 3 weeks preoperatively and for 5 days postoperatively. Groups 4 and 5 were given GH (somatotropin, 1 IU/d) for 5 days postoperatively. All the animals underwent a precise 4-cm midline celiotomy. Wound testing was performed on the sixth postoperative day, after removal of the sutures. The bursting strength (BS, mean +/- SD) for group 1 was 145 +/- 16 mm Hg. The BS for groups 4 (137 +/- 13 mm Hg) and 5 (134 +/- 7 mm Hg) were significantly stronger than those for groups 2 (115 +/- 15 mm Hg) and 3 (91 +/- 16 mm Hg). The authors conclude that postoperative systemic GH restored the wound BS in protein-malnourished animals treated with CS, to the level of the normally nourished controls.

Alanine Transaminase↗
PubMed1994

Cervical neurofibroma in a patient with von Recklinghausen's disease.

A case of a huge cervical neurofibroma associated with von Recklinghausen's disease is reported. The patient with von Recklinghausen's disease was a 48-year-old woman complaining of a rapidly growing mass around the neck for the last 6 months. In von Recklinghausen's disease, which corresponds to neurofibromatosis-I, gigantic tumors around the neck often occur. The present case was classified as a plexiform neurofibroma which is derived from the peripheral nervous system, and this type frequently shows malignant change in contrast to other types of neurofibroma. In general, it is difficult to determine the origin of the nerve in cervical neurofibromas. A total extirpation of the tumor was done in our case, and revealed the nerve of origin to be the vagal nerve. Pathologically, H-E stained specimens showed that the tumor was a benign neurofibroma. However, immunostaining of the majority of the tumor cells were positive for PCNA. These results suggest that the tumor of our case possessed a low malignant potential. To date, neither local recurrence nor distant metastasis has been found on subsequent examinations.

Cranial Nerve Neoplasms↗
PubMed1994

Work environment of plants manufacturing asbestos-containing products in Japan.

In 1985, a comprehensive study of asbestos-containing product plants (A/C, friction, textile) was performed. The data presented were based not on personal but on area sampling. A conversion equation from area sampling data to personal exposure values was developed. Exposure concentrations were 0.07-0.66 f ml-1. In workplaces which belonged to member companies of the Japan Asbestos Association, the percentage of workplaces whose exposure concentrations was less than 0.3 f ml-1 was 70% in 1985 (N = 510), but 98% in 1992 (N = 430). Concentrations in a new, well-controlled A/C plant were less than 0.1 f ml-1.

Asbestos↗
PubMed1994

Two alternative pathways of transcription initiation in the yeast negative regulatory gene GAL80.

The yeast GAL80 gene, encoding a negative regulatory protein of galactose-inducible genes, shows both constitutive and galactose-inducible expression. The inducible transcription is under the control of Gal4p, a common activator for the galactose-inducible genes, which binds to an upstream activation sequence, called UASG, spanning between -105 and -89 in the 5'-flanking region of GAL80. Here we demonstrate that the constitutive transcription started at +1, whereas the inducible transcription occurs from a set of downstream sites at +37, +47, +56, and +67. Both transcriptions were enhanced 10-fold by another UAS, whose 5' boundary is located between -195 and -185. Gal4p stimulated transcription, which depends on the TATA box located at -20, from all the downstream sites. By contrast, the constitutive transcription depended on a small region of less than 16 bp long encompassing the +1 site, which directed transcription even in the absence of both the TATA box and the UASs. When a fragment covering that region was inserted immediately upstream of the open reading frame of HIS3, the resulting gene fusion, if introduced into a his3 yeast strain, supported growth on histidine-lacking medium. We detected by gel retardation assay a protein specifically interacting with this fragment. All the transcriptions observed in the in vivo experiments were faithfully reproduced in a cell-free transcription system. From these results, we suggest that initiation of GAL80 transcription involves two alternative pathways; one is initiator dependent, and the other is Gal4p regulated and TATA dependent.

Base Sequence↗
PubMed1994

Regioselective cleavage reaction of the aromatic methylenedioxy ring. VI. Synthesis of phenothiazine analogues by using the cleavage reaction with sodium methoxide-thiols in dimethyl sulfoxide and evaluation of their biological activities.

The reactions of aromatic methylenedioxy compounds containing electron-withdrawing groups with sodium methoxide-thiols in dimethyl sulfoxide gave 3- and 4-hydroxybenzene derivatives in good yield by regioselective attack of the thiolate ions on the methylenedioxy ring. The formation mechanism and the reactivity of thiolate ions in the cleavage reaction of the methylenedioxy ring are discussed. Various biologically active compounds, 32a, 32d, 36b, 38b, 41b and 44-47, were prepared from the 4-hydroxybenzene derivatives and their Ca2+ antagonistic activities were evaluated. Among these compounds, 2-(2-bromophenylthiomethoxy)-10-(2-diethylaminoacetyl)-3- methoxyphenothiazine (46) showed the most potent Ca2+ antagonistic activity. Biological activity could be conveniently evaluated by measurement of the peak height of the vanadyl ion (+4 oxidation ion) signal produced by redox reaction between the phenothiazine derivatives and vanadate ion +5 oxidation ion) with ESR spectroscopy.

Animals↗
PubMed1994

Purification and characterization of D-xylose isomerase from Bifidobacterium adolescentis.

D-Xylose isomerase was purified to homogeneity from cell-free extracts of Bifidobacterium adolescentis by ammonium sulfate fractionation and chromatographies on DEAE-cellulose and Butyl-Toyopearl. The molecular weight of the purified enzyme was estimated to be 168,000 by gel filtration on TSKgel G-3000SW, and 53,000 on SDS-polyacrylamide gel electrophoresis. The optimum pH was around 7 and the enzyme was stable at pH 7-8. The enzyme required bivalent cations, Mg2+, Co2+, or Mn2+ for the activity, particularly Mn2+ to be best. The enzyme had a pI of 4.3, and the Km for D-xylose was 4 mM. The N-terminal amino acid sequence of the enzyme was not similar to those of D-xylose isomerases from other sources such as Clostridium thermosulfurogenes, Escherichia coli, or Bacillus subtilis.

Aldose-Ketose Isomerases↗
PubMed1994

Vanadium distribution in rats and DNA cleavage by vanadyl complex: implication for vanadium toxicity and biological effects.

Vanadium ion is toxic to animals. However, vanadium is also an agent used for chemoprotection against cancers in animals. To understand both the toxic and beneficial effects we studied vanadium distribution in rats. Accumulation of vanadium in the liver nuclei of rats given low doses of compounds in the +4 or +5 oxidation state was greater than in the liver nuclei of rats given high doses of vanadium compounds or the vanadate (+5 oxidation state) compound. Vanadium was incorporated exclusively in the vanadyl (+4 oxidation state) form. We also investigated the reactions of vanadyl ion and found that incubation of DNA with vanadyl ion and hydrogen peroxide (H2O2) led to intense DNA cleavage. ESR spin trapping demonstrated that hydroxyl radicals are generated during the reactions of vanadyl ion and H2O2. Thus, we propose that the mechanism for vanadium-dependent toxicity and antineoplastic action is due to DNA cleavage by hydroxyl radicals generated in living systems.

Animals↗
PubMed1994

Study on the castability of Co-Cr alloy for cast plates. Part 4. Effects of sectional area, number of sprues and alloy components on castability.

Co-Cr alloy is used more frequently than Ni-Cr alloy as a nonprecious alloy for cast plates in Japan. Titanium with good biocompatibility has often been contained in the composition of this Co-Cr alloy. However, since the melting temperature of Co-Cr alloy is very high, about 1300 degrees C, and it oxidizes easily, a vacuum-pressure casting machine capable of melting this alloy in a reduced atmosphere has recently been developed. In this study, using the vacuum-pressure casting machine, the possible effects of sectional area and the number of sprues attached to the cast plate wax pattern, as well as the alloy components, on the castability of three kinds of Co-Cr alloy containing titanium were examined. It was found that all of these parameters had significant effects on Co-Cr alloy castability.

Chromium Alloys↗
PubMed1994

[Surgical repairs of anomalous pulmonary venous connection to superior vena cava and right atrial junction].

We recently encountered a case of total anomalous pulmonary venous connection (TAPVC, Darling Ib) and 3 cases of partial anomalous pulmonary venous connections (PAPVC) to the superior vena cava. We surgically treated these 4 cases by different procedures which were selected according to the morphological features of individual cases. In the case of TAPVC (Darling Ib), we created a right atrial wall flap, according to the method of Vargas, so that the blood from the abnormal pulmonary vein could pass the left atrium via the superior vena cava and atrial septal defect. In 3 cases of PAPVC, we modified some techniques of right atrial incision and closure by suturing. Through these surgical procedures, none of the 4 patients developed postoperative stenosis of the pulmonary venous pathway or arrhythmias. Various surgical procedures have been reported for the treatment of anomalous pulmonary venous connection, an anomaly involving direct connection of the pulmonary vein to the superior vena cava or to the right atrial junction of the superior vena cava. However, the incidence of postoperative stenosis or obstruction of the pulmonary venous pathway or postoperative sick sinus syndrome has been high with these procedures.

Adult↗
PubMed1994

[A case report of successful management of intraoperative aortic dissection during aorta-coronary bypass and aortic valve replacement].

A 70-year-old woman underwent aortic valve replacement and coronary artery bypass surgery with a saphenous vein graft for aortic regurgitation and 99% stenosis in the right coronary artery. During the period of weaning from the cardiopulmonary bypass enlargement of the ascending aorta and bleeding from the suture line were observed. The intraoperative diagnosis of ascending aortic dissection (DeBakey type I) was made with transesophageal and transthoracic echocardiography. Cardiopulmonary bypass was reinstituted and the patients was cooled to 20 degrees C. Under circulatory arrest and continuous retrograde cerebral perfusion through the superior vena cava the intimal tear at the point of infusion cannula was removed and the ascending aorta was reconstructed by direct suture bolstered with Teflon felt strips. Following completion of the repair no further dissection was seen, and the patient was successfully weaned from cardiopulmonary bypass. There were no signs of neurologic complications. Although intraoperative aortic dissection is uncommon, it can be a fatal iatrogenic complication of cardiac operations. Prompt recognition and surgical repair of the injuries are essential to achieve a successful outcome. The combination of transesophageal echocardiography and transthoracic echocardiography permits the immediate diagnosis of aortic dissection. And it is suggested that continuous retrograde cerebral perfusion through the superior vena cava protects the brain for 52 minutes of cerebral circulatory arrest at the lowest nasopharyngeal temperature of 18.7 degrees C. This technique is simple, and required neither special preoperative preparation or special equipment, so that it is suitable especially for intraoperative aortic dissection such as this case.

Aged↗
PubMed1994

[A successful case of external conduit operation for tetralogy of Fallot with pulmonary atresia at the age of 17 months].

We report a successful case of external conduit operation in a 7.2 kg male infant. A 17-month-old boy was admitted because of increasing cyanosis and polycythemia. He had undergone classical Blalock-Taussig shunt at the age of 51 days with the diagnosis of tetralogy of Fallot with pulmonary atresia. Cardiac catheterization showed stenosis of the right pulmonary artery related to the site of the shunt. We chose external conduit operation and correction of the right pulmonary artery stenosis instead of additional shunt and correction of the stenosis with cardiopulmonary bypass. He is in a good postoperative condition. It is preferable that external conduit operation is applied to similar infant cases from the standpoint of exercise ability, myocardial degeneration and postoperative arrhythmia.

Blood Vessel Prosthesis↗
PubMed1994

[The indications and limitations of open heart surgery without homologous blood transfusion in children and infants].

Open heart surgery without homologous blood transfusion in adults is a generalized method, but not in children and infants. We have attempted to perform open heart surgery without blood transfusion in small children and infants, and report here our experiences and ideas in this regard. The number of open heart surgeries we performed on patients less than 15 years old was 117 from April 1988 to April 1993. In 57 patients among them we attempted open heart surgery with bloodless priming in the cardiopulmonary bypass circuit. Eleven patients were given blood transfusion during the operation or the post-operative period. Another 46 discharged without blood transfusion. From April 1988 to December 1990 (the earlier period) we used the conventional style cardio-pulmonary bypass circuit with gravity venous drainage for 12 patients undergoing open heart surgery without blood transfusion. The lowest weight of these patients was 13 kg and the main diseases were ASD and mild VSD. From January 1991 to April 1993 (the later period), we used the new type cardio-pulmonary bypass circuit with lower priming volume for 34 patients undergoing open heart surgery without blood transfusion. The youngest age was 7 months and the lowest weight was 6.5 kg. The diseases were ASD (9), mild VSD and VSD/PH (15), TOF (6) and other (4). In the new cardiopulmonary bypass system, the venous reservoir and cardiotomy sucker are given negative pressure ((-10)-(-40) mmHg) with a vacuum not a pump, and only one roller pump is used for the arterial pump.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗