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S Tada

Publications and source records attributed to S Tada.

At least 55 records · Page 3Linked to original sources
PubMed2000

Chronic intestinal pseudo-obstruction due to dialysis-related amyloid deposition in the propria muscularis in a hemodialysis patient.

Dialysis-related amyloidosis (DRA) is one of the most serious complications interfering with rehabilitation in dialysis patients. Here, we report a case of beta2-microglobulin (beta2M)-related amyloidosis, in which the patient developed a severe intestinal pseudo-obstruction. The patient was a 42-year-old male who had been undergoing hemodialysis for 13 years, and who had no history of osteoarticular involvement of DRA. The first symptoms of the disease were severe abdominal fullness and nausea after meals. The whole intestinal wall biopsy revealed massive amyloid deposition in the propria muscularis. The patient became malnourished and died of acute subendocardial infarction 3 years after the onset. An autopsical examination revealed a massive deposition of amyloid, which was positively stained with anti-beta2M antibody but not AA amyloid, predominantly in the gastrointestinal muscular layer, including the tongue, esophagus, stomach, small intestines, colon, and rectum. These results suggest that the gastrointestinal involvement of beta2M-related amyloidosis might occur during the course of hemodialysis treatment, and that this possibility should be considered if patients suffer from intestinal pseudo-obstruction without osteoarticular symptoms.

Adult↗
PubMed1999

The RLF-B component of the replication licensing system is distinct from Cdc6 and functions after Cdc6 binds to chromatin.

Replication licensing factor (RLF) is an essential initiation factor that can prevent re-replication of DNA in a single cell cycle [1] [2]. It is required for the initiation of DNA replication, binds to chromatin early in the cell cycle, is removed from chromatin as DNA replicates and is unable to re-bind replicated chromatin until the following mitosis. Chromatography of RLF from Xenopus extracts has shown that it consists of two components termed RLF-B and RLF-M [3]. The RLF-M component consists of complexes of all six Xenopus minichromosome maintenance (MCM/P1) proteins (XMcm2-7), which bind to chromatin in late mitosis and are removed as replication occurs [3] [4] [5] [6] [7]. The identity of RLF-B is currently unknown. At least two factors must be present on chromatin before licensing can occur: the Xenopus origin recognition complex (XORC) [8] [9] and Xenopus Cdc6 (XCdc6) [10]. XORC saturates Xenopus sperm chromatin at approximately one copy per replication origin whereas XCdc6 binds to chromatin only if XORC is bound first [9] [10] [11]. Although XORC has been shown to be a distinct activity from RLF-B [9], the relationship between XCdc6 and RLF-B is currently unclear. Here, we show that active XCdc6 is loaded onto chromatin in extracts with defective RLF, and that both RLF-M and RLF-B are still required for the licensing of XCdc6-containing chromatin. Furthermore, RLF-B can be separated from XCdc6 by immunoprecipitation and standard chromatography. These experiments demonstrate that RLF-B is both functionally and physically distinct from XCdc6, and that XCdc6 is loaded onto chromatin before RLF-B function is executed.

Animals↗
PubMed1999

Spontaneously developed aneurysm of the ductus arteriosus in an adult.

We report an unusual adult case of aneurysm associated with the ductus arteriosus. A 67-year-old female, who suffered recurrent nerve palsy, was diagnosed as having an aneurysm of the ductus arteriosus. The aneurysm, located in the medial aspect of the aortic ischimus and projected toward the pulmonary artery, was successfully repaired using a Dacron patch. A pathologic review of the aneurysm revealed the degeneration of the aortic media.

Aged↗
PubMed1999

Induction of apoptosis in rat hepatic stellate cells by disruption of integrin-mediated cell adhesion.

Cell-matrix adhesion is recognized as a physiologic determinant of cell growth and survival. Integrin occupancy seems to be a primary role. We sought to investigate the signal transduction pathways for integrin effects on cell survival in hepatic stellate cells. Integrin function was antagonized by the soluble integrin recognition sequence pentapeptide Gly-Arg-Gly-Asp-Ser (GRGDS) in primary cultures of rat hepatic stellate cells. Integrin antagonism with GRGDS peptide induced apoptosis. To investigate signal transduction mechanisms for the effect of integrins on cell survival in hepatic stellate cells, the expression of p53, Bcl-2, and Bax was analyzed. Incubation with soluble GRGDS peptide resulted in increased expression of p53 and decreased the Bcl-2/Bax ratio. In conclusion, these findings indicate that the abrogation of cell adhesion with soluble GRGDS peptide plays a critical role in the induction of apoptosis of rat hepatic stellate cells.

Animals↗
PubMed1999

Role of Rho small GTP binding protein in the regulation of actin cytoskeleton in hepatic stellate cells.

BACKGROUND/AIMS: In the fibrotic response to liver injury, hepatic stellate cells are activated, leading to the myofibroblastic cell shape, with actin cytoskeletal reorganization and increased extracellular matrix production. The reorganization of actin cytoskeleton suggests that the small GTP binding protein Rho might modulate the process of this myofibroblastic change. The aim of this study was to investigate the role of Rho in the phenotypic changes of hepatic stellate cells. METHODS: The phenotypic changes were investigated by the overexpression of Rho regulator, Rho GDI or dominant negative mutant of Rho in mouse hepatic stellate cell line, GRX cells. In activated rat hepatic stellate cells, the effects of microinjection of Botulinus toxin C3, which is the specific inhibitor for Rho, were analyzed. Furthermore, the effect of C3 on the type I collagen accumulation in hepatic stellate cells was investigated. RESULTS: Overexpression of Rho GDI or the dominant negative mutant of Rho caused the shrinkage cell shape and suppressed stress fiber formation. Microinjection of toxin C3 caused a markedly distorted cell shape and the disappearance of stress fibers in rat stellate cells. In addition, C3 strongly suppressed collagen accumulation in activated stellate cells. CONCLUSIONS: These results suggest that Rho regulates the actin cytoskeletal reorganization, and may be implicated in the collagen accumulation in activated stellate cells. These findings provide evidence for the role of Rho in the myofibroblastic phenotype in hepatic stellate cells.

Actins↗
PubMed1999

Effects of central and peripheral injection of leptin on food intake and on brain Fos expression in the Otsuka Long-Evans Tokushima Fatty rat with hyperleptinaemia.

Hyperleptinaemia is observed in obese animals and humans, suggesting that leptin resistance rather than leptin deficiency is a characteristic feature of obesity. This study was designed to determine whether peripherally or centrally administered leptin is effective on the short-term food intake and expression of Fos protein in the hypothalamus in the Otsuka Long-Evans Tokushima Fatty (OLETF) or Long-Evans Tokushima Otsuka (LETO) rat, as a control. The OLETF rat exhibits a polygenic syndrome of hyperphagia, obesity, hyperinsulinaemia, and hyperglycaemia. Male OLETF rats of 5, 8, and 14 weeks of age became heavier than LETO rats. Serum leptin concentrations were not significantly different between LETO and OLETF rats at the age of 5 weeks, but in 8- and 14-week-old OLETF rats were increased to 3.4 and 2.9 times those of LETO rats, respectively. The 8-week-old OLETF and LETO rats were given intraperitoneal (i.p.) injections with recombinant mouse leptin to measure the kinetics. There was a dramatic increase in plasma leptin concentration at 1 h, a decline by 3 h, and the concentrations 6 h after injection were similar to the basal levels. There were no significant difference between OLETF and LETO rats. In LETO rats at 5, 8 and 14 weeks of age, i.p. injection of leptin significantly decreased food intake. Whereas 5-week-old OLETF rats responded to leptin with a decrease in food intake, 8- and 14-week-old OLETF rats became resistant to peripherally administered leptin. In contrast, intracerebroventricular (i.c.v.) injections of leptin were very effective in inhibiting food intake in both OLETF and LETO rats at 14 weeks of age. Intraperitoneal injection of leptin in the LETO rats at each age increased the number of Fos-positive nuclei detected in the ventromedial hypothalamic (VMH), the dorsomedial hypothalamic (DMH) and arcuate nuclei, whereas there was no significant increase in the number of cells expressing c-fos protein in the hypothalamus of the 8- and 14 week-old OLETF rats with hyperleptinaemia. On the other hand, increased expression of c-fos protein in the VMH, DMH and arcuate nuclei following i.c.v. injection of leptin was observed in both OLETF and LETO rats at 5, 8 and 14 weeks of age. These data demonstrated that obese OLETF rats are peripherally leptin resistant, while they retain sensitivity to centrally administered leptin.

Animals↗
PubMed1999

Changes in association of the Xenopus origin recognition complex with chromatin on licensing of replication origins.

During late mitosis and early G1, a series of proteins are assembled onto replication origins that results in them becoming 'licensed' for replication in the subsequent S phase. In Xenopus this first involves the assembly onto chromatin of the Xenopus origin recognition complex XORC, and then XCdc6, and finally the RLF-M component of the replication licensing system. In this paper we examine changes in the way that XORC associates with chromatin in the Xenopus cell-free system as origins become licensed. Restricting the quantity of XORC on chromatin reduced the extent of replication as expected if a single molecule of XORC is sufficient to specify a single replication origin. During metaphase, XOrc1 associated only weakly with chromatin. In early interphase, XOrc1 formed a strong complex with chromatin, as evidenced by its resistance to elution by 200 mM salt, and this state persisted when XCdc6 was assembled onto the chromatin. As a consequence of origins becoming licensed the association of XOrc1 and XCdc6 with chromatin was destabilised, and XOrc1 became susceptible to removal from chromatin by exposure to either high salt or high Cdk levels. At this stage the essential function for XORC and XCdc6 in DNA replication had already been fulfilled. Since high Cdk levels are required for the initiation of DNA replication, this 'licensing-dependent origin inactivation' may contribute to mechanisms that prevent re-licensing of replication origins once S phase has started.

Animals↗
PubMed1999

[A young male of systemic lupus erythematosus with hepatic lesions showing multiple low density spots in CT of liver].

A 19-year-old man was admitted to our hospital due to low grade fever and polyarthralgia with history of photosensitivity. Laboratory findings showed the elevated transaminases, leukocytopenia and thrombocytopenia. Examinations in regard to autoimmune diseases revealed the positive antinuclear antibody and positive LE test. The computed tomography (CT) showed the multiple low density spots in liver. CT guided liver biopsy specimens regarding to these low density spots showed the hepatic lesions with mild inflammatory cell infiltration and subtle piecemeal necrosis. The patient was diagnosed as systemic lupus erythematosus (SLE) with hepatic lesions based on the clinical symptoms and the laboratory data. Rheumatoid arthritis was excluded because of intact joints X-ray findings. Autoimmune hepatitis was also denied because of the fulfillment of definite diagnostic criteria of SLE and minimal histological changes of liver. Prednisolone therapy improved his clinical manifestations and normalized both the laboratory data of liver function and the immunological abnormalities in SLE, so the multiple spots in CT of liver also disappeared.

Adult↗
PubMed1999

[Diagnosis of thyroid nodules by Doppler ultrasonography: a comparison between color Doppler and power Doppler ultrasonography].

The purpose of this study was to assess the usefulness of color and power Doppler imaging in thyroid nodules. The following 4 items were compared between malignant thyroid nodules (34 cases) and benign nodules (51 cases): 1) vascularity; 2) distribution of tumor vessels (none, marginal, peripheral, central); 3) nature of tumor vessels (tortuosity, interruption); and 4) FFT analysis. The distribution of tumor vessels on color Doppler images, nature of tumor vessels on power Doppler images, and the indices of PI, RI, and ATI in FFT analysis were useful in making the differential diagnosis between malignant and benign nodules. In terms of vascularity, including the distribution of tumor vessels on power Doppler images and nature of tumor vessels on color Doppler images, no statistically significant differences were found between malignant and benign nodules. Power Doppler images depicted tumor vessels in more detail than color Doppler images and were considered to extend the application of FFT analysis.

Diagnosis, Differential↗
PubMed1999

[Interferon].

Explore the source record for details and available documents.

Humans↗
PubMed1998

Cloning of two isoforms of mouse DNA helicase Q1/RecQL cDNA; alpha form is expressed ubiquitously and beta form specifically in the testis.

We cloned cDNAs encoding mouse homologues for the human DNA helicase Q1/RecQL (human helicase Q1) which has homology with the Escherichia coli RecQ protein and found that they encode two isoforms. The two isoforms are identical over the entire sequence except for the carboxyl terminal sequence spanning less than 30 amino acids. One of the two isoforms, alpha, contains a sequence, KKRK, in the carboxyl terminus, which is also contained in human helicase Q1 and was confirmed to function as the nuclear localization signal. The other form, beta, does not contain such a sequence. Expression of mouse helicase Q1 mRNA is extremely and relatively high in the testis and the thymus, respectively. RT-PCR analysis revealed that helicase Q1alpha was expressed in all tissues tested and the beta form was expressed only in the testis. A survey of expression of Q1alpha and Q1beta mRNA in the testis after birth revealed that Q1alpha mRNA is expressed in all testes of mice aged from 7 days to 8 weeks, and the expression of Q1beta mRNA begins 14 days after birth, corresponding to the appearance of cells in the pachytene stage.

Amino Acid Sequence↗
PubMed1998

Breast masses: color Doppler, power Doppler, and spectral analysis findings.

PURPOSE: To determine the diagnostic efficacy of power Doppler sonography (PDS) with spectral analysis for breast diseases, we retrospectively compared PDS and color Doppler sonography (CDS) in patients with breast lesions. METHODS: One hundred thirty-eight women with palpable breast lesions were examined with PDS (65 women) and/or CDS (73 women). We calculated peak velocity, end-diastolic velocity, pulsatility index (PI), and resistance index (RI). RESULTS: On a 4-point subjective visual vascularity scale, PDS demonstrated higher vascularity than did CDS. Although smaller and more subtle vessels could be detected only with PDS, the PI and RI differed significantly between malignant and benign lesions when either PDS or CDS was used. However, logistic regression analysis showed that high PI and RI were associated with malignancy only when CDS was used. When PDS was used, PI was significantly higher in invasive ductal carcinomas with fibrous stroma and ill-defined margins (associated with a poor prognosis) than in invasive ductal carcinomas without fibrous stroma or with well-defined margins. CONCLUSIONS: Doppler spectral analysis of malignant breast lesions using PDS may contribute to the determination of prognosis.

Breast Neoplasms↗
PubMed1998

Infrahyoid spread of deep neck abscess: anatomical consideration.

The aim of this study was to determine the pathway of infrahyoid extension of the oropharyngeal abscess considering the anatomy of the fascial spaces by cross-sectional imaging. CT scans and MR images were retrospectively reviewed in ten patients with known infrahyoid extension of oropharyngeal abscesses (eight with acute tonsillitis, two with acute phlegmonous oropharyngitis). In seven of eight patients tonsillar abscesses descended along the deep cervical fascia converging on the hyoid bone and further accumulated in the anterior cervical space through which extension to the mediastinum took place in four patients. In seven patients the abscesses involved the retropharyngeal space at the infrahyoid neck. In two of these seven patients the abscesses directly extended down into the upper mediastinum through the retropharyngeal space. In one patients of the seven mediastinal spread of an abscess occurred through the posterior cervical space, not through the retropharyngeal space. Cross-sectional imaging is valuable in the evaluation of deep neck abscesses and the pathway of spread. The anterior cervical space in the infrahyoid neck is important for mediastinal extension of pharyngeal abscesses.

Abscess↗
PubMed1998

Molecular cloning and characterization of the gene encoding N'-[(5'-phosphoribosyl)-formimino]-5-aminoimidazole-4-carboxamide ribonucleotide (BBM II) isomerase from Arabidopsis thaliana.

We have isolated an Arabidopsis BBM II isomerase cDNA from an Arabidopsis cDNA library, by means of functional complementation of the E. coli hisA mutant strain HfrG6. The isolated cDNA encodes a polypeptide of 304 amino acids with a calculated molecular weight of 33,363. Sequence comparison with the HIS6 proteins of yeasts revealed that Arabidopsis BBM II isomerase contains an N-terminal extension of approximately 40 amino acids that shows the general properties of chloroplast transit peptides. This finding is consistent with the localization of other histidine biosynthetic enzymes, such as imidazoleglycerolphosphate dehydratase and histidinol dehydrogenase, in the chloroplasts in higher plants. The primary structure of the mature protein was 50% and 42% identical, respectively, to the HIS6 proteins of Schizosaccharomyces pombe and Saccharomyces cerevisiae, respectively, while no prominent sequence similarity to the bacterial BBM II isomerase was found. That the isolated Arabidopsis cDNA actually encodes a functionally active BBM II isomerase activity was confirmed in an in vitro enzyme assay using a crude extract prepared from strain HfrG6 transformed with the Arabidopsis BBM II isomerase cDNA.

Aldose-Ketose Isomerases↗
PubMed1998

Comparative features of double-contrast barium studies in patients with isosporiasis and strongyloidiasis.

OBJECTIVE: To compare the gastrointestinal features of isosporiasis and strongyloidiasis. METHODS: Two patients with isosporiasis and three patients with strongyloidiasis were assessed by double-contrast radiography of the duodenum and small intestine, with reference to histology of the duodenal biopsy specimens. RESULTS: Both conditions affected the duodenum and the proximal jejunum, and showed similar radiographic changes as the diseases progressed. Thus, three patients with diarrhoea lasting 1 year or less showed only minimal or irregularly thickened mucosal folds, which seemed to result from mucosal inflammation. Two patients with long-standing disease periods (17 years and 30 years) presented a markedly granular mucosal appearance with effacement of the folds on radiography. These chronological differences in the radiographic features seemed to reflect the degree of villous atrophy. CONCLUSION: Isosporiasis has similar radiographic features of strongyloidiasis.

Aged↗
PubMed1998

Genetic risk factor for abdominal aortic aneurysm: HLA-DR2(15), a Japanese study.

PURPOSE: Autoimmunity has been proposed to play a role in the pathogenesis of the abdominal aortic aneurysm (AAA). Several autoimmune diseases are associated with specific HLA DR alleles. These experiments were carried out to determine whether the same HLA DR types that have been reported to be associated with AAA in a mixed North American population are similarly associated with AAA in a more homogeneous group of patients in Japan. METHOD: HLA DR typing was performed by a serologic method on samples of peripheral blood of patients with nonspecific infrarenal AAA in Nagasaki University Hospital in Japan. The frequencies of HLA DR antigens were compared with those of volunteers approximately matched for age and sex from the same referral area. RESULTS: HLA DR haplotypes were determined in 46 Japanese patients with AAA and in 50 patients in a control group. The HLA-DR2(15) antigen was observed in 27 (58.7%) patients (29 alleles 31.5%) with AAA and in 14 (28%) subjects (16 alleles 26.0%) in the control group (p < 0.005). CONCLUSIONS: The data suggest that HLA-DR2(15) has an important role as a genetic risk factor for AAA in Japanese patients, as previously reported in a mixed North American population.

Aged↗
PubMed1998

Endoscopic and pathological manifestations of the gastrointestinal tract in familial amyloidotic polyneuropathy type I (Met30).

OBJECTIVES: To evaluate the characteristic changes in the gastrointestinal tract in familial amyloidotic polyneuropathy (FAP) (Met30), both fibre gastroscopy and colonoscopy studies were performed in FAP (Met30) patients. Microscopic changes were also examined in autopsied and biopsied materials from patients with FAP, and compared with data from autopsied samples from patients with AL amyloidosis, and secondary amyloidosis patients. DESIGN: Endoscopic and histopathological study. SETTING: Kumamoto University Hospital, Kumamoto, Japan. SUBJECTS: Nine patients with FAP (Met30) underwent fibre gastroscopy and colonoscopy. Six autopsied and 23 biopsied gastrointestinal samples from FAP patients, four from autopsied amyloidosis (including two myeloma associated form), and two from autopsied secondary amyloidosis patients were examined for histopathological study. MAIN OUTCOME MEASURES: Fibre gastroscopy and colonoscopy were employed for macroscopic study. Congo red and H-E staining were performed for histopathological study. Macroscopic changes in the gastrointestinal tract and microscopic differences in the amyloid distribution pattern were compared between the different types of amyloidosis. RESULTS: Fibre gastroscopy and colonoscopy for nine FAP patients revealed that four showed a fine granular appearance in the duodenum, three showed lack of lustre, and two showed mucosal friability in the gastrointestinal tract; however, no macroscopic abnormality was observed in four other FAP patients. Histopathological examination of tissue from FAP patients revealed that, although a small amount of amyloid was recognized in the submucosa perivascular layer, a significant amount of amyloid was seen in and around the nerves of the gastrointestinal tract, but very little in Auerbach's nerve plexus. In total, the amount of deposited amyloid in the tissues was small compared with that in other types of systemic amyloidosis, such as AL and secondary amyloidosis. CONCLUSION: These results suggest that the major reason why FAP patients show such severe gastrointestinal symptoms, compared with other types of systemic amyloidosis, may be because of the deposition of a significant amount of amyloid in the nerves in the gastrointestinal tract.

Adult↗