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1.
Cell Stem Cell ; 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39357516

RESUMO

Mitochondrial adaptations dynamically reprogram cellular bioenergetics and metabolism and confer key properties for human cancers. However, the selective regulation of these mitochondrial responses remains largely elusive. Here, inspired by a genetic screening in acute myeloid leukemia (AML), we identify RAS effector RREB1 as a translational regulator and uncover a unique translation control system for nuclear-encoded mitochondrial proteins in human cancers. RREB1 deletion reduces mitochondrial activities and succinate metabolism, thereby damaging leukemia stem cell (LSC) function and AML development. Replenishing complex II subunit SDHD rectifies these deficiencies. Notably, inhibition of complex II re-sensitizes AML cells to venetoclax treatment. Mechanistically, a short RREB1 variant binds to a conserved motif in the 3' UTRs and cooperates with elongation factor eEF1A1 to enhance protein translation of nuclear-encoded mitochondrial mRNAs. Overall, our findings reveal a unique translation control mechanism for mitochondrial adaptations in AML pathogenesis and provide a potential strategy for targeting this vulnerability of LSCs.

2.
Blood Sci ; 6(4): e00206, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39281854

RESUMO

Hematopoietic stem cells (HSCs) maintain homeostasis in the hematopoietic ecosystem, which is tightly regulated at multiple layers. Acute myeloid leukemia (AML) is a severe hematologic malignancy driven by genetic and epigenetic changes that lead to the transformation of leukemia stem cells (LSCs). Since somatic mutations in DNA methylation-related genes frequently occur in AML, DNA methylation is widely altered and functions as a starting engine for initiating AML. Additionally, RNA modifications, especially N6-methyladenosine (m6A), also play an important role in the generation and maintenance of the hematopoietic ecosystem, and AML development requires reprogramming of m6A modifications to facilitate cells with hallmarks of cancer. Given the complex pathogenesis and poor prognosis of AML, it is important to fully understand its pathogenesis. Here, we mainly focus on DNA methylation and RNA m6A modification in hematopoiesis and AML and summarize recent advances in this field.

3.
AAPS J ; 25(3): 44, 2023 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-37084114

RESUMO

During the write-up of the meeting summary reports from the 2019 dissolution similarity workshop held at the University of Maryland's Center of Excellence in Regulatory Science and Innovation (M-CERSI), several coauthors continued their discussions to develop a "best-practice" document defining the steps required to assess dissolution profiles in support of certain biowaivers and postapproval changes. In previous reports, current challenges related to dissolution profile studies were discussed such that the steps outlined in the two flow charts ("decision trees") presented here can be applied. These decision trees include both recommendations for the use of equivalence procedures between reference and test products as well as application of the dissolution safe space concept. Common approaches towards establishing dissolution safe spaces are described. This paper encourages the preparation of protocols clearly describing why and how testing is performed along with the expected pass/fail criteria prior to generating data on the materials to be evaluated. The target audience of this manuscript includes CMC regulatory scientists, laboratory analysts, as well as statisticians from industry and regulatory health agencies involved in the assessment of product quality via in vitro dissolution testing. Building upon previous publications, this manuscript provides a solution to the current ambiguity related to dissolution profile comparison. The principles outlined in this and previous manuscripts provide a basis for global regulatory alignment in the application of dissolution profile assessment to support manufacturing changes and biowaiver requests.


Assuntos
Solubilidade
4.
Cell Stem Cell ; 30(1): 69-85.e7, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36574771

RESUMO

N6-methyladenosine (m6A) is a common chemical modification for mammalian mRNA and exhibits high dynamics in various biological processes. However, dynamics of m6A RNA methylome during leukemogenesis remains unknown. Here, we delineate a comprehensive m6A landscape during acute myeloid leukemia (AML) development and identify PRMT6 as a key for maintaining AML stem cells. We observe an obvious change in m6A methylome during leukemogenesis and find that protein arginine methyltransferase PRMT6 and m6A reader IGF2BP2 maintain the function of human and murine leukemia stem cells (LSCs). Genetic deletion or pharmacological inhibition of PRMT6 damages AML development and LSC function. Mechanistically, IGF2BP2 stabilizes PRMT6 mRNA via m6A-mediated manner, which catalyzes H3R2me2a and suppresses lipid transporter MFSD2A expression. PRMT6 loss upregulates MFSD2A expression that increases docosahexaenoic acid levels and impairs LSC maintenance. Collectively, our findings reveal a critical role of PRMT6-MFSD2A signaling axis in AML development and provide a therapeutic strategy for targeting LSCs.


Assuntos
Leucemia Mieloide Aguda , RNA , Humanos , Animais , Camundongos , RNA/metabolismo , Epigenoma , RNA Mensageiro/metabolismo , Células-Tronco Neoplásicas/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Lipídeos , Mamíferos/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Nucleares/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo
5.
AAPS J ; 24(3): 54, 2022 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-35386051

RESUMO

The pharmaceutical industry and regulatory agencies rely on dissolution similarity testing to make critical product decisions as part of drug product life cycle management. Accordingly, the application of mathematical approaches to evaluate dissolution profile similarity is described in regulatory guidance with the emphasis given to the similarity factor f2 with little discussion of alternative methods. In an effort to highlight current practices to assess dissolution profile similarity and to strive toward global harmonization, a workshop entitled "In Vitro Dissolution Similarity Assessment in Support of Drug Product Quality: What, How, When" was held on May 21-22, 2019 at the University of Maryland, Baltimore. This manuscript provides in-depth discussion of the mathematical principles of the model-independent statistical methods for dissolution profile similarity analyses presented in the workshop. Deeper understanding of the testing objective and statistical properties of the available statistical methods is essential to identify methods which are appropriate for application in practice. A decision tree is provided to aid in the selection of an appropriate statistical method based on the underlying characteristics of the drug product. Finally, the design of dissolution profile studies is addressed regarding analytical and statistical recommendations to sufficiently power the study. This includes a detailed discussion on evaluation of dissolution profile data for which several batches per reference and/or test product are available.


Assuntos
Solubilidade , Baltimore
6.
Biotechnol Lett ; 43(7): 1357-1369, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33796959

RESUMO

BACKGROUND: Enterovirus71 (EV71), the major cause of hand, foot, and-mouth disease (HFMD), has increasingly become a public health challenge. Type I interferons (IFNs) can regulate innate and adaptive immune responses to pathogens. MicroRNAs (miRNAs) play regulatory roles in host innate immune responses to viral infections. However, the roles of miR-103 and miR-107 in EV71 infection remain unclear. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to determine the expression of miR-103, miR-107, suppressor of cytokine signaling 3 (SOCS3), VP1, IFN-α, and IFN-ß. Virus titers were measured by 50% tissue culture infectious dose (TCID50) assay. Western blot assay was conducted to detect the protein levels of VP1, IFN-α, IFN-ß, SOCS3, signal transducer and activator of transcription 3 (STAT3), and phospho-STAT3 (p-STAT3). Immunofluorescence assay was used to detect the protein level of VP1. The concentrations of IFN-α and IFN-ß were examined by Enzyme-linked immunosorbent assay (ELISA). The interaction between SOCS3 and miR-103/miR-107 was predicted by starBase and verified by dual-luciferase reporter assay and RNA pull-down assay. RESULTS: MiR-103 and miR-107 were downregulated and SOCS3 was upregulated in serum from patients with EV71 and EV71-infected cells. Overexpression of miR-103 and miR-107 repressed EV71 replication by inhibiting EV71 titers and VP1 expression. Moreover, upregulation of miR-103 and miR-107 enhanced EV71-triggered the production of type I IFNs. In addition, miR-103 and miR-107 directly targeted SOCS3, and SOCS3 upregulation reversed the effects of miR-103 and miR-107 on EV71 replication and type I IFN response. Importantly, miR-103 and miR-107 increased STAT3 phosphorylation by targeting SOCS3 after EV71 infection. CONCLUSION: MiR-103 and miR-107 suppressed EV71 replication and increased the production of type I IFNs by regulating SOCS3/STAT3 pathway, which might provide a novel strategy for developing effective antiviral therapy.


Assuntos
Enterovirus Humano A/fisiologia , Infecções por Enterovirus/genética , Interferon Tipo I/metabolismo , MicroRNAs/genética , Proteína 3 Supressora da Sinalização de Citocinas/genética , Animais , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Linhagem Celular , Chlorocebus aethiops , Infecções por Enterovirus/imunologia , Regulação da Expressão Gênica , Humanos , Fosforilação , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Regulação para Cima , Células Vero , Replicação Viral
7.
Biol Res ; 54(1): 10, 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33726823

RESUMO

BACKGROUNDS: Parkinson's disease (PD) is a common age-related neurodegenerative disorder worldwide. This research aimed to investigate the effects and mechanism underlying long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in PD. METHODS: SK-N-SH and SK-N-BE cells were treated with MPP+ to establish the MPP+-stimulated cell model of PD, and MALAT1 expression was determined. Then, the effects of MALAT1 depletion on cell proliferation and apoptosis were determined in the MPP+-stimulated cell model of PD. Besides, the correlations between microRNA-135b-5p (miR-135b-5p) and MALAT1 or glycoprotein nonmetastatic melanoma protein B (GPNMB) in MPP+-stimulated cell model of PD were explored. RESULTS: MALAT1 was increasingly expressed and downregulation of MALAT1 promoted cell proliferation while inhibited apoptosis in MPP+-stimulated cells. Besides, miR-135b-5p was a target of MALAT1 and directly targeted to GPNMB. Further investigation indicated that suppression of MALAT1 regulated cell proliferation and apoptosis by miR-135b-5p/GPNMB axis. CONCLUSION: Our findings reveal that MALAT1/miR-135b-5p/GPNMB axis regulated cell proliferation and apoptosis in MPP+-stimulated cell model of PD, providing a potential biomarker and therapeutic target for PD.


Assuntos
Apoptose , Proliferação de Células , Glicoproteínas de Membrana/genética , MicroRNAs/genética , Doença de Parkinson/genética , RNA Longo não Codificante/genética , Células Cultivadas , Humanos
8.
Biol. Res ; 54: 10-10, 2021. graf, ilus
Artigo em Inglês | LILACS | ID: biblio-1505803

RESUMO

BACKGROUNDS: Parkinson's disease (PD) is a common age-related neurodegenerative disorder worldwide. This research aimed to investigate the effects and mechanism underlying long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in PD. METHODS: SK-N-SH and SK-N-BE cells were treated with MPP+ to establish the MPP+-stimulated cell model of PD, and MALAT1 expression was determined. Then, the effects of MALAT1 depletion on cell proliferation and apoptosis were determined in the MPP+-stimulated cell model of PD. Besides, the correlations between microRNA-135b-5p (miR-135b-5p) and MALAT1 or glycoprotein nonmetastatic melanoma protein B (GPNMB) in MPP+-stimulated cell model of PD were explored. RESULTS: MALAT1 was increasingly expressed and downregulation of MALAT1 promoted cell proliferation while inhibited apoptosis in MPP+-stimulated cells. Besides, miR-135b-5p was a target of MALAT1 and directly targeted to GPNMB. Further investigation indicated that suppression of MALAT1 regulated cell proliferation and apoptosis by miR-135b-5p/GPNMB axis. CONCLUSION: Our findings reveal that MALAT1/miR-135b-5p/GPNMB axis regulated cell proliferation and apoptosis in MPP+-stimulated cell model of PD, providing a potential biomarker and therapeutic target for PD.


Assuntos
Humanos , Doença de Parkinson/genética , Glicoproteínas de Membrana/genética , Apoptose , MicroRNAs/genética , Proliferação de Células , RNA Longo não Codificante/genética , Células Cultivadas
9.
Appl Spectrosc ; 74(1): 108-115, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31617385

RESUMO

Transmission Raman spectroscopy is an emerging technique, capable of quantitative analysis of drug products nondestructively using a multivariate data analysis approach. We developed and validated a chemometric method to quantify the active pharmaceutical ingredient in coated tablets of hot-melt extruded amorphous solid dispersion. A partial least squares regression (PLSR) model was developed and validated based on transmission Raman spectra data collected from coated tablet samples with variations in the content of active pharmaceutical ingredient, excipients, water content, a key oxidative degradant, milled extrudate particle size distribution, and tablet hardness. The method was proven to be accurate, linear, specific, and robust. Our work demonstrates that transmission Raman spectroscopy (TRS) is a viable, cost-effective, secondary method to high-performance liquid chromatography (HPLC) for quantitation of active pharmaceutical ingredient (API) in coated tablets of hot-melt extruded amorphous solid dispersion.


Assuntos
Tecnologia de Extrusão por Fusão a Quente , Análise Espectral Raman/métodos , Comprimidos/análise , Calibragem , Cromatografia Líquida de Alta Pressão , Excipientes/química , Análise dos Mínimos Quadrados , Pirrolidinas/química , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Comprimidos/química , Compostos de Vinila/química
10.
Oncol Lett ; 14(5): 5853-5860, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29113217

RESUMO

Grape seed proanthocyanidins (GSPs) have been reported to possess a wide array of pharmacological and biochemical properties. Recently, GSPs have been reported to inhibit various types of colorectal cancer; however, the mechanism(s) involved remain unclear. The present study investigated the effects of GSPs on HCT-116 human colorectal carcinoma cell line. Exposure of these cells to GSPs for 48 h resulted in a significant concentration-dependent inhibition of cell viability. Further investigation indicated that GSPs induced apoptosis of these cells. Analyses of mRNA expression levels using reverse transcription-quantitative polymerase chain reaction and protein expression levels by western blotting revealed that this was associated with increased expression levels of p53 tumor suppressor protein, cytochrome c, and pro-apoptotic proteins, apoptosis regulator Bax (Bax) and Bcl-2 homologous antagonist/killer. Furthermore, decreased expression levels of the anti-apoptotic protein, B cell lymphoma-2 and activation of caspase-2, caspase-3 and caspase-9 were demonstrated. GSP-induced loss of mitochondrial membrane potential was also detected by JC-1 assay. These findings suggested that GSPs induced colon cancer cell apoptosis via the mitochondrial signaling pathway. This provided evidence indicating that GSPs may provide potential chemotherapeutic agents for colorectal cancer.

11.
J Biomech ; 49(9): 1686-1691, 2016 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-27126984

RESUMO

Anterior cruciate ligament (ACL) injuries are one of the most frequently injured knee ligaments. Despite reconstruction, many individuals report difficulty returning to high level activities that require greater dynamic stability. Since few methods have been tested to assess dynamic stability post ACL reconstruction (ACLR), the purpose of this study was to evaluate between and within dynamic knee stability in control and ACLR individuals using Nyquist and Bode stability criteria. Sixteen control and sixteen post ACLR individuals performed a walking protocol. Nyquist and Bode stability criteria were implemented to classify and quantify individual step-to-step sagittal plane dynamic knee stability from the gait waveforms at initial contact, 15% and 30% of stance based on the resulting gain and phase margins. An ANOVA compared differences in phase margins between the control and ACLR limbs and found that the ACLR limbs were overall significantly more unstable than the non-reconstructed and control limbs (p=0.001). The results indicated that the ACLR individuals who exhibited stable steps adopted a more compensatory strategy aimed to stabilize the knee. These methods of evaluating dynamic knee stability may help clinicians to assess dynamic knee stability progression throughout rehabilitation and help assess return-to-sport with minimal risk to the individual.


Assuntos
Reconstrução do Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/fisiologia , Articulação do Joelho/fisiologia , Caminhada/fisiologia , Adolescente , Adulto , Ligamento Cruzado Anterior/cirurgia , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/cirurgia , Adulto Jovem
12.
Am J Public Health ; 105(8): e119-25, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26066946

RESUMO

OBJECTIVES: We investigated how much time passes before gasoline price changes affect traffic crashes. METHODS: We systematically examined 2004 to 2012 Mississippi traffic crash data by age, gender, and race. Control variables were unemployment rate, seat belt use, alcohol consumption, climate, and temporal and seasonal variations. RESULTS: We found a positive association between higher gasoline prices and safer roads. Overall, gasoline prices affected crashes 9 to 10 months after a price change. This finding was generally consistent across age, gender, and race, with some exceptions. For those aged 16 to 19 years, gasoline price increases had an immediate (although statistically weak) effect and a lagged effect, but crashes involving those aged 25 to 34 years was seemingly unaffected by price changes. For older individuals (≥ 75 years), the lagged effect was stronger and lasted longer than did that of other age groups. CONCLUSIONS: The results have important health policy implications for using gasoline prices and taxes to improve traffic safety.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Gasolina/economia , Acidentes de Trânsito/economia , Adolescente , Adulto , Fatores Etários , Idoso , Custos e Análise de Custo/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mississippi/epidemiologia , Modelos Estatísticos , Fatores Sexuais , Fatores de Tempo , Adulto Jovem
13.
Cell Biochem Biophys ; 71(2): 725-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25315638

RESUMO

This retrospective analysis was set to understand the epidemiological status of the critically ill obstetric patients in Dongguan city, Guangdong, China. Understanding the risk factors for the death cases can provide scientific evidences for future preventive strategies to decrease the maternal mortality rate. This retrospective included the statistical data and clinical data on the cases of critically ill and dead obstetric patients admitted to Dongguan People's Hospital and Dongguan Maternal & Child Health Hospital from September 1st, 2009 to August 31st, 2013. Data included numbers of the critically ill maternal and obstetric women, common obstetric and maternal comorbidities and complications in the critically ill patients, the basic characteristics of maternal and obstetric deaths, records of regular prenatal examinations, the time intervals between onset of acute symptoms and ICU admission, blood purification, and the acute physiology and chronic health evaluation II (APACHE II) score. During the 5-year period, there were increasing trend of critically ill pregnant and obstetric patients, and the prevalence rate of critically ill obstetric patients was 8.99-9.28 %. The most common obstetric causes of admission were massive postpartum hemorrhage (63.54 %), followed by pregnancy-associated hypertension (15.85 %) and placenta previa (8.92 %). The most common non-obstetric causes of admission were acute heart failure (1.98 %). In the observed period, 20 critically ill obstetric patients died in these two hospitals (mortality rate 0.24 %, 20/8,129). The mean age of dead women was (30.3 ± 6.6) years old and mean gestational age was (30.1 ± 9.3) weeks. 75 % of the patient had more than two pregnancies. Over 90 % of the patients received education below junior high school level. 85 % of the patients were non-Dongguan natives and regular prenatal care rate was only 15 % on dead cases. The most common causes of death were pregnancy-associated hypertension, acute heart failure, and massive postpartum hemorrhage. The dead patients experienced longer interval between onset of acute symptoms and ICU admission (media = 62.5 h), higher APACHE II score (25.4 ± 5.4), and lower blood purification treatment rate (10 %). The incidence of critically ill pregnant and obstetric patients is high in Dongguan city. The group of dead obstetric patients, the majority of which were non-Dongguan natives, usually experienced above-average pregnancies, lower educational level, lower regular prenatal care rate, and longer interval between onset of acute symptoms and ICU admission. Critically ill obstetric patients may benefit from publicized informed relevant education, government-supported health care, preventative interventions of critical obstetric and medical complications, timely ICU admission after onset of acute symptoms, and the enhanced support of organ functions within the ICU.


Assuntos
Estado Terminal/epidemiologia , Obstetrícia/estatística & dados numéricos , Adulto , China/epidemiologia , Estado Terminal/mortalidade , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Gravidez , Estudos Retrospectivos , Fatores de Risco
14.
Mol Ecol ; 21(22): 5473-83, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23043276

RESUMO

Biological invasions have been accelerated by a variety of human activities. Propagule pressure, the number of introduced individuals and independent introductions, is probably to be influenced by these human activities and may be an important factor for successful range expansion in new environments. We tested whether the current distribution of the predatory ladybeetle Coccinella septempunctata in the introduced range (USA) is the result of multiple historical human introductions or natural range expansion from the first established populations in the USA. To test this hypothesis, we compared historical records of propagule size, propagule number, specific introduction locations and the date of each introduction, with estimates of genetic variation in mitochondrial DNA (cytochrome oxidase I). Our results indicated that genetic diversity in the introduced range was positively correlated with historical records of propagule size and number and negatively correlated with distance to nearest introduction point, suggesting that multiple human releases were successful. Higher genetic diversity in populations found near introduction points suggest that initial founder effects were limited, but lower genetic diversity found farther from introduction points is probably the result of serial founder effects during secondary range expansion. These results suggest that the current distribution of C. septempunctata in the introduced range is the result of a combination of human releases and short-range expansion from multiple established populations in the introduced range.


Assuntos
Besouros/genética , Efeito Fundador , Variação Genética , Genética Populacional , Animais , DNA Mitocondrial/genética , Haplótipos , Atividades Humanas , Humanos , Espécies Introduzidas , Dados de Sequência Molecular , Estados Unidos
15.
Zhonghua Jie He He Hu Xi Za Zhi ; 32(6): 418-21, 2009 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-19957775

RESUMO

OBJECTIVE: To evaluate whether the clinical characteristics of chronic cough were helpful in determining its specific causes. METHODS: Patients with chronic cough were evaluated by a validated systematic diagnostic protocol. The patients with identified single cause were divided into 4 groups accordingly: cough-variant asthma (CVA), upper airway cough syndrome (UACS) or post-nasal drip syndrome (PNDS), eosinophilic bronchitis (EB), gastroesophageal reflux related cough (GERC), and the characteristics of the timing, character, onset and associated manifestations of chronic cough in different causes were compared. RESULTS: A total of 196 patients met the inclusion criteria, including 55 with EB, 45 with UACS, 50 with CVA and 46 with GERC. No significant difference was found in age, gender and course among EB, UACS, CVA and GERC. The incidence of nocturnal cough in CVA was 26.0% (13/44), significantly higher than in EB (9.1% (5/55), chi2 = 5.272, P<0.05), UACS (2.2% (1/45), chi2 = 10.657, P<0.01) and GERC (0% (0/46), chi2 = 13.833, P<0.01). The specificity of nocturnal cough for CVA was 95.9%. The sensitivity and specificity of cough associated with meals in GERC was 52.2% (24/46) and 83.3%, and regurgitation associated symptom in GERC were 69.6% (32/46) and 80.0%, which were significantly higher than other groups. The incidence of postnasal drip, rhinitis associated symptom and case history of nasal diseases in UACS were 66.7% (30/45), 88.9% (40/45) and 82.2% (37/45), and the specificity of them were 89.4%, 65.6% and 63.6% respectively. CONCLUSION: The timing character and some associated symptoms of chronic cough are useful in predicting a single cause.


Assuntos
Tosse/diagnóstico , Tosse/etiologia , Adolescente , Adulto , Idoso , Asma/complicações , Asma/diagnóstico , Doença Crônica , Diagnóstico Diferencial , Feminino , Refluxo Gastroesofágico/complicações , Refluxo Gastroesofágico/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Nasais/complicações , Doenças Nasais/diagnóstico , Rinite/complicações , Rinite/diagnóstico , Adulto Jovem
16.
Environ Entomol ; 37(1): 150-61, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18348806

RESUMO

Host location by parasitoids and dipteran predators of bark beetles is poorly understood. Unlike coleopteran predators that locate prey by orienting to prey pheromones, wasps and flies often attack life stages not present until after pheromone production ceases. Bark beetles have important microbial symbionts, which could provide sources of cues. We tested host trees, trees colonized by beetles and symbionts, and trees colonized by symbionts alone for attractiveness to hymenopteran parasitoids and dipteran predators. Field studies were conducted with Ips pini in Montana. Three pteromalid wasps were predominant. All were associated with the second and third instars of I. pini. Heydenia unica was more attracted to logs colonized by either I. pini or the fungus Ophiostoma ips than logs alone or blank controls (screen with no log). Rhopalicus pulchripennis was more attracted to logs colonized by I. pini than logs alone or blank controls. Dibrachys cavus was attracted to logs but did not distinguish whether or not they were colonized. Two dolichopodid predators were predominant. A Medetera species was more attracted to colonized than uncolonized logs and more attracted to logs than blank controls. It was also more attracted to logs colonized with the yeast Pichia scolyti than uncolonized logs, but attraction was less consistent. An unidentified dolichopodid was more attracted to logs colonized with I. pini, O. ips, and the bacteria Burkholderia sp., than to uncolonized logs. It was also attracted to uncolonized logs. Its responses were less consistent and pronounced than H. unica. These results suggest some parasitoids and dipteran predators exploit microbial symbionts of bark beetles to locate hosts. Overall, specialists showed strong attraction to fungal cues, whereas generalists were more attracted by plant volatiles. These results also show how microbial symbionts can have conflicting effects on host fitness.


Assuntos
Besouros/microbiologia , Dípteros/fisiologia , Ecossistema , Comportamento Predatório/fisiologia , Vespas/fisiologia , Animais , Ascomicetos/fisiologia , Burkholderia/fisiologia , Besouros/fisiologia , Feminino , Larva/fisiologia , Masculino , Odorantes , Pichia/fisiologia , Densidade Demográfica , Distribuição Aleatória , Estações do Ano , Simbiose/fisiologia , Árvores/microbiologia , Árvores/parasitologia
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