Long-term follow-up on the effects of sodium oxybate on daytime sleepiness and sleep architecture in patients with narcolepsy type 1. / Efecto a largo plazo del oxibato de sodio en la somnolencia diurna y en la estructura del sueño en pacientes con narcolepsia de tipo 1.

INTRODUCTION: Sodium oxybate (SXB) was administered for the first time in 1979 in 16 patients with narcolepsy with cataplexy (NT1) that improved up to 20 months. AIMS: To evaluate the effect of SXB on daytime sleepiness and sleep architecture by video-polysomnography in a sample of 23 NT1 adult patients (13 men, 10 females) treated up to three years. Additional goal was to study the presence of sleep comorbidities. PATIENTS AND METHODS: NT1 patients were diagnosed according to International Classification of Sleep Disorders, third edition. We conducted a longitudinal observational study and a video-polysomnography comparing the sleep parameters of patients treated with an initial nocturnal dose of 4.5 g of SXB after six months (FU-1), one year (FU-2) and three years (FU-3) of uninterrupted treatment. Video-polysomnography parameters were analyzed including apnea-hypopnea and periodic leg movements indexes. RESULTS: Patients were HLA-DQB1*06:02 positive except a familial case. Thirteen patients (56%) discontinued SXB treatment over the three-year of the study. The two-nightly doses has been one of the reason for discontinuing treatment as well as insufficient compliance, mild or severe side effects, comorbidities and pregnancy. We found significant differences at FU-2 in sleep structure with an increased in stage N2 (p < 0.03) and a higher periodic leg movements index (p < 0.01). At FU-3 we found significant differences in sleep structure with an increase in stage N1 (p = 0.03) and in comorbidities (periodic leg movements and apnea-hypopnea indexes). There was not significant change on daytime sleepiness during the study. CONCLUSIONS: SXB was administered in low-medium doses. Two-nightly doses and sleep fragmentation linked to sleep comorbidities at long-term lead to drug withdrawal.

TITLE: Efecto a largo plazo del oxibato de sodio en la somnolencia diurna y en la estructura del sueño en pacientes con narcolepsia de tipo 1.Introducción. El oxibato de sodio (SXB) se utilizó en 1979 en 16 enfermos con narcolepsia-cataplejía (NT1) que mejoraron tras 20 meses de tratamiento. Objetivos. Evaluar el efecto del SXB en la somnolencia diurna y en la estructura del sueño mediante videopolisomnografía en una muestra de 23 enfermos de NT1 (13 hombres y 10 mujeres) tratados durante tres años. Investigamos adicionalmente la presencia de comorbilidad. Pacientes y métodos. Diagnosticamos a los enfermos de acuerdo con la Clasificación Internacional de Trastornos del Sueño, tercera edición. Realizamos un estudio longitudinal, observacional y de videopolisomnografía, comparando los parámetros de sueño y los índices de apnea-hipopnea y de movimientos periódicos de las piernas de los enfermos, tratados con una dosis nocturna inicial de 4,5 g de SXB al cabo de seis meses (C-1), un año (C-2) y tres años (C-3) de tratamiento ininterrumpido. Resultados. Todos los enfermos eran HLA-DQB1*06:02 positivos, excepto un caso familiar. Trece enfermos (56%) interrumpieron el tratamiento debido a las dos tomas nocturnas, así como a la presencia de efectos secundarios, comorbilidad y embarazo. Encontramos diferencias significativas en C-2 en la estructura del sueño con aumento del estadio N2 (p < 0,03) y del índice de movimientos periódicos de las piernas (p < 0,01). En el control C-3 encontramos diferencias significativas en la estructura del sueño con aumento del estadio N1 (p = 0,03), y de los índices de movimientos periódicos de las piernas y de apnea-hipopnea. Conclusiones. El SXB se administró en dos dosis nocturnas, lo que, unido a la fragmentación del sueño y a la aparición de comorbilidades, condujo a la interrupción del tratamiento a largo plazo.

Efecto a largo plazo del oxibato de sodio en la somnolencia diurna y en la estructura del sueño en pacientes con narcolepsia de tipo 1 / Long-term follow-up on the effects of sodium oxybate on daytime sleepiness and sleep architecture in patients with narcolepsy type 1

Introducción: El oxibato de sodio (SXB) se utilizó en 1979 en 16 enfermos con narcolepsia-cataplejía (NT1) que mejoraron tras 20 meses de tratamiento. Objetivos: Evaluar el efecto del SXB en la somnolencia diurna y en la estructura del sueño mediante videopolisomnografía en una muestra de 23 enfermos de NT1 (13 hombres y 10 mujeres) tratados durante tres años. Investigamos adicionalmente la presencia de comorbilidad. Pacientes y métodos: Diagnosticamos a los enfermos de acuerdo con la Clasificación Internacional de Trastornos del Sueño, tercera edición. Realizamos un estudio longitudinal, observacional y de videopolisomnografía, comparando los parámetros de sueño y los índices de apnea-hipopnea y de movimientos periódicos de las piernas de los enfermos, tratados con una dosis nocturna inicial de 4,5 g de SXB al cabo de seis meses (C-1), un año (C-2) y tres años (C-3) de tratamiento ininterrumpido.Resultados: Todos los enfermos eran HLA-DQB1*06:02 positivos, excepto un caso familiar. Trece enfermos (56%) interrumpieron el tratamiento debido a las dos tomas nocturnas, así como a la presencia de efectos secundarios, comorbilidad y embarazo. Encontramos diferencias significativas en C-2 en la estructura del sueño con aumento del estadio N2 (p < 0,03) y del índice de movimientos periódicos de las piernas (p < 0,01). En el control C-3 encontramos diferencias significativas en la estructura del sueño con aumento del estadio N1 (p = 0,03), y de los índices de movimientos periódicos de las piernas y de apnea-hipopnea. Conclusiones: El SXB se administró en dos dosis nocturnas, lo que, unido a la fragmentación del sueño y a la aparición de comorbilidades, condujo a la interrupción del tratamiento a largo plazo.(AU)

Introduction: Sodium oxybate (SXB) was administered for the first time in 1979 in 16 patients with narcolepsy with cataplexy (NT1) that improved up to 20 months. Aims: To evaluate the effect of SXB on daytime sleepiness and sleep architecture by video-polysomnography in a sample of 23 NT1 adult patients (13 men, 10 females) treated up to three years. Additional goal was to study the presence of sleep comorbidities. Patients and methods: NT1 patients were diagnosed according to International Classification of Sleep Disorders, third edition. We conducted a longitudinal observational study and a video-polysomnography comparing the sleep parameters of patients treated with an initial nocturnal dose of 4.5 g of SXB after six months (FU-1), one year (FU-2) and three years (FU-3) of uninterrupted treatment. Video-polysomnography parameters were analyzed including apnea-hypopnea and periodic leg movements indexes. Results: Patients were HLA-DQB1*06:02 positive except a familial case. Thirteen patients (56%) discontinued SXB treatment over the three-year of the study. The two-nightly doses has been one of the reason for discontinuing treatment as well as insufficient compliance, mild or severe side effects, comorbidities and pregnancy. We found significant differences at FU-2 in sleep structure with an increased in stage N2 (p < 0.03) and a higher periodic leg movements index (p < 0.01). At FU-3 we found significant differences in sleep structure with an increase in stage N1 (p = 0.03) and in comorbidities (periodic leg movements an apnea-hypopnea indexes). There was not significant change on daytime sleepiness during the study. Conclusions: SXB was administered in low-medium doses. Two-nightly doses and sleep fragmentation linked to sleep comorbidities at long-term lead to drug withdrawal.(AU)

Social Cognition in Autism and Schizophrenia Spectrum Disorders: The Same but Different?

Social cognition impairment is a core shared phenotype in both schizophrenia spectrum disorders (SSD) and autism spectrum disorders (ASD). This study compares social cognition performance through four different instruments in a sample of 147 individuals with ASD or SSD and in healthy controls. We found that both clinical groups perform similarly to each other and worse than healthy controls in all social cognition tasks. Only performance on the Movie for the Assessment of Social Cognition (MASC) test was independent of age and intelligence. Proportionately, individuals in the control group made significantly more overmentalization errors than both patients group did and made fewer undermentalization errors than patients with SSD did. AUC analyses showed that the MASC was the instrument that best discriminated between the clinical and control groups. Multivariate analysis showed negative symptom severity as a potential mediator of the association between social cognition deficit and poor global functioning.

Potentially inappropriate medications in older adults living with HIV.

OBJECTIVES: We assessed the prevalence of potentially inappropriate medication (PIM) among older (≥ 65 years) people living with HIV (O-PLWH) in the region of Madrid. METHODS: We analysed the dispensation registry of community and hospital pharmacies from the Madrid Regional Health Service (SERMAS) for the period between 1 January and 30 June 2017, looking specifically at PIMs according to the 2019 Beers criteria. Co-medications were classified according to the Anatomical Therapeutic Chemical (ATC) classification system. RESULTS: A total of 6 636 451 individuals received medications. Of these individuals, 22 945 received antiretrovirals (ARVs), and of these 1292 were O-PLWH. Overall, 1135 (87.8%) O-PLWH were taking at least one co-medication, and polypharmacy (at least five co-medications) was observed in 852 individuals (65.9%). A PIM was identified in 482 (37.3%) O-PLWH. Factors independently associated with PIM were polypharmacy [adjusted odds ratio (aOR) 7.08; 95% confidence interval (CI) 5.16-9.72] and female sex (aOR 1.75; 95% CI 1.30-2.35). The distribution of PIMs according to ATC drug class were nervous system drugs (n = 369; 28.6%), musculoskeletal system drugs (n = 140; 10.8%), gastrointestinal and metabolism drugs (n = 72; 5.6%), cardiovascular drugs (n = 61; 4.7%), respiratory system drugs (n = 13; 1.0%), antineoplastic and immunomodulating drugs (n = 10; 0.8%), and systemic anti-infectives (n = 2; 0.2%). Five drugs accounted for 84.8% of the 482O PLWH with PIMs: lorazepam (38.2%), ibuprofen (18.0%), diazepam (10.2%), metoclopramide (9.9%), and zolpidem (8.5%). CONCLUSIONS: Prescription of PIMs is highly prevalent in O-PLWH. Consistent with data in uninfected elderly people, the most frequently observed PIMs were benzodiazepines and nonsteroidal anti-inflammatory drugs . Targeted interventions are warranted to reduce inappropriate prescribing and polypharmacy in this vulnerable population.

Long term comparative evaluation of two types of absorbable meshes in partial abdominal wall defects: an experimental study in rabbits.

PURPOSE: Synthetic prosthetic materials that are fully absorbable seek to reduce the host foreign body reaction and promote host tissue regeneration. This preclinical trial was designed to analyse, in the long term, the behaviour of two prosthetic meshes, one synthetic and one composed of porcine collagen, in abdominal wall reconstruction. METHODS: Partial defects were created in the abdominal walls of New Zealand rabbits and repaired using a synthetic absorbable mesh (Phasix™) or a non-crosslinked collagen bioprosthesis (Protexa™). After 3, 6, 12 and 18 months, specimens were recovered for light microscopy and collagen expression analysis to examine new host tissue incorporation, macrophage response and biomechanical strength. RESULTS: Both materials showed good host tissue incorporation in line with their spatial structure. At 18 months postimplant, Protexa™ was highly reabsorbed while the biodegradation of Phasix™ was still incomplete. Collagenization of both materials was good. Macrophage counts steadily decreased over time in response to Phasix™, yet persisted in the collagen meshes. At 18 months, zones of loose tissue were observed at the implant site in the absence of herniation in both implant types. The stress-stretch behaviour of Phasix™ implants decreased over time, being more pronounced during the period of 12-18 months. Nevertheless, the abdominal wall repaired with Protexa™ became stiffer over time. CONCLUSION: Eighteen months after the implant both materials showed good compatibility but the biodegradation of Phasix™ and Protexa™ was incomplete. No signs of hernia were observed at 18 months with the stress-stretch relations being similar for both implants, regardless of the more compliant abdominal wall repaired with Protexa™ at short term.

Efficacy of antimicrobial agents delivered to hernia meshes using an adaptable thermo-responsive hyaluronic acid-based coating.

PURPOSE: Mesh-related infection is a critical outcome for patients with hernia defect stabilized with synthetic or biological meshes. Even though bioactive meshes loaded with antibiotics or antiseptics are slowly emerging in the market, the available solutions still lack versatility. Here, we proposed a polymer solution, i.e., hyaluronic acid-poly(N-isopropylacrylamide) (HApN), which forms a hydrogel to be used as coating for meshes only when it reaches body temperature. METHODS: We assessed how the gelation of HApN was influenced by the incorporation of different antibiotic and antiseptic formulations, and how this gel can be used to coat several mesh types. The impact of the coating on the elastic behavior of a macroporous mesh was tested under cyclic elongation condition. Finally, we selected two different coating formulations, one based on antibiotics (gentamicin + rifampicin) and one based on antiseptic (chlorhexidine) and tested in vitro their antimicrobial efficacies. RESULTS: HApN can be used as carrier for different antimicrobial agents, without having a strong influence on its gelation behavior. Porous or dense meshes can be coated with this polymer, even though the stability was not optimal on macroporous meshes such as Optilene when pores are too large. HApN loaded with drugs inhibited in vitro the growth of several Gram-positive and Gram-negative bacteria. CONCLUSION: Compared to the available technologies developed to endow meshes with antibacterial activity, the proposed HApN offers further versatility with potential to prevent mesh-related infection in hernioplasty.

Experimental study on the use of a chlorhexidine-loaded carboxymethylcellulose gel as antibacterial coating for hernia repair meshes.

PURPOSE: Biomaterials with an antimicrobial coating could avoid mesh-associated infection following hernia repair. This study assesses the use of a chlorhexidine-loaded carboxymethylcellulose gel in a model of Staphylococcus aureus mesh infection. METHODS: A 1% carboxymethylcellulose gel containing 0.05% chlorhexidine was prepared and tested in vitro and in vivo. The in vitro tests were antibacterial activity (S. aureus; agar diffusion test) and gel cytotoxicity compared to aqueous 0.05% chlorhexidine (fibroblasts; alamarBlue). For the in vivo study, partial abdominal wall defects (5 × 2 cm) were created in New Zealand white rabbits (n = 15) and inoculated with 0.25 mL of S. aureus (106 CFU/mL). Defects were repaired with a lightweight polypropylene mesh (Optilene) without coating (n = 3) or coated with a carboxymethylcellulose gel (n = 6) or chlorhexidine-loaded carboxymethylcellulose gel (n = 6). Fourteen days after surgery, bacterial adhesion to the implant (sonication, immunohistochemistry), host tissue incorporation (light microscopy) and macrophage reaction (immunohistochemistry) were examined. RESULTS: Carboxymethylcellulose significantly reduced the toxicity of chlorhexidine (p < 0.001) without limiting its antibacterial activity. While control and gel-coated implants were intensely contaminated, the chlorhexidine-gel-coated meshes showed a bacteria-free surface, and only one specimen showed infection signs. The macrophage reaction in this last group was reduced compared to the control (p < 0.05) and gel groups. CONCLUSIONS: When incorporated in the carboxymethylcellulose gel, chlorhexidine showed reduced toxicity yet maintained its bactericidal effect at the surgery site. Our findings suggest that this antibacterial gel-coated polypropylene meshes for hernia repair prevent bacterial adhesion to the mesh surface and have no detrimental effects on wound repair.

Biomechanical and histologic evaluation of two application forms of surgical glue for mesh fixation to the abdominal wall.

The use of an adhesive for mesh fixation in hernia repair reduces chronic pain and minimizes tissue damage in the patient. This study was designed to assess the adhesive properties of a medium-chain (n-butyl) cyanoacrylate glue applied as drops or as a spray in a biomechanical and histologic study. Both forms of glue application were compared to the use of simple-loose or continuous-running polypropylene sutures for mesh fixation. Eighteen adult New Zealand White rabbits were used. For mechanical tests in an ex vivo and in vivo study, patches of polypropylene mesh were fixed to an excised fragment of healthy abdominal tissue or used to repair a partial abdominal wall defect in the rabbit respectively. Depending on the fixation method used, four groups of 12 implants each or 10 implants each respectively for the ex vivo and in vivo studies were established: Glue-Drops, Glue-Spray, Suture-Simple and Suture-Continuous. Biomechanical resistance in the ex vivo implants was tested five minutes after mesh fixation. In vivo implants for biomechanical and histologic assessment were collected at 14 days postimplant. In the ex vivo study, the continuous suture implants showed the highest failure sample tension, while the implants fixed with glue showed lower failure sample tension values. However, the simple and continuous suture implants returned the highest stretch values. In the in vivo implants, failure sample tension values were similar among groups while the implants fixed with a continuous running suture had the higher stretch values, and the glue-fixed implants the lower stretch values. All meshes showed good tissue integration within the host tissue regardless of the fixation method used. Our histologic study revealed the generation of a denser, more mature repair tissue when the cyanoacrylate glue was applied as a spray rather than as drops.

In vitro assessment of an antibacterial quaternary ammonium-based polymer loaded with chlorhexidine for the coating of polypropylene prosthetic meshes.

PURPOSE: This study assesses the use of an absorbable polymer loaded with chlorhexidine (CHX) as an antibacterial coating for polypropylene (PP) meshes employed in hernia repair. METHODS: The polymer N,N-dimethyl-N-benzyl-N-(2-methacryloyloxyethyl) ammonium bromide was loaded with CHX (1 % w/w). Fragments (1 cm2) of Optilene® Mesh Elastic were coated either with the unloaded (POL) or CHX-loaded polymer (POL-CHX). Uncoated fragments (PP) served as controls. The release kinetics of the POL-CHX coating was monitored by HPLC. Sterile fragments were placed on agar plates previously contaminated with 106 CFU of Staphylococcus aureus (Sa) ATCC25923, Staphylococcus epidermidis (Se) ATCC12228, or Escherichia coli (Ec) ATCC25922 and incubated at 37 °C for 1/2/7 days. At each time point, inhibition halos were measured and bacterial adhesion to the meshes quantified by sonication and scanning electron microscopy. Coating cytotoxic effects were examined on cultured fibroblasts. RESULTS: The polymer coating gradually released CHX over 3 days. Inhibition halos were produced only around the POL-CHX-coated meshes and these were significantly smaller for Ec than Sa or Se (p < 0.01). While POL-CHX prevented bacterial adhesion to the mesh, the reduced bacterial yields over time were observed for the POL-coated versus control PP meshes (p < 0.001). By day 7, only Ec remained attached to the surface of control meshes. The POL coating was not cytotoxic, yet POL-CHX reduced the viability of cultured fibroblasts. CONCLUSIONS: When loaded with the antiseptic CHX, this quaternary ammonium-based polymer coating released its contents in a controlled manner indicating its potential prophylactic use to reduce the risk of infection following PP mesh implantation.

Prostheses size dependency of the mechanical response of the herniated human abdomen.

BACKGROUND: Hernia repairs still exhibit clinical complications, i.e. recurrence, discomfort and pain and mesh features are thought to be highly influent. The aim of this study is to evaluate the impact of the defect size and mesh type in an herniated abdominal wall using numerical models. METHODS: To do so, we have started from a FE model based on a real human abdomen geometry obtained by MRI, where we have provoked an incisional hernia of three different sizes. The surgical procedure was simulated by covering the hernia with a prostheses, and three surgical meshes with distinct mechanical properties were used for the hernia repair: an isotropic heavy-weight mesh (Surgipro @), a slightly anisotropic light-weight mesh (Optilene @) and a highly anisotropic medium-weight mesh (Infinit @). The mechanical response of the wall to a high intraabdominal pressure (corresponding to a coughing motion) was analyzed here. RESULTS: Our findings suggest that the anisotropy of the mesh becomes more relevant with the increase of the defect size. Additionally, according to our results Optilene @ showed the closest deformation to the natural distensibility of the abdomen while Infinit @ should be carefully used due to its excessive compliance.

Biomechanical and morphological study of a new elastic mesh (Ciberlastic) to repair abdominal wall defects.

The aim of this study was to conduct a preclinical evaluation of the behaviour of a new type of abdominal LW prosthesis (Ciberlastic), which was designed with a non-absorbable elastic polyurethane monofilament (Assuplus, Assut Europe, Italy) to allow greater adaptability to mechanical area requirements and higher bio-mimicking with the newly formed surrounding tissues. Our hypothesis was that an increase in the elasticity of the mesh filament could improve the benefits of LW prostheses. To verify our hypothesis, we compared the short- and long-term behaviour of Ciberlastic and Optilene(®) elastic commercial meshes by repairing the partially herniated abdomen in New Zealand White rabbits. The implanted meshes were mechanically and histologically assessed at 14 and 180 days post-implant. We mechanically characterized the partially herniated repaired muscle tissue and also determined mesh shrinkage at different post-implant times. This was followed by a histological study in which the tissue incorporation process was analysed over time. The new prosthesis designed by our group achieved good behaviour that was similar to that of Optilene(®), one of the most popular LW prostheses on the market, with the added advantage of its elastic property. The mechanical properties are significantly lower than those of the polypropylene Optilene(®) mesh, and the new elastic mesh meets the basic mechanical requirements for positioning in the abdominal wall, which was also demonstrated by the absence of recurrences after implantation in the experimental model. We found that the growth of a connective tissue rich in collagen over the hernial defect and the proper deposit of the collagen fibres in the regenerated tissue substantially modified the original properties of the mesh, thereby increasing its biomechanical strength and making the whole tissue/mesh stiffer.

Tissue integration and inflammatory reaction in full-thickness abdominal wall repair using an innovative composite mesh.

PURPOSE: When composite meshes are used in abdominal wall repair, seroma formation may persist and delay the desired integration leading to recurrence. This study compares tissue integration and inflammatory response in abdominal wall repair with composites with different absorbable synthetic barriers. METHODS: Full-thickness defects created in the abdominal wall of rabbits were repaired using polypropylene prosthesis or the following composites: Physiomesh™ (Phy); Ventralight™ (Vent) and "new composite mesh" (Ncm) not yet used clinically in humans. The collected seroma was evaluated for IFN-γ/IL-4 by ELISA. Tissue integration, anti- (IL-13/TGFß-1/IL-10/IL-4) and pro-inflammatory (TNF-α/IL-6/IFN-γ/VEGF) cytokine mRNA expression and TGFß/VEGF immunolabeling were evaluated at 14 and 90 days post-implant. RESULTS: Seroma was observed in 10 of 12 Phy/Vent and 4 of 12 Ncm. Wound fluid IFN-γ showed a time-dependent significant increase in Vent and tendency to decrease in Ncm, while all composites exhibited IL-4 upward trend. Prostheses were fully infiltrated by an organized connective tissue at end time although the area had shown prior seroma. A stable mesothelium was developed, except in adhesion areas. Vent/Phy displayed a significant increase in TNF-α/IFN-γ-mRNA over time. Significant decrease in VEGF mRNA was observed in Phy/Ncm, while a significant increase of TGFß-1 mRNA was evident in all composites over time. Ncm exhibited the highest TGFß protein expression area at short term and the greatest percentage of VEGF positive vessels at end time. CONCLUSION: Ncm could be an appropriate candidate to improve clinical outcome showing the lower development of seroma and optimal tissue integration with minimal pro-inflammatory cytokine response over time and consistent pro-wound healing cytokine expression.

Biaxial Mechanical Evaluation of Absorbable and Nonabsorbable Synthetic Surgical Meshes Used for Hernia Repair: Physiological Loads Modify Anisotropy Response.

The aim of this study was to obtain information about the mechanical properties of six meshes commonly used for hernia repair (Surgipro(®), Optilene(®), Infinit(®), DynaMesh(®), Ultrapro™ and TIGR(®)) by planar biaxial tests. Stress-stretch behavior and equibiaxial stiffness were evaluated, and the anisotropy was determined by testing. In particular, equibiaxial test (equal simultaneous loading in both directions) and biaxial test (half of the load in one direction following the Laplace law) were selected as a representation of physiologically relevant loads. The majority of the meshes displayed values in the range of 8 and 18 (N/mm) in each direction for equibiaxial stiffness (tangent modulus under equibiaxial load state in both directions), while a few achieved 28 and 50 (N/mm) (Infinit (®) and TIGR (®)). Only the Surgipro (®) mesh exhibited planar isotropy, with similar mechanical properties regardless of the direction of loading, and an anisotropy ratio of 1.18. Optilene (®), DynaMesh (®), Ultrapro (®) and TIGR (®) exhibited moderate anisotropy with ratios of 1.82, 1.84, 2.17 and 1.47, respectively. The Infinit (®) scaffold exhibited very high anisotropy with a ratio of 3.37. These trends in material anisotropic response changed during the physiological state in the human abdominal wall, i.e. T:0.5T test, which the meshes were loaded in one direction with half the load used in the other direction. The Surgipro (®) mesh increased its anisotropic response (Anis[Formula: see text] = 0.478) and the materials that demonstrated moderate and high anisotropic responses during multiaxial testing presented a quasi-isotropic response, especially the Infinit(®) mesh that decreased its anisotropic response from 3.369 to 1.292.

[Hospital biomedical research through the satisfaction of a Health Research Institute professionals]. / La investigación biomédica hospitalaria a través de la satisfacción de los profesionales de un Instituto de Investigación Sanitaria.

OBJECTIVE: A Health Research Institute is a powerful strategic commitment to promote biomedical research in hospitals. To assess user satisfaction is an essential quality requirement. The aim of this study is to evaluate the professional satisfaction in a Health Research Institute, a hospital biomedical research centre par excellence. METHODS: Observational study was conducted using a satisfaction questionnaire on Health Research Institute researchers. The explored dimensions were derived from the services offered by the Institute to researchers, and are structured around 4 axes of a five-year Strategic Plan. A descriptive and analytical study was performed depending on adjustment variables. Internal consistency was also calculated. RESULTS: The questionnaire was completed by 108 researchers (15% response). The most valued strategic aspect was the structuring Areas and Research Groups and political communication and dissemination. The overall rating was 7.25 out of 10. Suggestions for improvement refer to the need for help in recruitment, and research infrastructures. High internal consistency was found in the questionnaire (Cronbach alpha of 0.9). CONCLUSIONS: So far research policies in health and biomedical environment have not been sufficiently evaluated by professionals in our field. Systematic evaluations of satisfaction and expectations of key stakeholders is an essential tool for analysis, participation in continuous improvement and advancing excellence in health research.

Developing a new methodology to characterize in vivo the passive mechanical behavior of abdominal wall on an animal model.

The most common surgical repair of abdominal wall hernia goes through implanting a mesh that substitutes the abdominal muscle/fascia while it is healing. To reduce the risk of relapse or possible complications, this mesh needs to mimic the mechanical behavior of the muscle/fascia, which nowadays is not fully determined. The aim of this work is to develop a methodology to characterize in vivo the passive mechanical behavior of the abdominal wall. For that, New Zealand rabbits were subjected to pneumoperitoneum tests, taking the inner pressure from 0 mmHg to 12 mmHg, values similar to those used in human laparoscopies. Animals treated were divided into two groups: healthy and herniated animals with a surgical mesh (polypropylene Surgipro(TM) Covidien) previously implanted. All experiments were recorded by a stereo rig composed of two synchronized cameras. During the postprocessing of the images, several points over the abdominal surface were tracked and their coordinates extracted for different levels of internal pressure. Starting from that, a three dimensional model of the abdominal wall was reconstructed. Pressure-displacement curves, radii of curvature and strain fields were also analysed. During the experiments, animals tissue mostly deformed during the first levels of pressure, showing the noticeable hyperelastic passive behavior of abdominal muscles. Comparison between healthy and herniated specimen displayed a strong stiffening for herniated animals in the zone where the high density mesh was situated. Cameras were able to discern this change, so this method can be used to measure the possible effect of other meshes.

Bacterial adhesion to biological versus polymer prosthetic materials used in abdominal wall defect repair: do these meshes show any differences in vitro?

PURPOSE: Although clinical data suggest the similar performance of collagen-based biological prosthetic materials to some polymer materials, the use of a biomesh for abdominal hernia repair in a setting of infection is controversial. This in vitro study compares the adhesion of two Staphylococcus strains to polymer and biological meshes. METHODS: Sterile fragments of Optilene(®) (Op), Surgipro™ (Surg), Preclude(®) (Precl), TIGR(®) (TIGR), Bio-A(®) (BioA), Permacol™ (Perm), Surgisis(®) (SIS), and Tutomesh(®) (Tuto) were inoculated with 10(6) CFU of S. aureus (Sa) or S. epidermidis (Se) (n = 18 per strain per mesh). The first five meshes are polymer materials while Perm, SIS and Tuto are biomeshes. After 24/48 h of incubation, bacterial adhesion was examined by sonication, scanning electron microscopy (SEM) and light microscopy. RESULTS: Sa and Se showed a high affinity for the absorbable meshes (TIGR, BioA, Perm, SIS, Tuto) (p < 0.001). Precl yielded the lowest bacterial loads (p < 0.001). Surg, Precl and BioA underwent no substantial change over time, while Op (p < 0.001) and TIGR (p < 0.05) showed decreasing bacterial loads during incubation. The Sa-contaminated biomeshes behaved similarly while biomeshes inoculated with Se returned higher bacterial yields at 48 h, especially SIS (p < 0.001). SEM and light microscopy observations revealed planktonic bacteria and biofilms on the polymer surface and bacterial niches in biomesh pores. CONCLUSIONS: Within 48 h of contamination, the absorbable polymer and biological meshes exhibited high bacterial loads. Given their lower affinity for both bacterial strains, the conventional non-absorbable polymer materials could be better candidates for use in contaminated surgical fields.

Assessment of pain in critically ill children. Is cutaneous conductance a reliable tool?

PURPOSE: The purpose of this study is to assess the usefulness and accuracy of skin conductance (SC) as a tool to evaluate the level of sedation and pain in pediatric critical patients during painful procedures and to compare it with hemodynamic variables, clinical scales, and bispectral index (BIS). MATERIALS AND METHODS: This is a prospective observational study in 61 critical children undergoing invasive procedures. Hemodynamic data (heart rate and arterial blood pressure), clinical scales punctuation (Ramsay, COMFORT, and numeric rating pain scales), BIS, and the number of fluctuations of SC per second were collected before, during, and at the end of the procedure. RESULTS: The mean age of the patients was 42.9 (range, 1 month to 16 years). Seventy-two point six percent were postcardiac surgery patients. Nonmuscle-relaxed patients showed a moderate increase in heart rate (P = .02), numeric rating pain scales (P = .03), and Ramsay scale (P = .002). The number of fluctuations of SC per second increased significantly during the procedure (basal, 0.1; maneuver, 0.2; P = .015), but it never reached the level considered as pain or stress nor did it precede clinical scales or BIS. None of the variables studied showed a significant change during the procedure in muscle-relaxed patients. CONCLUSIONS: Skin conductance was not found to be more sensitive or faster than clinical scales for the assessment of pain or stress in critical children undergoing painful procedures. Skin conductance was not useful in muscle-relaxed children.