413 research outputs found

    A model of maxilla resection to test new hybrid implants:macroporous titanium and tissue engineering elements

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    Maxillary bone loss in commonly found in humans, due to bone ageing, tooth loos, periodontal disease and, more severely, to trauma, radiotherapy and tumor resection. Masillofacial reconstructive surgery is a still unmet clinical demand, available therapies include grafting of autologous or heterologous bone tissue and/or the implantation of metallic plates, buy these treatments are still unable to resume form and function. The emrgence of 3D-printing technology applied to metal alloys now allows the manufacturing of customized, patient-tailored prosthetic implants. However, poor bone quiality at the implant site due to ageing or disease still hamper proper osseointegration. By combining Electron Beam Melting metal sintering and tissue engineering, we are developing hybrid maxillofacial implants, wher a metal framework of Ti6Al4V alloy confers both and appropiaate shape and mechanical stabilty, while stem cells and osteogenic molecules stimulate bone growth into the metal framework, thus pormoting osseointegration. We hereby present the in vitro work driving to the development of our hybrid maxillofacial prostheses, as well as the setting up of an in vivo model of complete maxilla full resection, created in order to test the prostheses in a preclinical studyUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Sources and Sinks of Diversification and Conservation Priorities for the Mexican Tropical Dry Forest

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    Elucidating the geographical history of diversification is critical for inferring where future diversification may occur and thus could be a valuable aid in determining conservation priorities. However, it has been difficult to recognize areas with a higher likelihood of promoting diversification. We reconstructed centres of origin of lineages and identified areas in the Mexican tropical dry forest that have been important centres of diversification (sources) and areas where species are maintained but where diversification is less likely to occur (diversity sinks). We used a molecular phylogeny of the genus Bursera, a dominant member of the forest, along with information on current species distributions. Results indicate that vast areas of the forest have historically functioned as diversity sinks, generating few or no extant Bursera lineages. Only a few areas have functioned as major engines of diversification. Long-term preservation of biodiversity may be promoted by incorporation of such knowledge in decision-making

    Challenges of functional imaging research of pain in children

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    Functional imaging has revolutionized the neurosciences. In the pain field it has dramatically altered our understanding of how the brain undergoes significant functional, anatomical and chemical changes in patients with chronic pain. However, most studies have been performed in adults. Because functional imaging is non-invasive and can be performed in awake individuals, applications in children have become more prevalent, but only recently in the pain field. Measures of changes in the brains of children have important implications in understanding neural plasticity in response to acute and chronic pain in the developing brain. Such findings may have implications for treatments in children affected by chronic pain and provide novel insights into chronic pain syndromes in adults. In this review we summarize this potential and discuss specific concerns related to the imaging of pain in children

    Robust Reproducible Resting State Networks in the Awake Rodent Brain

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    Resting state networks (RSNs) have been studied extensively with functional MRI in humans in health and disease to reflect brain function in the un-stimulated state as well as reveal how the brain is altered with disease. Rodent models of disease have been used comprehensively to understand the biology of the disease as well as in the development of new therapies. RSN reported studies in rodents, however, are few, and most studies are performed with anesthetized rodents that might alter networks and differ from their non-anesthetized state. Acquiring RSN data in the awake rodent avoids the issues of anesthesia effects on brain function. Using high field fMRI we determined RSNs in awake rats using an independent component analysis (ICA) approach, however, ICA analysis can produce a large number of components, some with biological relevance (networks). We further have applied a novel method to determine networks that are robust and reproducible among all the components found with ICA. This analysis indicates that 7 networks are robust and reproducible in the rat and their putative role is discussed

    Neurosyphilis manifesting with unilateral visual loss and hyponatremia: a case report

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    <p>Abstract</p> <p>Background</p> <p>Syphilis is called the chameleon of the diseases due to its variety of its clinical presentations, potentially affecting every organ of the body. Incidence of this ancient disease is once again on the increase worldwide.</p> <p>Case presentation</p> <p>We here report an unusual case of neurosyphilis manifesting with unilateral visual loss and hyponatremia. The patient also had primary syphilitic lesions and was concomitantly diagnosed with Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) infection. Treatment with ceftriaxone and prednisolone, completely resolved the hyponatremia and visual acuity was partially restored.</p> <p>Conclusion</p> <p>Awareness of syphilis as a differential diagnosis is important as previously unreported presentations of neurosyphilis can arise, especially in HIV infected patients.</p

    Substitution of adeno-associated virus Rep protein binding and nicking sites with human Chromosome 19 sequences

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    <p>Abstract</p> <p>Background</p> <p>Adeno-associated virus type 2 (AAV2) preferentially integrates its DNA at a ~2 kb region of human chromosome 19, designated <it>AAVS1 </it>(also known as <it>MBS85</it>). Integration at <it>AAVS1 </it>requires the AAV2 replication (Rep) proteins and a DNA sequence within <it>AAVS1 </it>containing a 16 bp Rep recognition sequence (RRS) and closely spaced Rep nicking site (also referred to as a terminal resolution site, or <it>trs</it>). The AAV2 genome is flanked by inverted terminal repeats (ITRs). Each ITR contains an RRS and closely spaced <it>trs</it>, but the sequences differ from those in <it>AAVS1</it>. These ITR sequences are required for replication and packaging.</p> <p>Results</p> <p>In this study we demonstrate that the <it>AAVS1 </it>RRS and <it>trs </it>can function in AAV2 replication, packaging and integration by replacing a 61 bp region of the AAV2 ITR with a 49 bp segment of <it>AAVS1 </it>DNA. Modifying one or both ITRs did not have a large effect on the overall virus titers. These modifications did not detectably affect integration at <it>AAVS1</it>, as measured by semi-quantitative nested PCR assays. Sequencing of integration junctions shows the joining of the modified ITRs to <it>AAVS1 </it>sequences.</p> <p>Conclusions</p> <p>The ability of these <it>AAVS1 </it>sequences to substitute for the AAV2 RRS and <it>trs </it>provides indirect evidence that the stable secondary structure encompassing the <it>trs </it>is part of the AAV2 packaging signal.</p

    Promoter regions of Plasmodium vivax are poorly or not recognized by Plasmodium falciparum

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    BACKGROUND: Heterologous promoter analysis in Plasmodium has revealed the existence of conserved cis regulatory elements as promoters from different species can drive expression of reporter genes in heterologous transfection assays. Here, the functional characterization of different Plasmodium vivax promoters in Plasmodium falciparum using luciferase as the reporter gene is presented. METHODS: Luciferase reporter plasmids harboring the upstream regions of the msp1, dhfr, and vir3 genes as well as the full-length intergenic regions of the vir23/24 and ef-1α genes of P. vivax were constructed and transiently transfected in P. falciparum. RESULTS: Only the constructs with the full-length intergenic regions of the vir23/24 and ef-1α genes were recognized by the P. falciparum transcription machinery albeit to values approximately two orders of magnitude lower than those reported by luc plasmids harbouring promoter regions from P. falciparum and Plasmodium berghei. A bioinformatics approach allowed the identification of a motif (GCATAT) in the ef-1α intergenic region that is conserved in five Plasmodium species but is degenerate (GCANAN) in P. vivax. Mutations of this motif in the P. berghei ef-1α promoter region decreased reporter expression indicating it is active in gene expression in Plasmodium. CONCLUSION: Together, this data indicates that promoter regions of P. vivax are poorly or not recognized by the P. falciparum transcription machinery suggesting the existence of P. vivax-specific transcription regulatory elements

    Human milk and mucosal lacto- and galacto-N-biose synthesis by transgalactosylation and their prebiotic potential in Lactobacillus species

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    Lacto-N-biose (LNB) and galacto-N-biose (GNB) are major building blocks of free oligosaccharides and glycan moieties of glyco-complexes present in human milk and gastrointestinal mucosa. We have previously characterized the phospho-β-galactosidase GnbG from Lactobacillus casei BL23 that is involved in the metabolism of LNB and GNB. GnbG has been used here in transglycosylation reactions, and it showed the production of LNB and GNB with N-acetylglucosamine and N-acetylgalactosamine as acceptors, respectively. The reaction kinetics demonstrated that GnbG can convert 69 ± 4 and 71 ± 1 % of o-nitrophenyl-β-D-galactopyranoside into LNB and GNB, respectively. Those reactions were performed in a semi-preparative scale, and the synthesized disaccharides were purified. The maximum yield obtained for LNB was 10.7 ± 0.2 g/l and for GNB was 10.8 ± 0.3 g/l. NMR spectroscopy confirmed the molecular structures of both carbohydrates and the absence of reaction byproducts, which also supports that GnbG is specific for β1,3-glycosidic linkages. The purified sugars were subsequently tested for their potential prebiotic properties using Lactobacillus species. The results showed that LNB and GNB were fermented by the tested strains of L. casei, Lactobacillus rhamnosus (except L. rhamnosus strain ATCC 53103), Lactobacillus zeae, Lactobacillus gasseri, and Lactobacillus johnsonii. DNA hybridization experiments suggested that the metabolism of those disaccharides in 9 out of 10 L. casei strains, all L. rhamnosus strains and all L. zeae strains tested relies upon a phospho-β-galactosidase homologous to GnbG. The results presented here support the putative role of human milk oligosaccharides for selective enrichment of beneficial intestinal microbiota in breast-fed infants

    Phylogenetic relationships within Chamaecrista sect. Xerocalyx (Leguminosae, Caesalpinioideae) inferred from the cpDNA trnE-trnT intergenic spacer and nrDNA ITS sequences

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    Chamaecrista belongs to subtribe Cassiinae (Caesalpinioideae), and it comprises over 330 species, divided into six sections. The section Xerocalyx has been subjected to a profound taxonomic shuffling over the years. Therefore, we conducted a phylogenetic analysis using a cpDNA trnE-trnT intergenic spacer and nrDNA ITS/5.8S sequences from Cassiinae taxa, in an attempt to elucidate the relationships within this section from Chamaecrista. The tree topology was congruent between the two data sets studied in which the monophyly of the genus Chamaecrista was strongly supported. Our analyses reinforce that new sectional boundaries must be defined in the Chamaecrista genus, especially the inclusion of sections Caliciopsis and Xerocalyx in sect. Chamaecrista, considered here paraphyletic. The section Xerocalyx was strongly supported as monophyletic; however, the current data did not show C. ramosa (microphyllous) and C. desvauxii (macrophyllous) and their respective varieties in distinct clades, suggesting that speciation events are still ongoing in these specimens

    Altered ureteric branching morphogenesis and nephron endowment in offspring of diabetic and insulin-treated pregnancy

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    <div><p>There is strong evidence from human and animal models that exposure to maternal hyperglycemia during <i>in utero</i> development can detrimentally affect fetal kidney development. Notwithstanding this knowledge, the precise effects of diabetic pregnancy on the key processes of kidney development are unclear due to a paucity of studies and limitations in previously used methodologies. The purpose of the present study was to elucidate the effects of hyperglycemia on ureteric branching morphogenesis and nephrogenesis using unbiased techniques. Diabetes was induced in pregnant C57Bl/6J mice using multiple doses of streptozotocin (STZ) on embryonic days (E) 6.5-8.5. Branching morphogenesis was quantified <i>ex vivo</i> using Optical Projection Tomography, and nephrons were counted using unbiased stereology. Maternal hyperglycemia was recognised from E12.5. At E14.5, offspring of diabetic mice demonstrated fetal growth restriction and a marked deficit in ureteric tip number (control 283.7±23.3 vs. STZ 153.2±24.6, mean±SEM, <i>p</i>&lt;0.01) and ureteric tree length (control 33.1±2.6 mm vs. STZ 17.6±2.7 mm, <i>p</i> = 0.001) vs. controls. At E18.5, fetal growth restriction was still present in offspring of STZ dams and a deficit in nephron endowment was observed (control 1246.2±64.9 vs. STZ 822.4±74.0, <i>p&lt;</i>0.001). Kidney malformations in the form of duplex ureter and hydroureter were a common observation (26%) in embryos of diabetic pregnancy compared with controls (0%). Maternal insulin treatment from E13.5 normalised maternal glycaemia but did not normalise fetal weight nor prevent the nephron deficit. The detrimental effect of hyperglycemia on ureteric branching morphogenesis and, in turn, nephron endowment in the growth-restricted fetus highlights the importance of glycemic control in early gestation and during the initial stages of renal development.</p> </div
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