Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
2.
Int J Impot Res ; 35(3): 309-322, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36997741

RESUMEN

Demographically diverse surveys in the United States suggest that 5-10% of non-voluntarily circumcised American males wish that they had not been circumcised. Similar data are unavailable in other countries. An unknown proportion of circumcised males experience acute circumcision-related distress; some attempt to regain a sense of bodily integrity through non-surgical foreskin restoration. Their concerns are often ignored by health professionals. We conducted an in-depth investigation into foreskin restorers' lived experiences. An online survey containing 49 qualitative and 10 demographic questions was developed to identify restorers' motivations, successes, challenges, and experiences with health professionals. Targeted sampling was employed to reach this distinctive population. Invitations were disseminated to customers of commercial restoration devices, online restoration forums, device manufacturer websites, and via genital autonomy organizations. Over 2100 surveys were submitted by respondents from 60 countries. We report results from 1790 fully completed surveys. Adverse physical, sexual, emotional/psychological and self-esteem impacts attributed to circumcision had motivated participants to seek foreskin restoration. Most sought no professional help due to hopelessness, fear, or mistrust. Those who sought help encountered trivialization, dismissal, or ridicule. Most participants recommended restoration. Many professionals are unprepared to assist this population. Circumcision sufferers/foreskin restorers have largely been ill-served by medical and mental health professionals.


Asunto(s)
Circuncisión Masculina , Prepucio , Masculino , Humanos , Estados Unidos , Prepucio/cirugía , Motivación , Salud Mental , Circuncisión Masculina/métodos , Circuncisión Masculina/psicología , Conducta Sexual
4.
Mammalia ; 84(3): 227-238, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-34290454

RESUMEN

Small mammal communities in the Neotropics are composed largely of sigmodontine rodents. However, many questions regarding these communities remain unanswered, especially those pertaining to fine-scale sympatry and habitat selection. To address this, we examined sigmodontine community structure and vegetation in the western margin of the Upper Paraná Atlantic Forest and the southwestern-most extent of the Cerrado (CE) (an extensive South American savanna ecoregion) of Paraguay. Vegetation classifications were derived from satellite imagery combined with maps based on extensive ground-based surveys. The three most abundant species (Akodon montensis, Hylaeamys megacephalus, and Oligoryzomys nigripes) were found most often in microsympatry with conspecifics, and were negatively associated with other species. Akodon montensis was associated with high forest (HF), and H. megacephalus with bamboo understory (BU), whereas O. nigripes did not exhibit a habitat preference. The first two species' distributions within the landscape were found to be driven primarily by habitat selection, and O. nigripes by a behavioral response (avoidance) to the presence of the other two species. Moreover, habitat influences whether or not a particular species associates with, or avoids, conspecifics or other species.

6.
PLoS One ; 13(8): e0201307, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30067840

RESUMEN

Four of the nine sigmodontine tribes have species that serve as reservoirs of rodent-borne hantaviruses (RBO-HV), few have been studied in any depth. Several viruses have been associated with human cases of hantavirus pulmonary syndrome often through peridomestic exposure. Jabora (JABV) and Juquitiba (JUQV), harbored by Akodon montensis and Oligoryzomys nigripes, respectively, are endemic and sympatric in the Reserva Natural de Bosque Mbaracayú (RNBM), Paraguay, a protected area of the Interior Atlantic Forest. Rodent communities were surveyed along a 30 km stretch of the RNBM in eight vegetation classifications (Low, High, Bamboo, Riparian and Liana Forests, Bamboo Understory, Cerrado, and Meadow/Grasslands). We collected 417 rodents from which 11 species were identified; Akodon montensis was the predominant species (72%; 95%CI: 64.7%-76.3%), followed by Hylaeamys megacephalus (15% (11.2%-18.2%)) and Oligoryzomys nigripes (9% (6.6%-12.4%)). We examined the statistical associations among habitat (vegetation class) type, rodent species diversity, population structure (age, sex, and weight), and prevalence of RBO-HV antibody and/or viral RNA (Ab/RNA) or characteristic Leishmania tail lesions. Ab/RNA positive rodents were not observed in Cerrado and Low Forest. A. montensis had an overall Ab/RNA prevalence of 7.7% (4.9%-11.3%) and O. nigripes had an overall prevalence of 8.6% (1.8%-23.1%). For A. montensis, the odds of being Ab/RNA positive in High Forest was 3.73 times of the other habitats combined. There was no significant difference among age classes in the proportion of Ab/RNA positive rodents overall (p = 0.66), however, all 11 RNA-positive individuals were adult. Sex and habitat had independent prognostic value for hantaviral Ab/RNA in the study population; age, presence of tail scar/lesion (19% of the rodents) and weight did not. Adjusting for habitat, female rodents had less risk of becoming infected. Importantly, these data suggest habitat preferences of two sympatric rodent reservoirs for two endemic hantaviruses and the importance of including habitat in models of species diversity and habitat fragmentation.


Asunto(s)
Reservorios de Enfermedades/virología , Infecciones por Hantavirus/epidemiología , Orthohantavirus/aislamiento & purificación , Enfermedades de los Roedores/epidemiología , Roedores/virología , Animales , Reservorios de Enfermedades/clasificación , Ecosistema , Femenino , Infecciones por Hantavirus/virología , Síndrome Pulmonar por Hantavirus/epidemiología , Síndrome Pulmonar por Hantavirus/virología , Humanos , Masculino , Paraguay/epidemiología , Enfermedades de los Roedores/virología , Roedores/clasificación
10.
J Vis Exp ; (121)2017 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-28447987

RESUMEN

Live-cell imaging is used to simultaneously capture time-lapse images of angiotensin type 1a receptors (AT1aR) and intracellular compartments in transfected human embryonic kidney-293 (HEK) cells following stimulation with angiotensin II (Ang II). HEK cells are transiently transfected with plasmid DNA containing AT1aR tagged with enhanced green fluorescent protein (EGFP). Lysosomes are identified with a red fluorescent dye. Live-cell images are captured on a laser scanning confocal microscope after Ang II stimulation and analyzed by software in three dimensions (3D, voxels) over time. Live-cell imaging enables investigations into receptor trafficking and avoids confounds associated with fixation, and in particular, the loss or artefactual displacement of EGFP-tagged membrane receptors. Thus, as individual cells are tracked through time, the subcellular localization of receptors can be imaged and measured. Images must be acquired sufficiently rapidly to capture rapid vesicle movement. Yet, at faster imaging speeds, the number of photons collected is reduced. Compromises must also be made in the selection of imaging parameters like voxel size in order to gain imaging speed. Significant applications of live-cell imaging are to study protein trafficking, migration, proliferation, cell cycle, apoptosis, autophagy and protein-protein interaction and dynamics, to name but a few.


Asunto(s)
Imagenología Tridimensional , Microscopía Confocal , Receptor de Angiotensina Tipo 1/metabolismo , Supervivencia Celular , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Humanos , Lisosomas/metabolismo , Transporte de Proteínas
11.
Front Cell Neurosci ; 9: 417, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26578882

RESUMEN

Actively generated mechanical forces play a central role in axon growth and guidance, but the mechanisms that underly force generation and regulation in growing axons remain poorly understood. We report measurements of the dynamics of traction stresses from growth cones of actively advancing axons from postnatal rat DRG neurons. By tracking the movement of the growth cone and analyzing the traction stress field from a reference frame that moves with it, we are able to show that there is a clear and consistent average stress field that underlies the complex spatial stresses present at any one time. The average stress field has strong maxima on the sides of the growth cone, directed inward toward the growth cone neck. This pattern represents a contractile stress contained within the growth cone, and a net force that is balanced by the axon tension. Using high time-resolution measurements of the growth cone traction stresses, we show that the stress field is composed of fluctuating local stress peaks, with a large number peaks that live for a short time, a population of peaks whose lifetime distribution follows an exponential decay, and a small number of very long-lived peaks. We show that the high time-resolution data also reveal that the tension appears to vary randomly over short time scales, roughly consistent with the lifetime of the stress peaks, suggesting that the tension fluctuations originate from stochastic adhesion dynamics.

13.
J Virol ; 87(20): 10997-1007, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23903835

RESUMEN

In vitro, ribavirin acts as a lethal mutagen in Hantaan virus (HTNV)-infected Vero E6 cells, resulting in an increased mutation load and viral population extinction. In this study, we asked whether ribavirin treatment in the lethal, suckling mouse model of HTNV infection would act similarly. The HTNV genomic RNA (vRNA) copy number and infectious virus were measured in lungs of untreated and ribavirin-treated mice. In untreated, HTNV-infected mice, the vRNA copy number increased for 10 days postinfection (dpi) and thereafter remained constant through 26 dpi. Surprisingly, in ribavirin-treated, HTNV-infected mice, vRNA levels were similar to those in untreated mice between 10 and 26 dpi. Infectious virus levels, however, were different: in ribavirin-treated mice, the amount of infectious HTNV was significantly decreased relative to that in untreated mice, suggesting that ribavirin reduced the specific infectivity of the virus (amount of infectious virus produced per vRNA copy). Mutational analysis revealed a ribavirin-associated elevation in mutation frequency in HTNV vRNA similar to that previously reported in vitro. Codon-based analyses of rates of nonsynonymous (dN) and synonymous (dS) substitutions in the S segment revealed a positive selection for codons within the HTNV N protein gene in the ribavirin-treated vRNA population. In contrast, the vRNA population in untreated, HTNV-infected mice showed a lower level of diversity, reflecting purifying selection for the wild-type genome. In summary, these experiments show two different evolutionary paths that Hantavirus may take during infection in a lethal murine model of disease, as well as the importance of the in vivo host environment in the evolution of the virus, which was not apparent in our prior in vitro model system.


Asunto(s)
Antivirales/administración & dosificación , Evolución Molecular , Virus Hantaan/genética , Fiebre Hemorrágica con Síndrome Renal/virología , ARN Viral/genética , Ribavirina/administración & dosificación , Animales , Animales Recién Nacidos , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Femenino , Virus Hantaan/aislamiento & purificación , Fiebre Hemorrágica con Síndrome Renal/tratamiento farmacológico , Pulmón/virología , Ratones , Ratones Endogámicos ICR , Tasa de Mutación , Embarazo , Análisis de Secuencia de ADN , Carga Viral
14.
PLoS One ; 8(3): e58138, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23536784

RESUMEN

New insight into the biomechanics of cancer cell motility in 3D extracellular matrix (ECM) environments would significantly enhance our understanding of aggressive cancers and help identify new targets for intervention. While several methods for measuring the forces involved in cell-matrix interactions have been developed, previous to this study none have been able to measure forces in a fibrillar environment. We have developed a novel assay for simultaneously measuring cell mechanotransduction and motility in 3D fibrillar environments. The assay consists of a controlled-density fibrillar collagen gel atop a controlled-stiffness polyacrylamide (PAA) surface. Forces generated by living cells and their migration in the 3D collagen gel were measured with the 3D motion of tracer beads within the PAA layer. Here, this 3D fibril force assay is used to study the role of the invasion-associated protein kinase Src in mechanotransduction and motility. Src expression and activation are linked with proliferation, invasion, and metastasis, and have been shown to be required in 2D for invadopodia membranes to direct and mediate invasion. Breast cancer cell line MDA-MD-231 was stably transfected with GFP-tagged constitutively active Src or wild-type Src. In 3D fibrillar collagen matrices we found that, relative to wild-type Src, constitutively active Src: 1) increased the strength of cell-induced forces on the ECM, 2) did not significantly change migration speed, and 3) increased both the duration and the length, but not the number, of long membrane protrusions. Taken together, these results support the hypothesis that Src controls invasion by controlling the ability of the cell to form long lasting cellular protrusions to enable penetration through tissue barriers, in addition to its role in promoting invadopodia matrix-degrading activity.


Asunto(s)
Colágeno/metabolismo , Neoplasias/metabolismo , Familia-src Quinasas/metabolismo , Fenómenos Biomecánicos , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Movimiento Celular , Extensiones de la Superficie Celular/metabolismo , Activación Enzimática , Matriz Extracelular/metabolismo , Femenino , Adhesiones Focales/metabolismo , Expresión Génica , Humanos , Metaloproteinasa 14 de la Matriz/genética , Metaloproteinasa 14 de la Matriz/metabolismo , Neoplasias/genética , Transporte de Proteínas , Transfección , Familia-src Quinasas/genética
15.
PLoS One ; 8(2): e56602, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23441208

RESUMEN

To capture the possible genotypic and phenotypic differences of the 2009 influenza A virus H1N1 pandemic (H1N1pdm) strains circulating in adult hospitalized patients, we isolated and sequenced nine H1N1pdm viruses from patients hospitalized during 2009-2010 with severe influenza pneumonia in Kentucky. Each viral isolate was characterized in mice along with two additional H1N1 pandemic strains and one seasonal strain to assess replication and virulence. All isolates showed similar levels of replication in nasal turbinates and lung, but varied in their ability to cause morbidity. Further differences were identified in cytokine and chemokine responses. IL-6 and KC were expressed early in mice infected with strains associated with higher virulence. Strains that showed lower pathogenicity in mice had greater IFNγ, MIG, and IL-10 responses. A principal component analysis (PCA) of the cytokine and chemokine profiles revealed 4 immune response phenotypes that correlated with the severity of disease. A/KY/180/10, which showed the greatest virulence with a rapid onset of disease progression, was compared in additional studies with A/KY/136/09, which showed low virulence in mice. Analyses comparing a low (KY/136) versus a high (KY/180) virulent isolate showed a significant difference in the kinetics of infection within the lower respiratory tract and immune responses. Notably by 4 DPI, virus titers within the lung, bronchoalveolar lavage fluid (BALf), and cells within the BAL (BALc) revealed that the KY/136 replicated in BALc, while KY/180 replication persisted in lungs and BALc. In summary, our studies suggest four phenotypic groups based on immune responses that result in different virulence outcomes in H1N1pdm isolates with a high degree of genetic similarity. In vitro studies with two of these isolates suggested that the more virulent isolate, KY/180, replicates productively in macrophages and this may be a key determinant in tipping the response toward a more severe disease progression.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/fisiología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/virología , Fenotipo , Adulto , Animales , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Línea Celular , Citocinas/metabolismo , Femenino , Genes Virales , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/inmunología , Gripe Humana/virología , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/virología , Macrófagos/inmunología , Macrófagos/virología , Masculino , Ratones , Persona de Mediana Edad , Infecciones por Orthomyxoviridae/mortalidad , Análisis de Componente Principal , Virulencia , Replicación Viral , Pérdida de Peso
16.
Conserv Biol ; 27(1): 35-44, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23305381

RESUMEN

Many of the challenges conservation professionals face can be framed as scale mismatches. The problem of scale mismatch occurs when the planning for and implementation of conservation actions is at a scale that does not reflect the scale of the conservation problem. The challenges in conservation planning related to scale mismatch include ecosystem or ecological process transcendence of governance boundaries; limited availability of fine-resolution data; lack of operational capacity for implementation; lack of understanding of social-ecological system components; threats to ecological diversity that operate at diverse spatial and temporal scales; mismatch between funding and the long-term nature of ecological processes; rate of action implementation that does not reflect the rate of change of the ecological system; lack of appropriate indicators for monitoring activities; and occurrence of ecological change at scales smaller or larger than the scale of implementation or monitoring. Not recognizing and accounting for these challenges when planning for conservation can result in actions that do not address the multiscale nature of conservation problems and that do not achieve conservation objectives. Social networks link organizations and individuals across space and time and determine the scale of conservation actions; thus, an understanding of the social networks associated with conservation planning will help determine the potential for implementing conservation actions at the required scales. Social-network analyses can be used to explore whether these networks constrain or enable key social processes and how multiple scales of action are linked. Results of network analyses can be used to mitigate scale mismatches in assessing, planning, implementing, and monitoring conservation projects.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Apoyo Social , Conservación de los Recursos Naturales/economía , Ecosistema
17.
PLoS Genet ; 8(12): e1003140, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23300462

RESUMEN

Experimental autoimmune orchitis (EAO), the principal model of non-infectious testicular inflammatory disease, can be induced in susceptible mouse strains by immunization with autologous testicular homogenate and appropriate adjuvants. As previously established, the genome of DBA/2J mice encodes genes that are capable of conferring dominant resistance to EAO, while the genome of BALB/cByJ mice does not and they are therefore susceptible to EAO. In a genome scan, we previously identified Orch3 as the major quantitative trait locus controlling dominant resistance to EAO and mapped it to chromosome 11. Here, by utilizing a forward genetic approach, we identified kinesin family member 1C (Kif1c) as a positional candidate for Orch3 and, using a transgenic approach, demonstrated that Kif1c is Orch3. Mechanistically, we showed that the resistant Kif1c(D2) allele leads to a reduced antigen-specific T cell proliferative response as a consequence of decreased MHC class II expression by antigen presenting cells, and that the L(578) → P(578) and S(1027) → P(1027) polymorphisms distinguishing the BALB/cByJ and DBA/2J alleles, respectively, can play a role in transcriptional regulation. These findings may provide mechanistic insight into how polymorphism in other kinesins such as KIF21B and KIF5A influence susceptibility and resistance to human autoimmune diseases.


Asunto(s)
Resistencia a la Enfermedad/genética , Genes Dominantes , Cinesinas/genética , Orquitis , Alelos , Animales , Enfermedades Autoinmunes/genética , Enfermedades Autoinmunes/inmunología , Expresión Génica , Genes MHC Clase II , Predisposición Genética a la Enfermedad , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos DBA , Orquitis/genética , Orquitis/inmunología , Sitios de Carácter Cuantitativo/genética , Testículo/inmunología
19.
Methods Mol Biol ; 571: 239-54, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19763971

RESUMEN

During development a variety of cell types are guided by molecular concentration gradients to form tissues and organ systems. In the nervous system, the migration and neuronal pathfinding that occurs during development is organized and driven by "guidance cues." Some of these cues are substrate bound or nondiffusible, while many are diffusible and form gradients within the developing embryo to guide neurons and neurites to their appropriate destination. There have been many approaches used to discover and characterize the multitude of guidance cues, their cognate receptors, and how these cues and receptors are regulated to achieve the highly detailed connections found in the nervous system. Here we present a method for creating precisely controlled gradients of molecular factors within a three-dimensional culture environment. The method is based on a non contact mediated delivery of biomolecules to the surface of a collagen gel. The factors are printed in a pattern on the top of a gel containing the tissue or cell type of interest embedded in the gel. The formation of the gradient is dependent upon the diffusion of the printed molecule in the gel. The concentration of the factor within the gel becomes independent of depth rapidly, and the gradient becomes smooth on a similar time scale. The gradients formed can remain relatively stable for a day or more. Moreover, the steepness and molar concentration of tropic or trophic factors within the gradient can be controlled.


Asunto(s)
Quimiotaxis/fisiología , Neuronas/citología , Animales , Movimiento Celular/fisiología , Colágeno/química , Difusión , Ratas , Ratas Sprague-Dawley
20.
J Neurosci Methods ; 179(2): 278-83, 2009 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-19428538

RESUMEN

We demonstrate effective guidance of neurites extending from PC12 cells in a three-dimensional collagen matrix using a focused infrared laser. Processes can be redirected in an arbitrarily chosen direction in the imaging plane in approximately 30 min with an 80% success rate. In addition, the application of the laser beam significantly increases the rate of neurite outgrowth. These results extend previous observations on 2D coated glass coverslips. We find that the morphology of growth cones is very different in 3D than in 2D, and that this difference suggests that the filopodia play a key role in optical guidance. This powerful, flexible, non-contact guidance technique has potentially broad applications in tissues and engineered environments.


Asunto(s)
Conos de Crecimiento/efectos de la radiación , Regeneración Tisular Dirigida/métodos , Rayos Láser , Óptica y Fotónica/métodos , Estimulación Luminosa/métodos , Animales , Diferenciación Celular/fisiología , Diferenciación Celular/efectos de la radiación , Forma de la Célula/fisiología , Forma de la Célula/efectos de la radiación , Colágeno/fisiología , Conos de Crecimiento/fisiología , Conos de Crecimiento/ultraestructura , Regeneración Tisular Dirigida/instrumentación , Regeneración Nerviosa/fisiología , Regeneración Nerviosa/efectos de la radiación , Neuritas/fisiología , Neuritas/efectos de la radiación , Neuritas/ultraestructura , Neurogénesis/fisiología , Neurogénesis/efectos de la radiación , Óptica y Fotónica/instrumentación , Técnicas de Cultivo de Órganos , Células PC12 , Estimulación Luminosa/instrumentación , Seudópodos/fisiología , Seudópodos/efectos de la radiación , Seudópodos/ultraestructura , Ratas , Ingeniería de Tejidos/métodos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...