Biomedical subjects

T Asaga

Publications and source records attributed to T Asaga.

At least 19 recordsLinked to original sources

PubMed2001

[Induction of apoptosis in breast cancer cells by preoperative oral administration of 5-fluorouracil].

We investigated whether 5-fluorouracil (5-FU) can induce apoptosis in breast cancer cells. Preoperatively, 23 breast cancer patients were divided into a group treated with 5-FU at 200 mg/day for 2 weeks (Group A) and a non-treatment group (Group B), and breast cancer tissues were taken postoperatively. DNA fragmentation by agarose electrophoresis and the TUNEL method were used to investigate the induction of apoptosis. The labeling rate with Ki-67 was measured to study the reproductive activity of tumor cells. The involvement of p53 in the apoptosis decision mechanism was also studied. DNA was more fragmented in Group A than in Group B. The apoptosis index by the TUNEL method was 1.88 +/- 1.03 in Group A, which was significantly higher than 0.36 +/- 0.86 in Group B. The labeling rate with Ki-67 was significantly higher in Group B(62.3 +/- 21.7) than in Group A (29.8 +/- 16.0). There was no difference in the protein expression of p53 regardless of the presence or absence of DNA fragmentation. These results indicate that 5-FU administration induces apoptosis in breast cancer cells and significantly inhibits their reproductive activity. Involvement of p53 in the apoptosis decision mechanism was not demonstrated.

Administration, Oral↗

PubMed2001

[A phase I study of docetaxel (TXT) and doxifluridine (5'-DFUR) combination therapy in patients with advanced and recurrent breast cancer].

We investigated efficacy and tolerance of chemotherapy with doxifluridine (5'-DFUR) and docetaxel (TXT) in advanced/recurrent breast cancer. Subjects were enrolled by central registration. The regimen included 5'-DFUR orally for 14 consecutive days, and TXT intravenously on day 8. It was repeated every 3 weeks, as long as possible, including dosage levels of 5 scheduled steps. Patient registration was started in August 1999 and 5 patients given level 1 regimen (5'-DFUR, 800 mg/day; TXT, 50 mg/m2) were evaluated. Although the results revealed neutropenia of grade 3 in 4/5 patients and leukocytopenia in 2/5 patients, no other side effects were observed. Taking into consideration the toxicity profiles of each drug in level 1, a level 2b regimen (5'-DFUR, 800 mg/day; TXT, 60 mg/m2) was accepted. Seven patients were registered for level 2b dosage and were examined for the safety of the regimen. Two patients discontinued the level 2b regimen due to percutaneous adverse reactions (DLT) and 6/7 patients developed neutropenia of grade 4. Clinical effects in level 1 group included: 1 CR, 2 PR, 1 long NC (NC longer than 24 weeks), and 1 NE, for a response rate of 60.0% (3/5 patients). Those in level 2b included: 2 CR, 2 PR, 1 NC, and 2 NE, for a response rate of 57.1% (4/7 patients). Based on the safety and efficacy of the combined therapy, the recommended dosage of this regimen is 5'-DFUR, 800 mg/day, combined with TXT, 60 mg/m2. A Phase II study is being conducted using this dosage.

Adult↗

PubMed2000

Significance of the parathyroid hormone-related protein expression in breast carcinoma.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) is produced by various neoplasms and is known to be a causative factor of hypercalcemia of malignancy. It has also been suggested to act as a cytokine for tumor progression. The purpose of this study was to clarify the significance of PTHrP expression in breast carcinoma. METHODS: PTHrP expression was examined in 177 surgically resected breast carcinoma specimens by immunohistochemistry using a monoclonal antibody against the for PTHrP, The relationship of PTHrP expression with clinicopathological factors was analyzed and the clinical courses of the patients are reported. RESULTS: Positive PTHrP staining was detected in 113 ( 64%) of the breast tumors. Among the positive cases, 36 (32%) of the tumors clearly showed strong expression. When the PTHrP expression was divided into three categories, a significant positive relationship was found between PTHrP expression and histological grade of tumor. PTHrP expression was also significantly related to bone metastasis but the staining degree of PTHrP was not. The patients with positive PTHrP tended to have poor outcome in proportion to the staining degree. Univariate analysis demonstrated a significantly shorter overall survival for patients expressing PTHrP, and in multivariate analysis showed that PTHrP status and nodal status were associated with a significantly shorter overall survival. CONCLUSION: Our results suggest that PTHrP expression is not only correlated with bone metastasis but is also related to the progression of breast carcinoma, and that overexpression of PTHrP may be a potential prognostic factor for human breast carcinoma.

Adult↗

PubMed1999

Apoptosis and proliferative activity in thyroid tumors.

To clarify the growth mechanisms of thyroid tumors, we examined apoptotic cells in 61 thyroid tumors, consisting of 14 adenomas, 35 papillary carcinomas, 4 follicular carcinomas, and 8 undifferentiated carcinomas, using terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate digoxigenin-nick end labeling (TUNEL). The proliferative activity was also evaluated immunohistochemically using the monoclonal antibody to Ki-67 antigen (MIB-1) in the same tumors. The apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells, and a proliferation index (PI), being the percentage of Ki-67 positive cells, was calculated for each tumor. The overall level of AI was very low in all histotypes of the thyroid tumors analyzed, the mean AI being 0.5 +/- 0.4 in adenoma, 0.4 +/- 0.3 in differentiated carcinoma, and 1.8 +/- 1.5 in undifferentiated carcinoma. The PI in the thyroid tumor subtypes was significantly lower in adenoma and differentiated carcinoma, at 0.5 +/- 0.7 and 1.1 +/- 0.7, respectively, than that in undifferentiated carcinoma at 14.5 +/- 3.7 (P < 0.05). There was no correlation between clinicopathological factors and AI or PI in differentiated thyroid carcinoma. Our findings suggest that apoptosis occurs infrequently in thyroid tumors, and that proliferative activity markedly differs according to the thyroid tumor subtypes. Moreover, the ratio between proliferating cells and apoptotic cells may reflect thyroid tumor progression.

Adenocarcinoma, Follicular↗

PubMed1998

[Orbital and stomach metastasis from invasive lobular breast carcinoma].

Orbital or ocular metastatic tumors may originate from breast cancer. Few studies have been made regarding their histopathological classification. A 71-year-old female noted a tumor in the right orbital region. She had had bilateral breast cancer 2 years before and gastric cancer 5 months before. Histopathology had shown stage II invasive ductal cancer (scirrhus) in the right breast and stage III invasive lobular cancer in the left. Signet-ring cells were present in the breast and gastric cancers. Biopsy of the right lower eyelid showed poorly differentiated adenocarcinoma with signet-ring cells. Indian file pattern, which is specific for invasive lobular cancer, was also present, suggesting that the orbital tumor had metastatized from the left breast cancer. Genetic analysis of the gastric cancer using polymerase chain reaction showed a mutation at exon 8 of the p53 tumor suppressor gene, indicating the cancer to be metastatic. These results led to the conclusion that invasive lobular cancer of the left breast was the primary lesion for the gastric and orbital metastases. This case also illustrates that signet-ring cells, which are usually seen in gastric cancer, may be present in invasive lobular breast cancer and in orbital metastasis.

Aged↗

PubMed1998

[Hepatocyte growth factor (HGF) in fluid from operation fields of breast surgery].

Recently, it is suggested that hepatocyte growth factor (HGF) is produced by fibroblasts with Interleukin-1. Therefore tumor cells seem to be promoted by HGF in the operation fields. We measured HGF in serum and fluid from operation fields, and evaluated its clinical significance. Fifty-one breast cancer patients who underwent breast surgery were enrolled. Serum HGF was measured on the day before operation and on the first, fifth and seventh postoperative days and fluid HGF on the first and fifth postoperative days, both by ELISA method. Fluid HGF was 10-12 fold higher than serum HGF. This result indicated that fibroblasts in the operation fields probably produced HGF. Moreover, invasive surgery and long operation time induced higher HGF concentrations. Serum HGF concentrations were higher in stage IV cases than in stage I-III cases. This probably means that not only fibroblasts but also breast cancer tissues secrete HGF. Fluid addition to the culture promoted MCF-7 cells in cultivation. We suggest that HGF was produced in the operation fields by fibroblasts and that HGF promotes tumor cells.

Breast Neoplasms↗

PubMed1997

[Efficacy of ring-shape cover in active skin surface warming in neonates--a retrospective comparative study with conventional methods].

UNLABELLED: Prevention of perioperative hypothermia is one of the most essential factor for neonatal anesthesia. Recently the forced-air warming system has been considered the most effective method in preventing perioperative hypothermia in adults, in children, and in infants during maxillofacial operations. However, its use for abdominal or thoracic surgery in neonates has not been examined. In the present study, we studied the effects of the forced-air warmer with a ring-shape cover, and compared this method with the conventional method retrospectively. PATIENTS AND METHODS: Sixteen neonates, 13 for abdominal and 3 for thoracic surgery were anesthetized with oxygen-air (nitrous oxide) sevoflurane (isoflurane or enflurane) in combination with/without fentanyl. They were divided into two groups; one for forced-air warming (F-group), and another for conventional methods (C-group). The patients' mean age, height and weight, the duration of anesthesia, infusion rate (ml.kg-1.hr-1), and urine output did not differ each other. Patients in F-group were placed in the center of the ring-shape cover and received heated air from their surroundings. We did not use any other warming equipment or means except for an artificial nose and a warming mattress. "Medium" heated air (38 degrees C) or unheated, room temperature air were used when necessary. The operating room temperature was kept around 25 degrees C. Patients in the C-group were placed on a warming mattress and under an infrared radiant heater with the room temperature of 30 degrees C. Their extremities were covered with aluminum-foil. Rectal, deep forehead, and deep sole temperatures were monitored throughout anesthesia. RESULTS AND CONCLUSION: In F-group, temperatures were well maintained, while C-group failed to maintain. In F-group, the mean value of base excess at the beginning of the operation was -1.8 mM, but it was restored to normal level without administration of sodium bicarbonate. No complications were found. Thus, compared to conventional methods, the forced-air warming system with a ring-shaped cover is an efficient method for body temperature management in neonatal anesthesia.

Anesthesia, General↗

PubMed1996

[In vitro chemosensitivity test for seven undifferentiated thyroid carcinoma cell lines using MTT assay].

In the current study, we ran a chemosensity test on 7 human undifferentiated carcinoma cell lines against 10 anticancer compounds using MTT assay. Efficacy was estimated by comparing fifty percent inhibitory concentration (IC50) with the peak plasma concentration. The results showed that the 7 cell lines could be divided into two groups which had different (high or low) chemosensitivity, and that in the high sensitivity group, ACD, VCR, and etoposide were indicated as useful drugs. Our results suggest that it may be impossible to rescue all undifferentiated carcinoma patients by chemotherapy alone because the tumor may consist of 2 clones which have a different chemosensitivity.

Antineoplastic Agents↗

PubMed1995

Dual-energy subtraction mammography.

Dual-energy subtraction mammography was performed for breast examinations. To obtain a dual-energy subtraction image with a digital radiography unit, high- and low-energy images were obtained at an appropriate time interval under different x-ray exposure conditions. In about 50% of the patients with breast cancer included in this study, we obtained better diagnostic accuracy with dual-energy subtraction images than with conventional mammography. In some cases of breast cancer, it is possible to diagnose intraductal spread of this lesion on the subtracted images. Furthermore, abnormal lesions commonly observed on mammography in cases of fibrocystic disease tended to be erased on subtracted images. Thus, dual-energy subtraction mammography provided useful information for diagnosing breast diseases. However, there were several cases in which the subtracted images lacked sufficient image quality, and several technical problems with subtraction are thought to remain.

Breast Neoplasms↗

PubMed1994

Production of cytokines by thyroid carcinoma cell lines.

Five cell lines were established from four undifferentiated carcinomas and one squamous cell carcinoma of the thyroid. The levels of several kinds of cytokines were measured in the conditioned media of these cell lines by enzyme-linked immunosorbent assay (ELISA). Interleukin-6 (IL-6) was produced by four of the five cell lines, interleukin-1 alpha (IL-1 alpha) by three cell lines, and granulocyte-colony stimulating factor (G-CSF) by two cell lines. The mRNA of IL-1 alpha or IL-6 was detected by Northern blot analysis in all the cell lines which secreted these cytokines into culture medium. These results suggest that undifferentiated carcinoma and squamous cell carcinoma of the thyroid frequently produce cytokines. Further studies are needed to clarify the possible clinical effects of these cytokines in patients with thyroid carcinoma.

Aged↗

PubMed1994

Alteration of tumorigenicity in undifferentiated thyroid carcinoma cells by introduction of normal chromosome 11.

The tumorigenicity of various cell lines has been shown to be suppressed by the introduction of chromosome 11 and other chromosomes via micro-cell-mediated chromosome transfer. In this study, we investigated whether a human undifferentiated thyroid carcinoma cell line, TTA-1, was suppressed by the introduction of normal human chromosome 11 or 10. Chromosome 10 or 11 was transferred from A9 cells containing a single human chromosome 10 or 11 tagged with pSV2-neo plasmid DNA into TTA-1 cells, by microcell fusion. The tumorigenicity of the TTA-1 cells and their colony-forming efficiency in soft agar were suppressed by chromosome 11, but not by chromosome 10. These results suggest that normal human chromosome 11 carries a putative tumor suppressor gene that affects the tumor-associated phenotypes of TTA-1 cells.

Animals↗

PubMed1994

[Evaluation of parasternal (Ps) and supraclavicular (Sc) node dissection combined with targeting chemotherapy (activated carbon particle adsorbing aclarubicin) in breast cancer with Ps node involvement--usefulness of extended surgery for improvement of prognosis].

We treated breast cancer patients with Ps node involvement using an extended surgery (Ps+Sc, n = 17, group A) combined with targeting chemotherapy and compared the survival rate by this method with that by the dissection of the Ps node alone (n = 23, group B) to assess the prognosis of advanced breast cancer by extended surgery. 1) Overall patients: The disease-free survival rate was significantly higher in group A, while the overall survival rate was not significant. 2) Survival rate in relation to the number of metastatic Ps nodes or axillary (Ax) nodes: In patients with Ps = 1 or Ax < or = 3, the difference in the overall and disease-free rates were not significant. In patients with Ps > or = 2 or Ax > or = 4, both overall and disease-free rates were significantly higher in group A. It was therefore suggested that extended surgery should be performed if metastasis is found in 2 or more Ps nodes in the frozen section intraoperatively. The result of this study, although it is not a randomized trial, suggested a possibility that extended surgery may improve the prognosis of advanced breast cancer.

Aclarubicin↗

PubMed1993

[The growth activity and DNA ploidy in anaplastic carcinoma transplanted to nude mice].

Recently, nuclear DNA contents of various human tumors were studied, and DNA aneuploidy was thought to have prognostic significance in many kinds of malignant tumors. Although the same significance was reported in thyroid carcinoma, the anaplastic thyroid carcinoma which is one of the most aggressive tumor in human malignant neoplasms, not always shows DNA aneuploidy. Therefore, using 3 xenografts established from 3 patients with anaplastic thyroid carcinomas, we investigated their growth activity, DNA ploidy and chromosome abnormalities. Two of these xenografts grew relatively fast in nude mice showing diploid or near diploid state in a flow cytometric study, and also, showed many structural abnormalities in chromosome analysis by the G-banding technique. The remaining one xenograft showed slower growth and aneuploidy, and had extensive numerical but less structural variability in its chromosomal constitution. These results indicate that some tumors showed DNA diploidy and have structural chromosome abnormalities and also suggest that the prognostic value of quantitative DNA measurement is limited in such tumors.

Aneuploidy↗

PubMed1992

Proliferative activity in thyroid tumors.

To clarify the proliferative activity of papillary thyroid carcinoma, the bromodeoxyuridine (BrdU) labeling index (LI) of 61 various thyroid tumors was investigated using an in vitro labeling technique and immunohistochemical staining with anti-BrdU monoclonal antibody. The mean LI (+/- standard deviation) of 31 papillary carcinomas, 12 adenomas, 10 adenomatous goiters, 3 follicular carcinomas, and 2 medullary carcinomas were 1.2% (+/- 1.3%), 0.6% (+/- 0.3%), 0.7% (+/- 0.6%), 1.5% (+/- 2.2%), and 0.7% (+/- 0.6%), respectively. The LI of the papillary carcinomas ranged from 0.1% to 4.6%, and approximately 66% of these showed less than a 1% similarity with almost all benign tumors. However, the LI of the two malignant lymphomas and the one anaplastic carcinoma were more than 13%. When the LI of the papillary carcinomas was compared with their various prognostic factors, there was no correlation with tumor size, nodal status, or morphologic features. However, the patients who were 50 years of age or older tended to have relatively high LI, and the LI of the papillary carcinomas correlated with patient age. According to these results, the biologic characteristics of papillary carcinomas vary with age and high proliferative activity may contribute to the poor prognosis of this tumor in elderly patients.

Adenoma↗

PubMed1991

The enhancement of tumor growth after partial hepatectomy and the effect of sera obtained from hepatectomized rats on tumor cell growth.

In the process of liver regeneration, the participation of various types of growth stimulators and changes in immune responses have been reported. Here, we examined the growth of subcutaneously transplanted AH130 cells and Walker 256 cells after partial hepatectomy. In the case of tumor cells being transplanted on the same day as partial hepatectomy, the increase in tumor size in hepatectomized rats was significantly greater compared with that in non-treated rats or in those having undergone a simple laparotomy. When the transplantation of tumor cells was done on the 7th day after partial hepatectomy, however, the increase was less marked. We also examined the effect of serum obtained from rats after partial hepatectomy on the in vitro growth of these tumor cells. Growth enhancement was observed with medium containing serum drawn from rats 1 to 4 days after partial hepatectomy. These results suggest that the growth of tumor cells was stimulated during liver regeneration and that some humoral factors participated in the process. Furthermore, as the conditions of the in vitro method appear to mimic those of the in vivo method, the in vitro approach should be very useful for analysis of the factors responsible.

Animals↗

PubMed1990

Bradykinin induces inositol 1,4,5-trisphosphate-dependent hyperpolarization in K+ M-current-deficient hybrid NL308 cells: comparison with NG108-15 neuroblastoma x glioma hybrid cells.

External application of bradykinin (BK) to mouse neuroblastoma X mouse fibroblast hybrid NL308 cells and mouse neuroblastoma X rat glioma hybrid NG108-15 cells produced a transient outward (hyperpolarizing) current. In NG108-15 cells, BK also induced an inward (depolarizing) current associated with a decrease in input membrane conductance, which results from the inhibition of a voltage-sensitive potassium current, the M-current. However, in NL308 cells, either no depolarization was elicited by BK or, even if the BK-induced depolarization was evoked, it was associated with an increased conductance. To explain the above difference, the intracellular second messenger system of NL308 cells was examined in detail. BK induced the rapid accumulation (three- to fivefold higher than the control level) of inositol 1,4,5-trisphosphate (InsP3) in NL308 cells. The cytosolic Ca2+ concentration was also elevated to 540 nM from 180 nM at a basal level. This seems to be enough to activate a voltage-independent and Ca2(+)-sensitive K+ current, resulting in the hyperpolarization. Intracellular injection of InsP3 replicated the hyperpolarization. NL308 cells possess protein kinase C (C-kinase), with specific activities of C-kinase in cytosolic and membrane fractions being 233 and 24 pmol/min/mg protein, respectively. The activity associated with particulates became higher after phorbol dibutyrate (PDBu) treatment. But NL308 cells did not show the characteristic inward relaxation by step hyperpolarizations and the outward rectification in the current-voltage relationship, indicating that the M current is deficient in NL308 cells. Therefore, application of PDBu failed to mimic the inward current. The results suggest the role of InsP3 and C-kinase in controlling two K+ currents.

Animals↗

PubMed1990

[Extended radical mastectomy using preoperative local injection of activated carbon particle adsorbing aclarubicin (ACR-CH)].

ACR-CH was injected prior to surgery of breast cancer. Incidence of black staining of regional lymph nodes and concentration of ACR in the nodes were examined in order to evaluate the usefulness of preoperative local injection of ACR-CH. 1) In 13 cases of extended radical mastectomy, black staining was seen in nodes of all the regions. Especially, in parasternal, retromanubrial, anterior mediastinal and supraclavicular nodes, 46% or more of the nodes were stained and ACR concentration of 6-7 micrograms/g was obtained. 2) When incidence of black staining of the metastasis-free nodes was compared with that of the nodes with metastasis, it was 79% in the metastasis free nodes and 42% in the nodes with metastasis. The average ACR concentration was 54.16 +/- 123.16 in the stained nodes and 2.58 +/- 3.59 in unstained nodes, the former being significantly higher than the latter. 3) Majority of the stained nodes with metastasis had only very small metastatic foci and nodes with significant metastasis were only very rarely stained. 4) In conclusion, we believe that anticancer effect of ACR-CH can be expected to small metastatic foci in the parasternal lymph nodes and more distal nodes, dissection of which tends to be incomplete at extended radical mastectomy, as well as to free cancer cells in the lymph vessels.

Aclarubicin↗

PubMed1988

[Dual-energy subtraction radiography of the breast].

Dual-energy projection radiography was applied to breast examination. To perform the dual-energy subtraction radiography using a digital radiography unit, high and low-energy exposures were made at an appropriate time interval under differing X-ray exposure conditions. Dual-energy subtraction radiography was performed in 41 cancer patients in whom the tumor shadow was equivocal or the border of cancer infiltration was not clearly demonstrated by compression mammography, and 15 patients with benign diseases such as fibrocystic disease, cyst and fibroadenoma. In 21 cases out of the 41 cancer patients, the dual-energy subtraction radiography clearly visualized the malignant tumor shadows and the border of cancer infiltration and the daughter nodules by removing the shadows of normal mammary gland. On the other hand, benign diseases such as fibrocystic disease and cyst could be diagnosed as such, because the tumor shadow and the irregularly concentrated image of mammary gland disappeared by the dual-energy subtraction. These results suggest that this new technique will be useful in examination of breast masses.

Breast Neoplasms↗