372 research outputs found

    Blue rubber-bleb naevus syndrome: report of a case with consumption coagulopathy complicated by manifest thrombosis

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    Abstract Blue rubber-bleb naevus (BRBN) syndrome is a rare disorder characterized by subcutaneous and gastrointestinal haemangiomas. The latter may lead to bleeding complications. A case is reported in which a process of chronic intravascular coagulation resulted in serious thrombotic complications. In the presence of a chronic consumption coagulopathy, it remains uncertain whether antiplatelet drugs are of prophylactic antithrombotic value

    Worm blobs as entangled living polymers:From topological active matter to flexible soft robot collectives

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    Recently, the study of long, slender living worms has gained attention due to their unique ability to form highly entangled physical structures, exhibiting emergent behaviors. These organisms can assemble into an active three-dimensional soft entity referred to as the “blob”, which exhibits both solid-like and liquid-like properties. This blob can respond to external stimuli such as light, to move or change shape. In this perspective article, we acknowledge the extensive and rich history of polymer physics, while illustrating how these living worms provide a fascinating experimental platform for investigating the physics of active, polymer-like entities. The combination of activity, long aspect ratio, and entanglement in these worms gives rise to a diverse range of emergent behaviors. By understanding the intricate dynamics of the worm blob, we could potentially stimulate further research into the behavior of entangled active polymers, and guide the advancement of synthetic topological active matter and bioinspired tangling soft robot collectives.</p

    The cystic fibrosis defect approached from different angles - New perspectives on the gene, the chloride channel, diagnosis and therapy

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    Abstract The search for the basic defect in cystic fibrosis (CF) has reached a decisive stage since the recent identification of the responsible gene. Electrophysiological and biochemical research had defined the CF defect as a dysregulation of epithelial chloride channels. The putative protein product of the now identified gene shares properties with other known transport proteins, but it is not necessarily itself a chloride channel protein. Elucidation of the primary cellular defect will certainly have important aetiological and hopefully therapeutic implications. The identification of the major gene mutation already has significant consequences for genetic counselling and prenatal diagnosis. Heterozygote detection at the population level awaits identification of the probably heterogenous mutations on about 30% of the CF chromosomes. At present, about 50% of CF patients are homozygous for the recently identified major CF mutation

    Bile Acid Malabsorption in Cystic Fibrosis; Membrane Vesicles, a Tool for Revealing the Role of the Ileal Brush Border Membrane

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    ABSTRACT. Increased fecal bile acid loss in cystic fibrosis (CF) may result from ileal dysfunction. A method to quantitate in vitro Na+‐dependent taurocholate uptake into brush border membrane vesicles prepared from frozen ileum and ileal biopsy specimen is described. This transport across the ileal brush border membrane can be measured selectively, in contrast to in vivo measurements which represent a complex overall process. Preliminary results obtained with ileal specimen of 2 CF patients, suggest that in vitro bile acid uptake is low but not abnormal. Copyrigh

    A mutation which disrupts the hydrophobic core of the signal peptide of bilirubin UDP-glucuronosyltransferase, an endoplasmic reticulum membrane protein, causes Crigler-Najjar type II

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    Crigler-Najjar (CN) disease is caused by a deficiency of the hepatic enzyme, bilirubin UDP-glucuronosyltransferase (B-UGT). We have found two CN type II patients, who were homozygous for a leucine to arginine transition at position 15 of B-UGT1. This mutation is expected to disrupt the hydrophobic core of the signal peptide of B-UGT1. Wild type and mutant B-UGT cDNAs were transfected in COS cells. Mutant and wild type mRNA were formed in equal amounts. The mutant protein was expressed with 0.5% efficiency, as compared to wild type. Mutant and wild type mRNAs were translated in vitro. Wild type transferase is processed by microsomes, no processing of the mutant protein was observed

    Studying biological tissue with fluorescence lifetime imaging: microscopy, endoscopy, and complex decay profiles

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    We have applied fluorescence lifetime imaging (FLIM) to the autofluorescence of different kinds of biological tissue in vitro, including animal tissue sections and knee joints as well as human teeth, obtaining two-dimensional maps with functional contrast. We find that fluorescence decay profiles of biological tissue are well described by the stretched exponential function (StrEF), which can represent the complex nature of tissue. The StrEF yields a continuous distribution of fluorescence lifetimes, which can be extracted with an inverse Laplace transformation, and additional information is provided by the width of the distribution. Our experimental results from FLIM microscopy in combination with the StrEF analysis indicate that this technique is ready for clinical deployment, including portability that is through the use of a compact picosecond diode laser as the excitation source. The results obtained with our FLIM endoscope successfully demonstrated the viability of this modality, though they need further optimization. We expect a custom-designed endoscope with optimized illumination and detection efficiencies to provide significantly improved performance. © 2003 Optical Society of America.Peer Reviewe

    Changes in globus pallidus with (pre)term kernicterus

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    OBJECTIVE: We report serial magnetic resonance (MR) and sonographic behavior of globus pallidus in 5 preterm and 3 term infants with kernicterus and describe the clinical context in very low birth weight preterm infants. On the basis of this information, we suggest means of diagnosis and prevention. METHODS: Charts and MR and ultrasound images of 5 preterm infants and 3 term infants with suspected bilirubin-associated brain damage were reviewed. Included were preterm infants with severe hearing loss, quadriplegic hypertonia, and abnormal hypersignal of globus pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150, the diagnosis was confirmed during the neonatal period. The others were picked up as outpatients and scanned at 12 or 22 months' corrected age. Three instances of term kernicterus were included for comparison of serial MRI in the neonatal period and early infancy: they were caused by glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration plus fructose 1-6 biphosphatase deficiency. RESULTS: Five preterm infants of 25 to 29 weeks' gestational age presented with total serum bilirubin (TSB) levels below exchange transfusion thresholds commonly advised. Mixed acidosis was present in 3 infants around the TSB peak. The bilirubin/albumin molar ratio was >0.5 in all, in the absence of displacing drugs. All failed to pass bedside hearing screen tests and had severe hearing loss on auditory brain response testing. Symmetrical homogeneous hyperechogenicity of globus pallidus was the alerting feature in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in this child. The other infants presented with severe developmental delay as a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was normal on T1- but hyperintense on T2-weighted MR images at 12
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