Do newborn lambs with black and white hair-coats in an equatorial semi-arid environment maintain homeothermy?

We assessed newborn lambs from two hair-coat sheep breeds, the black Santa Ines (n = 29) and white Dorper (n = 26), to determine how they behaviourally and physiologically respond to the prevailing thermal conditions in an equatorial semi-arid environment. Measurements of hair-coat surface temperature, rectal temperature and the lambs' exposure to sun were recorded across the first 24 h of life every hour, after the lambs had received colostrum. Lambs and ewes were kept in a lambing pen and could freely move between a shaded area or be exposed to sun. During the study period, the air temperature ranged between 20 ºC and 34 ºC. When exposed to sun, lambs and ewes could experience as much as 1200 W m-2 of solar irradiance. Santa Ines lambs exhibited higher (highest density interval at 95%, HDI) hair-coat surface temperatures than did Dorper lambs. Overall, both Santa Ines and Dorper lambs sustained homeothermy, with a mean rectal temperature ranging from 38.7 ºC to 39.1 ºC between night and daytime phase, and a mean amplitude of ~ 0.8 ºC. Nevertheless, from 10:00 to 15:00, some lambs were found to be moderately hyperthermic. Five Santa Ines and three Dorper lambs had rectal temperatures above 40 ºC, and one Santa Ines lamb, while exposed to sun, had a rectal temperature of 41.3 ºC. Over this time period, lambs were more likely to move to shade (HDI at 95%). From 00:00 to 06:00, despite the air temperature being lower than the hair-coat surface, favouring high rates of sensible heat loss to the environment, no lamb exhibited signs of hypothermia (rectal temperature < 37.5 ºC). In conclusion, haired newborn lambs coped well with high levels of radiant heat during the daytime and lower temperatures at night. However, providing access to shade during the daytime is important to improve the welfare of newborn lambs delivered in equatorial semi-arid regions.

Action mechanisms of probiotics on Candida spp. and candidiasis prevention: an update.

Due to the high incidence of fungal infections caused by Candida species and their increasing resistance to antimicrobial treatments, alternative therapies such as probiotics have been studied. It has been show that several species of the genus Lactobacillus have anti-Candida activity, probably by direct inhibition, through competition for adhesion sites or production of secondary metabolites, and by indirect inhibition, through stimulation of the immune system of their host. However, the mechanisms of inhibition of these probiotics on Candida species have not yet been fully elucidated since this effect is related to more than one inhibition pathway. In the literature, several in vitro and in vivo studies have been developed seeking to elucidate the probiotics mechanisms of action. These studies have been focused on C. albicans inhibition assays, including analysis of antimicrobial activity, adherence capacity, biofilms formation, filamentation and interference on virulence genes, as well as assays of experimental candidiasis in invertebrate and vertebrate models. In this context, the purpose of this review was to gather different studies focused on the action mechanism of probiotic strains on Candida sp. and to discuss their impact on the candidiasis prevention.

Enteric viruses' dissemination in a private reserve of natural heritage.

This study aimed to assess anthropogenic impact of surrounding population in the Private Reserve of Natural Heritage at Pantanal, the world's largest freshwater wetland ecosystem located in the centre of South America. Viral aetiological agents of acute gastroenteritis as rotavirus A (RVA), noroviruses, human adenoviruses, klassevirus and of hepatitis, as hepatitis A virus, were investigated in different aquatic matrices. Annual collection campaigns were carried out from 2009 to 2012, alternating dry and rainy seasons. Viral particles present in the samples were concentrated by the adsorption-elution method, with negatively charged membranes, and detected by qualitative and quantitative PCR. From a total of 43 samples at least one virus was detected in 65% (28) of them. Viruses were detected in all matrices with concentrations ranging from 2 × 102 to 8·3 × 104 genome copies per litre. A significant higher RVA frequency was observed in the dry season. Our data revealing dissemination of human enteric viruses in water matrices both inside and outside the reserve could be useful to trace faecal contamination in the environment and to minimize the risk of infection by exposure of susceptible individuals. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is part of a collaborative project designed to investigate the environmental and health conditions of the Private Reserve of Natural Heritage at Pantanal, the largest seasonally flooded wetland in the world. The project aimed to promote health and quality of human and wildlife extending technical-scientific knowledge about pathogens present in the region. By assessing the occurrence of human enteric viruses in different water matrices we demonstrated the anthropogenic impact of surrounding population and pointed out the potential risk of infection by exposure of susceptible individuals.

Carbon nanotube-amorphous silicon hybrid solar cell with improved conversion efficiency.

We report a hybrid solar cell based on single walled carbon nanotubes (SWNTs) interfaced with amorphous silicon (a-Si). The high quality carbon nanotube network was dry transferred onto intrinsic a-Si forming Schottky junction for metallic SWNT bundles and heterojunctions for semiconducting SWNT bundles. The nanotube chemical doping and a-Si surface treatment minimized the hysteresis effect in current-voltage characteristics allowing an increase in the conversion efficiency to 1.5% under an air mass 1.5 solar spectrum simulator. We demonstrated that the thin SWNT film is able to replace a simultaneously p-doped a-Si layer and transparent conductive electrode in conventional amorphous silicon thin film photovoltaics.

Towards a full integration of vertically aligned silicon nanowires in MEMS using silane as a precursor.

Silicon nanowires present outstanding properties for electronics, energy, and environmental monitoring applications. However, their integration into microelectromechanical systems (MEMS) is a major issue so far due to low compatibility with mainstream technology, which complicates patterning and controlled morphology. This work addresses the growth of 〈111〉 aligned silicon nanowire arrays fully integrated into standard MEMS processing by means of the chemical vapor deposition-vapor liquid solid method (CVD-VLS) using silane as a precursor. A reinterpretation of the galvanic displacement method is presented for selectively depositing gold nanoparticles of controlled size and shape. Moreover, a comprehensive analysis of the effects of synthesis temperature and pressure on the growth rate and alignment of nanowires is presented for the most common silicon precursor, i.e., silane. Compared with previously reported protocols, the redefined galvanic displacement together with a silane-based CVD-VLS growth methodology provides a more standard and low-temperature (<650 °C) synthesis scheme and a compatible route to reliably grow Si nanowires in MEMS for advanced applications.

A new sheep model with automatized analysis of biomaterial-induced bone tissue regeneration.

Presently, several bone graft substitutes are being developed or already available for clinical use. However, the limited number of clinical and in vivo trials for direct comparison between these products may complicate this choice. One of the main reasons for this scarcity it is the use of models that do not readily allow the direct comparison of multiple bone graft substitutes, due especially to the small number of implantation sites. Although sheep cancellous bone models are now well established for these purposes, the limited availability of cancellous bone makes it difficult to find multiple comparable sites within a same animal. These limitations can be overcome by the monocortical model here proposed as it consists in 5-6 holes (5 mm Ø), in the femoral diaphysis, with similar bone structure, overlying soft tissue and loading pattern for all defects. Associated to this model, it is also described a fast histomorphometric analysis method using a computer image segmentation test (Threshold method) to assess bone regeneration parameters. The information compiled through the experimental use of 45 sheep in several studies allowed determining that this ovine model has the potential to demonstrate differences in bone-forming performance between various scaffolds. Additionally, the described histomorphometric method is fast, accurate and reproducible.

Biological evaluation of alginate-based hydrogels, with antimicrobial features by Ce(III) incorporation, as vehicles for a bone substitute.

A novel hydrogel, based on an alginate/hyaluronate mixture and Ce(III) ions, with effective bioactive and antimicrobial ability was developed to be used as vehicle of a synthetic bone substitute producing an injectable substitute (IBS). Firstly, three different IBSs were prepared using three developed alginate-based hydrogels, the hydrogel Alg composed by alginate, the hydrogel Alg/Ch composed by an alginate/chitosan mixture and the hydrogel Alg/HA composed by an alginate/hyaluronate mixture. MG63 cells viability on the IBSs was evaluated, being observed a significantly higher cell viability on the Alg/HA_IBS at all time points, which indicates a better cell adaptation to the material, increasing their predisposition to produce extracellular matrix and thus allowing a better bone regeneration. Moreover, SEM analysis showed evident filopodia and a spreader shape of MG63 cells when seeded on Alg/HA_IBS. This way, based upon the in vitro results, the hydrogel Alg/HA was chosen to the in vivo study by subcutaneous implantation in an animal model, promoting a slight irritating tissue response and visible tissue repairing. The next step was to grant antimicrobial properties to the hydrogel that showed the best biological behavior by incorporation of Ce(III) ions into the Alg/HA, producing the hydrogel Alg/HA2. The antimicrobial activity of these hyaluronate-based hydrogels was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans. Results showed that Ce(III) ions can significantly enhance the hydrogel antimicrobial ability without compromising the osteoconductivity improvement promoted by the vehicle association to the synthetic bone substitute.

Template-assisted CoPd nanowire arrays: magnetic properties and FORC analysis.

Highly hexagonally ordered CoPd alloy nanowire arrays were synthesized through electrochemical deposition techniques into the nanopores of anodic alumina membranes used as templates. Two different electrolytes were used for this purpose, one with pH = 4.1 and the other with pH = 7. Under applying different electrodeposition parameters and by adjusting both, the current density and the electrolyte composition, it could be possible make to vary the composition of CoPd alloy nanowires in a wide range. Their composition and morphology were investigated by SEM and EDX. The magnetic properties of the nanowires array have been measured with a VSM as a function of the temperature, ranging from RT down to 50 K, for different CoPd alloy nanowires composition. Also, the temperature influence on the reversible-irreversible magnetization processes related with the magnetization reversal of the CoPd nanowires array has been analyzed by first order reversal curve (FORC) method.

Riboflavin did not provide anti-inflammatory or antioxidant effects in an experimental model of sepsis.

We aimed to evaluate whether the administration of riboflavin to septic animals reduces inflammation, oxidative stress, organ dysfunction, and mortality. C57BL/6 mice, 6-8 weeks old, were allocated to the study group (polymicrobial sepsis induced by cecal ligation and puncture (CLP) + antibiotic + iv riboflavin), control (CLP + antibiotic + iv saline), or naïve (non-operated controls). Serum concentrations of alanine aminotransferase (ALT), creatine kinase-MB (CK-MB), urea, and creatinine, and markers of inflammation [interleukin (IL)-6, tumor necrosis factor (TNF)-α, keratinocyte-derived chemokine (KC), and macrophage inflammatory protein (MIP)-2)], and oxidative stress (malondialdehyde (MDA) were measured 12 h after the experiment. Animal survival rates were calculated after 7 days. Means between groups were compared using linear regression models adjusted under the Bayesian approach. No significant difference was observed between control and study groups in serum concentrations of IL-6 (95% credible interval) (-0.35 to 0.44), TNF-α (-15.7 to 99.1), KC (-0.13 to 0.05), MIP-2 (-0.84 to 0.06), MDA (-1.25 to 2.53), or ALT (-6.6 to 11.5). Serum concentrations of CK-MB (-145.1 to -30.1), urea (-114.7 to -15.1), and creatinine (-1.14 to -0.01) were higher in the study group. Survival was similar in both groups (P=0.8). Therefore, the use of riboflavin in mice undergoing sepsis induced by CLP did not reduce inflammation, oxidative stress, organ dysfunction, or mortality compared with placebo.

A Physiological behavior and tolerance of Lactuca sativa to lead nitrate and silver nitrate heavy metals.

This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.

The application of Bonelike® Poro as a synthetic bone substitute for the management of critical-sized bone defects - A comparative approach to the autograft technique - A preliminary study.

The effective treatment of non-unions and critical-sized defects remains a challenge in the orthopedic field. From a tissue engineering perspective, this issue can be addressed through the application bioactive matrixes to support bone regeneration, such as Bonelike®, as opposed to the widespread autologous grafting technique. An improved formulation of Bonelike® Poro, was assessed as a synthetic bone substitute in an ovine model for critical-sized bone defects. Bone regeneration was assessed after 5 months of recovery through macro and microscopic analysis of the healing features of the defect sites. Both the application of natural bone graft or Bonelike® Poro resulted in bridging of the defects margins. Untreated defect remained as fibrous non-unions at the end of the study period. The characteristics of the newly formed bone and its integration with the host tissue were assessed through histomorphometric and histological analysis, which demonstrated Bonelike® Poro to result in improved healing of the defects. The group treated with synthetic biomaterial presented bone bridges of increased thickness and bone features that more closely resembled the native spongeous and cortical bone. The application of Bonelike® Poro enabled the regeneration of critical-sized lesions and performed comparably to the autograph technique, validating its octeoconductive and osteointegrative potential for clinical application as a therapeutic strategy in human and veterinary orthopedics.

Exogenous progestogens differentially alter gene expression of immature cumulus-oocyte complexes in sheep.

This study evaluated the role of progesterone (P4) and medroxyprogesterone acetate (MAP) on the molecular status of immature cumulus-oocyte complexes (COCs) and the implications for oocyte quality in sheep. The number of viable COCs per ewe and the rate of COCs screened for developmental competence by brilliant cresyl blue positive (BCB+) were similar (P > 0.05), respectively, across treatments (P4: 7.7 ± 0.7 and 4.7 ± 1.2; MAP: 5.7 ± 1.0 and 3.5 ± 2.3; and control: 5.7 ± 1.1 and 3.6 ± 2.4). The COCs' gene expression was altered by exogenous progestogens compared with the control group: markers of steroidogenic pathway (FSH receptor [FSHr], LH receptor [LHr], and estradiol receptor α) and of quality (zygote arrest 1, growth differentiation factor 9, and B-cell lymphoma 2) were in abundance in P4 (P < 0.05). In addition, reelin protein (RELN) was downregulated, and Bcl-2 was upregulated in MAP (P < 0.05). In the P4 vs MAP comparison, FSHr, LHr, and RELN genes were upregulated (P < 0.05) in the P4 group. In conclusion, P4 and MAP promoted dissimilar effects on transcriptome profiling of immature BCB-selected COCs, possibly due to the differences in the chemical structure of progestogens and concentrations of serum P4. Exogenous P4 impacted positively on the profile of genes related to oocyte quality.

The Southern Ocean Exchange: porous boundaries between humpback whale breeding populations in southern polar waters.

Humpback whales (Megaptera novaeangliae) are a cosmopolitan species and perform long annual migrations between low-latitude breeding areas and high-latitude feeding areas. Their breeding populations appear to be spatially and genetically segregated due to long-term, maternally inherited fidelity to natal breeding areas. In the Southern Hemisphere, some humpback whale breeding populations mix in Southern Ocean waters in summer, but very little movement between Pacific and Atlantic waters has been identified to date, suggesting these waters constituted an oceanic boundary between genetically distinct populations. Here, we present new evidence of summer co-occurrence in the West Antarctic Peninsula feeding area of two recovering humpback whale breeding populations from the Atlantic (Brazil) and Pacific (Central and South America). As humpback whale populations recover, observations like this point to the need to revise our perceptions of boundaries between stocks, particularly on high latitude feeding grounds. We suggest that this "Southern Ocean Exchange" may become more frequent as populations recover from commercial whaling and climate change modifies environmental dynamics and humpback whale prey availability.

Innovative tailor made dextran based membranes with excellent non-inflammatory response: In vivo assessment.

In this work, dextran based membranes with potential to be used as implantable devices in Tissue Engineering and Regenerative Medicine (TERM) were prepared by a straightforward strategy. Briefly, two polymers approved by the Food and Drug Administration, viz. dextran and poly(ε-caprolactone) (PCL) were functionalized with methacrylate moieties, and subjected to photocrosslinking. Employing different weight ratios of each polymer in the formulations allowed to obtain transparent membranes with tunable physicochemical properties and low adverse host tissue response. Independently of the material, all formulations have shown to be thermally stable up to 300 °C whilst variations in the polymer ratio resulted in membranes with different glass transition temperatures (Tg) and flexibility. The swelling capacity ranged from 50% to 200%. On the other hand, in vitro hydrolytic degradation did not show to be material-dependent and all membranes maintained their structural integrity for more than 30 days, losing only 8-12% of their initial weight. Preliminary in vitro biological tests did not show any cytotoxic effect on seeded human dental pulp stem cells (hDPSCs), suggesting that, in general, all membranes are capable of supporting cell adhesion and viability. The in vivo biocompatibility of membranes implanted subcutaneously in rats' dorsum indicate that M100/0 (100%wt dextran) and M25/75 (25 %wt dextran) formulations can be classified as "slight-irritant" and "non-irritant", respectively. From the histological analysis performed on the main tissue organs it was not possible to detect any signs of fibrosis or necrosis thereby excluding the presence of toxic degradation by-products deposited or accumulated in these tissues. In combination, these results suggest that the newly developed formulations hold great potential as engineered devices for biomedical applications, where the biological response of cells and tissues are greatly dependent on the physical and chemical cues provided by the substrate.

Physical and optical characterization of Er3+ doped lead-zinc-borate glass.

This paper reports on the systematic optical characterization of Er3+ (1.0%) doped lead-zinc-borate glass from the measured absorption, luminescence and fluorescence lifetime decay curve profiles. By the application of the Judd-Ofelt theory, spectral intensities of the absorption bands have been analysed and these absorption results have been used in evaluating the luminescence properties of the Er3+ doped lead-zinc-borate glass. Stimulated emission cross-sections (sigmapE) of the measured emission transitions have been computed. Based on the measured glass density, and refractive indices, other related physical parameters have also been evaluated. Further, the structural and morphology of the glass material have also been investigated from X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis.

Absorption and emission analysis of RE3+(Sm3+ and Dy3+): lithium boro tellurite glasses.

This paper reports on the development and spectral analysis of Sm3+ (1.0%) and Dy3+ (1.0%) doped lithium-boro-tellurite glasses. A bright orange (4G5/2-->6H7/2) along with a red (4G5/2-->6H9/2) and a yellow (4G5/2-->6H5/2) emission transition have been measured from Sm3+ doped lithium-boro-tellurite glass. Both blue (4F9/2-->6H15/2) and yellow (4F9/2-->6H13/2) emission bands have been obtained from Dy3+ glass. From the measured decay profiles, the lifetimes of the emissions of the Sm3+ glass (4G5/2-->6H5/2, 7/2, 9/2 and 11/2) at an excitation of 401 nm have been found to be in the range 0.47-0.81 ms, and with respect to the Dy3+ emissions (4F9/2-->6H15/2 and 13/2), with excitation at 450 nm, are measured to be in the range of 0.302-0.307 ms. Stimulated emission cross-sections (sigmapE) of the measured emission transitions have also been computed and the values are in the range of (0.38-1.20) x 10(-20) cm2 for Sm3+ and for Dy3+ doped lithium-boro-tellurite glass the values are (0.66-1.39) x 10(-20) cm2.

Return to emergency department after pediatric urology procedures.

BACKGROUND: Unplanned postoperative return visits to the emergency department (ED) and readmission represent a quality bench outcome and pose a considerable cost burden to health-care systems. OBJECTIVE: The aim of this study is to evaluate ED return visits after pediatric urology procedures in a tertiary care children's hospital, trying to identify potential causes. This may constitute a platform for future improvement areas. MATERIALS AND METHODS: A Quality Board-approved retrospective study was performed identifying all urologic cases completed between October 2012 and September 2015. Baseline demographics, American Society of Anesthesia class, operating surgeon, type of admission, type and duration of surgical procedure, and type of anesthesia given were evaluated. Patients who returned to the ED within 30 days of the surgery date were identified. The ED records were reviewed for time of return, etiology for visit, and management received. Univariate and subsequent multivariate logistic regression statistical analyses were performed to identify variables associated with ED return. Odds ratio (OR) and 95% confidence intervals (95% CIs) were generated to determine the significance of relationships. RESULTS: Total of 4125 cases was identified. Median age was 32.9 months, with 85.1% of them being male. 349 (8.5%) cases returned to the ED within 30 days of the surgery. The majority of the returned patients, 295 (84.5%), managed conservatively with medications or reassurance, whereas 54 (15.5%) required readmission, and of those readmitted, 15 (4.3%) cases needed further surgical interventions, mainly urinary tract drainage procedures. Multivariate logistic regression analysis identified that the age, residence, admission type, inguinoscrotal surgery, and duration of surgical procedure were significantly associated with ED return (Table). The most common reason for the ED visit was UTI in 17.2%, followed by stent and catheter issues in 14.3%, wound-related in 14.3%, and bleeding in 11.7%. DISCUSSION: Pediatric literature show varying rates of ED return ranging from 2.4% to 2.6% after urologic procedures. Our return to ED rate exceeds that found in US studies, which can perhaps be attributed to the differences between the Canadian and US health-care systems. As found with other studies, age, inpatient admission, procedure type, and increased operative time were related to ED returns, possibly because of the difficulty of young children expressing themselves and the presumed complex nature of longer operations that mostly need inpatient admission. The most common reason for ED return in this study as in others was presumptive UTI. A known limitation of this study is its retrospective nature, along with the possible missed visits of patients who presented to outside hospitals. CONCLUSION: We present an account of the status of ED return visits after pediatric urology procedures in our institute. The majority of ED returns can be managed conservatively and are probably preventable.

Dental pulp stem cells and Bonelike® for bone regeneration in ovine model.

Development of synthetic bone substitutes has arisen as a major research interest in the need to find an alternative to autologous bone grafts. Using an ovine model, the present pre-clinical study presents a synthetic bone graft (Bonelike®) in combination with a cellular system as an alternative for the regeneration of non-critical defects. The association of biomaterials and cell-based therapies is a promising strategy for bone tissue engineering. Mesenchymal stem cells (MSCs) from human dental pulp have demonstrated both in vitro and in vivo to interact with diverse biomaterial systems and promote mineral deposition, aiming at the reconstruction of osseous defects. Moreover, these cells can be found and isolated from many species. Non-critical bone defects were treated with Bonelike® with or without MSCs obtained from the human dental pulp. Results showed that Bonelike® and MSCs treated defects showed improved bone regeneration compared with the defects treated with Bonelike® alone. Also, it was observed that the biomaterial matrix was reabsorbed and gradually replaced by new bone during the healing process. We therefore propose this combination as an efficient binomial strategy that promotes bone growth and vascularization in non-critical bone defects.

Use of hybrid chitosan membranes and N1E-115 cells for promoting nerve regeneration in an axonotmesis rat model.

Many studies have been dedicated to the development of scaffolds for improving post-traumatic nerve regeneration. The goal of this study was to develop and test hybrid chitosan membranes to use in peripheral nerve reconstruction, either alone or enriched with N1E-115 neural cells. Hybrid chitosan membranes were tested in vitro, to assess their ability in supporting N1E-115 cell survival and differentiation, and in vivo to assess biocompatibility as well as to evaluate their effects on nerve fiber regeneration and functional recovery after a standardized rat sciatic nerve crush injury. Functional recovery was evaluated using the sciatic functional index (SFI), the static sciatic index (SSI), the extensor postural thrust (EPT), the withdrawal reflex latency (WRL) and ankle kinematics. Nerve fiber regeneration was assessed by quantitative stereological analysis and electron microscopy. All chitosan membranes showed good biocompatibility and proved to be a suitable substrate for plating the N1E-115 cellular system. By contrast, in vivo nerve regeneration assessment after crush injury showed that the freeze-dried chitosan type III, without N1E-115 cell addition, was the only type of membrane that significantly improved posttraumatic axonal regrowth and functional recovery. It can be thus suggested that local enwrapping with this type of chitosan membrane may represent an effective approach for the improvement of the clinical outcome in patients receiving peripheral nerve surgery.