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Biomedical subjects

T Ueda

Publications and source records attributed to T Ueda.

At least 1,081 records · Page 60Linked to original sources
PubMed1990

[Management of coronary artery bypass grafting surgery by continuous ambulatory peritoneal dialysis in a patient with chronic renal failure under hemodialysis].

A 64-year-old patient with chronic renal failure underwent coronary artery bypass grafting (CABG) because of the frequent severe angina during hemodialysis. Intraoperative hemodialysis and extra-corporeal ultrafiltration method (ECUM) was used during cardiopulmonary bypass. Postoperative management was successfully performed by continuous ambulatory peritoneal dialysis (CAPD), which made hemodynamics stable and prevented postoperative bleeding, providing with adequate fluid removal and satisfactory control of serum chemistry.

Coronary Artery Bypass↗
PubMed1990

Prediction of esophageal varices in cirrhosis by per-rectal portal scintigraphy.

Portal circulation in patients with chronic liver disease was evaluated by per-rectal portal scintigraphy, and per-rectal portal shunt indices were calculated to estimate the extent of the portosystemic shunt. The purpose was to identify patients with cirrhosis at special risk of developing esophageal varices. The cumulative incidence of varices in 3 years of the study in patients whose shunt index was originally 20% or over, was significantly higher than that in patients whose shunt index was originally under 20%. The cumulative survival rate in 7 years of the study in patients whose shunt index was originally under 70% was significantly higher than that in patients whose shunt index was originally 70% or over. The information obtained by calculating the shunt index could be used by physicians in out-patient clinics when deciding the schedule with which to monitor patients using barium esophagogram or endoscopy, and choosing the examination method.

Esophageal and Gastric Varices↗
PubMed1990

[A case report of combined composite valve graft replacement of the aortic root and graft replacement of the abdominal aorta].

A 55-year-old man who had both aortic root aneurysm with severe aortic regurgitation and enlarging abdominal aortic aneurysm was admitted to our hospital. We employed the combined composite valve graft replacement of the aortic root and Y-graft replacement of the infrarenal abdominal aorta at one stage operation. At the operation, median sternotomy was made and the composite graft replacement of the aortic root was performed under cardiopulmonary bypass prior to the abdominal procedure. After cardiopulmonary bypass was removed, abdominal incision was made. Although ventricular arrhythmias and mild hypotension transiently occurred when the abdominal aorta was clamped, the Y-graft replacement was also completed uneventfully, and no complication occurred postoperatively. We conclude that the combined operation of the aortic root and the abdominal aorta is clinically feasible in certain situation.

Aorta↗
PubMed1990

[Gastric secretion in vagotomized stomach and transplant stomach in rat].

The gastric phase of gastric secretion is well documented. The object of this study was to estimate the relationship between the host and the graft stomach in rats. Our findings revealed individual variations in total gastric secretion, while the mean secretory volume in syngeneic transplants remained relatively constant throughout the observation period. No significant changes in the secretion of free acid or pepsin were noted. Histologic studies were made of the myenteric nerve plexus and submucosal muscle. The creation of various models of gastric pouches and transplantation of the stomach have added valuable data to gastric physiology and transplant immunology.

Animals↗
PubMed1990

[Measurement of portal systemic circulation by oral and per-rectal administration of I-123 iodoamphetamine].

In an earlier study, we measured the portal circulation noninvasively by Tc-99m pertechnetate per-rectal portal scintigraphy. This method makes it possible to see the portal circulation and to diagnose portal hypertension from the images of the liver and heart. However, the method mainly reflects circulation from the inferior mesenteric vein, the contribution of which to the portal circulation is less than that of the superior mesenteric vein. Here, we devised capsules of I-123 iodoamphetamine (IMP) that dissolve when the pH changes to evaluate the portal circulation arising from the superior mesenteric vein. I-123 IMP enclosed in an enteric-coated capsule was prepared and given orally, just before I-123 IMP was injected into the rectum. The per-rectal portal shunt index (RSI) and oral portal shunt index (OSI) were calculated from the count of radioactivity of the liver and lungs. The RSI and OSI of patients with cirrhosis were both higher than those of the patients with chronic hepatitis. In individual patients, the RSI was higher than the OSI. This noninvasive method seemed to be useful in evaluation of the portal systemic circulation in chronic liver diseases.

Administration, Oral↗
PubMed1990

[Benign paroxysmal torticollis in infancy: case report].

Since Snyder reported first twelve cases of benign paroxysmal torticollis in infancy (BPT) in 1969, about 30 cases have been reported mainly in the North America and Europe, but not in Japan. The authors experienced such a case of one-year-old boy. The attack occurred at the age of 2 months for the first time and continued to repeat every 2 weeks periodically. The head tiltings were always noticed when he woke up in the morning and lasted for about 5 to 6 days, but they disappeared during sleep. He tilted his head to the lateral side more often to the left than to the right. There were associated symptoms and signs including irritability, vomiting, gait disturbance, and abnormal truncal posture during the attacks. He did not demonstrate any neurological abnormalities between the attacks. The study of cerebrospinal fluid, caloric test, computed tomography, electroencephalography and brainstem auditory evoked responses were also normal. The frequency of the attacks gradually decreased after the age of 2 years and disappeared at the age of 3 years, and he has not complained of severe headache or vertigo up to 6 years of age. This case is reported to emphasize that BPT has to be included in the differential diagnosis of acquired torticollis. And it is required to accumulate such cases to elucidate its etiological factors.

Diagnosis, Differential↗
PubMed1990

[Operative results of distal aortic arch aneurysms--approaching methods, bypass techniques and complications].

Ten patients underwent repair of aneurysms of the distal aortic arch from 1985 to 1989. There were 8 men and 2 women: aged 58 to 77 (average age 67 years). Seven patients had sacciform aneurysms which were closed by graft patch aortoplasty, and three patients had fusiform aneurysms which were corrected by inserting tube grafts. Seven aneurysms operated since 1988 were approached through median sternotomy continued with left anterior thoracotomy, so called door open method. This approach presented good view of the diseased aorta, and effective for preventing recurrent and phrenic nerve palsy. We used temporary bypass for 4 patients, cardiopulmonary bypass for 4 patients (separate carotid artery perfusion for 2 patients) and centrifugal pump for 2 patients during aortic cross clamping. One patient died intraoperatively from intractable bleeding and two patients died postoperatively from brain damage due to embolic episodes during the operations. These patients showed the severely irregular intima in the aortic arch and were complicated with rupture of the aneurysm or dissections arising from the aneurysms. It should be noticed that careless manipulation of the aortic arch and the brachiocephalic vessels cause cerebral complications in such cases.

Aged↗
PubMed1989

Malignant lymphomas of bone in Japan.

Thirty-four cases of primary non-Hodgkin's lymphoma (NHL) of bone collected from hospitals in Japan were histologically and immunohistologically reviewed, and the results were compared with those in Western countries. There were no remarkable differences in age, sex, and the distribution of bone tumors between Japanese and Western cases. Sixteen cases (47%) diagnosed previously as "reticulum cell sarcoma" were reclassified as diffuse NHL of large cell (seven cases), mixed type (four cases), immunoblastic type (three cases), clear cell type (one case), and multilobated type (one case). The cases with small lymphocytic type with plasmacytoid features (lymphoplasmacytic type) were more common in Japan (35% of our cases) than in Western countries. The distribution of histologic subtypes, except for lymphoplasmacytic and T-cell lymphomas, in the current cases was similar to that in Western countries. However, immunohistochemistry showed that Japanese cases contained a much higher frequency of T-cell lymphoma (10% of all cases) than Western cases. Histologic grade according to the Working Formulation correlated well with clinical stage. There may be a tendency towards better prognosis with lower grade tumors, but this was not statistically significant.

Adolescent↗
PubMed1989

Role of the extra G-C pair at the end of the acceptor stem of tRNA(His) in aminoacylation.

All sequenced histidine tRNAs have one additional nucleotide at the 5' end compared with other tRNA species. To investigate the role of this unique structure in aminoacylation, we constructed in vitro transcripts corresponding to the E. coli histidine tRNA sequence and its variants at the G-1-C73 base pair, by using T7 RNA polymerase transcription system. A transcript having a wild-type sequence with no modified bases was a good substrate for histidyl-tRNA synthetase (HisRS), and aminoacylation activity was affected by introduction of a triphosphate at the 5' terminus. Base replacements at position 73 caused a marked decrease of Vmax, and deletion and substitution of the G-1 had a remarkable effect on the aminoacylation. A mutant having an A-1-U73 pair was also not a good substrate for HisRS. Comparison among G-1-deficient mutants showed that A was preferable rather than C as the base at position 73. These data demonstrate that the set of the G-1-C73 pair at the end of the acceptor stem of histidine tRNA is crucial for the catalytic process of aminoacylation.

Acylation↗
PubMed1989

Rabbit intestine contains a protein that inhibits the dissociation of GDP from and the subsequent binding of GTP to rhoB p20, a ras p21-like GTP-binding protein.

A novel regulatory protein for rhoB p20, a ras p21-like GTP-binding protein (G protein), was partially purified from the cytosol fraction of rabbit intestine. This protein, designated as rhoB p20 GDP dissociation inhibitor (GDI), inhibited the dissociation of GDP from rhoB p20. rhoB p20 GDI also inhibited the binding of guanosine 5'-(3-O-thio)triphosphate (GTP gamma S) to the GDP-bound form of rhoB p20 but not of that to the guanine nucleotide-free form. GDI did not affect the GTPase activity of rhoB p20 and by itself showed no GTP gamma S-binding activity. GDI was inactive for other ras p21/ras p21-like G proteins including c-Ha-ras p21, smg p21 and smg p25A. The Mr value of GDI was estimated to be about 27,000 from the S value. These results indicate that rabbit intestine contains a novel regulatory protein that inhibits the dissociation of GDP from and thereby the subsequent binding of GTP to rhoB p20.

Animals↗
PubMed1989

Tissue distribution of smg p25A, a ras p21-like GTP-binding protein, studied by use of a specific monoclonal antibody.

We made a monoclonal antibody specifically recognizing smg p25A among many ras p21-like GTP-binding proteins and investigated the tissue distribution of smg p25A by use of this antibody. By immunoblot analysis, smg p25A was detected in rat brain and bovine adrenal medulla but not in bovine adrenal cortex or other rat tissues including thymus, spleen, lung, heart, liver and kidney. However, by immunocytochemical studies, smg p25A was detected not only in the synaptic areas of rat brain and the chromaffin cells of bovine adrenal medulla but also in the endocrine cells of rat pancreatic islets, the acinar cells of rat exocrine pancreas and the exocrine cells of rat submaxillary gland. These results suggest that smg p25A is involved in the regulation of secretory processes not only in synapses but also in other endocrine and exocrine secretory cells.

Adrenal Medulla↗
PubMed1989

Characterization of the solubilized and reconstituted ATP-dependent vesicular glutamate uptake system.

We have previously provided evidence for ATP-dependent glutamate uptake into synaptic vesicles, and, based upon the unique properties of the vesicular uptake system, we have proposed that the vesicular glutamate translocator plays a crucial role in selecting glutamate for neurotransmission. In this study, we have solubilized the vesicular glutamate uptake system, proposed to consist of at least a glutamate translocator and a proton pump Mg-ATPase, from rat brain synaptic vesicles, and reconstituted the functional ATP-dependent glutamate uptake system into liposomes. The glutamate uptake in the reconstituted system is dependent upon ATP, markedly potentiated by low millimolar concentrations of chloride and inhibited by agents known to dissipate electrochemical proton gradients. Moreover, it exhibited low affinity for glutamate (Km = 2 mM), yet high specificity for glutamate; thus, it did not recognize aspartate and other agents known to interact with glutamate receptors. These properties are indistinguishable from those observed in intact synaptic vesicles. The solubilized functional components of the glutamate uptake system, alone or as a complex, have been estimated to have a Stokes radius in the range of 69 to 84 A. The reconstitution experiments described here provide a functional assay for the solubilized vesicular glutamate uptake system and represent an initial step towards the purification of the glutamate translocator.

Adenosine Triphosphate↗
PubMed1989

Prognostic significance of Ki-67 reactivity in soft tissue sarcomas.

Proliferative activity of soft tissue sarcomas (STS) in 34 cases was estimated by immunohistochemical procedures (avidin-biotin complex [ABC] method) with monoclonal antibody Ki-67 which reacts with a nuclear antigen expressed in all phases of cell cycle except G0. In 20 of 34 cases (59%), varying numbers of Ki-67-positive tumor cells were detected with a range from 5 to 382 per 10 high power fields (HPF) (mean 57.2/10 HPF). Ki-67 index (the number of Ki-67-positive tumor cells/10 HPF) positively correlated with mitotic count (r = 0.428, P less than 0.02), cellularity (r = 0.447, P less than 0.01), and histologic grade (r = 0.473, P less than 0.01). The Ki-67 low index group (less than 50/10 HPF) showed more favorable prognosis than the high index group (more than 50/10 HPF) (P less than 0.005). Three cases with low mitotic count and unfavorable prognosis were proved to be the Ki-67 high index group (142-382/10 HPF). These results indicated that reactivity of tumor cells for Ki-67 is a useful prognostic marker in the patients with STS, and might be used as one of the histologic factors for the grading of STS.

Adolescent↗
PubMed1989

Phosphorylation of gamma-aminobutyrate (GABA)/benzodiazepine receptors by cyclic AMP-dependent protein kinase.

Preparations of gamma-aminobutyrate (GABA)/benzodiazepine receptor from pig cerebral cortex are composed of three major bands of polypeptides (51, 55 and 57 kDa) which are purified in a ratio of approx. 2:1:1 respectively. Treatment of purified receptor preparations with cyclic AMP-dependent protein kinase resulted in major incorporation of 32P into the 55 kDa band only. The maximum incorporation achieved was 0.6 mol of 32P/mol of 55 kDa polypeptide. The phosphorylated receptor subunit (beta-subunit) displays the same apparent Mr as a band labelled irreversibly with the GABA receptor agonist [3H]muscimol. The two nonphosphorylated subunit polypeptides (51 and 57 kDa) are each labelled irreversibly with [3H]flunitrazepam and are recognized by anti-peptide antibodies specific for alpha-subunits.

Animals↗
PubMed1989

GTPase activating proteins for the smg-21 GTP-binding protein having the same effector domain as the ras proteins in human platelets.

Two proteins stimulating the GTPase activity of the smg-21 GTP-binding protein (smg p21) having the same effector domain as the ras proteins (ras p21s) are partially purified from the cytosol fraction of human platelets. These proteins, designated as smg p21 GTPase activating protein (GAP) 1 and 2, do not stimulate the GTPase activity of c-Ha-ras p21. The GAP activity for c-Ha-ras p21 is also detected in the cytosol fraction of human platelets. smg p21 GAP1 and 2 are separated from c-Ha-ras p21 GAP by column chromatographies. The activity of smg p21 GAP1 and 2 is killed by tryptic digestion or heat boiling. The Mr values of smg p21 GAP1 and 2 are similar and are estimated to be 2.5-3.5 x 10(5) by gel filtration analysis. These results indicate that there are two GAPs for smg p21 in addition to a GAP for c-Ha-ras p21 in human platelets.

Blood Platelets↗
PubMed1989

Glutamate uptake into synaptic vesicles of bovine cerebral cortex and electrochemical potential difference of proton across the membrane.

Measurements have been made of the ATP-dependent membrane potential (delta psi) and pH gradient (delta pH) across the membranes of the synaptic vesicles purified from bovine cerebral cortex, using the voltage-sensitive dye bis[3-propyl-5-oxoisoxazol-4-yl]pentamethine oxanol and the delta pH-sensitive fluorescent dye 9-aminoacridine respectively. A pre-existing small delta pH (inside acidic) was detected in the synaptic vesicles, but no additional significant contribution by MgATP to delta pH was observed. In contrast, delta psi (inside positive) increased substantially upon addition of MgATP. This ATP-dependent delta psi was reduced by thiocyanate anion (SCN-), a delta psi dissipator, or carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP), a protonmotive-force dissipator. Correspondingly, a substantially larger glutamate uptake occurred in the presence of MgATP, which was inhibited by SCN- and FCCP. A nonhydrolysable analogue of ATP, adenosine 5'-[beta gamma-methylene]triphosphate, did not substitute for ATP in either delta psi generation or glutamate uptake. The results support the hypothesis that a H+-pumping ATPase generates a protonmotive force in the synaptic vesicles at the expense of ATP hydrolysis, and the protonmotive force thus formed provides a driving force for the vesicular glutamate uptake. The delta psi generation by ATP hydrolysis was not affected by orthovanadate, ouabain or oligomycin, but was inhibited by N-ethylmaleimide, quercetin, trimethyltin, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulphonic acid. These results indicate that the H+-pumping ATPase in the synaptic vesicle is similar to that in the chromaffin granule, platelet granule and lysosome.

Adenosine Triphosphatases↗
PubMed1989

Imbalance of deoxyribonucleoside triphosphates, DNA double-strand breaks, and cell death caused by 2-chlorodeoxyadenosine in mouse FM3A cells.

The mechanism of the cytotoxic action of 2-chlorodeoxyadenosine in mouse FM3A cells was investigated. Imbalance of the dNTP pools occurred within 3 h of treatment with 20 microM 2-chlorodeoxyadenosine; the dATP and dGTP pools were depleted and the dTTP pool increased. 2-Chlorodeoxyadenosine added to the culture medium broke mature DNA strands, giving fragments of 100-200 kilobase pairs as found by orthogonal-field-alternation gel electrophoresis. DNA strand breaks, measured by this technique, were observed in the treated cells about 12 h after the addition. The cells also lost viability at about 12 h. Breaks in the single and double strands of DNA, as measured by alkaline and neutral filter elution, became evident 18 h after treatment with 20 microM 2-chlorodeoxyadenosine; there were as many single-strand breaks as would be caused by 130 rads of gamma-ray irradiation. Double-strand breaks were equivalent to those caused by 2180 rads of gamma-ray irradiation. Comparison of the ratio of single- and double-strand breaks caused by 2-chlorodeoxyadenosine to that following radiation suggested that 2-chlorodeoxyadenosine broke only double strands. Cycloheximide inhibited the breakage of DNA double strands and the cell death caused by this compound. Flow cytometric studies of cytostasis brought about by 2-chlorodeoxyadenosine in FM3A cells showed that cells accumulated in the earlier part of the S phase. 2-Chlorodeoxyadenosine decreased DNA synthesis more than RNA or protein synthesis. The breaks in double strands of DNA were probably important in the cell death caused by 2-chlorodeoxyadenosine. The intracellular dNTP imbalance may trigger these events.

Animals↗