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Biomedical subjects

A Nishimura

Publications and source records attributed to A Nishimura.

At least 217 records · Page 12Linked to original sources
PubMed1987

Response of pancreatic tumor to intraoperative radiotherapy: medical imaging and pathologic system approach.

For analyzing the local reaction of pancreatic carcinoma to electron intraoperative radiotherapy, successive computed tomography scanning for tumor volumetry was employed, together with surgical clip localization for tumor area using orthogonal x-rays. Soon after radiotherapy the tumor volume and clipped tumor region began to decrease. After a certain interval, computed tomography volumetry revealed that the irradiated tumor had started to increase in size again, whereas the clipped area had not. Autopsies demonstrated that the increase related chiefly to cancer regrowth outside the primary radiation field.

Aged↗
PubMed1987

Radioprotective effects of thiomethylhydantoin derivatives on Escherichia coli and mice.

Protection of Escherichia coli NIHJ and C57BL mice from the effects of 60Co gamma-rays provided by S-alk(en)yl-L-cysteines and their hydantoin derivatives was examined. E. coli (10(6) cells/ml) suspended in a 20 mM aqueous solution of one of the drugs was irradiated with 60 Gy of gamma-rays. Five week-old male mice were exposed to 5.0-9.5 Gy of gamma-rays after a single intraperitoneal injection of 0.75 mmol/kg body weight of each compound. In both E. coli and mice, S-allyl compounds afforded more effective radioprotection than S-propyl compounds. The replacement of the alpha-hydrogen of S-substituted cysteines by methyl groups decreased the radioprotective effect. Hydantoin derivatives were much more radioprotective than the original sulfur-containing amino acids. Especially, DL-5-allylthiomethyl-5-methylhydantoin had a remarkable radioprotective effect in mice. The gamma-radiolysis mechanism of thiomethylhydantoin derivatives was discussed in connection with the radioprotective effect of the drugs.

Animals↗
PubMed1987

Prognostic significance of pancreatic tumor regression after intraoperative radiotherapy.

Tumor volume measurement using tumor-margin clipping radiography was performed for estimating tumor regression of eight pancreatic adenocarcinomas treated with intraoperative electron irradiation. Half of the tumors regressed exponentially from the first day of treatment, but the other half increased slightly within the first week, after which volume reduction occurred. The volume-halving time was calculated from the regression curve. A wide distribution of volume-halving times as well as initial tumor volumes was seen in all patients. No correlation was found between these variables, but the former correlated well with survival time (r2 = 0.80). This well-known technique may offer a chance to foresee the prognosis of the disease by determining the volume-halving time.

Adenocarcinoma↗
PubMed1987

[Study on the erroneous diagnosis of fine needle aspiration of breast cancer].

A histological examination of the breast tumors in 852 patients, after they had received fine needle aspiration, was performed. The false positive and false negative cases were then studied; 32 false positive and 15 false negative cases respectively. As causes for misunderstanding, five items were pointed out in the false positive cases and three in the false negative ones. There were 5 false positive cases in which cellatypia was remarkable, and 3 false negative cases whose cellatypia was not significant. Cytologic diagnosis by fine needle aspiration for these 8 patients was difficult.

Adult↗
PubMed1986

Indications for replacement of the Beall 103 and 104 disc valves.

Because of the unpredictable risk of failure of the Beall 103 and 104 valves, 29 patients who had such a valve implanted between 1969 and 1975 were identified in 1979 and studied to determine clinical status, degree of hemolysis, and valve function by cinefluoroscopy and echocardiography. Seven had valve replacement early after initial study because of cardiac symptoms or severe hemolysis or both. Of the 22 patients followed from January, 1980 to August, 1985, 13 experienced new symptoms or hemolysis, and had valve replacement. Serial observations over a mean of 2.8 years in patients with an isolated Beall valve eventually requiring operation for severe valve wear showed increasing hemolysis frequently concomitant with onset of cardiac symptoms. There were no perioperative deaths in 20 Beall valve replacements, which included 9 multiple valve operations. The mean interval to replacement for all patients was 8.5 years. When the only prosthetic valve was the Beall mitral valve, severe valve wear was associated with higher levels of lactate dehydrogenase (LDH) (1,117 +/- 67 IU [+/- standard error]) than those with mild or moderate valve wear at reoperation (LDH, 565 +/- 68 IU; p less than 0.01). Cinefluoroscopy identified abnormal disc motion in 3 patients, all with clinical deterioration; all patients with disc to cage ratios of 0.90 or less had severe valve wear, but more patients with severe wear had normal ratios. Cardiac catheterization frequently did not show major abnormalities. The onset of new cardiac symptoms or evidence of increasing hemolysis from serial serum LDH determinations or evidence of abnormal disc size or motion by cinefluoroscopy indicate a high probability of severe Beall valve wear.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Surgical treatment for carcinoma at the confluence of the major hepatic ducts.

During the period of November 1976 through October 1984, we have treated 46 patients with carcinoma at the confluence of the major hepatic ducts. Curative resection of the tumor (where no carcinoma cells at the margin of the resected portion were found macroscopically and microscopially), was performed upon ten patients, palliative resections were done in 11, palliative resection and intraoperative radiotherapy (IOR) in ten, bile duct drainage and IOR in three, and percutaneous transhepatic cholangiodrainage in 12. Among the ten patients who underwent curative operation, five are living six to 104 months after operation while the remaining five died four to 72 months postoperatively. Of the 11 patients who underwent palliative resection, five are alive two to 22 months after operation and six died between four and 20 months after operation. For the ten patients with carcinoma in the advanced stages, palliative resection with IOR was performed. Eight patients died 20 days to 16 months after operation while two patients are alive 13 and 14 months after the procedure. Of the three patients who underwent drainage of the bile duct and IOR, two died three months after operation and one patient survived 34 months. Twelve patients underwent drainage of the bile duct only and all died after 13 months. To perform a curative operation for carcinoma located at the confluence of major hepatic ducts, it is necessary to resect the right or left lobe, including the caudate lobe, in many instances. For the patients with carcinoma in the advanced stages, the possibility of long term survival period after operation exists through the use of the combined techniques of IOR and palliative resection of the tumor.

Adult↗
PubMed1984

Intraoperative radiotherapy for advanced carcinoma of the pancreas.

A detailed retrospective analysis of the efficacy of intraoperative radiotherapy (IOR) in advanced carcinoma of the pancreas is presented. During a 10-year period from 1973 through 1982, 70 patients with advanced carcinoma of the pancreas were treated by multimodal methods, separate or combined therapy of surgery, IOR, and chemotherapy in two different institutions. Among these, 33 patients underwent IOR, mostly combined with additive surgery. A single dose of 20.1 to 40.0 Gy with 8 to 25 meV electrons was delivered through radiation cones ranging from 6 to 10 cm in diameter. Excellent relief was noticed in 50% of the patients who had complained of pain. Among Stage IV patients, a significant difference of survival rate was observed between IOR and control groups (P less than 0.05); the mean survival time of the IOR group was 4.6 +/- 2.6 (SD) and that of the control group 2.5 +/- 1.4 (SD) months. Intraoperative radiotherapy proved to be effective in prolonging the survival of patients with advanced stage of the lesion.

Adult↗
PubMed1982

[FT-207 maintenance therapy of malignant gynecologic cancer].

Maintenance treatment with FT-207 was applied to 92 patients with uterine cancers after initial treatments were performed. Daily dosage of FT-207 was either 600 or 800 mg and the drug was administered orally. The duration of 6 months and the total dosage of 100 g were proposed as administration schedule and 34 patients (37%) received this regimen. Side effects during the treatment were observed in 35 cases (38%). Gastrointestinal disturbance was most frequently observed and other side effects included myelosuppression, general fatigue, hepatic dysfunction and skin toxicities. There were no serious side effects, the treatment was continued in most patients and was interrupted only in 7 cases (8%). In the cases of recurrence or advanced cancer, however, the side effect was the predominant cause for interruption of administration. As for the antitumor effect of the treatment, a survival rate of the patients with cervical cancer of early stages was evaluated. Three-year survival rate in the treatment group was higher comparing to the one reported hitherto.

Antineoplastic Agents↗
PubMed1982

[Toxic effects of prolonged oral administration of tegafur (FT-207)].

FT-207 capsules and enteric coated capsules were administered for the chemotherapy of various cancer patients. Twenty-three cases of cancer patients were treated with FT-207 alone orally more than 52 weeks up to 199 weeks continuously with daily dose of 600-800mg with capsules, and 600-1200mg with enteric coated capsules, except one case with markedly light body weight (28kg). There were 3 breast, 1 colon, 1 duodenal, 1 ovary, 11 stomach, 4 hepatic duct, 1 pancreas and 1 double cancer with colon and uterus. Special attention was given to the bone marrow, hepatic, renal, pulmonary and cardiac impairment. There was a mild hepatic enzyme derangement in some cases, but clinically not serious. No meaningful bone marrow, renal, pulmonary or cardiac side reactions were observed. This study confirmed that continuous prolonged oral FT-207 administration was well tolerated and no serious side reactions were observed. However, this was not a controlled study, so that it is still advisable to give oral FT-207 under periodic check up including CBC, SMA-12, chest X-ray and EKG controls.

Administration, Oral↗
PubMed1981

Effect of phosphate concentration on the kinetics of bovine liver glutamate dehydrogenase self-association.

The kinetics of the self-association of bovine liver glutamate dehydrogenase was studied at various phosphate buffer concentrations (pH 7.3) at 11.5 degrees C by means of the temperature-jump technique with scattered light detection. The observed relaxation times were well explained by the random association model of Thusius et al. With increasing phosphate concentration, the association rate constant derived from the model decreased, while the dissociation rate constant was left almost constant. Relaxation amplitude was also dependent on the phosphate concentration. The changes in the rate constant and relaxation amplitude with phosphate concentration are well elucidated by assuming that glutamate dehydrogenase is protected from association by specific masking of the association site by phosphate ions.

Animals↗