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Biomedical subjects

K Ohsato

Publications and source records attributed to K Ohsato.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Multicenter cooperative study of pre- and post-operative adjuvant chemotherapy in the treatment of colorectal cancer. North Kyushu Co-operative Study Group for Cancer Chemotherapy].

The usefulness of pre- and post-operative adjuvant chemotherapy in colorectal cancer patients was studied by the North Kyushu Co-operative Study Group for Cancer Chemotherapy (21 participating institutions). Comparisons were made among group I given a tegafur suppository preoperatively+tegafur oral preparation postoperatively, group II given a tegafur suppository preoperatively+UFT oral preparation postoperatively and group III given a tegafur oral preparation postoperatively. No differences were seen in the incidence of postoperative complications depending on whether or not tegafur suppositories were administered preoperatively. There were also no differences in the symptom or incidence of side effects due to postoperative administration of tegafur or UFT. In a study of 5-FU concentration in the lymph nodes due to preoperative tegafur administration and recurrences, the concentration of 5-FU was significantly higher in the lymph nodes of cases without recurrences than in those with recurrences, and it was suggested that a relation exists between the concentration of agent and recurrences. The concentration of 5-FU in the lymph nodes of Dukes B patients was significantly higher in cases without recurrences than in those with recurrences. The non-recurrence rate (healthy rate) was better in the group given UFT postoperatively than in that administered tegafur postoperatively although the difference was not significant.

Administration, Oral↗
PubMed1992

Role of multipotent fibroblasts in the healing colonic mucosa of rabbits. Ultrastructural and immunocytochemical study.

Light- and electron microscopy and immunocytochemistry were used to study the healing colonic mucosa of rabbits after experimental excision. Between 3 and 5 days, abundant young fibroblasts which retained many features of mesenchymal cells invaded the growing capillaries into the loose connective tissue of the healing colonic mucosa. Our electron microscopy revealed the transformation of these young fibroblasts into smooth muscle cells, into histiocyte-like cells involved in phagocytotic activity, and into vasoformative cells incorporated into the growing capillaries. The mitotic proliferation of pre-existing smooth muscle cells at the ulcer margin did not seem to be the major reason for re-establishment of the muscular tissue. The present immunocytochemistry revealed an active production of fibronectin in rough endoplasmic reticulum in the young fibroblasts. This may mean that this glycoprotein is involved in the re-establishment of both connective and muscular tissues by enhancement of adhesion and chemoattractant activities of such cells. In addition, the immunoreaction of endothelial cells of the growing capillaries suggests a role of this glycoprotein in the acceleration of the neocapillarization.

Animals↗
PubMed1992

[Serum concentration of HCFU and 5-FU after oral administration of HCFU in postoperative digestive cancer patients].

In an attempt to establish the optimum dose of HCFU, the effect of the presence of stomach on the absorption of HCFU and both the rise and maintenance of blood HCFU levels was evaluated in patients with gastric cancer (total gastrectomy group) and with colorectal cancer (non-gastrectomy group). The blood concentrations of HCFU fractions and 5-FU were determined in terms of pharmacokinetic parameters in these groups. The Tmax was significantly different between the two groups, with HCFU fraction and 5-FU levels that were significantly higher in the total gastrectomy group 30 minutes after administration. No differences were found in Cmax or AUC. There were no significant differences in Cmax or AUC among the various subgroups given different doses of HCFU (100, 150 and 200 mg) in either group, although dose-dependency was observed. Similar results were obtained in crossover tests. The 5-FU remained at an effective concentration of 0.05 microgram/ml, 4 hours after a single dose of 100 mg HCFU.

Administration, Oral↗
PubMed1991

Scatter factor from human embryonic lung fibroblasts is probably identical to hepatocyte growth factor.

Human embryonic lung fibroblasts (MRC5) produced scatter factor which enhanced motility of Madin-Darby canine kidney (MDCK) epithelial cells and a factor which stimulates DNA synthesis of adult rat hepatocytes in primary culture. These activities were both completely neutralized by antibody against human hepatocyte growth factor (HGF). Human recombinant HGF induced a marked scattering of MDCK cells. Moreover, MRC5 cells highly expressed 6kb mRNA which hybridized with HGF cDNA probe and scatter factor cDNA cloned from the MRC5 cDNA library had the same sequence as that of HGF cDNA from human leukocytes. These results indicate that HGF possesses scatter factor activity and the scatter factor derived from the MRC5 cells is probably identical to HGF.

Animals↗
PubMed1991

[Multihospital co-operative study of post-operative adjuvant chemotherapy in the treatment of gastric cancer-(Part 3). Comparisons between tegafur and UFT. North Kyushu Co-operative Study Group for Cancer Chemotherapy].

The North Kyushu Co-operative Study Group for Cancer Chemotherapy (21 participating facilities) carried out a comparative study of post-operative adjuvant chemotherapy in the treatment of 243 patients after surgery of gastric cancer in stages II, III and IV over 27 months period starting from October 1983. The patients were divided randomly into group A (treated with 20 mg of MMC on the day of the surgery and 10 mg of MMC on the following day, and with a daily dose 600 mg of orally administered tegafur starting from two weeks after the surgery. In addition to the above treatments, patients with Stage IV were treated with 10 mg of MMC every three months starting from four weeks after the surgery) and group B (treated with MMC in a similar manner to group A, and with 600m g of UFT instead of the tegafur). Thirty-three patients (13.6%) were excluded or dropped out, and the remaining 210 cases were analyzed. No severe side effects appeared in either of the groups, and a long-term administration was safe. The five-year survival rate among the radical surgery patient was significantly higher in the UFT group compared with the tegafur group (p less than 0.05). Significantly higher survival rate in the UFT group was observed (p less than 0.05) for the cases of poorly-differentiated adenocarcinoma. From the above results it appears that an addition of UFT to the treatment with MMC is useful in post-operative adjuvant chemotherapy for gastric cancer.

Adenocarcinoma↗
PubMed1990

Self-regulating factor present in culture supernatants of regenerating hepatocytes in adult rats.

The auto-regulation mechanism of liver regeneration after partial hepatectomy was investigated in rats. Hepatocytes isolated from the individual remnant livers at various times after 70% removal of the liver were cultured, and determination of DNA synthesis of the cultured hepatocytes and collection of culture supernatants were performed. The maximum value of DNA synthesis was observed at 1 day after the operation and then gradually decreased, and the liver weights recovered rapidly during 2-4 days. The culture supernatants harvested from these primary cultured hepatocytes isolated from the rats at 2, 3 and 4 days after the operation suppressed dose-dependently DNA synthesis of hepatocytes which were isolated from normal rats and stimulated by epidermal growth factor (EGF) and insulin in vitro. The supernatants were non-cytotoxic against hepatocytes, and the activity of them was fairly stable for acid and heat treatments but not for proteolytic enzyme. No inhibition of the binding of EGF to the receptors on hepatocytes was observed. Furthermore, the factor showed an inhibitory activity of mitogen-induced DNA synthesis of human peripheral blood lymphocytes in culture. These results suggested that hepatocytes themselves might modulate the process of liver regeneration by secreting a growth inhibitory factor.

Animals↗
PubMed1990

Increased fibrin/fibrinogen degradation products without increase of plasmin-alpha 2-plasmin inhibitor complex after hepatectomy for hepatocellular carcinoma.

To clarify the meaning of increased serum fibrin/fibrinogen degradation products (FDP) in the postoperative period of hepatectomy, blood coagulation and fibrinolysis were studied using recently devised laboratory assays of a group of 30 patients with hepatocellular carcinoma. Twenty of these cases were associated with liver cirrhosis. As a control group, 15 patients with colorectal carcinoma without liver diseases were also selected. In the early postoperative period following hepatectomy, a hypercoagulable state designated as intravascular thrombin generation was confirmed from the finding of increased plasma levels of fibrinopeptide A (FPA). Fibrinopeptide B beta 15-42 (B beta 15-42) in the plasma also increased immediately after the peak of FPA, followed by a gradual decline in B beta 15-42 levels. On the other hand, FDP in the serum increased significantly rather late in the postoperative period following hepatectomy without increased levels of plasmin-alpha 2-plasmin inhibitor complex. However, postoperative increase of fibrin/fibrinogen degradation products-D (FDP-D) was modest and not different from the colectomy group. Therefore, the relevance of intravascular coagulation in the hepatectomy for the patients with liver cirrhosis seems not to be significant, and then such an increase of FDP in the serum seems to be related to other mechanisms.

Adult↗
PubMed1990

Clinical application of spectral analysis of bowel sounds in intestinal obstruction.

The bowel sounds of 21 patients with mechanical obstruction of the intestine were studied. A computer analysis of bowel sounds was performed using a signal processor. Bowel sounds of patients were classified into 3 types (Types I, II, and III) based on the histograms, although these were not distinguishable on auscultation. The lower, peak, and upper frequencies were 173 +/- 25 Hz, 273 +/- 64 Hz, and 667 +/- 58 Hz, respectively, in Type I; 309 +/- 121 Hz, 632 +/- 94 Hz, and 878 +/- 116 Hz, respectively, in Type II; and 330 +/- 120 Hz, 612 +/- 86 Hz, and 766 +/- 82 Hz, respectively, in Type III. High frequency sounds above 900 Hz were recorded in Types I and II but not in Type III. The ratio of the operated patients was 0, 23, and 100 percent in Types I, II, and III, respectively. The intervals between the times of admission and operation were 4.3 days and 1.2 days in Types II and III, respectively. Thus, it appears that the methods described by the authors could provide a very objective assessment of the severity and help determine the treatment (conservative or operative) of each patient.

Adult↗
PubMed1990

Cadmium toxicity in perinatal rat hepatocytes: electron microscopy, X-ray microanalysis, and morphometric analysis.

Effects of cadmium on the fetal and postnatal rat hepatocytes were studied with an electron microscope and an X-ray microanalyzer. Pregnant and lactating Wistar rat dams at 15 and 21 days of pregnancy and at 3 days after delivery received intraperitoneal injections of cadmium sulfate (1 mg/kg body weight) for 3 days. On the day following the last injection, the livers were isolated from the fetal and suckling rats and provided for electron microscopy. The livers from the untreated fetal and newborn rats served as control. Large bile canaliculi, which were formed by five or more hepatocytes, were frequently observed in the cadmium-treated perinatal rat livers. The intercellular space between each adjacent hepatocyte was widened. By X-ray microanalysis, cadmium peaks were preferentially detected out from intramitochondrial granules of the cadmium-treated hepatocytes. By morphometric analysis, the increase both in the mitochondria volume and in the number of intramitochondrial granules was evident in the cadmium-treated hepatocytes when compared to those of control. These data suggest the preferential accumulation of cadmium in mitochondria of the hepatocytes interferes with the morphogenesis of the perinatal rat liver.

Animals↗
PubMed1990

Computed tomography and magnetic resonance imaging of nonhemorrhagic, metastatic melanoma of the brain--case report.

Malignant melanoma frequently metastasizes to the central nervous system. Characteristic features of such lesions are increased density on computed tomography (CT) and shortening of the T1 and T2 on magnetic resonance (MR) imaging. Intratumoral hemorrhage, rather than melanin, is considered to be mainly responsible for these unique radiological features. The authors report a case involving a nonhemorrhagic, metastatic intracerebral melanoma. CT revealed a high-density mass, and MR imaging demonstrated a hyperintense mass both on T1- and T2-weighted images. These observations suggest that melanin is in fact a major determinant of the increased density on CT scans and the high signal intensity on T1-weighted MR images. On T2-weighted images, the paramagnetic effect appears to vary according to the melanin content.

Brain Neoplasms↗
PubMed1990

[Early diastolic dysfunction of the left ventricle and its relation to histopathological findings in patients with diabetes mellitus].

The relation of left ventricular diastolic function and the histopathological findings of the myocardium in patients with diabetes mellitus were observed using echocardiography and endomyocardial biopsy. The subjects consisted of six diabetic patients (mean age 49.3 years) and eight normal control subjects (mean age 44.8 years). Coronary angiography had no significant stenotic lesions in their coronary arteries. Their diabetic complications were mild to moderate in severity. Echoes from the left ventricular margin of the septum and from the posterior left ventricular wall were traced on a digitizing board; then the isovolumic relaxation period, rapid filling period, slow filling period and atrial contraction period were determined to calculate fractional shortening (FS), isovolumic relaxation time (IRT), and three filling volumes (RFV, SFV and ACV). The quotients of the left ventricular filling volume and stroke volume were also determined. Right ventricular endomyocardial biopsies were performed to determine the diameters of myocytes, the percentage of fibrosis and the eccentricity e, as a parameter of the degree of myocardial dysarrangement. The results were as follows: IRT was significantly longer and RFV/SV was significantly greater in patients with diabetes mellitus than those among the controls. Also the diameters of myocytes and the percentage of fibrosis were significantly greater, while the eccentricity e was less compared to that of the controls. There were no significant correlations, among IRT, RFV/SV, the diameters of myocytes, and eccentricity e, but the percentage of fibrosis significantly correlated with IRT and RFV/SV (r = 0.62, r = -0.63). IRT and RFV/SV were mainly responsible for the percentage of fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Early diastolic dysfunction of the left ventricle affected by hypertrophy and abnormal histopathology in hypertrophic cardiomyopathy].

In this study, we investigated correlations of left ventricular hypertrophy and its histopathology with diastolic dysfunction in patients with hypertrophic cardiomyopathy. Nine control subjects and 14 hypertrophic cardiomyopathy (HCM) patients with asymmetrical septal hypertrophy were evaluated. M-mode echocardiography was used to assess fractional shortening (FS), isovolumic relaxation time (IRT), and the left ventricular filling volume index during rapid and slow filling periods and atrial contraction period (RFVI, SFVI and ACVI). End-diastolic thickness of the interventricular septum and posterior wall was determined using biventriculography. Right ventricular endomyocardial biopsies were performed to calculate the diameters of myocytes, the percentage of fibrosis and the eccentricity e which indicates the degree of myocardial disarrangement including disorganization. The FS was normal in the two groups. The IRT of the HCM group was significantly greater and the RFVI significantly less than those of the controls. The left ventricular wall thickness, the diameters of myocytes and the percentage of fibrosis in the HCM group were significantly greater; and the eccentricity e was significantly less, suggesting that myocardial disarrangement was significantly more severe than that in the controls. Significant positive correlations were observed between the IRT and the wall thickness (r = 0.647), between the diameter of myocytes (r = 0.681) and the percentage of fibrosis (r = 0.628), and there was a significantly negative correlation between the IRT and the eccentricity e (r = -0.759). There was a significantly negative correlation between the RFVI and the wall thickness (r = -0.663); and a significantly positive correlation between the RFVI and the eccentricity e (r = 0.579). Multiple regression analyses showed that the diameter of myocytes, the percentage of fibrosis and the eccentricity e all correlated significantly with the IRT (R = 0.821) and the RFVI (R =0.604). The standard regression coefficients of the diameter of myocytes, the percentage of fibrosis and the eccentricity e were 0.253, 0.278 and -0.431 in respect to IRT, and those of the percentage of fibrosis and the eccentricity e were -0.204 and 0.469 in respect to RFVI, respectively. These results indicated that diastolic dysfunction in hypertrophic cardiomyopathy is related not only to the degree of left ventricular hypertrophy, but also to the degree of myocardial hypertrophy, increased interstitial fibrosis, and especially to myocardial disarrangement including disorganization.

Adult↗
PubMed1990

Relation of histopathological features to prognosis of gallbladder cancer.

Sixty-four cases of gallbladder cancer surgically removed were histologically divided into three groups, that is, papillary adenocarcinoma, tubular adenocarcinoma, and undifferentiated carcinoma, and were compared clinicopathologically. The results are as follows. Papillary adenocarcinoma showed little gender preponderance and had a low association with gallstones. Underlying chronic cholecystitis or epithelial metaplasia was infrequent. Most cases were in the early stage, with favorable prognosis. Tubular adenocarcinoma, seen predominantly in females with gallstones, showed a downward invasive growth with unfavorable prognosis. Chronic cholecystitis and epithelial metaplasia were frequent. Undifferentiated carcinomas were common in females with gallstones, and their prognosis was the worst of the three. It was concluded that papillary adenocarcinoma differed from both tubular adenocarcinoma and undifferentiated carcinoma in biological behavior. The former appears to arise mainly from the native gallbladder epithelium, whereas the latter two types frequently arise from metaplastic epithelium.

Adenocarcinoma↗
PubMed1989

Bile composition after total proctocolectomy with interposed jejunal segment as neorectum.

Changes of bile composition in gallbladder bile and serum chemistries were investigated in nine dogs after proctocolectomy and ileoanal anastomosis, using an interposed jejunal segment as a neorectum. A significant decrease in cholic acid and an increase in deoxycholic acid were observed 24 weeks after the operation, although there was no significant change of total bile acid and phospholipids in the bile. Concentration of cholesterol and cholesterol saturation index in bile increased after total proctocolectomy. Although serum triglyceride levels became lower compared with the nontreated control group, concentrations of total protein, serum cholesterol, total lipids, blood sugar, and electrolytes showed no significant difference. This operative procedure apparently did not impair intestinal absorption of bile acid, but did increase the biliary cholesterol saturation index.

Anal Canal↗
PubMed1989

[Multihospital randomized study on adjuvant chemotherapy with mitomycin C and futraful or UFT in gastric cancer--(Part 2). Comparisons between futraful and UFT. North Kyushu Co-operative Study Group for Cancer Chemotherapy].

A comparative multicenter study was carried out on postoperative adjuvant chemotherapy on 243 gastrectomy patients from October 1983 to December 1985. The medications were assigned at random to 2 groups of patients by the envelope method: group A (administered 20 mg of MMC on the day of surgery and 10 mg of MMC on the day after surgery, and started on tegafur at a dose of 600 mg/day 2 weeks after surgery); group B (similarly treated with MMC and started on UFT at a dose of 600 mg/day 2 weeks after surgery). Further, patients presenting in stage IV were administered MMC intravenously every 3 months, starting 4 weeks after surgery. The final drug effect evaluations were made in 210 patients excluding 33 dropouts (13.6%). The incidence of side effects was somewhat higher in group B than in group A, but their frequency was low and no serious symptoms were observed. For patients with poorly differentiated adenocarcinoma and were carried out curative operation, the 3-year survival rate was significantly higher in group B than in group A.

Adenocarcinoma↗
PubMed1989

Local chemotherapy for rectal polyposis: intraluminal administration of 5-fluorouracil for postoperative control of adenomas in the retained rectum in familial polyposis.

We administered the anticancer drug 5-fluorouracil locally to treat rectal adenomas in four patients with familial adenomatous polyposis who had undergone total colectomy and ileorectal anastomosis. The drug was administered either in suppository form or in high concentration as a rectal enema. One patient was treated successfully with 5-fluorouracil suppositories without any side effects, but the suppository regimen had to be stopped in three other patients because of severe rectal urgency. However, one of these patients was treated effectively with rectal administration of a high-dose 5-fluorouracil solution. Adenomas near the anastomotic site or dentate line were difficult to treat. Although severe urgency was seen in most patients, we think that the intraluminal administration of anticancer agents may prove effective in treating polyposis of the rectum retained after colectomy in familial polyposis. It deserves further study.

Adenomatous Polyposis Coli↗