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Biomedical subjects

S Shimada

Publications and source records attributed to S Shimada.

At least 55 records · Page 3Linked to original sources
PubMed2001

Angled rigid neuroendoscope for continuous intraoperative visual monitoring: technical note.

We developed and tested a new, angled rigid endoscope as a tool for performing continuous visual monitoring during microsurgery. The shaft of the scope is angled 110 degrees at its midportion using a prism. We used the scope continuously in 30 cases including 15 pituitary tumours, 7 brain tumours, 7 cerebral aneurysms, and one hemifacial spasm. For pituitary tumours the tip of the scope was positioned in the sphenoid sinus or in the cavity formed by tumour removal; for cerebral aneurysms it was placed behind the parent artery or the aneurysmal neck. Image quality was acceptable for intraoperative monitoring. In no case did the neuroendoscope have a deleterious impact on th e proper function of the microscope or surgical instruments. This angled rigid scope was more effective for intraoperative monitoring than conventional straight scopes.

Endoscopes↗
PubMed2001

Recurrent pregnancy loss: etiology of thrombophilia.

Congenital and acquired thrombophilia are associated with an increased risk of pregnancy-associated venous thrombosis and fetal loss. Two hundred eighty-nine patients with a history of recurrent spontaneous abortion were subjected to screening examinations for the etiology of these abortions. Endocrine abnormality (28.0%), uterine abnormality (10.4%), autoimmune diseases (1.4%), antiphospholipid antibody syndrome (4.5%), and balanced type chromosome translocation (4.2%) were found as underlying causes of recurrent abortions, and the remaining 55.0% of the 289 patients were classified as having an unexplained etiology. Congenital thrombophilia such as protein C (PC) deficiency, protein S (PS) deficiency, antithrombin deficiency, and factor V Leiden mutation was not frequently detected; only one patient had PS deficiency. A reduced factor XII activity was found at a frequency of 4.2%. The frequency of methylene tetrahydrofolate reductase gene C677T mutation in recurrent aborters (0.38) was the same as that found in a fertile control group. Although the prevalence of anti-beta2-glycoprotein I antibody (abeta2-GPI) syndrome was very low (1.7%), patients with a high titer of immunoglobulin G (IgG) class abeta2-GPI, despite anticoagulation therapy, experienced severe fetomaternal complications in subsequent pregnancies. The rate (13.8%) of positive tests for serum IgA class abeta2-GPI in patients with unexplained etiology was higher than that in the controls (0%) (P < .05). We conclude that congenital thrombophilia is rare in Japanese patients who had experienced consecutive spontaneous abortions.

Abortion, Habitual↗
PubMed2001

Characterization of early gastric cancer and proposal of the optimal therapeutic strategy.

BACKGROUND AND AIMS: The optimal protocol of the treatment for early gastric cancer has not been fully established. The current study was designed to elucidate the relationship between the depth of tumors with or without an ulcer and the presence of lymph node metastasis and to establish the optimal and practical therapeutic strategy for patients with early gastric cancer. PATIENTS AND METHODS: A retrospective analysis of 1051 patients with early gastric cancer treated by gastrectomy with D1 or D2 lymph node dissection was performed. The patients were divided into those with mucosal (M) tumors and those with submucosal (SM) tumors. These 2 groups were subclassified, depending on the coexistence of ulcer or the degree of submucosal invasion, and were characterized in relation to clinicopathologic factors and 5-year prognosis. RESULTS: The incidence of lymph node metastases from SM tumors (19.8%, 85 of 430) was more frequent than that from M tumors (2.3%, 14 of 621) (P <.001). All M tumors with lymph node involvement, including tumors smaller than 1.5 cm in diameter, had ulceration or ulceration scar in the lesions. SM tumors that had invaded less than 200 microm in depth (SM1a) had significantly less lymph node involvement than those with deeper invasion. The node metastases were confined to epigastric lymph nodes (N1) in both M tumors with ulceration or ulceration scar and SM1a tumors. CONCLUSIONS: All macroscopic M tumors without ulceration or ulceration scar should be considered for endoscopic mucosal resection. The need for reoperation for a formal gastrectomy with lymphadenectomy or a limited surgical operation will vary depending on the pathologic analysis of endoscopic mucosal resection specimens (depth of invasion, presence of ulceration).

Adult↗
PubMed2001

The nucleotide sequence of dinitrophenyl-specific IgE and Fc(epsilon)RI alpha-subunit obtained from FE-3 hybridoma cells.

FE-3 cells were established by Hanashiro et al. by hybridizing mouse myeloma cells (Sp2/0-Ag14/SF) with rat spleen cells that were freshly isolated from Brown-Norway rats sensitized with DNP-As. FE-3 cells can constitutively secrete IgE without stimulation by cytokines. Our preliminary experiments demonstrated that the IgE secretion was decreased at 3 days after start of culture and the addition of exogenous IgE into culture media depressed the secretion of IgE. Thus, we hypothesized that the IgE production in FE-3 cells may be regulated by a signal transduction through the binding of IgE to its high affinity receptor (Fc(epsilon)RI) or to an IgE binding protein on the cell surface. In this study, we aimed to identify the nucleotide sequence of IgE FE-3 and compared with those of mouse IgE and IgE IR162 to find a structural heterogeneity in the Fc region of IgE FE-3. We also tested if the mRNA of Fc(epsilon)RI was expressed in FE-3 cells using the reverse transcriptase-polymerase chain reaction (RT-PCR) method with the combination of sequencing analysis. Consequently, the cDNA sequence of IgE FE-3 was identical to that of the CH3 and CH4 domains in the epsilon-chain of rat IgE IR162, whereas the cDNA of Fc(epsilon)RI was identical to that of mouse, suggesting that the genes of IgE FE-3 and Fc(epsilon)RI was derived from that of rat spleen cells and mouse myeloma cells, respectively.

Animals↗
PubMed2001

OARE-1, a Ty1-copia retrotransposon in oat activated by abiotic and biotic stresses.

Transcriptionally active Ty1-copia LTR-retrotransposons were found in oat using RT-PCR for amplifying the reverse transcriptase domain. Sequence analysis of the RT-PCR clones suggested that oat LTR-retrotransposons consist of at least seven groups, which were tentatively designated as Oatrt1 to Oatrt7. A full length copy of Oatrt1 was isolated from an oat genomic library, and was designated OARE-1. OARE-1 was 8,665 bp long and a member of the BARE-1 subgroup. The oat genome carried it in multiple copies (at least 10,000 copies / a hexaploid genome). The expression of OARE-1 was intensively induced by wounding, UV light, jasmonic acid and salicylic acid, and its pattern was very similar to that of the PAL (phenylalanin ammonia lyase) gene. Furthermore, OARE-1 was highly activated by infection with an incompatible race of the crown rust fungus, Puccinia coronata. These results suggest that OARE-1 is highly sensitive to various abiotic and biotic stimuli leading to plant defense responses.

Amino Acid Sequence↗
PubMed2001

Relationships among bone mineral densities, static alignment and dynamic load in patients with medial compartment knee osteoarthritis.

OBJECTIVE: To investigate the relationships among bone mineral density (BMD), static alignment and the adduction moment of the knee in patients with tibiofemoral osteoarthritis (OA). METHODS: Sixty-nine patients with medial compartment knee OA underwent radiographic evaluation, gait analysis and BMD measurements at the proximal tibia and lumbar spine. RESULTS: The bone mineral distribution of the medial to lateral part of the proximal tibia correlated significantly with the peak knee adduction moment and the mechanical axis. Furthermore, the adduction moment correlated significantly with the mechanical axis. However, the BMD of the lumbar spine and the bone mineral distribution of the posterior to anterior part of the proximal tibia did not correlate with any other measurement. CONCLUSIONS: Our results suggest that the bone mineral distribution of the proximal tibia is directly affected but lumbar BMD is not influenced by the local mechanical stress around the knee with medial compartment OA.

Absorptiometry, Photon↗
PubMed2001

Percutaneous embolization of the distal pancreatic duct to treat intractable pancreatic juice fistula.

Pseudocysts and post-necrotic collections of the pancreas are sometimes treated by percutaneous drainage. In cases of post-necrotic collection, intractable pancreatic juice fistula is often formed by disruption of the main pancreatic duct in the necrotized region. We radically treated intractable pancreatic juice fistulae by selective cannulation into the distal pancreatic duct via the route for percutaneous drainage of post-necrotic collections to extinguish the exocrine function of the caudal pancreas. We performed this procedure in two patients in whom the major pancreatic duct was damaged at the body of the pancreas, which was extensively necrotic. Although mild symptoms of acute pancreatitis appeared in both patients after the first procedure, they recovered without severe side effects. Neither recurrence of pancreatic juice fistulae nor reduction of the glucose tolerance was caused by removing the exocrine function of the caudal pancreas in either patient 32 and 24 months after treatment, respectively. This method is an effective treatment modality with which to treat intractable pancreatic juice fistulae with damage of the main pancreatic duct.

Adult↗
PubMed2001

Characterization of mumps virus isolated in saitama prefecture, Japan, by sequence analysis of the SH gene.

Mumps virus (MuV) strains isolated from cerebrospinal fluid and throat swabs from patients in Saitama Prefecture and Tokyo, Japan, from 1997 to 2000 were examined by analyzing the SH gene nucleotide sequence (316-nt). Eighteen of the 20 strains studied were divided into three genotypes, recognized as B, G, and H in previous reports. Two genotypes (G and H) are believed to be new in Japan. Two of the 20 strains belonged to none of the previously reported genotypes (A-I), but were closely related to two known strains, MP94-H and Loug1/UK97. We propose that the two strains identified in this study together with the previously reported strains, MP94-H and Loug1/UK97, form a new genotype, designated J, based on the divergence of the SH gene nucleotide sequences between these four strains and other strains reported (genotypes A-I). Our results also suggest that more than two genotypes circulated in Saitama Prefecture from 1997 to 1999, but only one, genotype G, was in evidence in 2000. Genotype B was earlier reported as the predominant strain in Japan, but it became undetectable by the year 2000. These results provide important epidemiological data on mumps in Japan.

Amino Acid Sequence↗
PubMed2001

High NK cell activity in early pregnancy correlates with subsequent abortion with normal chromosomes in women with recurrent abortion.

PROBLEM: The aim of this study was to assess the role of natural killer (NK) cells in pregnant women with a history of recurrent spontaneous abortion (RSA). METHOD OF STUDY: Consecutive 66 pregnant women with a history of RSA were prospectively assessed for peripheral NK cell activity, percentage of the NK cell subsets, and subsequent pregnancy outcome. RESULTS: NK cell activity in women with subsequent live birth (group I) at 4-5 gestational weeks (GW) (mean +/- SD, 32.5 +/- 12.31%) significantly decreased at 6-7 GW (28.1 +/- 12.1%) and at 8 9 GW (28.0 +/- 11.8%). NK cell activity in women with subsequent abortion with normal chromosomes (group II) at 6 7 GW (41.2 +/- 19.0%) was significantly higher than that in group I women, while NK cell activity at 6-7 GW in women with subsequent abortion with abnormal chromosomes (group III) was the same as the level in group I women. CONCLUSIONS: High NK cell activity at 6-7 GW correlates with subsequent abortion with normal chromosomes.

Abortion, Habitual↗
PubMed2001

[Characterization of enterovirus type 71 isolated in Saitama Prefecture in 2000].

Coxsackievirus A16 (CA16) has been isolated mainly from hand, foot and mouth disease patients for the past several years in Saitama Prefecture, Japan, but in 2000, enterovirus 71 (EV71) was isolated with high frequency. Also, many cases with aseptic meningitis were reported unusually. We determined partial nucleotide sequences of EV71 isolated in this year and compared them with those of the viruses isolated previously. Eighteen strains of EV71 were isolated from May to September in 2000. The sequence analysis of about 700 nucleotides between 5' NCR and VP2 region indicated that the EV71 strains isolated in Saitama Pref. in 2000 were classified into three groups. The first group was consisted of the strains which showed 89 to 91% nucleotide similarity with TW/2086/98, NCKU 9822 isolated in Taiwan and strain SA/448/99 isolated in Saitama Pref. in 1999. The second group was highly similar to both Taiwan strains and SA/448/99 (92 to 93% nucleotide similarity). The first and second groups were also considered to be subgroups belonging to the same group. And the third group was highly similar to 18/Sin/97, 13/Sin/98 isolated in Singapore. These viruses were genetically close to MS7423/87, which has shown neurovirulence. Furthermore, from geographical origin of specimens, we found that the Taiwan like strains were isolated in the west area (Kawagoe, Tokorozawa) and Singapore like strains were isolated in the south area (Urawa, Kawaguchi, Toda). Also, almost every EV71 strains isolated from the patient with aseptic meningitis were close to Singapore strains. It was found that EV71 strains isolated in 2000 were different from the strains isolated past in Saitama Pref. and some of them were close to the neurovirulent strain.

Base Sequence↗
PubMed2001

Axin facilitates Smad3 activation in the transforming growth factor beta signaling pathway.

Axin acts as a negative regulator in Wnt signaling through interaction with various molecules involved in this pathway, including beta-catenin, adenomatous polyposis coli, and glycogen synthase kinase 3beta. We show here that Axin also regulates the effects of Smad3 on the transforming growth factor beta (TGF-beta) signaling pathway. In the absence of activated TGF-beta receptors. Axin physically interacted with Smad3 through its C-terminal region located between the beta-catenin binding site and Dishevelled-homologous domain. An Axin homologue, Axil (also called conductin), also interacted with Smad3. In the absence of ligand stimulation, Axin was colocalized with Smad3 in the cytoplasm in vivo. Upon receptor activation, Smad3 was strongly phosphorylated by TGF-beta type I receptor (TbetaR-I) in the presence of Axin, and dissociated from TbetaR-I and Axin. Moreover, the transcriptional activity of TGF-beta was enhanced by Axin and repressed by an Axin mutant which is able to bind to Smad3. Axin may thus function as an adapter of Smad3, facilitating its activation by TGF-beta receptors for efficient TGF-beta signaling.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Characterization of a mouse colonic system B(0+) amino acid transporter related to amino acid absorption in colon.

Previous experiments have shown that an amino acid transport system B(0+) transporter in cultured colonic epithelial cells mediates amino acid absorption. Here we describe the cloning and functional characterization of a system B(0+) transporter selectively expressed in the colon. Using the combination of an expressed sequence tag database search and RT-PCR approaches, we cloned a mouse colonic amino acid transporter, designated mCATB(0+). Northern blot analysis revealed that mCATB(0+) was selectively expressed in the large intestine. In situ hybridization showed the mCATB(0+) mRNA to be localized in absorptive epithelial cells. When expressed in Xenopus oocytes, mCATB(0+) exhibited a Na(+)-dependent stereoselective uptake and a broad specificity for neutral and cationic amino acids, which is characteristic of amino acid transport system B(0+). In vivo [(3)H]glycine uptake assay demonstrated that a system B(0+)-like transporter protein was expressed on the apical surface of the colonic absorptive cells. Our data suggest that a mouse colonic amino acid transporter mCATB(0+) may absorb amino acids from the intestinal contents in the colon.

Amino Acid Sequence↗
PubMed2001

NK cell activity and subsets in women with a history of spontaneous abortion. Cause, number of abortions, and subsequent pregnancy outcome.

OBJECTIVE: The aim of this study was to assess the role of NK cells in nonpregnant women with a history of spontaneous abortion. STUDY DESIGN: 113 nonpregnant women with a history of spontaneous abortion were assessed for peripheral NK cell activity and percentage of NK cell subsets, in relation to the cause of abortions, the number of spontaneous abortions, and subsequent pregnancy outcome (n = 56). RESULTS: Neither NK cell activity nor subsets showed a significant difference in relation to the cause or number of spontaneous abortions. NK cell activity in nonpregnant women who later experienced subsequent abortion with normal chromosomes (n = 10) (mean +/- SD: 42.8 +/- 15.8%) was relatively higher than that in women with subsequent live birth (control, n = 39) (32.1 +/- 13.7%) (p = 0.099). NK cell activity in women who later experienced subsequent abortion with abnormal chromosomes (n = 7) (28.7 +/- 21.4%) was the same as the level in the control. CONCLUSION: Peripheral NK cell activity or subsets during nonpregnant status were not related to the cause or number of previous spontaneous abortions. A relation between preconceptional NK cell activity and later experiencing abortion with normal chromosomes should be further studied.

Abortion, Habitual↗
PubMed2001

Characterization of a fission yeast mutant which displays defects in cell wall integrity and cytokinesis.

The fission yeast cps6-153 mutant was originally isolated based on its hypersensitivity to the spindle poison isopropyl N-3-chlorophenyl carbamate (CIPC). The mutant also shows defects in both cell wall integrity and cytokinesis, resulting in the accumulation of unseparated cells with weakened cell walls. The arrested cells display a disoriented alignment of cytoplasmic microtubules. When the mutant cells are cultivated at high temperature (35 degrees C), both cell walls and septa become very thick. Electron microscopy revealed the disorganized structure of the thickened cell walls and septa, in which fibrillar components were not completely masked with an amorphous matrix. rad25+ was cloned from a genomic library by complementation of the mutant phenotypes, suggesting the involvement of Rad25p, one of two 14-3-3 proteins in S. pombe, in the pathway of cell wall integrity and cytokinesis.

Cell Division↗
PubMed2001

Electron microscopic cytochemical studies of anionic sites in the rat spleen.

The distribution patterns of the intensity of negative charge on the free surfaces (glycocalyx of the plasma membrane) of endothelial cells (ECs) in blood vessels and reticular cells (RCs) in the splenic cord of the rat spleen were studied by an electron microscopic cytochemical method using polyethyleneimine (PEI) as a cationic probe. Spleens from adult male rats were perfusion-fixed with 0.5% glutaraldehyde -4% paraformaldehyde containing 0.05% cetylpyridinium chloride and then perfused with 0.5% PEI at pH 7.4. On the free surfaces (glycocalyx of the plasma membrane) of the ECs examined, distinct PEI-positive reactions were observed in blood vessels, such as trabecular arteries, central arteries, arterial capillaries, pulp veins and trabecular veins. These PEI-positive electron-dense substances in the trabecular arteries, central arteries, and trabecular veins took the shape of a band of 170-250 nm in thickness. On the other hand, the corresponding ultrastructure of the ECs lining the splenic sinuses and the RCs in the splenic cord showed exceedingly weak PEI reactions. The PEI-reactive deposits were significantly thinner than those in the above blood vessels. As the thickness of the electron-dense substances can be related to the density of the negative charge, these results suggest that there is a high intensity of negative charge on the free surfaces (glycocalyx of the plasma membrane) of ECs in blood vessels where blood cells and plasma pass into the red pulp or are discharged from the red pulp. In contrast, the splenic sinuses and RCs, which are the main components of the red pulp, contain weakly negative-charged sites. This may contribute to the microcirculation of the splenic blood vessels and elucidate the possible physiological functions of the spleen, such as blood storage.

Animals↗
PubMed2001

Force developmental phase and reliability in explosive and voluntary grip exertions.

The purposes of this study were to clarify the reliability of two types of grip exertions, explosive grip exertion and voluntary grip exertion up to the maximal grip strength and to examine their force patterns using force-time parameters. Subjects were 100 healthy young male volunteers (age: 17.8+/-2.50 yr.) who had no upper limb injury. Grip strength was measured two times with voluntary grip and then two times with explosive grip. 11 parameters derived from the force-time curve were selected to measure the developmental phase of muscle contraction. The reliability of maximal grip strength in explosive and voluntary grip exertions was very high (intraclass correlation = .95, .93). The difference between two trials in explosive grip tended to be smaller than that for voluntary grip, and reliability of the exertion pattern was higher for explosive grip than voluntary grip. The times to reach 90% of the maximal grip strength and the maximal grip strength in explosive grip were shorter than those in voluntary grip. The other 8 force-time parameters had higher values in explosive grip than voluntary grip and higher reliabilities. The force-time parameters reflect the properties of explosive exertion. The results suggest the possibility that static explosive strength could be evaluated using these force-time parameters.

Adolescent↗