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Biomedical subjects

J Yoshida

Publications and source records attributed to J Yoshida.

At least 397 records · Page 22Linked to original sources
PubMed1987

Cell growth-inhibitory action of SAGP, an antitumor glycoprotein from Streptococcus pyogenes (Su strain).

An antitumor acidic glycoprotein (SAGP) from Streptococcus pyogenes (Su strain) inhibited the growth of BALB/3T3 cells in culture in a dose-dependent manner (0.03-10.0 micrograms/ml). This effect of SAGP was abolished by washing the cells, suggesting that SAGP weakly binds to the cell membrane. The ability of the cells to form colonies was unaffected by three days exposure to SAGP. Cell cycle analysis by flow cytometry revealed an accumulation of SAGP-treated cells in the S-phase. SAGP (3 micrograms/ml) reduced the incorporation of 3H-thymidine into the cells to approximately half of the control level. These results suggest that SAGP inhibits the growth of target cells by acting on their surface membrane and decreasing the rate of DNA synthesis.

Bacterial Proteins↗
PubMed1987

Studies on new antibiotics SF2415. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities.

A new species of Streptomyces is described for which the name Streptomyces aculeolatus is proposed. The organism produces new antibiotics SF2415A1, A2, A3, B1, B2 and B3 active against Gram-positive bacteria. Empirical molecular formulae of the antibiotics SF2415A1, A2, A3, B1, B2 and B3 were determined to be C26H31N2O5Cl, C26H30N2O5, C26H30N2O5Cl2, C26H33O5Cl, C26H32O5 and C26H32O5Cl2, respectively.

Animals↗
PubMed1987

Effects of a new vasodilator, nicorandil, on exercise-induced impairment of left ventricular function in patients with old myocardial infarction.

Hemodynamic effects of nicorandil on exercise-induced impairment of left ventricular function were studied in nine patients with old myocardial infarction but without angina pectoris. Hemodynamic data were obtained by symptom-limited supine multistage bicycle ergometer exercise testing before and 1 h after single oral administration of 15 mg of nicorandil. Systolic and diastolic blood pressure at rest decreased significantly after nicorandil administration (p less than 0.01). A most remarkable change in the hemodynamic response to supine dynamic exercise after nicorandil was a decrease in pulmonary artery wedge pressure (both at rest and at peak exercise, p less than 0.001). An index cardiac function, obtained from the relation between pulmonary artery wedge pressure and left ventricular stroke work index, improved significantly after nicorandil. The ration of pressure-rate product to coronary sinus flow, which is an index of the ratio of myocardial oxygen consumption to myocardial oxygen supply, decreased significantly (p less than 0.05) after nicorandil administration. Reproducibility of the testings was also studied in six patients with old myocardial infarction. Invasive hemodynamic variables between two successive symptom-limited supine leg exercise testings, except pulmonary artery wedge pressure, were reproducible in patients with old myocardial infarction but without angina pectoris. Only pulmonary artery wedge pressure at rest in the second exercise testing showed a significantly lower value (p less than 0.05). It is concluded that nicorandil is a useful drug for improvement of exercise-induced impairment of left ventricular function with an increase in myocardial oxygen supply.

Adult↗
PubMed1987

[Controlled multimodality treatment of brain stem gliomas].

Thirty-eight children were diagnosed as having a brain stem glioma at Nagoya University. Thirty-three patients in our previous series from 1957 to 1983, were treated traditionally with radiation and at late stage with shunting operation for hydrocephalus and/or suboccipital decompression, but not with direct operation for tumors. In general, tumors constantly grew regardless histology and their mean survival time was only 7.0 months even with transient neurological remission. On the other hand, recent five patients since 1984 were treated with prospective multimodality treatment. According to neuroradiological studies by X ray and/or NMR, CT scanning, the brain stem glioma cases were classified into subgroups of intrinsic and exophytic. Then the former were treated non-surgically with adjuvant therapy of Interferon-ACNU-Radiation (IAR) and the latter were treated surgically at first by resection of the tumor followed by adjuvant therapy of IAR or interferon-CDDP. Four out of five patients responded to adjuvant therapy (complete response = 2, partial response = 2, response rate = 80%) and they are all alive after 7-28 months follow-up period. It is concluded from our results that CT scanning can diagnose the accurate location and nature of brain stem gliomas, surgical therapy benefits at least in exophytic cases, and IAR adjuvant therapy may prolong the survival time of patients.

Adolescent↗
PubMed1987

[Clinical trials of combination chemotherapy using cis-platinum with aclarubicin in intracranial rhabdomyosarcoma].

Combination chemotherapy of Cis-platinum with Aclarubicin was performed in patients with intracranial alveolar rhabdomyosarcoma. These patients were treated with Cis-platinum (20 mg/day) and Aclarubicin (20 mg/day) for 5 days. After two trials with about a four-week interval, complete tumor regression on CT scan was observed. Mild gastrointestinal toxicity was observed in these patients but the symptoms were transient and soon disappeared. No other side effects appeared, on or after treatment. This result demonstrated that combination chemotherapy of Cis-platinum and Aclarubicin is an effective regimen for remission induction chemotherapy in patients with intracranial sarcoma.

Aclarubicin↗
PubMed1987

[Basic studies on chemotherapy of brain tumors by means of liposomes: affinity of sulfatide-inserted liposomes to human glioma cells].

In order to utilize liposomes for the treatment of brain tumors, we examined the interaction between the cells and the liposomes prepared from phosphatidylcholine, cholesterol, and sulfatide (molar ratio, 7:2:1), which were able to deliver the encapsulated materials into the brain through the blood-brain barrier. With a variety of human cell lines, the incorporation of the liposomes and the release of the liposomal contents into cells were studied by spectrofluorometry and flow cytometry by use of encapsulated 6-carboxy-fluorescein. It was found that the amounts of liposomes incorporated into cells were dependent on the dose of liposomes and type of cells. At the same concentration of liposomes, the highest incorporation was found for glioma cells, which was further confirmed by electron microscopy with ferritin-containing liposomes. These results indicate that the liposomes composed of sulfatide, phosphatidylcholine and cholesterol have a high affinity for human glioma cells and should be useful for the chemotherapy of glioma when antitumor drugs are encapsulated into them.

Antineoplastic Agents↗
PubMed1987

[Combination chemotherapy with aclarubicin and cisplatinum against malignant intracranial tumor--an in vitro study].

Augmentation of cytotoxicity against cultured human tumor cell lines (5 gliomas, 2 neuroblastomas, 2 sarcomas) using a combination of Aclarubicin (ACR) and Cisplatinum (CDDP) was analysed in vitro from the viewpoints of cell growth inhibition and alteration of the DNA histogram. Synergistic effects of the combination of the two agents were observed in 7 of the 9 cell lines. In sarcoma cell lines, effects were demonstrated even by a low dose of 0.1 microgram/ml CDDP and 0.01 microgram/ml ACR. Flow cytometry studies of the DNA histogram showed increase of accumulation in the S phase following the G2-M phase and reduction of G1 phase cells in response to the combination. From the present experimental studies in vitro, it is concluded that combination chemotherapy with ACR and CDDP may be effective for sarcoma and ACNU-resistant glioma. The mechanism of the synergistic effect produced by the combination is suggested to be impairment of RNA synthesis by ACR which prevents the repair of DNA damage induced by CDDP.

Aclarubicin↗
PubMed1987

Hemobilia: review of recent experience with a worldwide problem.

Between 1981 and 1985, the reported incidence of hemobilia increased for two major reasons. First, a more sophisticated and better-trained medical community could entertain the diagnosis readily in certain settings and had broader access to diagnostic methods that precisely defined the source of bleeding into the biliary tract. Second, there was wider use of percutaneous techniques of diagnosis and treatment of biliary diseases. Once the diagnosis of hemobilia was made by endoscopic or arteriographic means, physicians and surgeons were quicker to institute proper therapeutic measures. For this reason, the mortality associated with hemobilia decreased compared with that reported earlier. The medical community must be aware that modern treatments are now the most common cause of this problem. Since invasive diagnostic methods are increasingly used by nonsurgeons, it is imperative that these patients are studied in the context of complete consultation with surgeons who can use definitive treatments when required.

Abdominal Injuries↗