Biomedical subjects

T Yasuda

Publications and source records attributed to T Yasuda.

At least 163 records · Page 9Linked to original sources

PubMed1999

Cell-specific expression of the diphtheria toxin A-chain coding sequence under the control of the upstream region of the human alpha-fetoprotein gene.

BACKGROUND AND OBJECTIVES: Development of the system to express a suicide gene selectively in tumor cells is essential for gene therapy. We constructed a plasmid containing the diphtheria toxin A (DTA) fragment linked to human alpha-fetoprotein (AFP) promoter and enhancer, and tested whether it can exert its cytocidal effect selectively on AFP-producing cells. METHODS: The chloramphenical acetyltransferase (CAT) reporter gene or DTA gene was linked to the 5' upstream region of the AFP gene. The plasmids were transfected into AFP-producing or non-producing cells by the lipopolyamine-coated DNA method. Expression of CAT activity and effects on cell growth of transfected cells were assessed. RESULTS: When the AFP-producing cells HuH-7 or HepG2 were cotransfected with CAT reporter plasmid and pAF5.1DTA plasmid, the CAT activity was greatly suppressed. In contrast, cotransfection with pAF5.1DTA-R, the inversely inserted DTA gene, did not inhibit CAT activity. Furthermore, cell growth of HuH-7 cells transfected with pAF5.1DTA plasmid was significantly inhibited compared with HuH-7 cells transfected with DTA-R plasmid. CONCLUSIONS: Our results indicate that selective killing of AFP-producing cells will be attained by introducing the DTA gene linked to the promoter and enhancer region of AFP.

Carcinoma, Hepatocellular↗

PubMed1999

nRap GEP: a novel neural GDP/GTP exchange protein for rap1 small G protein that interacts with synaptic scaffolding molecule (S-SCAM).

Synaptic scaffolding molecule (S-SCAM) has six PDZ domains through which it interacts with N-methyl-d-aspartate receptors and neuroligin at synaptic junctions. We isolated here a novel S-SCAM-binding protein. This protein has one PDZ, one Ras association, one Ras GDP/GTP exchange protein (Ras GEP) domain, and one C-terminal consensus motif for binding to PDZ domains. We named it nRap GEP (neural Rap GEP). nRap GEP moreover has an incomplete cyclic AMP (cAMP)-binding (CAB) domain. The domain organization of nRap GEP is similar to that of Epac/cAMP-guanine nucleotide exchange factor (GEF) I, except that Epac/cAMP-GEFI has complete CAB and Ras GEP domains but lacks the other two domains and the C-terminal motif. nRap GEP showed GEP activity for Rap1 but did not bind cAMP. nRap GEP was specifically expressed in rat brain. Immunohistochemical analysis revealed that nRap GEP and S-SCAM were localized at synaptic areas of the cerebellum. These results suggest that nRap GEP is a novel neural Rap1-specific GEP which is associated with S-SCAM.

Adaptor Proteins, Signal Transducing↗

PubMed1999

Yersinia pseudotuberculosis blocks the phagosomal acidification of B10.A mouse macrophages through the inhibition of vacuolar H(+)-ATPase activity.

Yersinia pseudotuberculosis survived and multiplied in the phagosomes of B10.A mouse peritoneal macrophages. As one of the possible mechanisms for the bacteria's survival in the phagosomes, we demonstrated that live Y. pseudotuberculosis inhibited the phagosomal acidification; pH within phagosomes containing the live Y. pseudotuberculosis remained at about 6.0, whereas pH within phagosomes containing the dead Y. pseudotuberculosis fell to about 4. 5. This ability to inhibit intraphagosomal acidification was also shared by mutants lacking the 42 Md virulence plasmid, indicating that it is chromosomally encoded. The phagosomes containing dead bacteria raised the pH to 6.2 after the treatment of their macrophages with an inhibitor (bafilomycin A1) specific for V-ATPase. Although the amount of V-ATPase in the A and B subunits on the phagosomes was not significantly different between the live and dead bacteria infection, the phagosomes containing live bacteria had a 10-fold smaller V-ATPase activity than those containing the dead bacteria. These results indicated that the inhibition of phagosomal acidification by Y. pseudotuberculosis infection was due to the attenuation of V-ATPase activity, and not due to the exclusion of V-ATPase subunits from the phagosome membrane as found in Mycobacterium avium.

Animals↗

PubMed1999

Leiomyosarcoma of the thoracic aorta.

This case involves a patient with aortic leiomyosarcoma. A patient clinically suspected of type IIIa dissecting aortic aneurysm underwent surgery. The descending thoracic aorta was found to be filled with a soft, yellow tumor and was replaced with a woven Dacron graft. Microscopy of the surgical specimen revealed large, atypical spindle cells with numerous mitoses in bundles intersecting at 90 degrees, suggesting leiomyosarcoma. This diagnosis was confirmed immunohistochemical study. The postoperative course was uneventful and the patient was discharged on postoperative day 40; however, the patient developed bronchopneumonia due to malignant pleuritis 3 months postoperatively and died on postoperative day 103.

Aged↗

PubMed1999

Survival and postoperative complications after extended surgery for non-small-cell lung cancer. A retrospective study.

OBJECTIVE: We evaluated survival after extended surgery in patients with non-small-cell lung cancer and the effects of induction therapy on results and complications. SUBJECTS AND METHODS: Between April 1987 and March 1998, 127 patients with pathological T3 (pT3) or T4 (pT4) non-small-cell lung cancer underwent extended surgery combined with resection of neighboring organs. Of these, 35 received induction therapy. In the remaining 92, surgery preceded other therapy. Long-term results and postoperative respiratory complications were analyzed and compared between the patients with and without induction therapy. RESULTS: Overall 5-year survival after extended surgery was 37%. Five-year survival rates in the pT3 was 41% and that in the pT4 group 28% (p = 0.030). Five-year survival rate in the pN0-1 was 46% and that in the pN2-3 group 26% (p = 0.003). No significant difference was observed in survival curves between patients with and without induction therapy. Induction therapy responders showed better survival than nonresponders. To prevent postoperative fatal complications due to bronchopleural fistula, we prophylactically covered the bronchial stump using autologous tissue in 31 induction therapy patients, and no mortality due to complications was seen in this group. CONCLUSION: Long-term survival after extended surgery was observed in pT3 and pT4 patients, especially among those with a pN0-1 status. Induction therapy responders may be considered good candidates for extended surgery because of the favorable prognosis in contrast to that for nonresponders.

Carcinoma, Non-Small-Cell Lung↗

PubMed1999

Combined resection of the aorta for an esophageal carcinoma invading the aorta through a right transthoracic approach.

The prognosis of esophageal carcinoma invading the thoracic aorta has been extremely poor, as it has been either not resected or only palliatively resected. In recent years a remarkable improvement in survival has been achieved in advanced esophageal carcinoma through an aggressive dissection of the upper mediastinal lymph nodes. This implied that resection only of the aorta without lymph node dissection in these patients was not adequate for curability. Although a resection of the aorta would seem to be performed more easily through a left thoracotomy than through a right thoracotomy, the upper mediastinal lymph node dissection was unsatisfactory through a left thoracotomy. Therefore, we performed combined resection of the aorta using a temporary aorta-aorta bypass together with upper mediastinal lymph node dissection through a right thoracotomy for four patients with the esophageal carcinoma invading the thoracic aorta. This operative procedure was performed safely, and had the advantage that full observation on the extent of the carcinoma was attained together with subsequent radical lymph node dissection in the same field through only the right thoracic approach. This operation may provide a possibility for cure to patients with an esophageal carcinoma invading the aorta, who would otherwise receive only palliative treatment.

Aged↗

PubMed1999

The role of the labyrinth, proprioception and plantar mechanosensors in the maintenance of an upright posture.

The maintenance of an upright posture in man requires information from vision, the labyrinth, proprioception and plantar mechanosensors. In order to evaluate the role of the labyrinth, proprioception and plantar mechanosensors, stabilometry was performed in subjects with closed eyes. Ten patients with bilateral severe or complete labyrinthine paresis were studied, as well as 9 patients with severe proprioceptive disorders and 10 normal healthy persons whose plantar mechanosensors were anesthetized by hypothermia. Both the area of sway and the total locus length (accumulated shift distance length) were evaluated. On closing eyes, in patients with labyrinthine disorders demonstrated that the area of sway increased more than length. On the other hand, in patients with proprioceptive disorders, length increased more than the area. In plantar anesthetized subjects, similar to the labyrinthine disorder cases, the area of sway increased more than length. These findings suggest that the labyrinth is a main monitor of the area of body sway, while proprioception is a principle monitor of the velocity of body movement of sway (or locus length). The plantar mechanosensor monitors the area of body sway similar to the labyrinth, but works less than the labyrinth. The locus length is the distance per minute and reflects the velocity of body sway. Thus, the length per area is a parameter for the velocity of body sway per area. Since proprioceptive disorders increase both the locus length and the length per area, present findings suggest that if proprioception is damaged, the body begins to move faster. Compensated labyrinthine disorders have a tendency to increase the length per area, indicating that if a labyrinthine disorder is compensated, the body adapts and moves faster to maintain an upright posture.

Achilles Tendon↗

PubMed1999

Pancreatic bladder or double gallbladder draining into pancreatic duct?

We report a case of pancreatic bladder which could also be interpreted as double gallbladder draining into the pancreatic duct. A 6-year-old Japanese boy underwent a cholecystectomy of the smaller bladder under the diagnosis of duplication of the gallbladder, leaving the normal gallbladder and an unremarkable biliary ductal system. The smaller bladder was histologically similar to the gallbladder tissue. At age 25, relaparotomy was performed. It was confirmed that the residual aberrant duct from the smaller bladder joined directly with the duct of Wirsung and that the patient had fusiform dilatation of the extrahepatic bile duct. The extrahepatic portion of the bile duct was excised along with the "normal" gallbladder and the residual aberrant duct. The present anomaly seems to validate the designation of pancreatic bladder whose cystic duct joined directly with the pancreatic duct, but may also be explained from the view point of double gallbladder.

Bile Ducts↗

PubMed1999

No psychological emergence reactions in schizophrenic surgical patients immediately after propofol, fentanyl, and ketamine intravenous anesthesia.

PURPOSE: We attempted to determine the frequency of adverse psychological events after total intravenous anesthesia with propofol-fentanyl-ketamine (PFK) in surgical schizophrenic patients. METHODS: PFK was used in 25 schizophrenic patients undergoing various surgical procedures from 1995 to 1997. Adverse events occurring during and after anesthesia were recorded. Psychiatric follow-up was also done during the first 3 postoperative weeks at least. RESULTS: One patient died postoperatively of airway obstruction from concomitant severe malignant thyroid disease, but in the remaining patients neither respiratory nor cardiovascular states during or after anesthesia became unstable. None of the patients developed adverse psychological emergence reactions immediately after anesthesia. Two patients undergoing major surgical procedures exhibited delirium in the early postoperative days despite taking their routine antipsychotic drugs postoperatively. CONCLUSIONS: We suggest that PFK maintains stable respiratory and cardiovascular states, and causes no psychological emergence reactions in schizophrenic surgical patients. However, adverse psychological events may occur postoperatively, probably due to continued psychic stress. We therefore recommend appropriate perioperative management and further psychological studies for such patients.

Journal Article↗

PubMed1999

Radiation-associated ischemic coloproctitis: report of two cases.

Radiation-associated ischemic coloproctitis is a rare clinical entity caused by vascular insufficiency to the rectosigmoid colon. It most commonly occurs after radiotherapy for gynecological cancer. We present herein the cases of two patients who developed radiation-associated coloproctitis with transmural necrosis and eventual perforation. Perforation of the rectosigmoid colon occurred 3.5 years after radiotherapy in case 1, a 46-year-old woman, and presented as a well-defined small area of transmural necrosis. Conversely, in case 2, a 55-year-old woman, it occurred 1.5 years after radiotherapy, and presented as segmental, diffuse transmural necrosis. The lesion in case 1 had been caused by intramural vascular obliteration due to marked fibrosis of the bowel wall, while that in case 2 had been caused by occlusion of the mesenteric artery with thrombosis. Both patients underwent Hartmann's resection without rectal excision, and survived the perforative event.

Colon, Sigmoid↗

PubMed1999

Phase II study of limited surgery for early gastric cancer: segmental gastric resection.

BACKGROUND: Endoscopic resection for treatment of early gastric cancer (EGC) is widely performed. Recently, however, surgeons began performing a limited operation for EGC when endoscopic resection was not indicated. This report discusses the surgical technique and the results of the limited operation, which is generally referred to as "segmental resection" (SR). METHODS: Since 1990, a total of 50 patients with intramucosal invasive EGC of the middle stomach underwent SR. The procedure included a limited gastrectomy, limited lymph node dissection, and preservation of the vagal nerve. We examined the surgical risk, postoperative complications, and patient survival rates and compared the results for the SR-treated patients (group A) with results for patients with EGC who underwent subtotal gastrectomy and systemic lymph node dissection (group B). RESULTS: Blood loss was less in group A (239 +/- 180 ml) than in group B (342 +/- 176 ml) (P < .05). The incidence of postoperative complications was also lower in group A (2.0%) than in group B (14.0%) (P < .05). The incidence of postoperative cholelithiasis was lower in group A (4.0%) than in group B (18.0%) (P < .05). All patients in both groups are alive without recurrence. CONCLUSIONS: Compared with distal gastrectomy, SR for EGC of the middle stomach decreased the surgical risk and postoperative complications without increasing the recurrence rate.

Female↗

PubMed1999

Collagenofibrotic glomerulopathy: a systemic disease.

Collagenofibrotic glomerulopathy is a recently discovered entity that is characterized by massive accumulation of spiraled and frayed collagen fibrils in mesangial and subendothelial areas, and elevated serum levels of procollagen III peptide. We report the autopsy of a patient who received continuous ambulatory peritoneal dialysis (CAPD) therapy for 7 years. Autopsy disclosed that massive accumulation of peculiar collagen fibers was found not only in the kidney, but also in many organs including spleen, liver, myocardium, and thyroid gland. Although the possibility remains that CAPD for 7 years might change or aggravate the deposition of abnormal collagen, the current case suggests a possibility that collagenofibrotic glomerulopathy is a systemic disorder with abnormal metabolism of type III collagen.

Adult↗

PubMed1999

Resistance to nitric oxide-mediated apoptosis in HL-60 variant cells is associated with increased activities of Cu,Zn-superoxide dismutase and catalase.

Nitric oxide (NO) released from (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1- ium-1,2-diolate (DETA/NO or NOC-18) induces apoptosis in human leukemia HL-60 cells. In this study, we isolated a HL-60 variant cell line, HL-NR6, that is resistant to DETA/NO toxicity as assessed by DNA fragmentation, morphology, and colony forming ability. The variant cells also showed resistance to reactive oxygen species (ROS) such as superoxide and hydrogen peroxide as well as NO donors, but not to anti-tumor drugs. We found that HL-NR6 cells when compared with HL-60 cells possessed twice the activities of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase, but no change in Mn-SOD nor in glutathione peroxidase. Immunoblotting confirmed the high levels of both enzymes in the variant cell. We also observed that ROS generation following DETA/NO exposure was substantially higher in HL-60 cells than in HL-NR6 cells, using the 2',7'-dichlorofluorescein fluorometric method. Moreover, the SOD mimetic Mn(III) tetrakis(1-methyl-4-pyridyl) porphyrin and exogenous catalase effectively attenuated DETA/NO-elicited DNA fragmentation in HL-60 cells. Taken together, these data suggested that the NO resistance in HL-NR6 cells is associated with the increased Cu,Zn-SOD/catalase and that NO-mediated apoptosis in HL-60 cells is correlated with the generation of ROS and derived molecules like peroxynitrite.

Apoptosis↗

PubMed1999

Simultaneous typing of the STR loci, vWF and HumTPO, using discontinuous polyacrylamide gel electrophoresis.

Analyses of short tandem repeat (STR) loci are very useful for improving the accuracy of paternity determination. Combined use of several STRs makes this test even more accurate. We have devised a simple but effective method which consists of the co-amplification of two STR loci (vWF and HumTPO) in a single test tube, separation of the PCR products using discontinuous polyacrylamide gel electrophoresis, and detection using sensitive silver staining. An appropriate combination of PCR primer pairs gave a high resolution and good separation of the two STR bands in the same lane on the same gel. Many combinations of STR loci have potential usefulness in paternity and individualization testing or population genetic studies in forensic practice.

Journal Article↗

PubMed1999

Molecular, biochemical and immunological studies of hen pancreatic deoxyribonuclease I.

Deoxyribonuclease I (DNase I) was purified from the hen pancreas to electrophoretic homogeneity using six-step column chromatography. The purified enzyme showed a molecular mass of about 33 kDa and maximum activity at pH 7.0. It required divalent cations, Mg2+ and Ca2+, for its activity and was inhibited by EDTA, EGTA and an antibody specific to the purified enzyme but not by G-actin. A 1066-bp cDNA encoding hen DNase I was constructed from the total RNA of a hen pancreas using a combination of the reverse transcriptase-polymerase chain reaction and rapid amplification of cDNA ends methods, followed by sequencing. The cDNA was expressed in Escherichia coli, and the recombinant polypeptide exhibited significant enzyme activity. The mature hen DNase I protein was found to consist of 262 amino acids. In human and bovine DNase I four amino acid residues, Glu-13, Tyr-65, Val-67 and Ala-114 are involved in actin binding, whereas in the hen DNase I these positions were occupied by Asp, Phe, Ser and Phe, respectively. A survey of the DNase I distribution in 15 hen tissues showed that the pancreas had the highest levels of both DNase I enzyme activity and DNase I gene expression. The results of our phylogenetic and immunological analyses indicate that the hen DNase I is not closely related to the mammalian enzymes. This is the first report in which has been described the results of molecular, biochemical and immunological analyses on hen DNase I.

Amino Acid Sequence↗

PubMed1999

Metabolism of paeonol in rats.

As a part of our studies on the metabolism of active components from traditional Chinese medicines, paeonol was orally administered to rats. The urinary metabolites were analyzed by 3D HPLC, and their structures were determined to be 2, 4-dihydroxyacetophenone-5-O-sulfate (P1), resacetophenone-2-O-sulfate (P2), 2-hydroxy-4-methoxyacetophenone-5-O-sulfate (P3), paeonol-2-O-sulfate(P4), resacetophenone (P5), and unchanged paeonol, on the basis of their chemical and spectral data. Among these metabolites, P2-P4 and paeonol were detected in the plasma after the oral administration of paeonol. Furthermore, the bile of rats given paeonol orally was found to contain P3, suggesting the enterohepatic circulation of paeonol.

Acetophenones↗

PubMed1999

The gene mutated in adult-onset type II citrullinaemia encodes a putative mitochondrial carrier protein.

Citrullinaemia (CTLN) is an autosomal recessive disease caused by deficiency of argininosuccinate synthetase (ASS). Adult-onset type II citrullinaemia (CTLN2) is characterized by a liver-specific ASS deficiency with no abnormalities in hepatic ASS mRNA or the gene ASS (refs 1-17). CTLN2 patients (1/100,000 in Japan) suffer from a disturbance of consciousness and coma, and most die with cerebral edema within a few years of onset. CTLN2 differs from classical citrullinaemia (CTLN1, OMIM 215700) in that CTLN1 is neonatal or infantile in onset, with ASS enzyme defects (in all tissues) arising due to mutations in ASS on chromosome 9q34 (refs 18-21). We collected 118 CTLN2 families, and localized the CTLN2 locus to chromosome 7q21.3 by homozygosity mapping analysis of individuals from 18 consanguineous unions. Using positional cloning we identified a novel gene, SLC25A13, and found five different DNA sequence alterations that account for mutations in all consanguineous patients examined. SLC25A13 encodes a 3.4-kb transcript expressed most abundantly in liver. The protein encoded by SLC25A13, named citrin, is bipartite in structure, containing a mitochondrial carrier motif and four EF-hand domains, suggesting it is a calcium-dependent mitochondrial solute transporter with a role in urea cycle function.

Adult↗

PubMed1999

Effects of exhaustive exercise on biochemical characteristics of sarcoplasmic reticulum from rat soleus muscle.

This study examined the effects of acute high-intensity and moderate-intensity exercise on Ca2+-stimulated adenosine triphosphatase (ATPase) activity and the Ca2+ and ATP dependence of Ca2+-ATPase of the sarcoplasmic reticulum (SR) in the soleus muscle. The rats were run on 10% grade at 50 m min(-1) or 25 m min(-1) until fatigued (avg. time to exhaustion 2.8 and 87.7 min, respectively). The catalytic activities of SR Ca2+-ATPase were significantly depressed immediately after both types of exercise. Kinetic analyses demonstrated that the Ca2+ affinity of Ca2+-ATPase was elevated by both types of exercise adopted in the present investigation whereas the increase in the ATP affinity was brought about by only high-intensity exercise. These results suggest that exhaustive exercise may induce in slow-twitch muscle fibre the environmental changes, which adversely affect SR Ca2+-ATPase activity and can overcome the positive influence arising from the increase in the Ca2+ and/or ATP affinities of SR Ca2+-ATPase.

Animals↗