Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Chem Inf Model ; 64(8): 3400-3410, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38537611

RESUMO

Lactobacillus kefir alcohol dehydrogenase (LkADH) and ketoreductase from Chryseobacterium sp. CA49 (ChKRED12) exhibit different chemoselectivity and stereoselectivity toward a substrate with both keto and aldehyde carbonyl groups. LkADH selectively reduces the keto carbonyl group while retaining the aldehyde carbonyl group, producing optically pure R-alcohols. In contrast, ChKRED12 selectively reduces the aldehyde group and exhibits low reactivity toward ketone carbonyls. This study investigated the structural basis for these differences and the role of specific residues in the active site. Molecular dynamics (MD) simulations and quantum chemical calculations were used to investigate the interactions between the substrate and the enzymes and the essential cause of this phenomenon. The present study has revealed that LkADH and ChKRED12 exhibit significant differences in the structure of their respective active pockets, which is a crucial determinant of their distinct chemoselectivity toward the same substrate. Moreover, residues N89, N113, and E144 within LkADH as well as Q151 and D190 within ChKRED12 have been identified as key contributors to substrate stabilization within the active pocket through electrostatic interactions and van der Waals forces, followed by hydride transfer utilizing the coenzyme NADPH. Furthermore, the enantioselectivity mechanism of LkADH has been elucidated using quantum chemical methods. Overall, these findings not only provide fundamental insights into the underlying reasons for the observed differences in selectivity but also offer a detailed mechanistic understanding of the catalytic reaction.


Assuntos
Aldeídos , Cetonas , Simulação de Dinâmica Molecular , Cetonas/química , Cetonas/metabolismo , Aldeídos/química , Aldeídos/metabolismo , Especificidade por Substrato , Teoria Quântica , Lactobacillus/enzimologia , Lactobacillus/metabolismo , Domínio Catalítico , Álcool Desidrogenase/metabolismo , Álcool Desidrogenase/química
2.
Plant Physiol Biochem ; 190: 11-23, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36087542

RESUMO

Underground infection of Fusarium oxysporum resulted in great yield losses in chrysanthemum (Chrysanthemum morifolium Ramat.) industry. However, the effect of F. oxysporum root disease on the terpenes production in above- and below-ground parts of plant is completely unexplored. The aim of this study was to investigate the systematic impact of Fusarium infection underground on the terpene production in aboveground parts of chrysanthemum. Terpene production in above- and below-ground parts was profiled in a time series of post-inoculation by GC-MS. Total terpenes were significantly induced from roots and leaves of Fusarium-infected versus healthy plants. These terpenes included monoterpenes, sesquiterpenes and diterpenes, in which sesquiterpenes were primarily induced in roots and leaves, while monoterpenes were produced only in leaves. Through transcriptome analysis, 8 differentially expressed terpene synthase genes (TPSs) were screened out. The relative expression levels of 8 TPS genes at different developmental stage and tissues indicated the spatial delay of the TPS genes in leaves. The induced terpenes from roots and leaves showed consistency with the expression pattern of TPS genes. The biochemical function of Cm-j-TPS1/2/7 were verified by enzymatic assay. Additionally, it's found that the content of salicylic acid (SA) in root and leaf significantly increased by F. oxysporum infection, suggesting a role of the SA signaling pathway in defense. Together, these results reveal the defense response of above- and below-ground parts of plants to root fungal attack and provide a theoretical basis for the effective prediction and control of F. oxysporum infection in chrysanthemum.


Assuntos
Chrysanthemum , Fusariose , Fusarium , Sesquiterpenos , Chrysanthemum/metabolismo , Fusarium/metabolismo , Monoterpenos , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo , Terpenos
3.
Chemosphere ; 303(Pt 2): 134663, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35447204

RESUMO

Low molybdenum (Mo) bioavailability in acidic soil obstructs vegetable nitrogen assimilation and thus increases the health risk of vegetable ingestion due to nitrate accumulation. Constantly providing available Mo in acidic soil is a challenge for decreasing nitrate accumulation in vegetables. In this study, three Mo application methods, including biochar-based Mo slow-release fertilizer (Mo-biochar), seed dressing, and basal application, were investigated to enhance Mo bioavailability in acidic soil and nitrogen assimilation in Chinese flowering cabbage (Brassica parachinensis). The results showed that Mo-biochar constantly and sufficiently supplied Mo nutrients throughout the growing period of Brassica parachinensis, as evidenced by the soil available Mo, plant Mo uptake, and Mo values. The improved Mo supply was attributed to the alleviation of acidic soil (pH from 5.10 to 6.99) and the slow release of Mo adsorbed on biochar. Mo-biochar increased the nitrate reductase (NR) activity by 238.6% and glutamate dehydrogenase activity by 27.5%, indicating an enhancement of the rate-limiting steps of nitrogen assimilation, especially for nitrate reduction and amino acid synthesis. The increase in Mo-containing NR could be directly ascribed to the high level of Mo in Brassica parachinensis. Compared with the control, the nitrate content of Brassica parachinensis decreased by 42.9% due to the nitrate reduction induced by increased NR. Additionally, Mo-biochar was beneficial to vegetable growth and quality. In contrast, the transformation from NO3- to NH4+ was blocked with Mo seed dressing and basal application because of low Mo bioavailability in the soil, resulting in a high nitrate content in Brassica parachinensis. Conclusively, Mo-biochar can slowly release Mo and improve the neutral environment for Mo bioavailability, which is an effective strategy to mitigate the high nitrate accumulation of vegetables planted in acidic soil.


Assuntos
Brassica , Fertilizantes , Brassica/metabolismo , Carvão Vegetal , China , Fertilizantes/análise , Molibdênio/farmacologia , Nitratos/metabolismo , Nitrogênio/análise , Solo/química
4.
J Sci Food Agric ; 101(13): 5583-5590, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33709452

RESUMO

BACKGROUND: Most countries set regulatory values for the total trace element (TE) concentrations in soil, although there is growing interest in using a risk-based approach to evaluate the bioavailable TE using dilute salt extractants or other soil parameters, including pH and organic carbon. The present study compares the current regulatory system (based on total TEs and pH) and a risk-based approach using 0.01 mol L-1 CaCl2 to estimate the bioavailable fraction. RESULTS: In total, 150 paired samples of Chinese flowering cabbages (Brassica parachinensis) and their growth soils were collected, and the total and extractable concentrations of chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As) and mercury (Hg), as well as soil pH and organic matter content, were measured. No more than 3.33% of the edible parts exceeded Chinese food safety standards, even when growing in soils exceeding the current regulatory thresholds by over 50%. The total soil Cd (1.5 mg kg-1 ), as well as the extractable concentrations of Cd (0.1 mg kg-1 ), Ni (0.03 mg kg-1 ) and Zn (0.1 mg kg-1 ), are the key factors affecting the TE concentrations in B. parachinensis. CONCLUSION: Our findings suggest that the current soil regulatory guidelines for safe production of B. parachinensis are overly strict and conservative. A risk-based approach based on the extractable TE concentrations would provide a better indication for plant uptake of soil TEs and avoid the waste of farmlands that can still produce safe vegetables. Future research should focus on providing crop-specific available TE concentration guidelines to promote effective utilization of farmlands. © 2021 Society of Chemical Industry.


Assuntos
Brassica/química , Oligoelementos/análise , Arsênio/análise , Brassica/classificação , Brassica/crescimento & desenvolvimento , Cádmio/análise , China , Cromo/análise , Cobre/análise , Inocuidade dos Alimentos , Mercúrio/análise , Metais Pesados/análise , Níquel/análise , Solo/química , Poluentes do Solo/análise , Verduras/química , Verduras/classificação , Verduras/crescimento & desenvolvimento , Zinco/análise
5.
Metallomics ; 13(4)2021 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-33765153

RESUMO

Hyperaccumulators have exceptional phloem translocation capability for heavy metals. This study aims at quantifying the mobility and accumulation of Ni and Co via the phloem in the model hyperaccumulator Noccaea caerulescens. "Phloem loading capability (PLC)," which is calculated by the "Metal content in phloem sap/Metal content in leaves," was introduced to evaluate the metal phloem mobility, while "Phloem mobility value (PMV)" was used for the normalization of PLC, which sets the PLC of Sr as PMV 0 and that of Rb as 100. The results showed that the PMVs of Ni and Co were 63 and 47, respectively. And the phloem mobility of Rb, Ni, Co, and Sr could be graded as highly mobile, mobile, intermediate, and immobile accordingly. The phloem stream can supply up to 19.1% and 16.0% of the total Ni and Co accumulated in the young leaves, respectively, while for Rb and Sr, the phloem contributes to 29% and 1.4% of the total Rb or Sr, indicating phloem contribution of certain metal is directly linked with its mobility. The results of this study raise the importance of phloem translocation on metal accumulation in shoots and provide insights on the metal cycling process in hyperaccumulators.


Assuntos
Brassicaceae/metabolismo , Cobalto/metabolismo , Níquel/metabolismo , Floema/metabolismo , Raízes de Plantas/metabolismo , Brassicaceae/crescimento & desenvolvimento , Cobalto/análise , Níquel/análise , Raízes de Plantas/crescimento & desenvolvimento
6.
Biol Trace Elem Res ; 199(10): 3987-3997, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33405084

RESUMO

This investigation was aimed at determining the concentration levels of five toxic heavy metals (lead, cadmium, chromium, arsenic, and mercury) in dried Porphyra and Laminaria samples from coastal city of China. Inductively coupled plasma-mass spectrometry (ICP-MS) was used for determination of lead, cadmium and total arsenic. Atomic fluorescence spectrometry was used for mercury, and liquid chromatography coupled with ICP-MS was used for arsenic speciation. The mean concentrations of lead, cadmium, chromium, total arsenic, and mercury were 0.96 ± 0.03 mg/kg, 2.62 ± 0.07 mg/kg, 1.64 ± 0.08 mg/kg, 36.67 ± 0.53 mg/kg, and 7.56 ± 0.42 µg/kg for Porphyra samples and 0.61 ± 0.03 mg/kg, 0.48 ± 0.02 mg/kg, 3.78 ± 0.56 mg/kg, 43.85 ± 1.42 mg/kg, and 46.61 ± 2.02 µg/kg for Laminaria samples. The results were comparable with previous similar research. The potential health risk assessment was conducted by comparing the calculated weekly intakes of toxic metals from Porphyra and Laminaria with provisional tolerable weekly intake. Consumption of these seaweeds does not seem to pose a risk for the consumers' health regarding their content of heavy metals. However, the potential health risk of cadmium should not be overlooked for consumers with high intake of Porphyra.


Assuntos
Arsênio , Laminaria , Mercúrio , Metais Pesados , Porphyra , Arsênio/análise , Arsênio/toxicidade , Cádmio/análise , China , Cidades , Contaminação de Alimentos/análise , Chumbo/toxicidade , Mercúrio/análise , Metais Pesados/análise , Metais Pesados/toxicidade
7.
Medicine (Baltimore) ; 98(33): e16863, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31415420

RESUMO

Heart rate variability (HRV) is an objective measure of emotional regulation. This study aimed to estimate the accuracy with which an artificial neural network (ANN) algorithm could classify emotions using HRV data that were obtained using wristband heart rate monitors.Four emotions were evoked during gameplay: pleasure, happiness, fear, and anger. Seven normalized HRV features (i.e., 3 time-domain features, 3 frequency-domain features, and heart rate), which yielded 29,727 segments during gameplay, were collected and analyzed first by statistics and then classified by the trained ANN model.General linear model adjusted for individual differences in HRV showed that all HRV features significantly differed across emotions, despite disparities in their magnitudes and associations. When compared to neutral status (i.e., no emotion evoked), the mean of R-R interval was significantly higher for pleasure and fear but lower for happiness and anger. In addition, pleasure evidenced the HRV features that suggested a superior parasympathetic to sympathetic activation. Happiness was associated with a prominent sympathetic activation. These statistical findings suggest that HRV features significantly differ across emotions evoked by gameplay. When further utilizing ANN-based emotion classification, the accuracy rates for prediction were above 75.0% across the 4 emotions with accuracy rates for classification of paired emotions ranging from 82.0% to 93.4%.For classifying emotion in an individual person, the trained ANN model utilizing HRV features yielded a high accuracy rate in our study. ANN is a time-efficient and accurate means to classify emotions using HRV data obtained from wristband heart rate monitors. Thus, this integrated platform can help monitor and quantify human emotions and physiological biometrics.


Assuntos
Ira/fisiologia , Medo/fisiologia , Felicidade , Frequência Cardíaca/fisiologia , Redes Neurais de Computação , Prazer/fisiologia , Adulto , Algoritmos , Humanos , Masculino , Smartphone , Jogos de Vídeo/psicologia , Dispositivos Eletrônicos Vestíveis , Adulto Jovem
8.
Huan Jing Ke Xue ; 39(6): 2680-2687, 2018 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965623

RESUMO

In order to explore the spatial and temporal variations of algal functional groups in the Zipingpu reservoir, a typical channel-type reservoir in the southwest mountainous area of China, water samples were collected from eight sections of the Zipingpu reservoir from April 2016 to March 2017.A total of 21 algal functional groups were identified as B, C, D, F, G, H1, J, L0, LM, MP, N, P, S2, T, W1, W2, X1, X2, X3, Y, and Z. Based on the analysis of the dominant degree (y > 0.02), the algal functional groups were dominated by W2, Y, L0, W1, MP, and B. The C-R-S strategy of algal growth in the Zipingpu reservoir showed that R-type was a more dominant type than the S- and C-type for the majority of the time. Peridinium (group L0, type S) was the significant algae in the Zipingpu reservoir algal bloom event in June 2016.Redundancy analysis (RDA) was used to explore the relationship between algal functional groups and environmental factors. The results showed that algal density, chlorophyll a, water temperature, and biochemical oxygen demand were the major factors influencing the spatiotemporal succession of algal functional groups across the eight sampling sections, with water temperature having the highest influence.


Assuntos
Clorofila A/análise , Eutrofização , Água Doce/análise , Fitoplâncton/classificação , Análise da Demanda Biológica de Oxigênio , China , Fitoplâncton/crescimento & desenvolvimento , Análise Espaço-Temporal , Temperatura
9.
Ecotoxicol Environ Saf ; 158: 266-273, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-29715631

RESUMO

Organoarsenic arsanilic acid (ASA) contamination of paddy soil is a serious but less concerned hazard to agriculture and health of people consuming rice as staple food, for rice is one major pathway of arsenic (As) exposure to human food. To date little research has studied the effect of ASA on biochemical process of rice. Silicon (Si) application is able to reduce the toxicities of heavy metals in numerous plants, but little information about ASA. This work investigated whether and how Si influenced alleviation of ASA toxicity in rice at biochemical level to have a better understanding of defense mechanism by Si against ASA stress. Results showed that ASA reduced rice growth, disturbed protein metabolism, increased lipid peroxidation but decreased the efficiencies of antioxidant activities compared to control plants, more severe in roots than in shoots. The addition of Si in ASA-stressed rice plants noticeably increased growth and development as well as soluble protein contents, but decreased malondialdehyde (MDA) contents in ASA-stressed rice plants, suggesting that Si did have critical roles in ASA detoxification in rice. Furthermore, increased superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities along with elevated glutathione (GSH) and ascorbic acid (AsA) contents implied the active involvement of ROS scavenging and played, at least in part, to Si-mediated alleviation of ASA toxicity in rice, and these changes were related to rice genotypes and tissues. The study provided physio-chemical mechanistic evidence on the beneficial effect of Si on organoarsenic ASA toxicity in rice seedlings.


Assuntos
Ácido Arsanílico/toxicidade , Oryza/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Plântula/efeitos dos fármacos , Silício/farmacologia , Antioxidantes/farmacologia , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Fenômenos Químicos , Glutationa/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Oryza/metabolismo , Peroxidase , Raízes de Plantas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Plântula/metabolismo , Solo/química , Superóxido Dismutase/metabolismo
10.
Environ Pollut ; 236: 699-705, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29453185

RESUMO

The present study combines high-resolution measurements at various distances from a world-class gigantic petrochemical complex with model simulations to test a method to assess industrial emissions and their effect on local air quality. Due to the complexity in wind conditions which were highly seasonal, the dominant wind flow patterns in the coastal region of interest were classified into three types, namely northeast monsoonal (NEM) flows, southwest monsoonal (SEM) flows and local circulation (LC) based on six years of monitoring data. Sulfur dioxide (SO2) was chosen as an indicative pollutant for prominent industrial emissions. A high-density monitoring network of 12 air-quality stations distributed within a 20-km radius surrounding the petrochemical complex provided hourly measurements of SO2 and wind parameters. The SO2 emissions from major industrial sources registered by the monitoring network were then used to validate model simulations and to illustrate the transport of the SO2 plumes under the three typical wind patterns. It was found that the coupling of observations and modeling was able to successfully explain the transport of the industrial plumes. Although the petrochemical complex was seemingly the only major source to affect local air quality, multiple prominent sources from afar also played a significant role in local air quality. As a result, we found that a more complete and balanced assessment of the local air quality can be achieved only after taking into account the wind characteristics and emission factors of a much larger spatial scale than the initial (20 km by 20 km) study domain.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental , Poluição do Ar/análise , Indústria Química , Indústrias , Dióxido de Enxofre/análise , Vento
11.
J Food Prot ; 77(8): 1424-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25198608

RESUMO

Very few studies have investigated the difference in the distribution of metal elements between rice and rice bran samples. In this study, the concentrations of 27 metal elements (Li, Be, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb, and U) in 56 polished rice and their corresponding bran samples were determined. A significant difference in concentrations of all elements except Ag and Cd was found between rice and bran (P < 0.05), with bran/rice ratios of 1.21 to 36.3. High concentrations of metal elements, especially that of the heavy metal Cr, in bran samples present a potential safety issue for bran products, such as food and feed containing bran. Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios also were determined. The (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios in bran were generally higher than those in rice (P < 0.0001), and rice and bran samples were distinctly different from each other, indicating that Pb isotope composition is an effective for discriminating between bran and rice samples.


Assuntos
Contaminação de Alimentos/análise , Isótopos/análise , Metais/análise , Oryza/química , Sementes/química
12.
J Sci Food Agric ; 93(8): 1967-73, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23592555

RESUMO

BACKGROUND: Human exposure to cadmium (Cd) is largely attributed to consumption of vegetables grown in polluted soils. In China, guidelines set for Cd in soils are uniform for different crops and diverse soil types, but not risk based. A high-density sampling of 711 paired soil and vegetables was carried out across Guangdong, South China. We aimed to model the transfer of Cd from soil to leafy, rootstalk and fruit vegetables, and to set regional guidelines of Cd [total and diethylenetriaminepentaacetic acid (DTPA) -extractable] in soil for vegetable safe production. RESULTS: Both total and DTPA-extractable Cd concentrations in soil were good predictors for Cd in vegetables. The transfer of Cd in soil to vegetables could be estimated by nonlinear models, with better fit when using DTPA-extractable Cd than total Cd in soil. The calculated thresholds of soil total Cd were 2.42, 0.94 and 1.57 mg kg(-1) whereas those of soil DTPA-extractable Cd were 1.08, 0.33 and 0.63 mg kg(-1) for leafy, rootstalk and fruit vegetable fields in Guangdong, respectively, all higher than the national soil Cd threshold. CONCLUSION: Cadmium-contaminated risk for vegetable production in Guangdong province might have been over-estimated according to the Chinese Environmental Quality Standard for Soil.


Assuntos
Cádmio/química , Poluentes do Solo/química , Solo/química , Verduras , Agricultura , China , Concentração de Íons de Hidrogênio
13.
Zhonghua Er Ke Za Zhi ; 42(9): 693-6, 2004 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-15482674

RESUMO

OBJECTIVE: Alpha-thalassemia is one of the most common monogene disorders in the world. Most frequently, it is caused by deletions of alpha-globin gene (-alpha or --), and less commonly resulted from the non-deletional mutation (alpha(T)alpha). Hemoglobin H (HbH) disease is the most severe type among survivors of alpha-thalassemia. The clinical presentation of children with the disease was highly heterogeneous. The aim of this study was to investigate the effect of alpha-globin genotypes in the children with HbH disease on predicting the phenotypic severity and to define the factors involved in the disease progress. METHODS: Forty-three children with the disease in Zhuhai area of Guangdong, China were examined by using established techniques to detect genotypes of alpha-globin and to determine all hematological parameters. All detailed clinical data of the cases were recorded. Then clinical and hematological findings, and the correlation with genotypes were evaluated. RESULTS: Six alpha-thalassemia mutations were detected and interacted to produce 5 HbH disease genotypes. Of these genotypes, -alpha(3.7)/--(SEA)(60%), -alpha(4.2)/--(SEA) (19%) and alpha(CS)alpha/--(SEA) (12%) HbH diseases were prevalent in the area. Compared with -alpha(3.7)/--(SEA) HbH disease, significantly lower red blood cell (RBC) count, hemoglobin (Hb), mean corpuscular hemoglobin (MCHC) and HbA(2) (P < 0.05, 0.01, 0.01 and 0.01, respectively), and significantly higher mean corpuscular hemoglobin volume (MCV) and HbH levels (both P < 0.01), and more severe clinical phenotypes were found in the HbH disease with alpha(T)alpha/--(SEA) genotype. While the differences were much more significant when compared with -alpha(3.7)/--(SEA) then compared with -alpha(4.2)/--(SEA) not only in the hematological parameters, but also in the severity of clinical phenotypes. In addition, HbH levels showed anegatively correlation with the RBC count (r = -0.39, P < 0.01). CONCLUSION: The phenotypes of HbH disease may be mainly related to the underlying genotypes. The children with alpha(T)alpha/--(SEA) genotype presented with more severe hematological and clinical phenotypes followed by the -alpha(4.2)/--(SEA) and then -alpha(3.7)/--(SEA) genotypes. But phenotypic severity was not simply related to the degree of alpha-globin deficiency. HbH levels were found to exacerbate anemia. These data might provide comprehensive and very valuable and basic information for the management of HbH disease, genetic counseling and prenatal diagnosis.


Assuntos
Genótipo , Hemoglobina H/genética , Fenótipo , alfa-Globinas/genética , Criança , China , Progressão da Doença , Humanos
14.
Chinese Journal of Pediatrics ; (12): 693-696, 2004.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-238157

RESUMO

<p><b>OBJECTIVE</b>Alpha-thalassemia is one of the most common monogene disorders in the world. Most frequently, it is caused by deletions of alpha-globin gene (-alpha or --), and less commonly resulted from the non-deletional mutation (alpha(T)alpha). Hemoglobin H (HbH) disease is the most severe type among survivors of alpha-thalassemia. The clinical presentation of children with the disease was highly heterogeneous. The aim of this study was to investigate the effect of alpha-globin genotypes in the children with HbH disease on predicting the phenotypic severity and to define the factors involved in the disease progress.</p><p><b>METHODS</b>Forty-three children with the disease in Zhuhai area of Guangdong, China were examined by using established techniques to detect genotypes of alpha-globin and to determine all hematological parameters. All detailed clinical data of the cases were recorded. Then clinical and hematological findings, and the correlation with genotypes were evaluated.</p><p><b>RESULTS</b>Six alpha-thalassemia mutations were detected and interacted to produce 5 HbH disease genotypes. Of these genotypes, -alpha(3.7)/--(SEA)(60%), -alpha(4.2)/--(SEA) (19%) and alpha(CS)alpha/--(SEA) (12%) HbH diseases were prevalent in the area. Compared with -alpha(3.7)/--(SEA) HbH disease, significantly lower red blood cell (RBC) count, hemoglobin (Hb), mean corpuscular hemoglobin (MCHC) and HbA(2) (P < 0.05, 0.01, 0.01 and 0.01, respectively), and significantly higher mean corpuscular hemoglobin volume (MCV) and HbH levels (both P < 0.01), and more severe clinical phenotypes were found in the HbH disease with alpha(T)alpha/--(SEA) genotype. While the differences were much more significant when compared with -alpha(3.7)/--(SEA) then compared with -alpha(4.2)/--(SEA) not only in the hematological parameters, but also in the severity of clinical phenotypes. In addition, HbH levels showed anegatively correlation with the RBC count (r = -0.39, P < 0.01).</p><p><b>CONCLUSION</b>The phenotypes of HbH disease may be mainly related to the underlying genotypes. The children with alpha(T)alpha/--(SEA) genotype presented with more severe hematological and clinical phenotypes followed by the -alpha(4.2)/--(SEA) and then -alpha(3.7)/--(SEA) genotypes. But phenotypic severity was not simply related to the degree of alpha-globin deficiency. HbH levels were found to exacerbate anemia. These data might provide comprehensive and very valuable and basic information for the management of HbH disease, genetic counseling and prenatal diagnosis.</p>


Assuntos
Criança , Humanos , China , Progressão da Doença , Genótipo , Hemoglobina H , Genética , Fenótipo , alfa-Globinas , Genética
15.
Di Yi Jun Yi Da Xue Xue Bao ; 22(5): 434-6, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12390707

RESUMO

OBJECTIVE: To evaluate the feasibility of using gap-PCR for routine screening of alpha-thalassemia in clinical laboratory. METHODS: A total of 382 clinical blood samples randomly collected from the population of Zhuhai city were screened for alpha-thalassemia determinants with hematological and gap-PCR method respectively in a double-blind manner. Parallel analysis with Southern blotting was performed to verify the genotyping results by PCR. RESULTS: Of the 382 samples tested, 3 common alpha-thalassemia genes with genotypes of --(SEA)/alpha alpha, -alpha(3.7)/alpha alpha and -alpha(4.2)/alpha alpha were detected in 21 (5.50%), 7 (1.83%) and 3 (0.79%) cases respectively by gap-PCR, including 7 cases with normal phenotype and 3 case of iron-deficiency anemia. The overall incidence of alpha-thalassemia was 8.12% in the population of Zhuhai city, as determined by gap-PCR, in total agreement with the results by Southern blotting. Only 21 of the 31 alpha-thalassemia cases were identified by hematological analysis (besides 2 cases with alpha-thalassemia phenotype undetermined), which had a false-negative rate of 32.3%. Seven silent alpha-thalassemia and 3 mild alpha-thalassemia cases failed to be detected by hematological analysis, resulting in a rate of 2.62% for failure of detection. CONCLUSION: Gap-PCR method is specific and feasible as a better alternative for alpha-thalassemia screening, especially advantageous in detecting silent carriers in comparison with hematological method.


Assuntos
Triagem de Portadores Genéticos/métodos , Reação em Cadeia da Polimerase/métodos , Talassemia alfa/genética , DNA/genética , Feminino , Genótipo , Heterozigoto , Humanos , Masculino , Fenótipo , Talassemia alfa/diagnóstico
16.
J Environ Sci (China) ; 14(3): 393-8, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12211992

RESUMO

The equilibrium-perturb technique was used in the flume reaeration experiment. The interfacial mass transfer coefficients of DO were obtained by implementation of the oxygen-flux theory in the study. The turbulence characteristics of the flow field were investigated by numerical simulation approach. The expression of interfacial mass transfer coefficient related with velocity and turbulence kinetic energy was built. Examination with the experimental datum of different cases showed the validation of the expression.


Assuntos
Modelos Teóricos , Movimentos da Água , Poluentes da Água/análise , Gases , Cinética , Oxigênio/análise , Volatilização
17.
Yi Chuan ; 24(2): 121-4, 2002 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-16118122

RESUMO

The carcinogenesis of the human cervical precancerous lesion,cervical carcinoma is known closely associated with human papillomavirus (HPV). The purpose of this article is to identify whether HSV and CMV play as co-factor role in the carcinogenesis. Eighty-one cases of various cervical lesions were analyzed by HPV6/11, HPV16/18 in situ hybridization. Meanwhile, HPV, HSV and CMV were determined in 103 cases of various cervical lesions. The results show that the distribution of positive hybridization signal was consistent with the distribution of Koilocytic cells in HE stain. Of these cervical specimens investigated, the positive rates of HPV16/18 and HPV6/11 using ISH were 51% and 64%, respectively,the infection rates of HPV16/18, HPV6/11, HSV and CMV using PCR were 21%,4% 23% and 0%, respectively. The co-operation effect of HPV and HSV occurred in the oncogenesis of human cervical carcinoma, and moreover, the cellular and molecular biological mechanisms were discussed.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...