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Biomedical subjects

Y Masuda

Publications and source records attributed to Y Masuda.

At least 469 records · Page 26Linked to original sources
PubMed1993

Thymidine uptake in vitro as a prognostic indicator for primary gastric cancer.

BACKGROUND: Prognostic significance of in vitro thymidine uptake by cancer cells remains unclear in patients with gastric cancer. METHODS: In 173 patients with operable gastric cancer, the relations between thymidine uptake by gastric cancer cells in semi-solid media and their clinicopathologic features as well as their survival lengths were studied. RESULTS: There were significant correlations between in vitro thymidine uptake and such clinicopathologic features as lymph node metastasis (P = 0.00002), lymphatic invasion (P = 0.003), vessel invasion (P = 0.006), peritoneal metastasis (P = 0.010), depth of invasion (P = 0.011), and hepatic metastasis (P = 0.032). Ninety-five of 173 cancers (54.9%) that incorporated 1000 or more cpm in a single well were designated as being a high uptake group. Other gastric cancers (78 of 173; 45.1%) were designated as being a low uptake group. The overall survival rate of the patients was demonstrated to be significantly longer in the group with a low thymidine uptake than with a high uptake (P < 0.00001). The multivariate analysis showed that thymidine is one of the two variables that are the most highly correlated with the probability of patient death (P = 0.00044). CONCLUSIONS: These results indicated that in vitro thymidine uptake is an independent prognostic parameter for gastric cancer and may be useful for selecting patients who would benefit from more intensive therapy.

Aged↗
PubMed1993

Molecular cloning and functional expression of a cDNA encoding a human pituitary adenylate cyclase activating polypeptide receptor.

A functional cDNA clone for a human pituitary adenylate cyclase activating polypeptide (PACAP) receptor was isolated from a human pituitary cDNA library. The cDNA encoded a polypeptide consisting of 525 amino acids with putative seven hydrophobic domains. Chinese hamster ovary (CHO)-K1 cells transfected with the cDNA specifically bound PACAP and mediated PACAP-triggered intracellular accumulation of cAMP, indicating that this cDNA encoded a functional human PACAP Type I receptor. This receptor was structurally related to the vasoactive intestinal peptide (VIP), secretin, calcitonin and parathyroid hormone receptors and is much more homologous to a rat PACAP receptor. Northern blot analysis revealed that PACAP receptor mRNAs were expressed mainly in the brain and widely distributed in the central nervous system.

Amino Acid Sequence↗
PubMed1993

K(+)-driven sinusoidal efflux of glutathione disulfide under oxidative stress in the perfused rat liver.

Tert-butyl hydroperoxide (BHP), hydrogen peroxide and diamide caused a rapid and simultaneous release of glutathione disulfide (GSSG) and K+ in the isolated perfused rat liver. Both BHP-induced effluxes were suppressed by prior depletion of hepatic glutathione, but not by co-infusion of desferrioxamine which prevented lipid peroxidation and cell death. High K+ media decreased the GSSG efflux even though hepatic GSSG levels remained high. The GSSG and K+ effluxes were repeatable if cellular K+ recovered after a short BHP exposure. Ouabain inhibited the K+ re-uptake and decreased the response to repeated BHP challenge. Thus, sinusoidal efflux of GSSG under oxidative stress may be driven by a K+ gradient.

Animals↗
PubMed1993

Molecular cloning and functional expression of rat cDNAs encoding the receptor for pituitary adenylate cyclase activating polypeptide (PACAP).

Two types of cDNA encoding PACAP receptors were isolated from the rat brain cDNA library by homology screening with a cDNA probe for VIP receptor. Nucleotide sequence analysis indicated that these two types of receptor mRNA were generated by alternative splicing mechanisms. These two cloned cDNAs were introduced into CHO cells respectively. Resultant transformants showed specific binding to [125I]PACAP27 which was displaced by unlabeled PACAP27 but not by VIP. Thus, these receptors are two subtypes of Type I PACAP receptor (Type I-A and Type I-B). The amino acid sequences of rat PACAP receptors deduced by the cDNAs showed a remarkable similarity with rat receptors for VIP, secretin, glucagon, and GHRH. A 6.5 kb significant hybridizing signal of the PACAP receptor mRNA was detected in the rat brain, and slight signal was also detected in the lung and the liver.

Alternative Splicing↗
PubMed1993

Determination of corticosteroids in plasma by high-performance liquid chromatography after pre-column derivatization with 2-(4-carboxyphenyl)-5,6-dimethylbenzimidazole.

2-(4-Carboxyphenyl)-5,6-dimethylbenzimidazole (CDB) was used as a pre-column derivatization reagent for corticosteroids analysed by high-performance liquid chromatography with fluorimetric detection. Eight corticosteroids were derivatized with CDB to their esters in acetonitrile containing 4-piperidinopyridine and 1-isopropyl-3-(3-dimethylaminopropryl)carbodiimide perchlorate. The resulting CDB esters were extracted with a Sep-Pak C18 cartridge and the esters were separated on a reversed-phase column (Zorbax ODS) with water-methanol (25:75, v/v) containing 5 mmol/l tetramethylammonium hydrogensulphate as the mobile phase. The limits of detection for steroids were 0.06-0.3 pg per 100 microliters of plasma (signal-to-noise = 3). The within-day relative standard deviations (n = 6) were 7.8-11.1%, and day-to-day relative standard deviations (n = 6) were 7.0-10.4%.

Adrenal Cortex Hormones↗
PubMed1993

En bloc resection for cancer of the gastric cardia without thoracotomy.

Thirty-five consecutive patients underwent en bloc resection of cardia cancer without thoracotomy. All tumors were adenocarcinoma. The operative procedure involved wide resection of the peri-hiatal diaphragm, dissection of the upper abdominal and lower mediastinal lymph nodes, and resection of the stomach including a portion of the lower thoracic esophagus without thoracotomy. The resection area of the diaphragm included not only the crural muscle as in other methods, but also the diaphragmatic tissue surrounding the esophageal hiatus. Through the enlarged hiatus, dissection of the mediastinum was possible up to the carina from the abdominal cavity. The mediastinal node stations were affected in 25% of patients whose tumor invaded to the serosa. Hypotension with or without atrial arrhythmias and pleural tears occurred during surgery in 20 patients (57%) and in 18 patients (51%), respectively. Postoperatively, hypoxia requiring reintubation developed in 7 patients (19%), pleural effusions needed tube drainage in 16 patients (46%), atelectasis in 5 patients (14%), and anastomotic leaks in 3 patients (9%). They were all successfully treated. The cumulative 5-year survival rate for 21 patients with stages I (2 patients), II (9), and III (10) diseases was 62%, whereas none of the patients with stage IV disease lived for more than 2 years after surgery. Because thoracotomy is avoided, the procedure is better tolerated by debilitated patients. We believe this technique is a reasonable and safe alternative to the left thoracotomy approach for resection of cancer of the gastric cardia.

Adenocarcinoma↗
PubMed1993

Eosinophil cationic protein in the nasal secretions of patients with mite allergic rhinitis.

In 25 patients with mite nasal allergy and 13 healthy control subjects, levels of eosinophil cationic protein (ECP) and histamine in nasal secretions were examined before and after challenge with mite extract. The ECP level was found to be significantly higher in the washings taken 30 minutes after challenge compared with the washings taken before challenge (P < .05). ECP levels measured both before and after mite extract challenge were found to be significantly higher in the patients than in the controls (P < .01). These facts suggest that the ECP affects the nasal mucosa by causing injury to ciliated cells and by acceleration of the processes of modification and inhibition of the allergic reaction.

Adolescent↗
PubMed1993

Isolation of temperature-sensitive aminoacyl-tRNA synthetase mutants from an Escherichia coli strain harboring the pemK plasmid.

The pem locus, which is responsible for the stable maintenance of the low copy number plasmid R100, contains the pemK gene, whose product has been shown to be a growth inhibitor. Here, we attempted to isolate mutants which became tolerant to transient induction of the PemK protein. We obtained 20 mutants (here called pkt for PemK tolerance), of which 9 were temperature sensitive for growth. We analyzed the nine mutants genetically and found that they could be classified into three complementation groups, pktA, pktB and pktC, which corresponded to three genes, ileS, gltX and asnS, encoding isoleucyl-, glutamyl- and asparaginyl-tRNA synthetases, respectively. Since these amino-acyl-tRNA synthetase mutants did not produce the PemK protein upon induction at the restrictive temperature, these mutants could be isolated because they behaved as if they were tolerant to the PemK protein. The procedure is therefore useful for isolating temperature-sensitive mutants of aminoacyl-tRNA synthetases.

Amino Acyl-tRNA Synthetases↗
PubMed1993

Changes in plasma dopamine-beta-hydroxylase activity during the perioperative period of cardiac surgery: an index of sympathetic nerve activity.

To evaluate the usefulness of plasma dopamine-beta-hydroxylase (DBH) activity as an index of sympathetic nerve activity during cardiac operations, we examined the serial changes in plasma DBH activity, in relation to the plasma noradrenaline (NA) level and hemodynamic parameters, in patients who underwent cardiac surgery. The plasma DBH activity decreased significantly after cardiopulmonary bypass, and remained low during dopamine (DA) infusion until 72 h after the operation. However, recovery of the hemodynamic parameters, being the mean arterial pressure, heart rate and cardiac index, was seen as early as 1-3 h postoperatively. It was therefore assumed that the plasma DBH activity takes a long time to recover after an operation. The time-course changes in the plasma NA level were quite different from the changes in DBH activity, with an apparent negative correlation being observed between them. Thus, there is a possibility that exogenously administered DA, as well as increased plasma NA, might inhibit DBH activity during cardiac surgery. Moreover, since catecholamines are often administered upon completion of cardiac surgery, measurement of the plasma catecholamine level would be inappropriate for evaluating real sympathetic nerve activity. From the results of this study, it is surmised that measurement of the plasma DBH activity could be useful for estimating the intrinsic sympathetic nerve activity of patients who have undergone cardiac surgery.

Adult↗
PubMed1993

Elimination of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) from human blood in the Yusho and Yu-Cheng rice oil poisonings.

The pharmacokinetics of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in humans was studied by monitoring the blood concentrations of individuals who ingested a contaminated rice oil in Japan (yusho) in 1968 and in Taiwan (yu-cheng) in 1979. Sixteen yusho patients were followed from 1982 to 1990 and three yu-cheng individuals from 1980 to 1989. From the three yu-cheng patients, blood lipid values for the two persistent toxic congeners, 2,3,4,7,8-pentachlorodibenzofuran (PnCDF) and 1,2,3,4,7,8-hexachlorodibenzofuran (HxCDF), varied from 50 micrograms/kg at first sampling to about 1 micrograms/kg at last sampling corresponding to half-lives for elimination (t1/2) of 2-21/2 years. The blood lipid values for the same PCDF congeners in yusho patients varied from 5 micrograms/kg down to 0.1 micrograms/kg. The calculated t1/2 were more variable with median values closer to 10 years. Planar PCBs #126 and #169 were present at lower concentrations than the PCDFs. For seven of the other PCB congeners, half-lives for elimination in the yu-cheng individuals varied from 1.2 up to 4.6 yr depending on the degree of chlorination. For the yusho patients, the elimination for the PCBs was longer. These results show that clearance of the toxic PCDFs and PCBs in humans is non-linear with faster elimination at higher exposure followed by slower decreases as background levels are approached. Such a clearance pattern can best be explained by a two compartment liver and fat pharmacokinetic model.

Adolescent↗
PubMed1993

Amplified bcl-2/JH rearrangements in reactive lymphadenopathy.

Using the polymerase chain reaction (PCR) to examine the occurrence of bcl-2/JH joining produced by t(14;18) chromosomal translocation, amplified DNA was detected in 2 of 18 lymph nodes showing reactive lymphadenopathy. The PCR was repeated in these two lymph nodes using the same DNA samples, but no amplification was detected at the second attempt. Thus the amplified DNA was considered to be derived from one copy of joined bcl-2/JH in one cell, or from a few copies in a few clonal cells with the same joined bcl-2/JH. These results suggest that false joining of bcl-2/JH at the t(14;18) junction may occur in reactive lymph nodes.

Base Sequence↗
PubMed1993

Dose-response relation and time course of action of pipecuronium in patients anesthetized with nitrous oxide and sevoflurane.

The dose-response relation of pipecuronium, the time course of its neuromuscular blocking effects, and the reversibility of the residual block by neostigmine have been investigated in patients under sevoflurane/N2O Anesthesia using a neuromuscular transmission analyzer (Accelograph, Biometer, Denmark). After an initial dose of pipecuronium (0.04 mg.kg(-1), i.v.), the maximum block rate, onset time, the time from administration until 25% recovery and 50% recovery of control twitch height of the first response to train-of-four nerve stimulation and the interval time of administration of maintenance dose (0.005 mg.kg(-1), i.v.) were 93.7 +/- 7.68%, 5.0 +/- 1.84, 55.4 +/- 23.92, 73.0 +/- 29.44 and 38.7 +/- 15.50 minutes, respectively. The average intubation score (excellent; 0, good; 1 fair; 2, poor; 3) was 0.63 +/- 0.56 at the level of 95.88 +/- 5.06% block. Neostigmine (1.5 mg) promptly reversed the residual neuromuscular blockade induced by pipecuronium (reversal time: 10.1 +/- 2.98 minutes). No side effects attributable to pipecuronium was seen in this study. In conclusion, pipecuronium is a very useful nondepolarizing neuromuscular blocking agent especially for moderately long surgical procedure over 4-5 hours.

Journal Article↗
PubMed1993

Immunohistologic studies of Kikuchi's disease.

An immunohistologic study of lymph nodes from 21 patients with Kikuchi's disease (histiocytic necrotizing lymphadenitis) was performed. The cell components of the affected areas were mainly CD4-positive cells, CD8-positive T cells, alpha/beta T-cell gene receptor-positive T cells, and lysozyme-staining cells. CD3-positive or alpha/beta T-cell gene receptor-positive T cells were composed mainly of CD8-positive and CD11b-negative cytotoxic T cells. Double staining demonstrated that CD4-positive cells usually were positive for Ki-M1p, a marker of plasmacytoid monocytes, but negative for T-cell markers. Although some lysozyme and CD4 double-positive cells were recognized, most CD4-positive cells were negative for lysozyme. The results indicate that CD4-positive cells in the affected foci of Kikuchi's disease were mainly composed of plasmacytoid monocytes.

Adolescent↗
PubMed1993

Studies on the hypotensive mechanisms of NZ-105, a new dihydropyridine derivative, in rats and rabbits.

1. Intravenous administration of NZ-105 caused a slow-onset and long-lasting hypotension in anesthetized SHR. 2. Centrally administered NZ-105 (0.04 mg/kg) slightly decreased blood pressure. 3. The hypotension of NZ-105 (0.1 mg/kg, i.v.) was not affected by atropine, propranolol, diphenhydramine plus cimetidine, aminophylline or indomethacin. 4. In ganglion-blocked rats, NZ-105 (0.003-0.3 mg/kg, i.v.) inhibited the pressor response to several hypertensive agents to a similar degree. 5. In pithed SHR, NZ-105 (0.03 mg/kg, i.v.) showed the same degree of hypotensive action as in non-treated SHR. 6. NZ-105 did not inhibit reflex responses to tilting in conscious rabbits. 7. Thus NZ-105 exerts its hypotensive action through the mechanisms of peripheral origin.

Animals↗
PubMed1993

Anticonvulsant effects of U-54494A and U-50488H in genetically epilepsy-prone rats and DBA/2 mice: a possible involvement of glycine/NMDA receptor complex.

1. The effects of U-54494A and U-50488H on convulsions produced by sound have been studied in genetically epilepsy-prone DBA/2 mice and genetically epilepsy-prone rats. 2. Both compounds showed a dose-dependent anticonvulsant activity. U-54494A was less potent as an anticonvulsant than U-50488H in genetically epilepsy-prone rats and elicited a similar potency to that of U-50488H in DBA/2 mice when administered intracerebroventricularly or intraperitoneally. 3. Similar sedative and hypothermic effects were observed after the highest dose of U-54494A and U-50488H in DBA/2 mice. U-50488H seems to exhibit a greater sedative effect and to affect the rotarod test in rats much more than U-54494A. U-54494A elicited a better therapeutic index than U-50488H. 4. The anticonvulsant properties of both compounds are antagonized by high doses of naloxone and nor-binaltorphimine, a selective kappa-opioid antagonist. 5. The effects of U-50488H and U-54494A in DBA/2 mice were also antagonized by the glycine/NMDA receptor antagonist D-serine. 6. The present results suggest a possible interaction between kappa-opioid and the glycine/NMDA receptors during epileptic phenomena.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1993

Cytokine (interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6)-possessing cells in lymph nodes of malignant lymphoma.

Interleukin (IL)-1 alpha, IL-1 beta, tumor necrosis factor (TNF) alpha, and IL-6 are the most important triggers in the response of the immune system to infection and neoplasia. We examined the histochemical distribution of cytokine-possessing cells in neoplastic lymph nodes of 68 malignant lymphomas. The HLA-DR positive interdigitating reticulum cells (IRCs), histiocytes/macrophages (H/Ms) and epithelioid histiocytes with these cytokines were frequently encountered in Hodgkin's disease, B cell lymphoma of lymphoplasmacytic/cytoid, centroblastic and immunoblastic types, and T cell lymphoma of Lennert's and anaplastic large cell types. In almost all cases of B cell lymphoma of chronic lymphocytic leukemia, centrocytic, follicular centroblastic/centrocytic, Burkitt's types and T cell lymphoma of lymphoblastic, angioimmunoblastic lymphadenopathy and pleomorphic types, the cytokine-possessing cells were rarely or occasionally present. These lymphomas with less cytokines had also few or occasionally encountered IRCs, while H/Ms were frequently or occasionally present. Well-developed dendritic reticulum cells in some types of lymphoma had few cytokines. The population of cytokine-possessing cells was related with histologic type of lymphoma and the volume of IRCs. The IRCs might act as an important initiator of reactive cells against tumor cells. In addition, neoplastic T cells influenced the cytokines' possession of IRCs and H/Ms. Although lacunar, Hodgkin's and Reed-Sternberg cells in Hodgkin's disease and the neoplastic cells in peripheral T cell lymphoma showed weak positive reaction of TNF alpha in one third of the cases, lymphoma cells in the majority might have few cytokines, especially IL-1s and IL-6.

Adolescent↗