Platelet lysate-loaded photocrosslinkable hyaluronic acid hydrogels for periodontal endogenous regenerative technology

The integrity and function of the periodontium can be compromised by traumatic injuries or periodontitis. Currently available clinical therapies are able to stop the progression of periodontitis and allow the healing of periodontal tissue. However an optimal strategy capable of restoring the anatomy and functionality of the lost periodontal tissue is still to be achieved. Herein is proposed the development of an injectable hydrogel system able to release a growth factors and cells to the periodontal defect. This injectable system is based on a photocrosslinkable hydrogel, prepared from methacrylated Hyaluronic Acid (me-HA) and incorporating Platelet Lysate (PL). The delivery of growth factors and cells in situ is expected to enhance regeneration of the periodontium. Various formulations of me-HA containing increasing PL concentrations were studied for achieving the formation of stable photocrosslinkable hydrogels. The produced hydrogels were subsequently characterized to assess mechanical properties, degradation, protein/growth factor release profile, antimicrobial activity and response towards human Periodontal Ligament fibroblasts (hPDLFs). The results demonstrated that it was possible to obtain stable photocrosslinkable hydrogels incorporating different amounts of PL that can be released in a sustained manner. Furthermore, the incorporation of PL improved (p<0.02) the viscoelastic properties of the hydrogels and enhanced their resilience to the degradation by hyaluronidase (HAase). Additionally, the PL showed to provide antimicrobial properties. Finally, hPDLFs, either seeded or encapsulated into the developed hydrogels, showed enhanced proliferation over time (p<0.05), proportionally to the increasing amounts of PL present in the hydrogel formulations

Bone turnover markers for early detection of fracture healing disturbances: A review of the scientific literature

Imaging techniques are the standard method for assessment of fracture healing processes. However, these methods are perhaps not entirely reliable for early detection of complications, the most frequent of these being delayed union and non-union. A prompt diagnosis of such disorders could prevent prolonged patient distress and disability. Efforts should be directed towards the development of new technologies for improving accuracy in diagnosing complications following bone fractures. The variation in the levels of bone turnover markers (BTMs) have been assessed with regard to there ability to predict impaired fracture healing at an early stage, nevertheless the conclusions of some studies are not consensual. In this article the authors have revised the potential of BTMs as early predictors of prognosis in adult patients presenting traumatic bone fractures but who did not suffer from osteopenia or postmenopausal osteoporosis. The available information from the different studies performed in this field was systematized in order to highlight the most promising BTMs for the assessment of fracture healing outcome

Genetic diversity of Brazilian isolates of feline immunodeficiency virus

We isolated Feline immunodeficiency virus (FIV) from three adult domestic cats, originating from two open shelters in Brazil. Viruses were isolated from PBMC following co-cultivation with the feline T-lymphoblastoid cell line MYA-1. All amplified env gene products were cloned directly into pGL8MYA. The nucleic acid sequences of seven clones were determined and then compared with those of previously described isolates. The sequences of all of the Brazilian virus clones were distinct and phylogenetic analysis revealed that all belong to subtype B. Three variants isolated from one cat and two variants were isolated from each of the two other cats, indicating that intrahost diversity has the potential to pose problems for the treatment and diagnosis of FIV infection

Strong signature of natural selection within an FHIT intron implicated in prostate cancer risk

Previously, a candidate gene linkage approach on brother pairs affected with prostate cancer identified a locus of prostate cancer susceptibility at D3S1234 within the fragile histidine triad gene (FHIT), a tumor suppressor that induces apoptosis. Subsequent association tests on 16 SNPs spanning approximately 381 kb surrounding D3S1234 in Americans of European descent revealed significant evidence of association for a single SNP within intron 5 of FHIT. In the current study, resequencing and genotyping within a 28.5 kb region surrounding this SNP further delineated the association with prostate cancer risk to a 15 kb region. Multiple SNPs in sequences under evolutionary constraint within intron 5 of FHIT defined several related haplotypes with an increased risk of prostate cancer in European-Americans. Strong associations were detected for a risk haplotype defined by SNPs 138543, 142413, and 152494 in all cases (Pearson's χ2 = 12.34, df 1, P = 0.00045) and for the homozygous risk haplotype defined by SNPs 144716, 142413, and 148444 in cases that shared 2 alleles identical by descent with their affected brothers (Pearson's χ2 = 11.50, df 1, P = 0.00070). In addition to highly conserved sequences encompassing SNPs 148444 and 152413, population studies revealed strong signatures of natural selection for a 1 kb window covering the SNP 144716 in two human populations, the European American (π = 0.0072, Tajima's D= 3.31, 14 SNPs) and the Japanese (π = 0.0049, Fay & Wu's H = 8.05, 14 SNPs), as well as in chimpanzees (Fay & Wu's H = 8.62, 12 SNPs). These results strongly support the involvement of the FHIT intronic region in an increased risk of prostate cancer. © 2008 Ding et al

Surface modification of starch based biomaterials by oxygen plasma or UV-irradiation

Radiation is widely used in biomaterials science for surface modification and sterilization. Herein, we describe the use of plasma and UV-irradiation to improve the biocompatibility of different starch-based blends in terms of cell adhesion and proliferation. Physical and chemical changes, introduced by the used methods, were evaluated by complementary techniques for surface analysis such as scanning electron microscopy, atomic force microscopy, contact angle analysis and X-ray photoelectron spectroscopy. The effect of the changed surface properties on the adhesion of osteoblast-like cells was studied by a direct contact assay. Generally, both treatments resulted in higher number of cells adhered to the modified surfaces. The importance of the improved biocompatibility resulting from the irradiation methods is further supported by the knowledge that both UV and plasma treatments can be used as cost-effective methods for sterilization of biomedical materials and devices.I. P. thanks the FCT for providing her a postdoctoral scholarship (SFRH/BPD/8491/2002). This work was partially supported by FCT, through funds from the POCTI and/or FEDER programs, The European Union funded STREP Project HIPPOCRATES (NNM-3-CT-2003-505758) and the European NoE EXPERTISSUES (NMP3-CT-2004-500283)

Enzymatic degradation of starch thermoplastic blends using samples of different thickness

The material studied was a thermoplastic blend of corn starch with a poly(ethylene-vinyl alcohol) copolymer, SEVA-C. The influence of both the material’s exposed surface and enzyme concentration on degradation kinetics was studied. As α-amylase is present in the blood plasma, experiments were performed, varying the material thickness and the α-amylase between 50 and 100 units/l, at 37°C, lasting up to 90 days. Four different batches using SEVA-C and starch samples of different thickness were performed. The positive correlation between degradation rate and the exposed material surface was confirmed, since thin films with larger exposed surfaces were degraded faster than thick square plates having the same total mass. The degradation extent depends on the total amount of amorphous starch present in the formulation rather than on the amount of enzyme used and the minimum thickness to ensure maximum degradation was estimated to be close to 0.25 mm

Activation of Type 1 Cannabinoid Receptor (CB1R) promotes neurogenesis in murine subventricular zone cell cultures

The endocannabinoid system has been implicated in the modulation of adult neurogenesis. Here, we describe the effect of type 1 cannabinoid receptor (CB1R) activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ) stem/progenitor cell cultures. Expression of CB1R was detected in SVZ-derived immature cells (Nestin-positive), neurons and astrocytes. Stimulation of the CB1R by (R)-(+)-Methanandamide (R-m-AEA) increased self-renewal of SVZ cells, as assessed by counting the number of secondary neurospheres and the number of Sox2+/+ cell pairs, an effect blocked by Notch pathway inhibition. Moreover, R-m-AEA treatment for 48 h, increased proliferation as assessed by BrdU incorporation assay, an effect mediated by activation of MAPK-ERK and AKT pathways. Surprisingly, stimulation of CB1R by R-m-AEA also promoted neuronal differentiation (without affecting glial differentiation), at 7 days, as shown by counting the number of NeuN-positive neurons in the cultures. Moreover, by monitoring intracellular calcium concentrations ([Ca2+](i)) in single cells following KCl and histamine stimuli, a method that allows the functional evaluation of neuronal differentiation, we observed an increase in neuronal-like cells. This proneurogenic effect was blocked when SVZ cells were co-incubated with R-m-AEA and the CB1R antagonist AM 251, for 7 days, thus indicating that this effect involves CB1R activation. In accordance with an effect on neuronal differentiation and maturation, R-m-AEA also increased neurite growth, as evaluated by quantifying and measuring the number of MAP2-positive processes. Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.Fundacao para a Ciencia e a Tecnologia - Portugal [POCTI/SAU-NEU/68465/2006, PTDC/SAU-NEU/104415/2008, PTDC/SAU-NEU/101783/2008, POCTI/SAU-NEU/110838/2009]; Fundacao Calouste Gulbenkian [96542]; Fundacao para a Ciencia e Tecnologiainfo:eu-repo/semantics/publishedVersio

Distinct stem cells subpopulations isolated from human adipose tissue exhibit different chondrogenic and osteogenic differentiation potential

Recently adipose tissue has become a research topic also for the searching for an alternative stem cells source to use in cell based therapies such as tissue engineer. In fact Adipose Stem Cells (ASCs) exhibit an important differentiation potential for several cell lineages such as chondrogenic, osteogenic, myogenic, adipogenic and endothelial cells. ASCs populations isolated using standard methodologies (i.e., based on their adherence ability) are very heterogeneous but very few studies have analysed this aspect. Consequently, several questions are still pending, as for example, on what regard the existence/ or not of distinct ASCs subpopulations. The present study is originally aimed at isolating selected ASCs subpopulations, and to analyse their behaviour towards the heterogeneous population regarding the expression of stem cell markers and also regarding their osteogenic and chondrogenic differentiation potential. Human Adipose derived Stem Cells (hASCs) subpopulations were isolated using immunomagnetic beads coated with several different antibodies (CD29, CD44, CD49d, CD73, CD90, CD 105, Stro-1 and p75) and were characterized by Real Time RT-PCR in order to assess the expression of mesenchymal stem cells markers (CD44, CD73, Stro-1, CD105 and CD90) as well as known markers of the chondrogenic (Sox 9, Collagen II) and osteogenic lineage (Osteopontin, Osteocalcin). The obtained results underline the complexity of the ASCs population demonstrating that it is composed of several subpopulations, which express different levels of ASCs markers and exhibit distinctive differentiation potentials. Furthermore, the results obtained clearly evidence of the advantages of using selected populations in cell-based therapies, such as bone and cartilage regenerative medicine approaches.EU funded Marie Curie Actions Alea Jacta Est for a PhD fellowship. This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283)

Innate immune responses and antioxidant/oxidant imbalance are major determinants of human Chagas disease.

We investigated the pathological and diagnostic role of selected markers of inflammation, oxidant/antioxidant status, and cellular injury in human Chagas disease. METHODS: Seropositive/chagasic subjects characterized as clinically-symptomatic or clinically-asymptomatic (n = 116), seronegative/cardiac subjects (n = 102), and seronegative/healthy subjects (n = 45) were analyzed for peripheral blood biomarkers. RESULTS: Seropositive/chagasic subjects exhibited an increase in sera or plasma levels of myeloperoxidase (MPO, 2.8-fold), advanced oxidation protein products (AOPP, 56%), nitrite (5.7-fold), lipid peroxides (LPO, 12-17-fold) and malondialdehyde (MDA, 4-6-fold); and a decline in superoxide dismutase (SOD, 52%) and glutathione (GSH, 75%) contents. Correlation analysis identified a significant (p0.95). The MPO (r = 0.664) and LPO (r = 0.841) levels were also correlated with clinical disease state in chagasic subjects (p<0.001). Seronegative/cardiac subjects exhibited up to 77% decline in SOD, 3-5-fold increase in LPO and glutamate pyruvate transaminase (GPT) levels, and statistically insignificant change in MPO, AOPP, MDA, GPX, GSH, and creatine kinase (CK) levels. CONCLUSIONS: The interlinked effects of innate immune responses and antioxidant/oxidant imbalance are major determinants of human Chagas disease. The MPO, LPO and nitrite are excellent biomarkers for diagnosing seropositive/chagasic subjects, and MPO and LPO levels have potential utility in identifying clinical severity of Chagas diseaseFil: Dhiman, Monisha. University Of Texas Medical Branch. Department Of Microbiology & Immunology And Pathology; United State of America;Fil: Coronado, Yun A.. University Of Texas Medical Branch. Department Of Microbiology & Immunology And Pathology; United State of America;Fil: Vallejo, Cecilia K.. University Of Texas Medical Branch. Department Of Microbiology & Immunology And Pathology; United State of America;Fil: Petersen, John R.. University of Texas Medical Branch. Department of Pathology; United States of America;Fil: Ejilemele, Adetoum. University of Texas Medical Branch. Department of Pathology; United States of America;Fil: Nuñez, Sonia. Hospital Público de Gestión Descentralizada San Bernardo (HPGDSA); Argentina;Fil: Zago, María Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Salta. Instituto de Patologia Experimental; Argentina;Fil: Spratt, Heidi. Departments of Biochemistry and Molecular Biology and Preventive Medicine and Community Health. University of Texas Medical Branch; United States of America;Fil: Garg, Nisha Jain. University of Texas Medical Branch. Department of Pathology; United States of America

Non-pharmacological interventions for weight gain in patients with schizophrenia taking antipsychotics

INTRODUCTION: Schizophrenic patients have a higher prevalence of obesity than the general population. There are several factors implicated in weight gain, including poor dietary conditions, sedentary lifestyle and antipsychotic drugs use. Obesity is also associated with metabolic disturbances such as diabetes mellitus. Weight gain interventions are necessary in this population, especially non-pharmacological interventions. OBJECTIVE: To review the non-pharmacological interventions for weight gain management in patients with schizophrenia. METHODS: Eight clinical trials and four open-label studies using these interventions were found. The methodology, strength and limitations of the studies were reviewed. CONCLUSIONS: Non-pharmacological interventions seem to have an important effect on weight gain prevention and control, and should be encouraged and adapted to patients and in mental health institution's reality.INTRODUÇÃO: Pacientes com esquizofrenia têm maior prevalência de obesidade em comparação à população geral. Esse fato está relacionado a uma alimentação inadequada, ao sedentarismo e ao uso de antipsicóticos. O aumento da obesidade associa-se a diversos distúrbios metabólicos, como o diabetes melito. As intervenções para prevenção e controle do ganho de peso são necessárias nessa população, em especial as intervenções não farmacológicas. OBJETIVO: Revisar os estudos sobre intervenções não farmacológicas para prevenção e controle do ganho de peso em pacientes com esquizofrenia. MÉTODOS: Foram encontrados oito estudos controlados e quatro não controlados sobre intervenções não farmacológicas. Foi feita uma revisãosobre a metodologia e os fatores positivos e limitações dos estudos. CONCLUSÕES: As intervenções não farmacológicas parecem ter um efeito importante em termos de prevenção e controle do ganho de peso e, portanto, devem ser incentivadas e adaptadas à realidade dos pacientes e serviços de saúde., Universidade Federal de São Paulo (UNIFESP) Departamento de PsiquiatriaUNIFESP Disciplina de Endocrinologia Departamento de MedicinaUNIFESP, Depto. de PsiquiatriaUNIFESP, Disciplina de Endocrinologia Depto. de MedicinaSciEL