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Biomedical subjects

M Shirakawa

Publications and source records attributed to M Shirakawa.

At least 91 records · Page 5Linked to original sources
PubMed1991

Inhibition of lipoxygenase by phenolic compounds.

Eugenol dose-dependently inhibited 5-HETE (5-hydroxy-5,8,10, 14-eicosatetraenoic acid) and 15-HETE formation by human polymorphonuclear leucocytes. p-Chlorophenol, guaiacol and phenol also inhibited the lipoxygenases. Formation of HETEs by rat dental pulp was inhibited by eugenol and p-chlorophenol. The concentrations of the phenolics required to inhibit lipoxygenases were in the similar range with those used for inhibiting cyclooxygenase. These results showed that phenolic compounds inhibited lipoxygenases and thus suggest that these compounds may be dual inhibitors of lipoxygenase and cyclooxygenase.

Animals↗
PubMed1990

Congenital arteriovenous fistula in the gluteal region--a report of five cases.

Five cases of congenital arteriovenous fistula in the gluteal region have been encountered in our department in the past 20 years. In all cases, the fistulous masses were in the connective tissue between the gluteal muscles and well-localized. Preoperative angiography showed the feeding arteries to be the superior gluteal, the inferior gluteal, and/or the lateral femoral circumflex arteries, and all the arteriovenous fistulae were excised almost completely with success. In this report, we emphasize the importance of precise estimation of the feeding arteries on preoperative angiography and ligating them before excising the fistulous masses, to ensure safe surgical treatment.

Adolescent↗
PubMed1990

Aortobronchial fistula after an aortic operation.

A 71-year-old man with a postoperative aortobronchial fistula was successfully treated. The fistula occurred between the left lower lobe and the descending thoracic aorta, to which a distal anastomosis of a temporary bypass graft had been placed during thoracic aortic aneurysmectomy 3 years before. For saving patients with this complication, early surgical treatment during episodes of intermittent hemoptysis is important. The use of an omentum pedicle flap for the isolation of the suture line is a important adjunct.

Aged↗
PubMed1990

Efficient expression and Zn(II)-dependent structure of the DNA binding domain of the yeast GAL4 protein.

Three protein fragments of different sizes which contain the DNA binding domain of transcription factor GAL4 from Saccharomyces cerevisiae have been expressed in functional forms in Escherichia coli. DNase I footprinting and gel retardation assays showed that the purified proteins bound to the same DNA sequence on the gal1-gal10 promoter as intact GAL4 does. Denaturation--refolding experiments demonstrated that Zn(II) is necessary for maintenance of the conformation of the DNA binding domain of GAL4, as judged on UV-CD and 1H-NMR measurements, as well as for specific DNA binding.

Amino Acid Sequence↗
PubMed1990

Binding specificity of Fusobacterium nucleatum to human erythrocytes, polymorphonuclear leukocytes, fibroblasts, and HeLa cells.

Eighteen strains of Fusobacterium nucleatum were studied with respect to their adherence to human erythrocytes, polymorphonuclear leukocytes, fibroblasts, and HeLa cells. Four types of adherence were found: 1) sugar-sensitive adherence 2) amino acid-sensitive adherence 3) unknown adherence 4) weak adherence. There was no obvious correlation between the patterns of hemagglutination and adherence to other cells. The results indicate not only a complex network of bacterial receptors on human cells, but also a variety of types of bacterial adherence as expressed by the selectivity of the bacterial binding to specific cell surfaces.

Acetylgalactosamine↗
PubMed1990

[Histo-pathology of the regenerating process in the tissue around the periodontally diseased teeth of beagle dogs. Clinical and histological analysis following flap surgery].

The regenerating process in tissue around periodontally diseased teeth (PDTs) and non-diseased teeth (NDTs) was studied with clinical and histological analysis following flap surgery. PDTs were prepared in the premolars of 7 beagle dogs by which surgically denuding the root surfaces by removing the alveolar bone. The denuded sites were covered with gutta-percha plates and gingival epithelial tissues and exposed to the oral environment for 4 weeks. Then flap surgery was performed on the PDTs. As control sites, the root surfaces of the NDTs were denuded by removing the alveolar bone at the time of flap surgery. The root surfaces of the PDTs and NDTs were planed with curette scalers at one root site but not at the other site. Clinical and histopathological findings were evaluated at fixed intervals for 32 weeks after surgery. Results of observation were as follows. 1. In the clinical evaluations, the gingival inflammation index, probing depth and attachment level were improved in the root planing (PR) group of both the PDTs and the NDTs, but in the non RP group of PDTs there was no improvement. 2. In the histologic observation, the position of the gingival margin, length of regenerated junctional epithelium, depth of gingival sulcus and the level of connective tissue attachment in the RP groups recovered in both the PDTs and the NDTs but not in the non RP groups.

Animals↗
PubMed1990

[Adult T-cell leukemia associated with pure red cell aplasia-like lesion].

An adult T cell leukemia associated with pure red cell aplasia-like lesion was described in this paper. A 51 year-old woman was admitted because of headache and palpitation in October 1988. On admission, physical examination showed marked pallor but no detectable superficial lymphadenopathies. Hepatosplenomegaly was not observed. The blood examination revealed normocytic anemia with Hb of 6.6 g/dl and marked leukocytosis of 18,800/microliters with 43% ATL cells. The bone marrow aspirate showed moderate infiltration of ATL cells and a few erythroblasts. The bone marrow biopsy disclosed moderate infiltration of ATL cells, only a few erythroblasts with maturation arrest and marked fibrosis. The erythropoietin in serum was elevated (686 IU/microliters). To clarify the mechanism of development of the PRCA-like lesion, the peripheral blood lymphocytes (ATL cells) or serum of the patient was added to in vitro erythroid colony formation. The patient's serum increased BFU-E but either serum or lymphocytes didn't inhibit the growth of CFU-E compared with control.

Anemia↗
PubMed1990

[A successfully treated case of aortouretric fistula associated with pelvic exenteration].

A 64-year-old man was hospitalized for massive bleeding from the cutaneous ureterostomy. He had undergone pelvic exenteration with the ureterostomy for rectal cancer invading the bladder five months previously and retrograde ureteric catheters were inserted bilaterally into the ureters. An aortography revealed a pseudoaneurysm of the abdominal aorta in the region transversed by the left ureter. He was successfully treated by en bloc resection of the aortoureteric fistula and the left ureter and repair of the aorta by Dacron patchplasty. Left nephrectomy was also performed because of pyelonephritis. He has had no signs of cancer recurrence or graft infection five years after this operation.

Aorta, Abdominal↗
PubMed1989

[Histological study on gingival tissue reattachment after periodontal surgery. Effects of hydroxyapatite ceramic implantation to denuded dentin surfaces in rats].

The purpose of this study was to evaluate histological regeneration of epithelial and connective tissue attachment to the denuded dentin surface after hydroxyapatite ceramic granule (HAP) implantation. HAP (particle size 100-300 microns, burn temperature 900 degrees C) were implanted into dehiscent defects of alveolar bone which eliminated about a 1 x 1 mm area at mesial and palatal sites of the upper 1st molar in 20 male Wistar rats. Subsequently the root cementum was removed totally and dentin was denuded. Same osseous defects were formed but HAP was not implanted at any contralateral site for the purpose of control. Results of 8-week examination using light and electron microscopy were as follows: 1. In the HAP group junctional epithelium was regenerated on the denuded dentin surface 2 weeks after implantation and epithelial down growth was less than at the control site. 2. In the HAP group connective tissue reattachment with new cementum formation was observed at 2 to 4 weeks after implantation, the healing period tended to be shorter than at the control site and the connective tissue reattachment level was located more coronally. 3. In ultrastructural findings collagen fiber bundles attached to the denuded dentin surface had fibers continuing around HAP granules.

Animals↗