PubMed Health⌕ Search

Biomedical subjects

T Sugawara

Publications and source records attributed to T Sugawara.

At least 19 recordsLinked to original sources
PubMed2006

Phenotypes and genotypes in epilepsy with febrile seizures plus.

In the last several years, mutations of sodium channel genes, SCN1A, SCN2A, and SCN1B, and GABA(A) receptor gene, GABRG2 were identified as causes of some febrile seizures related epilepsies. In 19 unrelated Japanese families whose probands had febrile seizures plus or epilepsy following febrile seizures plus, we identified 2 missense mutations of SCN1A to be responsible for the seizure phenotypes in two FS+ families and another mutation of SCN2A in one family. The combined frequency of SCN1A, SCN2A, SCN1B, SCN2B, and GABRG2 mutations in Japanese patients with FS+ was 15.8%. One family, which had R188W mutation in SCN2A, showed digenic inheritance, and another modifier gene was thought to take part in the seizure phenotype. The phenotypes of probands were FS+ in 5, FS+ and partial epilepsy in 10, FS+ and generalized epilepsy in 3, and FS+ and unclassified epilepsy in 1. We proposed the term epilepsy with febrile seizures plus (EFS+), because autosomal-dominant inheritance in EFS+ might be rare, and most of EFS+ display a complex pattern of inheritance, even when it appears to be an autosomal-dominant inheritance. There is a possibility of simultaneous involvement of multiple genes for seizure phenotypes.

Adolescent↗
PubMed2006

Both N-terminal and C-terminal regions of steroid sulfatase are important for enzyme activity.

Steroid sulfatase (STS) is localized in the endoplasmic reticulum and catalyzes desulfation of 3beta-hydroxysteroid sulfates. X-linked ichthyosis (XLI) is an inherited skin disorder caused by deficiency of STS enzyme activity. We previously reported a case in which XLI with a one-base change in the STS gene and variation in amino acid Q560P developed. In this study, we performed molecular analysis to determine the importance of terminal regions of STS and the effect of mutant STS on STS enzyme activity. To examine the effect of terminal truncated STS on the enzyme activity, N- and C-terminal truncated STS expression vectors were transfected into COS-1 cells. The activity of truncated STS lacking the N-terminal regions declined, and the activity of C-terminal-truncated STS declined with extension of the truncated C-terminal region. Although the results of pulse-chase experiments showed that a one-base mutant STS (Q560P) and C-terminal-truncated STS (deltaC2 (1-559)) had no effects on protein synthesis and degradation, the mutant STS and C-terminal-truncated STS have dominant negative effect on STS enzyme activity when the STS mutant or truncated STS protein and a wild-type STS protein coexist in cells. Results of coprecipitation of the truncated STS with an STS-FLAG fusion protein showed that STS formed a dimer conformation in cells. In this study, we have shown that both the N-terminal region and C-terminal region are important for STS enzyme activity. The C-terminal mutant has a dominant negative effect on wild-type STS.

Amino Acids↗
PubMed2005

Multiple spinal dural arteriovenous fistulas.

Multiple spinal dural arteriovenous fistulas (DAVFs) have been rarely reported and only two such cases are found in the literature. A 71-year-old man complained of muscle weakness and hypesthesia in both legs and angiographically diagnosed as thoracic DAVF. The fistula was surgically treated, however, the symptoms recurred 14 months after the first treatment. Angiography revealed a new fistula in the lumbar region and this was also treated surgically. In the previously reported cases of multiple spinal DAVFs, the second fistulas were also diagnosed after the initial treatment. Symptomatic patients after the initial treatment of DAVF should be re-examined angiographically.

Aged↗
PubMed2004

Characterization of binding between SF-1 and Sp1: predominant interaction of SF-1 with the N-terminal region of Sp1.

The transcription factor specificity protein 1 (Sp1) binds to GC boxes and interacts with many transcription factors to regulate gene expression. Steroidogenic factor-1 (SF-1) is an orphan nuclear receptor and plays a major role in regulation of the human steroidogenic acute regulatory (StAR) gene. We demonstrated that there is interaction between SF-1 and Sp1 on the human StAR promoter. In the present study, we examined the mechanism of the interaction between Sp1 and SF-1 on the human StAR gene promoter. Results of glutathione S-transferase (GST) pull-down assays and a mammalian two-hybrid assay showed that SF-1 interacted with Sp1 through the N-terminal domains of Sp1. Results of electrophoretic mobility shift assays using nuclear extracts showed that Sp1 is associated with SF-1-DNA complex formation. The density of SF-1-DNA complex was much greater when recombinant Sp1 was added to the incubation mixture. These results suggest that Sp1 interacts with SF-1 and that Sp1 enhances SF-1-DNA complex formation to regulate human StAR transcription.

Animals↗
PubMed2004

Early pathophysiologic feature of arthropathy in juvenile dogs induced by ofloxacin, a quinolone antimicrobial agent.

Arthropathy in dogs induced by ofloxacin, a quinolone antimicrobial agent, was pathophysiologically investigated. In the in vivo studies, ofloxacin was administered orally once or twice at 20 mg/kg/day to male juvenile (3-month-old, n=3) or adult (36-month-old, n=2) dogs, and the humeral and femoral heads were examined pathologically. Unlike adult dogs, fluid-filled vesicles were macroscopically observed on the articular surfaces of one juvenile dog 24 hours after a single treatment with ofloxacin. These lesions were seen in all juvenile dogs by twice dosing. Microscopically, fissures or cavity formations in the middle zone of the articular cartilage were noted only in juvenile dogs. Furthermore, the cartilage matrix from the abnormal area to the articular surface showed a decreased safranin-O staining intensity, suggesting proteoglycan depletion. Ultrastructurally, chondrocytes in the middle zone of juvenile dogs displayed dilatation of the cisternae in the rough endoplasmic reticulum as an initial hallmark. In the in vitro studies, chondrocytes isolated from the articular cartilage of naive juvenile dogs were exposed to ofloxacin at 6.3-100 microg/ml for 24 hours. Although no changes were noted in the deoxyribonucleic acid synthesis, protein synthesis, or proteoglycan release at concentrations of up to 100 microg/ml, the proteoglycan synthesis was evidently decreased in a dose-dependent manner from 12.5 microg/ml. The results obtained suggest that the inhibitory action of ofloxacin on proteoglycan syntheses in the chondrocytes may largely contribute to the early morphologic features in the articular cartilage of the juvenile dog.

Age Factors↗
PubMed2004

Expression of enzyme associated with steroid hormone synthesis and local production of steroid hormone in endometrial carcinoma cells.

Endometrial carcinoma is a common malignancy of the genital tract. In the present study, we examined the expression of human steroidogenic acute regulatory (StAR) protein, P450 side-chain cleavage enzyme (P450 scc), 17alpha-hydroxylase/17,20-desmolase (P45017alpha) and aromatase (P450 arom) in endometrial carcinoma cells to clarify the ability of these cells to produce steroid hormones. The results of RT-PCR analysis showed that StAR, P450 scc and P45017alpha genes were expressed in endometrial carcinoma cells. To examine the protein expression of StAR and P450 scc, we performed Western blotting using extracts from carcinoma cells. StAR protein and P450 scc were detected in both HHUA and HOUA-1 cells. The production of pregnenolone in HHUA cells increased 2.4-fold with transfection of a StAR expression vector and 4.3-fold with transfection of an F2 side-chain cleavage system. The RT-PCR product of 3beta-hydroxysteroid dehydrogenase was present in endometrial carcinoma cells. In endometrial carcinoma cells, the production of progesterone also increased with over-expression of StAR and the F2 system. Results of steroid metabolic assays showed that endometrial carcinoma cells produced not only 17alpha-hydroxyprogesterone but also androstenedione. Endometrial carcinoma cells express enzymes that are associated with the production of steroid hormones. Locally produced steroid hormones may have effects on tumor proliferation and tumorigenesis.

17-alpha-Hydroxyprogesterone↗
PubMed2002

Frequent mutations of SCN1A in severe myoclonic epilepsy in infancy.

Mutations in the neuronal voltage-gated sodium channel alpha-subunit type I gene (SCN1A) were found responsible for severe myoclonic epilepsy in infancy (SMEI). The authors describe novel mutations of SCN1A in Japanese patients with SMEI. They screened 12 unrelated patients and a pair of monozygotic twins and detected 10 mutations that lead to truncation of the protein.

Diseases in Twins↗
PubMed2002

Autosomal dominant epilepsy with febrile seizures plus with missense mutations of the (Na+)-channel alpha 1 subunit gene, SCN1A.

Evidence that febrile seizures have a strong genetic predisposition has been well documented. In families of probands with multiple febrile convulsions, an autosomal dominant inheritance with reduced penetrance is suspected. Four candidate loci for febrile seizures have been suggested to date; FEB1 on 8q13-q21, FEB2 on 19p, FEB3 on 2q23-q24, and FEB4 on 5q14-15. A missense mutation was identified in the voltage-gated sodium (Na(+))-channel beta 1 subunit gene, SCN1B at chromosome 19p13.1 in generalized epilepsy with the febrile seizures plus type 1 (GEFS+1) family. Several missense mutations of the (Na(+))-channel alpha 1 subunit (Nav1.1) gene, SCN1A were also identified in GEFS+2 families at chromosome 2q23-q24.3. The aim of this report is precisely to describe the phenotypes of Japanese patients with novel SCN1A mutations and to reevaluate the entity of GEFS+. Four family members over three generations and one isolated (phenotypically sporadic) case with SCN1A mutations were clinically investigated. The common seizure type in these patients was febrile and afebrile generalized tonic-clonic seizures (FS+). In addition to FS+, partial epilepsy phenotypes were suspected in all affected family members and electroencephalographically confirmed in three patients of two families. GEFS+ is genetically and clinically heterogeneous, and associated with generalized epilepsy and partial epilepsy as well. The spectrum of GEFS+ should be expanded to include partial epilepsies and better to be termed autosomal dominant epilepsy with febrile seizures plus (ADEFS+).

Adult↗
PubMed2001

Delayed treatment with polynitroxyl albumin reduces infarct size after stroke in rats.

Nitroxides are antioxidants that are known to protect cells from oxidative damage. Polynitroxyl albumin (PNA) is a compound of human serum albumin covalently labeled with nitroxides that exhibits a prolonged half-life and an enhanced antioxidant activity. Adult male Sprague-Dawley rats were subjected to 90 min intraluminal middle cerebral artery occlusion and the drug was administered intravenously immediately or 2 h after reperfusion. The effects of the drug were evaluated 24 h after reperfusion. Infarct volume was significantly reduced in immediate (79% reduction) and delayed (53% reduction) PNA-treated groups. The efficacy of a single, delayed i.v. injection of PNA suggests that PNA has great promise in the treatment of acute human stroke.

Albumins↗
PubMed2001

Molecular cloning and structural analysis of human sterol C5 desaturase.

Sterol C5 desaturase (SC5D) converts lathosterol to 7-dehydrocholesterol in cholesterol biosynthesis. In this study, we investigated the genome structure of SC5D and transcription of the human SC5D gene to try to elucidate the mechanism by which cholesterol synthesis is regulated. The SC5D gene had a structural gene from a single copy from genome DNA that contained five exons and four introns. The human SC5D was found to be located in chromosome 11q24.2-24.3 by fluorescence in situ hybridization mapping. Human SC5D mRNA transcripts, of which the major transcript was a 2 kb and the minor transcripts were 8 kb and 1.4 kb mRNA transcripts, were detected in almost all of the tissues examined. The human SC5D gene contained a GC box instead of a TATA box upstream of the transcript start sites. Human SC5D transcription started from several transcription start sites, and the first start site was located 31 bp upstream of the translation start site (ATG). The expression level of SC5D mRNA extracted from human liver carcinoma cells decreased as the amount of cholesterol added to the culture medium was increased. Inhibition of SC5D transcription was ascribed to the suppression of promoter activity of SC5D.

Acetyl Coenzyme A↗
PubMed2001

Proton relay in a one-dimensional hydrogen-bonded chain composed of water molecules and a squaric acid derivative.

The crystal structure of a hydrated crystal of bis(squaryl)biphenyl (BSQB*4H2O), in which two squaric acid moieties are connected with a 4,4'-biphenyl unit, was characterized by the presence of a one-dimensional hydrogen-bonded chain composed of BSQB and water molecules. X-ray crystallographic analysis showed that BSQB exists in a dianion form and that, on average, two of the four water molecules are protonated. The enhanced temperature dependence of the thermal parameters of the oxygen atoms of the water molecules suggested dynamic disorder of the water molecules. The solid-state magic angle spinning deuterium NMR spectrum of BSQB*4D2O revealed that deuterons are exchanged between heavy water molecules and oxonium ions with an exchange rate of ca. 700 Hz around 250 K and that deuterons start to migrate in a hydrogen-bonded cluster of water molecules. Ac dielectric measurements were also used to examine the dynamic process in the hydrated crystal. The dielectric permittivity of the crystal dramatically increased above 250 K with a distinct frequency dependence (epsilon' = 4.7 x 10(4) at 340 K and 1 kHz). The frequency dependence of tan delta at 290 K exhibited a maximum at 3.0 kHz, and this maximum shifted to lower frequencies when the temperature of the crystal decreased. These experimental results suggested that in the one-dimensional hydrogen-bonded chain of BSQB*4H2O a proton relay between oxonium ions and water molecules occurred within a cluster of four water molecules and that the relay was transmitted to the adjacent cluster mediated by the modulation of the negative charge distribution of the BSQB dianion. These phenomena were interpreted as the solitonic migration of the charged domain boundaries along the one-dimensional hydrogen-bonded chain.

Crystallography, X-Ray↗
PubMed2001

Regulation and role of interleukin 6 in wounded human epithelial keratinocytes.

Dermal wounding is accompanied by inflammation and the resulting proinflammatory cytokines, including interleukin (IL)-6, are thought to play an important role in the repair process. IL-6 is produced by normal human keratinocytes to various dermatological diseases and we have recently shown it is also required for normal wound repair. However, neither the events responsible for its induction nor its role in repair have been clearly identified. Using a recently developed in vitro wounding model, we demonstrate that IL-6 mRNA is expressed and immunoreactive IL-6 is released from cultures of human epidermal keratinocytes (NHEKs) following wounding. The transcription factors, NF kappa B and NF-IL-6 (C/EBP beta), which coordinately help regulate IL-6 expression, were activated following wounding and preceded the appearance of IL-6. Addition of IL-1 alpha to NHEK cultures increased IL-6 production and activated NF kappa B and C/EBP beta. Addition of the IL-1 alpha receptor antagonist inhibited both IL-6 mRNA expression and the transcription factors following wounding. Immunoreactive IL-1 alpha was detected in the medium following wounding in the absence of new message. Furthermore, addition of IL-6 to NHEK cultures decreased the expression of keratins 1 and 10, differentiation markers of keratinocytes, while proliferation was not affected. Taken together, these data indicate that constitutive keratinocyte-derived IL-1 alpha is a stimulus for IL-6 production in wounded epidermis, the response involves NF kappa B and C/EBP beta transcription factors, and IL-6 may be associated with modulation of keratinocyte differentiation rather than proliferation.

Adult↗
PubMed2001

Nav1.1 mutations cause febrile seizures associated with afebrile partial seizures.

Recent evidence has suggested that the neuronal voltage-gated sodium channel alpha(1)-subunit gene (Na(v)1.1: SCN1A) is responsible for generalized epilepsy with febrile seizures plus (GEFS+2). Here the authors report two novel disease mutations of Na(v)1.1 in patients with febrile seizures associated with afebrile partial seizures. One is a Val1428Ala substitution in the pore-forming region, and the other is Ala1685Val in the transmembrane helix. These results support the previous findings and contribute to the reliable diagnosis of epilepsy.

Amino Acid Sequence↗
PubMed2001

Angiotensin-converting enzyme inhibition attenuates hypofibrinolysis and reduces cardiac perivascular fibrosis in genetically obese diabetic mice.

BACKGROUND: Obesity and insulin resistance are associated with accelerated macrovascular and microvascular coronary disease, cardiomyopathic phenomena, and increased concentrations and activity in blood of plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of fibrinolysis. METHODS AND RESULTS: To determine whether hypofibrinolysis in blood and tissues and its potential sequelae could be attenuated pharmacologically, we studied genetically modified obese mice. By 10 weeks of age, obese mice exhibited increases in left ventricular weight and glucose and immunoreactive insulin in blood. PAI-1 activity in blood measured spectrophotometrically was significantly elevated as well. The difference compared with values in lean controls widened by 20 weeks of age. Perivascular fibrosis in coronary arterioles and small coronary arteries was evident in obese mice 10 and 20 weeks of age, paralleling increases in PAI-1 and tissue factor expression evident by immunohistochemical image analysis, in situ hybridization, and reverse transcription-polymerase chain reaction. Inhibition of ACE activity initiated in obese mice 10 weeks of age and continued for 20 weeks arrested the increase in PAI-1 activity in blood and in cardiac PAI-1 and tissue factor mRNA as well as coronary perivascular fibrosis. CONCLUSIONS: Thus, inhibition of proteo(fibrino)lysis and augmented tissue factor expression in the heart precede and may contribute to the coronary perivascular fibrosis seen with obesity and insulin resistance. Furthermore, inhibition of ACE activity can attenuate all 3 phenomena.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

A missense mutation of the Na+ channel alpha II subunit gene Na(v)1.2 in a patient with febrile and afebrile seizures causes channel dysfunction.

Generalized epilepsy with febrile seizures plus (GEFS+), a clinical subset of febrile seizures (FS), is characterized by frequent episodes beyond 6 years of age (FS+) and various types of subsequent epilepsy. Mutations in beta1 and alpha(I)-subunit genes of voltage-gated Na(+) channels have been associated with GEFS+1 and 2, respectively. Here, we report a mutation resulting in an amino acid exchange (R188W) [corrected] in the gene encoding the alpha-subunit of neuronal voltage-gated Na(+) channel type II (Na(v)1.2) in a patient with FS associated with afebrile seizures. The mutation R188W [corrected] occurring on Arg(187), a highly conserved residue among voltage-gated Na(+) channels, was not found in 224 alleles of unaffected individuals. Whole-cell patch clamp recordings on human embryonic kidney (HEK) cells expressing a rat wild-type (rNa(v)1.2) and the corresponding mutant channels showed that the mutant channel inactivated more slowly than wild-type whereas the Na(+) channel conductance was not affected. Prolonged residence in the open state of the R188W [corrected] mutant channel may augment Na(+) influx and thereby underlie the neuronal hyperexcitability that induces seizure activity. Even though a small pedigree could not show clear cosegregation with the disease phenotype, these findings strongly suggest the involvement of Na(v)1.2 in a human disease and propose the R188W [corrected] mutation as the genetic defect responsible for febrile seizures associated with afebrile seizures.

Amino Acid Substitution↗