1,359 research outputs found

    Brown-pigmented Mycobacterium mageritense as a cause of prosthetic valve endocarditis and bloodstream infection

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    Mycobacterium spp. are a rare cause of endocarditis. Herein, we describe a case of Mycobacterium mageritense prosthetic valve endocarditis. This organism produced an unusual brown pigment on solid media. Cultures of valve tissue for acid-fast bacilli might be considered in some cases of apparently culture-negative prosthetic valve endocarditis

    Super-radiant light scattering from trapped Bose Einstein condensates

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    We propose a new formulation for atomic side mode dynamics from super-radiant light scattering of trapped atoms. A detailed analysis of the recently observed super-radiant light scattering from trapped bose gases [S. Inouye {\it et al.}, Science {\bf 285}, 571 (1999)] is presented. We find that scattered light intensity can exhibit both oscillatory and exponential growth behaviors depending on densities, pump pulse characteristics, temperatures, and geometric shapes of trapped gas samples. The total photon scattering rate as well as the accompanied matter wave amplification depends explicitly on atom number fluctuations in the condensate. Our formulation allows for natural and transparent interpretations of subtle features in the MIT data, and provides numerical simulations in good agreement with all aspects of the experimental observations.Comment: 24 pages,16 figures, submitted to Phys.Rev.

    Mechanism of action of probiotics

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    The modern diet doesn't provide the required amount of beneficial bacteria. Maintenance of a proper microbial ecology in the host is the main criteria to be met for a healthy growth. Probiotics are one such alternative that are supplemented to the host where by and large species of Lactobacillus, Bifidobacterium and Saccharomyces are considered as main probiotics. The field of probiotics has made stupendous strides though there is no major break through in the identification of their mechanism of action. They exert their activity primarily by strengthening the intestinal barrier and immunomodulation. The main objective of the study was to provide a deep insight into the effect of probiotics against the diseases, their applications and proposed mechanism of action

    Metabolic improvements following Roux-en-Y surgery assessed by solid meal test in subjects with short duration type 2 diabetes

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    BACKGROUND: Glucose homeostasis improves within days following Roux-en-Y gastric bypass (RYGB) surgery. The dynamic metabolic response to caloric intake following RYGB has been assessed using liquid mixed meal tolerance tests (MMTT). Few studies have evaluated the glycemic and hormonal response to a solid mixed meal in subjects with diabetes prior to, and within the first month following RYGB. METHODS: Seventeen women with type 2 diabetes of less than 5 years duration participated. Fasting measures of glucose homeostasis, lipids and gut hormones were obtained pre- and post-surgery. MMTT utilizing a solid 4 oz chocolate pudding performed pre-, 2 and 4 weeks post-surgery. Metabolic response to 4 and 2 oz MMTT assessed in five diabetic subjects not undergoing surgery. RESULTS: Significant reductions in fasting glucose and insulin at 3 days, and in fasting betatrophin, triglycerides and total cholesterol at 2 weeks post-surgery. Hepatic insulin clearance was greater at 3 days post-surgery. Subjects exhibited less hunger and greater feelings of fullness and satisfaction during the MMTT while consuming 52.9 ± 6.5% and 51.0 ± 6.5% of the meal at 2 and 4 weeks post-surgery respectively. At 2 weeks post-surgery, glucose and insulin response to MMTT were improved, with greater GLP-1 and PYY secretion. Improved response to solid MMTT not replicated by consumption of smaller pudding volume in diabetic non-surgical subjects. CONCLUSIONS: With a test meal of size and composition representative of the routine diet of post-RYGB subjects, improved glycemic and gut hormone responses occur which cannot be replicated by reducing the size of the MMTT in diabetic subjects not undergoing surgery

    Use of epidermic and granulocyte-colony stimulating growth factors in the prevention and treatment of necrotizing enterocolitis of the newborn

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    OBJETIVO: Revisar os conhecimentos existentes em relação ao uso de fatores de crescimento epidérmico e estimulador de colônias de granulócitos na prevenção e/ou no tratamento da enterocolite necrosante (ECN) durante o período neonatal. FONTES DE DADOS: Revisão da literatura, nas bases de dados Medline, Lilacs, SciELO e PubMed, utilizando os unitermos "recém-nascidos", "enterocolite" e "fatores de crescimento", no período de 2003 a 2007. Nesta busca, 49 artigos foram encontrados, sendo 17 pertinentes ao tema. Também foram utilizados outros artigos, independente do ano de publicação, relacionados a aspectos definidores da ECN no recém-nascido. SÍNTESE DOS DADOS: A ECN continua sendo responsável por uma elevada morbimortalidade neonatal. Os mecanismos fisiopatológicos vêm sendo elucidados e, a partir deles, são discutidas novas terapias, como o uso de fatores de crescimento, destacando-se o fator de crescimento epidérmico e o fator estimulador de colônias de granulócitos. CONCLUSÕES: O uso de fatores de crescimento no tratamento e prevenção da ECN neonatal parece promissor. É necessário maior número de ensaios clínicos para comprovar sua eficácia e segurança. Enquanto isso, a melhor prática médica continua sendo a prevenção da doença.OBJECTIVE: To review the literature regarding the use of hematopoietic and epidermic growth factors for prevention or treatment of neonatal necrotizing enterocolitis (NEC). DATA SOURCES: Literature review of Medline, Lilacs, SciELO and Pubmed databases, using the key-words "newborn", "enterocolitis" and "growth factors", from 2003 to 2007. Fourty-nine papers were retrieved, but only 17 related to the subject. Other studies that described some clinical aspects of enterocolitis were also included, regardless of the year of publication. DATA SYNTHESIS: Necrotizing and enterocolitis has been an important cause of morbidity and mortality in the neonatal period. As the knowledge about the pathophysiology of this disease improves, new therapies, such as the administration of epidermal growth factor and granulocyte colony-stimulating factor, are being discussed. CONCLUSIONS: The use of growth factors for treatment and prevention of NEC seems promising. However, further clinics assays are needed to evaluate the effectiveness and the safety of these growth factors. At this moment, the best clinical practice is the prevention of the disease

    Shale gas production: potential versus actual greenhouse gas emissions

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    Estimates of greenhouse gas (GHG) emissions from shale gas production and use are controversial. Here we assess the level of GHG emissions from shale gas well hydraulic fracturing operations in the United States during 2010. Data from each of the approximately 4000 horizontal shale gas wells brought online that year are used to show that about 900 Gg CH[subscript 4] of potential fugitive emissions were generated by these operations, or 228 Mg CH[subscript 4] per well—a figure inappropriately used in analyses of the GHG impact of shale gas. In fact, along with simply venting gas produced during the completion of shale gas wells, two additional techniques are widely used to handle these potential emissions: gas flaring and reduced emission 'green' completions. The use of flaring and reduced emission completions reduce the levels of actual fugitive emissions from shale well completion operations to about 216 Gg CH[subscript 4], or 50 Mg CH[subscript 4] per well, a release substantially lower than several widely quoted estimates. Although fugitive emissions from the overall natural gas sector are a proper concern, it is incorrect to suggest that shale gas-related hydraulic fracturing has substantially altered the overall GHG intensity of natural gas production

    Adaptive tuning functions arise from visual observation of past movement

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    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality

    Prospective randomized comparison of open versus laparoscopic management of splenic artery aneurysms: a 10-year study

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    Abstract BACKGROUND: The literature does not support the choice between open and laparoscopic management of splenic artery aneurysms (SAA). METHODS: We designed a prospective, randomized comparison between open and laparoscopic surgery for SAA. Primary end points were types of surgical procedures performed and clinical outcomes. Analysis was developed on an intention-to-treat basis. RESULTS: Fourteen patients were allocated to laparotomy (group A) and 15 to laparoscopy (group B). Groups displayed similar patient- and aneurysm-related characteristics. The conversion rate to open surgery was 13.3 %. The type of surgical procedure performed on the splenic artery was similar in the two groups: aneurysmectomy with splenic artery ligature or direct anastomosis was performed in 51 % and 21 % of patients in group A and in 60 % and 20 % in group B, respectively. The splenectomy rate was similar (14 % vs. 20 %). Postoperative splenic infarction was observed in one case in each group. Laparoscopy was associated with shorter procedures (p = 0.0003) and lower morbidity (25 % vs. 64 %, p = 0.045). Major morbidity requiring interventional procedures and blood transfusion was observed only in group A. Laparoscopy was associated with quicker resumption of oral diet (p < 0.001), earlier drain removal (p = 0.046), and shorter hospital stay (p < 0.01). During a mean follow-up of 50 months, two patients in group A required hospital readmission. In group B, two patients developed a late thrombosis of arterial anastomoses. CONCLUSIONS: Our study demonstrates that laparoscopy permits multiple technical options, does not increase the splenectomy rate, and reduces postoperative complications. It confirms the supposed clinical benefits of laparoscopy when ablative procedures are required but laparoscopic anastomoses show poor long-term results

    Expressions of Multiple Neuronal Dynamics during Sensorimotor Learning in the Motor Cortex of Behaving Monkeys

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    Previous studies support the notion that sensorimotor learning involves multiple processes. We investigated the neuronal basis of these processes by recording single-unit activity in motor cortex of non-human primates (Macaca fascicularis), during adaptation to force-field perturbations. Perturbed trials (reaching to one direction) were practiced along with unperturbed trials (to other directions). The number of perturbed trials relative to the unperturbed ones was either low or high, in two separate practice schedules. Unsurprisingly, practice under high-rate resulted in faster learning with more pronounced generalization, as compared to the low-rate practice. However, generalization and retention of behavioral and neuronal effects following practice in high-rate were less stable; namely, the faster learning was forgotten faster. We examined two subgroups of cells and showed that, during learning, the changes in firing-rate in one subgroup depended on the number of practiced trials, but not on time. In contrast, changes in the second subgroup depended on time and practice; the changes in firing-rate, following the same number of perturbed trials, were larger under high-rate than low-rate learning. After learning, the neuronal changes gradually decayed. In the first subgroup, the decay pace did not depend on the practice rate, whereas in the second subgroup, the decay pace was greater following high-rate practice. This group shows neuronal representation that mirrors the behavioral performance, evolving faster but also decaying faster at learning under high-rate, as compared to low-rate. The results suggest that the stability of a new learned skill and its neuronal representation are affected by the acquisition schedule.United States-Israel Binational Science FoundationIsrael Science FoundationIda Baruch FundRosetrees Trus

    Immunoregulatory gene polymorphisms in women with preeclampsia

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    The costimulatory molecules CD28, cytotoxic T-lymphocyte antigen-4 (CTLA-4) (cytotoxic T-lymphocyte-associated antigen-4) and inducible costimulator (ICOS) are believed to have a critical modulatory role in the immune response. However, few studies have been performed on the role of these immune regulatory molecules and their polymorphisms in women with preeclampsia (PE). the aim of our study was to evaluate the CTLA4 (+49 A/G) (rs 231775), CD28 (+17 T/C) (rs 3116496) and ICOS (-1564 T/C) (rs 4675378) gene polymorphisms in Brazilian women with PE. This case-control study included 130 patients with PE and 261 control women without any obstetric or systemic disorders. Genomic DNA was extracted from peripheral blood, and the polymorphism genotyping was performed by digesting the PCR products with the restriction endonucleases BbvI (CTLA-4), Afel (CD28) and AluI (ICOS). Data were analyzed by X(2) or Fisher's exact test; a P-value of < 0.05 was considered as significant. There were significant differences in the ICOS genotype and allelic frequencies between the PE and control groups (P=0.01 and P=0.01, respectively). We found a significantly lower frequency of the ICOS (-1564) T allele in women with mild PE compared with the controls. There were no differences in the CTLA-4 (+49 A/G) and CD28 (+17 T/C) genotypes and allelic frequencies between the PE patients and controls. Our data suggest that PE is associated with ICOS, but is not associated with the CTLA-4 or CD28 gene polymorphisms. Hypertension Research (2011) 34, 384-388; doi:10.1038/hr.2010.247; published online 16 December 2010Fundacao de Amparo a PesquisaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo, Dept Obstet, BR-01415002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Obstet, BR-01415002 São Paulo, BrazilFundacao de Amparo a Pesquisa: 07/57446-0Web of Scienc
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