RESUMEN
OBJECTIVE: To investigate speech development of children aged 5 and 10 years with repaired unilateral cleft lip and palate (UCLP) and identify speech characteristics when speech proficiency is not at 'peer level' at 10 years. Estimate how the number of speech therapy visits are related to speech proficiency at 10 years, and what factors are predictive of whether a child's speech proficiency at 10 years is at 'peer level' or not. DESIGN: Longitudinal complete datasets from the Scandcleft project. PARTICIPANTS: 320 children from nine cleft palate teams in five countries, operated on with one out of four surgical methods. INTERVENTIONS: Secondary velopharyngeal surgery (VP-surgery) and number of speech therapy visits (ST-visits), a proxy for speech intervention. MAIN OUTCOME MEASURES: 'Peer level' of percentage of consonants correct (PCC, > 91%) and the composite score of velopharyngeal competence (VPC-Sum, 0-1). RESULTS: Speech proficiency improved, with only 23% of the participants at 'peer level' at 5 years, compared to 56% at 10 years. A poorer PCC score was the most sensitive marker for the 44% below 'peer level' at 10-year-of-age. The best predictor of 'peer level' speech proficiency at 10 years was speech proficiency at 5 years. A high number of ST-visits received did not improve the probability of achieving 'peer level' speech, and many children seemed to have received excessive amounts of ST-visits without substantial improvement. CONCLUSIONS: It is important to strive for speech at 'peer level' before age 5. Criteria for speech therapy intervention and for methods used needs to be evidence-based.
RESUMEN
We have performed a systematic molecular dynamics investigation of the effects of overlap of collision cascades in tungsten with pre-existing vacancy-type defects. In particular, we focus on the implications for fusion neutron irradiated tungsten in relation to comparisons with damage production under ion irradiation conditions. We find that overlap of a cascade with a vacancy-type defect decreases the number of new defects with roughly the same functional dependence as previously shown for interstitial clusters. We further find that different mechanisms govern the formation of dislocation loops, resulting in different Burgers vectors, depending on the degree of overlap between the cascade and the defect. Furthermore, we show that overlapping cascades consistently decrease the size of the pre-existing defect. We also observe void-induced cascade splitting at energies far below the subcascade splitting threshold in tungsten. The impact of these mechanisms on radiation damage accumulation and dose rate effects are discussed.
RESUMEN
Overlap of collision cascades with previously formed defect clusters become increasingly likely at radiation doses typical for materials in nuclear reactors. Using molecular dynamics, we systematically investigate the effects of different pre-existing self-interstitial clusters on the damage produced by an overlapping cascade in bcc iron and tungsten. We find that the number of new Frenkel pairs created in direct overlap with an interstitial cluster is reduced to essentially zero, when the size of the defect cluster is comparable to that of the disordered cascade volume. We develop an analytical model for this reduced defect production as a function of the spatial overlap between a cascade and a defect cluster of a given size. Furthermore, we discuss cascade-induced changes in the morphology of self-interstitial clusters, including transformations between [Formula: see text] and [Formula: see text] dislocation loops in iron and tungsten, and between C15 clusters and dislocation loops in iron. Our results provide crucial new cascade-overlap effects to be taken into account in multi-scale modelling of radiation damage in bcc metals.
RESUMEN
The impacts of ions and neutrons in metals cause cascades of atomic collisions that expand and shrink, leaving microstructure defect debris, i.e. interstitial or vacancy clusters or loops of different sizes. In De Backer et al (2016 Europhys. Lett. 115 26001), we described a method to detect the first morphological transition, i.e. the cascade fragmentation in subcascades, and a model of primary damage combining the binary collision approximation and molecular dynamics (MD). In this paper including W, Fe, Be, Zr and 20 other metals, we demonstrate that the fragmentation energy increases with the atomic number and decreases with the atomic density following a unique power law. Above the fragmentation energy, the cascade morphology can be characterized by the cross pair correlation functions of the multitype point pattern formed by the subcascades. We derive the numbers of pairs of subcascades and observed that they follow broken power laws. The energy where the power law breaks indicates the second morphological transition when cascades are formed by branches decorated by chaplets of small subcascades. The subcascade interaction is introduced in our model of primary damage by adding pairwise terms. Using statistics obtained on hundreds of MD cascades in Fe, we demonstrate that the interaction of subcascades increases the proportion of large clusters in the damage created by high energy cascades. Finally, we predict the primary damage of 500 keV Fe ion in Fe and obtain cluster size distributions when large statistics of MD cascades are not feasible.
RESUMEN
BACKGROUND AND PURPOSE: The formation of reactive oxygen species (ROS) is increased in heart failure (HF). However, the causal and mechanistic relationship of ROS formation with contractile dysfunction is not clear in detail. Therefore, ROS formation, myofibrillar protein oxidation and p38 MAP kinase activation were related to contractile function in failing rabbit hearts. EXPERIMENTAL APPROACH AND KEY RESULTS: Three weeks of rapid left ventricular (LV) pacing reduced LV shortening fraction (SF, echocardiography) from 32 +/- 1% to 13 +/- 1%. ROS formation, as assessed by dihydroethidine staining, increased by 36 +/- 8% and was associated with increased tropomyosin oxidation, as reflected by dimer formation (dimer to monomer ratio increased 2.28 +/- 0.66-fold in HF vs. sham, P < 0.05). Apoptosis (TdT-mediated dUTP nick end labelling staining) increased more than 12-fold after 3 weeks of pacing when a significant increase in the phosphorylation of p38 MAP kinase and HSP27 was detected (Western blotting). Vitamins C and E abolished the increases in ROS formation and tropomyosin oxidation along with an improvement of LVSF (19 +/- 1%, P < 0.05 vs. untreated HF) and prevention of apoptosis, but without modifying p38 MAP kinase activation. Inhibition of p38 MAP kinase by SB281832 counteracted ROS formation, tropomyosin oxidation and contractile failure, without affecting apoptosis. CONCLUSIONS AND IMPLICATIONS: Thus, p38 MAP kinase activation appears to be upstream rather than downstream of ROS, which impacts on LV function through myofibrillar oxidation. p38 MAP kinase inhibition is a potential target to prevent or treat HF.
Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Especies Reactivas de Oxígeno/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Citoesqueleto de Actina/metabolismo , Animales , Antioxidantes/farmacología , Apoptosis , Ácido Ascórbico/farmacología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Sistemas de Liberación de Medicamentos , Insuficiencia Cardíaca/tratamiento farmacológico , Imidazoles/farmacología , Masculino , Contracción Miocárdica , Oxidación-Reducción/efectos de los fármacos , Fosforilación , Pirimidinas/farmacología , Conejos , Función Ventricular Izquierda , Vitamina E/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidoresRESUMEN
We have investigated the involvement of potassium channels in the NO-induced relaxation of small ET-1 precontracted arteries from placentas of normal pregnancies in the presence of the potassium channel modulating agents charybdotoxin, 4-AP, glibenclamide, TEA and the blocker of soluble guanylyl cyclase, ODQ, respectively. We have studied the effect of the NO-donor S-nitroso-N-acetylpenicillamine (SNAP) in vessels precontracted by different concentrations of potassium and we have also investigated the presence of BK(Ca) channels in placental arteries by immunohistochemistry and immunoblotting. Our results show that charybdotoxin, an inhibitor of large- and intermediate-conductance Ca(2+)-activated potassium channels, inhibits relaxation in placental arteries. In presence of both charybdotoxin and ODQ, the inhibition of relaxation was significantly stronger, which indicates that NO-induced relaxation of human placental arteries is partly mediated through cGMP, and partly through a direct effect on potassium channels of the BK(Ca) type. The NO-donor SNAP preferentially relaxes contractions induced by 75 mM K(+) as compared to 100 mM K(+). This effect profile is a unique feature of drugs acting by K(+) channel opening. The immunohistochemistry shows that BK(Ca) channels are located both in smooth muscle and in endothelium in placental arteries.
Asunto(s)
Donantes de Óxido Nítrico/farmacología , Placenta/irrigación sanguínea , Canales de Potasio Calcio-Activados/efectos de los fármacos , S-Nitroso-N-Acetilpenicilamina/farmacología , Vasodilatación , Adulto , Arterias/química , Arterias/efectos de los fármacos , Caribdotoxina/farmacología , Endotelina-1/farmacología , Inhibidores Enzimáticos/farmacología , Femenino , Humanos , Inmunohistoquímica , Oxadiazoles/farmacología , Placenta/química , Placenta/efectos de los fármacos , Potasio/farmacología , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio Calcio-Activados/agonistas , Canales de Potasio Calcio-Activados/análisis , Embarazo , Quinoxalinas/farmacologíaRESUMEN
In order to explore the role of nitric oxide (NO) in the control of fetoplacental vascular tone in normal pregnancy we have examined the effects of NO donors on uteroplacental arteries pre-contracted with the vasoconstrictor endothelin-1 (ET-1) or serotonin (5-HT). We have furthermore examined the effects of guanylate cyclase inhibitors on the NO-induced relaxation. Segments of placental arteries (n=102) obtained from 39 placentas immediately after delivery were mounted in organ baths and superfused with Krebs-Ringer solution at 37 degrees C. The vessel segments were exposed to drugs for various intervals and the tension was recorded isometrically and registered on a polygraph. Cyclic guanosine monophosphate (cGMP) analysis was performed after extraction of vessel segments using a specific radioimmunoassay. The placental artery segments responded to ET-1 and 5-HT with a dose-dependent vasoconstriction. After pre-contraction with ET-1 (10(-7) M) or 5-HT (10(-6) M), the vessels relaxed in response to the NO donors glyceryltrinitrate (GTN) (10(-6) M) and S-nitroso-N-acetyl-penicillamine (SNAP) (10(-5) M). In the presence of the non-specific guanylate cyclase inhibitor LY 83583 (10(-6) M), the vessels responded with a small contraction. In the presence of the soluble guanylate cyclase (sGC) inhibitor 1H[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) the non-treated vessels responded with a relaxation. 1H[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one gave no obvious relaxation in pre-contracted vessels. Addition of 8-Br-cGMP, the cell-permeant analogue of cGMP, with or without pre-contraction had no effect on the vessels. Cyclic guanosine monophosphate analysis showed that GTN treatment caused an increase in cGMP after 12 min. Our results indicate that NO acts as a vasodilator in placental vessels. The cGMP-dependent mechanisms may be involved in NO-induced relaxation but cGMP-independent mechanisms appear also to be involved.
Asunto(s)
GMP Cíclico/análogos & derivados , Endotelina-1/farmacología , Donantes de Óxido Nítrico/farmacología , Óxido Nítrico/metabolismo , Placenta/irrigación sanguínea , Placenta/efectos de los fármacos , Serotonina/farmacología , Vasoconstricción/efectos de los fármacos , Adulto , Aminoquinolinas/farmacología , GMP Cíclico/metabolismo , GMP Cíclico/farmacología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiología , Nitroglicerina/farmacología , Circulación Placentaria/efectos de los fármacos , Embarazo , S-Nitroso-N-Acetilpenicilamina/farmacología , Transducción de Señal/efectos de los fármacos , Superóxido Dismutasa/metabolismo , Tionucleótidos/farmacología , Vasoconstrictores/farmacología , Vasodilatación/efectos de los fármacosRESUMEN
BACKGROUND: In addition to cell lysis, apoptosis has been advanced as the origin of circulating DNA on the basis of several observations. Plasma or serum DNA often presents a ladder pattern reminiscent of that displayed by apoptotic cells when subjected to electrophoresis. However, the phenomenon of active release of DNA from cells might also be expected to result in a ladder pattern on electrophoresis. Non-dividing cells, such as lymphocytes, frog auricles and cultured cell lines including HL-60, spontaneously release a nucleoprotein complex within a homeostatic system in which newly synthesized DNA is preferentially released. CONCLUSION: In relation to DNA synthesis, the phenomenon of extracellular DNA in different culture conditions favors apoptosis or spontaneous active DNA release.
Asunto(s)
Apoptosis , ADN/sangre , Electroforesis en Gel de Agar , Células HL-60 , HumanosRESUMEN
Bid plays an essential role in Fas-mediated apoptosis of the so-called type II cells. In these cells, following cleavage by caspase 8, the C-terminal fragment of Bid translocates to mitochondria and triggers the release of apoptogenic factors, thereby inducing cell death. Here we report that Bid is phosphorylated by casein kinase I (CKI) and casein kinase II (CKII). Inhibition of CKI and CKII accelerated Fas-mediated apoptosis and Bid cleavage, whereas hyperactivity of the kinases delayed apoptosis. When phosphorylated, Bid was insensitive to caspase 8 cleavage in vitro. Moreover, a mutant of Bid that cannot be phosphorylated was found to be more toxic than wild-type Bid. Together, these data indicate that phosphorylation of Bid represents a new mechanism whereby cells control apoptosis.
Asunto(s)
Apoptosis/fisiología , Proteínas Portadoras/metabolismo , Caspasas/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Secuencia de Aminoácidos , Animales , Proteína Proapoptótica que Interacciona Mediante Dominios BH3 , Proteínas Portadoras/genética , Quinasa de la Caseína II , Caseína Quinasas , Caspasa 8 , Caspasa 9 , Fraccionamiento Celular , Línea Celular , Proteínas de Unión al ADN/metabolismo , Granzimas , Humanos , Immunoblotting , Ratones , Datos de Secuencia Molecular , Fosforilación , Inhibidores de Proteínas Quinasas , Proteínas Quinasas/aislamiento & purificación , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Serina Endopeptidasas/metabolismo , Receptor fas/metabolismoRESUMEN
Aniridia is a severe eye disease characterized by iris hypoplasia; both sporadic cases and familial cases with an autosomal dominant inheritance exist. Mutations in the PAX6 gene have been shown to be the genetic cause of the disease. Some of the sporadic cases are caused by large chromosomal deletions, some of which also include the Wilms tumor gene (WAGR syndrome), resulting in an increased risk of developing Wilms tumor. Based on the unique registration of both cancer and aniridia cases in Denmark, we have made the most accurate risk estimate to date for Wilms tumor in sporadic aniridia. We have found that patients with sporadic aniridia have a relative risk of 67 (confidence interval: 8.1-241) of developing Wilms tumor. Among patients investigated for mutations, Wilms tumor developed in only two patients out of 5 with the Wilms tumor gene (WT1) deleted. None of the patients with smaller chromosomal deletions or intragenic mutations were found to develop Wilms tumor. Our observations suggest a smaller risk for Wilms tumor than previous estimates, and that tumor development requires deletion of WT1. We report a strategy for the mutational analysis of aniridia cases resulting in the detection of mutations in 68% of sporadic cases and 89% of familial cases. We also report four novel mutations in PAX6, and furthermore, we have discovered a new alternatively spliced form of PAX6.
Asunto(s)
Aniridia/epidemiología , Aniridia/genética , Proteínas de Homeodominio/genética , Neoplasias Renales/epidemiología , Neoplasias Renales/genética , Mutación , Tumor de Wilms/epidemiología , Tumor de Wilms/genética , Empalme Alternativo , Secuencia de Aminoácidos , Aniridia/complicaciones , Secuencia de Bases , Cartilla de ADN/genética , Dinamarca/epidemiología , Proteínas del Ojo , Femenino , Eliminación de Gen , Genes del Tumor de Wilms , Genética de Población , Humanos , Neoplasias Renales/complicaciones , Masculino , Datos de Secuencia Molecular , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Proteínas Represoras , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Riesgo , Homología de Secuencia de Aminoácido , Tumor de Wilms/complicacionesRESUMEN
The GJB2 (connexin 26) gene, one of the major genes responsible for autosomal recessive deafness, has been investigated previously by a variety of techniques, including PCR-SSCP and sequencing of the entire gene for screening of unknown mutations, and allele-specific PCR, ASO, and PCR-mediated site-directed mutagenesis for the detection of the common mutation 35delG. Here, we present the development of a DGGE method for the characterization of the full spectrum of mutations in the GJB2 gene. The GJB2 cDNA and flanking sequences were amplified in three overlapping segments. We screened 26 Greek patients with prelingual, sensorineural deafness, where syndromic forms and environmental causes of deafness had been excluded. The 35delG mutation was detected in 28 chromosomes (53.8%), while another three sequence variations accounted for 7.6% of the alleles. The sequence variation R127H, previously described in a few Spanish and Balkan patients, was detected in two patients as the sole mutation. A novel sequence variation, K224Q, was identified as the sole mutation in one patient. Use of this approach may contribute to the full description of mutations in this important deafness gene.
Asunto(s)
Conexinas/genética , Análisis Mutacional de ADN , Pérdida Auditiva Sensorineural/genética , Mutación , Alelos , Secuencia de Bases , Conexina 26 , Cartilla de ADN/química , Electroforesis en Gel de Agar , Femenino , Frecuencia de los Genes , Genotipo , Grecia/epidemiología , Pérdida Auditiva Sensorineural/etnología , Humanos , Masculino , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Reacción en Cadena de la PolimerasaRESUMEN
Mutations in the developmental control gene PAX6 have been shown to be the genetic cause of aniridia, which is a severe panocular eye disease characterised by iris hypoplasia. The inheritance is autosomal dominant with high penetrance but variable expressivity. Here we describe a mutational analysis of 27 Danish patients using a dideoxy fingerprinting method, which identified PAX6 mutations in 18 individuals with aniridia. A thorough phenotype description was made for the 18 patients. A total of 19 mutations, of which 16 were novel, are described. Among these were five missense mutations which tended to be associated with a milder aniridia phenotype, and in fact one of them seemed to be non-penetrant. Four of the five missense mutations were located in the paired domain. We also describe a third alternative spliced PAX6 isoform in which two of the four missense mutations would be spliced out. Our observations support the concept of dosage effects of PAX6 mutations as well as presenting evidence for variable expressivity and gonadal mosaicism.
Asunto(s)
Aniridia/genética , Proteínas de Unión al ADN/genética , Proteínas de Homeodominio , Mutación , Empalme Alternativo , Aniridia/fisiopatología , Dermatoglifia del ADN , Proteínas del Ojo , Humanos , Mutagénesis Insercional , Mutación Missense , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Fenotipo , Isoformas de Proteínas , Proteínas Represoras , Eliminación de SecuenciaRESUMEN
Here we report that in staurosporine-induced apoptosis of HeLa cells, Bid, a BH3 domain containing protein, translocates from the cytosol to mitochondria. This event is associated with a change in conformation of Bax which leads to the unmasking of its NH2-terminal domain and is accompanied by the release of cytochrome c from mitochondria. A similar finding is reported for cerebellar granule cells undergoing apoptosis induced by serum and potassium deprivation. The Bax-conformational change is prevented by Bcl-2 and Bcl-xL but not by caspase inhibitors. Using isolated mitochondria and various BH3 mutants of Bid, we demonstrate that direct binding of Bid to Bax is a prerequisite for Bax structural change and cytochrome c release. Bcl-xL can inhibit the effect of Bid by interacting directly with Bax. Moreover, using mitochondria from Bax-deficient tumor cell lines, we show that Bid- induced release of cytochrome c is negligible when Bid is added alone, but dramatically increased when Bid and Bax are added together. Taken together, our results suggest that, during certain types of apoptosis, Bid translocates to mitochondria and binds to Bax, leading to a change in conformation of Bax and to cytochrome c release from mitochondria.
Asunto(s)
Apoptosis , Proteínas Portadoras/metabolismo , Grupo Citocromo c/metabolismo , Mitocondrias/enzimología , Conformación Proteica , Proteínas Proto-Oncogénicas c-bcl-2 , Proteínas Proto-Oncogénicas/química , Animales , Proteína Proapoptótica que Interacciona Mediante Dominios BH3 , Secuencia de Bases , Transporte Biológico , Proteínas Portadoras/genética , Células Cultivadas , Cartilla de ADN , Células HeLa , Humanos , Mutagénesis Sitio-Dirigida , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Ratas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteína X Asociada a bcl-2RESUMEN
Bcl-2 family members either promote or repress programmed cell death. Bax, a death-promoting member, is a pore-forming, mitochondria-associated protein whose mechanism of action is still unknown. During apoptosis, cytochrome C is released from the mitochondria into the cytosol where it binds to APAF-1, a mammalian homologue of Ced-4, and participates in the activation of caspases. The release of cytochrome C has been postulated to be a consequence of the opening of the mitochondrial permeability transition pore (PTP). We now report that Bax is sufficient to trigger the release of cytochrome C from isolated mitochondria. This pathway is distinct from the previously described calcium-inducible, cyclosporin A-sensitive PTP. Rather, the cytochrome C release induced by Bax is facilitated by Mg2+ and cannot be blocked by PTP inhibitors. These results strongly suggest the existence of two distinct mechanisms leading to cytochrome C release: one stimulated by calcium and inhibited by cyclosporin A, the other Bax dependent, Mg2+ sensitive but cyclosporin insensitive.
Asunto(s)
Grupo Citocromo c/metabolismo , Membranas Intracelulares/fisiología , Magnesio/metabolismo , Mitocondrias Hepáticas/fisiología , Proteínas Proto-Oncogénicas/metabolismo , Animales , Ácido Bongcréquico/farmacología , Células COS , Ciclosporina/farmacología , Femenino , Células HeLa , Humanos , Magnesio/farmacología , Ratones , Ratones Endogámicos , Mitocondrias Hepáticas/efectos de los fármacos , Permeabilidad , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Recombinantes/metabolismo , Transfección , Proteína X Asociada a bcl-2RESUMEN
We have examined the contractile response to the vasoconstrictor endothelin-1 (ET-1) in uteroplacental arteries from normal pregnant women in the presence and absence of specific ET-receptor antagonists and agonists, and the vasodilator nitric oxide. Segments of placental arteries (n = 97) obtained from 37 placentas immediately after delivery were mounted in organ baths superfused with Krebs-Ringer solution at 37 degrees C. The tension was recorded isometrically and registered on a polygraph. We found that the placental artery segments responded to ET with a dose-dependent vasoconstriction. Half-maximal response was obtained at 2.6 x 10(-8) M. At 10(-7) M, the contractile response was 52% of the maximum KCl-response. The ET-1 induced contraction at 10(-7) M was inhibited by 74% after addition of the ETA-antagonist BQ-123 (10(-6) M), and by 58% by the ETB-antagonist BQ-788 (10(-6) M). Both BQ-123 and BQ-788 almost completely abolished the response to ET (10(-7) M). The selective ETB-agonist IRL-1620 also elicited vasoconstriction in the placental artery with a half maximal response at 8 x 10(-7) M. On a molar basis at 10(-7) M, the contraction by IRL-1620 as compared to ET was 30-fold lower. The contractile response of IRL-1620 (10(-6) M) was inhibited by 99% by BQ-788 (10(-6) M). After pre-contraction of the placental arteries with ET-1 (10(-7) M), the vessels relaxed in response to the nitric oxide donor, nitroglycerin (10(-6) M). The present results show that ET-1 contracts placental arteries through both ETA- and ETB-receptor activation. Nitric oxide (10(-6) M) was able to relax more than half of the initial ET-1 contraction, indicating that nitric oxide may be an important vasodilator in the placenta.
Asunto(s)
Endotelinas/farmacología , Placenta/irrigación sanguínea , Receptores de Endotelina/efectos de los fármacos , Adulto , Arterias/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Antagonistas de los Receptores de Endotelina , Femenino , Humanos , Técnicas In Vitro , Contracción Muscular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Óxido Nítrico/fisiología , Nitroglicerina/farmacología , Embarazo , Receptor de Endotelina A , Receptor de Endotelina B , Receptores de Endotelina/agonistas , Vasodilatadores/farmacologíaRESUMEN
We have quantified activity-dependent uptake of the fluorescent dye FM1-43 in combination with immunocytochemistry for synaptic vesicle-associated proteins (SVPs) at individual synapses in primary cultures of rat cortical neurons. We show that expression of synaptic proteins is highly variable and that the levels of synaptophysin (p38), synapsin I and sv2, but not synapsin II, correlate with the extent of FM1-43 labelling at synapses. The data indicate that SVP levels affect the uptake of FM1-43 with different efficacy (p38 > synapsin I > sv2 or synapsin II). We also found that the relative levels of SVPs vary at individual boutons of single neurons grown in isolation, which indicates that differential regulation of specific SVPs may contribute to the selective modulation of activity at synapses of the same neuron.
Asunto(s)
Corteza Cerebral/fisiología , Proteínas del Tejido Nervioso/biosíntesis , Neuronas/fisiología , Sinapsis/fisiología , Vesículas Sinápticas/fisiología , Animales , Animales Recién Nacidos , Células Cultivadas , Corteza Cerebral/citología , Colorantes Fluorescentes , Proteínas del Tejido Nervioso/análisis , Neuronas/ultraestructura , Compuestos de Piridinio/farmacocinética , Compuestos de Amonio Cuaternario/farmacocinética , Ratas , Sinapsis/ultraestructura , Sinapsinas/biosíntesis , Vesículas Sinápticas/ultraestructura , Sinaptofisina/biosíntesisRESUMEN
Williams syndrome (WS) is associated with a submicroscopic deletion of the elastin gene (ELN) at 7q11.23. The deletion encompasses closely linked DNA markers. We have investigated 44 patients referred for possible WS using fluorescence in situ hybridization (FISH) analysis with a P1 clone containing an insert from the ELN, as well as performing genotype analysis of patients and parents with four DNA polymorphisms. Twenty-four patients were found to have deletions, 19 of whom were found clinically to have typical WS. The facial features were especially characteristic. None of the patients without detectable deletions was reported to have typical WS features, although one had supravalvular aortic stenosis, hypercalcemia, and mental retardation. No evidence was found in this material for variability of the size of the deletion. Our study supports the usefulness of analysis of ELN deletion in WS patients, both for confirmation of diagnosis and for genetic counselling.
Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 7 , Elastina/genética , Polimorfismo Genético , Síndrome de Williams/genética , Adolescente , Adulto , Niño , Preescolar , Bandeo Cromosómico , Mapeo Cromosómico , ADN/química , ADN/genética , Repeticiones de Dinucleótido , Femenino , Eliminación de Gen , Humanos , Hibridación Fluorescente in Situ , Lactante , Cariotipificación , Masculino , Síndrome de Williams/fisiopatologíaRESUMEN
The neuron-specific protein SCG10 and the ubiquitous protein stathmin are two members of a family of microtubule-destabilizing factors that may regulate microtubule dynamics in response to extracellular signals. To gain insight into the function of these proteins in the nervous system, we have compared their intracellular distribution in cortical neurons developing in culture. We have used double-immunofluorescence microscopy with specific antibodies for stathmin and SCG10 in combination with antibodies for axonal, microtubule, and synaptic marker proteins. Stathmin and SCG10 were coexpressed in individual neurons. While both proteins were highly expressed in developing cultures during differentiation, their subcellular localization was strikingly different. Stathmin showed a cytosolic distribution, mainly in cell bodies, whereas SCG10 strongly labeled the growth cones of axons and dendrites. During neurite outgrowth, SCG10 appeared as a single concentrated spot in a region of the growth cone where the microtubules are known to be particularly dynamic. Disassembly of labile microtubules by nocodazole caused a dispersal of the SCG10 staining into punctate structures, indicating that its subcellular localization is microtubule-dependent. Upon maturation and synapse formation, the levels of both stathmin and SCG10 decreased to become undetectable. These observations demonstrate that the expression of both proteins is associated with neurite outgrowth and suggest that they perform their roles in this process in distinct subcellular compartments.
Asunto(s)
Corteza Cerebral/química , Proteínas de Microtúbulos , Factores de Crecimiento Nervioso/análisis , Neuronas/química , Fosfoproteínas/análisis , Animales , Proteínas Portadoras , Células Cultivadas , Senescencia Celular/fisiología , Corteza Cerebral/citología , Regulación hacia Abajo , Técnica del Anticuerpo Fluorescente , Proteínas de la Membrana , Microtúbulos/química , Ratas , Estatmina , Sinapsis/metabolismoRESUMEN
UNLABELLED: High-resolution pinhole-SPECT (PSPECT) is a new method for examining the thyroid gland. METHODS: The camera is tilted slightly so that it is as close to the thyroid as possible. Patients are injected with 185-260 MBq (5-7 mCi) of [99mTc]pertechnetate and examined for 20 min. The reconstruction algorithm is based on filtered back-projection. RESULTS: We performed static scintigraphy on the thyroids of 114 patients, followed by PSPECT. The major advantage of P SPECT is high resolution. Three- and 4-mm-pinholes produce resolutions of 6 mm and 7 mm, respectively, while resolutions obtained with a parallel collimator are always above 15 mm. The second advantage associated with this method is the good visualization of the cold nodules surrounded by higher activity. Finally, the reconstruction program provides exact sizes of thyroids. CONCLUSION: SPECT is a powerful tool for examining the thyroid.