Synthesis and characterization of a bovine collagen: GAG scaffold with Uruguayan raw material for tissue engineering

Tissue engineering (TE) and regenerative medicine offer strategies to improve damaged tissues by using scaffolds and cells. The use of collagen-based biomaterials in the field of TE has been intensively growing over the past decades. Mesenchymal stromal cells (MSCs) and dental pulp stem cells (DPSCs) are promising cell candidates for development of clinical composites. In this study, we proposed the development of a bovine collagen type I: chondroitin-6-sulphate (CG) scaffold, obtained from Uruguayan raw material (certified as free bovine spongiform encephalopathy), with CG crosslinking enhancement using different gamma radiation doses. Structural, biomechanical and chemical characteristics of the scaffolds were assessed by Scanning Electron Microscopy, axial tensile tests, FT-IR and Raman Spectroscopy, respectively. Once we selected the most appropriate scaffold for future use as a TE product, we studied the behavior of MSCs and DPSCs cultured on the scaffold by cytotoxicity, proliferation and differentiation assays. Among the diverse porous scaffolds obtained, the one with the most adequate properties was the one exposed to 15 kGy of gamma radiation. This radiation dose contributed to the crosslinking of molecules, to the formation of new bonds and/or to the reorganization of the collagen fibers. The selected scaffold was non-cytotoxic for the tested cells and a suitable substrate for cell proliferation. Furthermore, the scaffold allowed MSCs differentiation to osteogenic, chondrogenic, and adipogenic lineages. Thus, this work shows a promising approach to the synthesis of a collagen-scaffold suitable for TE.

Processing methods for human amniotic membrane as scaffold for tissue engineering with mesenchymal stromal human cells

Tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function. The aims of this work were to compare chemically and physically processed human Amniotic Membranes (hAM) and analyze the cytocompatibility and proliferation rate (PR) of two primary human mesenchymal stromal cell lines, from different sources and donor conditions seeded over these scaffolds. The evaluated hAM processes were: cold shock to obtain a frozen amniotic membrane (FEAM) with remaining dead epithelial cells, denudation of hAM with trypsin for 20/10 min (DEAM20/10) or treatment with sodium dodecyl sulfate to decellularized hAM (DAM). All samples were sterilized with gamma radiation. The selection of the treated hAM to then generate composites was performed by scanning and transmission electron microscopy and characterization by X-ray diffraction, selecting DEAM10 and FEAM as scaffolds for cell seeding. Two sources of primary human stromal cells were used, both developed by our researchers, human Dental Pulp Stem Cells (hDPSC) from living donors and human Mesenchymal Stromal Cells (hMSC) from bone marrow isolated from brain dead donors. This last line of cells conveys a novel source of human cells that, to our knowledge, have not been tested as part of this type of construct. We developed four in vitro constructs without cytotoxicity signs and with different PR depending on the scaffolds and cells. hDPSC and hMSC grew over both FEAM and DEAM10, but DEAM10 allowed higher PR.

Distinct cellular roles for PDCD10 define a gut-brain axis in cerebral cavernous malformation

Cerebral cavernous malformation (CCM) is a genetic, cerebrovascular disease. Familial CCM is caused by genetic mutations in KRIT1, CCM2, or PDCD10 Disease onset is earlier and more severe in individuals with PDCD10 mutations. Recent studies have shown that lesions arise from excess mitogen-activated protein kinase kinase kinase 3 (MEKK3) signaling downstream of Toll-like receptor 4 (TLR4) stimulation by lipopolysaccharide derived from the gut microbiome. These findings suggest a gut-brain CCM disease axis but fail to define it or explain the poor prognosis of patients with PDCD10 mutations. Here, we demonstrate that the gut barrier is a primary determinant of CCM disease course, independent of microbiome configuration, that explains the increased severity of CCM disease associated with PDCD10 deficiency. Chemical disruption of the gut barrier with dextran sulfate sodium augments CCM formation in a mouse model, as does genetic loss of Pdcd10, but not Krit1, in gut epithelial cells. Loss of gut epithelial Pdcd10 results in disruption of the colonic mucosal barrier. Accordingly, loss of Mucin-2 or exposure to dietary emulsifiers that reduce the mucus barrier increases CCM burden analogous to loss of Pdcd10 in the gut epithelium. Last, we show that treatment with dexamethasone potently inhibits CCM formation in mice because of the combined effect of action at both brain endothelial cells and gut epithelial cells. These studies define a gut-brain disease axis in an experimental model of CCM in which a single gene is required for two critical components: gut epithelial function and brain endothelial signaling.

Rho Kinase Inhibition Blunts Lesion Development and Hemorrhage in Murine Models of Aggressive Pdcd10/Ccm3 Disease

Background and Purpose- Previously, murine models Krit1 ^+/- Msh2 ^{-/ -} and Ccm2 ^{+/ -} Trp53 ^{-/ -} showed a reduction or no effect on cerebral cavernous malformation (CCM) burden and favorable effects on lesional hemorrhage by the robust Rock (Rho-associated protein kinase) inhibitor fasudil and by simvastatin (a weak pleiotropic inhibitor of Rock). Herein, we concurrently investigated treatment of the more aggressive Pdcd10/Ccm3 model with fasudil, simvastatin, and higher dose atorvastatin to determined effectiveness of Rock inhibition. Methods- The murine models, Pdcd10 ^{+/ -} Trp53 ^{-/ -} and Pdcd10 ^{+/ -} Msh2 ^{-/ -}, were contemporaneously treated from weaning to 5 months of age with fasudil (100 mg/kg per day in drinking water, n=9), simvastatin (40 mg/kg per day in chow, n=11), atorvastatin (80 mg/kg per day in chow, n=10), or with placebo (n=16). We assessed CCM volume in mouse brains by microcomputed tomography. Lesion burden was calculated as lesion volume normalized to total brain volume. We analyzed chronic hemorrhage in CCM lesions by quantitative intensity of Perls staining in brain sections. Results- The Pdcd10 ^{+/ -} Trp53 ^{-/ -} /Msh2 ^{-/ -} models showed a mean CCM lesion burden per mouse reduction from 0.0091 in placebos to 0.0042 ( P=0.027) by fasudil, and to 0.0047 ( P=0.025) by atorvastatin treatment, but was not changed significantly by simvastatin. Hemorrhage intensity per brain was commensurately decreased by Rock inhibition. Conclusions- These results support the exploration of proof of concept effect of high-dose atorvastatin on human CCM disease for potential therapeutic testing.

Abstract TMP106: Intestinal Barrier Leakage Exacerbates Cerebral Cavernous Malformation Development in Murine Models

Introduction: A serendipitous discovery demonstrating a greater cerebral cavernous malformation (CCM) burden within a murine CCM disease model housed in an unclean vivarium than in a cleaner facility led to the observation of intestinal microbiome involvement in CCM development through lipopolysaccharide from gram negative bacteria. Hence we investigated the effect on CCM development in CCM models by genetic or chemical disruption of the intestinal barrier.

Hypothesis: Intestinal barrier disruption increases CCM burden in CCM murine models.

Methods: Acute iBECre; Ccm3 fl/fl mice were bred to be deficient ( Muc2 +/- , Muc2 -/- ) in the mucin 2 gene with CCM assessment at P21. CCM burden was assessed in the following 3 chronic models at 5 months of age. The murine model Ccm3 +/- housed in an unclean vivarium was treated with 1% p80 emulsifier starting at 21 days of age (n=22) or with placebo (n=16). Less CCM penetrant Ccm1 +/- mice housed in a clean facility were contemporaneously treated with 2% dextran sodium sulfate (DSS) starting at 21 days of age (n=22) or with placebo (n=17). More CCM penetrant Ccm1 +/- Msh2 -/- mice housed in an unclean vivarium were treated with 0.5% DSS starting at 2 months of age (n=11) or with placebo (n=6). We assessed CCM volume in brains by micro-computed tomography.

Results: Mean CCM volume in acute Ccm3 -/- models doubled from 1.8 mm 3 with no Muc2 loss (n=11) to 4.7 mm 3 with homozygotic Muc2 loss (p<0.001, n=10) with an increasing trend to 2.6 mm 3 with heterozygotic Muc2 loss (p=0.07, n=15). Mean CCM volume/brain volume (X 10 6 ) per mouse doubled from 10.7 in placebos to 24.4 (p=0.01) by emulsifier treatment in the Ccm3 +/- chronic model and significantly increased from 0.1 in placebos to 9.2 (p<0.001) by 2% DSS treatment in the Ccm1 +/- model, with an increasing trend from 11.0 in placebos to 15.2 (p=0.086) by 0.5% DSS treatment in the Ccm1 +/- Msh2 -/- model.

Conclusion: CCM lesion development was enhanced by intestinal barrier disruption in 4 CCM models, regardless of the method used (genetic or chemical), time of onset, murine genotype or vivarium cleanliness status. Ongoing investigations include an early onset studies in the unclean vivarium with the Ccm1 +/- Msh2 -/- mice receiving 0.5% DSS and the Ccm3 +/- mice receiving 2% DSS.

Analysis of the Quality of Clinical Trials Published in Spanish-Language Dermatology Journals Between 1997 and 2012

INTRODUCTION

The value of randomized clinical trials (RCTs) undertaken to identify an association between an intervention and an outcome is determined by their quality and scientific rigor.

OBJECTIVE

To assess the methodological quality of RCTs published in Spanish-language dermatology journals.

METHODS

By way of a systematic manual search, we identified all the RCTs in journals published in Spain and Latin America between 1997 (the year in which the CONSORT statement was published) and 2012. Risk of bias was evaluated for each RCT by assessing the following domains: randomization sequence generation, allocation concealment, blinding of patients and those assessing outcomes, missing data, and patient follow-up. Source of funding and conflict of interest statements, if any, were recorded for each study.

RESULTS

The search identified 70 RCTs published in 21 journals. Most of the RCTs had a high risk of bias, primarily because of gaps in the reporting of important methodological aspects. The source of funding was reported in only 15 studies.

DISCUSSION AND CONCLUSIONS

In spite of the considerable number of Spanish and Latin American journals, few RCTs have been published in the 15 years analyzed. Most of the RCTs published had serious defects in that the authors omitted methodological information essential to any evaluation of the quality of the trial and failed to report sources of funding or possible conflicts of interest for the authors involved. Authors of experimental clinical research in dermatology published in Spain and Latin America need to substantially improve both the design of their trials and the reporting of results.

Healthcare quality indicators of peripheral artery disease based on systematic reviews

OBJECTIVES

Peripheral artery disease (PAD) is a major health problem whose clinical management includes multiple options regarding risk factor control, diagnosis, and medical and surgical treatment. The aim was to generate indicators based on systematic reviews to evaluate the quality of healthcare provided in PAD.

METHODS

Electronic searches were run for systematic reviews in The Cochrane Library (Issue 6, 2011), MEDLINE, EMBASE, and other databases (up to June 2011). Conclusive systematic reviews of high methodological quality were selected to formulate clinical recommendations. Indicators were derived from clinical recommendations with moderate to very high strength of evidence as assessed by the GRADE system.

RESULTS

From 1,804 reviews initially identified, 29 conclusive and high-quality systematic reviews were selected and nine clinical recommendations were formulated with a moderate to very high strength of recommendation. Six indicators were finally generated: four on pharmacological interventions, antiplatelet agents, naftidrofuryl, cilostazol, and statins; and two lifestyle interventions, exercise and tobacco cessation. No indicators were derived for diagnostic tests or surgical techniques. Most indicators targeted patients with intermittent claudication.

CONCLUSIONS

These quality indicators will help clinicians to assess the appropriateness of healthcare provided in PAD. The development of evidence-based indicators in PAD is limited by the lack of methodological quality of the research in this disease, the inconclusiveness of the evidence on diagnostic and surgical techniques, and the dynamic nature of the vascular diseases field.

Temperature oscillations of magnetization observed in nanofluid ferromagnetic graphite

We report on unusual magnetic properties observed for nanofluid room temperature ferromagnetic graphite (with an average particle size of [Formula: see text] nm). More precisely, the measured magnetization exhibits a low temperature anomaly (attributed to the manifestation of finite size effects below the quantum temperature [Formula: see text]) as well as pronounced temperature oscillations above T = 50 K (attributed to manifestation of the hard-sphere type of pair correlations between ferromagnetic particles in the nanofluid).

[1,3-Bis(diphenylphosphino)propane]trichlorooxorhenium(V)

Trichlorooxo[1,3-propanediylbis(diphenylphosphine)-P,P ']rhenium(V), [ReCl(3)O(C(27)H(26)P(2))], crystallizes with four formula units per unit cell. The crystal structure consists of neutral complexes of [ReOCl(3)(dppp)] [dppp is 1,3-bis(diphenylphosphino)propane] packed by H.pi-ring interactions. The Re atom is octahedrally coordinated to the oxo anion, three Cl atoms and two P atoms from the dppp ligand. The six-membered ring formed by the bidentate dppp ligand and the rhenium metal centre is in a chair conformation. The title compound is an intermediate in the synthesis of bis(dppp) complexes of rhenium.

The effects of subanesthetic concentrations of sevoflurane and nitrous oxide, alone and in combination, on analgesia, mood, and psychomotor performance in healthy volunteers

We studied the effects of subanesthetic concentrations of sevoflurane and nitrous oxide, alone and in combination, on analgesia, mood, and psychomotor performance in human volunteers. We hypothesized that nitrous oxide and sevoflurane would produce both opposing and potentiating effects within the same study. Over the course of three sessions, 20 subjects inhaled 0%, 0.2%, or 0.4% end-tidal sevoflurane for a 68-min period that was divided into four 17-min blocks. During either the second or fourth block, 30% end-tidal nitrous oxide was added to the concentration of sevoflurane being inhaled. Pain response, psychomotor performance, and mood were evaluated during the second and fourth blocks. Pain ratings were higher when sevoflurane and nitrous oxide were administered together than when nitrous oxide was administered alone, which indicates that sevoflurane attenuated the analgesic effects of nitrous oxide. Sevoflurane increased self-reported ratings of sleepiness, and the addition of nitrous oxide decreased these ratings. Nitrous oxide potentiated psychomotor impairment that was induced by sevoflurane. The combination of sevoflurane and nitrous oxide produced both opposing and potentiating effects within the same study. The results suggest that nitrous oxide and sevoflurane may act through different neurochemical mechanisms on some end points, such as analgesia and sleepiness.

IMPLICATIONS

Healthy volunteers inhaled subanesthetic concentrations of sevoflurane and nitrous oxide. Sevoflurane made nitrous oxide less effective as an analgesic, and nitrous oxide made sevoflurane less effective as a sedative. The two drugs may work at cross purposes on different end points of anesthesia.

Two absorption furosemide prodrugs

The structures of two absorption furosemide prodrugs, hexanoyloxymethyl 4-chloro-N-furfuryl-5-sulfamoyl-anthranilate (C19H23CIN2O7S), (I), and benzoyloxymethyl 4-chloro-N-furfuryl-5-sulfamoylanthranilate (C20H17CIN2O7S), (II), are described in this paper and compared with furosemide and four other prodrugs. The molecular conformations of both compounds are similar to those of the other prodrugs; the packing and the crystal system are the primary differences. Compound (I) crystallizes in the trigonal space group R3 and compound (II) in the monoclinic space group P2(1)/n. The packing of both structures is stabilized by a three-dimensional hydrogen-bond network.