Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Pediatr Cardiol ; 39(4): 665-673, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29307026

RESUMO

A right aortic arch (RAA) with a left arterial duct (LAD) together encircle the trachea and have the potential to cause tracheobronchial compression and published guidelines recommend bronchoscopy in symptomatic patients. The aim of the study was to describe the incidence of tracheal compression in a cohort of prenatally diagnosed RAA and LAD. Retrospective review of clinical course and imaging of prenatal cases of RAA and LAD assessed with flexible bronchoscopy over an 11-year period. 34 cases of prenatally diagnosed RAA with LAD underwent bronchoscopy at median age of 9 months (range 0.4-123) of whom 11 had respiratory symptoms and 23 were asymptomatic. In the neonatal period, three cases demonstrated respiratory symptoms. An aberrant left subclavian artery (ALSA) was identified in 29 cases. Pulsatile tracheal compression was identified in 32/34 (94%) cases and two cases showed normal tracheal appearances. Significant tracheal compression (> 70% occlusion) was present in 25/34 (74%) cases of which 16 were asymptomatic. Significant carinal compression (> 70% occlusion) was identified in 14/34 (42%) cases, an ALSA was observed in 13/14. Surgical relief of a vascular ring has been performed in 27 (79%) cases at a median age of 15 months (range 0.6-128 months). At surgery, a fibrous remnant of an atretic left aortic arch was identified in 11/27 (41%) cases. Significant tracheal compression may be present in infants even without symptoms. If early relief of airway compression is to be achieved to promote normal development of tracheal cartilage, early bronchoscopy should be considered.


Assuntos
Síndromes do Arco Aórtico/complicações , Broncoscopia/métodos , Doenças da Traqueia/epidemiologia , Aneurisma/complicações , Aorta Torácica/anormalidades , Síndromes do Arco Aórtico/diagnóstico , Anormalidades Cardiovasculares/complicações , Criança , Pré-Escolar , Canal Arterial/anormalidades , Feminino , Humanos , Incidência , Lactente , Masculino , Gravidez , Diagnóstico Pré-Natal/métodos , Estudos Retrospectivos , Artéria Subclávia/anormalidades , Traqueia/patologia , Doenças da Traqueia/diagnóstico , Doenças da Traqueia/etiologia
2.
Echocardiography ; 34(4): 587-593, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28191731

RESUMO

BACKGROUND: Quantitative echocardiographic assessment of right ventricular function is important in children with hypoplastic left heart syndrome (HLHS). The aim of this study was to examine the repeatability of different echocardiographic techniques, both manual and automated, to measure fractional area change (FAC) in patients with HLHS and to correlate these measurements with magnetic resonance imaging (MRI)-derived ejection fraction (EF). METHODS: Fifty-one children with HLHS underwent transthoracic echocardiography and cardiac MRI under the same general anesthetic as part of routine inter-stage assessment. FAC was measured from the apical four-chamber view using three different techniques: velocity vector imaging (VVI) (Syngo USWP 3.0; Siemens Healthineers), QLAB (Q-lab R 10.0; Philips Healthcare), and manual endocardial contour tracing (Xcelera, Philips Healthcare). Intra- and inter-observer variability was calculated using intra-class correlation coefficient (ICC). FAC was correlated with MRI EF calculated using a single standard method. RESULTS: Fractional area change had a good correlation with MRI-derived EF with an R value for VVI, QLAB, and manual methods of .7, .6, and .4, respectively. Intra- and inter-observer variability for FAC was good for automated echocardiographic methods (ICC>.85) but worse for manual method particularly inter-observer variability of FAC and end-systolic area. Both automated techniques tended to produce higher FAC values compared with manual measurements (P<.001). CONCLUSION: Automation improves the repeatability of FAC in HLHS. There are some differences between automated software in terms of correlation with MRI-derived EF. Measurement bias and wide limits of agreement mean that the same echocardiographic technique should be used during the follow-up of individual patients.


Assuntos
Ecocardiografia/métodos , Síndrome do Coração Esquerdo Hipoplásico/complicações , Processamento de Imagem Assistida por Computador/métodos , Disfunção Ventricular Direita/complicações , Disfunção Ventricular Direita/diagnóstico por imagem , Adolescente , Criança , Pré-Escolar , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Síndrome do Coração Esquerdo Hipoplásico/fisiopatologia , Lactente , Imageamento por Ressonância Magnética , Masculino , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Software , Disfunção Ventricular Direita/fisiopatologia
3.
Cardiol Young ; 27(1): 131-138, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27055807

RESUMO

Introduction The hybrid procedure is one mode of initial palliation for hypoplastic left heart syndrome. Subsequently, patients proceed with either the "three-stage" pathway - comprehensive second stage followed by Fontan completion - or the "four-stage" pathway - Norwood procedure, hemi-Fontan, or Fontan completion. In this study, we describe somatic growth patterns observed in the hybrid groups and a comparison primary Norwood group. METHODS: A retrospective analysis of patients who have undergone hybrid procedure and Fontan completion was performed. Weight-for-age and height-for-age z-scores were recorded at each operation. RESULTS: We identified 13 hybrid patients - eight in the three-stage pathway and five in the four-stage pathway - and 49 Norwood patients. Weight: three stage: weight decreased from hybrid procedure to comprehensive second stage (-0.4±1.3 versus -2.3±1.4, p<0.01) and then increased to Fontan completion (-0.4±1.5 versus -0.6±1.4, p<0.01); four stage: weight decreased from hybrid procedure to Norwood (-2.0±1.4 versus -3.3±0.9, p=0.06), then stabilised to hemi-Fontan. Weight increased from hemi-Fontan to Fontan completion (-2.7±0.6 versus -1.0±0.7, p=0.01); primary Norwood group: weight decreased from Norwood to hemi-Fontan (p<0.001) and then increased to Fontan completion (p<0.001). Height: height declined from hybrid procedure to Fontan completion in the three-stage group. In the four-stage group, height decreased from hybrid to hemi-Fontan, and then increased to Fontan completion. The Norwood group decreased in height from Norwood to hemi-Fontan, followed by an increase to Fontan completion. CONCLUSION: In this study, we show that patients undergoing the hybrid procedure have poor weight gain before superior cavopulmonary connection, before returning to baseline by Fontan completion. This study identifies key periods to target poor somatic growth, a risk factor of morbidity and worse neurodevelopmental outcomes.


Assuntos
Desenvolvimento Infantil/fisiologia , Técnica de Fontan/métodos , Síndrome do Coração Esquerdo Hipoplásico/fisiopatologia , Procedimentos de Norwood/métodos , Cuidados Paliativos , Feminino , Seguimentos , Humanos , Síndrome do Coração Esquerdo Hipoplásico/cirurgia , Lactente , Masculino , Período Pós-Operatório , Estudos Retrospectivos , Resultado do Tratamento
4.
J Neurosci ; 35(1): 396-408, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25568131

RESUMO

Fragile X syndrome (FXS) is the leading cause of both intellectual disability and autism resulting from a single gene mutation. Previously, we characterized cognitive impairments and brain structural defects in a Drosophila model of FXS and demonstrated that these impairments were rescued by treatment with metabotropic glutamate receptor (mGluR) antagonists or lithium. A well-documented biochemical defect observed in fly and mouse FXS models and FXS patients is low cAMP levels. cAMP levels can be regulated by mGluR signaling. Herein, we demonstrate PDE-4 inhibition as a therapeutic strategy to ameliorate memory impairments and brain structural defects in the Drosophila model of fragile X. Furthermore, we examine the effects of PDE-4 inhibition by pharmacologic treatment in the fragile X mouse model. We demonstrate that acute inhibition of PDE-4 by pharmacologic treatment in hippocampal slices rescues the enhanced mGluR-dependent LTD phenotype observed in FXS mice. Additionally, we find that chronic treatment of FXS model mice, in adulthood, also restores the level of mGluR-dependent LTD to that observed in wild-type animals. Translating the findings of successful pharmacologic intervention from the Drosophila model into the mouse model of FXS is an important advance, in that this identifies and validates PDE-4 inhibition as potential therapeutic intervention for the treatment of individuals afflicted with FXS.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Modelos Animais de Doenças , Síndrome do Cromossomo X Frágil/enzimologia , Plasticidade Neuronal/fisiologia , Inibidores da Fosfodiesterase 4/farmacologia , Animais , Animais Geneticamente Modificados , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/genética , Drosophila , Feminino , Síndrome do Cromossomo X Frágil/tratamento farmacológico , Síndrome do Cromossomo X Frágil/genética , Masculino , Camundongos , Camundongos Knockout , Plasticidade Neuronal/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/uso terapêutico
5.
Front Pediatr ; 11: 1123939, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36999083

RESUMO

Background: Patent ductus arteriosus (PDA) and diaphragmatic dysfunction are frequently seen in newborn infants but their relationship remains unknown. We aimed to use point of care ultrasound to compare diaphragmatic kinetics in infants with a PDA compared to in those without a PDA. Methods: M-mode ultrasonography was used to measure the mean inspiratory velocity (V I) in newborn infants with and without a haemodynamically significant PDA admitted in the Neonatal Unit at King's College Hospital during a three month period. Results: Seventeen diaphragmatic ultrasound studies were reviewed from 14 infants with a median (IQR) gestational age of 26.1 (25.8-30.6) weeks, birth weight of 780 (660-1385) gr at a postnatal age of 18 (14-34) days. Eight scans had evidence of a PDA. The median (IQR) VI was significantly lower in scans with a PDA [1.01 (0.78-1.86) cm/s] compared to the ones without a PDA [3.21 (2.80-3.59) cm/s, p < 0.001]. The median (IQR) gestational age was lower in infants with a PDA [25.8 (25.6-27.3) weeks] compared to infants without a PDA [29.0 (26.1-35.1) weeks, p = 0.007]. Using multivariable linear regression analysis the VI was independently associated with a PDA (adjusted p < 0.001) but not with the gestational age (adjusted p = 0.659). Conclusions: Patent ductus arteriosus was associated with a lower mean inspiratory velocity in neonates and this effect was independent of gestational age.

6.
Ticks Tick Borne Dis ; 14(1): 102056, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36399958

RESUMO

Cytauxzoon felis is a tick-borne piroplasmid hemoparasite that causes life-threatening disease in cats. Despite the critical role that ticks play in pathogen transmission, our knowledge regarding the C. felis life cycle remains limited to the feline hosts. Specific life stages of C. felis within the tick host have never been visualized microscopically and previous investigations have been limited to molecular detection by polymerase chain reaction (PCR). Sporozoites are the infectious stage of piroplasmids that are transmitted by ticks. In other tick-borne piroplasmids, sporozoite-based vaccines play a key role in disease prevention and management. We believe sporozoites have similar potential for cytauxzoonosis. Therefore, the objective of this study was to use different molecular and microscopic techniques to detect and evaluate C. felis sporozoites in tick salivary glands (SG). A total of 140 Amblyomma americanum adults that were fed on C. felis-infected cats as nymphs were included for this study. Specifically, dissected SGs were quartered and subjected to C. felis RT-PCR, RNAscope® in situ hybridization (ISH), histology, direct azure staining, and transmission electron microscopy (TEM). Cytauxzoon felis RT-PCR was also performed on half tick (HT) carcasses after SG dissection. Cytauxzoon felis RNA was detected in SGs of 17/140 ticks. Of these, 7/17 ticks had microscopic visualization via ISH and/or TEM. The remaining 10/17 ticks had only molecular detection of C. felis in SGs via RT-PCR without visualization. Cytauxzoon felis RNA was detected solely in HT carcasses via RT-PCR in 9/140 ticks. In ISH-positive tick SGs, hybridization signals were present in cytoplasms of SG acinar cells. TEM captured rare C. felis organisms with characteristic ultrastructural features of sporozoites. This study describes the first direct visualization of any developing stage of C. felis in ticks. Forthcoming studies should employ a combination of molecular and microscopic techniques to investigate the C. felis life cycle in A. americanum.


Assuntos
Amblyomma , Glândulas Salivares , Gatos , Animais , Microscopia Eletrônica de Transmissão
7.
Radiology ; 263(2): 547-54, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22517963

RESUMO

PURPOSE: To identify which rest phase (systolic or diastolic) is optimum for assessing or measuring cardiac structures in the setting of three-dimensional (3D) whole-heart imaging in congenital heart disease (CHD). MATERIALS AND METHODS: The study was approved by the institutional review board; informed consent was obtained. Fifty children (26 male and 24 female patients) underwent 3D dual-phase whole-heart imaging. Cardiac structures were analyzed for contrast-to-noise ratio (CNR) and image quality. Cross-sectional measurements were taken of the aortic arch, right ventricular (RV) outflow tract (RVOT) and pulmonary arteries. Normally distributed variables were compared by using paired t tests, and categorical data were compared by using Wilcoxon signed-rank test. RESULTS: Mean CNR and image quality were significantly (all P < .05) greater in systole for the right atrium (CNR, 8.9 vs 7.5; image quality, 438 vs 91), left atrium (CNR, 8.0 vs 5.3; image quality, 1006 vs 29), RV (CNR, 10.6 vs 8.2; image quality, 131 vs 23), LV (CNR, 9.4 vs 7.7; image quality, 125 vs 28), and pulmonary veins (CNR, 6.2 vs 4.9; image quality, 914 vs 32). Conversely, diastolic CNR was significantly higher in the aorta (9.2 vs 8.2; P = .013) and diastolic image quality was higher for the left pulmonary artery (238 vs 62; P = .007), right pulmonary artery (219 vs 35; P < .001), and for imaging of an area after an arterial stenosis (164 vs 7; P < .001). All aortic arch and RVOT cross-sectional measurements were significantly (P < .05) greater in systole (narrowest point of arch, 70 vs 53 mm(2); descending aorta, 71 vs 58 mm(2); transverse arch, 293 vs 275 mm(2); valvar RVOT, 291 vs 268 mm(2); supravalvar RVOT, 337 vs 280 mm(2); prebifurcation RVOT, 329 vs 259 mm(2)). CONCLUSION: Certain structures in CHD are better imaged in systole and others in diastole, and therefore, the dual-phase approach allows a higher overall success rate. This approach also allows depiction of diameter changes between systole and diastole and is therefore preferable to standard single-phase sequences for the planning of interventional procedures.


Assuntos
Técnicas de Imagem de Sincronização Cardíaca/métodos , Cardiopatias Congênitas/diagnóstico , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Adolescente , Criança , Pré-Escolar , Diástole , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Lactente , Recém-Nascido , Masculino , Estatísticas não Paramétricas , Sístole
8.
J Neurosci ; 30(19): 6782-92, 2010 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-20463240

RESUMO

The diversity of protein isoforms arising from alternative splicing is thought to modulate fine-tuning of synaptic plasticity. Fragile X mental retardation protein (FMRP), a neuronal RNA binding protein, exists in isoforms as a result of alternative splicing, but the contribution of these isoforms to neural plasticity are not well understood. We show that two isoforms of Drosophila melanogaster FMRP (dFMR1) have differential roles in mediating neural development and behavior functions conferred by the dfmr1 gene. These isoforms differ in the presence of a protein interaction module that is related to prion domains and is functionally conserved between FMRPs. Expression of both isoforms is necessary for optimal performance in tests of short- and long-term memory of courtship training. The presence or absence of the protein interaction domain may govern the types of ribonucleoprotein (RNP) complexes dFMR1 assembles into, with different RNPs regulating gene expression in a manner necessary for establishing distinct phases of memory formation.


Assuntos
Proteínas de Drosophila/metabolismo , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Memória de Curto Prazo/fisiologia , Memória/fisiologia , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Sequência de Bases , Ritmo Circadiano/fisiologia , Análise Mutacional de DNA , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Proteína do X Frágil da Deficiência Intelectual/genética , Masculino , Dados de Sequência Molecular , Atividade Motora/fisiologia , Testes Neuropsicológicos , Isoformas de Proteínas/metabolismo , Comportamento Sexual Animal/fisiologia , Fatores de Tempo
9.
J Neurosci ; 30(28): 9510-22, 2010 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-20631179

RESUMO

Alzheimer's disease (AD) is the leading cause of cognitive loss and neurodegeneration in the developed world. Although its genetic and environmental causes are not generally known, familial forms of the disease (FAD) are attributable to mutations in a single copy of the Presenilin (PS) and amyloid precursor protein genes. The dominant inheritance pattern of FAD indicates that it may be attributable to gain or change of function mutations. Studies of FAD-linked forms of presenilin (psn) in model organisms, however, indicate that they are loss of function, leading to the possibility that a reduction in PS activity might contribute to FAD and that proper psn levels are important for maintaining normal cognition throughout life. To explore this issue further, we have tested the effect of reducing psn activity during aging in Drosophila melanogaster males. We have found that flies in which the dosage of psn function is reduced by 50% display age-onset impairments in learning and memory. Treatment with metabotropic glutamate receptor (mGluR) antagonists or lithium during the aging process prevented the onset of these deficits, and treatment of aged flies reversed the age-dependent deficits. Genetic reduction of Drosophila metabotropic glutamate receptor (DmGluRA), the inositol trisphosphate receptor (InsP(3)R), or inositol polyphosphate 1-phosphatase also prevented these age-onset cognitive deficits. These findings suggest that reduced psn activity may contribute to the age-onset cognitive loss observed with FAD. They also indicate that enhanced mGluR signaling and calcium release regulated by InsP(3)R as underlying causes of the age-dependent cognitive phenotypes observed when psn activity is reduced.


Assuntos
Cognição/fisiologia , Aprendizagem/fisiologia , Memória/fisiologia , Presenilinas/genética , Fatores Etários , Análise de Variância , Animais , Animais Geneticamente Modificados , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Cognição/efeitos dos fármacos , Corte , Drosophila melanogaster , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Aprendizagem/efeitos dos fármacos , Lítio/farmacologia , Masculino , Memória/efeitos dos fármacos , Corpos Pedunculados/metabolismo , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/metabolismo , Presenilinas/metabolismo , Distribuição Aleatória , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Receptores de Glutamato Metabotrópico/genética , Receptores de Glutamato Metabotrópico/metabolismo
10.
Cell Mol Life Sci ; 67(17): 2991-3004, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20386952

RESUMO

Metallocarboxypeptidase D (CPD) functions in protein and peptide processing. The Drosophila CPD svr gene undergoes alternative splicing, producing forms containing 1-3 active or inactive CP domains. To investigate the function of the various CP domains, we created transgenic flies expressing specific forms of CPD in the embryonic-lethal svr (PG33) mutant. All constructs containing an active CP domain rescued the lethality with varying degrees, and full viability required inactive CP domain-3. Transgenic flies overexpressing active CP domain-1 or -2 were similar to each other and to the viable svr mutants, with pointed wing shape, enhanced ethanol sensitivity, and decreased cold sensitivity. The transgenes fully compensated for a long-term memory deficit observed in the viable svr mutants. Overexpression of CP domain-1 or -2 reduced the levels of Lys/Arg-extended adipokinetic hormone intermediates. These findings suggest that CPD domains-1 and -2 have largely redundant functions in the processing of growth factors, hormones, and neuropeptides.


Assuntos
Proteínas de Drosophila/fisiologia , Fenótipo , Estrutura Terciária de Proteína/fisiologia , Proteínas/fisiologia , Processamento Alternativo/fisiologia , Animais , Animais Geneticamente Modificados , Drosophila , Proteínas de Drosophila/genética , Componentes do Gene , Memória/fisiologia , Estrutura Terciária de Proteína/genética , Proteínas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Asas de Animais/anatomia & histologia
11.
Biogerontology ; 11(3): 347-62, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20039205

RESUMO

Fragile X syndrome afflicts 1 in 2,500 individuals and is the leading heritable cause of mental retardation worldwide. The overriding clinical manifestation of this disease is mild to severe cognitive impairment. Age-dependent cognitive decline has been identified in Fragile X patients, although it has not been fully characterized nor examined in animal models. A Drosophila model of this disease has been shown to display phenotypes bearing similarity to Fragile X symptoms. Most notably, we previously identified naive courtship and memory deficits in young adults with this model that appear to be due to enhanced metabotropic glutamate receptor (mGluR) signaling. Herein we have examined age-related cognitive decline in the Drosophila Fragile X model and found an age-dependent loss of learning during training. We demonstrate that treatment with mGluR antagonists or lithium can prevent this age-dependent cognitive impairment. We also show that treatment with mGluR antagonists or lithium during development alone displays differential efficacy in its ability to rescue naive courtship, learning during training and memory in aged flies. Furthermore, we show that continuous treatment during aging effectively rescues all of these phenotypes. These results indicate that the Drosophila model recapitulates the age-dependent cognitive decline observed in humans. This places Fragile X in a category with several other diseases that result in age-dependent cognitive decline. This demonstrates a role for the Drosophila Fragile X Mental Retardation Protein (dFMR1) in neuronal physiology with regard to cognition during the aging process. Our results indicate that misregulation of mGluR activity may be causative of this age onset decline and strengthens the possibility that mGluR antagonists and lithium may be potential pharmacologic compounds for counteracting several Fragile X symptoms.


Assuntos
Envelhecimento/psicologia , Transtornos Cognitivos/tratamento farmacológico , Modelos Animais de Doenças , Animais , Animais Geneticamente Modificados , Comportamento Animal , Drosophila , Feminino , Aprendizagem , Masculino , Memória
12.
Cell Motil Cytoskeleton ; 66(8): 483-99, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19267341

RESUMO

Ciliary guanine nucleotide exchange factors (GEFs) potentially activate G proteins in intraflagellar transport (IFT) cargo release. Several classes of GEFs have been localized to cilia or basal bodies and shown to be functionally important in the prevention of ciliopathies, but ciliary Arl-type Sec 7 related GEFs have not been well characterized. Nair et al. [ 1999] identified a Paramecium ciliary Sec7 GEF, PSec7. In Tetrahymena, Gef1p (GEF1), tentatively identified by PSec7 antibody, possesses ciliary and nuclear targeting sequences and like PSec7 localizes to cilia and macronuclei. Upregulation of GEF1 RNA followed deciliation and subsequent ciliary regrowth. Corresponding to similar Psec7 domains, GEF1domains contain IQ-like motifs and putative PH domains, in addition to GBF/BIG canonical motifs. Genomic analysis identified two additional Tetrahymena GBF/BIG Sec7 family GEFs (GEF2, GEF3), which do not possess ciliary targeting sequences. GEF1 and GEF2 were HA modified to determine cellular localization. Cells transformed to produce appropriately truncated GEF1-HA showed localization to somatic and oral cilia, but not to macronuclei. Subtle defects in ciliary stability and function were detected. GEF2-HA localized near basal bodies but not to cilia. These results indicate that GEF1 is the resident Tetrahymena ciliary protein orthologous to PSec7. Cell Motil. Cytoskeleton 2009. (c) 2009 Wiley-Liss, Inc.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/metabolismo , Proteínas de Protozoários/metabolismo , Tetrahymena thermophila/metabolismo , Animais , Cílios/metabolismo , Imunofluorescência , Genoma de Protozoário , Fatores de Troca do Nucleotídeo Guanina/química , Fatores de Troca do Nucleotídeo Guanina/genética , Macronúcleo/metabolismo , Microscopia Imunoeletrônica , Estrutura Terciária de Proteína , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Tetrahymena thermophila/ultraestrutura
13.
Dev Biol ; 314(1): 150-60, 2008 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-18164285

RESUMO

Ciliated protozoa possess cellular axes reflected in the arrangement of their ciliature. Upon transverse fission, daughter cells develop an identical ciliary pattern, ensuring perpetuation of the cellular phenotype. Experimentally manipulated cells can be induced to form atypical phenotypes, capable of intraclonal propagation and regeneration after encystment. One such phenotype in the ciliate Tetmemena pustulata (formerly Stylonychia pustulata) is the mirror-imaged doublet. These cells possess two distinct sets of ciliature, juxtaposed on the surfaces in mirror image symmetry, with a common anterior-posterior axis. We have examined whether individual ciliary components of Tetmemena mirror-image doublets are mirror imaged. Ultrastructural analysis indicates that despite global mirror imaging of the ciliature, detailed organization of the membranelles is reversed in the mirror-image oral apparatus (OA), such that the ciliary effective stroke propels food away from the OA. Assembly of compound ciliary structures of both OAs starts out identically, but as the structures associated with the mirror-image OA continue to form, the new set of membranelles undergoes a 180 degrees planar rotation on the ventral surface relative to the same structures in the typical OA. The overall symmetry of the OA thus appears to be separable from the more localized assembly of individual basal bodies. True mirror imagery of the membranelles would require new enantiomorphic forms of the individual ciliary components, particularly the basal bodies, which is never observed. These observations suggest a mechanistic hypothesis with implications for the development of left-right asymmetry not only in ciliates, but perhaps also in development of left-right asymmetry in general.


Assuntos
Cilióforos/ultraestrutura , Animais , Cílios/ultraestrutura , Cilióforos/citologia , Microscopia Eletrônica
14.
J Neuropathol Exp Neurol ; 78(10): 930-938, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504677

RESUMO

Tau hyperphosphorylation, mostly at serine (Ser) or threonine (Thr) residues, plays a key role in the pathogenesis of Alzheimer disease (AD) and other tauopathies. Rodent studies show similar hyperphosphorylation in the developing brain, which may be involved in regulating axonal growth and plasticity, but detailed human studies are lacking. Here, we examine tau phosphorylation by immunohistochemistry and immunoblotting in human fetal and adult autopsy brain tissue. Of the 20 cases with sufficient tissue preservation, 18 (90%) showed positive staining for S214 (pSer214), with the majority also positive for CP13 (pSer202), and PHF-1 (pSer396/pSer404). AT8 (pSer202/pThr205) and RZ3 (pThr231) were largely negative while PG5 (pSer409) was negative in all cases. Immunoblotting showed tau monomers with a similar staining pattern. We also observed phospho-tau aggregates in the fetal molecular layer, staining positively for S214, CP13, and PHF1 and negative for thioflavin S. These corresponded to high-molecular weight (∼150 kD) bands seen on Western blots probed with S214, PHF1, and PG5. We therefore conclude that fetal phosphorylation overlaps with AD in some residues, while others (e.g. T231, S409) appear to be unique to AD, and that tau is capable of forming nontoxic aggregates in the developing brain. These findings suggest that the fetal brain is resilient to formation of toxic aggregates, the mechanism for which may yield insights into the pathogenesis of tau aggregation and toxicity in the aging brain.


Assuntos
Doença de Alzheimer/patologia , Encéfalo/embriologia , Tauopatias/patologia , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosforilação , Agregados Proteicos , Tauopatias/metabolismo
16.
PLoS One ; 12(12): e0190174, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29261805

RESUMO

Life-history traits influence colonization, persistence, and extinction of species on islands and are important aspects of theories predicting the geographical distribution and evolution of species. We used data collected from a large freshwater lake (1,413 km2) in central Canada to test the effects of island area and isolation on species richness and abundance of carabid beetles as a function of body size, wing length, and breeding season. A total of 10,018 individual beetles from 37 species were collected during the frost-free period of 2013 using transects of pitfall traps on 30 forested islands ranging in area from 0.2 to 980.7 ha. Life-history traits improved the predictive ability and significantly modified the shape of species-area and abundance-area curves. Abundance and richness of small-bodied (< 13.9 mm), macropterous (winged), and spring-breeding species decreased with island area and increased with isolation. In contrast, richness and abundance of larger-bodied (> 14.0 mm) and flightless species increased with area, but not isolation. Body size of female Carabus taedatus Fabricius, the largest-bodied species, was positively related to island area, while body size on the adjacent mainland was most similar to that on smaller islands. Overall, species with large body size and low dispersal ability, as indicated by flightlessness, were most sensitive to reductions in area. We suggest that large-bodied, flightless species are rare on small islands because habitat is less suitable for them and immigration rates are lower because they depend on freshwater drift for dispersal to islands.


Assuntos
Biodiversidade , Besouros/fisiologia , Ilhas , Lagos , Animais , Tamanho Corporal , Canadá , Geografia , Análise de Regressão , Especificidade da Espécie
17.
Front Behav Neurosci ; 10: 136, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27445731

RESUMO

Fragile X is the most common monogenic disorder associated with intellectual disability (ID) and autism spectrum disorders (ASD). Additionally, many patients are afflicted with executive dysfunction, ADHD, seizure disorder and sleep disturbances. Fragile X is caused by loss of FMRP expression, which is encoded by the FMR1 gene. Both the fly and mouse models of fragile X are also based on having no functional protein expression of their respective FMR1 homologs. The fly model displays well defined cognitive impairments and structural brain defects and the mouse model, although having subtle behavioral defects, has robust electrophysiological phenotypes and provides a tool to do extensive biochemical analysis of select brain regions. Decreased cAMP signaling has been observed in samples from the fly and mouse models of fragile X as well as in samples derived from human patients. Indeed, we have previously demonstrated that strategies that increase cAMP signaling can rescue short term memory in the fly model and restore DHPG induced mGluR mediated long term depression (LTD) in the hippocampus to proper levels in the mouse model (McBride et al., 2005; Choi et al., 2011, 2015). Here, we demonstrate that the same three strategies used previously with the potential to be used clinically, lithium treatment, PDE-4 inhibitor treatment or mGluR antagonist treatment can rescue long term memory in the fly model and alter the cAMP signaling pathway in the hippocampus of the mouse model.

18.
Environ Entomol ; 43(1): 139-45, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24472206

RESUMO

Captures of insects in pitfall traps are affected by features of trap design that may confound the interpretation of data. One such feature is a lid suspended over the opening of the trap to exclude debris and rainwater. In this study, we tested whether use of these lids affected captures of carabid beetles by altering the light conditions at the opening to the trap. In one experiment, we examined the effects of lid transparency (opaque, semitransparent, or transparent) on catch rates. In a second experiment, we manipulated the heights (high, medium, or low) of vegetation adjacent to the traps to test for lid transparency and vegetation height interactions. We found that significantly more carabids were captured with use of transparent lids compared with other lid transparencies. Fewest Agonum cupreum Dejean, 1831, were captured with use of opaque lids. No other effects were detected. Given these results, we advocate the use of transparent lids, which provide the benefits of traditional opaque lids while minimizing the effects of lid use on light conditions at the opening to the trap.


Assuntos
Besouros , Ecossistema , Entomologia/instrumentação , Solo , Animais , Biodiversidade , Plantas , Densidade Demográfica
19.
J Am Soc Echocardiogr ; 26(1): 52-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23098782

RESUMO

BACKGROUND: The geometry and heterogeneity of the right ventricle in hypoplastic left heart syndrome makes objective echocardiographic assessment of systolic function challenging. Consequently, subjective echocardiographic assessment of right ventricular (RV) function is still routinely undertaken. The aims of this study were to compare this with magnetic resonance imaging (MRI), investigate the impact of experience and training on the accuracy of subjective assessment, and critically analyze the role of echocardiography to detect impaired systolic function. METHODS: A retrospective analysis of prospectively acquired data was performed. Children with hypoplastic left heart syndrome underwent routine preoperative cardiac MRI and echocardiography under the same general anesthetic. Echocardiograms were reviewed, and members of the congenital heart disease team with differing echocardiography experience subjectively graded RV systolic function (good, moderate, or poor). This was compared with MRI-derived ejection fraction. RESULTS: Twenty-eight patients at different palliative stages were included. Twenty-eight observers were divided into five experience categories (congenital heart disease junior trainees to attending cardiologists). Median agreement was 47.6% (range, 31.4%-58.2%), with the lowest agreement among junior trainees and the highest among attending cardiologists. When used as a screening test for poor RV systolic function, the median sensitivity of echocardiography was 0.89 (range, 0.86-0.96), and median specificity was 0.45 (range, 0.26-0.55). The highest sensitivity was observed among junior trainees but with the lowest specificity. The highest specificity was observed among attending cardiologists (0.55). CONCLUSIONS: Agreement between echocardiographic and MRI RV ejection fraction improves with experience but remains suboptimal. When used as a screening test for poor RV function, echocardiography is sensitive, but specificity is heavily influenced by operator experience.


Assuntos
Ecocardiografia Doppler/métodos , Síndrome do Coração Esquerdo Hipoplásico/diagnóstico , Imagem Cinética por Ressonância Magnética/métodos , Contração Miocárdica , Função Ventricular Direita/fisiologia , Pré-Escolar , Feminino , Seguimentos , Humanos , Síndrome do Coração Esquerdo Hipoplásico/fisiopatologia , Síndrome do Coração Esquerdo Hipoplásico/cirurgia , Lactente , Masculino , Prognóstico , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença , Sístole
20.
PLoS Negl Trop Dis ; 7(4): e2151, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23593519

RESUMO

The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis.


Assuntos
Brugia Malayi/metabolismo , Brugia Malayi/microbiologia , Citoesqueleto/metabolismo , Proteínas de Membrana/metabolismo , Simbiose/fisiologia , Wolbachia/metabolismo , Wolbachia/fisiologia , Animais , Proteínas de Bactérias/metabolismo , Proteínas de Protozoários/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA