Biomedical subjects

H Miyachi

Publications and source records attributed to H Miyachi.

115 records · Page 7Linked to original sources

PubMedDate not supplied

Mastopathy-mimicking ultrasonographic appearance in a case with Burkitt's lymphoma.

We report a case of Burkitt's lymphoma, which was suspected to involve both breasts. US showed a replacement of the normal breast tissues by a diffusely mixed or mottled pattern of echo texture, associated by hypoechoic cyst-like masses with slight internal echogenicity. This pattern was indistinguishable from the sonographic changes produced by a mastopathy. These findings disappeared after successful chemotherapy for the Burkitt's lymphoma, suggesting that the ultrasonographic pattern of mastopathy was caused by the infiltration of the breast tissues by the lymphomatous cells.

Breast Neoplasms↗

PubMedDate not supplied

Translocation t(11;22)(q23;q11) in an adult with acute monoblastic leukemia.

A 66-year-old woman with acute monoblastic leukemia with t(11;22)(q23;q11), which was subsequently transformed into myeloblastic leukemia is reported. Such karyotype abnormality has not been reported in acute monoblastic leukemia. Cytogenetic analysis revealed 47,XX,+8,t(11;22)(q23;q11) in 19 out of 20 metaphases and 46,XX,del(7)(q22-q36),t(11;22)(q23;q11) in the remaining metaphase. Variant Ph1 was ruled out due to the absence of chimeric bcr-alb mRNAs. In remission cytogenetic findings showed normal karyotype. After 4 months, the patient relapsed with 20% myeloblasts replacing monoblasts in bone marrow. Cytogenetic analysis revealed 46,XX,del(7)(q22-q36),t(11;22)(q23;q11) in all metaphases. A possible explanation for this lineage switch may be the involvement of myelomonocytic progenitor cells.

Aged↗

PubMedDate not supplied

Multicenter evaluation of the Elecsys CA 125 II assay.

The technical performance and clinical usefulness of the newly developed Elecsys CA 125 II assay (Boehringer Mannheim) was evaluated in a multicenter study. Imprecision studies were carried out using control sera and human pool sera with CA 125 concentrations from 11 to 1026 U/ml. Within-run CVs between 0.7 to 4.8% (median 1.7%) and between-day CVs between 2.4 to 10.9% (median 5.7%) were found. Method comparison studies with Enzymun-Test CA 125 II carried out in four laboratories yielded slopes between 0.94 to 1.07 and intercepts < 3 U/ml. A good comparability of the Elecsys CA 125 II assay was also found with one MEIA and the Centocor" IRMA. For a second MEIA and a second IRMA the slopes were 1.23 and 1.42, and the corresponding correlation coefficients were 0.987 and 0.977, respectively. The Elecys CA 125 II concentrations are clearly related to the tumor stage of ovarian carcinoma patients. The maximum of diagnostic efficiency of ovarian carcinoma patients compared with patients of benign gynecological diseases is reached at 150 U/ml with a specificity of 93% and a sensitivity of 69%. Follow-up studies of ovarian carcinoma patients reflect the status of the disease and the effect of various therapeutic applications. The technical and clinical evaluation of the Elecsys CA 125 II assay show a superior analytical performance with a broad measuring range up to 5000 U/ml and a short measuring time of 18 minutes.

Biomarkers, Tumor↗

PubMedDate not supplied

Modulation of multidrug resistance in a cancer cell line by anti-multidrug resistance-associated protein (MRP) ribozyme.

Multidrug resistance-associated protein (MRP) is the major candidate molecule responsible for non-P-glycoprotein (PGp)-mediated multidrug resistance. We used a hammerhead anti-MRP ribozyme (alpha MRP-Rz) to inactivate MRP function in a multidrug resistant cancer cell line, KB8-5. The beta-actin promoter-driven alpha MRP-Rz sequence (pH beta/alpha MRP-Rz) was introduced into KB8-5 cells (KB8-5/alpha MRP-Rz) and we evaluated growth of the cell line. The gene expression of multidrug resistance-related molecules was estimated. Drug sensitivity was estimated by MTT assay in vitro. MRP mRNA expression was decreased in KB8-5/alpha MRP-Rz cells. The MTT assay showed increased IC50 values or resistance to doxorubicin (DOX), etoposide (VP-16) and cisplatin (CDDP) in KB8-5/alpha MRP-Rz cells. No significant differences were observed in expression of multidrug resistance gene (MDR1), thymidylate synthase, glutathione S-transferase pi or topoisomerase II alpha. The hammerhead ribozyme-mediated simple suppression of MRP mRNA expression was not sufficient to reverse multidrug resistance in the cancer cell line KB8-5.

ATP Binding Cassette Transporter, Subfamily B↗

PubMedDate not supplied

Collateral sensitivity to azidothymidine in methotrexate resistant human leukemia cells.

Resistance to methotrexate (MTX) is a well established clinical problem and strategies to circumvent this would obviously be beneficial. The human leukemia cell line, CCRF-CEM, was grown in folinic acid to study MTX resistance-reflecting more in vivo conditions. A 15.8-fold resistant subline, CEM/MTX, was evolved by stepwise increases in MTX exposure. The MTX resistant cell line exhibited both increased dihydrofolate reductase (DHFR) activity due to gene amplification as well as impaired MTX uptake. An additional mechanism of resistance to MTX was a 2-fold increase in thymidine kinase (TK). As a result of this increased TK activity, the CEM/MTX cells were collaterally sensitive to the nucleoside analogue, azidothymidine (AZT). CEM cells resistant to MTX possess properties that can be exploited by AZT and these studies may have clinical implications.

Drug Resistance↗

PubMedDate not supplied

Dihydrofolate reductase gene expression characterized by the PCR assay in human leukemia cells.

A modified enzymatic amplification (PCR) method has been used to detect overexpression of the dihydrofolate reductase gene in human leukemic cells resistant to methotrexate (MTX) from both patient samples and cell lines in culture. Quantitation of DHFR mRNA by the PCR assay has been demonstrated to be more accurate and more sensitive than Northern blotting. This assay be useful in screening patients relapsing with drug resistance.

Base Sequence↗

PubMedDate not supplied

Molecular basis of cisplatin resistance in human carcinomas: model systems and patients.

In this review, cisplatin resistance will be summarized. We will discuss characteristics of potential mechanisms of resistance in tissues from patients with ovarian, colon and breast carcinoma. Secondly, a new molecular biology assay will be discussed which detects changes in gene expression in cisplatin-resistant cells. Finally, based on the biochemical and molecular properties of cisplatin-resistant tumors, new strategies to exploit or circumvent cisplatin resistance in human tumors will be entertained.

Cisplatin↗