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Biomedical subjects

Y Iwata

Publications and source records attributed to Y Iwata.

At least 55 records · Page 3Linked to original sources
PubMed2000

A case of cavernous hemangioma of the small intestine diagnosed by scintigraphy with Tc-99m-labeled red blood cells.

Hemangioma of the small intestine is rare, and the preoperative diagnosis of it is difficult. We report a patient with gastrointestinal bleeding for whom Tc-99m-labeled red blood cell scintigraphy was useful in diagnosing cavernous hemangioma of the small intestine. A 25-year-old man was referred to our hospital for recurrent iron deficiency anemia. Because of the patient's severe anemia, imaging was performed to locate the bleeding lesion in the gastrointestinal tract. Scintigraphy with Tc-99m-labeled red blood cells revealed pooling indicating a tumor and extravasation of blood from the tumor. Scintigraphy with Tc-99m pertechnetate revealed no abnormal accumulation. Partial resection of the small intestine was done, and cavernous hemangioma of the small intestine was diagnosed by using the specimen of resected tissue.

Adult↗
PubMed2000

A case of recurrent cholangitis after bile duct injury during laparoscopic cholecystectomy: value of scintigraphy with Tc-99m GSA and hepatobiliary scintigraphy for indication of lobectomy.

A 39-year-old woman with acute cholecystitis and gallstones underwent laparoscopic cholecystectomy. She suffered from recurrent episodes of cholangitis due to injury of the major bile ducts during laparoscopic cholecystectomy. Hepatobiliary scintigraphy with Tc-99m Sn-N-pyridoxyl-5-methyltryptophan was performed. Although normal bile excretion was found from the left hepatic duct to the percutaneous transhepatic biliary drainage (PTBD) tube, excretion from the right hepatic lobe was prolonged. Scintigraphy with Tc-99m diethylenetriaminepentaacetic acid-galactosyl human serum albumin demonstrated atrophy of the right hepatic lobe and enlargement of the left hepatic lobe. Cholangiography via the PTBD tube revealed complete obstruction of the left hepatico-jejunal anastomosis and could not enhance the right intrahepatic bile duct. A right hepatic lobectomy was performed because of the atrophy, glissonitis and the absence of an appropriate bile duct for reconstruction. Postoperatively she was active and exhibited no evidence of recurrent cholangitis.

Adult↗
PubMed2000

Infective endocarditis affecting both systemic and pulmonary circulations predisposed by a ventricular septal defect.

A 39-year-old woman was admitted to our hospital presenting persisting fever. An echocardiographic examination showed severe aortic and mitral valve regurgitation with moderate tricuspid regurgitation. Small left-to-right shunt through the ventricular septal defect was identified. Vegetation was also detected on the tricuspid, mitral, and aortic valves. At one month after admission, the patient showed sudden onset of headache and abdominal pain. A computed tomographic scan demonstrated cerebral and splenic infarction. A pulmonary perfusion scintigram demonstrated perfusion defects in left-S1 and right-S6 regions. At 4 months after admission, as operation was performed. The aortic valve was replaced with a #23 mm CarboMedics prosthesis and the mitral valve with a #29 mm Carbo Medics prosthesis. Tricuspid valve plasty was performed, with closure of He laceration and perforation of the anterior leaflet combined with a commissuroplasty, according to Kay's method. Ventricular septal defect was closed with a bovine pericardial patch. She was discharged at 19 days after the operation, and is leading a good life. Pervasion of the organism seemed to be initiated from the mitral valve which was conveyed by the blood stream to the aortic valve, and to the tricuspid valve through the ventricula septal defect. Left heart evaluation may be important in cases with infective endocarditis and ventricula septal defect.

Adult↗
PubMed2000

One-step hysteroscopic removal of sinking submucous myoma in two infertile patients.

OBJECTIVE: To report one-step resectoscopic removal of submucous myomas that were pushed back into the muscular layer by increased intrauterine pressure during hysteroscopic procedures. DESIGN: Case report. SETTING: Kawasaki Municipal Hospital, Kawasaki, Japan. PATIENT(S): Two infertile women presenting with menorrhagia in whom submucous myoma with a broad base was diagnosed. INTERVENTION(S): One patient was pretreated with GnRH agonist for 4 months; the other patient did not receive this treatment. Resectoscopic myomectomies were performed under close sonographic monitoring. MAIN OUTCOME MEASURE(S): Clinical symptoms and conception status. RESULT(S): Tumor sinking occurred during the hysteroscopic procedures, but complete resectoscopic removal of the submucous myomas was achieved under sonographic and hysteroscopic visualization. One patient experienced hyponatremia but recovered after conservative treatment. Both patients conceived after myoma removal. CONCLUSION(S): Sinking myomas, which may cause infertility, can be removed with a one-step hysteroscopic procedure. Sinking of submucous myomas during hysteroscopy might be caused by pretreatment with GnRH agonist and by increased intrauterine pressure during hysteroscopy. We recommend that intrauterine pressure be <45 mmHg, equivalent to hanging a bag of fluid under gravity control 70 cm above the patient's uterus, at the beginning of operations for sinking myomas.

Adult↗
PubMed2000

Conformational analysis and docking study of potent factor XIIIa inhibitors having a cyclopropenone ring.

A conformational analysis and docking study of potent factor XIIIa inhibitors having a cyclopropenone ring were carried out in an attempt to obtain structural insight into the inhibition mechanism. First, stable conformers of the inhibitors alone were obtained from the conformational analysis by systematic search and molecular dynamics. Next, a binding form model of factor XIIIa was built based on an X-ray crystal structure of the enzyme. Finally, the docking study of the inhibitors into the model's binding site was performed. From the resulting stable complex structures, it was found that the cyclopropenone ring fits the active site located at the base of the binding cavity with high complementarity. The carbonyl oxygen of the cyclopropenone ring formed a hydrogen bond to the indole NH group of Trp279 and the terminal carbon atom of the reactive C=C double bond was in close proximity to the sulfur atom of the catalytic residue, Cys314. This binding mode suggests a possible inhibition mechanism, whereby the cysteine residue reacts with the cyclopropenone ring of the inhibitor, forming an enzyme-ligand adduct. In addition, the higher interaction energies between factor XIIIa and the inhibitors alluded to the probable binding sites of the ligand side chain.

Cyclopropanes↗
PubMed2000

Up-regulation of monocyte chemoattractant protein-1 in tubulointerstitial lesions of human diabetic nephropathy.

BACKGROUND: We previously described that monocyte chemoattractant protein-1 (MCP-1) plays an important role in progressive glomerular and interstitial damage in inflammatory renal diseases. However, the expression of MCP-1 in diabetic nephropathy remains to be investigated. METHODS: We examined whether locally expressed MCP-1 participates in human diabetic nephropathy via recruiting and activating monocytes/macrophages (Mphi). Urinary and serum MCP-1 levels were measured by enzyme-linked immunosorbent assay in 45 patients with diabetic nephropathy. The presence of MCP-1 in diseased kidneys was determined by immunohistochemical and in situ hybridization analyses. RESULTS: Urinary MCP-1 levels were significantly elevated in patients with diabetic nephrotic syndrome and advanced tubulointerstitial lesions. Moreover, urinary levels of MCP-1 were well correlated with the number of CD68-positive infiltrating cells in the interstitium. In contrast, serum MCP-1 levels remained similar to those of healthy volunteers. Furthermore, we detected the MCP-1-positive cells in the interstitium of diabetic nephropathy via both immunohistochemical and in situ hybridization analyses. CONCLUSION: These observations suggest that locally produced MCP-1 may be involved in the development of advanced diabetic nephropathy, especially in the formation of tubulointerstitial lesions possibly through Mphi recruitment and activation. Moreover, up-regulation of MCP-1 may be a common pathway involved in the progressive tubulointerstitial damage in diabetic nephropathy as well as inflammatory renal diseases.

Adolescent↗
PubMed2000

Assessment of hepatic blood flow by PET with 15O water: correlation between per-rectal portal scintigraphy with 99Tc(m)-pertechnetate and scintigraphy with 99Tc(m)-GSA.

We performed positron emission tomography with 15O water (H2(15)O) to measure hepatic arterial and portal blood flow. In addition, portal haemodynamics and hepatic functional reserve were measured by per-rectal portal scintigraphy and scintigraphy with galactosyl human serum albumin, respectively. We studied 15 patients who had cirrhosis of the liver with underlying viral infection. After the intravenous injection of H2(15)O, positron emission tomography was performed. Blood samples were obtained after beginning the emission scan. The blood samples and positron emission tomographic images were analysed to calculate the radioactivity in the blood and liver. One-compartment model analysis was used to estimate hepatic arterial and portal blood flow. Computer acquisition of gamma-camera data was started just before the injection of 99Tc(m)-galactosyl human serum albumin. A receptor index and an index of blood clearance were calculated on the basis of the radioactivity of the liver and heart. A 99Tc(m)-pertechnetate solution was instilled into the rectum; serial scintigrams were performed and radioactivity curves for the liver and heart were recorded sequentially. A per-rectal portal shunt index was calculated from the curves. Median portal blood flow was 80 ml x 100 g(-1) x min(-1), median hepatic arterial blood flow was 56 ml x 100 g(-1) x min(-1), and median total hepatic blood flow was 138 ml x 100 g(-1) x min(-1) in patients with cirrhosis. The correlations between portal blood flow and the Child-Turcotte classification score, portal shunt index and receptor index were all significant. Our results show that hepatic arterial and portal blood flow can be measured by positron emission tomography with H2(15)O non-invasively and physiologically. This technique may be useful in pathophysiological studies of liver disease.

Hepatitis, Viral, Human↗
PubMed2000

Preparation of novel synthons, uniquely functionalized tetrahydrofuran and tetrahydropyran derivatives.

The dianion of the acetoacetic ester reacts with epibromohydrin derivatives to afford a mixture of (Z)-2-alkoxycarbonylmethylidenetetrahydrofuran derivative and (E)-2-alkoxycarbonylmethylidenetetrahydropyran derivative. The selective formation of the tetrahydrofuran derivative is achieved by the use of LiClO4 as the additive. The preparation of the optically active tetrahydrofuran derivatives and tetrahydropyran derivatives is also examined, and the optical purity and absolute configuration of the products is elucidated.

Furans↗
PubMed2000

Conformational analysis of 2-[2-(3-methoxyphenyl) ethyl]phenoxyalkylamines with high 5-HT2 receptor binding affinity.

A conformational analysis of three groups of 2-[2-(3-methoxyphenyl)ethyl]phenoxyalkylamines with high 5-HT2 receptor binding affinity has been performed using the systematic search. Two groups of compounds with different lengths of alkyl chains connecting the amine nitrogen and the central oxygen showed a one order difference in their 5-HT2 receptor binding affinity. The computational analysis of these compounds confirmed the differences in the N--O distances between the two groups, quantitatively. A probable active conformation was proposed based on a superimposition of the stable conformations over a rigid molecule, mianserin. Two hydroxy derivatives in the third group showed a significant difference in their binding affinity depending on the stereochemistry of the hydroxy group. The difference in the energetically favorable order of the stable conformations reasonably explained the relationship between the stereochemistry and the binding activity. A molecular dynamics-based conformational search was also carried out to compare it with the systematic search.

Alkanes↗
PubMed2000

[A case of total cavopulmonary connection by utilization of coronary sinus as a hepatic venous return].

A 2-year-old boy with polysplenia, double outlet right ventricle after pulmonary banding and unilateral bidirectional shunt was operated on. A modified total cavopulmonary connection was done by utilization of coronary sinus as a retrograde route for the hepatic venous return. Left SVC was transected and its distal end was anastomosed to the left pulmonary artery after PA angioplasty. An equine pericardial patch was placed over the ostia of the hepatic vein and coronary sinus. Two ostia of the coronary veins were excluded from the created route. The proximal end of the left SVC was anastomosed to the inferior side of the left pulmonary artery. Postoperative course was uneventful. The postoperative angiogram showed smooth hepatic venous return through the coronary sinus and no pressure gradient was recorded between hepatic vein and pulmonary artery.

Child, Preschool↗
PubMed2000

[Neurosarcoidosis with girdle sensation and polyradiculoneuropathy masquerading as Guillain-Barré syndrome].

We herein report two patients with neurosarcoidosis presenting girdle sensation in the trunk and polyradiculoneuritis. The first patient, a 53-year-old woman, manifested subacute progressive paresthesia in all four limbs and below the Th 3 level with girdle sensation from the thorax to lower abdomen and mild weakness in the left upper limb and the bilateral lower limbs. The patient was diagnosed to have sarcoidosis based on a biopsy of the scalenus anticus lymph nodes. The second patient, a 63-year-old woman, showed an acute onset of weakness and paresthesia in all four limbs and girdle sensation from the Th 5 to Th 8 level. On examination, she demonstrated diminished tendon reflexes in all four limbs, mild to severe weakness in all four limbs, paresthesia in all four limbs and below the Th 5 level. Although Guillain-Barré syndrome was initially suspected in this patient, the presence of girdle sensation led us to examine the possibility of neurosarcoidosis. Her examination demonstrated an abnormal accumulation of gallium in the bilateral hilar lymph nodes and mediastinum on scintigraphy, an elevated CD 4/CD 8 ratio in the bronchoalveolar lavage fluid, a negative tuberculin reaction, and elevated serum lysozyme level. These findings thus fulfilled the clinical criteria for sarcoidosis. None of the two patients showed any abnormalities in the thoracic cord MRI. In the first patient F wave was not evoked in either upper or lower limbs, while in the second patient temporal dispersion on M wave was observed in the right median and both ulnar nerves. We therefore consider the girdle sensation to have not been caused by myelopathy but instead by polyradiculopathy. When sarcoid peripheral neuropathy masquerades as Guillain-Barré syndrome, then the presence of girdle sensation may help diagnosis of neurosarcoidosis.

Diagnosis, Differential↗
PubMed2000

[Postoperative evaluation of EC/IC bypass surgery--long-term follow up study by donor artery compression test].

Focal cerebral vascular dependency of donor arteries was evaluated in 45 patients who had undergone EC/IC bypass surgery. During EEG recording, digital compression was applied to the anastomosed donor superficial temporal artery (STA) at the preauricular region. The appearance of slow waves on the EEG recording suggests hypofunction of the local brain. In cases showing positive response to the STA compression test, we suggest that the blood supply via STA is an essential collateral route to the ischemic brain. The test was periodically repeated in the postoperative follow-up period for a mean of seven years. Eleven cases (24%) showed positive results in the STA compression test during the long-term postoperative follow-up period.

Adult↗
PubMed2000

[A case of high-age minimal change nephrotic syndrome relapse after 18-year remission and effective treatment with steroid and cyclosporin combined therapy].

We describe the clinical course of a 69-year-old woman, who suffered from minimal change nephrotic syndrome(MCNS) after long-term remission. In 1979, she was admitted to Kanazawa University Hospital due to MCNS verified by renal biopsy and was treated with oral prednisolone(initially 40 mg/day) for two years. She suffered from edema again in 1999 with massive proteinuria. Renal biopsy revealed minor glomerular abnormality without any deposition of immunoglobulins or complements. Electron microscopic findings showed extensive foot process effacement. Therefore, we diagnosed this case as a recurrence of MCNS. She was treated with the combination of methylprednisolone pulse therapy(500 mg, 3 days), oral prednisolone(20 mg/day) and cyclosporin(CyA, 3 mg/kg/day), which could induce earlier complete remission. These results suggest that recurrence after long-term remission could occur in adult-onset MCNS and that the combination therapy of prednisolone and CyA may be effective for the induction of early remission in MCNS.

Administration, Oral↗
PubMed1999

Enhanced phosphatidylinositol 3-kinase activity and high phosphorylation state of its downstream signalling molecules mediated by ret with the MEN 2B mutation.

We compared the intracellular signalling pathways through Ret tyrosine kinase activated by glial cell line-derived neurotrophic factor (GDNF), multiple endocrine neoplasia (MEN) 2A, or MEN 2B mutation. Tyrosine phosphorylation of Grb2-associated binder-1 (Gab1) and activation of phosphatidylinositol 3-kinase (PI 3-kinase) were induced at higher levels by GDNF stimulation or the MEN 2B mutation than by the MEN 2A mutation. Tyrosine-phosphorylated Gab1 was a major component that interacted with the active PI 3-kinase in vivo. In addition, we found that p62Dok and PKB/Akt were phosphorylated in a PI 3-kinase-dependent manner and the levels of their phosphorylation were significantly higher in the MEN 2B transfectant than in the MEN 2A transfectant. Tyrosine phosphorylation of p62Dok resulted in its complex formation with the Ras GTPase-activating protein (RasGAP) and the Nck adaptor protein. These findings thus suggested that high levels of activation of PI 3-kinase and of phosphorylation of its downstream signalling molecules may be associated with the clinical phenotype of MEN 2B.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Sarcomatoid carcinoma of the lung: a clinicopathologic study of 37 cases.

BACKGROUND: Spindle and giant cell carcinomas of the lung are rare subtypes and are regarded as one type of lung carcinoma, termed pleomorphic carcinoma in the Armed Forces Institute of Pathology classification. This classification is different from the World Health Organization classification. METHODS: Thirty-seven cases of sarcomatoid (spindle and/or giant cell) carcinoma of the lung were studied by light microscopy, conventional histochemistry, and immunohistochemistry to establish their clinical and histologic characteristics. RESULTS: The patient population was comprised of 29 men and 8 women ages 33-81 years. Seventeen patients died of their disease and there was no statistically significant difference in patient prognosis between sarcomatoid carcinoma and nonsarcomatoid carcinoma of the lung. Using light microscopy, 5 cases (13.5%) comprised entirely of sarcomatoid components without carcinomatous elements were classified as Group A. In the remaining 32 cases (86. 5%), classified as Group B, carcinomatous components were present (adenocarcinoma [18 cases; 48.7%], squamous cell carcinoma [8 cases; 21.6%], and large cell carcinoma [6 cases; 16.2%]). Sarcomatoid components were divided further into three categories: spindle cell type, giant cell type, and mixed spindle and giant cell type. Immunohistochemically, the sarcomatoid components of all 37 cases were positive for cytokeratins. Statistically, there was no significant prognostic difference between the 37 cases of sarcomatoid carcinoma and 647 cases of nonsarcomatoid, nonsmall cell carcinoma of the lung (P = 0.8537). CONCLUSIONS: The sarcomatoid portions in all sarcomatoid carcinomas in the current study showed an epithelial differentiation, and there was no apparent difference in biologic behavior between sarcomatoid carcinoma and ordinary lung carcinoma.

Adult↗
PubMed1999

Characterization of the promoter region of the human RFP gene.

The RFP gene encodes a Ring finger protein that has a tripartite motif consisting of a Ring finger, a B-box finger and a coiled-coil domain. In the present study, we cloned and characterized the promoter region of the human RFP gene. The nucleotide sequence of the promoter was GC-rich and had no typical TATA and CAAT boxes. Instead, it contained one AP2 and two Sp1 binding sites within 100 base pairs upstream of the transcription initiation site. Analysis by the luciferase assay revealed that the activity of this promoter region is very strong in both human and mouse cell lines, although the activity in human cells was approximately 10-15 fold higher than that in mouse cells. In addition, the AP2 and Sp1 binding sites appeared to synergistically function for the promoter activity. Thus, the promoter of the RFP gene could be useful for high levels of expression of various genes in culture cells.

3T3 Cells↗