Search PubMed⌕ Search

Biomedical subjects

I Watanabe

Publications and source records attributed to I Watanabe.

At least 163 records · Page 9Linked to original sources
PubMed1996

Differential effects of ketamine and pentobarbitone on acetylcholine release from the rat hippocampus and striatum.

Using microdialysis, we examined the effects of ketamine and pentobarbitone on acetylcholine (ACh) release from the rat hippocampus and striatum. Ketamine 25 and 50 mg kg-1 increased ACh release from the hippocampus to 295% and 353% of basal release, respectively, but not from the striatum. SCH 23390 1 mumol litre-1, a D1 antagonist, significantly inhibited the facilitatory effect of ketamine 50 mg kg-1 on hippocampal ACh release (to 241% of basal level). In contrast, pentobarbitone 20 and 40 mumg kg-1 decreased basal ACh release from both the hippocampus by 41% and 69%, respectively, and the striatum by 37% and 58%, respectively. The results suggest that ketamine and pentobarbitone exert opposite effects on ACh release from the rat hippocampus and that the stimulating effect of ketamine may involve dopamine D1 receptors.

Acetylcholine↗
PubMed1996

Thymic carcinoma of the thyroid.

A highly malignant case of intrathyroidal thymic carcinoma showing morphological and biochemical evidence identical with mediastinal thymoma is presented. A 32-year-old female, who had previously undergone total colectomy with ileo-proctostomy due to familial adenomatous polypnosis, was operated on for a tumor (3.4 x 4.5 cm) originating from the left thyroid lobe. A minute focus (diam. 0.8 cm) of papillary adenocarcinoma also existed in the upper pole of the right lobe. The main tumor was morphologically an epithelial thymoma with scanty lymphocyte intermixing and showed medullary differentiation with apparent Hassall's corpuscles. Mitosis was frequent and numerous tumor thrombi were in the subcapsular veins. Five months after the total thyroidectomy and lymph node dissection, a subcutaneous recurrence of the tumour (diam. 2.3 cm) appeared in the anterior cervical region. The cystic contents of the recurrent tumor revealed a high titer of thymosin alpha 1-Other organs, including thymus, lungs, and adrenals, had all been free of neoplastic changes clinically and radiologically for 5 months after her first admission until the local tumor recurrence.

Adult↗
PubMed1996

Influence of high dose inhaled steroids on hypothalamo-pituitary-adrenal axis function in Japanese patients with asthma: a comparison over the course of time.

Although the influence of high dose inhaled steroids on hypothalamo-pituitary-adrenal (HPA) function in patients with asthma has been extensively studied worldwide, there has been limited information on Japanese asthmatics, especially in terms of a prospective analysis of HPA function in the course of time. We analyzed the changes in HPA function using 2 serial short tetracosactrin tests (STT) separated by an interval of one year in 11 Japanese asthmatics who were treated with high dose inhaled steroids alone [beclomethasone dipropionate (BDP); mean dose 982 micrograms/day] during the period between 2 STTs. Mean values of plasma cortisol before administration of ACTH, maximum cortisol and the rise in cortisol in response to ACTH in the 2 STTs were 7.8, 20.5 and 12.7 micrograms/dl for the 1st test, and 8.9, 23.6 and 14.7 micrograms/dl for the 2nd test, respectively. Overall, there was no significant change in the course of time in each of these 3 values. Although the results of the 1st STT proved to be abnormal in 3 patients who had been receiving systemic steroids before their 1st STT, they improved uniformly in their 2nd STT. In the remaining 8 patients, who had never received systemic steroids, 4 patients showed improvements while the other 4 showed deterioration in HPA function in their serial STTs over the course of time. The dose of BDP was 800 micrograms/day in the former 4 patients, while it was 1,200 micrograms/day in the latter 4. Furthermore, only one patient, in whom BDP had been increased from 800 micrograms/day to 1,200 micrograms/day between the 2 tests, developed an abnormal response in the 2nd STT. On the other hand, one patient whose BDP dose was increased from 800 micrograms/day to 1,600 micrograms/day showed an improvement in HPA function in the 2nd test. These results indicate that the threshold dose of BDP which may cause HPA suppression in Japanese asthmatics lies between 800-1,200 micrograms/day, although there is a large inter-individual variation in terms of such doses.

Administration, Inhalation↗
PubMed1996

Localization of thrombomodulin in a rabbit eye.

PURPOSE: To show the distribution of an anticoagulant factor, thrombomodulin, in a rabbit eye. METHODS: Immunohistochemical staining using polyclonal anti-rabbit thrombomodulin antibody was performed with the excised eyes of pigmented adult rabbits. Streptavidin-biotin method was used to obtain intense staining. RESULTS: The endothelium of the chorioretinal vessels showed positive linear staining. The ciliary non-pigmented epithelium showed granular staining, while the pigmented epithelium stained negatively. The positive staining was also detected in the trabecular plexus endothelium. The vascular endothelium of the ciliary body stained weakly. CONCLUSIONS: It is suggested that thrombomodulin in the vessel walls and the aqueous drainage apparatus works to maintain normal blood fluidity and aqueous outflow. The role of nonvascular thrombomodulin in the ciliary non-pigmented epithelium is unclear.

Animals↗
PubMed1996

Plasma cholesterol-suppressing effect of papain-hydrolyzed pork meat in rats fed hypercholesterolemic diet.

The effects of papain-hydrolyzed pork meat on plasma and liver cholesterol levels were studied in rats fed a cholesterol-enriched diet. In rats fed the low-molecular-weight fraction of papain-hydrolyzed pork meat, the plasma cholesterol concentration, more particularly the VLDL and LDL cholesterol concentrations, were significantly lower (p < 0.01) than in the rats fed untreated pork meat or soybean protein. Feeding with this fraction rather than with untreated pork meat also led to a significantly lower liver cholesterol concentration (p < 0.01) and increased fecal excretion of neutral and acidic steroids. The low-molecular-weight fraction contained peptides with molecular weights of 3,000 or less and had an amino acid composition similar to that of pork meat itself. This study suggests that peptides produced by papain-hydrolysis of pork meat have a hypocholesterolemic activity through their interference with the steroid absorption process.

Animals↗
PubMed1996

Fine structure of the acinar and duct cell components in the parotid and submandibular salivary glands of the rat: a TEM, SEM, and HRSEM study.

Parenchymal and stromal components of the rat parotid and submandibular glands were examined by conventional and high resolution scanning electron microscopy (HRSEM). Freeze-fractured specimens were subjected to HCl and NaOH extraction procedures to better differentiate connective tissue and cellular components. In addition, the internal three-dimensional morphology of the secretory acinar cells and duct cells was revealed by maceration with a dilute osmium tetroxide solution to selectively remove some of the cytoplasmic components. SEM and HRSEM examination of the HCl-treated samples of both glands revealed a fine filamentous network immediately surrounding each acinus. Coarser bundles of collagen that linked neighboring acini were also observed. NaOH-extracted samples selectively removed the cellular components and showed more clearly the three-dimensional structure of the connective-tissue stroma. A dense-collagenous network surrounded each lobule while more internal regions consisted of a honeycomb-like pattern of evacuated spaces previously occupied by secretory acini. These spaces were smoothened in appearance and often interconnected. Apically-located secretory granules and profiles of the rough endoplasmic reticulum and Golgi apparatus in perinuclear regions were encountered in the acinar and duct cells of macerated samples by HRSEM. In addition, a phenylephrine-induced experimental condition performed in some rats resulted in a significant increase in secretory granule size and density of the serous cells.

Adrenergic alpha-Agonists↗
PubMed1996

Prosthodontic treatment for a patient with advanced hydantoin-associated gingival hyperplasia: a case report.

A patient in whom gingival hyperplasia was caused by prolonged use of an anticonvulsant drug (hydantoin) is described. Advanced gingival hyperplasia and significant displacement of the remaining teeth caused severe damage, especially to the patient's appearance. It was not possible to cure the problems completely with routine periodontal treatment. It was decided to extract all the remaining teeth and restore function and esthetics early with complete dentures. Cephalometric analysis was used to determine the degree to which the teeth had drifted. During fabrication of the dentures, the analysis was very useful in deciding the position of the anterior teeth and checking the vertical dimension of occlusion.

Adult↗
PubMed1996

[Computed tomographic findings in septic pulmonary emboli secondary to renal abscess].

A 73-year-old woman with diabetes mellitus and hypothyroidism had been well until 4 days before she presented with fever, productive coughing, and general malaise. Dyspnea gradually worsened, and she was admitted to Kobe City General Hospital. She appeared toxic and was in moderate respiratory distress on admission. There were scattered rales in both lung fields. The abdomen was soft with no tenderness. A chest roentgenogram showed peripheral infiltrates in both lung fields. Arterial blood gas analysis showed a Po2 of 48.6 Torr and Pco2 of 27.2 Torr. A blood culture on admission showed Escherichia coli. Computerized tomography of the chest showed multiple nodules of various sizes in the peripheral lung fields. Some nodules had necrotic centers and feeding vessels. Wedge-shaped lesions abutting the pleura were also seen. These findings strongly suggested septic pulmonary emboli. An abscess in the left kidney, which was considered to be the source of the septic pulmonary emboli, was found with Ga scintigraphy, ultrasonography, and computerized tomography of the abdomen. Treatment with antibacterial drugs was effective against the lung lesions but not the renal abscess. A left nephrectomy was done. In the proper clinical setting, characteristic CT features of septic emboli can contribute to early diagnosis of this disease.

Abscess↗
PubMed1996

Optic sharp edge or convexity: comparison of effects on posterior capsular opacification.

Posterior capsular opacification was evaluated in 46 eyes with an implanted sharp-edged biconvex (BC) lens, 108 eyes with the sharp-edged convex-plano (CP) lens, 160 eyes with the round-edged BC lens and 58 eyes with the round-edged CP lens. In each eye, the intraocular lens had been fixed in the sac after continuous circular capsulorrhexis, with the optic edge completely enclosed by the anterior capsule. Two years postoperatively, the posterior capsules of these eyes were photographed and the degree of opacification was classified as Grade 1 (clear) to Grade 4 (severely opacified). In the sharp-edged BC group, 91% of the eyes were Grade 1; 4% Grade 2; 2% Grade 3; 2% Grade 4. In the sharp-edged CP group, the corresponding percentages were 83, 7, 4, and 6; for the round-edged BC group: 18, 27, 24, and 31; and for the round-edged CP group: 34, 17, 28, and 21. These findings suggest that the most significant factor in prevention of posterior capsular opacification is the sharpness of the optic edge. We believe that the sharp optic edge creates higher pressure on the posterior capsule and acts as a barrier to lens epithelial cell migration.

Aged↗
PubMed1996

The arrangement of the trabecular bone in the vestibular surface of the human fetus mandible. I. A scanning electron microscopy study (1).

The characteristics of trabecular bone in human fetuses at three to six months intra-uterine life were studied in the vestibular surface of the mental and body portions of the mandible. Rounded trabeculae disposed vertically were observed in the alveolar region of the mental portion until 3 months of age. Bundles of collagen fibers were present longitudinally in the alveolar region of the mandibular body: laminar and longitudinal trabeculae lying parallel to the mandible base were seen in the basilar region. In 4 to 6-month old fetuses rounded trabeculae were observed in the alveolar region of the mental portion; in the medium region, the trabeculae were oblique while in the basilar region they were longitudinal and parallel to mandible base. In the alveolar region of the mandibular body, trabeculae with a rounded aspect were seen: in the medium region, they were straight, oblique and longitudinal to the mandible ramus: in the basilar region, the trabeculae were longitudinal and parallel to mandible base. The alveolar foramina exhibit differing diameters and shapes in the mental and body portions: thick bundles of collagen fibers and osteocyte lacunae of varying diameters were present in the bone surface.

Embryonic and Fetal Development↗
PubMed1996

Effect of CO2 laser on Class V cavities of human molar teeth under a scanning electron microscope.

The purpose of this study was to evaluate the effects of CO2 laser on dentin of class V cavities of extracted human molar teeth using a scanning electron microscope. SEM showed a smooth area with concentric lines formed by melting with subsequent recrystallization of dentin, areas of granulation, vitrified surface, numerous cracks, and irregular areas of descamative dentin. These data indicate that CO2 laser (4 and 6 watts) produces dentin alterations and limit its clinical applications.

Carbon Dioxide↗
PubMed1995

Cloning, characterization and expression of the gene encoding cytochrome P-450sca-2 from Streptomyces carbophilus involved in production of pravastatin, a specific HMG-CoA reductase inhibitor.

Pravastatin, a drug for treating hypercholesterolemia, is produced by hydroxylation of ML-236B-Na in Streptomyces carbophilus (Sc) catalyzed by the cytochrome P-450sca (CytP-450sca) monooxygenase system. The gene (cytP-450sca-2) encoding CytP-450sca-2 was cloned from Sc. The gene had an open reading frame of 1233 bp, encoding a 410-amino-acid protein. The partial sequencing of the purified CytP-450sca-2 revealed that the N-terminal Met had been removed. CytP-450sca-2 contained the heme-binding HR2 region characteristic of all CytP-450, as well as the putative oxygen-binding site proposed in CytP-450cam from Pseudomonas putida. ML-236B.Na enhanced transcription of cytP-450sca-2, suggesting that substrate induction in Sc is transcriptionally regulated. S. lividans (Sl) transfected with cytP-450sca-2 converted ML-236B.Na to pravastatin, indicating the cloned gene to be functional in Sl.

Amino Acid Sequence↗
PubMed1995

NF1 gene mutations in Japanese with neurofibromatosis 1 (NF1).

Neurofibromatosis 1 (NF1) is an autosomal dominant disease characterized by abnormalities in multiple tissues derived from the neural crest. We analysed 50 unrelated Japanese patients for NF1 mutations by using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis for exons 28 to 36. Here, we demonstrate a single base pair (bp) insertional mutations in exon 31 in one patient (5843insA/5844insA/5845insA/5846insA) and a single adenine to guanine transitional mutation 4 bp upstream from the 3' end of intron 31 in two unrelated cases. The insertional mutation in exon 31 was novel and resulted in premature termination of the transcript. The other intron 31 mutations resulted in 4 bp insertions of cDNA between exon 31 and exon 32 with premature termination of the transcript, indicating that those transitions of intron 31 caused aberrant splice acceptor sites upstream from the 5' end of exon 32. However, as the same mutation of intron 31 has been reported previously in two cases of unrelated Caucasians, the splice junction mutation of intron 31 is thought to be common among different ethnic groups.

Adenine↗
PubMed1995

Diverse incidences of individual oligopeptides (dipeptidic to hexapeptidic) in proteins of human, bakers' yeast, and Escherichia coli origin registered in the Swiss-Prot data base.

Oligopeptidic permutations of the 20 amino acid residues give rise to proteins of diverse functions. Our long-term goal is to produce a lexicon of oligopeptides, classifying them into at least five categories: (i) ubiquitous, (ii) function specific, (iii) group specific, (iv) species specific, and (v) nonexistent. To begin with, we report on the varying frequencies of individual oligopeptides (dipeptidic to hexapeptidic in length) found among 2862 human proteins, 1942 Saccharomyces cerevisiae proteins, and 2672 Escherichia coli proteins registered in the Swiss-Prot data base (version 29.0, released in June 1994). At all lengths (dipeptides to hexapeptides), homooligopeptides were very prominent among the most frequently occurring varieties in proteins of human and bakers' yeast origins. However, this was not the case with E. coli. While all of the expected 20(3) varieties of tripeptides were found among human proteins, three tripeptides (Cys-Cys-Trp, Trp-Trp-Cys, and Trp-Trp-His) were missing from the bakers' yeast proteins. Three tripeptides (Cys-Ile-Trp, Cys-Met-Tyr, and Cys-Trp-Trp) were also absent from E. coli proteins. Inasmuch as the Swiss-Prot data base already contained 67% of the expected total of 4000 E. coli proteins, it is virtually certain that 96,000 varieties of hexapeptides containing at least one or another of the three missing tripeptides noted above shall be nonexistent in E. coli. Furthermore, the observation of missing tripeptides in the bakers' yeast proteins suggests that nonexistent hexapeptides shall be highly phylum specific. Because of the sample size, only a small fraction of the 20(6) varieties of hexapeptides were expected to be encountered in the present survey. Indeed, only 1.2-1.5% of the possible hexapeptides were found, and the average copy number of observed hexapeptides varied between 1.06 and 1.25. Nevertheless, 33 varieties of hexapeptides occurred in 102-169 copies among human proteins. Furthermore, 15 of the 33 varieties contained such rarely used residues as Tyr, His, Cys, and Trp.

Amino Acid Sequence↗
PubMed1995

Role of protein kinase C activation in synthesis of complement components C2 and factor B in interferon-gamma-stimulated human fibroblasts, glioblastoma cell line A172 and monocytes.

The synthesis of C2 and factor B, the key components of complement system, is performed by various kinds of cells and is also up-regulated by interferon-gamma (IFN-gamma). By using human fibroblasts, human glioblastoma cell line A172 and monocytes, we investigated the signal-transduction mechanism for IFN-gamma-induced synthesis of C2 and factor B. The C2 and factor B synthesis induced by IFN-gamma in all three cell types was inhibited by a protein kinase C (PKC) inhibitor, 1-(5-isoquinolinyl-sulphonyl)-2-methylpiperazine (H-7). The depletion of PKC in these cell types after treatment with phorbol 12-myristate 13-acetate (PMA) resulted in inhibition of IFN-gamma-induced C2 production. In addition, IFN-gamma treatment elicited a decrease in cytoplasmic PKC in A172 cells, indicating that PKC is activated by IFN-gamma. These results suggest that PKC is crucial for IFN-gamma-induced C2 and factor B synthesis. Northern-blot analysis showed that the effects at H-7 were at least partly mediated by modulation of C2 and factor B mRNA abundance in A172 cells. Since treatment of fibroblasts and A172 cells with IFN-gamma had no effect on intracellular Ca2+ concentration, and since neither EGTA nor nifedipine inhibited C2 or factor B synthesis induced by IFN-gamma, we concluded that intracellular Ca2+ mobilization was not involved in the effect of IFN-gamma. In addition, genistein, herbimycin A and N-(6-aminohexyl)-5-chloro-1-naphthalene-sulphonamide (W-7) had no inhibitory effect on IFN-gamma-mediated action in any of the three cell types, which suggests that IFN-gamma acts independently of tyrosine kinases and calmodulin-dependent protein kinases.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

Thermal stress and diabetic complications.

Activities of erythrocyte aldose reductase were compared in 34 normal subjects, 45 diabetic patients, and nine young men following immersion in water at 25, 39, and 42 degrees C. Mean basal enzyme activity was 1.11 (SEM 0.12) U/g Hb and 2.07 (SEM 0.14) U/g Hb in normal controls and diabetic patients, respectively (P < 0.0001). Activities of the enzyme showed a good correlation with hemaglobin A1 (HbA1) concentrations (P < 0.01) but not with fasting plasma glucose concentrations. After immersion at 42 degrees C for 10 min, enzyme activity was increased by 37.6% (P < 0.01); however, the activity decreased by 52.2% (P < 0.005) after immersion for 10 min at 39 degrees C and by 47.0% (P < 0.05) at 25 degrees C. These changes suggest that heat stress might aggravate diabetic complications, and body exposure to hot environmental conditions is not recommended for diabetic patients.

Adult↗
PubMed1995

Elevated levels of heat-shock protein 70 (HSP70) in the mononuclear cells of patients with non-insulin-dependent diabetes mellitus.

Increased free radicals and reduced levels of antioxidants have been reported in diabetes mellitus. Since heat-shock protein 70 (HSP70) is a stress-induced protein and is suggested to play a protective role against oxidative stress, we have investigated whether HSP7O acts as one of the defense systems against this stress. We separated mononuclear cells from diabetic patients (N=12) and age- and sex-matched healthy controls (N =12), and detected HSP70 by western blot analysis. The results were expressed by the ratio of the density determined by laser densitometry, to that of 10 mu g of purified HSP70. HSP70 levels in the mononuclear cells of diabetic patients (0.78 + or- 0.56) were significantly high, compared with healthy subjects (0.43 + or - 0.23) (P < 0.05). No correlation was found between HSP7O and hemoglobin A1c, fasting plasma glucose, duration of diabetes or diabetic complications except age. A negative correlation was found between HSP70 and age (r = -0.658, P < 0.05). These results suggest that HSP70 levels in the mononuclear cells are elevated reflecting increased oxidative stress in patients with diabetes.

Adult↗