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Biomedical subjects

Y Dobashi

Publications and source records attributed to Y Dobashi.

At least 73 records · Page 4Linked to original sources
PubMed1994

Alteration of immunoreactivity by hydrated autoclaving, microwave treatment, and simple heating of paraffin-embedded tissue sections.

The effects of treatment in a hydrated autoclave (121 degrees C, 2 atm for 20 min), microwave oven (in water), and simple heating (60 degrees C overnight in distilled water or 90 degrees C for 10 min in ZnSO4) on the stainability of 56 antigens by commercially available antibodies in formalin-fixed paraffin-embedded tissue sections were evaluated. The detectability of nuclear antigens, glycoprotein, lymphocytic surface markers, and chromogranin A was significantly and reproducibly improved by these treatments, whereas the detectability of viral antigens and peptide hormones was attenuated or unchanged. This enhancement includes not only the distinctiveness of the positive staining, but also the number of positive cells, as revealed by comparing serial sections. Among these four heating procedures, microwave heating and autoclaving were more effective than the others on p53, c-erbB-2, and CA125, whereas simple heating was best for smooth-muscle actin (HHF35 and CGA7). Generally the effects of the heating procedures for these antigens were consistent among the cases, but the effects on GFAP varied with the case. The alterations we observed could significantly influence the interpretation of immunohistochemical staining of currently popular tumor markers such as p53 in terms of their prevalence (28% vs 64% in gastric cancer; 36% vs 82% in metastatic liver cancer) and other diagnostically important markers.

Antigen-Antibody Reactions↗
PubMed1994

Hepatic resection under the intermittent selective portal branch occlusion by balloon catheter.

BACKGROUND: In hepatic resection, it is important to control intrahepatic blood flow to minimize blood loss. Intermittent and selective vascular occlusion, if possible, are advisable. STUDY DESIGN: For this purpose, we created the double balloon catheter, which when introduced into a lobar or a smaller branch of the intrahepatic portal vein through a branch of the ileocolic vein, made it possible to occlude these branches temporarily during hepatic resection. The small balloon located at the tip of the catheter made it easy to introduce the catheter to the portal branch selectively, under the guidance of ultrasonography. Another balloon was inflated intermittently to occlude selective portal blood flow. Using this technique, hepatic resection was achieved in 18 consecutive patients: 13 with hepatocellular carcinomas (11 with cirrhosis, two with chronic hepatitis), one with cholangiocellular carcinoma, three with metastatic carcinomas, and one with intrahepatic calculi. RESULTS: In these cases, 19 hepatic resections were performed; two left hepatectomies, one extended right hepatectomy, one right hepatectomy, six segmentectomies, eight subsegmentectomies, and one partial hepatectomy. In each case, well demarcated hepatic tissue delineated by ischemic change was removed with minimal bleeding and little impairment to the residual hepatic tissue, resulting in a good postoperative course. CONCLUSIONS: This double balloon catheter can replace the dissection of the hepatoduodenal ligament for hepatic resection, which causes bleeding, especially in patients with cirrhosis, and results in less cell injury of the residual hepatic parenchyma.

Aged↗
PubMed1994

[A clinical study of fulminant Legionnaires' disease].

Seven cases of fulminant Legionnaires' disease treated at Kitasato University Hospital between 1985 and 1992 were reviewed. These patients were male with a mean age of 55.9 years (range, 37-67 yrs), and five were heavy alcohol drinkers. All seven patients required mechanical ventilation. Four patients recovered (group 1) and three expired due to respiratory failure (group 2). The mean interval from initial symptoms to the development of respiratory failure was 8.8 days in group 1 and 6.0 days in group 2, except in the one patient with lung cancer (case 6). The progression of pneumonia was more rapid in group 2. The mean intervals from admission to administration of erythromycin were 1.5 days and 3.5 days, respectively, in groups 1 and 2. In group 1, pulmonary infiltrates and respiratory insufficiency worsened for the first few days after erythromycin administration but improved thereafter. The average duration of ventilatory care in group 1 was 13.3 days. The administration of rifampicin combined with erythromycin may be useful for the treatment of fulminant Legionnaires' disease. When fulminant pneumonia is encountered in a middle-aged or elderly male alcoholic, Legionnaires' disease should be suspected and erythromycin administration with rifampicin should be initiated as early as possible.

Adult↗
PubMed1993

Overexpression of p53 as a possible prognostic factor in human thyroid carcinoma.

A total of 110 cases of thyroid carcinomas were examined immunohistochemically to evaluate the overexpression of mutant forms of p53 protein in the light of their relationship with their histological subtypes. A polyclonal antibody, CM-1, was applied to the routine formalin-fixed, paraffin-embedded tissues for this survey. Overall, immunohistochemically detected p53 expression confined to the nucleus was identified in 22.7% of the thyroid carcinomas. A significant difference in the positivity of p53 among histological subtypes was noted; the positivity was 11.1% of the cases in well-differentiated papillary carcinoma, 14.3% in well-differentiated follicular carcinoma, 40.9% in poorly differentiated carcinoma, and 63.6% in undifferentiated carcinoma. No immunohistochemical positivity was found in adjacent non-neoplastic tissues or in benign lesions, including follicular adenoma, adenomatous goiter, and chronic thyroiditis. These results suggest that overexpression of p53 is not a responsible factor for the oncogenesis itself, but rather that it plays a crucial role in aggressive subtypes of thyroid carcinomas. Additionally, the distinct entity of poorly differentiated carcinoma, previously categorized in the well-differentiated carcinoma under the name of papillary or follicular carcinoma, was statistically confirmed.

Carcinoma↗
PubMed1993

Possible association of p53 overexpression and mutation with high-grade chondrosarcoma.

Overexpression and point mutation of the p53 protein/gene was investigated in a series of chondrosarcoma by an immunohistochemical approach, and direct sequencing of the genomic DNA, respectively. In 2 of the 16 cases studied, both of which were high grade chondrosarcomas (grade III), immunodetectable p53 was identified. Histologically, one was ordinary type and the other a clear cell variant. However, no positivity was observed in the other cases including nine of low grade, ordinary type, three of low grade, clear cell type, and two of extraskeletal myxoid chondrosarcoma. Direct sequencing, following polymerase chain reaction amplification of exons 5-9 of the p53 gene in 14 cases, in which fresh materials were available, successfully demonstrated base substitution mutations in only two cases with detectable p53 overexpression on immunohistochemistry. Their details were GTC (valine) to TTC (phenylalanine) at codon 157 in exon 5, and CGT (arginine) to CAT (histidine) at codon 273 in exon 8. No mutation was detected in the other 12 cases which were negative for p53 immunostaining. These findings strongly suggest that p53 mutation plays a crucial role in the biologically aggressive subtype, and possibly in the process of tumor progression in human chondrosarcoma.

Adult↗
PubMed1993

Immunohistochemical localization of epidermal growth factor in human main and accessory lacrimal glands.

Immunohistochemical localization of epidermal growth factor (EGF) in human main and accessory lacrimal glands has been investigated using monoclonal and polyclonal antibodies. Positive stain of EGF was localized in the cytoplasm of the acinar cells and the epithelial cells of the intra- and interlobular ducts of the main lacrimal glands, including both the palpebral and orbital lobes, and of the accessory lacrimal glands (gland of Krause, gland of Wolfring) as well. Meibomian glands showed weak immunoreactivity. Positive stain in the conjunctival epithelium including goblet cells was not observed. These results suggest that the mature form of EGF is produced in both the main and accessory human lacrimal glands and secreted into the tear fluid as a constant and crucial component.

Aged↗
PubMed1992

Polymorphism of coagulation factor XIII B subunit: further occurrence of FXIIIB*15 in Japanese and phenotyping in bloodstains.

The polymorphism of FXIIIB was investigated in 555 unrelated Japanese individuals using isoelectric focusing and immunoblotting. Five common phenotypes and a rare variant type FXIIIB 15-3 were observed. The allele frequencies were FXIIIB*1 = 0.3063, FXIIIB*2 = 0.0162, FXIIIB*3 = 0.6766 and FXIIIB*15 = 0.0009. Phenotyping was also possible from bloodstains stored at 37 degrees C for up to 4 months and from bloodstains stored at room temperature and at 4 degrees C for over 6 months. The FXIIIB system can provide a new powerful genetic marker for the medicolegal grouping of bloodstains.

Alleles↗
PubMed1992

Polypoid cystic adenomyosis of the uterus: report of a case.

A case of focal adenomyosis of the uterus with unusual gross features is presented. The patient, a 43-year-old woman, had experienced abnormal vaginal bleeding for 8 years. Hysteroscopy revealed a polypoid mass compatible with a submucosal leiomyoma, and a hysterectomy was performed. The uterus showed a 7 x 5 x 3-cm firm polypoid mass attached to the anterior wall that occupied most of the uterine cavity and protruded through the cervical os. It contained a large, central, cystic cavity filled with bloody fluid that communicated with the endometrial cavity through a fistula-like tract. Both the surface of the mass and the inside of the cystic cavity were covered by endometrial mucosa, and there were endometrial islands in the intervening wall. The differential diagnosis of this unique form of adenomyosis included polypoid submucosal leiomyoma with invagination of endometrium, endometrial polyp, submucosal leiomyoma with invagination of endometrium, endometrial polyp, and uterine diverticulum.

Adult↗
PubMed1992

[The effect of stationary time of punch in the process of compression on dividing properties of scored tablets].

The significance of the stationary time of punch in the process of compression on the dividing properties of scored tablets was investigated in several tablets prepared from lactose, corn starch, hydroxypropyl starch, synthetic aluminum silicate, microcrystalline cellulose or Perfiller. The dividing strength of scored tablets was not affected by the stationary time of punch. The effect of the stationary time of punch on the coefficient of variation of divided tablet weight differed in the compacting characteristics and compaction profiles of powders. In case of tablets prepared from microcrystalline cellulose, the effect of stationary time of punch was not observed. However, in the other excipients, there existed a specific stationary time of punch to minimize the coefficient of variation of divided tablet weight. The time was different due to the change of compression pressure. The coefficient of variation of divided tablet weight showed minimum at the longer stationary time of punch when tablets were compressed at the low compression pressure, and the time showed a tendency to become short with the increase of compression pressure. These results suggested that the effect of the stationary time of punch on the coefficient of variation of divided tablet weight was concerned with the compaction structure of powders produced by the movement of punch in the process of compression.

Pressure↗
PubMed1992

[Plasma catecholamine levels during air-oxygen-enflurane anesthesia compared with those during nitrous oxide-oxygen-enflurane anesthesia].

This study was designed to investigate the differences in plasma levels of epinephrine, norepinephrine and dopamine during air-oxygen-enflurane anesthesia (AOE) and those during nitrous oxide-oxygen-enflurane anesthesia (GOE). These catecholamine levels were measured at 8 carefully defined points before and during hysterectomy or ovariectomy in two groups of each ten patients. Plasma levels of epinephrine decreased significantly immediately after intubation in both groups. In the AOE group, epinephrine levels increased significantly 30 and 60 minutes after the beginning of the operation. In the GOE group, however, epinephrine levels decreased significantly 15 and 30 minutes after the beginning of the operation. The difference between the two groups was statistically significant. Plasma levels of norepinephrine increased significantly after the beginning of the operation in the GOE group but no significant differences were found in the AOE group except the levels 60 minutes after the operation. The difference between the two groups was statistically significant 15 minutes after the operation. Plasma levels of dopamine remained unchanged in the two groups. Mean arterial pressure changed with intubation and surgical stress in the two groups. The arterial pressure was significantly higher 30 minutes after the operation in the GOE group compared with AOE group. Pulse rate increased significantly during anesthesia and surgery in the GOE group. It is concluded that AOE induces more increase of plasma epinephrine and less release of plasma norepinephrine compared with GOE.

Adult↗
PubMed1992

[Therapeutic modality for esophago-gastric varices analyzed by endoscopic ultrasonography].

For 64 cases with portal hypertensive disease, we investigated the intramural and extramural structure of the stomach and esophagus by endoscopic ultrasonography (EUS). Variously developed intra- or extra-mural vascular structures had a relationship to the endoscopic variceal form, and the communicating (inflow) vessels to varices were found in 35 of 50 primary treated cases (70%). We classified the esophago-gastric varices into three types according to the vascular structure, such as the esophageal type, the esophago-gastric type and the solitary gastric type. From the analyses of these collateral structures, we should select a treatment as follows. In the esophageal type which has a few inflow vessels, it is easy to eliminate the varices by obturating the inflow vessels by endoscopic injection sclerotherapy (EIS). In the esophago-gastric type, which has many enlarged inflow vessels, the Hassab operation is effective to devascularize extramural inflow vessels, and the combination of EIS is necessary to sclerous the intramural varices. In the solitary gastric type which is a part of the downward porto-systemic shunt, Hassab operation is recommended to prevent the rupture of varices for the subtype with intramural running vessels, but conservative therapy is enough for the subtype without intramural running vessel.

Collateral Circulation↗
PubMed1991

Polymorphism of complement factor I: population study in Japanese and phenotyping in bloodstains.

Polymorphism of the complement component factor I (IF) was investigated in 645 unrelated Japanese individuals using isoelectric focusing and immunoblotting. The allele frequencies were IF*A = 0.1031 and IF*B = 0.8969. The population data fitted the Hardy-Weinberg law. Phenotyping was also possible from bloodstains stored at 37 degrees C for up to 1 week, at room temperature for up to 2 weeks and at 4 degrees C for up to 5 weeks. The IF system can be a useful supplement for the medicolegal identification of bloodstains, but seems useless in Caucasoids.

Blood Stains↗
PubMed1991

Membrane-anchored forms of EGF stimulate focus formation and intercellular communication.

Epidermal growth factor (EGF) is the prototype for a small family of soluble proteins that bind to and activate the EGF receptor. These proteins are derived from larger propeptides that are anchored to the plasma membrane. Although the signalling properties of soluble EGF are well-characterized, the signalling potential of the membrane-anchored form had not been determined. We therefore investigated whether membrane-anchored EGF can stimulate the EGF receptor. An EGF mini-gene expression system that we had previously constructed for expression of soluble EGF was modified to encode anchored forms of EGF. In the encoded proteins EGF was fused to the spacer in the EGF propeptide that separates EGF from the transmembrane domain. The spacer was followed by vesicular stomatitis virus G protein transmembrane and cytoplasmic domain sequences. Three forms of EGF/G fusion protein were expressed in rat fibroblasts. The plasmids for expression of anchored EGF induced focus formation in rat fibroblasts, indicating that anchored EGF can cause autocrine transformation. When mixed with indicator HeLa cells, cell lines expressing EGF/G fusion proteins activated the HeLa EGF receptor. This activation was mediated by cell-associated, rather than soluble EGF. The finding that membrane-anchored EGF is capable of activating the EGF receptor on neighboring cells has broad implications for the functions of EGF in the organism.

Animals↗
PubMed1990

Chemical change involved in the oxidative reductive depolymerization of hyaluronic acid.

The oxidative reductive depolymerization (ORD) of hyaluronate has been investigated. A solution of hyaluronate (Mr 4.07 x 10(5] in phosphate buffer (pH 7.2) was incubated in the presence of Fe2+ for 24 h at 37 degrees C under an oxygen atmosphere to yield depolymerized hyaluronate (ORD fragments; an average Mr of 2,600). The ORD fragments contain 21 and 24% less hexosamine and uronic acid, respectively, but no olefinic linkage. They were exhaustively digested with chondroitinase AC-II. The resulting oligosaccharides and monosaccharides were separated by gel filtration and ion-exchange chromatography, and their structures were determined by proton and carbon-13 NMR, fast atom bombardment mass spectrometry, and chromatographic techniques combined with chemical modifications. The following structures derived from the reducing ends of the ORD fragments were identified: 4,5-unsaturated GlcA(beta 1----3)-N-acetyl-D-glucosaminic acid (where GlcA- represents glucuronosyl-) (21%), 4,5-unsaturated GlcA(beta 1----3)GlcNAc(beta 1----3)-D-arabo-pentauronic acid (24%), and N-acetyl-D-glucosamine (51%). The following structures derived from the nonreducing ends were identified: L-threo-tetro-dialdosyl-(1----3)GlcNAc (a tentative structure, 8%), N-acetylhyalobiuronic acid (20%), and N-acetyl-D-glucosamine (45%). The results indicate that the ORD reaction of hyaluronate proceeds essentially by random destruction of unit monosaccharides due to oxygen-derived free radicals, followed by secondary hydrolytic cleavage of the resulting unstable glycosidic substituents.

Acetylglucosamine↗
PubMed1989

Enantiomer resolution of D- and L-alpha-amino acid derivatives by supercritical fluid chromatography on novel chiral diamide phases with carbon dioxide.

The rapid resolution of racemic N-4-nitrobenzoylamino acid isopropyl esters was accomplished without the loss of enantioselectivity by supercritical fluid chromatography (SFC) on novel chiral valine-diamide phases with carbon dioxide and a polar methanol modifier. In each stationary phase, a chiral moiety was anchored to the silica gel surface by a long decamethylene spacer. The enantioselectivity in SFC was comparable to that in liquid chromatography using 2-propanol-n-hexane. The time required for analysis was less than 5 min, and the range of enantiomer resolution (Rs) was 10.8-1.25. On using 2-propanol in place of methanol the separation was improved, but was accompanied by a decrease in column efficiency. The end-capping effect of the remaining surface silanols on enantiomer resolution is discussed.

Amino Acids↗