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Biomedical subjects

Y Baba

Publications and source records attributed to Y Baba.

At least 199 records · Page 11Linked to original sources
PubMed1994

Synthesis and aldose reductase inhibitory activity of 2-substituted-6-fluoro-2,3-dihydrospiro [4H-1-benzopyran-4, 4'-imidazolidine]-2',5'-diones.

Optically active and racemic 2-substituted-6-fluoro-2,3-dihydrospiro[4H-1-benzopyran-4, 4'-imidazolidine]-2',5'-diones were synthesized from (+)-, (-)-, and (+-)-6-fluoro-3,4-dihydro-4-oxo-2H-1-benzopyran-2-carboxylic acid. These compounds were then evaluated for in vitro and in vivo aldose reductase inhibitory activity. The 2S,4S isomers were found to be more potent aldose reductase inhibitors than the other corresponding stereoisomers. Among these compounds, (2S,4S)-6-fluoro-2,3-dihydro-2',5'-dioxospiro[4H-1-benzopyran-4, 4'-imidazolidine]-2-carboxamide ((+)-1b, SNK-860, CAS 105300-43-4) showed the most potent in vitro and in vivo activity.

Aldehyde Reductase↗
PubMed1993

High-resolution separation of DNA restriction fragments by capillary electrophoresis in cellulose derivative solutions.

The performance and the efficiency of several cellulose derivatives as a molecular sieving agent for the capillary electrophoretic separation of DNA restriction fragments were investigated. All fragments up to 12,000 base pairs (bp) in the 1-kbp DNA ladder were resolved using linear polyacrylamide-coated capillaries filled with a buffer solution containing 0.5% cellulose derivative and the separation was completed within 17 min. High-concentration (0.7%) cellulose derivative solutions are effective for the complete separation of small fragments (50-1000 bp) of a HincII and a HaeIII digest of phi X174 DNA. A plate number of 0.5-1 x 10(6) plates per metre was achieved. The migration time and the resolution of DNA fragments were manipulated by varying several parameters, such as the size (viscosity) and the concentration of cellulose derivatives and the applied field strength. Some guidelines are presented for choosing these parameters, depending on the size of the DNA fragments being separated.

Bacteriophage phi X 174↗
PubMed1993

Effect of urea concentration on the base-specific separation of oligodeoxynucleotides in capillary affinity gel electrophoresis.

Base-specific separations of oligodeoxynucleotides were achieved with high resolution by electrophoresis, using a urea-gel capillary, in which poly(9-vinyladenine) (PVAd) was utilized as an affinity ligand. The migration behaviour and the plate number of oligodeoxynucleotides were investigated as a function of urea concentration between 2 and 10 M in capillary gel electrophoresis (CGE) as well as capillary affinity gel electrophoresis (CAGE). The migration time in CGE separation increases as urea concentration increases. An increase in the viscosity of the gel buffer medium as well as a change in the conformation of oligodeoxynucleotides is found to be a predominant factor for an increase in the migration time. The migration time and the plate number of oligothymidylic acids, which interact with PVAd in CAGE, is manipulated by differing urea concentration, which leads to the change in the dissociation process of a specific hydrogen bonding between oligothymidylic acids and PVAd. The migration time of oligodeoxyadenylic acids, which do not interact with PVAd in CAGE, increases with an increase in urea concentration as in CGE separation. The plate number of oligodeoxyadenylic acid was not affected by the urea concentration.

Adenine↗
PubMed1993

Prediction of the behaviour of oligonucleotides in high-performance liquid chromatography and capillary electrophoresis.

The present state of studies on prediction of the chromatographic and electrophoretic behaviour of oligonucleotides is reviewed; particular emphasis is given to high-performance liquid chromatographic and capillary electrophoretic separations. Attention is paid to fundamental theory for the prediction of retention and migration times, and bandwidths. The article also deals with the applicability of the theory to the computer-assisted prediction and the computer simulation for these two types of separation of oligonucleotides. Optimization of separation conditions using the computer simulation system is briefly described.

Animals↗
PubMed1993

Hepatocellular carcinoma with or without cirrhosis: a comparison of CT and angiographic presentations in the United States and Japan.

We compared the computed tomographic (CT) and angiographic presentations of hepatocellular carcinoma (HCC) with or without cirrhosis in the United States and Japan. Tumors in the United States were advanced and less frequently associated with liver cirrhosis (association of cirrhosis: United States 56.2%, Japan 91.0%. In patients with cirrhosis, the size of the tumor tended to be smaller, and nodular tumors (single or multiple) were frequent. In early stage of HCCs with cirrhosis, tumors were hypovascular without a capsule. In advanced stage, tumors were hypervascular and a capsule was frequently observed around the tumor both with CT and angiography. HCCs without cirrhosis were seen in younger patients. These tumors were large at the time of diagnosis. A massive or diffuse mass without a capsule was frequently seen. Most tumors were hypodense on precontrast CT and hypervascular on angiography. Lymph node enlargement was significantly frequent. The radiological characteristics of HCC in both countries were significantly different depending upon associated cirrhosis, as well as the time of the diagnosis.

Adult↗
PubMed1993

Castleman disease. Unusual retroperitoneal location indistinguishable from malignant tumor in preoperative angiographic appearance.

Castleman disease (angiofollicular lymph node hyperplasia) has been reported rarely as a solitary retroperitoneal mass radiographically indistinguishable from retroperitoneal malignancies. We report a case of a hyaline-vascular variant of Castleman disease presenting as a pararenal mass. The computerized tomographic and angiographic appearances of this lesion are presented, and the clinical importance of the differential diagnosis of retroperitoneal tumors is discussed.

Adult↗
PubMed1993

Dicentric Y chromosome in azoospermic males.

Two azoospermic, infertile men with a pseudodicentric Y chromosome are reported. The small isodicentric Y chromosomes were composed of duplicated short arm and proximal long arm Y, as proven by fluorescence in situ hybridisation using a Y centromere-specific DNA probe, pDP97, and a short arm probe pY-80. Both lacked germinal cells in the gonads. It was assumed that the azoospermia was caused by deletion or disruption of the azoospermic factor gene located at distal Yq11. Patient 2 measured 147 cm (-4.1 SD) in height and so it was assumed that he had also lost the "statural determinants" gene.

Adult↗
PubMed1993

A flow visualization study of centrifugal blood pumps developed for long-term usage.

We have developed centrifugal pumps for long-term circulatory assistance, with the final goal of a completely implantable ventricular assist device or total artificial heart. The previous model, NCVC-0, was characterized by a nonseal design and few flow-stagnating parts and acquired high durability and antithrombogenicity. To improve its pumping performance, NCVC-0 was modified. In the new model, NCVC-1, the profile shape of the impeller was changed from flat to conical, the number of vanes from 4 to 6, and the vane entrance angle from 30 degrees to 60 degrees. A flow visualization study performed by means of a combination of the polystyrene tracer method and the light-cutting method indicated decreased flow turbulence between vanes in NCVC-1, which corresponded well with the increased pumping performance. Flow visualization is a useful method to evaluate the design elements that are closely related to the pumping performance of a centrifugal blood pump.

Equipment Design↗
PubMed1993

Orally administered manganese chloride: enhanced detection of hepatic tumors in rats.

To evaluate its potential as a tissue-specific hepatobiliary magnetic resonance (MR) contrast agent, manganese chloride was orally administered to rats in increasing doses of 100-1,500 mumol/kg MnCl2, and the relaxation times of liver, pancreas, kidney, and heart were measured with ex vivo relaxometry and in vivo MR imaging. Two hours after ingestion of 200 mumol/kg MnCl2, liver T1 was decreased by 48%, whereas tumor T1 decreased by only 9%. On spin-echo MR images, the signal-to-noise ratio in liver increased by 54%; the contrast-to-noise ratio in tumor, by 375%. The T1 of pancreas, kidney, and heart decreased by 8%, 23%, and 13%, respectively. At subjective assessment, the signal intensity of the upper gastrointestinal tract was reduced, likely because of the high concentration of manganese in the lumen, and delineation of the intestine from other abdominal structures was improved. These results indicate that orally administered MnCl2 causes substantial, reproducible, and tissue-specific enhancement of liver. Because enhancement of tumor was minimal, orally administered MnCl2 may potentially be used to improve detection of hepatic tumors.

Administration, Oral↗
PubMed1993

Intrahepatic cholangiocarcinoma: spin-echo and contrast-enhanced dynamic MR imaging.

OBJECTIVE: Our purpose was to identify the conventional spin-echo and contrast-enhanced dynamic MR imaging features of intrahepatic cholangiocarcinoma. MATERIALS AND METHODS: Eight patients with pathologically proved intrahepatic cholangiocarcinoma were examined with conventional spin-echo and contrast-enhanced dynamic MR imaging with a 1.5-T superconductive unit. The results were analyzed to include the signal intensity of the mass relative to liver parenchyma on conventional spin-echo images and the pattern and degree of enhancement on dynamic MR images. RESULTS: The characteristic appearance of intrahepatic cholangiocarcinoma was a large mass with an irregular margin, satellite nodules, and a central scar. Tumors were hypointense relative to liver parenchyma on T1-weighted spin-echo images and hyperintense on T2-weighted spin-echo images. On dynamic MR studies, tumors characteristically had minimal or moderate rim enhancement with progressive and concentric filling with contrast material. CONCLUSION: Our study suggests that intrahepatic cholangiocarcinoma has a typical pattern on contrast-enhanced dynamic MR images.

Adenoma, Bile Duct↗
PubMed1993

Expanded primary T nodules in the palatine tonsils from patients with IgA nephropathy.

We designed a study to investigate the morphological expression of immune responses in the palatine tonsils from patients with IgA nephropathy. To distinguish between the histological characteristics of the tonsils in habitual tonsillitis (47 patients) and IgA nephropathy (11 patients), we studied the T nodules, B-lymphoid follicles, germinal centers, areas of mixed T and B lymphocytes, lacunar epithelium and connective tissues; then we compared patients with habitual tonsillitis and IgA nephropathy. The T nodules in patients with IgA nephropathy were enlarged, and this change was not accompanied by atrophy of B-lymphoid follicles. Morphologically, primary T nodules were predominant. In reactive lymph nodes, T nodules generally play an important role in the extra-follicular maturation of stimulated B lymphocytes into Ig-secreting plasma cells. Therefore the enlarged primary T nodules remind us that this maturation may occur more frequently in the tonsils of patients with IgA nephropathy than in those with habitual tonsillitis. This suggests that some immunoregulatory dysfunction exists in the secretory immune system of mucosa-associated lymphoid tissues in patients with IgA nephropathy.

Adult↗
PubMed1993

[Treatment for cardiac rupture following acute myocardial infarction].

We experienced thirty-three patients with cardiac free wall rupture following acute myocardial infarction (AMI). Twelve patients received reperfusion therapy. Surgical closure of cardiac rupture was performed in twelve patients under cardiopulmonary bypass (CPB). Two of these patients were placed on percutaneous cardiopulmonary support system (PCPS) immediately after the onset of blow out rupture. Cardiac rupture occurred in 19 patients within 3 days from the onset of AMI (early rupture) and in 14 patients 4 days after the onset (delayed rupture). All five patients with successful reperfusion were in the early rupture group, while there were no patients with successful reperfusion in the delayed rupture group. In 12 surgical patients, 7 patients had blow out rupture and 5 patients had oozing rupture. In 7 patients with blow out rupture, four patients could not be disconnected from CPB and 2 patients had cerebral death. One patient received PCPS support showed no mental disturbance after surgery, but he died of renal failure 6 days after surgery. Three out of 5 patients with oozing rupture survived. The interval from the onset of hypotension to establishment of cardiopulmonary support was 5 minutes and 60 minutes in two patients using PCPS. However it averaged 94 minutes in 5 patients using usual CPB. It is suggested that early reperfusion therapy may prevent delayed cardiac rupture following AMI, and surgical therapy using PCPS may be useful for the treatment of cardiac blow out rupture.

Adult↗
PubMed1993

[A new departure of an incorporated round visits; anesthesiologists and pharmacists ].

We commenced a new trial of an incorporated round visit. Members of round visit are 4 anesthesiologists and 2 pharmaceutists. This new trial gives us the following advantages; 1. We can get the newest drug informations at bed side during the round visit. 2. We can select a more reasonable therapy for patients through discussions. 3. Cooperative development of clinical studies concerning a new model or style of drugs may be possible. This new style of round visit is also of benefit for patients because it leads to administration of more pertinent drugs. We recommend to have a chance of cooperation between anesthesiologists and pharmaceutists in other hospitals.

Anesthesia Department, Hospital↗
PubMed1993

[Interferon therapy after ablation of Kent bundle for a patient with chronic hepatitis type B complicated with WPW syndrome].

Cardiotoxicity of interferon-alpha or gamma, such as fatal arrhythmia and myocardial infarction, has been reported. Therefore cardiotoxicity of interferon should be seriously considered before administration for patients with a pre-existing heart disease. We treated a patient with chronic active hepatitis type B, coexisted with Wolff-Parkinson-White syndrome, who has had frequent attacks of paroxysmal atrial fibrillation. To prevent the occurrence of fatal arrhythmia with an interferon therapy in this patient, we performed radiofrequency catheter ablation of the Kent bundle. After the successful ablation, we could safely administered recombinant interferon alpha-2b for chronic hepatitis type B.

Adult↗
PubMed1993

[Clinical study of sonography and percutaneous nephrostomy in pyonephrosis].

Sonography and percutaneous nephrostomy (PNS) were performed on 16 patients with pyonephrosis and the following results were obtained. Sonography revealed a dilated collecting system in all cases within which, however, neither debris nor gas was observed in any case, the pelvocaliceal system appeared hypoechoic in 2 cases and anechoic in 14 cases. From the clinical symptoms and the dilated collecting system demonstrated by sonography, pyonephrosis was diagnosed in 14 cases. The purulent fluid aspirated from the collecting system confirmed the diagnosis in all cases. The clinical condition was stabilized by PNS and antibacterial therapy in all cases. However, in 5 of the patients with pyrexia for more than 6 days before PNS, sepsis developed in 3 cases and pyrexia continued for more than 3 days after the treatment in 4 cases. The affected 11 kidneys showing recovery of renal function following PNS were all salvaged by elective surgery. These findings suggest that prompt diagnosis by needle aspiration is necessary, even in the absence of any sonographically characteristic findings, whenever pyonephrosis is suspected. Our experience suggests that PNS is a useful therapeutic procedure for pyonephrosis.

Adult↗