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K Sugihara

Publications and source records attributed to K Sugihara.

At least 91 records · Page 5Linked to original sources
PubMed1999

Conversion of dieldrin to aldrin by intestinal bacteria in rats.

The present study provides the evidence that dieldrin is reductively metabolized to aldrin by intestinal bacteria in rats. When dieldrin was incubated with the cecal contents of rats, aldrin, a reduced metabolite of the epoxide, was isolated from the incubation mixture. The metabolite was identified unequivocally by UV and mass spectral comparison with an authentic sample, and on the basis of its TLC and HPLC behavior. The cecal contents of rats exhibited epoxide reductase activity toward dieldrin under anaerobic conditions. However, only marginal activity was observed under aerobic conditions. Four pure strains of intestinal bacteria exhibited epoxide reductase activities to varying degrees under anaerobic conditions. The highest activity was observed in Clostridium sporogenes. Cell-free extracts of the intestinal bacteria in rat cecal contents showed reductase activity when supplemented with both NAD(P)H and FMN under anaerobic conditions.

Aldrin↗
PubMed1999

DT-diaphorase-like quinone reductase in rat plasma.

The present study provides the evidence that DT-diaphorase-like quinone reductase exists in rat plasma. The quinone reductase activity toward menadione was found in rat plasma in the presence of NADH or NADPH. The enzyme activity was induced by pretreatment with 3-methylcholanthrene, but was not affected by phenobarbital. The 3-methylcholanthrene-induced quinone reductase activity was separated into three fractions (F1, F2, and F3) by gel filtration, which showed NAD(P)H-linked, NADH-linked, and NAD(P)H-linked activities, respectively. F1, which was induced by 3-methylcholanthrene, was inhibited by dicumarol, and cross-reacted with rat liver DT-diaphorase antibody.

Animals↗
PubMed1999

Infrequent germ-line mutation of the E-cadherin gene in Japanese familial gastric cancer kindreds.

Germ-line mutation of the E-cadherin gene was reported in familial gastric cancer (FGC) kindreds from New Zealand. Therefore, we analyzed all of the exons of E-cadherin by PCR-single-strand conformational polymorphism analysis in 16 patients from 14 Japanese FGC kindreds. However, no germ-line mutation was detected, suggesting that a predisposition to FGCs by E-cadherin gene mutation is infrequent in Japanese cases.

Adolescent↗
PubMed1999

Relationship between intratumoral dihydropyrimidine dehydrogenase activity and gene expression in human colorectal cancer.

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme for 5-fluorouracil catabolism. In this study, both the enzymatic activity and mRNA level of DPD were estimated in the tumor tissue and adjacent normal mucosa of 51 patients with colorectal cancer. Although no significant difference in enzymatic activity was observed between tumor tissue and normal mucosa (70.4 and 70.7 pmol/min/mg protein, respectively), the mRNA level in normal mucosa was significantly higher than that in tumor tissue (1.37 and 0.39, respectively; P<0.01). A linear relationship was noted between DPD activity and the DPD mRNA level in cancerous tissue (r(s) = 0.714, P<0.001). Thus, the DPD mRNA level as determined by reverse transcription-PCR can be used to indicate the DPD activity of colorectal cancers.

Colorectal Neoplasms↗
PubMed1999

[Dihydropyrimidine dehydrogenase gene expression in patients with hepatic metastases from colorectal cancer].

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme for 5-FU catabolism. Recently, much interest has been taken in the relation between the antitumor effect of 5-FU and DPD expression in gastrointestinal cancers. In this study, we compared DPD mRNA of 11 hepatic metastatic foci with that of 50 primary foci in colorectal cancer patients. DPD mRNA levels in hepatic metastatic foci were significantly higher than those in primary foci (median DPD/GAPDH ratio 0.79 vs 0.44, p = 0.035). Even in 6 cases available to compare DPD mRNA expression in matched primary and metastatic foci, the same significant difference was obtained (median DPD/GAPDH ratio 0.80 vs 0.36, p = 0.028). Our results suggested that the efficacy of intra-arterial infusion for metastatic liver tumor is mainly due to the fact that the high concentration of 5-FU is enough to overcome the high clearance of 5-FU, which is caused by DPD.

Colorectal Neoplasms↗
PubMed1999

A unique tertiary amine N-oxide reduction system composed of quinone reductase and heme in rat liver preparations.

The results of this study show the quinone-dependent reduction of tertiary amine N-oxides to the corresponding tertiary amines by rat liver preparations. The reduction of imipramine N-oxide to imipramine mediated by liver mitochondria, microsomes, and cytosol proceeded in the presence of both NAD(P)H and menadione under anaerobic conditions. When menadione was replaced with 1, 4-naphthoquinone or 9,10-anthraquinone, similar results were obtained in the cytosolic reduction. The quinone-dependent reducing activity in liver cytosol was inhibited by dicumarol and carbon monoxide. This result suggested that the activity is caused by DT-diaphorase, a cytosolic quinone reductase, and hemoproteins in liver cytosol. In fact, catalase and hemoglobin showed the ability to reduce imipramine N-oxide when supplemented with DT-diaphorase. The hemoproteins also exhibited the N-oxide reductase activity with reduced menadione, menadiol. The N-oxide reductase activity of the hemoproteins was also exhibited with 1,4-dihydroxynaphthalene, 1,4,9, 10-tetrahydroxyanthracene, or 1,4-dihydroxy-9,10-anthraquinone. Furthermore, hematin revealed a significant N-oxide-reducing activity in the presence of menadiol. The reduction appears to proceed in two steps. The first step is reduction of menadione to menadiol by a quinone reductase with NADPH or NADH. The second step is nonenzymatic reduction of tertiary amine N-oxides to tertiary amines by menadiol, catalyzed by the heme group of hemoproteins. Cyclobenzaprine N-oxide and brucine N-oxide were also transformed similarly to the corresponding amine by the quinone-dependent reducing system.

Animals↗
PubMed1998

Rac1 is required for the formation of three germ layers during gastrulation.

The Rac1, a member of the Rho family proteins, regulates actin organization of cytoskeleton and cell adhesion. We used genetic analysis to elucidate the role of Rac1 in mouse embryonic development. The rac1 deficient embryos showed numerous cell deaths in the space between the embryonic ectoderm and endoderm at the primitive streak stage. Investigation of the primary epiblast culture isolated from rac1 deficient embryos indicated that Rac1 is involved in lamellipodia formation, cell adhesion and cell migration in vivo. These results suggest that Rac1-mediated cell adhesion is essential for the formation of three germ layers during gastrulation.

Animals↗
PubMed1998

Size- and invasion-dependent increase in cyclooxygenase 2 levels in human colorectal carcinomas.

Nonsteroidal anti-inflammatory drugs reduce the incidence and mortality of colorectal carcinoma. Their chemopreventive effects appear to be due to inhibition of cyclooxygenase (COX)-2. Here, we have studied the relationship between the COX-2 mRNA levels and pathological characteristics in 43 primary colorectal carcinomas. COX-2 levels were significantly higher in tumors with larger sizes and in those with deeper invasions but were not correlated with whether the patients had metastasis or not. These results suggest that larger carcinomas produce more COX-2 to support their own growth and that COX-2 inhibitors may be effective agents of carcinoma growth suppression.

Adult↗
PubMed1998

Resection of both hepatic and pulmonary metastases in patients with colorectal carcinoma.

BACKGROUND: More than 40% of patients who undergo curative resection of advanced colorectal carcinoma can be expected to have recurrence of the disease. The most frequent sites of recurrence are the liver (33% of patients) and lung (22%). Interest has therefore focused on treating hepatic or pulmonary metastases, or both, to improve the outcomes of these patients. Although surgical resection has become an increasingly accepted treatment for resectable localized hepatic or localized pulmonary metastases from colorectal carcinoma, the value of aggressive surgery for the removal of both hepatic and pulmonary metastases from patients with primary colorectal carcinoma remains to be clarified. METHODS: Data on 30 patients who had undergone resection of both hepatic and pulmonary metastases from colorectal carcinoma were included in the study. RESULTS: Independent, significant prognostic features were found to be the time that hepatic or pulmonary metastases occurred and the distribution of pulmonary metastases. Median survival times were 30 months (range, 7-108 months) after resection of both hepatic and pulmonary metastases and 48.5 months (range, 11-149 months) after excision of the primary colorectal tumor. Actuarial 1-, 3-, and 5-year survival after resection of both hepatic and pulmonary metastases was 86.7%, 49.3%, and 43.8%, respectively. No perioperative mortality occurred. There were three cases of minor morbidity, which the authors considered acceptable. CONCLUSIONS: Resection of both hepatic and pulmonary metastases from colorectal carcinoma may help to prolong the survival of a small group of patients with these metastases.

Adult↗
PubMed1998

Lithium inhibits the reverse tolerance and the c-Fos expression induced by methamphetamine in mice.

To elucidate the mechanism of psychostimulant-induced reverse tolerance, the effects of lithium on ambulatory activity and cerebral c-Fos protein expression were investigated in mice injected with methamphetamine (2 mg/kg, s.c., 1-5 times). The ambulatory activity enhanced by either acute or chronic methamphetamine injection was delayed or diminished by LiCl pretreatment (170 mg/kg, s.c., 1 h before methamphetamine). The c-Fos expression in the dorsal lateral geniculate nucleus and in the striatum was significantly increased by acute but not chronic injection of methamphetamine, and the increases were significantly suppressed by LiCl pretreatment. Although how the Li-sensitive c-Fos expressions in the dorsolateral geniculate nucleus and striatum are related to methamphetamine-induced behavioral excitation is unclear, these results suggest that lithium at least functionally interferes with the formation of the state of reverse tolerance to methamphetamine in the mouse.

Animals↗
PubMed1998

Abnormal expression of CD44 variants in the exfoliated cells in the feces of patients with colorectal cancer.

BACKGROUND & AIMS: Recent investigations have shown that CD44 variant exons are frequently overexpressed in human colorectal adenocarcinoma. The aim of this study was to investigate abnormal expression of the CD44 gene in exfoliated cells from patients with colorectal cancer. METHODS: Exfoliated cells in feces from 25 patients with colorectal cancer before and after surgery and from 15 healthy volunteers were analyzed. CD44 standard, variant 6, and variant 10 messenger RNA (mRNA) expressions were examined in the exfoliated cells in feces by using reverse-transcription polymerase chain reaction followed by Southern hybridization with exon-specific probes. RESULTS: CD44 standard mRNA was detected in all samples before and after surgery and in all healthy volunteers. CD44 variant 6 and variant 10 mRNA were detected in 17 of 25 patients (68%) and 15 of 25 patients (60%), respectively, in individual feces obtained before surgery. CD44 variant 6 mRNA and variant 10 mRNA were detected in postoperative samples in 3 of 25 patients (12%) and 7 of 25 patients (28%), respectively. Fifteen of 17 patients who were positive for CD44v6 based on preoperative fecal samples became negative after surgery (88.2%). Similarly, 12 of 15 patients who were CD44v10 positive in preoperative fecal samples were negative postoperatively (80%). CONCLUSIONS: These results suggest that analysis of CD44 variant expression in the exfoliated cells in feces can provide a noninvasive diagnostic test for colorectal cancer.

Adult↗
PubMed1998

Orthokeratinized odontogenic cyst: a clinicopathological and immunocytochemical study of 15 cases.

AIMS: Intraosseous jaw cysts with a solely orthokeratinized lining epithelium have been suggested to differ from the typical odontogenic keratocysts (OKC) by exhibiting a less aggressive behaviour. We report 15 cases of such cyst type under the term of 'orthokeratinized odontogenic cyst (OOC)' and compared their clinical, histological and immunocytochemical features with that of OKC. METHODS AND RESULTS: The cysts of the present series were all solitary lesions, occurred mostly in young male patients, and showed a predilection for the posterior mandible areas. Follow-up of 14 patients, nine of whom were treated by simple enucleation, revealed no recurrence over a period of 3.5-12 years after surgery. None of the patients had any association with the naevoid basal cell carcinoma syndrome. Furthermore, histological and immunocytochemical comparison between OOC and OKC revealed marked differences in their morphology and epithelial expression. The lining epithelium of OOC lacked the typical features of OKC and appeared to show a lower proliferative activity. CONCLUSION: These findings suggest that OOC is clinicopathologically separate from other types of odontogenic cysts and may thus constitute a distinct clinical entity.

Adult↗
PubMed1998

Reductive dechlorination of DDT to DDD by rat blood.

The present study provides evidence that the reductive dechlorination of DDT (p, p'-dichlorodiphenyltrichloroethane) to DDD (p, p'-dichlorodiphenyldichloroethane) mediated by rat blood proceeds in the presence of both a reduced pyridine nucleotide and a flavin. The reduction appears to proceed in two steps. The first step is reduction of a flavin such as FAD, FMN or riboflavin by NADPH or NADH, either enzymatically or nonenzymatically. The second step is nonenzymatic reductive dechlorination of DDT by the reduced flavin, catalyzed by the heme group of hemoglobin.

Animals↗
PubMed1998

Macroscopic features at the deepest site of tumor penetration predicting liver metastases of colorectal cancer.

Liver metastasis is the gravest prognostic factor in colorectal cancer. To identify a reliable indicator for liver metastasis, we evaluated macroscopic features and seven established histopathological findings at the cut section containing the deepest penetration using univariate and multivariate analyses in 417 colorectal cancers. Macroscopic features were divided into two types, streak type and non-streak type, according to the presence or absence of white streak(s) at the advancing margin of tumor invasion. Streak type was observed in 109 patients (26%). The frequency of liver metastasis in streak type tumors (56%) was significantly higher than that in non-streak type tumors (13%) (p < 0.001). The white streak corresponded histologically with cancer cells showing focal dedifferentiation with marked stromal and perivascular fibrosis extending towards the serosa or adventitia. In 343 curatively treated patients, univariate analysis showed that recurrent liver metastasis was significantly associated with macroscopic features, venous invasion, focal dedifferentiation and lymph node metastasis. Multivariate analysis disclosed that macroscopic features and lymph node metastasis were independent indicators of liver metastasis. These macroscopic features, corresponding histologically to stromal behavior against invading cancer cells, are a simple and useful indicator of liver metastasis of colorectal cancer.

Colonic Neoplasms↗
PubMed1998

Perianal Paget's disease associated with rectal carcinoma: a case report.

A 58-year-old man was referred to us because of anal bleeding. Digital rectal examination revealed a 1.2 x 0.8 cm-sessile villous tumor located in the anal canal and lower rectum. Pruritus was lacking and there were no erythematous lesions or any skin lesion in the perianal region. Histologic examination of the excised lesion revealed the presence of an adenocarcinoma within a villous adenoma. The malignancy exhibited well, moderately and poorly differentiated areas with signet-ring cell elements. Because the carcinoma had massively invaded into the submucosa, additional abdominoperineal resection was performed. Microscopic examination of the obtained specimens showed incidental Paget's disease of the anal skin. Although perianal Paget's disease associated with rectal cancer is rare, cautious pathologic examination of the anal and perianal skin in cases with anorectal carcinoma is necessary, even if there are no suggestive clinical findings. If there is perianal Paget's disease, surgical resection with sufficient apparently normal skin and close follow-up are necessary.

Adenocarcinoma↗
PubMed1998

Sleep behavior of pregnant women using sleep log.

Sleep log study, which was designed to study sleep characteristics by questionnaire, was performed on 172 pregnant women about the relationship between their pregnancy and their night sleep. Sleep behavior by sleep log revealed that they woke more frequently during the course of their pregnancy and that their total sleep time decreased gradually toward the end of their pregnancy. According to their subjective evaluations, these shortages of night sleep could not be made up with the morning naps in the multiparas as was the case of the primiparas. These changes in sleep characteristics have been studied from biological, psychological and social factors view points.

Adult↗