Search PubMed⌕ Search

Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 199 records · Page 11Linked to original sources
PubMed1994

[Cytofluorometric chase of the cancer cells after release from G2-block induced by peplomycin].

To study the alteration of nuclear DNA content of cancer cells after peplomycin (PEP) treatment, DNA cytofluorometry was performed in combination with 3H-thymidine (3H-TdR) autoradiography using cultured A431 cells. The cells in the logarithmic growth were treated with PEP (1.25 micrograms/ml) for 24 hr, during the first 4 hr of which they were pulse-labeled with 3H-TdR (2.4 x 10(4) Bq/ml). After washing with PBS, the cells were then cultured without both PEP and 3H-TdR, fixed at different times and stained with propidium iodide (PI) for the auto-stage cytofluorometry, which enabled DNA content analysis for labeled and unlabeled cells by repeated scanning of the same cell population. The nuclear DNA content histograms demonstrated that A431 cells were mostly arrested in G2 phase of 4C stem line by treatment with PEP for 24 hr. This G2 block lasted up to 8 hr after removal of the drug, and thereafter, marked polyploidization associated with DNA synthesis occurred, showing almost no mitotic figures, while only a few cells returned to G1 phase via M phase. During the period of 72-120 hr, however, the fractions of advanced polyploid cells (DNA content > or = 8C) gradually decreased and the DNA content distribution pattern became eventually similar to the original one as seen before PEP treatment. From these results we hypothesized as follows: 1) At S-G2 boundary, there is some control mechanism that checks whether the cells, after S phase, can enter the M phase or not. 2) The cells, which are not permitted to enter mitosis by the control mechanism, show marked polyploidization. 3) Only the cells that enter into mitosis can live and proliferate, though the advanced polyploid cells die shortly. 4) This control mechanism might be related to the precision of DNA repair that is checked at the G2-M checkpoint.

Autoradiography↗
PubMed1994

[A case of Borrmann type 4 gastric cancer responding to sequential methotrexate and 5-fluorouracil combined with CDDP].

A case of Borrmann type 4 gastric cancer responding to sequential methotrexate and 5-fluorouracil combined with cis-diamminedichloroplatinum (CDDP) is reported. A 57-year-old woman was admitted to our hospital complaining of abdominal fullness. Upper gastrointestinal series and gastrofiberscopy revealed almost the entire stomach was involved with Borrmann type 4 cancer. Gastrectomy could not be performed because of peritoneal dissemination. However, the patient responded to sequential methotrexate and 5-fluorouracil therapy and CDDP administration. She enjoyed more than one year of hospital-free survival period and survived for almost two years.

Adenocarcinoma↗
PubMed1993

Age-related change in the proportion of amyloid precursor protein mRNAs in the gray matter of cerebral cortex.

Alternative splicing of a transcript of amyloid precursor protein (APP) gene generates at least three types of mRNA coding for APP770, APP751, and APP695; the former two harbor, while the latter one lacks a Kunitz-type serine protease inhibitor (KPI). We compared, by using the RNase protection technique, APP mRNAs expression between gray and white matters in the frontal lobe, with special reference to Alzheimer's disease (AD) and aging. The proportions (y) of APP770 plus APP751 mRNAs in the white matter were nearly twice as much as those in the gray matter, both in control (non-AD) and AD brains; the difference between the two matters was statistically significant. Furthermore, in the gray matter of control, there was a positive correlation (y = 1.07 x-57.1, r = 0.899) between the age (x) and the proportion (y), but not in the white matter where the proportion varied markedly among individuals. In AD brains, no significant correlation was found in either of the two matters. These results indicated that the APP mRNAs proportion in the gray matter may serve as a molecular index of the brain aging in non-AD persons.

Aged↗
PubMed1993

Functional expression of human P-glycoprotein in Schizosaccharomyces pombe.

Human MDR1 cDNA was introduced into the human cultured cells KB-3-1 and Schizosaccharomyces pombe pmd1 null mutant KN3. The drug sensitivity of KB-G2 and KN3/pgp, expressing human P-glycoprotein, was examined. KB-G2 was resistant to the peptide antibiotics valinomycin and gramicidin D as well as having a typical multidrug resistance (MDR) phenotype. KN3/pgp was resistant to valinomycin and actinomycin D, but not to adriamycin. The ATP-hydrolysis-deficient mutant did not confer KN3 resistance to these antibiotics. Human P-glycoprotein expressed in S. pombe seemed to lack N-glycosylation. The N-glycosylation-deficient mutant, however, conferred a typical MDR phenotype on KB-3-1. These results suggest that human P-glycoprotein functions as an efflux pump of valinomycin and actinomycin D in the membrane of S. pombe.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Erythrocyte galactokinase assay with high performance liquid chromatography.

An assay for erythtocyte galactokinase based on high performance liquid chromatographic determination of galactose 1-phosphate (Gal-1-P) is described. The determination of Gal-1-P was applied to a post-column fluorometric detection of reducing sugars using arginine. This method is as sensitive and accurate as conventional radioisotopic methods, but needs no radioisotopic facilities. It requires only a small blood sample and is suitable as a follow-up test in neonatal screening.

Adult↗
PubMed1993

Association of the antibodies against human papillomavirus 16 E4 and E7 proteins with cervical cancer positive for human papillomavirus DNA.

Occurrence of the antibodies against human papillomavirus (HPV) 16 proteins E4 and E7 is specifically but independently associated with cervical cancer. To correlate HPV DNA and antibody data, we examined the biopsy specimens and sera, by polymerase chain reaction (PCR) and by ELISA, respectively, from 51 patients with cervical cancer (including 3 recurrent cases) and 22 with cervical intra-epithelial neoplasia. Consensus primers for the L1 region were used for PCR and bacterially expressed, purified fusion protein HPV-16 E4 and non-fusion protein HPV-16 E7 were used for ELISA. HPV-16 DNA and other HPV types were detected in 17 and 25, respectively, out of 51 cases of cervical cancer. Ten out of the 17 HPV-16-DNA-positives were positive either for anti-E4 or for anti-E7: positivities for anti-E4, for anti-E7, and for both were 6/17, 5/17 and 1/17 respectively. Three anti-E7-positives consisted of those for HPV-33, -52 and -58 DNA, suggesting that limited cross-reaction occurred between the HPV types. Among the HPV-16-DNA-positive cases of cancer, lymph-node or distant metastasis was recorded more frequently in the seropositives than in the seronegatives. Our results show that the HPV-16 anti-E4 or anti-E7 occurs in some, but not in all, of the HPV-16-DNA-positive cases, and support the hypothesis that the presence of the HPV-16 antibodies can be used as a marker for possible metastasis.

Adult↗
PubMed1993

Enzymatic diagnosis of steroid sulfatase deficiency by high performance liquid chromatography.

We established a reversed phase high performance liquid chromatographic (HPLC) method of assaying lymphocyte steroid sulfatase activity using estrone sulfate as the substrate. Application of this method for diagnosis of 8 patients allowed us to clearly distinguish the patients from the normal controls. This method is simpler and less expensive than the method previously reported, since neither radioisotope labeled substrates nor radioisotope facilities are required. We consider it to be easily used and widely available in most clinical laboratories.

Adult↗
PubMed1993

P-glycoprotein-mediated transcellular transport of MDR-reversing agents.

Understanding of the interactions between P-glycoprotein and multidrug resistance (MDR) reversing agents is important in designing more effective MDR modulators. We examined transcellular transport of several MDR modulators by using a drug-sensitive epithelial cell line, LLC-PK1, and its transformant cell line, LLC-GA5-COL300, which expresses human P-glycoprotein on the apical surface. Basal-to-apical transports of azidopine and diltiazem across the LLC-GA5-COL300 monolayer were increased and apical-to-basal transports were decreased compared to those across the LLC-PK1 monolayer, indicating that P-glycoprotein transports azidopine and diltiazem. Movements of nitrendipine and staurosporine across the epithelial monolayer were not affected by P-glycoprotein. These results suggests that some MDR modulators exert their inhibitory effect not only by blocking the initial binding of anticancer drugs but throughout the course of the transport process.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Human P-glycoprotein transports cyclosporin A and FK506.

Cyclosporin A, a cyclic undecapeptide, and FK506 are efficient immunosuppressive agents. They also attract attention as effective P-glycoprotein modulators that inhibit P-glycoprotein from binding to anticancer drugs and overcome multidrug resistance. Cyclosporin A itself interacts with a common binding site of P-glycoprotein to which Vinca alkaloids and verapamil bind. We were interested to determine whether cyclosporin A and FK506 are substrates for P-glycoprotein to transport, and we studied their transcellular transport. In LLC-PK1 cells, derived from porcine kidney proximal tubule and forming a highly polarized epithelium, cyclosporin A was transported in a saturable manner. LLC-GA5-COL300, a transformant cell line derived by transfecting LLC-PK1 with human MDR1 cDNA isolated from normal adrenal gland, expresses P-glycoprotein specifically on the apical surface and shows a typical multidrug-resistant phenotype. LLC-GA5-COL300 cells showed increased transport of cyclosporin A from the basal to the apical side. Kinetic analysis showed that this transport was a typical saturable transport with the calculated apparent Michaelis constant (Kappm) and the maximum flux (Vmax) as 8.4 microM and 2.4 nmol/mg protein/h, respectively. LLC-GA5-COL300 also showed increased transport of FK506 from the basal to the apical side. These results indicate that P-glycoprotein transports the immunosuppressive agents cyclosporin A and FK506.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Mother-to-child transmission of human T-lymphotropic virus type I (HTLV-I): an extended follow-up study on children between 18 and 22-24 years old in Okinawa, Japan.

The significant difference observed between the seroprevalence of HTLV-I in adults and in children is as yet unexplained. To evaluate a hypothetical explanation of the existence of seroconversion cases of "seronegative carriers" for this phenomenon, 21 of 55 children who had been born to seropositive mothers and who remained seronegative until the age of 18 years were further followed up at the ages of 22 and/or 24 years. None of the 21 seronegative children born to seropositive mothers seroconverted, either at 22 years or at 24 years. In addition, the polymerase-chain-reaction (PCR) technique could not prove the existence of the HTLV-I provirus genome in peripheral mononuclear cells (PBMC) of 10 of these children. Our results fail to prove the possibility of viral latency of HTLV-I in mother-to-child transmission. Therefore, the hypothetical seroconversion of "seronegative carriers" after adulthood cannot be an explanation.

Adolescent↗
PubMed1993

Frequent isolation of human herpesvirus 7 from saliva samples.

Human herpesvirus 7 (HHV-7) was isolated frequently from saliva specimens. The isolation rates were 81% (13/16) in adults, 70% (7/10) in children over 1 year old, and none (0/7) in children less than 1 year old, respectively, indicating that infection of HHV-7 occurs during early infancy and the virus shedding rate after infection is very high. Human herpesvirus 6 (HHV-6) was not isolated from saliva specimens although some studies on isolation of HHV-6 from saliva was reported previously.

Adult↗
PubMed1993

Phylogenetic relationships of ferns deduced from rbcL gene sequence.

Part of the large subunit of the ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) gene (rbcL) was sequenced from three fern species: Adiantum capillus-veneris, Botrypus strictus, and Osmunda cinnamomea var. fokiensis. This region included 1,333 base pairs, about 90% of the gene. Maximum likelihood analysis of the deduced amino acid sequences indicated that (1) Botrypus (Ophioglossaceae) clustered monophyletically with other ferns (Adiantum, Angiopteris, Osmunda); the closest relative to Botrypus among the three species was Osmunda, which did not support the hypothesis that the Ophioglossaceae are linked to the progymnosperm-seed plant lineage. (2) Eusporangiate ferns containing Botrypus (Ophioglossaceae) and Angiopteris (Marattiaceae) were a paraphyletic group. (3) Seed plants and the four fern species examined formed a monophyletic group, but ferns and bryophytes (liverwort) did not. Variations in rates of substitution for synonymous and nonsynonymous codons were found in fern lineages.

Amino Acid Sequence↗
PubMed1993

A case of cerebral glioblastoma with extensive cerebrospinal fluid dissemination: diagnostic value of immunohistochemical examination and MR imaging.

A 9-year, 6-month-old boy presented with peripheral-type multiple cranial nerve palsy due to extensive cerebrospinal fluid (CSF) dissemination of intracranial glioblastoma multiforme. Tissue obtained from biopsy did not stain for glial fibrillary acidic protein (GFAP). The relationship between GFAP-negative tumor cells and extensive CSF dissemination agreed with recent reports. Magnetic resonance imaging with gadolinium-DPTA enhancement clearly depicted not only the cranial meningeal dissemination but also spinal metastasis. Magnetic resonance imaging showed undoubted usefulness in demonstrating disseminated glioblastoma.

Brain↗
PubMed1993

Prevalence of type 2 (non-insulin-dependent) diabetes mellitus and impaired glucose tolerance in the Japanese general population: the Hisayama Study.

We determined the population-based prevalence of diabetes mellitus in members of the Japanese community, Hisayama aged 40-79 years old by a 75-g oral glucose tolerance test. The basic population used to calculate diabetic prevalence was 1,077 men (72.8% of the whole population in the same age range) and 1,413 women (80.8%) including ten diabetic patients on insulin therapy. In addition, we compared the prevalence of history of diabetes which was acquired by interview or questionnaire, between participants and non-participants in the 75-g oral glucose tolerance test, but they were not statistically different. The age-adjusted prevalence of diabetes to world population was 12.7% for men and 8.4% for women, and that of impaired glucose tolerance was 19.6% for men and 18.4% for women. These figures were much higher than those previously reported from several Japanese communities. The results obtained from the present study could reveal true prevalence of diabetes among the Japanese population. In addition, the reasons for the increasing prevalence of diabetes among the recent Japanese population are also discussed.

Adult↗