471 research outputs found
Nitrides as ammonia synthesis catalysts and as potential nitrogen transfer reagents
In this article, an overview of the application of selected metal nitrides as ammonia synthesis catalysts is presented. The potential development of some systems into nitrogen transfer reagents is also described
The Functional DRD3 Ser9Gly Polymorphism (rs6280) Is Pleiotropic, Affecting Reward as Well as Movement
Abnormalities of motivation and behavior in the context of reward are a fundamental component of addiction and mood disorders. Here we test the effect of a functional missense mutation in the dopamine 3 receptor (DRD3) gene (ser9gly, rs6280) on reward-associated dopamine (DA) release in the striatum. Twenty-six healthy controls (HCs) and 10 unmedicated subjects with major depressive disorder (MDD) completed two positron emission tomography (PET) scans with [11C]raclopride using the bolus plus constant infusion method. On one occasion subjects completed a sensorimotor task (control condition) and on another occasion subjects completed a gambling task (reward condition). A linear regression analysis controlling for age, sex, diagnosis, and self-reported anhedonia indicated that during receipt of unpredictable monetary reward the glycine allele was associated with a greater reduction in D2/3 receptor binding (i.e., increased reward-related DA release) in the middle (anterior) caudate (p<0.01) and the ventral striatum (p<0.05). The possible functional effect of the ser9gly polymorphism on DA release is consistent with previous work demonstrating that the glycine allele yields D3 autoreceptors that have a higher affinity for DA and display more robust intracellular signaling. Preclinical evidence indicates that chronic stress and aversive stimulation induce activation of the DA system, raising the possibility that the glycine allele, by virtue of its facilitatory effect on striatal DA release, increases susceptibility to hyperdopaminergic responses that have previously been associated with stress, addiction, and psychosis
Case report of MR perfusion imaging in Sinking Skin Flap Syndrome: growing evidence for hemodynamic impairment
<p>Abstract</p> <p>Background</p> <p>The syndrome of the sinking skin flap (SSSF) with delayed sensorimotor deficits after craniectomy is not well known and often neglected. Among various postulated causes, there is evidence that disturbed brain perfusion may be related to the observed symptoms, and that cranioplasty reliably alleviates these symptoms. We report a case of sinking skin flap syndrome (SSFS) with recovery from neurological sensorimotor deficits after cranioplasty correlated with pre- and postsurgical MR brain perfusion studies.</p> <p>Case Presentation</p> <p>A 42-year-old woman presented with slowly progressive sensorimotor paresis of her left arm after decompressive extensive craniectomy due to subarachnoid hemorrhage four months ago. Her right cranium showed a "sinking skin flap". After cranioplastic repair of her skull defect, the patient fully recovered from her symptoms. Before cranioplasty, reduced brain perfusion in the right central cortical region was observed in MR-perfusion images. After cranioplasty, a marked increase in brain perfusion was observed which correlated with objective clinical recovery.</p> <p>Conclusion</p> <p>There is increasing evidence that impaired blood flow is responsible for delayed motor deficits in patients with sinking skin flap syndrome in the area of compressed brain regions. Symptoms should be evaluated by brain perfusion imaging complementing surgical decision-making.</p
Dissecting complex transcriptional responses using pathway-level scores based on prior information
<p>Abstract</p> <p>Background</p> <p>The genomewide pattern of changes in mRNA expression measured using DNA microarrays is typically a complex superposition of the response of multiple regulatory pathways to changes in the environment of the cells. The use of prior information, either about the function of the protein encoded by each gene, or about the physical interactions between regulatory factors and the sequences controlling its expression, has emerged as a powerful approach for dissecting complex transcriptional responses.</p> <p>Results</p> <p>We review two different approaches for combining the noisy expression levels of multiple individual genes into robust pathway-level differential expression scores. The first is based on a comparison between the distribution of expression levels of genes within a predefined gene set and those of all other genes in the genome. The second starts from an estimate of the strength of genomewide regulatory network connectivities based on sequence information or direct measurements of protein-DNA interactions, and uses regression analysis to estimate the activity of gene regulatory pathways. The statistical methods used are explained in detail.</p> <p>Conclusion</p> <p>By avoiding the thresholding of individual genes, pathway-level analysis of differential expression based on prior information can be considerably more sensitive to subtle changes in gene expression than gene-level analysis. The methods are technically straightforward and yield results that are easily interpretable, both biologically and statistically.</p
Postherpetic Neuralgia: Role of Gabapentin and Other Treatment Modalities
Postherpetic neuralgia (PHN) is a chronic and painful condition that may occur after a herpes zoster infection. The frequency of PHN after untreated zoster varies widely. Age is the most important risk factor for development of PHN. The condition occurs in an estimated 50% of patients older than 50 years. The pain of PHN can be severe and debilitating and is frequently associated with allodynia. Although in most patients pain remits within the first year, it may persist for a lifetime. Tricyclic antidepressants (TCAs), topical agents, opioids, and gabapentin, a structural Γ-amino butyric acid (GABA) analogue, are the only agents that have demonstrated efficacy in randomized clinical trials for treatment of both the shooting and the burning form of pain associated with PHN. TCAs are among the most commonly used classes of agents for treating PHN and are effective in a significant proportion of patients. However, various adverse events can limit treatment. These side effects tend to be more acute in the elderly, the population most likely to suffer from PHN. Topical agents have led to mild to moderate improvement in patients with PHN but are usually ineffective as monotherapy for this condition. Until recently, carbamazepine was the only antiepileptic drug evaluated for the treatment of PHN. Over the past few years, however, gabapentin has received increasing attention as a useful treatment for neuropathic pain. Gabapentin lacks significant drug-drug interactions and has a favorable safety profile, which makes it particularly useful for treatment of PHN.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65597/1/j.1528-1157.1999.tb00933.x.pd
Eficácia do exercício físico na fadiga dos pacientes com câncer durante o tratamento ativo: revisão sistemática e meta-análise
El objetivo del estudio fue determinar la efectividad del ejercicio físico en la fatiga de pacientes con cáncer durante el tratamiento activo. Las bases de datos de PubMed Central, EMBASE y OVID fueron consultadas hasta abril de 2014 para identificar ensayos clínicos aleatorizados, que evaluaran el efecto del ejercicio en la fatiga de pacientes con cáncer sometidos a tratamiento activo. Once estudios (n = 1.407) fueron incluidos. La quimioterapia fue el tratamiento más común (n = 1.028). Los estudios tuvieron bajo riesgo de sesgo y alta calidad metodológica. Las estimaciones de efecto mostraron que el ejercicio físico mejoró significativamente la fatiga (SMD = -3,0; IC95%: -5,21; -0,80), p < 0,0001. Se encontraron efectos similares para el entrenamiento de resistencia (SMD = -4,5; IC95%: -7,24; -1,82), p = 0,001. Se encontraron mejoras significativas en pacientes con cáncer de mama y de próstata (p < 0,05). El ejercicio es una intervención segura y eficaz en el control de la fatiga en pacientes sometidos a tratamiento activoThis study aimed to determine the effectiveness of physical exercise in decreasing fatigue in cancer patients during active treatment. The PubMed Central, EMBASE, and OVID databases were consulted up to April 2014 to identify randomized clinical trials that evaluated the effect of exercise on fatigue in cancer patients undergoing active treatment. Eleven studies (n = 1,407) were included. Chemotherapy was the most common form of treatment (n = 1,028). The studies showed a low risk of bias and high methodological quality. Effect estimates showed that physical exercise significantly improved fatigue (SMD = -3.0; 95%CI: -5.21; -0.80), p < 0.0001. Similar effects were found for resistance training (SMD = -4.5; 95%CI: -7.24; -1.82), p = 0.001. Significant improvements were found in breast and prostate cancer patients (p < 0.05). Exercise is a safe and effective intervention in the management fatigue in cancer patients undergoing active treatmentO objetivo foi determinar a efetividade do exercício físico sobre a fadiga em pacientes com câncer durante o tratamento ativo. As bases de dados PubMed Central, EMBASE e OVID foram consultadas até abril de 2014 para identificar ensaios clínicos randomizados que avaliaram o efeito do exercício sobre a fadiga em pacientes com câncer em tratamento ativo. Onze estudos (n = 1.407) foram incluídos. A quimioterapia foi o tratamento mais comum (n = 1.028). Os estudos tiveram baixo risco de viés e alta qualidade metodológica. As estimativas de efeito mostraram que o exercício melhorou significativamente a fadiga (DMP = -3,0; IC95%: -5,21; -0,80), p < 0,0001. Efeitos semelhantes sobre o treinamento de resistência (DMP = -4,5; IC95%: -7,24; -1,82), p = 0,001 foram encontrados. O exercício físico é uma intervenção segura e eficaz contra a fadiga em pacientes submetidos ao tratamento ativoEl presente trabajo forma parte del Proyecto Práctica del autoexamen de seno y los conocimientos, factores de riesgo y estilos de vida relacionados con el cáncer de mama en mujeres jóvenes de la Universidad Santo Tomás de Bogotá: un análisis transversal (9ª Convocatoria FODEIN- Código del proyecto 4110060001 - 008)
Hospital variation in transfusion and infection after cardiac surgery: a cohort study
<p>Abstract</p> <p>Background</p> <p>Transfusion practices in hospitalised patients are being re-evaluated, in part due to studies indicating adverse effects in patients receiving large quantities of stored blood. Concomitant with this re-examination have been reports showing variability in the use of specific blood components. This investigation was designed to assess hospital variation in blood use and outcomes in cardiac surgery patients.</p> <p>Methods</p> <p>We evaluated outcomes in 24,789 Medicare beneficiaries in the state of Michigan, USA who received coronary artery bypass graft surgery from 2003 to 2006. Using a cohort design, patients were followed from hospital admission to assess transfusions, in-hospital infection and mortality, as well as hospital readmission and mortality 30 days after discharge. Multilevel mixed-effects logistic regression was used to calculate the intrahospital correlation coefficient (for 40 hospitals) and compare outcomes by transfusion status.</p> <p>Results</p> <p>Overall, 30% (95 CI, 20% to 42%) of the variance in transfusion practices was attributable to hospital site. Allogeneic blood use by hospital ranged from 72.5% to 100% in women and 49.7% to 100% in men. Allogeneic, but not autologous, blood transfusion increased the odds of in-hospital infection 2.0-fold (95% CI 1.6 to 2.5), in-hospital mortality 4.7-fold (95% CI 2.4 to 9.2), 30-day readmission 1.4-fold (95% CI 1.2 to 1.6), and 30-day mortality 2.9-fold (95% CI 1.4 to 6.0) in elective surgeries. Allogeneic transfusion was associated with infections of the genitourinary system, respiratory tract, bloodstream, digestive tract and skin, as well as infection with <it>Clostridium difficile</it>. For each 1% increase in hospital transfusion rates, there was a 0.13% increase in predicted infection rates.</p> <p>Conclusion</p> <p>Allogeneic blood transfusion was associated with an increased risk of infection at multiple sites, suggesting a system-wide immune response. Hospital variation in transfusion practices after coronary artery bypass grafting was considerable, indicating that quality efforts may be able to influence practice and improve outcomes.</p
Inflammatory Monocytes and Neutrophils Are Licensed to Kill during Memory Responses In Vivo
Immunological memory is a hallmark of B and T lymphocytes that have undergone a previous encounter with a given antigen. It is assumed that memory cells mediate better protection of the host upon re-infection because of improved effector functions such as antibody production, cytotoxic activity and cytokine secretion. In contrast to cells of the adaptive immune system, innate immune cells are believed to exhibit a comparable functional effector response each time the same pathogen is encountered. Here, using mice infected by the intracellular bacterium Listeria monocytogenes, we show that during a recall bacterial infection, the chemokine CCL3 secreted by memory CD8+ T cells drives drastic modifications of the functional properties of several populations of phagocytes. We found that inflammatory ly6C+ monocytes and neutrophils largely mediated memory CD8+ T cell bacteriocidal activity by producing increased levels of reactive oxygen species (ROS), augmenting the pH of their phagosomes and inducing antimicrobial autophagy. These events allowed an extremely rapid control of bacterial growth in vivo and accounted for protective immunity. Therefore, our results provide evidence that cytotoxic memory CD8+ T cells can license distinct antimicrobial effector mechanisms of innate cells to efficiently clear pathogens
Microbiological profiles of sputum and gastric juice aspirates in Cystic Fibrosis patients.
Gastro-Oesophageal Reflux (GOR) is a key problem in Cystic Fibrosis (CF), but the relationship between lung and gastric microbiomes is not well understood. We hypothesised that CF gastric and lung microbiomes are related. Gastric and sputum cultures were obtained from fifteen CF patients receiving percutaneous endoscopic gastrostomy feeding. Non-CF gastric juice data was obtained through endoscopy from 14 patients without lung disease. Bacterial and fungal isolates were identified by culture. Molecular bacterial profiling used next generation sequencing (NGS) of the 16S rRNA gene. Cultures grew bacteria and/or fungi in all CF gastric juice and sputa and in 9/14 non-CF gastric juices. Pseudomonas aeruginosa(Pa) was present in CF sputum in 11 patients, 4 had identical Pa strains in the stomach. NGS data from non-CF gastric juice samples were significantly more diverse compared to CF samples. NGS showed CF gastric juice had markedly lower abundance of normal gut bacteria; Bacteroides and Faecalibacterium, but increased Pseudomonas compared with non-CF. Multivariate partial least squares discriminant analysis demonstrated similar bacterial profiles of CF sputum and gastric juice samples, which were distinct from non-CF gastric juice. We provide novel evidence suggesting the existence of an aerodigestive microbiome in CF, which may have clinical relevance
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