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1.
Phys Rev Lett ; 126(12): 125101, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33834792

RESUMO

Multipoint in situ observations of the solar wind are used to identify the magnetic topology and current density of turbulent structures. We find that at least 35% of all structures are both actively evolving and carrying the strongest currents, actively dissipating, and heating the plasma. These structures are comprised of ∼1/5 3D plasmoids, ∼3/5 flux ropes, and ∼1/5 3D X points consistent with magnetic reconnection. Actively evolving and passively advecting structures are both close to log-normally distributed. This provides direct evidence for the significant role of strong turbulence, evolving via magnetic shearing and reconnection, in mediating dissipation and solar wind heating.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33746555

RESUMO

The use of air sensor technology is increasing worldwide for a variety of applications, however, with significant variability in data quality. The United States Environmental Protection Agency held a workshop in July 2019 to deliberate possible performance targets for air sensors measuring particles with aerodynamic diameters of 10 µm or less (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide (SO2). These performance targets were discussed from the perspective of non-regulatory applications and with the sensors operating primarily in a stationary mode in outdoor environments. Attendees included representatives from multiple levels of government organizations, sensor developers, environmental nonprofits, international organizations, and academia. The workshop addressed the current lack of sensor technology requirements, discussed fit-for-purpose data quality needs, and debated transparency issues. This paper highlights the purpose and key outcomes of the workshop. While more information on performance and applications of sensors is available than in past years, the performance metrics, or parameters used to describe data quality, vary among the studies reports and there is a need for more clear and consistent approaches for evaluating sensor performance. Organizations worldwide are increasingly considering, or are in the process of developing, sensor performance targets and testing protocols. Workshop participants suggested that these new guidelines are highly desirable, would help improve data quality, and would give users more confidence in their data. Given the wide variety of uses for sensors and user backgrounds, as well as varied sensor design features (e.g., communication approaches, data tools, processing/adjustment algorithms and calibration procedures), the need for transparency was a key workshop theme. Suggestions for increasing transparency included documenting and sharing testing and performance data, detailing best practices, and sharing data processing and correction approaches.

3.
Clin Genet ; 93(2): 365-367, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28542865

RESUMO

There is a broad phenotypic spectrum of patients with 17p13.3 deletions. One of the most prominent feature is lissencephaly caused by haploinsufficiency of the gene PAFAH1B1. The deletion of this gene and those distal to it, results in Miller-Dieker syndrome, however there have been many reports of patients with haploinsufficiency of the distal genes alone. The deletions of these genes including YWHAE CRK and TUSC5 have been studied extensively and YWHAE has been postulated to be the cause of neurological abnormalities. The patients with deletions of the Miller-Dieker syndrome distal region present with variable clinical features including brain abnormalities, growth retardation, developmental delay, facial dysmorphisms and seizures. While there have been many patients reported to have deletions involving the YWHAE gene along with other genes, here we present the first detailed clinical description of a patient with deletion of YWHAE alone, allowing a more accurate characterization of the pathogenicity of YWHAE haploinsufficiency. The patient reported here demonstrated brain abnormalities, learning disabilities, and seizures supporting the role of YWHAE in these features. We review the literature and use this case report to better characterize and further confirm the genotype-phenotype relationship of the genes within the critical region of Miller-Dieker Syndrome.


Assuntos
Proteínas 14-3-3/genética , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/genética , Deficiência Intelectual/genética , Deficiências da Aprendizagem/genética , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Adulto , Encéfalo/anormalidades , Encéfalo/patologia , Criança , Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/fisiopatologia , Hibridização Genômica Comparativa , Feminino , Haploinsuficiência , Humanos , Deficiência Intelectual/patologia , Deficiências da Aprendizagem/fisiopatologia , Masculino , Proteínas de Membrana/genética , Proteínas Supressoras de Tumor/genética
4.
Transfus Med ; 25(4): 234-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26190553

RESUMO

An important element in the development of voluntary blood donation schemes throughout the world has been the attention given to minimising the risk to recipients of donated blood, primarily the risk of transfusion transmitted infections. In response to the appearance of human immunodeficiency virus (HIV) in the 1980s a range of national policies emerged that excluded populations at high risk of contracting HIV from donating blood, with a particular focus on men who have sex with men (MSM), the primary reason being the protection of recipients of donated blood. Recently some countries, including the UK, have revised their policies, informed by advances in screening tests, epidemiological evidence of transmission rates and an increasing concern about unfair discrimination of specific groups in society. Policy makers face a difficult task of balancing safety of recipients; an adequate blood supply for those who require transfusion; and societal/legal obligations to treat everyone fairly. Given that no transfusion is risk free, the question is what degree of risk is acceptable in order to meet the needs of recipients and society. Decisions about acceptance of risk are complex and policy makers who set acceptable risk levels must provide ethically justifiable reasons for their decisions. We suggest it is possible to provide a set of reasons that stakeholders could agree are relevant based on careful evaluation of the evidence of all relevant risks and explicit acknowledgement of other morally relevant values. We describe using such a process in the Safety of Blood Tissue and Organs (SaBTO) review of donor deferral criteria related to sexual behaviour.


Assuntos
Doadores de Sangue , Seleção do Doador/normas , Doadores de Sangue/ética , Segurança do Sangue/ética , Segurança do Sangue/normas , Patógenos Transmitidos pelo Sangue , Canadá , Seleção do Doador/ética , Ética , Europa (Continente) , Feminino , Política de Saúde , Humanos , Controle de Infecções/normas , Masculino , Risco , Medição de Risco , Gestão de Riscos , Assunção de Riscos , Comportamento Sexual , Justiça Social , Valores Sociais , Reino Unido
5.
Animal ; 9(3): 534-43, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25407839

RESUMO

In New Zealand, agriculture is predominantly based on pastoral grazing systems and animal excreta deposited on soil during grazing have been identified as a major source of nitrous oxide (N2O) emissions. Forage brassicas (Brassica spp.) have been increasingly used to improve lamb performance. Compared with conventional forage perennial ryegrass (Lolium perenne L.), a common forage in New Zealand, forage brassicas have faster growth rates, higher dry matter production and higher nutritive value. The aim of this study was to determine the partitioning of dietary nitrogen (N) between urine and dung in the excreta from sheep fed forage brassica rape (B. napus subsp. oleifera L.) or ryegrass, and then to measure N2O emissions when the excreta from the two different feed sources were applied to a pasture soil. A sheep metabolism study was conducted to determine urine and dung-N outputs from sheep fed forage rape or ryegrass, and N partitioning between urine and dung. Urine and dung were collected and then used in a field plot experiment for measuring N2O emissions. The experimental site contained a perennial ryegrass/white clover pasture on a poorly drained silt-loam soil. The treatments included urine from sheep fed forage rape or ryegrass, dung from sheep fed forage rape or ryegrass, and a control without dung or urine applied. N2O emission measurements were carried out using a static chamber technique. For each excreta type, the total N2O emissions and emission factor (EF3; N2O-N emitted during the 3- or 8-month measurement period as a per cent of animal urine or dung-N applied, respectively) were calculated. Our results indicate that, in terms of per unit of N intake, a similar amount of N was excreted in urine from sheep fed either forage rape or ryegrass, but less dung N was excreted from sheep fed forage rape than ryegrass. The EF3 for urine from sheep fed forage rape was lower compared with urine from sheep fed ryegrass. This may have been because of plant secondary metabolites, such as glucosinolates in forage rape and their degradation products, are transferred to urine and affect soil N transformation processes. However, the difference in the EF3 for dung from sheep fed ryegrass and forage rape was not significant.


Assuntos
Brassica napus/metabolismo , Dieta/veterinária , Fezes/química , Lolium/metabolismo , Óxido Nitroso/análise , Carneiro Doméstico/metabolismo , Agricultura/métodos , Animais , Nova Zelândia , Nitrogênio/metabolismo , Óxido Nitroso/urina , Valor Nutritivo/fisiologia , Ovinos
6.
Lung ; 192(5): 749-58, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24907066

RESUMO

BACKGROUND: Lung cancer remains a major disease burden in Victoria (Australia) and requires a complex and multidisciplinary approach to ensure optimal care and outcomes. To date, no uniform mechanism is available to capture standardized population-based outcomes and thereby provide benchmarking. The establishment of such a data platform is, therefore, a primary requisite to enable description of process and outcome in lung cancer care and to drive improvement in the quality of care provided to individuals with lung cancer. MATERIALS AND METHODS: A disease quality registry pilot has been established to capture prospective data on all adult patients with clinical or tissue diagnoses of small cell and non-small cell lung cancer. Steering and management committees provide clinical governance and supervise quality indicator selection. Quality indicators were selected following extensive literature review and evaluation of established clinical practice guidelines. A minimum dataset has been established and training and data capture by data collectors is facilitated using a web-based portal. Case ascertainment is established by regular institutional reporting of ICD-10 discharge coding. Recruitment is optimized by provision of opt-out consent. RESULTS: The collection of a standardized minimum data set optimizes capacity for harmonized population-based data capture. Data collection has commenced in a variety of settings reflecting metropolitan and rural, and public, and private health care institutions. The data set provides scope for the construction of a risk-adjusted model for outcomes. A data access policy and a mechanism for escalation policy for outcome outliers has been established. CONCLUSIONS: The Victorian Lung Cancer Registry provides a unique capacity to provide and confirm quality assessment in lung cancer and to drive improvement in quality of care across multidisciplinary stakeholders.


Assuntos
Benchmarking/normas , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Avaliação de Processos e Resultados em Cuidados de Saúde/normas , Melhoria de Qualidade/normas , Indicadores de Qualidade em Assistência à Saúde/normas , Sistema de Registros/normas , Carcinoma de Pequenas Células do Pulmão/terapia , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidade , Projetos Piloto , Carcinoma de Pequenas Células do Pulmão/diagnóstico , Carcinoma de Pequenas Células do Pulmão/mortalidade , Fatores de Tempo , Resultado do Tratamento , Vitória/epidemiologia
7.
Lab Chip ; 14(8): 1469-76, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24615248

RESUMO

Microfluidic devices based on the Coulter principle require a small aperture for cell counting. For applications using such cell counting devices, the volume of the sample also needs to be metered to determine the absolute cell count in a specific volume. Hence, integrated methods to characterize and meter the volume of a fluid are required in these microfluidic devices. Here, we present fluid flow characterization and electrically-based sample metering results of blood through a measurement channel with a cross-section of 15 µm × 15 µm (i.e. the Coulter aperture). Red blood cells in whole blood are lysed and the remaining fluid, consisting of leukocytes, erythrocyte cell lysate and various reagents, is flown at different flow rates through the measurement aperture. The change in impedance across the electrodes embedded in the counting channel shows a linear relationship with the increase in the fluid flow rate. We also show that the fluid volume can be determined by measuring the decrease in pulse width, and increase in number of cells as they pass through the counting channel per unit time.


Assuntos
Contagem de Células/métodos , Eletricidade , Técnicas Analíticas Microfluídicas/métodos , Eritrócitos/citologia , Humanos , Modelos Teóricos
8.
Philos Trans A Math Phys Eng Sci ; 371(1991): 20120287, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23588048

RESUMO

Climate sensitivity is commonly taken to refer to the equilibrium change in the annual mean global surface temperature following a doubling of the atmospheric carbon dioxide concentration. Evaluating this variable remains of significant scientific interest, but its global nature makes it largely irrelevant to many areas of climate science, such as impact assessments, and also to policy in terms of vulnerability assessments and adaptation planning. Here, we focus on local changes and on the way observational data can be analysed to inform us about how local climate has changed since the middle of the nineteenth century. Taking the perspective of climate as a constantly changing distribution, we evaluate the relative changes between different quantiles of such distributions and between different geographical locations for the same quantiles. We show how the observational data can provide guidance on trends in local climate at the specific thresholds relevant to particular impact or policy endeavours. This also quantifies the level of detail needed from climate models if they are to be used as tools to assess climate change impact. The mathematical basis is presented for two methods of extracting these local trends from the data. The two methods are compared first using surrogate data, to clarify the methods and their uncertainties, and then using observational surface temperature time series from four locations across Europe.

9.
Artigo em Inglês | MEDLINE | ID: mdl-23366620

RESUMO

We have developed a microfabricated chip that creates a purified white blood cell (WBC) population from whole blood samples and then electrically analyzes the WBCs at the same time as measuring sample volume flown. The flow metering is based on the measurement of the electrical admittance between microelectrodes inside a microfluidic channel. We found that the admittance related to the flow rate linearly. WBC counts which correlated with the flow rate shows how this technique is a viable method in metering and analyzing blood and other biological samples in a point-of-care environment.


Assuntos
Microfluídica/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito , Fluxo Sanguíneo Regional , Eletrodos , Humanos , Contagem de Leucócitos
10.
Int J Biochem Cell Biol ; 44(2): 393-403, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22138224

RESUMO

The membrane associated MMP, MT1-MMP, is a critical pericellular protease involved in tumour cell invasion and angiogenesis and is highly up-regulated in numerous human cancers. It therefore represents an exciting new therapeutic cancer-specific target. We have generated recombinant human scFv antibodies against the non-catalytic, hemopexin domain of MT1-MMP that modulate its interactions with collagen. One of these is an effective inhibitor of the invasive capacity of cancer cells and of angiogenesis in model systems. This demonstrates that targeting sites outside the catalytic domain presents a potential novel approach to proteinase inhibition that could have applications in cancer therapeutics.


Assuntos
Hemopexina/imunologia , Metaloproteinase 14 da Matriz/imunologia , Inibidores de Metaloproteinases de Matriz , Anticorpos de Cadeia Única/farmacologia , Linhagem Celular Tumoral , Colágeno/química , Colágeno/metabolismo , Hemopexina/química , Humanos , Metaloproteinase 14 da Matriz/química , Estrutura Terciária de Proteína , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/isolamento & purificação
12.
13.
Phys Rev E Stat Nonlin Soft Matter Phys ; 79(4 Pt 1): 041124, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19518190

RESUMO

Lévy flights and fractional Brownian motion have become exemplars of the heavy-tailed jumps and long-ranged memory widely seen in physics. Natural time series frequently combine both effects, and linear fractional stable motion (lfsm) is a model process of this type, combining alpha-stable jumps with a memory kernel. In contrast complex physical spatiotemporal diffusion processes where both the above effects compete have for many years been modeled using the fully fractional kinetic equation for the continuous-time random walk (CTRW), with power laws in the probability density functions of both jump size and waiting time. We derive the analogous kinetic equation for lfsm and show that it has a diffusion coefficient with a power law in time rather than having a fractional time derivative like the CTRW. We discuss some preliminary results on the scaling of burst "sizes" and "durations" in lfsm time series, with applications to modeling existing observations in space physics and elsewhere.

14.
Phys Rev E Stat Nonlin Soft Matter Phys ; 79(3 Pt 2): 036109, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19392020

RESUMO

The accurate estimation of scaling exponents is central in the observational study of scale-invariant phenomena. Natural systems unavoidably provide observations over restricted intervals; consequently, a stationary stochastic process (time series) can yield anomalous time variation in the scaling exponents, suggestive of nonstationarity. The variance in the estimates of scaling exponents computed from an interval of N observations is known for finite variance processes to vary as approximately 1N as N-->infinity for certain statistical estimators; however, the convergence to this behavior will depend on the details of the process, and may be slow. We study the variation in the scaling of second-order moments of the time-series increments with N for a variety of synthetic and "real world" time series, and we find that in particular for heavy tailed processes, for realizable N , one is far from this approximately 1N limiting behavior. We propose a semiempirical estimate for the minimum N needed to make a meaningful estimate of the scaling exponents for model stochastic processes and compare these with some "real world" time series.

15.
Neuroscience ; 159(3): 1079-88, 2009 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-19272339

RESUMO

Functional studies suggest that nitric oxide (NO) modulates sympathetic outflow by enhancing synaptic GABAergic function. Furthermore, the paraventricular nucleus of the hypothalamus (PVN), an important site for autonomic and endocrine homeostasis constitutes an important center mediating NO actions on sympathetic outflow. However, the exact anatomical organization of GABA and NO releasing neurons with the PVN neurons that regulate autonomic activity is poorly understood. The present study addressed this by identifying PVN-presympathetic neurons in the rat with the retrograde tracer Fluorogold injected into T2 segment of the spinal cord or herpes simplex virus injected into the adrenal medulla (AM). GABAergic or nitric oxide cell bodies were identified by antibodies directed towards GABA or glutamate decarboxylase (GAD67) enzyme or neuronal nitric oxide synthase. This revealed a population of GABAergic neurons to be synaptically associated with a chain of pre-sympathetic neurons targeting the AM. Furthermore, this GABAergic population is not a cellular source of NO. Within the PVN, the majority of cellular nitric oxide was localized to non-spinally projecting neurons while for the PVN-spinally projecting neuronal pool only a minority of neuron were immunopositive for neuronal nitric oxide synthase. In summary, nitrergic and GABAergic neurons are associated with a hierarchical chain of neurons that regulate autonomic outflow. This anatomical arrangement supports the known function role of a NO-GABA modulation of sympathetic outflow.


Assuntos
Núcleos da Linha Média do Tálamo/anatomia & histologia , Núcleos da Linha Média do Tálamo/metabolismo , Neurônios/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Ácido gama-Aminobutírico/metabolismo , Medula Suprarrenal/anatomia & histologia , Animais , Glutamato Descarboxilase/metabolismo , Proteínas de Fluorescência Verde , Imuno-Histoquímica , Fotomicrografia , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Simplexvirus , Medula Espinal/anatomia & histologia
16.
J Thromb Haemost ; 6(2): 366-75, 2008 02.
Artigo em Inglês | MEDLINE | ID: mdl-18045240

RESUMO

BACKGROUND: The single-nucleotide polymorphism (SNP) rs5918 in the ITGB3 gene defines the human platelet antigen-1 (HPA-1) system encoding a Leu (HPA-1a) or Pro (HPA-1b) at position 33. HPA-1 antibodies are clinically the most relevant in the Caucasoid population, but detection currently requires alpha(IIb)beta3 integrin from the platelets of HPA-genotyped donors. OBJECTIVES: We set out to define the beta3 integrin domains required for HPA-1a antibody binding and produce recombinant soluble beta3 peptides for HPA-1 antibody detection. METHODS: We designed two sets (1a and 1b) of four soluble beta3 domain-deletion peptides (deltaSDL, deltabetaA, PSIHybrid, PSI), informed by crystallography studies and computer modeling. The footprints of three human HPA-1a-specific phage antibodies were defined by analyzing binding patterns to the beta3 peptides and canine platelets, and models of antibody-antigen interfaces were derived. Specificity and sensitivity for HPA-1a detection were assessed using sera from 140 cases of fetomaternal alloimmune thrombocytopenia (FMAIT). RESULTS: Fusion of recombinant proteins to calmodulin resulted in high-level expression in Drosophila S2 cells of all eight beta3 peptides. Testing of FMAIT samples indicated that deltabetaA-Leu33 is the superior peptide for HPA-1a antibody detection, with 96% sensitivity and 95% specificity. The existence of type I and II categories of HPA-1a antibodies was confirmed by the study of HPA-1a phage antibody footprints and the reactivity pattern of clinical samples with the four beta3-Leu33 peptides, but there was no correlation between antibody category and clinical severity of FMAIT. CONCLUSIONS: Soluble recombinant beta3 peptides can be used for detection of clinical HPA-1a antibodies.


Assuntos
Antígenos de Plaquetas Humanas/imunologia , Epitopos/imunologia , Integrina beta3/imunologia , Isoanticorpos/imunologia , Trombocitopenia Neonatal Aloimune/imunologia , Animais , Reações Antígeno-Anticorpo , Antígenos de Plaquetas Humanas/química , Antígenos de Plaquetas Humanas/genética , Plaquetas/metabolismo , Cães , Ensaio de Imunoadsorção Enzimática , Epitopos/química , Feminino , Humanos , Recém-Nascido , Integrina beta3/química , Integrina beta3/genética , Hemorragias Intracranianas/etiologia , Hemorragias Intracranianas/imunologia , Isoanticorpos/sangue , Isoanticorpos/química , Modelos Moleculares , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/química , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/imunologia , Polimorfismo de Nucleotídeo Único , Gravidez , Ligação Proteica , Conformação Proteica , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/imunologia , Deleção de Sequência , Trombocitopenia Neonatal Aloimune/diagnóstico
17.
J Thromb Haemost ; 6(2): 376-83, 2008 02.
Artigo em Inglês | MEDLINE | ID: mdl-18031296

RESUMO

BACKGROUND: Antibodies against human platelet antigens (HPA) are clinically important in fetal-maternal alloimmune thrombocytopenia, refractoriness to platelet transfusions and post-transfusion purpura. Of the 16 HPAs, nine are located on the beta3 subunit of the alphaIIb beta3 integrin. Antibody detection is generally based on platelet-derived alphaIIb beta3 from HPA-genotyped donors. Recombinant allelic beta3 peptides, expressed at high levels would improve consistency in antibody detection, but the expression of soluble and monomeric integrins expressing complex dependent epitopes has previously proved challenging. OBJECTIVES: We aimed to generate three recombinant beta3 peptides for the detection of antibodies against HPA-4, HPA-8bw and five of the six remaining low frequency beta3 alloantigens. METHODS: The removal of the specificity-determining loop from the betaA domain and fusion of truncated beta3 to calmodulin was exploited to obtain expression of monomeric protein. Using site-directed mutagenesis, the mutations for HPA-4b and HPA-8bw were introduced in the ITGB3*001 haplotype. A third peptide for the detection of antibodies against HPA coded by non-synonymous single nucleotide polymorphisms of low frequency was generated by the introduction of five mutations forming the basis of HPA-6bw, -7bw, -10bw, -11bw, and -16bw antigens. RESULTS: Reactivity of the three peptides with beta3-specific murine monoclonal antibodies and human HPA-1a phage antibodies confirmed the structural integrity of the recombinant fragments, and reactivity with a unique panel of polyclonal anti-HPA sera confirmed expression of the relevant HPA epitopes. CONCLUSIONS: These data demonstrate that beta3 integrin domain-deletion fragments are suitable molecular targets for HPA antibody detection.


Assuntos
Antígenos de Plaquetas Humanas/imunologia , Epitopos/imunologia , Integrina beta3/imunologia , Isoanticorpos/imunologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/imunologia , Trombocitopenia Neonatal Aloimune/imunologia , Animais , Anticorpos Monoclonais/imunologia , Reações Antígeno-Anticorpo , Antígenos de Plaquetas Humanas/química , Antígenos de Plaquetas Humanas/genética , Plaquetas/metabolismo , Epitopos/química , Feminino , Humanos , Recém-Nascido , Integrina beta3/química , Integrina beta3/genética , Isoanticorpos/sangue , Isoanticorpos/química , Camundongos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/química , Polimorfismo de Nucleotídeo Único , Gravidez , Ligação Proteica , Conformação Proteica , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/imunologia , Deleção de Sequência , Trombocitopenia Neonatal Aloimune/diagnóstico
18.
Vox Sang ; 93(4): 325-30, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18070277

RESUMO

BACKGROUND AND OBJECTIVES: Fetomaternal alloimmune thrombocytopenia (FMAIT) is caused by maternal antibodies against a human platelet antigen (HPA) present on fetal, but absent from maternal platelets. We identified and characterized a case of FMAIT due to anti-HPA-1a in a mother with an HPA-1a1b genotype. MATERIALS AND METHODS: The first child of a 29-year-old mother presented with a petechial rash and a platelet count of 8 x 10(9) per l. Upon routine serological investigation, a discrepancy between the HPA-1a genotype and phenotype prompted the sequencing of the 15 exons of the ITGB3 (integrin beta3, GPIIIa and CD61) gene in the mother. RESULTS: The mother was genotypically HPA-1a1b heterozygous but phenotyped as HPA-1a negative. Sequencing of the ITGB3 exons confirmed HPA-1a1b heterozygosity, but also identified a novel single nucleotide insertion in exon 10 leading to a frameshift and premature termination at amino acid 471 of ITGB3. Maternal anti-HPA-1a was detected but with a pattern typical for a low-affinity antibody. Three transfusions of HPA-1a and -5b negative neonatal platelet concentrates were required to return to a safe platelet count. CONCLUSION: A rare ITGB3 allele was uncovered by the investigation of a severe case of alloimmune thrombocytopenia in a mother with HPA-1a antibodies who genotyped as HPA-1a1b.


Assuntos
Antígenos de Plaquetas Humanas/imunologia , Trombocitopenia Neonatal Aloimune/diagnóstico , Trombocitopenia Neonatal Aloimune/imunologia , Adulto , Sequência de Bases , Análise Mutacional de DNA , Feminino , Triagem de Portadores Genéticos/métodos , Genótipo , Humanos , Recém-Nascido , Integrina beta3 , Isoanticorpos/análise , Isoanticorpos/imunologia , Fenótipo , Transfusão de Plaquetas , Gravidez , Trombocitopenia Neonatal Aloimune/terapia
19.
Neuroscience ; 150(2): 487-97, 2007 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-17942240

RESUMO

Neurones in the lumbosacral spinal cord are known to play a significant role in ejaculation. In these same areas neurones containing nitric oxide synthase (NOS) have been described. This raised the question as to whether there is a physiological role for nitrous oxide (NO) in the spinal cord in sexual behavior. We first established immunohistochemical localization of NOS positive neurones in the lumbosacral spinal cord. NOS positive neurones were found in several areas of the lumbosacral cord. Namely the intermediolateral column (IML) at L(1)-L(4) and sacral cord; the dorsal gray commissure above the central canal at L(1)-L(2); the ventral gray area of lamina X below the central canal at L(3)-L(4); the superficial laminae of the dorsal horn at all levels. Secondly, we examined the role of NO in the generation of synchronized bursting activity within the vas deferens nerve and associated penile muscles, typical of sexual responses in the male anesthetized rat. NO modulators were applied directly to the spinal cord at T(13)-L(4) via a catheter placed subdurally (intrathecal) and their effect on the genital responses evoked by systemic administration of p-chloroamphetamine (PCA) or apomorphine (apo) (both 1 mg/kg) was observed. All responses evoked by PCA (n=4) or apo (n=3) were abolished or reduced (n=1) during intrathecal NOS inhibition using N((G)) nitro-L-Arginine methyl ester (l-NAME, 200 mM, 20-microl). NOS inhibition using l-NAME was reversed with simultaneous intrathecal application of the NO substrate l-arginine (100 mM, 20-microl, n=3). The selective neuronal NOS inhibitor 1-(2-trifluoro-methylphenyl) imidazole (100 mM, 20-microl, TRIM) also abolished all responses evoked by PCA (n=3). There was evidence that the responses within the vas deferens nerve (VDN) after PCA or apo were enhanced following NO donation using sodium nitroprusside (SNP, 1 mM, 20-microl). Furthermore, a PCA-like response within the VDN was evoked following intrathecally applied l-glutamic acid (200 mM, 20-microl) in six of 26 animals and also by intrathecal SNP in two of eight animals. In conclusion the results suggest a significant excitatory role for NO in the bursting pattern of synchronized discharge generated in autonomic and somatic outflows from the lumbosacral cord by neurones governing ejaculation.


Assuntos
Ejaculação/fisiologia , Músculo Esquelético/inervação , Neurônios/metabolismo , Óxido Nítrico/fisiologia , Medula Espinal/metabolismo , Sistema Nervoso Simpático/metabolismo , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Agonistas de Dopamina/farmacologia , Ejaculação/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Ácido Glutâmico/farmacologia , Imuno-Histoquímica , Injeções Espinhais , Masculino , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Músculo Esquelético/fisiologia , Rede Nervosa/anatomia & histologia , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/metabolismo , Neurônios/efeitos dos fármacos , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/análise , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Células do Corno Posterior/efeitos dos fármacos , Células do Corno Posterior/metabolismo , Ratos , Ratos Wistar , Medula Espinal/anatomia & histologia , Medula Espinal/efeitos dos fármacos , Fibras Simpáticas Pós-Ganglionares/metabolismo , Sistema Nervoso Simpático/anatomia & histologia , Sistema Nervoso Simpático/efeitos dos fármacos , Ducto Deferente/inervação , Ducto Deferente/fisiologia
20.
J Thromb Haemost ; 4(6): 1197-205, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16706959

RESUMO

BACKGROUND: Common genetic variants of cell surface receptors contribute to differences in functional responses and disease susceptibility. We have previously shown that single nucleotide polymorphisms (SNPs) in platelet glycoprotein VI (GP6) determine the extent of response to agonist. In addition, SNPs in the GP6 gene have been proposed as risk factors for coronary artery disease. METHODS: To completely characterize genetic variation in the GP6 gene we generated a high-resolution SNP map by sequencing the promoter, exons and consensus splice sequences in 94 non-related Caucasoids. In addition, we sequenced DNA encoding the ligand-binding domains of GP6 from non-human primates to determine the level of evolutionary conservation. RESULTS: Eighteen SNPs were identified, six of which encoded amino acid substitutions in the mature form of the protein. The single non-synonymous SNP identified in the exons encoding the ligand-binding domains, encoding for a 103Leu > Val substitution, resulted in reduced ligand binding. Two common protein isoforms were confirmed in Caucasoid with frequencies of 0.82 and 0.15. Variation at the GP6 locus was characterized further by determining SNP frequency in over 2000 individuals from different ethnic backgrounds. CONCLUSIONS: The SNPs were polymorphic in all populations studied although significant differences in allele frequencies were observed. Twelve additional GP6 protein isoforms were identified from the genotyping results and, despite extensive variation in GP6, the sequence of the ligand-binding domains is conserved. Sequences from non-human primates confirmed this observation. These data provide valuable information for the optimal selection of genetic variants for use in future association studies.


Assuntos
Éxons , Frequência do Gene , Glicoproteínas da Membrana de Plaquetas/genética , Polimorfismo de Nucleotídeo Único , Sequência de Aminoácidos , Animais , Plaquetas/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular , Drosophila/genética , Genótipo , Haplótipos , Humanos , Desequilíbrio de Ligação , Dados de Sequência Molecular , Peptídeos/metabolismo , Glicoproteínas da Membrana de Plaquetas/metabolismo , Primatas/genética , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA
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