203 research outputs found
Cross-Modal Plasticity in Cuban Visually-Impaired Child Cochlear Implant Candidates: Topography of Somatosensory Evoked Potentials
ABSTRACT INTRODUCTION Studies of neuroplasticity have shown that the brain's neural networks change in the absence of sensory input such as hearing or vision. However, little is known about what happens when both sensory modalities are lost (deaf-blindness). Hence, this study of cortical reorganization in visually-impaired child cochlear implant (CI) candidates
Repurposing a photosynthetic antenna protein as a super-resolution microscopy label
Techniques such as Stochastic Optical Reconstruction Microscopy (STORM) and Structured Illumination Microscopy (SIM) have increased the achievable resolution of optical imaging, but few fluorescent proteins are suitable for super-resolution microscopy, particularly in the far-red and near-infrared emission range. Here we demonstrate the applicability of CpcA, a subunit of the photosynthetic antenna complex in cyanobacteria, for STORM and SIM imaging. The periodicity and width of fabricated nanoarrays of CpcA, with a covalently attached phycoerythrobilin (PEB) or phycocyanobilin (PCB) chromophore, matched the lines in reconstructed STORM images. SIM and STORM reconstructions of Escherichia coli cells harbouring CpcA-labelled cytochrome bd 1 ubiquinol oxidase in the cytoplasmic membrane show that CpcA-PEB and CpcA-PCB are suitable for super-resolution imaging in vivo. The stability, ease of production, small size and brightness of CpcA-PEB and CpcA-PCB demonstrate the potential of this largely unexplored protein family as novel probes for super-resolution microscopy
Sn-Beta zeolites with borate salts catalyse the epimerization of carbohydrates via an intramolecular carbon shift
Carbohydrate epimerization is an essential technology for the widespread production of rare sugars. In contrast to other enzymes, most epimerases are only active on sugars substituted with phosphate or nucleotide groups, thus drastically restricting their use. Here we show that Sn-Beta zeolite in the presence of sodium tetraborate catalyses the selective epimerization of aldoses in aqueous media. Specifically, a 5 wt% aldose (for example, glucose, xylose or arabinose) solution with a 4:1 aldose:sodium tetraborate molar ratio reacted with catalytic amounts of Sn-Beta yields near-equilibrium epimerization product distributions. The reaction proceeds by way of a 1,2 carbon shift wherein the bond between C-2 and C-3 is cleaved and a new bond between C-1 and C-3 is formed, with C-1 moving to the C-2 position with an inverted configuration. This work provides a general method of performing carbohydrate epimerizations that surmounts the main disadvantages of current enzymatic and inorganic processes.National Science Foundation (U.S.). Materials Research Science and Engineering Centers (Program) (Award DMR-0819762)DuPont MIT Alliance (Graduate Research Fellowship)National Institutes of Health (U.S.) (Grant EB-001960)National Institutes of Health (U.S.) (Grant EB-002026)National Science Foundation (U.S.). Graduate Research Fellowship Program (Grant 1122374
Apparent diffusion coefficient restriction in the white matter: going beyond acute brain territorial ischemia
BACKGROUND: Reduction of apparent diffusion coefficient (ADC) values in white matter is not always ischaemic in nature.
METHODS: We retrospectively analysed our MRI records featuring reduced ADC values in the centrum semiovale without grey matter involvement or significant vasogenic oedema.
RESULTS: Several conditions showed the aforementioned MR findings: moose-horn lesions on coronal images in X-linked Charcot-Marie-Tooth disease; small fronto-parietal lesions in Menkes disease; marked signal abnormalities in the myelinised regions in the acute neonatal form of maple syrup urine disease; strip-like involvement of the corpus callosum in glutaric aciduria type 1; persistent periventricular parieto-occipital abnormalities in phenylketonuria; diffuse signal abnormalities with necrotic evolution in global cerebral anoxia or after heroin vapour inhalation; almost completely reversible symmetric fronto-parietal lesions in methotrexate neurotoxicity; chain-like lesions in watershed ischaemia; splenium involvement that normalises in reversible splenial lesions or leads to gliosis in diffuse axonal injury.
CONCLUSION: Neuroradiologists must be familiar with these features, thereby preventing misdiagnosis and inappropriate management
Association of Inherited Variation in Toll-Like Receptor Genes with Malignant Melanoma Susceptibility and Survival
The family of Toll-like receptors (TLRs) is critical in linking innate and acquired immunity. Polymorphisms in the genes encoding TLRs have been associated with autoimmune diseases and cancer. We investigated the genetic variation of TLR genes and its potential impact on melanoma susceptibility and patient survival. The study included 763 cutaneous melanoma cases recruited in Germany and 736 matched controls that were genotyped for 47 single nucleotide polymorphisms (SNPs) in 8 TLR genes. The relationship between genotype, disease status and survival was investigated taking into account patient and tumor characteristics, and melanoma treatment. Analysis of 7 SNPs in TLR2, 7 SNPs in TLR3 and 8 SNPs in TLR4 showed statistically significant differences in distribution of inferred haplotypes between cases and controls. No individual polymorphism was associated with disease susceptibility except for the observed tendency for TLR2-rs3804099 (odds ratio OR = 1.15, 95% CI 0.99–1.34, p = 0.07) and TLR4-rs2149356 (OR = 0.85, 95% CI 0.73–1.00, p = 0.06). Both polymorphisms were part of the haplotypes associated with risk modulation. An improved overall survival (Hazard ratio HR 0.53, 95% CI 0.32–0.88) and survival following metastasis (HR 0.55, 95% CI 0.34–0.91) were observed in carriers of the variant allele (D299G) of TLR4-rs4986790. In addition various TLR2, TLR4 and TLR5 haplotypes were associated with increased overall survival. Our results point to a novel association between TLR gene variants and haplotypes with melanoma survival. Our data suggest a role for the D299G polymorphism in the TLR4 gene in overall survival and a potential link with systemic treatment at stage IV of the disease. The polymorphic amino acid residue, located in the ectodomain of TLR4, can have functional consequences
Very few frequent syndromes
Dismorfología, Citogenética y Clínica: Resultados sobre los datos del ECEMCThis section is based on two facts: First, that the majority of the malformation syndromes are very few frequent. Second, the progressive generalization in our country of the prenatal diagnosis with a high resolution echography performed to all women between 18-20 weeks of gestation as a Service of the National Health System, together with the possibility of voluntary interruption of gestation if fetal anomalies are detected. Thus, the impact of prenatal diagnosis is that the frequency at birth of these syndromes shows an important and progressive decreasing trend. For these reasons, in addition to the difficulty for pediatricians and geneticists or our population to diagnose these usually rare syndromes, the impact of prenatal diagnosis increases the usual difficulties that the young pediatricians and geneticists have to identify these pathologies. This increases the possibility that some affected patients can remain undiagnosed for a long time, or even never be diagnosed. As started last year in this section of the "Boletín del ECEMC", we present other six syndromes of low frequency in our country.N
Do Gene Variants Influencing Adult Adiposity Affect Birth Weight? A Population-Based Study of 24 Loci in 4,744 Danish Individuals
Several obesity risk alleles affecting adult adiposity have been identified by the recent wave of genome wide association studies. We aimed to examine the potential effect of these variants on fetal body composition by investigating the variants in relation to birth weight and ponderal index of the newborn.Midwife records from the Danish State Archives provided information on mother's age, parity, as well as birth weight, birth length and prematurity of the newborn in 4,744 individuals of the population-based Inter99 study. Twenty-four risk alleles showing genome-wide associations with adult BMI and/or waist circumference were genotyped. None of the 24 risk variants tested showed an association with birth weight or ponderal index after correction for multiple testing. Birth weight was divided into three categories low (≤10(th) percentile), normal (10(th)-90(th) percentile) and high birth weight (≥90th percentile) to allow for non-linear associations. There was no difference in the number of risk alleles between the groups (p = 0.57). No interactions between each risk allele and birth weight in the prediction of adult BMI were observed. An obesity risk score was created by summing up risk alleles. The risk score did not associate with fetal body composition. Moreover there was no interaction between the risk score and birth weight/ponderal index in the prediction of adult BMI.24 common variants associated with adult adiposity did not affect or interact with birth weight among Danes suggesting that the effects of these variants predominantly arise in the post-natal life
Síndromes muy poco frecuentes
Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCIn an attempt to facilitate the knowledge of the malformation syndromes that have very few frequencies to pediatricians and first health care physicians, particularly to those of rural areas, we have selected six new syndromes. As in previous years, the syndromes are selected from the ECEMC database registry. In this Boletín we include the following syndromes: Townes-Bröcks, MMT, Smith-Lemli-Opitz, Coffin-Siris, Espleno-gonadal fusion, and Silver-Russell syndromes. For each syndrome, we described the most important clinical characteristics, and the present knowledge of their causal factors.N
Epidermolysis bullosa (EB): Pathogenesis, clinical, diagnostic and genetic aspects, molecular basis, epidemiological aspects, management of patients with EB and translational implications of mutation analysis
Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCUnder the term "Epidermolysis Bullosa" (EB), there is a heterogeneous group of vesicular disorders that are generally congenital and of
genetic origin, and affect skin and often mucosas. It is remarkable the extreme fragility of these epithelia; the vesicles arise spontaneously
as well as induced by even slight trauma or the influence of high temperatures. Their content is sero-hemorrhagic and in the scarring can
be very difficult. As a consecuence of the scarring processes, joint contractures and fusion of digits (pseudo-syndactyly) can occur.
Pathogenetically, EB is caused by abnormal blistering at the basement membrane zone in the dermal-epidermal attachment zone and its
surroundings. This is due to alterations in the attachment complexes, and some mutations have been identified in a total of 10 genes
expressed in such level. Four main types of EB can be distinguished (simple, junctional, dystrophic and hemidesmosomal), depending on
the level at which the cleavage that forms the bulla takes place, although about 30 subtypes have been described. The clinical characteristics
or optic microscopy are not adequate for diagnosis, and it is mandatory to perform electron microscopy, immunofluorescent and
immunohistochemical studies, as well as mutation analysis if available. Regarding the epidemiological aspects, in the Spanish Collaborative
Study of Congenital Malformations (ECEMC), since 1976 up to December 2004, a total of 2,204,264 liveborn infants were controlled and,
among them 27 cases have been identified, for a minimum frequency of 0.12 per 10,000 (95% confidence interval:0.08-0.18). It seems
generally accepted that the determination of the frequency of EB is subject to multiple biases and registration of cases is always incomplete.
We have also reviewed the issues related to management of EB patients by clinicians.N
Risk of subsequent invasive breast carcinoma after in situ breast carcinoma in a population covered by national mammographic screening
Sweden was the first country to establish a nationwide breast cancer screening service. We used the Swedish Family-Cancer Database to evaluate the risk of invasive carcinoma after in situ carcinoma of the breast. Risk estimates for contralateral and ipsilateral invasive malignancies following age and histology specific in situ breast carcinomas were calculated using Poisson's regression analysis. The agreement between concordant and discordant morphologies of invasive and in situ breast cancer was measured using the kappa statistic. Women with in situ breast cancer showed a relative risk of 2.03 for contralateral and 3.94 for ipsilateral invasive breast cancer. The risk was higher for in situ carcinomas diagnosed before the age of 50 years and after lobular in situ breast cancers. A comparison of the risks during the past decades suggested that the risk of ipsilateral breast cancer has increased in Sweden but that of contralateral breast cancer has remained unchanged. In situ and the subsequent invasive breast cancers did not seem to share their morphologies
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