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S Ota

Publications and source records attributed to S Ota.

At least 145 records · Page 8Linked to original sources
PubMed1994

Role of protective drugs in the prevention of ulcer relapse.

The efficacy of gastric acid suppressive drugs, such as histamine H2-receptor antagonists and H+K+ ATPase inhibitors, in the management of peptic ulcer diseases has been well established. They accelerate the healing of peptic ulcers, and maintenance therapy with these drugs prevents ulcer relapse. However, they do not modulate the natural course of peptic ulcer. Sucralfate, a protective drug, has been shown to be equally effective in ulcer healing and the prevention of ulcer relapse. Some reports suggest that the relapse rate of ulcers treated successfully with sucralfate is less than that seen with histamine H2-receptor antagonists. Sucralfate has a true cytoprotective effect against agents noxious to gastric epithelial cells in monolayer culture. This action might be associated with its therapeutic efficacy in the treatment and prevention of ulcer diseases. The role played by other protective drugs in the management of ulcer diseases is less clear and requires further studies.

Anti-Ulcer Agents↗
PubMed1994

Bile salts stimulate mucous glycoprotein secretion from cultured rabbit gastric mucosal cells.

Resistance of gastric mucosa to damage is increased after exposure to mild irritants such as bile salts (adaptive cytoprotection). Mucus secretion also contributes to gastric cytoprotection. We investigated whether bile salts stimulate mucous glycoprotein secretion from cultured rabbit gastric mucosal cells. Because prostaglandins (PGs) stimulate mucus secretion, we assessed the role of endogenous PG release in bile salt-stimulated mucus secretion. Because Ca2+ plays a role in PGE2 release, the role of extracellular Ca2+ on PGE2 release and mucus secretion by bile salts was also studied. Rabbit gastric mucosal cells were prepared with collagenase and ethyl-enediaminetetraacetic acid. These cells were cultured as described previously. Cytotoxicity of bile salts was quantified by measuring chromium 51 release from prelabeled cells. PGE2 was measured by radioimmunoassay. Mucous glycoprotein secretion was assessed by tritiated glucosamine release assay. Deoxycholate (DC) and glycodeoxycholate (GDC) stimulated tritiated glucosamine release in doses that were not cytotoxic to the cultured cells. DC stimulated PGE2 release that was blocked by deprivation of extracellular Ca2+. GDC did not stimulate PGE2 release. Neither DC-stimulated nor GDC-stimulated mucus secretion was affected by indomethacin. Deprivation of extracellular Ca2+ did not affect DC-stimulated or GDC-stimulated mucus secretion. Bile salts stimulated mucous glycoprotein secretion from cultured rabbit gastric mucosal cells. This effect occurred independently of changes in endogenous PGE2 or extracellular Ca2+ concentrations.

Animals↗
PubMed1993

Establishment and characterization of a human mixed-lineage, T-lymphoid/myeloid cell line (USP-91).

We report the establishment of a novel cell line from a pediatric patient with recurrent non-Hodgkin's lymphoma. This cell line, termed USP-91, showed both T-lymphoid cell as well as myeloid (ie, nonlymphoid) cell characteristics using a comprehensive multiparameter approach. The initial growth of this cell line was dependent on the presence of the murine stromal cell line, 14F1.1. Subsequently, a phenotypically stable, stroma-independent cell line was established. Although the recurrent biopsy material and the derivative cell line, USP-91, were clonally-derived from T-lineage lymphoid cells, as evidenced by the same rearrangement of the T-cell receptor-beta locus, USP-91 coexpressed both the T-cell antigens CD7, CD3, and CD4, and the myeloid antigens CD13, CD33, CD11b, and CD34. The myeloid features of USP-91 were most consistent with monocytic differentiation as these cells expressed alpha-napthol acetate esterase, lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, as well as the cell surface receptor for macrophage colony-stimulating factor. In addition, incubation in the presence of phorbol esters induced USP-91 to exhibit morphologic and functional properties of mature mononuclear phagocytes. The expression of this bilineage phenotype suggests that USP-91 represents the malignant transformation of a progenitor cell capable of either myelomonocytic or T-lymphoid differentiation.

Animals↗
PubMed1993

Malignant rhabdoid tumor. A study with two established cell lines.

BACKGROUND: Malignant rhabdoid tumor (MRT), originally described as a rare renal sarcoma in childhood, has been known to express phenotypic diversity. In this study, unique characteristics of the MRT cells were investigated by using established cell lines. METHODS: Immunocytochemical, ultrastructural, cytogenetic, and molecular (by polymerase chain reaction, PCR) analyses were done for two MRT cell lines, one of renal and one of extrarenal origin, before and after differentiation-induction with either 12-O-tetradecanoyl phorbol-13-acetate (TPA) or transretinoic acid (RA). RESULTS: The proliferating cells in the original tumor tissues as well as in the established cell lines demonstrated neural, epithelial, and mesenchymal markers morphologically. Both cell lines had karyotypic abnormalities including chromosome 22q11.2. The cell line from the extrarenal MRT, Tm87-16, demonstrated distinct morphologic changes with neuroblastic differentiation and produced numerous neuritic processes after treatment with either TPA or RA. The cell line from the renal MRT, STM91-01, suggested schwannian differentiation but did not change morphologically after chemical induction. Both cell lines expressed c-myc, but did not express N-myc, MyoD1, tyrosine hydroxylase, or neural cell adhesion molecule (N-CAM). With PCR and immunocytochemical study, a high level of chromogranin expression was detected by the cells of Tm87-16 only after TPA induced differentiation. CONCLUSIONS: MRT cells demonstrated diverse phenotype of neuro-ecto-mesenchymal differentiation. The results of this study suggest that MRT may be derived from a primitive pluripotential cell, such as neural crest or equivalent. MRT, therefore, might be categorized as one of the subsets of primitive neuroectodermal tumor.

Gene Expression Regulation, Neoplastic↗
PubMed1993

Hepatocyte growth factor induces mitogenic reaction to the rabbit gastric epithelial cells in primary culture.

Hepatocyte Growth Factor (HGF) was originally identified as hepatotrophic factor for liver regeneration. More recently, HGF was revealed to stimulate proliferation of various epithelial cells. At present study, we have investigated the mitogenic effect of HGF on gastric epithelial cells in the primary culture system. HGF remarkably stimulated proliferation of these cells dose dependently and synergistically with EGF and insulin. Mitogenic action of HGF might be mediated not by intracellular Ca2+ but by tyrosine kinase pathway. Conditioned medium of cultured fibroblast-like cells showed proliferative effects on cultured gastric epithelial cells in a similar way as exogenous HGF. These results suggest that HGF might be involved in the repair process of gastric mucosa.

Animals↗
PubMed1993

Roles of Ca2+ and protein kinase C in regulation of prostaglandin E2 release by cultured rabbit gastric epithelial cells.

Prostaglandin (PG) has been reported to be one of the important protective factors in the gastric mucosa. However the mechanism of the regulation of endogenous PG production has not been well studied. We investigated the possible roles of Ca2+, cAMP, and protein kinase C (PKC) in the regulation of PGE2 release from cultured rabbit gastric mucosal cells. PGE2 was measured by radioimmunoassay. A23187 (Ca2+ ionophore) at 2 x 10(-6) M significantly increased PGE2 release. Deprivation of Ca2+ from the medium blocked the A23187-induced increase of PGE2. TMB-8 (a putative inhibitor of Ca2+ release from intracellular stores) did not have any significant effects on the increase of PGE2-induced by A23187. Thus, A23187 increased PGE2 through the influx of extracellular Ca2+. W7 or compound 48/80 (calmodulin inhibitors) did not alter the response of PGE2 caused by A23187. Exogenous administration of cAMP, forskolin (an activator of adenylate cyclase), or 2-chloroadenosine (a possible activator of adenylate cyclase through adenosine A2 receptor) had neither significant effects on PGE2 release nor an effect on A23187-induced increase of PGE2 release. 12-O-tetradecanoylphorbol 13-acetate (TPA, an activator of PKC) significantly stimulated PGE2 release in a dose-dependent fashion, whereas another phorbol ester with no biological activity did not. A23187 at 0.8 x 10(-6) M, but not cAMP, potentiated the TPA-induced increase of PGE2. Mepacrine (a phospholipase A2 inhibitor) reduced the A23187- and TPA-induced increase of PGE2. These results suggest that Ca2+ and protein kinase C may play important roles in the regulation of PGE2 release by cultured rabbit gastric cells.

2-Chloroadenosine↗
PubMed1993

Primary colonic epithelial cell culture of the rabbit producing prostaglandins.

We have established primary colonic epithelial cell culture from adult rabbits and examined effects of anti-inflammatory drugs on prostaglandin (PG) E2 production. Colonic epithelium of adult rabbits was scraped and minced into small pieces. They were incubated for isolation in Hanks' balanced salt solution with 0.35% collagenase and Earle's solution with 1 mM EDTA. Isolated cells were cultured in Coon's modified Ham's F-12 medium with 10% fetal bovine serum and antibiotics on collagen coated cell wells. The medium was refed twice a week. The production of PGs was assessed by high pressure liquid chromatography (HPLC). PGE2 and PGF2 alpha were measured by radioimmunoassay. Within 24 hours after inoculation, the cell clumps attached to the surface of the wells and cells began to spread out and grow. Monolayer cultures became confluent in 4 days. Phase contrast microscopy showed that these cells consisted of a homogeneous population of epithelial cells with large oval nuclei, polyhedral shape, and organized sheet-like growth pattern. HPLC profile showed synthesis of 6-keto-PGF1 alpha, thromboxane B2, PGF2 alpha, PGE2, and PGD2 by cultured cells. Quantitatively, 117 +/- 7 ng/mg-protein/hour PGE2 and 7.4 +/- 0.7 ng/mg-protein/hour PGF2 alpha were produced. While hydrocortisone (10(-4) - 10(-2) M) did not show a significant effect on PGE2 production, indomethacin (10(-8) - 10(-6) M), and 5-aminosalicylic acid (2X10(-4)-5X10(-3) M) inhibited PGE2 production. We have established relatively convenient procedure for primary culture of colonic epithelial cells from adult rabbits. Different actions of anti-inflammatory drugs on PGE2 synthesis suggest that these cultured cells might be a good tool for the various cellular functional studies of normal colonic epithelial cells.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Activation of Ca(2+)-dependent K+ current by acetylcholine and histamine in a human gastric epithelial cell line.

The effects of acetylcholine (ACh) and histamine (His) on the membrane potential and current were examined in JR-1 cells, a mucin-producing epithelial cell line derived from human gastric signet ring cell carcinoma. The tight-seal, whole cell clamp technique was used. The resting membrane potential, the input resistance, and the capacitance of the cells were approximately -12 mV, 1.4 G ohms, and 50 pF, respectively. Under the voltage-clamp condition, no voltage-dependent currents were evoked. ACh or His added to the bathing solution hyperpolarized the membrane by activating a time- and voltage-independent K+ current. The ACh-induced hyperpolarization and K+ current persisted, while the His response desensitized quickly (< 1 min). These effects of ACh and His were mediated predominantly by m3-muscarinic and H1-His receptors, respectively. The K+ current induced by ACh and His was inhibited by charybdotoxin, suggesting that it is a Ca(2+)-activated K+ channel current (IK.Ca). The measurement of intracellular Ca2+ ([Ca2+]i) using Indo-1 revealed that both agents increased [Ca2+]i with similar time courses as they increased IK.Ca. When EGTA in the pipette solution was increased from 0.15 to 10 mM, the induction of IK.Ca by ACh and His was abolished. Thus, both ACh and His activate IK.Ca by increasing [Ca2+]i in JR-1 cells. In the Ca(2+)-free bathing solution (0.15 mM EGTA in the pipette), ACh evoked IK.Ca transiently. Addition of Ca2+ (1.8 mM) to the bath immediately restored the sustained IK.Ca. These results suggest that the ACh response is due to at least two different mechanisms; i.e., the Ca2+ release-related initial transient activation and the Ca2+ influx-related sustained activation of IK.Ca. Probably because of desensitization, the Ca2+ influx-related component of the His response could not be identified. Intracellularly applied inositol 1,4,5-trisphosphate (IP3), with and without inositol 1,3,4,5-tetrakisphosphate (IP4), mimicked the ACh response. IP4 alone did not affect the membrane current. Under the steady effect of IP3 or IP3 plus IP4, neither ACh nor His further evoked IK.Ca. Intracellular application of heparin or of the monoclonal antibody against the IP3 receptor, mAb18A10, inhibited the ACh and His responses in a concentration-dependent fashion. Neomycin, a phospholipase C (PLC) inhibitor, also inhibited the agonist-induced response in a concentration-dependent fashion. Although neither pertussis toxin (PTX) nor N-ethylmaleimide affected the ACh or His activation of IK,Ca, GDP beta S attenuated and GTP gamma S enhanced the agonist response.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholine↗
PubMed1993

Primary structure of scombrine gamma, protamine isolated from spotted mackerel (Scomber australasicus).

Spotted mackerel protamine, scombrine, was isolated from the sperm of a spotted mackerel (Scomber australasicus) by extraction with sulfuric acid and fractionated into one major (scombrine II) and one minor (scombrine I) components by chromatography on CM-Sephadex C-25. Scombrine II gave a single band, whereas scombrine I gave three bands upon PAGE. Scombrine II (scombrine gamma) consists of 34 amino acid residues, and its sequence is: Pro-Arg-Arg-Arg-Arg-Arg-Ala-Ser-Arg-Pro-Val-Arg-Arg-Arg-Arg-Arg- Ala-Arg-Arg-Ser-Thr-Ala-Val-Arg-Arg-Arg-Arg-Arg-Val-Val-Arg-Arg-Arg-Arg. The ion spray mass spectrum shows that scombrine gamma has a molecular mass of 4,532.13 Da. The other minor component (scombrine I) is considered to be a mixture of degradation products of scombrine gamma based on the results of PAGE and ion spray mass spectrometry. Scombrine gamma has a similar sequence to sardaine Z2 from striped bonito except for two positions.

Amino Acid Sequence↗
PubMed1993

Antiulcer drugs and gastric prostaglandin E2: an in vitro study.

Prostaglandin (PG) has been reported to be an important protective and acid-suppressive factor in the gastric mucosa. Although the mechanisms of some antiulcer drugs are attributed to their stimulatory effects on endogenous prostaglandins, an understanding of these actions has not been established. In the present study we investigated the effects of antiulcer drugs on PGE2 using cultured gastric mucosal cells. Rabbit gastric mucosal cells were cultured after isolation with collagenase and ethylenediaminetetraacetic acid. PGE2 was measured by enzyme-linked immunoassay. Histamine H2-blockers (cimetidine, ranitidine, famotidine), omeprazole, and sucralfate did not modulate the media content of PGE2, whereas sofalcone dose- and time-dependently increased it. Sofalcone-induced increase of PGE2 was dose-dependently prevented by indomethacin. Sofalcone did not affect intracellular Ca2+ as assessed by the calcium-sensitive probe indo-1. Deprivation of Ca2+ in the media did not modulate the action of sofalcone. Sofalcone significantly suppressed 15-OH-PG dehydrogenase. These results suggest that among the various antiulcer drugs only sofalcone increases PGE2, which may be a factor in its therapeutic effect against peptic ulcer diseases.

Animals↗
PubMed1993

[Effect of hydronephrosis on the contralateral blood flow and glomerular volume].

We designed a following experiment to appraise the effect of unilateral hydronephrosis on the contralateral kidney using weanling rats whose kidneys were in a growing stage. Rats were divided into 4 groups. Complete unilateral (left) ureteral obstruction (CUUO) was made on the experiment rats, and these went through the following procedures on the day 3 after CUUO; 1) Group R: CUUO released, 2) Group N: left nephrectomy performed, 3) Group S: CUUO continued. Sham-operations were performed on the days 0 and 3 to the controls. Renal cortical blood flow and glomerular volume of the contralateral (right) kidneys were determined on the days 5, 7, 9, 14 and 21. Blood flow to the renal cortex per unit volume (ml/min/100 cm3; measured with Laser blood perfusion monitor) in the contralateral kidneys increased gradually in the all groups, but statistical significance was not confirmed in the observed period between any groups. Increases in total renal blood flow (wet kidney weight times renal cortical blood flow per unit volume; g x ml/min/100 cm3) were proportional to the measured wet kidney weight in the all groups. Notably in the group N, a significant increase was noted compared to the group R and the controls. Glomerular volume (GV) of the contralateral kidneys did not show significant changes on the day 3 compared to the controls. GV significantly grew up during the day 5 to the day 14 (2 to 11 days after the relief of CUUO) in the group R and then it settled to the level of the controls on the day 21.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Renal function of contralateral kidney after total or partial removal of kidney with ectopic ureter].

The effects of partial or total removal of the kidney with ectopic ureter on the contralateral kidney were evaluated using DMSA renal uptake rate on 8 patients. After partial nephrectomy on 6 cases, the affected residual kidneys showed significant decrease in DMSA renal uptake rate in 2 cases in which the extirpated kidneys had normal renal tissue in part but did not show significant change in DMSA uptake rate in 4 cases in which the extirpated kidneys were dominated mainly with dysplasia. Post-operative increase in DMSA uptake rate of the contralateral kidneys were significant in 3 of 4 patients who had the operation before they became 2 years old. In 2 of these 3 cases, pre-operative scintigram showed extremely low rate of DMSA renal uptake. Four cases aged 2 years old and over did not show post-operative increase in the uptake rate. As we have previously reported on the cases with hydronephrosis, these results suggest that 1) existence of obstruction caused by ectopic ureter inhibit the development of the contralateral kidney and 2) the growth of the kidney can resume the release of that obstruction, if the release is made while the kidneys are still in developing stage.

Child↗
PubMed1993

[Studies on reflux nephropathy--renal tubular and glomerular damage evaluated by various urinary indices].

Measurements were performed on beta 2-microglobulin (beta 2-MG), alpha 1-microglobulin (alpha 1-MG), N-acetyl-beta-D-glucosaminidase (NAG) as indices of renal tubular damage and microalbumin as an index of renal glomerular damage in 204 cases with primary vesicoureteral reflux (VUR). Investigations were made on the relationship between each index and extent of renal cortical damage from the findings of 99mTc-dimercapto-succinic acid (DMSA) renoscintigraphy, and also on the changes of each index before and after antireflux operation. At the first examination, high values of urinary beta 2-MG, alpha 1-MG, NAG and albumin were noted in 36%, 40%, 50% and 34% of cases with VUR respectively. Almost all the cases with high indices values before the operation showed improvement in those values accompanied with disappearance of VUR after the operation. These findings suggest that renal tubular and glomerular damage were induced by the sterile reflux itself. High values of urinary indices were confirmed in 16% (beta 2-MG), 40% (alpha 1-MG), 27% (NAG) and 32% (albumin) cases after a lapse of 2 years or longer since antireflux operation or spontaneous disappearance of VUR. In some of these cases indices values showed some improvement but have not returned to normal levels, and in other cases indices were within normal limits preoperatively but turned out to be high levels during the observation period even after the disappearance of VUR. Most of these cases were accompanied with severe cortical damage of unilateral or bilateral kidneys on DMSA renoscintigraphy. Based on these findings, we suggest that overload to residual nephron, caused by reduced mass of functional nephron, is playing an important role on raising the values of various urinary indices.

Acetylglucosaminidase↗
PubMed1993

[The effect of unilateral ureteral obstruction on the contralateral renal growth in weanling rats].

The effect of unilateral hydronephrosis on the growth of contralateral kidney were evaluated with weanling rats of which kidneys were in growing stage (body weighted between 80 g and 90 g). These rats underwent complete unilateral ureteral obstruction (CUUO) on day 0. They were divided into 3 groups and went through second operations on day 3 (CUUO-3) as follows; a) CUUO released, b) nephrectomy performed and c) CUUO continued. Sham-operation was performed on day 0 and on day 3 to the controls. Wet weights and bromodeoxy-uridine (BrdU) labeling index (L.I.) (index for cell proliferation in the uriniferous tubules) of the contralateral kidneys were measured for the evaluation. The wet weights were significantly higher in all the groups than that of the controls throughout the observation period on and after the day 3. The group that underwent nephrectomy demonstrated a sharp rise in L.I. after the day 7. In the group that was continued in CUUO, the L.I. started to rise later than its rise in nephrectomised group but the index caught up at the time when the blood flow completely disappeared in the kidneys of the ligated side. L.I. in the group of which CUUO was released became significantly higher than that of controls on the day 7 and remained its significance until the day 21 in spite of resolution of the hydronephrosis. To reveal the effect of length of obstructed term, the same trial was carried out that rats endured in CUUO for 5 days (CUUO-5) till the second operation. This turned out lower L.I. in the CUUO-5 than the CUUO-3. These results suggest that the presence of hydronephrosis made by CUUO suppress the growth (cell proliferation) of contralateral kidney and also duration of obstruction can be critical on the renal growth that shorter obstructed period turns out preferable for cell proliferation after relief of CUUO.

Animals↗
PubMed1993

[Comparative study of HPV infection and proliferating cell nuclear antigen of uterine cervix].

We investigated the proliferating activity of human papillomavirus (HPV) infection in cervical neoplasia obtained from 37 mild dysplasia, 26 moderate dysplasia, 34 severe dysplasia and 26 carcinoma in situ (CIS) and 10 normal cervical epithelium by in situ hybridization (ISH) with biotinylated HPV 6, 11, 16 and 18 DNA probes and by immunohistochemical staining with monoclonal antibody (PC10) to proliferating cell nuclear antigen (PCNA). The results were as follows: 1) The immunohistochemical study of PCNA was useful as a marker to detect proliferating activity in formalin-fixed, paraffin-embedded tissue sections. The PCNA labelling index was significantly increased as the grade of cervical neoplasia become higher (normal cervical epithelium: 3.5%, mild dysplasia: 10.3%, moderate dysplasia: 16.9%, severe dysplasia: 23.7%, CIS: 36.3%) (p < 0.01). 2) The PCNA labelling index of the HPV type 6, 11, 16, 18 positive group was not significantly different from that of the no HPV detected group in each grade of cervical lesions. 3) The PCNA labelling index group positive for HPV 16, 18 DNA was significantly higher than the HPV 6, 11 positive group and the no HPV detected group at every grade of dysplasia (p < 0.05). The precancerous lesions positive for HPV type 16 or 18 were thought to be a high risk group judging from the proliferating activity. These results suggest that PCNA can be used as one of the growth factors in cervical neoplasia and that HPV type 16 and 18 infection had a significant proliferating cell activity in every grade of cervical dysplasia.

Antigens, Neoplasm↗
PubMed1993

[Age-related changes in nerve action potentials of median nerve--an analysis using intraneural neurography].

Age-related decrease in peripheral nerve conduction velocity and the amplitude of sensory nerve action potentials is well established in humans. However, evaluation of the sensory nerve action potentials is subject to technical constraints because of its small size and variability of the values. To elucidate age-related differences, we determined the amplitude of median nerve action potentials in 52 healthy individuals aged 16 to 88 years by means of intraneural neurography. A tungsten microelectrode was inserted into the median nerve trunk at the elbow, and compound nerve action potentials evoked by supramaximal electrical stimulation were recorded. The action potentials consisted mainly of triphasic waves. Maximal conduction velocity (Y, m/sec) declined very mildly with age (X, year), showing the regression line of Y = 67.5 - 0.062X. The peak to peak amplitude of the potentials was 466.6 +/- 20.8 (SE) microV and declined gradually with a decrement of 13 microV per decade in the individuals under the age of 50 years. By contrast, in individuals above the age of 50 years, the amplitude (Y, microV) declined steeply, showing the regression line of Y = 977.1 - 9.86X (r = -0.75, p < 0.001) with age (X, year). A significant correlation was observed between amplitude of the sensory nerve action potentials obtained by the conventional technique and that obtained by the intraneural neurography. Nevertheless, an accelerated decrease was not found in the amplitude of the sensory nerve action potentials with age above 50, probably due to the variability of the values.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗