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INTRODUCTION: This retrospective, matched case-control cohort study describes the incidence, indications, anesthesia techniques and outcomes of pregnancies complicated by surgery in a single tertiary-referral hospital. METHODS: Retrospective review of the hospital records of 171 patients who had non-obstetric surgery in the current pregnancy, between 2001 and 2016. Pregnancy outcomes of these women were firstly compared with all contemporary non-exposed patients (n=35â¯411), and secondly with 684 non-exposed control patients, matched for age, time of delivery and parity. RESULTS: The incidence of non-obstetric surgery during pregnancy was 0.48%, mostly performed during the second trimester (44%) and under general anesthesia (81%). Intra-abdominal surgery (44%) was the most commonly performed procedure, predominantly using laparoscopy (79%). Women undergoing surgery delivered earlier and more frequently preterm (25% vs. 17%, P=0.018); and birth weight was significantly lower [median (95% CI) 3.16 (3.06 to 3.26) vs. 3.27 (3.22 to 3.32) kg, P=0.044]. When surgery was performed under general anesthesia, low birth weight was more frequent (22% vs 6%, P=0.046). Overall pregnancy outcomes were neither influenced by trimester nor location (intra- vs extra-abdominal) of surgery. However, preterm birth rate secondary to surgery was higher for interventions during the third trimester, compared with other trimesters (10% vs 0, Pâ¯<0.001). CONCLUSION: Pregnant women who underwent surgery delivered preterm more frequently and their babies had lower birth weights. Laparoscopic surgery did not increase the incidence of adverse pregnancy outcomes. General anesthesia was associated with low birth weight. Whether these associations suggest causation or reflect the severity of the underlying condition remains speculative.
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Anestesia General/métodos , Complicaciones del Embarazo/cirugía , Derivación y Consulta , Peso al Nacer , Femenino , Humanos , Recién Nacido , Embarazo , Resultado del Embarazo , Estudios Retrospectivos , Centros de Atención Terciaria , Factores de TiempoRESUMEN
Quantitative Susceptibility Mapping (QSM) MRI at 7 Tesla and 11-Carbon Pittsburgh-Compound-B PET were used for investigating the relationship between brain iron and Amyloid beta (Aß) plaque-load in a context of increased risk for Alzheimer's disease (AD), as reflected by the Apolipoprotein E ε4 (APOE-e4) allele and mild cognitive impairment (MCI) in elderly subjects. Carriers of APOE-e4 with normal cognition had higher cortical Aß-plaque-load than non-carriers. In MCI an association between APOE-e4 and higher Aß-plaque-load was observable both for cortical and subcortical brain-regions. APOE-e4 and MCI was also associated with higher cortical iron. Moreover, cerebral iron significantly affected functional coupling, and was furthermore associated with increased Aß-plaque-load (R2-adjusted = 0.80, p < 0.001) and APOE-e4 carrier status (p < 0.001) in MCI. This study confirms earlier reports on an association between increased brain iron-burden and risk for neurocognitive dysfunction due to AD, and indicates that disease-progression is conferred by spatial colocalization of brain iron deposits with Aß-plaques.
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Péptidos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Disfunción Cognitiva/metabolismo , Hierro/metabolismo , Anciano , Anciano de 80 o más Años , Apolipoproteína E4/genética , Encéfalo/patología , Estudios de Casos y Controles , Disfunción Cognitiva/diagnóstico por imagen , Demografía , Femenino , Heterocigoto , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Tomografía de Emisión de Positrones , Corteza Prefrontal/metabolismo , Corteza Prefrontal/patologíaRESUMEN
BACKGROUND: The Cobb angle measurement is well established for the measurement of coronal deformity aspect of scoliotic curves. The effect of positional differences in relation to the apex side of the scoliosis is not yet fully quantified. While theoretically plausible that positioning error with rotation toward the apex of the scoliosis would decrease the Cobb angle, the relations are not investigated yet and were object of this study. MATERIALS AND METHODS: Multiple measurements of the Cobb angle were performed, while turning a spine-pelvic cadaveric specimen with a right-sided thoracic scoliosis of 47° (in neutral position) from 45° to -45° in steps of 5° using biplanar radiography. Statistical methods were applied to find the critical position, in which measurement errors potentially become clinically relevant (Cobb angle deviation >5°). RESULTS: Turning the specimen to the right (toward the apex of the scoliosis) produced during the first -15° of rotation, a Cobb angle ranging from 47° to 45°. At -20°, the Cobb angle was 42°, at -25° rotation 37° and at -30° rotation 36°. Above -30° rotation, the measured Cobb angle decreased to 36° (77 % of the original Cobb angle). No relevant differences were found by rotating the specimen to the left (away from the apex) (47° at neutral rotation and 44° at maximal error rotation of +45°). CONCLUSION: The influence of rotational misplacement of the patient at the time of image acquisition on Cobb angle measurements is negligible for a rotational misplacement of ±20° of rotation for a idiopathic right-sided thoracic scoliosis of 47°. Over 20° of rotational misplacement of the patient toward the apex of the scoliosis falsely decreases the Cobb angle.
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Posicionamiento del Paciente , Escoliosis/diagnóstico por imagen , Vértebras Torácicas/diagnóstico por imagen , Humanos , Procesamiento de Imagen Asistido por Computador , Radiografía , RotaciónRESUMEN
BACKGROUND: To date, no attempt has been made to investigate the agreement between qualitative bone scintigraphy (BS) and the presence of complex regional pain syndrome 1 (CRPS 1) and the agreement between a negative BS in the absence of CRPS 1. AIMS: To summarize the existing evidence quantifying the concordance of qualitative BS in the presence or absence of clinical CRPS 1. DATA SOURCES: We searched Medline, Embase, Dare and the Cochrane Library and screened bibliographies of all included studies. STUDY ELIGIBILITY CRITERIA: We selected diagnostic studies investigating the association between qualitative BS results and the clinical diagnosis of CRPS 1. The minimum requirement for inclusion was enough information to fill the two-by-two tables. RESULTS: Twelve studies met our inclusion criteria and were included in the meta-analysis. The pooled mean sensitivity of 12 two-by-two tables was 0.87 (95% CI, 0.68-0.97) and specificity was 0.69 (95% CI, 0.47-0.85). The pooled mean sensitivity for the subgroup with clearly defined diagnostic criteria (seven two-by-two tables) was 0.80 (95% CI, 0.44-0.95) and specificity was 0.73 (95% CI, 0.40-0.91). CONCLUSIONS: Based on this study, clinicians must be advised that a positive BS is not necessarily concordant with presence of absence or CRPS 1. Given the moderate level of concordance between a positive BS in the absence of clinical CRPS 1, discordant results potentially impede the diagnosis of CRPS 1.
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Huesos/diagnóstico por imagen , Distrofia Simpática Refleja/diagnóstico por imagen , Adulto , Humanos , Persona de Mediana Edad , Cintigrafía , Sensibilidad y EspecificidadRESUMEN
Between June 2001 and November 2008 a modified Dunn osteotomy with a surgical hip dislocation was performed in 30 hips in 28 patients with slipped capital femoral epiphysis. Complications and clinical and radiological outcomes after a mean follow-up of 3.8 years (1.0 to 8.5) were documented. Subjective outcome was assessed using the Harris hip score and the Western Ontario and McMaster Universities osteoarthritis index questionnaire. Anatomical or near-anatomical reduction was achieved in all cases. The epiphysis in one hip showed no perfusion intra-operatively and developed avascular necrosis. There was an excellent outcome in 28 hips. Failure of the implants with a need for revision surgery occurred in four hips. Anatomical reduction can be achieved by this technique, with a low risk of avascular necrosis. Cautious follow-up is necessary in order to avoid implant failure.
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Epífisis Desprendida/cirugía , Cabeza Femoral/diagnóstico por imagen , Articulación de la Cadera/cirugía , Osteotomía/métodos , Adolescente , Hilos Ortopédicos , Niño , Epífisis/irrigación sanguínea , Epífisis Desprendida/diagnóstico por imagen , Femenino , Necrosis de la Cabeza Femoral/diagnóstico por imagen , Necrosis de la Cabeza Femoral/etiología , Cuello Femoral/cirugía , Estudios de Seguimiento , Humanos , Masculino , Osteotomía/efectos adversos , Periostio/lesiones , Periostio/cirugía , Radiografía , Flujo Sanguíneo Regional , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: To document fetal stress hormone and Doppler changes after intrauterine transfusions (IUTs) in either the intrahepatic portion of the umbilical vein (IHV) or the placental cord insertion (PCI). METHOD: Pregnant women scheduled for IUT for fetal anemia (N = 25) were included prospectively. Cortisol, ß-endorphin and noradrenalin concentrations in fetal plasma and middle cerebral artery pulsatility index before and after transfusion were compared. Transfusions were performed through the (IHV), thus puncturing the fetus, or at the PCI. RESULTS: There were no measurable differences between the transfusion sites. CONCLUSION: In anemic fetuses undergoing transfusion, Doppler changes and fetal stress hormone changes were unrelated to the site of needle insertion.
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Anemia/terapia , Transfusión de Sangre Intrauterina , Enfermedades Fetales/terapia , Feto/metabolismo , Hormonas/metabolismo , Estrés Fisiológico/fisiología , Anemia/congénito , Anestésicos Intravenosos , Transfusión de Sangre Intrauterina/efectos adversos , Femenino , Sangre Fetal/química , Sangre Fetal/metabolismo , Enfermedades Fetales/sangre , Enfermedades Fetales/metabolismo , Indicadores de Salud , Hormonas/análisis , Hormonas/sangre , Humanos , Hidrocortisona/análisis , Hidrocortisona/sangre , Hidrocortisona/metabolismo , Arteria Cerebral Media/fisiología , Norepinefrina/análisis , Norepinefrina/sangre , Norepinefrina/metabolismo , Piperidinas/administración & dosificación , Placebos , Embarazo , Flujo Pulsátil/fisiología , Remifentanilo , betaendorfina/análisis , betaendorfina/sangre , betaendorfina/metabolismoRESUMEN
BACKGROUND: The limited duration of spinal labour analgesia combined with problems associated with maintenance of epidural analgesia, have prompted the search for combinations that could prolong spinal analgesia. A randomised, double-blind trial was carried out to test the hypotheses (a) that initial spinal labour analgesia is prolonged by administering clonidine and neostigmine epidurally whilst (b) the hourly local anaesthetic consumption is reduced. METHODS: Seventy labouring patients received spinal analgesia with ropivacaine and sufentanil. Fifteen minutes after spinal injection, 10 mL of study solution was administered epidurally. The study solution was plain saline or neostigmine 500 microg combined with clonidine 75 microg. Outcome parameters were duration of spinal analgesia, local anaesthetic consumption and number of patients delivering without additional epidural analgesia. RESULTS: Epidural clonidine and neostigmine significantly prolonged initial analgesia: 144 (105-163) min vs. 95 (70-120) min in the placebo group and reduced hourly ropivacaine consumption: 7.5 (3.0-11.9) mg vs. 12.7 (9.6-16.9) mg. More patients in the experimental group delivered before the first request for additional analgesia (9 vs. 2). CONCLUSION: Epidural administration of neostigmine 500 microg and clonidine 75 microg, following the intrathecal injection of ropivacaine and sufentanil, prolongs analgesia and reduces hourly ropivacaine consumption.
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Analgesia Epidural/métodos , Analgesia Obstétrica/métodos , Analgésicos/farmacología , Inhibidores de la Colinesterasa/farmacología , Clonidina/farmacología , Neostigmina/farmacología , Adulto , Amidas/administración & dosificación , Analgésicos/administración & dosificación , Anestésicos Locales/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Inhibidores de la Colinesterasa/administración & dosificación , Clonidina/administración & dosificación , Método Doble Ciego , Combinación de Medicamentos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Neostigmina/administración & dosificación , Dimensión del Dolor , Satisfacción del Paciente , Embarazo , Ropivacaína , Factores de Tiempo , Resultado del TratamientoRESUMEN
Production of reactive oxygen species (ROS) is a widely reported response of plants to wounding. However, the nature of enzymes responsible for ROS production and metabolism in the apoplast is still an open question. We identified and characterized the proteins responsible for the wound-induced production and detoxification of ROS in the apoplast of wheat roots (Triticum aestivum L.). Compared to intact roots, excised roots and leachates derived from them produced twice the amount of superoxide (O2(*-)). Wounding also induced extracellular peroxidase (ECPOX) activity mainly caused by the release of soluble peroxidases with molecular masses of 37, 40 and 136 kD. Peptide mass analysis by electrospray ionization-quadrupole time-of-flight-tandem mass spectrometry (ESI-QTOF-MS/MS) following lectin affinity chromatography of leachates showed the presence of peroxidases in unbound (37 kD) and bound (40 kD) fractions. High sensitivity of O2(*-)-producing activity to peroxidase inhibitors and production of O2(*-) by purified peroxidases in vitro provided evidence for the involvement of ECPOXs in O2(*-) production in the apoplast. Our results present new insights into the rapid response of roots to wounding. An important component of this response is mediated by peroxidases that are released from the cell surface into the apoplast where they can display both oxidative and peroxidative activities.
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Peroxidasa/metabolismo , Raíces de Plantas/metabolismo , Superóxidos/metabolismo , Triticum/metabolismo , Peróxido de Hidrógeno/metabolismo , Proteínas de Plantas/metabolismo , Estrés Fisiológico , Espectrometría de Masas en TándemRESUMEN
BACKGROUND: Accidental dural puncture (ADP) and post-dural puncture headache (PDPH) are important complications of obstetric regional anaesthesia. METHODS: Between January 1997 and October 2006 in our tertiary obstetric referral centre 17 198 neuraxial blocks were recorded; 965 epidural, 16193 combined spinal-epidural and 40 spinal. Records of all parturients who experienced either ADP or PDPH were reviewed. RESULTS: There were 89 ADPs (0.5%), 55 observed and 34 in which PDPH followed unrecognised dural puncture. Following known ADP, 28 women had epidural catheters re-sited at a different lumbar interspace and 27 had intrathecal catheters for at least 24 h. Thirty-one women developed PDPH after observed ADP; the incidence of PDPH was similar after puncture with needle and catheter, after epidural and CSE techniques, after 27- and 29-gauge pencil-point spinal needles and after spinal and epidural catheter insertion (61% vs 52%; P>0.05). All headaches presented within 72 h. A blood patch was needed in 26/55 women after known ADP and 27/34 unrecognised ADP. A repeat blood patch was needed in 8 (15%). DISCUSSION: The incidence of ADP, PDPH, blood patching and repeat blood patching is similar to previous studies. Many ADPs are unrecognised during epidural insertion. CSE does not appear to increase the risk of ADP or PDPH; 29-gauge rather than 27-gauge pencil-point spinal needles conferred no benefit. Inserting the epidural catheter intrathecally did not significantly reduce the incidence of PDPH and blood patching in our series.
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Anestesia Epidural/efectos adversos , Anestesia Obstétrica/efectos adversos , Anestesia Raquidea/efectos adversos , Cefalea Pospunción de la Duramadre/epidemiología , Punción Espinal/efectos adversos , Adulto , Femenino , Humanos , Incidencia , Cefalea Pospunción de la Duramadre/terapia , EmbarazoRESUMEN
Surgery during pregnancy is relatively common. The present review of the literature will focus on relevant issues such as maternal safety during non-obstetric surgery in pregnancy, teratogenicity of anesthetic drugs, the avoidance of fetal asphyxia, the prevention of preterm labor, the safety of laparoscopy, the need to monitor the fetal heart rate and will finally give a practical approach to manage these patients.
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Anestesia , Complicaciones del Embarazo/cirugía , Procedimientos Quirúrgicos Operativos , Adulto , Anestésicos/efectos adversos , Asfixia/prevención & control , Femenino , Enfermedades Fetales/prevención & control , Monitoreo Fetal , Humanos , Recién Nacido , Trabajo de Parto Prematuro/prevención & control , Embarazo , TeratógenosRESUMEN
BACKGROUND: Patients do not respond to treatment in a predictable manner. Individual preconceptions determine help seeking, compliance and treatment outcome, yet clinicians rarely explore these issues. The illness perception approach sees the patient as an active participant in the healthcare process. AIMS: The aim of this study was to investigate the illness perceptions of people with dysphonia. The subsidiary aims were to correlate the Illness Perception Questionnaire with any psychological distress identified and a self-report measure of dysphonia, and to consider any potential implications for patient management. DESIGN: Prospective, cross-sectional observation. SETTING: Primary and secondary care, two general and four community hospitals. PARTICIPANTS: Fifty adult patients with dysphonia due to benign disease completed three self-administered questionnaires, which investigated their illness perceptions, psychological distress and perceptions of the impact of the presenting 'illness'. MEASURES: The dysphonia was categorised as being due to functional (n=40) or organic (n=10) causes. All the voices were rated by an expert listener according to the GRBAS (grade, roughness, breathiness, aesthenia, strain) scale. PARTICIPANTS completed the Illness Perception Questionnaire, the Vocal Performance Questionnaire and the Hospital Anxiety and Depression scale. RESULTS: Patients showed a wide variation in perception of causation. They had no strong perceptions about the causes, consequences or duration of the presenting dysphonia. Functional dysphonics reported greater consequences, lower perceived control and increased anxiety when compared to patients with organic dysphonia. In terms of cure/control, all patients expected treatment to be helpful but this expectancy reduced as time increased. Anxiety was more associated with functional dysphonia, however, only 17 per cent of the subjects in this group showed clinically significant levels of signs of psychological distress. CONCLUSIONS: Lay illness representations often diverge from the clinician's understanding of the presenting problem and strongly influence treatment behaviour. Early exploration of illness perceptions may enhance health behaviour and maximise the impact of intervention.
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Actitud Frente a la Salud , Trastornos de la Voz/psicología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Percepción , Proyectos Piloto , Índice de Severidad de la Enfermedad , Encuestas y CuestionariosRESUMEN
The objective of this study was to determine the prevalence of enterohemorrhagic Escherichia coli (EHEC), E. coli O157, Salmonella, and Listeria monocytogenes in retail food samples from Seattle, Wash. A total of 2,050 samples of ground beef (1,750 samples), mushrooms (100 samples), and sprouts (200 samples) were collected over a 12-month period and analyzed for the presence of these pathogens. PCR assays, followed by culture confirmation were used to determine the presence or absence of each organism. Of the 1,750 ground beef samples analyzed, 61 (3.5%) were positive for EHEC, and 20 (1.1%) of these were positive for E. coli O157. Salmonella was present in 67 (3.8%) of the 1,750 ground beef samples. Of 512 ground beef samples analyzed, 18 (3.5%) were positive for L. monocytogenes. EHEC was found in 12 (6.0%) of the 200 sprout samples, and 3 (1.5%) of these yielded E. coli O157. Of the 200 total sprout samples, 14 (7.0%) were positive for Salmonella and none were positive for L. monocytogenes. Among the 100 mushroom samples, 4 (4.0%) were positive for EHEC but none of these 4 samples were positive for E. coli O157. Salmonella was detected in 5 (5.0%) of the mushroom samples, and L. monocytogenes was found in 1 (1.0%) of the samples.
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Escherichia coli/aislamiento & purificación , Contaminación de Alimentos/análisis , Listeria monocytogenes/aislamiento & purificación , Productos de la Carne/microbiología , Medicago sativa/microbiología , Salmonella/aislamiento & purificación , Agaricales , Animales , Bovinos , Seguridad de Productos para el Consumidor , Escherichia coli O157/aislamiento & purificación , Microbiología de Alimentos , Humanos , Incidencia , Reacción en Cadena de la Polimerasa/métodos , WashingtónRESUMEN
We present an optical scheme to actively suppress statistical noise in Laser Speckle Imaging (LSI). This is achieved by illuminating the object surface through a diffuser. Slow rotation of the diffuser leads to statistically independent surface speckles on time scales that can be selected by the rotation speed. Active suppression of statistical noise is achieved by accumulating data over time. We present experimental data on speckle contrast and noise for a dynamically homogenous and a heterogeneous object made from Teflon. We show experimentally that for our scheme spatial and temporal averaging provide the same statistical weight to reduce the noise in LSI: The standard deviation of the speckle contrast value scales with the effective number N of independent speckle as 1/ radicalN.
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Shiga toxin-producing Escherichia coli (STEC) is increasingly recognized as a common cause of diarrhea. STEC infection is a major public health threat because of its ability to cause serious and potentially life-threatening illnesses. The main reservoirs of STEC are believed to be the intestinal tracts of animals. Several studies have investigated the prevalence of STEC in various food items. The objective of this study was to determine the prevalence of STEC in the Seattle ground beef supply. In addition, the relative amount of STEC contamination between stores was compared, and possible differences between types of ground beef based on fat content (9, 16, and 23%) were investigated. A survey of Stx-I and/or Stx-II genes in fecal samples from cattle at a local slaughterhouse was also conducted. Of 296 ground beef samples tested from area retail grocery stores, 16.8% were positive for the presence of the toxin genes. Our data showed that there was no statistically significant difference (P > 0.05) in the prevalence of STEC between the ground beef samples of different fat contents and between grocery store chains. Of the 103 cattle fecal samples tested, 19 (18.4%) were found positive for the presence of Stx-I and/or Stx-II genes. The presence of a rather high percentage of STEC in the food supply in the absence of large number of cases suggests that not all STEC lineages are pathogenic for humans.
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Escherichia coli/aislamiento & purificación , Heces/microbiología , Productos de la Carne/microbiología , Toxinas Shiga/genética , Animales , Bovinos , Diarrea/microbiología , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Grasas , Microbiología de Alimentos , Humanos , Prevalencia , Washingtón/epidemiologíaRESUMEN
A PCR approach was used to clone thyrotropin-releasing hormone receptors (TRH-R) from the brain and anterior pituitary of the teleost Catostomus commersoni (cc), the white sucker. Two distinct TRH-R, designated ccTRH-R1 and ccTRH-R2, were identified. ccTRH-R1 was similar to mammalian TRH-R of the subtype 1, whereas ccTRH-R2 exhibited the highest identity (61% at the amino acid level) with the recently discovered rat TRH-R2. It is postulated that ccTRH-R2 and rat TRH-R2 are members of the same TRH-R subfamily 2. Functional expression of ccTRH receptors in human embryonic kidney cells and in Xenopus laevis oocytes demonstrated that both ccTRH receptors were fully functional in both systems. Oocytes expressing either receptor responded to the application of TRH by an induction of membrane chloride currents, indicating that ccTRH-R of both subtypes are coupled to the inositol phosphate/calcium pathway. The analysis of genomic clones revealed, for the first time, both similarities and differences in the structure of TRH-R subtype genes. Both ccTRH-R genes contained an intron within the coding region at the beginning of transmembrane domain (TM) 6. The position of this intron is highly conserved, as it was found at an identical position in the human TRH-R1 gene. The ccTRH-R2 gene contained an additional intron at the end of TM 3 that was not found in any of the TRH-R1 genes identified so far. The analysis of the gene structure of ccTRH-R and the amino acid sequence comparisons of mammalian and teleost TRH-R of both subtypes suggest that TRH receptors have been highly conserved during the course of vertebrate evolution. A common ancestral TRH receptor gene that could be found much earlier in evolution, possibly in invertebrates, might be the origin of ccTRH-R genes.
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Cipriniformes/genética , Evolución Molecular , Receptores de Hormona Liberadora de Tirotropina/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Células Cultivadas , Clonación Molecular , Cipriniformes/fisiología , ADN/química , ADN/genética , ADN/aislamiento & purificación , Humanos , Datos de Secuencia Molecular , Oocitos/fisiología , Especificidad de Órganos , Receptores de Hormona Liberadora de Tirotropina/clasificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido , Xenopus laevisAsunto(s)
Anticuerpos Monoclonales/inmunología , Proteínas de Ciclo Celular/inmunología , Técnica del Anticuerpo Fluorescente Indirecta/métodos , Inmunohistoquímica/métodos , Antígeno Ki-67/análisis , Ciclo Celular , Proteínas de Ciclo Celular/análisis , Células Cultivadas , Humanos , Antígeno Ki-67/inmunología , Leucocitos Mononucleares/química , Linfoma Folicular/química , Linfoma Folicular/diagnóstico , Componente 6 del Complejo de Mantenimiento de Minicromosoma , Neoplasias/diagnóstico , Oocitos/químicaRESUMEN
The postsynaptic density is the ultrastructural entity containing the neurotransmitter reception apparatus of excitatory synapses in the brain. A recently identified family of multidomain proteins termed Src homology 3 domain and ankyrin repeat-containing (Shank), also known as proline-rich synapse-associated protein/somatostatin receptor-interacting protein, plays a central role in organizing the subsynaptic scaffold by interacting with several synaptic proteins including the glutamate receptors. We used the N-terminal ankyrin repeats of Shank1 and -3 to search for interacting proteins by yeast two-hybrid screening and by affinity chromatography. By cDNA sequencing and mass spectrometry the cytoskeletal protein alpha-fodrin was identified as an interacting molecule. The interaction was verified by pull-down assays and by coimmunoprecipitation experiments from transfected cells and brain extracts. Mapping of the interacting domains of alpha-fodrin revealed that the highly conserved spectrin repeat 21 is sufficient to bind to the ankyrin repeats. Both interacting partners are coexpressed widely in the rat brain and are colocalized in synapses of hippocampal cultures. Our data indicate that the Shank1 and -3 family members provide multiple independent connections between synaptic glutamate receptor complexes and the cytoskeleton.
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Proteínas Adaptadoras Transductoras de Señales , Repetición de Anquirina , Encéfalo/ultraestructura , Proteínas Portadoras/metabolismo , Proteínas de Microfilamentos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Encéfalo/embriología , Química Encefálica , Proteínas Portadoras/aislamiento & purificación , Secuencia Conservada , Hipocampo/ultraestructura , Proteínas de Microfilamentos/aislamiento & purificación , Proteínas del Tejido Nervioso/aislamiento & purificación , Unión Proteica , Ratas , Sinapsis/química , Sinapsis/ultraestructura , Distribución Tisular , Técnicas del Sistema de Dos Híbridos , Dominios Homologos srcRESUMEN
mRNA localization is a complex pathway. Besides mRNA sorting per se, this process includes aspects of regulated translation. It requires protein factors that interact with defined sequences (or sequence motifs) of the transcript, and the protein/RNA complexes are finally guided along the cytoskeleton to their ultimate destinations. The mRNA encoding the vasopressin (VP) precursor protein is localized to the nerve cell processes in vivo and in primary cultured nerve cells. Sorting of VP transcripts to dendrites is mediated by the last 395 nucleotides of the mRNA, the dendritic localizer sequence, and it depends on intact microtubules. In vitro interaction studies with cytosolic extracts demonstrated specific binding of a protein, enriched in nerve cell tissues, to the radiolabeled dendritic localizer sequence probe. Biochemical purification revealed that this protein is the multifunctional poly(A)-binding protein (PABP). It is well known for its ability to bind with high affinity to poly(A) tails of mRNAs, prerequisite for mRNA stabilization and stimulation of translational initiation, respectively. With lower affinities, PABP can also associate with non-poly(A) sequences. The physiological consequences of these PABP/RNA interactions are far from clear but may include functions such as translational silencing. Presumably, the translational state of mRNAs subject to dendritic sorting is influenced by external stimuli. PABP thus could be a component required to regulate local synthesis of the VP precursor and possibly of other proteins.
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Encéfalo/metabolismo , Neuronas/metabolismo , ARN Mensajero/genética , Proteínas de Unión al ARN/metabolismo , Vasopresinas/genética , Secuencia de Aminoácidos , Animales , Cromatografía de Afinidad , Clonación Molecular , Dendritas/metabolismo , Regulación de la Expresión Génica , Datos de Secuencia Molecular , Proteínas de Unión a Poli(A) , Biosíntesis de Proteínas , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , ARN Mensajero/análisis , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/aislamiento & purificación , Ratas , Vasopresinas/metabolismoRESUMEN
We cloned the mouse TRH receptor type 2 (mTRH-R2) gene, which is 92% identical with rat TRH-R2 and 50% identical with mTRH-R1 at the amino acid level, and identified an intron within the coding sequence that is not present in the TRH-R1 gene structure. Similar to its rat homolog, mTRH-R2 binds TRH with an affinity indistinguishable from mTRH-R1, signals via the phosphoinositide pathway like mTRH-R1, but exhibits a higher basal signaling activity than mTRH-R1. We found that regulator of G protein signaling 4 (RGS4), which differentially inhibits signaling by other receptors that couple to Gq, inhibits TRH-stimulated signaling via mTRH-R1 and mTRH-R2 to similar extents. In contrast, other RGS proteins including RGS7, RGS9, and GAIP had no effect on signaling by mTRH-R1 or mTRH-R2 demonstrating the specificity of RGS4 action. Interestingly, RGS4 markedly inhibited basal signaling by mTRH-R2. Inhibition of basal signaling of mTRH-R2 by RGS4 suggests that modulation of agonist-independent signaling may be an important mechanism of regulation of G protein-coupled receptor activity under normal physiologic circumstances.
Asunto(s)
Proteínas RGS/farmacología , Receptores de Hormona Liberadora de Tirotropina/fisiología , Transducción de Señal/efectos de los fármacos , Hormona Liberadora de Tirotropina/farmacología , Secuencia de Aminoácidos/genética , Animales , Northern Blotting , Línea Celular , Clonación Molecular , Humanos , Ratones , Datos de Secuencia Molecular , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiología , Receptores de Hormona Liberadora de Tirotropina/genéticaRESUMEN
Juxtamembrane residues in the putative third intracellular (I3) loops of a number of G protein-coupled receptors (GPCRs) have been shown to be important for coupling to G proteins. According to standard hydropathy analysis, the I3 loop of the mouse TRH receptor type 1 (mTRH-R1) is composed of 51 amino acids from position-213 to position-263. We constructed deletion and site-specific I3 loop TRH-R mutants and studied their binding and TRH-stimulated signaling activities. As expected, the effects of these mutations on TRH binding were small (less than 5-fold decreases in affinity). No effect on TRH-stimulated signaling activity was found in a mutant receptor in which the I3 loop was shortened to 16 amino acids by deleting residues from Asp-226 to Ser-260. In contrast, mutants with deletions from Asp-222 to Ser-260 or from Asp-226 to Gln-263 exhibited reduced TRH-stimulated signaling. In the region near transmembrane helix 6, single site-specific substitution of either Arg-261 or Lys-262 by neutral glutamine had little effect on signaling, but mutant TRH-Rs that were substituted by glutamine at both basic residues exhibited reduced TRH-stimulated activity. The reduced signaling activity of this doubly substituted mutant was reversed by over expressing the a subunit of Gq. These data demonstrate that the juxtamembrane regions in the TRH-R I3 loop are important for coupling to Gq.