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Biomedical subjects

T Ueda

Publications and source records attributed to T Ueda.

At least 865 records · Page 48Linked to original sources
PubMed1993

[Determining factors of successful percutaneous transvenous mitral commissurotomy and eligible indications for the procedure].

The aim of this report is to investigate the factors which influence mean left atrial pressure (LAP) after percutaneous transvenous mitral commissurotomy (PTMC) and the characteristics of patients in whom PTMC is most effective. Fifty one patients with symptomatic mitral stenosis underwent PTMC. The patients included 8 males and 43 females, aged 26-66 years (mean age of 46). These patients were classified into two groups according to LAP after PTMC: 31 cases with LAP after PTMC of 12 mmHg or less (group A) and 20 cases with LAP after PTMC greater than 12 mmHg (group B). The patients of group A were younger (44 +/- 6 vs 48 +/- 6 years, p < 0.05), and had atrial fibrillation (af) less frequently (35 vs 65%, p < 0.05), and had mitral valve calcification less frequently (29 vs 65%, p < 0.01). Before PTMC, LAP (19 +/- 6 vs 23 +/- 5 mmHg, p < 0.01) was lower and mitral valve area (MVA) (0.95 +/- 0.24 vs 0.81 +/- 0.15 cm2, p < 0.05) larger in group A. Symptoms graded according to the New York Heart Association functional classification system were similar in both groups before PTMC. After the procedure, final MVA (1.79 +/- 0.69 vs 1.40 +/- 0.50 cm2, p < 0.05) was larger and systolic pulmonary artery pressure (32 +/- 9 vs 39 +/- 7 mmHg, p < 0.01) lower in group A. Mitral regurgitation > or = 3-grade tended to complicate more frequently (3 vs 20%, NS) in group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Evaluation of isokinetic hip strength after rotational acetabular osteotomy.

Fifty-four patients with dysplastic hip and secondary degenerative arthrosis (58 hips) underwent rotational acetabular osteotomy (RAO) using a conventional anterior-posterior method or a new technique involving detachment of the greater trochanter. Pre- and postoperative hip abductor strength (HAS) and knee extensor strength (KES) were evaluated using an isokinetic dynamometer. Postoperative HAS in patients treated by detachment of the greater trochanter reached preoperative levels 16 weeks postoperatively. Comparison of the postoperative HAS based on the two different surgical approaches showed that RAO by detachment of the greater trochanter was superior to the conventional method. Pre- and postoperative HAS showed a good correlation. Postoperative improvements in HAS over presurgical values were not significant in patients with advanced-stage arthrosis and severely dysplastic hips. Preoperative HAS should serve as an index for determining whether RAO is undertaken using detachment of the greater trochanter.

Acetabulum↗
PubMed1993

[Exposure to DMTP by sprayers and the urinary excretion of metabolites].

Exposure in vinyl hothouses to DMTP (0,0-dimethyl-s-(2-methoxy-1,3,4-thiadiazol-5(4H)-onyl-(4)-m ethyl)- dithiophosphate) was studied in 5 spray-operators and one assistant worker. To determine the level of exposure to DMTP, concentrations in the atmosphere, concentration in atmosphere near the operators breathing zone, skin levels from penetration through the operator's clothing, and urinary excretion of metabolites of DMTP (2,3-dihydro-5-methoxy-3-methyl-sulphonyl methyl-1,3,4-thiadiazol-2-one and 2,3-dihydro-5-methoxy-3-methyl-sulphinyl methyl-1,3,4-thiadiazol-2-one) were measured. The results were as follows; 1. DMTP concentrations in the atmosphere were 10.0-18.0 micrograms/m3, and concentrations in the atmosphere near the operators breathing zone were 5.4-33.6 micrograms/m3 during spraying. 2. Metabolites of DMTP were detected in all sprayers. Levels were 1.5 to 31.6 micrograms/day for the sulphonyl-metabolite. But it was not detected in the assistant sprayer. 3. Urinary concentrations of the DMTP metabolite were maximum 15-20 h after spraying. 4. Amount of DMTP adherent on the skin was estimated to be 0.4 to 71.3 micrograms for spray-operators. Variations resulted from differences in condition of protective clothing. 5. DMTP appeared to be absorbed not only through the respiratory system, but also through the skin.

Female↗
PubMed1993

[Prophylactic effect of methylprednisolone on cisplatin-induced nephrotoxicity in rats].

Cis-diamminedichloroplatinum (II) (cisplatin) is a very effective antitumor drug, but It has an adverse effect of nephrotoxicity. There are many reports concerning protective agents against cisplatin nephrotoxicity, but clinically useful modalities are very few. In the present study, prophylactic effects of methylprednisolone (MP) on cisplatin-induced nephrotoxicity were examined. Male Sprague-Dawley rats were injected iv with 6.5 mg/kg of cisplatin combined with a subcutaneous MP given sc in various doses at various timing. Rats were killed 5 days after cisplatin injection to determine BUN and serum creatinine levels. BUN and serum creatinine levels in rats pretreated with MP 4 or 2 hr before cisplatin injection were significantly lower than those in rats received cisplatin alone. Our preliminary results suggest that pretreatment with MP is an effective means of protection against cisplatin-induced nephrotoxicity.

Animals↗
PubMed1993

Proteases--structures, mechanism and inhibitors.

Proteases have been divided into four mechanistic classes: serine proteases, metalloproteases, aspartic proteases, and cysteine proteases. Once a new enzyme is classified by the use of general inhibitors, it is possible to design reactive inhibitors by using mechanistic information learned through study of other members of the same protease family. The most useful types of inhibitors for serine proteases are transition-state inhibitors including alpha-ketoesters and phosphonates, and mechanism-based inhibitors such as heterocyclic isocoumarin inhibitors. Some of these inhibitors are quite specific toward individual target serine proteases. Many proteases are involved in various disease states, and potent inhibitors of these enzymes have the potential to be developed as new therapeutic agents. In the future, it is likely than numberous specific protease inhibitors will be tested clinically for the treatment of human disease.

Amino Acid Sequence↗
PubMed1993

[Experimental study of liver regeneration and tumor growth following partial hepatectomy].

An experimental study was performed aiming to clarify the mechanism of early recurrence of hepatocellular carcinoma following hepatectomy. AH109A ascites hepatoma cells were implanted in a liver or subcutaneous tissue of male Donryu rats 5 days prior to 70% partial hepatectomy (H group) or simple laparotomy (L group) or non operation control (C group). Rats were sacrificed at 1, 3, 7 postoperative days. Tumor size, labelling index (LI), tissue blood flow (TBF) and regeneration rate of the remnant liver were measured. Tumor size of the remnant liver in hepatectomy group was 492 +/- 117 mm3 against 129 +/- 63 mm3 in laparotomy group showing enhancement of tumor growth following partial hepatectomy with statistical significance (p < 0.01). On the contrary, there was no difference in the growth of subcutaneous tumor among H, L, C group. A significant increase of LI in both liver and subcutaneous tumor cells comparable to regenerating liver cells at 24 hours after hepatectomy was observed in H group. It suggests that some humoral hepatotrophic factors increased DNA synthesis of not only tumor cells but liver cells. TBF in the tumor and remnant area of the liver were increased. This result supports that increased hepatotrophic factors and TBF led to the enhancement of tumor growth in the remnant liver following partial hepatectomy.

Animals↗
PubMed1993

[Composite resection of sciatic nerve for local recurrence of rectal cancer].

Three patients with local recurrence of rectal cancer involving the sciatic nerve underwent radical pelvic exenteration combined with sciatic nerve resection. This surgical procedure resulted in complete relief of intolerable cancer pain in all patients. After the rehabilitation, all could walk unassisted by wearing only a below-the-knee leg brace. The first patient died 16 months postoperatively due to multiple liver metastasis, but no local recurrence was documented. The second patient is alive 13 months postoperatively with bone and liver metastasis and pelvic wall recurrence. The third patient is alive 7 months postoperatively with no evidence of disease. Composite resection of lateral sciatic nerve improved the quality of life in patients who had local recurrence of rectal cancer with sciatic nerve involvement.

Adult↗
PubMed1993

[Evaluation of clinical usefulness of 99mTc-GSA, a functional hepatic imaging agent--correlation with per-rectal portal scintigraphy].

Liver scintigraphy using 99mTc-GSA, which binds specifically to the asialoglycoprotein receptors on the surface of the hepatocytes, was performed in 41 patients with chronic liver disease (11 chronic hepatitis cases and 30 liver cirrhosis) to investigate the correlations between the images and the various liver function tests. Two liver functional indexes, HH15 for plasma clearance of 99mTc-GSA and LHL15 for liver accumulation of 99mTc-GSA, showed significant differences between the chronic hepatitis group and the decompensated liver cirrhosis group. These indexes also showed significant correlations with the liver function tests such as serum albumin level and prothrombin time. HH15 and LHL15 correlated with the per-rectal portal shunt index obtained in 10 patients by 99mTcO4- per-rectal portal scintigraphy. These results suggest that HH15 and LHL15 have value as new liver functional indexes.

Adult↗
PubMed1993

[Pharmacodynamics and action mechanism of antitumor agents].

In the aspects of pharmacodynamics of antitumor agents, the blood level of administered drug is elevated first and maintained for a certain period of time. Then the drug reaches to tumor cells and is incorporated into the cells. After activated, it induces damage of DNA strands, inhibition of DNA synthesis and suppression of the cell proliferation. Each agent shows different behavior in each step of pharmacodynamics. 1) Blood drug level; distribution of antitumor agent in red and white blood cells, and plasma after administration is different among drugs. Lipophilic drug such as behenoyl ara-C is well absorbed and stored in red blood cell membrane, which is re-utilized effectively for the maintenance of plasma drug levels. Drugs having strong DNA binding affinity such as anthracycline, are accumulated in white blood cells and their blood levels are correlated with the white blood cells counts. 2) Incorporation of antitumor agents into the cells; especially incorporation of nucleoside analogs are correlated with the number of nucleoside transport sites of the cell membrane. Drug incorporation is also greatly influenced by activation and inactivation of drug in the cells. 3) Activation of the drugs in the cells; the activation reactions require the corresponding enzymes and cofactors. Activation of ara-C depended on deoxy cytidine kinase activity, whereas activation of 6-mercaptopurine required hypoxanthine guanine phosphoribosyl transferase and phosphoribosyl pyrophosphate. The latter is the limiting factor of the activation reaction. In a case of rapid activation of a certain drug, such as ara-C, in a cell suspension, intracellular concentration of its active form exceeded extracellular concentration of the drug within 10 min of the incubation time. 4) Effects of nucleotide pool changes by antitumor agent on activation of the other antitumor drug; inhibitors of riboside diphosphate reductase, such as fludarabine or hydroxyurea, reduced deoxynucleoside triphosphates pools, and the reduction resulted in the decrease of feedback inhibition of deoxy cytidine kinase. Subsequently, activation of ara-C to its nucleotides was increased. 5) DNA damage by antitumor agents and its repair; a part of DNA damages induced by labile DNA binder are repaired. Inhibition of the repair would be effective for increasing antitumor effects. 6) Suppression of drug inactivation; in a case of ara-C, inactivation is nearly 100 times higher than activation. A number of procedures for suppressing the drug inactivation have been investigated to increase production of intracellular active form of the drug.(ABSTRACT TRUNCATED AT 400 WORDS)

Antineoplastic Agents↗
PubMed1993

Results of surgery for portacaval shunt in a patient with situs inversus diagnosed and evaluated by per rectal portal scintigraphy.

A 70-yr-old man diagnosed with situs inversus was hospitalized because of hepatic encephalopathy. Per rectal portal scintigraphy showed portal hypertension and a region with high radionuclide activity in the right lateral region of the abdomen. In percutaneous transhepatic portograms, a giant portacaval shunt was seen in the region with high radionuclide activity. After the portacaval shunt was obstructed surgically, the hepatic encephalopathy disappeared. In per rectal portal scintigraphy done 2 wk after surgery, the pattern was normal and the region with high radionuclide activity had disappeared.

Aged↗
PubMed1993

[Clinical use of an expanded polytetrafluoroethylene sheets (GORE-TEX SHEETS) as a pericardial substitute after aorto coronary bypass grafting].

Reoperation after cardiovascular surgical procedures are often accompanied by the possibility of injuring the heart the great vessels, and extracardiac grafts during resternotomy. To reduce the risk associated with resternotomy and to facilitate dissection of intrapericardial adhesion, we have used GORE-TEX SHEET as pericardial substitute since January, 1989. In case GORE-TEX SHEET are implanted in the mediastinum, prolongation of the foreign body reaction, mediastinitis, increasing postoperative hemorrhage should be in mind. In this study, the biocompatibility of GORE-TEX SHEET was examined clinically. The following postoperative indices such as duration of fever, change of the WBC counts, WBC fraction, CRP, mediastinal hemorrhage are evaluated. These results showed no statistical significance between GORE-TEX SHEET group and autologous pericardial group by the randomized study. We recommend use of GORE-TEX SHEET as a pericardial substitute in cases of major cardiovascular operation using median sternotomy.

Aged↗
PubMed1993

[A case of myocardial revascularization in a patient after renal transplantation].

A 46-year-old woman after renal transplantation 10 years ago underwent CABG using the right internal thoracic artery to LAD, the left internal thoracic artery to Circumflex and the right gastroepiploic artery to RCA, with the diagnosis of unstable angina (triple vessels disease) after failed PTCA. The postoperative course has been uneventful. To our knowledge, this is the first case who underwent GABG after renal transplantation in Japan.

Angina, Unstable↗
PubMed1993

[Treatment of myelodysplastic syndromes with cytokines].

To evaluate the effects of colony-stimulating factors (CSFs) on pathological cells from myelodysplastic syndromes (MDS), CD34-positive cell fractions (mainly blast cells) from nineteen MDS patients and four normal volunteers were successfully enriched by the use of immunomagnetic beads, and their responsiveness to CSFs was examined in short-term liquid suspension cultures. Considerable parts of blast cells from MDS patients remained immature as compared with the favorable maturation of normal blast cells, especially in high-risk MDS group that included two prominent cases with a remarkable blast cell growth without maturation induction by CSFs. Short-term clinical administrations of G-CSF often brought about hematological improvements on MDS patients. Other cytokines are also reported to be of use on some patients. However, a few cases progressed to overt leukemia in relation to G-CSF treatment. Much care should be taken with in vivo application of CSFs to high-risk MDS patients, although there may be no effective clue to foresee the risk of leukemic transformation yet.

Adult↗
PubMed1993

Action mechanism of idarubicin (4-demethoxydaunorubicin) as compared with daunorubicin in leukemic cells.

To characterize a new anthracycline agent, idarubicin (4-demethoxydaunorubicin) and to establish its reasonable and appropriate use in the chemotherapy of acute leukemia, we examined its mode of action and compared it with the results obtained for daunorubicin. Idarubicin was shown to have the characteristic features of the action mechanism of anthracyclines, such as having a strong binding capacity to DNA, in terms of frequency and efficiency and reducing the template activity of DNA by binding to DNA or inducing DNA strand breaks in leukemic cells and inhibiting the DNA polymerase reaction. Idarubicin was superior to daunorubicin in terms of intracellular accumulation and binding capacity to DNA, which may result in idarubicin having much stronger activity in inducing DNA strand breaks than daunorubicin. These excellent properties of idarubicin were considered to explain idarubicin having stronger antileukemic effects than daunorubicin. The efficacy of idarubicin in multidrug-resistant cells is also discussed.

Daunorubicin↗
PubMed1993

Epidural compression of the spinal cord caused by vertebral osteoblastic metastasis of prostate carcinoma. A case report.

A 71-year-old man with prostate cancer developed epidural compression of the spinal cord caused by bony protuberances expanding from a vertebral osteoblastic metastasis. Pathologic examination of the metastatic lesion showed that both tumor and thickened vertebral trabeculae broke through the cortex and formed bony protuberances. The periosteal new bone appeared not to arise from a reactive periosteum but from the tumor breaking through the cortex. A biologic interaction between the tumor and the host may be responsible for the rare periosteal new bone formation.

Adenocarcinoma↗