924 resultados para Lipid Layer
Resumo:
The study of cross-reactivity in allergy is key to both understanding. the allergic response of many patients and providing them with a rational treatment In the present study, protein microarrays and a co-sensitization graph approach were used in conjunction with an allergen microarray immunoassay. This enabled us to include a wide number of proteins and a large number of patients, and to study sensitization profiles among members of the LTP family. Fourteen LTPs from the most frequent plant food-induced allergies in the geographical area studied were printed into a microarray specifically designed for this research. 212 patients with fruit allergy and 117 food-tolerant pollen allergic subjects were recruited from seven regions of Spain with different pollen profiles, and their sera were tested with allergen microarray. This approach has proven itself to be a good tool to study cross-reactivity between members of LTP family, and could become a useful strategy to analyze other families of allergens.
Resumo:
Imaging mass spectrometry (IMS) represents an innovative tool in the cancer research pipeline, which is increasingly being used in clinical and pharmaceutical applications. The unique properties of the technique, especially the amount of data generated, make the handling of data from multiple IMS acquisitions challenging. This work presents a histology-driven IMS approach aiming to identify discriminant lipid signatures from the simultaneous mining of IMS data sets from multiple samples. The feasibility of the developed workflow is evaluated on a set of three human colorectal cancer liver metastasis (CRCLM) tissue sections. Lipid IMS on tissue sections was performed using MALDI-TOF/TOF MS in both negative and positive ionization modes after 1,5-diaminonaphthalene matrix deposition by sublimation. The combination of both positive and negative acquisition results was performed during data mining to simplify the process and interrogate a larger lipidome into a single analysis. To reduce the complexity of the IMS data sets, a sub data set was generated by randomly selecting a fixed number of spectra from a histologically defined region of interest, resulting in a 10-fold data reduction. Principal component analysis confirmed that the molecular selectivity of the regions of interest is maintained after data reduction. Partial least-squares and heat map analyses demonstrated a selective signature of the CRCLM, revealing lipids that are significantly up- and down-regulated in the tumor region. This comprehensive approach is thus of interest for defining disease signatures directly from IMS data sets by the use of combinatory data mining, opening novel routes of investigation for addressing the demands of the clinical setting.
Resumo:
RESUME Les gènes des PPARs jouent des rôles importants dans la régulation du métabolisme énergétique, lipidique et glucidique. Le présent travail, caractérise et analyse les défauts placentaires responsables de la mort embryonnaire des souris mutantes pour PPARβ et pour PPARγ, entre le jour E9.5 et E10.5. Les placentas issus d'embryons PPARP présentent un sévère retard de croissance, alors que les placentas mutants PPARγ montrent de graves défauts vasculaires. Nous montrons que les placentas issus d'embryons PPARβ-/-, au jour E9.5 présentent une réduction prononcée de la couche de cellules géantes, associée à une diminution des niveaux de protéines exprimées par les cellules géantes, tel que le placenta lactogène-I et la « proliferin ». Par ailleurs, nous montrons que le traitement d'un lignée trophoblastique par un ligand spécifique de PPARP augmente considérablement leur différentiation en cellules géantes. Cette différentiation dépendante de la voie de signalisation P13-kinase, s'accompagne d'une élévation de l'expression de l'ADRP, une protéine de structure associée aux vésicules lipidiques. Ainsi nous démontrons que PPAR5 est un régulateur majeur de la différentiation des cellules géantes, lesquelles sont primordiales aussi bien pour l'établissement de la structure placentaire, que pour la fonction endocrine. Par contre, les placentas PPARγ-/- présentent un défaut de vascularisation. Le niveau d'une protéine anti-angiogénique, la « proliferin-related protein », est très basse et ne peut pas contre-balancer l'élévation normale de la protéine pro-angiogénique « proliferin ». La formation des vaisseaux se trouve alors altérée. Ainsi, PPARγ constitue un régulateur majeur de l'activité anti-angiogénique. En conclusion, ce travail fournit de nouveaux éléments sur le rôle complémentaires de PPARβet PPARγ dans les événements complexes qui régissent le développement placentaire. SUMMARY Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors involved in energy homeostasis and growth. Herein, we characterize the placental defects that cause embryonic lethality around E9.5/E10.5 in PPARβ- and in PPARγ-deficient mouse lines. Most but not all PPARβ-null mutants die around E9.5/E10.5 with severe growth retardation. The placentas from PPARβ-/- embryos at E9.5 exhibit a strongly reduced giant cell layer, associated with reduced levels of proteins expressed by giant cells such as Placental lactogen-I and Proliferin. Ectopic treatment of a rat trophoblast cell line with PPARβ ligand markedly accelerated PI3 kinase-dependent giant cell differentiation. In addition, we demonstrate that ADRP, a pen-related lipid droplet-bound protein, is up-regulated by PPARβ in differentiated Rcho-1 cells. These results indicate that PPARβ is a crucial regulator of the differentiation secondary giant cells, which play a major role in the establishment of the placental structure as well as an important endocrine function. In contrast, the main alteration of the PPARγ-null placentas concerns the vasculogenesis. We show that in these placentas, the level of the anti-angiogenic proliferin-related protein is very low, and cannot balance the normal elevation of the pro-angiogenic proliferin expression, leading to the defective placental vessel formation. Consistently, the dramatic increase of PPARγ expression in late stage of gestation in wild-type mice is likely a major regulator of the anti-angiogenic activity, particularly important at the end of the pregnancy. This work emphasizes the important and complementary roles of PPARβ and PPARγ in mouse placental development and provides new tools for understanding the complex regulatory events that governs placental development and function. Understanding the function of PPARβ and PPARγ are of crucial interest with respect to human placental development and associated pathologies.
Resumo:
Non-bilayer phospholipid arrangements are three-dimensional structures that form when anionic phospholipids with an intermediate structure of the tubular hexagonal phase II are present in a bilayer of lipids. Antibodies that recognise these arrangements have been described in patients with antiphospholipid syndrome and/or systemic lupus erythematosus and in those with preeclampsia; these antibodies have also been documented in an experimental murine model of lupus, in which they are associated with immunopathology. Here, we demonstrate the presence of antibodies against non-bilayer phospholipid arrangements containing mycolic acids in the sera of lepromatous leprosy (LL) patients, but not those of healthy volunteers. The presence of antibodies that recognise these non-bilayer lipid arrangements may contribute to the hypergammaglobulinaemia observed in LL patients. We also found IgM and IgG anti-cardiolipin antibodies in 77% of the patients. This positive correlation between the anti-mycolic-non-bilayer arrangements and anti-cardiolipin antibodies suggests that both types of antibodies are produced by a common mechanism, as was demonstrated in the experimental murine model of lupus, in which there was a correlation between the anti-non-bilayer phospholipid arrangements and anti-cardiolipin antibodies. Antibodies to non-bilayer lipid arrangements may represent a previously unrecognised pathogenic mechanism in LL and the detection of these antibodies may be a tool for the early diagnosis of LL patients.
Resumo:
Summary: The mammalian epidermis is a pluristratified epithelium composed of 90% keratinocytes, and its main function is to serve as barrier for the body. The epithelial sodium channel (ENaC), formed by three homologous subunits α, β and γ is found in a variety of epithelia including epidermis. Previous studies showed that ENaC modulates different aspects of epidermal differentiation, such as synthesis of differentiation-specific proteins and lipid secretion. ENaC plays also a critical role in sodium homeostasis of renal and pulmonary epithelia, and its activity is thereby well controlled by hormones and non-hormonal factors, such as the serine protease CAP1 (channel-activating protease 1), also termed prostasin encoded by Prss8 gene. Serine proteases are proteolytic enzymes involved in numerous physiological and pathological processes in the epidermis. In order to evaluate the role of β and γENaC in epidermis, we analyzed the skin phenotype of β and γENaC null mutant (βENaC-/- and γENaC-/-) mice in comparison with the phenotype of αENaC-deficient mice. Furthermore, keratin14-specific CAP1-deficient mice (Prss8lox/Δ /K14-Cre) were generated in order to unveil the role of the serine protease CAP1 in epidermal development and function. This study reveals that the skin phenotype of βENaC and γENaC null mutant mice is less severe than the one of αENaC-deficient mice. However, all these mice present a common premature lipid secretion in the mid-granular layer of the epidermis. Further, the composition of the lipids of the stratum corneum in αENaC-deficient mice is strongly altered, suggesting that epidermal barrier function is compromised. K14-specific CAP1-deficient newborn mice are born at the expected Mendelian ratio, but die soon after birth, showing that CAP1 is required for postnatal survival. The epidermis of these mice exhibits striking malformations of the stratum corneum showing hyperkeratosis. These defects seriously affect both inward and outward epidermal barrier function, leading to rapid and fatal dehydration. As in αENaC-deficient mice, the lipid composition of the stratum corneum of K14-specific CAP1-deficient mice is disturbed. Furthermore, lack of CAP1 leads to the selective loss of filaggrin monomers, important for keratins aggregation and skin moisturization, and to an increased of aberrant profilaggrin precursors. In conclusion, both ENaC and CAP1 expression in the epidermis are crucial for keratinocyte differentiation processes and/or barrier function. Since the abnormalities in K14-specific CAP1-deficient mice resemble key features of human skin ichthyosis, in particular Harlequin ichthyosis, the study of ENaC and CAP1 mutant mice might allow new insights into mechanisms underlying skin diseases. Résumé: L'épiderme des mammifères est un épithélium pluristratifié, protégeant le corps contre les perturbations extérieures et la déshydratation. Le canal épithélial à sodium (ENaC), formé de trois sous-unités α, β et γ, est exprimé dans de nombreux épithélia, comme l'épiderme. Des études ont montré que l'absence de la sous-unité αENaC modulait différents aspects de la différenciation des kératinocytes de l'épiderme, comme la synthèse de protéines spécifiques ou la sécrétion de lipides dans la couche granulaire de l'épiderme. ENaC joue également un rôle crucial dans l'homéostasie du sodium dans les épithélia électriquement étanches, comme l'épithélium rénal ou pulmonaire. L'activité de ENaC est par conséquent finement régulée, en partie par des hormones, mais aussi par des facteurs non-hormonaux, telle que la sérine protéase CAP1 (« channel-activating protease 1 >>) (nommée également prostasine et codée par le gène Prss8). Le but de ce travail a donc été d'étudier le rôle des sous-unités β et γENaC dans l'épiderme en comparaison avec celui de la sous-unité α en utilisant des souris mutantes βENaC-/- et γENaC-/-. Dans un deuxième temps, le phénotype d'une souris chez qui CAP1 a été spécifiquement invalidé dans l'épiderme (Prsslox/Δ/K14-Cre) a été analysé, dans le but de mettre en évidence le rôle de cette protéase dans l'épiderme. Comme déjà montré pour les souris αENaC-/-, la sécrétion des lipides dans la couche granulaire de l'épiderme des souris βENaC-/- et γENaC-/- est prématurée. Cependant, l'hyperplasie et l'expression anormale des protéines marqueurs de la différenciation présents chez les souris αENaC-/- n'ont pas été observés dans l'épiderme des souris βENaC-/- et γENaC-/-. La composition lipidique de la couche cornée des souris αENaC-/- est fortement altérée suggérant que la fonction de barrière de l'épiderme de ces souris est compromise. Les souris mutantes CAP1 ont quant à elles révélé des malformations sévères de leur couche cornée, affectant la fonction de barrière de leur épiderme et conduisant à la mort de ces souris par déshydratation quelques jours après leur naissance. De plus, la composition en lipides de la couche cornée ainsi que la taille des cellules cornées, les cornéocytes, de ces souris sont modifiées par rapport aux souris contrôles. L'invalidation de la protéine CAP1 dans l'épiderme conduit aussi à la perte de la filaggrine, une protéine cruciale pour l'agrégation des kératines dans la couche cornée et le maintien du niveau d'hydratation de la peau, et à l'accumulation de ses précurseurs. En conclusion, l'expression de ENaC et de CAP1 est cruciale pour la différenciation de l'épiderme et/ou sa fonction de barrière. De plus, le phénotype des souris mutantes CAP1 présente des caractéristiques qui ressemblent à celles observées dans certaines pathologies humaines cutanées, comme l'ichthyose d'Harlequin. L'étude des souris mutantes ENaC et CAP1 pourrait donc apporter de nouvelles connaissances dans les mécanismes impliqués dans l'ichthyose d'Harlequin ou d'autres maladies de la peau chez l'homme. Résumé tout public: La peau est le plus grand organe vital du corps humain. Sa fonction principale est de protéger le corps comme une barrière, contre les agressions extérieures et la déshydratation. De nombreuses maladies de la peau résultent d'une perte de fonction de cette barrière. Bien que les pathologies cutanées soient très bien décrites, leur cause génétique n'est en général pas encore connue. La souris est alors un modèle de choix pour la recherche fondamentale. En effet, grâce aux progrès récents de la science, le génome de la souris peut aujourd'hui être modifié dans le but d'étudier le rôle de nombreuses protéines. Dans différents organes, comme le rein et le poumon, le canal épithélial à sodium (ENaC), composé de trois sous-unités protéiques homologues (α, β, et γ), joue un rôle essentiel dans la réabsorption du sodium. L'activité de ENaC est régulée par de nombreux facteurs hormonaux et non-hormonaux, telle que la protéase CAP1 (« channel-activating protease 1 »). L'invalidation de la sous-unité αENaC chez la souris a permis de montrer que dans la peau, le canal ENaC est impliqué dans la différenciation des cellules de l'épiderme et la croissance des poils. Durant ce travail, le phénotype des souris chez qui la protéine βENaC, γENaC ou CAP1 a été invalidée (souris mutantes), a été étudié dans le but de mieux comprendre le rôle des sous-unités du canal ENaC et de son régulateur CAP1 dans la peau. Les résultats de ce projet ont montré que les souris mutantes βENaC et γENaC présentent un épiderme anormal avec une synthèse prématurée de lipides dans la couche granulaire, suggérant l'implication de ENaC dans la fonction de barrière de la peau. De plus, quand CAP1 est invalidé de manière totale chez les souris, le développement embryonnaire est perturbé et ces souris meurent avant la naissance. CAP1 a donc été invalidé spécifiquement dans l'épiderme des souris. Ces souris mutantes « épiderme-spécifique » naissent normalement, mais meurent peu après la naissance de déshydratation. La couche superficielle de l'épiderme, appelée couche cornée, de ces souris est malformée et ne confère plus à la peau sa fonction de barrière. De plus, les composants de la couche cornée, les cellules cornées entourées de lipides, sont sévèrement altérés. Le phénotype de ces souris ressemble aux caractéristiques présentes chez les patients atteints d'ichthyoses, en particulier l'ichthyose d'Harlequin. En conclusion, le canal ENaC ainsi que son régulateur CAP1 jouent un rôle clé dans les processus de différenciation de l'épiderme et/ou de sa fonction de barrière. De plus, les souris mutantes pour CAP1 et ENaC se révéleront peut-être comme des modèles appropriés dans l'étude de l'ichthyose d'Harlequin ou d'autres maladies cutanées.
Resumo:
Leprosy is an infectious disease caused by Mycobacterium leprae that affects the skin and nerves, presenting a singular clinical picture. Across the leprosy spectrum, lepromatous leprosy (LL) exhibits a classical hallmark: the presence of a collection of M. leprae-infected foamy macrophages/Schwann cells characterised by their high lipid content. The significance of this foamy aspect in mycobacterial infections has garnered renewed attention in leprosy due to the recent observation that the foamy aspect represents cells enriched in lipid droplets (LD) (also known as lipid bodies). Here, we discuss the contemporary view of LD as highly regulated organelles with key functions in M. leprae persistence in the LL end of the spectrum. The modern methods of studying this ancient disease have contributed to recent findings that describe M. leprae-triggered LD biogenesis and recruitment as effective mycobacterial intracellular strategies for acquiring lipids, sheltering and/or dampening the immune response and favouring bacterial survival, likely representing a fundamental aspect of M. leprae pathogenesis. The multifaceted functions attributed to the LD in leprosy may contribute to the development of new strategies for adjunctive anti-leprosy therapies.
Resumo:
During episodes of trauma carnitine-free total parenteral nutrition (TPN) may result in a reduction of the total body carnitine pool, leading to a diminished rate of fat oxidation. Sixteen patients undergoing esophagectomy were divided randomly in two equal isonitrogenous groups (0.2 g/kg.day). Both received TPN (35 kcal/kg.day; equally provided as long-chain triglycerides and glucose) over 11 days without (group A) and with (group B) L-carnitine supplementation (12 mg/kg.day = 75 mumol/kg.day). Compared with healthy controls, the total body carnitine pool prior to the operation was significantly reduced in both groups, suggesting a state of semistarvation and muscle wasting. In group A the plasma levels of total carnitine and its subfractions (free carnitine, short- and long-chain acylcarnitine) remained stable during the study whereas in group B the total plasma carnitine concentration rose mainly due to an increase in free carnitine. In group A the cumulative urinary carnitine losses were 11.5 +/- 2.6 mmol (= 15.5 +/- 3.1% of the estimated total body carnitine pool). In group B 3.1 +/- 1.9 mmol (= 11.1 +/- 7.6%) of the infused carnitine was retained in the immediate postoperative phase until day 6, but this amount was completely lost at completion of the study period. No significant differences in the respiratory quotient or in the plasma levels of triglycerides, free fatty acids, and ketone bodies were observed, between or within the groups, before the operation and after 11 days of treatment. It is concluded that the usefulness of carnitine supplementation during postoperative TPN was not apparent in the present patient material.
Resumo:
SUMMARY Following the complete sequencing of the human genome, the field of nutrition has begun utilizing this vast quantity of information to comprehensively explore the interactions between diet and genes. This approach, coined nutrigenomics, aims to determine the influence of common dietary ingredients on the genome, and attempts to relate the resulting different phenotypes to differences in the cellular and/or genetic response of the biological system. However, complementary to defining the biological outcomes of dietary ingredients, we must also understand the influence of the multiple factors (such as the microbiota, bile, and function of transporters) that may contribute to the bioavailability, and ultimately bioefficacy, of these ingredients. The gastrointestinal tract (GIT) is the body's foremost tissue boundary, interacting with nutrients, exogenous compounds and microbiota, and whose condition is influenced by the complex interplay between these environmental factors and genetic elements. In order to understand GIT nutrient-gene interactions, our goal was to comprehensively elucidate the region-specific gene expression underlying intestinal functions. We found important regional differences in the expression of members of the ATP-binding cassette family of transporters in the mouse intestine, suggesting that absorption of dietary compounds may vary along the GIT. Furthermore, the influence of the microbiota on host gene expression indicated that this luminal factor predominantly influences immune function and water transport throughout the GIT; however, the identification of region-specific functions suggest distinct host-bacterial interactions along the GIT. Thus, these findings reinforce that to understand nutrient bioavailability and GIT function, one must consider the physiologically distinct regions of the gut. Nutritional molecules absorbed by the enterocytes of the GIT enter circulation and will be selectively absorbed and metabolised by tissues throughout the body; however, their bioefficacy in the body will depend on the unique and shared molecular mechanisms of the various tissues. Using a nutrigenomic approach, the biological responses of the liver and hippocampus of mice fed different long chain-polyunsaturated fatty acids diets revealed tissue-specific responses. Furthermore, we identified stearoyl-CoA desaturase as a hepatic target for arachidonic acid, suggesting a potentially novel molecular mechanism that may protect against diet-induced obesity. In summary, this work begins to unveil the fundamentally important role that nutrigenomics will play in unravelling the molecular mechanisms, and those exogenous factors capable of influencing these mechanisms, that regulate the bioefficacy of nutritional molecules. RÉSUMÉ Suite au séquençage complet du génome humain, le domaine de la nutrition a commencé à utiliser cette vaste quantité d'information pour explorer de manière globale les interactions entre la nourriture et les gènes. Cette approche, appelée « nutrigenomics », a pour but de déterminer l'influence d'ingrédients couramment utilisés dans l'alimentation sur le génome, et d'essayer de relier ces différents phénotypes, ainsi révélés, à des différences de réponses cellulaires et/ou génétiques. Cependant, en plus de définir les effets biologiques d'ingrédients alimentaires, il est important de comprendre l'influence des multiples facteurs (telle que la microflore, la bile et la fonction des transporteurs) pouvant contribuer à la bio- disponibilité et par conséquent à l'efficacité de ces ingrédients. Le tractus gastro-intestinal (TGI), qui est la première barrière vers les tissus, interagit avec les nutriments, les composés exogènes et la microflore. La fonction de cet organe est influencée par les interactions complexes entre les facteurs environnementaux et les éléments génétiques. Dans le but de comprendre les interactions entre les nutriments et les gènes au niveau du TGI, notre objectif a été de décrire de manière globale l'expression génique spécifique de chaque région de l'intestin définissant leurs fonctions. Nous avons trouvé d'importantes différences régionales dans l'expression des transporteurs de la famille des « ATP-binding cassette transporter » dans l'intestin de souris, suggérant que l'absorption des composés alimentaires puisse varier le long de l'intestin. De plus, l'étude des effets de la microflore sur l'expression des gènes hôtes a indiqué que ce facteur de la lumière intestinale influence surtout la fonction immunitaire et le transport de l'eau à travers l'intestin. Cependant, l'identification des fonctions spécifiques de chaque région suggère des interactions distinctes entre l'hôte et les bactéries le long de l'intestin. Ainsi, ces résultats renforcent l'idée que la compréhension de la bio-disponibilité des nutriments, et par conséquent la fonction du TGI, doit prendre en considération les différences régionales. Les molécules nutritionnelles transportées par les entérocytes jusqu'à la circulation sanguine, sont ensuite sélectivement absorbées et métabolisées par les différents tissus de l'organisme. Cependant, leur efficacité biologique dépendra du mécanisme commun ou spécifique de chaque tissu. En utilisant une approche « nutriogenomics », nous avons pu mettre en évidence les réponses biologiques spécifiques du foie et de l'hippocampe de souris nourris avec des régimes supplémentés avec différents acides gras poly-insaturés à chaîne longue. De plus, nous avons identifié la stearoyl-CoA desaturase comme une cible hépatique pour l'acide arachidonique, suggérant un nouveau mécanisme moléculaire pouvant potentiellement protéger contre le développement de l'obésité. En résumé, ce travail a permis de dévoiler le rôle fondamental qu'une approche telle que la « nutrigenomics » peut jouer dans le décryptage des mécanismes moléculaires et de leur régulation par des facteurs exogènes, qui ensemble vont contrôler l'efficacité biologique des nutriments.
Resumo:
Technological limitations and power constraints are resulting in high-performance parallel computing architectures that are based on large numbers of high-core-count processors. Commercially available processors are now at 8 and 16 cores and experimental platforms, such as the many-core Intel Single-chip Cloud Computer (SCC) platform, provide much higher core counts. These trends are presenting new sets of challenges to HPC applications including programming complexity and the need for extreme energy efficiency.In this work, we first investigate the power behavior of scientific PGAS application kernels on the SCC platform, and explore opportunities and challenges for power management within the PGAS framework. Results obtained via empirical evaluation of Unified Parallel C (UPC) applications on the SCC platform under different constraints, show that, for specific operations, the potential for energy savings in PGAS is large; and power/performance trade-offs can be effectively managed using a cross-layerapproach. We investigate cross-layer power management using PGAS language extensions and runtime mechanisms that manipulate power/performance tradeoffs. Specifically, we present the design, implementation and evaluation of such a middleware for application-aware cross-layer power management of UPC applications on the SCC platform. Finally, based on our observations, we provide a set of recommendations and insights that can be used to support similar power management for PGAS applications on other many-core platforms.
Resumo:
The adipokine resistin is an insulin-antagonizing factor that also plays a regulatory role in inflammation, immunity, food intake, and gonadal function and also regulates growth hormone (GH) secretion in rat adenopituitary cells cultures with the adipokine. Although adipose tissue is the primary source of resistin, it is also expressed in other tissues, including the pituitary. The aim of this study is to investigate the possible action of resistin on the lipid metabolism in the pituitary gland in vivo (rats in two different nutritional status, fed and fast, treated with resistin on acute and a chronic way) and in vitro (adenopituitary cell cultures treated with the adipokine). Here, by a combination of in vivo and in vitro experimental models, we demonstrated that central acute and chronic administration of resistin enhance mRNA levels of the lipid metabolic enzymes which participated on lipolysis and moreover inhibiting mRNA levels of the lipid metabolic enzymes involved in lipogenesis. Taken together, our results demonstrate for the first time that resistin has a regulatory role on lipid metabolism in the pituitary gland providing a novel insight in relation to the mechanism by which this adipokine can participate in the integrated control of lipid metabolism.
Resumo:
PURPOSE: Two mutations (R555Q and R124L) in the BIGH3 gene have been described in anterior or Bowman's layer dystrophies (CDB). The clinical, molecular, and ultrastructural findings of five families with CDB was reviewed to determine whether there is a consistent genotype:phenotype correlation. METHODS: Keratoplasty tissue from each patient was examined by light and electron microscopy (LM and EM). DNA was obtained, and exons 4 and 12 of BIGH3 were analyzed by polymerase chain reaction and single-stranded conformation polymorphism/heteroduplex analysis. Abnormally migrating products were analyzed by direct sequencing. RESULTS: In two families with type I CDB (CDBI), the R124L mutation was defined. There were light and ultrastructural features of superficial granular dystrophy and atypical banding of the "rod-shaped bodies" ultrastructurally. Patients from three families with "honeycomb" dystrophy were found to carry the R555Q mutation and had characteristic features of Bowman's dystrophy type II (CDBII). CONCLUSIONS: There is a strong genotype:phenotype correlation among CBDI (R124L) and CDBII (R555Q). LM and EM findings suggest that epithelial abnormalities may underlie the pathology of both conditions. The findings clarify the confusion over classification of the Bowman's layer dystrophies.
Resumo:
Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.
Resumo:
In mice, barrels in layer IV of the somatosensory cortex correspond to the columnar representations of whisker follicles. In barrelless (BRL) mice, barrels are absent, but functionally, a columnar organization persists. Previously we characterized the aberrant geometry of thalamic projection of BRL mice using axonal reconstructions of individual neurons. Here we proceeded with the analysis of the intracortical projections from layer VI pyramidal neurons, to assess their contribution to the columnar organization. From series of tangential sections we reconstructed the axon collaterals of individual layer VI pyramidal neurons in the C2 barrel column that were labelled with biocytin [controls from normal (NOR) strain, 19 cells; BRL strain, nine cells]. Using six morphological parameters in a cluster analysis, we showed that layer VI neurons in NOR mice are distributed into four clusters distinguished by the radial and tangential extent of their intracortical projections. These clusters correlated with the cortical or subcortical projection of the main axon. In BRL mice, neurons were distributed within the same four clusters, but their projections to the granular and supragranular layers were significantly smaller and their tangential projection was less columnar than in NOR mice. However, in both strains the intracortical projections had a preference for the appropriate barrel column (C2), indicating that layer VI pyramidal cells could participate in the functional columnar organization of the barrel cortex. Correlative light and electron microscopy analyses provided morphometric data on the intracortical synaptic boutons and synapses of layer VI pyramidal neurons and revealed that projections to layer IV preferentially target excitatory dendritic spines and shafts.
Resumo:
INTRODUCTION Rilpivirine (RPV) has a better lipid profile than efavirenz (EFV) in naïve patients (1). Switching to RPV may be convenient for many patients, while maintaining a good immunovirological control (2). The aim of this study was to analyze lipid changes in HIV-patients at 24 weeks after switching to Eviplera® (emtricitabine/RPV/tenofovir disoproxil fumarate [FTC/RPV/TDF]). MATERIALS AND METHODS Retrospective, multicentre study of a cohort of asymptomatic HIV-patients who switched from a regimen based on 2 nucleoside reverse transcriptase inhibitors (NRTI)+protease inhibitor (PI)/non nucleoside reverse transcriptase inhibitor (NNRTI) or ritonavir boosted PI monotherapy to Eviplera® during February-December, 2013; all had undetectable HIV viral load for ≥3 months prior to switching. Patients with previous failures on antiretroviral therapy (ART) including TDF and/or FTC/3TC, with genotype tests showing resistance to components of Eviplera®, or who had changed the third drug of the ART during the study period were excluded. Changes in lipid profile and cardiovascular risk (CVR), and efficacy and safety at 24 weeks were analyzed. RESULTS Among 305 patients included in the study, 298 were analyzed (7 cases were excluded due to lack of data). Men 81.2%, mean age 44.5 years, 75.8% of HIV sexually transmitted. 233 (78.2%) patients switched from a regimen based on 2 NRTI+NNRTI (90.5% EFV/FTC/TDF). The most frequent reasons for switching were central nervous system (CNS) adverse events (31.0%), convenience (27.6%) and metabolic disorders (23.2%). At this time, 293 patients have reached 24 weeks: 281 (95.9%) have continued Eviplera®, 6 stopped it (3 adverse events, 2 virologic failures, 1 discontinuation) and 6 have been lost to follow up. Lipid profiles of 283 cases were available at 24 weeks and mean (mg/dL) baseline vs 24 weeks are: total cholesterol (193 vs 169; p=0.0001), HDL-c (49 vs 45; p=0.0001), LDL-c (114 vs 103; p=0.001), tryglycerides (158 vs 115; p=0.0001), total cholesterol to HDL-c ratio (4.2 vs 4.1; p=0.3). CVR decreased (8.7 vs 7.5%; p= 0.0001). CD4 counts were similar to baseline (653 vs 674 cells/µL; p=0.08), and 274 (96.8%) patients maintained viral suppression. CONCLUSIONS At 24 weeks after switching to Eviplera®, lipid profile and CVR improved while maintaining a good immunovirological control. Most subjects switched to Eviplera® from a regimen based on NNRTI, mainly EFV/FTC/TDF. CNS adverse events, convenience and metabolic disorders were the most frequent reasons for switching.