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1.
Eur Rev Med Pharmacol Sci ; 28(6): 2272-2287, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38567590

RESUMO

OBJECTIVE: This study aimed to systematically evaluate the efficacy, safety and optimal dose of polyethylene glycol loxenatide (PEX168) for treating type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: Clinical trials of PEX168 for T2DM were identified in 8 databases, with a build time limit of January 2023. Included studies were subjected to meta-analysis and trial sequential analysis (TSA). RESULTS: On the efficacy endpoint, the meta-analysis showed that PEX168 100 µg significantly reduced 0.86% glycated hemoglobin type A1c (HbA1c) (MD -0.86, 95% CI -1.02 - -0.70,  p<0.00001), 1.11 mmol/L fasting plasma glucose (FPG) (MD -1.11, 95% CI -1.49 - -0.74, p<0.00001) and 1.91 mmol/L 2h postprandial glucose (PPG) (MD -1.91, 95% CI -3.35 - -0.46, p=0.01) compared with placebo. The TSA showed that all these benefits were conclusive. On safety endpoints, total adverse events (AEs), gastrointestinal (GI) AEs, serious AEs, and hypoglycemia were comparable to placebo for PEX168 100 µg (p>0.05). In the dose comparison, the HbA1c, FPG, and 2h PPG of PEX168 200 µg were comparable to 100 µg (p>0.05), while GI AEs were significantly higher than 100 µg (RR=2.84, 95% CI 1.64-4.93,  p=0.0002). CONCLUSIONS: PEX168 100 µg can significantly lower blood glucose and does not increase the risk of total AEs, GI AEs, and hypoglycemia, which may be a preferred glucagon-like peptide-1 receptor agonist for type 2 diabetes mellitus.


Assuntos
Diabetes Mellitus Tipo 2 , Hipoglicemia , Peptídeos , Polietilenoglicóis , Humanos , Hipoglicemiantes , Hemoglobinas Glicadas , 60650 , Glicemia , Hipoglicemia/induzido quimicamente , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas
2.
ESMO Open ; 9(4): 102993, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38613910

RESUMO

BACKGROUND: Triple-negative breast cancer (TNBC) subtyping by gene profiling has provided valuable clinical information. Here, we aimed to evaluate the relevance of TNBC subtyping using immunohistochemistry (IHC), which could be a more clinically practical approach, for prognostication and applications in patient management. METHODS: A total of 123 TNBC cases were classified using androgen receptor (AR), CD8, Forkhead box C1 protein (FOXC1), and doublecortin-like kinase 1 (DCLK1) into luminal androgen receptor (LAR), basal-like immunosuppressive (BLIS), mesenchymal-like (MES), and immunomodulatory (IM) subtypes. The IM cases were further divided into the IM-excluded and IM-inflamed categories by CD8 spatial distribution. Their clinicopathological and biomarker profiles and prognoses were evaluated. RESULTS: LAR (28.6%) and MES (11.2%) were the most and least frequent subtypes. The IHC-TNBC subtypes demonstrated distinct clinicopathological features and biomarker profiles, corresponding to the reported features in gene profiling studies. IM-inflamed subtype had the best outcome, while BLIS had a significantly poorer survival. Differential breast-specific marker expressions were found. Trichorhinophalangeal syndrome type 1 (TRPS1) was more sensitive for IM-inflamed and BLIS, GATA-binding protein 3 (GATA3) for IM-excluded and MES, and gross cystic disease fluid protein 15 (GCDFP15) for LAR subtypes. CONCLUSIONS: Our findings demonstrated the feasibility of IHC surrogates to stratify TNBC subtypes with distinct features and prognoses. The IM subtype can be refined by its CD8 spatial pattern. Breast-specific marker expression varied among the subtypes. Marker selection should be tailored accordingly.

3.
Eur Rev Med Pharmacol Sci ; 27(18): 8812-8828, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37782191

RESUMO

OBJECTIVE: The purpose of this study is to use bibliometrics to explore the research overview and research hotspots. MATERIALS AND METHODS: The relevant literature on intestinal flora and diabetic nephropathy in the Web of Science Core Collection was sorted out, and VOSviewer, CiteSpace, Scimago Graphica and other software were used to conduct data visualization analysis on the number of publications, countries, institutions, journals, authors, keywords and citations. RESULTS: A total of 124 relevant literatures were included. From 2015 to 2022, the number of published papers increased every year. The countries, institutions and journals that published the most articles in this field are China, Isfahan University Medical Science and Frontiers in Pharmacology. Liu Bicheng and Mirlohi Maryam are the authors with the most published articles in this field. The main keywords of research in this field are obesity, inflammation, oxidative stress, indoxyl sulfate, short-chain fatty acids (SCFAs) and Chinese herbal medicine. CONCLUSIONS: This is the first bibliometric analysis of diabetic nephropathy and gut microbiota, reporting hot spots and emerging trends. Obesity, inflammation, oxidative stress, indoxyl sulfate, SCFAs and Chinese herbal medicine are the main keywords of current research, and SCFAs and Chinese herbal medicine may be the hotspots of future research.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Medicamentos de Ervas Chinesas , Microbioma Gastrointestinal , Humanos , Indicã , Bibliometria , Inflamação , Obesidade
5.
Zhonghua Bing Li Xue Za Zhi ; 51(8): 719-725, 2022 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-35922161

RESUMO

Objective: To explore clinicopathological features of low-grade oncocytic tumor (LOT) of the kidney and to analyze its relationship to hybrid oncocytic/chromophobe tumor (HOCT) of the kidney, renal oncocytoma (RO), and chromophobe renal cell carcinoma (chRCC). Methods: Seven LOTs were identified from the pathologic archives of two hospitals, including Xiangya Hospital (5 cases) and the Second Xiangya Hospital (2 cases) of Central South University between 2012 and 2019. Clinical data of the LOTs were collected. The tumor morphology was analyzed and immunohistochemistry was performed. Results: All LOTs occurred in adults, aged from 49 to 72 years (median 56.0 years, mean 60.7 years). The tumor size ranged from 2.5 to 6.0 cm (median 4.3 cm, mean 4.3 cm). There were three male and four female patients. Three cases occurred in the left kidney and four in the right. All the tumors were solitary lesions without the clinicopathologic background of Birt-Hogg-Dubé (BHD) syndrome or oncocytosis. Five patients had available follow-up data (follow-up period 23-95 months, median 69.0 months, mean 64.6 months) and all were alive without disease. Microscopically, all LOTs were well-circumscribed (7/7). Three LOTs were partly encapsulated. The tumors demonstrated a predominant growth pattern comprising prominently compact small nests surrounded by delicately branching thin-walled blood vessels, imparting an organoid architecture (7/7), but variable numbers of glandular or gland-like structures were often seen among the small nests (7/7). There were frequently areas with loose, edematous stroma, and the tumor cells exhibited reticular, trabecular, or single cell arrangements (6/7). Focal hemorrhage was also commonly present in both compact and loose areas (5/7). In addition, focally cystic formation and ossification occurred in the compact area of one case and in the loose area of another case. The tumor cells in LOT showed intermediate cytologic characteristics between RO and chRCC, including abundantly eosinophilic granular cytoplasm, ovoid to round nuclei with mostly smooth contours, discernable small nucleoli (RO features), frequently delicate perinuclear halos, and occasional binucleation (chRCC features). The tumors were typically CK7-positive and CD117-negative (7/7), and variable staining for PAX8 (5/7), P504s (2/7), and vimentin (1/7). They were negative for CK20, CD10 and FOXI1. All tumors retained SDHB immunostaining. Conclusions: LOT is a rare and indolent oncocytic renal tumor with homogeneously intermediate cytologic features between RO and chRCC. There are some clinicopathologic overlaps between LOT and sporadic HOCT. The distinctive morphology and immunophenotype of LOT suggest that it is potentially a distinct tumor entity.


Assuntos
Adenoma Oxífilo , Carcinoma de Células Renais , Neoplasias Renais , Adenoma Oxífilo/patologia , Adulto , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/patologia , Feminino , Fatores de Transcrição Forkhead , Humanos , Queratina-7 , Rim/patologia , Neoplasias Renais/patologia , Masculino
6.
BMC Public Health ; 21(1): 1821, 2021 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-34627194

RESUMO

BACKGROUND: Objectively measured differences in physical activity (PA) and sleep have been documented among people with osteoarthritis (OA) and rheumatoid arthritis (RA) compared to non-arthritic controls. However, it is not clear whether OA and RA subgroups also differ on these indexes or the extent to which distinct arthritis subgroups versus controls can be accurately identified on the basis of objective PA and sleep indexes compared to self-report responses on questionnaires. This study addressed these gaps. METHODS: This case-control study comprised Chinese adults with OA (N = 40) or RA (N = 40) diagnoses based on physician assessments as well as a control group of adults without chronic pain (N = 40). All participants wore a Sensewear Armband (SWA) for consecutive 7 days and completed the International Physical Activity Questionnaire Short Form-Chinese as well as Pittsburgh Sleep Diary to obtain objective and subjective PA and sleep data, respectively. RESULTS: There were no differences between the three groups on any self-report indexes of PA or sleep. Conversely, OA and RA subgroups displayed significantly lower PA levels and more sleep problems than controls did on a majority of SWA indexes, though arthritis subgroups were not differentiated from one another on these measures. Logistic regression analyses indicated four non-multicollinear SWA indexes (i.e., steps, active energy expenditure, vigorous activity, time awake after sleep onset) correctly identified the subgroup membership of 75.0-82.5% of participants with RA or OA while classification accuracy results were attenuated for controls. CONCLUSIONS: Where possible, objective measures should be used to assess PA and sleep of adults with OA and RA while particular self-report PA questionnaires should be used sparingly.


Assuntos
Artrite Reumatoide , Osteoartrite , Adulto , Estudos de Casos e Controles , China/epidemiologia , Exercício Físico , Humanos , Osteoartrite/epidemiologia , Autorrelato , Sono
8.
Ir J Psychol Med ; 38(2): 116-122, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32993833

RESUMO

OBJECTIVES: This study aimed to assess the impact of COVID-19 on presentations to an acute hospital with self-harm. METHODS: All presentations to University Hospital Galway with self-harm were assessed during the peak period of the coronavirus crisis in Ireland, over the 3 months from 1 March to 31 May 2020. These data were compared with presentations in the same months in the 3 years preceding (2017-2019). Data were obtained from the anonymised service database. RESULTS: This study found that in 2020, the rate of presentation with self-harm dropped by 35% from March to April and rose by 104% from April to May, peaking from mid-May. When trends over a 4-year period were examined, there was a significantly higher lethality of attempt (p < 0.001), and significant differences in diagnosis (p = 0.031) in 2020 in comparison with the three previous years. The increased lethality of presentations remained significant after age and gender were controlled for (p = 0.036). There were also significant differences in the underlying psychiatric diagnoses (p = 0.018), notably with a significant increase in substance misuse disorders presenting during the 2020 study period. CONCLUSIONS: COVID-19 showed a reduction in self-harm presentations initially, followed by a sharp increase in May 2020. If a period of economic instability follows as predicted, it is likely that this will further impact the mental health of the population, along with rates of self-harm and suicidal behaviours. There is a need for research into the longer-term effect of COVID-19 and lockdown restrictions, especially with respect to self-harm.


Assuntos
COVID-19 , Comportamento Autodestrutivo , Controle de Doenças Transmissíveis , Humanos , Irlanda/epidemiologia , SARS-CoV-2 , Comportamento Autodestrutivo/epidemiologia , Centros de Atenção Terciária
9.
J Control Release ; 330: 1095-1105, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33188827

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant disease, where even surgical resection and aggressive chemotherapy produce dismal outcomes. Immunotherapy is a promising alternative to conventional treatments, possessing the ability to elicit T cell-mediated killing of tumor cells and prevent disease recurrence. Immunotherapeutic approaches thus far have seen limited success in PDAC due to a poorly immunogenic and exceedingly immunosuppressive tumor microenvironment, which is enriched with dysfunctional and immunosuppressed antigen-presenting cells (APCs). We developed a highly potent immunostimulatory nanoparticle (immuno-NP) to activate and expand APCs in the tumor and induce local secretion of interferon ß (IFNß), which is a pro-inflammatory cytokine that plays a major role in APC recruitment. The effectiveness of the immuno-NP stems from its dual cargo of two synergistic immune modulators consisting of an agonist of the stimulator of interferon genes (STING) pathway and an agonist of the Toll-like receptor 4 (TLR4) pathway. We show the functional synergy of the dual-agonist cargo can be tweaked by adjusting the ratio of the two agonists loaded in the immuno-NP, leading to an increase in IFNß production (11-fold) compared to any single agonist immuno-NP variant. Using the orthotopic murine Panc02 model of PDAC, we show that systemic administration allowed immuno-NPs to deposit into the perivascular regions of the tumor, which coincided with the APC-rich tumor areas leading to predominant uptake of immuno-NPs by APCs. The immuno-NPs were effectively taken up by a significant portion of dendritic cells in the tumor (>56%). This led to a significant expansion of APCs, resulting in an 11.5-fold increase of dendritic cells and infiltration of lymphocytes throughout the pancreatic tumor compared to untreated animals.


Assuntos
Nanopartículas , Neoplasias Pancreáticas , Animais , Células Apresentadoras de Antígenos , Imunização , Imunoterapia , Camundongos , Neoplasias Pancreáticas/tratamento farmacológico , Microambiente Tumoral
10.
Mol Biol Evol ; 37(4): 1202-1210, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31825512

RESUMO

Evolution leaves heterogeneous patterns of nucleotide variation across the genome, with different loci subject to varying degrees of mutation, selection, and drift. In phylogenetics, the potential impacts of partitioning sequence data for the assignment of substitution models are well appreciated. In contrast, the treatment of branch lengths has received far less attention. In this study, we examined the effects of linking and unlinking branch-length parameters across loci or subsets of loci. By analyzing a range of empirical data sets, we find consistent support for a model in which branch lengths are proportionate between subsets of loci: gene trees share the same pattern of branch lengths, but form subsets that vary in their overall tree lengths. These models had substantially better statistical support than models that assume identical branch lengths across gene trees, or those in which genes form subsets with distinct branch-length patterns. We show using simulations and empirical data that the complexity of the branch-length model with the highest support depends on the length of the sequence alignment and on the numbers of taxa and loci in the data set. Our findings suggest that models in which branch lengths are proportionate between subsets have the highest statistical support under the conditions that are most commonly seen in practice. The results of our study have implications for model selection, computational efficiency, and experimental design in phylogenomics.


Assuntos
Modelos Genéticos , Filogenia , Simulação por Computador
11.
Proc Biol Sci ; 286(1912): 20191854, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31594499

RESUMO

Insects are a highly diverse group of organisms and constitute more than half of all known animal species. They have evolved an extraordinary range of traits, from flight and complete metamorphosis to complex polyphenisms and advanced eusociality. Although the rich insect fossil record has helped to chart the appearance of many phenotypic innovations, data are scarce for a number of key periods. One such period is that following the End-Permian Extinction, recognized as the most catastrophic of all extinction events. We recently discovered several 240-million-year-old insect fossils in the Mount San Giorgio Lagerstätte (Switzerland-Italy) that are remarkable for their state of preservation (including internal organs and soft tissues), and because they extend the records of their respective taxa by up to 200 million years. By using these fossils as calibrations in a phylogenomic dating analysis, we present a revised time scale for insect evolution. Our date estimates for several major lineages, including the hyperdiverse crown groups of Lepidoptera, Hemiptera: Heteroptera and Diptera, are substantially older than their currently accepted post-Permian origins. We found that major evolutionary innovations, including flight and metamorphosis, appeared considerably earlier than previously thought. These results have numerous implications for understanding the evolution of insects and their resilience in the face of extreme events such as the End-Permian Extinction.


Assuntos
Evolução Biológica , Insetos , Animais , Fósseis , Itália , Lepidópteros , Metamorfose Biológica , Suíça
13.
Nanoscale ; 11(24): 11910-11921, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31187845

RESUMO

Glioblastomas are highly lethal cancers defined by resistance to conventional therapies and rapid recurrence. While new brain tumor cell-specific drugs are continuously becoming available, efficient drug delivery to brain tumors remains a limiting factor. We developed a multicomponent nanoparticle, consisting of an iron oxide core and a mesoporous silica shell that can effectively deliver drugs across the blood-brain barrier into glioma cells. When exposed to alternating low-power radiofrequency (RF) fields, the nanoparticle's mechanical tumbling releases the entrapped drug molecules from the pores of the silica shell. After directing the nanoparticle to target the near-perivascular regions and altered endothelium of the brain tumor via fibronectin-targeting ligands, rapid drug release from the nanoparticles is triggered by RF facilitating wide distribution of drug delivery across the blood-brain tumor interface.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Portadores de Fármacos , Nanopartículas , Dióxido de Silício , Animais , Barreira Hematoencefálica , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Feminino , Compostos Férricos/química , Compostos Férricos/farmacocinética , Compostos Férricos/farmacologia , Camundongos , Camundongos Nus , Nanopartículas/química , Nanopartículas/uso terapêutico , Dióxido de Silício/química , Dióxido de Silício/farmacocinética , Dióxido de Silício/farmacologia
15.
Adv Ther (Weinh) ; 2(11)2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32953978

RESUMO

Glioblastomas (GBMs) remain highly lethal. This partially stems from the presence of brain tumor initiating cells (BTICs), a highly plastic cellular subpopulation that is resistant to current therapies. In addition to resistance, the blood-brain barrier limits the penetration of most drugs into GBMs. To effectively deliver a BTIC-specific inhibitor to brain tumors, we developed a multicomponent nanoparticle, termed Fe@MSN, which contains a mesoporous silica shell and an iron oxide core. Fibronectin-targeting ligands directed the nanoparticle to the near-perivascular areas of GBM. After Fe@MSN particles deposited in the tumor, an external low-power radiofrequency (RF) field triggered rapid drug release due to mechanical tumbling of the particle resulting in penetration of high amounts of drug across the blood-brain tumor interface and widespread drug delivery into the GBM. We loaded the nanoparticle with the drug 1400W, which is a potent inhibitor of the inducible nitric oxide synthase (iNOS). It has been shown that iNOS is preferentially expressed in BTICs and is required for their maintenance. Using the 1400W-loaded Fe@MSN and RF-triggered release, in vivo studies indicated that the treatment disrupted the BTIC population in hypoxic niches, suppressed tumor growth and significantly increased survival in BTIC-derived GBM xenografts.

16.
BMC Evol Biol ; 18(1): 70, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769015

RESUMO

BACKGROUND: Phylogenetic analysis of DNA from modern and ancient samples allows the reconstruction of important demographic and evolutionary processes. A critical component of these analyses is the estimation of evolutionary rates, which can be calibrated using information about the ages of the samples. However, the reliability of these rate estimates can be negatively affected by among-lineage rate variation and non-random sampling. Using a simulation study, we compared the performance of three phylogenetic methods for inferring evolutionary rates from time-structured data sets: regression of root-to-tip distances, least-squares dating, and Bayesian inference. We also applied these three methods to time-structured mitogenomic data sets from six vertebrate species. RESULTS: Our results from 12 simulation scenarios show that the three methods produce reliable estimates when the substitution rate is high, rate variation is low, and samples of similar ages are not all grouped together in the tree (i.e., low phylo-temporal clustering). The interaction of these factors is particularly important for least-squares dating and Bayesian estimation of evolutionary rates. The three estimation methods produced consistent estimates of rates across most of the six mitogenomic data sets, with sequence data from horses being an exception. CONCLUSIONS: We recommend that phylogenetic studies of ancient DNA sequences should use multiple methods of inference and test for the presence of temporal signal, among-lineage rate variation, and phylo-temporal clustering in the data.


Assuntos
DNA Antigo , Genômica/métodos , Mutação/genética , Vertebrados/genética , Animais , Sequência de Bases , Teorema de Bayes , Simulação por Computador , Evolução Molecular , Genoma Mitocondrial , Cavalos , Filogenia , Fatores de Tempo , Incerteza
17.
Clin Radiol ; 72(12): 1002-1013, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29032802

RESUMO

Transarterial radioembolisation (TARE) has gained increasing acceptance as an additional/alternative locoregional treatment option for hepatocellular carcinoma, and colorectal hepatic metastases that present beyond potentially curative options. This is a catheter-based transarterial selective internal brachytherapy that involves injection of radioactive microspheres (usually Y-90) that are delivered selectively to the liver tumours. Owing to the combined radioactive and microembolic effect, the findings at follow-up imaging are significantly different from that seen with other transarterial treatment options. Considering increasing confidence among clinicians, refinement in techniques and increasing number of ongoing trials, TARE is expected to gain further acceptance and become an important tool in the armamentarium for the treatment of liver malignancies. So it is imperative that all radiologists involved in the management of liver malignancies are well versed with TARE to facilitate appropriate discussion at multidisciplinary meetings to direct further management. In this article, we provide a comprehensive review on various aspects of radioembolisation with Y-90 for hepatocellular carcinoma including the patient selection, treatment planning, radiation dosimetry and treatment, side effects, follow-up imaging and future direction.


Assuntos
Embolização Terapêutica/métodos , Radioisótopos de Ítrio/uso terapêutico , Carcinoma Hepatocelular , Humanos , Neoplasias Hepáticas , Microesferas
18.
PeerJ ; 5: e3241, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28462044

RESUMO

Genomes evolve through a combination of mutation, drift, and selection, all of which act heterogeneously across genes and lineages. This leads to differences in branch-length patterns among gene trees. Genes that yield trees with the same branch-length patterns can be grouped together into clusters. Here, we propose a novel phylogenetic approach to explain the factors that influence the number and distribution of these gene-tree clusters. We apply our method to a genomic dataset from insects, an ancient and diverse group of organisms. We find some evidence that when drift is the dominant evolutionary process, each cluster tends to contain a large number of fast-evolving genes. In contrast, strong negative selection leads to many distinct clusters, each of which contains only a few slow-evolving genes. Our work, although preliminary in nature, illustrates the use of phylogenetic methods to shed light on the factors driving rate variation in genomic evolution.

19.
Proc Biol Sci ; 283(1825): 20152869, 2016 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-26888035

RESUMO

Parallel evolution is the independent appearance of similar derived phenotypes from similar ancestral forms. It is of key importance in the debate over whether evolution is stochastic and unpredictable, or subject to constraints that limit available phenotypic options. Nevertheless, its occurrence has rarely been demonstrated above the species level. Climate change on the Australian landmass over the last approximately 20 Myr has provided conditions conducive to parallel evolution, as taxa at the edges of shrinking mesic habitats adapted to drier biomes. Here, we investigate the phylogeny and evolution of Australian soil-burrowing and wood-feeding blaberid cockroaches. Soil burrowers (subfamily Geoscapheinae) are found in relatively dry sclerophyllous and scrubland habits, whereas wood feeders (subfamily Panesthiinae) are found in rainforest and wet sclerophyll. We sequenced and analysed mitochondrial and nuclear markers from 142 specimens, and estimated the evolutionary time scale of the two subfamilies. We found evidence for the parallel evolution of soil-burrowing taxa from wood-feeding ancestors on up to nine occasions. These transitions appear to have been driven by periods of aridification during the Miocene and Pliocene across eastern Australia. Our results provide an illuminating example of climate-driven parallel evolution among species.


Assuntos
Evolução Biológica , Mudança Climática , Baratas/genética , Animais , Austrália , DNA Espaçador Ribossômico/genética , Proteínas de Insetos/genética , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA
20.
Insect Mol Biol ; 25(2): 126-37, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26691197

RESUMO

Target site insensitivity because of mutations in the voltage-sensitive sodium channel gene (Vssc) is a major mechanism of resistance to pyrethroid insecticides in the house fly, Musca domestica. There are three known Vssc alleles that confer resistance to pyrethroids in the house fly: knock down resistance (kdr; L1014F), super-kdr (M918T + L1014F) and kdr-his (L1014H), but there has been no side-by-side comparison of the resistance levels that they confer. We compared the levels of resistance conferred by the three Vssc alleles in congenic strains to 19 structurally diverse pyrethroids, and compared the full-length Vssc cDNA sequences from each strain. Generally, the levels of resistance conferred were kdr-his < kdr < super-kdr. However, there was significant variation in this pattern, especially for super-kdr, for which both high and low resistance ratios were observed for several pyrethroids. We also examined the levels of resistance in heterozygotes. Resistance in each of the hybrids was generally inherited as an incompletely recessive trait, except for the kdr-his/kdr hybrids, which showed incompletely to completely dominant resistance (ie had resistance levels comparable to kdr homozygotes). The importance of these results to understanding the frequencies of these resistance alleles in natural populations, the evolution of insecticide resistance and resistance management strategies are discussed.


Assuntos
Moscas Domésticas/genética , Resistência a Inseticidas/genética , Canais de Sódio/genética , Alelos , Animais , DNA Complementar/genética , Heterozigoto , Moscas Domésticas/efeitos dos fármacos , Inseticidas/farmacologia , Mutação , Piretrinas/farmacologia
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