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1.
Artigo em Chinês | MEDLINE | ID: mdl-36725289

RESUMO

Objective: To explore the effects of fecal microbiota transplantation (FMT) on neurobehavior and gut microbiota of arsenic-exposed offspring rats. Methods: In April 2021, Thirty-six SPF SD rats aged 8 weeks were seleted, rats were ranked by weight and divided into four groups according to randomized block design, namely control group, arsenic exposure group (As group) , arsenic+normal saline group (As+NaCl group) and As+FMT group, 6 females and 3 males in each group. Fecal microbiota fluid were provided by feces of rats in control group. Rats drank tap water containing 75 mg/L sodium arsenite for one week and then were caged together. The arsenic exposure was terminated until the pups were born. Female rats with vaginal plug were treated with fecal microbiota fluid via gavage during neurodevelopmental teratogenic window period. The volume of gavage was 1 ml/100 g with once every two days, for a total of three times. Weight alterations of offspring rats were recorded every week after weaning, and when offspring rats grew up for 6 weeks, Morris test and open field experiment was used to observe learning and memory abilities, as well as neurobehavioral performance of autonomous exploration and tension, respectively. 16S rDNA sequencing technology was used to detect microbiota diversities in fecal samples of rats in As group and As+FMT group. Results: Compared with the control group, the ratio of swimming distance and staying time in the target quadrant and the times of crossing the platform of rats in As group decreased significantly, and the motor distance, times entering central zone and the number of grid crossing of rats decreased significantly (P<0.05) . Compared with As group, the ratio of swimming distance in target quadrant, the motor distance in central zone and times entering central zone of rats in As+FMT group were evidently increased (P<0.05) . The analysis of fecal microbiota diversities showed that, at the phyla level, the relative abundance of Bacteroidetes in feces of rats in As+FMT group was higher than that in As group (68.34% vs 60.55%) , while the relative abundance of Firmicutes was lower than that in As group (28.02% vs 33.48%) . At the genus level, the relative abundance of Prevotella in As+FMT group was significantly higher than that in As group, becoming the dominant genus (42.08% vs 21.78%) . Additionally, compared with As group, a total of 22 genus were increased with 21 decreased genus in As+FMT group (P<0.05) . LEfSe analysis showed that dominant genuses in As+FMT group were Prevotella and UCG_005, and their relative abundance was significantly higher than that of As group (P<0.05) . Conclusion: FMT may alleviate the impaired learning and memory ability and anxiety like behavior of the offspring rats exposed to arsenic, and improve the disrupted gut microbiota.


Assuntos
Arsênio , Microbioma Gastrointestinal , Masculino , Ratos , Animais , Feminino , Transplante de Microbiota Fecal , Ratos Sprague-Dawley , Fezes
2.
Artigo em Chinês | MEDLINE | ID: mdl-34365766

RESUMO

This paper analyzed the clinical data of 17 patients with inhalation dimethyl sulfate poisoning in Changzhou Third People's Hospital, in order to understand the clinical characteristics, treatment and prognosis of patients with inhalation dimethyl sulfate poisoning, and guide clinicians to make effective measures in time. Dimethyl sulfate poisoning progresses rapidly and dangerously. The prognosis is usually better if the patients are separated from the toxic environment as soon as possible, given glucocorticoids in early and short-term, closely observed respiratory tract injury, and treated with endotracheal intubation and invasive mechanical ventilation when necessary.


Assuntos
Respiração Artificial , Humanos , Ésteres do Ácido Sulfúrico
3.
Public Health ; 189: 20-25, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33126118

RESUMO

OBJECTIVES: Home-based self-screening and monitoring for obesity is particularly valuable for the prevention and control of chronic diseases. This study aimed to identify an anthropometric index suitable for home-based obesity screening in children and adolescents. STUDY DESIGN: The design of this study is a cross-sectional study. METHODS: A total of 14,042 students (6-17 years) from the Qibao Community, Minhang District, Shanghai, were studied in 2018. The percentage body fat (PBF), height, weight, waist circumference (WC) and hip circumference were measured. Body mass index (BMI), triponderal mass index (TMI), body adiposity index (BAI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were calculated. Partial correlation analysis was used to evaluate the relationships between these indices and PBF, and receiver operating characteristic (ROC) curves were used to evaluate their performance for obesity screening. RESULTS: BMI, TMI, WC and WHtR were found to strongly correlate with PBF (r ≥ 0.830, all P < 0.001). The optimal index for obesity screening in children (6-11 years) was BMI (area under the ROC curve [AUC] = 0.980 for boys and 0.981 for girls) and in adolescents (12-17 years) was TIM (AUC = 0.976 for boys and 0.945 for girls); however, the optimal cut-off values for BMI and TMI differed among the subgroups. The ROC curve analysis showed that WHtR had similar cut-off values in each subgroup (0.45 for boys of 6-11 years and 0.43 for the other subgroups), excellent performance in children (AUC>0.90) and good performance in adolescents (AUC = 0.960 for girls and 0.878 for boys). CONCLUSIONS: Owing to its accuracy and stable cut-off value for defining obesity, WHtR should be recommended for home-based obesity screening in children and adolescents.


Assuntos
Pesos e Medidas Corporais/métodos , Programas de Rastreamento/métodos , Obesidade Infantil/diagnóstico , Adiposidade , Adolescente , Índice de Massa Corporal , Peso Corporal , Criança , China , Estudos Transversais , Feminino , Humanos , Masculino , Curva ROC , Circunferência da Cintura , Razão Cintura-Estatura , Relação Cintura-Quadril
5.
Zhonghua Jie He He Hu Xi Za Zhi ; 43(4): 337-339, 2020 Apr 12.
Artigo em Chinês | MEDLINE | ID: mdl-32294816

RESUMO

The case reports 2 cases of novel coronavirus pneumonia diagnosed by concurrent bronchoalveolar lavage in our hospital, 1 case had a history of epidemiology, clinical symptoms and high imaging suspicion, but repeated negative throat swabs. One patient was diagnosed 2019-nCoV. Before the patient was discharged, the clinical symptoms disappeared, the chest CT showed significant improvement, and the pharynx swab was twice negative, reaching the discharge standard.We detected the ORF 1ab gene, the N gene and the nucleic acid of the new coronavirus in the broncho-alveolar lavage fluid of 2 patients. The results showed that the positive rate of bronchoalveolar lavage for detection of new coronavirus nucleic acid was high, and bronchoalveolar lavage for suspected or confirmed new coronavirus pneumonia patients with negative detection of nucleic acid in pharynx swabs but still residual lung lesions was helpful for early diagnosis, treatment and prognosis.


Assuntos
Líquido da Lavagem Broncoalveolar/virologia , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Betacoronavirus , Lavagem Broncoalveolar , COVID-19 , Teste para COVID-19 , Técnicas de Laboratório Clínico , Genes Virais , Humanos , Pandemias , Faringe/virologia , SARS-CoV-2
6.
Zhonghua Er Ke Za Zhi ; 56(8): 623-627, 2018 Aug 02.
Artigo em Chinês | MEDLINE | ID: mdl-30078246

RESUMO

Objective: To summarize and review the clinical and genetic features of neonatal sclerosing cholangitis (NSC) caused by DCDC2 variations. Methods: Whole exome sequencing was performed to identify DCDC2 variants in two Chinese siblings with NSC who were diagnosed in Children's Hospital of Fudan University in May 2017. Clinical, laboratory and genetic data of the two cases were summarized. Key words of "DCDC2" "neonatal sclerosing cholangitis" were searched in Chinese databases and PubMed for articles published until April 2018, and all the relevant literature were reviewed. Results: Patient 1 was a 3-year-and-2-month-old boy. He was admitted to our hospital due to cholestasis for 3 years. Laboratory findings showed elevated levels of gamma-glutamyl transpeptidase (161-1 092 U/L) and total cholesterol (5.4-7.7 mmol/L). Magnetic resonance cholangiopancreatography showed multiple dilations of intrahepatic bile ducts and bilateral hydronephrosis. Patient 2, the older brother of patient 1, was a 9-year-and-9-month-old boy. He was admitted to our hospital due to "cholestasis for 9 years" . CT angiography showed hydrocephalus and left internal carotid artery aneurysms with vascular malformations. A homozygous variant c.529dupA (NM_001195610) in DCDC2 gene was identified in patient 1 by whole exome sequencing. Patient 2 was a homozygote and his parents were heterozygotes with the variation. There has been 2 relevant articles published (Chinese 0, English 2), which reported 11 cases of DCDC2-related NSC in total. All the 13 patients, including the 2 cases reported here, had an onset of symptoms at 0 to 6 months of age. The most common clinical manifestation was cholestasis with high gamma-glutamyl transpeptidase levels, acholic stool, and progression to portal hypertension. Renal and neurological abnormalities were also frequently present. Hypercholesterolemia was observed in one case. Radiological findings revealed the characteristic strictures and dilatations of the intrahepatic and (or) extrahepatic biliary tree. Liver histological examination showed peripheral ductopenia, ductal plate malformation, fibrosis, and cirrhosis. Among the 13 patients, 10 patients required liver transplantation. A total of 7 types of DCDC2 variants were detected in 13 patients. Conclusions: DCDC2-related NSC is characterized by the onset of cholestasis with high gamma-glutamyl transpeptidase level and acholic stool in early infancy, which was likely to progress to cirrhosis in early childhood. Renal and neurological abnormalities are also frequently present.Cholangiography or magnetic resonance cholangiopancreatography show strictures and dilatations of the intrahepatic or (and) extrahepatic biliary tree. Identification of pathogenic DCDC2 variants would aid the diagnosis of NSC.


Assuntos
Colangite Esclerosante , Proteínas Associadas aos Microtúbulos , Criança , Pré-Escolar , Colangiografia , Colangite Esclerosante/complicações , Colangite Esclerosante/genética , Colestase/genética , Variação Genética , Humanos , Masculino , Proteínas Associadas aos Microtúbulos/genética , Irmãos
7.
Zhonghua Gan Zang Bing Za Zhi ; 26(12): 881-884, 2018 Dec 20.
Artigo em Chinês | MEDLINE | ID: mdl-30669777

RESUMO

The advancement and popularization of molecular diagnostic techniques has challenged and redefined the traditional concept of genetic metabolic disease. Regardless of disease origin, all genetic defects that lead to hepatobiliary dysfunction or structural abnormalities are termed as genetic liver disorders. Online Mendelian Inheritance in Man (OMIM) is a database consisting 693 genetic diseases with clear molecular mechanism of liver related phenotypes. Moreover, the effective measures to control infectious liver disease have strengthened the importance of research in the field of (adult and children) genetic liver disorders at home and abroad by well-recognized hepatologists. Notably, all patients with unexplained hepatopathy and multiple system diseases involving liver and gallbladder needs screening for genetic liver disorders, except for factors such as infection, immunity, drug-related, and anatomical abnormalities. We hope more patients with complicated liver disorders will benefit from definitive diagnosis and effective treatment in the near future with clear explanation of clinical phenotype, genotype, and metabolomics.


Assuntos
Doenças Genéticas Inatas , Hepatopatias , Criança , Bases de Dados Genéticas , Genótipo , Humanos , Hepatopatias/diagnóstico , Hepatopatias/genética , Hepatopatias/terapia , Fenótipo
8.
Sci Rep ; 7(1): 11666, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28916812

RESUMO

A series of Co nanocluster-assembled films with cluster sizes ranging from 4.5 nm to 14.7 nm were prepared by the plasma-gas-condensation method. The size-dependent electrical transport properties were systematically investigated. Both of the longitudinal resistivity ([Formula: see text]) and saturated anomalous Hall resistivity ([Formula: see text]) continuously increased with the decrease of the cluster sizes (d). The [Formula: see text] firstly increased and then decreased with increasing the temperature for all samples, which could be well described by involving the thermally fluctuation-induced tunneling (FIT) process and scattering. The tunneling effect was verified to result in the invalidation of classical anomalous Hall effect (AHE) scaling relation. After deducting the contribution from tunneling effect to [Formula: see text], the AHE scaling relation between [Formula: see text] and the scattering resistivity ([Formula: see text]) by varying the temperature was reconstructed. The value of scaling exponent γ increased with increasing Co cluster sizes. The size dependence of γ might be qualitatively interpreted by the interface and surface-induced spin flip scattering. We also determined the scaling relation between [Formula: see text] and [Formula: see text] at 5 K by changing the Co cluster sizes, and a large value of γ = 3.6 was obtained which might be ascribed to the surface and interfacial scattering.

9.
Artigo em Chinês | MEDLINE | ID: mdl-29871286

RESUMO

Objective:To explore the efficacy of a modified tympanic membrane surgical knife with suction and tube device in myringotomy with ventilation tube placement for the treatment of secretory otitis media.Method:From June of 2014 to December of 2015, 87 cases of secretory otitis media were randomly divided into two groups: One group was treated by general approach to achieve tympanic membrane tube insertion, and another group with modified method. The total effective rate,the rate of tube detachment at 3 months postoperatively, the rate of scar formation or tympanic membrane atrophy, the operation time and the success rate of tube insertion for the first time in two groups were analyzed retrospectively. Result:There was no significantly difference between two groups about the total effective rate,the rate of tube detachment and the rate of scar formation or tympanic membrane atrophy(P>0.05).However, the duration of operation in general method groupï¼»(11.4±4.3 min)]was significantly longer than that in modified method groupï¼»(8.1±3.6)minï¼½(t=5.412,P<0.05).In addition, the success rate of tube insertion in general group(81.2%) was significantly lower than that in modified group(93.7%)(χ²=5.397,P<0.05). Conclusion:The modified method contributed to shorten the duration of operation, improved the success rate of tube insertion and avoided the injury of tympanic membrane and external auditory canal caused by repeated operation.


Assuntos
Ventilação da Orelha Média/métodos , Otite Média com Derrame/terapia , Membrana Timpânica/patologia , Meato Acústico Externo , Humanos , Sucção
10.
Fa Yi Xue Za Zhi ; 32(5): 367-372, 2016 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-29205008

RESUMO

With the progress and development of the DNA test and imaging technique, and the evolution of evidence rule which bring the discussions about whether the individual identification using imaging data is outdated, and other disputes such as whether radiologic evidence could be suitable for contemporary evidence and be used to solve the posture difference of imaging test. This article summaries the domestic and foreign researches of individual identification using imaging data in the past 20 years and reviews the problems above.


Assuntos
DNA/análise , Genética Forense/normas , Humanos
11.
Mycorrhiza ; 16(5): 299-363, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16845554

RESUMO

A survey of 659 papers mostly published since 1987 was conducted to compile a checklist of mycorrhizal occurrence among 3,617 species (263 families) of land plants. A plant phylogeny was then used to map the mycorrhizal information to examine evolutionary patterns. Several findings from this survey enhance our understanding of the roles of mycorrhizas in the origin and subsequent diversification of land plants. First, 80 and 92% of surveyed land plant species and families are mycorrhizal. Second, arbuscular mycorrhiza (AM) is the predominant and ancestral type of mycorrhiza in land plants. Its occurrence in a vast majority of land plants and early-diverging lineages of liverworts suggests that the origin of AM probably coincided with the origin of land plants. Third, ectomycorrhiza (ECM) and its derived types independently evolved from AM many times through parallel evolution. Coevolution between plant and fungal partners in ECM and its derived types has probably contributed to diversification of both plant hosts and fungal symbionts. Fourth, mycoheterotrophy and loss of the mycorrhizal condition also evolved many times independently in land plants through parallel evolution.


Assuntos
Micorrizas/classificação , Micorrizas/isolamento & purificação , Plantas/microbiologia , Evolução Biológica , Micorrizas/genética , Filogenia
12.
Chemosphere ; 52(6): 997-1005, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12781233

RESUMO

Coke-plant wastewater was treated by an anaerobic-anoxic-aerobic (A(1)-A(2)-O) biofilm system and an anoxic-aerobic (A/O) biofilm system, respectively. At same or similar levels of hydraulic retention time (HRT), the two systems had almost identical chemical oxygen demand (COD) and NH(3) removals, but a different organic-N removal. Set-up of an acidogenic stage benefited for the removal of organic-N and the A(1)-A(2)-O system was more useful for total nitrogen removal than the A-O system. HRT did not have a substantial effect on the COD and NH(3)-N removal efficiencies, but considerably influenced the organic-N removal and distribution of oxidized nitrogen in the final effluent. The GC/MS analysis demonstrated that some refractory compounds were decomposed at the acidogenic stage and resulted in the production of some intermediates, which were more readily degraded in the subsequent aerobic stage. Hence, the A(1)-A(2)-O system had better effluent quality than the A-O system in terms of effluent composition.


Assuntos
Biofilmes , Resíduos Industriais , Nitrogênio/isolamento & purificação , Compostos Orgânicos/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Bactérias Aeróbias/metabolismo , Bactérias Anaeróbias/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Purificação da Água/métodos
13.
Artigo em Inglês | MEDLINE | ID: mdl-12716066

RESUMO

To optimize the efficiency of bioremediation, treatability studies are needed to understand the fate of pollutants and environmental conditions under which microorganism growth is promoted and efficient degradation of these pollutants result. This article presents a recommended procedure which may achieve these goals. Results and treatability comparisons for candidate compounds including carbon tetrachloride (CT), methyl-tert-butyl-ether (MTBE) and hexachlorobutadiene (HCBD) are presented and discussed. Culture redox potential (ORP) which is an indicator or free electron activity of a system appeared to have a significant impact on CT biodegradation. Optimum biodegradation of CT by Pseudomonas cepacia was observed between -100 and -200mv. Under the optimum environmental conditions established during the batch-scale biotransformation study, 98 to 99.9% of CT and 70% of MTBE introduced into the continuous fixed-biofilm reactor were degraded. The biphasic model simulating biodegradation of CT and MTBE provided an excellent correlation in the fixed-biofilm study and was simple to apply as compared with other models.


Assuntos
Butadienos/metabolismo , Tetracloreto de Carbono/metabolismo , Carcinógenos/metabolismo , Indústria Química , Poluentes Ambientais/metabolismo , Fungicidas Industriais/metabolismo , Biodegradação Ambiental , Pseudomonas/fisiologia
14.
Mol Phylogenet Evol ; 21(2): 167-75, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11697913

RESUMO

The second intron in the mitochondrial gene nad1 was surveyed using PCR, DNA sequencing, or Southern hybridization in 323 species (313 genera, 212 families) of seed plants. The intron was absent in all 22 species (22 genera, 8 families) of non-Pinaceae conifers studied, in Welwitschia mirabilis, and in seven angiosperms. Whereas absence of the intron in seven angiosperms and Welwitschia is likely due to seven independent losses when evaluated against the recently published multigene phylogenies, the lack of the intron in all non-Pinaceae conifers can be best explained by a single loss. These data suggest that the non-Pinaceae conifers represent a monophyletic group. We also conducted a phylogenetic analysis of seed plants using a combined data set of the partial exon and intron sequences of nad1 generated from this study and published sequences of mitochondrial cox1 and small subunit (SSU) rDNA, chloroplast rbcL, and nuclear 18S rDNA. The results supported the split of conifers into two groups: Pinaceae and non-Pinaceae conifers. The Gnetales were sister to Pinaceae, in agreement with the conclusion from other recent molecular phylogenetic studies that refute the anthophyte hypothesis.


Assuntos
Cycadopsida/genética , Proteínas Mitocondriais , Pinaceae/genética , Ribulose-Bifosfato Carboxilase , Sequência de Bases , Núcleo Celular/genética , Cycadopsida/classificação , DNA Mitocondrial/genética , DNA de Plantas/química , DNA de Plantas/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Evolução Molecular , Genes de Plantas/genética , Íntrons/genética , Dados de Sequência Molecular , NADH Desidrogenase/genética , Filogenia , Pinaceae/classificação , Proteínas de Plantas/genética , RNA Ribossômico/genética , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
15.
Mol Biol Evol ; 18(9): 1745-53, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11504854

RESUMO

Five groups of basal angiosperms, Amborella, Nymphaeales, Illiciales, Trimeniaceae, and Austrobaileya (ANITA), were identified in several recent studies as representing a series of the earliest-diverging lineages of the angiosperm phylogeny. All of these studies except one employed a multigene analysis approach and used gymnosperms as the outgroup to determine the ingroup topology. The high level of divergence between gymnosperms and angiosperms, however, has long been implicated in the difficulty of reconstructing relationships at the base of angiosperm phylogeny using DNA sequences, for fear of long-branch attraction (LBA). In this study, we replaced the gymnosperm sequences from the five-gene matrix (mitochondrial atp1 and matR, plastid atpB and rbcL, and nuclear 18S rDNA) used in our earlier study with four categories of divergent sequences--random sequences with equal base frequencies or equally AT- and GC-rich contents, homopolymers and heteropolymers, misaligned gymnosperm sequences, and aligned lycopod and bryophyte sequences--to evaluate whether the gymnosperms were an appropriate outgroup to angiosperms in our earlier study that identified the ANITA rooting. All 24 analyses performed rooted the angiosperm phylogeny at either Acorus or Alisma (or Alisma-Triglochin-Potamogeton in one case due to use of a slightly different alignment) and placed the monocots as a basal grade, producing genuine LBA results. These analyses demonstrate that the identification of ANITA as the basalmost extant angiosperms was based on historical signals preserved in the gymnosperm sequences and that the gymnosperms were an appropriate outgroup with which to root the angiosperm phylogeny in the multigene sequence analysis. This strategy of evaluating the appropriateness of an outgroup using artificial sequences and a series of outgroups with increments of divergence levels can be applied to investigations of phylogenetic patterns at the bases of other major clades, such as land plants, animals, and eukaryotes.


Assuntos
Magnoliopsida/genética , Filogenia , Núcleo Celular/genética , Cycadopsida/genética , DNA Mitocondrial/genética , Complexo I de Transporte de Elétrons , Magnoliopsida/classificação , NADH NADPH Oxirredutases/genética , Plastídeos/genética , ATPases Translocadoras de Prótons/genética , RNA Ribossômico 18S/genética , Ribulose-Bifosfato Carboxilase/genética
16.
Genetics ; 158(3): 1289-300, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11454775

RESUMO

Unlike in animals, the functional transfer of mitochondrial genes to the nucleus is an ongoing process in plants. All but one of the previously reported transfers in angiosperms involve ribosomal protein genes. Here we report frequent transfer of two respiratory genes, sdh3 and sdh4 (encoding subunits 3 and 4 of succinate dehydrogenase), and we also show that these genes are present and expressed in the mitochondria of diverse angiosperms. Southern hybridization surveys reveal that sdh3 and sdh4 have been lost from the mitochondrion about 40 and 19 times, respectively, among the 280 angiosperm genera examined. Transferred, functional copies of sdh3 and sdh4 were characterized from the nucleus in four and three angiosperm families, respectively. The mitochondrial targeting presequences of two sdh3 genes are derived from preexisting genes for anciently transferred mitochondrial proteins. On the basis of the unique presequences of the nuclear genes and the recent mitochondrial gene losses, we infer that each of the seven nuclear sdh3 and sdh4 genes was derived from a separate transfer to the nucleus. These results strengthen the hypothesis that angiosperms are experiencing a recent evolutionary surge of mitochondrial gene transfer to the nucleus and reveal that this surge includes certain respiratory genes in addition to ribosomal protein genes.


Assuntos
Núcleo Celular/enzimologia , DNA Mitocondrial/genética , Evolução Molecular , Isoenzimas/genética , Magnoliopsida/genética , Mitocôndrias/enzimologia , Succinato Desidrogenase/genética , Sequência de Aminoácidos , Sequência de Bases , DNA Complementar , Isoenzimas/química , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Succinato Desidrogenase/química
17.
Se Pu ; 19(5): 467-9, 2001 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-12545449

RESUMO

This paper presents a simple and accurate method for analyzing formaldehyde in polymer complex by headspace extraction derivatization and HPLC analysis. The sample preparatio of formaldehyde in polymer complex was based on a simple thermodynamic equilibrium in a closed and thermostat jar, and the gaseous formaldehyde in equilibrium could be absorbed and extracted by the liquid in the bottom of the jar. The formaldehyde was derivatized with 2,4-dinitrophenyl hydrazine before chromatography. The influences of temperature, equilibrium time, sample quantity and geometric form on the extraction efficiency were studied. The extraction and HPLC conditions were optimized. The limit of detection (LOD) was 0.1 mg/kg, and the relative standard deviation (RSD) was below 5%, and the recoveries were between 96%-103%. As a result, this method would meet the demands for analyzing microamounts of residual formaldehyde in polymer complex.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Formaldeído/análise , Polímeros/química , Substâncias Macromoleculares , Sensibilidade e Especificidade
19.
Nature ; 408(6810): 354-7, 2000 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-11099041

RESUMO

A central component of the endosymbiotic theory for the bacterial origin of the mitochondrion is that many of its genes were transferred to the nucleus. Most of this transfer occurred early in mitochondrial evolution; functional transfer of mitochondrial genes has ceased in animals. Although mitochondrial gene transfer continues to occur in plants, no comprehensive study of the frequency and timing of transfers during plant evolution has been conducted. Here we report frequent loss (26 times) and transfer to the nucleus of the mitochondrial gene rps10 among 277 diverse angiosperms. Characterization of nuclear rps10 genes from 16 out of 26 loss lineages implies that many independent, RNA-mediated rps10 transfers occurred during recent angiosperm evolution; each of the genes may represent a separate functional gene transfer. Thus, rps10 has been transferred to the nucleus at a surprisingly high rate during angiosperm evolution. The structures of several nuclear rps10 genes reveal diverse mechanisms by which transferred genes become activated, including parasitism of pre-existing nuclear genes for mitochondrial or cytoplasmic proteins, and activation without gain of a mitochondrial targeting sequence.


Assuntos
Núcleo Celular/genética , Evolução Molecular , Genes de Plantas , Magnoliopsida/genética , Mitocôndrias/genética , Recombinação Genética , Sequência de Aminoácidos , DNA Mitocondrial , DNA de Plantas , Magnoliopsida/classificação , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Reação em Cadeia da Polimerase , Proteínas Ribossômicas/genética , Homologia de Sequência de Aminoácidos
20.
Antivir Chem Chemother ; 11(3): 191-202, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10901290

RESUMO

A series of R and S enantiomers of 2-aminopurine methylenecyclopropane analogues of nucleosides was synthesized. Two diastereoisomeric lipophilic phosphate prodrugs derived from R and S enantiomers of 2,6-diaminopurine analogue were also prepared. Enantioselectivity (diastereoselectivity in case of prodrugs) of in vitro antiviral effects was investigated with human and murine cytomegalovirus (HCMV and MCMV, respectively), herpes simplex virus types 1 and 2 (HSV-1 and HSV-2, respectively), human immunodeficiency virus type 1 (HIV-1), hepatitis B virus (HBV), Epstein-Barr virus (EBV) and varicella zoster virus (VZV). Strong differences in enantioselectivity were found between the R and S enantiomers of adenine analogue and enantiomeric 2-aminopurine analogues. Thus, the enantiomers of adenine analogue were equipotent against HCMV but not MCMV, where the S enantiomer is strongly preferred. The same S preference was found throughout the 2-aminopurine series for both HCMV and MCMV. In contrast, R-synadenol in HIV-1 assays was the best agent, whereas the S enantiomers of moderately effective 2-amino-6-cyclopropylamino and 2-amino-6-methoxypurine analogues were preferred. Little enantiomeric preference was found for R and S enantiomers of synadenol and the corresponding enantiomers of 2,6-diaminopurine analogue against HBV. A mixed pattern of enantioselectivity was observed for EBV depending on the type of host cells and assay. Against VZV, the R and S enantiomers of adenine analogue were equipotent or almost equipotent, but throughout the series of 2-aminopurine analogues a distinct preference for the S enantiomers was found. The stereoselectivity pattern of both diastereoisomeric prodrugs mostly followed enantioselectivity of the parent analogues. The varying enantioselectivities in the series of purine methylenecyclopropane analogues are probably a consequence of differences in the mechanisms of action in different virus/host cell systems.


Assuntos
Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/síntese química , Ciclopropanos , Pró-Fármacos/farmacologia , Vírus/efeitos dos fármacos , Adenosina/síntese química , Adenosina/farmacologia , Alanina/síntese química , Alanina/farmacologia , Animais , Antivirais/farmacologia , Cromatografia Líquida de Alta Pressão , Citomegalovirus/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Vírus da Hepatite B/efeitos dos fármacos , Herpesviridae/efeitos dos fármacos , Herpesvirus Humano 3/efeitos dos fármacos , Herpesvirus Humano 4/efeitos dos fármacos , Humanos , Estrutura Molecular , Estereoisomerismo , Replicação Viral/efeitos dos fármacos
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