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Biomedical subjects

R Wada

Publications and source records attributed to R Wada.

At least 91 records · Page 5Linked to original sources
PubMed1996

[A case of advanced gastric cancer remarkably responding to preoperative UFT-E therapy].

We here reported a case of advanced gastric cancer remarkably responding to preoperative short-term UFT-E chemotherapy. UFT-E was orally administered preoperatively for about a month to the patient with type 2 advanced gastric cancer. After the chemotherapy the cancer was found to be remarkably decreased in size and denatured. The amount of residual cancer cells was limited by histopathological examination following the operation and diagnosed as Grade 3 based on the criteria of histological evaluation of chemotherapy for cancer. We continued to administer UFT-E postoperatively and the patient is still alive without symptoms.

Adenocarcinoma↗
PubMed1995

Adenocarcinoma arising from gastric immature teratoma. Report of a case in an adult and a review of the literature.

BACKGROUND: Gastric teratoma is an uncommon tumor and usually occurs in infancy or childhood. To the authors' knowledge, malignant transformation in gastric teratoma has not been reported previously. METHODS: An 83-year-old Japanese man presented with a large polypoid gastric tumor composed of teratomatous components and invasive adenocarcinoma. Numerous blocks of this tumor were analyzed histologically and immunohistochemically. RESULTS: Histologically, the gastric tumor consisted of teratomatous components with diverse maturation, such as fibroblastic mesenchymal cells, striated muscle cells, cartilaginous islands, neuroepithelial components, glial tissues, squamous cell nests, glandular components, and foci of adenocarcinoma infiltrating the benign gastric tissues adjacent to the tumor stalk. Metastatic foci of teratomatous components in the resected lymph nodes contained adenocarcinomatous glands. An immunohistochemical study helped confirm the differentiation in the immature components and the differential diagnosis between atypical neuroepithelial cells and the adenocarcinoma. CONCLUSION: This study indicates that the adenocarcinoma arose from immature gastric teratoma. A review of the literature suggests that this is the oldest reported patient with gastric teratoma and to the authors' knowledge is the first report describing gastric teratoma with malignant transformation.

Adenocarcinoma↗
PubMed1995

Phenylacetate synergizes with retinoic acid in inducing the differentiation of human neuroblastoma cells.

Phenylacetate, a natural metabolite of phenylalanine which was originally described as a plant growth hormone, has recently gained attention as a possible differentiation inducer for a variety of human tumor cell types. This interest prompted us to assess the ability of sodium phenylacetate (NaPA) to promote the differentiation of human neuroblastoma cells, both alone and in combination with retinoic acid (RA), a known inducer of neuroblastoma differentiation and maturation. Using the LA-N-5 cell line, we have determined that NaPA can stimulate the differentiation of neuroblastoma cells, as evidenced by dose-dependent inhibition of cell proliferation, neurite outgrowth, increased acetylcholinesterase activity and reduction of N-myc expression. Furthermore, NaPA and RA synergized in inducing differentiation, in that combination treatment resulted in cessation of cell growth along with morphologic and biochemical changes indicative of the loss of malignant properties. We have determined that NaPA can markedly enhance mRNA levels of the nuclear RA receptor-beta (RAR beta) in LA-N-5 cells prior to morphologic or other phenotypic changes induced by this compound. This effect appeared to be distinct from the ability of NaPA to alter tumor cell lipid metabolism via inhibition of protein isoprenylation. Thus among its varied effects on LA-N-5 cells, NaPA appears to interact with the RA pathway at the nuclear level by up-regulating RAR beta expression.

Cell Differentiation↗
PubMed1995

Detection of equine arteritis virus (EAV) by polymerase chain reaction (PCR) and differentiation of EAV strains by restriction enzyme analysis of PCR products.

A polymerase chain reaction (PCR) based assay capable of detecting and differentiating seven strains of equine arteritis virus (EAV) from around the world was developed. The primers for the PCR were chosen from the ORF6 gene encoding the unglycosylated membrane protein (M). Viral RNA from cell culture fluids infected with each of the seven EAV strains and RNA from the live vaccine, Arvac, was detected by PCR using four sets of primers. The sensitivity of detection was increased from 100 to 1,000 times by performing nested PCR enabling the detection of RNA at a level of 0.5-5 PFU. Differentiation among the virus strains and the live vaccine was achieved by cutting the PCR-amplified products from three sets of primers with six restriction endonucleases. Using this procedure it was possible to distinguish among the seven EAV strains used.

Base Sequence↗
PubMed1995

Ultrastructure and immuno-cytochemistry of BHK-21 cells infected with a modified Bucyrus strain of equine arteritis virus.

Morphogenesis of a modified Bucyrus strain of equine arteritis virus (EAV) in BHK-21 cells was studied. Bacillary tubules were first detected in the cytoplasm 8 h after infection, and mature virions 79 to 122 nm in diameter, 101 nm on average, were mostly observed in the cisternae of the rough endoplasmic reticulum (RER) at 12 h or later. They had isometrical cores and morphological subunits in the outer layer. Budding occurred from the RER and the outer nuclear membrane, but not from the cell surface. Structural linkage was detected between the tubule and the virus core. Aberrant strands were occasionally demonstrated within the nucleus 12 h after infection, and immunofluorescence and immunogold labeling revealed viral antigen also in the nucleus.

Animals↗
PubMed1995

Paget sarcoma of the cervical vertebrae: an autopsy case report and review of the literature.

A 69 year old Japanese woman was hospitalized for emergency treatment of sudden onset of tetraplegia and somnolence. The patient had a long history of occipital pain without definite diagnosis. After admission, the patient progressively developed generalized palsy including respiratory paralysis, and died of bronchopneumonia. Autopsy revealed osteosarcoma of the cervical vertebrae with the features of Paget's disease involving the skull and the cervical vertebrae. Paget sarcoma is rare in Japan, where Paget's disease of the bone is an uncommon condition. A review of the world literature failed to reveal any reports describing Paget sarcoma of the cervical vertebrae. The present report indicates that the development of Paget sarcoma in the upper cervical vertebrae may cause life-threatening neurologic complications.

Aged↗
PubMed1995

[Development and expression of p53 in superficial early colorectal carcinoma].

We evaluated the histopathological and immunohistochemical findings of 41 superficial early colorectal carcinomas within 20 mm in diameter and twice of normal mucosa in height for the development. These colorectal cancers were divided into intramucosal carcinoma (21 lesions) and submucosal invasive carcinoma (20 lesions), and classified into two groups: superficial elevated type (25 lesions) and superficial depressed type (16 lesions). The average maximum diameter of superficial elevated type was larger than it of superficial depressed type, furthermore the increase in tumor diameter and the pattern of the overexpression of p53 protein was correlated to the invasivity. On the other hand, we found the submucosal invasion and the overexpression of p53 protein in the smaller depressed type carcinoma. Considering the circumstances mentioned above, we recognized the different development between superficial elevated type and superficial depressed type in the superficial early colon cancer, and thought superficial depressed type was more invasive.

Adult↗
PubMed1994

Use of the serum neutralisation test for equine viral arteritis with different virus strains.

Serum cross neutralisation tests were conducted with a recent American isolate (84KY-A1) and a European isolate, (Wroclaw-2) and compared with the prototype and modified viruses of the Bucyrus strain of equine arteritis virus by using virus specific immune horse sera. The modified Bucyrus strain was neutralised and showed high neutralisation titres with all the immune sera. The prototype Bucyrus strain was also substantially neutralised, followed by the 84KY-A1 strain. As a result of the tests with the modified Bucyrus strain as the antigen, 20 seropositive horses were discovered among home-bred horses which had no previous record of clinical equine viral arteritis. Heat inactivation of the sera at 62 degrees C for 30 minutes caused the disappearance of all but the most positive reactions. When the prototype Bucyrus strain was used instead of the modified virus, no positive reactions were detectable. A serological survey, using the Bucyrus strain in a microtitre neutralisation test, was conducted with 1656 horse sera collected between 1988 and 1990 in Japan. The test disclosed only eight foreign-bred horses positive to the virus; they had been imported as competition horses. No circumstantial evidence of an effect of such horses as a source of infection for horse populations free of the virus was obtained.

Animals↗
PubMed1994

Retinoic acid up-regulates nuclear retinoic acid receptor-alpha expression in human neuroblastoma cells.

Retinoic acid (RA) nuclear receptors (RARs) are thought to mediate the cellular and molecular effects of RA on a wide variety of tissues. In most cell types, RAR alpha expression remains relatively constant following exposure to RA, while that of RAR beta is rapidly induced. In this study, we show that in human neuroblastoma, a cell type exceptionally sensitive to RA-induced differentiation, RAR alpha as well as RAR beta is markedly up-regulated by RA treatment. This effect was consistent in all 5 neuroblastoma cell lines tested and was reflected in a 2- to 5-fold increase in receptor mRNA levels as assessed by Northern-blot analysis. Using LA-N-5 human neuroblastoma cells, we found that receptor up-regulation occurred in a time- and dose-dependent fashion with increases in both RAR alpha and beta mRNA detectable 1-2 hr after the addition of RA. These inductions were not abrogated by cycloheximide, indicating that protein synthesis was not required for the RA responses. Nuclear run-off experiments combined with Northern-blot analysis of RAR alpha stability directly demonstrated that the up-regulation of RAR alpha mRNA levels reflected an increased rate of transcription without changes in message half-life. These findings, showing direct activation by RA of RAR alpha gene transcription in human neuroblastoma cells, suggest differences in the overall regulation of this receptor from that found in most other RA-inducible tissue.

Cell Differentiation↗
PubMed1993

Development of neutralizing antibody in horses infected with Ehrlichia risticii.

The role of the humoral immune response in ehrlichial infection is unknown. Development of neutralizing antibodies during a course of Ehrlichia risticii infection in a pony was examined in vitro by determining the inhibition of E. risticii infection of P388D1 cells in the presence of the sera. The pony experimentally infected with E. risticii developed significant neutralizing activity in the sera by 15 days postinfection when parasitemia started to decline. Neutralizing activity continued to rise after recovery from the disease up to 34 days postinfection at which time the experiment was terminated. In vitro neutralizing activities in the sera from 3 additional ponies infected with E. risticii were lower at 2 weeks than at 4 weeks postinfection. The sera from vaccinated/challenged ponies had comparable neutralizing activity to those of the recovered ponies at approximately 3 to 4 weeks postchallenge. Equine sera from infected or vaccinated/challenged ponies were also effective in protecting mice from E. risticii infection. These studies demonstrated the significant development of neutralizing activity in the sera of recovered or vaccinated/challenged ponies.

Animals↗