treatment decisions for acute achilles tendon ruptures

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Comfort and perceived air quality in refurbished social houses with mechanical ventialtion system: The impact of occupants behaviour

Abstract The ever-growing demand for a better indoor air quality in residential buildings is increasing the number of whole-house ventilation system installations in new constructions and renovation. In Italy, for residential sector, the national code does not prescribe the use of mechanical ventilation (MV) systems, so their installation is left to the choice of house owners. Two three-storey social housing apartment blocks in Northern Italy were studied. To reduce energy consumption, building envelopes as well as heating systems were refurbished. The thermal insulation was increased and the existing gas heater units were replaced with more efficient radiant ceiling systems. The refurbishment measures were the same for both constructions beside the MV system, which was installed in only one building. Indoor temperature and relative humidity were monitored for several apartments during the heating season. The occupants were surveyed to investigate their thermal comfort and perceived air quality. The occupants were interviewed to better understand their responses, and to know how they operate the heating system and the mechanical ventilation system (when present). Survey results show that there are no differences in terms of thermal comfort and perceived air quality between the occupants of the buildings with and without MV systems. The findings may be related to occupants' behaviour

Comfort and perceived air quality in refurbished social houses with mechanical ventilation system: The impact of occupants behaviour

The ever-growing demand for a better indoor air quality in residential buildings is increasing the number of whole-house ventilation system installations in new constructions and renovation. In Italy, for residential sector, the national code does not prescribe the use of mechanical ventilation (MV) systems, so their installation is left to the choice of house owners. Two three-storey social housing apartment blocks in Northern Italy were studied. To reduce energy consumption, building envelopes as well as heating systems were refurbished. The thermal insulation was increased and the existing gas heater units were replaced with more efficient radiant ceiling systems. The refurbishment measures were the same for both constructions beside the MV system, which was installed in only one building. Indoor temperature and relative humidity were monitored for several apartments during the heating season. The occupants were surveyed to investigate their thermal comfort and perceived air quality. The occupants were interviewed to better understand their responses, and to know how they operate the heating system and the mechanical ventilation system (when present). Survey results show that there are no differences in terms of thermal comfort and perceived air quality between the occupants of the buildings with and without MV systems. The findings may be related to occupants' behaviour. © 2015 The Authors

Response of human engineered cartilage based on articular or nasal chondrocytes to interleukin-1? and low oxygen

Previous studies showed that human nasal chondrocytes (HNC) exhibit higher proliferation and chondrogenic capacity as compared to human articular chondrocytes (HAC). To consider HNC as a relevant alternative cell source for the repair of articular cartilage defects it is necessary to test how these cells react when exposed to environmental factors typical of an injured joint. We thus aimed this study at investigating the responses of HNC and HAC to exposure to interleukin (IL)-1? and low oxygen. For this purpose HAC and HNC harvested from the same donors (N=5) were expanded in vitro and then cultured in pellets or collagen-based scaffolds at standard (19%) or low oxygen (5%) conditions. Resulting tissues were analyzed after a short (3 days) exposure to IL-1?, mimicking the initially inflammatory implantation site, or following a recovery time (1 or 2 weeks for pellets and scaffolds, respectively). After IL-1? treatment, constructs generated by both HAC and HNC displayed a transient loss of GAG (up to 21.8% and 36.8%, respectively) and, consistently, an increased production of metalloproteases (MMP)-1 and -13. Collagen type II and the cryptic fragment of aggrecan (DIPEN), both evaluated immunohistochemically, displayed a trend consistent with GAG and MMPs production. HNC-based constructs exhibited a more efficient recovery upon IL-1? withdrawal, resulting in a higher accumulation of GAG (up to 2.6-fold) compared to the corresponding HAC-based tissues. On the other hand, HAC displayed a positive response to low oxygen culture, while HNC were only slightly affected by oxygen percentage. Collectively, under the conditions tested mimicking the postsurgery articular environment, HNC retained a tissue-forming capacity, similar or even better than HAC. These results represent a step forward in validating HNC as a cell source for cartilage tissue engineering strategies

Meniscus matrix morphological composition: age-dependent evaluation in a swine model

Menisci are fibro-cartilaginous structures interposed between femoral condyle and tibial plateau, which have multiple functions in the stifle joint: act as shock absorbers, bear loaders and allow joint stability, congruity and lubrication (Sweigart et al., 2004; Proffen et al., 2012). It is well known that meniscal injuries lead to osteoarthritis and for these reasons, menisci are considered important target of investigation. Their important role in the knee wellness is only equalled by their deficiency in proper self-repairing.Nowadays, the gold standard technique is not just to remove the damaged meniscus, but to rebuild it or to replace it. For these reasons, studies are necessary to increase the knowledge about these small but essential structures (Streuli, 1999; Deponti et al., 2013). Composition and morphology are basic fundamental information for the development of engineered meniscal substitutes (Di Giancamillo et al., 2014). The analysis of the morphological, structural and biochemical changes, which occur during growth of the normal menisci, represent the goal of the present study. For this purpose, menisci from adult (7-month old), young (1-month old), and neonates (stillbirths) pigs were collected. Cellularity and glycosamiglycans (GAGs) deposition were evaluated by ELISA, while Collagen-1 and Collagen-2 were investigated by immunohistochemistry and Western blot analyses. Cellularity (P<0.01, all comparisons) and Collagen-1 (P<0.05, neonatal-young vs adult) decreased from neonatal to adult stage while GAGs (P<0.01 neonatal vs young-adult) and Collagen-2 (P<0.01 neonatal-young vs adult) showed the opposite trend. Immunohistochemistry revealed similar changes occurring during animal growth thus revealing that cellular phenotype, cellularity and protein expression, as well as fibers aggregation in the matrix, are dissimilar in the three ages analysed categories. These changes reflect the progressive menisci maturation and hyper-specialisation. We observed the correlation between biochemical and phenotype properties of swine menisci follow age-dependent changes during growth: starting with an immature cellular and fiber pattern to the mature organised and differentiated adult menisci.Acknowledgments: This work was funded by the “Finanziamento Piano Sviluppo Ateneo - Linea 2A

Meniscal femoral and tibial surfaces characterization in the swine model.

Menisci are wedge-like structures interposed, in the knee joint, between the femoral and the tibial articular heads (Kohn et al. 1995; Greis et al. 2002). Improving the articular surface, the cellular nutrition and the articular lubrication, they are essential structures for the prevention of gonarthrosis (Proctor et al.1989; Makris et al. 2011). This study is focused upon the relationship between the contact forces at the femoral and tibial surfaces and the corresponding structure of these meniscal surfaces. For this purpose, 20 adult (~9 months old) female pigs (Landrace x Large white, average weight 75–90 kg; n=80 meniscal samples) were obtained from a local slaughterhouse and dissected to isolate the menisci. Swine meniscal samples were evaluated from morphological (Safranin-O, Sirius Red and collagen type I and II) (Di Giancamillo et al. 2014), biochemical (DNA and glycosaminoglycans, or GAGs, contents) and biomechanical (compression and traction tests) points of view at the level of femoral and tibial meniscal surfaces. Results revealed a characterization of the meniscus which is biomechanical-dependent.  The femoral surface, morphologically characterized by the interposition of radial and oblique fibers and biomechanically by the femoral condyles compression, sliding and rolling forces, shows a higher compressive modulus (p<0.05) and a greater amount of cells and GAGs deposition (p<0.01 for each analysis). On the other hand, results from traction test revealed a higher tensile modulus (p<0.05) in the tibial surface, characterized by a circumferential arrangement of the fibers and a poorer GAGs deposition and cellular distribution (p<0.01). Results (summarized in the figure 1) from this work suggest that a biphasic “femoral-to-tibial” scaffold that mimic the different behavior and composition of the two meniscal surfaces could be useful in the light of meniscal replacement.

Results and complications of bilateral limb lengthening in achondroplasia: a retrospective analysis

BackgroundAchondroplasia is one of the main causes of disharmonic dwarfism. Patients with achondroplasia might have physical and psychological limitations due to their disproportionate stature. Surgical limb lengthening is the only practical option available to achieve a stature comparable to normal population range. The purpose of this study is to analyze results and complications of our lengthening protocol.MethodsA retrospective analysis was performed on 33 patients with achondroplasia (21 females and 12 males) undergoing simultaneous bilateral tibia or femur lengthening in four surgical stages from 2017 to 2021 (46 lengthening procedures, with a total of 56 tibias and 36 femurs). For each patient, patients’ characteristics and antero-posterior and lateral radiographs were obtained. The following parameters were analyzed: duration of lengthening with external fixator, amount of lengthening, complications or events that influenced outcomes and the healing index (HI).ResultsThe average tibial and femoral gain was 7.9 cm and 6.9 cm, respectively. The tibiae achieved better results than the femurs (p = 0.005). Nineteen complications were reported for 92 segments (20.7%), and the variables influencing complications were: step (p = 0.002) and fixation duration (p = 0.061).ConclusionsBilateral parallel lower limb lengthening in four surgical steps may be a viable technique in patients with achondroplasia