RESUMEN
Estuaries in rainfall poor regions are highly susceptible to climatic and hydrological changes. The Coorong, a Ramsar-listed estuarine-coastal lagoon at the end of the Murray-Darling Basin (Australia), has experienced declining ecological health over recent decades. Twenty years of environmental data were analysed to assess patterns and drivers of water quality changes. Large areas of the Coorong are now persistently hyper-saline (salinity >80 psu) and hypereutrophic (total nitrogen, TN > 4 mg L-1, total phosphorus, TP > 0.2 mg L-1, chlorophyll a > 50 µg L-1) which coincided with reduced flushing due to diminished freshwater inflows and increasing evapo-concentration. Sediment quality also was related to flushing, with higher concentrations of organic carbon, TN, TP and sulfides as salinity increased. While total nutrient levels are very high, dissolved inorganic nutrients are generally low. Increased lagoonal flushing would be beneficial to reduce the hypersalinisation and hypereutrophication and improve ecosystem health.
Asunto(s)
Ecosistema , Ríos , Clorofila A/análisis , Eutrofización , Australia , Nitrógeno/análisis , Fósforo/análisis , Monitoreo del Ambiente , Clorofila/análisisRESUMEN
BACKGROUND: Left ventricular (LV) filling pressures are normal in idiopathic pulmonary arterial hypertension (IPAH). However, direct and indirect interactions between the RV and LV can affect LV performance. We explored LV strain and LV intra-ventricular dyssynchrony in IPAH using feature tracking CMR (CMR-FT). METHODS: Seventy IPAH patients and 40 healthy volunteers were included. Patients underwent CMR and right heart catheterisation. The 4-chamber cine was used to calculate LV longitudinal strain (EllLV). LV circumferential (EccLV) and radial strain (ErrLV) were derived from a short axis cine. LV longitudinal, circumferential and radial intra-ventricular dyssynchrony indices were calculated. RESULTS: There were no differences between the IPAH and healthy volunteer group in LV ejection fraction (66.1% vs 64.2% p = 0.6672). EccLV (-29.1 vs -32.1 p = 0.0323) and EllLV (-16.6 vs -23.7 p < 0.0001) were lower in IPAH. In patients with more severe disease, there was greater impairment of ErrLV compared to mild disease (50.9 vs 87.5 P < 0.0001). LV synchrony was impaired in all directions in IPAH. ErrLV was associated with RV ejection fraction (r = 0.66), RV end-systolic volume index (r = -0.59), pulmonary vascular resistance (PVR)(r = 0.51) and stroke volume index (SVI)(r = 0.44). In a multivariate model with age, SVI and PVR, ErrLV (HR 0.970 p = 002) and radial dyssynchrony (HR 3.759 p < 0.0001) independently predicted survival. CONCLUSION: In IPAH, LV is dyssynchronous with impaired function. Measures of LV strain and intraventricular synchrony were associated with known markers of disease severity. These LV variables which are likely to be related to ventricular interaction, may add incremental value to known prognostic variables in IPAH.
Asunto(s)
Disfunción Ventricular Izquierda , Disfunción Ventricular Derecha , Hipertensión Pulmonar Primaria Familiar , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Volumen Sistólico , Disfunción Ventricular Izquierda/diagnóstico por imagen , Función Ventricular IzquierdaRESUMEN
Despite greater mental health co-morbidities and heavier alcohol use among PLWH, few studies have examined the role of the neighborhood alcohol environment on either alcohol consumption or mental health. Utilizing cross-sectional data from a cohort study in a southern U.S. metropolitan area, we examine the association between neighborhood alcohol environments on hazardous drinking and mental health among 358 in-care PLWH (84% African American, 31% female). Multilevel models were utilized to quantify associations between neighborhood alcohol exposure on hazardous drinking and effect modification by sex. Neighborhood alcohol density was associated with hazardous drinking among men but not women. Women living in alcohol dense neighborhoods were nearly two-fold likely to report depression compared to those in less dense neighborhoods, with no association between neighborhood alcohol density and depression among men. Neighborhood alcohol environments may be an important contextual factor to consider in reducing heavy alcohol consumption and improving mental health among PLWH.
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Consumo de Bebidas Alcohólicas/psicología , Bebidas Alcohólicas/provisión & distribución , Alcoholismo/epidemiología , Infecciones por VIH/psicología , Características de la Residencia/estadística & datos numéricos , Medio Social , Adulto , Negro o Afroamericano , Anciano , Consumo de Bebidas Alcohólicas/epidemiología , Bebidas Alcohólicas/estadística & datos numéricos , Estudios de Cohortes , Comorbilidad , Estudios Transversales , Etnicidad/psicología , Etnicidad/estadística & datos numéricos , Femenino , Infecciones por VIH/epidemiología , Humanos , Masculino , Salud Mental , Persona de Mediana Edad , Áreas de Pobreza , Factores Socioeconómicos , Población UrbanaRESUMEN
Asunto(s)
Infecciones por VIH/complicaciones , Infecciones por Mycobacterium no Tuberculosas/epidemiología , Micobacterias no Tuberculosas/aislamiento & purificación , Neumonía/epidemiología , Infecciones Oportunistas Relacionadas con el SIDA/diagnóstico , Infecciones Oportunistas Relacionadas con el SIDA/epidemiología , Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Adulto , Líquido del Lavado Bronquioalveolar/microbiología , Estudios de Cohortes , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Infecciones por Mycobacterium no Tuberculosas/diagnóstico , Neumonía/diagnóstico , Neumonía/microbiología , Prevalencia , Estudios Prospectivos , Esputo/microbiologíaRESUMEN
Interactions between Lipophrys pholis and its amphipod prey Echinogammarus marinus were used to investigate the effect of changing water temperatures, comparing current and predicted mean summer temperatures. Contrary to expectations, predator attack rates significantly decreased with increasing temperature. Handling times were significantly longer at 19° C than at 17 and 15° C and the maximum feeding estimate was significantly lower at 19° C than at 17° C. Functional-response type changed from a destabilizing type II to the more stabilizing type III with a temperature increase to 19° C. This suggests that a temperature increase can mediate refuge for prey at low densities. Predatory pressure by teleosts may be dampened by a large increase in temperature (here from 15 to 19° C), but a short-term and smaller temperature increase (to 17° C) may increase destabilizing resource consumption due to high maximum feeding rates; this has implications for the stability of important intertidal ecosystems during warming events.
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Perciformes/fisiología , Conducta Predatoria/fisiología , Temperatura , Anfípodos , Animales , Estaciones del AñoRESUMEN
The size and shape of the anal and dorsal fin in the blackstripe topminnow Fundulus notatus from lake and stream habitats across multiple ages and sexes were examined. Differences in the size and shape of anal and dorsal fins were sex-specific and not related to habitat differences. Males have longer and more pointed anal fins and longer, larger and more pointed dorsal fins than females. These sex differences occur predominantly in the older age class. The angle (i.e. pointedness) of the dorsal and anal fins is tightly correlated suggesting that fins follow a similar growth trajectory as individuals become sexually mature.
Asunto(s)
Aletas de Animales/anatomía & histología , Ecosistema , Fundulidae/anatomía & histología , Caracteres Sexuales , Animales , Femenino , Illinois , Lagos , Masculino , RíosRESUMEN
BACKGROUND/PURPOSE: The diagnosis of patients with pulmonary infiltrates and human immunodeficiency virus (HIV) infection remains a challenge. In current clinical practice the gold standard for Pneumocystis jirovecii pneumonia (PCP) diagnosis remains the identification of the organism in bronco alveolar lavage (BAL) using microscopy (e.g., silver stain). (1->3)-ß -d-glucan (BG) is a polysaccharide that is present within the cell wall of Pneumocystis and other fungi. METHODS: We analyzed serum and BAL lavage fluid from a cohort of 119 patients that did have HIV, a diagnosis of pneumonia and underwent bronchoscopy (FOB) for diagnosis of PCP. RESULTS: The discriminative power of serum BG for the diagnosis of PCP in this group of patients was very high. Using a cutoff of 300 pg/mL, the sensitivity, specificity, positive predictive value(PPV) and negative predictive value (NPV) were 91%, 92%, 89% and 93% respectively. A model for ROC with just serum BG (N = 108) had an AUC of 0.95. Serum procalcitonin (PCT) and BAL BG were not as accurate for the diagnosis of PCP. For BAL BG using a cutoff of 783 pg/mL, the sensitivity,specificity, positive predictive value (PPV) and negative predictive value (NPV) were 72%, 79%,72% and 79% respectively. The differences between the medians for serum PCT between the group with a without PCP did not reach statistical significance (p = 0.6137). CONCLUSION: The measurement of serum BG should be incorporated in the diagnostic work up of HIV positive patients with dyspnea and infiltrates on chest X X-ray. Our study confirms the diagnostic value of serum BG previously reported by others but we add a cutoff value that we believe is more accurate for patients with AIDS and suspicion of PCP.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/diagnóstico , Líquido del Lavado Bronquioalveolar/química , Neumonía por Pneumocystis/diagnóstico , beta-Glucanos/análisis , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Adulto , Biomarcadores/análisis , Biomarcadores/sangre , Recuento de Linfocito CD4 , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumonía por Pneumocystis/inmunología , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , beta-Glucanos/sangreRESUMEN
Bipolar disorder (BD) is associated with abnormal circadian rhythms. In treatment responsive BD patients, lithium (Li) stabilizes mood and reduces suicide risk. Li also affects circadian rhythms and expression of 'clock genes' that control them. However, the extent to which BD, Li and the circadian clock share common biological mechanisms is unknown, and there have been few direct measurements of clock gene function in samples from BD patients. Hence, the role of clock genes in BD and Li treatment remains unclear. Skin fibroblasts from BD patients (N=19) or healthy controls (N=19) were transduced with Per2::luc, a rhythmically expressed, bioluminescent circadian clock reporter gene, and rhythms were measured for 5 consecutive days. Rhythm amplitude and period were compared between BD cases and controls with and without Li. Baseline period was longer in BD cases than in controls. Li 1 mM increased amplitude in controls by 36%, but failed to do so in BD cases. Li 10 mM lengthened period in both BD cases and controls. Analysis of clock gene variants revealed that PER3 and RORA genotype predicted period lengthening by Li, whereas GSK3ß genotype predicted rhythm effects of Li, specifically among BD cases. Analysis of BD cases by clinical history revealed that cells from past suicide attempters were more likely to show period lengthening with Li 1 mM. Finally, Li enhanced the resynchronization of damped rhythms, suggesting a mechanism by which Li could act therapeutically in BD. Our work suggests that the circadian clock's response to Li may be relevant to molecular pathology of BD.
Asunto(s)
Antimaníacos/farmacología , Trastorno Bipolar/genética , Ritmo Circadiano/genética , Glucógeno Sintasa Quinasa 3/genética , Compuestos de Litio/farmacología , Miembro 1 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Proteínas Circadianas Period/efectos de los fármacos , Proteínas Circadianas Period/genética , Adulto , Antimaníacos/uso terapéutico , Trastorno Bipolar/tratamiento farmacológico , Trastorno Bipolar/metabolismo , Estudios de Casos y Controles , Células Cultivadas , Femenino , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Expresión Génica/efectos de los fármacos , Glucógeno Sintasa Quinasa 3 beta , Humanos , Compuestos de Litio/uso terapéutico , Masculino , Persona de Mediana Edad , Proteínas Circadianas Period/metabolismo , Adulto JovenRESUMEN
Bipolar disorder (BD) is characterized by disruptions in circadian rhythms such as sleep and daily activity that often normalize after lithium treatment in responsive patients. As lithium is known to interact with the circadian clock, we hypothesized that variation in circadian 'clock genes' would be associated with lithium response in BD. We determined genotype for 16 variants in seven circadian clock genes and conducted a candidate gene association study of these in 282 Caucasian patients with BD who were previously treated with lithium. We found that a variant in the promoter of NR1D1 encoding Rev-Erbα (rs2071427) and a second variant in CRY1 (rs8192440) were nominally associated with good treatment response. Previous studies have shown that lithium regulates Rev-Erbα protein stability by inhibiting glycogen synthase kinase 3ß (GSK3ß). We found that GSK3ß genotype was also suggestive of a lithium response association, but not statistically significant. However, when GSK3ß and NR1D1 genotypes were considered together, they predicted lithium response robustly and additively in proportion to the number of response-associated alleles. Using lymphoblastoid cell lines from patients with BD, we found that both the NR1D1 and GSK3ß variants are associated with functional differences in gene expression. Our findings support a role for Rev-Erbα in the therapeutic mechanism of lithium and suggest that the interaction between Rev-Erbα and GSK3ß may warrant further study.
Asunto(s)
Antimaníacos/uso terapéutico , Trastorno Bipolar/tratamiento farmacológico , Trastorno Bipolar/genética , Carbonato de Litio/uso terapéutico , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/genética , Trastorno Bipolar/psicología , Línea Celular Tumoral , Relojes Circadianos/genética , Péptidos y Proteínas de Señalización del Ritmo Circadiano/genética , ADN Complementario/biosíntesis , ADN Complementario/aislamiento & purificación , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Estudios de Asociación Genética , Variación Genética , Genotipo , Glucógeno Sintasa Quinasa 3/genética , Humanos , Polimorfismo de Nucleótido Simple , ARN/biosíntesis , ARN/aislamiento & purificaciónRESUMEN
BACKGROUND: When Pneumocystis DNA is recovered from respiratory specimens of patients without Pneumocystis pneumonia (PCP), patients are said to be colonised with Pneumocystis, although the significance of this state is unknown. Understanding risk factors for and outcomes of colonisation may provide insights into the life cycle and transmission dynamics of Pneumocystis jirovecii. METHODS: We performed a cross sectional study of the prevalence and clinical predictors of Pneumocystis colonisation in 172 HIV infected, PCP negative inpatients undergoing diagnostic evaluation of 183 episodes of pneumonia at either the Medical Center of Louisiana at New Orleans between 2003 and 2005 or San Francisco General Hospital between 2000 and 2005. DNA was extracted from sputum and bronchoalveolar lavage specimens and amplified using a nested PCR assay at the mitochondrial large subunit (18S) ribosomal RNA locus. Colonisation was deemed present if Pneumocystis DNA was identified by both gel electrophoresis and direct DNA sequencing. RESULTS: 68% (117/172) of all patients were colonised with Pneumocystis. No strong associations with colonisation were identified for any demographic factors. Among clinical factors, having a CD4+ T cell count =50 cells/mul (unadjusted OR 2.4, 95% CI 1.09 to 5.48; p = 0.031) and using PCP prophylaxis (unadjusted OR 0.55, 95% CI 0.29 to 1.07; p = 0.077) were associated with Pneumocystis colonisation, although the latter association may have been due to chance. After adjustment for CD4+ T cell count, use of PCP prophylaxis was associated with a decreased odds of colonisation (adjusted OR 0.45, 95% CI 0.21 to 0.98; p = 0.045). 11 patients who were colonised were subsequently readmitted for evaluation of a second episode of pneumonia; three were found to be colonised again, but none had PCP. CONCLUSIONS: The majority of hospitalised HIV infected patients with non-PCP pneumonia are colonised with Pneumocystis. Failure to use co-trimoxazole prophylaxis and severe immunosuppression are associated with an increase in the odds of colonisation. Pneumocystis colonisation among hospitalised patients does not commonly lead to PCP.
Asunto(s)
Linfocitos T CD4-Positivos , Infecciones por VIH/microbiología , Pneumocystis carinii/aislamiento & purificación , Neumonía por Pneumocystis/microbiología , Adulto , Anciano , Recuento de Linfocito CD4 , Estudios Transversales , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Pulmonary hypertension is associated with remodelling of pulmonary vessels. Chronic hypoxia is a common cause of pulmonary hypertension and pulmonary vascular remodelling. Vascular remodelling is characterised largely by fibroblast, smooth muscle and endothelial cell proliferation, which results in lumen obliteration. Chronic hypoxia elicits expression of mitogens, growth factors and cytokines by fibroblasts and endothelial cells, and also the suppression of endothelial nitric oxide synthase. Although hypoxic pulmonary vascular remodelling is associated with medial hypertrophy, many in vitro studies have found that hypoxia does not lead to a direct increase in smooth muscle cell proliferation. This paradox is not well understood and this review aims to examine the various reasons why this might be so. The present authors reviewed data from in vitro studies and also considered whether hypoxia could act on adjacent cells such as fibroblasts and endothelial cells to trigger smooth muscle cell proliferation. It is possible that hypoxia is sensed by fibroblasts, endothelial cells, or both, and relayed to adjacent pulmonary artery smooth muscle cells by intercellular signalling, causing proliferation. The present article reviews the data from in vitro studies of hypoxia on the three cellular components of the pulmonary vascular wall, namely endothelial cells, smooth muscle cells and fibroblasts.
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Endotelio Vascular/patología , Hipoxia/patología , Animales , Proliferación Celular , Células Endoteliales/metabolismo , Células Endoteliales/patología , Endotelio Vascular/metabolismo , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Hipertensión Pulmonar/metabolismo , Hipertensión Pulmonar/patología , Hipoxia/fisiopatología , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Arteria PulmonarAsunto(s)
Carbono/análisis , Monitoreo del Ambiente/estadística & datos numéricos , Sedimentos Geológicos/análisis , Fósforo/análisis , Compuestos de Amonio Cuaternario/análisis , Humedales , Sustancias Húmicas/análisis , Espectrometría de Masas , Tamaño de la Partícula , Queensland , Urbanización/tendenciasRESUMEN
Suprachiasmatic nucleus (SCN) neuroanatomy has been a subject of intense interest since the discovery of the SCN's function as a brain clock and subsequent studies revealing substantial heterogeneity of its component neurons. Understanding the network organization of the SCN has become increasingly relevant in the context of studies showing that its functional circuitry, evident in the spatial and temporal expression of clock genes, can be reorganized by inputs from the internal and external environment. Although multiple mechanisms have been proposed for coupling among SCN neurons, relatively little is known of the precise pattern of SCN circuitry. To explore SCN networks, we examine responses of the SCN to various photic conditions, using in vivo and in vitro studies with associated mathematical modeling to study spatiotemporal changes in SCN activity. We find an orderly and reproducible spatiotemporal pattern of oscillatory gene expression in the SCN, which requires the presence of the ventrolateral core region. Without the SCN core region, behavioral rhythmicity is abolished in vivo, whereas low-amplitude rhythmicity can be detected in SCN slices in vitro, but with loss of normal topographic organization. These studies reveal SCN circuit properties required to signal daily time.
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Ritmo Circadiano/fisiología , Núcleo Supraquiasmático/anatomía & histología , Núcleo Supraquiasmático/fisiología , Animales , Ritmo Circadiano/genética , Humanos , Ratones , Modelos Anatómicos , Modelos Neurológicos , Red Nerviosa/anatomía & histología , Red Nerviosa/fisiología , Neuropéptidos/genética , Neuropéptidos/fisiología , FotoperiodoRESUMEN
The effects of temperature change on phospholipid content in metacercariae of Posthodiplostomum minimum and their second intermediate hosts, Lepomis macrochirus, were examined to gauge similarities in the homeoviscous adaptation of host and parasite membranes to environmental thermal change. Heart, liver, and muscle tissues from individual L. macrochirus responded to environmental temperature declines with a decrease in the ratio of phosphatidylethanolamine (PE) to phosphatidylcholine (PC). Increases in membrane PE concentration increase membrane fluidity, maintaining fish membrane function as environmental temperature declines. However, the metacercariae of P. minimum exhibit changes in cholesterol levels, total lipid levels, and lipid composition (PE/PC) that contrast the normal changes for homeoviscous membrane adaptation exhibited by their fish intermediate hosts. The parasites seem to rely on their hosts for homeoviscous adaptation within normal developmental temperature ranges, pooling both cholesterol and PE as energetic stores for development and ontological transitions signaled by elevated temperatures.
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Lípidos de la Membrana/metabolismo , Perciformes/metabolismo , Perciformes/parasitología , Fosfolípidos/metabolismo , Temperatura , Trematodos/metabolismo , Aclimatación/fisiología , Animales , Colesterol/química , Colesterol/metabolismo , Enfermedades de los Peces/parasitología , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Hígado/química , Hígado/metabolismo , Fluidez de la Membrana/fisiología , Lípidos de la Membrana/química , Músculos/química , Músculos/metabolismo , Miocardio/química , Miocardio/metabolismo , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/metabolismo , Fosfolípidos/química , Distribución Aleatoria , Trematodos/química , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/veterinariaRESUMEN
We tested the hypothesis that TRPC3, a member of the canonical transient receptor potential (TRP) family of channels, mediates agonist-induced depolarization of arterial smooth muscle cells (SMCs). In support of this hypothesis, we observed that suppression of arterial SMC TRPC3 expression with antisense oligodeoxynucleotides significantly decreased the depolarization and constriction of intact cerebral arteries in response to UTP. In contrast, depolarization and contraction of SMCs induced by increased intravascular pressure, i.e., myogenic responses, were not altered by TRPC3 suppression. Interestingly, UTP-evoked responses were not affected by suppression of a related TRP channel, TRPC6, which was previously found to be involved in myogenic depolarization and vasoconstriction. In patch-clamp experiments, UTP activated a whole cell current that was greatly reduced or absent in TRPC3 antisense-treated SMCs. These results indicate that TRPC3 mediates UTP-induced depolarization of arterial SMCs and that TRPC3 and TRPC6 may be differentially regulated by receptor activation and mechanical stimulation, respectively.
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Arterias Cerebrales/fisiología , Canales Iónicos/metabolismo , Receptores de Superficie Celular/metabolismo , Vasoconstricción/fisiología , Animales , Arterias Cerebrales/citología , Potenciales Evocados/efectos de los fármacos , Expresión Génica , Canales Iónicos/genética , Masculino , Potenciales de la Membrana/fisiología , Miocitos del Músculo Liso/fisiología , Oligonucleótidos Antisentido/farmacología , Ratas , Ratas Sprague-Dawley , Canales Catiónicos TRPC , Uridina Trifosfato/metabolismo , Uridina Trifosfato/farmacología , Vasoconstricción/efectos de los fármacosRESUMEN
All cycles of IVF with pituitary down-regulation (n = 57) done at the Damansara Fertility Centre in the year 2000 were studied. All the 57 patients had controlled ovarian hyperstimulation, either using Metrodin HP (n = 27) or Gonal-F (n = 30). Of these, 53 patients reached oocyte pick-up, 26 patients in Metrodin HP group and 27 patients in Gonal-F group. Gonal-F resulted in a higher clinical pregnancy rate of 66.6% compared to Metrodin HP 38.5% (p < 0.05). The live birth rate tends to be higher in Gonal-F group (40.7%) compared to Metrodin HP (30.8%), (p > 0.05).
Asunto(s)
Fármacos para la Fertilidad Femenina/uso terapéutico , Fertilización In Vitro , Hormona Folículo Estimulante Humana/uso terapéutico , Hormona Folículo Estimulante/uso terapéutico , Infertilidad Femenina/terapia , Menotropinas/uso terapéutico , Inducción de la Ovulación , Resultado del Embarazo , Adulto , Femenino , Humanos , Malasia/epidemiología , Persona de Mediana Edad , Embarazo , Estudios RetrospectivosRESUMEN
BACKGROUND: Pulmonary hypertension is a common complication of chronic obstructive airways disease (COPD) and its presence implies a poor prognosis. However, it is difficult to measure and its specific contribution to symptoms is difficult to quantify. A micromanometer tipped pulmonary artery catheter was used to measure pulmonary artery pressure (PAP) during sleep and on exercise. METHODS: Ten patients (five with COPD receiving long term oxygen therapy and five normal individuals) were studied. Pulmonary artery pressure was recorded continuously during two periods of sleep (breathing oxygen followed by air for the COPD group) and during exercise. RESULTS: In the COPD group PAP during sleep on oxygen was significantly lower than PAP during sleep breathing air (mean (SD) difference 9.6 (5.3) mm Hg, 95% CI 4.9 to 14.3, p= 0.016). PAP during exercise was not significantly different from PAP during sleep breathing air (mean (SD) difference 0.8 (8.9) mm Hg, 95% CI -7.0 to 8.6, p= 0.851). In normal individuals the group mean (SD) PAP was 15 (5.9) mm Hg for the first nocturnal period and 15 (5.7) mm Hg for the second nocturnal period. PAP during exercise was not significantly different from PAP during sleep breathing air (mean (SD) difference 3.3 (2.2) mm Hg, 95% CI 1.1 to 5.5, p= 0.061). CONCLUSION: In patients with COPD, PAP rose significantly during sleep to levels similar to those measured during exercise, but this could be reversed with oxygen.
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Ejercicio Físico/fisiología , Arteria Pulmonar/fisiología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Presión Esfenoidal Pulmonar/fisiología , Adulto , Anciano , Prueba de Esfuerzo , Femenino , Humanos , Hipertensión Pulmonar/etiología , Hipertensión Pulmonar/fisiopatología , Masculino , Persona de Mediana Edad , Monitoreo Fisiológico , Oxígeno/uso terapéutico , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Sueño/fisiologíaRESUMEN
Whereas most people require more than 6 h of sleep to feel well rested, there appears to be a group of people who can function well on between 3 and 6 h of sleep. The aims of the present study were to compare 12 naturally short (3-6 h) sleepers (9 males 3 females, mean age 39.6 years, SD age 10.1 years) recruited by a media publicity campaign with age, gender and chronotype matched medium length (7-8.5 h) sleepers on various measures. Measurement instruments included diaries and questionnaires to assess sleep duration and timing, as well as questionnaire assessments of sleep pathology, morningness-eveningness, extroversion, neuroticism, pathological daytime sleepiness, subclinical hypomania, optimism, depressive symptoms, exercise, and work habits. Few measures showed reliable differences between naturally short sleepers and controls except the obvious ones related to sleep duration. There was, however, some evidence for subclinical hypomanic symptoms in naturally short sleepers.
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Registros Médicos , Trastornos del Sueño-Vigilia/diagnóstico , Encuestas y Cuestionarios , Adulto , Trastorno Bipolar/diagnóstico , Trastorno Bipolar/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos de la Personalidad/diagnóstico , Trastornos de la Personalidad/psicología , Inventario de Personalidad , Trastornos del Sueño-Vigilia/etiología , Factores de Tiempo , Vigilia/fisiologíaRESUMEN
Respiratory defenses against infection involve a diverse and complex system. Mechanical barriers limit exposure of the respiratory tract to potential pathogenic organisms, whereas the mucociliary apparatus and cough reflexes work to expel any microbes that may bypass the initial defenses. When microorganisms have gained entry to the lower respiratory tract, the alveolar macrophage and recruited phagocytes may eliminate the culprits before active infection can be established. Only after the failure of the innate immune defenses is a specific immune response mounted. Examination of clinical defects in host defense allows one to understand the importance of the multitude of components of the lung's immune defense system.
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Neumonía/inmunología , Sistema Respiratorio/inmunología , Formación de Anticuerpos/inmunología , Presentación de Antígeno/inmunología , Fenómenos Biomecánicos , Causalidad , Causas de Muerte , Humanos , Inmunidad Celular/inmunología , Inmunidad Mucosa , Inflamación/inmunología , Mediadores de Inflamación/inmunología , Linfocitos/inmunología , Macrófagos Alveolares/inmunología , Morbilidad , Fagocitos/inmunología , Neumonía/epidemiología , Neumonía/microbiología , Neumonía/prevención & control , Mucosa Respiratoria/inmunología , Estados Unidos/epidemiologíaRESUMEN
The present study was designed to determine whether myocardial atrophy is necessarily associated with changes in cardiac contractility. Myocardial unloading of normal hearts was produced via heterotopic transplantation in rats. Contractions of isolated myocytes (1.2 mM Ca2+; 37 degrees C) were assessed during field stimulation (0.5, 1.0, and 2.0 Hz), and papillary muscle contractions were assessed during direct stimulation (2.0 mM Ca2+; 37 degrees C; 0.5 Hz). Hemodynamic unloading was associated with a 41% decrease in median myocyte volume and proportional decreases in myocyte length and width. Nevertheless, atrophic myocytes had normal fractional shortening, time to peak contraction, and relaxation times. Despite decreases in absolute maximal force generation (F(max)), there were no differences in F(max)/ area in papillary muscles isolated from unloaded transplanted hearts. Therefore, atrophic remodeling after unloading is associated with intact contractile function in isolated myocytes and papillary muscles when contractile indexes are normalized to account for reductions in cell length and cross-sectional area, respectively. Nevertheless, in the absence of compensatory increases in contractile function, reductions in myocardial mass will lead to impaired overall work capacity.