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Biomedical subjects

M Iwata

Publications and source records attributed to M Iwata.

At least 595 records · Page 33Linked to original sources
PubMed1982

Irradiation-induced changes in nuclear shape and cell cycle.

Using human uterine cervical carcinoma cells transplanted in nude mice and mice leukemia L5178Y cells, changes in the cell cycle following irradiation were observed by flow cytometry (FCM), and changes in the cell nuclei during the course of irradiation were measured by FCM. Experiments in vivo as well as in vitro caused accumulation of cells in the G2 to M populations, resulting in the so-called G2 block phenomenon as revealed by FCM analysis of DNA distributions. The radiation-induced changes of nuclear shapes were dependent on abnormal mitoses, which occurred more frequently in the G2 to M phases. Therefore it is suggested that the G2 block phenomenon plays an important role in radiation-induced cell death because the process of cell death by irradiation has been shown to proceed via these abnormal mitoses.

Animals↗
PubMed1981

Local therapy of carcinoma of the uterine cervix: part I.

One-hundred-fifteen patients with cervical cancer were treated by placing bleomycin, carbazilquinone (Carboquone), and 5-fluorouracil suppositories in contact with cancer lesions located in the vaginal portion of the uterus or by inserting them into the cervical canal, twice a week, one to 14 times. The cancer lesions disappeared form 17 to 33 patients with Stage 0 lesions and 9 of 42 with Stage IA lesions. The remaining lesions were principally found in the deep portion of the cervical glands and tended to decrease the more often the suppositories were applied. This led to the presumption that if this local therapy had been carried on longer it would have eradicated even the remaining lesions from the patients with Stage 0 and IA lesions. The optimal per administration dose of bleomycin appeared to be 30 mg. The use of Witepsol (Dynamit Nobel Aktiengesellschaft, F.R.G.) suppository base was accompanied by frequent adverse reactions to it, which hindered the local therapy from being repeated over long periods of time. An equal amount mixture of hydroxypropyl cellulose and carbomer (Carbopol 934) as the suppository base was accompanied by relatively less adverse reactions, which permitted the prolonged local therapy with the suppositories. A trace of bleomycin was also found in the ovaries, but it did not cause microscopically evident histologic changes, nor did it affect the menstrual cycle. If early cancer can be treated completely by local therapy, it will be useful for the younger patient with early cervical cancer.

Adolescent↗
PubMed1981

[An occupational health survey on dry cleaning workers (author's transl)].

In order ot clarify the working conditions and health of dry cleaning workers, we investigated dry cleaning workshops in C ward of Nagoya City. We had the responses from 52 (91%) workshops and 181 (97%) workers. 26 (50%) of the workshops used petroleum solvents, 23 (46%) perchloroethylene, two (4%) 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (R 113), and one (2%) petroleum solvent plus perchloroethylene. Average amounts of solvents consumed per workshop were 1280 kg/year of petroleum solvents, 1450 kg/year of perchloroethylene, and 275 kg/year of R 113. Average number of workers employed in 19 workshops per workshop was 3.6 persons (median 2.0), and the remaining 33(63%) workshops had no employee. The workers complained of strange smell, irritation of eyes, unsteady feeling of head at high rate during week. They also had the high rate of complaints of shoulder stiffness, fatigability, lumbago, and the percentages of them were higher in the workers using petroleum solvents than those in the workers using perchloroethylene. More detailed surveys were made in 13 workshops out of 52. In these cases, average working hours were 11.1 per day and average years of using solvents were 12.9 in workshops using petroleum solvents, 8.4 in those using perchloroethylene including 3.1 years of petroleum solvents. Relatively high concentrations of solvents were detected under the nose of the workers pulling clothes out of dry cleaning machines, near the clothes just pulled out, and about 30 cm above the clothes at brushing with solvents before putting them into the machines. Perchloroethylene leaked from the dry cleaning machine in a workshop. Amount of the total trichlorinated compounds (TTC) in the urine of the workers directly engaged in dry cleaning with perchloroethylene tended to be larger than those of the indirect workers. TTC in both groups, however, were significantly larger than those in the control and in the workers using petroleum solvents. RBC, Hb, an Ht of the female workers in the petroleum solvents workshops were lower than those in perchloroethylene workshops. Liver function tests showed that the average values in the workers directly engaged in dry cleaning with perchloreothylene were significantly larger than those in the indirect workers. A case of malignant lymphoma, a case of liver dysfunction and a case of diabetes mellitus were found among workers directly engaged in dry cleaning. Workers in the small-sized dry cleaning workshops would not be prevented from exposure to organic solvents without the further improvement of administrative guidance and cooperation of the makers of dry cleaning machines and solvents.

Adult↗
PubMed1981

[Acute toxicity of ketoprofen intrarectally administered in rats, with special reference to histopathological changes (author's transl)].

Acute toxicity was studied on Ketoprofen, one of the non-steroidal antiinflammatory analgesics, using SPF rats. Ketoprofen was intrarectally administered in three forms such as pure powder (KP), KP suspension in CMC solution (KP-CMC) and a mixture of KP with powdered basic materials of capsule (KP-T10). The results obtained were as follows:1. LD50 values of terms of KP were 84 mg/kg in male rats and 122 mg/kg in female rats when KP-CMC was administered intrarectally, and 117 mg/kg in male and 92 mg/kg in female when KP-T10 was administered intrarectally., while peroral administration of KP-CMC showed LD50 values of 68 mg/kg in males and 78 mg/kg in females in terms of KP. 2. Major toxic signs of KP were ulceration on small intestines and peritonitis. Degeneration of hepathocytes and decrease in thymus lymphocytes were also observed. 3. Minimum lethal dose of KP-T10 was slightly higher than that of KP-CMC.

Administration, Oral↗
PubMed1981

[Toxicological study on the anorectal irritation and systemic organ toxicity evoked by long-term intrarectal administration of ketoprofen in rabbits (author's transl)].

Ketoprofen (KP) was administered intrarectally and perorally to rabbits weighing approximately 3 kg of both sexes for a period of 13 weeks, in order to study the anorectal irritation and chronic systemic organ toxicity of KP which was capsulated with the soft T10 capsule for rectal administration and with a hard capsule for peroral administration. Doses of capsulated drugs for one animal were 9.0 mg and 4.5 mg in terms of KP. All animals treated by these dose levels survived without showing any abnormal symptoms. Intrarectal administration of KP-T10 did not produce any mucosal lesions in digestive tracts, while peroral administration of KP with hard capsule induced ulcers in cecum or anus, and congestion in small intestines in a small number of cases. No pathological change was recognized in organs except for digestive tracts in all cases by autopsy. From the above results, it can be seen that the suppository of KP capsulated by the soft T10 does not show any irritating effect on anorectal mucosa and has no toxic effect on all organs systemically. Then, a suppository of KP-T10 can be used more harmlessly than the peroral capsulated KP.

Anal Canal↗
PubMed1981

[When does the brain atrophy in Creutzfeldt-Jakob disease? (author's transl)].

Chronological changes of computerized tomography (CT) findings and clinical signs and symptoms were studied in 3 patients of Creutzfeldt-Jakob disease. CT revealed no brain atrophy in the stage when the patients showed frequent myoclonus and fell rapidly into the state of akinetic mutism. One autopsied case of this stage showed no macroscopical brain atrophy at all. Microscopical examination revealed extensive spongiform change in cerebral cortices (except for hippocampus), thalamus, basal ganglia, midbrain and a part of cerebellar cortex, but neuronal loss and gliosis were not severe. In other 2 cases conspicuous brain atrophy was noted in CT several months after this rapidly worsening period. Therefore when discussing pathological findings of Creutzfeldt-Jakob disease, we must consider when the patient died in the clinical course of this disorder.

Adult↗
PubMed1981

[Effects of verapamil on systolic time intervals and relaxation time in hypertrophic cardiomyopathy (author's transl)].

In order to determine the effect of verapamil, a calcium-channel blocking agent, on systolic performance and relaxation in hypertrophic cardiomyopathy (HCM), 12 patients with HCM and 10 normal subjects were studied. Echocardiograms, phonocardiograms, carotid pulses, and apex cardiograms were recorded simultaneously at the control state and 5, 10, and 15 min after intravenous injection of 10 mg of verapamil. After verapamil administration, heart rate was unchanged, while systolic blood pressure was slightly reduced in both groups. In normal subjects no significant changes were observed in systolic time intervals, such as ET, delta ET, PEP, delta PEP and PEP/ET, and mean VCF, except slightly prolonged delta ET after 5 min of the injection. The duration of isovolumic relaxation, (IIa-D) interval, taken as the period from the aortic valve closure (IIa) to the onset of mitral valve cusp separation and the time from IIa to the O point of the apex cardiogram, (IIa-O) interval, were 58 +/- 5 and 123 +/- 16 msec, respectively. The maximum velocity of the left ventricular posterior wall in early diastole (PWDV) was 128 +/- 10 mm/sec. These intervals and the velocity were not significantly changed after verapamil administration. In patients with HCM, ET and delta ET were unchanged, but PEP and delta PEP prolonged at 10 and 15 min after verapamil administration. PEP/ET was increased and mean VCF was reduced at 15 min after injection. In comparison with normal subjects, IIa-D interval and Ha-O interval were prolonged definitely at control, 92 +/- 21 and 190 +/- 28 msec, respectively. PWDV was slower than normal, 86 +/- 18 mm/sec at control. After verapamil, these intervals were shortened and PWDV fastened significantly. These results indicated that verapamil is regarded to have slight intrinsic negative inotropic action, suggesting the beneficial effect to reduce intraventricular pressure gradient, and also improve impaired myocardial relaxation in HCM.

Adult↗
PubMed1981

DNA radiosensitivity in carcinoma of the human cervix.

The radiosensitivity of DNA in human cervix carcinoma was examined by using alkaline sucrose gradient centrifugation to measure radiation-induced single-strand breaks. The DNA strand-break efficiencies observed in DNA of 18 specimens fell into two distinct groups, radiosensitive and radioresistant. The difference in DNA radiosensitivity may be correlated with the pathological classifications of the carcinomas.

Biopsy↗
PubMed1980

Potentiation of anti-aggregating activity of PGI2 by 7-ethoxycarbonyl-6,8-dimethyl-4-hydroxymethyl-1(2H)-phthalazinone (EG-626) in rabbit platelets in vitro.

Anti-aggregating activity of 7-ethoxycarbonyl-6,8-dimethyl-4-hydroxymethyl-1(2H)-phthalazinone (EG 626) was tested using rabbit platelets in vitro. EG-626 alone, when added before, prevented platelet aggregation induced by ADP, as did PGI2, papaverine and dipyridamole. Spontaneous disaggregation was also accelerated when EG-626 was added after the maximal aggregation induced by ADP. EG-626 alone also inhibited platelet aggregation induced by collagen and arachidonic acid. ID50s of these agents in ADP-induced aggregation were 7-9 nM for PGI2, 223 microM for EG-626, 266 microM for papaverine and 957 microM for dipyridamole. When EG-626 was used in combination with PGI2, a threshold dose (50 microM) of EG-626 potentiated the antiaggregation effect of subthreshold dose (3 nM) of PGI2 upto 100% inhibition in collagen-induced platelet aggregation. The marked potentiating effect of EG-626 was accompanied by an accumulation of cyclic AMP in the platelets. These effects might be due to inhibition of phosphodiesterase. Papaverine and dipyridamole, other phosphodiesterase inhibitors, also potentiated the anti-aggregating activity of PGI2. The activity of papaverine, however, was one eighth of EG-626 and that of dipyridamole was much less. The most effective combination of PGI2 and EG-626 to induce 50% inhibition was obtained with 20% of ID50 of each agent, whereas that of PGI2 and papaverine or dipyridamole was 39 or 41%, respectively.

Animals↗
PubMed1980

Ia requirement in T cell response to various mitogenic lectins.

Various lectins, mainly T cell mitogens, were examined to determine the relationship between anti-Ia antiserum-treated T cell responses and the sugar specificities of these lectins. Anti-Ia antiserum and complement treatment diminished nylon wook column-purified T cell responses to most lectins such as concanavalin A, Lens culinaris hemagglutinin, Pisum sativum agglutinin, Witaria floribunda mitogen, Limulus polyphemus agglutinin and pokeweed mitogen, and the diminished response to these lectins could be restored by adding nylon wool-adherent cells, whereas the same treatment rather enhanced their response to Phaseolus vulgaris phytohemagglutinin. We concluded that whether t cell responses to various lectins require Ia-bearing cells more or less is independent of the sugar-binding specificities of these lectins.

Animals↗