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Biomedical subjects

T Yajima

Publications and source records attributed to T Yajima.

242 records · Page 14Linked to original sources
PubMed1966

Anion permeability of the olfactory receptive membrane.

The ionic mechanism of the electropositive olfactory receptor potential was studied in the bullfrog and the swamp frog. The positive receptor potential strikingly decreased in amplitude in chloride-free solution. When the olfactory epithelium was immersed in high-KCl-Ringer's solution and then in Cl-free, high-K solution, the polarity of the positive potential could be reversed. This is supposed to be due to the exit of the increased internal chloride ion. From the above two experiments it is concluded that the positive olfactory receptor potential depends primarily upon the influx of the chloride ion through the olfactory receptive membrane. Some contribution by potassium and possibly other ions may occur. The ability of other anions to substitute for chloride was examined. It was found that only Br-, F-, and HCO2- could penetrate the olfactory receptive membrane. The sieve hypothesis in the inhibitory post-synaptic membrane (Coombs, Eccles, and Fatt, 1955) is not applicable to the olfactory receptive membrane on the basis of the size of hydrated ions, but it may be applicable on the basis of the sizes of naked ions.

Animals↗
PubMedDate not supplied

Microscopic assay for the phagocytotic-collagenolytic performance (PCP index) of human gingival fibroblasts in vitro.

Using 16 human gingival fibroblasts cell lines from patients with periodontitis, Dilantin hyperplasia, and nonpathological gingiva, a microscopic assay was developed to quantitate the cells' ability to lyse collagen substrates. The method employs tissue culture chambers with one cover slip partially coated with a thin layer of undenatured fibrillar bovine collagen. The assay measures the relative numbers and sizes of holes in the collagen within defined regions of the cover slips effected by the phagocytotoc and collagenolytic performance (PCP) of the population of fibroblasts growing on the cover slip for 5 days. The effect on the PCP index by serum, heparin, prostaglandins, and endotoxin was evaluated.

Blood↗
PubMedDate not supplied

Neoadjuvant intraarterial high-dose chemotherapy and autologous peripheral blood stem cell transplantation for advanced breast cancer.

Eight locally advanced breast cancer patients were treated with neoadjuvant intraarterial high-dose chemotherapy (epirubicin) plus MPA combined with autologous PBSCT. All patients completed the scheduled treatment, and there were no toxic deaths. Patients were treated with an escalating dose of epirubicin (370-480 mg) and cyclophosphamide (0-6000 mg). The rate of clinical response was 100%. The rate of good histologic response was 87.5% in the main tumor and 75% in diseased lymph nodes. The 2-year survival rate was 100%. Six patients were disease-free at the time of writing. This treatment resulted in higher rates of clinical and histologic response when compared with standard-dose intraarterial chemotherapy.

Adult↗
PubMedDate not supplied

Neoadjuvant intra-arterial infusion chemotherapy combined with hormonal therapy for locally advanced breast cancer.

To determine the efficacy of combined neoadjuvant intra-arterial infusion chemotherapy and hormonal therapy for treating locally advanced breast cancer, we compared the outcomes of patients with or without this therapy, and also assessed histologic response. Ninety-four patients with locally advanced breast cancer (stage IIIa, 56; stage IIIb, 38). Nineteen stage IIIa and 17 stage IIIb patients received intra-arterial plus hormonal therapy while 37 stage IIIa and 21 stage IIIb patients with similar ages and follow-up durations did not. Treated patients received intra-arterial epirubicin plus oral medroxy-progesterone. Five-year disease-free survival rates were 77.5% for intra-arterially treated and 33.0% for other patients in stage IIIa, and 70.5% for intra-arterially treated and 38.1% for other patients in stage IIIb. Five-year overall survival rates were 94.4% for intra-arterially treated and 61.7% for other patients in stage IIIa, and 90.9% for intra-arterially treated and 56.3% for other patients in stage IIIb. Ten-year overall survival rates in stage IIIb were 90.9% for treated and 22.5% for other group patents. All differences were statistically significant (p<0.05). Good histologic response to intra-arterial therapy was seen in 75% of the primary tumors and 71% of involved lymph nodes. Neoadjuvant intra-arterial therapy with hormonal therapy yielded better survival rates than no intra-arterial therapy or our previous intra-arterial regimen.

Administration, Oral↗
PubMedDate not supplied

Telomerase activity is down regulated via decreases in hTERT mRNA but not TEP1 mRNA or hTERC during the differentiation of leukemic cells.

BACKGROUND: Recent studies have determined several telomerase-associated molecules, but the precise mechanisms regulating telomerase activity by those molecules has not been fully understood. MATERIALS AND METHODS: The telomerase activity was determined by TRAP assay. Using TaqMan RT-PCR, the quantitative and kinetic values of mRNA expression of the three telomerase-associated molecules were examined in HL60 cells differentiated with tumor necrosis factor mutant and all-transretinoic acid. RESULTS: The levels of telomerase activity in leukemic cell lines, leukemic cells from patients, and normal peripheral blood cells were distributed over a very wide range. Human telomerase catalytic subunit (hTERT) mRNA expression declined to nearly undetectable levels more rapidly than the inhibition of telomerase activity after treatment with these reagents in HL60 cells. Telomerase-associated protein (TEP1) mRNA increased approximately 6-fold over its level in untreated cells. The levels of human telomerase RNA component (hTERC) also increased approximately 2.7-fold at 5 days after treatment. CONCLUSIONS: These results suggest that telomerase activity is down-regulated mainly via decreases in hTERT, but not TEP1 and hTERC expression during the differentiation of leukemic cells.

Adolescent↗
PubMedDate not supplied

Quantitative analysis of the anti-apoptotic gene survivin expression in malignant haematopoietic cells.

BACKGROUND: In this study we investigated expression profiles of the anti-apoptotic gene survivin in malignant human haematopoietic cells. MATERIALS AND METHODS: Using a quantitative TaqMan reverse transcription-polymerase chain reaction, survivin and bcl-2 mRNA expression were examined in 12 malignant haematopoietic cell lines, in 21 patients with haematopoietic malignancies and in normal leukocyte fractions. RESULTS: Survivin mRNA levels, demonstrable in all 12 malignant cell lines, differed but showed no relationship to the cell of origin. Conversely, no survivin mRNA expression was detected in normal leukocyte fractions. Further, survivin mRNA was expressed in 16 out of 21 patients with malignancies. Five days after treatment of HL-60 cells with a combination of all-trans retinoic acid and tumor necrosis factor, survivin expression decreased to 14.1% of that in untreated cells. Further, survivin mRNA expression in K-562/ADR cells with acquired resistance to adriamycin was 1.7 times that in parent K-562 cells. CONCLUSION: Our results indicated the possibility that quantitation of survivin mRNA expression is a useful tool for the detection of haematopoietic tumor cells in clinical laboratory test and that survivin could be a target for treatment of haematopoietic malignancies.

Adolescent↗
PubMedDate not supplied

Quantitation of multiple myeloma oncogene 1/interferon-regulatory factor 4 gene expression in malignant B-cell proliferations and normal leukocytes.

BACKGROUND: We studied multiple myeloma oncogene 1/interferon-regulatory factor 4 (MUM1/IRF4) mRNA expression in various malignant human hematopoietic cell lines and normal leukocyte fractions. MATERIALS AND METHODS: A quantitative reverse transcription-polymerase chain reaction was used to assess expression and chromosomes were examined for anomalies by fluorescent in situ hybridization. RESULTS: Among 12 cell lines examined, mRNA transcripts were expressed only in B-lymphoblastic and myeloma cell lines. Myeloma cells and malignant cell lines derived from mature B cells expressed more transcript than cell lines derived from immature B cells. Transcript levels, however, showed no association with chromosomal translocations. Expression in B-cell fractions from healthy donors was much less than in the malignant cells. In addition, MUM1/IRF4 mRNA expressed in samples from patients with acute lymphoblastic leukemia derived from B cells but not T cells. CONCLUSION: Our results suggested that MUM1/IRF4 gene expression is related to stage of differentiation of malignant B cells and they indicated the possibility that the quantitative analysis of MUM1/IRF4 gene is a useful tool for detection of malignant B-cell proliferations in clinical laboratory tests.

Adolescent↗