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Biomedical subjects

R Yamada

Publications and source records attributed to R Yamada.

At least 505 records · Page 28Linked to original sources
PubMedDate not supplied

New oily agents for targeting chemoembolization for hepatocellular carcinoma.

PURPOSE: The evaluation of new oily agents for targeting chemoembolization for hepatocellular carcinoma. METHODS: Five types of oily preparation were injected into the hepatic artery of 54 rabbits inoculated with VX2 carcinoma cells in order to evaluate (1) the safety of these preparations, (2) their histologic distribution and the amount of agents remaining at tumor sites, and (3) computed tomographic (CT) images obtained. Of these preparations, three were made by mixing non-iodinated poppy seed oil and a thickener and then adjusted to have a viscosity lower than, equal to, or higher than that of lipiodol. A fourth preparation was a mixture of lipiodol and a thickener with a higher viscosity than lipiodol alone, and the fifth preparation was lipiodol alone. RESULTS: (1) No injury to the hepatic parenchyma was observed hematologically or histologically. (2) With increase in the viscosity, a significantly larger amount of agent remained at the tumor site. No agent was present at normal sites 14 days after intraarterial injection, regardless of which preparation was given. (3) On CT scans following intraarterial injection, tumor cells were visibly deeply stained in the non-iodinated preparation groups, while the lipiodol groups were not evaluable because of excessively high attenuation. CONCLUSION: The non-iodinated oily preparations and highly viscous oily preparations developed in the present study were more useful than lipiodol for treatment of hepatic tumors.

Animals↗
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Current status of angiography and interventional radiology in Japan: survey results.

PURPOSE: Because the practice of interventional radiology in Japan seems very different from that in western countries, a survey was conducted to define practice patterns and the current position of radiologists in the field of vascular and interventional radiology in Japan. MATERIALS AND METHODS: During the spring of 1992, a questionnaire was mailed to all institutions to which members of the Japanese Society of Angiography and Interventional Radiology belong. RESULTS: For abdominal, thoracic, and peripheral angiography, more than 50% of procedures were controlled by radiologists. The majority of abdominal embolotherapy (87%) and peripheral angioplasty (70%) procedures were performed by interventional radiologists. On the other hand, 64.3% of neurointerventions, 74% of abscess drainage, and 98% of coronary angioplasty procedures were performed by other specialists. In most institutions, embolotherapy for liver neoplasms was commonly performed by radiologists (97%). Peripheral and renal angioplasty and thrombolysis were performed by 74% of respondents, although less than 10 cases per year were encountered at 81% of institutions. Abscess drainage and biopsy were performed by radiologists in more than 50% of institutions. In other nonvascular interventional procedures, especially lithotripsy, the practice by and experiences of radiologists were very limited. Fifty-seven percent of radiology departments have beds allocated and radiologists serve as attending physicians for interventional purposes. CONCLUSION: The practice pattern of interventional radiology in Japan is quite different from that in other countries because of differences in patients' diseases, historical backgrounds, number of interventional radiologists, and department organization.

Adult↗
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Dose-dependency of hepatocellular necrosis in a canine model of chemoembolization.

PURPOSE: The degree of local tissue toxicity from hepatic arterial chemoembolization relative to the dose of anticancer drugs was evaluated in 13 dogs. MATERIALS AND METHODS: Animals were divided into four groups. Group 1 was the control group in which embolization was performed with gelatin sponge particles only (n = 4); group 2 animals underwent embolization with 0.4 mg/kg of Adriamycin (ADR) and 0.2 mg/kg of mitomycin C (MMC) (n = 4); group 3, with 0.8 mg/kg of ADR and 0.4 mg/kg of MMC (n = 2); and group 4, with 1.6 mg/kg of ADR and 0.8 mg/kg of MMC (n = 3). RESULTS: Animals were killed 1 week after embolization, and histopathologic evaluation was performed. The average percentage liver necrosis in the embolized lobe was 0% in group 1, 1% in group 2, 85% in group 3, and 92% in group 4. CONCLUSION: Hepatic arterial chemoembolization with high doses of anticancer drugs causes severe liver damage, but 0.4 mg/kg of ADR and 0.2 mg/kg of MMC is relatively safe, causing only minimal changes in this canine model.

Animals↗
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Granulocyte-colony stimulating factor enhances anti-tumour effect of hyperthermia.

The combined effect of granulocyte-colony stimulating factor (GCSF) and hyperthermia in the treatment of experimental tumours was studied to examine the possible involvement of activated granulocytes in the antitumour effect of hyperthermia. Two weeks after transplantation of SCC VII cells (1 x 10(5)) into the instep of the left leg of C3H/HeJ male mice, the mice were given subcutaneous injections of GCSF (0.2 mg/kg) for 4 days. On day 4, hyperthermia was applied locally at 43 degrees C for 40 min. Hyperthermia inhibited the tumour growth, and this effect was enhanced by pre-treating the animals with GCSF. The numbers of circulating neutrophils in control and GCSF-treated mice were 2728 +/- 517/microl and 3124 +/- 194/microl, respectively (p = 0.53). Hyperthermia increased the number of neutrophils to 4409 +/- 700/microl (p < 0.05). Hyperthermia combined with GCSF significantly increased the number of netrophils to 5479 +/- 691/microl (p < 0.01). Chemiluminescence analysis using L-012 revealed that GCSF enhanced the generation of reactive oxygen species by about 10-fold. Glutathione contents in tumours 24 h after hyperthermia decreased by about 50% in both the hyperthermia groups with or without GCSF, as compared to those in the control. The GCSF-enhanced anti-tumour activity of hyperthermia was markedly inhibited by administration of a long-acting superoxide dismutase derivative (SM-SOD). These results suggest that GCSF activates the ability to generate active oxygen species by neutrophils and, thereby, enhances the anti-tumour effect of hyperthermia.

Animals↗
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Peptidylarginine deiminase 4 (PADI4) identified as a conformation-dependent autoantigen in rheumatoid arthritis.

OBJECTIVE: Peptidylarginine deiminase (PADI) catalyses the post-translational modification of arginine to citrulline, which is specifically recognized by sera from rheumatoid arthritis (RA) patients. The PADI4 gene has recently been identified as a risk factor for RA. We aimed to determine whether PADI4 constitutes an autoantigen in RA. METHODS: Serum samples were obtained from 42 patients with RA, 19 patients with systemic lupus erythematosus (SLE), 23 patients with other rheumatic diseases, and 40 normal individuals. The presence of antibodies against recombinant human PADI4 (anti-PADI4) was examined using enzyme-linked immunosorbent assay (ELISA) and Western blotting. RESULTS: For ELISA, the prevalence of anti-PADI4 among RA patients (50%) was significantly higher than that of normal individuals (2.5%), SLE (10.5%), and other rheumatic diseases (4.3%), while for Western blot analysis, PADI4 was recognized only by a portion of the ELISA-positive serum samples. CONCLUSIONS: PADI4 is an autoantigen in some RA patients, and its conformational epitope(s) may be important.

Adult↗
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Inhibition of human telomerase by L-enantiomers of natural 2'-deoxyribonucleoside 5'-triphosphates.

In order to clarify whether L-enantiomers of natural 2'-deoxyribonucleoside 5'-triphosphates (dNTPs) are recognized by human telomerase, a quantitative telomerase assay based on the 'stretch PCR' method was developed and used for kinetic analysis. Among the four L-dNTPs, L-dTTP and L-dGTP inhibited telomerase activity and the others showed slight or no inhibitory effect. Lineweaver-Burk plot analysis showed that the inhibition mode L-dGTP was competitive with dGTP.

Deoxyguanine Nucleotides↗
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Intracranial papillary endothelial hyperplasia: occurrence of a case after surgery and radiosurgery.

Papillary endothelial hyperplasia (PEH) is considered a form of endothelial proliferation rather than a true neoplasm and is usually located in the skin or subcutis. We report a case of intracranial PEH that occurred after surgery for glioma and subsequent radiosurgery. CT and MR revealed an enhancing extra-axial mass located left posterolateral to the brainstem. Intracranial PEH is rare; to our knowledge, development of an intracranial PEH after surgery and radiosurgery has not been previously reported.

Adult↗
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Cytotoxicity of docosahexaenoic acid and eicosapentaenoic acid in tumor cells and the dependence on binding to serum proteins and incorporation into intracellular lipids.

Docosahexaenoic acid (DHA) inhibited the DNA synthesis in Ehrlich ascites tumor cells more markedly than eicosapentaenoic acid (EPA), which was more inhibitory than oleic-, linoleic-, linolenic-, and arachidonic acids. Their activities augmented according to the increase of number of double bonds in the molecule. To correlate the cytotoxicity with lipid syntheses in the cells, distribution of EPA and DHA incorporated into cellular lipids was assessed. EPA was incorporated into triglycerides (TG) and DHA into phosphatidylcholine (PC). These synthesis into TG and PC etc., which shattered from cytotoxicity, may be involved in tumor-cellular protecting actions against EPA or DHA. EPA and DHA involved in cytotoxicity exhibition are their free acid forms. Thus, as an anticancer reaction, intracellular accumulation in the free acid form of DHA was more marked than that of EPA.

Animals↗
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Tumor marker and MR imaging criteria for evaluating the efficacy of cyclic balloon-occluded arterial infusion for advanced cancer of the uterine cervix.

We have already reported satisfactory therapeutic results of cisplatin-based cyclic balloon-occluded arterial infusion chemotherapy (BOAI) enabling treatment by simple total hysterectomy (STH) in patients with advanced cervical cancer of the uterus (cervical cancer), with 2- and 5-year survival rates of 88.9% and 66. 7%, respectively. Considering the fact that 3 to 4 months are needed to complete BOAI, the present study was a retrospective assessment of 18 cervical cancer patients to prepare criteria for the early determination of the efficacy of BOAI in patients who can be treated by STH. The results showed that STH could be performed after the first BOAI in patients with SCC value decreased to 34.3+/-8.2% of the pretreatment value (p=0.0001) and whose tumor size had decreased by 45.1+/-7.5% (p=0.0002).

Aged↗
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Correlation of DNA synthesis-inhibiting activity and the extent of transmembrane permeation into tumor cells by unsaturated or saturated fatty alcohols of graded chain-length upon hyperthermia.

The carcinostatic activity has been studied for fatty acids of diverse species but scarcely for fatty alcohols. Three unsaturated fatty alcohols at 35-50 microM inhibited DNA synthesis and the proliferation of tumor cells by a combination with hyperthermia to greater extents in the order: oleyl (C18:1)-> linoleyl (C18:2)-> alpha-linolenyl (C18:3) alcohol, which is an order inverse to that known for the corresponding fatty acids (4). In contrast, two saturated fatty alcohols, palmityl (C16:0)- and stearyl (C18:0) alcohols, did not inhibit at the same concentrations. At 100 microM, palmityl alcohol inhibited, whereas stearyl alcohol did not. The effective fatty alcohols appreciably permeated the cells. The inhibition of the unsaturated fatty alcohols on DNA synthesis and proliferation was nearly proportional to the amount of their intercellular accumulation at 37 degrees C or 42 degrees C; the most inhibitory, oleyl alcohol, was the most membrane-permeable, whilst inversely the least inhibitory, alpha-linolenyl alcohol, was the least permeable. A proportional correlation was not observed for saturated fatty alcohols; palmityl alcohol underwent an approximate 2-fold more abundant accumulation than other fatty alcohols, but was weakly inhibitory. Thus, oleyl alcohol may exert an antitumor action via appropriately efficient transmembrane permeation and a combination with hyperthermia.

Animals↗
PubMedDate not supplied

Association between overexpression of cyclooxygenase-2 and suppression of apoptosis in advanced cancer of the uterine cervix after cyclic balloon-occluded arterial infusion.

Recent advances in cancer chemotherapy have drawn the attention of investigators to the usefulness of chemotherapy for cancer of the uterine cervix in general, and we ourselves have previously reported satisfactory therapeutic results of cisplatin-based cyclic balloon-occluded arterial infusion chemotherapy (BOAI), which enabled treatment by hysterectomy in patients with advanced cervical cancer. Nevertheless, there have been some patients in whom CDDP therapy by BOAI was ineffective, and hysterectomy was impracticable. In the present study we investigated the expression of cyclooxygenase-2 (COX-2) in these cases in an attempt to identify the cause of the lack of efficacy. The subjects of the study were 38 women with advanced cervical cancer classified as FIGO (International Federation of Gynecology and Obstetrics) stage III or higher who were admitted to the Department of Gynecology of Osaka City University Medical School Hospital between July 1993 and April 2000. All of these patients were treated by BOAI, and expression of COX-2, angiogenic factors, and cancer cell apoptosis, before and after BOAI were examined, and survival rates were compared. The 18 patients in whom BOAI was ineffective showed significantly higher expression of COX-2 after BOAI, and cancer cell apoptosis was inhibited. The 5-year survival rate of these patients was 16.8%, as opposed to 54.1% in the 20 patients in whom BOAI was effective. These results suggest that overexpression of COX-2 inhibits cancer cell apoptosis and adversely influences the prognosis.

Adult↗
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A case of Budd-Chiari syndrome successfully treated by transcatheter recanalization of the right hepatic vein and transjugular intrahepatic portosystemic shunt.

A 40-year-old man with Budd-Chiari syndrome due to chronic obstruction of the major hepatic veins was successfully treated by interventional radiologic procedures. Initially, partial splenic embolization was performed to improve thrombocytopenia and coagulopathy of blood. Second, recanalization was done by thrombolic therapy. Finally, the TIPS procedure was carried out through the recanalized right hepatic vein. This resulted in great improvement of Budd-Chiari syndrome, a marked decrease in pressure, and disappearance of gastroesophageal varices on endoscopy.

Adult↗
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MR imaging of the posterior fossa structures of human embryos and fetuses.

There have been few reports on MR imaging of the developing human fetal brain. The aim of this article is to establish a standard atlas of developing fetal brain, focusing in particular on posterior fossa structures. Eighty-eight formalin-fixed embryos and fetuses were examined using 1.5 Tesla MR units. Specimens ranged from Carnegie stage 17 to 28 gestational weeks. The morphologic changes in developing cerebellum, cerebellar fissures, pontine flexure, fourth ventricle, and cerebral aqueduct were observed in each developmental period. The height of the fourth ventricle and cerebral aqueduct and the thickness of the tectum and the tegmentum of the midbrain were measured. We obtained detailed MR images of the developmental changes in posterior fossa structures and produced an atlas of these images. Our study showed that the period of visualization of cerebellar structures and fissures was later on MR imaging than described in past anatomical and embryological studies. In addition, the sudden decrease in height of the fourth ventricle and the cerebral aqueduct found in our study might reflect the presence of communication between the fourth ventricle and subarachnoid space.

Brain↗
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Ultrasonographic evaluation of portal blood flow using transhepatic carbon dioxide injection.

BACKGROUND/AIMS: The evaluation of portal blood flow in hepatic mass is important for the diagnosis of hepatocellular carcinoma. We have designed a new method to easily evaluate portal blood flow in hepatic mass using ultrasonography with injection of carbon dioxide into the intrahepatic portal vein by direct puncture with a fine needle. METHODOLOGY: We evaluated 29 masses in the liver of 20 patients ultrasonically with injection of carbon dioxide into the intrahepatic portal vein. RESULTS: Of 29 space-occupying lesions (SOLs), 13 were found to have portal blood flow and 16 were found to have no portal flow by this method. All 15 SOLs which had no portal flow were histologically confirmed to be hepatocellular carcinoma. Of 13 SOLs with portal flow, 5 were confirmed to be hepatocellular carcinoma. For 7 of 9 SOLs in which both this method and arterial portographic computed tomography were performed, the results were in agreement. CONCLUSIONS: Ultrasonographic evaluation of portal blood flow using transhepatic carbon dioxide injection appears to be useful for the evaluation of portal flow in mass and may aid in the diagnosis and management of mass in patients with liver disease.

Adolescent↗
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Balloon-occluded arterial infusion chemotherapy, simple total hysterectomy, and radiotherapy as a useful combination-therapy for advanced cancer of the uterine cervix.

We first performed 3 or 4 courses of balloon-occluded arterial infusion (BOAI) chemotherapy in 19 patients with advanced cancer of uterine cervix classified as stage III-IV according to the International Federation of Gynecology and Obstetrics. In the patients in whom the first BOAI resulted in insufficient drug accumulation in tumor tissue, the ovarian arteries and veins were ligated to improve the therapeutic effect. Ultimately simple total hysterectomy and radiotherapy were performed in 9 patients in whom the uterus was resectable (the combination group), and radiotherapy alone was conducted in the other 10 patients in whom hysterectomy was not practicable (the incomplete group). The survival rates were significantly higher in the combination group (2-year survival 88. 9%; 5-year survival 66.7%) than in the incomplete group (p=0.0013).

Aged↗
PubMedDate not supplied

Abnormal cell morphology and cytotoxic effect are induced by 6-0-palmitol-ascorbate-2-0-phosphate, but not by ascorbic acid or hyperthermia alone.

A new derivative of ascorbic acid (AsA), 6-0-palmitoyl-ascorbate 2-0-phosphate (Asc2P6Pal) was developed to enhance the antitumor activity of AsA. When Ehrlich ascites tumor cells were treated with 50 microM Asc2P6Pal at 37 degrees C or 42 degrees C for 1 h and then cultured for 20 h, most of cells exhibited some morphological abnormalities, including exudation of intracellular granules together with other contents on the cell membrane surface, resulting in cell fragmentation. The abnormal features were further enhanced by a long term culture for 96 h and heat treatment at 42 degrees C. In contrast, no abnormality was detected for untreated cells or cells treated with AsA (free acid) at 37 degrees C or 42 degrees C. Cells cultured for 96 h after the treatment suffered from inhibition of DNA synthesis and proliferation. This inhibition was markedly enhanced by combination with the hyperthermic treatment at 42 degrees C, but not for a short-term culture of 20 h after the treatment. No effects were seen upon similar treatment with AsA. The abnormal cells produced during culture for 20 h after the treatment were evaluated to be viable, because they failed to be stained with trypan blue and retained most of the DNA synthesizing ability of Asc2P6Pal-untreated cells. However, they appeared and died after a continuous 76 h of culture (96 h).

Animals↗
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Meloxicam inhibits the growth of non-small cell lung cancer.

Cyclooxygenase (COX)-2 has been reported to play an important role in carcinogenesis. Meloxicam (preferential COX-2 inhibitor) inhibits the growth of COX-2 positive and COX-1 negative colorectal cancer cells. We evaluated the effects of meloxicam on the growth of lung cancer cells. By reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, COX-2 but not COX-1 was expressed in human non-small cell lung cancer (NSCLC) cell lines (A549 and PC14). In human small cell lung cancer (SCLC) cell line (H841), both COX-1 and COX-2 were not detected. MTT assay and prostaglandin (PG) E2 enzyme immunoassay showed that meloxicam inhibited the growth and PGE2 production of both A549 and PC14, but not H841 cells. These findings suggest that COX-2 may play an important role in the pathogenesis and progression of NSCLC, and that meloxicam may be a useful therapeutic agents in the treatment of NSCLC.

Antineoplastic Agents↗