Search PubMed⌕ Search

Biomedical subjects

Y Gotoh

Publications and source records attributed to Y Gotoh.

300 records · Page 17Linked to original sources
PubMed1977

[Effects of several catecholamine-related drugs on aggressive behavior, brain noradrenaline content and tyramine uptake by isolated mice].

Such effects were studied in male albino mice maintained under isolation circumstances for 7 weeks in order to induce aggressiveness. L-DOPA (25 mg/kg) was given concomitantly with DDC (75 mg/kg) or reserpine (0.1 mg/kg), or each was administered signly and intraperitoneally to subjects twice weekly. Two peaks on the aggressive degree were observed at the 3rd-4th and 6th weeks, respectively. At the first peak, mice treated with L-DOPA and/or reserpine demonstrated aggressive behavior to a higher degree than control mice but at the second peak, to a lower degree. Mice treated with L-DOPA and DDC showed the highest degree at the second peak. Tyramine uptake in the brain measured at the 6th week was enhanced in mice treated with combinations of L-DOPA with reserpine or DDC. Noradrenaline content in the brain was lowered in mice treated with L-DOPA and/or reserpine, in comparison with each control value; It is thus concluded that catecholamine-related drugs influence the degree of enhancement of aggressiveness in modes which vary depending on the form of action of each drug.

Aggression↗
PubMed1976

[On-line, high-speeded data analysis of cardiovascular function using hybrid systems (author's transl)].

In recent years application of computer techniques to various problems in biology has increased. In the field of anesthesia, where rapid changes appearing in a short time must be followed, the conventional, mannual methods are not applicable. So we have developed on-line computer analytical methods of cardiovascular function. Hybrid systems are the preferred methods in many biological problems, either because of efficiency and lower cost, or because of real time, on-line, closed-loop capabilities for direct use during experiments. As a computer output we used a graphic display computer and cathod ray tube devices. We applied these systems to analize and calculate cardiac work with other circulatory parameters. We got a ventricular function curve in visible form on CRT within 30 seconds after introducing the signals of left ventricular work and ventricular end-diastolic pressure into the analog computer. It was also useful to calculate vascular input impedence and myocardial maximal velocity of shortening. Finally causes of input errors in these analytical methods were discussed.

Animals↗
PubMed1971

Phenylmercuric acetate: metabolic conversion by microorganisms.

Phenylmercuric acetate, an organomercurial that has been widely used as a fungicide and slimicide, was found to be metabolized quickly by soil and aquatic microorganisms. One of the major metabolic products was identified to be diphenylmercury. In none of the cases has a methylmercury derivative been found among the microbial metabolic products of phenylmercuric acetate.

Acetates↗
PubMedDate not supplied

Hyperechoic lines as a sonographic confirmatory sign during percutaneous transhepatic biliary drainage.

BACKGROUND: In ultrasonically guided percutaneous transhepatic biliary drainage, we often can recognize hyperechoic lines at the tip of the needle when the duct is penetrated successfully. We evaluated the frequency of this phenomenon and analyzed whether it was a useful sign for confirming successful bile duct puncture. METHODS: In 65 patients with biliary tract diseases, 84 catheters were placed in the course of 108 attempts at puncture. Results of puncture and the presence of hyperechoic lines were investigated prospectively. RESULTS: When the ultrasonographic findings showed hyperechoic lines, successful puncture was significantly more frequent than when the findings did not show hyperechoic lines (53/55, 96%, vs. 31/59, 53%; p < 0.0001). When we judged the hyperechoic lines as the sign of successful puncture, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 63%, 93%, 96%, 48%, and 71%, respectively. CONCLUSION: Hyperechoic lines are a useful confirmatory sign of successful puncture. However, absence of these lines was not invariably associated with unsuccessful puncture.

Aged↗
PubMedDate not supplied

Intraductal ultrasonography for evaluating the patency of biliary metallic stents: correlation with cholangioscopic findings.

BACKGROUND: This is the first study to correlate intraductal ultrasonography (IDUS) with cholangioscopy in evaluating the patency of biliary metallic stents. METHODS: The findings of IDUS (probe 2.0 mm in diameter and 20-MHz frequency) through a percutaneous transhepatic (n = 24) or transpapillary (n = 2) approach were retrospectively reviewed without other information. Criteria for IDUS are as follows: type 1, the inside of the stent is free; type 2, the inner edge is smooth; type 3, the inner edge is irregular; type 4, the inside of the stent is totally occupied; type 5, the solid echo is connected to the outside mass; type 2+D, a hypoechoic line is seen between the bile duct wall and the inside solid component and the inner edge of the bile duct wall is smooth; type 3+D, an irregular hypoechoic line is seen between the bile duct wall and the inside solid component. RESULTS: In the control group (n = 11), IDUS showed type 1 (n = 9) or type 2 (n = 2). In the occluded group (n = 15), when IDUS showed type 3 or 5, the patients (n = 5) required additional stents (n = 3), microwave coagulation of the tumor (n = 1), or transient external drainage (n = 1). When IDUS showed type 4 (n = 5), after washing, the findings changed to type 2+D (n = 4). When IDUS after washing showed a smooth inner edge (type 2+D), the patients were treated without additional stents more frequently than the other groups (eight of nine vs. two of six), a significant distinction (p < 0.05). CONCLUSION: IDUS is useful in assessing the patency of metallic stents. When the inside of the stent is totally occupied, however, examination after washing is necessary.

Aged↗
PubMedDate not supplied

Chemical modification of silk fibroin with cyanuric chloride-activated poly(ethylene glycol): analyses of reaction site by 1H-NMR spectroscopy and conformation of the conjugates.

Solubilized silk fibroin (SF) in 0.1 M borate buffer (pH 9.4) was modified with 2-O-[methoxy(polyethylene glycol)]-4,6-dichloro-s-triazine (actPEG1) at 4 degrees C. The weight of the modified SF (PEG1-SF) was at least 3.2 times that of the starting material SF. Amino acid analysis of PEG1-SF suggested that the nucleophilic epsilon-amino group of the lysine residue and the nucleophilic imidazole group of the histidine residue in SF reacted with actPEG1. The 1H-NMR spectrum of PEG1-SF showed a downfield shift of the aromatic protons of the tyrosine residue from the corresponding protons of SF. The 1H-NMR spectrum of the SF reacted with cyanuric fluoride (CyF), whose fluorine atoms are known to react with the phenolic hydroxyl group of the tyrosine residue, also showed the downfield shift. These results suggested that the reaction site of SF with actPEG1 was the phenolic hydroxyl group of the tyrosine residue in addition to the lysine and histidine residues. The conformation of PEG1-SF in a solid state was examined by means of IR and X-ray measurement. The IR spectrum of PEG1-SF revealed a change in secondary structure from random coil to beta-sheet due to the coexistence of PEG molecules. The X-ray diffraction pattern of PEG1-SF indicated that the PEG molecules covalently bonding to SF narrowed the spacing of the interchain periodicity and promoted the formation of the interchain beta-sheet.

Amino Acids↗
PubMedDate not supplied

Fluctuating hearing loss following immune reaction in the endolymphatic sac of guinea pigs.

This study has investigated immune injuries to the inner ear auditory system of guinea pigs. Following secondary antigen challenge to the endolymphatic sac, the mean hearing threshold significantly increased in the early phase from day 1 to day 3 and thereafter recovered. In the early phase, hearing threshold significantly increased simultaneously to the elevation of perilymph antibody levels. The size of hydrops was not the only factor that causes an increase in hearing loss as well as in AP/SP ratio. Scale-out hearing loss was seen in 2 animals with severe degeneration of the stria vascularis as well as the organ of Corti associated with the inflammatory cellular infiltration especially in the perilymphatic space, even in the absence of keyhole limpet hemocyanin antigen in the cochlea. On the other hand, control animals did not suffer hearing loss. These results suggest that an immune reaction in the endolymphatic sac is a possible pathogenic etiology of Ménière's disease or sudden deafness.

Animals↗
PubMedDate not supplied

Sensitive enzyme immunoassay of cephalexin residues in milk, hen tissues, and eggs.

A sensitive enzyme immunoassay for cephalexin (CEX) was developed using the rabbit antiserum to CEX, beta-D-galactosidase-labeled CEX, and a double-antibody separation method. The immunogen of CEX was prepared by coupling the amino group of CEX to thiol groups introduced into bovine serum albumin by the use of N-(m-maleimidobenzoyloxy)succinimide as a cross-linker. Highly titered antiserum to CEX was produced in rabbits immunized with the immunogen. Enzyme labeling of CEX with beta-D-galactosidase was done by using N-(gamma-maleimidobutyryloxy)succinimide as the cross-linker. The limit of detection was 30 ng CEX/mL sample solution. Application of the method to CEX drug residues detected 30 ng/mL in milk, 60 ng/g in egg yolk, and 400 ng/g in hen tissue.

Animals↗
PubMedDate not supplied

Leiomyoma of the rectum.

Rectal leiomyoma is a rare disease. In Japan, only 77 cases were reported before 1984. A study was carried out by compiling information from clinical cases together with two recent cases of rectal leiomyoma. The patients were mainly in their 50s to 60s with a mean age of 53.6 years. The sex ratio of males to females, was 1.5:1. The most common main complaints were anal bleeding and melena and subsequently cylindrical shaped stool or constipation, attributable to rectal stenosis. The tumors were located at 8 cm or less from the anal verge in 87% of the case. Surgery is considered the best method of treatment. Five patients noted a recurrence and three underwent extirpation as their initial operation. Although it is frequently difficult to establish whether leiomyoma is benign or malignant, small lesions (less than 2 cm in diameter) are best treated by local excision.

Adolescent↗