RESUMEN
The survival motor neuron gene is present in humans in a telomeric copy, SMN1, and several centromeric copies, SMN2. Homozygous mutation of SMN1 is associated with proximal spinal muscular atrophy (SMA), a severe motor neuron disease characterized by early childhood onset of progressive muscle weakness. To understand the functional role of SMN1 in SMA, we produced mouse lines deficient for mouse Smn and transgenic mouse lines that expressed human SMN2. Smn-/- mice died during the peri-implantation stage. In contrast, transgenic mice harbouring SMN2 in the Smn-/- background showed pathological changes in the spinal cord and skeletal muscles similar to those of SMA patients. The severity of the pathological changes in these mice correlated with the amount of SMN protein that contained the region encoded by exon 7. Our results demonstrate that SMN2 can partially compensate for lack of SMN1. The variable phenotypes of Smn-/-SMN2 mice reflect those seen in SMA patients, providing a mouse model for this disease.
Asunto(s)
Atrofia Muscular Espinal/genética , Proteínas del Tejido Nervioso/genética , Animales , Secuencia de Bases , Células Cultivadas , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Cartilla de ADN , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , Atrofia Muscular Espinal/patología , Proteínas de Unión al ARN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteínas del Complejo SMN , Proteína 1 para la Supervivencia de la Neurona Motora , Proteína 2 para la Supervivencia de la Neurona Motora , TransgenesRESUMEN
BACKGROUND: As part of an ongoing clinical service programme for pre-school children with developmental delay in an Asian developing country, we analysed the effect of three assessment tests, that is, Bayley Scale of Infant Development-II, Leiter International Performance Scale - Revised and Wechsler Preschool and Primary Scale of Intelligence - Revised - Chinese, on the stability of intelligence quotient (IQ) of children from pre-school through early childhood. METHODS: The participants were 313 Taiwanese pre-school children with uneven or delayed cognitive profile and they were followed through early childhood. IQ stability was explored by different tests and among children of different clinical diagnosis: 168 children with non-autistic intellectual disability, 73 children with autism spectrum disorder, 58 children with mixed receptive-expressive language disorder and 14 children of other heterogeneous diagnoses. Stability of scores was evaluated using the r-squared for Pearson's coefficients to see the correlation between initial IQ (IQ1) and follow-up IQ (IQ2). Multiple linear regressions were also applied to see whether IQ1 had predictive ability for IQ2 and test-test difference in the total 313 children and each diagnostic subgroup. RESULTS: Results revealed that mean IQ1 was 65.8 ± 15.4 while mean IQ2 was 73.2 ± 17.9 for the total 313 children. The IQs were stable across an average follow-up duration of 38.6 ± 22.1 month from pre-school into early childhood. Patterns of positive correlations between IQ1 and IQ2 were noted by all the tests (r-squared = 0.43-0.5, all P < 0.001) and in the majority of diagnostic subgroups. Multiple regressions analysis also revealed that IQ1 could predict IQ2 significantly in all the tests (all P < 0.001). DISCUSSION: After careful choice of appropriate initial test, stability of IQ in children with developmental delay was noted from pre-school through early childhood. In addition, the translated version of cognitive assessment was valid for the required context of an Asian developing country. With the current emphasis on early identification and intervention for pre-school children with developmental delay, this information bears merit in clinical practice.
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Trastornos Generalizados del Desarrollo Infantil/diagnóstico , Discapacidades del Desarrollo/diagnóstico , Discapacidad Intelectual/diagnóstico , Pruebas de Inteligencia/normas , Trastornos del Desarrollo del Lenguaje/diagnóstico , Niño , Preescolar , Femenino , Humanos , Pruebas de Inteligencia/estadística & datos numéricos , Estudios Longitudinales , Masculino , Reproducibilidad de los Resultados , Taiwán , Escalas de WechslerRESUMEN
Plasmacytoid dendritic cells (pDCs) are critical in controlling adaptive immunity, but the mechanisms governing cytokine expression remain incompletely defined. Analogues of prostaglandin (PG)I(2), such as iloprost, can modulate functions of myeloid dendritic cells, but their involvement in the regulation of human pDCs remains unknown. To this end, the regulatory role of PGI(2) analogues on cytokine expression in pDCs was investigated. Circulating pDCs were magnetically sorted with BDCA-4 cell isolation kits from human peripheral blood mononuclear cells and treated with varying concentrations of iloprost with or without the addition of Toll-like receptor agonists, or an I prostanoid (IP) receptor antagonist, CAY10449. The levels of tumour necrosis factor (TNF)-alpha, interferon (IFN)-alpha and interleukin (IL)-10 were measured by ELISA. Iloprost induced IL-10 expression, but suppressed CpG oligodeoxynucleotide- (or imiquimod-) induced TNF-alpha and IFN-alpha production in pDCs. This effect was reversed by the addition of CAY10449. Forskolin, a cyclic adenosine monophosphate activator, conferred a similar modulating effect to that noted in iloprost-treated pDCs, although a higher concentration of forskolin was required to exert the same effect. Iloprost enhanced interleukin-10 and suppressed Toll-like receptor-mediated tumour necrosis factor-alpha and interferon-alpha production of human plasmacytoid dendritic cells via the I prostanoid receptor and, in part, the cyclic adenosine monophosphate pathway.
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Citocinas/biosíntesis , Células Dendríticas/citología , Epoprostenol/análogos & derivados , Regulación de la Expresión Génica , Benzofenonas/farmacología , Colforsina/farmacología , AMP Cíclico/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Iloprost/farmacología , Imidazoles/farmacología , Interferón-alfa/metabolismo , Interleucina-10/metabolismo , Oligonucleótidos/química , Inhibidores de Agregación Plaquetaria/farmacología , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Infants who are passively exposed to morphine or heroin through their addicted mothers usually develop neurobiological changes. The postsynaptic density 95 (PSD-95) protein, a submembranous cytoskeletal specialization, is dynamically linked with N-methyl-d-aspartate receptors (NMDARs) to form a synaptic complex in postsynaptic neurons. This complex serves important neurobiological functions, including mammalian learning and memory. However, the effects of prenatal morphine exposure on this synaptic complex are not well understood. In this study, we determined whether prenatal morphine exposure altered the synaptic complex association between PSD-95 and three major NMDAR subunits (NR1, NR2A, and NR2B), at the mRNA and protein levels, within the hippocampal CA1 subregion (an important integration area for mammalian learning and memory) of rat offspring along with the performance of long-term cognitive functions. Sprague-Dawley rat offspring from morphine-addicted mothers were studied at a younger age (postnatal day 14; P14) and at an older age (P45). Subsequently, an eight-arm radial maze task was applied to analyze the working and cued reference memory in such offspring (P45). The real-time polymerase chain reaction results showed that prenatal morphine exposure caused significant decreases in mRNA levels of the PSD-95 and three NMDAR subunits (NR1, NR2A, and NR2B) in offspring (P14 and P45). Similarly, at the protein level, immunoblotting showed that decreased whole levels of PSD-95 and NMDAR subunits were seen in offspring subjected with prenatal morphine. Furthermore, the protein interaction of the synaptic complex between the PSD-95 and NMDAR subunit, as indicated by coimmunoprecipitation, was less in prenatal morphine samples than in vehicle controls (P14 and P45). The prenatal morphine group also showed poorer performance for an eight-arm radial maze task than the vehicle-control group. These results are particularly important for a better understanding of certain opioid-mediated neurobehavioral cognitive changes in offspring associated with altered protein interaction between PSD-95 and NMDAR subunits within the developing brain.
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Trastornos del Conocimiento/etiología , Hipocampo/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de la Membrana/metabolismo , Morfina , Efectos Tardíos de la Exposición Prenatal , Subunidades de Proteína/metabolismo , Factores de Edad , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Peso Corporal/fisiología , Homólogo 4 de la Proteína Discs Large , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica/fisiología , Inmunoprecipitación/métodos , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Proteínas de la Membrana/genética , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/patología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Subunidades de Proteína/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismoRESUMEN
It is unknown whether formoterol and salmeterol, two long-acting beta(2)-adrenoreceptor agonists, have regulatory functions in the production of T-helper cell (Th) type 2- and Th1-related chemokines by monocytes and bronchial epithelial cells. In the present study, the effects of formoterol and salmeterol on lipopolysaccharide (LPS)-induced expression of the Th2-related chemokine macrophage-derived chemokine (MDC; CCL22) and the Th1-related chemokine interferon-gamma-inducible protein (IP)-10 (CXCL10) were investigated in a monocytic cell line, THP-1, and in human primary monocytes. In addition, their effects on the expression of the Th2-related chemokine thymus- and activation-regulated chemokine (TARC; CCL17) were evaluated in an epithelial cell line, BEAS-2B. Formoterol enhanced MDC but suppressed IP-10 production in monocytes induced by LPS. Higher doses of salmeterol were required to enhance LPS-induced MDC expression in THP-1 cells. Formoterol and salmeterol could significantly suppress TARC expression in BEAS-2B cells. These effects could be reversed by a selective beta(2)-adrenoreceptor antagonist, ICI-118551. Formoterol- and LPS-induced MDC expression was inhibited by budesonide. Both long-acting beta(2)-adrenoreceptor agonists suppressed thymus- and activation-regulated chemokine expression in bronchial epithelial cells mediated via beta(2)-adrenoreceptors. Formoterol at physiological concentrations could suppress lipopolysaccharide-induced T-helper cell type 1-related chemokine (interferon-gamma-inducible protein-10) but enhance T-helper cell type 2-related chemokine (macrophage-derived chemokine) expression in human monocytes. Long-acting beta(2)-adrenoreceptor agonists may increase T-helper cell type 2-related chemokine expression in monocytes and T-helper cell type 2 recruitment and, therefore, long-acting beta(2)-adrenoreceptor agonist monotherapy may not be an appropriate therapeutic option for asthma.
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Agonistas Adrenérgicos beta/farmacología , Albuterol/análogos & derivados , Quimiocinas/metabolismo , Células Epiteliales/efectos de los fármacos , Etanolaminas/farmacología , Macrófagos/efectos de los fármacos , Proteínas ADAM/metabolismo , Albuterol/farmacología , Bronquios/citología , Bronquios/efectos de los fármacos , Línea Celular , Quimiocina CCL17/metabolismo , Quimiocina CXCL10/metabolismo , Células Epiteliales/metabolismo , Fumarato de Formoterol , Humanos , Macrófagos/metabolismo , Xinafoato de Salmeterol , Células TH1/fisiología , Células Th2/fisiología , Proteínas Supresoras de Tumor/metabolismoRESUMEN
SETTING: Mzuzu Central Hospital, in the northern region of Malawi, which provides free antiretroviral therapy (ART) to human immunodeficiency virus (HIV) infected adults and children, including those with tuberculosis (TB). OBJECTIVES: To compare outcomes in HIV-infected children who have been started on ART because of 1) active TB, 2) a past history of TB in the last 2 years and 3) a non-TB diagnosis. DESIGN: Retrospective data collection using ART patient master cards and ART patient registers. RESULTS: Between July 2004 and September 2006, 439 (11%) children of a total 3908 patients were started on ART. There were 29 with active TB, 56 with a past history of TB in the last 2 years and 354 with a non-TB diagnosis. The three groups were similar in nutritional indices and CD4-lymphocyte percentages. The 6-month probability of survival was 0.86 in the active TB group, 0.94 in the past history of TB group and 0.89 in the non-TB group. 12-month survival probability for the same groups was 0.86, 0.86 and 0.88, respectively. CONCLUSION: HIV-infected children with active and previous TB who are started on ART have good outcomes that are similar to those of children started on ART due to a non-TB diagnosis.
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Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Tuberculosis/complicaciones , Adolescente , Antituberculosos/uso terapéutico , Niño , Preescolar , Femenino , Estudios de Seguimiento , Infecciones por VIH/mortalidad , Humanos , Lactante , Malaui , Masculino , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento , Tuberculosis/tratamiento farmacológicoRESUMEN
WI-38 and IMR90 human lung fibroblasts express B2 receptors for the peptide mediator bradykinin. These G-protein-coupled receptors which control cell growth, protein synthesis, and prostaglandin E2 (PGE2) production occur in three affinity forms, high (H, KD 440 pM), intermediate (I, KD 5.6 nM), and low (L, KD 42 nM). Utilizing specific monoclonal antireceptor antibodies which are able to distinguish among these B2 bradykinin receptor forms, we demonstrate regulated differential enhancement of their expression in fibroblasts. Activation of cellular second messenger regulatory pathways based on protein kinase C or protein kinase A drives B2 receptor affinity form expression in opposite directions, both of which are relevant to the levels of human bradykinin generation in vivo in the tissues of origin for these fibroblasts. On a spontaneous basis WI-38 human lung fibroblasts most frequently express the L form alone or the I+L forms concurrently. Activation of protein kinase C augments expression of both I and L affinity receptors within 30 min, increasing receptor number and enhancing PGE2 production. In contrast, activation of protein kinase A by 8-bromo-cAMP or forskolin enhances receptor expression and PGE2 production instead at the I to H types of affinity forms within 30 min. The effects of both kinase systems are blocked by serine/threonine (Ser/Thr) protein kinase inhibitors, indicating a role for phosphorylation at Ser or Thr residues in determining the cellular expression of bradykinin B2 receptor affinity forms. An increase in immunoprecipitable I form bradykinin receptors is detectable within 20 to 30 min after activation of either protein kinase C or protein kinase A. This time frame emphasizes the ability of human fibroblasts for rapid mobilization of B2 receptor affinity forms. Regulated expression of this repertoire of bradykinin B2 receptors at the level of receptor number and concurrent activity allows fibroblasts a sensitive means to adjust their responses to their cellular environment utilizing Ser/Thr phosphorylation events.
Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Fibroblastos/metabolismo , Pulmón/metabolismo , Proteína Quinasa C/metabolismo , Receptores de Bradiquinina/metabolismo , Bradiquinina/metabolismo , Línea Celular , AMP Cíclico/metabolismo , Dinoprostona/biosíntesis , Activación Enzimática , Fibroblastos/citología , Expresión Génica , Humanos , Pulmón/citología , Pruebas de Precipitina , Receptor de Bradiquinina B2 , TritioRESUMEN
IMR90 human fetal lung fibroblasts express bradykinin receptors activating the pathway for biosynthesis of PGE2. A receptor of the B2 subtype stimulates half-maximal PGE2 production at 4.8 nM bradykinin, and maximal output takes place at 25 nM bradykinin. Radioligand binding studies reveal a population of [3H]bradykinin binding sites whose affinity correlates with this B2 receptor's biologic activity, with a KD of 2.5 nM. As IMR90 cells reach 60% of their defined life span in culture, they spontaneously induce expression of a second site of lower affinity, with half-maximal binding of [3H]bradykinin at 44 nM. This second site displays a characteristic primary B2 receptor recognition profile, but differs from the 2.5 nM site on a secondary level in recognition among different B2 ligands. Bradykinin is the most potent ligand at both sites; they each preferentially recognize an N-terminal extended bradykinin peptide construct having selectivity for the rat myometrial B2 receptor, suggesting that both sites have structural features in common. However, they display diversity in their order of preference for Met-Lys-bradykinin versus Lys-Lys-bradykinin; at the 44 nM site this order is completely reversed from the order of potency exhibited at the 2.5 nM site. Expression of the second site changes the manner in which these fibroblasts control their PGE2 production; it affords a graded response of PGE2 production at bradykinin levels beyond those which would normally saturate the 2.5 nM site. The inducibility of the 44 nM site in cultured fibroblasts addresses in vivo conditions in an inflammatory environment where continuing generation of bradykinin-related peptides takes place and presents a possible mechanism for overriding constraints that would otherwise limit the progression of inflammation.
Asunto(s)
Bradiquinina/metabolismo , Cininas/metabolismo , Receptores de Neurotransmisores/metabolismo , Secuencia de Aminoácidos , Bradiquinina/química , Bradiquinina/farmacología , Células Cultivadas , Dinoprostona/biosíntesis , Fibroblastos/metabolismo , Humanos , Cininas/química , Cininas/farmacología , Pulmón/metabolismo , Datos de Secuencia Molecular , Ensayo de Unión Radioligante , Receptores de Bradiquinina , Receptores de Neurotransmisores/efectos de los fármacosRESUMEN
A Chinese male infant with arthrogryposis multiplex congenita (AMC), ventricular and atrial septal defects, and Werdnig-Hoffmann disease (WHD) had deletions of the telomeric copy of the survival motor neuron (SMN(T)) and neuronal apoptosis inhibitory protein genes. Children with AMC or congenital heart disease, or both, and motor neuron disease should undergo testing for SMN(T) deletion. This rare association further illustrates the variable phenotypic expressions of WHD.
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Proteínas del Tejido Nervioso/genética , Atrofias Musculares Espinales de la Infancia/genética , Artrogriposis/complicaciones , Artrogriposis/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Eliminación de Gen , Defectos del Tabique Interatrial/complicaciones , Defectos del Tabique Interatrial/genética , Defectos del Tabique Interventricular/complicaciones , Defectos del Tabique Interventricular/genética , Humanos , Recién Nacido , Masculino , Proteína Inhibidora de la Apoptosis Neuronal , Proteínas de Unión al ARN , Proteínas del Complejo SMN , Atrofias Musculares Espinales de la Infancia/complicacionesRESUMEN
Three Chinese patients, two boys and one girl, were afflicted with the typical clinical, myopathological and neuroradiological findings of Fukuyama congenital muscular dystrophy (FCMD). Polymorphism analysis of our patients did not reveal the founder haplotype (138-192-147-183 in D9S2105-D9S2170-D9S2171-D9S2107) of Japanese FCMD, even though one patient was descended from Japanese ancestry. Full mutational analysis of the fukutin gene revealed that there is neither 3 kb insertion nor point mutation. These findings suggest genetic heterogeneity between Chinese and Japanese FCMD patients.
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Heterogeneidad Genética , Distrofias Musculares/genética , Niño , Femenino , Humanos , Lactante , Masculino , Linaje , TaiwánRESUMEN
Dopamine pathway genes have been the subject of a variety of studies testing the association of candidate genes and liability for attention-deficit hyperactivity disorder (ADHD). Due to the known effects of stimulant medications such as methylphenidate on the dopamine transporter, a variety of case control and family-based transmission distortion genetic studies of ADHD have focused on DAT1 polymorphisms. The most widely reported positive finding has been with a variable number of tandem repeats (VNTR) polymorphism of unknown function in the 3' untranslated region of the DAT1 gene. In this report, we test for association of alleles of this polymorphism with ADHD using population-derived samples of twins. We use the transmission disequilibrium test and ADHD subtypes defined by both DSM-IV and latent class criteria. We fail to demonstrate any significant association or trend for association of any of the VNTR alleles with any of the variously defined ADHD subtypes.
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Trastorno por Déficit de Atención con Hiperactividad/genética , Glicoproteínas de Membrana , Proteínas de Transporte de Membrana/genética , Repeticiones de Minisatélite/genética , Proteínas del Tejido Nervioso , Gemelos/genética , Adolescente , Adulto , Alelos , Trastorno por Déficit de Atención con Hiperactividad/patología , Niño , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Salud de la Familia , Femenino , Frecuencia de los Genes , Humanos , Masculino , Polimorfismo GenéticoRESUMEN
Attention-deficit hyperactivity disorder (ADHD) is a common, highly heritable syndrome of childhood characterized by problems with inattention, hyperactivity, and impulsivity. A variety of case control and family-based transmission distortion genetic studies of ADHD have focused on the possible involvement of polymorphisms of the DRD4 receptor gene. The majority of studies have examined the association of variously defined ADHD with an exon 3 polymorphism containing a variable number of imperfect 48 base pair repeats. Recently, McCracken et al. [2000: Mol Psych 5:531-536] reported an association of the DSM-IV primarily inattentive ADHD subtype with a 5' 120 base pair repeat polymorphism in the DRD4 gene. In this report, we test for the possible association of these two polymorphisms with population-derived samples of DSM-IV ADHD subtypes. Furthermore, we extend previous studies by testing for associations with ADHD subtypes derived from latent-class analysis of interview responses. In contrast to most, but not all, previous studies, we failed to demonstrate any significant association of the exon 3 7-repeat allele with ADHD. Nor did we replicate the association of the 5'120 base pair repeat polymorphism. We do find a significant association of the exon 3 3-repeat allele with a novel talkative/impulsive latent-class-defined subtype of ADHD.
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Trastorno por Déficit de Atención con Hiperactividad/genética , Receptores de Dopamina D2/genética , Adolescente , Adulto , Alelos , Trastorno por Déficit de Atención con Hiperactividad/patología , Niño , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Repeticiones de Minisatélite/genética , Polimorfismo Genético , Receptores de Dopamina D4RESUMEN
Fragile X syndrome (FXS) is the most common form of familial mental retardation (MR). It is caused by the expansion of the CGG repeat in the FMR1 gene on the X chromosome. To date, FXS is not treatable, but can be prevented by prenatal genetic examination. Identifying women who carry a full mutation or premutation FMR1 gene is thus very important, and can be done by tracing family members of FXS subjects. However, most of the FXS subjects in Taiwan as well as those in many other countries have not been identified. In this study the authors attempt to develop reliable and inexpensive tests suitable for a large-scale screen of subjects with MR for FXS. Together with their previous study, a total of 311 male and 160 female subjects with MR were screened with nonradioactive Southern blot assay using mixed deoxyribonucleic acid from three subjects of the same sex. From these subjects, nine male subjects and one female FXS subject were diagnosed. All male subjects were also screened with nonradioactive polymerase chain reaction (PCR). These nine male FXS subjects were also detected on the basis of PCR amplification failure. No false-negative results were discerned. The PCR procedure was simplified further by combining it with an analysis of a blood spot on filter paper, which is a much simpler and cheaper method for sample collection and DNA preparation. This method was then used to screen 104 boys with MR. Two of them were suspected, and later confirmed with Southern blot assay, as subjects with FXS. This study suggests that simple PCR combined with blood spot analysis could be a reliable, inexpensive test that is feasible for a large-scale screening of male subjects with MR for FXS. However, Southern blot assay with mixed deoxyribonucleic acid is appropriate for screening female subjects. Based on this strategy, most FXS subjects could be identified easily for further management.
Asunto(s)
Síndrome del Cromosoma X Frágil/genética , Tamización de Portadores Genéticos/métodos , Pruebas Genéticas/métodos , Discapacidad Intelectual/genética , Proteínas de Unión al ARN , Southern Blotting , Niño , Preescolar , ADN/análisis , Análisis Mutacional de ADN , Femenino , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil , Síndrome del Cromosoma X Frágil/sangre , Síndrome del Cromosoma X Frágil/epidemiología , Humanos , Lactante , Recién Nacido , Discapacidad Intelectual/sangre , Discapacidad Intelectual/epidemiología , Masculino , Mutación , Proteínas del Tejido Nervioso/sangre , Reacción en Cadena de la Polimerasa , Taiwán/epidemiologíaRESUMEN
The ontogeny of presynaptic elements of GABAergic neurons has been studied in the cerebrum of the chick embryo both in vivo and in vitro. The specific activity of glutamate decarboxylase (GAD) in tissue extracts followed a rising curve and approached a plateau value after 28 days in vivo. One-half of the adult levels of GAD were achieved by day 20. The specific activity of Na+-gamma-aminobutyric acid (GABA) cotransport in membrane vesicles followed a similar pattern and reached maximal levels by 28 days in vivo. One-half of the adult levels of GABA uptake were observed at day 17. The development of these markers was also studied in cultured neurons prepared from the cerebrum of 8-day-old chick embryos. The GAD activity in neuronal extracts increased linearly with time in culture up to 14 days. At this point the specific activity had reached 20% of that observed for the adult cerebrum. The specific activity of GABA uptake by intact neurons followed a pattern similar to that for GAD from days 2 to 9 in culture. Both activities increased 4-5-fold during this period, but the level of GABA transport declined thereafter. In order to compare GABA uptake values for cultured cells with those for embryonic and adult brain, membrane vesicles were prepared from cultures. At the maximal level (9-10 days in culture) the vesicular GABA uptake represented 33% of that in the 18-day embryo and 20% of adult levels. Thus the presynaptic GABAergic components developed according to similar schedules both in vivo and in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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Telencéfalo/embriología , Ácido gamma-Aminobutírico/fisiología , Animales , Transporte Biológico , Células Cultivadas , Embrión de Pollo , Glutamato Descarboxilasa/metabolismo , Sodio/metabolismo , Telencéfalo/citología , Telencéfalo/metabolismo , Ácido gamma-Aminobutírico/metabolismoRESUMEN
Mutations of the telomeric survival motor neuron gene (SMN1) are related to spinal muscular atrophy (SMA). However, no phenotype-genotype correlation has been observed since the SMN1 gene is lacking in the majority of patients affected with either the severe form (type I) or the milder forms (types II and III). Here, we analyze the SMN, NAIP and P44 genes in 132 Chinese SMA patients and their families. At least three types of normal allele, and four types of mutant allele were found in this study. The combination of one normal allele with one mutant allele resulted in carriers of different types, and the combination of different mutant alleles accounted for the different genotypes among different types of SMA. Deletions of mutant alleles can be further subgrouped into four types, which includes involving SMN1, SMN1 and NAIP(T) (telomeric portion of NAIP gene), SMN1 and NAIP(T) and P44(T) (telomeric portion of P44 gene), and SMN1 and SMN2 (centromeric portion of SMN gene). Some of the severe (type I) SMA cases correlated with the extent of deletions in the SMN, NAIP and P44 genes or the dosage of SMN gene when both SMN1 and SMN2 are deleted. We also found two novel point mutations, an A insertion at codon 8 (AGT-->AAGT) and an A substitution at codon 228 (TTA-->TAA).
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Células del Asta Anterior/fisiopatología , Mutación/genética , Proteínas del Tejido Nervioso/genética , Factores de Iniciación de Péptidos/genética , Atrofias Musculares Espinales de la Infancia/genética , Células del Asta Anterior/patología , Quimera/genética , China , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Análisis Mutacional de ADN , Exones/genética , Femenino , Mutación del Sistema de Lectura/genética , Eliminación de Gen , Frecuencia de los Genes/genética , Pruebas Genéticas , Genotipo , Heterocigoto , Homocigoto , Humanos , Masculino , Proteína Inhibidora de la Apoptosis Neuronal , Linaje , Fenotipo , Proteínas de Unión al ARN , Proteínas del Complejo SMN , Proteína 1 para la Supervivencia de la Neurona Motora , Proteína 2 para la Supervivencia de la Neurona Motora , Telómero/genéticaRESUMEN
Spinal muscular atrophy (SMA) is a disorder characterized by degeneration of the anterior horn cells of the spinal cord. The gene most highly associated with SMA is the survival motor neuron (SMN) gene. In this study, we present an analysis of messenger RNA (mRNA) expression of the SMN gene in peripheral blood mononuclear cells in normal subjects, SMA carriers and patients from 20 SMA families. We found at least 6-8 different transcripts of SMN gene formed by alternative splicing involving exons 3, 5 and 7. We compared transcripts from the different types of SMA and found no definite differences in transcript patterns and amounts. Normal subjects with the telomeric SMN (SMN(T)) gene only had variable splicing resulting in several transcripts, the most dominant being a transcript containing all coding regions. However, SMA patients with the centromeric SMN (SMN(C)) gene only had a higher degree of splice variation and tended to show little or no exon 7. These results demonstrate that SMN(T) and SMN(C) genes participate in alternative splicing phenomena. The different splicing patterns support the view that the SMN(T) gene is responsible for SMA disease. We also analyzed the transcripts from several tissues of an SMA fetus who had a homozygous SMN(T) gene deletion. Different splicing patterns were also found in these tissues, and were similar to the splicing pattern of leukocytes. We compared the major transcripts from exons 4 to 8 of both the SMN(T) and SMN(C) genes and found that the relative proportion varied among normal subjects, SMA carriers and patients. This approach could be used as a novel diagnostic method. We suggest that analyzing the mRNA expression of the SMN gene in peripheral blood mononuclear cells offers an apparently reliable technique for separating SMA patients, carriers, and normal individuals.
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Enfermedades Fetales/metabolismo , Proteínas Fetales/genética , Leucocitos Mononucleares/química , Proteínas del Tejido Nervioso/genética , ARN Mensajero/biosíntesis , Eliminación de Secuencia , Atrofias Musculares Espinales de la Infancia/genética , Adulto , Empalme Alternativo , Southern Blotting , Centrómero/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Femenino , Enfermedades Fetales/diagnóstico , Enfermedades Fetales/genética , Proteínas Fetales/biosíntesis , Duplicación de Gen , Tamización de Portadores Genéticos , Heterocigoto , Homocigoto , Humanos , Masculino , Familia de Multigenes , Proteínas del Tejido Nervioso/biosíntesis , Diagnóstico Prenatal , ARN Mensajero/genética , Proteínas de Unión al ARN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteínas del Complejo SMN , Atrofias Musculares Espinales de la Infancia/diagnóstico , Atrofias Musculares Espinales de la Infancia/embriología , Telómero/genéticaRESUMEN
Human fibroblast cell culture systems have been used to model both molecular events associated with the aging process and the biochemical anomalies found in the aging-associated neurodegenerative disorder Alzheimer's disease (AD). We demonstrate modulation of bradykinin (BK) B2 receptors that results in Intermediate (I, Kd 2.5-5 nM) and Low (L, Kd 44 nM) receptor affinity states in two cellular model systems that target aging and aging-associated disorders: the human lung fibroblast cell line WI-38 model for cellular aging and a skin fibroblast cell line from a patient with early onset familial Alzheimer's disease. In both cellular models the generation of I and L BK B2 receptors is extremely rapid, occurring within 1 min of activation of protein kinase C (PKC) by phorbol ester. Blocking phosphoprotein phosphatase activity further augments the cellular content of I and L receptors in the Alzheimer's skin fibroblast cell line. These two lines of evidence suggest that a phosphorylation cascade modifying the receptors is responsible for the I and L states. The I and L receptors remain biologically active and enhance cellular responsiveness to elevated levels of BK that are found in tissue injury, one of the major risk factors for development of Alzheimer's disease. The Alzheimer's disease skin fibroblast cell line presents a cellular environment highly enriched in the amyloid Abeta1-42 peptide that is the hallmark of Alzheimer's plaque lesions in the brain. This Abeta-rich environment may serve to foster the signal transduction mechanism that generates I and L BK B2 receptors.
Asunto(s)
Envejecimiento/metabolismo , Enfermedad de Alzheimer/metabolismo , Receptores de Bradiquinina/biosíntesis , Enfermedad de Alzheimer/enzimología , Western Blotting , Línea Celular , Electroforesis en Gel de Poliacrilamida , Fibroblastos/metabolismo , Humanos , Pulmón/metabolismo , Masculino , Toxinas Marinas , Oxazoles/farmacología , Ésteres del Forbol/farmacología , Fosfoproteínas Fosfatasas/antagonistas & inhibidores , Fosforilación , Proteína Quinasa C/metabolismo , Receptor de Bradiquinina B2 , Piel/metabolismoRESUMEN
A 12-year-old girl with proximal muscle weakness and delayed psychomotor development from early infancy is presented. She had a myopathic face, high-arched palate, nasal tone vocalization, positive Gowers' sign, waddling gait and decreased deep tendon reflexes. Her IQ was 40 (PIQ = 39, VIQ = 51). The serum creatine kinase level and peripheral nerve conduction velocity as well as electrocardiogram were normal. The electromyogram showed myopathic changes. Magnetic resonance imaging (MRI) of thigh muscles revealed fatty infiltration of all muscle groups, the hypertrophic biceps femoris and semimembranous muscles being spared. A biopsy specimen from the left biceps brachii muscle revealed small caliber fibers, increased variability of fiber size and uniformity of type 1 fibers (greater than 99%). This case was diagnosed as having congenital nonprogressive myopathy with uniform type 1 fibers, and had a non-deteriorating clinical course as in most congenital nonprogressive myopathy cases.
Asunto(s)
Discapacidad Intelectual/patología , Músculos/patología , Enfermedades Musculares/patología , Niño , Femenino , Humanos , Discapacidad Intelectual/complicaciones , Imagen por Resonancia Magnética , Enfermedades Musculares/complicaciones , Enfermedades Musculares/congénitoRESUMEN
A 28-month-old male with generalized hypotonia and muscle weakness, a myopathic face, skeletal dysmorphism and delayed motor milestones from birth is reported. He gradually developed the ability of sitting and rolling over, but could not stand without support until 28 months. There was no intellectual impairment or seizures. Deep tendon reflexes were absent. The serum CK value, peripheral nerve conduction velocity and EMG were within normal limits. A muscle biopsy specimen showed mild variation in fiber size, and an increased number of type 2C fibers on histochemical examination, but no apparent abnormalities on electron microscopy. The baby was tentatively diagnosed as having minimal change myopathy or nonspecific congenital myopathy which is thought to be one of the congenital nonprogressive myopathies.
Asunto(s)
Enfermedades Musculares/congénito , Humanos , Lactante , Masculino , Músculos/patología , Enfermedades Musculares/patologíaRESUMEN
The study of the composition of human milk has attracted worldwide interest, since it represents the pattern of nutrients most suitable for the younger infant. In the present study, the concentration of Ca, Mg, Fe, Cu, and Zn was measured in a total of 211 samples of human milk. The analytical technique of inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the analysis. From the results, it indicates that the mean concentration of Zn is highest in the colostrum with decreasing concentrations as the lactation progressed. The effects of age, parity, and lactation history on the results are also analyzed. It shows that the Zn concentration in the colostrum in the older mothers (>30 yr) was higher than that of the younger ones (20-30 yr).