RESUMO
BACKGROUND: The primary disease vectors for dengue virus (DENV) transmission between humans are the mosquitoes Aedes aegypti and Aedes albopictus, with Ae. aegypti population size strongly correlated with DENV outbreaks. When a mosquito is infected with DENV, the virus migrates from the midgut to the salivary glands to complete the transmission cycle. How the virus crosses the hemocoel, resulting in systemic infection, is still unclear however. During viral infection and migration, the innate immune system is activated in defense. As part of cellular-mediated immunity, hemocytes are known to defend against bacteria and Plasmodium infection and may also participate in defending against DENV infection. Hemocytes are categorized into three cell types: prohemocytes, granulocytes, and oenocytoids. Here, we investigated which hemocytes can be infected by DENV and compare hemocyte infection between Ae. aegypti and Ae. albopictus. METHODS: Hemocytes were collected from Ae. aegypti and Ae. albopictus mosquitoes that were intrathoracically infected with DENV2-GFP. The collected hemocytes were then identified via Giemsa staining and examined microscopically for morphological differences and viral infection. RESULTS: All three types of hemocytes were infected by DENV, though the predominantly infected cell type was prohemocytes. In Ae. aegypti, the highest and lowest infection rates at 7 days post infection occurred in prohemocytes and granulocytes, respectively. Prohemocytes were also the primary infection target of DENV in Ae. albopictus, with similar infection rates across the other two hemocyte groups. The ratios of hemocyte composition did not differ significantly between non-infected and infected mosquitoes for either species. CONCLUSIONS: In this study, we showed that prohemocytes were the major type of hemocyte infected by DENV in both Ae. aegypti and Ae. albopictus. The infection rate of prohemocytes in Ae. albopictus was lower than that in Ae. aegypti, which may explain why systemic DENV infection in Ae. albopictus is less efficient than in Ae. aegypti and why Ae. albopictus is less correlated to dengue fever outbreaks. Future work in understanding the mechanisms behind these phenomena may help reduce arbovirus infection prevalence.
Assuntos
Aedes , Vírus da Dengue , Dengue , Animais , Humanos , Mosquitos Vetores , Glândulas SalivaresRESUMO
A key component of integrated vector management strategies is the efficient implementation of mosquito traps for surveillance and control. Numerous trap types have been created with distinct designs and capture mechanisms, but identification of the most effective trap type is critical for effective implementation. For dengue vector surveillance, previous studies have demonstrated that active traps utilizing CO2 attractant are more effective than passive traps for capturing Aedes mosquitoes. However, maintaining CO2 supply in traps is so labor intensive as to be likely unfeasible in crowded residential areas, and it is unclear how much more effective active traps lacking attractants are than purely passive traps. In this study, we analyzed Aedes capture data collected in 2019 from six urban areas in Kaohsiung City to compare Aedes mosquito catch rates between (passive) gravitraps and (active) fan-traps. The average gravitrap index (GI) and fan-trap index (FI) values were 0.68 and 3.39 respectively at peak catch times from June to August 2019, with consistently higher FI values calculated in all areas studied. We compared trap indices to reported cases of dengue fever and correlated them with weekly fluctuations in temperature and rainfall. We found that FI trends aligned more closely with case numbers and rainfall than GI values, supporting the use of fan-traps for Aedes mosquito surveillance and control as part of broader vector management strategies. Furthermore, combining fan-trap catch data with rapid testing for dengue infections may improve the early identification and prevention of future disease outbreaks.
Assuntos
Aedes , Controle de Mosquitos , Animais , Mosquitos Vetores , TaiwanRESUMO
The areas where dengue virus (DENV) is endemic have expanded rapidly, driven in part by the global spread of Aedes species, which act as disease vectors. DENV replicates in the mosquito midgut and is disseminated to the mosquito's salivary glands for amplification. Thus, blocking virus infection or replication in the tissues of the mosquito may be a viable strategy for reducing the incidence of DENV transmission to humans. Here we used the mariner Mos1 transposase to create an Aedes aegypti line that expresses virus-specific miRNA hairpins capable of blocking DENV replication. These microRNA are driven by the blood-meal-inducible carboxypeptidase A promoter or by the polyubiquitin promoter. The transgenic mosquitoes exhibited significantly lower infection rates and viral titers for most DENV serotypes 7 days after receiving an infectious blood meal. The treatment was also effective at day 14 post infection after a second blood meal had been administered. In viral transmission assay, we found there was significantly reduced transmission in these lines. These transgenic mosquitoes were effective in silencing most of the DENV genome; such an approach may be employed to control a dengue fever epidemic.
Assuntos
Aedes/virologia , Animais Geneticamente Modificados , Vírus da Dengue/patogenicidade , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Mosquitos Vetores/virologia , Aedes/genética , Animais , Linhagem Celular , Cricetinae , Cricetulus , Dengue/transmissão , Vírus da Dengue/genética , Fibroblastos/virologia , Mosquitos Vetores/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Sorogrupo , Transposases/genética , Transposases/metabolismo , Carga ViralRESUMO
Pleomorphic rhabdomyosarcomas of the uterus (PRMSu) is a rare malignant tumor of the female genital tract. Accurate diagnosis and effective treatment of PRMSu are important. We report an 81-year-old woman who was diagnosed with PRMSu. She had an extremely unusual presentation of secondary dyspnea because of an extremely large uterus (26.0 cm). Pelvic magnetic resonance imaging showed rare severe enlargement and intrauterine filling with tumor tissue, and she was initially diagnosed with uterine leiomyosarcoma. The patient underwent hysterectomy, as well as bilateral salpingo-oophorectomy and omentectomy, and was finally confirmed as having PRMSu by histopathology combined with immunohistochemistry. We performed a systematic review of the literature between 1982 and 2020 and focused on different treatment strategies and prognosis of PRMSu. A retrospective review of 28 cases was conducted and survival analysis was estimated by using the Kaplan-Meier method. We found that the accuracy of diagnosis of PRMSu completely depends on histopathology and immunohistochemistry because of no special clinical symptoms, no sensitive tumor markers, and no special imaging findings. Although there is no standardized approach for treating this rare disease, the treatment strategy of a surgical operation combined with adjuvant chemotherapy appears to be the best choice.
Assuntos
Leiomiossarcoma , Rabdomiossarcoma , Neoplasias Uterinas , Idoso de 80 Anos ou mais , Feminino , Humanos , Histerectomia , Leiomiossarcoma/diagnóstico por imagem , Leiomiossarcoma/cirurgia , Estudos Retrospectivos , Rabdomiossarcoma/diagnóstico por imagem , Rabdomiossarcoma/cirurgia , Neoplasias Uterinas/diagnóstico por imagem , Neoplasias Uterinas/cirurgiaRESUMO
The C-type lectins, one family of lectins featuring carbohydrate binding domains which participate in a variety of bioprocesses in both humans and mosquitoes, including immune response, are known to target DENV. A human C-type lectin protein CLEC18A in particular shows extensive glycan binding abilities and correlates with type-I interferon expression, making CLEC18A a potential player in innate immune responses to DENV infection; this potential may provide additional regulatory point in improving mosquito immunity. Here, we established for the first time a transgenic Aedes aegypti line that expresses human CLEC18A. This expression enhanced the Toll immune pathway responses to DENV infection. Furthermore, viral genome and virus titers were reduced by 70% in the midgut of transgenic mosquitoes. We found significant changes in the composition of the midgut microbiome in CLEC18A expressing mosquitoes, which may result from the Toll pathway enhancement and contribute to DENV inhibition. Transgenic mosquito lines offer a compelling option for studying DENV pathogenesis, and our analyses indicate that modifying the mosquito immune system via expression of a human immune gene can significantly reduce DENV infection.
Assuntos
Aedes/imunologia , Aedes/virologia , Animais Geneticamente Modificados , Dengue/imunologia , Lectinas Tipo C/imunologia , Aedes/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/imunologia , Vírus da Dengue , Modelos Animais de Doenças , Humanos , Mosquitos Vetores/genética , Mosquitos Vetores/imunologia , Mosquitos Vetores/virologiaRESUMO
Dengue virus (DENV), the pathogen that causes dengue fever, is mainly transmitted by Aedes aegypti. Surveillance of infected mosquitoes is a major component of integrated mosquito control methods for reducing the risk of vector-born disease outbreaks. However, a specialized rapid test for DENV detection in mosquitoes is not currently available. Utilizing immunoblotting, we found that the secretion of NS1 from both a DENV-infected mosquito cell line and mosquito bodies was below the detection threshold. However, when Triton X-100 was used to lyse infected mosquitoes, intracellular NS1 was released, and could then be effectively detected by the NS1 rapid test. The distribution of DENV NS1 in intrathoracically infected mosquitoes was different from that of orally infected mosquitoes. Next, we performed sensitivity tests by bisecting mosquitoes longitudinally; one half of each mosquito was subjected to the NS1 rapid test while the other half was used for qPCR confirmation. This modified test had a sensitivity of nearly 90% from five days post-infection onwards, while DENV had escaped from the midgut barrier. This adapted test offers a valuable, easy-to-use tool for mosquito surveillance, which is a crucial component of DENV disease control.
Assuntos
Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Dengue/diagnóstico , Mosquitos Vetores/virologia , Proteínas não Estruturais Virais/genética , Aedes/virologia , Animais , Linhagem Celular , Chlorocebus aethiops , Dengue/virologia , Células VeroRESUMO
Physiological trade-offs between mosquito immune response and reproductive capability can arise due to insufficient resource availability. C-type lectin family members may be involved in these processes. We established a GCTL-3-/- mutant Aedes aegypti using CRISPR/Cas9 to investigate the role of GCTL-3 in balancing the costs associated with immune responses to arboviral infection and reproduction. GCTL-3-/- mutants showed significantly reduced DENV-2 infection rate and gut commensal microbiota populations, as well as upregulated JAK/STAT, IMD, Toll, and AMPs immunological pathways. Mutants also had significantly shorter lifespans than controls and laid fewer eggs due to defective germ line development. dsRNA knock-down of Attacin and Gambicin, two targets of the AMPs pathway, partially rescued this reduction in reproductive capabilities. Upregulation of immune response following GCTL-3 knock-out therefore comes at a cost to reproductive fitness. Knock-out of other lectins may further improve our knowledge of the molecular and genetic mechanisms underlying reproduction-immunity trade-offs in mosquitoes.
RESUMO
Nuclear export and translation of intron-containing viral mRNAs are required for HIV-1 gene expression and replication. In this report, we provide evidence to show that DDX3 regulates the translation of HIV-1 mRNAs. We found that knockdown of DDX3 expression effectively inhibited HIV-1 production. Translation of HIV-1 early regulatory proteins, Tat and rev, was impaired in DDX3-depleted cells. All HIV-1 transcripts share a highly structured 5' untranslated region (UTR) with inhibitory elements on translation of viral mRNAs, yet DDX3 promoted translation of reporter mRNAs containing the HIV-1 5' UTR, especially with the transactivation response (TAR) hairpin. Interestingly, DDX3 directly interacts with HIV-1 Tat, a well-characterized transcriptional activator bound to the TAR hairpin. HIV-1 Tat is partially targeted to cytoplasmic stress granules upon DDX3 overexpression or cell stress conditions, suggesting a potential role of Tat/DDX3 complex in translation. We further demonstrated that HIV-1 Tat remains associated with translating mRNAs and facilitates translation of mRNAs containing the HIV-1 5' UTR. Taken together, these findings indicate that DDX3 is recruited to the TAR hairpin by interaction with viral Tat to facilitate HIV-1 mRNA translation.
Assuntos
RNA Helicases DEAD-box/metabolismo , Produtos do Gene tat/metabolismo , Infecções por HIV/metabolismo , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , RNA Helicases DEAD-box/genética , Técnicas de Silenciamento de Genes , Células HEK293 , Infecções por HIV/genética , Células HeLa , Humanos , Biossíntese de Proteínas , RNA Mensageiro/genética , RNA Viral/genéticaRESUMO
This study reports on a microfluidic system equipped with a sample pretreatment device and a nucleic acid amplification device for the rapid diagnosis of the human immunodeficiency virus-1 (HIV-1). The system analyzed proviral deoxyribonucleic acid (DNA) from an HIV-infected Jurkat T cell line. In order to ensure accurate diagnosis among other prevalent B-type strains, simultaneous detections of four conserved HIV-1 B-type DNA fragments were performed in this integrated microfluidic system. The entire protocol including cell lysis, extraction of DNA, polymerase chain reaction (PCR), and optical detection were successfully integrated in order to perform a rapid, automated diagnosis. Experimental results showed that four primer sets with conserved HIV-1 B-type sequences specific for the 167-bp RU5 promoter region, the 424-bp int, the 117-bp tat, and the 162-bp vpr coding regions were successfully amplified from the respective regions of the proviral DNA, even from a single infected cell. This accurate real-time detection was achieved within 95 min using the integrated optical system.
Assuntos
Técnicas Biossensoriais/instrumentação , Fracionamento Celular/instrumentação , DNA Viral/isolamento & purificação , HIV-1/isolamento & purificação , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , DNA Viral/genética , Desenho de Equipamento , Análise de Falha de Equipamento , HIV-1/genética , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Análise de Sequência de DNA/instrumentação , Integração de SistemasRESUMO
OBJECTIVE: To observe effects of Dan Wei Powder (Powder for treating the gall bladder and stomach) Tea Bag (DWSTB) on the aggregation rate of blood platelet in vivo and in vitro. METHODS: Increase of the platelet aggregation rate in the rat in vivo was induced by carrageenin, and increase of the rabbit platelet aggregation rate in vitro was induced by adenosine diphosphate (ADP) and collagen, respectively. The effects of DWSTB on the platelet aggregation rate were investigated in vivo and in vitro, respectively. RESULTS: The maximum in vivo platelet aggregation rate in the rat was significantly decreased after administration of 2.0 and 4.0 g x kg(-1) DWSTB (P < 0.05, P < 0.01). The maximum rabbit platelet aggregation rate induced by ADP and collagen in vitro were suppressed significantly by 2.0-16.0 mg x mL(-1) and 2.0-8.0 mg x mL(-1) DWSTB, respectively (P < 0.05, P < 0.01). And the effect of DWSTB on platelet aggregation was raised with increase of its dose. CONCLUSION: Dan Wei Powder Tea Bag can restrain the aggregation of platelet in vivo and in vitro.
Assuntos
Plaquetas/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Animais , Plaquetas/fisiologia , Masculino , Coelhos , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To investigate the status of job burnout in traditional Chinese medicine (TCM) doctors and explore the effect of occupational commitment on job burnout. METHODS: A test of occupational commitment and job burnout was carried out in 507 TCM doctors with occupational commitment questionnaire and Maslach Burnout Inventory-Human Services Survey (MBI-HSS). RESULTS: The age group of < 30 years scored lowest (2.352 +/- 0.660) in personal accomplishment compared with 30 years old group and 40 years old group [(2.136 +/- 0.704) and (2.127 +/- 0.628) respectively] (P < 0.01). The score of emotional exhaustion and depersonalization increased with educational levels. There was significantly negative correlation between job burnout and occupational commitment (P < 0.01). Occupational commitment had significant effect on job burnout (P < 0.01). Occupational trouble commitment was a major predictor for emotional exhaustion (P < 0.01). Professional self-efficacy commitment was a major predictor for depersonalization (P < 0.01). Affective commitment was a major predictor for personal accomplishment (P < 0.01). CONCLUSION: Occupational commitment is a good predictor for job burnout. Improving occupational commitment is an important measure to prevent job burnout.
Assuntos
Esgotamento Profissional/psicologia , Medicina Tradicional Chinesa , Médicos/psicologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto JovemRESUMO
OBJECTIVE: To test the structure validity of an occupational commitment scale for traditional Chinese medical (TCM) practitioners. METHODS: Based on in-depth interviews with 18 TCM practitioners and an open-ended questionnaire survey of 67 TCM practitioners, an occupational commitment scale was developed. The questionnaire was tested in 324 TCM practitioners and revised after an exploratory factor analysis (EFA). The revised questionnaire was tested again in another 507 TCM practitioners. A measurement model (structural equation model) by confirmation factor analysis (CFA) was used to confirm the construct validity of the questionnaire. The occupational change intention was used to verify the criterion-related validity of the questionnaire. The reliability of the questionnaire was tested with Cronbach's alpha coefficient. RESULTS: The EFA indicated that the occupational commitment scale consisted of four components from 13 items. The cumulative contribution of the four components reached 61.437%. The factor loading of each item attached to the relevant common factor ranged from 0.591 to 0.861. The CFA indicated a good fit of construct, with 1.79, 0.039, 0.97, 0.97, 0.98, and 0.72 fit index for chi2/ df, RMSEA, GFI, NNFI, CFI, and PNFI respectively. The occupational change intention correlated with the componets of occupational commitment negatively (P < 0.01). The Cronbach's alpha coefficients of the questionnaire and the four components ranged from 0.602 to 0.847. CONCLUSION: The occupational commitment scale for TCM practitioners has a valid structure of four dimensions, measuring affective commitment, limited alternatives commitment, professional self-efficacy commitment and occupational risk commitment. The questionnaire is valid and reliable.
Assuntos
Satisfação no Emprego , Medicina Tradicional Chinesa , Modelos Psicológicos , Lealdade ao Trabalho , Médicos/psicologia , Atitude do Pessoal de Saúde , China , Humanos , Reorganização de Recursos Humanos , Psicometria , Inquéritos e QuestionáriosRESUMO
Qiantang medical school came into being during the late Ming Dynasty and the early Qing Dynasty, and lasted for 200 years until Guang Xu Reign in the late Qing Dynasty. Lu Zhiyi and Zhang Suichen were the early representative figures; Zhang Zhicong, Zhang Xiju and Gao Shizong were the mid-period representative figures; and Zhong Xuelu was the late representative figure. They respected consistently the classics and the ancients, cultivated new talents, studied medical literature with a trinity of teaching, studying the classics and practising medicine as its characteristic. Eventually, it developed under the specific background of time and geographical environment as the only academic medical school enbodying teaching, studying the classics, and medical practice as a whole with distinguished achievements.
Assuntos
Medicina , Faculdades de Medicina , China , Humanos , Medicina Tradicional ChinesaRESUMO
OBJECTIVE: This study is purposed to explore the relationship between aggressively driving behavior and functional polymorphism in the promoter region of the monoamine oxidase-A (MAOA) gene. METHODS: A total of 348 automobile drivers were investigated with Deffenbacher's driver anger scale, driving vengeance questionnaire (DVQ) and driver aggression behavior questionnaire. Eighty-eight drivers were selected as more, medium and less aggressive group, each. Polymerase chain reaction (PCR) and 2.5% agarose gel electrophoresisi were adopted to detect the polymorphism of functional 30 bp-uVNTR in the promoter region of the X-chromosomal MAOA gene and their frequencies of varied genotypes were estimated. RESULTS: Two alleles with 3 and 4 repeats of 30 bp-uVNTR were detected in the drivers. Among the more aggressive group, number of the allele with 3 repeats of 30 bp-uVNTR (63/88) was significantly more than that with 4 repeats (25/88) (chi(2) = 10.21, P < 0.01), and number of the allele with 4 repeats of 30 bp-uVNTR was more in the less aggressive group, indicating that persons with allele of 3 repeats of 30 bp VNTR were more aggressive in their driving than those with 4 repeats. CONCLUSIONS: Aggressively driving behavior in drivers possibly related to their functional MAOA-uVNTR polymorphism. Effect of the gene on aggressively driving behavior should be further studied.
Assuntos
Agressão/fisiologia , Condução de Veículo/psicologia , Comportamento Impulsivo/genética , Monoaminoxidase/genética , Polimorfismo Genético/genética , Adulto , Encéfalo/fisiopatologia , Humanos , Comportamento Impulsivo/fisiopatologia , Masculino , Regiões Promotoras Genéticas , Receptores de Serotonina/genética , Serotonina/fisiologia , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: To find out the relationship of traffic accidents with life events, driving stress, aggressive driving, etc. METHODS: A total of 905 automobile drivers were investigated with life events scale (LES), general driver stress questionnaire, driver behavior inventory and accidents experience, etc. RESULTS: The scores of life events, driving stress, and aggressive driving in accident drivers (21.79 +/- 14.10, 23.81 +/- 11.86, 9.42 +/- 8.25 respectively) were higher than those in nonaccident drivers (16.82 +/- 8.45, 20.09 +/- 10.63, 5.66 +/- 7.54) (P < 0.01). The number of vehicle accidents was significantly correlated with the scores of LES, driving stress, driver's aggressive behavior, drowsy driving, weekly time of driving, drinking index (P < 0.05). A logistic analysis (Forward:LR) showed that the driving hour, drowsy driving, aggressive driving, and drinking index were closely related with traffic accidents (P < 0.01). CONCLUSION: Life events, driving stress and aggressive driving of the drivers are important factors related to traffic accidents.
Assuntos
Acidentes de Trânsito , Acontecimentos que Mudam a Vida , Adulto , Idoso , Condução de Veículo/psicologia , China , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
Tobacco carcinogens can damage DNA, leading to apoptosis. There may be individual variation in apoptotic capacity (AC), and this variation may explain difference in AC associated with risk of lung cancer, if genome integrity is not restored by efficient DNA repair. To test the hypothesis that genetically determined AC is associated with risk of lung cancer, we conducted a pilot case-control study of 68 patients with newly diagnosed, untreated lung cancer and 74 cancer-free controls. We measured the AC of their cultured peripheral blood lymphocytes in response to in vitro exposure to an ultimate tobacco carcinogen, benzo[a]pyrene diol epoxide (BPDE), by using terminal dUTP nucleotide end labeling and flow cytometry. We also investigated the frequency of the -A670G polymorphism in Fas, a gene involved in controlling the apoptotic pathway, by using polymerase chain reaction-restriction fragment length polymorphism analysis. After exposing the cells to 4 microM BPDE for 5 h, we observed a significantly lower AC in lung cancer patients (155.2+/-143.9%) than in the controls (216.6+/-184.6%) (P<0.05). Low AC was an independent risk factor (adjusted odds ratio (OR)=2.69, 95% confidence interval (CI)=1.18-6.15) for lung cancer after adjustment for age, sex, ethnicity, smoking status and apoptotic baseline in a logistic regression model. Although the Fas -A670G polymorphism was not an independent risk factor for lung cancer, it appeared to modulate the risk. The adjusted ORs for lung cancer risk associated with lower AC were 4.00 (95% CI=1.48-10.80) among those with the Fas -670 AG and GG genotypes and 0.97 (95% CI=0.18-5.30) among those with the Fas -670AA genotype. These data suggest that alteration in the apoptotic pathway may be a risk factor for lung cancer and this risk may be modulated by the Fas -A670G polymorphism. Larger prospective studies are needed to verify these findings.
Assuntos
Apoptose , Neoplasias Pulmonares/genética , Linfócitos/patologia , Polimorfismo Genético , Receptor fas/genética , 7,8-Di-Hidro-7,8-Di-Hidroxibenzo(a)pireno 9,10-óxido/toxicidade , Carcinógenos/toxicidade , Estudos de Casos e Controles , Células Cultivadas , Feminino , Citometria de Fluxo , Genótipo , Humanos , Neoplasias Pulmonares/metabolismo , Linfócitos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Fatores de RiscoRESUMO
The glutathione (GSH) metabolic characteristics and redox balance in three ecotypes of reed (Phragmites communis), swamp reed (SR), dune reed (DR), and heavy salt meadow reed (HSMR), from different habitats in desert regions of northwest China were investigated. The DR possessed the highest rate of GSH biosynthesis and metabolism with the lowest levels of total and reduced GSH and its biosynthetic precursors, gamma-glutamylcysteine (gamma-EC) and cysteine (Cys), of the three reed ecotypes. This suggests that a higher rate of GSH biosynthesis and metabolism, but not GSH accumulation, might be involved in the adaptation of this terrestrial reed ecotype to its dry habitat. The HSMR shared this profile although it exhibited the highest reduced thiol levels of the three ecotypes. Two key enzymes in the Calvin-cycle possessing exposed sulfhydryl groups, NADP(+)-dependent glyceraldehydes-3-phosphate dehydrogenase (G3PD) and fructose-1,6-bisphosphatase (FBPase), and other two key enzymes in the pentose-phosphate pathway (PPP), glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6-PGD), had very similar activities in the three reed ecotypes. Compared to the SR, the DR and HSMR had higher ratios of NADPH/NADP+ and NADH/NAD+, indicating that a more reduced redox status in the plant cells might be involved in the survival and adaptation of the two terrestrial reed ecotypes to long-term drought and salinity, respectively. These results suggest that changes of GSH metabolism and redox balance were important components of the adaptation of reed, a hydrophilic plant, to more extreme dune and saline habitats. The coordinated up-regulations of the rate of GSH biosynthesis and metabolism and reduction state of redox status of plant cells, conferred on the plant high resistance or tolerance to long-term drought and salinity.
Assuntos
Adaptação Fisiológica/fisiologia , Glutationa/metabolismo , Poaceae/metabolismo , Cloreto de Sódio/farmacologia , Adaptação Fisiológica/efeitos dos fármacos , Desastres , Ecologia , Meio Ambiente , Frutose-Bifosfatase/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Glutationa/biossíntese , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/metabolismo , Oxirredução , Fosfogluconato Desidrogenase/metabolismo , Poaceae/efeitos dos fármacos , Poaceae/genética , Água/metabolismoRESUMO
Dune reed, as an ecotype of reed plant (Phragmites communis Trin.), is an ideal material for studies on the adaptations of plant to environmental conditions. Scanning electron microscope, energy-dispersive X-ray analysis, and plant tissue culture techniques were used to investigate the effect of extreme temperature, salt, and polyethylene glycol-induced osmotic stress on the intracellular elements K, Na, Ca, and Cl in cultured cells from dune reed and swamp reed (as control). The results indicated that the percentages of the studied elements in dune reed cells exposed to various stresses increased or decreased obviously compared to the swamp reed cells. It has been found that a pattern of absorbing K and discharging Na exists in dune reed cells, which did not exist in swamp reed cells. The pattern is thought to be a significant physiological mechanism of the dune reed response to adverse environmental factors. In addition, the percentages of Ca and Cl in dune reed cells were also shown to increase at high temperature. The growth of cells along with their surface features under different stress conditions were observed and the results are discussed.
Assuntos
Poaceae/metabolismo , Células Cultivadas , Microanálise por Sonda Eletrônica , Microscopia Eletrônica de Varredura , Poaceae/citologiaRESUMO
BACKGROUND: Phenotypic differences in the ability to repair genetic damage induced by tobacco carcinogens may reflect genetic differences in susceptibility to squamous cell carcinoma of the head and neck (SCCHN). The objective of this study was to assess the variation in baseline expression of five nucleotide excision repair genes between individuals with SCCHN and cancer free controls. METHODS: The authors conducted a hospital-based case-control study of 57 SCCHN patients and 105 cancer free controls. Using peripheral blood lymphocytes, a multiplex reverse transcriptase-polymerase chain reaction assay was used to quantitate in vitro the mRNA levels of five genes (ERCC1, XPB/ERCC3, XPG/ERCC5, CSB/ERCC6, and XPC) involved in the nucleotide excision repair pathway. RESULTS: The levels of ERCC1, XPB/ERCC3, XPG/ERCC5, and CSB/ERCC6 transcripts were lower in cases than in controls (P =0.0001, 0.096, 0.001, and 0.0001, respectively). In multivariate logistic regression analysis (adjusting for age, gender, race, smoking status, and alcohol use), low expression of ERCC1, XPB/ERCC3, XPG/ERCC5, and CSB/ERCC6 was associated with a statistically significant increased risk for SCCHN (adjusted odds ratios [95% confidence intervals] 6.42 [2.63-15.69], 2.86 [1.39-5.90], 3.69 [1.73-7.90], and 2.46 [1.19-5.09], respectively). CONCLUSIONS: Reduced expression of ERCC1, XPB/ERCC3, XPG/ERCC5, and CSB/ERCC6 is associated with a more than two-fold increased risk of SCCHN.