Tourism in Azores Islands: Persistence in the Monthly Arrivals

This study analyses the persistence in the international monthly arrivals to the Azores Islands using a model based on fractional integration and seasonal autoregressions. The estimated fractional differencing parameter gives an indication of the long run evolution of the series. We use both aggregate data and disaggregate monthly data by location of origin and island destination. The results show that the aggregate series corresponding to the total number of arrivals is a nonstationary I(d) process with d above 1, and the most persistent ones are those travelling to Säo Miguel, especially from Holland, Finland, Norway, Germany, Denmark and the UK.Monthly arrivals; Seasonal fractional integration; Persistence; Azores Islands.

Atazanavir-Based Therapy Is Associated with Higher Hepatitis C Viral Load in HIV Type 1-Infected Subjects with Untreated Hepatitis C

Comunicación cortaWe assessed the relationship between atazanavir (ATV)-based antiretroviral treatment (ART) and plasma hepatitis C virus (HCV) viral load in a population of HIV/HCV-coinfected patients. HIV/HCV-coinfected patients who received ART based on a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI) were included. Patients were stratified by ART drug [ATV/rtv, lopinavir (LPV/rtv), efavirenz (EFV), nevirapine (NVP), and other PIs], HCV genotype (1/4 and 2/3), and IL28B genotype (CC and non-CC). The Kruskal-Wallis test and chi-squared test were used to compare continuous and categorical variables, respectively. Multivariate analysis consisted of a stepwise linear regression analysis. Six hundred and forty-nine HIV/HCV-coinfected patients were included. HCV genotype 1/4 patients who received ATV had higher HCV RNA levels [6.57 (5.9-6.8) log IU/ml] than those who received LPV [6.1 (5.5-6.5) log IU/ml], EFV [6.1 (5.6-6.4) log IU/ml], NVP [5.8 (5.5-5.9) log IU/ml], or other PIs [6.1 (5.7-6.4) log IU/ml] (p=0.014). This association held for the IL28B genotype (CC versus non-CC). The association was not found in patients carrying HCV genotypes 2/3. The linear regression model identified the IL28B genotype and ATV use as independent factors associated with HCV RNA levels. ATV-based therapy may be associated with a higher HCV RNA viral load in HIV/HCV-coinfected patients

Positioning of the cross-stitch on the modified Kessler core tendon suture

[EN] Cryopreserved human tendons were sutured with different variations of a modified Kessler-type grasping suture in a series of different designs in order to assess the influence of the distance between the cross-stitch on the core suture (5 and 10 mm from the cut tendon edge) on the peripheral suture. An original mathematical model was employed to explain the mechanical behavior (strength, deformation, and distribution of load) of the different suture designs. The effect of the peripheral epitendinous suture, combined with the distance of the core suture, was evaluated. The variation of core suture distance had no relevant consequences on the overall resilience of the design. However, increasing the distance between the cross-stitches of the core suture reduces the deformation that is absorbed not only by the core suture itself but also by the peripheral suture. Adding a peripheral epitendinous suture to a 10-mm design almost doubles the breaking load in absolute values. The mathematical model predicts that the peripheral suture will support a greater load when the distance of the core suture cross-stitches is increased. The evidence level is II.Gil Santos, L.; Monleón Pradas, M.; Gomar-Sancho, F.; Más Estellés, J. (2018). Positioning of the cross-stitch on the modified Kessler core tendon suture. Journal of the Mechanical Behavior of Biomedical Materials. 80:27-32. https://doi.org/10.1016/j.jmbbm.2018.01.018S27328

New bioreactor for mechanical stimulation of cultured tendon-like constructs: design and validation.

[EN] Objective: Although several different types of bioreactors are currently available with mechanical stimulation of constructs or prostheses for tendon regeneration, they are in many cases expensive and difficult to operate. This paper proposes a simple bioreactor to mechanically stimulate up to three constructs for tendon and ligament repair, composed of a stainless-steel frame and an electric motor. Methods: The deformation is produced by a cam wheel, whose eccentricity defines the maximum deformation. The test samples, braids of PLA seeded in surface with mouse fibroblasts, are immersed in the culture medium during mechanical stimulation. Results: Its advantages over existing similar bioreactor designs include: easy renewal of the culture medium and an external electric motor to avoid heating and contamination issues. After 14 days of stretching, the culture samples showed enhanced cellular proliferation and cell fiber alignment in addition to higher production of type I collagen. The cells initially seeded on the braid surface migrated to the inside of the braid. Conclusion: Although the results obtained have a poor statistical basis, they do suggest that the bioreactor could be usefully applied to stimulate constructs for tendon and ligament repair. Anyway, further experiments should be conducted in the future.This paper was funded through a researching contract with the Researching Association of the Textil Industries (AITEX, Alcoi, Spain).Araque Monrós, MC.; Gil-Santos, L.; Monleón Pradas, M.; Más Estellés, J. (2020). New bioreactor for mechanical stimulation of cultured tendon-like constructs: design and validation. Expert Review of Medical Devices. 17(10):1115-1121. https://doi.org/10.1080/17434440.2020.1825072111511211710Murray, G. A. W., & Semple, J. C. (1979). A review of work on artificial tendons. Journal of Biomedical Engineering, 1(3), 177-184. doi:10.1016/0141-5425(79)90040-2Ricci, J. L., Gona, A. G., Alexander, H., & Parsons, J. R. (1984). Morphological characteristics of tendon cells cultured on synthetic fibers. Journal of Biomedical Materials Research, 18(9), 1073-1087. doi:10.1002/jbm.820180910HUNTER, J. M., & SALISBURY, R. E. (1971). Flexor-Tendon Reconstruction in Severely Damaged Hands. The Journal of Bone & Joint Surgery, 53(5), 829-858. doi:10.2106/00004623-197153050-00001Hunter, J. M., Singer, D. I., Jaeger, S. H., & Mackin, E. J. (1988). Active tendon implants in flexor tendon reconstruction. The Journal of Hand Surgery, 13(6), 849-859. doi:10.1016/0363-5023(88)90259-6Walden, G., Liao, X., Donell, S., Raxworthy, M. J., Riley, G. P., & Saeed, A. (2017). A Clinical, Biological, and Biomaterials Perspective into Tendon Injuries and Regeneration. Tissue Engineering Part B: Reviews, 23(1), 44-58. doi:10.1089/ten.teb.2016.0181Araque Monrós C, Gil Santos L, Gironés Bernabé S, et al. Universitat Politècnica de València. Procedimiento de obtención de una prótesis biodegradable. Patent of invention nº P201130919. 2011.Freeman, J. W., Woods, M. D., & Laurencin, C. T. (2007). Tissue engineering of the anterior cruciate ligament using a braid–twist scaffold design. Journal of Biomechanics, 40(9), 2029-2036. doi:10.1016/j.jbiomech.2006.09.025Laurencin, C. T., & Freeman, J. W. (2005). Ligament tissue engineering: An evolutionary materials science approach. Biomaterials, 26(36), 7530-7536. doi:10.1016/j.biomaterials.2005.05.073Merolli, A., & Joyce, T. J. (Eds.). (2009). Biomaterials in Hand Surgery. doi:10.1007/978-88-470-1195-3Moreau, J. E., Bramono, D. S., Horan, R. L., Kaplan, D. L., & Altman, G. H. (2008). Sequential Biochemical and Mechanical Stimulation in the Development of Tissue-Engineered Ligaments. Tissue Engineering Part A, 14(7), 1161-1172. doi:10.1089/ten.tea.2007.0147Nirmalanandhan, V. S., Rao, M., Shearn, J. T., Juncosa-Melvin, N., Gooch, C., & Butler, D. L. (2008). Effect of scaffold material, construct length and mechanical stimulation on the in vitro stiffness of the engineered tendon construct. Journal of Biomechanics, 41(4), 822-828. doi:10.1016/j.jbiomech.2007.11.009Sumanasinghe, R. D., Osborne, J. A., & Loboa, E. G. (2008). Mesenchymal stem cell‐seeded collagen matrices for bone repair: Effects of cyclic tensile strain, cell density, and media conditions on matrix contraction in vitro. Journal of Biomedical Materials Research Part A, 88A(3), 778-786. doi:10.1002/jbm.a.31913Saber, S., Zhang, A. Y., Ki, S. H., Lindsey, D. P., Smith, R. L., Riboh, J., … Chang, J. (2010). Flexor Tendon Tissue Engineering: Bioreactor Cyclic Strain Increases Construct Strength. Tissue Engineering Part A, 16(6), 2085-2090. doi:10.1089/ten.tea.2010.0032Tohyama, H., & Yasuda, K. (2000). The effects of stress enhancement on the extracellular matrix and fibroblasts in the patellar tendon. Journal of Biomechanics, 33(5), 559-565. doi:10.1016/s0021-9290(99)00217-1Wang, T., Lin, Z., Day, R. E., Gardiner, B., Landao-Bassonga, E., Rubenson, J., … Zheng, M. H. (2013). Programmable mechanical stimulation influences tendon homeostasis in a bioreactor system. Biotechnology and Bioengineering, 110(5), 1495-1507. doi:10.1002/bit.24809Wang, T., Gardiner, B. S., Lin, Z., Rubenson, J., Kirk, T. B., Wang, A., … Zheng, M. H. (2013). Bioreactor Design for Tendon/Ligament Engineering. Tissue Engineering Part B: Reviews, 19(2), 133-146. doi:10.1089/ten.teb.2012.0295Abousleiman, R. I., Reyes, Y., McFetridge, P., & Sikavitsas, V. (2009). Tendon Tissue Engineering Using Cell-Seeded Umbilical Veins Cultured in a Mechanical Stimulator. Tissue Engineering Part A, 15(4), 787-795. doi:10.1089/ten.tea.2008.0102Masuda, T., Takahashi, I., Anada, T., Arai, F., Fukuda, T., Takano-Yamamoto, T., & Suzuki, O. (2008). Development of a cell culture system loading cyclic mechanical strain to chondrogenic cells. Journal of Biotechnology, 133(2), 231-238. doi:10.1016/j.jbiotec.2007.08.007Xu, Z. C., Zhang, W. J., Li, H., Cui, L., Cen, L., Zhou, G. D., … Cao, Y. (2008). Engineering of an elastic large muscular vessel wall with pulsatile stimulation in bioreactor. Biomaterials, 29(10), 1464-1472. doi:10.1016/j.biomaterials.2007.11.037TC-3F Ebers Medical Technology, S.L. [cited 2019 May 15]. Available from: https://ebersmedical.com/tissue-engineering/bioreactors/load-culture/tc-3f-bioreactor.CellScale biomaterials testing. [cited 2020 Mar 16]. Available from: https://cellscale.com/https://www.cellscale.com/products/mct6Lim, W. L., Liau, L. L., Ng, M. H., Chowdhury, S. R., & Law, J. X. (2019). Current Progress in Tendon and Ligament Tissue Engineering. Tissue Engineering and Regenerative Medicine, 16(6), 549-571. doi:10.1007/s13770-019-00196-wOftadeh, R., Connizzo, B. K., Nia, H. T., Ortiz, C., & Grodzinsky, A. J. (2018). Biological connective tissues exhibit viscoelastic and poroelastic behavior at different frequency regimes: Application to tendon and skin biophysics. Acta Biomaterialia, 70, 249-259. doi:10.1016/j.actbio.2018.01.041Vashaghian, M., Diedrich, C. M., Zandieh-Doulabi, B., Werner, A., Smit, T. H., & Roovers, J. P. (2019). Gentle cyclic straining of human fibroblasts on electrospun scaffolds enhances their regenerative potential. Acta Biomaterialia, 84, 159-168. doi:10.1016/j.actbio.2018.11.034Helms, F., Lau, S., Klingenberg, M., Aper, T., Haverich, A., Wilhelmi, M., & Böer, U. (2019). Complete Myogenic Differentiation of Adipogenic Stem Cells Requires Both Biochemical and Mechanical Stimulation. Annals of Biomedical Engineering, 48(3), 913-926. doi:10.1007/s10439-019-02234-zAraque-Monrós, M. C., García-Cruz, D. M., Escobar-Ivirico, J. L., Gil-Santos, L., Monleón-Pradas, M., & Más-Estellés, J. (2019). Regenerative and Resorbable PLA/HA Hybrid Construct for Tendon/Ligament Tissue Engineering. Annals of Biomedical Engineering, 48(2), 757-767. doi:10.1007/s10439-019-02403-0Yang, G., Crawford, R. C., & Wang, J. H.-C. (2004). Proliferation and collagen production of human patellar tendon fibroblasts in response to cyclic uniaxial stretching in serum-free conditions. Journal of Biomechanics, 37(10), 1543-1550. doi:10.1016/j.jbiomech.2004.01.005Surrao, D. C., Fan, J. C. Y., Waldman, S. D., & Amsden, B. G. (2012). A crimp-like microarchitecture improves tissue production in fibrous ligament scaffolds in response to mechanical stimuli. Acta Biomaterialia, 8(10), 3704-3713. doi:10.1016/j.actbio.2012.06.016Wang, J. H.-C. (2006). Mechanobiology of tendon. Journal of Biomechanics, 39(9), 1563-1582. doi:10.1016/j.jbiomech.2005.05.011Zhang, C., Zhu, J., Zhou, Y., Thampatty, B. P., & Wang, J. H.-C. (2019). Tendon Stem/Progenitor Cells and Their Interactions with Extracellular Matrix and Mechanical Loading. Stem Cells International, 2019, 1-10. doi:10.1155/2019/367464

A study of reproducibility of kinesiology tape applications: review, reliability and validity

Background: Literature addressing the mechanical properties of kinesiology tape is quite scarce. There are no studies which focus on the mechanical characteristics of kinesiology tape, its mechanical properties, nor its adherence following the ISO international standard test methods for tape elongation. Methods: This study quantified the mechanical characteristics of 380 samples of kinesiology tape from 19 different brands and in 4 different colors using a dynamometer. Mechanical testing was controlled by UNE EN ISO 13934-1. Results: Significant differences were found between tape brands in terms of grammage, maximum force tenacity, work, pre-elongation and percentage elongation (P < .001). Regarding kinesiology tape color, statistically significant differences were found between tape brands in terms of grammage, maximum force and tenacity (P < .001), work and pre-elongation (P < .05). When adherence was studied, statistically significant differences were found between tape brands in terms of maximum force and work (P < .001). Conclusions: The different kinesiology tapes presented different behaviors with regard to rupture and removal when applied to skin in dry state, wet state and after being submerged in artificial acidic sweat solution. Therefore, different kinesiology tape brands will produce different levels of strain even though the same elongation is used. Depending on the characteristics (body dimensions) and properties (skin elongation) of each subject in the sample, bandages with different elongations must be applied to achieve the same strain in all of the tapes and therefore produce the same effect. The absence of these data at this time limits the reliability of previous clinical studies, makes comparing their findings impossible and presents new challenges for research in this field

Cuticle Structure in Relation to Chemical Composition: Re-assessing the Prevailing Model

The surface of most aerial plant organs is covered with a cuticle that provides protection against multiple stress factors including dehydration. Interest on the nature of this external layer dates back to the beginning of the 19th century and since then, several studies facilitated a better understanding of cuticular chemical composition and structure. The prevailing undertanding of the cuticle as a lipidic, hydrophobic layer which is independent from the epidermal cell wall underneath stems from the concept developed by Brongniart and von Mohl during the first half of the 19th century. Such early investigations on plant cuticles attempted to link chemical composition and structure with the existing technologies, and have not been directly challenged for decades. Beginning with a historical overview about the development of cuticular studies, this review is aimed at critically assessing the information available on cuticle chemical composition and structure, considering studies performed with cuticles and isolated cuticular chemical components. The concept of the cuticle as a lipid layer independent from the cell wall is subsequently challenged, based on the existing literature, and on new findings pointing toward the cell wall nature of this layer, also providing examples of different leaf cuticle structures. Finally, the need for a re-assessment of the chemical and structural nature of the plant cuticle is highlighted, considering its cell wall nature and variability among organs, species, developmental stages, and biotic and abiotic factors during plant growth

Tenocytic induction of stem cells from bone marrow on polymeric microparticles for a new concept of tendon regenerative prosthesis

A new concept of a regenerative and resorbable prosthesis for tendon and ligament has been developed. The prosthesis consists of a poly-lactide acid (PLA) braid, microparticles in its interior serving as cell carriers, and a surface non-adherent coating. The aim of this study is to select the most suitable support, microparticles of poly-L-lactide (PLLA) or chitosan (CHT), for carrying the cells inside the hollow PLA braid. Microparticles of these polymers were manufactured and blended with microparticles of hyaluronic acid (HA). All of them were physically and biologically characterized. Cell viability, morphology and proliferation of human mesenchymal stem cells (hMSCs) on the different supports were evaluated and compared, revealing that PLLA microparticles were the most appropriate to be used as injectable cell-carrier. Finally, hMSCs differentiation into tenocytes was carried out on PLLA microparticles using bone morphogenetic protein-12 (BMP-12) and a mixture of transforming growth factor-β1 (TGF-β1) and insulin-like growth factor1 (IGF-1). Cell morphology was analyzed by electronic and confocal microscopy and cell differentiation was evaluated immunocytochemically for the presence of type I collagen and tenomodulin. Besides, the tenomodulin and decorin gene expression were measured by real-time quantitative polymerase chain reaction (RT-qPCR). Our results showed that the medium supplemented with BMP-12 promoted higher expression of tenomodulin and decorin, both of them differentiation markers of tenocytes. This approach might be relevant to future tissue engineering applications in reconstruction of tendon and ligament defects. Authors acknowledge support of the Spanish Instituto de Salud Carlos III through CIBERbbn and the Spanish Network on Cell Therapy (Red TerCel) initiatives.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Loss of function of Arabidopsis microRNA-machinery genes impairs fertility, and has effects on homologous recombination and meiotic chromatin dynamics

MicroRNAs (miRNAs) are ~22-nt single-stranded noncoding RNAs with regulatory roles in a wide range of cellular functions by repressing eukaryotic gene expression at a post-transcriptional level. Here, we analyzed the effects on meiosis and fertility of hypomorphic or null alleles of the HYL1, HEN1, DCL1, HST and AGO1 genes, which encode miRNA-machinery components in Arabidopsis. Reduced pollen and megaspore mother cell number and fertility were shown by the mutants analyzed. These mutants also exhibited a relaxed chromatin conformation in male meiocytes at the first meiotic division, and increased chiasma frequency, which is likely to be due to increased levels of mRNAs from key genes involved in homologous recombination. The hen1-13 mutant was found to be hypersensitive to gamma irradiation, which mainly causes double-strand breaks susceptible to be repaired by homologous recombination. Our findings uncover a role for miRNA-machinery components in Arabidopsis meiosis, as well as in the repression of key genes required for homologous recombination. These genes seem to be indirect miRNA targets

Study of degradation of a new PLA braided biomnaterial in buffer phosphate saline, basic and acid media, intended for the regeneration of tendons and ligaments

NOTICE: this is the author’s version of a work that was accepted for publication in Polymer Degradation and Stability. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Polymer Degradation and Stability, [Volume 98, Issue 9, September 2013, Pages 1563–1570] DOI 10.1016/j.polymdegradstab.2013.06.031The purpose of this study was to evaluate the effects of hydrolytic degradation on the properties of a PLA hollow braid designed as a new concept of biodegradable prosthesis for the regeneration of tendons and ligaments. The main function of the braided material is to bear mechanical loads while it is being replaced by the newly-generated tissue. The kinetics of braided material degradation is thus an important factor in determining the success of the product. In order to study this mechanism, PLA braid was subjected to a 12-month degradation process at 37 °C in PBS at pH 7.4 (to simulate the human physiological medium) and to accelerated degradation for one month in pH 12 and pH 3 solutions. Degradation of the braid subjected to hydrolysis was evaluated by weight loss, molecular weight distribution, mechanical properties, and calorimetric and morphologic analyses. The weight loss in a basic medium reached 21%, versus no significant change in the other media. Average molecular weight was reduced by approximately 50% in the three media, with loss of mechanical properties in all cases. The morphological changes were more evident in the PLA degraded in the basic medium. The crystallinity of the material increased at the first stages of degradation, regardless of the medium used.This work has been carried out thanks to the financial support of AITEX (Valencia, Spain).Araque Monrós, MC.; Vidaurre, A.; Gil Santos, L.; Gironés Bernabé, S.; Monleón Pradas, M.; Más Estellés, J. (2013). Study of degradation of a new PLA braided biomnaterial in buffer phosphate saline, basic and acid media, intended for the regeneration of tendons and ligaments. Polymer Degradation and Stability. 98(9):1563-1570. doi:10.1016/j.polymdegradstab.2013.06.031S1563157098

Mycoredoxins Are Required for Redox Homeostasis and Intracellular Survival in the Actinobacterial Pathogen Rhodococcus equi

[EN] Rhodococcus equi is a facultative intracellular pathogen that can survive within macrophages of a wide variety of hosts, including immunosuppressed humans. Current antibiotherapy is often ineffective, and novel therapeutic strategies are urgently needed to tackle infections caused by this pathogen. In this study, we identified three mycoredoxin-encoding genes (mrx) in the genome of R. equi, and we investigated their role in virulence. Importantly, the intracellular survival of a triple mrx-null mutant (Δmrx1Δmrx2Δmrx3) in murine macrophages was fully impaired. However, each mycoredoxin alone could restore the intracellular proliferation rate of R. equi Δmrx1Δmrx2Δmrx3 to wild type levels, suggesting that these proteins could have overlapping functions during host cell infection. Experiments with the reduction-oxidation sensitive green fluorescent protein 2 (roGFP2) biosensor confirmed that R. equi was exposed to redox stress during phagocytosis, and mycoredoxins were involved in preserving the redox homeostasis of the pathogen. Thus, we studied the importance of each mycoredoxin for the resistance of R. equi to different oxidative stressors. Interestingly, all mrx genes did have overlapping roles in the resistance to sodium hypochlorite. In contrast, only mrx1 was essential for the survival against high concentrations of nitric oxide, while mrx3 was not required for the resistance to hydrogen peroxide. Our results suggest that all mycoredoxins have important roles in redox homeostasis, contributing to the pathogenesis of R. equi and, therefore, these proteins may be considered interesting targets for the development of new anti-infectivesS