Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 71
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
DNA Cell Biol ; 39(4): 548-554, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32155344

RESUMO

The Qing-Tibet Plateau is characterized by low oxygen pressure, which is an important biomedical and ecological stressor. However, the variation in gene expression during periods of stay on the plateau has not been well studied. We recruited eight volunteers to stay on the plateau for 3, 7, and 30 days. Human Clariom D arrays were used to measure transcriptome changes in the mRNA expression profiles in these volunteers' blood. Analysis of variance (ANOVA) indicated that 699 genes were significantly differentially expressed in response to entering the plateau during hypoxic exposure. The genes with changes in transcript abundance were involved in the terms phosphoprotein, acetylation, protein binding, and protein transport. Furthermore, numerous genes involved in hematopoietic functions, including erythropoiesis and immunoregulation, were differentially expressed in response to hypoxia. This phenomenon may be one of reasons why the majority of people entering the plateau do not have excessive erythrocyte proliferation and are susceptible to infection.


Assuntos
Aclimatação/genética , Doença da Altitude/genética , Doença da Altitude/fisiopatologia , Hipóxia/fisiopatologia , Leucócitos/fisiologia , Altitude , Eritrócitos/citologia , Eritropoese/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Humanos , Leucopoese/genética , Masculino , Oxigênio , Tibet
2.
Obesity (Silver Spring) ; 28(2): 315-322, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31970910

RESUMO

OBJECTIVE: This study aimed to investigate the potential antiobesity effect of genetically modified Escherichia coli Nissle 1917 (EcN-GM) in mice fed a high-fat diet (HFD). METHODS: The mice were randomly divided into six groups: a normal diet group (ND), a HFD group, a HFD + EcN group, and three HFD + EcN-GM groups. The effects of EcN-GM on body weight, food intake, fat pad and organ weight, and an oral glucose tolerance test were measured, in addition to hepatic biochemistry and histological analysis. The mRNA expression of neuropeptides related to food intake regulation in the hypothalamus was also detected. RESULTS: The results showed that EcN-GM decreased body weight, body weight gain, food intake, fat pad weight, and hepatic weight of HFD mice. There were beneficial effects of EcN-GM on blood glucose, hepatic biochemistry, and hepatic histological alterations. A dramatic switch of food intake-regulating gene expression in the hypothalamus was also observed in mice. CONCLUSIONS: This work has revealed that a modified live bacterial therapeutic, EcN-GM, has potential beneficial effects on obesity. This effect may be related to the regulating of the neuropeptide expression of energy intake and expenditure in the hypothalamus. This study demonstrates a successful example of engineered EcN-GM as a novel approach for weight management.

3.
Int J Parasitol Drugs Drug Resist ; 12: 1-6, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31809965

RESUMO

BACKGROUND: Imported cases of infectious disease provide invaluable information about epidemiological conditions abroad, and should guide treatment decisions at home and abroad. Here, we examined cases of malaria imported from Africa to China for mutations eroding the efficacy of sulfadoxine-pyrimethamine (SP), sometimes used as an intermittent preventive treatment during for pregnant women and infants. METHODS: A total of 208 blood samples were collected from P. falciparum-infected workers who had returned from Western and Central Africa to Guangxi Province Frequency distribution. Samples were analyzed for the mutations in dhfr and dhps genes by PCR -sequencing. The prevalence of dhfr and dhps polymorphisms was analyzed. Among the isolates, polymorphisms were detected in mutants N51I, C59R, S108N and I164L of Pfdhfr and I431V, S436 A/F, A437G, K540 E/N, A581G and A613T of pfdhps. RESULTS: Mutations promoting drug resistance were widespread in this cohort. For pfdhfr and pfdhps, wild types were equally rare among patients returned from Western Africa and Central Africa. A triple-mutant dhfr haplotype was most prevalent (>70%). We report for the first time mutation I164L-dhfr and I431V-dhps in Ghana, and for the first time we found A581G to exceed a clinically-relevant threshold that may counter-indicate current clinical practices. For Pfdhps, the double-mutant IAGKAA was high prevalent haplotype in Ghana, Western Africa. The single-mutant ISGKAA was a majority haplotype in Cameroon. Alarmingly, a "super resistance" quintuple mutant was detected, for the first time, in parasites of West African origin (defined by IAGKAA/IRNI in combination with pfdhps 581G and dhfr I164L). This may limit the efficacy of this drug combination for even intermittent clinical applications. CONCLUSIONS: These data are cause for great concern and call for continued surveillance of the efficacy of SP in source and recipient populations, and should be considered when developing treatment policy for imported malaria cases in China and elsewhere.

4.
Plants (Basel) ; 8(12)2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31817831

RESUMO

Arid and semiarid apple producing areas suffer from severe alkalinity of soil, which strongly affects the yield and quality of apples. Dopamine (DA) is involved in metabolic activities in response to abiotic stress in plants. To detect the effects of exogenous DA application on the adaption of apple (Malus hupehensis) seedlings to alkali stress and as a protection from oxidative stress, 0.1 mM DA was identified as the most suitable concentration by hydroponic culture. Further experimentation showed that the growth and photosynthesis of apple seedlings were significantly inhibited under alkali stress, and more reactive oxygen species accumulated, compared with control. However, exogenous DA application suppressed the loss of the plant height, root length, chlorophyll levels, and photosynthetic capacity of apple seedlings that were caused by alkali stress. In the leaves of alkali stressed seedlings, the catalase, superoxide dismutase, and peroxidase activities were lower and hydrogen peroxide and malondialdehyde levels were higher than in the untreated plants. The presence of DA significantly alleviated such effects of alkali stress. In addition, exogenous DA application increased the antioxidant capacity of apple seedlings under alkali stress by increasing the level of chlorogenic acid. These results are significant for improving the alkali tolerance of apple in apple-producing areas with alkalized soil.

5.
PeerJ ; 7: e7943, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681516

RESUMO

In the Chinese Han population, prolonged exposure to hypoxic conditions can promote compensatory erythropoiesis which improves hypoxemia. However, Tibetans have developed unique phenotypes, such as downregulation of the hypoxia-inducible factor pathway through EPAS1 gene mutation, thus the mechanism of adaption of the Han population should be further studied. The results indicated that, under plateau hypoxic conditions, the plains population was able to acclimate rapidly to hypoxia through increasing EPAS1 mRNA expression and changing the hemoglobin conformation. Furthermore, the mutant genotype frequencies of the rs13419896, rs1868092 and rs4953354 loci in the EPAS1 gene were significantly higher in the Tibetan population than in the plains population. The EPAS1 gene expression level was lowest in the Han population carrying the A-A homozygous mutant of the rs13419896 locus but that it increased rapidly after these individuals entered the plateau. At this time, the hemoglobin content was lower in the homozygous mutant Han group than in the wild-type and heterozygous mutant populations, and the viscosity of blood was reduced in populations carrying the A-A haplotypes in rs13419896 and rs1868092 Among Tibetans, the group carrying homozygous mutations of the three SNPs also had lower hemoglobin concentrations than the wild-type. The Raman spectroscopy results showed that exposure of the Tibetan and Han population to hypoxic conditions changed the spatial conformation of hemoglobin and its binding ability to oxygen. The Tibetan population has mainly adapted to the plateau through genetic mutations, whereas some individuals adapt through changes in hemoglobin structure and function.

6.
Plants (Basel) ; 8(11)2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31717908

RESUMO

Soluble sugars and organic acids are the main determinants of fruit organoleptic quality. To investigate the genes responsible for the soluble sugar and organic acid contents of apple fruits, a label-free proteomic analysis involving liquid chromatography (LC)-mass spectrometry (MS)/MS was conducted with the fruits of two Malus species, M. sargentii and M. niedzwetzkyana, which exhibit significant differences in soluble sugar and organic acid contents. A total of 13,036 unique peptides and 1,079 differentially-expressed proteins were identified. To verify the LC-MS/MS results, five candidate proteins were further analyzed by parallel reaction monitoring. The results were consistent with the LC-MS/MS data, which confirmed the reliability of the LC-MS/MS analysis. The functional annotation of the differentially-expressed proteins, based on the gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, revealed that they were mainly related to biological processes and cellular components. Additionally, the main enriched KEGG pathways were related to metabolic processes. Moreover, 31 proteins involved in soluble sugar metabolism, organic acid metabolism, and H+-transport were identified. The results of this study may be useful for the comprehensive characterization of the complex mechanism regulating apple fruit-soluble sugar and organic acid contents.

7.
Travel Med Infect Dis ; : 101499, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31604130

RESUMO

BACKGROUND: Chloroquine (CQ) and primaquine (PQ) remain the frontline drugs for radical cure of uncomplicated P. vivax malaria in the Greater Mekong Sub-region (GMS). Recent reports of decreased susceptibility of P. vivax to CQ in many parts of the GMS raise concerns. METHODS: From April 2014 to September 2016, 281 patients with uncomplicated P. vivax infection attending clinics in border settlements for internally displaced people in northeast Myanmar were recruited into this study. Patients were treated with standard regimen of 3-day CQ and concurrent 14-day PQ (3.5 mg/kg total dose) as directly observed therapy, and followed for recurrent parasitemia within 28 days post-patency. RESULTS: Within the 28-day follow-up period, seven patients developed recurrent parasitemia, resulting in a cumulative rate of parasite recurrence of 2.6%. Five of the seven parasitemias recurred within two weeks, and two of those failed to clear within seven days, indicating high-grade resistance. CONCLUSION: Although failure of CQ/PQ treatment of P. vivax was relatively infrequent in northeast Myanmar, this study nonetheless confirms that CQ/PQ-resistant strains do circulate in this area, some of them of a highly resistant phenotype. It is thus recommended that patients who acquire vivax malaria in Myanmar be treated an artemisinin-combination therapy along with hypnozoitocidal primaquine therapy to achieve radical cure.

8.
Malar J ; 18(1): 309, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31514740

RESUMO

BACKGROUND: Intensive malaria transmission along international borders is a significant impediment to malaria elimination in the Greater Mekong Subregion (GMS) of Southeast Asia. Passive case detection (PCD) was used to study the dynamics and trends of malaria transmission at the China-Myanmar border to provide epidemiologic information for improved malaria control. METHODS: PCD was conducted in one hospital and 12 clinics near the Laiza town in northeast Myanmar from 2011 to 2016. Clinical malaria was diagnosed by microscopy and demographic information was captured using a structured questionnaire at the time of the patient's presentation for care. RESULTS: Over the study period, 6175 (19.7%) malaria cases were confirmed by microscopy from 31,326 suspected cases. The four human malaria parasite species were all identified, with Plasmodium vivax and Plasmodium falciparum accounting for 5607 (90.8%) and 481 (7.8%) of the confirmed cases, respectively. In contrast to the steady decline of malaria in the general GMS, the study site had an upward trend of malaria incidence with vivax malaria outbreaks in 2013 and 2016. Adult males, children under the age of 15, and those with occupations such as farming, being a soldier or student, had significantly higher risks of clinical malaria compared to having fevers from other aetiologies. A self-reported history of clinical malaria was also associated with a higher risk of confirmed malaria. CONCLUSIONS: The China-Myanmar border area has experienced an overall upward trend of malaria incidence in recent years with P. vivax becoming the predominant species. Evidence-based control strategies need to focus on high-risk populations.


Assuntos
Malária/epidemiologia , Plasmodium/isolamento & purificação , Fatores Socioeconômicos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Malária/diagnóstico , Masculino , Pessoa de Meia-Idade , Mianmar/epidemiologia , Plasmodium/classificação , Adulto Jovem
9.
Hortic Res ; 6: 75, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31231533

RESUMO

Drought stress can negatively impact apple fruit quality and yield. Apple microRNAs (miRNAs) participate in apple tree and fruit development, as well as in biotic stress tolerance; however, it is largely unknown whether these molecules are involved in the drought response. To identify drought-responsive miRNAs in Malus, we first examined the drought stress tolerance of ten F1 progenies of R3 (M. × domestica) × M. sieversii. We performed Illumina sequencing on pooled total RNA from both drought-tolerant and drought-sensitive plants. The sequencing results identified a total of 206 known miRNAs and 253 candidate novel miRNAs from drought-tolerant plants and drought-sensitive plants under control or drought conditions. We identified 67 miRNAs that were differentially expressed in drought-tolerant plants compared with drought-sensitive plants under drought conditions. Under drought stress, 61 and 35 miRNAs were differentially expressed in drought-tolerant and drought-sensitive plants, respectively. We determined the expression levels of seven out of eight miRNAs by stem-loop qPCR analysis. We also predicted the target genes of all differentially expressed miRNAs and identified the expression of some genes. Gene Ontology analyses indicated that the target genes were mainly involved in stimulus response and cellular and metabolic processes. Finally, we confirmed roles of two miRNAs in apple response to mannitol. Our results reveal candidate miRNAs and their associated mRNAs that could be targeted for improving drought tolerance in Malus species, thus providing a foundation for understanding the molecular networks involved in the response of apple trees to drought stress.

10.
Med Ultrason ; 21(2): 144-151, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31063517

RESUMO

AIMS: To determine the factors influencing ultrasound breast tumor size assessment accuracy. MATERIAL AND METHODS:  Five factors (tumor type, molecular subtype, histological size, histological grade, and breast density) were used to assess the measurement accuracy of breast ultrasound in tumor size. Size underestimation was defined as ultrasound index lesion diameter < histological size by at least 5 mm. RESULTS: Breast ultrasound underestimated tumor size significantly, especially in cases with intraductal components (p=0.002). There was a tendency for higher size underestimation in breast cancer tumors with high-histological grade (p=0.03), human epidermal growth factor receptor type 2 (HER2)-overexpressing breast cancer tumors (p=0.02) and hormone receptor (HR)-/HER2+ breast cancer tumors (p=0.008). Furthermore, core biopsy revealedhigher probability of size underestimation with intraductal components (p=0.002). Size underestimation was more frequent with larger histological size (p<0.001). Masses in non-dense breasts were significantly underestimated (p=0.036) compared to dense breasts. CONCLUSIONS: The size underestimation was influenced by pathological type, molecular subtype, and histological size. The pathological results of core biopsy were conducive for predicting tumor size pre-surgery in precise breast cancer diagnosis.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Carga Tumoral , Ultrassonografia Mamária/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/diagnóstico por imagem , Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
11.
Artigo em Inglês | MEDLINE | ID: mdl-31009824

RESUMO

Mutations in the Kelch domain of the K13 gene (PF3D7_1343700) were previously associated with artemisinin resistance in Plasmodium falciparum. This study followed the dynamics of the K13 polymorphisms in P. falciparum parasites from the China-Myanmar border area obtained in 2007-2016, and their in vitro sensitivities to artesunate (AS) and dihydroartemisinin (DHA). The 50% effective concentration (EC5072h) values of 133 culture-adapted field isolates to AS and DHA, measured by the conventional 72 h SYBR Green I-based assay, varied significantly among the parasites from different years; all were significantly higher than that of the reference strain 3D7. Compared with parasites from 2007 to 2008, ring survival rates almost doubled in parasites obtained in later years. Sequencing the full-length K13 genes identified 11 point mutations present in 85 (63.9%) parasite isolates. F446I was the predominant (55/133) variant, and its frequency was increased from 17.6% (3/17) in 2007 to 55.9% (19/34) in 2014-2016. No wild-type (WT) Kelch domain sequences were found in the 34 samples obtained from 2014 to 2016. In the 2014-2016 samples, a new mutation (G533S) appeared and reached 44.1% (15/34). Collectively, parasites with the Kelch domain mutations (after amino acid 440) had significantly higher ring survival rates than the WT parasites. Individually, F446I, G533S and A676D showed significantly higher ring survival rates than the WT. Although the drug sensitivity phenotypes measured by the RSA6h and EC5072h assays may be intrinsically linked to the in vivo clinical efficacy data, the values determined by these two assays were not significantly correlated. This study identified the trend of K13 mutations in parasite populations from the China-Myanmar border area, confirmed an overall correlation of Kelch domain mutations with elevated ring-stage survival rates, and emphasized the importance of monitoring the evolution and spread of parasites with reduced artemisinin sensitivity along the malaria elimination course.


Assuntos
Antiprotozoários/farmacologia , Artemisininas/farmacologia , Malária Falciparum/parasitologia , Proteínas dos Microfilamentos/genética , Mutação , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , China , Humanos , Proteínas dos Microfilamentos/metabolismo , Mianmar , Plasmodium falciparum/isolamento & purificação , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo
12.
Medicine (Baltimore) ; 97(47): e13182, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30461616

RESUMO

OBJECTIVE: The aim of our study was to qualitatively and quantitatively synthesize the evidence regarding ways to improve motivation of oral hygiene among orthodontic patients with fixed appliances and identify the effects of motivational methods via comparing the oral hygiene condition before and after the motivations. METHODS: An electronic search was conducted in PubMed, Ovid, Embase, and the Crochrane Library for relevant random controlled trials (RCT) and clinical controlled trial (CCT) published before May 1, 2017 with manual search in addition. Search and selection of studies, quality assessment, data extraction and synthesis was completed by 2 reviewers independently. Plaque index (PI) and gingival index (GI) at 1, 3, 6-month were pooled with Review Manager 5.3. Bias of included studies was evaluated. RESULTS: In total, 12 studies fulfilled the inclusion criteria of this systematic review, of which, 5 were included in the meta-analysis. Motivational methods had statistically significant advantage regarding PI in the experimental group over control group at 1, 3, 6-month, while GI was significantly better controlled in the study group at 3, 6-month. The quality of included studies was moderate. CONCLUSION: It is worthy for orthodontists to put in additional efforts to motivate patients to maintain good oral hygiene throughout the entire treatment process.


Assuntos
Motivação , Higiene Bucal , Braquetes Ortodônticos , Educação de Pacientes como Assunto/métodos , Higienistas Dentários , Índice de Placa Dentária , Humanos , Ortodontistas , Índice Periodontal
13.
Plant Physiol Biochem ; 133: 116-126, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30399545

RESUMO

Myo-inositol mediates various physiological processes and stress responses. Here, we investigated its role in Malus hupehensis Rehd. plants when grown hydroponically under saline conditions. Salt-stressed plants showed reduced growth and marked declines in photosynthetic activity and chlorophyll concentrations. However, pretreatment with 50 µM myo-inositol significantly alleviated those inhibitions and enabled plants to maintain their photosynthetic capacity. In addition to changing stomatal behavior, exogenous myo-inositol inhibited ROS accumulation and Na+ uptake. In contrast, activities of antioxidant systems were enhanced, and expression was elevated for genes involved in Na+ uptake (e.g., HKT1, NHX1, SOS1, and SOS2). This exogenous application also provoked the accumulation of sugars or sugar alcohols, which partially contributed to the maintenance of osmotic balance, and the scavenging of ROS, either directly or indirectly. In summary, myo-inositol appears to alleviate the salt-induced inhibition of physiological processes for M. hupehensis, not only by supporting the plant's antioxidant defense system but also by mediating Na+ and K+ homeostasis and the osmotic balance.


Assuntos
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Inositol/farmacologia , Malus/metabolismo , Oxirredutases/biossíntese , Proteínas de Plantas/biossíntese , Salinidade , Estresse Fisiológico/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
14.
Metabolites ; 8(4)2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30384454

RESUMO

Significant variation in organic acid components was detected in mature fruits of 101 apple accessions using high-performance liquid chromatography. The Malus species predominantly accumulated malic acid and citric acid, whereas wild fruits exhibited significantly higher levels of organic acid content than that in cultivated fruits. Differential accumulation patterns during fruit developmental stages was detected between malic acid and citric acid, thus suggesting a complex genetic regulation mechanism of organic acid metabolism in apple fruit. A highly positive correlation was detected between fruit total organic acid content with malic acid and citric acid content, thus suggesting that malic acid and citric acid are the principal determinants of apple fruit acidity. In contrast to malic acid, citric acid was predominantly detected in partial wild apples, while extremely low to undetectable concentrations of citric acid were observed in cultivated apple fruits; this is likely due to the genetic effects of parental characters. Our results provide vital information that could be useful for future studies on genetic analysis and improvement of organic acid accumulation in apple fruits.

15.
Int J Mol Sci ; 19(11)2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30356028

RESUMO

Malate dehydrogenase plays crucial roles in energy homeostasis, plant development and cold and salt tolerance, as it mediates the reversible conversion of malate to oxaloacetate. However, the evolutionary pattern of MDH genes in apple remains elusive. In this study, a total of 20 MDH genes were identified from the "Golden Delicious" apple draft genome. We revealed the physiological and biochemical properties, gene structure, and conserved motifs of MdMDH genes. Chromosomal localization and Ka/Ks ratio analysis of MdMDH genes revealed different selective pressures acted on duplicated MdMDH genes. Exploration of the phylogenetic relationships revealed six clades and similar frequencies between old and recent duplications, and significant differences in the evolutionary rates of the MDH gene family were observed. One MdMDH gene, MDP0000807458, which was highly expressed during apple fruit development and flower bud differentiation, was under positive selection. Thus, we speculated that MDP0000807458 is a likely candidate gene involved in regulation of flower bud differentiation and organic acid metabolism in apple fruits. This study provides a foundation for improved understanding of the molecular evolution of MdMDH genes and further facilitates the functional analysis of MDP0000807458 to unravel its exact role in flower bud differentiation and organic acid metabolism.


Assuntos
Evolução Molecular , Malato Desidrogenase/genética , Malus/genética , Proteínas de Plantas/genética , Genoma de Planta , Malato Desidrogenase/metabolismo , Malus/classificação , Malus/enzimologia , Filogenia , Proteínas de Plantas/metabolismo , Seleção Genética
16.
Int J Mol Sci ; 19(9)2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-30223432

RESUMO

The NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER family (NPF) proteins play important roles in moving substrates such as nitrate, peptides, amino acids, dicarboxylates, malate, glucosinolates, indole acetic acid (IAA), abscisic acid (ABA), and jasmonic acid. Although a unified nomenclature of NPF members in plants has been reported, this gene family has not been studied as thoroughly in apple (Malus × domestica Borkh.) as it has in other species. Our objective was to provide general information about apple MdNPFs and analyze the transcriptional responses of some members to different levels of nitrate supplies. We identified 73 of these genes from the apple genome and used phylogenetic analysis to organize them into eight major groups. These apple NPFs are structurally conserved, based on alignment of amino acid sequences and analyses of phylogenetics and conserved domains. Examination of their genomic structures indicated that these genes are highly conserved among other species. We monitored 14 cloned MdNPFs that showed varied expression patterns under different nitrate concentrations and in different tissues. Among them, NPF6.5 was significantly induced by both low and high levels of nitrate. When compared with the wild type, 35S:MdNPF6.5 transgenic apple calli were more tolerant to low-N stress, which demonstrated that this gene confers greater capacity for nitrogen uptake under those conditions. We also analyzed the expression patterns of those 73 genes in various tissues. Our findings benefit future research on this family of genes.


Assuntos
Proteínas de Transporte de Ânions/genética , Proteínas de Transporte de Ânions/metabolismo , Malus/genética , Malus/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Família Multigênica , Nitrogênio/metabolismo , Sequência de Aminoácidos , Proteínas de Transporte de Ânions/química , Mapeamento Cromossômico , Biologia Computacional/métodos , Sequência Conservada , Éxons , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Íntrons , Malus/classificação , Proteínas de Membrana Transportadoras/química , Anotação de Sequência Molecular , Filogenia , Plantas Geneticamente Modificadas , Domínios Proteicos
17.
Front Physiol ; 9: 1099, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30154732

RESUMO

Background: The number of red blood cells (RBCs) increases significantly in response to high-altitude hypoxic environments, and the RBC microRNA (miRNA) expression pattern is similar to that in whole blood. Studies have shown that miRNA in plasma can act as a circulating hypoxia-associated marker, but the effect of a high-altitude hypoxic environment on RBC-derived miRNAs has not yet been reported. Methods: Blood samples were collected from 20 Han Chinese individuals residing at 500 m (Sichuan Han), 10 migrant Han Chinese citizens residing at 3,658 m (Tibet Han) and 12 native Tibetans, and RBC indices measurements and miRNA sequencing analyses were performed for the three sample groups. The levels of some markedly altered miRNAs at high altitude were subsequently measured from 5 randomly selected samples of each group by real-time PCR. Bioinformatic analyses was performed to determine the potential target genes of selected hypoxia-associated miRNAs. Results: Marked changes of several RBC indices were observed among the Tibet Han population, the Tibetan population and the Sichuan Han population. A total of 516 miRNAs derived from RBCs were initially identified by miRNA sequencing in the three sample groups. Compared with the Sichuan Han population, 49 miRNAs were differentially expressed in the Tibet Han population (17 upregulated and 32 downregulated). 12 upregulated and 21 downregulated miRNAs were observed in the Tibetan population compared with the Sichuan Han population. A total of 40 RBC miRNAs were differentially expressed in the Tibetan population (15 upregulated and 25 downregulated) compared with the Tibet Han population. Two significantly altered miRNAs with the highest expression levels (miRNA-144-5p and miR-30b-5p) were selected for real-time PCR analysis, and the results were consistent with those of miRNA sequencing. Furthermore, bioinformatic analyses showed that some potential target genes of miR-144-5p and miR-30b-5p are involved in the erythroid- hypoxia-, and nitric oxide (NO)-related signaling pathways in response to hypoxia. Conclusion: Our findings provide clear evidence, for the first time, that a high-altitude hypoxic environment significantly affects human RBC miRNA profiles.

18.
J Biomed Res ; 32(3): 198-207, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29921747

RESUMO

In the current study, we sought to evaluate the diagnostic efficacies of conventional ultrasound (US), contrast-enhanced US (CEUS), combined US and CEUS and magnetic resonance imaging (MRI) in detecting focal solid breast lesions. Totally 117 patients with 120 BI-RADS category 4A-5 breast lesions were evaluated by conventional US and CEUS, and MRI, respectively. SonoVue was used as contrast agent in CEUS and injected as an intravenous bolus; nodule scan was performed 4 minutes after bolus injection. A specific sonographic quantification software was used to obtain color-coded maps of perfusion parameters for the investigated lesion, namely the time-intensity curve. The pattern of contrast enhancement and related indexes regarding the time-intensity curve were used to describe the lesions, comparatively with pathological results. Histopathologic examination revealed 46 benign and 74 malignant lesions. Sensitivity, specificity, and accuracy of US in detecting malignant breast lesions were 90.14%, 95.92%, and 92.52%, respectively. Meanwhile, CE-MRI showed sensitivity, specificity, and accuracy of 88.73%, 95.92%, and 91.67%, respectively. The area under the ROC curve for combined US and CEUS in discriminating benign from malignant breast lesions was 0.936, while that of MRI was 0.923, with no significant difference between them, as well as among groups. The time-intensity curve of malignant hypervascular fibroadenoma and papillary lesions mostly showed a fast-in/fast-out pattern, with no good correlation between them (kappa < 0.20). In conclusion, the combined use of conventional US and CEUS displays good agreement with MRI in differentiating benign from malignant breast lesions.

19.
Front Plant Sci ; 9: 755, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29922323

RESUMO

The frequency and intensity of water deficits is expected to increase because of global warming. Drought stress is often one of the most limiting factors for plant growth. We conducted greenhouse pot experiments to address how dopamine affects the drought-resistance traits of apple trees at the physiological and molecular levels. Our factorial design consisted of dopamine and no-dopamine applications combined with well-watered and moderate-drought conditions. Seedling biomass, photosynthesis rates, chlorophyll concentrations, and stomatal apertures were markedly reduced under stress but dopamine treatment mitigated the inhibiting effects of drought on plant growth and helped maintain strong photosynthesis, chlorophyll levels, and stomatal functioning. Concentrations of most macro-, micro-, and trace elements decreased in response to drought. This stress also diminished the uptake and transport of elements in the leaves and stems, but increased the partitioning of elements in the roots. Nutrient resorption proficiency decreased while nutrient resorption efficiency increased for most analyzed elements. Exogenous dopamine significantly increased the concentrations, uptake, and transport of nutrients under drought stress, and also altered their distribution within the whole plant. However, this molecule had a negative effect on nutrient resorption. Although transcript levels of a key chlorophyll degradation gene, pheide a oxygenase, and senescence-associate gene 12 were elevated upon drought treatment, dopamine significantly suppressed the upregulation of those genes under such stress conditions. These observations indicate that dopamine has an important anti-senescence effect that might be helpful for regulating nutrient uptake, transport, and resorption, and ultimately influencing overall plant growth. Thus, understanding the role of dopamine in drought tolerance introduces new possibilities to use this compound for agricultural purposes.

20.
Int J Parasitol Drugs Drug Resist ; 8(2): 320-328, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29793059

RESUMO

Multidrug-resistant Plasmodium falciparum in the Greater Mekong Subregion of Southeast Asia is a major threat to malaria elimination and requires close surveillance. In this study, we collected 107 longitudinal clinical samples of P. falciparum in 2007-2012 from the malaria hypoendemic region of the China-Myanmar border and measured their in vitro susceptibilities to 10 antimalarial drugs. Overall, parasites had significantly different IC50 values to all the drugs tested as compared to the reference 3D7 strain. Parasites were also genotyped in seven genes that were associated with drug resistance including pfcrt, pfmdr1, pfmrp1, pfdhfr, pfdhps, pfnhe1, and PfK13 genes. Despite withdrawal of chloroquine and antifolates from treating P. falciparum, parasites remained highly resistant to these drugs and mutations in pfcrt, pfdhfr, and pfdhps genes were highly prevalent and almost reached fixation in the study parasite population. Except for pyronaridine, quinine and lumefantrine, all other tested drugs exhibited significant temporal variations at least between some years, but only chloroquine and piperaquine had a clear temporal trend of continuous increase of IC50s. For the pfmrp1 gene, several mutations were associated with altered sensitivity to a number of drugs tested including chloroquine, piperaquine, lumefantrine and dihydroartemisinin. The association of PfK13 mutations with resistance to multiple drugs suggests potential evolution of PfK13 mutations amid multidrug resistance genetic background. Furthermore, network analysis of drug resistance genes indicated that certain haplotypes associated multidrug resistance persisted in these years, albeit there were year-to-year fluctuations of the predominant haplotypes.


Assuntos
Antimaláricos/farmacologia , Resistência a Múltiplos Medicamentos , Malária Falciparum/epidemiologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Artemisininas/farmacologia , China/epidemiologia , Cloroquina/farmacologia , Monitoramento Epidemiológico , Genótipo , Humanos , Técnicas In Vitro , Concentração Inibidora 50 , Lumefantrina/farmacologia , Malária Falciparum/parasitologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Mutação , Mianmar/epidemiologia , Proteínas de Protozoários/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA