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Biomedical subjects

Takeshi Shioya

Publications and source records attributed to Takeshi Shioya.

7 recordsLinked to original sources
PubMed2006

Helicobacter pylori infection with a duodenal ulcer in a 6-year-old boy.

A 6-year-old boy was hospitalized because of dark feces and facial pallor of 1 weeks duration. Other gastrointestinal symptoms, including vomiting and abdominal pain, were absent, but he felt dizziness when standing and fatigue on effort. Hematologic studies revealed iron-deficiency anemia, and endoscopy showed gastric erosions and a duodenal ulcer. All test results for Helicobacter pylori infection, including H. pylori antigen in stool, anti-H. pylori IgG immunoassay in serum, and the (13)C-urea breath test, were positive. Because an H. pylori-associated gastric ulcer had been diagnosed with endoscopy in the patients father 3 years earlier, father-son transmission was suspected. The patient was treated with triple-agent eradication therapy (proton pump inhibitor [lansoprazol], amoxicillin, and clarithromycin) for 2 weeks. One month after therapy was completed, eradication of H. pylori was confirmed by negative results on the stool antigen test. Peptic ulcer disease can occur in young children, as in this case. The stool antigen test kit is a useful and reliable method that can be used even in preschool children to diagnose H. pylori infection.

Child↗
PubMed2004

Synthesis and properties of highly fluorescent indolizino[3,4,5-ab]isoindoles.

We report here the synthesis, X-ray structures, optical and electrochemical properties, fabrication of light-emitting devices, and density functional calculations for indolizino[3,4,5-ab]isoindole (INI) derivatives. Strongly luminescent heterocycles based on the INI unit were synthesized by 1,3-dipolar cycloaddition reactions between pyrido[2,1-a]isoindole (PIS) and acetylene or ethylene derivatives. They are indolizino[3,4,5-ab]isoindoles 2-9 and 14-15, benzo[1',2'-1,2]indolizino[3,4,5-ab]isoindoles 10, pyridazino[4',5':1,2]indolizino[3,4,5-ab]isoindoles 12-13, and 2,3-hydropyridazino[4',5':1,2]indolizino[3,4,5-ab]isoindole-1,4-dione 11. The relative luminescence quantum yield can be as high as 90%. Their reduction and oxidation potentials and high luminescence can make these heterocycles possible alternatives to tris(8-hydroxyquinolinato)aluminum (Alq(3)). The brightness of the light-emitting device reached as high as 10(4) cd/m(2) and indolizino[3,4,5-ab]isoindole 3 emits beautifully blue light. The X-ray crystal structures of INI derivatives were obtained for the first time. The geometries obtained from X-ray data and density functional theory calculations shed more light on an interesting formally antiaromatic 16pi system, which is divided into 10pi and 6pi aromatic systems. We also report a relatively easy protonation of INI, which occurs at a carbon, rather than nitrogen atom.

Journal Article↗
PubMed2004

Cure of intractable pancreatic fistula by subcutaneous fistulojejunostomy.

Fistulojejunostomy was performed at the subcutaneous level in two patients with intractable pancreatic fistula that occurred after surgery for cancer of the ampulla of Vater and carcinoma of the lower bile duct. The treatment yielded mostly satisfactory results, though one patient incurred postoperative wound dehiscence, which was healed with conservative measures. Compared with conventional procedures, this method is technically easy to perform, as it does not involve surgical separation of the fistula up to a site deep within the abdominal cavity, rarely results in side injury, and poses few potential risks of cicatricial stenosis of the fistular lumen, because blood supply to the fistula is preserved. Subcutaneous fistulojejunostomy is considered to be recommendable for pancreatic fistulas that occur long after surgery and which are stenosed at the site of the pancreatojejunal stenosis and thus require surgical treatment.

Aged↗
PubMed2004

Facilitated sulfate transfer across the nitrobenzene-water interface as mediated by hydrogen-bonding ionophores.

Facilitated SO4(2-) transfers by hydrogen bond-forming ionophores are investigated across the nitrobenzene (NB)-water interface by using polarography with a dropping electrolyte electrode. Bis-thiourea 1, alpha,alpha'-bis(N'-p-nitrophenylthioureylene)-m-xylene, is found to significantly facilitate the transfer of the highly hydrophilic SO4(2-) whereas its counterpart, N-(p-nitrophenyl)-N'-propylthiourea (ionophore 2), cannot. In contrast to the predominant formation of a 1:1 complex with SO4(2-) in the bulk NB phase, the SO4(2-) transfer assisted by 1 is indeed based on the formation of a 1:2 complex between SO4(2-) and ionophore, even under the condition of [SO4(2-)]aq >> [1]org. Such an exclusive formation of the 1:2 (SO4(2-) to ionophore) complex at the NB-water interface is not observed with structurally similar bis-thiourea 3, alpha,alpha'-bis(N'-phenylthioureylene)-m-xylene, where p-nitrophenyl moietes of bis-thiourea 1 are simply replaced by phenyl groups. The facilitated transfer of SO4(2-) with bis-thiourea 1 is further compared to that of HPO4(2-) and H2PO4- across the NB-water interface, which was previously shown to be assisted by 1 through the formation of the 1:1 and 2:1 (anion to ionophore) complexes, respectively. On the basis of these examinations, unique binding behaviors of hydrogen bond-forming ionophores at the NB-water interface are discussed, with a view towards development of ionophore-based anion-selective chemical sensors.

Journal Article↗
PubMed2002

Metachronous adenocarcinoma occurring at a colostomy site after abdominoperineal resection for rectal carcinoma.

Carcinomas rarely occur at the site of a colostomy. A 73-year-old man underwent abdominoperineal resection (Miles' surgical procedure) for rectal carcinoma in September 1988. He did not return to the hospital until September 1995, when he was admitted with stricture of the stoma. Neither tumor nor ulcer was detected at the stoma. The tip of the doctor's little finger was able to pass through the stoma, and manual expanding alleviated the stricture. The patient did not return to the hospital again until August 1996, at age 81 years, when he visited the hospital because of complete stricture of the stoma. A biopsy revealed an adenomatous carcinoma, but the results of various examinations suggested no metastasis. A portion of the intestine, including the stoma and surrounding skin, was resected, and a new stoma was created in the descending colon. We report this rare carcinoma occurring at the site of a colostomy, and we review the literature.

Adenocarcinoma↗