Biomedical subjects
Publications and source records attributed to T Aiko.
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Thymidine phosphorylase (TP) has chemotactic and angiogenic activity in vitro, and it promotes tumor growth and inhibits apoptosis in vivo. It plays a key role in the invasiveness and metastasis of TP-expressing solid tumors. KB/TP cells transfected with a TP cDNA have been shown to be resistant to hypoxia-induced apoptosis, suggesting that TP has effects on tumor growth and cell death independent of its effects on angiogenesis. However, the mechanisms of cell death inhibition by TP are unknown. In the present study, we demonstrate that caspase-8 is cleaved in control transfectant KB cells early on during Fas-induced apoptosis. Caspase-8 activation leads to the loss of mitochondrial membrane potential, followed by the release of cytochrome c, the activation of caspase-3, and apoptosis. In contrast, Fas-induced caspase-8 cleavage is inhibited in KB/TP cells, which lead to inhibition of the downstream apoptotic cascade and inhibition of apoptosis. These findings indicate that TP plays an important role in intracellular apoptotic signal transduction in the Fas-induced apoptotic pathway. Therefore, inhibition of TP may suppress the progression of TP-overexpressing solid tumors by inducing apoptosis.
The incidence and circumstances of colonization by methicillin-resistant Staphylococcus aureus were prospectively investigated. Among 404 patients, 15 (3.7%) were carriers on admission, and 43 (10.6%) became colonized, mainly after surgical operation. A different mode of transmission was suggested in each ward.
The expression of MUC-1 mucin (membrane-associated mucin) and MUC-2 mucin (secretory mucin) were immunohistochemically examined in 46 invasive ductal carcinomas (IDC) and 16 intraductal papillary mucinous tumors (IPMT) of the pancreas. Intraductal papillary mucinous tumors usually reveal expansive growth. However, of the 16 IPMT examined in the present study, three showed an invasive growth pattern, which was similar to 'mucinous carcinoma', around the non-invasive growth areas. Of 46 IDC, MUC-1 mucin detected by monoclonal antibodies, DF3 and MY.1E12, was expressed in 44 cases (96%) and in 45 cases (98%), respectively, whereas MUC-2 mucin detected by polyclonal antibody, anti-MRP, was not expressed in any of the cases (0%). In contrast, in the non-invasive growth areas of the 16 IPMT, MUC-1 mucin detected by DF3 and MY.1E12 was expressed in four cases (25%) and in six cases (38%), respectively, whereas MUC-2 mucin detected by anti-MRP was expressed in 13 cases (81%). The invasive growth areas of the three IPMT showed positive expression of MUC-1 mucins detected by DF3 and MY.1E12, although the non-invasive growth areas showed negative expression of MUC-1 mucins, except for their focal positive expression in one of the three cases. These findings indicate that the invasive growth areas of IPMT acquire a characteristic of MUC-1 mucin expression that is usually seen in IDC.
Our previous immunohistochemical studies for the expression of MUC1 mucin antigen (which was detected by monoclonal antibody DF3) and MUC2 mucin antigen (which was detected by polyclonal antibody anti-MRP) in pancreatic and intrahepatic bile duct tumors demonstrated that invasive carcinoma with poor outcome showed a pattern of MUC1+ and MUC2- expression, whereas many of the noninvasive tumors with favorable outcome showed a pattern of MUC1- and MUC2+ expression. To clarify the relationship between the expression of these mucin antigens and the biological properties of gastric cancers, the expression of MUC1 and MUC2 mucin antigens was examined immunohistochemically in 136 patients with gastric cancer invading the submucosa or the deeper layer, and the survival of the antigen-positive and antigen-negative patient groups was compared using the Kaplan-Meier method. For MUC1 mucin expression, different glycoforms of MUC1 were examined using four monoclonal antibodies (NCL-MUC-1-CORE, DF3, MY.1E12, and HMFG-1). The patients with MUC1+ mucin antigen staining in the carcinoma showed significantly worse survival than those with MUC1- mucin antigen staining. In contrast, the patients with MUC2+ mucin antigen staining in the carcinoma showed significantly better survival than those with MUC2- mucin antigen staining. In conclusion, MUC1 antigen expression was associated with a poor outcome in patients with gastric cancer, irrespective of its glycosylation status, and MUC1 is thus considered to be a useful prognostic factor for poor outcome in patients. In contrast, MUC2 antigen expression is a prognostic factor associated with a favorable outcome in patients. In addition, combined evaluation of the MUC1 and MUC2 mucin staining is clinically useful to predict outcome in patients with gastric cancer.
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A 75-year-old male patient with advanced esophageal cancer was treated by radiotherapy and chemotherapy. External radiotherapy was performed by the field in field method. A total dose of 60 Gy was used in the small field (7 x 5 cm) (2.4 Gy/f and 25 f/5 wks) and a total dose of 45 Gy in the large field (14 x 6 cm) (1.8 Gy/f, 25 f/5 wks). Concurrent chemotherapy was performed at the 2nd and 5th weeks of the radiation therapy. In this chemotherapy of CDDP plus 5-FU, CDDP (25 mg/day) was given on days 1,3 and 5 of the week and 5-FU (500 mg/day) was given for 5 days by continuous infusion for the same week. By this treatment, a complete response (CR) was obtained, and no serious side effects were observed. After 1 year and 6 months, he is alive with no evidence of recurrence.
Multiblock copolymers consisting of aromatic polyamide(aramid) and poly(dimethylsiloxane) (PDMS) aramid-silicone resins (PASs) were synthesized by low temperature solution polycondensation, and PAS films were prepared by casting from an N,N'-dimethylacetamide solution. In this study, we investigated bovine serum albumin (BSA) adsorption, L929 cell adhesion, and tissue reaction on the surface of PAS in order to clarify the interaction between PAS and biomolecules. It was found that the amount of adsorbed biomolecules on PAS was extremely low in contrast with those on aramid and nylon films, and it was comparable to SILASTIC 500-1 film. This suppression of adsorption of biomolecules onto PAS seemed to be due to the low surface free energy of the outermost surface of PAS, where PDMS block was condensed.
Cisplatin incorporated into polylactic acid/polyethylene glycol acid blend polymeric microspheres was prepared as a dosage (CDDP-MS) by solvent evaporation method in oil-in-oil emulsion system. CDDP-MS and CDDP aqueous solutions (CDDP-SOL) were intraperitoneally administered to compare the tissue distribution of CDDP in 72 rats each. On 0.5, 1, 7, 14, 21 and 30 days, the omentum, lung, liver and kidney were removed, and the CDDP concentration was measured. The CDDP concentration of CDDP-MS group was maintained at a high level in the omentum for a long time. On the other hand, the CDDP level of the CDDP-MS group was low in the lung, liver and kidney, compared with the CDDP-SOL group. Additionally, acute toxicity of anticancer drug in CDDP-MS group was reduced, compared with CDDP-SOL. The effects of CDDP-MS, CDDP-SOL, empty-MS and non-therapy group on survival time were compared using intraperitoneally administered Yoshida sarcoma. The survival time in CDDP-MS, CDDP-SOL, non-therapy and empty-MS group were 43 +/- 24, 11.7 +/- 4.7, 9.8 +/- 1.1, and 7.8 +/- 1.1 days each. Consequently, it was suggested that CDDP-MS is useful as a tool in loco-regional chemotherapy using drug delivery system.
Cisplatin incorporated into polylactic acid/polyethylene glycol acid blend polymeric microspheres was prepared as a dosage (CDDP-MS) by the solvent evaporation method in an oil-in-oil emulsion system. When CDDP-MS was preserved in phosphate-buffer saline, the dissolution rate of cisplatin from CDDP-MS was 14% after one day, 25% after 5 days, 33% after 7 days, 66% after 21 days and 85% after 30 days. CDDP-MS and CDDP aqueous solution (CDDP-SOL) were intraperitoneally administered to compare the tissue distribution of cisplatin in 42 rats each. On days 0.5, 1, 5, 7, 14 and 21, omentum, lung, liver and kidney were removed, and the CDDP concentration was measured. The CDDP concentration of the CDDP-MS group was maintained at a high level in the omentum for a long time. On the other hand, the CDDP level of CDDP-MS group was low in the lung, liver and kidney, compared with the CDDP-SOL group. Consequently, it was suggested that CDDP-MS is useful as a carrier in a drug delivery system, since it improves the burst effect and releases CDDP for a long time without serious side effects.
Extended lymph node dissection in the neck and upper mediastinum often brings about postoperative pulmonary complications. Since September 1987, we have performed this type of lymph node dissection in 18 patients paying special attention to the preservation of tracheal proper sheath along with left bronchial artery and autonomic nerve branches. We compared their postoperative respiratory and circulatory outcomes with those of 17 patients in whom lymph node dissection was carried out without consideration for these aspects. Tracheal mucosal damage, respiratory functional parameters such as PaO2, AaDO2 and Qs/Qp and actual incidence of pneumonia significantly improved in recent cases undergoing meticulous dissection in the neck and upper mediastinum. However, neither circulatory dynamics nor incidences of recurrent nerve palsy and arrhythmia showed a significant improvement. The postoperative period required for reappearance of cough reflex was shorter in this group of patients, but the difference was not significant. The results indicated that pulmonary disorders occurring frequently after extended lymph node dissection for thoracic esophageal cancer was able to be well controlled by meticulous dissection procedure as mentioned above.
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Thirty-three patients with esophageal cancer were studied to assess the relationship between nutritional state and the acute phase protein responses. Blood samples taken preoperatively and days 1, 4, 7 and 14 after operation were analyzed for C-reactive protein, fibrinogen, alpha 1-antitrypsin, alpha 1-acid glycoprotein and haptoglobin. Significant Spearman's coefficients were found between percent of ideal body weight (IBW) and alpha 1-acid glycoprotein (r = -0.42), between prealbumin and alpha 1-anti-trypsin (r = -0.55), and between retinol-binding protein and alpha 1-antitrypsin (r = -0.51). Postoperatively, the levels of C-reactive protein, fibrinogen, alpha 1-anti-trypsin and alpha 1-acid glycoprotein were significantly lower in the poorly nourished group than in the other groups. The changes of acute phase proteins in the immediate postoperative period were affected by the preoperative nutritional state, and were less marked in the poorly nourished patients. Between two groups of patients in whom lymph node dissection was carried out in 2 or 3 areas, no significant differences were observed in the acute phase protein responses postoperatively. The measurement of acute phase proteins is very important in assessing the body defense capacity of the patient, but it should be noted that the changes may be affected by several factors including malnutrition.
To assess the nutritional status of the patients with esophageal cancer, we measured the areas of sternocleidomastoid and rectus abdominis muscles (SMA, RAMA) on real time ultrasound imaging and calculated muscle index (MI = (SMA+RAMA/Height)). Eighty-three patients with esophageal cancer were included in the present study. Preoperatively, significant Spearman's coefficients were found between MI and the percentage of standard arm circumference (R = 0.52) and between MI and the percentage of standard arm muscle circumference (R = 0.51). Postoperatively, patients with wide muscle area showed high values of prealbumin, transferrin and fibronectin. To study the changes after surgery, we also measured the area of quadriceps muscle in patients with esophageal cancer. The areas of quadriceps muscle in patients with dysphagia were much diminished than in those without dysphagia. Measurement of areas of muscles such as SMA, RAMA and quadriceps muscle was proved to be a useful procedure in evaluating the nutritional status of patients with esophageal cancer.
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One representative microsection from each lymph node was carefully surveyed for metastasis in a routine examination. To scrutinize the existence of occult metastasis, three additional sections were then made from half of the remaining lymph node. A total of 1,698 lymph nodes taken from 55 patients with carcinoma of the esophagus, stomach, colon, thyroid or breast were thus reexamined histologically. The initial examination was not able to prove any metastasis in these lymph nodes. Upon reexamination, however, involvement by cancer cells was detected in 10 nodes of 7 patients. The maximum diameter of the metastatic foci varied from 0.2 mm to 1.3 mm and was less than 0.5 mm in more than half of the nodes. The metastatic patterns in the nodes were classified into three types, i.e., marginal sinus type, medullary sinus type and mixed type. The marginal sinus type was the most frequent, with the mixed type being next and the medullary sinus type being found in only one node. Accordingly, surgeons should keep the possibility of occult metastasis in mind and the marginal sinus of the lymph node should be carefully examined in order to detect any small foci of metastasis.
The tracheo-bronchial mucosa of 27 surgical patients with esophageal cancer was examined by bronchofiberscope postoperatively, and the changes of the mucosa were divided into four grades, i.e., GI: no change or slight redness only (7 cases), GII: Severe redness or erosion (7 cases), GIII: Ulcer formation (11 cases) and GIV: Necrosis of the mucosa (2 cases). All the GI-III changes were reversible. However, GIV change was irreversible. The biopsy specimens were taken from the mucosa of the tracheal bifurcation on the 7th postoperative day, showing squamous metaplasia in 9 of 13 patients. Bilateral modified neck and upper mediastinal lymph node dissections were performed in 18 of 27 patients. The change of the mucosa was judged as GIII or IV in 12 of 18 patients (67%), whereas the change was less significant in the remaining 6 patients. Namely, the degree of mucosal change did not necessarily correspond with the extent of lymph node dissection. The changes of the mucosa were considered to be brought about not only by tracheo-bronchial ischemia but also by injurious effects on the pulmonary parenchyma following aggressive lymph node dissection. The assessment of the degree of the mucosal change might be a useful indicator for postoperative management of esophageal cancer patients.
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