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Biomedical subjects

S Watanabe

Publications and source records attributed to S Watanabe.

At least 307 records · Page 17Linked to original sources
PubMed2000

Surgical management of early stage central (hilar) and peripheral nonsmall cell lung carcinoma.

BACKGROUND: To the authors' knowledge, the definitions of early lung carcinoma used in Japan are not yet approved internationally. In the current study the diagnostic methods, pathology, and results of the surgical treatment of early hilar and peripheral nonsmall cell lung carcinoma cases defined by Japanese criteria are presented. METHODS: Between 1977 and 1998, 43 patients with early hilar lung carcinoma were encountered. These patients constituted 14.5% of 200 hilar lung carcinoma patients who underwent resection during the same period. Between 1973 and 1998, there were 174 early peripheral lung carcinomas, which comprised 14.8% of 1173 peripheral lung carcinoma patients who underwent resection during the same period. RESULTS: The 5-year and 10-year survival rates of the early hilar lung carcinoma were 100% and 96.9%, respectively. The majority of the patients underwent bronchoplastic surgery, such as sleeve lobectomy and parenchymal-sparing surgery including seven sleeve segmentectomies and two second carinal resections. The effectiveness of the parenchymal-sparing resections was assessed by the conventional pulmonary function test as well as perfusion and ventilation scanning. There were 174 cases of peripheral early lung carcinoma among the 218 cases of peripheral lung carcinoma with tumor dimensions of < or = 2 cm. The cell types were 142 (81.6%) cases of adenocarcinoma, 18 (10.3%) cases of squamous cell carcinoma, and 14 (8%) cases of other cell types. These 174 patients comprised 14.8% of 1173 patients with peripheral nonsmall cell lung carcinoma who underwent surgery during the same period. The 5-year and 10-year survival rates for adenocarcinoma were 89.6% and 86.8%, respectively. The 5-year and 10-year survival rates for other cell types were both 71.8%. The overall 5-year and 10-year survival rates were 86.8% and 84.6%, respectively. CONCLUSIONS: Early lung carcinoma in both the hilar and peripheral regions, is curable if it is properly diagnosed and treated.

Aged↗
PubMed2000

A new member of the HCO3(-) transporter superfamily is an apical anion exchanger of beta-intercalated cells in the kidney.

The kidneys play pivotal roles in acid-base homeostasis, and the acid-secreting (alpha-type) and bicarbonate-secreting (beta-type) intercalated cells in the collecting ducts are major sites for the final modulation of urinary acid secretion. Since the H(+)-ATPase and anion exchanger activities in these two types of intercalated cells exhibit opposite polarities, it has been suggested that the alpha- and beta-intercalated cells are interchangeable via a cell polarity change. Immunohistological studies, however, have failed to confirm that the apical anion exchanger of beta-intercalated cells is the band 3 protein localized to the basolateral membrane of alpha-intercalated cells. In the present study, we show the evidence that a novel member of the anion exchanger and sodium bicarbonate cotransporter superfamily is an apical anion exchanger of beta-intercalated cells. Cloned cDNA from the beta-intercalated cells shows about 30% homology with anion exchanger types 1-3, and functional expression of this protein in COS-7 cells and Xenopus oocytes showed sodium-independent and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid-insensitive anion exchanger activity. Furthermore, immunohistological studies revealed that this novel anion exchanger is present on the apical membrane of beta-intercalated cells, although some beta-intercalated cells were negative for AE4 staining. We conclude that our newly cloned transporter is an apical anion exchanger of the beta-intercalated cells, whereas our data do not exclude the possibility that there may be another form of anion exchanger in these cells.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2000

Characterization of the CIN85 adaptor protein and identification of components involved in CIN85 complexes.

CIN85 is an 85-kDa adaptor protein whose functions in signaling pathways are presently unknown. Using the yeast two-hybrid screen, the B cell linker protein (BLNK) was identified as a binding partner of CIN85. Coimmunoprecipitation experiments using mammalian cells revealed that CIN85 directly bound to BLNK through its SH3 domains. Immunostaining analysis showed that CIN85 and BLNK were colocalized in the cytoplasm. These results indicate a potential role of CIN85 in the B cell receptor-mediated signaling pathway. It was also found that Crk-I, Crk-II, p130(Cas), p85-PI3K, Grb2, and Sos1 were components of CIN85 complexes. CIN85 interacted with itself through its coiled-coil region, resulting in formation of a tetramer. Both the coiled-coil region and SH3 domains of CIN85 were responsible for its subcellular localization. Our data suggest that CIN85 may serve for regulation of various signaling events through formation of its diverse complexes.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Troglitazone induces apoptosis via the p53 and Gadd45 pathway in vascular smooth muscle cells.

Thiazolidinediones, activators of peroxisome proliferator-activated receptor (PPAR)gamma, have been reported to induce apoptosis in many types of cells. In the present study, we investigated the effects of thiazolidinediones, troglitazone, and pioglitazone on the cell growth of vascular smooth muscle cells, and identified a specific effect of troglitazone in addition to PPARgamma activation. Subconfluent rat culture vascular smooth muscle cells were treated with or without PPARgamma activators, troglitazone (1-30 microM), or pioglitazone (1-30 microM) for 72 h. After treatment, cell viability was significantly reduced by troglitazone in concentrations of 5-30 microM but not by pioglitazone. Vascular smooth muscle cells appeared to float and shrink 48 h after treatment with 20 microM of troglitazone. In situ DNA labeling showed that the nuclei of these cells were positively stained, and genomic DNA extracted from the cells showed nucleosomal laddering. Messenger RNA expression levels of c-myc, p21, bax, bcl-2, and bcl-x were not changed by the treatment with troglitazone. In contrast, along with the induction of vascular smooth muscle cell apoptosis, both the mRNA and protein expression levels of p53 and Gadd45 markedly increased in response to troglitazone. These results strongly suggest that troglitazone can induce vascular smooth muscle cell apoptosis and that this effect is caused primarily by activation of the p53 and Gadd45 pathway but not by PPARgamma activation.

Animals↗
PubMed2000

Considerable time from the onset of plaque rupture and/or thrombi until the onset of acute myocardial infarction in humans: coronary angiographic findings within 1 week before the onset of infarction.

BACKGROUND: It has been thought that the thrombi and bleeding in plaques that occur after plaque rupture or endothelial damage from vessels with mild stenosis suddenly occlude the lumen and cause acute myocardial infarction (AMI). However, our hypothesis is that thrombi and bleeding may not suddenly occlude the lumen. METHODS AND RESULTS: The study group consisted of 20 patients who had coronary angiograms performed within 1 week (3+/-3 days) before AMI and 20 control patients who had coronary angiograms performed 6 to 18 months (282+/-49 days) before AMI. The features of infarct-related coronary segments (IRCS) at 3 days before AMI were the presence of a significant stenosis of >50% (95% in incidence and 71+/-12% diameter stenosis) and Ambrose's type II eccentric lesions (plus multiple irregularities), an indicator of plaque rupture and/or thrombi (60% [70%]), and the features at 1 year before AMI were mild stenosis of <50% (95% incidence and 30+/-18% diameter stenosis) with rare Ambrose's type II eccentric lesions (plus multiple irregularities) (10% [10%]). The same relation was observed in each of the 4 subgroups with Q-wave infarction, non-Q-wave infarction, preceding effort angina within 1 month before AMI, and no preceding effort angina. CONCLUSIONS: The appearance of marked progression and Ambrose's type II eccentric lesion on coronary angiograms 3 days before AMI suggests the presence of a considerable time from the onset of plaque rupture and/or thrombi until the onset of AMI. These features may be predictors of AMI. The concept provides new insight into the mechanism and prevention of human AMIs.

Acute Disease↗
PubMed2000

A novel de novo mutation in the desmin gene causes desmin myopathy with toxic aggregates.

OBJECTIVE: To determine the cause and pathogenic mechanisms of a 21-year-old patient's cardioskeletal myopathy. The patient's muscle atrophy and weakness began in distal parts of limbs; cardiac and facial muscles were later involved. BACKGROUND: Desmin myopathy is a skeletal myopathy often associated with cardiomyopathy, caused by mutations in the desmin gene and characterized by desmin accumulation in affected muscle fibers, a leading marker of myofibrillar myopathies. Two kinds of deletions and seven missense mutations in the desmin gene have been identified. METHODS: Clinical examination, electron microscopy of muscle tissue, two-dimensional gel electrophoresis, DNA sequencing, restriction enzyme analysis, and gene transfection were performed. RESULTS: Electron microscopy showed disruption of sarcomeres at Z discs and electron-dense aggregates in biopsied skeletal and heart muscle. Two-dimensional gel electrophoresis of the patient's skeletal muscle proteins showed massive accumulation of desmin. The authors identified a novel desmin mutation, L385P in one allele in the carboxyl end of the rod domain 2B in the patient's leukocytes and skeletal muscle; neither parent had the mutation. Serologic study and DNA markers confirmed the de novo mutation. A peptide harboring desmin rod domains 2A and 2B with L385P tagged with green fluorescent protein induced cytoplasmic aggregates, nuclear DNA condensation, and cell death. CONCLUSIONS: A novel de novo mutation, L385P, causes desmin myopathy. An expression study indicated the toxic effect of the L385P mutation.

Adult↗
PubMed2000

Screening of the Men1 gene and discovery of germ-line and somatic mutations in apparently sporadic parathyroid tumors.

Hyperparathyroidism is the first manifestation in a majority of multiple endocrine neoplasia (MEN1) patients. To discriminate between sporadic and hereditary parathyroid tumors and characterize MEN1 somatic mutations, we examined MEN1 gene mutations in patients who had undergone surgery for sporadic parathyroid tumors. DNA was extracted from fresh frozen parathyroid tumor specimens from 112 patients as well as from peripheral blood leukocytes from 64 of the 112 patients. Sequence analysis was performed to examine exons 2-10 of the MEN1 gene for mutations. Loss of heterozygosity (LOH) was also examined by an analysis of codon 418 and 541, which lie within a polymorphic region of MEN1. Somatic MEN1 mutations were found in 25 of the 112 patients (22%). Two patients had two point mutations (508del33 and Y341X and 363insT and 1767delT, respectively). A total of 27 mutations were characterized, 20 of which have not been reported previously. There were 7 nonsense mutations, 10 frameshift mutations, 2 splice site deletions, 5 missense mutations, and 3 in-frame mutations. Nineteen mutations (70%) predicted truncation of the menin protein. Germ-line MEN1 mutations were found in 3 of 64 patients (5%) who had no family history of endocrine tumors associated with MEN1, and these patients were identified as MEN1 gene probands. LOH at the MEN1 locus was detected in three parathyroid tumors showing germ-line mutation. LOH was significantly frequent in parathyroid tumors with somatic MEN1 mutations (15 of 22 tumors, 68%) but not in those without germ-line or somatic MEN1 mutations (14 of 51 tumors, 28%; P = 0.0011). Our findings suggest that alterations of both alleles of the MEN1 gene may be associated not only with endocrine tumors of affected MEN1 patients but also with sporadic parathyroid tumors. Germ-line MEN1 gene analysis can distinguish heritable from nonheritable parathyroid tumors, and MEN1 gene evaluation of patients with apparently sporadic parathyroid tumor is recommended before parathyroid surgery.

Adult↗
PubMed2000

First isolation of Exophiala dermatitidis from a dog: identification by molecular analysis.

The present study deals with the first isolation of Exophiala dermatitidis from a dog. The dog had a history of multicentric lymphoma for 4 months. On physical examination, 10-15 black or purple subcutaneous nodules were detected on the dorsum of the right neck. Microscopic examination of biopsy specimen from the nodules disclosed lymphocytes, neutrophils and moniliform hyphae. The colony of the clinical isolate was flat with black aerial hyphae and a wet margin after 2 weeks incubation on Sabouraud's dextrose agar at 27 degrees C. The microscopic examination of the clinical isolate revealed that hyphae were brown, septate, and smooth, producing branched or unbranched conidiospores laterally or on the apex. The conidia were one celled, subglobose, elliptical to cylindrical, smooth and hyaline. Nucleotide sequence analysis of the chitin synthase 2 (CHS2) gene fragments from the isolate and a reference strain of E. dermatitidis showed more than 99% similarity.

Animals↗
PubMed2000

Self-consistent density functional calculation of field emission currents from metals

We have developed a fully self-consistent method which is suitable to examine field emission currents, on the basis of the density functional theory. In our method, the nearby counterelectrode is not necessary. By using this method, we have investigated field emission currents from a biased metallic surface represented by the jellium model. We have found that the energy barrier between the jellium and vacuum becomes lower than the Fermi energy under strong electric fields (e.g., 10 V/nm for r(s) = 4 bohr). In this situation, the slope of the Fowler-Nordheim plot becomes flatter than that under a weaker field.

Journal Article↗
PubMed2000

HTLV-I-associated myelopathy manifested after renal transplantation.

We report a patient with HTLV-I-associated myelopathy (HAM), who developed symptoms of myelopathy 4 years after cadaveric renal transplantation. Since he was seronegative before the transplantation, it is suggested that HTLV-I infection was transmitted via renal graft transplantation. He has been treated with immunosuppressive agents such as cyclosporin A (CsA), mycophenolate mofetil (MMF), and prednisolone (PSL) to prevent graft rejection. This case suggested that these immunosuppressive agents are poorly effective in suppressing either the onset or progression of HAM/TSP.

Humans↗
PubMed2000

Bovine lactoperoxidase and its recombinant: comparison of structure and some biochemical properties.

Biochemical properties of bovine lactoperoxidase isolated from milk and recombinant bovine lactoperoxidase expressed by Chinese hamster ovary cells were compared. The natural and recombinant lactoperoxidases showed the same conformational features as determined by circular dichroism (CD) measurements. The alpha-helix, beta-structure, and unordered structure contents were found to be 17. 8, 54.2, and 28.0% for the natural lactoperoxidase and 18.6, 50.1, and 31.3% for the recombinant lactoperoxidase, respectively. The microenvironments of aromatic amino acid residues in both lactoperoxidases seemed to be the same, although the CD spectral band due to the Soret band differed slightly. A difference in the pH-dependent spectral changes of absorbance at 413 nm was observed. From a pepsin hydrolysate of lactoperoxidase, a heme-binding peptide was isolated by reverse-phase HPLC and its amino acid sequence was examined.

Animals↗
PubMed2000

Reinforcing effects of methamphetamine in planarians.

Reinforcing properties of dopamine agonist, methamphetamine, for planarians were examined with the conditioned place preference (CPP) procedure. The planarians showed preference for the environment associated with methamphetamine administration. This reinforcing effect was antagonized by pretreatment with non-selective dopamine antagonist, haloperidol. Both selective D1 antagonist SCH23390 and selective D2 antagonist sulpiride also blocked the reinforcing effect of methamphetamine. These results suggest that reinforcing effects of dopaminergic drugs can be traced back to invertebrates such as planarians.

Amphetamine-Related Disorders↗
PubMed2000

Distinct mechanisms of alpha 5beta 1 integrin activation by Ha-Ras and R-Ras.

To investigate the possible roles of the Ras/Rho family members in the inside-out signals to activate integrins, we examined the ability of Ras/Rho small GTPases to stimulate avidity of alpha(5)beta(1) (VLA-5) to fibronectin in bone marrow-derived mast cells. We found that both Ha-Ras(Val-12) and R-Ras(Val-38) had strong stimulatory effects on adhesion and ligand binding activity of VLA-5 to fibronectin. However, only Ha-Ras(Val-12)-, but not R-Ras(Val-38)-induced adhesion was inhibited by wortmannin, which suggests that Ha-Ras(Val-12) is dependent on phosphatidylinositol (PI) 3-kinase on adhesion whereas R-Ras(Val-38) has another PI 3-kinase independent pathway to induce adhesion. The effector loop mutant Ha-Ras(Val-12)E37G, but not Y40C retained the ability to stimulate adhesion of mast cells to fibronectin. Consistently, PI 3-kinase p110delta, predominantly expressed in mast cells, interacted with Ha-Ras(Val-12) E37G, but not Y40C, which was also correlated with the levels of Akt phosphorylation in mast cells. Furthermore, marked adhesion was induced by a membrane-targeted version of p110delta. These results indicate that Ha-Ras(Val-12) activated VLA-5 through PI 3-kinase p110delta. The mutational effects of the R-Ras effector loop region on adhesion were not correlated with PI 3-kinase activities, consistent with our contention that R-Ras has a distinct pathway to modulate avidity of VLA-5.

Cell Adhesion↗
PubMed2000

The MMR question.

Explore the source record for details and available documents.

Antigens, Viral↗
PubMed2000

Massive accumulation of M and H subunits of neurofilament proteins in spinal motor neurons of neurofilament deficient Japanese quail, Quv.

Quiver (Quv) is a non-sense mutation of neurofilament protein L subunit (NF-L) that causes neurofilament deficiency with preserved microtubules in Japanese quail. Anti-NF-M and anti-NF-H mAbs stained cell bodies of motor neurons in Quv embryo spinal cords much more intense than those in control spinal cords. Volume of motor neurons in Quv spinal cords increased to 2.3 times of control motor neurons. Immunoblot of Quv spinal cords revealed a relative increase in non- and hypo-phosphorylated NF-M and NF-H, and a decrease in the total amount of NFs. Quv sciatic nerves showed faintly reacted phosphorylated NF-M and NF-H. These results suggest that deficiency of assembled neurofilament results in decreased axonal transport of NFs and accumulation of NFs in cell bodies of spinal motor neurons.

Animals↗
PubMed2000

Association between elevated brain natriuretic peptide levels and the development of left ventricular hypertrophy in patients with hypertension.

PURPOSE: To examine whether plasma levels of brain natriuretic peptide identify hypertensive patients at risk for progressive cardiac hypertrophy. SUBJECTS AND METHODS: We examined the association between plasma brain natriuretic peptide levels and left ventricular structural changes in 54 hypertensive patients and 28 normotensive control subjects. Patients were divided into those with elevated (n = 14) or normal (n = 40) levels of brain natriuretic peptide, based on a cutoff level of 41 pg/mL (2 SD above the mean in the control subjects). Left ventricular function and geometry were assessed echocardiographically at baseline and follow-up. RESULTS: At baseline, initial left ventricular chamber size, wall thickness, and systolic function did not differ between the hypertensive patients and normotensive subjects. After a mean (+/- SD) follow-up of 9 +/- 3 months, blood pressure was relatively unchanged in the hypertensive patients with normal brain natriuretic peptide levels, whereas there were significant increases in systolic blood pressure and pulse pressure (both P <0.05 versus baseline) in patients with elevated brain natriuretic peptide levels. Moreover, left ventricular midwall systolic function had decreased significantly at follow-up in those with elevated levels (P <0.05 versus baseline). At follow-up, the hypertensive patients with elevated brain natriuretic peptide levels had a significantly greater left ventricular mass index and relative wall thickness than those with normal levels. Multiple regression analyses determined that only initial plasma brain natriuretic peptide was significantly (P <0.01) associated with subsequent left ventricular hypertrophy. CONCLUSION: Plasma brain natriuretic peptide levels may identify hypertensive patients who are likely to have progressive cardiac hypertrophy.

Aged↗
PubMed2000

Tumor formation suppressed in gammadeltaT knock-out mice.

Tumor formation was examined in mice in which the beta-chain gene of alphabetaT was knocked out (alphabetaT-KO mice) or the delta-chain gene of gammadeltaT was knocked out (gammadeltaT-KO mice). Development of Hepa 1-6 cell hepatoma was observed in six of six alphabetaT-KO mice, in four of six wild-type mice, and in only one of six gammadeltaT-KO mice. These results imply that gammadeltaT cells play a role in suppression of killer cell activity in tumor-bearing mice.

Animals↗