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OBJECTIVE: Chronic cerebral hypoperfusion (CCH) can cause ischemic cerebral white matter lesions (IWML). The aim of this study was to explore the roles of A2A receptors (A2AR) in IWML and the effect of methylation in A2AR gene. MATERIALS AND METHODS: SD rat model of CCH was constructed by bilateral common carotid artery occlusion (BCCAO) method. The rats were then treated with DNA methyltransferase (DNMT) inhibitor (decitabine), agonist (CGS21680) and A2AR inhibitor (SCH58261). Morris water maze and Kluver-Barrera staining were used to assess spatial learning and reference memory after IWML, respectively. Gene transcription and protein expression were measured by qRT-PCR, Enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively. The concentration of malondialdehyde (MDA), activity of superoxide dismutase (SOD) and DNMT were detected by assay kit. Methylation of A2AR gene promoter region was detected by bisulfite sequencing PCR (BSP). RESULTS: We found that the down-regulated expression of A2AR in corpus callosum under CCH was associated with IWML and cognitive impairment. We further showed that A2AR agonist can reduce the IWML under CCH, and A2AR inhibitor can aggravate the IWML under CCH. We also found that the expression level of DNMTs in corpus callosum and the methylation level in the promoter region of A2AR gene were increased under CCH. DNMT inhibitors could protect white matter by inhibiting the methylation of A2AR promoter and rescue the downregulation of A2AR under CCH. CONCLUSIONS: Our results demonstrate that the downregulation of A2AR mediates IWML in CCH, and A2AR downregulation is related to the increased methylation of A2AR gene promoter. DNMT inhibitors play a protective role in IWML.
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Isquemia Encefálica , Disfunção Cognitiva , Substância Branca , Animais , Isquemia Encefálica/metabolismo , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Aprendizagem em Labirinto , Metilação , Ratos , Ratos Sprague-Dawley , Substância Branca/patologiaRESUMO
BACKGROUND: PET imaging of 18F-fluorodeoxygucose (FDG) is used widely for tumour staging and assessment of treatment response, but the biology associated with FDG uptake is still not fully elucidated. We therefore carried out gene set enrichment analyses (GSEA) of RNA sequencing data to find KEGG pathways associated with FDG uptake in primary breast cancers. METHODS: Pre-treatment data were analysed from a window-of-opportunity study in which 30 patients underwent static and dynamic FDG-PET and tumour biopsy. Kinetic models were fitted to dynamic images, and GSEA was performed for enrichment scores reflecting Pearson and Spearman coefficients of correlations between gene expression and imaging. RESULTS: A total of 38 pathways were associated with kinetic model flux-constants or static measures of FDG uptake, all positively. The associated pathways included glycolysis/gluconeogenesis ('GLYC-GLUC') which mediates FDG uptake and was associated with model flux-constants but not with static uptake measures, and 28 pathways related to immune-response or inflammation. More pathways, 32, were associated with the flux-constant K of the simple Patlak model than with any other imaging index. Numbers of pathways categorised as being associated with individual micro-parameters of the kinetic models were substantially fewer than numbers associated with flux-constants, and lay around levels expected by chance. CONCLUSIONS: In pre-treatment images GLYC-GLUC was associated with FDG kinetic flux-constants including Patlak K, but not with static uptake measures. Immune-related pathways were associated with flux-constants and static uptake. Patlak K was associated with more pathways than were the flux-constants of more complex kinetic models. On the basis of these results Patlak analysis of dynamic FDG-PET scans is advantageous, compared to other kinetic analyses or static imaging, in studies seeking to infer tumour-to-tumour differences in biology from differences in imaging. Trial registration NCT01266486, December 24th 2010.
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Neoplasias da Mama , Fluordesoxiglucose F18 , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/genética , Feminino , Glucose , Humanos , Cinética , Tomografia por Emissão de Pósitrons/métodos , Compostos RadiofarmacêuticosRESUMO
Objective: To compare and analyze the clinical features and potential risk factors of intracranial and extracranial arterial dissection. Methods: A total of 241 consecutive patients with cervicocerebral artery dissection (CAD) in the First Affiliated Hospital of Zhengzhou University from 2010 to 2019 were observed. The 241 CAD patients were divided into extracranial artery dissection group (EAD) (n=81) and intracranial artery dissection group (IAD) (n=160), clinical characteristics and risk factors were compared between the two groups. Results: Compared with EAD, the National Institute of Health Stroke Scale (NIHSS) score was higher in patients with ischemic stroke in the IAD group (P=0.015). Patients with IAD were more likely to present with headache (58.8% vs 37.0%, P<0.001), and dissection Aneurysms (76.3% vs 38.3%, P<0.001). Patients with EAD more likely to have a history of mild head and neck injuries (11.1% vs 4.4%, P=0.047) and often involved the anterior circulation (77.8% vs 20.0%, P<0.001). Multivariate Logistic regression analysis showed differences in a history of minor head and neck trauma (OR=3.53, 95%CI 1.04-11.97, P=0.042), anterior circulation involvement (OR=0.09, 95%CI 0.05-0.19, P<0.001), dissection aneurysms (OR=4.98, 95%CI 2.80-8.84, P<0.001), headache (OR=2.42, 95%CI 1.39-4.20, P=0.002) remained significant, and the NHISS score lost its significance. Conclusions: EAD often involves the anterior circulation and a history of mild injury to the head and neck. IAD is more prone to exhibit headache symptoms, and it is more likely to form a dissection aneurysm, and the symptoms of ischemic stroke are more severe.
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Dissecção Aórtica , Cefaleia , Humanos , Fatores de Risco , Acidente Vascular CerebralAssuntos
Sequenciamento do Exoma/métodos , Loci Gênicos/genética , Síndrome de Heterotaxia/genética , Teste Pré-Natal não Invasivo/métodos , Proteína Smad2/genética , Adulto , Feminino , Síndrome de Heterotaxia/diagnóstico por imagem , Síndrome de Heterotaxia/embriologia , Humanos , Linhagem , Gravidez , Fatores de Risco , Ultrassonografia Pré-NatalRESUMO
Periodontitis is a chronic inflammatory disease caused by the colonization of teeth by the bacterial plaque biofilm and the resultant host immune responses in adjacent periodontal tissues. Disease severity can vary dramatically between patients with periodontitis, with some subjects displaying inflammation without bony destruction (gingivitis), while others experience chronic progressive or rapidly aggressive gingival connective tissue damage and bone loss. To determine whether peripheral immune dysregulation is associated with periodontitis, we performed extensive analysis of immune cell subsets in peripheral blood from patients with chronic or aggressive periodontitis versus periodontally healthy control subjects. Peripheral blood mononuclear cells (PBMC) from patients with chronic periodontitis or aggressive periodontitis and from periodontally healthy controls were analysed by 8-10-colour flow cytometry for the frequencies of various lymphocyte subsets, including interleukin (IL)-17-, interferon (IFN)-γ-, tumour necrosis factor (TNF)-α- and IL-10-producing cells, and the frequencies and phenotype of monocytes. Cytokine levels in serum from the different groups were determined by Luminex assay. We found no significant differences in the frequencies of major immune cell populations [CD4+ T cells, CD8+ T cells, γδ T cells, CD4+ CD45RO+ CD25+ CD127low regulatory T cells (Tregs ), CD19+ B cells, CD14+ monocytes] or of cytokine-producing T cells, or in the phenotype of CD14+ monocytes in peripheral blood from these patient cohorts. Additionally, no significant differences were observed in serum levels of prototypical inflammatory cytokines. These results suggest that the local gingival inflammatory response is not reflected by obvious changes in major blood immune cell subset frequencies.
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Periodontite Agressiva/imunologia , Periodontite Crônica/imunologia , Gengiva/patologia , Gengivite/imunologia , Leucócitos Mononucleares/imunologia , Adulto , Periodontite Agressiva/patologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Periodontite Crônica/patologia , Feminino , Gengiva/citologia , Gengivite/patologia , Humanos , Interferon gama/sangue , Interleucina-10/sangue , Interleucina-17/sangue , Subpopulações de Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/sangue , Adulto JovemRESUMO
Current bibliometric analyses of the evolving trends in research scope category across different time periods using the H-classics method in implantology are considerably limited. The purpose of this study was to identify the classic articles in implantology to analyse bibliometric characteristics and associated factors in implantology for the past four decades. H-Classics in implantology were identified within four time periods between 1977 and 2016, based on the h-index from the Scopus® database. For each article, the principal bibliometric parameters of authorship, geographic origin, country origin, and institute origin, collaboration, centralisation, article type, scope of study and other associated factors were analysed in four time periods. A significant increase in mean numbers of authors per H-Classics was found across time. Both Europe and North America were the most productive region/country and steadily dominated this field in each time period. Collaborations of author, internationally and inter-institutionally had significantly increased across time. A significant decentralisation in authorships, institutes and journals was noted in past four decades. The journal of Clinical Oral Implant Researches has raised its importance for almost 30 years (1987-2016). Research on Complications, peri-implant infection/pathology/therapy had been increasing in production throughout each period. This is the first study to evaluate research trends in implantology in the past 40 years using the H-classics method, which through analysing via principle bibliometric characteristics reflected a historical perspective on evolutionary mainstream in the field. Prominence of research regarding complications may forecast innovative advancements in future.
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Pesquisa Biomédica , Implantação Dentária , Periodontia , Editoração/normas , Bibliometria , Bases de Dados Factuais , Implantes Dentários , HumanosRESUMO
Since its commercial introduction three-quarters of a century ago, fluid catalytic cracking has been one of the most important conversion processes in the petroleum industry. In this process, porous composites composed of zeolite and clay crack the heavy fractions in crude oil into transportation fuel and petrochemical feedstocks. Yet, over time the catalytic activity of these composite particles decreases. Here, we report on ptychographic tomography, diffraction, and fluorescence tomography, as well as electron microscopy measurements, which elucidate the structural changes that lead to catalyst deactivation. In combination, these measurements reveal zeolite amorphization and distinct structural changes on the particle exterior as the driving forces behind catalyst deactivation. Amorphization of zeolites, in particular, close to the particle exterior, results in a reduction of catalytic capacity. A concretion of the outermost particle layer into a dense amorphous silica-alumina shell further reduces the mass transport to the active sites within the composite.Catalyst deactivation in fluid catalytic cracking processes is unavoidably associated with structural changes. Here, the authors visualize the deactivation of zeolite catalysts by ptychography and other imaging techniques, showing pronounced amorphization of the outer layer of the catalyst particles.
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OBJECTIVES: Chronic periodontitis is a bone destructive inflammatory disease with an adverse impact on general health and suggested underlying factors in common with osteoporosis. A few studies have examined the possible relationship between chronic periodontitis and osteoporosis; however, the results remain inconclusive. This longitudinal follow-up study investigated the possible risk of patients with chronic periodontitis to present osteoporosis by using a population-based national health insurance data set in Taiwan. MATERIAL AND METHODS: A random sample consisting of 1 million individuals was collected from Taiwan's national health insurance data set. From the sample, a total of 29 463 patients with newly diagnosed periodontitis from 2002 to 2008 were recruited and compared with a matched cohort of 58 926 patients without periodontitis. All patients were tracked until an osteoporosis diagnosis, or death, until the end of 2011. Associated factors, such as gender, age and comorbidities were examined. Cox proportional-hazards regression was performed to examine the risk of osteoporosis for patients with or without periodontitis. RESULTS: Within the 6-year follow-up period, the incidence rates of osteoporosis in the periodontitis cohort and comparison group were 2.72 and 1.66 per 1000 person-years, respectively. Mild, moderate and severe periodontitis were found to have 1.56, 2.09 and 2.08 times the risk of osteoporosis respectively compared to patients without periodontitis. Log-rank analysis revealed that patients with periodontitis had significantly higher cumulative incidence rates of osteoporosis than the control group (P<.0001). CONCLUSION: This study found that patients with periodontitis had a higher risk of being diagnosed with osteoporosis.
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Periodontite Crônica/complicações , Periodontite Crônica/epidemiologia , Osteoporose/complicações , Osteoporose/epidemiologia , Adulto , Idoso , Doença da Artéria Coronariana/epidemiologia , Diabetes Mellitus/epidemiologia , Feminino , Seguimentos , Gota/epidemiologia , Humanos , Hiperlipidemias/epidemiologia , Hipertensão/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Vigilância da População , Pontuação de Propensão , Modelos de Riscos Proporcionais , Insuficiência Renal Crônica/epidemiologia , Medição de Risco , Acidente Vascular Cerebral/enzimologia , Taiwan/epidemiologiaRESUMO
Taiwan is an area where chronic hepatitis is endemic. Liver cancer is so common that it has been ranked first among cancer mortality rates since the early 1980s in Taiwan. Besides, liver cirrhosis and chronic liver diseases are the sixth or seventh in the causes of death. Therefore, as shown by the active research on hepatitis, it is not only a health threat, but also a huge medical cost for the government. The estimated total number of hepatitis B carriers in the general population aged more than 20 years old is 3,067,307. Thus, a case record review was conducted from all patients with diagnosis of acute hepatitis admitted to the Emergency Department (ED) of a well-known teaching-oriented hospital in Taipei. The cost of medical resource utilization is defined as the total medical fee. In this study, a fuzzy neural network is employed to develop the cost forecasting model. A total of 110 patients met the inclusion criteria. The computational results indicate that the FNN model can provide more accurate forecasts than the support vector regression (SVR) or artificial neural network (ANN). In addition, unlike SVR and ANN, FNN can also provide fuzzy IF-THEN rules for interpretation.
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Serviço Hospitalar de Emergência , Lógica Fuzzy , Custos de Cuidados de Saúde , Hepatite Viral Humana/economia , Doença Aguda , Hepatite Viral Humana/epidemiologia , Hepatite Viral Humana/terapia , Humanos , Modelos Teóricos , Taiwan/epidemiologiaRESUMO
This article presents an innovative design for inoculating the desired organisms to stratified geological layers at desired rates during in-situ bioaugmentation. The new delivery system consists of intermittent porous tubes connected in series with impermeable polyethylene tubes that run horizontally in each stratified layer of a contaminated aquifer. A bioaugmentation test using the new delivery system was conducted to inject an enriched culture of Escherichia coli (E. coli). Results of the test indicated that the distribution of E. coli through each porous tube was fairly uniform. A mathematical model previously developed to calculate the distribution of water flow through each porous tube was modified to calculate the distribution of E. coli. Geological layers often have different hydraulic conductivities. By controlling the permeability and the length of porous tubes placed in stratified layers, the new design provides a means to selectively deliver aqueous bacteria to various layers at desired rates according to aquifer heterogeneity.
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Biodegradação Ambiental , Recuperação e Remediação Ambiental/métodos , Escherichia coli/fisiologia , Água Subterrânea/química , Água Subterrânea/microbiologia , Modelos Teóricos , Permeabilidade , Porosidade , Movimentos da ÁguaRESUMO
We have fabricated surface-enhanced Raman scattering (SERS) substrates based on arrays of silver nanoparticles grown on porous anodic alumina templates. Using this nanotechnology platform, label-free and high-speed detection of bacteria are achieved. SERS spectra of various bacteria including Staphylococcus Aureus (Gram-positive bacterium), Klebsiella Pneumoniae (Gram-negative bacterium), and Mycobacterium Smegmatis (Mycobacterium) were recorded. The highly reproducible SERS-based technological platform is capable of differentiating different kinds of bacteria by PCA, LDA, clustering analysis, and SVM methods, which provides promising opportunity for biosensing of clinical microbes.
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Bactérias/isolamento & purificação , Técnicas Biossensoriais/instrumentação , Contagem de Colônia Microbiana/instrumentação , Nanoestruturas/química , Nanotecnologia/instrumentação , Análise Espectral Raman/instrumentação , Bactérias/química , Membrana Celular/química , Desenho de Equipamento , Análise de Falha de Equipamento , Luz , Nanoestruturas/ultraestrutura , Espalhamento de RadiaçãoRESUMO
Caspase-dependent apoptotic cell death has been extensively studied in cultured cells and during embryonic development, but the existence of analogous molecular pathways in single-cell species is uncertain. This has reduced enthusiasm for applying the advanced genetic tools available for yeast to study cell death regulation. However, partial characterization in mammals of additional genetically encoded cell death mechanisms, which lead to a range of dying cell morphologies and necrosis, suggests potential applications for yeast genetics. In this light, we revisited the topic of gene-dependent cell death in yeast to determine the prevalence of yeast genes with the capacity to contribute to cell-autonomous death. We developed a rigorous strategy by allowing sufficient time for gene-dependent events to occur, but insufficient time to evolve new populations, and applied this strategy to the Saccharomyces cerevisiae gene knockout collection. Unlike sudden heat shock, a ramped heat stimulus delivered over several minutes with a thermocycler, coupled with assessment of viability by automated counting of microscopic colonies revealed highly reproducible gene-specific survival phenotypes, which typically persist under alternative conditions. Unexpectedly, we identified over 800 yeast knockout strains that exhibit significantly increased survival following insult, implying that these genes can contribute to cell death. Although these death mechanisms are yet uncharacterized, this study facilitates further exploration.
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Apoptose , Saccharomyces cerevisiae/genética , Apoptose/genética , Técnicas de Inativação de Genes , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Temperatura Alta , Fenótipo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
BACKGROUND AND OBJECTIVE: The purpose of this study was to evaluate the effect of quercetin, a flavonol that exhibits anti-inflammatory properties, on experimental periodontal destruction in rats. MATERIAL AND METHODS: Osteoclast formation on maxillary palatal alveolus was induced with daily lipopolysaccharide (LPS) injections (0, 1 or 5 mg/mL) for 3 d. Five days later, the osteoclasts on bony surfaces were counted after histochemical staining for tartrate-resistant acid phosphatase. The effect of intragastric quercetin on the osteoclast formation was evaluated in the following three groups: quercetin (75 mg/kg/d by oral feeding); LPS (5 mg/mL); and quercetin plus LPS. Moreover, the effect of quercetin on the ligature-induced periodontitis around maxillary second and mandibular first molars was further evaluated by microcomputerized tomography (on days 0, 4, 8 and 12) and by histometry (on day 8). RESULTS: A dose-dependent increase in osteoclasts occurred after LPS injections. However, quercetin (75 mg/kg) reduced the 5 mg/mL LPS-induced osteoclasts. Using microcomputerized tomography, the bone crest levels at ligation sites were found to be significantly more apical than at the control sites on days 8 and 12; however, the apically located bone crests rebounded in rats from the quercetin-plus-ligation group. Histometry demonstrated significantly more coronal alveolar crest bone levels, less inflammatory cell-infiltrated connective tissue areas and less connective tissue attachments in the ligation-plus-quercetin group compared with those in the ligation group. CONCLUSION: As the quercetin could reduce the LPS-induced osteoclast formation and the ligature-enhanced periodontal inflammation and bone loss, we suggest that it may have an ameliorative effect on periodontal destruction.
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Perda do Osso Alveolar/tratamento farmacológico , Antioxidantes/uso terapêutico , Periodontite/tratamento farmacológico , Quercetina/uso terapêutico , Administração Oral , Perda do Osso Alveolar/diagnóstico por imagem , Animais , Antioxidantes/administração & dosagem , Relação Dose-Resposta a Droga , Ligadura , Lipopolissacarídeos , Masculino , Osteoclastos/efeitos dos fármacos , Quercetina/administração & dosagem , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Microtomografia por Raio-XRESUMO
AIM: To determine the prevalence of distolingual roots in mandibular first molar teeth in Taiwanese Han Chinese, and its impact on root morphology. METHODOLOGY: The presence of distolingual roots in 375 subjects (521 molars) were assessed from 624 patients attending the dental clinics of medical centres around Taiwan island from August 2004 to April 2007 using computed tomography. The following observations were made: (i) numbers of roots and canals, (ii) mesial and distal root types and (iii) levels of furca in the molars presence or absence of distolingual root. RESULTS: The mean age of the subject was 45; 43% were women. Among all the examined molars, 56%, 27% and 18% were two-, three- and four-rooted, respectively. Two per cent, 72% and 26% of molars had two, three and four canals, respectively. All of the four-rooted molars had four canals, but all of the molars with four canals varied in the number of roots. All molars with distolingual roots had two mesial canals. Bilateral consistency in terms of distolingual root, root canal number, root number and root type was observed in subjects with bilateral molars. In molars with distolingual roots, a higher prevalence of two mesial roots and a shorter mesial root trunk were observed than in teeth without distolingual roots. CONCLUSIONS: A distolingual root was found in 22% of molars and in 24% of the subjects examined. Most subjects with a distolingual root had them bilaterally. The presence of a distolingual root was associated with variation in the root morphology, including the furcation level, the root type and the number of roots and canals.
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Dente Molar/anatomia & histologia , Raiz Dentária/anatomia & histologia , Adulto , Povo Asiático/estatística & dados numéricos , Feminino , Humanos , Imageamento Tridimensional , Masculino , Mandíbula , Pessoa de Meia-Idade , Odontometria , Valores de Referência , Taiwan , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Little is known about the exposure profiles of melamine in children. We evaluated the association of clinical findings, exposure patterns and biomarkers with nephrolithiasis in children with potential exposure to melamine. METHODS: A case-control study was conducted in children aged 0-16 years with potential exposure to contaminated dairy products. Cases were defined as nephrolithiasis detected by renal ultrasonography. On the basis of different brands of contaminated dairy products consumed, subjects were classified into high exposure, low exposure and control groups with estimated melamine exposure levels of higher than 2.5 ppm, 0.05-2.5 ppm and lower than detection limits <0.05 ppm. We measured urine melamine for those with nephrolithiasis and age-matched and gender-matched controls within the subset of the study population. RESULTS: The duration of consumption of contaminated products was longer in children with nephrolithiasis in the high exposure group than in controls (median (IQR) 12.0 (3.3-24.0) vs 6.0 (4.0-7.0) months; p = 0.048). High melamine exposure levels were significantly associated with nephrolithiasis (OR 61.04 (95% CI 12.73 to 292.84)). The risk was found to increase with estimate melamine exposure levels (p for trend <0.001). Two among 10 affected subjects with nephrolithiasis showed elevated urine melamine levels. In comparison, levels of all 20 controls were lower than the detection limit. CONCLUSIONS: The risk of melamine-associated nephrolithiasis was related to duration of consumption of contaminated products and estimated melamine exposure levels. Though urine melamine was not a sensitive test, it might serve as an exposure biomarker in melamine-associated nephrolithiasis.
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Laticínios/análise , Contaminação de Alimentos , Nefrolitíase/induzido quimicamente , Triazinas/urina , Adolescente , Biomarcadores/urina , Estudos de Casos e Controles , Criança , Pré-Escolar , China , Feminino , Humanos , Lactente , Fórmulas Infantis , Recém-Nascido , Masculino , Nefrolitíase/diagnóstico por imagem , Nefrolitíase/epidemiologia , Fatores de Risco , Taiwan/epidemiologia , Fatores de Tempo , Triazinas/efeitos adversos , UltrassonografiaRESUMO
Genetic mutations affecting mitochondrial fission and fusion proteins cause human neurological disorders, but are assumed to be well tolerated in yeast. The conserved mitochondrial fission protein Dnm1/Drp1 is required for normal mitochondrial division, but also promotes cell death in mammals and yeast. Fis1, an outer mitochondrial membrane-anchored receptor for Dnm1/Drp1, also can promote cell death in mammals, but appears to have prosurvival activity in yeast. Here we report that deletion of the FIS1 gene in yeast consistently results in acquisition of a secondary mutation that confers sensitivity to cell death. In several independently derived FIS1 knockouts, tiling arrays and genomic sequencing identified the secondary mutation as a premature termination in the same stress-response gene, WHI2. The WHI2 mutation rescues the mitochondrial respiratory defect (petite formation) caused by FIS1 deficiency, but also causes a failure to suppress cell growth during amino-acid deprivation. Thus, loss of Fis1 drives the selection for specific compensatory mutations that confer defective growth control and cell death regulation, characteristic of human tumor cells. The important long-term survival function of Fis1 that is compensated by WHI2 mutation appears to be independent of fission factor Dnm1/Drp1 and its adaptor Mdv1, but may be mediated through a second adaptor Caf4, as WHI2 is also mutated in a CAF4 knockout.
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Viabilidade Microbiana , Proteínas Mitocondriais/deficiência , Mutação/genética , Saccharomyces cerevisiae/citologia , Aerobiose , Sequência de Aminoácidos , Aminoácidos/deficiência , Sequência de Bases , Proliferação de Células , Cromossomos Fúngicos/metabolismo , Análise Mutacional de DNA , Deleção de Genes , Duplicação Gênica , Genes Recessivos , Teste de Complementação Genética , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
Anomalous scaling in the statistics of an active scalar is studied in a shell model of homogeneous turbulent convection. We extend refined similarity ideas for homogeneous and isotropic turbulence to homogeneous turbulent convection and attribute the origin of the anomalous scaling to variations of the entropy transfer rate. We verify the consequences and thus the validity of our hypothesis by showing that the conditional statistics of the active scalar and the velocity at fixed values of entropy transfer rate are not anomalous but have simple scaling with exponents given by dimensional considerations, and that the intermittency corrections are given by the scaling exponents of the moments of the entropy transfer rate.