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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 739 records · Page 41Linked to original sources

[Treatment of brain tumors with anticancer pellet--experimental and clinical study (author's transl)].

Eighty three patients suffering from brain tumors have been treated by anticancer pellets containing 5-FU, urokinase, mitomycin and BUdR in dimethylsiloxan (Silastic) for three years. Constant and prolonged release of the chemicals from the anticancer pellet had already been proved in vitro. The amount of daily release were 1-3/1,000 of original volume. Tissue concentration of 5-FU was measured by bioassay system using staphylococcus 209 P strain with plate dilution method. In spite of the rapid disappearance of serum 5-FU, the local high accumulation of 5-FU was demonstrated in vivo. In rat neurogenic tumor, 1.104 microgram/g was detected on 60 days after the application of anticancer pellet containing 500 mg of 5-FU. The growth of tumor was also suppressed. The clinical study consists of 83 patients, 30 of glioblastoma, 19 of metastatic brain tumor, 13 of astrocytoma, 7 of oligodendroglioma, 4 of ependymoblastoma, 4 of malignant lymphoma and 6 of others. The median survival time of gliblastoma was prolonged to 71.5 weeks by the implantation of anticancer pellet from 40 weeks of control group. However, the median survival time of astrocytoma and metastatic brain tumor were 24 and 6 months, respectively, which have no significant difference from control groups. In the patients of metastatic brain tumor, the regrowth of metastatic foci in the brain was completely suppressed. However, most of them were succumbed from the original tumors. The concentration of 5-FU in several human tissue was measured in ten patients with different time intervals after the implantation of the anticancer pellet. Although they have different histologic patterns, the concentrations of 5-FU in human brain tumors were ranged from 0.05 to 0.67 microgram/g by 14 months after the implantation of the anticancer pellet. The adjacent cystic fluids also contain from 0.62 to 4.9 microgram/ml of 5-FU for two years. These results mean that they are keeping higher level of 5-FU than the tumoricidal level of 5-FU (0.056 microgram/g) for more than two years. On the other hand, no respective accumulation was demonstrated in other tissues. None of the patients showed any adverse reactions except a continuous slight fever up to 38 degrees C.

Adult↗

[Clinical evaluation of artificial blood substitute (fluosol-DA 20%) in patients of cerebral ischemia].

The efficacy of perfluorochemicals (Fluosol-DA 20%) as an erythrocyte substitute and the changes of regional cerebral blood flow (r-CBF) following the administration of Fluosol-DA were studied. Seventy-three patients suffering from cerebral ischemic diseases were treated by 10 m/kg of Fluosol-DA. Intravenous infusions were performed 126 times. Clinical efficacy could be estimated by neurological signs, r-CBF and EEG findings in 53 patients who were in acute or subacute stage of diseases. These patients were classified into three groups; 1) Vasospasm group consists of 21 patients and 43 times of infusion, 2) Stenosis or occlusion group consists of 21 patients and 29 times of infusion, and 3) Others. Improvement occurred in 65.1% and 65.5% of vasospasm, and occlusion group, respectively. No aggravated case was noted. One out of 126 infusions showed an exanthema. Changes of r-CBF was measured in 20 cases on 32 hemispheres by either inhalation or intra-arterial infection of 133Xenon. r-CBF was increased 25.0% after the administration of Fluosol-DA when measured by intraarterial injection of 133Xenon. The increase of 16.9% in r-CBF was found in 11 cases by the inhalation method. These values were well correlated with that of animal study using monkeys measured by hydrogen clearance method. From the comparison of the effect of Fluosol-DA and Hespander on r-CBF, the mechanism of increased r-CBF by Fluosol-DA 20%, which contains 2.9% of hydroxyethyl-starch, was considered to be not solely due to the lowering of blood viscosities but also due to the dilating effect on cerebral vessels.

Adolescent↗

Studies on chronic herpetic keratitis--estimation of virus-harboring ganglion cells.

The reservoir site of herpes simplex virus (HSV) during the chronic phase of herpetic keratitis was confined to the trigeminal ganglion. Other ocular tissues, the cerebrum and the cerebellum were also examined and not found positive for the isolation of HSV by cocultivation with green monkey kidney cells 28-224 days after infection. The percentage of virus-harboring trigeminal ganglionic cells was estimated by determining the number of dispersed ganglionic cells needed to produce cytopathology of HSV on 50% of Vero cell monolayers. The percentage of infected ganglionic cells were calculated to range from 0.5% to 0.3% during this chronic period.

Animals↗

Seroepidemiologic studies of acute hemorrhagic conjunctivitis virus (enterovirus type 70) in West Africa. I. Studies with human sera from Ghana collected eight years after the first outbreak.

In 1969 and early 1970, during the pre-epidemic period of acute hemorrhagic conjunctivitis (AHC) in the upper north regions of Ghana, 191 human sera were collected. In 1977, eight years after the first epidemic of AHC in Ghana, 1008 human sera were also collected in various regions of Ghana. These sera were examined for virus neutralizing (VN) antibody against the J670/71 strain of enterovirus type 70 (EV70). In the pre-epidemic 1969-1970 sera, a low prevalence rate (6%) of VN antibody, with a titer of greater than or equal to 1:8, was found; the geometric mean titer (GMT) was also very low (1:1.85). In the post-epidemic 1977 sera, a high prevalence rate (53%) of VN antibody was found in the Ghanaian population, and the calculated GMT was also high (1:7.36). A higher antibody prevalence was detected in coastal (Accra: prevalence rate of 58% and GMT of (1:7.84), forest (Kumasi: 58% and GMT 1:7.52) and peri-forest (Tamale: 51% and GMT 1:7.46) areas than in the tropical savanna area (Bolgatanga: 41% and GMT 1:5.13). The demonstration of VN antibody in children under seven years of age showed that EV70 was still widely distributed and highly active in Ghana. The VN antibody found in human sera was predominantly IgG.

Adolescent↗

Seroepidemiologic studies of acute hemorrhagic conjunctivitis virus (enterovirus type 70) in West Africa. II. Studies with human sera collected in West African countries other than Ghana.

Human sera were collected in Senegal, Nigeria, Ivory Coast, Dahomey, Liberia, Gabon and Togo during the pre-epidemic period of acute hemorrhagic conjunctivitis (AHC) from 1965 to 1969, and tested for virus neutralizing (VN) antibody to enterovirus type 70 (EV70). Of these, 1109 (91%) were antibody negative (less than equal to 1:4), 116 (9%) neutralized at a dilution of 1:8 or over, and 45 (4%) at dilutions of at least 1:16. The distribution pattern is not significantly different from that of sera collected from Kenya in 1967 or from army recruits in the United States, Argentina, Brazil and Colombia in the 1960s. Sera collected during the post-epidemic period (1970 to 1977) in Senegal, Sierra Leone, Mali, Upper Volta, Chad, Niger and Gabon were also examined; 1573 (68%) were VN antibody negative (less than or equal to 1:4), while 733 (32%) and 433 (19%) had titers of 1:8 or greater and 1:16 or over, respectively. There is a significant difference in distribution between pre- and post-epidemic antibody titers (p less than 0.001), although the incidence of AHC was lower in these countries than in Ghana and Southeast Asia. The prevalence of VN antibodies tends to be lower in the dry, hot inland areas and thus humid coastal monsoonal climates and dense populations seem to favor the spread of AHC.

Adolescent↗

Angiographic changes associated with recurrent reduction of carotid and cerebral blood flow in dogs, with special reference to transient focal cerebral ischemic attacks.

Morphological changes associated with recurrent reduction of blood flow in the partially constricted common carotid artery and that in the ipsilateral cerebrum were examined angiographically in anesthetized beagle dogs. During the recurrent reductions of carotid flow, spasm and small and multiple defects indicating platelet aggregates or thrombi in the constricted carotid segment were observed in 8 and 5 of 20 preparations, respectively. Also, large defects indicating thrombi were observed at the outlet of the constricted segment in the other 2 preparations. During the reduction of cerebral flow, spasm was observed in the internal carotid artery and cerebral arteries in 9 and 8 preparations, respectively. Also, obstruction of the cerebral arteries with "cut-off" sign indicating emboli was observed in the other 2 preparations. The changes appeared singly or in combination. It is suggested that spasm, platelet aggregates, thrombi and/or emboli were responsible for the recurrent reduction of carotid and cerebral blood flow.

Animals↗

Long-term clinical effect of calcium inhibitors in hypertrophic cardiomyopathy compared to the effect of beta-blocking agents. A preliminary report with special reference to the beneficial effect of nifedipine on angina pectoris.

Long-term clinical effects of beta-blockers (propranolol in most cases) and calcium inhibitors (nifedipine in most cases) were studied in 16 patients with hypertrophic cardiomyopathy. On overall subjective symptoms, beta-blockers were effective in 50% of symptomatic patients, while calcium inhibitors were effective in only 33%. On angina pectoris, however, calcium inhibitors were superior to beta-blockers in our patients. Blood pressure decreased with each drug, and the decrease was significant with nifedipine. Otherwise there was no change in physical findings with either drug. Long-term (more than 6 months) use of beta-blockers resulted in an increase in cardiothoracic ratio on chest X-ray, a decrease in left ventricular ejection fraction on echocardiogram and more pronounced ST-T change on electrocardiogram. Prolonged use of nifedipine resulted in a slight decrease in cardiothoracic ratio, but no systematic change on echocardiogram and on electrocardiogram.

Adrenergic beta-Antagonists↗

Effects of thromboxane synthetase inhibitors on cyclical reduction of coronary blood flow in dogs.

Effects of new inhibitors of thromboxane synthetase, (E)-3-([1-imidazolmethyl) phenyl]-2-propenoic acid and (E)-3-[4-(pyridylmethyl) phenyl]-2-methyl-2-propenoic acid on cyclical reduction of flow in the partially constricted coronary artery were examined in anesthetized beagle dogs. Intravenous injections of both agents with a dose of 20 mg/Kg eliminated the cyclical reduction induced by constriction in the majority of experiments. However, they failed to eliminate the cyclical reduction induced by indomethacin. Indomethacin-induced reduction was eliminated by prostaglandin I2 in all experiments. It is suggested that thromboxane A2 acted as an accelerator in the cyclical reduction of coronary flow induced by coronary constriction, but did not in the reduction induced by indomethacin.

Acrylates↗

Abnormalities in the contact activation through factor XII in Fujiwara trait: a deficiency in both high and low molecular weight kininogens with low level of prekallikrein.

Fujiwara trait, the first case of kininogen deficiency in Japan previously reported which did not show any clinical symptom except the prolonged activated partial thromboplastin time was further examined. The activated partial thromboplastin time of the patient was corrected by addition of normal, Factor XII deficient or Fletcher plasma, but not corrected by Fitzgerald or Williams plasma. It was also corrected by addition of highly purified bovine or human high molecular weight (HMW) kininogen, but not by low molecular weight (LMW) kininogen. When total kininogen was measured as the amount of bradykinin released by trypsin, only a trace amount was detected in Fujiwara as well as Williams plasma. No immunoreactive protein against anti-human-HMW-kininogen nor anti-human-LMW-kininogen was found in Fujiwara plasma. Acetone-kaolin-activated plasma kallikrein was not generated by Fujiwara plasma. Substitution with normal plasma in various ratios showed the generation of various plasma kallikrein activities. Calculations with these activities of mixed plasma gave the prekallikrein content of Fujiwara trait plasma about 30% of the normal level. These results suggest that Fujiwara trait is very similar to Williams trait in that both plasmas were deficient in HMW and LMW kininogens with reduced content of prekallikrein.

Factor XII↗