332 resultados para acute pulmonary thromboembolism
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Acute promyelocytic leukemia (APL) is associated with a reciprocal and balanced translocation involving the retinoic acid receptor-alpha (RARalpha). All-trans retinoic acid (ATRA) is used to treat APL and is a potent morphogen that regulates HOX gene expression in embryogenesis and organogenesis. HOX genes are also involved in hematopoiesis and leukemogenesis. Thirty-nine mammalian HOX genes have been identified and classified into 13 paralogous groups clustered on 4 chromosomes. They encode a complex network of transcription regulatory proteins whose precise targets remain poorly understood. The overall function of the network appears to be dictated by gene dosage. To investigate the mechanisms involved in HOX gene regulation in hematopoiesis and leukemogenesis by precise measurement of individual HOX genes, a small-array real-time HOX (SMART-HOX) quantitative polymerase chain reaction (PCR) platform was designed and validated. Application of SMART-HOX to 16 APL bone marrow samples revealed a global down-regulation of 26 HOX genes compared with normal controls. HOX gene expression was also altered during differentiation induced by ATRA in the PML-RARalpha(+) NB4 cell line. PML-RARalpha fusion proteins have been reported to act as part of a repressor complex during myeloid cell differentiation, and a model linking HOX gene expression to this PML-RARalpha repressor complex is now proposed.
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Premature infants are at risk for adverse motor outcomes, including cerebral palsy and developmental coordination disorder. The purpose of this study was to examine the relationship of antenatal, perinatal, and postnatal risk factors for abnormal development of the corticospinal tract, the major voluntary motor pathway, during the neonatal period. In a prospective cohort study, 126 premature neonates (24-32 weeks' gestational age) underwent serial brain imaging near birth and at term-equivalent age. With diffusion tensor tractography, mean diffusivity and fractional anisotropy of the corticospinal tract were measured to reflect microstructural development. Generalized estimating equation models examined associations of risk factors on corticospinal tract development. The perinatal risk factor of greater early illness severity (as measured by the Score for Neonatal Acute Physiology-II [SNAP-II]) was associated with a slower rise in fractional anisotropy of the corticospinal tract (P = 0.02), even after correcting for gestational age at birth and postnatal risk factors (P = 0.009). Consistent with previous findings, neonatal pain adjusted for morphine and postnatal infection were also associated with a slower rise in fractional anisotropy of the corticospinal tract (P = 0.03 and 0.02, respectively). Lessening illness severity in the first hours of life might offer potential to improve motor pathway development in premature newborns.
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The Newborn Individualized Developmental Care and Assessment Program (NIDCAP) is widely used in neonatal intensive care units and comprises 85 discrete infant behaviors, some of which may communicate infant distress. The objective of this study was to identify developmentally relevant movements indicative of pain in preterm infants.
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The purpose of this study was to assess relations and concordance between behavioral and physiologic reactivity to pain in preterm neonates at 32 weeks postconceptional age as a function of gestational age at birth.
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Heart rate (HR) has been widely studied as a measure of an individual's response to painful stimuli. It remains unclear whether changes in mean HR or the variability of HR are specifically related to the noxious stimulus (i.e. pain). Neither is it well understood how such changes reflect underlying neurologic control mechanisms that produce these responses, or how these mechanisms change during the first year of life. To study the changes in cardiac autonomic modulation that occur with acute pain and with age during early infancy, the relationship between respiratory activity and short-term variations of HR (i.e. respiratory sinus arrhythmia) was quantified in a longitudinal study of term born healthy infants who underwent a finger lance blood collection at 4 months of age (n = 24) and again at 8 months of age (n = 20). Quantitative respiratory activity and HR were obtained during baseline, lance, and recovery periods. Time and frequency domain analyses from 2.2-min epochs of data yielded mean values, spectral measures of low (0.04-0.15 Hz) and high (0.15-0.80 Hz) frequency power (LF and HF), and the LF/HF ratio. To determine sympathetic and parasympathetic cardiac activity, the transfer relation between respiration and HR was used. At both 4 and 8 months, mean HR increased significantly with the noxious event (p > 0.01). There were age-related differences in the pattern of LF, HF, and LF/HF ratio changes. Although these parameters all decreased (p > 0.01) at 4 months, LF and LF/HF increased at 8 months and at 8 months HF remained stable in response to the noxious stimulus. Transfer gain changes with the lance demonstrated a change from predominant vagal baseline to a sympathetic condition at both ages. The primary finding of this study is that a response to an acute noxious stimulus appears to produce an increase in respiratory-related sympathetic HR control and a significant decrease in respiratory-related parasympathetic control at both 4 and 8 months. Furthermore, with increasing age, the sympathetic and parasympathetic changes appear to be less intense, but more sustained.
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The cytogenetically normal subtype of acute myeloid leukemia (CN-AML) is associated with Intermediate risk which complicates therapeutic options. Lower overall HOX/TALE expression appears to correlate with more favorable prognosis/better response to treatment in some leukemias and solid cancer. The functional significance of the associated gene expression and response to chemotherapy is not known. Three independent microarray datasets obtained from large patient cohorts along with quantitative PCR validation was used to identify a four gene HOXA/TALE signature capable of prognostic stratification. Biochemical analysis was used to identify interactions between the four encoded proteins and targeted knockdown used to examine the functional importance of sustained expression of the signature in leukemia maintenance and response to chemotherapy. An eleven HOXA/TALE code identified in an Intermediate risk (n=315) compared to a Favourable group of patients (n=105) was reduced to a four gene signature of HOXA6, HOXA9, PBX3 and MEIS1 by iterative analysis of independent platforms. This signature maintained the Favorable/Intermediate risk partition and where applicable, correlated with overall survival in CN-AML. We further show that cell growth and function is dependent on maintained levels of these core genes and that direct targeting of HOXA/PBX3 sensitizes CN-AML cells to standard chemotherapy. Together the data support a key role for HOXA/TALE in CN-AML and demonstrate that targeting of clinically significant HOXA/PBX3 elements may provide therapeutic benefit to these patients.
Mesenchymal stem cells enhance survival and bacterial clearance in murine Escherichia coli pneumonia
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Rationale: Bacterial pneumonia is the most common infectious cause of death worldwide and treatment is increasingly hampered by antibiotic resistance. Mesenchymal stem cells (MSCs) have been demonstrated to provide protection against acute inflammatory lung injury; however, their potential therapeutic role in the setting of bacterial pneumonia has not been well studied.
Objective: This study focused on testing the therapeutic and mechanistic effects of MSCs in a mouse model of Gram-negative pneumonia.
Methods and results: Syngeneic MSCs from wild-type mice were isolated and administered via the intratracheal route to mice 4 h after the mice were infected with Escherichia coli. 3T3 fibroblasts and phosphate-buffered saline (PBS) were used as controls for all in vivo experiments. Survival, lung injury, bacterial counts and indices of inflammation were measured in each treatment group. Treatment with wild-type MSCs improved 48 h survival (MSC, 55%; 3T3, 8%; PBS, 0%; p<0.05 for MSC vs 3T3 and PBS groups) and lung injury compared with control mice. In addition, wild-type MSCs enhanced bacterial clearance from the alveolar space as early as 4 h after administration, an effect that was not observed with the other treatment groups. The antibacterial effect with MSCs was due, in part, to their upregulation of the antibacterial protein lipocalin 2.
Conclusions: Treatment with MSCs enhanced survival and bacterial clearance in a mouse model of Gram-negative pneumonia. The bacterial clearance effect was due, in part, to the upregulation of lipocalin 2 production by MSCs
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Morbidity and mortality have declined only modestly in patients with clinical acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), despite extensive research into the pathophysiology. Current treatment remains primarily supportive with lung-protective ventilation and a fluid conservative strategy. Pharmacologic therapies that reduce the severity of lung injury in preclinical models have not yet been translated to effective clinical treatment options. Consequently, further research in translational therapies is needed. Cell-based therapy with mesenchymal stem cells (MSCs) is one attractive new therapeutic approach. MSCs have the capacity to secrete multiple paracrine factors that can regulate endothelial and epithelial permeability, decrease inflammation, enhance tissue repair, and inhibit bacterial growth. This review will focus on recent studies, which support the potential therapeutic use of MSCs in ALI/ARDS, with an emphasis on the role of paracrine soluble factors.
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OBJECTIVE: To test whether simvastatin improves physiological and biological outcomes in patients undergoing esophagectomy.
BACKGROUND: One-lung ventilation during esophagectomy is associated with inflammation, alveolar epithelial and systemic endothelial injury, and the development of acute lung injury (ALI). Statins that modify many of the underlying processes are a potential therapy to prevent ALI.
METHODS: We conducted a randomized double-blind placebo-controlled trial in patients undergoing esophagectomy. Patients received simvastatin 80 mg or placebo enterally for 4 days preoperatively and 7 days postoperatively. The primary end point was pulmonary dead space (Vd/Vt) at 6 hours after esophagectomy or before extubation. Inflammation was assessed by plasma cytokines and intraoperative exhaled breath condensate pH; alveolar type 1 epithelial injury was assessed by plasma receptor for advanced glycation end products and systemic endothelial injury by the urine albumin-creatinine ratio.
RESULTS: Thirty-nine patients were randomized; 8 patients did not undergo surgery and were excluded. Fifteen patients received simvastatin and 16 received placebo. There was no difference in Vd/Vt or other physiological outcomes. Simvastatin resulted in a significant decrease in plasma MCP-1 on day 3 and reduced exhaled breath condensate acidification. Plasma receptor for advanced glycation end products was significantly lower in the simvastatin-treated group, as was the urine albumin-creatinine ratio on day 7 postsurgery. ALI developed in 4 patients in the placebo group and no patients in the simvastatin group although this difference was not statistically significant (P = 0.1).
CONCLUSIONS: In this proof of concept study, pretreatment with simvastatin in esophagectomy decreased biomarkers of inflammation as well as pulmonary epithelial and systemic endothelial injury.
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Multicenter studies assessing hand hygiene adherence and risk factors for poor performance are scarce. In an observational study involving 13 hospitals across Ontario, Canada, we found a mean adherence rate of 31.2%, and that adherence was positively associated with nurses, single rooms, contact precautions, and the availability of alcohol hand rub dispensers. Copyright © 2011 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
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This article describes health and social care professionals' perceptions of palliative care and facilitators and barriers to the delivery of such care for patients with advanced chronic obstructive pulmonary disease. Health professionals participated in semi structured interviews and focus groups which were analysed using content analysis. According to participants, care of patients with chronic obstructive pulmonary disease is focused upon the management of symptoms, with emphasis focused predominately on an acute model of care. Key barriers towards the delivery of palliative care included the reluctance to negotiatie end-of-life decisions and a perceived lack of understanding among patients and carers regarding the illness trajectory. Consequently the delivery of palliative care was viewed as a specialist role rather than an integral component of care. There is a need for education and training for health and social care professions to plan and provide high quality end-of-life care.
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It has long been recognised that the majority of care provided in chronic illness comes not from health and social care professionals, but from family and friends. One such illness is chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality in the developed world.To explore the specific care needs of informal caregivers of patients with advanced COPD, interviews were conducted with seven active family caregivers. Interviews were taped, transcribed and content analysed to obtain the caregivers' needs. Results confirm that family caregivers provide direct care with little support and assistance. Participants reported restricted activities of daily living and some emotional distress. There were knowledge deficiencies among caregivers relating to the COPD illness trajectory and little awareness of the potential of palliative care. Family caregivers need social and professional support while caring for a patient at home. This would help to ensure that their physical and emotional health does not suffer. There is a need to devise interventions to ensure family caregivers are supported.