430 research outputs found

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    ABSTRACT. Objective. To put forward a new concept -Blau arteritis, a form of large-vessel vasculitis phenotypically related to Takayasu disease but genetically and clinically part of an expanded phenotype of Blau syndrome. Methods. We provide a clinical description of a new case and summarize previously published cases of arteritis associated with Blau syndrome. Genetic testing was performed by direct sequencing of exon 4 of the NOD2 gene. Results. The case described and those reviewed from the literature demonstrate the emerging phenotype of Takayasu-like arteritis in patients with Blau syndrome. Although most patients described to date depict an otherwise classic Blau syndrome phenotype, the current case was atypical in that the predominant features were arteritic. A novel substitution, G464W, in a highly conserved position near the nucleotide oligomerization domain of the NOD2 protein is also described. Blau syndrome is a monogenic granulomatous disease characterized in its most typical form by a triad of exuberant polyarthritis, uveitis, and granulomatous dermatitis 1 . It is caused by single amino acid substitutions at or near the NACHT domain of NOD2 2 . Although its systemic expression is well recognized after the descriptions of the expanded phenotype of Blau syndrome 3,4 , large-vessel vasculitis remains one of its serious and yet underrecognized manifestations if not actively sought by the treating physician. We describe an 8-year-old girl with symptomatic Takayasu-like arteritis and cardiomyopathy against the background of Blau syndrome with a G464W substitution in NOD2. We reported a similar case in 1989 5 , while others have observed arteritis among children with both sporadic and familial Blau phenotype before the mutation was known MATERIALS AND METHODS A girl, now 11 years old, from rural India, presented to us for the first time at 18 months of age, with bilateral knee effusions of a few months' duration in the absence of rash, uveitis, or systemic features. From the age of 1 month she had had recurrent and unexplained episodes of fever. Her antinuclear antibody result was negative. With a working diagnosis of oligoarticular juvenile arthritis she was administered intraarticular steroids, to which she responded well. She was lost to followup for almost 6 years thereafter. At the age of 8 years, she presented with gradually progressive dyspnea and palpitations of 3 months' duration. She had not thrived, and at this stage she weighed 17.2 kg and her height was 113 cm. There were no systemic features but joint examination showed "boggy synovitis" of the right elbow and knee. Cardiovascular examination showed an irregular pulse with a pulsatile precordium and evidence of congestive heart failure. A rhythm strip on electrocardiography showed ventricular extra beats. The echocardiogram revealed dilated ventricles, generalized hypokinesia with an ejection fraction of 20%, mild tricuspid and aortic regurgitation, and abnormal echogenicity within the wall of the left ventricle. With oligoarticular arthritis in a setting of dilated cardiomyopathy, elevated erythrocyte sedimentation rate, and family history of recurrent unexplained fevers in her mother, a diagnosis of early-onset sarcoidosis was considered. Her eye examination continued to be normal and all biopsies requiring sedation were deferred because of poor cardiac function. Oral methotrexate 10 mg/m 2 and corticosteroids 2 mg/kg were initiated in addition to decongestive treatment consisting of digitalis, diuretics, and captopril. She showed a gradual but steady improvement in effort tolerance, although her ejection fraction on electrocardiography did not mirror her clinical improvement. One and a half years later on a routine followup she was found to be hypertensive. Her carotid pulsations were decreased and a renal bruit was detected. Antihypertensive treatment was instituted and a compute

    Personal non-commercial use only

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    ABSTRACT. Objective. To put forward a new concept -Blau arteritis, a form of large-vessel vasculitis phenotypically related to Takayasu disease but genetically and clinically part of an expanded phenotype of Blau syndrome. Methods. We provide a clinical description of a new case and summarize previously published cases of arteritis associated with Blau syndrome. Genetic testing was performed by direct sequencing of exon 4 of the NOD2 gene. Results. The case described and those reviewed from the literature demonstrate the emerging phenotype of Takayasu-like arteritis in patients with Blau syndrome. Although most patients described to date depict an otherwise classic Blau syndrome phenotype, the current case was atypical in that the predominant features were arteritic. A novel substitution, G464W, in a highly conserved position near the nucleotide oligomerization domain of the NOD2 protein is also described. Blau syndrome is a monogenic granulomatous disease characterized in its most typical form by a triad of exuberant polyarthritis, uveitis, and granulomatous dermatitis 1 . It is caused by single amino acid substitutions at or near the NACHT domain of NOD2 2 . Although its systemic expression is well recognized after the descriptions of the expanded phenotype of Blau syndrome 3,4 , large-vessel vasculitis remains one of its serious and yet underrecognized manifestations if not actively sought by the treating physician. We describe an 8-year-old girl with symptomatic Takayasu-like arteritis and cardiomyopathy against the background of Blau syndrome with a G464W substitution in NOD2. We reported a similar case in 1989 5 , while others have observed arteritis among children with both sporadic and familial Blau phenotype before the mutation was known MATERIALS AND METHODS A girl, now 11 years old, from rural India, presented to us for the first time at 18 months of age, with bilateral knee effusions of a few months' duration in the absence of rash, uveitis, or systemic features. From the age of 1 month she had had recurrent and unexplained episodes of fever. Her antinuclear antibody result was negative. With a working diagnosis of oligoarticular juvenile arthritis she was administered intraarticular steroids, to which she responded well. She was lost to followup for almost 6 years thereafter. At the age of 8 years, she presented with gradually progressive dyspnea and palpitations of 3 months' duration. She had not thrived, and at this stage she weighed 17.2 kg and her height was 113 cm. There were no systemic features but joint examination showed "boggy synovitis" of the right elbow and knee. Cardiovascular examination showed an irregular pulse with a pulsatile precordium and evidence of congestive heart failure. A rhythm strip on electrocardiography showed ventricular extra beats. The echocardiogram revealed dilated ventricles, generalized hypokinesia with an ejection fraction of 20%, mild tricuspid and aortic regurgitation, and abnormal echogenicity within the wall of the left ventricle. With oligoarticular arthritis in a setting of dilated cardiomyopathy, elevated erythrocyte sedimentation rate, and family history of recurrent unexplained fevers in her mother, a diagnosis of early-onset sarcoidosis was considered. Her eye examination continued to be normal and all biopsies requiring sedation were deferred because of poor cardiac function. Oral methotrexate 10 mg/m 2 and corticosteroids 2 mg/kg were initiated in addition to decongestive treatment consisting of digitalis, diuretics, and captopril. She showed a gradual but steady improvement in effort tolerance, although her ejection fraction on electrocardiography did not mirror her clinical improvement. One and a half years later on a routine followup she was found to be hypertensive. Her carotid pulsations were decreased and a renal bruit was detected. Antihypertensive treatment was instituted and a compute

    Gold Nanoparticles Generated in Ethosome Bilayers, As Revealed by Cryo-Electron-Tomography

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    Gold nanoparticles have been synthesized inside ethosomes, vesicles composed of phospholipid, ethanol and water, which could be very efficient not only in delivery probes to the skin but also as diagnostic and therapeutic multimodal agents. High efficiency encapsulation of gold nanoparticles is achieved by a simple strategy: the nanoparticles synthesis occurs simultaneously with the ethosomes formation, in the absence of any undesirable reducing agents. A three-dimensional reconstruction of a gold-embedded ethosome generated by cryoelectron tomography reveals that the gold particle is localized inside the lipid bilayer, leaving the ethosome surface and core free for further functionalization. The resulting gold nanoparticles are homogeneous in size and shape and, depending on synthesis temperature, the size ranges from 10 to 20 nm, as revealed by TEM. The ethosome-nanoparticles hybrids size has been investigated by means of dynamic light scattering and has been found to vary with temperature and gold salt concentration from 700 to 400 nm. Gold nanoparticles encapsulated ethosomes offer a versatile platform for the enhancement of pharmacological efficacy in transdermal and dermal delivery systems.Comment: 2 videos of the cryo-electron tomographic reconstruction in Supporting Informatio

    SIRT6 Promotes Hepatic Beta-Oxidation via Activation of PPARα

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    The pro-longevity enzyme SIRT6 regulates various metabolic pathways. Gene expression analyses in SIRT6 heterozygotic mice identify significant decreases in PPARα signaling, known to regulate multiple metabolic pathways. SIRT6 binds PPARα and its response element within promoter regions and activates gene transcription. Sirt6+/− results in significantly reduced PPARα-induced β-oxidation and its metabolites and reduced alanine and lactate levels, while inducing pyruvate oxidation. Reciprocally, starved SIRT6 transgenic mice show increased pyruvate, acetylcarnitine, and glycerol levels and significantly induce β-oxidation genes in a PPARα-dependent manner. Furthermore, SIRT6 mediates PPARα inhibition of SREBP-dependent cholesterol and triglyceride synthesis. Mechanistically, SIRT6 binds PPARα coactivator NCOA2 and decreases liver NCOA2 K780 acetylation, which stimulates its activation of PPARα in a SIRT6-dependent manner. These coordinated SIRT6 activities lead to regulation of whole-body respiratory exchange ratio and liver fat content, revealing the interactions whereby SIRT6 synchronizes various metabolic pathways, and suggest a mechanism by which SIRT6 maintains healthy liver

    Modulation of enhancer looping and differential gene targeting by Epstein-Barr virus transcription factors directs cellular reprogramming

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    Epstein-Barr virus (EBV) epigenetically reprogrammes B-lymphocytes to drive immortalization and facilitate viral persistence. Host-cell transcription is perturbed principally through the actions of EBV EBNA 2, 3A, 3B and 3C, with cellular genes deregulated by specific combinations of these EBNAs through unknown mechanisms. Comparing human genome binding by these viral transcription factors, we discovered that 25% of binding sites were shared by EBNA 2 and the EBNA 3s and were located predominantly in enhancers. Moreover, 80% of potential EBNA 3A, 3B or 3C target genes were also targeted by EBNA 2, implicating extensive interplay between EBNA 2 and 3 proteins in cellular reprogramming. Investigating shared enhancer sites neighbouring two new targets (WEE1 and CTBP2) we discovered that EBNA 3 proteins repress transcription by modulating enhancer-promoter loop formation to establish repressive chromatin hubs or prevent assembly of active hubs. Re-ChIP analysis revealed that EBNA 2 and 3 proteins do not bind simultaneously at shared sites but compete for binding thereby modulating enhancer-promoter interactions. At an EBNA 3-only intergenic enhancer site between ADAM28 and ADAMDEC1 EBNA 3C was also able to independently direct epigenetic repression of both genes through enhancer-promoter looping. Significantly, studying shared or unique EBNA 3 binding sites at WEE1, CTBP2, ITGAL (LFA-1 alpha chain), BCL2L11 (Bim) and the ADAMs, we also discovered that different sets of EBNA 3 proteins bind regulatory elements in a gene and cell-type specific manner. Binding profiles correlated with the effects of individual EBNA 3 proteins on the expression of these genes, providing a molecular basis for the targeting of different sets of cellular genes by the EBNA 3s. Our results therefore highlight the influence of the genomic and cellular context in determining the specificity of gene deregulation by EBV and provide a paradigm for host-cell reprogramming through modulation of enhancer-promoter interactions by viral transcription factors

    Multirater Validation of Peripapillary Hyperreflective Ovoid Mass-like Structures (PHOMS)

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    Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are a new retinal optical coherence tomography (OCT) finding. The Optic Disc Drusen Studies Consortium had made recommendations to distinguish PHOMS from true optic disc drusen (ODD) in 2018. While publications on PHOMS have increased since then, the accuracy of the definition of PHOMS and reliability of detection is unknown. In this multi-rater study, we demonstrate that the 2018 definition of PHOMS resulted in a poor multi-rater kappa of 0.356. We performed a Delphi consensus process to develop a consistent and refined definition of PHOMS with clear principles around the nature of PHOMS and how they differ from normal anatomy. Fifty explanatory teaching slides, provided as supplementary material, allowed our expert group of raters to achieve a good level of agreement (kappa 0.701, 50 OCT scans, 21 raters). We recommend adopting the refined definition for PHOMS

    Effective killing of the human pathogen Candida albicans by a specific inhibitor of non-essential mitotic kinesin Kip1p

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    Kinesins from the bipolar (Kinesin-5) family are conserved in eukaryotic organisms and play critical roles during the earliest stages of mitosis to mediate spindle pole body separation and formation of a bipolar mitotic spindle. To date, genes encoding bipolar kinesins have been reported to be essential in all organisms studied. We report the characterization of CaKip1p, the sole member of this family in the human pathogenic yeast Candida albicans. C. albicans Kip1p appears to localize to the mitotic spindle and loss of CaKip1p function interferes with normal progression through mitosis. Inducible excision of CaKIP1 revealed phenotypes unique to C. albicans, including viable homozygous Cakip1 mutants and an aberrant spindle morphology in which multiple spindle poles accumulate in close proximity to each other. Expression of the C. albicans Kip1 motor domain in Escherichia coli produced a protein with microtubule-stimulated ATPase activity that was inhibited by an aminobenzothiazole (ABT) compound in an ATP-competitive fashion. This inhibition results in ‘rigor-like’, tight association with microtubules in vitro. Upon treatment of C. albicans cells with the ABT compound, cells were killed, and terminal phenotype analysis revealed an aberrant spindle morphology similar to that induced by loss of the CaKIP1 gene. The ABT compound discovered is the first example of a fungal spindle inhibitor targeted to a mitotic kinesin. Our results also show that the non-essential nature and implementation of the bipolar motor in C. albicans differs from that seen in other organisms, and suggest that inhibitors of a non-essential mitotic kinesin may offer promise as cidal agents for antifungal drug discovery

    Treatment strategies in primary vitreoretinal lymphoma: a 17-center European collaborative study.

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    IMPORTANCE: The best treatment option for primary vitreoretinal lymphoma (PVRL) without signs of central nervous system lymphoma (CNSL) involvement determined on magnetic resonance imaging or in cerebrospinal fluid is unknown. OBJECTIVE: To evaluate the outcomes of treatment regimens used for PVRL in the prevention of subsequent CNSL. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort study was conducted at 17 referral ophthalmologic centers in Europe. We reviewed clinical, laboratory, and imaging data on 78 patients with PVRL who did not have CNSL on presentation between January 1, 1991, and December 31, 2012, with a focus on the incidence of CNS manifestations during the follow-up period. INTERVENTIONS: The term extensive treatment was used for various combinations of systemic and intrathecal chemotherapy, whole-brain radiotherapy, and peripheral blood stem cell transplantation. Therapy to prevent CNSL included ocular radiotherapy and/or ocular chemotherapy (group A, 31 patients), extensive systemic treatment (group B, 21 patients), and a combination of ocular and extensive treatment (group C, 23 patients); 3 patients did not receive treatment. A total of 40 patients received systemic chemotherapy. MAIN OUTCOMES AND MEASURES: Development of CNSL following the diagnosis of PVRL relative to the use or nonuse of systemic chemotherapy and other treatment regimens. RESULTS: Overall, CNSL developed in 28 of 78 patients (36%) at a median follow-up of 49 months. Specifically, CNSL developed in 10 of 31 (32%) in group A, 9 of 21 (43%) in group B, and 9 of 23 (39%) in group C. The 5-year cumulative survival rate was lower in patients with CNSL (35% [95% CI, 50% to 86%]) than in patients without CNSL (68% [95% CI, 19% to 51%]; P = .003) and was similar among all treatment groups (P = .10). Adverse systemic effects occurred in 9 of 40 (23%) patients receiving systemic chemotherapy; the most common of these effects was acute renal failure. CONCLUSIONS AND RELEVANCE: In the present series of patients with isolated PVRL, the use of systemic chemotherapy was not proven to prevent CNSL and was associated with more severe adverse effects compared with local treatment
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