Medico-legal studies on infanticide: statistics and a case of repeated neonaticide.
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Adult↗
Biomedical subjects
S Usami
Publications and source records attributed to S Usami.
Molecular mechanism of endothelial growth arrest by laminar shear stress.
This study was designed to elucidate the mechanism underlying the inhibition of endothelial cell growth by laminar shear stress. Tumor suppressor gene p53 was increased in bovine aortic endothelial cells subjected to 24 h of laminar shear stress at 3 dynes (1 dyne = 10 microN)/cm(2) or higher, but not at 1.5 dynes/cm(2). One of the mechanisms of the shear-induced increase in p53 is its stabilization after phosphorylation by c-Jun N-terminal kinase. To investigate the consequence of the shear-induced p53 response, we found that prolonged laminar shear stress caused increases of the growth arrest proteins GADD45 (growth arrest and DNA damage inducible protein 45) and p21(cip1), as well as a decrease in phosphorylation of the retinoblastoma gene product. Our results suggest that prolonged laminar shear stress causes a sustained p53 activation, which induces the up-regulation of GADD45 and p21(cip1). The resulting inhibition of cyclin-dependent kinase and hypophosphorylation of retinoblastoma protein lead to endothelial cell cycle arrest. This inhibition of endothelial cell proliferation by laminar shear stress may serve an important homeostatic function by preventing atherogenesis in the straight part of the arterial tree that is constantly subjected to high levels of laminar shearing.
Animals↗
Genomic structure and identification of novel mutations in usherin, the gene responsible for Usher syndrome type IIa.
Usher syndrome type IIa (USHIIa) is an autosomal recessive disorder characterized by moderate to severe sensorineural hearing loss and progressive retinitis pigmentosa. This disorder maps to human chromosome 1q41. Recently, mutations in USHIIa patients were identified in a novel gene isolated from this chromosomal region. The USH2A gene encodes a protein with a predicted molecular weight of 171.5 kD and possesses laminin epidermal growth factor as well as fibronectin type III domains. These domains are observed in other protein components of the basal lamina and extracellular matrixes; they may also be observed in cell-adhesion molecules. The intron/exon organization of the gene whose protein we name "Usherin" was determined by direct sequencing of PCR products and cloned genomic DNA with cDNA-specific primers. The gene is encoded by 21 exons and spans a minimum of 105 kb. A mutation search of 57 independent USHIIa probands was performed with a combination of direct sequencing and heteroduplex analysis of PCR-amplified exons. Fifteen new mutations were found. Of 114 independent USH2A alleles, 58 harbored probable pathologic mutations. Ten cases of USHIIa were true homozygotes and 10 were compound heterozygotes; 18 heterozygotes with only one identifiable mutation were observed. Sixty-five percent (38/58) of cases had at least one mutation, and 51% (58/114) of the total number of possible mutations were identified. The allele 2299delG (previously reported as 2314delG) was the most frequent mutant allele observed (16%; 31/192). Three new missense mutations (C319Y, N346H, and C419F) were discovered; all were restricted to the previously unreported laminin domain VI region of Usherin. The possible significance of this domain, known to be necessary for laminin network assembly, is discussed in the context of domain VI mutations from other proteins.
Amino Acid Sequence↗
The effects of intense click sounds on velocity storage in optokinetic after-nystagmus.
Vestibular evoked myogenic potentials (VEMP) occurring after click stimulation in cervical muscles are thought to be a polysynaptic response of otolith-vestibular nerve origin. In optokinetic after-nystagmus (OKAN) the direction of after-nystagmus changes and slow-phase velocity decreases with head tilt. This phenomenon may be an otolith response to the direction of gravity. We assumed that intense clicks might have some influence on OKAN via the otolith-vestibular nerve. Twelve normal subjects who showed VEMP at 75 dB normal hearing level (nHL) clicks were examined. The OKAN was recorded under four conditions: right monaural, left monaural and binaural stimulation by 75 dB nHL clicks, and absence of click stimulation. Horizontal optokinetic stimulation was applied using stepwise increasing speeds from 30 deg/s to 90 deg/s. Two seconds before the stimulus ended, clicks were sounded. The slow-phase velocity of the recorded electro-nystagmography was manually measured. There was no effect on OKAN with unilateral stimulation but binaural stimulation suppressed it. These results suggest that a velocity storage integrator is influenced by intense clicks via the otolithic area.
Acoustic Stimulation↗
Molecular cloning and characterization of two cDNAs encoding asparagine synthetase from Astragalus sinicus nodules.
Two cDNAs that encode asparagine synthetase were cloned from root nodules of Astragalus sinicus cv. Japan (Renge-sou). The expression of the transcripts was nodule-enhanced. The expression of both genes was reduced in nodules when (NH4)2SO4 was added to the culture medium. This is the first report of the inhibition of asparagine synthetase gene expression by ammonium in root nodules.
Journal Article↗
Alpha-anomer-selective glucosylation of menthol with high yield through a crystal accumulation reaction using lyophilized cells of Xanthomonas campestris WU-9701.
L-Menthyl alpha-D-glucopyranoside (alpha-MenG) is a desirable derivative of L-menthol with useful properties for the production of new flavors and novel food additives. Bacteria were screened for alpha-anomer-selective glucosylation activity toward l-menthol, resulting in the isolation of two strains, Xanthomonas campestris WU-9701 and Stenotrophomonas maltophilia WU-9702, from independent soil samples. Since the safety of X. campestris for use in the food industry is well established, WU-9701 was selected as the more suitable strain for further study. When 50 mg X. campestris WU-9701 lyophilized cells as a biocatalyst were incubated with 1.0 M maltose and 100 mg L-menthol in 10 ml of 10 mM H3BO3NaOHKCl buffer (pH 8.0) at 40 degrees C, alpha-MenG was accumulated, mainly in a crystalline form, through the anomer-selective synthesis reaction without any by-product formation. Under the optimal conditions, 202 mg alpha-MenG was obtained over 48 h with a highest conversion yield of 99.1% based on the supplied L-menthol. Crude alpha-MenG formed through this "crystal accumulation reaction" was easily collected from the reaction mixture by separation on filter paper. Plank-like crystals of purified alpha-MenG were subsequently obtained by recrystallization in ethyl acetate solution.
Journal Article↗
Two catalytic domains of Chlorella virus CVK2 chitinase.
VChti-1 chitinase encoded by the Chlorella virus CVK2 contained two catalytic domains belonging to family 18 glycosyl hydrolases. The first catalytic domain on a C-terminal-truncated derivative of vChti-1 generated exclusively chitobiose from chitotetraose, chitohexaose, and colloidal high-molecular mass chitin in the enzyme reaction, a typical characteristic of an exochitinase. In contrast, N-acetylglucosamine was produced from chitobiose as well as from chitooligosaccharides by the second catalytic domain on an N-terminal-truncated derivative of vChti-1. Therefore, the second domain possessed N-acetylglucosaminidase activity as well as endochitinase activity. The presence of two catalytic domains with different enzymatic properties in the viral enzyme seems to be necessary for hydrolyzing natural substrates in a cooperative fashion.
Journal Article↗
Mapping of cDNA clones on contig of Chlorella chromosome I.
Complementary DNA (cDNA) clones specific to the smallest chromosome (chromosome I) of Chlorella vulgaris C-169 were selected from cDNA libraries with probes of chromosome I DNA fragments amplified by degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR). A total of 15 clones was obtained, which included gene homologs for alpha-tubulin, inosine-5'-monophosphate dehydrogenase, beta-1,4-mannase, a TTG-binding protein, a heat shock protein, thioredoxin/protein disulfide isomerase, transcription factor NF-E2, an oxidoreductase, and UDP-n-acetylglucosamine enolpyruvyltransferase. These clones were definitely localized at specific sites on the chromosome I physical map constructed on the basis of overlapping cosmid clones (the contig). They were predominantly distributed within the left two-thirds of the chromosome. This contrasts with the distribution of repetitive elements such as short interspersed elements (SINEs), which are rather abundant in the right two-thirds of chromosome I. The comparative simplicity of the gene arrangement of Chlorella chromosome I suggests that it may be able to serve as a prototypic system for deciphering the complexity of huge plant chromosomes.
Journal Article↗
Analysis of double-strand-break repair by Chlorella retrotransposon Zepp.
To elucidate the contribution of LINE-like retrotransposon Zepps in formation and maintenance of chromosomal telomeres, newly formed mini-chromosomes in irradiated Chlorella vulgaris cells were isolated and structurally characterized. A mini-chromosome Y32 (approximately 400 kbp in size) was shown to have several copies of Zepp elements on both termini. On the right arm terminus, two copies of Zepps were found in a tandem array with poly(A) tracts facing towards the chromosome end. The poly(A) tail and a 3'-end of approximately 400 bp of the distal copy was replaced by telomeric repeats. On 5'-side of the proximal copy was another Zepp element in a reversed orientation. This newly formed telomeric structure is very similar to that found in the left arm terminus of chromosome I and support the model of Zepp-mediated maintenance of Chlorella telomeres.
Chlorella↗
Characterization of immediate early genes expressed in chlorovirus infection.
By Southern blot analysis of restriction fragments of a chlorovirus CVK2 genomic contig with probes of RNA expressed immediate early in infection, sixteen genes were specifically found to be expressed in the host cells. These genes include those for aminoacyl-tRNA synthetase, nucleolin, ribosomal protein S5, hyaluronan synthase, TFIID etc. All of these transcripts were polyadenylated and most likely expressed in the host nucleus. The structural characteristics of these genes are discussed in connection with their expression mechanism. The biological importance of the gene products in viral infection are also considered.
Chlorella↗
Three types of internal jugular vein reconstruction in bilateral radical neck dissection.
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Anastomosis, Surgical↗
The involvement of a cysteine proteinase in the nodule development in Chinese milk vetch infected with Mesorhizobium huakuii subsp. rengei.
Cys proteinases play important roles in plant cell development and senescence. A cDNA, AsNODf32, obtained by differential screening of a nodule cDNA library of the leguminous plant Chinese milk vetch (Astragalus sinicus), represents a nodule-specific Cys proteinase similar to that reported for the actinorhizal Alnus glutinosa-Flankia symbiosis. A characteristic feature of this proteinase is the presence of a putative vacuolar targetting signal, LQDA, within its propeptide. Expression of the AsNODf32 gene, which was studied on northern blots and in situ hybridization, showed good correlation with the onset of nodule senescence. In situ hybridization studies revealed that AsNODf32 was expressed in senescent-infected tissue at the base of the nodule, as well as in interzone II-III of the infected nodules. In addition to degrading old nodule tissues and bacteroids, AsNODf32 protein may be required as a component of tissue remodeling during nodule development.
Amino Acid Sequence↗
Prevalence of mitochondrial gene mutations among hearing impaired patients.
The frequency of three mitochondrial point mutations, 1555A-->G, 3243A-->G, and 7445A-->G, known to be associated with hearing impairment, was examined using restriction fragment length polymorphism (RFLP) analysis in two Japanese groups: (1) 319 unrelated SNHL outpatients (including 21 with aminoglycoside antibiotic injection history), and (2) 140 cochlear implantation patients (including 22 with aminoglycoside induced hearing loss). Approximately 3% of the outpatients and 10% of the cochlear implantation patients had the 1555A-->G mutation. The frequency was higher in the patients with a history of aminoglycoside injection (outpatient group 33%, cochlear implantation group 59%). One outpatient (0.314%) had the 3243A-->G mutation, but no outpatients had the 7445A-->G mutation and neither were found in the cochlear implantation group. The significance of the 1555A-->G mutation, the most prevalent mitochondrial mutation found in this study of a hearing impaired population in Japan, among subjects with specific backgrounds, such as aminoglycoside induced hearing loss, is evident.
Aminoglycosides↗
Prevalent connexin 26 gene (GJB2) mutations in Japanese.
The gene responsible for DNFB1 and DFNA3, connexin 26 (GJB2), was recently identified and more than 20 disease causing mutations have been reported so far. This paper presents mutation analysis for GJB2 in Japanese non-syndromic hearing loss patients compatible with recessive inheritance. It was confirmed that GJB2 mutations are an important cause of hearing loss in this population, with three mutations, 235delC, Y136X, and R143W, especially frequent. Of these three mutations, 235delC was most prevalent at 73%. Surprisingly, the 35delG mutation, which is the most common GJB2 mutation in white subjects, was not found in the present study. Our data indicated that specific combinations of GJB2 mutation exist in different populations.
Amino Acid Substitution↗
Sensorineural hearing loss associated with the mitochondrial mutations.
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DNA, Mitochondrial↗
Bilateral basal-cell adenomas in the parotid glands.
A rare case of bilateral basal-cell adenomas in the parotid glands of a 65-year-old woman is reported. There have been only four previous reported cases of bilateral parotid basal-cell adenomas, all of which occurred synchronously with dermal cylindromas. The present lesion is the first case reported in the English literature of bilateral parotid basal-cell adenoma without coexisting dermal cylindroma. Histological examination revealed that the left tumour had adenoid cystic change, which closely resembled adenoid cystic carcinoma. This case is of interest not only because of the raity of bilateral parotid basal-cell adenomas, but also because of the necessity for differentiation from adenoid cystic carcinoma in order to plan appropriate treatment.
Adenoma↗
Alpha-anomer-selective glucosylation of (+)-catechin by the crude enzyme, showing glucosyl transfer activity, of Xanthomonas campestris WU-9701.
Alpha-anomer-selective glucosylation of (+)-catechin was carried out using the crude enzyme, showing alpha-glucose transferring activity, of Xanthomonas campestris WU-9701 with maltose as a glucosyl donor. When 60 mg of (+)-catechin and 50 mg of the enzyme (5.25 units as maltose hydrolysing activity) were incubated in 10 ml of 10 mM citrate-Na2HPO4 buffer (pH 6.5) containing 1.2 M maltose at 45 degrees C, only one (+)-catechin glucoside was selectively obtained as a product. The (+)-catechin glucoside was identified as (+)-catechin 3'-O-alpha-D-glucopyranoside (alpha-C-G) by 13C-NMR, (1)H-NMR and two-dimensional HMBC analysis. The reaction at 45 degrees C for 36 h under the optimum conditions gave 12 mM alpha-C-G, 5.4 mg/ml in the reaction mixture, and the maximum molar conversion yield based on the amount of (+)-catechin supplied reached 57.1%. At 20 degrees C, the solubility in pure water of alpha-C-G, of 450 mg/ml, was approximately 100 fold higher than that of (+)-catechin, of 4.6 mg/ml. Since alpha-C-G has no bitter taste and a slight sweet taste compared with (+)-catechin which has a very bitter taste, alpha-C-G may be a desirable additive for foods, particularly sweet foods.
Journal Article↗
Contribution of cyanide-insensitive respiratory pathway, catalyzed by the alternative oxidase, to citric acid production in Aspergillus niger.
In Aspergillus niger, a cyanide (CN)- and antimycin A-insensitive and salicylhydroxamic acid (SHAM)-sensitive respiratory pathway exists besides the cytochrome pathway and is catalyzed by the alternative oxidase (AOX). In this study, A. niger WU-2223L, a citric acid-producing strain, was cultivated in a medium containing 120 g/l of glucose, which is the concentration usually needed for citric acid production, and the effects of 2% (v/v) methanol, an inducer of citric acid, 2 microM antimycin A, and 1 mM SHAM on AOX activities and citric acid production were investigated. The AOX activity, measured as duroquinol oxidase, was localized in the purified mitochondria regardless of the presence of any additives. When WU-2223L was cultivated with antimycin A or methanol, both citric acid production and citric acid productivity, shown as the ratio of production per mycelial dry weight, increased with the increase of both the activity of AOX and the rate of CN-insensitive and SHAM-sensitive respiration. On the other hand, when WU-2223L was cultivated with SHAM, an inhibitor of AOX, the CN-insensitive and SHAM-sensitive respiration was not detected and the citric acid production and the productivity drastically decreased, although mycelial growth was not affected. These results clearly indicated that the CN-insensitive and SHAM-sensitive respiration catalyzed by AOX, localized in the mitochondria, contributed to citric acid production by A. niger.
Aspergillus niger↗