974 resultados para Non-smooth optimization


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Asthma is characterised by an increased airway smooth muscle (ASM) area (ASMarea) within the airway wall. The present study examined the relationship of factors including severity and duration of asthma to ASMarea. The perimeter of the basement membrane (PBM) and ASMarea were measured on transverse sections of large and small airways from post mortem cases of fatal (n=107) and nonfatal asthma (n=37) and from control subjects (n=69). The thickness of ASM (ASMarea/PBM) was compared between asthma groups using multivariate linear regression. When all airways were considered together, ASMarea/PBM (in millimetres) was increased in nonfatal (median 0.04; interquartile range 0.013-0.051; p=0.034) and fatal cases of asthma (0.048; 0.025-0.078; p<0.001) compared with controls (0.036; 0.024-0.042). Compared with cases of nonfatal asthma, ASMarea/PBM was greater in cases of fatal asthma in large (p<0.001) and medium (p<0.001), but not small, airways. ASMarea/PBM was not related to duration of asthma, age of onset of asthma, sex or smoking. No effect due to study centre, other than that due to sampling strategy, was found. The thickness of the ASM layer is increased in asthma and is related to the severity of asthma but not its duration.

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Due to high rates of human papillomavirus (HPV) infection, the incidence of intraepithelial neoplasia and anal cancer, most studies concerning HPV in men seropositive for HIV have focused on the anal canal. Few studies have targeted the penile region in HIV-infected men. A total of 72 men seropositive for HIV and 72 men seronegative for HIV were followed-up for 6 months, and their penile exfoliated cells were tested for HPV DNA. There were no significant differences between the HIV-positive and HIV-negative men in persistence (respectively, 69.5% vs. 66.9%), clearance (respectively, 15.3% vs. 23.1%), and those men never infected with HPV during the four follow-up visits (15.2% for HIV-positive vs. 20% for HIV-negative). High-risk HPV types were detected more frequently in penile smears from men infected with HIV, while, in HIV-seronegative men, the low-risk HPV types were more abundant (P=0.001). Multiple infections with both high- and low-risk HPV types were significantly more frequent in HIV-seropositive compared to those who were HIV-seronegative (P=0.0004). The attendance rates at follow-up visits were 86%, 78%, and 58% in months 1, 2, and 6, respectively, for men infected with HIV and 93%, 72%, and 60% for the HIV-negative group. It is concluded that HIV infection can be considered a risk factor for clearance and persistence of HPV. Multiple infections with different types of HPV including high-risk HPVs are frequent in men who are infected with HIV. J. Med. Virol. 83:127-131, 2011. (C) 2010 Wiley-Liss, Inc.

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Neuromodulation is the branch of neurophysiology related to the therapeutic effects of electrical stimulations of the nervous system. There are currently different practical applications of neuromodulation techniques for the treatment of various neurological disorders, such as deep brain stimulation for Parkinson`s disease and repetitive transcranial magnetic stimulation (rTMS) for major depression. An increasing number of studies have been devoted to the analgesic effects of rTMS in chronic pain patients. RTMS has been used either as a therapeutic tool per se, or as a preoperative test in patients undergoing epidural precentral gyrus stimulation. High-frequency rTMS (a parts per thousand yen5 Hz) is considered to be excitatory, while low-frequency stimulation (a parts per thousand currency sign1 Hz) is considered to exert an inhibitory effect over neuronal populations of the primary motor cortex. However, other parameters of stimulation may play a central role on its clinical effects such as the type of coil, its orientation over the scalp, and the total number of rTMS sessions performed. Experimental data from animals, healthy volunteers, and neuropathic pain patients have suggested that stimulation of the primary motor cortex by rTMS is able to activate brain regions implicated in the processing of the different aspects of chronic pain, and influence brain regions involved in the endogenous opioid system. Over twenty prospective randomized sham-controlled trials have studied the analgesic effects of rTMS on chronic pain. Most of the patients included in these trials had central or peripheral neuropathic pain. Although most studies used a single session of stimulation, recent studies have shown that the analgesic effects of rTMS may outlast the stimulation period for many days when repetitive sessions are performed. This opens the possibility to use rTMS as a therapeutic tool of its own in the armamentarium against neuropathic pain.

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Parkinson`s disease (PD) is considered a multisystem disorder involving dopaminergic, noradrenergic. serotoninergic. and cholinergic systems, characterized by motor and non-motor symptoms. The causes of the non-motor symptoms in PD are multifactorial and unlikely to be explained by single lesions However, several evidence link them to damage of specific brainstem nuclei Numerous brainstem nuclei are engaged in fundamental homeostatic mechanisms, including gastrointestinal regulation, pain perception, mood control, and sleep-wake cycles In addition, these nuclei are locally interconnected in a complex manner and are subject to supraspinal control. The objective of this review is to provide a better overview of the current knowledge about the consequences of the involvement of specific brainstem nuclei to the most prevalent non-motor symptoms occurring in PD The multidisciplinary efforts of research directed to these non-nigral brainstem nuclei, in addition to the topographical and chronological spread of the disease - especially in the prodromal stages of PD. are discussed (C) 2009 Elsevier B V. All rights reserved

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Background: Recurrent 15q13.3 microdeletions were recently identified with identical proximal (BP4) and distal (BP5) breakpoints and associated with mild to moderate mental retardation and epilepsy. Methods: To assess further the clinical implications of this novel 15q13.3 microdeletion syndrome, 18 new probands with a deletion were molecularly and clinically characterised. In addition, we evaluated the characteristics of a family with a more proximal deletion between BP3 and BP4. Finally, four patients with a duplication in the BP3-BP4-BP5 region were included in this study to ascertain the clinical significance of duplications in this region. Results: The 15q13.3 microdeletion in our series was associated with a highly variable intra-and inter-familial phenotype. At least 11 of the 18 deletions identified were inherited. Moreover, 7 of 10 siblings from four different families also had this deletion: one had a mild developmental delay, four had only learning problems during childhood, but functioned well in daily life as adults, whereas the other two had no learning problems at all. In contrast to previous findings, seizures were not a common feature in our series (only 2 of 17 living probands). Three patients with deletions had cardiac defects and deletion of the KLF13 gene, located in the critical region, may contribute to these abnormalities. The limited data from the single family with the more proximal BP3-BP4 deletion suggest this deletion may have little clinical significance. Patients with duplications of the BP3-BP4-BP5 region did not share a recognisable phenotype, but psychiatric disease was noted in 2 of 4 patients. Conclusions: Overall, our findings broaden the phenotypic spectrum associated with 15q13.3 deletions and suggest that, in some individuals, deletion of 15q13.3 is not sufficient to cause disease. The existence of microdeletion syndromes, associated with an unpredictable and variable phenotypic outcome, will pose the clinician with diagnostic difficulties and challenge the commonly used paradigm in the diagnostic setting that aberrations inherited from a phenotypically normal parent are usually without clinical consequences.

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Wildlife tourism has the potential to contribute to conservation through a variety of mechanisms. This chapter presents a preliminary assessment of the extent to which this potential is currently being realised, comparing tourism based on viewing of animals in captive settings (with a focus on federated zoos) with that in free-ranging situations (wildlife watching). The key mechanisms involved are: direct wildlife management and research; use of income derived from wildlife tourism to fund conservation; education of visitors to behave in a more conservation-friendly manner; political lobbying in support of conservation; and provision of a socio-economic incentive for conservation. All of these occur in at least some zoos and wildlife-watching situations, and collectively the contribution of non-consumptive wildlife tourism to conservation is significant, though impossible to quantify. The key strengths of the zoo sector in this regard are its inputs into captive breeding and its potential to educate large numbers of people. in contrast, wildlife watching provides significant socio-economic incentives for conservation of natural habitats. There seem to be significant opportunities for expanding the role of non-consumptive wildlife tourism in conservation.

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Mechanisms regulating NADPH oxidase remain open and include the redox chaperone protein disulfide isomerase (PDI). Here, we further investigated PDI effects on vascular NADPH oxidase. VSMC transfected with wild-type PDI (wt-PDI) OF PDI mutated in all four redox cysteines (mut-PDI) enhanced (2.5-fold) basal cellular ROS production and membrane NADPH oxidase activity, with 3-fold increase in Nox1, but not Nox4 mRNA. However, further ROS production, NADPH oxidase activity and Nox1 mRNA increase triggered by angiotensin-II (AngII) were totally lost with PDI overexpression, suggesting preemptive Nox1 activation in such cells. PDI overexpression increased Nox4 mRNA after AngII stimulus, although without parallel ROS increase. We also show that Nox inhibition by the nitric oxide donor GSNO is independent of PDI. PDI silencing decreased specifically Nox1 mRNA and protein, confirming that PDI may regulate Nox1 at transcriptional level in VSMC. Such data further strengthen the role of PDI as novel NADPH oxidase regulator. (C) 2009 Elsevier Inc. All rights reserved.

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Fear of heights, or acrophobia, is one of the most frequent subtypes of specific phobia frequently associated to depression and other anxiety disorders. Previous evidence suggests a correlation between acrophobia and abnormalities in balance control, particularly involving the use of visual information to keep postural stability. This study investigates the hypotheses that (1) abnormalities in balance control are more frequent in individuals with acrophobia even when not exposed to heights, that (2) acrophobic symptoms are associated to abnormalities in visual perception of movement; and that (3) individuals with acrophobia are more sensitive to balance-cognition interactions. Thirty-one individuals with specific phobia of heights and thirty one non-phobic controls were compared using dynamic posturography and a manual tracking task. Acrophobics had poorer performance in both tasks, especially when carried out simultaneously. Previously described interference between posture control and cognitive activity seems to play a major role in these individuals. The presence of physiologic abnormalities is compatible with the hypothesis of a non-associative acquisition of fear of heights, i.e., not associated to previous traumatic events or other learning experiences. Clinically, this preliminary study corroborates the hypothesis that vestibular physical therapy can be particularly useful in treating individuals with fear of heights.