Microbial cellulose from a komagataeibacter intermedius strain isolated from commercial wine vinegar

In this study a new bacterial cellulose (BC) producer isolated from commercial vinegar is identified as Komagataeibacter intermedius JF2 based on the examination of general taxonomical characteristics, 16S rDNA sequence analysis, and MALDI-TOF mass spectrometry. The cellulose produced is studied in terms of morphology by scanning electron microscopy, crystallinity by X-Ray diffraction, structure by Fourier transform infrared spectroscopy, and water absorption capacity. BC yield and characteristics of the cellulose produced by the new isolated JF2 are compared with those of the well-known and commonly-used BC producer Komagataeibacter xylinus. Yield of cellulose production was higher for JF2 than for K. xylinus grown on several culture media. JF2 exhibited maximum BC production (1.6 g/L) growing on HS medium supplemented with mannitol. The molecular structure of the produced cellulose was the same for both strains and it was in concordance with that of BC. The nanocellulose fibers produced by JF2 showed a higher degree of crystallinity and a more homogeneous size distribution than those produced by K. xylinus. The results suggested that Komagataeibacter intermedius JF2 could be a suitable candidate as a BC producer for biotechnological applications.Peer ReviewedPostprint (author's final draft

MiRNA profiling of whole trabecular bone: identification of osteoporosis-related changes in MiRNAs in human hip bones

Background MicroRNAs (miRNAs) are important regulators of gene expression, with documented roles in bone metabolism and osteoporosis, suggesting potential therapeutic targets. Our aim was to identify miRNAs differentially expressed in fractured vs nonfractured bones. Additionally, we performed a miRNA profiling of primary osteoblasts to assess the origin of these differentially expressed miRNAs. Methods Total RNA was extracted from (a) fresh femoral neck trabecular bone from women undergoing hip replacement due to either osteoporotic fracture (OP group, n = 6) or osteoarthritis in the absence of osteoporosis (Control group, n = 6), matching the two groups by age and body mass index, and (b) primary osteoblasts obtained from knee replacement due to osteoarthritis (n = 4). Samples were hybridized to a microRNA array containing more than 1900 miRNAs. Principal component analysis (PCA) plots and heat map hierarchical clustering were performed. For comparison of expression levels, the threshold was set at log fold change > 1.5 and a p-value < 0.05 (corrected for multiple testing). Results Both PCA and heat map analyses showed that the samples clustered according to the presence or absence of fracture. Overall, 790 and 315 different miRNAs were detected in fresh bone samples and in primary osteoblasts, respectively, 293 of which were common to both groups. A subset of 82 miRNAs was differentially expressed (p < 0.05) between osteoporotic and control osteoarthritic samples. The eight miRNAs with the lowest p-values (and for which a validated miRNA qPCR assay was available) were assayed, and two were confirmed: miR-320a and miR-483-5p. Both were over-expressed in the osteoporotic samples and expressed in primary osteoblasts. miR-320a is known to target CTNNB1 and predicted to regulate RUNX2 and LEPR, while miR-483-5p down-regulates IGF2. We observed a reduction trend for this target gene in the osteoporotic bone. Conclusions We identified two osteoblast miRNAs over-expressed in osteoporotic fractures, which opens novel prospects for research and therapy

Reactivation of ancestral strains of HIV-1 in the gp120 V3 env region in patients failing antiretroviral therapy and subjected to structured treatment interruption

We analyzed gp120V3 HIV-1 env region genetic diversity of 27 patients failing antiretrovirals and subjected to 12-week structured treatment interruption (STI). Based on heteroduplex mobility assays, eight patients presented low pre- and post-STI genetic diversity (G1); five presented high pre-STI but low post-STI diversity (G2); five presented low pre-STI and high post-STI diversity (G3); and nine, high pre- and post-STI diversity (G4). One patient from G1, two from G2 and two from G3 were subjected to proviral DNA end-point PCR and sequencing. in three patients, the dramatic disturbance caused by STI resulted in ancestral viral progeny activation, which repopulated the cell reservoir. in two patients presenting highly homogeneous sequences and low immune selective pressure (dN/dS ratio < 1), this phenomenon was not observed. the mechanisms involved in viral evolution, in which antiretroviral therapy also applies selective pressure, sometimes affects coreceptor usage of circulating viruses, leading to the suppression of x4 strains. (c) 2006 Published by Elsevier Inc.Universidade Federal de São Paulo, Escola Paulista Med, Lab Retrovirol, BR-04039032 São Paulo, BrazilFundacao Pro Sangue, BR-05403000 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Lab Retrovirol, BR-04039032 São Paulo, BrazilWeb of Scienc

In Vivo Evaluation of 3-Dimensional Polycaprolactone Scaffolds for Cartilage Repair in Rabbits

Background: Cartilage tissue engineering using synthetic scaffolds allows maintaining mechanical integrity and withstanding stress loads in the body, as well as providing a temporary substrate to which transplanted cells can adhere. Purpose: This study evaluates the use of polycaprolactone (PCL) scaffolds for the regeneration of articular cartilage in a rabbit model. Study Design: Controlled laboratory study. Methods: Five conditions were tested to attempt cartilage repair. To compare spontaneous healing (from subchondral plate bleeding) and healing due to tissue engineering, the experiment considered the use of osteochondral defects (to allow blood flow into the defect site) alone or filled with bare PCL scaffold and the use of PCL-chondrocytes constructs in chondral defects. For the latter condition, 1 series of PCL scaffolds was seeded in vitro with rabbit chondrocytes for 7 days and the cell/scaffold constructs were transplanted into rabbits’ articular defects, avoiding compromising the subchondral bone. Cell pellets and bare scaffolds were implanted as controls in a chondral defect. Results: After 3 months with PCL scaffolds or cells/PCL constructs, defects were filled with white cartilaginous tissue; integration into the surrounding native cartilage was much better than control (cell pellet). The engineered constructs showed histologically good integration to the subchondral bone and surrounding cartilage with accumulation of extracellular matrix including type II collagen and glycosaminoglycan. The elastic modulus measured in the zone of the defect with the PCL/cells constructs was very similar to that of native cartilage, while that of the pellet-repaired cartilage was much smaller than native cartilage. Conclusion: The results are quite promising with respect to the use of PCL scaffolds as aids for the regeneration of articular cartilage using tissue engineering techniques.The support of the Spanish Ministry of Science through projects No. MAT2007-66759-C03-01 and MAT2007-66759C03-02 (including FEDER financial support) is acknowledged. Dr Gomez Tejedor acknowledges the support given by the government of Valencia, the Generalitat Valenciana, through the GVPRE/2008/160 project. The support of Grant 2005SGR 00762 and 2005SGR 00848 (Catalan Department of Universities, Research and the Information Society) is also acknowledged. The Aging and Fragile Elderly cooperative research network (Red Tematica de Investigacion Cooperativa en Envejecimiento y Fragilidad [RETICEF]) and the Bioengineering, Biomaterials and Nanomedicine research network (Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina [CIBER BBN]) are initiatives of the Instituto de Salud Carlos III (ISCIII). The group of the Centro de Investigacion Principe Felipe (CIPF) acknowledges funding in the framework of the collaboration agreement among the ISCIII, the Conselleria de Sanidad de la Comunidad Valenciana, and the CIPF for the "Investigacion Basica y Traslacional en Medicina Regenerativa."Martinez-Diaz, S.; Garcia-Giralt, N.; Lebourg, MM.; Gómez-Tejedor, JA.; Vila, G.; Caceres, E.; Benito, P.... (2010). In Vivo Evaluation of 3-Dimensional Polycaprolactone Scaffolds for Cartilage Repair in Rabbits. American Journal of Sports Medicine. 38(3):509-519. https://doi.org/10.1177/0363546509352448S50951938

Diet suppresses tumour initiation by maintaining quiescence of mutation-bearing neural stem cells

Glioblastoma is thought to originate from neural stem cells (NSCs) of the subventricular zone that acquire genetic alterations. In the adult brain, NSCs are largely quiescent, suggesting that deregulation of quiescence maintenance may be a pre-requisite for tumour initiation. Although inactivation of the tumour suppressor p53 is a frequent event in gliomagenesis, whether, or how, it affects quiescent NSCs (qNSCs) remains unclear. Here we show that p53 maintains quiescence by inducing fatty acid oxidation (FAO) and that acute p53 deletion in qNSCs results in their premature activation to a proliferative state. Mechanistically, this occurs through direct transcriptional induction of PPARGC1a, which in turn activates PPARα to upregulate FAO genes. Strikingly, dietary supplementation with fish oil containing omega-3 fatty acids, natural PPARα ligands, fully restores quiescence of p53-deficient NSCs and delays tumour initiation in a glioblastoma mouse model. Thus, diet can silence glioblastoma driver mutations, with important implications for cancer prevention

Diet suppresses glioblastoma initiation in mice by maintaining quiescence of mutation-bearing neural stem cells

Glioblastoma is thought to originate from neural stem cells (NSCs) of the subventricular zone that acquire genetic alterations. In the adult brain, NSCs are largely quiescent, suggesting that deregulation of quiescence maintenance may be a prerequisite for tumor initiation. Although inactivation of the tumor suppressor p53 is a frequent event in gliomagenesis, whether or how it affects quiescent NSCs (qNSCs) remains unclear. Here, we show that p53 maintains quiescence by inducing fatty-acid oxidation (FAO) and that acute p53 deletion in qNSCs results in their premature activation to a proliferative state. Mechanistically, this occurs through direct transcriptional induction of PPARGC1a, which in turn activates PPARα to upregulate FAO genes. Dietary supplementation with fish oil containing omega-3 fatty acids, natural PPARα ligands, fully restores quiescence of p53-deficient NSCs and delays tumor initiation in a glioblastoma mouse model. Thus, diet can silence glioblastoma driver mutations, with important implications for cancer prevention

Development and validation of an HIV risk exposure and indicator conditions questionnaire to support targeted HIV screening

The aim of our study was to develop a Spanish-structured HIV risk of exposure and indicator conditions (RE&IC) questionnaire. People attending to an emergency room or to a primary clinical care center were offered to participate in a prospective, 1 arm, open label study, in which all enrolled patients filled out our developed questionnaire and were HIV tested. Questionnaire accuracy, feasibility, and reliability were evaluated. Valid paired 5329 HIV RE&IC questionnaire and rapid HIV tests were performed, 69.3% in the primary clinical care center, 49.6% women, median age 37 years old, 74.9% Spaniards, 20.1% Latin-Americans. Confirmed hidden HIV infection was detected in 4.1%, while HIV RE&IC questionnaire was positive in 51.2%. HIV RE&IC questionnaire sensitivity was 100% to predict HIV infection, with a 100% negative predictive value. When considered separately, RE or IC items sensitivity decreases to 86.4% or 91%, and similarly their negative predictive value to 99.9% for both of them. The majority of people studied, 90.8% self-completed HIV RE&IC questionnaire. Median time to complete was 3 minutes. Overall HIV RE&IC questionnaire test-retest Kappa agreement was 0.82 (almost perfect), likewise for IC items 0.89, while for RE items was lower 0.78 (substantial). A feasible and reliable Spanish HIV RE&IC self questionnaire accurately discriminated all non–HIV-infected people without missing any HIV diagnoses, in a low prevalence HIV infection area. The best accuracy and reliability were obtained when combining HIV RE&IC items