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1.
Plant Physiol ; 189(3): 1482-1500, 2022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35325205

RESUMO

Nucleus-encoded circular RNAs (ncircRNAs) have been widely detected in eukaryotes, and most circRNA identification algorithms are designed to identify them. However, using these algorithms, few mitochondrion-encoded circRNAs (mcircRNAs) have been identified in plants, and the role of plant mcircRNAs has not yet been addressed. Here, we developed a circRNA identification algorithm, mitochondrion-encoded circRNA identifier, based on common features of plant mitochondrial genomes. We identified 7,524, 9,819, 1,699, 1,821, 1,809, and 5,133 mcircRNAs in maize (Zea mays), Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), tomato (Solanum lycopersicum), cucumber (Cucumis sativus), and grape (Vitis vinifera), respectively. These mcircRNAs were experimentally validated. Plant mcircRNAs had distinct characteristics from ncircRNAs, and they were more likely to be derived from RNA degradation but not intron backsplicing. Alternative circularization was prevalent in plant mitochondria, and most parental genomic regions hosted multiple mcircRNA isoforms, which have homogenous 5' termini but heterogeneous 3' ends. By analysis of mitopolysome and mitoribosome profiling data, 1,463 mcircRNAs bound to ribosomes were detected in maize and Arabidopsis. Further analysis of mass spectrometry-based proteomics data identified 358 mcircRNA-derived polypeptides. Overall, we developed a computational pipeline that efficiently identifies plant mcircRNAs, and we demonstrated mcircRNAs are widespread and translated in plants.


Assuntos
Arabidopsis , Oryza , Solanum lycopersicum , Vitis , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Oryza/genética , Plantas/metabolismo , RNA Circular/genética , RNA de Plantas/genética , RNA de Plantas/metabolismo , Vitis/genética , Zea mays/genética , Zea mays/metabolismo
2.
Biochem J ; 478(4): 721-734, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33410908

RESUMO

Osteoporosis is a prevalent systemic skeletal disorder entailing bone fragility and increased fracture risk, often emerging in post-menopausal life. Emerging evidence implicates the dysregulation of microRNAs (miRNAs or miRs) in the progression of osteoporosis. This study investigated the effect of miR-199a-3p on osteoporosis and its underlying mechanism. We first examplished an ovariectomized (OVX)-induced rat osteoporosis model, and then isolated mesenchymal stem cells (MSCs) from bone marrow of the model rats. The overexpression and knock down of miR-199a-3p were conducted in OVX rats and MSCs to verify the role of miR-199a-3p on MSC differentiation. Calcium nodules were measured using alizarin red S (ARS) staining. RT-qPCR and Western blot assay were performed to measure the expression of miR-199a-3p, Kdm3a and osteogenic differentiation-related markers in rat tissues and cells. The correlation between miR-199a-3p and Kdm3a was confirmed using dual-luciferase reporter assay. The enrichment of Kdm3a at the Erk2 and Klf2 promoter was assessed using chromatin immunoprecipitation (ChIP) assay. Isolated MSCs were positive for CD29, CD44, CD90, and CD45, suggesting successful isolation of MSCs. There was increased expression of miR-199a-3p and inhibited osteogenic differentiation in OVX rats. Kdm3a was negatively targeted by miR-199a-3p. Our results also demonstrated that Kdm3a elevated the expression of Erk2 and Erk2 by promoting Erk2 and Klf2 demethylation, which further contributed to osteogenic differentiation. Overall, our results revealed a regulatory network of miR-199a-3p in osteogenic differentiation, highlighting miR-199a-3p as a potential target for therapeutic interventions in osteoporosis.


Assuntos
Histona Desmetilases/genética , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , Osteogênese/genética , Osteoporose/genética , Animais , Antígenos CD/biossíntese , Azepinas/farmacologia , Azepinas/uso terapêutico , Osso e Ossos/patologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Redes Reguladoras de Genes , Genes Reporter , Histona Desmetilases/antagonistas & inibidores , Histona Desmetilases/biossíntese , Humanos , Fatores de Transcrição Kruppel-Like/biossíntese , Fatores de Transcrição Kruppel-Like/genética , MicroRNAs/biossíntese , Proteína Quinase 1 Ativada por Mitógeno/biossíntese , Proteína Quinase 1 Ativada por Mitógeno/genética , Osteoporose/metabolismo , Osteoporose/patologia , Osteoporose Pós-Menopausa/genética , Ovariectomia , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Ratos , Ratos Sprague-Dawley
3.
Cardiology ; 146(6): 678-689, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34348269

RESUMO

BACKGROUND: Percutaneous coronary intervention (PCI) has been an effective treatment for acute coronary syndrome (ACS) patients. Acute kidney injury (AKI) is one of the common complications after PCI, which seriously affects the living quality and survival time of patients. The approach followed for the patient with AKI after PCI depends on the clinical context and may vary by resource availability. SUMMARY: This review focuses on the pathophysiologies, influencing factors, and preventive measures of AKI in patients with ACS after PCI. The knowledge may better serve the patients and improve their outcomes. Key Messages: Many studies have been carried out for the definition and standard of AKI in the past few years. Etiologies of AKI after PCI included renal damage of contrast medium and atherosclerotic embolism, cardiac insufficiency and surgical factors on renal function. Basic conditions, treatment modalities, and perioperative changes are major risk factors of AKI. Studies have reported that the prevention of contrast-induced nephropathy, modulating the volume overload, some pharmaceuticals and blood purification treatment are helpful to prevent the occurrence of AKI.


Assuntos
Síndrome Coronariana Aguda , Injúria Renal Aguda , Intervenção Coronária Percutânea , Síndrome Coronariana Aguda/terapia , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/prevenção & controle , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Fatores de Risco
4.
Plant J ; 79(5): 797-809, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24923534

RESUMO

RNA editing modifies cytidines (C) to uridines (U) at specific sites in the transcripts of mitochondria and plastids, altering the amino acid specified by the DNA sequence. Here we report the identification of a critical editing factor of mitochondrial nad7 transcript via molecular characterization of a small kernel 1 (smk1) mutant in Zea mays (maize). Mutations in Smk1 arrest both the embryo and endosperm development. Cloning of Smk1 indicates that it encodes an E-subclass pentatricopeptide repeat (PPR) protein that is targeted to mitochondria. Loss of SMK1 function abolishes the C â†’ U editing at the nad7-836 site, leading to the retention of a proline codon that is edited to encode leucine in the wild type. The smk1 mutant showed dramatically reduced complex-I assembly and NADH dehydrogenase activity, and abnormal biogenesis of the mitochondria. Analysis of the ortholog in Oryza sativa (rice) reveals that rice SMK1 has a conserved function in C â†’ U editing of the mitochondrial nad7-836 site. T-DNA knock-out mutants showed abnormal embryo and endosperm development, resulting in embryo or seedling lethality. The leucine at NAD7-279 is highly conserved from bacteria to flowering plants, and analysis of genome sequences from many plants revealed a molecular coevolution between the requirement for C â†’ U editing at this site and the existence of an SMK1 homolog. These results demonstrate that Smk1 encodes a PPR-E protein that is required for nad7-836 editing, and this editing is critical to NAD7 function in complex-I assembly in mitochondria, and hence to embryo and endosperm development in maize and rice.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/genética , Proteínas de Plantas/genética , Edição de RNA , Zea mays/genética , Sequência de Aminoácidos , Evolução Biológica , Respiração Celular , DNA de Plantas/química , DNA de Plantas/genética , Endosperma/genética , Endosperma/crescimento & desenvolvimento , Endosperma/ultraestrutura , Mitocôndrias/genética , Mitocôndrias/ultraestrutura , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Dados de Sequência Molecular , Mutagênese Insercional , Oryza/crescimento & desenvolvimento , Oryza/ultraestrutura , Fenótipo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , RNA de Plantas/genética , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/ultraestrutura , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/ultraestrutura , Alinhamento de Sequência , Análise de Sequência de DNA , Zea mays/crescimento & desenvolvimento , Zea mays/ultraestrutura
5.
J Clin Microbiol ; 53(4): 1371-4, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25631792

RESUMO

We developed a new Boson chemiluminescence immunoassay (CIA) and evaluated its application with cross-sectional analyses. Our results indicated that the Boson CIA demonstrated strong discriminatory power in diagnosing syphilis and that it can be used as a first-line screening test for syphilis serodiagnosis using the European Centre for Disease Prevention and Control algorithm or as a confirmatory test when combined with a patient's clinical history.


Assuntos
Algoritmos , Medições Luminescentes/métodos , Sífilis/diagnóstico , China/epidemiologia , Humanos , Sensibilidade e Especificidade , Sífilis/epidemiologia
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 17(7): 721-5, 2015 Jul.
Artigo em Zh | MEDLINE | ID: mdl-26182279

RESUMO

OBJECTIVE: To investigate the risk factors for attention deficit hyperactivity disorder (ADHD) and to provide a basis for future prevention and treatment of this disease. METHODS: Following a systematic search for case-control studies on the risk factors for ADHD in China between 2000 and 2014, relevant family risk factors were extracted accordingly. The quality of selected studies was evaluated according to the NOS scale. A Meta analysis on the selected studies was conducted using Stata 12.0 software. RESULTS: A total of 16 studies were selected, involving 2 167 children with ADHD and 2 148 normal controls. Results of Meta analysis showed that good parenting (OR=0.32, 95% CI: 0.26-0.40), nuclear family (OR=0.56, 95% CI: 0.41-0.76), high education level of father (OR=0.56, 95% CI: 0.41-0.76), high education level of mother (OR=0.65, 95% CI: 0.47-0.89), and extroversion of mother (OR=0.33, 95% CI: 0.18-0.61) are favorable factors for ADHD. Poor parental relationship (OR=1.90, 95% CI: 1.17-3.06) and family history of ADHD (OR=5.86, 95% CI: 3.67-9.35) are risk factors for ADHD. CONCLUSIONS: Good parenting, nuclear family, high education level of parents, and mother with extroversion are protective factors for ADHD, whereas poor parental relationship and family history of ADHD are associated with an increased risk for ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/etiologia , Transtorno do Deficit de Atenção com Hiperatividade/genética , Família , Humanos , Fatores de Risco
7.
Zhongguo Dang Dai Er Ke Za Zhi ; 17(9): 980-3, 2015 Sep.
Artigo em Zh | MEDLINE | ID: mdl-26412183

RESUMO

OBJECTIVE: To study the possible relationship between serum zinc levels and attention deficit hyperactivity disorder (ADHD) in Chinese children. METHODS: Following a systematic search for case-control studies on the serum zinc levels in Chinese children with ADHD published between 2000 and 2015, a Meta analysis was conducted using Stata 12.0 software. RESULTS: A total of 17 studies, including 2 177 children with ADHD and 2 900 normal children, were enrolled. The Meta analysis showed that serum zinc levels in children with ADHD were lower than normal children (SMD= -1.33; 95%CI: -2.22, -0.44; P=0.003). The sensitivity analysis indicated that the results were reliable. Eggerγs test did not find the existence of publication bias. CONCLUSIONS: Serum zinc levels may be associated with susceptibility to ADHD in children.


Assuntos
Zinco/sangue , Transtorno do Deficit de Atenção com Hiperatividade/sangue , Estudos de Casos e Controles , Criança , Humanos
8.
Clin Infect Dis ; 58(8): 1116-24, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24550376

RESUMO

BACKGROUND: Algorithms for the diagnosis of syphilis continue to be a source of great controversy, and numerous test interpretations have perplexed many clinicians. METHODS: We conducted a cross-sectional study of 24 124 subjects to analyze 3 syphilis testing algorithms: traditional algorithm, reverse algorithm, and the European Centre for Disease Prevention and Control (ECDC) algorithm. Every serum sample was simultaneously evaluated using the rapid plasma reagin, Treponema pallidum particle agglutination, and chemiluminescence immunoassay tests. With the results of clinical diagnoses of syphilis as a gold standard, we evaluated the diagnostic accuracy of the 3 syphilis testing algorithms. The κ coefficient was used to compare the concordance between the reverse algorithm and the ECDC algorithm. RESULTS: Overall, 2749 patients in our cohort were diagnosed with syphilis. The traditional algorithm had the highest negative likelihood ratio (0.24), a missed diagnosis rate of 24.2%, and only 75.81% sensitivity. However, both the reverse and ECDC algorithms had higher diagnostic efficacy than the traditional algorithm. Their sensitivity, specificity, and accuracy were 99.38%-99.85%, 99.98%-100.00%, and 99.93%-99.96%, respectively. Moreover, the overall percentage of agreement and κ value between the reverse and the ECDC algorithms were 99.9% and 0.996, respectively. CONCLUSIONS: Our research supported use of the ECDC algorithm, in which syphilis screening begins with a treponemal immunoassay that is followed by a second, different treponemal assay as a confirmatory test in high-prevalence populations. In addition, our results indicated that nontreponemal assay is unnecessary for syphilis diagnosis but can be recommended for determining serological activity and the effect of syphilis treatment.


Assuntos
Sorodiagnóstico da Sífilis/métodos , Treponema pallidum/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Soro/imunologia , Adulto Jovem
9.
Clin Infect Dis ; 59(3): 384-9, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24803377

RESUMO

BACKGROUND: The prozone phenomenon is known to be associated with high antibody titers; other associations, such as host factors, have not been elucidated. METHODS: A retrospective analysis was conducted to evaluate the incidence of the prozone phenomenon of the syphilis rapid plasma reagin (RPR) test among 46 856 clinical samples, between June 2010 and June 2013. Logistic regression was used to analyze the risk factors of the prozone phenomenon. RESULTS: Our results showed that the incidence of the prozone phenomenon was low (0.83%) and could occur during any clinical phase, particularly during primary and secondary syphilis. Pregnancy and neurosyphilis were associated with the prozone phenomenon; sex, age, and whether the patient had been treated were not. The results also revealed that the prozone phenomenon not only occurred in patients with a high titer but also could occur in patients with a moderate/low titer. In fact, almost 31% of the patients with the prozone phenomenon had titers ≤1:16. CONCLUSIONS: The prozone phenomenon in the RPR test was associated with the phase of syphilis, pregnancy, and neurosyphilis as well as a range of RPR titers between 1:8 and 1:512. This latter finding is in contrast to previous reports that the prozone phenomenon is associated with very high RPR titers.


Assuntos
Reaginas/sangue , Sífilis/diagnóstico , Adolescente , Adulto , Idoso , Testes de Aglutinação , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Gravidez , Estudos Retrospectivos , Fatores de Risco , Sorodiagnóstico da Sífilis , Adulto Jovem
10.
Int J Biometeorol ; 57(1): 67-73, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22392839

RESUMO

Surface albedo greatly affects the radiation energy balance of croplands and is a significant factor in crop growth monitoring and yield estimation. Precise determination of surface albedo is thus important. This study aimed to examine the influence of growth stages (tillering, jointing, heading, filling and maturity) on albedo and its diurnal asymmetry by measuring diurnal albedo variations. Results indicated that the daily mean surface albedo generally exhibited an increased tendency during tillering to heading but decreased after heading. Surface albedos were much higher in the morning than the corresponding values of the same solar elevation angles in the afternoon when the solar elevation angle was less than 40°, indicating a diurnal asymmetry in surface albedo. However, less difference was found in surface albedos between forenoon and afternoon when the solar elevation angle was greater than 40°. Dew droplets on the leaf surface in the morning were assumed to be the main factor resulting in the diurnal asymmetry in albedo of spring wheat.


Assuntos
Fenômenos Ópticos , Luz Solar , Triticum , China , Ritmo Circadiano , Clima Desértico , Estações do Ano , Temperatura , Vento
11.
Food Chem ; 401: 134125, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36096004

RESUMO

The influence and its mechanism of ultrasound on acetaldehyde/glyoxylic acid competing bridged the polymerization coloration of flavan-3-ols in model wine solution were investigated by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and kinetics and thermodynamic model. The results indicate that ultrasound could significantly accelerate the polymerization coloration and further modify wine color. In addition, the polymerization reaction conformed first-order reaction model, and the reaction rate constant (k) values were markedly increased by ultrasound, accelerating the coloration reaction, especially in the model wine containing glyoxylic acid. Besides, the polymerization processing was non-spontaneous and endothermic according to the thermodynamic analysis. In conclusion, ultrasound was indeed conducive to accelerate glyoxylic acid/acetaldehyde-bridged the polymerization of flavan-3-ols and further effect the wine color, which could provide a theoretical basis for the scientific analysis of the mechanism of ultrasound modifying wine color.


Assuntos
Vinho , Vinho/análise , Acetaldeído/análise , Glioxilatos/química , Cromatografia Líquida de Alta Pressão , Polifenóis/análise , Polímeros/análise , Flavonoides/análise
12.
J Bone Miner Metab ; 30(6): 666-73, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22743851

RESUMO

In this study we analyzed the independent effect of angiotensin-converting enzyme (ACE) inhibitor use on bone loss in elderly Chinese. The subjects were from two cohort studies which investigated the risk factors of osteoporotic fractures in Hong Kong-dwelling elderly Chinese. A total of 2161 subjects (1280 male, 881 female) were selected for this analysis. The results showed that unadjusted annualized percentage bone loss of male ACE inhibitor users was not different from non-users; however, female ACE inhibitor users had significantly greater bone loss both in total hip and femoral neck than non-users. After adjusting for significant confounders, female continuous ACE inhibitor users had significantly greater bone loss at total hip and femoral neck. In conclusion, continuous use of ACE inhibitors over 4 years was associated with increased bone loss in total hip and femoral neck in older Chinese women.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Doenças Ósseas Metabólicas/induzido quimicamente , Colo do Fêmur/efeitos dos fármacos , Ossos Pélvicos/efeitos dos fármacos , Idoso , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Povo Asiático , Densidade Óssea/efeitos dos fármacos , Estudos de Coortes , Feminino , Humanos , Masculino , Fraturas por Osteoporose/prevenção & controle , Fatores Sexuais
13.
Intern Emerg Med ; 16(8): 2193-2199, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34021853

RESUMO

Dialysis patients with erythropoietin hypo-responsiveness suffered from refractory anemia. Roxadustat reversibly binds and inhibits hypoxia-inducible factor-prolyl hydroxylase (HIF-PHD), resulting in increased endogenous EPO which stimulates erythropoiesis, theoretically has an advantage over exogenous EPO in anti-anemia therapy. From September 2019 to October 2020, 32 dialysis patients with hypo-responsiveness to erythropoietin were evaluated. During the 24-week follow-up period, all patients were taken off erythropoietin and switched to roxadustat. Dosage adjustments were administrated according to the fluctuation of hemoglobin level during the treatment. Parameters about anemia, iron metabolism and biochemical indexes were collected, and adverse events were recorded. A total of 31 patients completed the clinical observation, with varying degrees of malnutrition-inflammation. Post treatment, the levels of transferrin and total iron-binding capacity were increased, while that of transferrin saturation and cholesterol decreased. 15 cases (accounting for 48.39%, designated as fulfilled group) met the target level of hemoglobin, while 16 cases (51.61%, non-fulfilled group) did not. The baseline conditions of the above two groups were compared. The levels of hypersensitive C-reactive protein, interleukin-6 and serum ferritin in the non-fulfilled group were higher than those in the fulfilled group, and the levels of residual renal function, serum albumin, iron, transferrin and total iron-binding capacity were lower than those in the fulfilled group. Linear regression analysis showed that increase of HsCRP had a negative effect on the improvement of Hb. One case of adverse reaction grade 3 and four cases of grade 2 occurred throughout the study, yet all were relieved after therapy. Significant anti-anemia effects could be achieved in most patients with erythropoietin hypo-responsiveness after treatment with roxadustat, accompanied by relatively mild and rare adverse reactions. The malnutrition-inflammation states of patients may interfere with the anti-anemia effect of roxadustat, and iron utilization is more important than iron storage in anemia improvement.


Assuntos
Eritropoetina/metabolismo , Glicina/análogos & derivados , Isoquinolinas/farmacologia , Insuficiência Renal Crônica/tratamento farmacológico , Adulto , Idoso , Diálise/métodos , Diálise/estatística & dados numéricos , Eritropoetina/biossíntese , Feminino , Glicina/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Insuficiência Renal Crônica/fisiopatologia
14.
Int J Clin Exp Pathol ; 14(4): 538-544, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33936379

RESUMO

Osteochondroma is one of the most common benign bone tumors. It usually grows on the metaphysis of long bones and rarely develops in bones of scapula, feet, hands, and pelvis. The management of this disease is en-bloc excision of the tumor. We present a 45-year-old female subject, who complained of having found a mass on the right hip for more than 20 years which was diagnosed to be osteochondroma on X-ray, computed tomography (CT) and 3-dimensional (3-D) reconstruction. We performed en-bloc excision for the patient. Pathologic examination of surgical specimen confirmed the diagnosis of osteochondroma. The patient made a complete recovery and there has been no recurrence after one year of follow-up. Osteochondroma usually represents an osteo-cartilaginous aberrant overgrowth of normal epiphyseal growth plates. The disease has a slow onset and a long history. X-rays and CT scans are sufficient for diagnosis before surgery and the final diagnosis should based on pathology. Differential diagnosis includes chondrosarcoma or other neoplasms. When osteochondroma causes pain, compression of peripheral nerves, or continuous growth and other clinical symptoms, en-bloc excision of the tumor is needed. Better recognition and more comprehensive evaluation of these rare cases should be highlighted to avoid misdiagnosis during our clinical practice.

15.
Sci Total Environ ; 722: 137849, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32179300

RESUMO

Soil nitrogen (N) mineralization is a microbially-mediated biogeochemical process that is strongly influenced by changing climates. However, little information is available on the mechanisms behind the response of N mineralization to prolonged warming coupled with drought in soils covered by biocrusts. We used open top chambers to investigate the rate of soil N transformation (ammonification, nitrification and mineralization), enzyme activity and gene abundance in response to warming coupled with reduced precipitation over three years (2016-2018). Warming and drought significantly reduced the N transformation rate, extracellular enzyme activity, and gene abundance in moss-covered soil. For cyanobacteria-covered soil, however, it inhibited enzyme activity and increased the abundance of the nitrification-related genes and therefore nitrification rate. Our treatments had no obvious effects on N transformation and enzyme activity, but reduced gene abundance in bare soil. Biocrusts may facilitate N transformation while the degradation of moss crust caused by climate warming will dampen any regulating effect of biocrusts on the belowground microbial community. Furthermore, belowground microbial communities can mediate N transformation under ongoing warming and reduced precipitation by suppressing ammonification- and nitrification-related gene families, and by stimulating nitrification-related gene families involved in cyanobacteria-covered soil. This study provides a basis for identifying the functional genes involved in key processes in the N cycle in temperate desert ecosystems, and our results further highlight the importance of different biocrusts organisms in the N cycle in temperate deserts as Earth becomes hotter and drier.


Assuntos
Microbiologia do Solo , Solo , Ecossistema , Genes Microbianos , Nitrogênio
16.
J Magn Reson Imaging ; 30(5): 1139-44, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19780185

RESUMO

PURPOSE: To investigate the differences in proximal femoral bone marrow blood perfusion indices between hypertensive and normotensive rats using perfusion magnetic resonance imaging (MRI). MATERIALS AND METHODS: Six-month-old male spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were used (12 of each). Dynamic contrast-enhanced MRI of the right hip was performed after bolus injection of Gd-DOTA administered through a tail vein cannula. In all, 800 images were acquired at 0.6 sec/image. Regions of interest (ROIs) were drawn comprising the medullary component of proximal femoral shaft and femoral head. MRI maximum enhancement (E(max)) and enhancement slope (E(slope)) were analyzed. RESULTS: The E(max) and E(slope) of proximal femoral shaft and femoral head of SHR were significantly lower than those of WKY (E(max): 107.4 +/- 18.2% vs. 130.6 +/- 21.5%, P = 0.009, and 76.0 +/- 12.5% vs. 97.9 +/- 6.9%, P < 0.001, respectively; E(slope): 3.01 +/- 0.63%/sec vs. 3.75 +/- 0.74%/sec, P = 0.016, and 1.95 +/- 0.33%/sec vs. 2.28 +/- 0.28%/sec, P = 0.012, respectively). The E(max) and E(slope) of femoral head were significantly lower than those of proximal femoral shaft in both SHR and WKY (P < 0.001). In both SHR and WKY, proximal femoral shaft and femoral head had a rather different contrast enhancement pattern. CONCLUSION: Proximal femoral shaft and femoral head bone marrow blood perfusion indices were significantly lower in hypertensive rats than in normotensive rats. Femoral head bone marrow was less perfused than proximal femoral shaft in both rats.


Assuntos
Células da Medula Óssea/citologia , Meios de Contraste/farmacologia , Fêmur/patologia , Hipertensão/patologia , Imageamento por Ressonância Magnética/métodos , Animais , Pressão Sanguínea , Densidade Óssea , Medula Óssea/patologia , Masculino , Perfusão , Pressão , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
17.
Lab Anim ; 43(3): 261-5, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19116290

RESUMO

The technical feasibility of dynamic contrast-enhanced magnetic resonance imaging (MRI) measurement of rat vertebral blood perfusion using a 1.5 T clinical scanner and a small surface coil was investigated in this study. Nine male 7-month-old Wistar-Kyoto rats were used. Computed tomographic assessment of lumbar vertebral bone mineral density (BMD) and MRI assessment of lumbar vertebral blood perfusion were performed twice with 8 weeks' interval. A 4.7 cm surface coil was used for receiving radiofrequency signal. Gadolinium-DOTA (0.3 mmol/kg) was injected through the tail vein of the rat as a quick bolus and dynamic MRI scan was carried out on the central sagittal plane of the lumbar spine for 8 min with a temporal resolution of 0.6 s. Blood perfusion parameters of wash-in rate, maximum enhancement and wash-out rate were derived from the dynamic MR images. No vertebral body size and vertebral BMD difference was detected between the two time points (P=0.222 and 0.123, respectively). Wash-in rate was 0.105 (+/-0.016)% and 0.111 (+/-0.018)%, maximum enhancement 126.5 (+/-10.6)% and 129.2 (+/-13.4)%, and wash-out rate 0.788 (+/-0.182)% and 0.792 (+/-0.182)% for the two time points. With these parameters, no difference was found between the two time points with a P value of 0.575, 0.889 and 0.754, respectively. We conclude that dynamic contrast-enhanced MRI measurement of rat vertebral blood perfusion using a 1.5 T clinical scanner and a small surface coil is feasible and reliable. This technique offers a non-invasive means to probe vertebral blood perfusion changes associated with rat disease models.


Assuntos
Vértebras Lombares/irrigação sanguínea , Angiografia por Ressonância Magnética/veterinária , Animais , Densidade Óssea/fisiologia , Compostos Heterocíclicos , Aumento da Imagem/métodos , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/metabolismo , Angiografia por Ressonância Magnética/métodos , Masculino , Compostos Organometálicos , Ratos , Ratos Endogâmicos WKY , Fluxo Sanguíneo Regional/fisiologia , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/veterinária
18.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 26(2): 183-6, 2009 Apr.
Artigo em Zh | MEDLINE | ID: mdl-19350512

RESUMO

OBJECTIVE: To determine the gene mutation spectrum of patients with 6-pyruvoyltetrahydrobiopterin synthesis deficiency (PTPSD) in Mainland China. METHODS: The 6-pyruvoyltetrahydrobiopterin synthesis gene lz(PTS)lz was analyzed in 55 PTPSD patients by using PCR-restriction fragment length polymorphism (PCR-RFLP) and direct DNA sequencing. The relationship between the genotype and phenotype was analyzed. RESULTS: Eighteen mutations were identified and the detection rate of gene mutation was 95.28%. Four hot-spot mutations, namely P87S (40.57%), N52S(13.21%), D96N(12.26%) and IVS1nt-291A to G(10.38%) were found in this study, and the first three were associated with severe phenotype. The P87L was reported firstly in Chinese patients, and the Q13X, M80T, IVS4nt-2A to G, L93M and K131N were novel mutations. CONCLUSION: The P87S, N52S, D96N and IVS1nt-291A to G mutations are the hot-spots mutations of the PTS gene in Chinese PTPSD patients. Using PCR-RFLP technique to screen the mutations in the PTS gene can increase the efficiency of gene diagnosis.


Assuntos
Doenças Metabólicas/genética , Fenilalanina Hidroxilase/genética , Pterinas/metabolismo , Esteroide 21-Hidroxilase/genética , Adulto , Povo Asiático/genética , Sequência de Bases , China , Análise Mutacional de DNA , Feminino , Genótipo , Humanos , Masculino , Mutação , Linhagem , Fenilalanina Hidroxilase/metabolismo , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Gravidez , Esteroide 21-Hidroxilase/metabolismo
19.
Sci Total Environ ; 692: 631-639, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539971

RESUMO

Isotopic composition of gross rainfall has been extensively used as a conservative tracer to track water movement and other hydrological processes in vegetated ecosystems. Recent studies from forest ecosystems, however, demonstrated that vegetation canopies can alter the isotopic composition of rainwater during rainfall partitioning into throughfall and stemflow, likely leading to errors and biases in aforementioned studies. No known studies, to date, had investigated this topic in shrub-dominated arid and semi-arid ecosystems where water is typically the driving factor in ecological, hydrological and biogeochemical processes. In this study, event-based gross rainfall, the throughfall and stemflow induced by shrubs of Caragana korshinskii were measured and samples were collected within a water-limited arid desert ecosystem of northern China, and their water stable isotopes (18O and 2H) were also analyzed in the laboratory. We mainly aimed to investigate whether there is an isotopic enrichment or depletion in stemflow and throughfall in comparison to gross rainfall, and to evaluate the possible underlying mechanisms. Our results indicated an enrichment of both isotopes in stemflow, while a general more depletion in throughfall than in gross rainfall, which is presumably affected by a combinative effects of canopy evaporation, isotopic exchange, and selective canopy storage. Deuterium excess of stemflow were found to be significantly higher (P < 0.05) than that of gross rainfall and throughfall. Moreover, we detected the pronounced "amount effect", with a significant (P < 0.05) negative relationship between isotopic composition and the amount of gross rainfall, throughfall, and stemflow, respectively. Our study is expected to contribute to an improved understanding of physical processes and water routing in shrub canopies within vast arid desert ecosystems.


Assuntos
Caragana/metabolismo , Deutério/análise , Isótopos de Oxigênio/análise , Chuva/química , Movimentos da Água , Água/metabolismo , China , Hidrologia , Água/química
20.
Chin J Traumatol ; 11(1): 62-4, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18230296

RESUMO

Total knee arthroplasty (TKA) is now a standard treatment for serious osteoarthritis all over the world. Although it is a standard treatment, it has many complications, among which deep vein thrombosis (DVT) is the exclusive blood vessel complication that has been reported. However, we found a new blood vessel complication of TKA in this study, which is spontaneous arteriorrhexis in the affected lower limb.


Assuntos
Artroplastia do Joelho , Perna (Membro)/irrigação sanguínea , Músculo Esquelético/irrigação sanguínea , Doenças Vasculares Periféricas/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Ruptura Espontânea
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