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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 1,261 records · Page 70Linked to original sources
PubMed1987

[A study of hepato-biliary and alimentary scintigrams using a triple tracer method].

In order to evaluate the gastric emptying and postprandial mixing of bile with food, the scintigraphies of hepatobiliary and gastrointestinal tracts by using three different kinds of radioisotopes were performed simultaneously (99mTc-E.HIDA for hepatobiliary scintigraphy, 111In-DTPA containing orange juice and 131I-albumin containing scrambled egg for gastrointestinal scintigraphy). This method was available for observation of gastric emptying of liquid and solid foods and also examination of the mixing effect of bile and food quantitatively.

Bile↗
PubMed1987

[Multidisciplinary treatment of maxillary cancer].

Cases of maxillary cancer treated at our institute can be divided into two groups. In the first group (1971-1982, N = 85), we treated maxillary cancer by preoperative intraarterial infusion of 5-FU and Linac X-ray irradiation (60 Gy/6 weeks), followed by maxillectomy. In the second group (1982-1986, N = 32), we further combined intraarterial or intravenous chemotherapy using CDDP preoperatively or postoperatively depending upon the stage of the cancer. Five-year survival rate was 64.7% in the first group and 73.9% in the second. In the first group, the most frequent cause of death was distant metastasis without local recurrence. In the second group, the histopathological effect of chemotherapy and radiotherapy was improved with a reduced frequency of distant metastasis and it has now become possible to have 5-year survivors from among N2 and M1 cases. Judging from the histopathological effects of chemotherapy and radiotherapy, it seems possible to treat T2 and some T3 cases of maxillary cancer without performing maxillectomy. However, in T4 and most of T3 cases in which early recurrence is difficult to detect, it seems safer to combine total maxillectomy primarily.

Adenocarcinoma↗
PubMed1987

Isolation of complementary DNA clones for genes exhibiting reduced expression after treatment of mouse teratocarcinoma stem cells with a tumor-promoting phorbol ester.

For the study of the effects of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) on early mammalian cell differentiation, a complementary DNA (cDNA) library was constructed on the poly(A)+RNAs extracted from undifferentiated F9 cells derived from a 129/Sv mouse teratocarcinoma OTT6050, and screening was done for the cNDA sequences corresponding to the mRNAs, the levels of which decreased significantly in the F9 cells after the TPA treatment. From about 80,000 clones screened, 3 different cDNA clones, pFT27, pFT43, and pFT60, were isolated and characterized. Levels of the RNAs hybridizable to these clones were decreased by fourfold to more than fiftyfold within 1-10 hours in the presence of TPA. Northern blotting experiments identified transcripts corresponding to these clones: pFT27 hybridized to 3.0 kb RNA, pFT43 hybridized to 1.5 kb RNA, and pFT60 hybridized to 1.0 kb RNA. The levels of these 3 transcripts were also decreased after treatment of the undifferentiated F9 cells with retinoic acid (RA) and dibutyryl cyclic AMP (cAMP). The TPA-induced as well as the RA- and cAMP-induced decreases in the RNAs hybridizable to pFT27 were regulated at the transcriptional level, whereas similar decreases in the RNAs hybridizable to pFT43 and pFT60 were regulated at the post-transcriptional level. These findings show that TPA treatment shares common effects with RA and cAMP on the undifferentiated F9 cells.

Animals↗
PubMed1987

Decrease in the c-myb gene transcript during differentiation of mouse teratocarcinoma stem cells.

Transcript of the c-myb gene, one of the proto-oncogenes, was clearly detected in undifferentiated mouse F9 teratocarcinoma stem cells, but not in terminally differentiated mouse parietal endoderm PYS-2 cells. As F9 cells can be induced to differentiate into parietal endoderm-like cells by the addition of retinoic acid and dibutyryl cAMP, we examined levels of the c-myb transcript under this experimental condition and found that the c-myb transcript was decreased significantly. Thus, a decrease in the c-myb transcript is probably related to early differentiation of mammalian cells.

Animals↗
PubMed1987

T cell gamma gene rearrangements in hematologic neoplasms.

Rearrangements of the T cell gamma (T gamma) gene were studied in primary neoplastic cells from 75 patients with leukemia or lymphoma. T gamma gene rearrangements were observed in 19 of 21 T cell neoplasms; 14 of 21 immature B cell leukemias, including 4 out of 5 patients with rearrangements of both immunoglobulin heavy-chain (JH) and T cell receptor beta chain (T beta) genes; none out of 16 nonlymphoid leukemias. Thus, T gamma gene rearrangement is frequently found in immature B cells and is not always found in T cells showing T beta gene rearrangement, but it is not detected in nonlymphoid cells. Furthermore, T gamma gene rearrangement in cells with the germline configuration of the JH and T beta genes was observed. These results indicate that the detection of T gamma gene rearrangement does not allow a clear assignment to a particular lineage. However, an analysis of T gamma gene rearrangement provides a further potential tool to establish the lymphoid cellular origin and clonality of hematologic neoplasms and identify the normal stages of lymphocyte differentiation.

B-Lymphocytes↗