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1.
Nucleic Acids Res ; 51(D1): D1263-D1275, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36243960

RESUMO

Widespread drug resistance has become the key issue in global healthcare. Extensive efforts have been made to reveal not only diverse diseases experiencing drug resistance, but also the six distinct types of molecular mechanisms underlying this resistance. A database that describes a comprehensive list of diseases with drug resistance (not just cancers/infections) and all types of resistance mechanisms is now urgently needed. However, no such database has been available to date. In this study, a comprehensive database describing drug resistance information named 'DRESIS' was therefore developed. It was introduced to (i) systematically provide, for the first time, all existing types of molecular mechanisms underlying drug resistance, (ii) extensively cover the widest range of diseases among all existing databases and (iii) explicitly describe the clinically/experimentally verified resistance data for the largest number of drugs. Since drug resistance has become an ever-increasing clinical issue, DRESIS is expected to have great implications for future new drug discovery and clinical treatment optimization. It is now publicly accessible without any login requirement at: https://idrblab.org/dresis/.


Assuntos
Descoberta de Drogas , Bases de Dados Factuais , Resistência a Medicamentos
2.
Am J Epidemiol ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38879743

RESUMO

Polybrominated diphenyl ethers (PBDEs) exposure is associated with preterm birth. Laboratory studies suggest that PBDEs lead to elevated oxidative stress, a known contributor to preterm birth in epidemiologic studies. We hypothesized that elevated levels of PBDEs would be associated with increased oxidative stress during human pregnancy. Participants in this analysis were enrolled in the Chemicals in Our Bodies cohort and resided in the San Francisco Bay Area (N=201). Four PBDEs (BDE-47, -99, -100, -153) were measured in second trimester serum. Urinary oxidative stress biomarkers were measured at two timepoints (second and third trimester) and included 8-isoprostane-prostaglandin-F2α [8-iso-PGF2α], 2,3-dinor-5,6-dihydro-8-iso-PGF2α, 2,3-dinor-8-iso-PGF2α, and prostaglandin-F2α [PGF2α]. Associations between individual PBDEs and oxidative stress biomarkers (averaged and trimester specific) were examined using linear regression. Quantile g-computation and Bayesian kernel machine regression (BKMR) were used to assess cumulative effects of PBDEs. Quantile g-computation showed that higher concentrations of PBDEs were associated with increasing 8-iso-PGF2α, 2,3-dinor-8-iso-PGF2α, and PGF2α. Associations were greatest in magnitude for second trimester levels of 2,3-dinor-8-iso-PGF2α (mean change per quartile increase=0.25, 95% confidence interval=0.09, 0.41). Associations were similar using BKMR and linear regression. Our findings suggest that oxidative stress may be a plausible biological pathway by which PBDE exposure might lead to preterm birth.

3.
Environ Health ; 20(1): 76, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193151

RESUMO

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) and polybrominated diphenyl ethers (PBDEs) are endocrine disrupting chemicals with widespread exposures across the U.S. given their abundance in consumer products. PFAS and PBDEs are associated with reproductive toxicity and adverse health outcomes, including certain cancers. PFAS and PBDEs may affect health through alternations in telomere length. In this study, we examined joint associations between prenatal exposure to PFAS, PBDEs, and maternal and newborn telomere length using mixture analyses, to characterize effects of cumulative environmental chemical exposures. METHODS: Study participants were enrolled in the Chemicals in Our Bodies (CIOB) study, a demographically diverse cohort of pregnant people and children in San Francisco, CA. Seven PFAS (ng/mL) and four PBDEs (ng/g lipid) were measured in second trimester maternal serum samples. Telomere length (T/S ratio) was measured in delivery cord blood of 292 newborns and 110 second trimester maternal whole blood samples. Quantile g-computation was used to assess the joint associations between groups of PFAS and PBDEs and newborn and maternal telomere length. Groups considered were: (1) all PFAS and PBDEs combined, (2) PFAS, and (3) PBDEs. Maternal and newborn telomere length were modeled as separate outcomes. RESULTS: T/S ratios in newborn cord and maternal whole blood were moderately correlated (Spearman ρ = 0.31). In mixtures analyses, a simultaneous one quartile increase in all PFAS and PBDEs was associated with a small increase in newborn (mean change per quartile increase = 0.03, 95% confidence interval [CI] = -0.03, 0.08) and maternal telomere length (mean change per quartile increase = 0.03 (95% CI = -0.03, 0.09). When restricted to maternal-fetal paired samples (N = 76), increasing all PFAS and PBDEs combined was associated with a strong, positive increase in newborn telomere length (mean change per quartile increase = 0.16, 95% CI = 0.03, 0.28). These associations were primarily driven by PFAS (mean change per quartile increase = 0.11 [95% CI = 0.01, 0.22]). No associations were observed with maternal telomere length among paired samples. CONCLUSIONS: Our findings suggest that PFAS and PBDEs may be positively associated with newborn telomere length.


Assuntos
Poluentes Ambientais/toxicidade , Retardadores de Chama/toxicidade , Fluorocarbonos/toxicidade , Éteres Difenil Halogenados/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Telômero/efeitos dos fármacos , Adulto , Monitoramento Biológico , Poluentes Ambientais/análise , Ácidos Graxos/análise , Ácidos Graxos/toxicidade , Feminino , Retardadores de Chama/análise , Fluorocarbonos/análise , Éteres Difenil Halogenados/análise , Humanos , Recém-Nascido , Masculino , Exposição Materna , Troca Materno-Fetal , Gravidez , Ácidos Sulfônicos/análise , Ácidos Sulfônicos/toxicidade
4.
Proc Natl Acad Sci U S A ; 115(20): 5093-5098, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29712826

RESUMO

Amino acids are the building blocks for protein biosynthesis and find use in myriad industrial applications including in food for humans, in animal feed, and as precursors for bio-based plastics, among others. However, the development of efficient chemical methods to convert abundant and renewable feedstocks into amino acids has been largely unsuccessful to date. To that end, here we report a heterogeneous catalyst that directly transforms lignocellulosic biomass-derived α-hydroxyl acids into α-amino acids, including alanine, leucine, valine, aspartic acid, and phenylalanine in high yields. The reaction follows a dehydrogenation-reductive amination pathway, with dehydrogenation as the rate-determining step. Ruthenium nanoparticles supported on carbon nanotubes (Ru/CNT) exhibit exceptional efficiency compared with catalysts based on other metals, due to the unique, reversible enhancement effect of NH3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing membrane distillation to facilitate product purification is proposed and validated. Overall, this study offers a rapid and potentially more efficient chemical method to produce amino acids from woody biomass components.


Assuntos
Aminoácidos/metabolismo , Biomassa , Nanopartículas/química , Nanotubos de Carbono/química , Aminoácidos/química , Catálise , Hidrogenação , Níquel/química , Rutênio/química
5.
Environ Health ; 19(1): 100, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938446

RESUMO

BACKGROUND: Perfluoroalkyl substances (PFAS) and polybrominated diphenyl ethers (PBDEs) are used in consumer products for their water repellent and flame retardant properties, respectively. However, there is widespread prenatal exposure and concern about their potential harm to the developing fetus. Here, we utilized data from a demographically diverse cohort of women in San Francisco, CA to examine associations between prenatal exposure to PFAS and PBDEs with gestational age and birth weight for gestational age z-scores. METHODS: Women included in this analysis were enrolled in the Chemicals in our Bodies (CIOB) cohort study (N = 506). PFAS and PBDEs were measured in serum obtained during the second trimester of pregnancy. Linear regression models were used to calculate crude and adjusted ß coefficients for the association between PFAS and PBDE concentrations in tertiles and gestational age and birth weight z-scores. Individual PFAS and PBDE concentrations, as well as their sums, were examined in separate models. RESULTS: The highest compared to lowest tertile of BDE-47 was associated with shorter gestational age (ß = - 0.49, 95% confidence interval [CI] = - 0.95, - 0.02). Additionally, exposure to BDE-47 and BDE-99 in the middle tertile was also associated with a reduction in birth weight z-scores (ß = - 0.26, 95% CI = -0.48, - 0.04; ß = - 0.25, 95% CI = -0.47, - 0.04, respectively) compared to those in the lowest tertile of exposure. No consistent associations were observed between increasing PFAS concentrations and gestational age or birth weight z-scores. DISCUSSION: Among a diverse group of pregnant women in the San Francisco Bay Area, we found non-linear associations between prenatal exposure to PBDEs during the second trimester of pregnancy and birth weight z-scores. However, most PFAS congeners were not associated with adverse birth outcomes. PFAS and PBDE concentrations were lower in our cohort relative to other studies. Future research should assess the effects of emerging and persistent PFAS and PBDEs on birth outcomes, as some congeners are being phased out and replaced by chemically similar structures.


Assuntos
Peso ao Nascer/efeitos dos fármacos , Poluentes Ambientais/efeitos adversos , Retardadores de Chama/efeitos adversos , Fluorocarbonos/efeitos adversos , Idade Gestacional , Éteres Difenil Halogenados/efeitos adversos , Exposição Materna/efeitos adversos , Adulto , Estudos de Coortes , Poluentes Ambientais/sangue , Feminino , Retardadores de Chama/metabolismo , Fluorocarbonos/sangue , Éteres Difenil Halogenados/sangue , Humanos , Gravidez , São Francisco , Adulto Jovem
6.
Angew Chem Int Ed Engl ; 59(6): 2289-2293, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-31773819

RESUMO

Chemical synthesis of amino acids directly from biomass feedstock is rare. Reported here is a one-step protocol to convert crude glycerol, from the biodiesel industry, into 43 % alanine over a Ru1 Ni7 /MgO catalyst. The multifunctional catalytic system promotes glycerol conversion into lactic acid, and then into alanine. X-ray absorption spectroscopy and scanning transmission electron microscopy revealed the existence of bimetallic RuNi species, whereas density-functional theory calculations suggested Ni-doped Ru substantially decreased the Ea of C-H bond dissociation of lactate alkoxide to form pyruvate, which is the rate-determining step. The catalytic route established in this work creates new opportunities for glycerol utilization and enriches the substrate scope of renewable feedstock to access value-added amino acids.


Assuntos
Alanina/biossíntese , Glicerol/metabolismo , Amônia/química , Biocombustíveis , Catálise , Complexos de Coordenação/química , Teoria da Densidade Funcional , Glicerol/química , Ácido Láctico/química , Níquel/química , Rutênio/química , Espectroscopia por Absorção de Raios X
7.
BMC Plant Biol ; 19(1): 471, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694540

RESUMO

BACKGROUND: Meiosis of newly formed allopolyploids frequently encounter perturbations induced by the merging of divergent and hybridizable genomes. However, to date, the meiotic properties of allopolyploids with dysploid parental karyotypes have not been studied in detail. The allotetraploid Cucumis ×hytivus (HHCC, 2n = 38) was obtained from interspecific hybridization between C. sativus (CC, 2n = 14) and C. hystrix (HH, 2n = 24) followed by chromosome doubling. The results of this study thus offer an excellent opportunity to explore the meiotic properties of allopolyploids with dysploid parental karyotypes. RESULTS: In this report, we describe the meiotic properties of five chromosomes (C5, C7, H1, H9 and H10) and two genomes in interspecific hybrids and C. ×hytivus (the 4th and 14th inbred family) through oligo-painting and genomic in situ hybridization (GISH). We show that 1) only two translocations carrying C5-oligo signals were detected on the chromosomes C2 and C4 of one 14th individual by the karyotyping of eight 4th and 36 14th plants based on C5- and C7-oligo painting, and possible cytological evidence was observed in meiosis of the 4th generation; 2) individual chromosome have biases for homoeologous pairing and univalent formation in F1 hybrids and allotetraploids; 3) extensive H-chromosome autosyndetic pairings (e.g., H-H, 25.5% PMCs) were observed in interspecific F1 hybrid, whereas no C-chromosome autosyndetic pairings were observed (e.g. C-C); 4) the meiotic properties of two subgenomes have significant biases in allotetraploids: H-subgenome exhibits higher univalent and chromosome lagging frequencies than C-subgenome; and 5) increased meiotic stability in the S14 generation compared with the S4 generation, including synchronous meiosis behavior, reduced incidents of univalent and chromosome lagging. CONCLUSIONS: These results suggest that the meiotic behavior of two subgenomes has dramatic biases in response to interspecific hybridization and allopolyploidization, and the meiotic behavior harmony of subgenomes is a key subject of meiosis evolution in C. ×hytivus. This study helps to elucidate the meiotic properties and evolution of nascent allopolyploids with the dysploid parental karyotypes.


Assuntos
Cromossomos de Plantas , Cucumis/genética , Meiose/genética , Tetraploidia , Coloração Cromossômica , Hibridização Genética , Hibridização in Situ Fluorescente/métodos , Cariótipo , Translocação Genética
8.
J Plant Res ; 132(3): 419-429, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30903398

RESUMO

Dendrobium officinale is a traditional medicinal herb with a variety of bioactive components. Alkaloid is one of the major active ingredients of Dendrobium plants, and its immune regulatory effects have been well-studied. Although a number of genes involved in the biosynthetic pathway of alkaloids have been elucidated, the regulation mechanism underlying the methyl-jasmonate (MeJA)-induced accumulation of alkaloids in D. officinale is largely unknown. In our study, a total of 4,857 DEGs, including 2,943 up- and 1,932 down-regulated genes, were identified between the control and MeJA-treated groups. Kyoto Encyclopedia of Genes and Genomes annotation showed that a number of DEGs were associated with the putative alkaloid biosynthetic pathway in D. officinale. The main group of Dendrobium alkaloids are sesquiterpene alkaloids, which are the downstream products of mevalonate (MVA) and methylerythritol 4-phosphate (MEP) pathway. Several MVA and MEP pathway genes were significantly up-regulated by the MeJA treatment, suggesting an active precursor supply for the alkaloid biosynthesis under MeJA treatment. A number of MeJA-induced P450 family genes, aminotransferase genes and methyltransferase genes were identified, providing several important candidates to further elucidate the sesquiterpene alkaloid biosynthetic pathway of D. officinale. Furthermore, a large number of MeJA-induced transcript factor encoding genes were identified, suggesting a complex genetic network affecting the sesquiterpene alkaloid metabolism in D. officinale. Our data aids to reveal the regulation mechanism underlying the MeJA-induced accumulation of sesquiterpene alkaloids in D. officinale.


Assuntos
Acetatos/metabolismo , Alcaloides/metabolismo , Ciclopentanos/metabolismo , Dendrobium/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Dendrobium/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Redes e Vias Metabólicas , Reguladores de Crescimento de Plantas/fisiologia , Reação em Cadeia da Polimerase em Tempo Real
9.
Chromosoma ; 126(6): 713-728, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28688040

RESUMO

Allopolyploidy and homoeologous recombination are two important processes in reshaping genomes and generating evolutionary novelties. Newly formed allopolyploids usually display chromosomal perturbations as a result of pairing errors at meiosis. To understand mechanisms of stabilization of allopolyploid species derived from distant chromosome bases, we investigated mitotic stability of a synthetic Cucumis allotetraploid species in relation to meiosis chromosome behavior. The Cucumis × hytivus is an allotetraploid synthesized from interspecific hybridization between cucumber (Cucumis sativus, 2n = 14) and its wild relative Cucumis hystrix (2n = 24) followed by spontaneous chromosome doubling. In the present study, we analyzed the wild parent C. hystrix and the latest generation of C. hytivus using GISH (genomic in situ hybridization) and cross-species FISH (fluorescence in situ hybridization). The karyotype of C. hystrix was constructed with two methods using cucumber fosmid clones and repetitive sequences. Using repeat-element probe mix in two successive hybridizations allowed for routine identification of all 19 homoeologous chromosomes of allotetraploid C. hytivus. No aneuploids were identified in any C. hytivus individuals that were characterized, and no large-scale chromosomal rearrangements were identified in this synthetic allotetraploid. Meiotic irregularities, such as homoeologous pairing, were frequently observed, resulting in univalent and intergenomic multivalent formation. The relatively stable chromosome structure of the synthetic Cucumis allotetraploid may be explained by more deleterious chromosomal viable gametes compared with other allopolyploids. The knowledge of genetic and genomic information of Cucumis allotetraploid species could provide novel insights into the establishment of allopolyploids with different chromosome bases.


Assuntos
Cromossomos de Plantas , Cucumis/genética , Genoma de Planta , Hibridização Genética , Poliploidia , Hibridização in Situ Fluorescente , Cariótipo , Meiose , Pólen/genética , Sequências Repetitivas de Ácido Nucleico
10.
Genome ; 61(6): 397-404, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29611431

RESUMO

Cucumis anguria is a potential genetic resource for improving crops of the genus Cucumis, owing to its broad-spectrum resistance. However, few cytogenetic studies on C. anguria have been reported because of its small metaphase chromosomes and the scarcity of distinguished chromosomal landmarks. In this study, 14 single-copy genes from cucumber and rDNAs were used as probes for FISH to identify the individual chromosomes of C. anguria. The distinctive signal distribution patterns of the probes allowed us to distinguish each chromosome of C. anguria (A01-A12). Further, detailed chromosome characteristics were obtained through pachytene chromosome FISH. The lengths of pachytene chromosomes varied from 54.80 to 143.41 µm. The proportion of heterochromatin regions varied from 13.56% to 63.86%. Finally, the chromosomal homeologous relationship between C. anguria and cucumber (C1-C7) was analyzed. The results showed that A06 + A09, A03 + A12, A02 + A04, and A01 + A11 were homeologs of C1, C2, C3, and C6, respectively. Furthemore, chromosomes A08, A10, and A05 were homeologs of C4, C5, and C7, respectively. Chromosome identification and homeologous relationship analysis between C. anguria and cucumber lay the foundation for further research of genome structure evolution in species of Cucumis.


Assuntos
Cromossomos de Plantas/genética , Cucumis/genética , Homologia de Sequência do Ácido Nucleico , Genes de Plantas , Heterocromatina/genética , Cariótipo
11.
Environ Sci Technol ; 51(8): 4697-4704, 2017 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-28304169

RESUMO

In response to health concerns and widespread human exposures, two widely used commercial formulations of polybrominated diphenyl ethers (PBDEs) were banned in the United States in 2005. Initial biomonitoring data have provided early indications of reduced human exposures since these bans took effect. Our objective was to evaluate temporal trends in PBDE serum levels among a population of older California women during a four-year period, beginning approximately five years after these formulations were banned. Automated solid phase extraction and gas chromatography/high resolution mass spectrometry were used to measure PBDE levels in blood collected during 2011-2015 among 1253 women (ages 40-94) participating in the California Teachers Study. Only congeners with detection frequencies (DF) ≥ 75% were included in the present analysis: BDE-47 (DF = 88%); BDE-100 (DF = 78%); and BDE-153 (DF = 80%). Results from age- and race/ethnicity-adjusted linear regression analyses indicated modest, but statistically significant, average annual percent increases in the serum concentrations of all three PBDEs over the four-year study period. While not without limitations, these results, in the context of other biomonitoring data, suggest that earlier reported declines in PBDE levels may have plateaued and may now be starting to increase. Further biomonitoring to ascertain current trends and determinants of population exposures is warranted.


Assuntos
Éteres Difenil Halogenados/sangue , Bifenil Polibromatos/sangue , Idoso , California , Monitoramento Ambiental , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Pessoa de Meia-Idade , Extração em Fase Sólida
12.
Genome ; 59(7): 449-57, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27334092

RESUMO

Ribosomal DNAs are useful cytogenetic markers for chromosome analysis. Studies investigating site numbers and distributions of rDNAs have provided important information for elucidating genome organization and chromosomal relationships of many species by fluorescence in situ hybridization. But relevant studies are scarce for species of the genus Cucumis, especially in wild species. In the present study, FISH was conducted to investigate the organization of 45S and 5S rDNA among 20 Cucumis accessions, including cultivars and wild accessions. Our results showed that the number of 45S rDNA sites varied from one to five pairs in different accessions, and most of these sites are located at the terminal regions of chromosomes. Interestingly, up to five pairs of 45S rDNA sites were observed in C. sativus var. sativus, the species which has the lowest chromosome number, i.e., 2n = 14. Only one pair of 5S rDNA sites was detected in all accessions, except for C. heptadactylus, C. sp, and C. spp that had two pairs of 5S rDNA sites. The distributions of 5S rDNA sites showed more variation than 45S rDNA sites. The phylogenetic analysis in this study showed that 45S and 5S rDNA have contrasting evolutionary patterns. We find that 5S rDNA has a polyploidization-related tendency towards the terminal location from an interstitial location but maintains a conserved site number, whereas the 45S rDNA showed a trend of increasing site number but a relatively conserved location.


Assuntos
Mapeamento Cromossômico , Cromossomos de Plantas , Cucumis/genética , DNA de Plantas/genética , DNA Ribossômico/genética , RNA Ribossômico 5S/genética , RNA Ribossômico/genética , África , Ásia , Evolução Molecular , Variação Genética , Genoma de Planta , Hibridização in Situ Fluorescente/métodos , Cariotipagem , Filogenia , Poliploidia , Especificidade da Espécie
13.
Environ Sci Technol ; 50(7): 3945-53, 2016 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-26906616

RESUMO

As consumer products treated with polybrominated diphenyl ethers (PBDEs) reach the end of their life cycle, they often are discarded into solid-waste facilities, offering a potential reservoir for exposure. The likelihood of exposures to PBDEs by residents living near those sites rarely has been explored. This study collected blood samples from 923 female participants in the California Teachers Study in 2011-2013 and examined the association between participants' residential proximity to solid-waste facilities with potential release of PBDEs and serum levels of three congeners (BDE-47, BDE-100, and BDE-153). General linear regression analysis was used to examine the association, adjusting for age, race, body-mass index, neighborhood socioeconomic status, and urban residency. Compared to participants living >10 km from any selected site, those living within 2 km had 45% higher BDE-47 (95% CI: 5-100%) and BDE-100 (95% CI: 0-109%) levels, and those living between 2 and 10 km had 35% higher BDE-47 (95% CI: 0-82%) and 29% higher BDE-100 (95% CI: -9 to 82%) levels. No associations were found for BDE-153. Living close to some solid waste sites may be related to higher serum BDE-47 and BDE-100 levels. Studies with comprehensive exposure assessments are needed to confirm these initial observations.


Assuntos
Monitoramento Ambiental , Éteres Difenil Halogenados/sangue , Características de Residência , Resíduos Sólidos , Idoso , Idoso de 80 Anos ou mais , California , Feminino , Humanos , Lipídeos/química , Pessoa de Meia-Idade , Bifenil Polibromatos/sangue
14.
BMC Genomics ; 16(1): 730, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26407707

RESUMO

BACKGROUND: Differentiation and copy number of repetitive sequences affect directly chromosome structure which contributes to reproductive isolation and speciation. Comparative cytogenetic mapping has been verified an efficient tool to elucidate the differentiation and distribution of repetitive sequences in genome. In present study, the distinct chromosomal structures of five Cucumis species were revealed through genomic in situ hybridization (GISH) technique and comparative cytogenetic mapping of major satellite repeats. RESULTS: Chromosome structures of five Cucumis species were investigated using GISH and comparative mapping of specific satellites. Southern hybridization was employed to study the proliferation of satellites, whose structural characteristics were helpful for analyzing chromosome evolution. Preferential distribution of repetitive DNAs at the subtelomeric regions was found in C. sativus, C hystrix and C. metuliferus, while majority was positioned at the pericentromeric heterochromatin regions in C. melo and C. anguria. Further, comparative GISH (cGISH) through using genomic DNA of other species as probes revealed high homology of repeats between C. sativus and C. hystrix. Specific satellites including 45S rDNA, Type I/II, Type III, Type IV, CentM and telomeric repeat were then comparatively mapped in these species. Type I/II and Type IV produced bright signals at the subtelomeric regions of C. sativus and C. hystrix simultaneously, which might explain the significance of their amplification in the divergence of Cucumis subgenus from the ancient ancestor. Unique positioning of Type III and CentM only at the centromeric domains of C. sativus and C. melo, respectively, combining with unique southern bands, revealed rapid evolutionary patterns of centromeric DNA in Cucumis. Obvious interstitial telomeric repeats were observed in chromosomes 1 and 2 of C. sativus, which might provide evidence of the fusion hypothesis of chromosome evolution from x = 12 to x = 7 in Cucumis species. Besides, the significant correlation was found between gene density along chromosome and GISH band intensity in C. sativus and C. melo. CONCLUSIONS: In summary, comparative cytogenetic mapping of major satellites and GISH revealed the distinct differentiation of chromosome structure during species formation. The evolution of repetitive sequences was the main force for the divergence of Cucumis species from common ancestor.


Assuntos
Mapeamento Cromossômico , Estruturas Cromossômicas , Cucumis/genética , Sequências Repetitivas de Ácido Nucleico , Hibridização Genômica Comparativa , Citogenética , DNA de Plantas/genética , DNA Ribossômico/genética , DNA Satélite/genética , Evolução Molecular , Cariótipo , Especificidade da Espécie , Telômero/genética
15.
Environ Sci Technol ; 49(5): 2948-58, 2015 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-25643236

RESUMO

Concern about persistent organic pollutants (POPs) in Californians prompted the state's biomonitoring program to conduct a study in firefighters, who are occupationally exposed to high levels of POPs. In this work we present serum concentrations of several classes of POPs (polybrominated diphenyl ethers [PBDEs], polychlorinated biphenyls [PCBs], and organochlorine pesticides [OCPs]) in 101 Southern California firefighters. Despite recently reported declining trends of PBDEs in Californians, high levels were measured in firefighters' serum (Σ5PBDEs: median = 59.1 ng/(g of lipid); range = 18.8-714 ng/(g of lipid)) in comparison to other populations in California during the same period. In addition, nearly one-third of subjects had particularly high serum levels of decabromodiphenyl ether (BDE-209), consistent with other recent results in firefighters; this pattern may be a marker of recent firefighting activity. In contrast, serum levels of PCBs and OCPs measured in firefighters' sera were not elevated compared to U.S. levels. Multivariable analysis indicated that lower levels of serum PBDEs were associated with turnout gear cleaning and storage practices after fires. Our study supports the hypothesis that firefighting activities are likely to increase exposure to PBDEs and that good housekeeping and personal hygiene practices may reduce exposure to these compounds.


Assuntos
Bombeiros , Éteres Difenil Halogenados/análise , Exposição Ocupacional/efeitos adversos , California , Monitoramento Ambiental , Humanos , Hidrocarbonetos Clorados/análise , Praguicidas/análise
16.
Chimia (Aarau) ; 69(3): 120-4, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26507214

RESUMO

The overuse of fossil fuels has caused an energy crisis and associated environment issues. It is desirable to utilize renewable resources for the production of chemicals. This review mainly introduces our recent work on the transformation of renewable carbon resources including the conversion of cellulose, lignin, and chitin into sustainable chemicals. Various transformation routes have been established to form value-added chemicals, and accordingly a variety of effective catalytic systems have been developed, either based on metal catalysis and/or acid-base catalysis, to enable the desired transformation.

17.
BMC Genomics ; 15: 1158, 2014 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-25534138

RESUMO

BACKGROUND: Cucumber, Cucumis sativus L., is an economically important vegetable crop which is processed or consumed fresh worldwide. However, the narrow genetic base in cucumber makes it difficult for constructing high-density genetic maps. The development of massively parallel genotyping methods and next-generation sequencing (NGS) technologies provides an excellent opportunity for developing single nucleotide polymorphisms (SNPs) for linkage map construction and QTL analysis of horticultural traits. Specific-length amplified fragment sequencing (SLAF-seq) is a recent marker development technology that allows large-scale SNP discovery and genotyping at a reasonable cost. In this study, we constructed a high-density SNP map for cucumber using SLAF-seq and detected fruit-related QTLs. RESULTS: An F2 population of 148 individuals was developed from an intra-varietal cross between CC3 and NC76. Genomic DNAs extracted from two parents and 148 F2 individuals were subjected to high-throughput sequencing and SLAF library construction. A total of 10.76 Gb raw data and 75,024,043 pair-end reads were generated to develop 52,684 high-quality SLAFs, out of which 5,044 were polymorphic. 4,817 SLAFs were encoded and grouped into different segregation patterns. A high-resolution genetic map containing 1,800 SNPs was constructed for cucumber spanning 890.79 cM. The average distance between adjacent markers was 0.50 cM. 183 scaffolds were anchored to the SNP-based genetic map covering 46% (168.9 Mb) of the cucumber genome (367 Mb). Nine QTLs for fruit length and weight were detected, a QTL designated fl3.2 explained 44.60% of the phenotypic variance. Alignment of the SNP markers to draft genome scaffolds revealed two mis-assembled scaffolds that were validated by fluorescence in situ hybridization (FISH). CONCLUSIONS: We report herein the development of evenly dispersed SNPs across cucumber genome, and for the first time an SNP-based saturated linkage map. This 1,800-locus map would likely facilitate genetic mapping of complex QTL loci controlling fruit yield, and the orientation of draft genome scaffolds.


Assuntos
Mapeamento Cromossômico/métodos , Cucumis sativus/genética , Frutas/anatomia & histologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Análise de Sequência de DNA/métodos , Mapeamento Cromossômico/economia , Análise Custo-Benefício , Cucumis sativus/anatomia & histologia , Frutas/genética , Técnicas de Genotipagem , Sequenciamento de Nucleotídeos em Larga Escala/economia , Tamanho do Órgão , Análise de Sequência de DNA/economia
18.
Chemosphere ; 358: 142201, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38692367

RESUMO

Thallium (Tl) is a potential toxicity element that poses significant ecological and environmental risks. Recently, a substantial amount of Tl has been released into the environment through natural and human activities, which attracts increasing attention. The determination of this hazardous and trace element is crucial for controlling its pollution. This article summarizes the advancement and progress in optimizing Tl detection techniques, including atomic absorption spectroscopy (AAS), voltammetry, inductively coupled plasma (ICP)-based methods, spectrophotometry, and X-ray-based methods. Additionally, it introduces sampling and pretreatment methods such as diffusive gradients in thin films (DGT), liquid-liquid extraction, solid phase extraction, and cloud point extraction. Among these techniques, ICP-mass spectrometry (MS) is the preferred choice for Tl detection due to its high precision in determining Tl as well as its species and isotopic composition. Meanwhile, some new materials and agents are employed in detection. The application of novel work electrode materials and chromogenic agents is discussed. Emphasis is placed on reducing solvent consumption and utilizing pretreatment techniques such as ultrasound-assisted processes and functionalized magnetic particles. Most detection is performed in aqueous matrices, while X-ray-based methods applied to solid phases are summarized which provide non-destructive analysis. This work improves the understanding of Tl determination technology while serving as a valuable resource for researchers seeking appropriate analytical techniques.


Assuntos
Monitoramento Ambiental , Tálio , Tálio/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Espectrofotometria Atômica , Extração em Fase Sólida/métodos , Espectrometria de Massas/métodos , Extração Líquido-Líquido/métodos
19.
Int J Low Extrem Wounds ; 23(1): 70-79, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36648167

RESUMO

To analyze and evaluate the clinical efficacy of Chinese and Western medical techniques in the treatment of severe diabetic foot ulcers complicated with necrotizing fasciitis of the lower leg and summarize the treatment experience of such patients to identify a new method of limb salvage treatment. A total of 46 patients with severe diabetic foot ulcers and necrotizing fasciitis of the lower leg were treated with such techniques as surgical debridement, bone drilling, open joint fusion, and microskin implantation. Wounds were treated with moisture-exposed burn therapy (a regenerative medical treatment for burns, wounds, and ulcers) and moisture-exposed burn ointment (a traditional Chinese medicine); underlying diseases were also treated effectively. The wound healing time, rate of high amputation, and mortality of these patients were summarized, and the clinical efficacy of such treatments was evaluated. Of the 46 patients enrolled, 38 patients were cured, with a cure rate of 82.61%. The average wound healing time was 130 ± 74.37 days. Two patients underwent high amputations, with an amputation rate of 4.35%, and 4 deaths occurred, with a mortality rate of 8.70%. The combination of Chinese and Western medical techniques in the treatment of severe diabetic foot ulcers complicated with necrotizing fasciitis of the lower leg not only effectively saved patients' lives and promoted wound healing but also greatly reduced the rates of high amputation and disability.


Assuntos
Diabetes Mellitus , Pé Diabético , Fasciite Necrosante , Humanos , Perna (Membro) , Fasciite Necrosante/complicações , Fasciite Necrosante/diagnóstico , Fasciite Necrosante/cirurgia , Pé Diabético/complicações , Pé Diabético/diagnóstico , Pé Diabético/cirurgia , Extremidade Inferior , Amputação Cirúrgica
20.
Biomed Pharmacother ; 177: 117089, 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38972148

RESUMO

Hepatocellular carcinoma (HCC) holds a prominent position among global cancer types. Classically, HCC manifests in individuals with a genetic predisposition when they encounter risk elements, particularly in the context of liver cirrhosis. Peroxisome proliferator-activated receptors (PPARs), which are transcription factors activated by fatty acids, belong to the nuclear hormone receptor superfamily and play a pivotal role in the regulation of energy homeostasis. At present, three distinct subtypes of PPARs have been recognized: PPARα, PPARγ, and PPARß/δ. They regulate the transcription of genes responsible for cellular development, energy metabolism, inflammation, and differentiation. In recent years, with the rising incidence of HCC, there has been an increasing focus on the mechanisms and roles of PPARs in HCC. PPARα primarily mediates the occurrence and development of HCC by regulating glucose and lipid metabolism, inflammatory responses, and oxidative stress. PPARß/δ is closely related to the self-renewal ability of liver cancer stem cells (LCSCs) and the formation of the tumor microenvironment. PPARγ not only influences tumor growth by regulating the glucose and lipid metabolism of HCC, but its agonists also have significant clinical significance for the treatment of HCC. Therefore, this review offers an exhaustive examination of the role of the three PPAR subtypes in HCC progression, focusing on their mediation of critical cellular processes such as glucose and lipid metabolism, inflammation, oxidative stress, and other pivotal signaling pathways. At the end of the review, we discuss the merits and drawbacks of existing PPAR-targeted therapeutic strategies and suggest a few alternative combinatorial therapeutic approaches that diverge from conventional methods.

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