986 resultados para Telangiectasia-like Disorder


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Preeclampsia is a human pregnancy-specific disorder characterized by a placental pro-inflammatory response in combination with an imbalance of angiogenic factors and clinical symptoms, including hypertension and proteinuria. Insufficient uteroplacental oxygenation in preeclampsia due to impaired trophoblast invasion during placentation is believed to be responsible for many of the molecular events leading to the clinical manifestations of this disease. We investigated the use of hypoxic treatment of the dual placental perfusion system as a model for preeclampsia. A modified perfusion technique allowed us to achieve a mean soluble oxygen tension within the intervillous space (IVS) of 5-7% for normoxia and <3% for hypoxia (as a model for preeclampsia). We assayed for the levels of different inflammatory cytokines, oxidative stress markers, as well as other factors, such as endothelin (ET)-1 that are known to be implicated as part of the inflammatory response in preeclampsia. Our results show a significant increase under hypoxia in the levels of different inflammatory cytokines, including IL-6 (P=0.002), IL-8 (P<0.0001), TNF-α (P=0.032) and IFN-γ (P=0.009) at 360 min in maternal venous samples (n=6). There was also a significant increase in ET-1 levels under hypoxia both on the maternal side at 30 min (P=0.003) and fetal side at 360 min (P=0.036) (n=6). Other markers of oxidative stress, including malondialdehyde and 8-iso-protaglandin F2α (P=0.009) also show increased levels. Overall, these findings indicate that exposure of ex vivo dually perfused placental tissue to hypoxia provides a useful model for mimicking the inflammatory response characteristic of preeclampsia. This would therefore provide a powerful tool for studying and further delineating the molecular mechanisms involved in the underlying pathophysiology of preeclampsia.

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Human pregnancy is accompanied by a mild systemic inflammatory response, which includes the activation of monocytes circulating in maternal blood. This response is exaggerated in preeclampsia, a placental-dependent disorder specific to human pregnancies. We and others showed that placental syncytiotrophoblast membrane microparticles (STBM) generated in vitro from normal placentas stimulated peripheral blood monocytes, which suggest a contribution of STBM to the systemic maternal inflammation. Here, we analyzed the inflammatory potential of STBM prepared from preeclamptic placentas on primary monocytes and investigated the mode of action in vitro. STBM generated in vitro by placental villous explants of normal or preeclamptic placentas were co-incubated with human peripheral blood monocytes. In some cases, inhibitors of specific cellular functions or signaling pathways were used. The analysis of the monocytic response was performed by flow cytometry, enzyme-linked immunoassays, real-time PCR, and fluorescence microscopy. STBM derived from preeclamptic placentas up-regulated the cell surface expression of CD54, and stimulated the secretion of the pro-inflammatory interleukin (IL)-6 and IL-8 in a similar, dose-dependent manner as did STBM prepared from normal placentas. STBM bound to the cell surface of monocytes, but phagocytosis was not necessary for activation. STBM-induced cytokine secretion was impaired in the presence of inhibitors of toll-like receptor (TLR) signaling or when nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation was blocked. Our results suggest that the inflammatory reaction in monocytes may be initiated by the interaction of STBM with TLRs, which in turn signal through NF-κB to mediate the transcription of genes coding for pro-inflammatory factors.

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The studies completed herein explore different phenotypes related to the genetic defects that predispose individuals to a disruption of normal hemostasis. In the first study, a novel autosomal dominant bleeding disorder, which is characterized by excessive bleeding with trauma or surgery and menorrhagia in affected women, was studied in a large family (16 affected individuals) from east Texas. Affected members had a prolongation of their PT and/or aPTT, but normal clinical coagulation studies. Previous linkage analysis by Kuang et. al. (2001) mapped the defective gene to 1g23-24 (LODmax 7.22), which contains the gene for coagulation factor V (FV). I identified an alteration (A2440G) in the FV gene in exon 13 that segregated with the disease and was not present in 62 controls. Interestingly, this alteration resulted in a 22-fold up-regulation of a novel alternative splicing variant in patients' RNA versus controls. This translated into a similar fold increase in a 250-kDa isoform of FV seen in patients' plasma versus controls. A recombinant of this splicing event exhibited an increased sensitivity to cleavage by activated protein C (APC) that was more striking in the presence of PS. In addition, this novel isoform had increased APC cofactor activity, thus increasing the degradation of FVIIIa. These data indicated that A2440G up-regulates an alternatively spliced transcript of FV, and increases a FV isoform that hinders coagulation as opposed to promoting it like its wild-type counterpart. ^ The second study reports the largest screening to date of African Americans in two independent cohorts for a rare prothrombin variant, C20209T, which is suspected to be associated with thrombotic disease. The Texas Medical Center Genetics Resource (TexGen) Stroke DNA repository revealed 1.67% (Fisher p=0.27) of African American stroke patients were heterozygous for the 20209*T allele. Screening of the Atherosclerosis Risk in Communities Study (ARIC) cohort (n=3470) for the 20209*T allele revealed a population prevalence of 0.58% in individuals of African American descent; however, all associations with thrombotic disease were negative. Analysis of these two independent cohorts revealed that, unlike its neighbor G20210A, the C20209T variant does not increase the risk of thrombotic events in the African American population. ^

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The ATM gene is mutated in the syndrome of ataxia telangiectasia (AT), associated with neurologic dysfunction, growth abnormalities, and extreme radiosensitivity. Insulin-like growth factor-I receptor (IGF-IR) is a cell surface receptor with tyrosine kinase activity that can mediate mitogenesis, cell transformation, and inhibition of apoptosis. We report here that AT cells express low levels of IGF-IR and show decreased IGF-IR promoter activity compared with wild-type cells. Complementation of AT cells with the ATM cDNA results in increased IGF-IR promoter activity and elevated IGF-IR levels, whereas expression in wild-type cells of a dominant negative fragment of ATM specifically reduces IGF-IR expression, results consistent with a role for ATM in regulating IGF-IR expression at the level of transcription. When expression of IGF-IR cDNA is forced in AT cells via a heterologous viral promoter, near normal radioresistance is conferred on the cells. Conversely, in ATM cells complemented with the ATM cDNA, specific inhibition of the IGF-IR pathway prevents correction of the radiosensitivity. Taken together, these results establish a fundamental link between ATM function and IGF-IR expression and suggest that reduced expression of IGF-IR contributes to the radiosensitivity of AT cells. In addition, because IGF-I plays a major role in human growth and metabolism and serves as a survival and differentiation factor for developing neuronal tissue, these results may provide a basis for understanding other aspects of the AT syndrome, including the growth abnormalities, insulin resistance, and neurodegeneration.

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We numerically investigate the effects of inhomogeneities in the energy spectrum of aperiodic semiconductor superlattices, focusing our attention on Thue-Morse and Fibonacci sequences. In the absence of disorder, the corresponding electronic spectra are self-similar. The presence of a certain degree of randomness, due to imperfections occurring during the growth processes, gives rise to a progressive loss of quantum coherence, smearing out the finer details of the energy spectra predicted for perfect aperiodic superlattices and spurring the onset of electron localization. However, depending on the degree of disorder introduced, a critical size for the system exists, below which peculiar transport properties, related to the pre-fractal nature of the energy spectrum, may be measured.

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Introduction: Autism Spectrum Disorder (ASD) is a frequent and complex neurodevelopmental disorder, characterized by impairments in social communication and repetitive behaviors and with a high male to female ratio: ~4:1. Genetic factors, including rare Copy Number Variants (CNVs), have a substantial impact in ASD risk 1, and are associated with specific phenotypic manifestations 2. Recent studies reported that rare inherited CNVs are enriched in mothers of ASD children compared with mothers of controls and are preferentially transmitted from mothers to ASD children suggesting a sex bias in CNV transmission; further, the imbalanced transmission of small pathogenic CNVs from unaffected mothers to their sons with ASD has been described 3, 4. An increased prevalence of autism - like personality traits is found in unaffected relatives of ASD children, suggesting a genetic liability of a broader autism phenotype (BAP) 5. The BAP in parents of autistic children can be assessed by the Social Responsiveness Scale (SRS) 6 and Broad Autism Phenotype Questionnaire (BAPQ) 7 reports . The SRS is 65 - item questionnaire to identify sub - clinical social impairments and interpersonal behaviour in individuals . The BAPQ is a 36 - item questionnaire measures social aloofness, rigid personality, and pragmatic language deficits in both parents and children.

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Aim: Familial Hypercholesterolemia (FH) is a common autosomal dominant disorder, caused by mutations in genes involved in cholesterol’s clearance (LDLR, APOB, PCSK 9). Clinical diagnosis is usually based on high total cholesterol or LDL-C levels and family history of premature coronary heart disease. Using an extended lipid profile of paediatric dyslipidemic patients, we aim to identify biomarkers for a better diagnosis of FH in clinical settings.

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To examine abnormal patterns of frontal cortical-subcortical activity in response to emotional stimuli in euthymic individuals with bipolar disorder type I in order to identify trait-like, pathophysiologic mechanisms of the disorder. We examined potential confounding effects of total psychotropic medication load and illness variables upon neural abnormalities.

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Az írás arra a kérdésre keresi a választ, hogy a két évtized után tartóssá, vagyis trenddé váló gazdasági és társadalmi eltérések a "posztkommunista" országok között milyen okokra vezethetők vissza. Másodsorban azt elemzi, mi a jelentősége e sokrétű különbségek modellszerű kategorizálásának. Ennek alapja az állami szerepvállalás mértéke és minősége. Végül harmadikként azt a kérdéskört vizsgálja, hogy az eltérések milyen következményekkel járnak. A fő következtetés az, hogy a közösségi választások ugyan jelentősek, ezek szerepe azonban a pályafüggőséghez képest sokkal kisebb, mint azt a legtöbb elmélet föltételezi. Az eredmény - Hayekkel szólva (Hayek [1995]) - emberi cselekvés, ámde nem emberi tervezet szülötte. _____ The article seeks to discover what causes can be traced for the economic and social differences that have become permanent or a trend after two decades. Secondly, it analy-ses what importance this model-like categorization of manifold differences bears. Thirdly and lastly, it examines the sphere of questions to do with the consequences of these differences. The main conclusion is that the community choices are significant, but their role is much less, by comparison with career dependence, than most theories assume. Achievement, to quote Hayek (1995) is borne of human endeavour, not human planning.

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Placenta growth factor (PlGF) deficient mice are fertile at a Mendelian ratio. Interestingly, low maternal plasma levels of PlGF are strongly associated with early onset of preeclampsia, a pregnancy hypertensive disorder characterised by high blood pressure, proteinuria and fetal growth restriction. PlGF is increasingly being recognised as an early diagnostic biomarker, but the physiological importance of PlGF in the pathogenesis of preeclampsia is unknown. We investigated whether the decreased levels of PlGF in pregnancy exacerbate the fetal growth restriction associated with preeclampsia in the presence of high sFlt-1 and the potential of hydrogen sulphide to ameliorate these effects. Pregnant PlGF−/− mice were injected with adenovirus encoding sFlt-1 (Ad-sFlt-1) at 1 × 109 pfu/ml at E10.5 and mean arterial blood pressure (MAP), biochemical and histological analysis of maternal kidney, placenta and embryos were assessed at the end of pregnancy. Ad-sFlt-1 significantly increased MAP and induced severe glomerular endotheliosis in PlGF−/− mice compared to wild-type animals. Soluble Flt-1 also significantly elevated albumin–creatinine ratio and increased levels of urinary kidney injury molecule-1, a marker for proximal tubule injury. Furthermore, sFlt-1 over expression increased fetal resorption rate in the PlGF−/− mice and promoted abnormal placental vascularisation. To determine whether placental PlGF is critical for preventing fetal growth restriction associated with preeclampsia, we generated haploinsufficient PlGF+/− placentas and embryos in dams and exposed to high sFlt-1 environment. These mothers showed reduced fetal resorption, gestational hypertension and proteinuria when compared to pregnant PlGF−/− mice. Furthermore, treatment with hydrogen sulphide-releasing agent, GYY4137, significantly reduced resorption, hypertension and proteinuria observed in Ad-sFlt-1 treated pregnant PlGF−/− mice. Our study shows that placental PlGF is a critical protective factor against the damaging effects of high sFlt-1 associated with preeclampsia and activation of the hydrogen sulphide pathway may rescue preeclampsia phenotypes even under low PlGF environment.

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Life's perfect partnership starts with the placenta. If we get this right, we have the best chance of healthy life. In preeclampsia, we have a failing placenta. Preeclampsia kills one pregnant woman every minute and the life expectancy of those who survive is greatly reduced. Preeclampsia is treated roughly the same way it was when Thomas Edison was making the first silent movie. Globally, millions of women risk death to give birth each year and almost 300,000 lose their lives in this process. Over half a million babies around the world die each year as a consequence of preeclampsia. Despite decades of research, we lack pharmacological agents to treat it. Maternal endothelial dysfunction is a central phenomenon responsible for the clinical signs of preeclampsia. In the late nineties, we discovered that vascular endothelial growth factor (VEGF) stimulated nitric oxide release. This led us to suggest that preeclampsia arises due to the loss of VEGF activity, possibly due to a rise in soluble Flt-1 (sFlt-1), the natural antagonist of VEGF. Researchers have shown that high sFlt-1 elicits preeclampsia-like signs in pregnant rats and sFlt-1 increases before the clinical signs of preeclampsia in pregnant women. We demonstrated that removing or reducing this culprit protein from preeclamptic placenta restored the angiogenic balance. Heme oxygenase-1 (HO-1 or Hmox1) that generates carbon monoxide (CO), biliverdin (rapidly converted to bilirubin) and iron is cytoprotective. We showed that the Hmox1/CO pathway prevents human placental injury caused by pro-inflammatory cytokines and suppresses sFlt-1 and soluble endoglin release, factors responsible for preeclampsia phenotypes. The other key enzyme we identified is the hydrogen sulfide generating cystathionine-gamma-lyase (CSE or Cth). These are the only two enzyme systems shown to suppress sFlt-1 and to act as protective pathways against preeclampsia phenotypes in animal models. We also showed that when hydrogen sulfide restores placental vasculature, it also improves lagging fetal growth. These molecules act as the inhibitor systems in pregnancy and when they fail, this triggers preeclampsia. Discovering that statins induce these enzymes led us to an RCT to develop a low-cost therapy (StAmP Trial) to prevent or treat preeclampsia. If you think of pregnancy as a car then preeclampsia is an accelerator–brake defect disorder. Inflammation, oxidative stress and an imbalance in the angiogenic milieu fuel the ‘accelerator’. It is the failure in the braking systems (the endogenous protective pathway) that results in the ‘accelerator’ going out of control until the system crashes, manifesting itself as preeclampsia.

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INTRODUCTION: Low circulating levels of placenta growth factor (PlGF) is strongly associated with the onset of preeclampsia, a maternal hypertensive disorder characterized by high blood pressure and proteinuria after 20 weeks of gestation. Although, PlGF-deficient mice are born healthy and fertile at a Mendelian ratio, the physiological importance of PlGF in the pathogenesis of preeclampsia is unclear. We hypothesised that decreased levels of PlGF in pregnancy exacerbates the fetal growth restriction associated with preeclampsia in the presence of high sFlt-1. METHODS: Pregnant PlGF-/- mice were injected with adenovirus encoding sFlt-1 (Ad-sFlt-1) at high (i) 1.5x109 pfu/ml and low (ii) 0.5x109 pfu/ml doses. Mean arterial blood pressure (MBP), biochemical and histological assessments of maternal kidney, placenta and embryos were performed. RESULTS: Ad-sFlt-1 significantly increased MBP and induced severe glomerular endotheliosis in PlGF-/- mice at E10.5 gestation compared to wild-type animals. High sFlt-1 also significantly elevated albumincreatinine ratio and increased levels of urinary kidney injury molecule-1, a marker for proximal tubule injury.At a high dose of sFlt-1, there was complete fetal resorption in the pregnant PlGF-/- mice, and even the lower dose of sFlt-1 induced severe fetal resorption and abnormal placental vascularization. Hydrogen sulphide-releasing agent, GYY4137, significantly reduced resorption, hypertension and proteinuria in Ad-sFlt-1 treated pregnant PlGF-/- mice. To determine if placental PlGF is critical for preventing fetal growth restriction associated with preeclampsia, we generated haploinsufficient PlGF+/- placentas and embryos were generated in wild-time dams and exposed to high sFlt-1 environment. This resulted in reduced fetal resorption, gestational hypertension and proteinuria when compared to pregnant PlGF-/- mice. CONCLUSIONS: Placental PlGF is a critical protective factor against the damaging effects of high sFlt-1 in preeclampsia and the hydrogen sulphide pathway may rescue preeclampsia phenotypes.

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Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder characterized by alterations in social functioning, communicative abilities, and engagement in repetitive or restrictive behaviors. The process of aging in individuals with autism and related neurodevelopmental disorders is not well understood, despite the fact that the number of individuals with ASD aged 65 and older is projected to increase by over half a million individuals in the next 20 years. To elucidate the effects of aging in the context of a modified central nervous system, we investigated the effects of age on the BTBR T + tf/j mouse, a well characterized and widely used mouse model that displays an ASD-like phenotype. We found that a reduction in social behavior persists into old age in male BTBR T + tf/j mice. We employed quantitative proteomics to discover potential alterations in signaling systems that could regulate aging in the BTBR mice. Unbiased proteomic analysis of hippocampal and cortical tissue of BTBR mice compared to age-matched wild-type controls revealed a significant decrease in brain derived neurotrophic factor and significant increases in multiple synaptic markers (spinophilin, Synapsin I, PSD 95, NeuN), as well as distinct changes in functional pathways related to these proteins, including "Neural synaptic plasticity regulation" and "Neurotransmitter secretion regulation." Taken together, these results contribute to our understanding of the effects of aging on an ASD-like mouse model in regards to both behavior and protein alterations, though additional studies are needed to fully understand the complex interplay underlying aging in mouse models displaying an ASD-like phenotype.

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Autism spectrum disorders (ASD) are complex heterogeneous neurodevelopmental disorders of an unclear etiology, and no cure currently exists. Prior studies have demonstrated that the black and tan, brachyury (BTBR) T+ Itpr3tf/J mouse strain displays a behavioral phenotype with ASD-like features. BTBR T+ Itpr3tf/J mice (referred to simply as BTBR) display deficits in social functioning, lack of communication ability, and engagement in stereotyped behavior. Despite extensive behavioral phenotypic characterization, little is known about the genes and proteins responsible for the presentation of the ASD-like phenotype in the BTBR mouse model. In this study, we employed bioinformatics techniques to gain a wide-scale understanding of the transcriptomic and proteomic changes associated with the ASD-like phenotype in BTBR mice. We found a number of genes and proteins to be significantly altered in BTBR mice compared to C57BL/6J (B6) control mice controls such as BDNF, Shank3, and ERK1, which are highly relevant to prior investigations of ASD. Furthermore, we identified distinct functional pathways altered in BTBR mice compared to B6 controls that have been previously shown to be altered in both mouse models of ASD, some human clinical populations, and have been suggested as a possible etiological mechanism of ASD, including "axon guidance" and "regulation of actin cytoskeleton." In addition, our wide-scale bioinformatics approach also discovered several previously unidentified genes and proteins associated with the ASD phenotype in BTBR mice, such as Caskin1, suggesting that bioinformatics could be an avenue by which novel therapeutic targets for ASD are uncovered. As a result, we believe that informed use of synergistic bioinformatics applications represents an invaluable tool for elucidating the etiology of complex disorders like ASD.

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The psychosis phenotype is thought to exist on a continuum, such that the same symptoms experienced by individuals diagnosed with psychotic disorders can also manifest in the general population to a less severe degree. The subclinical psychotic-like experiences reported by healthy individuals share a number of risk factors with psychotic disorders and confer greater risk of developing a psychotic disorder. Thus, healthy individuals with psychotic-like experiences comprise a valid population in which to study the underlying mechanisms of clinically significant psychotic symptoms. In this thesis, we aimed to further our understanding of psychotic-like experiences and the individuals who report them. We explored the relationships between tasks measuring different aspects of self-awareness and self-reported psychotic-like experiences using data obtained from 30 university students. We found that greater sensitivity to the difference between one’s own voice and another person’s voice predicted fewer symptoms of persecutory ideation. Additionally, we found that greater tendency to misattribute one’s own voice to an external source predicted greater symptoms of persecutory ideation.