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1.
Ecol Appl ; 32(5): e2600, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35343018

RESUMO

Novel approaches to quantifying density and distributions could help biologists adaptively manage wildlife populations, particularly if methods are accurate, consistent, cost-effective, rapid, and sensitive to change. Such approaches may also improve research on interactions between density and processes of interest, such as disease transmission across multiple populations. We assess how satellite imagery, unmanned aerial system (UAS) imagery, and Global Positioning System (GPS) collar data vary in characterizing elk density, distribution, and count patterns across times with and without supplemental feeding at the National Elk Refuge (NER) in the US state of Wyoming. We also present the first comparison of satellite imagery data with traditional counts for ungulates in a temperate system. We further evaluate seven different aggregation metrics to identify the most consistent and sensitive metrics for comparing density and distribution across time and populations. All three data sources detected higher densities and aggregation locations of elk during supplemental feeding than non-feeding at the NER. Kernel density estimates (KDEs), KDE polygon areas, and the first quantile of interelk distances detected differences with the highest sensitivity and were most highly correlated across data sources. Both UAS and satellite imagery provide snapshots of density and distribution patterns of most animals in the area at lower cost than GPS collars. While satellite-based counts were lower than traditional counts, aggregation metrics matched those from UAS and GPS data sources when animals appeared in high contrast to the landscape, including brown elk against new snow in open areas. UAS counts of elk were similar to traditional ground-based counts on feed grounds and are the best data source for assessing changes in small spatial extents. Satellite, UAS, or GPS data can provide appropriate data for assessing density and changes in density from adaptive management actions. For the NER, where high elk densities are beneath controlled airspace, GPS collar data will be most useful for evaluating how management actions, including changes in the dates of supplemental feeding, influence elk density and aggregation across large spatial extents. Using consistent and sensitive measures of density may improve research on the drivers and effects of density within and across a wide range of species.


Assuntos
Cervos , Animais , Animais Selvagens , Sistemas de Informação Geográfica , Imagens de Satélites , Neve
2.
Sci Total Environ ; 690: 522-533, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31301493

RESUMO

Oil and gas (energy) development in the Williston Basin, which partly underlies the Prairie Pothole Region in central North America, has helped meet U.S. energy demand for decades. Historical handling and disposal practices of saline wastewater co-produced during energy development resulted in salinization of surface and groundwater at numerous legacy energy sites. Thirty years of monitoring (1988-2018) at Goose Lake, which has been producing since the 1960s, documents long-term spatial and temporal changes in water quality from legacy energy development. Surface water quality was highly variable and decoupled from changes in groundwater quality, likely due to annual and regional climatic fluctuations. Therefore, changes in surface water-quality were not considered a reliable indicator of subsurface chloride migration. However, chloride concentrations in monitoring wells near wastewater sources exhibited systematic temporal reductions allowing for estimates of the time required for natural attenuation of groundwater to U.S. Environmental Protection Agency acute and chronic chloride toxicity benchmarks and a local background level. Point attenuation rates differed based on sediment type (outwash vs till) and yielded a range of predicted years when water-quality targets will be reached: acute - 2045 to 2113; chronic - 2069 to 2160; background - 2126 to 2275. Bulk attenuation rates from four separate years of data were used to calculate the distances chloride could migrate downgradient from the largest wastewater source. Potential distances of downgradient migration before dilution to water-quality targets decreased from 1989 to 2018: acute - 949 to 673 m; chronic - 1220 to 922 m; background - 1878 to 1525 m. Several downgradient wetlands are within these distances and will continue to receive saline contaminated groundwater for years. While these results demonstrate chloride attenuation at a legacy energy site, they also highlight the persistence of saline wastewater contamination and the need to mitigate future spills to prevent long-term salinization from energy development.

3.
Environ Pollut ; 248: 260-268, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30798027

RESUMO

Energy production in the Williston Basin, located in the Prairie Pothole Region of central North America, has increased rapidly over the last several decades. Advances in recycling and disposal practices of saline wastewaters (brines) co-produced during energy production have reduced ecological risks, but spills still occur often and legacy practices of releasing brines into the environment caused persistent salinization in many areas. Aside from sodium and chloride, these brines contain elevated concentrations of metals and metalloids (lead, selenium, strontium, antimony and vanadium), ammonium, volatile organic compounds, hydrocarbons, and radionuclides. Amphibians are especially sensitive to chloride and some metals, increasing potential effects in wetlands contaminated by brines. We collected bed sediment and larval amphibians (Ambystoma mavortium, Lithobates pipiens and Pseudacris maculata) from wetlands in Montana and North Dakota representing a range of brine contamination history and severity to determine if contamination was associated with metal concentrations in sediments and if metal accumulation in tissues varied by species. In wetland sediments, brine contamination was positively associated with the concentrations of sodium and strontium, both known to occur in oil and gas wastewater, but negatively correlated with mercury. In amphibian tissues, selenium and vanadium were associated with brine contamination. Metal tissue concentrations were higher in tadpoles that graze compared to predatory salamanders; this suggests frequent contact with the sediments could lead to greater ingestion of metal-laden materials. Although many of these metals may not be directly linked with energy development, the potential additive or synergistic effects of exposure along with elevated chloride from brines could have important consequences for aquatic organisms. To effectively manage amphibian populations in wetlands contaminated by saline wastewaters we need a better understanding of how life history traits, species-specific susceptibilities and the physical-chemical properties of metals co-occurring in wetland sediments interact with other stressors like chloride and wetland drying.


Assuntos
Anuros/fisiologia , Monitoramento Ambiental , Sais/toxicidade , Águas Residuárias/toxicidade , Poluentes Químicos da Água/toxicidade , Áreas Alagadas , Ambystoma , Animais , Sedimentos Geológicos , Larva/efeitos dos fármacos , Metais/toxicidade , América do Norte , Poluentes Químicos da Água/análise
4.
Environ Pollut ; 239: 722-732, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29723822

RESUMO

Wetlands in the Prairie Pothole Region (PPR) of North America support macroinvertebrate communities that are integral to local food webs and important to breeding waterfowl. Macroinvertebrates in PPR wetlands are primarily generalists and well adapted to within and among year changes in water permanence and salinity. The Williston Basin, a major source of U.S. energy production, underlies the southwest portion of the PPR. Development of oil and gas results in the coproduction of large volumes of highly saline, sodium chloride dominated water (brine) and the introduction of brine can alter wetland salinity. To assess potential effects of brine contamination on macroinvertebrate communities, 155 PPR wetlands spanning a range of hydroperiods and salinities were sampled between 2014 and 2016. Brine contamination was documented in 34 wetlands with contaminated wetlands having significantly higher chloride concentrations, specific conductance and percent dominant taxa, and significantly lower taxonomic richness, Shannon diversity, and Pielou evenness scores compared to uncontaminated wetlands. Non-metric multidimensional scaling found significant correlations between several water quality parameters and macroinvertebrate communities. Chloride concentration and specific conductance, which can be elevated in naturally saline wetlands, but are also associated with brine contamination, had the strongest correlations. Five wetland groups were identified from cluster analysis with many of the highly contaminated wetlands located in a single cluster. Low or moderately contaminated wetlands were distributed among the remaining clusters and had macroinvertebrate communities similar to uncontaminated wetlands. While aggregate changes in macroinvertebrate community structure were observed with brine contamination, systematic changes were not evident, likely due to the strong and potentially confounding influence of hydroperiod and natural salinity. Therefore, despite the observed negative response of macroinvertebrate communities to brine contamination, macroinvertebrate community structure alone is likely not the most sensitive indicator of brine contamination in PPR wetlands.


Assuntos
Monitoramento Ambiental/métodos , Pradaria , Invertebrados/classificação , Sais/análise , Áreas Alagadas , Animais , Biodiversidade , América do Norte , Indústria de Petróleo e Gás , Salinidade
5.
Sci Total Environ ; 616-617: 355-362, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29127790

RESUMO

Understanding long-term implications of energy development on ecosystem function requires establishing regional datasets to quantify past development and determine relationships to predict future development. The Piceance Basin in western Colorado has a history of energy production and development is expected to continue into the foreseeable future due to abundant natural gas resources. To facilitate analyses of regional energy development we digitized all well pads in the Colorado portion of the basin, determined the previous land cover of areas converted to well pads over three time periods (2002-2006, 2007-2011, and 2012-2016), and explored the relationship between number of wells per pad and pad area to model future development. We also calculated the area of pads constructed prior to 2002. Over 21million m2 has been converted to well pads with approximately 13million m2 converted since 2002. The largest land conversion since 2002 occurred in shrub/scrub (7.9million m2), evergreen (2.1million m2), and deciduous (1.3million m2) forest environments based on National Land Cover Database classifications. Operational practices have transitioned from single well pads to multi-well pads, increasing the average number of wells per pad from 2.5 prior to 2002, to 9.1 between 2012 and 2016. During the same time period the pad area per well has increased from 2030 m2 to 3504 m2. Kernel density estimation was used to model the relationship between the number of wells per pad and pad area, with these curves exhibiting a lognormal distribution. Therefore, either kernel density estimation or lognormal probability distributions may potentially be used to model land use requirements for future development. Digitized well pad locations in the Piceance Basin contribute to a growing body of spatial data on energy infrastructure and, coupled with study results, will facilitate future regional and national studies assessing the spatial and temporal effects of energy development on ecosystem function.

6.
Analyst ; 141(22): 6251-6258, 2016 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-27704090

RESUMO

A quantum dot-based ratiometrically responsive fluorescent sensor for unlabeled single-stranded DNA (ssDNA) is reported. Several technical issues concerning the development of high yield ssDNA-QD conjugation chemistry were addressed. The DNA sensor was synthesized by conjugating methacrylic phosphoramidite-functional oligonucleotides to water-soluble cadmium zinc sulfide core/zinc sulfide shell quantum dots (CdZnS/ZnS QDs). Duplex DNA was formed when the QD-bound ssDNA was incubated with its complement. Next, titration with PicoGreen resulted in FRET energy transfer from the dot to the dsDNA intercalating dye. The resulting ratio of the dye to QD integrated emissions is a calibratable metric for label-free DNA detection with a LOD of 3.8 nmol.


Assuntos
DNA/química , Transferência Ressonante de Energia de Fluorescência , Oligonucleotídeos/química , Pontos Quânticos/química , Espectrometria de Fluorescência
7.
PLoS One ; 11(7): e0158115, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27462989

RESUMO

Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light ("solar flux") in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world's largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.


Assuntos
Animais Selvagens , Energia Solar , Animais , Biodiversidade , California , Monitoramento Ambiental , Voo Animal , Projetos Piloto , Especificidade da Espécie
8.
Sci Total Environ ; 566-567: 1511-1518, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27318516

RESUMO

The Williston Basin in the Northern Great Plains has experienced rapid energy development since 2000. To evaluate the land cover changes resulting from recent (2000-2015) development, the area and previous land cover of all well pads (pads) constructed during this time were determined, the amount of disturbed and reclaimed land adjacent to pads was estimated, land cover changes were analyzed over time for three different well types, and the effects from future development were predicted. The previous land cover of the 12,990ha converted to pads was predominately agricultural (49.5%) or prairie (47.4%) with lesser amounts of developed (2.3%), aquatic (0.5%), and forest (0.4%). Additionally, 12,121ha has likely been disturbed and reclaimed. The area required per gas well remained constant through time while the land required per oil well increased initially and then decreased as development first shifted from conventional to unconventional drilling and then to multi-bore pads. For non-oil-and-gas wells (i.e. stratigraphic test wells, water wells, and injection wells), the area per well increased through time likely due to increased produced water disposal requirements. Future land cover change is expected to be 2.7 times greater than recent development with much of the development occurring in five counties in the core Bakken development area. Direct land cover change and disturbance from recent and expected development are predicted to affect 0.4% of the landscape across the basin; however, in the core Bakken development area, 2.3% of the landscape will be affected including 2.1% of the remaining grassland. Although future development will result in significant land cover change, evolving industry practices and proactive siting decisions, such as development along energy corridors and placing pads in areas previously altered by human activity, have the potential to reduce the ecological effects of future energy development in the Williston Basin.

9.
Environ Monit Assess ; 187(4): 200, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25797884

RESUMO

The Williston Basin, located in the Northern Great Plains, is experiencing rapid energy development with North Dakota and Montana being the epicenter of current and projected development in the USA. The average single-bore well pad is 5 acres with an estimated 58,485 wells in North Dakota alone. This landscape-level disturbance may provide a pathway for the establishment of non-native plants. To evaluate potential influences of energy development on the presence and abundance of non-native species, vegetation surveys were conducted at 30 oil well sites (14 ten-year-old and 16 five-year-old wells) and 14 control sites in native prairie environments across the Williston Basin. Non-native species richness and cover were recorded in four quadrats, located at equal distances, along four transects for a total of 16 quadrats per site. Non-natives were recorded at all 44 sites and ranged from 5 to 13 species, 7 to 15 species, and 2 to 8 species at the 10-year, 5-year, and control sites, respectively. Respective non-native cover ranged from 1 to 69, 16 to 76, and 2 to 82%. Total, forb, and graminoid non-native species richness and non-native forb cover were significantly greater at oil well sites compared to control sites. At oil well sites, non-native species richness and forb cover were significantly greater adjacent to the well pads and decreased with distance to values similar to control sites. Finally, non-native species whose presence and/or abundance were significantly greater at oil well sites relative to control sites were identified to aid management efforts.


Assuntos
Monitoramento Ambiental , Indústrias Extrativas e de Processamento , Espécies Introduzidas , Plantas/classificação , Meio Ambiente , Montana , North Dakota
10.
Sci Total Environ ; 508: 534-45, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25468531

RESUMO

Contamination to aquatic resources from co-produced water (brine) associated with energy development has been documented in the northeastern portion of the Williston Basin; an area mantled by glacial drift. The presence and magnitude of brine contamination can be determined using the contamination index (CI) value from water samples. Recently, the U.S. Geological Survey published a section (~2.59 km(2)) level risk assessment of brine contamination to aquatic resources for Sheridan County, Montana, using oilfield and hydrogeological parameters. Our goal was to improve the Sheridan County assessment (SCA) and evaluate the use of this new Williston Basin assessment (WBA) across 31 counties mantled by glacial drift in the Williston Basin. To determine if the WBA model improved the SCA model, results from both assessments were compared to CI values from 37 surface and groundwater samples collected to evaluate the SCA. The WBA (R(2)=0.65) outperformed the SCA (R(2)=0.52) indicating improved model performance. Applicability across the Williston Basin was evaluated by comparing WBA results to CI values from 123 surface water samples collected from 97 sections. Based on the WBA, the majority (83.5%) of sections lacked an oil well and had minimal risk. Sections with one or more oil wells comprised low (8.4%), moderate (6.5%), or high (1.7%) risk areas. The percentage of contaminated water samples, percentage of sections with at least one contaminated sample, and the average CI value of contaminated samples increased from low to high risk indicating applicability across the Williston Basin. Furthermore, the WBA performed better compared to only the contaminated samples (R(2)=0.62) versus all samples (R(2)=0.38). This demonstrates that the WBA was successful at identifying sections, but not individual aquatic resources, with an increased risk of contamination; therefore, WBA results can prioritize future sampling within areas of increased risk.


Assuntos
Monitoramento Ambiental , Água Subterrânea/química , Sais/análise , Poluentes Químicos da Água/análise , Camada de Gelo/química , Montana , Medição de Risco
11.
Phys Chem Chem Phys ; 16(3): 837-55, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24296551

RESUMO

The use of nanomaterials, specifically fluorescent semiconductor quantum dots (QDs), for biological imaging and sensing has become very topical. Here we present a historical synopsis of research in this field to help elucidate the origins of the most recent advances in QD-based technology. We further aim to educate the novice researcher concerning many important aspects of QD synthesis, water-solubilization, functionalization, and usage in biological imaging and sensing that are generally not discussed in the literature. We will also summarize several recent transformative examples of using quantum dots for in vitro and in vivo studies.


Assuntos
Corantes Fluorescentes/química , Pontos Quânticos , Água/química , Animais , Células COS , Compostos de Cádmio/síntese química , Compostos de Cádmio/química , Chlorocebus aethiops , Corantes Fluorescentes/síntese química , Células HEK293 , Humanos , Camundongos , Compostos de Selênio/síntese química , Compostos de Selênio/química , Semicondutores , Solubilidade , Sulfetos/síntese química , Sulfetos/química , Compostos de Zinco/síntese química , Compostos de Zinco/química
12.
Sci Total Environ ; 472: 1152-62, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24364993

RESUMO

Water (brine) co-produced with oil in the Williston Basin is some of the most saline in the nation. The Prairie Pothole Region (PPR), characterized by glacial sediments and numerous wetlands, covers the northern and eastern portion of the Williston Basin. Sheridan County, Montana, lies within the PPR and has a documented history of brine contamination. Surface water and shallow groundwater in the PPR are saline and sulfate dominated while the deeper brines are much more saline and chloride dominated. A Contamination Index (CI), defined as the ratio of chloride concentration to specific conductance in a water sample, was developed by the Montana Bureau of Mines and Geology to delineate the magnitude of brine contamination in Sheridan County. Values >0.035 indicate contamination. Recently, the U.S. Geological Survey completed a county level geographic information system (GIS)-based vulnerability assessment of brine contamination to aquatic resources in the PPR of the Williston Basin based on the age and density of oil wells, number of wetlands, and stream length per county. To validate and better define this assessment, a similar approach was applied in eastern Sheridan County at a greater level of detail (the 2.59 km(2) Public Land Survey System section grid) and included surficial geology. Vulnerability assessment scores were calculated for the 780 modeled sections and these scores were divided into ten equal interval bins representing similar probabilities of contamination. Two surface water and two groundwater samples were collected from the section with the greatest acreage of Federal land in each bin. Nineteen of the forty water samples, and at least one water sample from seven of the ten selected sections, had CI values indicating contamination. Additionally, CI values generally increased with increasing vulnerability assessment score, with a stronger correlation for groundwater samples (R(2)=0.78) than surface water samples (R(2)=0.53).


Assuntos
Monitoramento Ambiental , Água Doce/química , Sais/análise , Poluentes Químicos da Água/análise , Indústrias Extrativas e de Processamento , Sistemas de Informação Geográfica , Água Subterrânea/química , Resíduos Industriais/análise , Montana
13.
Int J Pediatr Otorhinolaryngol ; 75(3): 401-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21242005

RESUMO

BACKGROUND: Pediatric blunt or sharp laryngotracheal injuries are infrequent because of the softer cartilages and the protection of the prominent mandible. These injuries usually occur secondary to striking furniture or via the "clothesline" injury. METHODS: We present five cases of pediatric laryngotracheal injury (thyroid cartilage, true vocal cords, cricoid cartilage, cricotracheal junction, and posterior tracheal wall). RESULTS: We examined the need for intubation, need for tracheostomy, length of intubation, length of hospital stay, interval until direct laryngoscopy, use of steroids, post-injury swallowing, and post-injury phonation. DISCUSSION: Three of the five patients were intubated either prior to arrival or upon arrival to the emergency department. Two of the patients underwent direct laryngoscopy on the day of arrival. Three patients received steroids. CT (computed tomography) was not helpful in diagnosis or decision regarding treatment. The patients with thyroid cartilage fracture, cricoid cartilage fracture, cricotracheal separation, and posterior tracheal wall tear required open repair. The tracheal wall injury, cricoid fracture, and cricotracheal separation were repaired with sutures and the thyroid cartilage fracture with a plate and screws. One tracheal stent was placed. Two open repairs were performed within 24h of injury. The patient with posterior tracheal wall injury experienced persistent dysphagia and dysphonia, which may have been secondary to intraoperative dissection. CONCLUSION: Dyspnea was not necessarily indicative of the severity of injury in our patients. CT added little information about the integrity of the larynx not already known by physical examination. Open repair was usually indicated for the blunt neck injuries in our series. Oral intubation proved less difficult than tracheostomy in our patient with cricoid cartilage fracture.


Assuntos
Laringe/lesões , Traqueia/lesões , Adolescente , Placas Ósseas , Parafusos Ósseos , Broncoscopia , Criança , Pré-Escolar , Transtornos de Deglutição/etiologia , Disfonia/etiologia , Dispneia/etiologia , Fraturas de Cartilagem/cirurgia , Fraturas Cominutivas/cirurgia , Granuloma/etiologia , Granuloma/cirurgia , Humanos , Intubação Intratraqueal , Laringoscopia , Laringe/cirurgia , Masculino , Sons Respiratórios/etiologia , Estudos Retrospectivos , Stents , Esteroides/uso terapêutico , Suturas , Tomografia Computadorizada por Raios X , Traqueia/cirurgia , Traqueostomia
14.
Ann Otol Rhinol Laryngol ; 118(7): 475-8, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19708483

RESUMO

OBJECTIVES: Ultrasound-guided needle localization techniques have been used to direct the resection of targeted axillary lymph nodes in the management of breast cancer. To date, there has been only one other description of this technique as a localization method to direct cancer resection in the neck. We offer further support for the broader application of this technique by reporting its use in the successful identification and resection of recurrent papillary thyroid cancer after a paratracheal node dissection failed to localize the cancer. METHODS: We report a case and discuss the relevant literature regarding ultrasound-guided localization and resection of recurrent well-differentiated thyroid cancer. RESULTS: We were able to achieve successful identification and resection of recurrent papillary thyroid cancer using this technique. CONCLUSIONS: This technique may be useful in the treatment of selected cases of recurrent thyroid cancer to increase the efficacy and safety of surgical resection.


Assuntos
Carcinoma Papilar/cirurgia , Esvaziamento Cervical/métodos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/cirurgia , Cirurgia Assistida por Computador , Neoplasias da Glândula Tireoide/cirurgia , Carcinoma Papilar/diagnóstico por imagem , Carcinoma Papilar/secundário , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/patologia , Ultrassonografia
15.
Cerebellum ; 8(3): 192-201, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19424768

RESUMO

Among ten sodium channel alpha-subunit genes mapped in human and mouse genomes, the SCN8A gene is primarily expressed in neurons and glia. Mice with two types of Scn8a null mutations--Scn8a ( med ) and Scn8a ( medTg )--live for only 21-24 days, but those with incomplete mutations-Scn8a ( medJ ) and Scn8a ( medJo )--and those with knockout of Scn8a only in cerebellar Purkinje cells live to adult age. We review here previous work on cerebellum and related regions of Scn8a mutant mice and include some newer immunohistochemical and microchemical results. The resurgent sodium current that underlies the repeated firing of Purkinje cells is reduced in Scn8a mutant and knockout mice. Purkinje cells of mutant mice have greatly reduced spontaneous activity, as do the analogous cartwheel cells of the dorsal cochlear nucleus. Up-regulation of GABA(A) receptors in regions to which Purkinje cells project may partially compensate for their decreased activity in the mutant mice. The somata of cerebellar Purkinje cells of Scn8a ( medJ ) and Scn8a ( medJo ) mice, as revealed by PEP-19 immunoreaction, are slightly smaller than normal, and their axons, especially in Scn8a ( medJo ) mice, sometimes show enlargements similar to those in other types of mutant mice. Density of GABA-like immunoreactivity is decreased in Purkinje somata and regions of termination in deep cerebellar and vestibular nuclei of Scn8a ( medJ ) mice, but measured GABA concentration is not significantly reduced in microdissected samples of these regions. The concentrations of taurine and glutamine are significantly increased in cerebellar-related regions of Scn8a ( medJ ) mice, possibly suggesting up-regulation of glial amino acid metabolism.


Assuntos
Cerebelo/metabolismo , Camundongos Mutantes/anatomia & histologia , Mutação/genética , Proteínas do Tecido Nervoso/genética , Canais de Sódio/genética , Aminoácidos/metabolismo , Animais , Regulação da Expressão Gênica/genética , Glutamina/metabolismo , Humanos , Camundongos , Canal de Sódio Disparado por Voltagem NAV1.6 , Proteínas do Tecido Nervoso/metabolismo , Células de Purkinje , Taurina/metabolismo , Ácido gama-Aminobutírico/metabolismo
16.
Laryngoscope ; 118(10): 1781-6, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18758382

RESUMO

OBJECTIVES: To evaluate the impact of facial nerve sacrifice and postoperative radiotherapy on the outcome of adenoid cystic carcinoma of the parotid gland. STUDY DESIGN: Inception cohort. METHODS: Retrospective review of Department of Pathology, SNOMED database, and Tumor Registry including health-related quality of life data for the subset enrolled in the longitudinal Outcomes Assessment Project. Fisher exact, chi, and Wilcoxon tests were used to determine significant differences. RESULTS: Fifty-two cases (follow-up mean: 9.1 years, range: 0.5-40.8 years) demonstrated local control rates of 84.6% (5 years), 76.9% (10 years), and 50% (20 years). Compared with facial nerve preservation, facial nerve sacrifice had better control at 5 years (100 vs. 78.9% P = .259) while having detrimental effects on eating, speech, and esthetics. Local control at 5 years was significantly better (P = .048) with postoperative radiotherapy (100%) than without (84.6%). Overall survival was 79.4% (5 years), 50% (10 years), and 32.3% (20 years). At 10 years, there was a trend toward improved survival with facial nerve sacrifice (58.8 vs. 46.8%, P = .569) and postoperative radiotherapy (62.4 vs. 39.3%, P = .409). Eleven patients with lung metastases survived an average of 67.8 months after metastases were identified. Only 4 of 46 patients N0 patients (8.3%) subsequently developed lymph node metastases. CONCLUSION: Selective facial nerve sacrifice was associated with trends toward improved local control and survival but worse quality of life. Patients managed with postoperative radiotherapy had better local control rates than those without. N0 patients rarely developed metastases to regional lymph nodes.


Assuntos
Carcinoma Adenoide Cístico/cirurgia , Nervo Facial/cirurgia , Neoplasias Parotídeas/cirurgia , Carcinoma Adenoide Cístico/radioterapia , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Parotídeas/radioterapia , Qualidade de Vida , Radioterapia Adjuvante
17.
Otol Neurotol ; 28(8): 1091-3, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18084823

RESUMO

OBJECTIVE: A benign epithelioid peripheral nerve sheath tumor is described in the setting of congenital facial nerve (FN) paralysis. This is the first reported case in the English literature. PATIENT: A 10-month-old girl with unilateral congenital FN paralysis. INTERVENTIONS: Auditory brainstem evoked potential study, gadolinium-enhanced magnetic resonance imaging, temporal bone computed tomography, and transmastoid FN decompression with tumor resection. MAIN OUTCOME MEASURES: Follow-up for tumor recurrence and postoperative FN function. RESULTS: The child underwent a transmastoid FN exploration with resection of a 0.6-cm spherical tumor analyzed to be a benign epithelioid peripheral nerve sheath tumor. There is no evidence of recurrence, and FN function was unchanged at 1 year postoperatively. CONCLUSION: Benign epithelioid peripheral nerve sheath tumor can cause congenital facial nerve palsy.


Assuntos
Doenças do Nervo Facial/congênito , Doenças do Nervo Facial/etiologia , Neoplasias Epiteliais e Glandulares/congênito , Neoplasias Epiteliais e Glandulares/complicações , Neoplasias de Bainha Neural/congênito , Neoplasias de Bainha Neural/complicações , Descompressão Cirúrgica , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Nervo Facial/fisiologia , Paralisia Facial/congênito , Paralisia Facial/etiologia , Feminino , Gadolínio , Humanos , Lactente , Imageamento por Ressonância Magnética , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias de Bainha Neural/patologia , Radiografia , Osso Temporal/diagnóstico por imagem
18.
Am J Otolaryngol ; 25(5): 364-7, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15334404

RESUMO

We report a case of a morbidly obese young woman in her third trimester of pregnancy presenting with a history of goiter and respiratory disease. The recent history of this patient was significant for worsening respiratory symptoms over a period of 2 weeks, and, on presentation at 36 weeks gestation, she was stridorous, dyspneic at rest, and had a hoarse voice. Evaluation revealed a morbidly obese individual with a large goiter. She was biochemically euthyroid. Fiberoptic laryngoscopy revealed a left true vocal cord paresis, and ultrasound evaluation was significant for diffuse multinodular enlargement, with each lobe measuring greater than 10 cm and the isthmus measuring 5. Pulmonary function testing revealed a significant degree of upper airway obstruction without significant lower airway disease. Given the patient's clinical signs and symptoms, her tenuous airway, poor candidacy for urgent tracheotomy, and her proximity to delivery, it was agreed that the patient should undergo elective cesarean section and at its completion undergo subtotal thyroidectomy for the obstructive goiter.


Assuntos
Obstrução das Vias Respiratórias/etiologia , Bócio/cirurgia , Obesidade Mórbida/complicações , Complicações na Gravidez/cirurgia , Adulto , Obstrução das Vias Respiratórias/fisiopatologia , Obstrução das Vias Respiratórias/cirurgia , Cesárea , Dispneia/etiologia , Feminino , Bócio/complicações , Humanos , Laringoscopia , Gravidez , Complicações na Gravidez/etiologia , Terceiro Trimestre da Gravidez , Sons Respiratórios/etiologia , Tireoidectomia , Resultado do Tratamento , Paralisia das Pregas Vocais/diagnóstico , Paralisia das Pregas Vocais/etiologia
19.
Arch Otolaryngol Head Neck Surg ; 128(2): 123-30, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11843718

RESUMO

BACKGROUND: Acute bacterial rhinosinusitis (ABRS) is a common illness that is routinely managed by physicians from several different specialties. However, the actual diagnostic and treatment preferences of physicians from these different specialties are not known. OBJECTIVE: To determine whether the radiographic evaluation and management of community-acquired ABRS differs according to medical specialty. DESIGN, SETTING, AND PARTICIPANTS: Randomized survey of 450 board-certified physicians in the United States from family medicine, general internal medicine, and otolaryngology. MAIN OUTCOME MEASURES: Responding physicians' use of diagnostic radiography as well as choice and duration of antimicrobial and adjunctive treatments of ABRS. RESULTS: Otolaryngologists were more likely to use supportive diagnostic radiography (P =.04). They were also more likely to treat patients with adjunctive therapy, such as topical decongestants (P =.01), guaifenesin (P =.01), and saline nasal irrigation (P =.01), in addition to antibiotics. Otolaryngologists prescribed more medications to treat patients with ABRS than primary care physicians (P =.01). There were no significant differences in diagnosis and management by family physicians and general internists. CONCLUSIONS: Otolaryngologists use more health care resources to diagnose and treat ABRS than primary care physicians despite an absence of evidence that such tests and treatments lead to better outcomes. Otolaryngologists typically treat a patient population with a higher prevalence of ABRS and frequently see referred patients with recurrent acute sinusitis and chronic rhinosinusitis, which may explain their tendency to treat patients more aggressively. Nevertheless, these survey results illustrate a lack of consensus within the medical community regarding the evaluation and management of community-acquired ABRS, suggesting that widely accepted evidence-based practice guidelines need to be developed.


Assuntos
Infecções Bacterianas/diagnóstico por imagem , Infecções Bacterianas/terapia , Medicina de Família e Comunidade , Medicina Interna , Otolaringologia , Padrões de Prática Médica , Rinite/diagnóstico por imagem , Rinite/terapia , Sinusite/diagnóstico por imagem , Sinusite/terapia , Doença Aguda , Adulto , Infecções Comunitárias Adquiridas/diagnóstico por imagem , Infecções Comunitárias Adquiridas/terapia , Coleta de Dados , Humanos , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Radiografia , Distribuição Aleatória
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