951 resultados para MB


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The aims of this study were to examine the plasma concentrations of inflammatory mediators including cytokines induced by a single bout of eccentric exercise and again 4 weeks later by a second bout of eccentric exercise of the same muscle group. Ten untrained male subjects performed two bouts of the eccentric exercise involving the elbow flexors (6 sets of 5 repetitions) separated by four weeks. Changes in muscle soreness, swelling, and function following exercise were compared between the bouts. Blood was sampled before, immediately after, 1 h, 3 h, 6 h, 24 h (1 d), 48 h (2 d), 72 h (3 d), 96 h (4 d) following exercise bout to measure plasma creatine kinase (CK) activity, plasma concentrations of myoglobin (Mb), interleukin (IL)-1 beta, IL-1 receptor antagonist (IL-1ra), IL-4, IL-6, IL-8, IL-10, IL-12p40, tumor necrosis factor (TNF)-alpha, granulocyte colony-stimulating factor (G-CSF), myeloperoxidase (MPO), prostaglandin E-2 (PGE(2)), heat shock protein (HSP) 60 and 70. After the first bout, muscle soreness increased significantly, and there was also significant increase in upper arm circumference; muscle function decreased and plasma CK activity and Mb concentration increased significantly. These changes were significantly smaller after the second bout compared to the first bout, indicating muscle adaptation to the repeated bouts of the eccentric exercise. Despite the evidence of greater muscle damage after the first bout, the changes in cytokines and other inflammatory mediators were quite minor, and considerably smaller than that following endurance exercise. These results suggest that eccentric exercise-induced muscle damage is not associated with the significant release of cytokines into the systemic circulation. After the first bout, plasma G-CSF concentration showed a small but significant increase, whereas TNF-alpha and IL-8 showed significant decreases compared to the pre-exercise values. After the second bout, there was a significant increase in IL-10, and a significant decrease in IL-8. In conclusion, although there was evidence of severe muscle damage after the eccentric exercise, this muscle damage was not accompanied by any large changes in plasma cytokine concentrations. The minor changes in systemic cytokine concentration found in this study might reflect more rapid clearance from the circulation, or a lack of any significant metabolic or oxidative demands during this particular mode of exercise. In relation to the adaptation to the muscle damage, the anti-inflammatory cytokine IL-10 might work as one of the underlying mechanisms of action.

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P>Approximately 50% of all carriers of 2q21-q31 deletions present epileptic seizures. The band 2q24 constitutes the smallest commonly deleted segment in these patients, and contains the voltage-gated sodium channel genes SCN1A and SCN2A, associated with Dravet syndrome and benign familial neonatal-infantile seizures, respectively. A further putative locus involving epilepsy in the region was previously identified through disruption of the SLC4A10 gene by translocation. In the course of performing high-resolution DNA copy number analyses on syndromic mentally impaired individuals, we encountered three patients with overlapping deletions in chromosome region 2q24. Two of these patients exhibited epileptic seizures in addition to mental deficiency. The deletion in one of the epileptic patients did not include the SCN cluster, demonstrating that a less severe form of epilepsy maps to an adjacent genomic region. This second region comprises about 3 Mb and contains the candidate gene SLC4A10, providing further support for the potential role of this gene in epilepsy.

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Nanocomposite materials have received considerable attention in recent years due to their novel properties. Grain boundaries are considered to play an important role in nanostructured materials. This work focuses on the finite element analysis of the effect of grain boundaries on the overall mechanical properties of aluminium/alumina composites. A grain boundary is incorporated into the commonly used unit cell model to investigate its effect on material properties. By combining the unit cell model with an indentation model, coupled with experimental indentation measurements, the ''effective'' plastic property of the grain boundary is estimated. In addition, the strengthening mechanism is also discussed based on the Estrin-Mecking model.

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The cypridinid ostracod, Sheina orri, was found on the gills of healthy epaulette sharks, Hemiscyllium, ocellatum, collected from the Great Barrier Reef, Australia, Seventeen of the 28 fish examined had ostracods attached to their gills. Detailed investigation of the gills and ostracods using light microscopy and scanning electron microscopy revealed that ostracods anchor themselves to the gill tissues using their mandibular and maxillular claws. These claws appear to be adapted for this purpose and the process of attachment causes some damage to the host tissues. The observation that ostracods were often located in distinct pockets, formed by local distortion of shark respiratory lamellae, strongly suggests that they had been attached to the gills for considerable time. (C) 1997 Australian Society for Parasitology.

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Myelin proteolipid protein (PLP) contains 2 immunodominant encephalitogenic epitopes in SJL mice, namely PLP residues 139-151 and 178-191. DM20, a minor isoform of PLP, lacks residues 116-150 and consequently contains only the single major encephalitogenic epitope 178-191. However, it has been found previously that bovine DM20 is not encephalitogenic in SJL mice. Since residue 188 within peptide 178-191 is phenylalanine (F) in murine DM20 and alanine (A) in bovine DM20, we tested the effect of this difference on the immune responses and induction of EAE. SJL mice were immunized with either highly purified murine or bovine DM20. Residues 178-191 were found to be immunodominant for each, but only murine and not bovine DM20 was encephalitogenic. A synthetic peptide corresponding to the murine 178-191 sequence (F188) was also encephalitogenic, whereas the peptide corresponding to the bovine sequence (A188) was not. Both F188 and A188 bind with high affinity to I-A(s) and both are recognized by the SJL T cell repertoire. A188-specific T cell lines reacted to both A188 and F188, but F188-specific T cell lines were not stimulated by A188. F188-specific T cell lines produced mRNA for the Th1 cytokines IL2 and IFN gamma and, in passive transfer experiments, were encephalitogenic upon stimulation with F188, but not A188. In contrast, A188-specific T cell lines produced mRNA for IL4, IL5 and IL10, in addition to IL2 and IFN gamma, and were not encephalitogenic after stimulation with either F188 or A188. Cotransfer of A188-specific T cell lines with F188-specific T cell lines resulted in protection from EAE. Thus, A188 induces a functionally different phenotype of T cells from that induced by F188. Taken together these data suggest that the failure of bovine DM20 to induce EAE may be attributable to induction of protective rather than pathogenic T cells by the immunodominant epitope.

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Samples of dermal and epidermal tissues of epaulette sharks Hemiscyllium ocellatum were examined histologically to assess damage caused by tagging. Tissues from around tag sites were removed at time intervals ranging from 100 min to 284 days post-tagging. These samples showed acute and chronic responses to tagging. Acute responses consisted of localized tissue breakdown and haemorrhaging, and occurred within the first few hours after tag insertion. At 10 h post-tagging, an intermediate response was apparent. This phase was characterized by further haemorrhaging and red and white blood cell movement into the wound area. The chronic response observed in the 10-284-day post-tagging samples was characterized by fibrous tissue formation to sequester the tag. This tissue presumably protects the adjacent musculature from further trauma produced by movement of the tag and provides a continuous barrier between the internal and external milieu. Tissue repair appeared to progress consistently in all specimens and no secondary infections at the tag site were seen. Tagging produced only localized tissue disruption and did not appear to be detrimental to the long term health of individual sharks. Our findings show that spaghetti style dart tagging is an acceptable method for marking individuals (40-75+ cm total length) of this species. (C) 1997 The Fisheries Society of the British Isles.

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BACKGROUND Marshall bundles (MBs) are the muscle bundles within the ligament of Marshall. OBJECTIVE This trial sought to the electrophysiological characteristics of the MB and the anatomical connections between MB and left atrium (LA) in patients with persistent atrial fibrillation (AF). METHODS We enrolled 72 patients (male: female 59: 13, age 59.9 +/- 9.4 years) who underwent MB mapping and ablation for AF. MB mapping was done via an endocardial or epicardial approach during sinus rhythm and AF. RESULTS Recordings were successful in 64 of 72 patients (89%). A single connection was noted in 11 of 64 patients between the MB and the coronary sinus (CS) muscle sleeves. The MB recordings showed distinct MB potentials with a proximal-to-distal activation pattern during sinus rhythm. During AF, organized passive activations and dissociated slow MB ectopic activities were commonly observed in this type of connection. Double connections to both CS and LA around left pulmonary veins were noted in 23 of 64 patients (36%). After the ablation of the distal connection, MB recording showed typical double potentials as in single connection. Multiple connections were noted in 30 of 64 patients (47%). During sinus rhythm, the earliest activation was in the middle of the MB. The activation patterns were irregular and variable in each patient. During AF, rapid and fractionated complex activations were noted in all patients of this group. CONCLUSION We documented 3 different types of MB-LA connections. Rapid and fractionated activations were most commonly observed in the MB that had multiple LA connections.

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Our aim was to evaluate the interaction between breast cancer cells and nodal fibroblasts, by means of their gene expression profile. Fibroblast primary cultures were established from negative and positive lymph nodes from breast cancer patients and a similar gene expression pattern was identified, following cell culture. Fibroblasts and breast cancer cells (MDA-MB231, MDA-MB435, and MCF7) were cultured alone or co-cultured separated by a porous membrane (which allows passage of soluble factors) for comparison. Each breast cancer lineage exerted a particular effect on fibroblasts viability and transcriptional profile. However, fibroblasts from positive and negative nodes had a parallel transcriptional behavior when co-cultured with a specific breast cancer cell line. The effects of nodal fibroblasts on breast cancer cells were also investigated. MDA MB-231 cells viability and migration were enhanced by the presence of fibroblasts and accordingly, MDA-MB435 and MCF7 cells viability followed a similar pattern. MDA-MB231 gene expression profile, as evaluated by cDNA microarray, was influenced by the fibroblasts presence, and HNMT, COMT, FN3K, and SOD2 were confirmed downregulated in MDA-MB231 co-cultured cells with fibroblasts from both negative and positive nodes, in a new series of RT-PCR assays. In summary, transcriptional changes induced in breast cancer cells by fibroblasts from positive as well as negative nodes are very much alike in a specific lineage. However, fibroblasts effects are distinct in each one of the breast cancer lineages, suggesting that the inter-relationships between stromal and malignant cells are dependent on the intrinsic subtype of the tumor.

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The ADAM23 gene is frequently silenced in different types of tumors, and, in breast tumors, silencing is correlated with tumor progression, suggesting that it might be associated with the acquisition of a metastatic phenotype. ADAM23 exerts its function mainly through the disintegrin domain, because its metalloprotease domain is inactive. Analysis of ADAM23 binding to integrins has revealed a specific interaction with alpha(v)beta(3) integrin mediated by the disintegrin domain. Altered expression of alpha(v)beta(3) integrin has been observed in different types of tumors, and expression of this integrin in the activated form has been shown to promote metastasis formation. Here, we investigated the possibility that interaction between ADAM23 and alpha(v)beta(3) integrin might negatively modulate alpha(v)beta(3) activation during metastatic progression. ADAM23 expression was knocked down using short hairpin RNA in the MDA-MB-435 cell line, which has been extensively used as a model for alpha(v)beta(3) integrin activation. Ablation of ADAM23 enhanced alpha(v)beta(3) integrin activation by at least 2- to 4-fold and ADAM23 knockdown cells showed enhanced migration and adhesion to classic alpha(v)beta(3) integrin ligands. Ablation of ADAM23 expression also enhanced pulmonary tumor cell arrest in immunodeficient mice. To complement our findings with clinical evidence, we showed that silencing of ADAM23 gene by DNA promoter hypermethylation in a collection of 94 primary breast tumors was significantly associated with lower distant metastases-free and disease-specific survivals and was an independent prognostic factor for poor disease outcome. Our results strongly support a functional role of ADAM23 during metastatic progression by negatively modulating alpha(v)beta(3) integrin activation. [Cancer Res 2009;69(13):5546-52]

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This investigation focused on the finite element analyses of elastic and plastic properties of aluminium/alumina composite materials with ultrafine microstructure. The commonly used unit cell model was used to predict the elastic properties. By combining the unit cell model with an indentation model, coupled with experimental indentation measurements, the plastic properties of the composites and the associated strengthening mechanism within the metal matrix material were investigated. The grain size of the matrix material was found to be an important factor influencing the mechanical properties of the composites studied. (C) 1997 Elsevier Science S.A.

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Familial Mediterranean fever (FMF) is a recessive disorder of inflammation caused by mutations in a gene (designated MEFV) on chromosome 16p13.3, We have recently constructed a 1-Mb cosmid contig that includes the FMF critical region. Here we show genotype data for 12 markers from our physical map, including 5 newly identified microsatellites, in FMF families. Intrafamilial recombinations placed MEFV in the similar to 285 kb between D16S468/D16S3070 and D16S3376. We observed significant linkage disequilibrium in the North African Jewish population, and historical recombinants in the founder haplotype placed MEFV between D16S3082 and D16S3373 (similar to 200 kb). In smaller panels of Iraqi Jewish, Arab, and Armenian families, there were significant allelic associations only for D16S3370 and D16S2617 among the Armenians. A sizable minority of Iraqi Jewish and Armenian carrier chromosomes appeared to be derived from the North African Jewish ancestral haplotype. We observed a unique FMF haplotype common to Iraqi Jews, Arabs, and Armenians and two other haplotypes restricted to either the Iraqi Jewish or the Armenian population. These data support the view that a few major mutations account for a large percentage of the cases of FMF and suggest that same of these mutations arose before the affected Middle Eastern populations diverged from one another. (C) 1997 Academic Press.

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The identification of genes responsible for the rare cases of familial leukemia may afford insight into the mechanism underlying the more common sporadic occurrences. Here we test a single family with 11 relevant meioses transmitting autosomal dominant acute myelogenous leukemia (AML) and myelodysplasia for linkage to three potential candidate loci. In a different family with inherited AML, linkage to chromosome 21q22.1-22.2 was recently reported; we exclude linkage to 21q22.1-22.2, demonstrating that familial AML is a heterogeneous disease. After reviewing familial leukemia and observing anticipation in the form of a declining age of onset with each generation, we had proposed 9p21-22 and 16q22 as additional candidate loci. Whereas linkage to 9p21-22 can be excluded, the finding of a maximum two-point LOD score of 2.82 with the microsatellite marker D16S522 at a recombination fraction theta = 0 provides evidence supporting linkage to 16q22. Haplotype analysis reveals a 23.5-cM (17.9-Mb) commonly inherited region among all affected family members extending from D16S451 to D1GS289, In order to extract maximum linkage information with missing individuals, incomplete informativeness with individual markers in this interval, and possible deviance from strict autosomal dominant inheritance, we performed nonparametric linkage analysis (NPL) and found a maximum NPL statistic corresponding to a P-value of .00098, close to the maximum conditional probability of linkage expected for a pedigree with this structure. Mutational analysis in this region specifically excludes expansion of the AT-rich minisatellite repeat FRA16B fragile site and the CAG trinucleotide repeat in the E2F-4 transcription factor. The ''repeat expansion detection'' method, capable of detecting dynamic mutation associated with anticipation, more generally excludes large CAG repeat expansion as a cause of leukemia in this family.

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Medulloblastoma (MB) is the most common malignant brain tumor of children. To identify the genetic alterations in this tumor type, we searched for copy number alterations using high-density microarrays and sequenced all known protein-coding genes and microRNA genes using Sanger sequencing in a set of 22 MBs. We found that, on average, each tumor had 11 gene alterations, fewer by a factor of 5 to 10 than in the adult solid tumors that have been sequenced to date. In addition to alterations in the Hedgehog and Wnt pathways, our analysis led to the discovery of genes not previously known to be altered in MBs. Most notably, inactivating mutations of the histone-lysine N-methyltransferase genes MLL2 or MLL3 were identified in 16% of MB patients. These results demonstrate key differences between the genetic landscapes of adult and childhood cancers, highlight dysregulation of developmental pathways as an important mechanism underlying MBs, and identify a role for a specific type of histone methylation in human tumorigenesis.

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Objectives: estimate the Prevalence and track the risk factors associated with, Maternity blues (MB). Methods: a transversal study was performed with 113 women, on the tenth day of puerperium. The following instruments were used: Pitt Scale (1968), Stein (1980), Inventory for stressful life events by Holmes & Rahe (1967), and a questionnaire with sociodemographic and obstetric data. Results: the prevalence of MB was 32.7% according to the Stein scale. In the univariated analysis, civil status and tobacco use were associated with MB, Legally married women and nonsmokers showed a risk approximately 4 times lower of experiencing the problem. Conclusions: MB was very prevalent in this sample, Obstetricians must be aware of this condition which may be associated with postpartum depression.

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Rearrangements of 1p36 are the most frequently detected abnormalities in diagnostic testing for chromosomal cryptic imbalances and include variably sized simple terminal deletions, derivative chromosomes, interstitial deletions, and complex rearrangements. These rearrangements result in the specific pattern of malformation and neurodevelopmental disabilities that characterizes monosomy 1p36 syndrome. Thus far, no individual gene within this region has been conclusively determined to be causative of any component of the phenotype. Nor is it known if the rearrangements convey phenotypes via a haploinsufficiency mechanism or through a position effect. We have used multiplex ligation-dependent probe amplification to screen for deletions of 1p36 in a group of 154 hyperphagic and overweight/obese, PWS negative individuals, and in a separate group of 83 patients initially sent to investigate a variety of other conditions. The strategy allowed the identification and delineation of rearrangements in nine subjects with a wide spectrum of clinical presentations. Our work reinforces the association of monosomy 1p36 and obesity and hyperphagia, and further suggests that these features may be associated with non-classical manifestations of this disorder in addition to a submicroscopic deletion of similar to 2-3 Mb in size. Multiplex ligation probe amplification using the monosomy 1p36 syndrome-specific kit coupled to the subtelomeric kit is an effective approach to identify and delineate rearrangements at 1p36. (C) 2009 Wiley-Liss, Inc.