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Human airway smooth muscle (HASM) contraction plays a central role in regulating airway resistance in both healthy and asthmatic bronchioles. In vitro studies that investigate the intricate mechanisms that regulate this contractile process are predominantly conducted on tissue culture plastic, a rigid, 2D geometry, unlike the 3D microenvironment smooth muscle cells are exposed to in situ. It is increasingly apparent that cellular characteristics and responses are altered between cells cultured on 2D substrates compared with 3D topographies. Electrospinning is an attractive method to produce 3D topographies for cell culturing as the fibers produced have dimensions within the nanometer range, similar to cells' natural environment. We have developed an electrospun scaffold using the nondegradable, nontoxic, polymer polyethylene terephthalate (PET) composed of uniaxially orientated nanofibers and have evaluated this topography's effect on HASM cell adhesion, alignment, and morphology. The fibers orientation provided contact guidance enabling the formation of fully aligned sheets of smooth muscle. Moreover, smooth muscle cells cultured on the scaffold present an elongated cell phenotype with altered contractile protein levels and distribution. HASM cells cultured on this scaffold responded to the bronchoconstrictor bradykinin. The platform presented provides a novel in vitro model that promotes airway smooth muscle cell development toward a more in vivo-like phenotype while providing topological cues to ensure full cell alignment.
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Adhesión Celular/fisiología , Músculo Liso/citología , Miocitos del Músculo Liso/citología , Tereftalatos Polietilenos/farmacología , Ingeniería de Tejidos/métodos , Andamios del Tejido , Materiales Biocompatibles/farmacología , Adhesión Celular/efectos de los fármacos , Técnicas de Cultivo de Célula , Proliferación Celular , Células Cultivadas , Microambiente Celular , Humanos , Pulmón/citología , Modelos Biológicos , NanofibrasRESUMEN
BACKGROUND: Few epidemiological studies of systemic lupus erythematosus (SLE) have been conducted in Australia, and current management practice and levels of unmet need in this country are not well characterised. AIM: To perform a systematic literature review to identify Australia-specific information on SLE, particularly areas of unmet need. METHODS: MEDLINE, EMBASE and the Cochrane Library were searched (1 January 1990 to 29 November 2013). All articles on prevalence, disease characteristics, management and outcomes of SLE in Australia were included. RESULTS: There is limited published information on SLE in Australia. Of 24 articles included, 18 described results from observational studies, three were narrative reviews, one was a clinical update, and two were medical education articles. In remote regions, SLE was reported to be more prevalent in Aboriginal Australians than non-Aboriginal Australians; information in urban populations is lacking. Asian Australians may be more affected by SLE than non-Asian Australians. Pregnancy outcomes may also be adversely affected. Many Australians with SLE may experience high levels of unmet need, including delayed diagnosis, ongoing symptoms, flares, depression/anxiety, sleeping difficulty and decreased quality of life. Published guidance on the SLE management in Australia is limited and dated. CONCLUSIONS: Published information on SLE in Australia is limited, but suggests that ethnicity may affect the prevalence and disease characteristics and that many Australians with SLE have unmet needs. Improvements in diagnosis, treatment and management are needed to alleviate these needs. Up-to-date guidance on the management of SLE would benefit healthcare professionals and patients.
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Depresión/etiología , Fatiga/etiología , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/epidemiología , Trastornos del Sueño-Vigilia/etiología , Adulto , Australia/epidemiología , Depresión/diagnóstico , Fatiga/diagnóstico , Femenino , Humanos , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/psicología , Lupus Eritematoso Sistémico/terapia , Masculino , Persona de Mediana Edad , Evaluación de Necesidades , Educación del Paciente como Asunto , Prevalencia , Calidad de Vida , Perfil de Impacto de Enfermedad , Trastornos del Sueño-Vigilia/diagnóstico , Apoyo SocialRESUMEN
INTRODUCTION: This work reports on a systematic approach to select MRI sequences, quantify inter-observer image registration variation and determine patient positioning for the clinical implementation of MR-guided adaptive radiotherapy (MRgRT) in patients with oropharyngeal (H&N) and lung cancer. METHODS: A total of 30 participants (N=10 H&N and N=10 lung cancer patients and N=10 healthy participants) were scanned on the Elekta Unity Magnetic Resonance Linear Accelerator (MRL). Participant experience questionnaires were used to determine the most appropriate positioning device for lung treatments and tolerability of H&N immobilization devices within the confined MR Linac environment. Visual guided assessments (VGAs) completed by three observers (one oncologist and two radiographers) were used to determine the most suitable tissue weighting (using vendor-provided 3D T1w and T2w sequences) for online image registration. Offline MRI to CT and MRI to MRI rigid registrations were undertaken by nine radiographers using bony and soft tissue matching. Single-factor ANOVA and paired t-tests were utilized to determine the interobserver variation. RESULTS: Based on oncologist and patient feedback, lung cancer patients would be treated in a vac-bag with their arms by their sides, while H&N cancer patients would be immobilized using a 5-point fixation device and 5-point personalized thermoplastic shell. There was no clear preference for T1w or T2w images in the H&N cohort. However, observers preferred T2w sequences for tumour and organ at risk (OAR) visualization in the lung images. When a bony match was conducted, single-factor ANOVA tests showed no statistically significant differences between all H&N image registration types (p=0.09). For the soft-tissue registrations, T1w-CT and T1w-T1w registrations showed a statistically significant (p=0.01) reduction in inter-observer variability over T2w-CT registrations. Paired t-tests showed no statistically significant differences for bony or soft tissue matches using T1w or T2w sequences to the planning CT in the lung cohorts (p=0.63 and p=0.52, respectively). CONCLUSION: We describe the systematic approach to the selection of strategies for imaging, immobilization, and online image registration we used for H&N and lung cancer treatments on the MRL. This has facilitated the selection of the most appropriate adaptive MRgRT strategies for treating these sites at our institution.
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BACKGROUND: Feelings of entrapment and deficits in social problem-solving skills have been associated with risk for suicidal behavior in the context of depression. However, few studies have examined the effect of age on the association between these risk factors and suicidal behavior across most of the adult lifespan. METHODS: In a three-site study, we tested interactions of age with feelings of entrapment and social problem-solving style in 105 depressed patients with a recent suicide attempt, 95 depressed patients with no history of suicide attempt, and 97 demographically similar non-psychiatric participants (age 16-80). Attempter/non-attempter differences, age interactions, and the relative contribution of entrapment and social problem-solving style to past attempter were examined. RESULTS: Entrapment significantly interacted with age such that it discriminated past attempters from depressed non-attempters better at older ages. Social Problem-Solving Inventory (SPSI) total score and most subscales did not distinguish past attempters, but the SPSI Impulsive Style Problem-Solving was an effective discriminator of past suicide attempts across the full adult lifespan and did not interact with age. In a multipredictor model, both the entrapment by age interaction and SPSI Impulsive Style Problem-Solving score were significant predictors for the classification of attempters. LIMITATIONS: The cross-sectional nature of our research design limited conclusions that may be drawn about individual change over time or cohort effects. CONCLUSIONS: Entrapment did not distinguish past attempters at younger ages but became a better discriminator in middle to late adulthood. An impulsive problem-solving style was associated with past suicide attempts across the full adult lifespan.
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Longevidad , Ideación Suicida , Humanos , Adulto , Adolescente , Adulto Joven , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Estudios Transversales , Intento de Suicidio/psicología , Emociones , Conducta ImpulsivaRESUMEN
Heart cells were loaded with sodium by treatment with toxic doses of acetyl strophanthidin. After this treatment, an increase in extracellular calcium resulted in a transient net outward sodium flux against its electrochemical gradient and in net cellular uptake of calcium. It is concluded that the free energy for the net outward sodium movement was derived from the increased calcium gradient and that these ion movements took place through the sodium-calcium exchange. While in the normal physiological state the sodium-calcium exchange produces calcium extrusion from the cell, these experiments demonstrate its reversibility.
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Calcio/metabolismo , Miocardio/metabolismo , Sodio/metabolismo , Animales , Transporte Biológico Activo , Citoplasma/metabolismo , Potenciales de la Membrana , Potasio/metabolismo , Conejos , Sarcolema/metabolismoRESUMEN
Ventricular myocytes exhibit a nifedipine-sensitive inward calcium current (ICa) and contracture when they are voltage clamped from -40 to 0 millivolt in the presence of caffeine and in the absence of extracellular sodium. However, upon repolarization they fail to relax because neither the sarcoplasmic reticulum nor the sodium-calcium exchange can reduce intracellular calcium. Sudden application of extracellular sodium during the contracture (but after repolarization) causes immediate relaxation and activates a transient inward sodium-calcium exchange current (INa-Ca), whose peak slightly precedes mechanical relaxation. The total charge carried by the nifedipine-sensitive ICa is twice the total charge carried by the transient inward INa-Ca. Assuming an exchange stoichiometry of three sodium to one calcium, these results indicate that all the calcium entering the cell during the initial depolarization is extruded by the sodium-calcium exchange.
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Canales de Calcio/fisiología , Proteínas Portadoras/fisiología , Corazón/fisiología , Animales , Cafeína/farmacología , Calcio/metabolismo , Conductividad Eléctrica , Cobayas , Potenciales de la Membrana , Contracción Miocárdica/efectos de los fármacos , Miocardio/metabolismo , Nifedipino/farmacología , Retículo Sarcoplasmático/metabolismo , Sodio/metabolismo , Sodio/farmacología , Intercambiador de Sodio-CalcioRESUMEN
Cell contraction and relaxation were measured in single voltage-clamped guinea pig cardiomyocytes to investigate the contribution of sarcolemmal Na+-Ca2+ exchange to mechanical relaxation. Cells clamped from -80 to 0 millivolts displayed initial phasic and subsequent tonic contractions; caffeine reduced or abolished the phasic and enlarged the tonic contraction. The rate of relaxation from tonic contractions was steeply voltage-dependent and was significantly slowed in the absence of a sarcolemmal Na+ gradient. Tonic contractions elicited in the absence of a Na+ gradient promptly relaxed when external Na+ was applied, reflecting activation of Na+-Ca2+ exchange. It appears that a voltage-dependent Na+-Ca2+ exchange can rapidly mechanically relax mammalian heart muscle.
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Corazón/fisiología , Contracción Miocárdica , Animales , Cafeína/farmacología , Estimulación Eléctrica , Cobayas , Técnicas In Vitro , Potenciales de la Membrana/efectos de los fármacos , Contracción Miocárdica/efectos de los fármacos , Perfusión , Sarcolema/efectos de los fármacos , Sarcolema/fisiologíaRESUMEN
BACKGROUND: Rates of violence in the USA have fluctuated widely over the past few decades. Theorists have examined period and cohort effects, but there appear to be no studies examining these effects on progression in developmental pathways towards violence. OBJECTIVE: To assess whether differences in progression among individuals in the Pittsburgh Youth Study are consistent with period or cohort effects. DESIGN: Multivariate logistic regression was conducted to examine differences between cohorts in the odds of progressing through the developmental pathway towards violence. Adjusted and unadjusted odds ratios (ORs) and corresponding 95% CI are reported. SETTING: Pittsburgh Pennsylvania, from 1987 to 2000. SUBJECTS: Two cohorts of male adolescents from the Pittsburgh Youth Study. The youngest cohort (n = 503) was followed from median ages 7 to 20, and the oldest cohort (n = 506) was followed up from median ages 13 to 25. MAIN OUTCOME MEASURE: The odds of progression along a developmental pathway towards violence. RESULTS: There was no statistically significant difference between the cohorts in progression from minor aggression to physical fighting (OR = 1.13, 95% CI 0.77 to 1.65). However, after adjustment for major risk factors, the oldest cohort was significantly more likely to progress from physical fighting to violence (OR = 2.34, 95% CI 1.39 to 3.92). CONCLUSIONS: These results provide initial evidence that cohort effects, which would be present early in development, do not contribute significantly to later differences in reported violence and raises the possibility of whether period effects can explain these differences.
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Desarrollo del Adolescente , Violencia/psicología , Adolescente , Conducta del Adolescente , Adulto , Envejecimiento/psicología , Niño , Métodos Epidemiológicos , Humanos , Masculino , Pennsylvania/epidemiología , Clase Social , Violencia/estadística & datos numéricos , Adulto JovenRESUMEN
Alterations in cation homeostasis during and after recovery from myocardial ischemia may account for some of the reversible and irreversible components of myocardial cell injury. To investigate possible mechanisms involved, we exposed cultured layers of spontaneously contracting chick embryo ventricular cells to media containing 1 mM cyanide (CN) and 20 mM 2-deoxyglucose (2-DG), and zero glucose for up to 6 h, and then allowed cultured cells to recover in serum-free culture medium for 24 h. Changes in Na, K, and Ca contents, 42K uptake and efflux, ATP content, cell water content, and lactate dehydrogenase (LDH) release were measured, and compared with changes produced by exposure to 10(-3) M ouabain and severe hypoxia. Exposure to CN and 2-DG caused marked increase in cell Na (sevenfold) and Ca (fivefold) contents, and a decrease in K content (one-fifth normal), coincident with ATP depletion to one-tenth normal levels. This produced only slight cell injury, evidenced by increased LDH release. Recovery for 24 h resulted in return to near normal values (expressed in nanomoles per milligram of protein) of Na, Ca, and ATP contents. However, there was failure of cell K content to return to normal, associated with a persistent reduced net uptake of 42K, and an increase in the rate of 42K efflux. These abnormalities in K homeostasis were associated with a decrease in cell volume and water content per milligram of protein. More marked ATP depletion (to 1/100 normal values) was produced by hypoxia plus 2-DG and zero glucose, and was associated with much more severe cell injury manifested by LDH loss. Ouabain exposure resulted in a much greater Ca gain (20-30-fold), relative to increase in Na content, than did either CN and 2-DG or hypoxia; and ouabain effects were not reversible (after a 15-fold or greater increase in Ca content was produced) and were associated with significant LDH release. We conclude that these cells are resistant to cell injury caused by moderately severe Ca overload and ATP depletion produced by exposure to CN and 2-DG. However, metabolic inhibition of ATP production produces persistent abnormalities in K homeostasis, associated with functional abnormalities.
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Adenosina Trifosfato/metabolismo , Cationes/metabolismo , Enfermedad Coronaria/metabolismo , Función Ventricular , Animales , Embrión de Pollo , Cianuros/farmacología , Desoxiglucosa/farmacología , Homeostasis , L-Lactato Deshidrogenasa/metabolismo , Contracción Miocárdica , Ouabaína/farmacología , Factores de Tiempo , Equilibrio HidroelectrolíticoRESUMEN
The kinetics of contractions and Ca(2+) transients are slowed in myocytes from failing hearts. The mechanisms accounting for these abnormalities remain unclear. Myocardial infarction (MI) was produced by ligation of the circumflex artery in rabbits. We used confocal microscopy to record spatially resolved Ca(2+) transients during field stimulation in left ventricular (LV) myocytes from control and infarcted hearts (3 weeks). Compared with controls, Ca(2+) transients in myocytes adjacent to the infarct had lower peak amplitudes and prolonged time courses. Control myocytes showed relatively uniform changes in [Ca(2+)] throughout the cell after electrical stimulation. In contrast, in MI myocytes [Ca(2+)] increased inhomogeneously and localized increases in [Ca(2+)] occurred throughout the rising and falling phases of the Ca(2+) transient. Ca(2+) content of the sarcoplasmic reticulum did not differ between MI and control myocytes. Peak L-type Ca(2+) current density was reduced in MI myocytes. The macroscopic gain function was not different in control and MI myocytes when calculated as the amplitude of the Ca(2+) transient/peak I:(Ca). However, when calculated as the peak rate of rise of the Ca(2+) transient/peak I:(Ca), the gain function was modestly decreased in the MI myocytes. Application of isoproterenol (100 nmol/L) improved the synchronization of Ca(2+) release in MI myocytes at both 0.5 and 1 Hz. The poorly coordinated production of Ca(2+) sparks in myocytes from infarcted rabbit hearts likely contributes to the diminished and slowed macroscopic Ca(2+) transient. These abnormalities can be largely overcome when phosphorylation of Ca(2+) cycling proteins is enhanced by ss-adrenergic stimulation.
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Señalización del Calcio , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Disfunción Ventricular Izquierda/metabolismo , Potenciales de Acción , Agonistas Adrenérgicos beta/farmacología , Animales , Calcio/metabolismo , Canales de Calcio Tipo L/metabolismo , Modelos Animales de Enfermedad , Isoproterenol/farmacología , Masculino , Infarto del Miocardio/complicaciones , Miocardio/citología , Técnicas de Placa-Clamp , Conejos , Retículo Sarcoplasmático/metabolismo , Procesos Estocásticos , Disfunción Ventricular Izquierda/etiologíaRESUMEN
In small-scale, subsistence agriculture in the tropics and the subtropics, traditional farming practices have evolved that provide a sustainable means of reducing the incidence and damage caused by pests including nematodes. Other newer, cultural and low-input practices can also be successfully introduced in small-scale farming. In sustainable and subsistence farming systems, nematodes and some other pests can be managed by integrating different farming practices into four strategies: preventing the introduction and spread of nematodes; using direct, nonchemical, cultural and physical control methods; encouraging naturally occurring biological control agents; and maintaining or enhancing the biodiversity inherent in multiple cropping and multiple cultivar traditional farming systems to increase the available resistance or tolerance to nematodes.
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Depletion of Brca1 leads to defects in mouse mammary gland development and mammary tumors in humans and mice. To explore the role of microRNAs (miRNAs) in this process, we examined the mammary glands of MMTV-Cre Brca1(Co/Co) mice for differential miRNA expression using a candidate approach. Several miRNAs were differentially expressed in mammary tissue at day 1 of lactation and in mammary epithelial cell lines in which Brca1 messenger RNA (mRNA) levels have been reduced. Functional studies revealed that several of these miRNAs regulate mammary epithelial cell function in vitro, including miR-206. Creation and analysis of MMTV-miR-206 transgenic mice showed no effect on lactational mammary development and no tumors, but indicates a role in mammary tissue remodeling in mature mice, potentially involving Igf-1 and Sfrp1. These results indicate the potential of miRNAs to mediate the consequences of Brca1 loss and suggest a novel function for miR-206.
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Alveolar soft part sarcoma (ASPS) is an unusual tumor with highly characteristic histopathology and ultrastructure, controversial histogenesis, and enigmatic clinical behavior. Recent cytogenetic studies have identified a recurrent der(17) due to a non-reciprocal t(X;17)(p11.2;q25) in this sarcoma. To define the interval containing the Xp11.2 break, we first performed FISH on ASPS cases using YAC probes for OATL1 (Xp11.23) and OATL2 (Xp11.21), and cosmid probes from the intervening genomic region. This localized the breakpoint to a 160 kb interval. The prime candidate within this previously fully sequenced region was TFE3, a transcription factor gene known to be fused to translocation partners on 1 and X in some papillary renal cell carcinomas. Southern blotting using a TFE3 genomic probe identified non-germline bands in several ASPS cases, consistent with rearrangement and possible fusion of TFE3 with a gene on 17q25. Amplification of the 5' portion of cDNAs containing the 3' portion of TFE3 in two different ASPS cases identified a novel sequence, designated ASPL, fused in-frame to TFE3 exon 4 (type 1 fusion) or exon 3 (type 2 fusion). Reverse transcriptase PCR using a forward primer from ASPL and a TFE3 exon 4 reverse primer detected an ASPL-TFE3 fusion transcript in all ASPS cases (12/12: 9 type 1, 3 type 2), establishing the utility of this assay in the diagnosis of ASPS. Using appropriate primers, the reciprocal fusion transcript, TFE3-ASPL, was detected in only one of 12 cases, consistent with the non-reciprocal nature of the translocation in most cases, and supporting ASPL-TFE3 as its oncogenically significant fusion product. ASPL maps to chromosome 17, is ubiquitously expressed, and matches numerous ESTs (Unigene cluster Hs.84128) but no named genes. The ASPL cDNA open reading frame encodes a predicted protein of 476 amino acids that contains within its carboxy-terminal portion of a UBX-like domain that shows significant similarity to predicted proteins of unknown function in several model organisms. The ASPL-TFE3 fusion replaces the N-terminal portion of TFE3 by the fused ASPL sequences, while retaining the TFE3 DNA-binding domain, implicating transcriptional deregulation in the pathogenesis of this tumor, consistent with the biology of several other translocation-associated sarcomas. Oncogene (2001) 20, 48 - 57.
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Cromosomas Humanos Par 17/genética , Proteínas de Unión al ADN/genética , Proteínas de Neoplasias/genética , Proteínas de Fusión Oncogénica/genética , Sarcoma de Parte Blanda Alveolar/genética , Factores de Transcripción/genética , Translocación Genética , Cromosoma X/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Axila , Secuencia de Bases , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Southern Blotting , Niño , Rotura Cromosómica , Mapeo Cromosómico , ADN Complementario/aislamiento & purificación , Extremidades , Femenino , Perfilación de la Expresión Génica , Humanos , Hibridación Fluorescente in Situ , Péptidos y Proteínas de Señalización Intracelular , Cariotipificación , Masculino , Datos de Secuencia Molecular , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/aislamiento & purificación , Proteínas de Fusión Oncogénica/biosíntesis , Proteínas de Fusión Oncogénica/aislamiento & purificación , Especificidad de Órganos/genética , ARN Mensajero/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de Proteína , Células Tumorales CultivadasRESUMEN
PURPOSE: The Ewing tumor (ET) family of peripheral primitive neuroectodermal tumors (pPNETs) are primitive small round-cell tumors (SRCTs) of the bone and soft tissue that occur predominantly in children and adolescents. However, pPNETs only rarely enter the differential diagnosis of bone and soft tissue SRCTs in adults. Recently, gene fusions between the EWS gene and different members of the ETS transcription factor family have been shown to occur in virtually all pPNETs and thus constitute a pathognomonic marker for this tumor subclass. The aim of the present study was to document EWS/ETS fusion gene expression in suspected pPNETs of adults as objective evidence for the existence of this tumor family in older patients. PATIENTS AND METHODS: The three contributing molecular diagnostic laboratories retrospectively compiled a cohort of all SRCT cases in which EWS/ETS gene fusions had been shown by molecular analysis. This cohort was surveyed for cases that occurred in patients aged 40 years or older, which were then analyzed for their clinical and pathologic features. RESULTS: Nine patients between 40 and 65 years of age were found to have tumors positive for EWS/ETS gene fusions. Standard histopathologic and clinical features of these cases, other than age, were similar to those of childhood pPNETs. Patients were initiated on appropriate therapy after molecular analysis confirmed the diagnosis of pPNET. CONCLUSION: Identification of an EWS/ETS gene fusion is useful in providing objective evidence of the diagnosis of pPNET in patients over the age of 40 years. This diagnosis should be considered in adults who present with bone and soft tissue SRCTs and appropriate biopsy specimens should be collected for molecular analysis at the time of diagnosis.
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Aberraciones Cromosómicas , Tumores Neuroectodérmicos Periféricos Primitivos/genética , Tumores Neuroectodérmicos Primitivos/genética , Proteínas de Fusión Oncogénica/genética , Factores de Transcripción/genética , Adulto , Anciano , ADN de Neoplasias/análisis , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Cariotipificación , Masculino , Persona de Mediana Edad , Tumores Neuroectodérmicos Primitivos/patología , Tumores Neuroectodérmicos Periféricos Primitivos/patología , Reacción en Cadena de la PolimerasaRESUMEN
Rabbit right ventricular papillary muscles were cooled from 30 to approximately 1 degree C immediately after discontinuing electrical stimulation (0.5 Hz). This produced a contracture that was 30-50% of the preceding twitch magnitude and required 20-30 s to develop. The contractures were identical in cooling solutions with normal (144 mM) or low (2.0 mM) Na. They were therefore not Na-withdrawal contractures. Contracture activation was considerably slower than muscle cooling (approximately 2.5 s to cool below 2 degrees C). Cooling contractures were suppressed by caffeine treatment (10.0 mM). Rapid cooling did not cause sufficient membrane depolarization (16.5 +/- 1.2 mV after 30 s of cooling) to produce either a voltage-dependent activation of contracture or a gated entry of Ca from the extracellular space. Contractures induced by treating resting muscles with 5 X 10(-5) M strophanthidin at 30 degrees C exhibited pronounced tension noise. The Fourier spectrum of this noise revealed a periodic component (2-3 Hz) that disappeared when the muscle was cooled. Cooling contractures decayed with rest (t1/2 = 71.0 +/- 9.3 s). This decay accelerated in the presence of 10.0 mM caffeine and was prevented and to some extent reversed when extracellular Na was reduced to 2.0 mM. 20 min of rest resulted in a net decline in intracellular Ca content of 1.29 +/- 0.38 mmol/kg dry wt. I infer that cooling contractures are principally activated by Ca from the sarcoplasmic reticulum (SR). The properties of these contractures suggest that they may provide a convenient relative index of the availability of SR Ca for contraction. The rest decay of cooling contractures (and hence the decay in the availability of activating Ca) is consistent with the measured loss in analytic Ca during rest. The results suggest that contraction in heart muscle can be regulated by an interaction between sarcolemmal and SR Ca transport.
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Calcio/metabolismo , Frío , Contracción Miocárdica , Miocardio/metabolismo , Animales , Transporte Biológico , Cafeína/farmacología , Calcio/fisiología , Análisis de Fourier , Técnicas In Vitro , Potenciales de la Membrana , Contracción Miocárdica/efectos de los fármacos , Conejos , Sarcolema/metabolismo , Retículo Sarcoplasmático/metabolismo , Estrofantidina/farmacología , Factores de TiempoRESUMEN
The relative magnitudes and functional significance of Ca extrusion by Na-Ca exchange and by an Nao-independent mechanism were investigated in monolayer cultures of chick embryo ventricular cells. Abrupt exposure of cells in 0-Nao, nominally 0-Cao solution to 20 mM caffeine produced a large contracture (3.94 +/- 0.90 micron of cell shortening) that relaxed with a t1/2 of 8.60 +/- 1.22 s. An abrupt exposure to caffeine plus 140 mM Na resulted in a contracture that was smaller in amplitude (1.53 +/- 0.50 micron) and relaxed much more rapidly (t1/2 = 0.77 +/- 0.09 s). An abrupt exposure to caffeine in 0-Nao solutions produced an increase in 45Ca efflux that persisted for 20 s, and a net loss of Ca content, determined by atomic absorption spectroscopy (AAS), of approximately 4 nmol/mg protein, within 35 s. A comparable net loss of Ca was demonstrated in the presence of 100 microM [Ca]o. The abrupt exposure of cultured cells to 0 Nao in 1.8 mM Ca produced a Ca uptake, estimated with 45Ca, of 3.2 nmol/mg protein X 15 s, but produced no increase in cell Ca content (AAS). In cells in which a 30% increase in Nai was produced by 5 min exposure to 10(-6) M ouabain, the abrupt exposure to 0 Nao produced a Ca uptake of 6 nmol/mg protein X 15 s and an increase in Ca content (AAS) of 4 nmol/mg protein. We conclude that there is an Nao-independent mechanism for Ca extrusion in these cells, presumably a Ca-ATPase Ca pump, with a limited Ca transport capacity of no more than 2 nmol/mg protein X 15 s. This is five times smaller than the demonstrated maximum capacity of the Na-Ca exchanger in these cells. The relaxation of twitch tension in these cells seems to be dependent primarily on sarcoplasmic reticulum uptake of Ca, with a secondary role provided by the Na-Ca exchanger. The Ca pump appears to contribute little to beat-to-beat relaxation.
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Calcio/metabolismo , Corazón/fisiología , Sodio/farmacología , Animales , Transporte Biológico Activo/efectos de los fármacos , Cafeína/farmacología , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Embrión de Pollo , Ventrículos Cardíacos/efectos de los fármacos , Cinética , Potenciales de la Membrana , Función VentricularRESUMEN
BACKGROUND: While previous studies have shown an increased rate of suicidal behavior in the relatives of suicide victims, it is unclear if this is attributable merely to increased familial rates of psychiatric disorders. Therefore, we conducted a family study of adolescent suicide victims (suicide probands) and community control probands (controls) to determine if the rates of suicidal behavior were higher in the relatives of adolescent suicide probands even after adjusting for differences in the familial rates of psychiatric disorders. METHOD: The relatives of 58 adolescent suicide probands and 55 demographically similar controls underwent assessment for Axis I and II psychiatric disorders, lifetime history of aggression, and history of suicidal behavior (attempts and completions) using a combination of family study and family history approaches. RESULTS: The rate of suicide attempts was increased in the first-degree relatives of suicide probands compared with the relatives of controls, even after adjusting for differences in rates of proband and familial Axis I and II disorders (odds ratio, 4.3; 95% confidence intervals, 1.1-16.6). On the other hand, the excess rate of suicidal ideation found in the relatives of suicide probands was explained by increased familial rates of psychiatric disorders. Among suicide probands, higher ratings of aggression were associated with higher familial loading for suicide attempts. CONCLUSIONS: Liability to suicidal behavior might be familially transmitted as a trait independent of Axis I and II disorders. The transmitted spectrum of suicidal behavior includes attempts and completions, but not ideation, and the transmission of suicidal behavior and aggression are related.
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Familia , Trastornos Mentales/epidemiología , Intento de Suicidio/estadística & datos numéricos , Suicidio/estadística & datos numéricos , Adolescente , Adulto , Factores de Edad , Agresión/psicología , Intervalos de Confianza , Femenino , Humanos , Masculino , Oportunidad Relativa , Linaje , Prevalencia , Suicidio/psicología , Intento de Suicidio/psicologíaRESUMEN
BACKGROUND: Cognitive behavioral therapy has been shown to be more efficacious than alternative psychosocial interventions for the acute treatment of adolescents with major depressive disorder. However, the long-term impact of brief psychosocial interventions on the course of adolescent depression is not well established. METHODS: One hundred seven adolescents with major depressive disorder randomly assigned to 12 to 16 weeks of cognitive behavioral therapy, systemic behavioral family therapy, or nondirective supportive therapy were evaluated for 2 years after the psychotherapy trial to document the subsequent course and predictors of major depressive disorder. RESULTS: There were no long-term differential effects of the 3 psychotherapies. Most participants (80%) recovered (median time, 8.2 months from baseline), and 30% had a recurrence (median time, 4.2 months from recovery). Twenty-one percent were depressed during at least 80% of the follow-up period. Severity of depression (at baseline) and presence of self-reported parent-child conflict (at baseline and during the follow-up period) predicted lack of recovery, chronicity, and recurrence. Despite the similarity to clinically referred patients at baseline, patients recruited via advertisement were less likely to experience a recurrence. CONCLUSIONS: There were no significant differences in long-term outcome among cognitive behavioral therapy, systematic behavioral family therapy, and nondirective supportive therapy. While most participants in this study eventually recovered, those with severe depression and self-perceived parent-child conflict are at greater risk for chronic depression and recurrences.
Asunto(s)
Terapia Cognitivo-Conductual , Trastorno Depresivo/terapia , Terapia Familiar , Psicoterapia Centrada en la Persona , Psicoterapia Breve , Adolescente , Enfermedad Crónica , Trastorno Depresivo/psicología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Relaciones Padres-Hijo , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Recurrencia , Factores de Riesgo , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
PURPOSE: A specific TLS-CHOP fusion gene resulting from the t(12;16) is present in at least 95% of myxoid liposarcomas (MLS). Three common forms of the TLS-CHOP fusion have been described, differing by the presence or absence of TLS exons 6-8 in the fusion product. Type 5-2 (also known as type II) consists of TLS exons 1-5 fused to CHOP exon 2; type 7-2 (also known as type I) also includes TLS exons 6 and 7 in the fusion, whereas type 8-2 (also known as type III) fuses TLS exons 1-8 to CHOP exon 2. We sought to determine the impact of TLS-CHOP fusion transcript structure on clinical outcome in a group of well-characterized MLS cases. We also analyzed P53 status, because this parameter has been found to have a significant prognostic impact in other sarcomas with chromosomal translocations. METHODS: We analyzed TLS-CHOP fusion transcripts by reverse-transcription PCR using RNA extracted from frozen tissue in 82 MLS confirmed previously to harbor a CHOP rearrangement either by Southern blotting or by cytogenetic detection of the t(12;16). Parameters analyzed included age, location, size, percentage of round cell (RC) component, areas of increased cellularity, necrosis, and surgical margins. In 71 (87%) cases, adequate tumor tissue was available for immunohistochemical analysis of P53 status, using DO7 antibody. The Kaplan-Meier method, log-rank, and Cox regression tests were used for survival analyses. RESULTS: Most MLS were >10 cm (73%), arising in the thigh (70%), and localized at presentation (89%). RC component was <5% in 47 (57%) cases and > or =5% in 35 (43%). The TLS-CHOP fusion transcript was type 5-2 in 55 (67%), type 7-2 in 16 cases (20%), and type 8-2 in 8 (10%). One tumor had a unique variant fusion, between exon 6 TLS and exon 2 CHOP. Two other cases (2%) showed an EWS-CHOP fusion transcript. Overexpression of P53 (defined as > or =10% nuclear staining) was detected in 12 (17%) cases. High histological grade (defined as > or =5% RC; P < 0.01), presence of necrosis (> or =5% of tumor mass; P < 0.05), and overexpression of P53 (P < 0.001) correlated with reduced metastatic disease-free survival in localized tumors. The presence of negative surgical margins (P < 0.01) and extremity location (P = 0.02) were found to be significant in predicting local recurrence in the entire group as well as localized cases by univariate and multivariate analysis. Although there was no significant correlation between TLS-CHOP transcript type and histological grade or disease-specific survival, an association was found between the P53 status and type 5-2 fusion (P < 0.01). CONCLUSION: In contrast to some other translocation-associated sarcomas, the molecular variability of TLS-CHOP fusion transcript structure does not appear to have a significant impact on clinical outcome in MLS. Instead, high histological grade (> or =5% RC), presence of necrosis, and P53 overexpression are predictors of unfavorable outcome in localized MLS.