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Biomedical subjects

T Kitagawa

Publications and source records attributed to T Kitagawa.

At least 289 records · Page 16Linked to original sources
PubMed1993

Balloon pulmonary valvuloplasty for infants with severe tetralogy of Fallot.

Balloon pulmonary valvuloplasty was performed in 3 infants with severe tetralogy of Fallot at days 24, 54 and 86 because of progressive hypoxemia. In two patients, the balloon catheter (4 cm long, 5-8 mm diameter) could not pass through the pulmonary valve. This necessitated a smaller balloon and required a two-step procedure. Initially, a coronary artery balloon (2 cm long, 3.5 mm diameter) was used. Following balloon valvuloplasty, arterial oxygen saturation increased from 63 to 83% in case 1, from 69 to 85% in case 2 and 63 to 86% in case 3. Immediate postvalvuloplasty right ventricular cineangiography revealed that the maximal opening diameter of the pulmonary valve leaflets increased from 1-2 mm to 3-4 mm in cases 1 and 3, and from 2-3 mm to 4-5 mm in case 2. No significant complications occurred. Echocardiographic follow-up data showed that the diameter of the right ventricular outflow tract and pulmonary arteries increased with age. The present results show that the pulmonary valvuloplasty is an effective procedure for relief of pulmonary valve stenosis in tetralogy of Fallot and to improve oxygenation and growth of the pulmonary arteries and right ventricular outflow tract without the need of an immediate aortopulmonary shunt.

Cardiac Catheterization↗
PubMed1993

Possible association of p53 overexpression and mutation with high-grade chondrosarcoma.

Overexpression and point mutation of the p53 protein/gene was investigated in a series of chondrosarcoma by an immunohistochemical approach, and direct sequencing of the genomic DNA, respectively. In 2 of the 16 cases studied, both of which were high grade chondrosarcomas (grade III), immunodetectable p53 was identified. Histologically, one was ordinary type and the other a clear cell variant. However, no positivity was observed in the other cases including nine of low grade, ordinary type, three of low grade, clear cell type, and two of extraskeletal myxoid chondrosarcoma. Direct sequencing, following polymerase chain reaction amplification of exons 5-9 of the p53 gene in 14 cases, in which fresh materials were available, successfully demonstrated base substitution mutations in only two cases with detectable p53 overexpression on immunohistochemistry. Their details were GTC (valine) to TTC (phenylalanine) at codon 157 in exon 5, and CGT (arginine) to CAT (histidine) at codon 273 in exon 8. No mutation was detected in the other 12 cases which were negative for p53 immunostaining. These findings strongly suggest that p53 mutation plays a crucial role in the biologically aggressive subtype, and possibly in the process of tumor progression in human chondrosarcoma.

Adult↗
PubMed1993

[Lymphedema].

Explore the source record for details and available documents.

Humans↗
PubMed1993

Health-risk appraisal applied to ordinary AMHTS.

The main purpose of an automatic health testing system (AMHTS) has changed from early detection to primary prevention. Health-risk appraisal is now widely available as a tool of health education aiming at the modification of unhealthy lifestyles. However, the opportunity to offer appropriate health education was less frequent for those who had no particular findings during AMHTS. The results of an AMHTS should be evaluated from the viewpoint of health-risk appraisal, because the system is expected to supply useful information regarding one's lifestyle. Our system consists of two health-risk appraisal subsystems. One subsystem estimates the degree of improvement in medical indicators after a patient's lifestyle has been modified. The other subsystem predicts the occurrence of abnormal findings in medical indicators. These health-risk appraisal subsystems provide patients with information about their health-risks, based on their AMHTS results. Our health-risk appraisal subsystems should play an important role in future health education through the application of ordinary AMHTS.

Health Education↗
PubMed1993

Systemic deposits of thorium in thorotrast patients with particular reference to sites of minor storage.

It is well established that injected Thorotrast is deposited in the liver, spleen, bone marrow, and lymph nodes, but accumulations in organs with lower macrophage activity have previously been given little attention. In this work, neutron activation analysis has been used to investigate concentrations of thorium in autopsy samples taken at sites of major and minor deposition in 24 Thorotrast patients. In the latter category, the highest values were found in the testis [40 x 10(-6) g/g(wet)], followed by those in the adrenal gland, gallbladder, lung, and pancreas. The resulting alpha-particle dose rates (mGy/year) are tentatively estimated to be 8.5 to the testis, 5.5 to the gallbladder, and 5.3 to the lung. These results may be relevant to the residual excess mortality among Thorotrast patients after diseases of the principal organs of deposition have been excluded; they also support previous indications that thorium deposited in pulmonary tissues is responsible for an important component of the total dose to the lung. In another context, our data may bear on the connection, postulated elsewhere, between exposure to alpha-particle emitters and elevated incidence of leukemia in the children of workers engaged in the reprocessing of nuclear fuel.

Adult↗
PubMed1993

[Hepatocarcinogenesis in terms of HGF and its receptor].

Hepatocyte growth factor (HGF) is a highly potent growth stimulator of hepatocytes and c-met proto-oncogene has recently been identified as its high-affinity receptor. Since the c-met gene expression is found in many types of cells, carcinogenic and/or transforming activity through autocline or paracline mechanism of HGF-c-met/HGFR system has become point of interest. By transfecting HGF into a unique immortalized mouse hepatocytes (MLE-10), which expresses c-met at high level, we were able to first demonstrate transforming activity of HGF by autocline mechanism.

Animals↗
PubMed1993

Hepatocyte growth factor transforms immortalized mouse liver epithelial cells.

Transforming activity of hepatocyte growth factor (HGF) was demonstrated utilizing immortalized but not fully transformed mouse hepatocytes (MLE-10). Rat HGF cDNA, expressed under the control of a cytomegalovirus promoter, was transfected together with the neomycin resistance gene (PSV2neo) into MLE-10 cells by the calcium phosphate method, and propagated G418-resistant colonies were harvested colony by colony. After checking for integration and expression of exogenous HGF, five cell lines (MLE-10-HGF-1-5) were established. Three cell lines transfected with the vector only (MLE-10-CMV-1-3) were also established in the same manner. All MLE-10-HGF cell lines grew much faster than the MLE-10-CMV and original MLE-10 cells in culture and produced large colonies in soft agar, which colony production was blocked by the addition of anti-HGF antibody to the agar. After addition of HGF, original and MLE-10-CMV lines produced colonies in soft agar. The high-HGF-production lines (MLE-10-HGF-4 and -5) also gave rise to tumors within 2 weeks when implanted into the nude mice subcutis. In contrast, all MLE-10-CMV and original MLE-10 cells were negative in these growth assays. A rough parallelism between the level of HGF expression and the growth rate in both soft agar and nude mice subcutis was evident among MLE-10-HGF cell lines. Those with higher HGF production tended to grow in a scattered fashion in culture. High-affinity HGF receptor, HGFR/met, was expressed in MLE-10 and all the derived cell lines. Since HGF and/or HGFR/met gene expression is seen in various tumors and the serum HGF level is elevated in patients with hepatic disease, the present results indicate a possible significance of HGF and its receptor system in carcinogenesis, most probably via autocrine and/or paracrine mechanisms.

Animals↗
PubMed1993

[Multidisciplinary treatment of advanced invasive thymoma].

From February 1988 to September 1992, six patients with Stage III or IV invasive thymoma were enrolled onto our study of multidisciplinary treatment, which included chemotherapy, surgery, and radiotherapy. The chemotherapy consisted of cisplatin (20 mg/m2 continuous 24-hour infusion on days 1 through 4), doxorubicin (40 mg/m2 on day 1), and methylprednisolone (1,000 mg on days 1 through 4 and 500 mg days 5 and 6). Two patients received surgery (incomplete resection) and postoperative chemo/radiotherapy, and four patients received induction chemotherapy followed by surgery and chemo/radiotherapy. All patients with induction chemotherapy showed a partial response and underwent complete (n = 2) or partial (n = 2) resection. Four patients are alive with no evidence of disease for 31 to 55 months after the diagnoses. But two with partial resection after chemotherapy died of recurrent disease. Multidisciplinary treatment including chemotherapy may be a new therapeutic choice in management of advanced invasive thymoma.

Adult↗
PubMed1993

[Arteriosclerosis obliterans that was improved by LDL apheresis].

We reported here a case of arteriosclerosis obliterans (ASO) in which clinical symptoms and signs were improved after repeated LDL apheresis. The patient was a 70-year-old man who was diagnosed as having ASO in 1989. Although drug treatment started for the arterial disease, such clinical manifestations as rubor and intermittent claudication were gradually worsening. In 1991, the patient was also found to have diabetes mellitus (DM), leading to admission for its treatment. Insulin therapy was initially required, but it finally became possible to maintain a good control of DM with diet therapy alone. Since hypercholesterolemia (402 mg/dl) was noted on admission, we began to give the patient pravastatin. In response to the medication, serum total cholesterol (TC) levels declined to 270 mg/dl, but no further improvement was obtained. We therefore decided to perform LDL apheresis on the patient, hoping the improvement of both ASO and hypercholesterolemia. After six series of LDL apheresis were performed during 4 weeks, ASO-related signs and symptoms (i. e., intermittent claudication) were remarkably improved, and serum TC levels were decreased below 200 mg/dl. Our experience in the present case suggested that this procedure would be useful as an effective choice of treatment for ASO, but further studies as to the indication and protocol of this therapeutic maneuver will be clearly needed.

Aged↗
PubMed1993

[A case of pseudoaneurysm of the thoracic aorta with Behçet's disease].

A 54-year-old female with incomplete type of Behçet's disease was operated on because of impending rupture of the thoracic aneurysm. There was a saccular pseudoaneurysm below the left subclavian artery, and a punched out lesion of the aorta was recognized. The defect of the aortic wall was closed with a PTFE patch. Before and after the operation, we have given prednisolone. The postoperative course was uneventful. Two years later, there was no recurrence of pseudoaneurysm near the PTFE patch. In many reports, aneurysms of Behçet's disease are saccular pseudoaneurysms, and have high incidence of complications about anastomosis postoperatively. We need a further follow-up about this patient.

Aortic Aneurysm, Thoracic↗
PubMed1993

[Cardioprotective effect of cromakalim, a K+ channel opener, on isolated globally ischemic and reperfused rat hearts].

Examination was made of cardioprotective effect related to the ATP-sensitive K+ (KATP) channel on isolated globally ischemic reperfused rat hearts using cromakalim, a putative ATP-sensitive K+ channel opener. The hearts were subjected to 20 min Langendorff perfusion with Krebs Henseleit Bicarbonate Buffer (KHBB) (70 cmH2O, 37 degrees C), followed by 30 min ischemia at 36 degrees C, and 30 min reperfusion with KHBB, with (cromakalim group) or without (control group) pretreatment by 10 microM cromakalim added to KHBB for 5 min prior to ischemia. Before ischemia, no significant change in heart rate (HR), left ventricular developed pressure (LVDP) or coronary flow (CF) by 10 microM cromakalim could be detected. The two groups were the same in CF during reperfusion, but recovery of HR and LVDP significantly improved in the cromakalim group. Creatine kinase (CK) leakage in the cromakalim group was significantly less than in the control group during reperfusion. Cromakalim is thus shown to reduce the myocardial injury during ischemia and reperfusion. Intracellular Ca2+ content of the cromakalim group appeared lower than that of the control group at 30 min of reperfusion. At 5-30 min of reperfusion, in the cromakalim group, intracellular Ca2+ storage was prevented, leading to a good recovery of cardiac function, while in the control group, intracellular Ca2+ increased and recovery of cardiac function was poor. After pretreatment with 10 microM cromakalim, intracellular K+ content of the cromakalim group was significantly lower than in the control group before ischemia. At 5 min of reperfusion, intracellular K+ content of the cromakalim group was slightly less than that of the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Clonal growth of hepatitis B virus-integrated hepatocytes in cirrhotic liver nodules.

A total of 83 cirrhotic nodules (pseudolobules) individually collected from 11 cirrhotic livers of hepatitis B virus carrier patient were analyzed for the frequency and mode of hepatitis B virus integration as well as histological features. Southern blot analysis disclosed discrete bands at higher molecular weight region in 26 of 83 nodules (31.3%), indicating a clonal growth of hepatocytes with viral integration. Considerable variation (0-75%) existed in the positive rates for discrete bands in nodules among livers. Molecular cloning revealed the sequence flanking an integrated viral sequence to be host DNA and thus confirmed true integration. Histological analysis, however, did not reveal any neoplastic-appearing foci of growth within nodules, despite the fact that the detection sensitivity would predict clones of more than 10(5) cells to give rise to clonal integration patterns on Southern blot analysis. The question of whether clonal expansion of hepatocytes reflects any viral integration-associated growth advantage and/or a preneoplastic condition awaits future studies.

Adult↗
PubMed1992

Capillary gas chromatographic method for the determination of the thromboxane A2 receptor antagonist S-1452 and its metabolites in human plasma.

A capillary gas chromatographic method for the determination of a newly developed thromboxane A2 antagonist, S-1452, and its metabolites in human plasma has been developed. This nitrogenous compound was detected as the free acid (+)-S-145 using a nitrogen-phosphorus detector. The two metabolites bisnor-(+)-S-145 and tetranor-(+)-145 were also assayed. The three compounds, which all possess carboxylic acid group, were converted into their hexafluoro-2-propyl esters with hexafluoropropan-2-ol-pentafluoropropionic anhydride as reagent. The esterification resulted in a decreased background response from the detector, and hence higher sensitivity and better precision. The glucuronides of the three compounds were also assayed after alkaline hydrolysis. The plasma concentration of the glucuronide of I was more than twice that of the free acid. This method allows determination of the three compounds at more than 2 ng/ml with a precision of 2-6% and an accuracy variation of less than +/- 5%. The analysis was performed within 2 min after injection to assay the sample rapidly from the Phase I test. The method is suitable for pharmacokinetic studies.

Bridged Bicyclo Compounds↗
PubMed1992

Capillary gas chromatographic method for the determination of the thromboxane A2 receptor antagonist S-1452 and its metabolites in human urine.

A capillary gas chromatographic method using a sulphur-specific detector (Hall's electrolytic conductivity detector) was established to determine the thromboxane A2 antagonist S-1452 and its metabolites in human urine. The target species were the free acid (+)-S-145 of the drug and its nine metabolites: the three hydroxyl forms of (+)-S-145 (I, II and III), bis-nor-(+)-S-145 (IV) the hydroxylated forms of IV (V and VI), tetranor-(+)-S-145 (VII) and the hydroxylated forms of VII (VIII and IX). These ten compounds, which have the same sulphur-containing functional group in common, were determined simultaneously. Their conjugated forms, which were assumed to be glucuronides, were also assayed after hydrolysis. The first derivatization was esterification with diazomethane. The second, for the hydroxylated compounds, was trimethylsilylation with bis(trimethylsilyl)trifluoroacetamide. The ten analytes appeared as separate peaks without mutual interference during 5 min. Hall's detector distinguished the ten analytes selectively from the other urinary components, which removed the need for complex clean-up procedures and led to higher sensitivity with a lower noise level. The method is sensitive enough for the assay of substances present at more than 0.1 micrograms/ml of urine. All the compounds could be determined with a high level of precision and accuracy, with 2-5% relative standard deviation and within +/- 5% deviation from the actual value. Day-to-day measurements verified the reproducibility of the method. Recovered substances were quantified by following the time course, and the analytical data together with previously obtained plasma data clarified the metabolism pharmacokinetically.

Bridged Bicyclo Compounds↗
PubMed1992

[MR angiography of the lung using 3-dimensional imaging method].

Three-Dimensional MR angiography (3D-MRA) of the lung was performed in 5 healthy volunteers and 14 patients with primary pulmonary cancer in the hilum, and compared with 2D-MRA. As 3D-MRA could be obtained with single breath holding after intravenous bolus injection of Gd-DTPA, pulmonary vessels of the hilum and peripheral zone were demonstrated more definitely than those of 2D-MRA. In all patients except one case, the relation between the tumor and pulmonary vessels was visualized more clearly by 3D-MRA than 2D-MRA. This technique is considered a non-invasive and effective method for evaluation of pulmonary vessels in the patient with hilar tumor.

Humans↗
PubMed1992

Lung cancers associated with thorotrast exposure: high incidence of small-cell carcinoma and implications for estimation of radon risk.

The widely accepted concept that the alpha-emitting radionuclide radon (222Rn, 220Rn) induces lung cancers in humans has been based on the excess of lung tumours observed in underground miners extracting uranium or other substances. However, this poses the important question of whether radon is the only carcinogenic factor because such miners are also heavily exposed to mine dusts including silicates, diesel exhaust, etc. in their working environment. Patients to whom Thorotrast was administered continuously exhale radon (220Rn) derived from 232Th deposits in the body and therefore provide a good model for lung carcinogenesis by radon without concomitant dust exposure. We therefore investigated lung-cancer incidence in our epidemiological follow-up series, analysing the histological types of 11 lung cancers which were found among 359 Thorotrast autopsy cases and measuring radioactivity in the breath of living Thorotrast patients. The study revealed that, while the proportion of small-cell lung cancers considered to be related to alpha-particles was significantly increased, the overall lung cancer incidence was not significantly higher than in controls, in spite of the high level of 220Rn in the patients' breath. This result suggests that radon in the lung does induce cancers (particularly small-cell carcinomas) but that the induction rate is not as high as expected from risk factors associated with mining. Thus, excess lung cancers among the miners might be related to the combined effects of exposure to radon and mine dusts, and not solely to radon.

Aged↗
PubMed1992

Resonance Raman study on the active-site structure of a cooperative hemerythrin.

Resonance Raman spectra were observed for the oxy and azidomet forms of a cooperative hemerythrin (Hr) isolated from Lingula unguis and a noncooperative Hr from Siphonosoma cumanense. The O-O stretching frequency of the oxy derivative of the L. unguis Hr was lower in the high-affinity form generated at pH 7.6 than in the low-affinity form generated at pH 6.2, while that of the S. cumanense Hr did not change at those two pH values. The Fe-O-Fe symmetric stretching mode of L. unguis azidomet-Hr exhibited a frequency shift between pH 7.6 and 6.2, while that of S. cumanense was not shifted. However, the corresponding band of the oxy form did not show a pH-dependent frequency change. Therefore, it is noted that the azidomet form is not a suitable model for studying a mechanism of cooperativity, contrary to the structural similarity between the oxy and azidomet forms. The Fe-O2 as well as Fe-N3 stretching frequencies were found to have no relation with the oxygen affinity. Upon exchange of solvent from H2O to D2O, the O-O and Fe-O2 stretching modes of L. unguis Hr were shifted to higher and lower frequencies, respectively, and their magnitudes were the same for the high- and low-affinity forms. The same frequency shifts were observed for S. cumanense Hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗