200 research outputs found
Temporal fossa arachnoid cyst presenting with bilateral subdural hematoma following trauma: two case reports
<p>Abstract</p> <p>Introduction</p> <p>Intracranial arachnoid cysts are considered to be congenital malformations with a predilection for the temporal fossa. They are often asymptomatic but can sometimes be symptomatic due to enlargement or hemorrhage. There are multiple case reports of arachnoid cysts becoming symptomatic with hemorrhagic complications following head trauma. In such cases, the bleeding is often confined to the side ipsilateral to the arachnoid cyst. Occurrence of contralateral subdural hematomas in patients with temporal fossa arachnoid cysts has rarely been observed and is reported less frequently in the medical literature.</p> <p>Case presentation</p> <p>We report two cases of people (a 23-year-old man and a 41-year-old man) with temporal fossa arachnoid cysts complicated by a subdural hematoma following head injury. Both patients developed a subdural hematoma contralateral to the side of a temporal fossa arachnoid cyst. It is likely that lack of adequate intracranial cushioning in the presence of an intracranial arachnoid cyst may result in injury not only to ipsilateral but also to contralateral bridging veins, following head trauma.</p> <p>Conclusion</p> <p>It is important to identify and report such rare complications with intracranial arachnoid cysts, so that asymptomatic patients with an intracranial arachnoid cyst can be counseled about such possibilities following head trauma.</p
Asian-Specific total knee system: 5-14 year follow-up study
<p>Abstract</p> <p>Background</p> <p>Knee size and body size differ in Asians compared with Caucasians. Nevertheless, many total knee arthroplasty (TKA) prostheses used worldwide are made for Western Caucasian subjects. As a result, an Asian's knee might not fit these prostheses. We studied the Flexible Nichidai Knee (FNK) system, a new model of TKA for Asian patients. The purpose of this report is to investigate the outcomes of this prosthesis retrospectively.</p> <p>Methods</p> <p>We investigated 1055 primary TKAs in 595 patients who underwent FNK for osteoarthritis (OA) in Japan and were followed for > 5 years. The knee score and function score were used for clinical evaluation. We examined the range of motion (ROM) preoperatively and at final follow-up and radiographic assessments. In addition, postoperative complications were investigated. A survivorship analysis was also conducted using two endpoints: revision for any reason and aseptic failure.</p> <p>Results</p> <p>890 knees in 502 patients were available for study (follow-up rate of 96.0%). The mean follow-up term was 8.3 years (range, 5.0-14.1 years). The knee and function score significantly improved from 41.3 to 90.3 and from 39.1 to 76.2 points, respectively (p < 0.001). The mean ROM in FNK posterior cruciate retaining (CR) type and FNK posterior-stabilized (PS) type ameliorated significantly from 107.8° and 95.6° to 110.7° and 110.4°, respectively (p < 0.01). Ten knees underwent revision surgery (infection in 3 cases, instability in 2, loosening in 2, and non-union of femoral supracondylar fracture, severe pain, and recurrent hemarthrosis in 1 each). The survivorship rate was 99.4% (95% CI, 99.0-99.8) at 5 years (n = 952 patients at risk) and 96.2% (95% CI, 91.9-100) at 12.5 years (n = 49 patients at risk).</p> <p>Conclusion</p> <p>The FNK prosthesis for Asians achieved excellent mid- to long-term survivorship and clinical results.</p
Population transcriptomics of Drosophila melanogaster females
<p>Abstract</p> <p>Background</p> <p>Variation at the level of gene expression is abundant in natural populations and is thought to contribute to the adaptive divergence of populations and species. Gene expression also differs considerably between males and females. Here we report a microarray analysis of gene expression variation among females of 16 <it>Drosophila </it><it>melanogaster </it>strains derived from natural populations, including eight strains from the putative ancestral range in sub-Saharan Africa and eight strains from Europe. Gene expression variation among males of the same strains was reported previously.</p> <p>Results</p> <p>We detected relatively low levels of expression polymorphism within populations, but much higher expression divergence between populations. A total of 569 genes showed a significant expression difference between the African and European populations at a false discovery rate of 5%. Genes with significant over-expression in Europe included the insecticide resistance gene <it>Cyp6g1</it>, as well as genes involved in proteolysis and olfaction. Genes with functions in carbohydrate metabolism and vision were significantly over-expressed in the African population. There was little overlap between genes expressed differently between populations in females and males.</p> <p>Conclusions</p> <p>Our results suggest that adaptive changes in gene expression have accompanied the out-of-Africa migration of <it>D. melanogaster</it>. Comparison of female and male expression data indicates that the vast majority of genes differing in expression between populations do so in only one sex and suggests that most regulatory adaptation has been sex-specific.</p
Decoding of Superimposed Traces Produced by Direct Sequencing of Heterozygous Indels
Direct Sanger sequencing of a diploid template containing a heterozygous insertion or deletion results in a difficult-to-interpret mixed trace formed by two allelic traces superimposed onto each other. Existing computational methods for deconvolution of such traces require knowledge of a reference sequence or the availability of both direct and reverse mixed sequences of the same template. We describe a simple yet accurate method, which uses dynamic programming optimization to predict superimposed allelic sequences solely from a string of letters representing peaks within an individual mixed trace. We used the method to decode 104 human traces (mean length 294 bp) containing heterozygous indels 5 to 30 bp with a mean of 99.1% bases per allelic sequence reconstructed correctly and unambiguously. Simulations with artificial sequences have demonstrated that the method yields accurate reconstructions when (1) the allelic sequences forming the mixed trace are sufficiently similar, (2) the analyzed fragment is significantly longer than the indel, and (3) multiple indels, if present, are well-spaced. Because these conditions occur in most encountered DNA sequences, the method is widely applicable. It is available as a free Web application Indelligent at http://ctap.inhs.uiuc.edu/dmitriev/indel.asp
Differential stability of 2′F-ANA•RNA and ANA•RNA hybrid duplexes: roles of structure, pseudohydrogen bonding, hydration, ion uptake and flexibility
Hybrids of RNA with arabinonucleic acids 2′F-ANA and ANA have very similar structures but strikingly different thermal stabilities. We now present a thorough study combining NMR and other biophysical methods together with state-of-the-art theoretical calculations on a fully modified 10-mer hybrid duplex. Comparison between the solution structure of 2′F-ANA•RNA and ANA•RNA hybrids indicates that the increased binding affinity of 2′F-ANA is related to several subtle differences, most importantly a favorable pseudohydrogen bond (2′F–purine H8) which contrasts with unfavorable 2′-OH–nucleobase steric interactions in the case of ANA. While both 2′F-ANA and ANA strands maintained conformations in the southern/eastern sugar pucker range, the 2′F-ANA strand’s structure was more compatible with the A-like structure of a hybrid duplex. No dramatic differences are found in terms of relative hydration for the two hybrids, but the ANA•RNA duplex showed lower uptake of counterions than its 2′F-ANA•RNA counterpart. Finally, while the two hybrid duplexes are of similar rigidities, 2′F-ANA single strands may be more suitably preorganized for duplex formation. Thus the dramatically increased stability of 2′F-ANA•RNA and ANA•RNA duplexes is caused by differences in at least four areas, of which structure and pseudohydrogen bonding are the most important
Elastic Stable Intramedullary Nailing (ESIN), Orthoss® and Gravitational Platelet Separation - System (GPS®): An effective method of treatment for pathologic fractures of bone cysts in children
<p>Abstract</p> <p>Background</p> <p>The different treatment strategies for bone cysts in children are often associated with persistence and high recurrence rates of the lesions. The safety and clinical outcomes of a combined mechanical and biological treatment with elastic intramedullary nailing, artificial bone substitute and autologous platelet rich plasma are evaluated.</p> <p>Methods</p> <p>From 02/07 to 01/09 we offered all children with bone cysts the treatment combination of elastic intramedullary nailing (ESIN), artificial bone substitute (Orthoss<sup>®</sup>) and autologous platelet rich plasma, concentrated by the Gravitational Platelet Separation (GPS<sup>®</sup>) - System. All patients were reviewed radiologically for one year following the removal of the intramedullary nailing, which was possible because of cyst obliteration.</p> <p>Results</p> <p>A cohort of 12 children (4 girls, 8 boys) was recruited. The mean patient age was 11.4 years (range 7-15 years). The bone defects (ten humeral, two femoral) included eight juvenile and four aneurysmal bone cysts. Five patients suffered from persistent cysts following earlier unsuccessful treatment of humeral bone cyst after pathologic fracture; the other seven presented with acute pathologic fractures. No peri- or postoperative complications occurred. The radiographic findings showed a total resolution of the cysts in ten cases (Capanna Grade 1); in two cases a small residual cyst remained (Capanna Grade 2). The intramedullary nails were removed six to twelve months (mean 7.7) after the operation; in one case, a fourteen year old boy (Capanna Grade 2), required a further application of GPS<sup>® </sup>and Orthoss<sup>® </sup>to reach a total resolution of the cyst. At follow-up (20-41 months, mean 31.8 months) all patients showed very good functional results and had returned to sporting activity. No refracture occurred, no further procedure was necessary.</p> <p>Conclusions</p> <p>The combination of elastic intramedullary nailing, artificial bone substitute and autologous platelet rich plasma (GPS<sup>®</sup>) enhances the treatment of bone cysts in children, with no resulting complications.</p
The Transcriptional Response of Drosophila melanogaster to Infection with the Sigma Virus (Rhabdoviridae)
Bacterial and fungal infections induce a potent immune response in Drosophila melanogaster, but it is unclear whether viral infections induce an antiviral immune response. Using microarrays, we examined the changes in gene expression in Drosophila that occur in response to infection with the sigma virus, a negative-stranded RNA virus (Rhabdoviridae) that occurs in wild populations of D. melanogaster. We detected many changes in gene expression in infected flies, but found no evidence for the activation of the Toll, IMD or Jak-STAT pathways, which control immune responses against bacteria and fungi. We identified a number of functional categories of genes, including serine proteases, ribosomal proteins and chorion proteins that were overrepresented among the differentially expressed genes. We also found that the sigma virus alters the expression of many more genes in males than in females. These data suggest that either Drosophila do not mount an immune response against the sigma virus, or that the immune response is not controlled by known immune pathways. If the latter is true, the genes that we identified as differentially expressed after infection are promising candidates for controlling the host's response to the sigma virus
Potential pitfalls of modelling ribosomal RNA data in phylogenetic tree reconstruction: Evidence from case studies in the Metazoa
<p>Abstract</p> <p>Background</p> <p>Failure to account for covariation patterns in helical regions of ribosomal RNA (rRNA) genes has the potential to misdirect the estimation of the phylogenetic signal of the data. Furthermore, the extremes of length variation among taxa, combined with regional substitution rate variation can mislead the alignment of rRNA sequences and thus distort subsequent tree reconstructions. However, recent developments in phylogenetic methodology now allow a comprehensive integration of secondary structures in alignment and tree reconstruction analyses based on rRNA sequences, which has been shown to correct some of these problems. Here, we explore the potentials of RNA substitution models and the interactions of specific model setups with the inherent pattern of covariation in rRNA stems and substitution rate variation among loop regions.</p> <p>Results</p> <p>We found an explicit impact of RNA substitution models on tree reconstruction analyses. The application of specific RNA models in tree reconstructions is hampered by interaction between the appropriate modelling of covarying sites in stem regions, and excessive homoplasy in some loop regions. RNA models often failed to recover reasonable trees when single-stranded regions are excessively homoplastic, because these regions contribute a greater proportion of the data when covarying sites are essentially downweighted. In this context, the RNA6A model outperformed all other models, including the more parametrized RNA7 and RNA16 models.</p> <p>Conclusions</p> <p>Our results depict a trade-off between increased accuracy in estimation of interdependencies in helical regions with the risk of magnifying positions lacking phylogenetic signal. We can therefore conclude that caution is warranted when applying rRNA covariation models, and suggest that loop regions be independently screened for phylogenetic signal, and eliminated when they are indistinguishable from random noise. In addition to covariation and homoplasy, other factors, like non-stationarity of substitution rates and base compositional heterogeneity, can disrupt the signal of ribosomal RNA data. All these factors dictate sophisticated estimation of evolutionary pattern in rRNA data, just as other molecular data require similarly complicated (but different) corrections.</p
Fractures in myelomeningocele
BACKGROUND: In patients with myelomeningocele (MMC), a high number of fractures occur in the paralyzed extremities, affecting mobility and independence. The aims of this retrospective cross-sectional study are to determine the frequency of fractures in our patient cohort and to identify trends and risk factors relevant for such fractures. MATERIALS AND METHODS: Between March 1988 and June 2005, 862 patients with MMC were treated at our hospital. The medical records, surgery reports, and X-rays from these patients were evaluated. RESULTS: During the study period, 11% of the patients (n = 92) suffered one or more fractures. Risk analysis showed that patients with MMC and thoracic-level paralysis had a sixfold higher risk of fracture compared with those with sacral-level paralysis. Femoral-neck z-scores measured by dual-energy X-ray absorptiometry (DEXA) differed significantly according to the level of neurological impairment, with lower z-scores in children with a higher level of lesion. Furthermore, the rate of epiphyseal separation increased noticeably after cast immobilization. Mainly patients who could walk relatively well were affected. CONCLUSIONS: Patients with thoracic-level paralysis represent a group with high fracture risk. According to these results, fracture and epiphyseal injury in patients with MMC should be treated by plaster immobilization. The duration of immobilization should be kept to a minimum (<4 weeks) because of increased risk of secondary fractures. Alternatively, patients with refractures can be treated by surgery, when nonoperative treatment has failed
Genomic analysis of Sparus aurata reveals the evolutionary dynamics of sex-biased genes in a sequential hermaphrodite fish
Sexual dimorphism is a fascinating subject in evolutionary biology and mostly results from sex-biased expression of genes, which have been shown to evolve faster in gonochoristic species. We report here genome and sex-specific transcriptome sequencing of Sparus aurata, a sequential hermaphrodite fish. Evolutionary comparative analysis reveals that sex-biased genes in S. aurata are similar in number and function, but evolved following strikingly divergent patterns compared with gonochoristic species, showing overall slower rates because of stronger functional constraints. Fast evolution is observed only for highly ovary-biased genes due to female-specific patterns of selection that are related to the peculiar reproduction mode of S. aurata, first maturing as male, then as female. To our knowledge, these findings represent the first genome-wide analysis on sex-biased loci in a hermaphrodite vertebrate species, demonstrating how having two sexes in the same individual profoundly affects the fate of a large set of evolutionarily relevant genes.European Union
KBBE.2013.1.2-10
European Community
311920
Fondazione Cassa di Risparmio Padova e Rovigo
FCT - Foundation for Science and Technology
research grant SPARCOMP under the Call ARISTEIA I of the National Strategic Reference Framework - by the EU
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Hellenic Republic through the European Social Fundinfo:eu-repo/semantics/publishedVersio
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