Biomedical subjects

K Asanuma

Publications and source records attributed to K Asanuma.

97 records · Page 6Linked to original sources

PubMedDate not supplied

Management of tracheal wall resection for thyroid carcinoma by tracheocutaneous fenestration and delayed closure using auricular cartilage.

BACKGROUND: In the case of advanced thyroid carcinoma invading the trachea, surgical procedures for tracheal resection are selected in relation to the degree of invasion. We created a tracheocutaneous fenestration that was later closed with a free auricular cartilage autograft. We present a simple and effective method for permanent closure of tracheostoma. METHODS: The surgical procedure for delayed closure consists of three steps: (1) preparing the hinge flap with additional undermining of the subcutaneous layer and the strap muscles; (2) removing a portion of the conchal cartilage from the auricle, which is easily performed with a semicircular skin incision along the anthelix of the ear; and (3) placing the conchal cartilage with its convex surface upward just over the sutured hinge flap layer. RESULTS: Under local anesthesia, we successfully employed this reconstructive procedure for 5 patients. Unfortunately, however, in one patient, we had to reopen the closed tracheocutaneous fenestration on the second postoperative day because of an acute problem that was independent of the closure surgery. Four patients remain in satisfactory condition for more than 2 years since the closure of tracheostoma. CONCLUSIONS: The auricular cartilage free graft is a relatively simple procedure which supplies tracheal wall skeletal support for the permanent closure of the tracheocutaneous fenestration.

Aged↗

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

Hematopoietic progenitor cell counts performed by the Sysmex SE-9000 analyzer can guide timing of peripheral blood stem cell harvest.

BACKGROUND: We studied whether the hematopoietic progenitor cell (HPC) count in peripheral blood as evaluated by an automated counter, the Sysmex SE-9000, correlated with CD34 positive (+) cell count and therefore could guide the timing of peripheral blood stem cell (PBSC) harvest. MATERIALS AND METHODS: HPC count and flow cytometric CD34+ cell count were measured in 90 peripheral blood samples and 30PBSC samples. The correlation between HPC count and apheretic CD34+ cell yield was examined in 19 patients. RESULTS: HPC count showed good correlations with CD34+ cell count in peripheral blood (r = 0.699) and PBSC (r = 0.892). The correlation between peripheral blood HPC count and apheretic CD34+ cell yield also was good (r = 0.789). CONCLUSION: Automated HPC counting can be used as a screening test to guide the timing of PBSC harvest.

Adult↗

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↗

PubMedDate not supplied

MRI of malignant melanoma of liver.

We report MR images of primary malignant melanoma of the liver. The tumor showed heterogeneously increased signal intensity on both T1- and T2-weighted images. After the administration of gadolinium-DTPA, the lesion presented irregular enhancement. Autopsy revealed a large black mass surrounded by fibrous tissue. The tumor consisted of atypical cells with melanin pigment, and had intratumoral degeneration, necrosis, and hemorrhage.

Aged↗

PubMedDate not supplied

BK virus-induced osteosarcoma (Os515) as a model of human osteosarcoma.

BK virus was isolated by Gardner et al in 1971 from the urine of an immunosuppressed patient with a kidney allograft. Antibodies to this virus are ubiquitous in the general populations worldwide, but the oncogenic capacity of BKV in humans had not been reported. The virus transformed in vitro permissive human and non-permissive animal cells, and the transformed cells had the T antigen. Intracerebral and intravenous inoculation of BKV in newborn hamsters induced malignant tumours (mainly ependymomas, malignant insulinomas, and osteosarcomas). Subcutaneous and intraperitoneal routes were also effective. The virus was only rescued from a few tumours by fusion with human embryonic cells or Vero cells. Brain tumours appeared earlier and osteosarcomas developed in animals which survived for more than 6 months. Many of the osteosarcomas were bony and grew slowly with frequent lung metastases, and a few osteosarcomas were soft and grew rapidly without lung metastases. Experimental targeting chemotherapy with doxorubicin (DX)-containing immunoliposomes was performed against Os515 osteosarcoma. In in vitro experiments, DX-Lip-MoAb29 showed a more significant inhibitory effect on cultured Os515 cells than free Dx and DX-Lip. DX-Lip DNP had less effect. In in vivo experiments, DX-Lip-MoAb29 suppressed the growth of Os515 tumour isografts in hamsters and prolonged the survival of recipients more significantly than free DX.

Animals↗