Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 138
Filtrar
1.
Plant Cell ; 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38943676

RESUMO

The cell wall shapes plant cell morphogenesis and affects the plasticity of organ growth. However, the way in which cell wall establishment is regulated by ethylene remains largely elusive. Here, by analyzing cell wall patterns, cell wall composition and gene expression in rice (Oryza sativa, L.) roots, we found that ethylene induces cell wall thickening and the expression of cell wall synthesis-related genes, including CELLULOSE SYNTHASE-LIKE C1, 2, 7, 9, 10 (OsCSLC1, 2, 7, 9, 10) and CELLULOSE SYNTHASE A3, 4, 7, 9 (OsCESA3, 4, 7, 9). Overexpression and mutant analyses revealed that OsCSLC2 and its homologs function in ethylene-mediated induction of xyloglucan biosynthesis mainly in the cell wall of root epidermal cells. Moreover, OsCESA-catalyzed cellulose deposition in the cell wall was enhanced by ethylene. OsCSLC-mediated xyloglucan biosynthesis likely plays an important role in restricting cell wall extension and cell elongation during the ethylene response in rice roots. Genetically, OsCSLC2 acts downstream of ETHYLENE-INSENSITIVE3-LIKE1 (OsEIL1)-mediated ethylene signaling, and OsCSLC1, 2, 7, 9 are directly activated by OsEIL1. Furthermore, the auxin signaling pathway is synergistically involved in these regulatory processes. These findings link plant hormone signaling with cell wall establishment, broadening our understanding of root growth plasticity in rice and other crops.

2.
Twin Res Hum Genet ; : 1-6, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37650223

RESUMO

The aim of this study was to investigate the prevalence of anemia in twin pregnancies and the influence of anemia on maternal and neonatal outcomes. This retrospective study included twin pregnant women who delivered in a tertiary hospital in China from January 2018 to December 2018. Patients were divided by WHO criteria (hemoglobin <11.0 g/dL): the anemic and nonanemic groups. Patients with anemia were further classified as recovered or unrecovered subgroup after oral iron therapy. Maternal and neonatal outcomes in women carrying twins were compared using Student's t test and the chi-squared test or the Fisher exact test. Univariable and multivariable logistic regression models were used to determine the association of maternal and neonatal characteristics with anemia. Linear regression analysis was used to estimate mean birth weight and gestational week. The prevalence of anemia was 42.6% (182/427) in twin pregnancies. The anemic group had higher rates of low 1-minute Apgar score (4.4% vs. 1.8%, p = .028), perinatal death (1.9% vs. 0.2%, p = .012) and neonatal intensive care unit (NICU) admission (27.2% vs. 20.2%, p = .017; adjusted OR, 1.478; 95% CI [1.07, 2.044]). The recovered subgroup had lower NICU admission rate (13.5% vs. 30.3%, p = .006; OR, 0.388; 95% CI [0.186, 0.809]), higher gestational week and birth weight (ß, 0.954 week; 95% CI [0.114, 1.794] and ß, 171.01 g; 95% CI [9.894, 332.126] respectively). The prevalence of anemia in twin gestation is high. Anemia is associated with adverse neonatal outcomes, and correction of anemia significantly improved the pregnancy outcomes.

3.
Adv Exp Med Biol ; 1417: 93-118, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37223861

RESUMO

Hepatitis E virus (HEV) usually causes acute self-limiting hepatitis but sometimes leads to chronic infection in immunocompromised persons. HEV is not directly cytopathic. Immunologically mediated events after HEV infection are believed to play important roles in the pathogenesis and clearance of infection. The anti-HEV antibody responses have been largely clarified since the determination of major antigenic determinant of HEV, which is located in the C-terminal portion of ORF2. This major antigenic determinant also forms the conformational neutralization epitopes. Robust anti-HEV immunoglobulin M (IgM) and IgG responses usually develop 3-4 weeks after infection in experimentally infected nonhuman primates. In humans, potent specific IgM and IgG responses occur in the very early phase of the disease and are critical in eliminating the virus, in concert with the innate and adaptive T-cell immune responses. Testing anti-HEV IgM is valuable in the diagnosis of acute hepatitis E. The long-term persistence and protection of anti-HEV IgG provide the basis for estimating the prevalence of HEV infection and for the development of a hepatitis E vaccine. Although human HEV has four genotypes, all the viral strains are considered to belong to a single serotype. It is becoming increasingly clear that the innate and adaptive T-cell immune responses play critical roles in the clearance of the virus. Potent and multispecific CD4+ and CD8+ T cell responses to the ORF2 protein occur in patients with acute hepatitis E, and weaker HEV-specific CD4+ and CD8+ T cell responses appear to be associated with chronic hepatitis E in immunocompromised individuals.


Assuntos
Vírus da Hepatite E , Hepatite E , Animais , Humanos , Vírus da Hepatite E/genética , Imunoglobulina G , Epitopos , Imunidade , Imunoglobulina M
4.
Clin Gastroenterol Hepatol ; 20(12): 2826-2837.e9, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34902570

RESUMO

BACKGROUND & AIMS: Data on long-term tenofovir alafenamide (TAF) therapy for pregnant women with active chronic hepatitis B (CHB) (immune clearance and reactivation phases, currently and previously diagnosed) and their infants are lacking. METHODS: Pregnant women with active CHB treated with TAF and tenofovir disoproxil fumarate (TDF) were enrolled in this multicenter prospective study, and infants received immunoprophylaxis. The primary outcomes were rates of adverse (safety) events in pregnant women and defects in infants and fetuses. The secondary outcomes were virologic responses in pregnant women, infants' safety, hepatitis B surface antigen (HBsAg) status, and growth conditions. RESULTS: One hundred three and 104 pregnant women were enrolled and 102 and 104 infants were born in the TAF and TDF groups, respectively. In the TAF group, the mean age, gestational age, alanine aminotransferase level, and viral loads at treatment initiation were 29.3 years, 1.3 weeks, 122.2 U/L, and 5.1 log10 IU/mL, respectively. TAF was well-tolerated, and the most common adverse event was nausea (29.1%) during a mean of 2 years of treatment. Notably, 1 (1.0%) TAF-treated pregnant woman underwent induced abortion due to noncausal fetal cleft lip and palate. No infants in either group had birth defects. In the TAF group, the hepatitis B e antigen seroconversion rate was 20.7% at postpartum month 6, infants had normal growth parameters, and no infants were positive for HBsAg at 7 months. The TDF group had comparable safety and effectiveness profiles. CONCLUSIONS: TAF administered throughout or beginning in early pregnancy is generally safe and effective for pregnant women with active CHB and their infants.


Assuntos
Fenda Labial , Fissura Palatina , Hepatite B Crônica , Hepatite B , Feminino , Humanos , Gravidez , Recém-Nascido , Adulto , Antígenos de Superfície da Hepatite B , Hepatite B Crônica/tratamento farmacológico , Gestantes , Estudos Prospectivos , Fenda Labial/induzido quimicamente , Fenda Labial/tratamento farmacológico , Fissura Palatina/induzido quimicamente , Fissura Palatina/tratamento farmacológico , Tenofovir/efeitos adversos , Adenina/efeitos adversos , China , Antivirais/efeitos adversos , Hepatite B/diagnóstico
5.
Microvasc Res ; 139: 104252, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34520772

RESUMO

Soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating antiangiogenic protein, is involved in the pathogenesis of atherosclerosis (AS), and the underlying mechanism is still unclear. Here, we attempted to investigate the mechanism of action of sFlt-1 in AS. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low density lipoprotein (ox-LDL) to induce cell injury. ox-LDL treatment increased LC3-II/LC3-I ratio, Beclin-1 expression and GFP-LC3 puncta in HUVECs, suggesting that ox-LDL may induce autophagic flux impairment in HUVECs. ox-LDL-treated HUVECs displayed a decrease of sFlt-1 levels. Moreover, ox-LDL treatment reduced cell proliferation and elevated apoptosis in HUVECs, which was abrogated by sFlt-1 overexpression. Up-regulation of sFlt-1 repressed the activity of PI3K/AKT/mTOR signaling pathway and enhanced autophagy in HUVECs following ox-LDL treatment. Additionally, sFlt-1 overexpression-mediated increase of autophagy in ox-LDL-treated HUVECs was abolished by 3-methyladenine (autophagy inhibitor). 3-methyladenine abrogated the impact of sFlt-1 overexpression on proliferation and apoptosis in ox-LDL-treated HUVECs. This work confirmed that overexpression of sFlt-1 activated autophagy by repressing PI3K/Akt/mTOR signaling pathway, and thus alleviated ox-LDL-induced injury of HUVECs. Therefore, this study suggests that sFlt-1 may be a potential target for AS treatment.


Assuntos
Aterosclerose/enzimologia , Autofagia/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/enzimologia , Lipoproteínas LDL/toxicidade , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Apoptose/efeitos dos fármacos , Aterosclerose/genética , Aterosclerose/patologia , Proteína Beclina-1/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Transdução de Sinais , Regulação para Cima , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética
6.
Eur Radiol ; 32(9): 6545-6553, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35357538

RESUMO

OBJECTIVE: To evaluate the efficacy of parameters derived from [68Ga]Ga-PSMA-11 PET/CT images in predicting pathological HIF-2α expression in primary tumors among patients with renal cell carcinoma (RCC). METHODS: Fifty-three RCC patients with preoperative [68Ga]Ga-PSMA-11 PET/CT scans and complete surgical specimens were retrospectively enrolled in this study. Radiographic parameters were obtained from PET/CT images, and immunohistochemistry was used to measure the expression of HIF-2α and PSMA. Continuous variables and categorical variables were analyzed by the Mann-Whitney U test and chi-square test, respectively. ROC analysis was used to test the efficacy of several preoperative parameters in identifying pathological HIF-2α expression. Univariable logistic regression analyses were performed for significant parameters to predict pathological HIF-2α expression in RCC. RESULTS: Of the 53 tumors, 29 (54.7%) had high expression of HIF-2α. The SUVmax was significantly different in the HIF-2α expression subgroups (p < 0.001). SUVmax emerged as the most significant parameter to differentiate HIF-2α expression subgroups (high vs. low), with the AUC of 0.93 (95% CI 0.85-1.00, p < 0.001), sensitivity of 90%, and specificity of 88%. Furthermore, SUVmax was confirmed as the most significant predictor of HIF-2α expression level by univariable logistic regression model analysis (odds ratio 1.39, 95% CI 1.17-1.65, p < 0.001). Consistent with the radiographic results of [68Ga]Ga-PSMA-11 PET/CT, the staining intensity of pathological PSMA was significantly higher in HIF-2α-high-expressing tumors (p = 0.003). CONCLUSIONS: [68Ga]Ga-PSMA-11 PET/CT was superior in identifying pathological HIF-2α expression in primary tumors of RCC patients, demonstrating its potential application in predicting responses to HIF-2α antagonists. KEY POINTS: • [68Ga]Ga-PSMA-11 PET/CT could potentially predict the HIF-2α expression of primary tumors among patients with RCC. • SUVmaxof [68Ga]Ga-PSMA-11 PET/CT was the most significant predictor of HIF-2α expression level. • This probability could help predict the therapeutic response of patients with RCC to HIF-2α antagonists.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/antagonistas & inibidores , Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/tratamento farmacológico , Ácido Edético , Radioisótopos de Gálio , Humanos , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/tratamento farmacológico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Estudos Retrospectivos
7.
Q J Nucl Med Mol Imaging ; 66(1): 67-73, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31359744

RESUMO

BACKGROUND: Conflicting results have been revealed on the relationship between PSMA uptake values (SUVs) on prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) and prostate cancer (PCa) aggressiveness. This study is to validate the relationship between SUVs with PCa aggressiveness and its role in evaluation of clinically significant PCa (csPCa) and risk stratification. METHODS: We retrospectively enrolled 51 patients who underwent [68Ga]-PSMA PET/CT (PET/CT) before radical prostatectomy (RP). PET/CT results were corrected with whole mount histology. The relationship between SUVs and aggressiveness related indictors including Gleason score, T stage, initial PSA and tumor size were analyzed. The cutoff value for detection of overall PCa, csPCa and intermediate/high-risk PCa were calculated by receiver operating characteristics (ROC) analysis. RESULTS: Both SUVmax and SUVmean positively correlated with Gleason score (SUVmax Spearman r=0.546 P<0.01, SUVmean Spearman r=0.359 P<0.01), PSA level (SUVmax Spearman r=0.568 P<0.01, SUVmean Spearman r=0.529 P<0.01) and tumor volume SUVmax Spearman r=0.635 P<0.01, SUVmean Spearman r=0.590 P<0.01). Tumors with T3 stage had significant higher SUV uptake than T2 (SUVmax 17.49±10.50 vs 9.90±8.7, P<0.01 and SUVmean 17.49±10.50 vs 9.90±8.7, P<0.01). ROC analysis showed cutoff of SUVmax (3.8) and SUVmean (2.8) for overall PCa detection. ROC analysis showed that csPCa and intermediate/high risk PCa had the same cutoff on both SUVmax (8.4) and SUVmean (6.8). CONCLUSIONS: PSMA uptake on PSMA PET/CT positively correlated with Gleason score, T stage, initial PSA and tumor volume. Both SUVmax and SUVmean can be applied as parameters for csPCa detection and risk classification.


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata , Humanos , Masculino , Gradação de Tumores , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Estudos Retrospectivos
8.
Clin Infect Dis ; 73(9): e3317-e3323, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32634824

RESUMO

BACKGROUND: Passive-active immunoprophylaxis against mother-to-child transmission (MTCT) of hepatitis B virus (HBV) recommends administering hepatitis B immunoglobulin (HBIG) and birth-dose hepatitis B vaccine in infants within 12 or 24 hours after birth. With this protocol, MTCT of HBV still occurs in 5-10% infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg). The present study aimed to investigate whether earlier administration of HBIG and hepatitis B vaccine after birth can further increase protection efficacy. METHODS: We conducted a prospective, multi-center observational study in infants born to mothers with HBV infection, in whom neonatal HBIG and birth dose hepatitis B vaccine were administered within one hour after birth. The infants were followed up for HBV markers at 7-14 months of age. RESULTS: A total of 1140 pregnant women with HBV were enrolled, and 982 infants (9 twins) of 973 mothers were followed up at 9.6 ± 1.9 months of age. HBIG and birth-dose vaccine were administered in newborn infants within a median of 0.17 (0.02-1.0) hours after birth. The overall rate of MTCT was 0.9% (9/982), with none (0%) of the 607 infants of HBeAg-negative mothers and 9 (2.4%) of 375 infants of HBeAg-positive mothers acquiring HBV. All 9 HBV-infected infants were born to mothers with HBV DNA >2.75 × 106 IU/mL. Maternal HBV DNA levels >2 × 106 IU/mL were an independent risk factor (odds ratio, 10.627; 95% confidence interval, 2.135-∞) for immunoprophylaxis failure. CONCLUSIONS: Earlier use (within 1 hour after birth) of HBIG and hepatitis B vaccine can provide better protection efficacy against MTCT of HBV.


Assuntos
Hepatite B , Complicações Infecciosas na Gravidez , Feminino , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B , Vacinas contra Hepatite B , Antígenos E da Hepatite B , Vírus da Hepatite B , Humanos , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Estudos Prospectivos
9.
Plant Cell ; 30(10): 2286-2307, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30309900

RESUMO

Sorghum (Sorghum bicolor) is the fifth most popular crop worldwide and a C4 model plant. Domesticated sorghum comes in many forms, including sweet cultivars with juicy stems and grain sorghum with dry, pithy stems at maturity. The Dry locus, which controls the pithy/juicy stem trait, was discovered over a century ago. Here, we found that Dry gene encodes a plant-specific NAC transcription factor. Dry was either deleted or acquired loss-of-function mutations in sweet sorghum, resulting in cell collapse and altered secondary cell wall composition in the stem. Twenty-three Dry ancestral haplotypes, all with dry, pithy stems, were found among wild sorghum and wild sorghum relatives. Two of the haplotypes were detected in domesticated landraces, with four additional dry haplotypes with juicy stems detected in improved lines. These results imply that selection for Dry gene mutations was a major step leading to the origin of sweet sorghum. The Dry gene is conserved in major cereals; fine-tuning its regulatory network could provide a molecular tool to control crop stem texture.


Assuntos
Variação Genética , Proteínas de Plantas/genética , Sorghum/genética , Fatores de Transcrição/genética , Parede Celular/genética , Parede Celular/metabolismo , Grão Comestível/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Estudo de Associação Genômica Ampla , Haplótipos , Proteínas de Plantas/metabolismo , Caules de Planta/fisiologia , Seleção Genética , Sorghum/fisiologia
10.
Emerg Infect Dis ; 25(5): 1028-1029, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31002064

RESUMO

In China in 2013, a man acquired rabies after sucking wounds of his son, who had been bitten by a stray dog. The man declined postexposure prophylaxis (hyperimmunoglobulin and vaccine) and died; the son accepted prophylaxis and survived. Physicians should be aware of rabies transmission through mucosal exposure and encourage postexposure prophylaxis.


Assuntos
Mucosa Bucal/virologia , Vírus da Raiva , Raiva/epidemiologia , Raiva/transmissão , Adolescente , Adulto , Animais , Mordeduras e Picadas , Notificação de Doenças , Cães , Evolução Fatal , História do Século XXI , Humanos , Masculino , Profilaxia Pós-Exposição , Raiva/história
11.
BMC Pregnancy Childbirth ; 18(1): 292, 2018 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-29980185

RESUMO

BACKGROUND: Pregnancy is a unique physiological condition with the cellular immune functions compromised at some extents to allow the mature of growing fetus. Whether pregnancy may influence the replication of hepatitis B virus (HBV) is less studied. The present study aimed to investigate the influence of pregnancy on the replication of HBV and expression of viral antigens by comparing the levels of HBV DNA and viral antigens in pregnant and non-pregnant women. METHODS: A total of 727 HBsAg-positive serum samples, collected from 214 pregnant women and 513 non-pregnant women of childbearing age, were included. Based on the pregnancy status, subjects were divided into four groups: nulliparous (n = 158), pregnant (n = 214), 7-12 months postpartum (n = 170), and 2-5 years postpartum (n = 185). The levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) were quantitatively measured with microparticle enzyme immunoassay. HBV DNA levels were detected by fluorescent real-time PCR. RESULTS: The median ages of four groups were 25.0, 25.3, 26.2 and 29.3 years, respectively (p < 0.01). HBeAg-positive proportions were 34.2, 33.6, 35.3 and 29.2%, respectively (p = 0.624). HBV DNA levels in HBeAg-positive women were higher than those in HBeAg-negative women (7.88 vs 2.62 log IU/ml, p < 0.001). HBV DNA levels in the four groups with positive HBeAg were 7.8, 7.7, 8.0 and 8.0 log IU/ml, respectively (p = 0.057), while HBsAg titers were 4.4, 4.5, 4.6 and 4.8 log IU/ml (p = 0.086) and HBeAg titers were 3.1, 3.0, 3.1 and 3.0 log S/CO (p = 0.198). In the four groups with negative HBeAg, HBV DNA levels were 2.3, 2.6, 2.5 and 2.8 log IU/ml, respectively (p = 0.085), while HBsAg titers were 3.1, 3.3, 3.3 and 3.0 log IU/ml (p = 0.06). CONCLUSIONS: Serum levels of HBV DNA and viral antigens showed no significant changes in nulliparous, pregnant, and postpartum women, regardless of the HBeAg status. The results indicate that pregnancy has little influence on the replication of HBV and the expression of viral antigens.


Assuntos
Antígenos de Superfície da Hepatite B/sangue , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/fisiologia , Hepatite B , Período Pós-Parto/sangue , Complicações Infecciosas na Gravidez , Carga Viral/métodos , Adulto , China/epidemiologia , DNA Viral/sangue , Feminino , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Hepatite B/imunologia , Humanos , Avaliação de Resultados em Cuidados de Saúde , Paridade/imunologia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/imunologia , Replicação Viral/imunologia
12.
Clin Infect Dis ; 73(1): 166-167, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32818227
16.
Plant Physiol ; 166(1): 181-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25006026

RESUMO

Xyloglucan (XyG) has been reported to contribute to the aluminum (Al)-binding capacity of the cell wall in Arabidopsis (Arabidopsis thaliana). However, the influence of O-acetylation of XyG, accomplished by the putative O-acetyltransferase TRICHOME BIREFRINGENCE-LIKE27 (TBL27 [AXY4]), on its Al-binding capacity is not known. In this study, we found that the two corresponding TBL27 mutants, axy4-1 and axy4-3, were more Al sensitive than wild-type Columbia-0 plants. TBL27 was expressed in roots as well as in leaves, stems, flowers, and siliques. Upon Al treatment, even within 30 min, TBL27 transcript accumulation was strongly down-regulated. The mutants axy4-1 and axy4-3 accumulated significantly more Al in the root and wall, which could not be correlated with pectin content or pectin methylesterase activity, as no difference in the mutants was observed compared with the wild type when exposed to Al stress. The increased Al accumulation in the wall of the mutants was found to be in the hemicellulose fraction. While the total sugar content of the hemicellulose fraction did not change, the O-acetylation level of XyG was reduced by Al treatment. Taken together, we conclude that modulation of the O-acetylation level of XyG influences the Al sensitivity in Arabidopsis by affecting the Al-binding capacity in the hemicellulose.


Assuntos
Alumínio/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Glucanos/metabolismo , Resolvases de Junção Holliday/metabolismo , Polissacarídeos/metabolismo , Xilanos/metabolismo , Acetilação , Proteínas de Arabidopsis/genética , Parede Celular/metabolismo , Resolvases de Junção Holliday/genética , Raízes de Plantas/metabolismo
17.
Plant Cell ; 24(11): 4731-47, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23204407

RESUMO

Xyloglucan endohydrolase (XEH) and xyloglucan endotransglucosylase (XET) activities, encoded by xyloglucan endotransglucosylase-hydrolase (XTH) genes, are involved in cell wall extension by cutting or cutting and rejoining xyloglucan chains, respectively. However, the physiological significance of this biochemical activity remains incompletely understood. Here, we find that an XTH31 T-DNA insertion mutant, xth31, is more Al resistant than the wild type. XTH31 is bound to the plasma membrane and the encoding gene is expressed in the root elongation zone and in nascent leaves, suggesting a role in cell expansion. XTH31 transcript accumulation is strongly downregulated by Al treatment. XTH31 expression in yeast yields a protein with an in vitro XEH:XET activity ratio of >5000:1. xth31 accumulates significantly less Al in the root apex and cell wall, shows remarkably lower in vivo XET action and extractable XET activity, has a lower xyloglucan content, and exhibits slower elongation. An exogenous supply of xyloglucan significantly ameliorates Al toxicity by reducing Al accumulation in the roots, owing to the formation of an Al-xyloglucan complex in the medium, as verified by an obvious change in chemical shift of (27)Al-NMR. Taken together, the data indicate that XTH31 affects Al sensitivity by modulating cell wall xyloglucan content and Al binding capacity.


Assuntos
Alumínio/toxicidade , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Regulação Enzimológica da Expressão Gênica , Glucanos/metabolismo , Xilanos/metabolismo , Sequência de Aminoácidos , Arabidopsis/química , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Parede Celular/metabolismo , Quelantes/análise , Quelantes/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica de Plantas , Glucanos/análise , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Mutagênese Insercional , Especificidade de Órgãos , Fenótipo , Filogenia , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/enzimologia , Folhas de Planta/genética , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Plantas Geneticamente Modificadas , Polissacarídeos/análise , Polissacarídeos/metabolismo , Proteínas Recombinantes de Fusão , Plântula/química , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/genética , Análise de Sequência de DNA , Xilanos/análise
19.
BMC Infect Dis ; 15: 560, 2015 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-26653888

RESUMO

BACKGROUND: China is an endemic area for hepatitis E virus (HEV). The previous surveys of anti-HEV seroprevalence are cross-sectional. This study aimed to investigate the prevalence of infection among pregnant women and their children in Jiangsu, China, and to observe postpartum anti-HEV evolution. METHODS: Sera from 497 women collected during pregnancy and 6-year postpartum and from their 497 children were screened for anti-HEV by ELISA and confirmed by Western blotting. HEV RNA was detected by reverse transcription-nested PCR. RESULTS: Of the pregnant women, 3 (0.6 %) were anti-HEV IgM positive and 55 (11.1 %) were IgG positive. At 6-year postpartum, 18 anti-HEV IgG positive samples became negative and 18 others became IgG positive; the accumulated prevalence in this cohort of women was at least 14.7 % (73/497). Of the 497 children, the positive rates of anti-HEV IgM and IgG were 0.2 % and 0.4 %, respectively. None of the 18 children from mothers with anti-HEV IgG seroconversion was anti-HEV IgG positive. CONCLUSIONS: Our data indicate that the constant seroprevalence of anti-HEV IgG in adults may be resulted from the balance of negative seroconversion due to waning immunity and positive seroconversion due to novel infections, and the risk of intra-family transmission of HEV was low. The data also imply that cross-sectional seroepidemiological survey may underestimate the prevalence of HEV infection, due to the natural decay of pathogen-specific IgG.


Assuntos
Vírus da Hepatite E/imunologia , Hepatite E/epidemiologia , Adulto , Western Blotting , Criança , Pré-Escolar , China/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Anticorpos Anti-Hepatite/sangue , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Reação em Cadeia da Polimerase , Período Pós-Parto , Gravidez , Gestantes , Prevalência , RNA Viral/análise , RNA Viral/metabolismo , Estudos Soroepidemiológicos , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa