Search PubMed⌕ Search

Biomedical subjects

Y Isobe

Publications and source records attributed to Y Isobe.

At least 73 records · Page 4Linked to original sources

Vasoactive intestinal peptide and gastrin-releasing peptide play distinct roles in the suprachiasmatic nucleus.

Vasoactive intestinal peptide and gastrin-releasing peptide levels were measured in the punched-out suprachiasmatic nucleus tissue from rats kept under a prolonged dim light (in vivo). Vasoactive intestinal peptide content increased from 4 to 8 h, returned to the baseline level at 12 to 16 h, and then increased again until 36 h after the light was switched off (dim light). Gastrin-releasing peptide level, in contrast, showed no significant changes, but a slight decrease from 1 to 4 h was detected under the dim light. In suprachiasmatic nucleus explant-slice culture, in vitro, Arg-vasopressin release increased transiently or showed a decrease at 30 min after exposure to vasoactive intestinal peptide or gastrin-releasing peptide, respectively. Treatment with anti-vasoactive intestinal peptide and anti-gastrin-releasing peptide antibodies reversed these effects. These findings suggest reciprocal roles of vasoactive intestinal peptide and gastrin-releasing peptide in Arg-vasopressin release.

Animals↗

Balloon-occluded retrograde transvenous obliteration (BRTO), a promising nonsurgical therapy for ectopic varices: a case report of successful treatment of duodenal varices by BRTO.

We present a patient with massive tarry stool, diagnosed as duodenal varices bleeding. Endoscopic ligation (EL) therapy was carried out for the varices, but because the possibility of re-bleeding remained, we treated the varices with balloon-occluded retrograde transvenous obliteration (BRTO), and duodenal varices were successfully decompressed without any complications. BRTO might be a novel therapeutic approach for ectopic varices, including duodenal varices.

Catheterization↗

[The role of angiography for the detection of early carcinomas].

So far ultrasonography or CT, MRI had not been advanced, the angiographical examination was illuminated as the most valuable examination for the abdominal organs. But nowadays, US, or CT are further superior to angiographical examination on the detectability of lesions in the abdominal solid organs, still less on the early carcinomas. The role of angiography is now analysis of vascular anatomical localization of lesion and technical application for therapeutic intervention. Therefore, the final curtain has been closed on the diagnostic stage of the angiography.

Angiography↗

Cloning of cDNA for rat eosinophil major basic protein.

We have determined the complete nucleotide sequence for the cDNA encoding rat eosinophil major basic protein (MBP) using the rapid amplification of cDNA ends (RACE) procedure. The deduced amino acid sequence revealed that the rat prepro-MBP has three functional domains, namely the signal peptide, the acidic peptide that contains numerous acidic amino acids, and the mature MBP, as in human and guinea pig MBP.

Amino Acid Sequence↗

The anti-emetic activity of GK-128 in Suncus murinus.

In Suncus murinus, various emetic responses and the anti-emetic activity of a new 5-hydroxytryptamine3 (5-HT3) receptor antagonist, GK-128 (2-[(2-methylimidazol-1-yl) methyl benzo[f]thiochromen-1-one monohydrochloride hemihydrate), were investigated. Cancer chemotherapeutic agents, cisplatin and cyclophosphamide, dose-dependently induced emesis of long-lasting duration. The 5-HT3 receptor agonist, 2-methyl-5-HT, and copper sulfate also induced emesis of short duration. However, another 5-HT3 receptor agonist, m-chlorophenylbiguanide, was not consistently emetic. GK-128 inhibited the emetic responses induced by chemotherapeutic agents and 2-methyl-5-HT with similar potency. The anti-emetic action of GK-128 was more potent than that of ondansetron, Y-25130, granisetron and metoclopramide. The order of potency of these drugs, except granisetron, was consistent with that of their 5-HT3 receptor binding affinity in rat cortex. GK-128 failed to inhibit copper sulfate-induced emesis. These data suggest that GK-128 has a potent inhibitory effect on emesis via the 5-HT3 receptor, and that the 5-HT3 receptor involved in emesis in Suncus murinus may be different from the classically defined 5-HT3 receptor in other animals such as rats, dogs and ferrets.

Animals↗

Arg-vasopressin content in the suprachiasmatic nucleus of rat pups: circadian rhythm and its development.

To investigate the development of Arg-vasopressin (AVP) content and its diurnal rhythm in the suprachiasmatic nucleus (SCN), AVP was measured by enzyme immunoassay in the rat pup SCN punched out from tissue slices obtained at postnatal day (PD) 1, 5, 10, 12 and 20 from animals maintained under a light-dark cycle (LD). The AVP levels, measured at a restricted time of day, increased from PD1 reaching the adult level at PD10-12. Diurnal rhythm similar to that in adults was evident at PD10-12 under the LD conditions used. The peak value of AVP was observed at the earlier light period, and its trough occurred at the end of the light period. The circadian rhythm remained for 7 days under constant dark (DD) or constant light (LL) conditions. These results indicate that the AVP, one of the output signals from the SCN, starts to oscillate after PD10-12, and shows a free-running rhythm during the nursing period.

Animals↗

Day-night differences in the contents of vasoactive intestinal peptide, gastrin-releasing peptide and Arg-vasopressin in the suprachiasmatic nucleus of rat pups during postnatal development.

To investigate the developmental features of peptide levels in the suprachiasmatic nucleus (SCN), the contents of vasoactive intestinal polypeptide (VIP), gastrin-releasing peptide (GRP) and Arg-vasopressin (AVP) were measured in punched-out SCN tissue from rat pups on postnatal days (PD) 4, 15 and 20 using a specific enzyme immunoassay. The VIP content was high at night, and the day-night difference was largest at PD4 throughout the developmental stage. GRP and AVP contents increased following the maturation. GRP levels were higher during the dark than the light period from PD4 to PD20. Subjective day-night differences were also observed in blinded pups. Our results indicate that VIP, GRP and AVP in the SCN already show a diurnal rhythm in the SCN during the nursing period.

Age Factors↗

Comparative study on topical and oral administration of ofloxacin for Pseudomonas corneal ulcer in rabbits.

Pseudomonas aeruginosa is one of the most frequently isolated microorganisms in bacterial corneal ulcers in Japan and other countries. We evaluated a topical application of 0.3% ofloxacin (OFLX) for Pseudomonas corneal ulcer in rabbits and compared it to the clinical effects of OFLX in topical and oral applications. All corneas in the control groups of both experiments showed total leukoma with a score of 4 on the seventh day. On the other hand, in the preventive experiment, all the scores in the OFLX-treated group were 0, and those in the therapeutic experiment were smaller than those of both the control and oral groups. The results indicate that topical OFLX is effective on Pseudomonas corneal ulcer in rabbits.

Administration, Oral↗

Assessment of malocclusion of Japanese junior high school pupils aged 12-13 years in Iwate prefecture according to the Dental Aesthetic Index (DAI).

The purpose of this investigation is to grasp the actual condition of malocclusion in Japanese junior high school pupils using the Dental Aesthetic Index (DAI). A total of 218 junior high school pupils aged 12-13 years were examined according to DAI. About 40% of the subjects had incisal crowding. The percentage of subjects with incisal spacing was 24%, and 71% of them had diastema of 1 mm or more. The percentage of subjects with anterior irregularity on the upper and lower arch was 39% and 33%, respectively. The percentage of subjects with anterior maxillary overjet and mandibular protrusion of 1 mm or more was 85% and 6% respectively. Dislocation by more than a half-cusp in the proximal or distal relationship in the molars was observed in 26% of all subjects. Mean +/- SD of DAI score was 25.3 +/- 7.3.

Adolescent↗

Stability of a 1 beta-methylcarbapenem antibiotic, meropenem (SM-7338) in aqueous solution.

The stability and the degradation products of 1 beta-methylcarbapenem, meropenem in aqueous solution were investigated. In pH 4-8 dilute solution, pseudo-first-order degradation was observed, and good stability of meropenem in aqueous solution was demonstrated by the effect of 1 beta-methyl group against hydrolysis of beta-lactam ring. As degradation products, the beta-lactam hydrolyzed product and the dimer product resulting from intermolecular aminolysis of beta-lactam ring by the amine of the second molecule were described.

Anti-Infective Agents↗

[A case of duodenal duplication and a review of reported cases].

We report a case of duodenal duplication and review of literatures on 43 cases reported in Japan including ours. A 34-year-old female who was admitted with chief complaints of epigastric pain and hematoemesis. An endoscopic examination and a hypotonic duodenography revealed a protruding tumor with bleeding ulcer. Wedge resection of the duodenum, including the lesion, was performed. A diagnosis of duodenal duplication was made by histopathological examination.

Adult↗

[Rapid diagnosis of adenoviral conjunctivitis by enzyme-linked immunosorbent assay (Adenoclone)].

We evaluated an enzyme-linked immunosorbent assay test (Adenoclone) for the rapid diagnosis of adenovirus infection in 589 cases of acute follicular conjunctivitis. Of 255 cases of adenoviral conjunctivitis proven by positive virus isolation. Adenoclone was positive in 51.0% by visual determination and 40.4% by spectrophotometry. Twenty-seven of 130 cases giving visually positive results were interpreted to be negative by spectrophotometry. In 334 adenovirus-negative cases, Adenoclone was negative in 99.1% and 99.4 by visual and spectrophotometric determination, respectively. Adenoclone was less sensitive in cases of adenovirus 3, 4 or 37, infections than in those of adenovirus 8, and also showed lower sensitivity in cases presenting mild conjunctivitis. Adenoclone is a rapid and easy test with high specificity but low sensitivity, and thus the test seems to be helpful in diagnosing adenoviral conjunctivitis.

Adenovirus Infections, Human↗

Nitric oxide blocks the cell cycle of mouse macrophage-like cells in the early G2+M phase.

The effects of nitric oxide produced by macrophage-like cells (Mm1) on the cell cycle were investigated. Mm1 cells lost proliferative activity in the presence of interleukin-6 (IL-6) and a subpopulation accumulated in the G2+M phase. This level increased in proportion to the incubation time. The DNA content of the cells was slightly lower than that of Mm1 cells treated with vinblastine or demecolcine, drugs which block the cell cycle in the M phase. The peak of the early G2+M phase was reduced by treatment with NG-mono-methyl-L-arginine. However, after treatment with exogenous nitric oxide or sodium nitroprusside, the G0/G1 phase increased, but the early-G2+M and the S phase decreased. The flow cytometry pattern in IL-6-treated Mm1 was the same as that of cytochalasin B-treated Mm1. These data suggest that endogenous nitric oxide affects the microfilament system of IL-6-treated Mm1 cells and blocks the cell cycle in the early G2+M phase.

Animals↗

Effects of anisosmotic conditions on the cytoskeletal architecture of cultured PC12 cells.

PC12 cells show a classical volume regulatory process when submitted to hypo-osmotic conditions. The present study examined the effects of such osmotic shock on the structural organization of different cytoskeletal elements. Results were obtained by use of different light and electron microscopy techniques combined with immunostaining methods. It appeared that the osmotically induced changes in cell volume were concomitant with important modifications in the organization of the microfilament network. Microfilaments concentrated in the perinuclear area, leaving only radial extensions of poorly organized structures in the cytoplasm. The latter were the only actin structures immunologically stained in the cytoplasm and seemed to anchor to the plasma membrane. Measurements of the fluorescence intensity of PC12 cells treated with FITC-labeled phalloidin indicated a progressive depolymerization, followed by a repolymerization of F-actin. This occurs in parallel with microfilament reorganization and volume regulatory processes. The appearance of microfilament reorganization was a function of both the incubation period and the amplitude of the osmolarity changes. During the first minutes of osmotic shock, a decrease was observed in the density and length of microvilli, which normally cover the PC12 cell surfaces, suggesting an early reorganization of the underlying microfilament network. Microtubules and intermediate filament networks were not affected by the hypo-osmotic conditions.

Actin Cytoskeleton↗

Synergistic antitumor activity of combination chemotherapy with mitomycin C and cisplatin against human gastric cancer xenografts in nude mice.

A new combined cancer chemotherapy regimen of mitomycin C (MMC) and cisplatin (DDP) showed synergistic antitumor activity against human gastric cancer xenografts St-40 and SC-1-NU in BALB/c nu/nu mice. The drugs were administered intraperitoneally at doses of 2 or 4 mg/kg for MMC and 3 or 6 mg/kg for DDP, respectively. To clarify the schedule-dependent antitumor activity of MMC and DDP against St-40 and SC-1-NU, different sequential therapies were conducted. Simultaneous administration of these agents showed the highest antitumor activity against SC1-NU among the three regimens used, whereas the sequence of MMC followed by DDP showed higher antitumor activity than the reverse sequence against St-40. The intratumoral concentration of platinum was significantly increased in St-40 treated with the sequence MMC to DDP, in comparison with the sequence DDP to MMC. The maximum tolerated dose (MTD) of this combination was 4 mg MMC plus 6 mg DDP per kg in all the combinations, and these MTDs were 2/3 of the corresponding values for their single use. Since this combination increased the antitumor activity of each single agent without any increase in their toxicity, it would appear to be useful clinically.

Adenocarcinoma↗

Three-dimensional distributions of desmin and vimentin in cultured hamster cardiomyocytes using the immunogold deep-etching replica technique.

The distributions of desmin and vimentin intermediate filaments in cultured hamster heart cells were examined by immunofluorescent microscopy and an immunogold deep-etching replica technique in combination with electron microscopy. Fluorescent studies showed the overall staining patterns of the myocytes as well as the fibroblasts. Monoclonal antibodies (Da, D3) to desmin showed punctate staining for the myocytes, while polyclonal desmin (pD) stained in a filamentous pattern. Fibroblasts stained strongly with monoclonal anti-vimentin (Va), but did not stain with the desmin probes. Deep-etched immunogold studies confirmed at the ultrastructural level that monoclonal anti-desmin antibodies stain individual intermediate filaments in an intermittent pattern. Monoclonal (D3) antibody stained the intermediate filaments heavily and continuously at the cell peripheries, while it stained intermittently in the cell body, similar to the Da monoclonal. Monoclonal anti-vimentin stained only intermediate filaments in fibroblasts. Our studies show a heterogeneity of staining within the cultured heart cells when various anti-desmin and anti-vimentin antibodies are used.

Animals↗

Cavernous transformation of the portal vein coinciding with early gastric cancer and cholelithiasis.

A 71-year-old man who developed jaundice with a high-grade fever was admitted to our hospital. The episode was ascribed to cholecysto-choledocholithiasis. In the preoperative evaluation, a cavernous transformation of the portal vein and an early gastric cancer were found. The patient thereafter underwent an operation for those pathologies after the endoscopic removal of a choledochal stone; cholecystectomy, and a distal gastrectomy with regional lymph node dissection for gastric cancer. The proposed procedures of gastrectomy and cholecystectomy were completed without any major difficulty because no markedly enlarged collateral veins were found in the area where the regional lymph node dissection was carried out. Thanks to advances in imaging modalities, an asymptomatic cavernous transformation of the portal vein coinciding with gastric cancer such as that seen in the present case may be increasingly encountered in the future. The greatest caution, however, needs to be exerted at operation to minimize any unexpected bleeding and to avoid any interruption of the porto-portal shunts in such cases. Further, the reestablishment of the portal blood supply to the liver might be required in advanced cases of gastric cancer, where regional lymph node dissection may necessitate skeletonization of the hepatoduodenal ligament for curative purposes.

Adenocarcinoma↗