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1.
Artigo em Inglês | MEDLINE | ID: mdl-38662118

RESUMO

PURPOSE: The skin and/or nipple-sparing approach has become an oncologically sound and desirable choice for women choosing mastectomy. Indocyanine green (ICG) perfusion imaging has been shown to reduce ischemic complications in mastectomy skin flaps. Immediate reconstruction requires a well-vascularized skin flap capable of tolerating full expansion. Identification of the perforating subcutaneous vessels to the skin envelope may allow for better and more consistent blood vessel preservation and flap perfusion. METHODS: The authors conducted an institutional review board-approved prospective study with 41 patients to assess the feasibility of using ICG perfusion imaging to visualize, cutaneously map, and preserve the vessels that supply the skin flap and nipple-areolar complex. For each patient, the number of vessels initially mapped, the number of vessels preserved, the extent to which each vessel was preserved, and the proportion of the flap with adequate perfusion (as defined by the SPY-Q > 20% threshold) was recorded and analyzed. RESULTS: Vessels were able to be identified and marked in a high majority of patients (90%). There was a moderate linear relationship between the number of vessels marked and the number preserved. Successful mapping of vessels was associated with lower rates of wound breakdown (p = 0.036). Mapping and preserving at least one vessel led to excellent flap perfusion (> 90%). No increase in complications was observed from utilizing ICG angiography preoperatively. CONCLUSION: This prospective study using preoperative ICG perfusion mapping demonstrated safety, feasibility, and good prognostic outcomes. LEVEL OF EVIDENCE: III.

2.
Brain ; 146(12): 5198-5208, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37647852

RESUMO

Genetic variants in the SLC6A1 gene can cause a broad phenotypic disease spectrum by altering the protein function. Thus, systematically curated clinically relevant genotype-phenotype associations are needed to understand the disease mechanism and improve therapeutic decision-making. We aggregated genetic and clinical data from 172 individuals with likely pathogenic/pathogenic (lp/p) SLC6A1 variants and functional data for 184 variants (14.1% lp/p). Clinical and functional data were available for a subset of 126 individuals. We explored the potential associations of variant positions on the GAT1 3D structure with variant pathogenicity, altered molecular function and phenotype severity using bioinformatic approaches. The GAT1 transmembrane domains 1, 6 and extracellular loop 4 (EL4) were enriched for patient over population variants. Across functionally tested missense variants (n = 156), the spatial proximity from the ligand was associated with loss-of-function in the GAT1 transporter activity. For variants with complete loss of in vitro GABA uptake, we found a 4.6-fold enrichment in patients having severe disease versus non-severe disease (P = 2.9 × 10-3, 95% confidence interval: 1.5-15.3). In summary, we delineated associations between the 3D structure and variant pathogenicity, variant function and phenotype in SLC6A1-related disorders. This knowledge supports biology-informed variant interpretation and research on GAT1 function. All our data can be interactively explored in the SLC6A1 portal (https://slc6a1-portal.broadinstitute.org/).


Assuntos
Proteínas da Membrana Plasmática de Transporte de GABA , Estudos de Associação Genética , Mutação de Sentido Incorreto , Humanos , Proteínas da Membrana Plasmática de Transporte de GABA/genética , Proteínas da Membrana Plasmática de Transporte de GABA/metabolismo , Fenótipo
3.
Brain ; 146(4): 1342-1356, 2023 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-36226386

RESUMO

Understanding the exact molecular mechanisms involved in the aetiology of epileptogenic pathologies with or without tumour activity is essential for improving treatment of drug-resistant focal epilepsy. Here, we characterize the landscape of somatic genetic variants in resected brain specimens from 474 individuals with drug-resistant focal epilepsy using deep whole-exome sequencing (>350×) and whole-genome genotyping. Across the exome, we observe a greater number of somatic single-nucleotide variants in low-grade epilepsy-associated tumours (7.92 ± 5.65 single-nucleotide variants) than in brain tissue from malformations of cortical development (6.11 ± 4 single-nucleotide variants) or hippocampal sclerosis (5.1 ± 3.04 single-nucleotide variants). Tumour tissues also had the largest number of likely pathogenic variant carrying cells. low-grade epilepsy-associated tumours had the highest proportion of samples with one or more somatic copy-number variants (24.7%), followed by malformations of cortical development (5.4%) and hippocampal sclerosis (4.1%). Recurring somatic whole chromosome duplications affecting Chromosome 7 (16.8%), chromosome 5 (10.9%), and chromosome 20 (9.9%) were observed among low-grade epilepsy-associated tumours. For germline variant-associated malformations of cortical development genes such as TSC2, DEPDC5 and PTEN, germline single-nucleotide variants were frequently identified within large loss of heterozygosity regions, supporting the recently proposed 'second hit' disease mechanism in these genes. We detect somatic variants in 12 established lesional epilepsy genes and demonstrate exome-wide statistical support for three of these in the aetiology of low-grade epilepsy-associated tumours (e.g. BRAF) and malformations of cortical development (e.g. SLC35A2 and MTOR). We also identify novel significant associations for PTPN11 with low-grade epilepsy-associated tumours and NRAS Q61 mutated protein with a complex malformation of cortical development characterized by polymicrogyria and nodular heterotopia. The variants identified in NRAS are known from cancer studies to lead to hyperactivation of NRAS, which can be targeted pharmacologically. We identify large recurrent 1q21-q44 duplication including AKT3 in association with focal cortical dysplasia type 2a with hyaline astrocytic inclusions, another rare and possibly under-recognized brain lesion. The clinical-genetic analyses showed that the numbers of somatic single-nucleotide variant across the exome and the fraction of affected cells were positively correlated with the age at seizure onset and surgery in individuals with low-grade epilepsy-associated tumours. In summary, our comprehensive genetic screen sheds light on the genome-scale landscape of genetic variants in epileptic brain lesions, informs the design of gene panels for clinical diagnostic screening and guides future directions for clinical implementation of epilepsy surgery genetics.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Epilepsia , Malformações do Desenvolvimento Cortical , Humanos , Epilepsia/patologia , Encéfalo/patologia , Epilepsia Resistente a Medicamentos/genética , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia Resistente a Medicamentos/metabolismo , Genômica , Malformações do Desenvolvimento Cortical/complicações , Malformações do Desenvolvimento Cortical/genética , Malformações do Desenvolvimento Cortical/metabolismo , Epilepsias Parciais/metabolismo , Nucleotídeos/metabolismo
4.
Water Sci Technol ; 83(8): 1893-1906, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33905360

RESUMO

Anthropogenic loss of phosphorus to surface waters not only causes environmental problems but depletes valuable phosphorus reserves. In this study, magnesium amended biochars and magnesium silicate, synthesized from corn cobs and rice straw, respectively, were evaluated for phosphorus uptake including the effects of pH and alkalinity. The overall goal was to close the phosphorus loop by recovering phosphorus from animal waste and reusing it as fertilizer. After phosphorus uptake, spent materials were tested for phosphorus release using modified soil tests representing different soil pH and alkalinity conditions. In experiments using model animal wastewaters containing both ammonia and bicarbonate alkalinity, dissolved phosphorus was removed by struvite (MgNH4PO4·6H2O) formation, whereas in deionized water, dissolved phosphorus was removed by adsorption. Alkalinity in the model animal wastewaters competed with phosphate for dissolved or solid-associated magnesium, thereby reducing phosphorus uptake. Spent materials released significant phosphorus in waters with bicarbonate alkalinity. This work shows that abundant agricultural wastes can be used to synthesize solids for phosphorus uptake, with the spent materials having potential application as fertilizers.


Assuntos
Oryza , Fósforo , Animais , Fertilizantes , Fosfatos , Estruvita , Águas Residuárias , Zea mays
5.
Gland Surg ; 8(3): 249-257, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31328104

RESUMO

BACKGROUND: We have previously shown that breast cancer surgery affects breast specific sensuality, and that women who undergo mastectomy may have worse sexual function outcomes than those who undergo lumpectomy. It is less clear if patients who undergo prophylactic mastectomy are equally as affected as those with a cancer diagnosis. We sought to compare sexual function outcomes and their relationship to depression and anxiety between BRCA mutation carriers (mBRCA) with and without cancer in order to guide surgical counseling and improve survivorship outcomes. METHODS: A confidential, cross-sectional survey was distributed electronically to mBRCA at least 18 years of age. The survey included investigator-generated questions, the Female Sexual Function Index (FSFI), and the Hospital Anxiety and Depression Scale (HADS) surveys. Responses were analyzed in total and divided into two subgroups: those with and without breast cancer. RESULTS: Sixty-three mBRCA responded (37%) of 170 email addresses were identified, and 77% were postmenopausal. Although more than half of all mBRCA reported that the role of the breast in intimacy was important, most patients without cancer and all of those with cancer experienced an impressive decline in certain breast-specific sensuality parameters postoperatively. Among those without cancer, anxiety scores were not different between those choosing prophylactic mastectomy and high-risk screening (HRS). Sexual function as measured by the FSFI was negatively correlated with depression and anxiety in mBRCA. FSFI scores were not significantly different between those with and without cancer. However, the median FSFI of mBRCA with cancer, those undergoing HRS, and those who underwent prophylactic mastectomy indicated sexual dysfunction. CONCLUSIONS: As the availability of genetic testing increases, more women are found to harbor BRCA mutations and must choose between HRS and prophylactic surgery. Women with BRCA mutations, both with and without breast cancer, are susceptible to derangements in sexual function during the course of both screening or treatment, and this appears to be negatively correlated to depression and anxiety.

6.
Am J Clin Oncol ; 42(6): 500-506, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31094713

RESUMO

OBJECTIVES: Sexual dysfunction is common in breast cancer survivors. Our survey study aimed to delineate the relative associations between sexual dysfunction and breast cancer treatment including surgical modalities and adjuvant therapies. METHODS: Women in surveillance following breast cancer surgery were eligible for our survey incorporating the Female Sexual Function Index. Analysis involved multiple log-binomial regression to evaluate the association between sexual dysfunction (Female Sexual Function Index≤26.55) and treatment modality. RESULTS: Of the 600 completed surveys, the final eligible analytic sample included 278 sexually active respondents. Overall, 65%, 27%, and 8% underwent lumpectomy, mastectomy with reconstruction, and mastectomy alone, respectively. In total, 74.5% reported receipt of radiation; 47.8% chemotherapy; 27.3% tamoxifen, and 31.4% aromatase inhibitor (AI). No significant difference in prevalence of sexual dysfunction was observed by surgical modality, even when adjusted for adjuvant therapy. Chemotherapy or radiation was not associated with sexual dysfunction when adjusted for surgical modality. The prevalence of sexual dysfunction was 1.6 times higher for the AI group compared with the no endocrine therapy group (P=0.01), when adjusted for other treatment groups. CONCLUSIONS: Our study demonstrated that the highest rates of sexual dysfunction were among breast cancer survivors treated with AI. Neither surgical modality, chemotherapy, nor radiation was associated with sexual dysfunction. These data may guide clinicians in counseling sexually active breast cancer patients in treatment planning and survivorship.


Assuntos
Neoplasias da Mama/terapia , Sobreviventes de Câncer/estatística & dados numéricos , Quimioterapia Adjuvante/efeitos adversos , Mastectomia/efeitos adversos , Radioterapia Adjuvante/efeitos adversos , Disfunções Sexuais Fisiológicas/etiologia , Neoplasias da Mama/patologia , Neoplasias da Mama/psicologia , Sobreviventes de Câncer/psicologia , Estudos Transversais , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Prognóstico
7.
Washington, D.C; Banco Interamericano de Desarrollo; 2019. 40 p. ilus, tab.
Não convencional em Espanhol | LILACS | ID: biblio-1348254

RESUMO

La transformación digital mejora la calidad y efi- ciencia de la atención médica mediante la obten- ción de información y su uso apropiado para la toma de decisiones en todos los niveles del sistema de salud


Assuntos
Humanos , Tecnologia/organização & administração , Telemedicina , Consulta Remota , Registros Eletrônicos de Saúde , Estratégias de eSaúde
8.
Hum Mutat ; 39(11): 1476-1484, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30311377

RESUMO

The field of epilepsy genetics is advancing rapidly and epilepsy is emerging as a frequent indication for diagnostic genetic testing. Within the larger ClinGen framework, the ClinGen Epilepsy Gene Curation Expert Panel is tasked with connecting two increasingly separate fields: the domain of traditional clinical epileptology, with its own established language and classification criteria, and the rapidly evolving area of diagnostic genetic testing that adheres to formal criteria for gene and variant curation. We identify critical components unique to the epilepsy gene curation effort, including: (a) precise phenotype definitions within existing disease and phenotype ontologies; (b) consideration of when epilepsy should be curated as a distinct disease entity; (c) strategies for gene selection; and (d) emerging rules for evaluating functional models for seizure disorders. Given that de novo variants play a prominent role in many of the epilepsies, sufficient genetic evidence is often awarded early in the curation process. Therefore, the emphasis of gene curation is frequently shifted toward an iterative precuration process to better capture phenotypic associations. We demonstrate that within the spectrum of neurodevelopmental disorders, gene curation for epilepsy-associated genes is feasible and suggest epilepsy-specific conventions, laying the groundwork for a curation process of all major epilepsy-associated genes.


Assuntos
Epilepsia/genética , Testes Genéticos , Humanos , Mutação/genética , Fenótipo
9.
Am J Med Genet C Semin Med Genet ; 178(1): 46-53, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29675991

RESUMO

The skill sets of genetic counselors are strongly utilized in industry, as evidenced by 20% of genetic counselors reporting employment within industry in 2016. In addition, industry genetic counselors are expanding their roles, taking on new responsibilities, and creating new opportunities. These advances have impacted the profession as a whole including, but not limited to, genetic counseling training curricula, a shift back to genetic counseling directly to patients, and a growing influence of genetic counselors on industry test offerings. Industry genetic counselors and training programs are working together to address the challenges and opportunities presented by workforce changes and novel interpretations of how genetic counselors' core competencies can be utilized. Counseling of patients by industry genetic counselors has become more commonplace and addresses a need for alternate service delivery models. Industry genetic counselors often provide significant contributions to test development, education, marketing, and interpretation. Beyond these broad examples, individual industry genetic counselors have created unique niches for themselves, using their genetic counseling training combined with unique opportunities offered through industry, as illustrated by genetic counselors' various roles and responsibilities highlighted here.


Assuntos
Conselheiros , Aconselhamento Genético , Testes Genéticos , Genética Médica/organização & administração , Pesquisa Biomédica , Biotecnologia , Biologia Computacional , Conselheiros/educação , Indústria Farmacêutica , Humanos , Medicina de Precisão , Diagnóstico Pré-Natal , Sequenciamento do Exoma
10.
Epilepsia ; 59(5): 1062-1071, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29655203

RESUMO

OBJECTIVE: We evaluated >8500 consecutive, unselected patients with epilepsy and neurodevelopmental disorders who underwent multigene panel testing to determine the average age at molecular diagnosis and diagnostic yield of 70 genes. METHODS: We reviewed molecular test results for 70 genes known to cause epilepsy and neurodevelopmental disorders using next generation sequencing (NGS) and exon-level array comparative genomic hybridization (aCGH). A positive result was defined as the presence of 1 or 2 pathogenic or likely pathogenic (P/LP) variants in a single gene, depending on the mode of inheritance of the associated disorder. RESULTS: Overall, 22 genes were found to have a high yield of positive findings by genetic testing, with SCN1A and KCNQ2 accounting for the greatest number of positive findings. In contrast, there were no positive findings in 16 genes. Most of the P/LP variants were sequence changes identified by NGS (90.9%), whereas ~9% were gross deletions or duplications detected by exon-level aCGH. The mean age of molecular diagnosis for the cohort was 5 years, 8 months (ranging from 1 week to 47 years). Recurrent P/LP variants were observed in 14 distinct genes, most commonly in MECP2, KCNQ2, SCN1A, SCN2A, STXBP1, and PRRT2. Parental testing was performed in >30% of positive cases. All variants identified in CDKL5, STXBP1, SCN8A, GABRA1, and FOXG1 were de novo, whereas 85.7% of variants in PRRT2 were inherited. SIGNIFICANCE: Using a combined approach of NGS and exon-level aCGH, testing identified a genetic etiology in 15.4% of patients in this cohort and revealed the age at molecular diagnosis for patients. Our study highlights both high- and low-yield genes associated with epilepsy and neurodevelopmental disorders, indicating which genes may be considered for molecular diagnostic testing.


Assuntos
Epilepsia/diagnóstico , Epilepsia/genética , Testes Genéticos , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/genética , Adolescente , Adulto , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Adulto Jovem
11.
Genet Med ; 20(4): 403-410, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28837158

RESUMO

PurposeMosaicism probably represents an underreported cause of genetic disorders due to detection challenges during routine molecular diagnostics. The purpose of this study was to evaluate the frequency of mosaicism detected by next-generation sequencing in genes associated with epilepsy-related neurodevelopmental disorders.MethodsWe conducted a retrospective analysis of 893 probands with epilepsy who had a multigene epilepsy panel or whole-exome sequencing performed in a clinical diagnostic laboratory and were positive for a pathogenic or likely pathogenic variant in one of nine genes (CDKL5, GABRA1, GABRG2, GRIN2B, KCNQ2, MECP2, PCDH19, SCN1A, or SCN2A). Parental results were available for 395 of these probands.ResultsMosaicism was most common in the CDKL5, PCDH19, SCN2A, and SCN1A genes. Mosaicism was observed in GABRA1, GABRG2, and GRIN2B, which previously have not been reported to have mosaicism, and also in KCNQ2 and MECP2. Parental mosaicism was observed for pathogenic variants in multiple genes including KCNQ2, MECP2, SCN1A, and SCN2A.ConclusionMosaic pathogenic variants were identified frequently in nine genes associated with various neurological conditions. Given the potential clinical ramifications, our findings suggest that next-generation sequencing diagnostic methods may be utilized when testing these genes in a diagnostic laboratory.


Assuntos
Epilepsia/genética , Frequência do Gene , Predisposição Genética para Doença , Variação Genética , Mosaicismo , Transtornos do Neurodesenvolvimento/genética , Alelos , Substituição de Aminoácidos , Epilepsia/diagnóstico , Estudos de Associação Genética , Testes Genéticos , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Transtornos do Neurodesenvolvimento/diagnóstico , Pais , Sequenciamento do Exoma
12.
J Neurogenet ; 31(1-2): 30-36, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28460589

RESUMO

Pathogenic missense and truncating variants in the GABRG2 gene cause a spectrum of epilepsies, from Dravet syndrome to milder simple febrile seizures. In most cases, pathogenic missense variants in the GABRG2 gene segregate with a febrile seizure phenotype. In this case series, we report a recurrent, de novo missense variant (c0.316 G > A; p.A106T) in the GABRG2 gene that was identified in five unrelated individuals. These patients were described to have a more severe phenotype than previously reported for GABRG2 missense variants. Common features include variable early-onset seizures, significant motor and speech delays, intellectual disability, hypotonia, movement disorder, dysmorphic features and vision/ocular issues. Our report further explores a recurrent pathogenic missense variant within the GABRG2 variant family and broadens the spectrum of associated phenotypes for GABRG2-associated disorders.


Assuntos
Anormalidades Múltiplas/patologia , Mutação de Sentido Incorreto , Receptores de GABA-A/genética , Índice de Gravidade de Doença , Anormalidades Múltiplas/genética , Adolescente , Criança , Epilepsia/genética , Epilepsia/patologia , Feminino , Humanos , Lactente , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Masculino , Transtornos Motores/genética , Transtornos Motores/patologia , Transtornos dos Movimentos/genética , Transtornos dos Movimentos/patologia , Hipotonia Muscular/genética , Hipotonia Muscular/patologia , Linhagem , Fenótipo , Distúrbios da Fala/genética , Distúrbios da Fala/patologia
13.
Environ Sci Process Impacts ; 18(10): 1266-1273, 2016 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-27711891

RESUMO

Trichloroethylene (TCE) and tetrachloroethylene (PCE) are common ground water contaminants susceptible to reductive dechlorination by FeS (mackinawite) in anaerobic environments. The objective of this study was to characterize the mineral-associated products that form when mackinawite reacts with TCE and PCE. The dissolved products of the reaction included Cl- and Fe2+, and trace amounts of cis 1,2-dichloroethylene (for TCE) and TCE (for PCE). Selected area electron diffraction (SAED) analysis identified greigite as a mackinawite oxidation product formed after reaction between TCE or PCE and FeS over seven weeks. Release of Fe2+ is consistent with the solid state transformation of mackinawite to greigite, resulting in depletion of the solid with Fe. X-ray photoelectron spectroscopy of the sulfur 2p peak showed a shift to a higher binding energy after FeS reacted with TCE or PCE, also observed in other studies of mackinawite oxidation to greigite. The results may help efforts to maintain the reactivity of FeS generated to remediate chlorinated aliphatic contaminants in ground water.


Assuntos
Compostos Ferrosos/química , Ferro/química , Sulfetos/química , Tetracloroetileno/química , Tricloroetileno/química , Poluentes Químicos da Água/química , Dicloroetilenos/química , Recuperação e Remediação Ambiental , Oxirredução
14.
Environ Sci Technol ; 50(11): 5489-97, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27138348

RESUMO

This paper investigated the mackinawite (FeS)-associated products formed during reaction between FeS and carbon tetrachloride (CT) at pH 7 and 8. At pH 8, reaction of FeS with CT led to formation of abundant spherical particles with diameters between 50 and 400 nm on the FeS surface and in solution; far fewer such particles were observed at pH 7. Analysis of the FeS surface by energy dispersive X-ray spectroscopy after reaction with CT at pH 8 showed decreased sulfur and elevated oxygen compared to unreacted FeS. The spherical particles that formed upon FeS reaction with CT were mostly amorphous with localized areas of poorly crystalline two-line ferrihydrite. X-ray photoelectron spectroscopy indicated that the predominant Fe surface species after reaction with CT at pH 8 was Fe(III)-O, consistent with ferrihydrite and other amorphous iron (hydr)oxides as major products. Powder X-ray diffraction analysis suggested formation of greigite upon reaction of FeS with CT at pH 7. Both ferrihydrite and Fe(2+), which is a product of greigite dissolution, can react with dissolved HS(-) to form FeS, suggesting that, after oxidation by chlorinated aliphatics, FeS can be regenerated by addition or microbial generation of sulfide.


Assuntos
Tetracloreto de Carbono/química , Ferro/química , Compostos Férricos , Halogenação , Oxirredução , Sulfetos/química
15.
Opt Express ; 24(4): 3479-87, 2016 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-26907006

RESUMO

Microelectromechanical (MEMS) mirrors have extended vision capabilities onto small, low-power platforms. However, the field-of-view (FOV) of these MEMS mirrors is usually less than 90° and any increase in the MEMS mirror scanning angle has design and fabrication trade-offs in terms of power, size, speed and stability. Therefore, we need techniques to increase the scanning range while still maintaining a small form factor. In this paper we exploit our recent breakthrough that has enabled the immersion of MEMS mirrors in liquid. While allowing the MEMS to move, the liquid additionally provides a "Snell's window" effect and enables an enlarged FOV (≈ 150°). We present an optimized MEMS mirror design and use it to demonstrate applications in extreme wide-angle structured light.

16.
Environ Sci Process Impacts ; 17(11): 1930-40, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26452013

RESUMO

Hexavalent chromium (Cr(vi), present predominantly as CrO4(2-) in water at neutral pH) is a common ground water pollutant, and reductive immobilization is a frequent remediation alternative. The Cr(iii) that forms upon microbial or abiotic reduction often co-precipitates with naturally present or added iron (Fe), and the stability of the resulting Fe-Cr precipitate is a function of its mineral properties. In this study, Fe-Cr solids were formed by microbial Cr(vi) reduction using Desulfovibrio vulgaris strain RCH1 in the presence of the Fe-bearing minerals hematite, aluminum substituted goethite (Al-goethite), and nontronite (NAu-2, Clay Minerals Society), or by abiotic Cr(vi) reduction by dithionite reduced NAu-2 or iron sulfide (FeS). The properties of the resulting Fe-Cr solids and their behavior upon exposure to the oxidant manganese (Mn) oxide (birnessite) differed significantly. In microcosms containing strain RCH1 and hematite or Al-goethite, there was significant initial loss of Cr(vi) in a pattern consistent with adsorption, and significant Cr(vi) was found in the resulting solids. The solid formed when Cr(vi) was reduced by FeS contained a high proportion of Cr(iii) and was poorly crystalline. In microcosms with strain RCH1 and hematite, Cr precipitates appeared to be concentrated in organic biofilms. Reaction between birnessite and the abiotically formed Cr(iii) solids led to production of significant dissolved Cr(vi) compared to the no-birnessite controls. This pattern was not observed in the solids generated by microbial Cr(vi) reduction, possibly due to re-reduction of any Cr(vi) generated upon oxidation by birnessite by active bacteria or microbial enzymes. The results of this study suggest that Fe-Cr precipitates formed in groundwater remediation may remain stable only in the presence of active anaerobic microbial reduction. If exposed to environmentally common Mn oxides such as birnessite in the absence of microbial activity, there is the potential for rapid (re)formation of dissolved Cr(vi) above regulatory levels.


Assuntos
Cromo/análise , Recuperação e Remediação Ambiental/métodos , Compostos de Manganês/química , Óxidos/química , Poluentes Químicos da Água/análise , Cromo/química , Cromo/metabolismo , Água Subterrânea , Oxirredução , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo
17.
Am J Med Genet A ; 164A(11): 2914-21, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25124326

RESUMO

The γ-aminobutyric acid type A (GABAA ) receptor is one of the three main classes of receptors activated by GABA, the principal inhibitory neurotransmitter in the central nervous system. Mutations in genes encoding various subunits of this receptor (GABRA1, GABRA2, GABRA4, GABRA5, GABRA6, GABRB1, GABRB3, GABRG1, GABRG2, GABRG3, and GABRD) are implicated in a number of neurological and developmental disorders, including epilepsy and autism. To date, no human genetics studies have implicated mutations in GABRB2, encoding the ß2 subunit of the GABAA receptor, with neurodevelopmental disorders. Here we present a 12-year-old girl with intellectual disability and epilepsy, who was discovered by whole exome sequencing to have a de novo heterozygous missense variant in exon 4 of GABRB2 (c.236T>C; p.M79T). This variant is likely pathogenic, based on in silico analyses, as well as the fact that it results in the non-conservative substitution of a non-polar amino acid with a polar amino acid at a position that is evolutionarily conserved across multiple species. Our findings underscore the need for further investigation into the mechanisms by which mutations in GABRB2 contribute to neurological and developmental dysfunction.


Assuntos
Epilepsia/genética , Estudos de Associação Genética , Variação Genética , Deficiência Intelectual/genética , Receptores de GABA-A/genética , Sequência de Aminoácidos , Criança , Eletroencefalografia , Epilepsia/diagnóstico , Exoma , Feminino , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Deficiência Intelectual/diagnóstico , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Conformação Proteica , Receptores de GABA-A/química , Alinhamento de Sequência
18.
Chemosphere ; 101: 21-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24373227

RESUMO

Simple aluminum (hydr)oxides and layered double hydroxides were synthesized using common chemicals and equipment by varying synthesis temperature, concentrations of extra sulfate and citrate, and metal oxide amendments. Aluminum (hydr)oxide samples were aged at either 25 or 200°C during synthesis and, in some cases, calcined at 600 °C. Despite yielding increased crystallinity and mineral phase changes, higher temperatures had a generally negative effect on fluoride adsorption. Addition of extra sulfate during synthesis of aluminum (hydr)oxides led to significantly higher fluoride adsorption capacity compared to aluminum (hydr)oxides prepared with extra citrate or no extra ligands. X-ray diffraction results suggest that extra sulfate led to the formation of both pseudoboehmite (γ-AlOOH) and basaluminite (Al4SO4(OH)10⋅4H2O) at 200 °C; energy dispersive X-ray spectroscopy confirmed the presence of sulfur in this solid. Treatment of aluminum (hydr)oxides with magnesium, manganese, and iron oxides did not significantly impact fluoride adsorption. While layered double hydroxides exhibited high maximum fluoride adsorption capacities, their adsorption capacities at dissolved fluoride concentrations close to the World Health Organization drinking water guideline of 1.5 mg L(-1) were much lower than those for the aluminum (hydr)oxides.


Assuntos
Compostos de Alumínio/química , Hidróxido de Alumínio/síntese química , Óxido de Alumínio/síntese química , Cloretos/química , Fluoretos/isolamento & purificação , Purificação da Água , Adsorção , Cloreto de Alumínio , Água Potável/química , Compostos Férricos , Magnésio/química , Temperatura , Difração de Raios X
19.
Indian J Biochem Biophys ; 49(5): 329-41, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23259319

RESUMO

The use of cyclodextrins as tools to establish the role of cholesterol rafts in cellular functions has become a widely accepted procedure. However, the adverse effects of cyclodextrins as the cholesterol-depleting agents on cellular structure and functions are not reported in detail. Therefore, in the current study, we investigated the membrane-perturbing actions and cytotoxicity of the two widely used cellular cholesterol-depleting cyclodextrins methyl-beta-cyclodextrin (MbetaCD) and hydroxypropyl-beta-cyclodextrin (HPCD) in our well-established bovine pulmonary artery endothelial cell (BPAEC) in vitro model system. BPAECs treated with different concentrations of MbetaCD and HPCD (2% and 5%, wt/vol.) for 15-180 min showed significant loss of membrane cholesterol, cytotoxicity, cell morphology alterations, actin cytoskeletal reorganization, alterations in cellular proteins and membrane fatty acid composition, and decrease in trans-endothelial electrical resistance (TER). MbetaCD induced a marked loss of cellular proteins, as compared to that caused by HPCD under identical conditions. More noticeably, MbetaCD caused a drastic loss of membrane lipid fatty acids in BPAECs, as compared to HPCD which failed to cause such alteration. Removal of cholesterol by cyclodextrin (especially MbetaCD) treatment apparently caused loss of fluidity of the cell membrane and leakage of vital cellular molecules including proteins and fatty acids, and thus caused cytotoxicity and loss of cell morphology in BPAECs. Replenishment of cells with cholesterol following its depletion by MbetaCD treatment significantly attenuated the depletion of cellular cholesterol, cytotoxicity and morphological alterations in BPAECs, indicating the importance of membrane cholesterol in vascular EC integrity. Also, the current study offered a safer method of cholesterol removal from membranes and lipid rafts by HPCD, suggesting its use in studies to investigate the role of lipid raft-associated cholesterol in cellular functions.


Assuntos
Colesterol/metabolismo , Ciclodextrinas/farmacologia , Ciclodextrinas/toxicidade , Citoesqueleto/fisiologia , Células Endoteliais/fisiologia , Fluidez de Membrana/fisiologia , Microdomínios da Membrana/fisiologia , Animais , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Colesterol/isolamento & purificação , Citoesqueleto/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Microdomínios da Membrana/efeitos dos fármacos
20.
Hum Mutat ; 33(3): 485-7, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22213132

RESUMO

Congenital disorders of glycosylation (CDG) comprise a clinically and biochemically heterogeneous group of monogenetic-inherited, multisystemic diseases that affect the biosynthesis of N- and/or O-glycans linked to glycoconjugates. Recently, we identified the first patient with a defect in the cytosolic-orientated GDP-mannose:Man(3-4) GlcNAc(2)-PP-dolichol alpha-1,2-mannosyltransferase (ALG11), who presented an accumulation of shortened dolichol-linked oligosaccharides leading to CDG-Ip (ALG11-CDG). Here we describe an improved metabolic labeling method that allowed the identification of three new CDG-Ip cases that were missed so far in routine diagnostics. Although all CDG-Ip patients carry different mutations in the ALG11 gene, they share a variety of clinical syndromes like an unremarkable prenatal period followed by developmental delay, psychomotor, and mental retardation, strabismus convergens and seizures occurring in the first year of life.


Assuntos
Defeitos Congênitos da Glicosilação/genética , Criança , Pré-Escolar , Defeitos Congênitos da Glicosilação/enzimologia , Dolicóis/química , Feminino , Glicosilação , Humanos , Masculino , Manosiltransferases/genética , Oligossacarídeos/química , Oligossacarídeos/metabolismo
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