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1.
Infection ; 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38499828

RESUMEN

PURPOSE: In contrast to adults, immune protection against SARS-CoV-2 in children and adolescents with natural or hybrid immunity is still poorly understood. The aim of this study was to analyze different immune compartments in different age groups and whether humoral immune reactions correlate with a cellular immune response. METHODS: 72 children and adolescents with a preceding SARS-CoV-2 infection were recruited. 37 were vaccinated with an RNA vaccine (BNT162b2). Humoral immunity was analyzed 3-26 months (median 10 months) after infection by measuring Spike protein (S), nucleocapsid (NCP), and neutralizing antibodies (nAB). Cellular immunity was analyzed using a SARS-CoV-2-specific interferon-γ release assay (IGRA). RESULTS: All children and adolescents had S antibodies; titers were higher in those with hybrid immunity (14,900 BAU/ml vs. 2118 BAU/ml). NCP antibodies were detectable in > 90%. Neutralizing antibodies (nAB) were more frequently detected (90%) with higher titers (1914 RLU) in adolescents with hybrid immunity than in children with natural immunity (62.5%, 476 RLU). Children with natural immunity were less likely to have reactive IGRAs (43.8%) than adolescents with hybrid immunity (85%). The amount of interferon-γ released by T cells was comparable in natural and hybrid immunity. CONCLUSION: Spike antibodies are the most reliable markers to monitor an immune reaction against SARS-CoV-2. High antibody titers of spike antibodies and nAB correlated with cellular immunity, a phenomenon found only in adolescents with hybrid immunity. Hybrid immunity is associated with markedly higher antibody titers and a higher probability of a cellular immune response than a natural immunity.

2.
Laryngorhinootologie ; 102(2): 89-99, 2023 02.
Artículo en Alemán | MEDLINE | ID: mdl-36750110

RESUMEN

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial inflammatory disease of the mucous membranes of the nose and sinuses. Eosinophilic inflammation is described as a common endotype. The anti-IL5 antibody mepolizumab was approved in November 2021 as an add-on therapy to intranasal glucocorticosteroids for the treatment of adults with severe chronic rhinosinusitis with nasal polyps when systemic glucocorticosteroids or surgery do not provide adequate disease control. While national and international recommendations exist for the use of mepolizumab in CRSwNP, it has not yet been adequately specified how this therapy is to be monitored, what follow-up documentation is necessary, and when it should be terminated if necessary. METHODS: A literature search was performed to analyze previous data on the treatment of CRSwNP with mepolizumab and to determine the available evidence by searching Medline, Pubmed, the national and international trial and guideline registries and the Cochrane Library. Human studies published in the period up to and including 10/2022 were considered. RESULTS: Based on the international literature and previous experience by an expert panel, recommendations for follow-up, adherence to therapy intervals and possible therapy breaks, as well as termination of therapy when using mepolizumab for the indication CRSwNP in the German health care system are given on the basis of a documentation sheet. CONCLUSIONS: Understanding the immunological basis of CRSwNP opens up new non-surgical therapeutic approaches with biologics for patients with severe, uncontrolled courses. Here, we provide recommendations for follow-up, adherence to therapy intervals, possible therapy pauses, or discontinuation of therapy when mepolizumab is used as add-on therapy with intranasal glucocorticosteroids to treat adult patients with severe CRSwNP that cannot be adequately controlled with systemic glucocorticosteroids and/or surgical intervention.


Asunto(s)
Medicina Ambiental , Pólipos Nasales , Procedimientos Quírurgicos Nasales , Rinitis , Sinusitis , Adulto , Humanos , Rinitis/tratamiento farmacológico , Enfermedad Crónica , Sinusitis/tratamiento farmacológico , Atención a la Salud
3.
Schmerz ; 36(6): 422-428, 2022 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-34762202

RESUMEN

BACKGROUND: Cystic fibrosis (CF) is a rare genetic multisystemic disorder with progressive abdominal and pulmonary involvement. Pain is still an underestimated symptom in CF patients. METHODS: A comprehensive review of guidelines and scientific literature on the topic was performed and combined with findings from pain management in a young CF patient with progressive thoracic pain. RESULTS: German CF guidelines do not cover diagnosis and management of pain in these patients. Studies from Europe and the United States report interactions between intensity of pain and mortality in CF, but do not include data on the efficacy of pain management. These data and clinical observations of a CF patient with episodes of intense thoracic pain are used to illustrate the specific challenges in pain relief. CONCLUSION: Pain management in CF requires meticulous monitoring as well as an interdisciplinary approach and should be implemented in the German CF guidelines. The authors also want to suggest recommendations for the treatment of thoracic pain in CF. The range and severity of organ involvement complicates the use both of opioids and non-opioids. Especially opioid treatment carries the risk of hypoxia and opioid-induced constipation (OIC) and needs close medical supervision.


Asunto(s)
Fibrosis Quística , Humanos , Estados Unidos , Fibrosis Quística/complicaciones , Fibrosis Quística/diagnóstico , Fibrosis Quística/terapia , Manejo del Dolor , Analgésicos Opioides/efectos adversos , Estreñimiento , Dolor/tratamiento farmacológico
4.
Laryngorhinootologie ; 101(11): 855-865, 2022 11.
Artículo en Alemán | MEDLINE | ID: mdl-36150698

RESUMEN

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial inflammatory disease of the nasal and paranasal mucosa. A Type-2 inflammation is described as the most common endotype. Since October 2019 the anti-IL-4/-IL-13 antibody dupilumab has been approved in Germany as an add-on therapy to intranasal corticosteroids for the treatment of adults with severe chronic rhinosinusitis with nasal polyps, when systemic corticosteroids alone or surgery do not provide adequate disease control. While recommendations for the use of dupilumab in CRSwNP exist at both national and international levels, until now it has not been adequately established, how therapy should be monitored and when it should be discontinued in the German Health Care System. METHODS: A literature search was performed analyzing previous data on the treatment of CRSwNP with dupilumab and to determine the available evidence by searching Medline, Pubmed, the national and international trial and guideline registries and the Cochrane Library. Human studies published in the period up to 05/2022 were included. RESULTS: Based on international literature and previous experience, recommendations are given by an expert panel for follow-up and possible therapy breaks, therapy intervals or termination of therapy when using dupilumab for the indication CRSwNP in the German health care system based on a documentation form. CONCLUSIONS: Understanding the immunological basis of CRSwNP opens new non-surgical therapy approaches with biologics for patients with severe courses. The authors give recommendations for follow-up, possible therapy breaks, therapy intervals and a termination for dupilumab treatment as add-on therapy with intranasal corticosteroids for the treatment of adult patients with severe CRSwNP that cannot be adequately controlled with systemic corticosteroids and/or surgical intervention.


Asunto(s)
Pólipos Nasales , Rinitis , Sinusitis , Adulto , Humanos , Pólipos Nasales/tratamiento farmacológico , Rinitis/tratamiento farmacológico , Sinusitis/tratamiento farmacológico , Enfermedad Crónica , Corticoesteroides/uso terapéutico , Atención a la Salud , Documentación
5.
Phys Rev Lett ; 126(13): 137201, 2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33861132

RESUMEN

We present an experimental study of time refraction of spin waves (SWs) propagating in microscopic waveguides under the influence of time-varying magnetic fields. Using space- and time-resolved Brillouin light scattering microscopy, we demonstrate that the broken translational symmetry along the time coordinate results in a loss of energy conservation for SWs and thus allows for a broadband and controllable shift of the SW frequency. With an integrated design of SW waveguide and microscopic current line for the generation of strong, nanosecond-long, magnetic field pulses, a conversion efficiency up to 39% of the carrier SW frequency is achieved, significantly larger compared to photonic systems. Given the strength of the magnetic field pulses and its strong impact on the SW dispersion relation, the effect of time refraction can be quantified on a length scale comparable to the SW wavelength. Furthermore, we utilize time refraction to excite SW bursts with pulse durations in the nanosecond range and a frequency shift depending on the pulse polarity.

6.
BMC Biol ; 18(1): 161, 2020 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-33158442

RESUMEN

BACKGROUND: The Wolbachia incompatible insect technique (IIT) shows promise as a method for eliminating populations of invasive mosquitoes such as Aedes aegypti (Linnaeus) (Diptera: Culicidae) and reducing the incidence of vector-borne diseases such as dengue, chikungunya and Zika. Successful implementation of this biological control strategy relies on high-fidelity separation of male from female insects in mass production systems for inundative release into landscapes. Processes for sex-separating mosquitoes are typically error-prone and laborious, and IIT programmes run the risk of releasing Wolbachia-infected females and replacing wild mosquito populations. RESULTS: We introduce a simple Markov population process model for studying mosquito populations subjected to a Wolbachia-IIT programme which exhibit an unstable equilibrium threshold. The model is used to study, in silico, scenarios that are likely to yield a successful elimination result. Our results suggest that elimination is best achieved by releasing males at rates that adapt to the ever-decreasing wild population, thus reducing the risk of releasing Wolbachia-infected females while reducing costs. CONCLUSIONS: While very high-fidelity sex separation is required to avoid establishment, release programmes tend to be robust to the release of a small number of Wolbachia-infected females. These findings will inform and enhance the next generation of Wolbachia-IIT population control strategies that are already showing great promise in field trials.


Asunto(s)
Aedes/microbiología , Control de Mosquitos/métodos , Mosquitos Vectores/microbiología , Wolbachia/fisiología , Animales , Femenino , Masculino , Cadenas de Markov , Modelos Biológicos , Dinámica Poblacional
7.
Phys Rev Lett ; 125(9): 097201, 2020 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-32915598

RESUMEN

Using first-principles transport calculations, we predict that the anisotropic magnetoresistance (AMR) of single-crystal Co_{x}Fe_{1-x} alloys is strongly dependent on the current orientation and alloy concentration. An intrinsic mechanism for AMR is found to arise from the band crossing due to magnetization-dependent symmetry protection. These special k points can be shifted towards or away from the Fermi energy by varying the alloy composition and hence the exchange splitting, thus allowing AMR tunability. The prediction is confirmed by delicate transport measurements, which further reveal a reciprocal relationship of the longitudinal and transverse resistivities along different crystal axes.

8.
Med Mycol ; 57(2): 256-259, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29471422

RESUMEN

Histoplasma capsulatum var. duboisii (Hcd) infections have been well documented to cause chronic granulomatous disease, mainly involving the skin of baboons and humans in African countries primarily. This retrospective study classified the subspecies of Histoplasma and developed a phylogenetic tree utilizing DNA sequences extracted from formalin-fixed, paraffin embedded (FFPE) tissues from 9 baboons from a research colony in Texas histologically diagnosed with Hcd. Based on sequence analysis of ITS-2, Tub-1, and ARF, Hcd isolated from the archived samples closely aligns with the African clade and has 88% sequence homology with a sample isolated from an individual in Senegal.


Asunto(s)
Histoplasma/clasificación , Histoplasma/aislamiento & purificación , Histoplasmosis/veterinaria , Papio/microbiología , Filogenia , Enfermedades de los Primates/microbiología , África/epidemiología , Animales , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Formaldehído , Genes Fúngicos/genética , Histoplasma/genética , Histoplasmosis/epidemiología , Histoplasmosis/microbiología , Epidemiología Molecular , Adhesión en Parafina/veterinaria , Enfermedades de los Primates/epidemiología , Estudios Retrospectivos , Análisis de Secuencia de ADN , Texas/epidemiología
9.
Nutr Metab Cardiovasc Dis ; 29(1): 23-29, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30527352

RESUMEN

BACKGROUND AND AIMS: Pro-Neurotensin (NT), a stable surrogate parameter of NT, has recently been introduced as a peptide predicting the development of obesity, diabetes mellitus, cardiovascular diseases, and cardiovascular mortality. However, regulation of Pro-NT in gestational diabetes mellitus (GDM) remains uninvestigated. METHODS AND RESULTS: Pro-NT was quantified in 74 women with GDM, 74 healthy, gestational age-matched, pregnant controls, as well as in a second cohort comprising of 74 healthy, non-pregnant control women, using a chemiluminometric sandwich immunoassay. Pro-NT was correlated to measures of obesity, hypertension, glucose and lipid metabolism, renal function, and inflammation. Mean ± standard deviation of circulating Pro-NT levels were not significantly different in women with GDM (100.2 ± 75.7 pmol/l) as compared to healthy, pregnant controls (103.2 ± 37.4 pmol/l) and healthy, non-pregnant female controls (105.9 ± 38.9 pmol/l) (p = 0.661). Homeostasis model assessment of insulin resistance (HOMA-IR) and creatinine positively correlated with serum Pro-NT in multivariate regression analysis. In contrast, free fatty acids (FFA) were inversely correlated with circulating Pro-NT. Results sustained adjustment for pregnancy status. CONCLUSIONS: Circulating Pro-NT is not independently associated with GDM, but is with HOMA-IR, creatinine, and FFA even after adjustment for pregnancy status.


Asunto(s)
Diabetes Gestacional/sangre , Neurotensina/sangre , Precursores de Proteínas/sangre , Biomarcadores/sangre , Glucemia/análisis , Estudios de Casos y Controles , Creatinina/sangre , Estudios Transversales , Diabetes Gestacional/diagnóstico , Ácidos Grasos no Esterificados/sangre , Femenino , Humanos , Insulina/sangre , Resistencia a la Insulina , Embarazo
10.
Insect Mol Biol ; 27(6): 796-807, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29989657

RESUMEN

Wolbachia influence the fitness of their invertebrate hosts. They have effects on reproductive incompatibility and egg production. Although the former are well characterized, the mechanistic basis of the latter is unclear. Here, we investigate whether apoptosis, which has been implicated in fecundity in model insects, influences the interaction between fecundity and Wolbachia in the planthopper Laodelphax striatellus. Wolbachia-infected females produced about 30% more eggs than uninfected females. We used the terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling staining to visualize apoptosis. Microscopic observations indicated that the Wolbachia strain wStri increased the number of ovarioles that contained apoptotic nurse cells in both young and aged adult females. The frequency of apoptosis was much higher in the infected females. The increased fecundity appeared to be a result of apoptosis of nurse cells, which provide nutrients to the growing oocytes. In addition, cell apoptosis inhibition by caspase messenger RNA interference in Wolbachia-infected L. striatellus markedly decreased egg numbers. Together, these data suggest that wStri might enhance fecundity by increasing the number of apoptotic cells in the ovaries in a caspase-dependent manner. Our findings establish a link between Wolbachia-induced apoptosis and egg production effects mediated by Wolbachia, although the way in which the endosymbiont influences caspase levels remains to be determined.


Asunto(s)
Apoptosis , Caspasas/metabolismo , Hemípteros/fisiología , Wolbachia/fisiología , Secuencia de Aminoácidos , Animales , Caspasas/genética , Femenino , Fertilidad , Aptitud Genética , Hemípteros/microbiología , Ovario/microbiología , Ovario/fisiología
11.
Insect Mol Biol ; 27(6): 698-709, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29797479

RESUMEN

There is increasing evidence that mitochondrial genomes (mitogenomes) can be under selection, whereas the selective regimes shaping mitogenome evolution remain largely unclear. To test for mitogenome evolution in relation to the climate adaptation, we explored mtDNA variation in two spider mite (Tetranychus) species that distribute across different climates. We sequenced 26 complete mitogenomes of Tetranychus truncates, which occurs in both warm and cold regions, and nine complete mitogenomes of Tetranychus pueraricola, which is restricted to warm regions. Patterns of evolution in the two species' mitogenomes were compared through a series of dN /dS methods and physicochemical profiles of amino acid replacements. We found that: (1) the mitogenomes of both species were under widespread purifying selection; (2) elevated directional adaptive selection was observed in the T. truncatus mitogenome, perhaps linked to the cold climates adaptation of T. truncatus; and (3) the strength of selection varied across genes, and diversifying positive selection detected on ND4 and ATP6 pointed to their crucial roles during adaptation to different climatic conditions. This study gained insight into the mitogenome evolution in relation to the climate adaptation.


Asunto(s)
Clima , Evolución Molecular , Genoma Mitocondrial , Selección Genética , Tetranychidae/genética , Animales , Femenino , Variación Genética , Haplotipos
12.
Strahlenther Onkol ; 194(1): 31-40, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29038832

RESUMEN

PURPOSE: To assess the effect of a shrinking rectal balloon implant (RBI) on the anorectal dose and complication risk during the course of moderately hypofractionated prostate radiotherapy. METHODS: In 15 patients with localized prostate cancer, an RBI was implanted. A weekly kilovolt cone-beam computed tomography (CBCT) scan was acquired to measure the dynamics of RBI volume and prostate-rectum separation. The absolute anorectal volume encompassed by the 2 Gy equieffective 75 Gy isodose (V75Gy) was recalculated as well as the mean anorectal dose. The increase in estimated risk of grade 2-3 late rectal bleeding (LRB) between the start and end of treatment was predicted using nomograms. The observed acute and late toxicities were evaluated. RESULTS: A significant shrinkage of RBI volumes was observed, with an average volume of 70.4% of baseline at the end of the treatment. Although the prostate-rectum separation significantly decreased over time, it remained at least 1 cm. No significant increase in V75Gy of the anorectum was observed, except in one patient whose RBI had completely deflated in the third week of treatment. No correlation between mean anorectal dose and balloon deflation was found. The increase in predicted LRB risk was not significant, except in the one patient whose RBI completely deflated. The observed toxicities confirmed these findings. CONCLUSIONS: Despite significant decrease in RBI volume the high-dose rectal volume and the predicted LRB risk were unaffected due to a persistent spacing between the prostate and the anterior rectal wall.


Asunto(s)
Adenocarcinoma/radioterapia , Canal Anal/efectos de la radiación , Neoplasias de la Próstata/radioterapia , Dosis de Radiación , Hipofraccionamiento de la Dosis de Radiación , Traumatismos por Radiación/prevención & control , Recto/efectos de la radiación , Adenocarcinoma/diagnóstico por imagen , Anciano , Canal Anal/diagnóstico por imagen , Diseño de Equipo , Falla de Equipo , Hemorragia Gastrointestinal/diagnóstico por imagen , Hemorragia Gastrointestinal/prevención & control , Humanos , Masculino , Persona de Mediana Edad , Próstata/diagnóstico por imagen , Próstata/efectos de la radiación , Neoplasias de la Próstata/diagnóstico por imagen , Prótesis e Implantes , Traumatismos por Radiación/diagnóstico por imagen , Enfermedades del Recto/diagnóstico por imagen , Enfermedades del Recto/prevención & control , Recto/diagnóstico por imagen , Medición de Riesgo
13.
BMC Cardiovasc Disord ; 18(1): 146, 2018 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-30005637

RESUMEN

BACKGROUND: It has been suggested that changes in pulmonary veins (PV) and left atrium (LA) anatomy may have an influence on initiating atrial fibrillation (AF) and the effectiveness of pulmonary vein isolation (PVI) in patients (pts) with atrial fibrillation. The aim of the study was to assess anatomy abnormalities of the PV and LA in the patients with the history of AF and compare it with the control group(CG). METHODS: The multi-slice tomography (MSCT) scans were performed in 224 AF pts. before PVI (129 males, mean age 59 ± 9 yrs). The CG consisted of 40 pts. without AF (26 males, age 45 ± 9 yrs). LA and PV anatomy were evaluated. Diameters of PV ostia were measured in two directions: anterior-posterior (AP) and superior-inferior (SI) automatically using Vitrea 4.0. RESULTS: Pulmonary veins anatomy variants were observed more frequently in the atrial fibrillation group - 83 pts. (37%) vs 6 pts. (15%) in CG; 9% (21 pts) left common ostia (CO), 2% (5 pts) right CO, 19% (42 pts) additional right PV (APV), (1.8%) 4 pts. APV left, 8% right early branching (EB) and 3.5% left EB. The LA diameter differed significantly in AF vs CG group (41.2 ± 6 mm vs 35 ± 4.2 mm, p < 0.0001) respectively. CONCLUSIONS: The anomalies of pulmonary vein anatomy occurred more often in pts. with AF. They can be defined as an image biomarkers of atrial fibrillation. Right additional (middle) pulmonary vein was the most important anomaly detected in AF patients as well as enlargered diameters of the LA and PV ostia.


Asunto(s)
Fibrilación Atrial/diagnóstico por imagen , Angiografía por Tomografía Computarizada/métodos , Tomografía Computarizada Multidetector/métodos , Flebografía/métodos , Venas Pulmonares/anomalías , Venas Pulmonares/diagnóstico por imagen , Adulto , Anciano , Fibrilación Atrial/etiología , Fibrilación Atrial/cirugía , Estudios de Casos y Controles , Femenino , Atrios Cardíacos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Venas Pulmonares/cirugía , Factores de Riesgo , Adulto Joven
16.
Clin Exp Allergy ; 47(5): 693-703, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27770477

RESUMEN

BACKGROUND: Allergen-specific immunotherapy (AIT) with birch pollen generates Bet v 1-specific immunoglobulin (Ig)G4 which blocks IgE-mediated hypersensitivity mechanisms. Whether IgG4 specific for Bet v 1a competes with IgE for identical epitopes or whether novel epitope specificities of IgG4 antibodies are developed is under debate. OBJECTIVE: We sought to analyze the epitope specificities of IgE and IgG4 antibodies from sera of patients who received AIT. METHODS: 15 sera of patients (13/15 received AIT) with Bet v 1a-specific IgE and IgG4 were analyzed. The structural arrangements of recombinant (r)Bet v 1a and rBet v 1a_11x , modified in five potential epitopes, were analyzed by circular dichroism and nuclear magnetic resonance spectroscopy. IgE binding to Bet v 1 was assessed by ELISA and mediator release assays. Competitive binding of monoclonal antibodies specific for Bet v 1a and serum IgE/IgG4 to rBet v 1a and serum antibody binding to a non-allergenic Bet v 1-type model protein presenting an individual epitope for IgE was analyzed in ELISA and western blot. RESULTS: rBet v 1a_11x had a Bet v 1a - similar secondary and tertiary structure. Monomeric dispersion of rBet v 1a_11x was concentration and buffer-dependent. Up to 1500-fold increase in the EC50 for IgE-mediated mediator release induced by rBet v 1a_11x was determined. The reduction of IgE and IgG4 binding to rBet v 1a_11x was comparable in 67% (10/15) of sera. Bet v 1a-specific monoclonal antibodies inhibited binding of serum IgE and IgG4 to 66.1% and 64.9%, respectively. Serum IgE and IgG4 bound specifically to an individual epitope presented by our model protein in 33% (5/15) of sera. CONCLUSION AND CLINICAL RELEVANCE: Patients receiving AIT develop Bet v 1a-specific IgG4 which competes with IgE for partly identical or largely overlapping epitopes. The similarities of epitopes for IgE and IgG4 might stimulate the development of epitope-specific diagnostics and therapeutics.


Asunto(s)
Antígenos de Plantas/inmunología , Desensibilización Inmunológica , Epítopos/inmunología , Inmunoglobulina E , Inmunoglobulina G , Rinitis Alérgica Estacional , Animales , Femenino , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Masculino , Ratones , Rinitis Alérgica Estacional/sangre , Rinitis Alérgica Estacional/inmunología , Rinitis Alérgica Estacional/terapia
17.
J Evol Biol ; 30(6): 1153-1164, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28386918

RESUMEN

Heat resistance of ectotherms can be increased both by plasticity and evolution, but these effects may have trade-offs resulting from biotic interactions. Here, we test for predation costs in Drosophila melanogaster populations with altered heat resistance produced by adult hardening and directional selection for increased heat resistance. In addition, we also tested for genetic trade-offs by testing heat resistance in lines that have evolved under increased predation risk. We show that while 35/37 °C hardening increases heat resistance as expected, it does not increase predation risk from jumping spiders or mantids; in fact, there was an indication that survival may have increased under predation following a triple 37 °C compared to a single 35 °C hardening treatment. Flies that survived a 39 °C selection cycle showed lower survival under predation, suggesting a predation cost of exposure to a more severe heat stress. There was, however, no correlated response to selection because survival did not differ between control and selected lines after selection was relaxed for one or two generations. In addition, lines selected for increased predation risk did not differ in heat resistance. Our findings suggest independent evolutionary responses to predation and heat as measured in laboratory assays, and no costs of heat hardening on susceptibility to predation.


Asunto(s)
Drosophila melanogaster , Calor , Termotolerancia , Animales , Conducta Predatoria , Selección Genética
18.
Nature ; 476(7361): 450-3, 2011 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-21866159

RESUMEN

Dengue fever is the most important mosquito-borne viral disease of humans with more than 50 million cases estimated annually in more than 100 countries. Disturbingly, the geographic range of dengue is currently expanding and the severity of outbreaks is increasing. Control options for dengue are very limited and currently focus on reducing population abundance of the major mosquito vector, Aedes aegypti. These strategies are failing to reduce dengue incidence in tropical communities and there is an urgent need for effective alternatives. It has been proposed that endosymbiotic bacterial Wolbachia infections of insects might be used in novel strategies for dengue control. For example, the wMelPop-CLA Wolbachia strain reduces the lifespan of adult A. aegypti mosquitoes in stably transinfected lines. This life-shortening phenotype was predicted to reduce the potential for dengue transmission. The recent discovery that several Wolbachia infections, including wMelPop-CLA, can also directly influence the susceptibility of insects to infection with a range of insect and human pathogens has markedly changed the potential for Wolbachia infections to control human diseases. Here we describe the successful transinfection of A. aegypti with the avirulent wMel strain of Wolbachia, which induces the reproductive phenotype cytoplasmic incompatibility with minimal apparent fitness costs and high maternal transmission, providing optimal phenotypic effects for invasion. Under semi-field conditions, the wMel strain increased from an initial starting frequency of 0.65 to near fixation within a few generations, invading A. aegypti populations at an accelerated rate relative to trials with the wMelPop-CLA strain. We also show that wMel and wMelPop-CLA strains block transmission of dengue serotype 2 (DENV-2) in A. aegypti, forming the basis of a practical approach to dengue suppression.


Asunto(s)
Aedes/microbiología , Aedes/virología , Virus del Dengue/fisiología , Dengue/prevención & control , Control Biológico de Vectores/métodos , Wolbachia/clasificación , Wolbachia/fisiología , Aedes/fisiología , Animales , Dengue/transmisión , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Femenino , Aptitud Genética , Humanos , Insectos Vectores/microbiología , Insectos Vectores/fisiología , Insectos Vectores/virología , Masculino , Reproducción/fisiología , Saliva/virología
19.
Nature ; 476(7361): 454-7, 2011 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-21866160

RESUMEN

Genetic manipulations of insect populations for pest control have been advocated for some time, but there are few cases where manipulated individuals have been released in the field and no cases where they have successfully invaded target populations. Population transformation using the intracellular bacterium Wolbachia is particularly attractive because this maternally-inherited agent provides a powerful mechanism to invade natural populations through cytoplasmic incompatibility. When Wolbachia are introduced into mosquitoes, they interfere with pathogen transmission and influence key life history traits such as lifespan. Here we describe how the wMel Wolbachia infection, introduced into the dengue vector Aedes aegypti from Drosophila melanogaster, successfully invaded two natural A. aegypti populations in Australia, reaching near-fixation in a few months following releases of wMel-infected A. aegypti adults. Models with plausible parameter values indicate that Wolbachia-infected mosquitoes suffered relatively small fitness costs, leading to an unstable equilibrium frequency <30% that must be exceeded for invasion. These findings demonstrate that Wolbachia-based strategies can be deployed as a practical approach to dengue suppression with potential for area-wide implementation.


Asunto(s)
Aedes/microbiología , Aedes/virología , Virus del Dengue/fisiología , Dengue/prevención & control , Dengue/transmisión , Control Biológico de Vectores/métodos , Wolbachia/fisiología , Aedes/fisiología , Animales , Dengue/microbiología , Dengue/virología , Virus del Dengue/aislamiento & purificación , Drosophila melanogaster/microbiología , Femenino , Humanos , Insectos Vectores/microbiología , Insectos Vectores/fisiología , Insectos Vectores/virología , Masculino , Queensland , Factores de Tiempo , Wolbachia/aislamiento & purificación
20.
Orthopade ; 46(7): 610-616, 2017 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-28364351

RESUMEN

BACKGROUND: In osteotomies with larger correction angles, the capacity for elastic deformation is frequently exceeded, resulting in plastic deformation and fracture of the opposite cortex, which may lead to subsequent loss of correction. An anteroposterior drill hole at the apex of the horizontal osteotomy (= hinge) is supposed to increase the capacity of the bony hinge for elastic deformation and ideally to prevent fractures of the opposite cortex. MATERIALS AND METHODS: A high tibial osteotomy (HTO) using standard surgical technique was performed in 20 each of Synbones, Sawbones, and human cadaver tibial specimens. In 10 specimens per group, an additional anteroposterior hinge drilling was performed at the apex of the horizontal osteotomy. All fractures of the opposite cortex were photographically and radiographically documented. All fractures were classified according to fracture types 1-3 of the Takeuchi classification. RESULTS: Regardless of the study group, all tibial bones with an additional hinge drilling achieved larger correction angles during the spreading of the wedge until a fracture of the opposite cortex occurred. The average correction angle of all specimens without the drill hole was 2.7°, which increased to 4.8° with the hinge drill (increase by 77.8%). In correction angles exceeding 5°, all specimen showed a hinge fracture regardless of the presence or absence of a hinge drill. CONCLUSIONS: The hinge-protecting effect is restricted to small correction angles, i. e., to unload cartilage repair regions in the absence of severe malalignment. For the treatment of varus gonarthrosis, there is no fracture-protecting effect from a hinge drill.


Asunto(s)
Hueso Cortical/lesiones , Complicaciones Intraoperatorias/prevención & control , Traumatismos de la Rodilla/prevención & control , Articulación de la Rodilla/cirugía , Osteotomía/métodos , Tibia/cirugía , Fracturas de la Tibia/prevención & control , Hueso Cortical/diagnóstico por imagen , Humanos , Complicaciones Intraoperatorias/diagnóstico por imagen , Traumatismos de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/diagnóstico por imagen , Factores de Riesgo , Tibia/diagnóstico por imagen , Tibia/lesiones , Fracturas de la Tibia/diagnóstico por imagen
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