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Y Shiba

Publications and source records attributed to Y Shiba.

At least 55 records · Page 3Linked to original sources
PubMed1995

Immunocytochemical localization of motilin-containing cells in the rabbit gastrointestinal tract.

Motilin-immunopositive cells (Mo cells) are known to be present in the upper small intestine of various species, including man. However, whether Mo cells are present in the rabbit gastrointestinal tract remained to be elucidated. Therefore, this study was designed to investigate the distribution of Mo cells in the rabbit gastrointestinal tract by the avidin-biotin-peroxidase complex method using a new anti-motilin serum (CPV2) raised in chickens. The results of an enzyme-linked immunosorbent assay suggested that this antiserum recognized the C-terminal region of the motilin molecule. Motilin-immunopositive cells were found in the epithelia of the crypts and villi throughout the rabbit gastrointestinal tract from the gastric antrum to the distal colon, but no immunostaining occurred in the gastric body. Morphometric analysis revealed that Mo cells were localized preferentially in the upper small intestine, as reported for other species, and the cell densities (cells/mm2, mean +/- SE) were: gastric antrum (0.41 +/- 0.16), duodenum (8.2 +/- 0.8), jejunum (1.9 +/- 0.5), ileum (0.62 +/- 0.14), cecum (0.19 +/- 0.05), proximal colon (0.13 +/- 0.03), and distal colon (0.39 +/- 0.18). Our results demonstrated conclusively that Mo cells exist in the rabbit gastrointestinal tract and showed for the first time their regional distribution. Furthermore, our new chicken antiserum would appear to be a useful tool for the determination of plasma motilin concentrations by radioimmunoassay and for the immunoneutralization of endogenous motilin in the rabbit.

Animals↗
PubMed1995

Delayed inhibition of gap-junctional intercellular communication in the acinar cells of rat submandibular glands induced by parasympathectomy and cholinergic agonists.

In this study, the effects of parasympathectomy and cholinergic agonists on gap-junctional intercellular communication and salivary secretion were investigated to clarify the involvement of salivary secretion in delayed uncoupling between acinar cells of rat submandibular glands. Gap-junctional intercellular communication was monitored as dye-coupling in the acinar cells of isolated acini by the transfer of Lucifer Yellow CH. Parasympathectomy induced dye-uncoupling in the acinar cells isolated from denervated salivary glands 12 hr after parasympathectomy-induced salivary secretion. Intraperitoneal application of carbachol (CCh), acetylcholine, pilocarpine, but not isoproterenol, stimulated salivary secretion, and then induced dye-uncoupling in the acinar cells 12 hr later. Atropine suppressed both the salivary secretion and delayed dye-uncoupling induced by parasympathectomy and CCh, when atropine was applied intraperitoneally before the induction of salivary secretion. However, atropine did not suppress the delayed dye-uncoupling by intraperitoneal application of CCh, when atropine was injected after the cessation of CCh-induced secretion. These results suggest that delayed inhibition of gap-junctional intercellular communication by parasympathectomy and cholinergic agonists in rat submandibular glands might be related to the change of secretory function after salivary secretion.

Animals↗
PubMed1994

Autoradiographic study of motilin binding sites in the rabbit gastrointestinal tract.

Although motilin receptors have been demonstrated by ligand binding studies, there have been no morphological studies of motilin binding site distribution. Light microscopic macro- and micro-autoradiography using highly purified iodinated Tyr23 canine motilin (10(-10) M) was carried out on the gastric antrum, duodenum, cecum and distal colon of the rabbit. Motilin binding sites were found on the smooth muscle layers of the gastric antrum, duodenum and colon, but no positive binding reaction was detected in that of the cecum. Specific binding sites were particularly abundant in the circular muscle layers, with low concentrations in the longitudinal muscle layers of the gastric antrum, duodenum and colon. No motilin binding sites were found in the mucosa of the gastrointestinal tract and pancreas. The intensity of the positive reaction was inhibited when the tissue was incubated with 10(-8) M unlabeled motilin and was completely abolished by 10(-7) M unlabeled motilin. These results are consistent with the difference in contractile response to motilin between the muscle layers of the gastrointestinal tract.

Animals↗
PubMed1994

Effect of strict metabolic control on glucose handling by the liver and peripheral tissues in non-insulin-dependent diabetes mellitus.

To examine the effect of strict glycemic control on the insulin resistance of non-insulin-dependent diabetes mellitus (NIDDM), we applied euglycemic hyperinsulinemic clamp combined with an oral glucose load (OGL) to nine non-obese subjects with NIDDM and quantitated insulin-mediated glucose uptake by the liver (HGU) and peripheral tissues (PGU) simultaneously before and after 3 to 4 weeks of intimate glycemic control by preprandial regular insulin injections 3 times a day. The glucose infusion rate (GIR) required to maintain euglycemia during the clamp before OGL was considered as PGU. After OGL, the fraction of ingested glucose that is not extracted by the liver enters the systemic circulation and reduces the GIR required for the clamp. HGU was calculated from the difference between the amount of OGL and the cumulative decrements in GIR after OGL and was expressed as the ratio to the amount of OGL (%). Three to 4 weeks after initiation of strict metabolic control, FPG and HbA1c levels significantly improved (9.1 +/- 0.5 vs. 6.4 +/- 0.4 mmol/l, and 11.2 +/- 0.8 vs. 8.3 +/- 0.3%, P < 0.05). HGU significantly increased to 33.1 +/- 9.5 from 14.5 +/- 4.8%, while PGU did not change (38.2 +/- 5.2 vs. 37.4 +/- 3.9 mumol/kg.min). These data suggest that short-term strict metabolic control ameliorates insulin resistance in NIDDM mainly at the hepatic level.

Adult↗
PubMed1994

Keratin 19-like immunoreactivity in receptor cells of mammalian taste buds.

Three monoclonal antibodies, 4.62, LP2K and 170.2.14, were used to evaluate keratin 19-like immunoreactivity in gustatory epithelia. Keratin 19-like immunoreactivity was restricted to the intragemmal cells for all types of mammalian taste buds examined. These taste buds included fungiform, foliate and vallate taste buds in rat, gerbil and rabbit, and nasopalatine, epiglottal and palatine taste buds in rat. There was no keratin 19-like immunoreactivity in basal cells or in perigemmal cells lateral to the immunoreactive taste receptor cells. Denervation of the rat vallate papilla eliminated all taste buds, as well as all immunoreactive taste cells. That the immunoreactive material in the taste cells was keratin 19 was supported by the comparable staining of rat taste buds with each of three monoclonal antibodies specific for keratin 19. Furthermore, as predicted, these antibodies selectively stained luminal cells of rat bile ducts, bladder, salivary ducts, trachea, ureter and uterus. It was concluded that monoclonal antibodies against keratin 19 can usefully distinguish intragemmal taste receptor cells from keratinocytes, and from the perigemmal and basal cells of gustatory epithelia. Anti-keratin 19 antibodies may serve to identify differentiated taste cells in gustatory epithelia undergoing taste bud development, renewal, degeneration or regeneration.

Animals↗
PubMed1994

Metabolic coupling of glutathione between mouse and quail cardiac myocytes and its protective role against oxidative stress.

Cultured quail myocytes were much more resistant to H2O2 toxicity than cultured mouse myocytes. The intracellular concentration of glutathione ([GSH]i) and the activity of gamma-glutamylcysteine synthetase (gamma-GCS) in quail heart cells were about five and three times higher, respectively, than in mouse heart cells, although catalase and glutathione peroxidase (GSHpx) activity was similar in both. Preloading of gamma-glutamylcysteine monoethyl ester (gamma-GCE), a membrane-permeating GSH precursor, increased the H2O2 resistance of cultured mouse myocytes. These observations suggest that the high [GSH]i and the high activity of gamma-GCS in quail myocytes are responsible for their high resistance to H2O2. Both H2O2 sensitivity and [GSH]i of mosaic sheets composed of equal amounts of mouse and quail myocytes approximated those of sheets composed entirely of quail myocytes. From these observations, it is hypothesized that GSH was transferred from quail myocytes to mouse myocytes, probably through gap junctions between them, and that quail myocytes resynthesized GSH by a feedback mechanism, thus maintaining their intracellular GSH levels. When the fluorescent dye lucifer yellow was injected into a beating quail myocyte in a mosaic sheet, it spread to neighboring mouse myocytes but not to neighboring L cells (a cell line derived from mouse connective tissue). These observations indicate that existence of gap junctions in the region of cell contact between mouse and quail myocytes but not between quail myocytes and L cells. When quail myocytes preloaded with [3H]gamma-GCE were cocultured with mouse myocytes and L cells, the radioactivity was transmitted to neighboring mouse myocytes but not L cells. These observations show that GSH and/or its precursors can be transmitted from quail myocytes to mouse myocytes through gap junctions and that this can protect mouse myocytes from H2O2 toxicity. Mouse myocyte sheets composed of 10(4) cells or more showed higher resistance to H2O2 toxicity than single isolated mouse myocytes. Metabolic coupling of GSH between myocytes may contribute at least in part to this high resistance of the cell sheets.

Animals↗
PubMed1994

Selective alpha 1-adrenergic inhibition improves decrease glucose disposal in patients with essential hypertension.

This study evaluated insulin secretion and insulin sensitivity before and after short-term oral administration of doxazosin in patients with essential hypertension. The hypertensive group consisted of 11 nonobese subjects (aged 41.0 +/- 2.5 years (mean +/- SEM), body mass index 24.0 +/- 0.53 kg/m2). The normotensive group consisted of 12 subjects matched to the hypertensive group for age and body mass index. The hypertensive group showed significantly higher concentrations of prestimulated and stimulated plasma insulin and plasma C peptide than normal groups. The insulin-mediated glucose disposal rate during euglycaemic clamp (M-value) was significantly lower in the hypertensive group than in normal controls (7.32 +/- 0.56 vs 8.88 +/- 0.34 mg/kg/min, P < 0.05). After one month of doxazosin treatment blood pressure was significantly reduced (P < 0.05). The short-term administration of doxazosin improved the M-value significantly to 8.60 +/- 0.62 mg/kg/min without a significant change in stimulated plasma C-peptide level. These data show that hypertension is associated with increased insulin secretion and impaired insulin sensitivity. Selective alpha 1-adrenergic inhibition with doxazosin improves the decreased glucose disposal rate associated with hypertension.

Administration, Oral↗
PubMed1994

Inhibition of motilin-induced phase III contractions by pentagastrin in Heidenhain pouch dogs.

We compared the inhibitory effects of histamine and pentagastrin (PG) on motilin-induced upper gastrointestinal phase III activity in conscious dogs that had surgically prepared Heidenhain pouchs (HP). Contractile activity was measured by means of chronically implanted force transducers, and changes in pH of the perfusate through the HP were monitored simultaneously. Intravenous infusion of PG (4 micrograms/kg-hr) inhibited motilin-induced phase III activity both in the main stomach and in the HP, whereas histamine (40 micrograms/kg-hr) inhibited activity only in the main stomach. Famotidine (0.3 mg/kg, i.v., the dose that completely inhibited gastric acid secretion by PG or histamine) blocked the inhibition of phase III activity induced by histamine but did not affect PG-induced inhibition. L-364,718 (1 mg/kg, i.v.), which had no effect on the PG-induced decrease in the pH of the perfusate lowered by PG, reversed the inhibition of phase III activity by PG in the HP but not in the main stomach. However, L-364,718, when combined with famotidine, potently reversed the PG-induced inhibition of phase III activity both in the main stomach and in the HP. These results show that the inhibitory effect of PG on motilin-induced phase III activity is brought about by two distinctive mechanisms, gastric acid and the cholecystokinin receptors-dependent mechanism, whereas the histamine-induced inhibition is mediated only by gastric acid. In the vagally denervated HP, however, gastric acid is not involved in an inhibitory effect of PG.

Animals↗
PubMed1993

Secretion and overproduction of carboxypeptidase Y by a Saccharomyces cerevisiae ssl1 mutant strain.

Carboxypeptidase Y (CPY; EC 3.4.16.1) is the yeast vacuolar protease. To have CPY secreted and to increase its secretion level, we tried to express the prepro-CPY gene under the control of the inducible GAL10 promoter or constitutive ENO1 promoter on a multicopy plasmid. In the strains KK4, PEP4, and A2-1-1A, carrying the CPY expression plasmid, active CPY was not detected in the culture broth although the CPY activity was greatly increased inside the cells. In contrast, when we used a strain that contained the ssl1 (super-secretion of lysozyme) mutation, a large amount of active CPY (about 10-50 mg/liter) was detected in the culture broth. The ssl1 mutants secreted active CPY when the CPY level was increased by expressing it under the control of a strong promoter on a multicopy plasmid, while the endogenous expression of chromosomal CPY gene in the same ssl1 mutant caused a deficiency in the processing of pro-CPY to mature CPY.

Base Sequence↗
PubMed1992

[Vocal function in Reinke's edema--degree of the lesion and indication of the operation].

Fifty three cases of Reinke's edema were classified into 3 groups according to Yonekawa's proposed classification. Of these cases, 14 were Type I, 22 were Type II and 17 were Type III. In each case, psychoacoustic evaluation using the "GRBAS" scale and phonatory function tests (fundamental frequency, air flow rate, sound pressure level and maximum phonation time) using Nagashima PS-77 phonatory function analyzer were performed. Psychoacoustically, the voice quality before surgery was estimated moderately impaired, in general, with high grade Roughness accompanied by Asthenisity and Strainedness. Cases with more severe lesions showed much worse psychoacoustic evaluation results and severely impaired phonatoy function, but they also showed greater improvement after surgery. Phonatory function improved significantly within a month and psychoacoustic evaluation improved significantly from 1 to 3 months after surgery, though neither returned to the normal range. In conclusion, we consider that surgical therapy is appropriate in Type II and III cases, with voice therapy and cessation of smoking also necessary for good recovery.

Adult↗
PubMed1991

Dose effects of acetylcholine on the cell volume of rat mandibular salivary acini.

The effects of acetylcholine (ACh) on the cell volume of the isolated rat mandibular acini were studied stereologically using video-enhanced contrast optical microscopy. The lengths of major and minor axes of the acini were measured in the successive video images, from which the relative volume change was estimated. ACh induced a rapid shrinkage of the acinar cell to reach minimum volume within 1 min. Simultaneously, the acinus and acinar clump shrunk in the same proportion as the acinar cell. The initial volume decrease induced by ACh was dose dependent: 0.92 at 10(-8) M, 0.91 at 10(-6) M, 0.77 at 10(-5) M, 0.78 at 10(-4) M, and 0.75 at 10(-3) M (the relative volume compared with the resting control). During sustained stimulation by ACh for 3 min, the volume of acinar cell remained at the plateau level at concentrations lower than 10(-5) M ACh, whereas the volume increased by 0.1-0.15 at concentrations higher than 10(-4) M ACh. The dose-dependent manner of the cell volume coincided with the fluid secretion measured in the isolated perfused gland. The findings on the dose effects of ACh are discussed in connection with the intercellular communication and the movement of electrolytes.

Acetylcholine↗
PubMed1991

[Parapharyngeal space lesions: with a reference to biopsy].

We received seven cases of parapharyngeal space lesions and discussed on necessity of biopsy. Tumors originating in the parapharyngeal space were represented by parotid pleomorphic adenomas which showed bulging of soft palate and tonsillar fossa, and benign neurogenic tumors which showed bulging of the lateral wall of the meso-pharynx. In these cases, preoperative biopsy was not necessary unless the lesion was suspected, of malignancy by CT, MRI and so on. In the case of bulging of soft palate and tonsillar fossa, if CT or MRI finding shows that the tumor is localized in the median portion of the parapharyngeal space and is separated from greater vessels and nerves existing in the parapharyngeal space, therapeutic protocol might be planned after an establishment of histological diagnosis with biopsy. In the case of a bulging lateral wall of the meso-pharynx with a history of malignant neoplasm of the head and neck, lymph node metastasis should be thought about.

Adenocarcinoma↗
PubMed1991

[Results of chemo-radiotherapy for nasopharyngeal carcinoma].

We reported the data on 25 patients with nasopharyngeal carcinoma from 1984 to 1989, who received chemo-radiotherapy for initial treatment and follow-up by additional maintenance of chemotherapy for 2 years. The result of this study is as follows. 1. The 20 males and 5 females were included. 2. A median age of the patients was 62 years. 3. Stage grouping study showed 3 cases of stage II, 6 of stage III, and 16 of stage IV. 4. The local control rate was 92% and the rate of control in the cervical region was 96%. 5. However, the overall 4-year survival rate obtained by the Kaplan-Meiers method was 50%. 6. The cause of patients' death was mainly distant metastasis.

Adult↗
PubMed1990

Inhibition of gap-junctional intercellular communication and enhanced binding of fibronectin-coated latex beads by stimulation of DNA synthesis in quiescent 3T3-L1 cells.

To clarify the modulation of intercellular communication via gap junctions, associated with the growth induction of quiescent 3T3-L1 cells, we investigated the gap-junctional intercellular communication in growth-stimulated cells that were able to bind fibronectin-coated beads. When quiescent 3T3-L1 cells were incubated with fibronectin-coated beads for the first 2 h after the addition of calf serum, 24.0% of the cells bound and phagocytosed beads. Among the cells with bound beads, the percentage of the cells labeled concurrently with bromodeoxyuridine was 63.7% when examined 13 h after the addition of calf serum. Transient reduction of dye-coupling, measured with Lucifer Yellow CH, was observed only in the cells with bound beads 2 h after addition of calf serum, but it was not observed in the cells without bound beads. When the quiescent cells were incubated with fibronectin-coated beads for 2 h from 4-6 h after the addition of calf serum, the percentage of cells with bound beads increased to 53.1%, but the decrease in dye-coupling among the cells with bound beads was slight. These results suggest that the induction of cell growth causes a transient reduction in gap-junctional intercellular communication in 3T3-L1 cells with bound fibronectin-coated beads.

Animals↗
PubMed1990

Hematoma of the interatrial septum associated with complete atrioventricular block.

A 70-year-old man who had been treated for tongue cancer began to suffer from repeated syncopal attacks. His electrocardiogram indicated complete atrioventricular block. A permanent pacemaker was implanted. He was well for about 2 years after which time he developed dyspnea, suffered from general fatigue, and then suddenly died. A postmortem examination revealed a hematoma approximately 4 x 4. cm in size in the interatrial septum, connected to a noncoronary sinus and rupture of the noncoronary leaflet, which compressed the tricuspid and aortic valves. This hematoma might have been related to the conduction disturbance caused by destructive compression on the conduction system, and his death by the rupture of the noncoronary leaflet.

Aged↗