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1.
Arch Environ Contam Toxicol ; 72(4): 530-539, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28343339

RESUMEN

Extractable polycyclic aromatic hydrocarbons (EPAHs) and bound PAHs (BPAHs) were measured in a sediment core using conventional Soxhlet extraction and a more astringent extraction method, with the objectives of determining the influence of BPAHs on the historical reconstruction of PAHs and exploring the formation of BPAHs and long-term behaviors of PAHs in sediment. The results indicated that the formation of BPAHs was clearly sediment-depth and molecular-size dependent. BPAHs represents an important portion of PAHs in sediment and cannot be extracted by conventional Soxhlet extraction. This suggests that the previously developed vertical profile of PAHs is not the real chronology of PAHs and the plausible interpretation derived from the sedimentary records of PAHs needs reexamination. Based on the previous findings, a biphase model was proposed and the formation of BPAHs was predicted. Due to the different nature of geosorbents in sediment, redistribution of PAHs among these geosorbents logically leads to the formation of BPAHs and is kinetically favorable for smaller molecular PAHs. This is consistent with the obtained results. Many factors may influence the formation of BPAHs, such as the physicochemical structure of sediment and environmental conditions. There is still a long way to reveal the thermodynamical characteristics in action during the formation of BPAHs.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis
2.
Arch Insect Biochem Physiol ; 85(3): 164-79, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24532462

RESUMEN

The Middle East-Minor 1 cryptic species (MEAM1), Bemisia tabaci (Gennadius) is a globally invasive pest. It spreads widely due to its high fecundity and mutualistic interactions with the virus they vector. Feeding on virus (tomato yellow leaf curl China virus, TYLCCNV)-infected host plants improves their fecundity, however, the key factor regulating the signaling transduction in reproduction of whitefly remains to be identified. Here, we cloned a full length cDNA encoding an insulin-like peptide in MEAM1 (BtILP1) and investigated its expression profile, functions, and the expression induced by feeding on virus-infected tobacco plants. The full length cDNA of BtILP1 was 590 bps and encoded an open reading frame containing 149 amino acid residues. Multiple sequences alignment results showed BtILP1 contained the structural features typical of the insulin family. Expression dynamics associated with development showed the expression level of BtILP1 peaked at 5 days posteclosion (PE). During 1 to 3 days PE, BtILP1 was expressed highly in the head and abdomen of female adults and highly in the head during 5 to 7 days PE. Knockdown of the BtILP1 expression also impaired vitellogenin gene expression at both transcript and protein levels. Downregulating BtILP1 expression decreased fecundity of female adults and hatching rate of eggs. Feeding on virus-infected tobacco increased BtILP1 expression in MEAM1 female adults. We infer feeding on begomovirus-infected tobacco enhances the reproduction of MEAM1 by inducing BtILP1 expression. Our results give a new sight into the mutualistic interactions between virus and its insect vector.


Asunto(s)
Regulación de la Expresión Génica , Hemípteros/fisiología , Proteínas de Insectos/genética , Secuencia de Aminoácidos , Animales , Begomovirus/fisiología , ADN Complementario/genética , ADN Complementario/metabolismo , Conducta Alimentaria/fisiología , Femenino , Fertilidad/fisiología , Hemípteros/genética , Hemípteros/metabolismo , Hemípteros/virología , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Datos de Secuencia Molecular , Interferencia de ARN , Alineación de Secuencia , Nicotiana/fisiología , Nicotiana/virología , Transcriptoma
3.
Int J Biol Macromol ; 265(Pt 1): 130636, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38467214

RESUMEN

In insects, vision is crucial in finding host plants, but its role in nocturnal insects is largely unknown. Vision involves responses to specific spectra of photon wavelengths and opsins plays an important role in this process. Long-wavelength sensitive opsin (LW opsin) and blue-sensitive opsin (BL opsin) are main visual opsin proteins and play important in behavior regulation.We used CRISPR/Cas9 technology to mutate the long-wavelength-sensitive and blue wavelength-sensitive genes and explored the role of vision in the nocturnal invasive pest Tuta absoluta. Light wave experiments revealed that LW2(-/-) and BL(-/-) mutants showed abnormal wavelength tropism. Both LW2 and BL mutations affected the preference of T. absoluta for the green environment. Mutations in LW2 and BL are necessary to inhibit visual attraction. The elimination of LW2 and BL affected the preference of leaf moths for green plants, and mutations in both induced a preference in moths for white plants. Behavioral changes resulting from LW2(-/-) and BL(-/-) mutants were not affected by sense of smell, further supporting the regulatory role of vision in insect behavior. To the best of our knowledge, this is the first study to reveal that vision, not smell, plays an important role in the host-seeking behavior of nocturnal insects at night, of which LW2 and BL opsins are key regulatory factors. These study findings will drive the development of the "vision-ecology" theory.


Asunto(s)
Visión de Colores , Mariposas Nocturnas , Animales , Opsinas/genética , Opsinas/metabolismo , Especies Introducidas , Mariposas Nocturnas/genética , Mariposas Nocturnas/metabolismo , Insectos/metabolismo
4.
J Econ Entomol ; 116(1): 256-262, 2023 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-36625153

RESUMEN

Hymenopteran parasitoids generally show a haplo-diploid sex determination system. Haploid males are produced from unfertilized eggs, whereas diploid females develop from fertilized eggs (arrhenotokous). In some cases, diploid females develop from unfertilized eggs (thelytokous). Diglyphus wani (Hymenoptera: Eulophidae) is a biological control agent for agromyzid leafminers and have arrhenotokous and thelytokous strains. However, the morphological characteristics of two strains of D. wani are so similar that it is difficult to accurately distinguish them based on morphology. Here, a rapid molecular identification method was developed based on the mitochondrial gene cytochrome c oxidase I (COI) and one-step multiplex PCR. Two primer combinations, PC1 (Ar-F1/Th-F1/WR2) and PC2 (Ar-F1/Th-F4/WR2), were designed and repeatedly screened to distinguish two strains simultaneously, of which two special forward primers Th-F1/Th-F4 were used for the thelytokous strain and one special forward primer Ar-F1 was used for the arrhenotokous strain. In addition, a common reverse primer, WR2, was used for both strains. The PC1 and PC2 PCR assays were effective in distinguishing the two strains at different developmental stages and field colonies. This method provides a reliable, highly sensitive, and cost-effective tool for the rapid identification of the two strains of D. wani.


Asunto(s)
Himenópteros , Avispas , Femenino , Masculino , Animales , Himenópteros/genética , Reacción en Cadena de la Polimerasa Multiplex , Agentes de Control Biológico
5.
World J Gastrointest Endosc ; 15(9): 564-573, 2023 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-37744321

RESUMEN

BACKGROUND: We invented Endoscopic Ruler, a new endoscopic device to measure the size of varices in patients with cirrhosis and portal hypertension. AIM: To assess the feasibility and safety of Endoscopic Ruler, and evaluate the agreement on identifying large oesophageal varices (OV) between Endoscopic Ruler and the endoscopists, as well as the interobserver agreement on diagnosing large OV using Endoscopic Ruler. METHODS: We prospectively and consecutively enrolled patients with cirrhosis from 11 hospitals, all of whom got esophagogastroduodenoscopy (EGD) with Endoscopic Ruler. The primary study outcome was a successful measurement of the size of varices using Endoscopic Ruler. The secondary outcomes included adverse events, operation time, the agreement of identifying large OV between the objective measurement of Endoscopic Ruler and the empirical reading of endoscopists, together with the interobserver agreement on diagnosing large OV by Endoscopic Ruler. RESULTS: From November 2020 to April 2022, a total of 120 eligible patients with cirrhosis were recruited and all of them underwent EGD examinations with Endoscopic Ruler successfully without any adverse event. The median operation time of Endoscopic Ruler was 3.00 min [interquartile range (IQR): 3.00 min]. The kappa value between Endoscopic Ruler and the endoscopists while detecting large OV was 0.52, demonstrating a moderate agreement. The kappa value for diagnosing large OV using Endoscopic Ruler among the six independent observers was 0.77, demonstrating a substantial agreement. CONCLUSION: The data demonstrates that Endoscopic Ruler is feasible and safe for measuring the size of varices in patients with cirrhosis and portal hypertension. Endoscopic Ruler is potential to promote the clinical practice of the two-grade classification system of OV.

6.
J Environ Monit ; 14(9): 2475-81, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22842647

RESUMEN

A maar lake is an excellent ecosystem to study the atmospheric deposition of pollutants, as its contaminants are primarily by atmospheric deposition. In this study, a sediment core from Sihailongwan Maar Lake, Northeast China, was collected and the historical atmospherically deposited polycyclic aromatic hydrocarbons (PAHs) were analyzed. The concentrations of TPAHs (the sum of the US EPA proposed 16 priority PAHs, excluding naphthalene and pyrene) ranged from 473.9 to 2289 ng g(-1) with a slow increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments. The input rate of TPAHs, especially that of PAH(9) (the sum of fluoranthene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(ah)anthrathene, and benzo(ghi)perylene), correlated well to the Chinese historical socioeconomic data. This indicates that sediment PAHs were mainly derived from human activities and PAH(9) can be regarded as a better indicator of the local socioeconomic development. Source identification suggested that PAHs were originated primarily from mixed sources (e.g., coal and biomass burning and petroleum combustion), except for perylene which was mostly of diagenetic origin. In addition, the down-core PAHs profile clearly illustrated that PAHs sources in Northeast China experienced a transformation from low- and moderate temperature to high-temperature combustion processes, especially after the late 1980s. Additionally, an ecological risk assessment using two redefined biological thresholds (TEQ(ERL) and TEQ(ERM)) indicated that most of the PAHs measured in the present sediment core would not cause an immediate toxic effect; only FLU and PHEN are a potential source of concern for biological impairment.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/química , Lagos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/estadística & datos numéricos , China
7.
Arch Environ Contam Toxicol ; 60(4): 590-6, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-20623117

RESUMEN

Using data from a 25-year retrospective of polycyclic aromatic hydrocarbons (PAHs) in sediment core from Lake Hongfeng, Southwest China, their possible sources and potential toxicologic significance were investigated. The total PAH concentrations (16 priority PAHs as proposed by the United States Environmental Protection Agency) in sediments ranged from 2936.1 to 5282.3 ng/g and gradually increased from the analyzed deeper sediments to surface sediments. PAHs were dominated by low molecular-weight components, especially phenanthrene (PHEN) and fluorene (FLU). However, a significantly increased number of high molecular-weight (HMW) PAHs was found in upper segments. The temporal trends of individual PAH species suggest that there may have been a change in energy use from low- to high-temperature combustion, especially after approximately 2001. PAH input to Lake Hongfeng originated mainly from domestic coal combustion and biomass burning, whereas fuel combustion characteristics have also been found in recent years. Sediment-quality assessment implied that potential adverse biologic impact could be a probability for most low-ring PAHs (including naphthalene, acenaphthylene, acenaphthylene, FLU, PHEN, and anthracene). Nevertheless, more concern should be paid to HMW PAHs in the future due to their rapidly increasing trends in upper sediments. Because only one core was analyzed in this study, more work is needed to confirm the sources and toxicity of PAHs in Lake Hongfeng.


Asunto(s)
Monitoreo del Ambiente/métodos , Agua Dulce/química , Sedimentos Geológicos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , China
8.
J Insect Sci ; 11: 90, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21870987

RESUMEN

Oosorption is the resorption of oocytes in the ovaries, and is usually induced by environmental stress. It has been demonstrated in some insect species, but overall the mechanisms of oosorption are poorly understood. In this study, the oosorption in the endoparasitic wasp, Pteromalus puparum L. (Hymenoptera: Pteromalidae), was observed in response to starvation. To explore the details of oosorption in P. puparum, both levels of hemolymph vitellogenin and ovarian vitellin were determined using sandwich ELISA. The results indicated that both levels of vitellin and total protein in the ovaries were significantly decreased 48 h after eclosion in starved P. puparum, while those of vitellogenin and total protein in the hemolymph were increased. In addition, observation of the ultrastructure of mature oocytes in the ovarioles revealed changes in yolk protein content. Those protein yolk spheres and lipid yolk spheres that had accumulated in the oocytes, were transferred out of the oocytes of starved females. It was assumed that once oosorption was induced in P. puparum, vitellin in the oocytes was transported outside and released into the hemolymph. This information helps to elucidate a mechanism of oosorption in insects.


Asunto(s)
Oocitos/fisiología , Ovario/fisiología , Estrés Fisiológico , Vitelogeninas/metabolismo , Avispas/fisiología , Animales , Proteínas del Huevo/metabolismo , Femenino , Hemolinfa/metabolismo , Oocitos/ultraestructura , Inanición , Avispas/ultraestructura
9.
Zookeys ; 1071: 109-126, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34887696

RESUMEN

Diglyphus species are ecologically and economically important on agromyzid leafminers. In 2018, a thelytokous species, Diglyphuswani Liu, Zhu & Yefremova, was firstly reported and described. Subsequently, the arrhenotokous D.wani were discovered in Yunnan and Guizhou Provinces of China. We compared the morphological characteristics of thelytokous and arrhenotokous strains. However, the females of two strains had a strongly similar morphology and showed subtle differences in fore- and hind-wings. The difference was that forewing of arrhenotokous female was with denser setae overall, showing that costal cell with 2 ~ 4 rows of setae on dorsal surface and the setae of basal cell with 15 ~ 21 hairs and forewing of thelytokous female was with two rows of setae on dorsal surface and basal cell with 10 ~ 15 hairs generally. The setation beneath the marginal vein of the hind-wing of arrhenotokous female is denser than the same area of thelytokous female. To explore the genetic divergence between thelytokous and arrhenotokous strains of D.wani, the mitochondrial and nuclear gene were applied and sequenced. The polygenic analyses revealed that two strains can be distinguished by COI, ITS1 and ITS2. The mean sequence divergence between the two strains was 0.052, 0.010 and 0.007, respectively. Nevertheless, the 28S gene was unfeasible due to its containing a sharing haplotype between different strains. The two strains of D.wani are dominant parasitoids against agromyzid leafminers and such effective discernible foundation provides future in-depth studies on biological characteristics, along with insight into field application of two strains of D.wani.

10.
Sci Total Environ ; 760: 143416, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33246731

RESUMEN

High levels of dissolved arsenic (As) have been reported in many rivers running though the Tibetan Plateau (TP), the "Water Tower of Asia". However, the source, spatiotemporal variations, and geochemical behavior of dissolved As in these rivers remain poorly understood. In this study, hot spring, river water, and suspended particulate material samples collected from the Yarlung Tsangpo River (YTR) (upper reaches of the Brahmaputra River) system in 2017 and 2018 were analyzed. Spatial results shown that the upper reaches of YTR (Zone I) have comparatively high levels of dissolved As ([As]dissolved: mean 31.7 µg/L; 4.7-81.6 µg/L; n = 16), while the tributaries of the lower reaches (Zone II) have relatively low levels (mean 0.54 µg/L; 0.11-1.3 µg/L; n = 7). Seasonal results shown that the high [As]dissolved (6.1-22.4 µg/L) were found in September to June and low [As]dissolved (1.4-3.7 µg/L) were observed in July to August. Geothermal water is suspected as the main source of the elevated As levels in YTR due to the extremely high [As]dissolved in hot springs (1.13-9.76 mg/L) and abundance of geothermal systems throughout TP. However, the seasonal results suggested that weathering of As-containing rocks and minerals is also a key factor affecting the [As]dissolved in the river water in July to August (wet-season). Natural attenuation of As in main channel is dominated by dilution process due to the lower As concentrations in tributaries, but mostly occurred by both dilution and adsorption (or co-precipitation) processes in tributaries. This work highlights that the weathering process may have an important contribution to the dissolved As in the river waters in wet-season, and the geochemical behavior of As is largely transported conservatively in the main channel and relative non-conservatively in the tributaries in YTR system.

11.
Gen Comp Endocrinol ; 160(1): 102-8, 2009 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-19032957

RESUMEN

To elucidate the endocrine regulation of vitellogenesis in an endoparastic wasp (Pteromalus puparum), the titers of ecdysteroid and juvenile hormone (JH) from the whole bodies are measured using the method of radioimmunoassay and GC-MS, and compared with the levels of vitellogenin (Vg) mRNA in the fat bodies, hemolymph Vg and ovarian vitellin (Vt), respectively. The results show that the ecdysteroid titer and fat body Vg mRNA level have a similar dynamics tendency, and the peak titer is at adult eclosion. The titer of JH III and ovarian Vt also have a similar dynamics tendency, and the peak titer is at 48h after eclosion. The profiles of hemolymph Vg, Vg mRNA in fat bodies and ovarian Vt, are also measured in the wasps after treated with different amounts of 20-hydroxyecdysone (20HE) or JH III in female pupa and adults. The results show that 20HE stimulates Vg synthesis in the fat bodies and its release into the hemolymph, and that JH III only accelerates Vg sequestration in the oocytes. Decapitation, which is believed to terminate synthesis of JH in insects, can not inhibit vitellogenesis and oocyte maturation in P. puparum. Furthermore, Vg gene is expressed with a lower titer of JH and depressed by a higher titer of JH III. These studies suggest that ecdysteroids play a role in Vg synthesis and believed to be the dominant hormones in regulation of vitellogenesis in P. puparum, and JHs are not the essential factors to female reproduction in this wasp.


Asunto(s)
Ecdisteroides/fisiología , Hormonas Juveniles/fisiología , Vitelogénesis/fisiología , Animales , Ecdisteroides/genética , Femenino , Cromatografía de Gases y Espectrometría de Masas , Hormonas Juveniles/genética , ARN Mensajero , Radioinmunoensayo , Avispas
12.
Sci Rep ; 8(1): 3222, 2018 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-29459647

RESUMEN

Diglyphus species are dominant biocontrol agents for suppressing outbreaks of agromyzid leafminers in fields. In July 2015, we collected a new thelytokous species of Diglyphus in Qinghai, China. The wasp is here named as D. wani Liu, Zhu & Yefremova sp. nov., based on morphological and molecular analyses. The life history and biocontrol potential of the wasp were studied in the laboratory and by providing Liriomyza sativae larvae. The intrinsic rate of increase, finite rate of increase, and mean generation time were 0.2373 d-1, 1.2678 d-1, and 15.9 d, respectively. The wasps showed three types of host-killing behaviour, namely parasitism, host feeding and host stinging, resulting in 47.6, 94.4 and 3.4 host larvae killed per wasp over a lifetime, respectively. The finite total host-killing rate was 1.0071 and the wasp showed strong synovigeny. The wasp may be a crucial biocontrol agent against agromyzid leafminers.


Asunto(s)
Dípteros/crecimiento & desarrollo , Himenópteros/clasificación , Himenópteros/crecimiento & desarrollo , Estadios del Ciclo de Vida , Control Biológico de Vectores/métodos , Animales , China , Femenino , Himenópteros/anatomía & histología , Himenópteros/genética , Análisis de Supervivencia
13.
Gates Open Res ; 1: 16, 2018 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-29608200

RESUMEN

Background:Bemisia tabaci species ( B. tabaci), or whiteflies, are the world's most devastating insect pests. They cause billions of dollars (US) of damage each year, and are leaving farmers in the developing world food insecure. Currently, all publically available transcriptome data for B. tabaci are generated from pooled samples, which can lead to high heterozygosity and skewed representation of the genetic diversity. The ability to extract enough RNA from a single whitefly has remained elusive due to their small size and technological limitations. Methods: In this study, we optimised a single whitefly RNA extraction procedure, and sequenced the transcriptome of four individual adult Sub-Saharan Africa 1 (SSA1) B. tabaci. Transcriptome sequencing resulted in 39-42 million raw reads. De novo assembly of trimmed reads yielded between 65,000-162,000 Contigs across B. tabaci transcriptomes. Results: Bayesian phylogenetic analysis of mitochondrion cytochrome I oxidase (mtCOI) grouped the four whiteflies within the SSA1 clade. BLASTn searches on the four transcriptomes identified five endosymbionts; the primary endosymbiont Portieraaleyrodidarum and four secondary endosymbionts: Arsenophonus, Wolbachia, Rickettsia, and Cardinium spp. that were predominant across all four SSA1 B. tabaci samples with prevalence levels of between 54.1 to 75%. Amino acid alignments of the NusG gene of P. aleyrodidarum for the SSA1 B. tabaci transcriptomes of samples WF2 and WF2b revealed an eleven amino acid residue deletion that was absent in samples WF1 and WF2a. Comparison of the protein structure of the NusG protein from P. aleyrodidarum in SSA1 with known NusG structures showed the deletion resulted in a shorter D loop. Conclusions: The use of field-collected specimens means time and money will be saved in future studies using single whitefly transcriptomes in monitoring vector and viral interactions. Our method is applicable to any small organism where RNA quantity has limited transcriptome studies.

14.
J Agric Food Chem ; 55(22): 9152-8, 2007 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-17927196

RESUMEN

South China is probably one of the heaviest polybrominated diphenyl ether (PBDE) polluted regions in the world, thanks to the presence of huge and rapidly growing electronics manufacturing industries, as well as several of the world's largest e-waste recycling sites in the region. In the present work, a wide variety of nonfish seafood products collected from South China was analyzed for PBDE residues. The concentrations of PBDEs in seafood products were highly species-specific, and the magnitude of PBDE pollution was moderate in South China compared to the global levels. Congener patterns of PBDEs in seafood samples suggested that seafood products are prone to accumulating low-brominated congeners, and possible metabolic debromination of BDE-99 to BDE-47 could occur in certain organisms, such as crabs and mantis shrimp. Generally, the congener profile was dominated by BDE-209, and to a lesser extent by BDE-47 and BDE-99, which was consistent with the fact that Deca-BDE is mass-produced in China and with previous sediment results from the same area. The occurrence of BDE-209 in aquatic species from South China suggests that BDE-209 appears to be more bioavailable than previously thought, and the environmental fate and safety of BDE-209 require further investigation and call for a thorough reassessment.


Asunto(s)
Éteres/análisis , Contaminación de Alimentos/análisis , Bifenilos Polibrominados/análisis , Alimentos Marinos/análisis , China
15.
Environ Toxicol Chem ; 26(6): 1109-15, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17571674

RESUMEN

Seafood consumption is an important route of human exposure to organic contaminants. Residual levels of organochlorine pesticides (OCPs), including DDTs, hexachlorocyclohexanes (HCHs), heptachlor, aldrin, alpha-endosulfan, beta-endosulfan, dieldrin, endrin, endrin aldehyde, endrin ketone, methoxychlor, endosulfan sulfate, and heptachlor epoxide, were determined in a wide variety of seafood products collected from 11 coastal cities in southern China in June and October 2005. The results indicated that OCPs were predominated by DDTs and HCHs. The concentrations of other OCP components generally were low and were detectable in a small number of seafood samples only, probably reflective of the generally low levels of these OCPs in the study region and low bioaccumulation potentials in the species under investigation. Risk assessment against various standards clearly showed that seafood products were highly contaminated by DDTs and may pose health threat to local residents and the consumers all over the world. Furthermore, other OCP components, such as dieldrin and heptachlor, also impose lifetime cancer risk, especially to residents of coastal regions who often consume more seafood than those living inland. Therefore, continual monitoring of OCPs in various environment compartments, including biota and abiota, urgently is needed to mitigate effectively the impact of OCPs, particularly DDTs, on human health and the ecological environment.


Asunto(s)
Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Alimentos Marinos , China , Hidrocarburos Clorados/toxicidad , Plaguicidas/toxicidad , Medición de Riesgo , Especificidad de la Especie
16.
Sci Rep ; 7(1): 3623, 2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-28620217

RESUMEN

The whitefly Bemisia tabaci is a phloem-feeding pest that lives predominantly on herbaceous species and causes serious damage to hosts. Whitefly saliva is thought to contain proteins that modulate plant defences and facilitate feeding. A predicted secreted protein, laccase 1 (LAC1), was found in the salivary gland transcriptome of B. tabaci and might be existed in the watery saliva of B. tabaci. As LAC1 has a potential role in detoxification of secondary plant compounds in insects, we speculated that it may participate in the insect's response to plant defences. Here, we cloned the complete cDNA of LAC1 and found that (1) LAC1 was highly expressed in the salivary gland (SG) and midgut; (2) LAC1 transcript level in head (containing SG) was 2.1 times higher in plant-fed than in diet-fed whiteflies and 1.6 times higher in the head and 23.8 times higher in the midgut of whiteflies that fed on jasmonic acid (JA)-sprayed plants than on control plants; and (3) silencing LAC1 decreased the survival rate of plant-fed whiteflies but had a marginal effect on whiteflies raised on an artificial diet. These results indicate that LAC1 enables whiteflies to overcome the chemical defences of host plants and might act as an effector in saliva.


Asunto(s)
Hemípteros/fisiología , Interacciones Huésped-Parásitos , Lacasa/metabolismo , Plantas/parasitología , Animales , Regulación de la Expresión Génica , Hemípteros/clasificación , Hemípteros/enzimología , Lacasa/genética , Solanum lycopersicum/parasitología , Filogenia
17.
Micron ; 83: 1-10, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26826802

RESUMEN

The whitefly Bemisia tabaci MEAM1 species complex has invaded several parts of the world in the past 30 years and replaced native whitefly populations in the invaded regions, including certain areas of China. One of the possible reasons for the invasion is that MEAM1 whiteflies are more fecund than native species. However, the factors that affect the reproduction of the B. tabaci cryptic species are not clearly known. The regulation of oogenesis is thought to be one of the essential processes for egg formation and ovary development and could affect its population dynamics. In this study, the ovariole structure and oogenesis of the MEAM1 species complex was examined using light and transmission electron microscopy. Telotrophic ovarioles were observed in the MEAM1 species complex. Each ovariole had two well defined regions: the tropharium and the vitellarium. The tropharium always had more than ten trophocytes. The development of a single oocyte in the vitellarium has four phases: oocyte formation, previtellogenesis, vitellogenesis and choriogenesis. Two arrested oocytes, follicular cells and uncompleted oocytes were separated from the tropharium by microtubule and microfilaments. Early previtellogenesis oocytes absorbed nutrients and endosymbiont bacteria through a nutritive cord. However, the vitellogenesis of oocytes transmitted Vg through both the nutritive cord and the space between follicular cells. Each mature oocyte with deposited yolk proteins had only one bacteriocyte and was surrounded by a single layer of follicular cells. The oogenesis in the B. tabaci MEAM1 species complex concluded with the differentiation of oocytes, the transport of yolk and endosymbionts as well as the development and maturation of oocytes. This result provides important information that further defines the regulation of oogenesis in the B. tabaci complex.


Asunto(s)
Hemípteros , Oogénesis , Animales , Diferenciación Celular , Hemípteros/citología , Hemípteros/ultraestructura , Oocitos/citología , Oocitos/ultraestructura
18.
World J Gastroenterol ; 21(41): 11815-24, 2015 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-26557005

RESUMEN

Hepatic encephalopathy (HE) is a severe neuropsychiatric syndrome that most commonly occurs in decompensated liver cirrhosis and incorporates a spectrum of manifestations that ranges from mild cognitive impairment to coma. Although the etiology of HE is not completely understood, it is believed that multiple underlying mechanisms are involved in the pathogenesis of HE, and one of the main factors is thought to be ammonia; however, the ammonia hypothesis in the pathogenesis of HE is incomplete. Recently, it has been increasingly demonstrated that inflammation, including systemic inflammation, neuroinflammation and endotoxemia, acts in concert with ammonia in the pathogenesis of HE in cirrhotic patients. Meanwhile, a good number of studies have found that current therapies for HE, such as lactulose, rifaximin, probiotics and the molecular adsorbent recirculating system, could inhibit different types of inflammation, thereby improving the neuropsychiatric manifestations and preventing the progression of HE in cirrhotic patients. The anti-inflammatory effects of these current therapies provide a novel therapeutic approach for cirrhotic patients with HE. The purpose of this review is to describe the inflammatory mechanisms behind the etiology of HE in cirrhosis and discuss the current therapies that target the inflammatory pathogenesis of HE.


Asunto(s)
Antiinflamatorios/uso terapéutico , Encefalopatía Hepática/tratamiento farmacológico , Cirrosis Hepática/complicaciones , Animales , Encefalopatía Hepática/diagnóstico , Encefalopatía Hepática/etiología , Encefalopatía Hepática/metabolismo , Humanos , Mediadores de Inflamación/antagonistas & inhibidores , Mediadores de Inflamación/metabolismo , Cirrosis Hepática/diagnóstico , Transducción de Señal/efectos de los fármacos , Resultado del Tratamiento
19.
Sci Total Environ ; 470-471: 519-26, 2014 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-24176699

RESUMEN

In this work, sixteen U.S. EPA priority PAH compounds in the dated sediment cores were detected from five lakes in western China. In most lakes, the concentrations of the total PAHs (ΣPAHs) increased from the deep layers to the surface sediments. Two source categories, i.e. vehicular emission and biomass & domestic coal combustion were identified by Unmix, a factor analysis receptor model to explore the source contributions of PAHs in the dated sediments. The source apportionment results showed that biomass & domestic coal combustion contributed larger proportion of PAHs in the five lakes. The toxicities of PAHs in the dated sediments, assessed by BaP equivalent (BaPE) values showed that the BaPE increased gradually from the deep layers to the surface sediments in most lakes. For the first effort, the contribution of each source to BaPE was apportioned by Unmix-BaPE method, and the result indicated that the vehicular emission posed the highest toxic risk. The percentage contribution of vehicular emission for PAHs and BaPE also increased from the deep layers to the surface sediments, while biomass & domestic coal combustion exhibited the opposite tendency.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/química , Lagos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/estadística & datos numéricos , China
20.
World J Gastroenterol ; 20(26): 8638-45, 2014 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-25024620

RESUMEN

AIM: To evaluate the application of bipolar coagulation (BIP) in hepatectomy by comparing the efficacy of BIP alone, cavitron ultrasonic surgical aspirator (CUSA) + BIP and conventional clamp crushing (CLAMP). METHODS: Based on our database of patient records, a total of 380 consecutive patients who underwent hepatectomy at our hospital were retrospectively studied for the efficacy of BIP alone, CUSA + BIP and CLAMP. Of all the patients, 75 received saline-coupled BIP (Group A), 53 received CUSA + BIP (Group B), and 252 received CLAMP (Group C). The pre-, mid-, and postoperative clinical manifestations were compared, and the effects of those maneuvers were evaluated. RESULTS: There was no obvious difference among the preoperative indexes between the different groups. The operative time was longer in Groups A and B than in Group C (P < 0.001 for both). The amount of bleeding and the rate of transfusion during the operation were significantly higher in Group C than in Groups A and B (P < 0.001 for all). The incidence of postoperative complications in Group C (46.43%) was higher than that in Groups A (30.67%, P = 0.015) and B (28.30%, P = 0.016). The patients' liver function recovery and postoperative hospital stay were not significantly different. BIP could decrease intraoperative hemorrhage and postoperative complications compared to CLAMP. CONCLUSION: Simple saline-coupled BIP should be considered a safe and reliable technique for liver resection to decrease intraoperative hemorrhage and postoperative complications.


Asunto(s)
Electrocoagulación , Hepatectomía/métodos , Hepatopatías/cirugía , Cloruro de Sodio/administración & dosificación , Irrigación Terapéutica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Pérdida de Sangre Quirúrgica/prevención & control , Transfusión Sanguínea , China , Constricción , Electrocoagulación/efectos adversos , Electrocoagulación/instrumentación , Diseño de Equipo , Femenino , Hepatectomía/efectos adversos , Hepatectomía/instrumentación , Humanos , Tiempo de Internación , Hepatopatías/diagnóstico , Masculino , Persona de Mediana Edad , Tempo Operativo , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Recuperación de la Función , Estudios Retrospectivos , Cloruro de Sodio/efectos adversos , Instrumentos Quirúrgicos , Irrigación Terapéutica/efectos adversos , Irrigación Terapéutica/instrumentación , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Terapia por Ultrasonido/instrumentación , Adulto Joven
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