197 resultados para LOW-DIMENSION


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Objective: Aim of post operative treatments after cardiac surgery is to avoid low cardiac output syndrome (LCOS). Levosimendan, a new inotrope agent, has been demonstrated in adult patient to be an effective treatment for this purpose when classical therapy is not effective. It shows a positive effect on cardiac output, with fewer adverse effects and lower mortality than with dopamine. There is very few data on its benefit in the paediatric population. The aim of this study is to evaluate the effect of levosimendan in cardiac children with LCOS.Methods: Retrospective analysis of 25 children hospitalised in our PICU after cardiac surgery that demonstrated LCOS not responding to classical catecholamine therapy and who received levosimendan as rescue. LCOS parameters like urine output, mixed venous oxygen saturation (SvO2), arterio-venous differences in CO2 (AVCO2) and plasmatic lactate were compared before therapy and at 12, 24, 48 and 72 hours after the beginning of the levosimendan infusion. We also analyzed the effect on the utilisation of amines (amine score), adverse events and mortality.Results: After the beginning of levosimendan infusion, urine output (3.1 vs 5.3ml/kg/h, p=0.003) and SVO2 (56 vs 64mmHg, p=0.001) increase significantly during first 72 hours and at the same time plasmatic lactate (2.6 vs 1.4 mmole/l, p<0.001), AVCO2 (11 vs 8 mmHg, p=0.002) and amine score (63 vs 39, p=0.007) decrease significantly. No side effects were noted during administration of levosimendan. In this group of patients, mortality was 0%.Conclusion: Levosimendan is an effective treatment in children after congenital heart surgery. Our study, with a greater sample of patient than other studies, confirms the improvement of cardiac output already shown in other paediatric studies.

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Radiotherapy is a widely used treatment option in cancer. However, recent evidence suggests that doses of ionizing radiation (IR) delivered inside the tumor target volume, during fractionated radiotherapy, can promote tumor invasion and metastasis. Furthermore, the tissues that surround the tumor area are also exposed to low doses of IR that are lower than those delivered inside the tumor mass, because external radiotherapy is delivered to the tumor through multiple radiation beams, in order to prevent damage of organs at risk. The biological effects of these low doses of IR on the healthy tissue surrounding the tumor area, and in particular on the vasculature remain largely to be determined. We found that doses of IR lower or equal to 0.8 Gy enhance endothelial cell migration without impinging on cell proliferation or survival. Moreover, we show that low-dose IR induces a rapid phosphorylation of several endothelial cell proteins, including the Vascular Endothelial Growth Factor (VEGF) Receptor-2 and induces VEGF production in hypoxia mimicking conditions. By activating the VEGF Receptor-2, low-dose IR enhances endothelial cell migration and prevents endothelial cell death promoted by an anti-angiogenic drug, bevacizumab. In addition, we observed that low-dose IR accelerates embryonic angiogenic sprouting during zebrafish development and promotes adult angiogenesis during zebrafish fin regeneration and in the murine Matrigel assay. Using murine experimental models of leukemia and orthotopic breast cancer, we show that low-dose IR promotes tumor growth and metastasis and that these effects were prevented by the administration of a VEGF receptor-tyrosine kinase inhibitor immediately before IR exposure. These findings demonstrate a new mechanism to the understanding of the potential pro-metastatic effect of IR and may provide a new rationale basis to the improvement of current radiotherapy protocols.

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The sensitivity of altitudinal and latitudinal tree-line ecotones to climate change, particularly that of temperature, has received much attention. To improve our understanding of the factors affecting tree-line position, we used the spatially explicit dynamic forest model TreeMig. Although well-suited because of its landscape dynamics functions, TreeMig features a parabolic temperature growth response curve, which has recently been questioned. and the species parameters are not specifically calibrated for cold temperatures. Our main goals were to improve the theoretical basis of the temperature growth response curve in the model and develop a method for deriving that curve's parameters from tree-ring data. We replaced the parabola with an asymptotic curve, calibrated for the main species at the subalpine (Swiss Alps: Pinus cembra, Larix decidua, Picea abies) and boreal (Fennoscandia: Pinus sylvestris, Betula pubescens, P. abies) tree-lines. After fitting new parameters, the growth curve matched observed tree-ring widths better. For the subalpine species, the minimum degree-day sum allowing, growth (kDDMin) was lowered by around 100 degree-days; in the case of Larix, the maximum potential ring-width was increased to 5.19 mm. At the boreal tree-line, the kDDMin for P. sylvestris was lowered by 210 degree-days and its maximum ring-width increased to 2.943 mm; for Betula (new in the model) kDDMin was set to 325 degree-days and the maximum ring-width to 2.51 mm; the values from the only boreal sample site for Picea were similar to the subalpine ones, so the same parameters were used. However, adjusting the growth response alone did not improve the model's output concerning species' distributions and their relative importance at tree-line. Minimum winter temperature (MinWiT, mean of the coldest winter month), which controls seedling establishment in TreeMig, proved more important for determining distribution. Picea, P. sylvestris and Betula did not previously have minimum winter temperature limits, so these values were set to the 95th percentile of each species' coldest MinWiT site (respectively -7, -11, -13). In a case study for the Alps, the original and newly calibrated versions of TreeMig were compared with biomass data from the National Forest Inventor), (NFI). Both models gave similar, reasonably realistic results. In conclusion, this method of deriving temperature responses from tree-rings works well. However, regeneration and its underlying factors seem more important for controlling species' distributions than previously thought. More research on regeneration ecology, especially at the upper limit of forests. is needed to improve predictions of tree-line responses to climate change further.

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Energy expenditure was measured by means of a respiratory chamber in two groups of adult rural Gambian men. The first group (n = 29) had a low body mass index (BMI; in kg/m2) < 18.5), whereas the control group (n = 29) had a higher BMI (> 22). This study shows that the energy expenditure of Gambian men with low BMI is not different from that of Gambian men with normal BMI when the results are normalized for fat-free mass or for weight by analysis of covariance. In Gambian men the nutritional status thus does not seem to affect energy metabolism notably. No differences in respiratory quotient, diet-induced thermogenesis, net work efficiency, spontaneous physical activity, heart rate, or urinary catecholamine excretion were observed between the two groups. It is, however, interesting to note that the basal metabolic rate of Gambian men, regardless of their nutritional status, is approximately 10% (range 4-12% depending on the reference value used) lower than that predicted for individuals living in industrialized countries.

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Mammary carcinomas developing in SV40 transgenic WAP-T mice arise in two distinct histological phenotypes: as differentiated low-grade and undifferentiated high-grade tumors. We integrated different types of information such as histological grading, analysis of aCGH-based gene copy number and gene expression profiling to provide a comprehensive molecular description of mammary tumors in WAP-T mice. Applying a novel procedure for the correlation of gene copy number with gene expression on a global scale, we observed in tumor samples a global coherence between genotype and transcription. This coherence can be interpreted as a matched transcriptional regulation inherited from the cells of tumor origin and determined by the activity of cancer driver genes. Despite common recurrent genomic aberrations, e.g. gain of chr. 15 in most WAP-T tumors, loss of chr. 19 frequently occurs only in low-grade tumors. These tumors show features of "basal-like" epithelial differentiation, particularly expression of keratin 14. The high-grade tumors are clearly separated from the low-grade tumors by strong expression of the Met gene and by coexpression of epithelial (e.g. keratin 18) and mesenchymal (e.g. vimentin) markers. In high-grade tumors, the expression of the nonmutated Met protein is associated with Met-locus amplification and Met activity. The role of Met as a cancer driver gene is supported by the contribution of active Met signaling to motility and growth of mammary tumor-derived cells. Finally, we discuss the independent origin of low- and high-grade tumors from distinct cells of tumor origin, possibly luminal progenitors, distinguished by Met gene expression and Met signaling.

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The prevalence of abdominal aortic aneurysm (AAA) and its risk factors are well known in Western countries but few data are available from low- and middle- income countries. We are not aware of systematically collected population- based data on AAA in the African region. We evaluated the prevalence of AAA in a population- based cardiovascular survey conducted in the Republic of Seychelles in 2004 (Indian Ocean, African region). Among the 353 participants aged 50 to 64 years and screened with ultrasound, the prevalence of AAA was 0.3% (95% CI: 0- 0.9) and the prevalence of ectatic dilatations of the abdominal aorta was 1.5% (95% CI: 0.2- 2.8). The prevalence of AAA in the general population seemed lower in Seychelles than in Western countries, despite a high prevalence in Seychelles of risk factors of AAA, such as smoking (in men), high blood pressure and hypercholesterolaemia.

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BACKGROUND: The pattern of substrate utilization with diets containing a high or a low proportion of unavailable and slowly digestible carbohydrates may constitute an important factor in the control, time course, and onset of hunger in humans. OBJECTIVE: We tested the hypothesis that isoenergetic diets differing only in their content of unavailable carbohydrates would result in different time courses of total, endogenous, and exogenous carbohydrate oxidation rates. DESIGN: Two diets with either a high (H diet) or a low (L diet) content of unavailable carbohydrates were fed to 14 healthy subjects studied during two 24-h periods in a metabolic chamber. Substrate utilization was assessed by whole-body indirect calorimetry. In a subgroup of 8 subjects, endogenous and exogenous carbohydrate oxidation were assessed by prelabeling the body glycogen stores with [(13)C]carbohydrate. Subjective feelings of hunger were estimated with use of visual analogue scales. RESULTS: Total energy expenditure and substrate oxidation did not differ significantly between the 2 diets. However, there was a significant effect of diet (P: = 0.03) on the carbohydrate oxidation pattern: the H diet elicited a lower and delayed rise of postprandial carbohydrate oxidation and was associated with lower hunger feelings than was the L diet. The differences in hunger scores between the 2 diets were significantly associated with the differences in the pattern of carbohydrate oxidation among diets (r = -0.67, P: = 0. 006). Exogenous and endogenous carbohydrate oxidation were not significantly influenced by diet. CONCLUSIONS: The pattern of carbohydrate utilization is involved in the modulation of hunger feelings. The greater suppression of hunger after the H diet than after the L diet may be helpful, at least over the short term, in individuals attempting to better control their food intake.

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BACKGROUND: Both the human immunodeficiency virus (HIV) and hepatitis C virus (HCV), either alone or as coinfections, persist in their hosts by destroying and/or escaping immune defenses, with high morbidity as consequence. In some cases, however, a balance between infection and immunity is reached, leading to prolonged asymptomatic periods. We report a case of such an indolent co-infection, which could be explained by the development of a peculiar subset of Natural Killer (NK) cells. RESULTS: Persistently high peripheral levels of CD56+ NK cells were observed in a peculiar hemophiliac HIV/HCV co-infected patient with low CD4 counts, almost undetectable HIV viral load and no opportunistic infections. Thorough analysis of NK-subsets allowed to identify a marked increase in the CD56bright/dim cell ratio and low numbers of CD16+/CD56- cells. These cells have high levels of natural cytotoxicity receptors but low NCR2 and CD69, and lack both CD57 and CD25 expression. The degranulation potential of NK-cells which correlates with target cytolysis was atypically mainly performed by CD56bright NK-cells, whereas no production of interferon γ (IFN-γ) was observed following NK activation by K562 cells. CONCLUSIONS: These data suggest that the expansion and lytic capacity of the CD56bright NK subset may be involved in the protection of this « rare » HIV/HCV co-infected hemophiliac A patient from opportunistic infections and virus-related cancers despite very low CD4+ cell counts.

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BACKGROUND: In Switzerland and other developed countries, the number of tuberculosis (TB) cases has been decreasing for decades, but HIV-infected patients and migrants remain risk groups. The aim of this study was to compare characteristics of TB in HIV-negative and HIV-infected patients diagnosed in Switzerland, and between coinfected patients enrolled and not enrolled in the national Swiss HIV Cohort Study (SHCS). METHODS AND FINDINGS: All patients diagnosed with culture-confirmed TB in the SHCS and a random sample of culture-confirmed cases reported to the national TB registry 2000-2008 were included. Outcomes were assessed in HIV-infected patients and considered successful in case of cure or treatment completion. Ninety-three SHCS patients and 288 patients selected randomly from 4221 registered patients were analyzed. The registry sample included 10 (3.5%) coinfected patients not enrolled in the SHCS: the estimated number of HIV-infected patients not enrolled in the SHCS but reported to the registry 2000-2008 was 146 (95% CI 122-173). Coinfected patients were more likely to be from sub-Saharan Africa (51.5% versus 15.8%, P<0.0001) and to present disseminated disease (23.9% vs. 3.4%, P<0.0001) than HIV-negative patients. Coinfected patients not enrolled in the SHCS were asylum seekers or migrant workers, with lower CD4 cell counts at TB diagnosis (median CD4 count 79 cells/µL compared to 149 cells/µL among SHCS patients, P = 0.07). There were 6 patients (60.0%) with successful outcomes compared to 82 (88.2%) patients in the SHCS (P = 0.023). CONCLUSIONS: The clinical presentation of coinfected patients differed from HIV-negative TB patients. The number of HIV-infected patients diagnosed with TB outside the SHCS is similar to the number diagnosed within the cohort but outcomes are poorer in patients not followed up in the national cohort. Special efforts are required to address the needs of this vulnerable population.

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Low molecular weight dextran sulfate (DXS) has been reported to inhibit the classical, alternative pathway as well as the mannan-binding lectin pathway of the complement system. Furthermore, it acts as an endothelial cell protectant inhibiting complement-mediated endothelial cell damage. Endothelial cells are covered with a layer of heparan sulfate (HS), which is rapidly released under conditions of inflammation and tissue injury. Soluble HS induces maturation of dendritic cells (DC) via TLR4. In this study, we show the inhibitory effect of DXS on human DC maturation. DXS significantly prevents phenotypic maturation of monocyte-derived DC and peripheral myeloid DC by inhibiting the up-regulation of CD40, CD80, CD83, CD86, ICAM-1, and HLA-DR and down-regulates DC-SIGN in response to HS or exogenous TLR ligands. DXS also inhibits the functional maturation of DC as demonstrated by reduced T cell proliferation, and strongly impairs secretion of the proinflammatory mediators IL-1beta, IL-6, IL-12p70, and TNF-alpha. Exposure to DXS leads to a reduced production of the complement component C1q and a decreased phagocytic activity, whereas C3 secretion is increased. Moreover, DXS was found to inhibit phosphorylation of IkappaB-alpha and activation of NF-kappaB. These findings suggest that DXS prevents TLR-induced maturation of human DC and may therefore be a useful reagent to impede the link between innate and adaptive immunity.

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BACKGROUND: Protein-energy wasting is a frequent and debilitating condition in maintenance dialysis. We randomly tested if an energy-dense, phosphate-restricted, renal-specific oral supplement could maintain adequate nutritional intake and prevent malnutrition in maintenance haemodialysis patients with insufficient intake. METHODS: Eighty-six patients were assigned to a standard care (CTRL) group or were prescribed two 125-ml packs of Renilon 7.5(R) daily for 3 months (SUPP). Dietary intake, serum (S) albumin, prealbumin, protein nitrogen appearance (nPNA), C-reactive protein, subjective global assessment (SGA) and quality of life (QOL) were recorded at baseline and after 3 months. RESULTS: While intention to treat analysis (ITT) did not reveal strong statistically significant changes in dietary intake between groups, per protocol (PP) analysis showed that the SUPP group increased protein (P < 0.01) and energy (P < 0.01) intakes. In contrast, protein and energy intakes further deteriorated in the CTRL group (PP). Although there was no difference in serum albumin and prealbumin changes between groups, in the total population serum albumin and prealbumin changes were positively associated with the increment in protein intake (r = 0.29, P = 0.01 and r = 0.27, P = 0.02, respectively). The SUPP group did not increase phosphate intake, phosphataemia remained unaffected, and the use of phosphate binders remained stable or decreased. The SUPP group exhibited improved SGA and QOL (P < 0.05). CONCLUSION: This study shows that providing maintenance haemodialysis patients with insufficient intake with a renal-specific oral supplement may prevent deterioration in nutritional indices and QOL without increasing the need for phosphate binders.

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OBJECTIVES To compare subjective memory deficit (SMD) in older adults with and without dementia or depression across multiple centers in low- and middle-income countries (LAMICs). DESIGN Secondary analysis of data from 23 case control studies. SETTING Twenty-three centers in India, Southeast Asia (including China), Latin America and the Caribbean, Nigeria, and Russia. PARTICIPANTS Two thousand six hundred ninety-two community-dwelling people aged 60 and older in one of three groups: people with dementia, people with depression, and controls free of dementia and depression. MEASUREMENTS SMD was derived from the Geriatric Mental State examination. RESULTS Median SMD frequency was lowest in participants without dementia (26.2%) and higher in those with depression (50.0%) and dementia (66.7%). Frequency of SMD varied between centers. Depression and dementia were consistently associated with SMD. Older age and hypochondriasis were associated with SMD only in subjects without dementia. In those with dementia, SMD was associated with better cognitive function, whereas the reverse was the case in controls. CONCLUSION Associations with SMD may differ between subjects with and without dementia living in LAMICs.

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INTRODUCTION: The phase III EORTC 22033-26033/NCIC CE5 intergroup trial compares 50.4 Gy radiotherapy with up-front temozolomide in previously untreated low-grade glioma. We describe the digital EORTC individual case review (ICR) performed to evaluate protocol radiotherapy (RT) compliance. METHODS: Fifty-eight institutions were asked to submit 1-2 randomly selected cases. Digital ICR datasets were uploaded to the EORTC server and accessed by three central reviewers. Twenty-seven parameters were analysed including volume delineation, treatment planning, organ at risk (OAR) dosimetry and verification. Consensus reviews were collated and summary statistics calculated. RESULTS: Fifty-seven of seventy-two requested datasets from forty-eight institutions were technically usable. 31/57 received a major deviation for at least one section. Relocation accuracy was according to protocol in 45. Just over 30% had acceptable target volumes. OAR contours were missing in an average of 25% of cases. Up to one-third of those present were incorrectly drawn while dosimetry was largely protocol compliant. Beam energy was acceptable in 97% and 48 patients had per protocol beam arrangements. CONCLUSIONS: Digital RT plan submission and review within the EORTC 22033-26033 ICR provide a solid foundation for future quality assurance procedures. Strict evaluation resulted in overall grades of minor and major deviation for 37% and 32%, respectively.