994 resultados para Sickle cell anemia in children.


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T-lymphocyte infiltration in ovarian tumors has been linked to a favorable prognosis, hence, exploring the mechanism of T-cell recruitment in the tumor is warranted. We employed a differential expression analysis to identify genes over-expressed in early stage ovarian cancer samples that contained CD8 infiltrating T-lymphocytes. Among other genes, we discovered that TTF1, a regulator of ribosomal RNA gene expression, and SMARCE1, a factor associated with chromatin remodeling were overexpressed in first stage CD8+ ovarian tumors. TTF1 and SMARCE1 mRNA levels showed a strong correlation with the number of intra-tumoral CD8+ cells in ovarian tumors. Interestingly, forced overexpression of SMARCE1 in SKOV3 ovarian cancer cells resulted in secretion of IL8, MIP1b and RANTES chemokines in the supernatant and triggered chemotaxis of CD8+ lymphocytes in a cell culture assay. The potency of SMARCE1-mediated chemotaxis appeared comparable to that caused by the transfection of the CXCL9 gene, coding for a chemokine known to attract T-cells. Our analysis pinpoints TTF1 and SMARCE1 as genes potentially involved in cancer immunology. Since both TTF1 and SMARCE1 are involved in chromatin remodeling, our results imply an epigenetic regulatory mechanism for T-cell recruitment that invites deciphering.

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BACKGROUND A recent study using a rat model found significant differences at the time of diabetes onset in the bacterial communities responsible for type 1 diabetes modulation. We hypothesized that type 1 diabetes in humans could also be linked to a specific gut microbiota. Our aim was to quantify and evaluate the difference in the composition of gut microbiota between children with type 1 diabetes and healthy children and to determine the possible relationship of the gut microbiota of children with type 1 diabetes with the glycemic level. METHODS A case-control study was carried out with 16 children with type 1 diabetes and 16 healthy children. The fecal bacteria composition was investigated by polymerase chain reaction-denaturing gradient gel electrophoresis and real-time quantitative polymerase chain reaction. RESULTS The mean similarity index was 47.39% for the healthy children and 37.56% for the children with diabetes, whereas the intergroup similarity index was 26.69%. In the children with diabetes, the bacterial number of Actinobacteria and Firmicutes, and the Firmicutes to Bacteroidetes ratio were all significantly decreased, with the quantity of Bacteroidetes significantly increased with respect to healthy children. At the genus level, we found a significant increase in the number of Clostridium, Bacteroides and Veillonella and a significant decrease in the number of Lactobacillus, Bifidobacterium, Blautia coccoides/Eubacterium rectale group and Prevotella in the children with diabetes. We also found that the number of Bifidobacterium and Lactobacillus, and the Firmicutes to Bacteroidetes ratio correlated negatively and significantly with the plasma glucose level while the quantity of Clostridium correlated positively and significantly with the plasma glucose level in the diabetes group. CONCLUSIONS This is the first study showing that type 1 diabetes is associated with compositional changes in gut microbiota. The significant differences in the number of Bifidobacterium, Lactobacillus and Clostridium and in the Firmicutes to Bacteroidetes ratio observed between the two groups could be related to the glycemic level in the group with diabetes. Moreover, the quantity of bacteria essential to maintain gut integrity was significantly lower in the children with diabetes than the healthy children. These findings could be useful for developing strategies to control the development of type 1 diabetes by modifying the gut microbiota.

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To determine the positivity rate of human bocavirus (HBoV) 1 and 3 among children who presented with acute gastroenteritis symptoms during the period of 1994-2004 in the Central-West Region of Brazil, 762 faecal samples were tested using polymerase chain reaction (PCR) for the detection of HBoV DNA. Primers for a segment of the non-structural viral protein 1 (NS1) gene of HBoV-1 and HBoV-3 were used. Twelve HBoV-positive samples were further characterised via genomic sequencing and phylogenetic analysis. Of the samples tested, 5.8% (n = 44) were positive for HBoV-1 or HBoV-3 and co-infection was observed in 14 (31.8%) of the 44 HBoV-positive samples. Nine of the 14 samples were also positive for Rotavirus A and five were positive for Aichi virus. The genomic sequencing of the NS1 partial sequence of 12 HBoV-samples showed that 11 samples were characterised as HBoV-1 and that one was characterised as HBoV-3. The phylogenetic analysis showed that the HBoV-1 samples had a high sequence homology to others previously identified in China, Sweden and Brazil. This is the first study conducted in the Central-West Region of Brazil to detect HBoV-1 and HBoV-3 in faecal samples from children with acute gastroenteritis. Further studies are required to define the role of HBoVs as aetiological agents of gastroenteritis.

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Human immunodeficiency virus (HIV)-1 infection has an important impact on malaria. Plasmodium falciparum and HIV-1 co-infected patients (Pf/HIV) present with a high degree of anaemia, enhanced parasitaemia and decreased CD4+ T cell counts, which increase the risk of developing severe malaria. In addition, infection with either Pf or HIV-1 alone causes extensive immune activation. Our hypothesis was that lymphocyte activation is potentiated in Pf/HIV co-infected patients, consequently worsening their immunosuppressed state. To test this hypothesis, 22 Pf/HIV patients, 34 malaria patients, 29 HIV/AIDS patients and 10 healthy controls without malaria or HIV/acquired immune deficiency syndrome (AIDS) from Maputo/Mozambique were recruited for this study. As expected, anaemia was most prevalent in the Pf/HIV group. A significant variation in parasite density was observed in the Pf/HIV co-infected group (110-75,000 parasites/µL), although the median values were similar to those of the malaria only patients. The CD4+ T cell counts were significantly lower in the Pf/HIV group than in the HIV/AIDS only or malaria only patients. Lymphocyte activation was evaluated by the percentage of activation-associated molecules [CD38 expression on CD8+ and human leukocyte antigen-DR expression on CD3+ T cells]. The highest CD38 expression was detected in the Pf/HIV co-infected patients (median = 78.2%). The malaria only (median = 50%) and HIV/AIDS only (median = 52%) patients also exhibited elevated levels of these molecules, although the values were lower than those of the Pf/HIV co-infected cases. Our findings suggest that enhanced T-cell activation in co-infected patients can worsen the immune response to both diseases.

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Background. Sevelamer is a phosphate-binder used effectively for the treatment of hyperphosphatemia in patients treated with dialysis. Objectives. To describe the safety of sevelamer in children with hyperphosphatemia secondary to tumor lysis syndrome and the serum phosphate concentrations observed following its administration. Procedure. A retrospective chart review of all children with leukemia/lymphoma diagnosed between November 2002 and April 2004 who received sevelamer during their initial admission was conducted. We monitored the effects of sevelamer on serum phosphate concentration, calcium/phosphate product and renal function at hours 24, 48, and 72 from sevelamer initiation. Results. Thirteen patients received sevelamer during the Study period. Their median age was 13 years (range 2.7-17.9) and eight were boys. Nine children had acute lymphoblastic leukemia, one had acute myeloid leukemia and 3 had non-Hodgkin's lymphoma. The most frequently used dose of sevelamer was 400 mg orally twice daily. The median duration of sevelamer therapy was 2 days (range 1 -7). Two children were excluded from the efficacy analysis due to concurrent use of dialysis. Mean serum phosphate levels decreased after sevelamer administration, in eleven patients, from a baseline 2.2 mmol/L +/- 0.4 (95% Cl, 1.7-3.1) to 1.1 mmol/L +/- 0.2 at hour 72 (95%Cl, 0.6-1.5). The only toxicity attributed to sevelamer was mild vomiting in three patients. Conclusions. Sevelamer appears to be effective and tolerable for the treatment of hyperphosphatemia associated with tumor lysis syndrome.

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BACKGROUND Lichen planopilaris (LPP) is a rare variant of cutaneous lichen planus that preferentially involves hair follicles. OBSERVATION We describe the case of an 87-year-old woman with cicatricial alopecia due to lichen planopilaris. The diagnosis was based on clinical evaluation, histopathology and trichoscopy. Squamous cell carcinoma developed within the hairless area after 18 years of evolution. CONCLUSION It is necessary to consider the association between lichen planopilaris and squamous cell carcinoma and to ensure a close follow-up of LPP patients, especially when there is a long history of the disease or new a lesion develops, which does not correspond clinically or in trichoscopy to lichen planopilaris.

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Memory CD4 T cell responses are functionally and phenotypically heterogeneous. In the present study, memory CD4 T cell responses were analyzed in different models of Ag-specific immune responses differing on Ag exposure and/or persistence. Ag-specific CD4 T cell responses for tetanus toxoid, HSV, EBV, CMV, and HIV-1 were compared. Three distinct patterns of T cell response were observed. A dominant single IL-2 CD4 T cell response was associated with the model in which the Ag can be cleared. Polyfunctional (single IL-2 plus IL-2/IFN-gamma plus single IFN-gamma) CD4 T cell responses were associated with Ag persistence and low Ag levels. A dominant single IFN-gamma CD4 T cell response was associated with the model of Ag persistence and high Ag levels. The results obtained supported the hypothesis that the different patterns observed were substantially influenced by different conditions of Ag exposure and persistence.

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Summary Pseudomonas fluorescens CHAO is a soil bacterium which was isolated near Morens (Switzerland) and which protects plants from root-pathogenic fungi. This protection is due to extracellular secondary metabolites whose synthesis is regulated by the two-component system GacS/GacA in strain CHAO. Extracellular signals of bacterial origin activate this regulatory system. These signals are different from N-acyl-homoserine lactones, are extracted by dichloromethane and appear to have a low molecular weight. Preliminary evidence was obtained from a small molecule m/z 278 produced by strain CHAO. Similar signals capable of activating GacS/GacA-dependent regulation in strain CHAO were found in a large number of different Gram-negative bacteria. Once activated by signal(s), the sensor GacS is assumed to phosphorylate the response regulator GacA, which positively influences a regulatory cascade, resulting in the synthesis of secondary metabolites. This cascade includes three GacA-controlled small regulatory RNAs and two translational repressor proteins. The regulatory RNAs titrate the repressor proteins; this allows translation of target genes and the synthesis of exoenzymes and secondary metabolites such as antibiotics and hydrogen cyanide. A GFP-based sensor for signal detection was constructed in strain CHAO by fusing the gfp reporter gene to the rsmZ small RNA gene. CHAO mutants defective for signal production were isolated following transposon insertion mutagenesis. In one class of mutants obtained, the gacS gene was inactivated, indicating that GacS/GacA positively controls signal production. In a second class, the thiC gene required for thiamine (vitamin B1) biosynthesis was disrupted. Addition of excess (> 10E-6 M) thiamine to the medium restored signal production. By contrast, when the thiamine concentration was just sufficient to allow normal growth, no production of signal(s) was observed. The mechanism by which thiamine activates signal production remains to be elucidated. Résumé Pseudomonas fluorescens CHAO est une bactérie du sol, isolée près de Morens (Suisse), qui a la capacité de protéger les plantes contre des champignons pathogènes de la racine. Cette protection provient de métabolites secondaires excrétés par la bactérie, dont la synthèse est régulée par le système à deux composants GacS/GacA. Des signaux extracellulaires d'origine bactérienne activent ce système de régulation. Ces signaux, différents des N-acyl¬homosérines lactones, sont extraits par le dichlorométhane et semblent avoir une petite masse moléculaire. Une molécule (masse m/z 278) a été mise en évidence par des expériences préliminaires chez la souche CHAO. Des signaux similaires, capables d'activer la régulation dépendante de GacS/GacA chez la souche CHAO, ont été trouvés chez un grand nombre de bactéries à Gram négative. Une fois activé par le(s) signal(aux), le senseur GacS est supposé phosphoryler le régulateur de réponse GacA, qui influence positivement la cascade de régulation menant à la synthèse des métabolites secondaires. Cette cascade inclut trois petits ARNs régulateurs contrôlés par GacA et deux protéines répresseurs de la traduction. Les ARNs régulateurs titrent les protéines répresseurs, ce qui permet la traduction des gènes cibles et la synthèse d'exoenzymes et de métabolites secondaires tel les antibiotiques et le cyanure d'hydrogène. Un senseur basé sur la GFP pour la détection de signaux a été construit dans la souche CHAO en fusionnant le gène rapporteur gfp au gène de petit ARN rsmZ. Des mutants de CHAO déficients pour la production de signaux ont été isolés au moyen d'une mutagenèse par insertion de transposon. Chez une classe de mutants obtenus, le gène gacS a été inactivé, indiquant que GacS/GacA contrôle positivement la production de signaux. Dans une seconde classe, le gène thiC nécessaire à la biosynthèse de thiamine (vitamine B1) a été interrompu. L'addition en excès (> 10E-6 M) de thiamine au milieu restaure la production de signaux. A l'opposé, quand la concentration de thiamine est juste suffisante pour permettre une croissance normale, aucune production de signaux n'a été observée. Le mécanisme par lequel la thiamine active la production de signaux reste à élucider.

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During the season of high malaria transmission, most children are infected by Plasmodium, which targets red blood cells (RBCs), affecting haematological parameters. To describe these variations, we examined the haematological profiles of two groups of children living in a malaria-endemic area. A cross-sectional survey was conducted at the peak of the malaria transmission season in a rural area of Burkina Faso. After informed consent and clinical examination, blood samples were obtained from the participants for malaria diagnosis and a full blood count. Of the 414 children included in the analysis, 192 were not infected with Plasmodium, whereas 222 were asymptomatic carriers of Plasmodium infection. The mean age of the infected children was 41.8 months (range of 26.4-57.2) compared to 38.8 months (range of 22.4-55.2) for the control group (p = 0.06). The asymptomatic infected children tended to have a significantly lower mean haemoglobin level (10.8 g/dL vs. 10.4 g/dL; p < 0.001), mean lymphocyte count (4592/µL vs. 5141/µL; p = 0.004), mean platelet count (266 x 103/µL vs. 385 x 103/µL; p < 0.001) and mean RBC count (4.388 x 106/µL vs. 4.158 x 106/µL; p < 0.001) and a higher mean monocyte count (1403/µL vs. 1192/µL; p < 0.001) compared to the control group. Special attention should be applied when interpreting haematological parameters and evaluating immune responses in asymptomatic infected children living in malaria-endemic areas and enrolled in vaccine trials.

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In Europe, the combination of plerixafor + granulocyte colony-stimulating factor is approved for the mobilization of hematopoietic stem cells for autologous transplantation in patients with lymphoma and myeloma whose cells mobilize poorly. The purpose of this study was to further assess the safety and efficacy of plerixafor + granulocyte colony-stimulating factor for front-line mobilization in European patients with lymphoma or myeloma. In this multicenter, open label, single-arm study, patients received granulocyte colony-stimulating factor (10 μg/kg/day) subcutaneously for 4 days; on the evening of day 4 they were given plerixafor (0.24 mg/kg) subcutaneously. Patients underwent apheresis on day 5 after a morning dose of granulocyte colony-stimulating factor. The primary study objective was to confirm the safety of mobilization with plerixafor. Secondary objectives included assessment of efficacy (apheresis yield, time to engraftment). The combination of plerixafor + granulocyte colony-stimulating factor was used to mobilize hematopoietic stem cells in 118 patients (90 with myeloma, 25 with non-Hodgkin's lymphoma, 3 with Hodgkin's disease). Treatment-emergent plerixafor-related adverse events were reported in 24 patients. Most adverse events occurred within 1 hour after injection, were grade 1 or 2 in severity and included gastrointestinal disorders or injection-site reactions. The minimum cell yield (≥ 2 × 10(6) CD34(+) cells/kg) was harvested in 98% of patients with myeloma and in 80% of those with non-Hodgkin's lymphoma in a median of one apheresis. The optimum cell dose (≥ 5 × 10(6) CD34(+) cells/kg for non-Hodgkin's lymphoma or ≥ 6 × 10(6) CD34(+) cells/kg for myeloma) was harvested in 89% of myeloma patients and 48% of non-Hodgkin's lymphoma patients. In this prospective, multicenter European study, mobilization with plerixafor + granulocyte colony-stimulating factor allowed the majority of patients with myeloma or non-Hodgkin's lymphoma to undergo transplantation with minimal toxicity, providing further data supporting the safety and efficacy of plerixafor + granulocyte colony-stimulating factor for front-line mobilization of hematopoietic stem cells in patients with non-Hodgkin's lymphoma or myeloma.

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Dynamically polarized membrane proteins define different cell boundaries and have an important role in intercellular communication-a vital feature of multicellular development. Efflux carriers for the signalling molecule auxin from the PIN family are landmarks of cell polarity in plants and have a crucial involvement in auxin distribution-dependent development including embryo patterning, organogenesis and tropisms. Polar PIN localization determines the direction of intercellular auxin flow, yet the mechanisms generating PIN polarity remain unclear. Here we identify an endocytosis-dependent mechanism of PIN polarity generation and analyse its developmental implications. Real-time PIN tracking showed that after synthesis, PINs are initially delivered to the plasma membrane in a non-polar manner and their polarity is established by subsequent endocytic recycling. Interference with PIN endocytosis either by auxin or by manipulation of the Arabidopsis Rab5 GTPase pathway prevents PIN polarization. Failure of PIN polarization transiently alters asymmetric auxin distribution during embryogenesis and increases the local auxin response in apical embryo regions. This results in ectopic expression of auxin pathway-associated root-forming master regulators in embryonic leaves and promotes homeotic transformation of leaves to roots. Our results indicate a two-step mechanism for the generation of PIN polar localization and the essential role of endocytosis in this process. It also highlights the link between endocytosis-dependent polarity of individual cells and auxin distribution-dependent cell fate establishment for multicellular patterning.

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The present study investigates developmental changes in selective inhibition of symmetric movements with a lateralized switching task from bimanual to unimanual tapping in typically developing (TD) children and with Developmental Coordination Disorder (DCD) from 7 to 10 years old. Twelve right-handed TD children and twelve gender-matched children with DCD and probable DCD produce a motor switching task in which they have (1) to synchronize with the beat of an auditory metronome to produce bimanual symmetrical tapping and (2) to selectively inhibit their left finger's tapping while continuing their right finger's tapping and conversely. We assess (1) the development of the capacity to inhibit the stopping finger (number of supplementary taps after the stopping instruction) and (2) the development of the capacity to maintain the continuing finger (changes in the mean tempo and its variability for the continuing finger's tapping) and (3) the evolution of performance through trials. Results indicate that (1) TD children present an age-related increase in the capacity to inhibit and to maintain the left finger's tapping, (2) DCD exhibits persistent difficulties to inhibit the left finger's tapping, and (3) both groups improve their capacity to inhibit the left finger's movements through trials. In conclusion, the lateralized switching task provides a simple and fine tool to reveal differences in selective inhibition of symmetric movements in TD children and children with DCD. More theoretically, the specific improvement in selective inhibition of the left finger suggests a progressive development of inter-hemispheric communication during typical development that is absent or delayed in children with DCD.

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BACKGROUND: The activity of melanopsin containing intrinsically photosensitive ganglion retinal cells (ipRGC) can be assessed by a means of pupil responses to bright blue (appr.480 nm) light. Due to age related factors in the eye, particularly, structural changes of the lens, less light reaches retina. The aim of this study was to examine how age and in vivo measured lens transmission of blue light might affect pupil light responses, in particular, mediated by the ipRGC. METHODS: Consensual pupil responses were explored in 44 healthy subjects aged between 26 and 68 years. A pupil response was recorded to a continuous 20 s light stimulus of 660 nm (red) or 470 nm (blue) both at 300 cd/m2 intensity (14.9 and 14.8 log photons/cm2/s, respectively). Additional recordings were performed using four 470 nm stimulus intensities of 3, 30, 100 and 300 cd/m2. The baseline pupil size was measured in darkness and results were adjusted for the baseline pupil and gender. The main outcome parameters were maximal and sustained pupil contraction amplitudes and the postillumination response assessed as area under the curve (AUC) over two time-windows: early (0-10 s after light termination) and late (10-30 s after light termination). Lens transmission was measured with an ocular fluorometer. RESULTS: The sustained pupil contraction and the early poststimulus AUC correlated positively with age (p=0.02, p=0.0014, respectively) for the blue light stimulus condition only.The maximal pupil contraction amplitude did not correlate to age either for bright blue or red light stimulus conditions.Lens transmission decreased linearly with age (p<0.0001). The pupil response was stable or increased with decreasing transmission, though only significantly for the early poststimulus AUC to 300 cd/m2 light (p=0.02). CONCLUSIONS: Age did not reduce, but rather enhance pupil responses mediated by ipRGC. The age related decrease of blue light transmission led to similar results, however, the effect of age was greater on these pupil responses than that of the lens transmission. Thus there must be other age related factors such as lens scatter and/or adaptive processes influencing the ipRGC mediated pupil response enhancement observed with advancing age.