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Biomedical subjects

A Yamaguchi

Publications and source records attributed to A Yamaguchi.

At least 577 records · Page 32Linked to original sources
PubMed1989

Mechanism for increase of gastrin release by secretin in Zollinger-Ellison syndrome.

In patients with Zollinger-Ellison syndrome, serum gastrin level is increased by secretin and is decreased by somatostatin. To elucidate the cellular mechanism for these actions, we investigated the direct effects of secretin and somatostatin on dispersed gastrinoma cells from a patient with Zollinger-Ellison syndrome. In the presence of 3-isobutyl-1-methylxanthine, secretin significantly stimulated gastrin release from dispersed gastrinoma cells, which was inhibited by somatostatin. In the presence of guanosine 5'-triphosphate, furthermore, secretin enhanced adenylate cyclase activation in the membranes from these cells, and this activation was reduced by somatostatin, whereas neither secretin nor somatostatin affected inositol phospholipid turnover. On the other hand, removal of guanosine 5'-triphosphate from incubation medium abolished both the stimulatory effect of secretin and the inhibitory effect of somatostatin on adenylate cyclase activation. Furthermore, pertussis toxin pretreatment reversed the ability of somatostatin to inhibit secretin-induced increase in gastrin release and activation of adenylate cyclase. Thus, in this gastrinoma patient, secretin and somatostatin appeared to act directly on gastrinoma cells to stimulate and inhibit gastrin secretion, respectively, by modulating adenylate cyclase activation, probably via guanine nucleotide-binding proteins.

Adenylyl Cyclases↗
PubMed1989

Prostaglandin E2 and F2 alpha inhibit growth of human gastric carcinoma cell line KATO III with simultaneous stimulation of cyclic AMP production.

The effects of prostaglandins (PGs) on the growth of human gastric carcinoma cell line KATO III were investigated. PGE2 as well as PGF2 alpha significantly and dose-dependently inhibited the growth of this gastric carcinoma cell line (PGE2 greater than PGF2 alpha). This inhibition of cell growth by the PGs was associated with the increase in cyclic AMP production (PGE2 greater than PGF2 alpha), whereas inositol-phospholipid turnover was not affected by either PGE2 or PGF2 alpha as assessed by the formation of 3H-inositol phosphates. Furthermore, the proliferation of these gastric carcinoma cells was also suppressed by the administration of forskolin as well as of dibutyryl cyclic AMP. These results suggest that PGE2 and PGF2 alpha inhibit the growth of cultured human gastric carcinoma cells KATO III via stimulation of cyclic AMP production.

Bucladesine↗
PubMed1989

Presence and release of calcitonin gene-related peptide in rat stomach.

Immunoreactive (IR)-calcitonin gene-related peptide (CGRP) was identified throughout the entire stomach of rats, being most highly concentrated in the pyloric region, and the concentrations in muscular layers being higher than those in mucosal layers. In addition, IR-CGRP was also present in the venous effluent from isolated perfused rat stomach, and its release was stimulated by dibutyryl cyclic AMP or theophylline but not by glucagon. Gel chromatography as well as HPLC of both tissue extracts and gastric perfusate showed three identical major peaks of IR-CGRP, one of which coeluted with synthetic CGRP. These results suggest that CGRP in the stomach plays a role in the regulation of gastric function.

Animals↗
PubMed1989

Human chorionic gonadotropin in colorectal cancer and its relationship to prognosis.

The presence of human chorionic gonadotropin in large bowel cancers was studied immunohistochemically using an immunoperoxidase technique. HCG-positive tumour cells were present in 42 of 194 adenocarcinomas examined (22.0% of colon cancer and 21.2% of rectal cancers). On histological grading, the hCG-positive rate tended to rise as the degree of differentiation decreased. HCG was detected more frequently in cancers invading the total bowel wall (27%) than in those invading the partial wall (17.1%). Lymph node, liver or peritoneal metastases were present more frequently in hCG-positive tumours than in hCG-negative tumours. Furthermore, there was an intimate correlation between the presence of hCG-positive tumour cells and CEA doubling times in nine cases with untreated liver metastasis. The survival rate for patients with tissue hCG-positive cells was lower than for those with hCG-negative tumours. Thus, the presence of tissue hCG in colorectal cancers may be a biological marker of prognostic significance.

Adenocarcinoma↗
PubMed1989

Structure of the functional interleukin-2 receptor. Evidence for the association of human p55 and murine p75 molecules in a mouse T cell line.

The structural basis of the high affinity interleukin-2 receptor which was previously reconstituted in a cultured murine T cell line, EL4 by expressing either wild-type Tac antigen complementary DNA (cDNA) or a chimeric cDNA was characterized. The chimeric cDNA encodes a membrane portion whose extracellular portion consists of that of Tac antigen whereas transmembrane and cytoplasmic portions consists of those the human insulin beta chain. The Tac antigen/anti-Tac antibody complex was treated by chemical crosslinking reagents, purified by goat anti-mouse immunoglobulin (Ig), and was analysed by SDS-PAGE. We here demonstrated the presence in mouse EL4 transfectants of a novel membrane protein which is closely associated with the products of transfected cDNAs in the absence of interleukin-2. The protein is 75 kDa in size and is detected in cells which express high affinity interleukin-2 receptor but not in cells which only express low affinity interleukin-2 receptor. The transmembrane region and the cytoplasmic region of Tac antigen is not necessary for the formation of the complex consisting of Tac antigen and 75 kDa molecule, indicating that a murine 75 kDa molecule associates with Tac antigen extra-cellularly.

Animals↗
PubMed1989

Calcitonin gene-related peptide receptor antagonist human CGRP-(8-37).

From this study, we predicted that the human calcitonin gene-related peptide (hCGRP) fragment hCGRP-(8-37) would be a selective antagonist for CGRP receptors but an agonist for calcitonin (CT) receptors. In rat liver plasma membrane, where CGRP receptors predominate and CT appears to act through these receptors, hCGRP-(8-37) dose dependently displaced 125I-[Tyr0]rat CGRP binding. However, hCGRP-(8-37) had no effect on adenylate cyclase activity in liver plasma membrane. Furthermore, hCGRP-(8-37) inhibited adenylate cyclase activation induced not only by hCGRP but also by hCT. On the other hand, in LLC-PK1 cells, where calcitonin receptors are abundant and CGRP appears to act via these receptors, the bindings of 125I-[Tyr0]rat CGRP and 125I-hCT were both inhibited by hCGRP-(8-37). In contrast to liver membranes, interaction of hCGRP-(8-37) with these receptors led to stimulation of adenosine 3',5'-cyclic monophosphate (cAMP) production in LLC-PK1 cells, and moreover, this fragment did not inhibit the increased production of cAMP induced not only by hCT but also by hCGRP. Thus hCGRP-(8-37) appears to be a useful tool for determining whether the action of CGRP as well as that of CT is mediated via specific CGRP receptors or CT receptors.

Adenylyl Cyclases↗
PubMed1989

Epidermal growth factor receptor status and S-phase fractions in gastric carcinoma.

The correlation with epidermal growth factor (EGF) receptor expression and clinicopathologic findings were studied in 242 gastric carcinomas. They were stained for EGF receptor by means of an immunohistochemical technique using a monoclonal antibody against the receptor. S-Phase fractions were measured by in vivo bromodeoxyuridine (BrdU) labeling and indirect immunohistochemical staining using anti-BrdU monoclonal antibody. In normal gastric epithelium, EGF receptor immunoreactivity could not be found. EGF receptor was found in 76 (31.4%) of 242 gastric carcinomas. Diffusely infiltrating types of carcinomas were more likely than localized tumors to be EGF receptor-positive. In addition, EGF receptor-positive tumors had significantly higher values of BrdU labeling indices than EGF receptor-negative tumors. The patients with EGF receptor-positive carcinomas also had a poorer prognosis than did negative cases. These results suggested that EGF receptor-positive tumors may have higher proliferative activity and local extension may progress more rapidly, and also seem to show that EGF receptor status may possibly be a useful prognostic marker for gastric carcinomas.

Bromodeoxyuridine↗
PubMed1989

Effects of extracorporeal shock wave lithotripsy on urinary excretion of N-acetyl-beta-D-glucosamidase.

We investigated the effect of extracorporeal shock wave lithotripsy (ESWL) on the urinary excretion of N-acetyl-beta-D-glucosamidase (NAG) activities. No significant increases in NAG excretion were recognized between, before and after ESWL. However, there were significant increases in patients with renal calculi who received over 1,000 shock waves. Therefore, we should not neglect renal impairments which could be caused by extracorporeal shock wave exposure.

Acetylglucosaminidase↗
PubMed1989

Spontaneous regression of bovine cutaneous leukosis.

Biopsies of skin from a 2-year-old heifer with spontaneously regressing dermal leukosis were examined. The heifer was not infected with bovine leukemia virus and was negative for tumor-associated antigens of enzootic bovine lymphosarcoma. By hematological standards for bovine leukemia, the heifer was positive at about 60 days post-occurrence of the disease (POD). At 53 days POD, lymphoblastic neoplastic cells in the dermis reacted with anti-T lymphocyte monoclonal antibody by the avidin biotin peroxidase complex method. The cells had intracytoplasmic clustered dense bodies under electron microscopy. From 53 to 83 days POD, figures of the transepithelial elimination (TE) against neoplastic cells and perivascular infiltration of small lymphocytes were in the dermis. Small lymphocytes reacted with anti-T lymphocyte monoclonal antibody. At necropsy there were no neoplastic lesions; there were flat lymph node-like tissues in the subcutis. Many germinal centers were seen in the lymphatic organs. Blood lymphocytes at 46 days POD were stimulated by phytohemagglutinin-P and concanavalin A. Sera, taken until 75 days POD and at necropsy, showed an inhibitory effect on mitogen-induced blastogenesis of normal bovine lymphocytes. These results suggested the existence of a spontaneous regressive mechanism against neoplastic lesions by TE and tumor immunity.

Animals↗
PubMed1989

The bone marrow-derived stromal cell lines MC3T3-G2/PA6 and ST2 support osteoclast-like cell differentiation in cocultures with mouse spleen cells.

After our previous report that osteoclast-like multinucleated cells (MNCs) were formed in response to 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3] in cocultures of mouse spleen cells and osteoblast-rich populations freshly isolated from fetal mouse calvariae, we examined whether such primary osteoblast-like cells can be replaced by established cell lines in inducing osteoclast-like cell formation. We first used two clonal cell lines simultaneously established from newborn mouse calvariae. One was the osteoblastic cell line MC3T3-E1, and the other was the preadipose cell line MC3T3-G2/PA6. Tartrate-resistant acid phosphatase (TRACP; a marker enzyme of osteoclasts)-positive mononuclear cells and MNCs were formed in the cocultures of spleen cells and MC3T3-G2/PA6 cells in the presence of 1 alpha,25-(OH)2D3. Dexamethasone greatly potentiated TRACP-positive MNC formation induced by 1 alpha,25-(OH)2D3, whereas the glucocorticoid alone had no effect on it. In contrast, osteoblastic MC3T3-E1 cells failed to induce TRACP-positive cells in the cocultures. Another bone marrow-derived stromal cell line ST2 also induced TRACP-positive MNC formation in the cocultures in response to 1 alpha,25-(OH)2D3 and dexamethasone. Salmon calcitonin enhanced cAMP production in the cocultures only when TRACP-positive cells were formed. Autoradiographic studies demonstrated that [125I]calcitonin specifically bound to TRACP-positive cells formed in the cocultures. When spleen cells and either MC3T3-G2/PA6 or ST2 cells were cocultured on sperm whale dentine slices in the presence of 1 alpha,25-(OH)2D3 and dexamethasone, numerous resorption lacunae were formed. These results show that the two bone marrow-derived stromal cell lines can support osteoclast-like cell differentiation in cocultures with spleen cells.

Acid Phosphatase↗
PubMed1989

[Interaction between polyethylene films and bromhexine HCl in solid dosage forms. I. Effects of moisture contents in the solid dosage forms on the sorption of the drug].

The decrease of bromhexine HCl contents in granules and tablets was determined when the preparations were stored in polyethylene film package. Effects of temperature, contact area with film, excipients and moisture contents in the preparation on the remaining amount of bromhexin HCl were studied in order to investigate the interaction mechanism between bromhexine HCl and polyethylene film. It was observed that the decrease of bromhexine HCl was due to the sorption to the polyethylene film. The results indicated that the moisture contents of the dosage forms determined the rate of sorption predominantly, and that removal of adsorbed water from dosage forms was effective to prevent bromhexine HCl content decrease.

Adsorption↗
PubMed1989

[Influence of tooth extraction on postural stability].

A study was conducted to analyze how tooth extraction procedure would affect patient's physical equilibrium sensation, using the positional centric equilibrium measuring device. Forty-five health subjects, between the ages of 20 to 30, with no systemic nor equilibrium abnormalities were selected for this study. The results obtained were as follows. 1. No noticeable changes in the centric movement were observed during the postural change from a sitting to a standing position. 2. Centric movement was transiently increased immediately after the movement from a horizontal to standing position. The average arterial pressure was decreased immediately after the alteration in body posture, suggesting that changes in body posture may influence the controlling mechanism of BP. 3. Increases in the area and velocity of the centric movement were found immediately after and up to 10 minutes after, respectively, topical administration of the anesthetic. During this time span, no correlation found between centric movement changes and circulatory changes suggested that topical anesthesia might influence the recovery reflex via central nervous system. 4. The effect of the extraction procedure on the centric movement area and the anteroposterior centric movement speed lasted for 10 minutes after extraction. On the other hand, the increase in the velocity of bilateral centric movement as well as whole body centric movement was found up to a point immediately after extraction. No correlation was found between circulatory changes and centric movement changes. It therefore was assumed that the topical anesthesia affected the recovery reflex via central nervous system.

Adolescent↗
PubMed1989

[Effect of UFT on nuclear DNA distribution of gastric and colorectal carcinomas].

To evaluate the effect of UFT on nuclear DNA distribution of carcinoma, we measured the DNA content of biopsy specimens and resected specimens obtained from 18 patients by microfluorometry. The tumors consisted of 7 gastric and 11 colorectal carcinomas. Five patients who received administration of 400mg of UFT (400mg of tegafur) were classified as the chemotherapy group and another 13 patients were classified as the control group. 1) DNA indices of biopsy specimens and resected specimens of the same patients showed almost the same values both in the control group (r = 0.81) and in the chemotherapy group (r = 0.89) (p less than 0.05). 2) S and S + G2M fractions of resected specimens showed almost the same values as compared with those of corresponding biopsy specimen in the control group. However, in the chemotherapy group S and S + G2M fractions of resected specimens showed a tendency to be higher than those of corresponding biopsy specimen (0.05 less than p less than 0.1). This study indicates that the biopsy specimens are sufficient for DNA analysis and that UFT-induced DNA change may be increase of S and S + G2M fraction.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

[A case of complete rupture of the righ TMJ disc].

A case of complete rupture of the right TMJ disc was described. A 43 year old woman visited our hospital with the chief complaint of a mild pain in the right TMJ. Initially, a conservative treatment using the occlusal splint (condylar repositioning appliance) was carried out. This was because she had reciprocal clicking of the right TMJ which had occurred not long before and it seemed that the symptoms were due to the trouble with the disc. In spite of this treatment, for 6 months no improvement was obtained and the reciprocal clicking changed into crepitation. Moreover the double contrast arthrotomographic image indicated a perforation or a wide rupture of the disc, and deformities of the articular bone. Then a right TMJ osteoarthrosis with wide (complete) disc rupture was diagnosed, and a discectomy was performed. The symptoms were greatly reduced by this treatment. It was conceivable that the steroid which she had used for a long time to treat bronchial asthma caused a remarkable inhibition of the tissue repairing, and an internal derangement of the TMJ rapidly progressed to osteoarthrosis.

Adrenal Cortex Hormones↗
PubMed1989

[Clinical significance of serum NCC-ST 439 as a tumor marker for colorectal cancer].

Clinical significance of preoperative serum NCC-ST 439 level was studied in 119 cases of colorectal cancer (90 of primary, 29 cases of recurrent). The positive rates for serum NCC-ST 439 were 28.9% in primary and 65.5% in recurrent cases. The false positive rates for benign disease were 5.6%. These rates were low when compared with those for other tumor markers. The positive rates for serum NCC-ST 439 exhibited a strong correlation with wall invasion, lymph node and liver metastases. A combination assay of NCC-ST 439, CEA and CA 19-9 produced a high positive rates as 43.3% in primary and 86.2% in recurrent cases. These results demonstrate that measurement of serum NCC-ST 439 may be useful for cancer staging and improves the diagnostic rate in combination with CEA and CA 19-9.

Adenocarcinoma↗
PubMed1989

[Postpneumonectomy esophagopleural fistula--successful one-stage repair with omental flap and thoracoplasty].

A 69 year-old man, who had undergone left pneumonectomy for squamous cell carcinoma of the lung 21 months ago, was admitted with a high temperature and chest pain. A diagnosis of empyema was made, and a chest tube was inserted for drainage. Bronchopleural fistula was not noted. Noticing that food was leaking through the drainage tube, a diagnosis of esophagopleural fistula was made radiologically. Surgery was done in October, 1987, after irrigating an empyema space for two months. The fistula was approximately 4 cm below the carina, and it was closed directly. The omentum was sutured around the closed site to reinforce and obliterate the empyema space. Furthermore, additional thoracoplasty was done because the cavity was too large to close only with the omentum. The postoperative course was uneventful. He was able to eat specially prepared foods within 4 weeks, and was discharged on the 60th day after the operation. This patient could possibly be the first case who had undergone an omental flap for the closure of a postpneumonectomy esophagopleural fistula.

Aged↗
PubMed1989

[A clinicopathological study of recurrent gastric cancer cases treated by a resection of the remnant stomach].

Seventeen cases of a recurrent gastric cancer that were treated by a resection of the remnant stomach have been studied retrospectively. For first management 12 cases were given a Billroth 2 procedure, 4 cases a Billroth 1 procedure and 1 case a fundectomy. For the recurrent cancer, 13 cases were given a total resection of the gastric remnant and 4 cases a partial resection. The overall mortality rate was 12% and the survival rate was 58% at 1 year, and 8% at 5 years. We thus have concluded that a resection of the remnant stomach should be carried cut in cases of a recurrent gastric cancer whenever possible.

Adult↗