Skeletal muscle IL-15/IL-15Rα and myofibrillar protein synthesis after resistance exercise.

In vitro and in vivo studies described the myokine IL-15 and its receptor IL-15Rα as anabolic/anti-atrophy agents, however, the protein expression of IL-15Rα has not been measured in human skeletal muscle and data regarding IL-15 expression remain inconclusive. The purpose of the study was to determine serum and skeletal muscle IL-15 and IL-15Rα responses to resistance exercise session and to analyze their association with myofibrillar protein synthesis (MPS). Fourteen participants performed a bilateral leg resistance exercise composed of four sets of leg press and four sets of knee extension at 75% 1RM to task failure. Muscle biopsies were obtained at rest, 0, 4 and 24 hours post-exercise and blood samples at rest, mid-exercise, 0, 0.3, 1, 2, 4 and 24 hours post-exercise. Serum IL-15 was increased by ~5.3-fold immediately post-exercise, while serum IL-15Rα decreased ~75% over 1 hour post-exercise (P<.001). Skeletal muscle IL-15Rα mRNA and protein expression were increased at 4 hours post-exercise by ~2-fold (P<.001) and ~1.3-fold above rest (P=.020), respectively. At 24 hours post-exercise, IL-15 (P=.003) and IL-15Rα mRNAs increased by ~2-fold (P=.002). Myofibrillar fractional synthetic rate between 0-4 hours was associated with IL-15Rα mRNA at rest (r=.662, P=.019), 4 hours (r=.612, P=.029), and 24 hours post-exercise (r=.627, P=.029). Finally, the muscle IL-15Rα protein up-regulation was related to Leg press 1RM (r=.688, P=.003) and total weight lifted (r=.628, P=.009). In conclusion, IL-15/IL-15Rα signaling pathway is activated in skeletal muscle in response to a session of resistance exercise.

Phase transformation in AFM silicon tips.

We confirmed the occurrence of phase transformations in an atomic force microscopy silicon tip during loading and unloading experiments performed on a polycrystalline Ti sample. The influence of the phase transformations on the effective mechanical and electrical properties of the tip was observed with the help of load-unload curves measured simultaneously for the tip-sample contact stiffness k * and the effective electrical resistance of the system R eff. We used the atomic force acoustic microscopy (AFAM) method to determine the values of k *. To measure the changes in R eff, we combined a high voltage source/measure unit with the existing AFAM system. The data obtained showed that the phase transformation from Si-I to Si-II is preceded by other structural changes such as formation of distorted diamond structures and formation of Si-III. This conclusion was reached after observing a small hysteretic behavior in the load-unload stiffness curve accompanied by only very small changes in the resistance of the tip-sample system occurring on the unloading. The coinciding of a sudden increase in the values of the contact stiffness with a decrease in the resistance of the system indicated that the formation of metallic Si-II occurred in the subsequent measurements. The interpretation of our results found confirmation in the results of molecular dynamics and atomistic simulations performed for silicon under nanoindentation experiments.

Study of mechanical behavior of AFM silicon tips under mechanical load.

In this paper we address critical issues concerning calibration of AFM based methods used for nanoscale mechanical characterization of materials. It has been shown that calibration approaches based on macroscopic models for contact mechanics may yield excellent results in terms of the indentation modulus of the sample, but fail to provide a comprehensive and actual information concerning the tip-sample contact radius or the mechanical properties of the tip. Explanations for the severely reduced indentation modulus of the tip included the inadequacies of the models used for calculations of the tip-sample contact stiffness, discrepancies in the actual and ideal shape of the tip, presence of the amorphous silicon phase within the silicon tip, as well as negligence of the actual size of the stress field created in the tip during elastic interactions. To clarify these issues, we investigated the influence of the mechanical load applied to four AFM silicon tips on their crystalline state by exposing them to systematically increasing loads, evaluating the character of the tip-sample interactions via the load-unload stiffness curves, and assessing the state of the tips from HR-TEM images. The results presented in this paper were obtained in a series of relatively simple and basic atomic force acoustic microscopy (AFAM) experiments. The novel combination of TEM imaging of the AFM tips with the analysis of the load-unload stiffness curves gave us a detailed insight into their mechanical behavior under load conditions. We were able to identify the limits for the elastic interactions, as well as the hallmarks for phase transformation and dislocation formation and movement. The comparison of the physical dimensions of the AFM tips, geometry parameters determined from the values of the contact stiffness, and the information on the crystalline state of the tips allowed us a better understanding of the nanoscale contact.

Investigations on the possible impact of a glyphosate-containing herbicide on ruminal metabolism and bacteria in vitro by means of the 'Rumen Simulation Technique'.

AIMS: This study was performed in a well-established in vitro model to investigate whether the application of a glyphosate-containing herbicide might affect the bacterial communities and some biochemical parameters in a cow's rumen. METHODS AND RESULTS: The test item was applied in two concentrations (high and low) for 5 days. In a second trial, fermentation vessels were inoculated with Clostridium sporogenes before the high dose was applied. Effluents were analysed by biochemical, microbiological and genetic methods. A marginal increase in short-chain fatty acid production and a reduction in NH3 -N were observed. There were minor and rather equivocal changes in the composition of ruminal bacteria but no indications of a shift towards a more frequent abundance of pathogenic Clostridia species. Clostridium sporogenes counts declined consistently. CONCLUSIONS: No adverse effects of the herbicide on ruminal metabolism or composition of the bacterial communities could be detected. In particular, there was no evidence of a suspected stimulation of Clostridia growth. SIGNIFICANCE AND IMPACT OF THE STUDY: Antibiotic activity of glyphosate resulting in microbial imbalances has been postulated. In this exploratory study, however, intraruminal application of concentrations reflecting potential exposure of dairy cows or beef cattle did not exhibit significant effects on bacterial communities in a complex in vitro system. The low number of replicates (n = 3/dose) may leave some uncertainty.

Cancer Incidence in Five Continents: Inclusion criteria, highlights from Volume X and the global status of cancer registration.

Cancer Incidence in Five Continents (CI5), a longstanding collaboration between the International Agency for Research on Cancer and the International Association of Cancer Registries, serves as a unique source of cancer incidence data from high-quality population-based cancer registries around the world. The recent publication of Volume X comprises cancer incidence data from 290 registries covering 424 populations in 68 countries for the registration period 2003-2007. In this article, we assess the status of population-based cancer registries worldwide, describe the techniques used in CI5 to evaluate their quality and highlight the notable variation in the incidence rates of selected cancers contained within Volume X of CI5. We also discuss the Global Initiative for Cancer Registry Development as an international partnership that aims to reduce the disparities in availability of cancer incidence data for cancer control action, particularly in economically transitioning countries, already experiencing a rapid rise in the number of cancer patients annually.

Postimplantation host tissue response and biodegradation of biologic versus polymer meshes implanted in an intraperitoneal position.

BACKGROUND: This study compared the in vitro and in vivo behaviors at the peritoneal interface of a new polymer material (Bio-A) and of two biologic non-cross-linked materials (Tutomesh [Tuto] and Strattice [St]), all biodegradable. METHODS: Omentum mesothelial cells from rabbits were seeded onto the three prosthetic materials tested. At 1, 4, 8, 16, and 24 h after implantation, mesothelial cover was performed using a scanning electron microscope (SEM). In the in vivo study, 3 × 3 cm mesh fragments were placed on the parietal peritoneum of the same rabbits and fixed at the four corners with individual stitches. The implants were randomized such that six fragments of each material were implanted in nine animals (2 per animal). Adhesion formation was quantified by sequential laparoscopy and image analysis 3, 7, and 14 days after implantation. The animals were killed at 90 days, and the meshes were subjected to microscopy and immunohistochemistry. RESULTS: The in vitro mesothelial cover was significantly greater for St than for Bio-A at each time point. The percentage of cover for St was also higher than for Tuto 16 and 24 h after seeding and higher for Tuto than for Bio-A at all time points. Compared with the biologic meshes, significantly higher adhesion percentages were recorded for Bio-A. At 90 days after implantation, differences in absorption measured as percentage of reduction in mesh thickness were detected among all the meshes. The least absorbed was St. The neoperitoneum thickness was significantly greater for the biologic meshes than for the polymer mesh, although this variable also differed significantly between St and Tuto. Macrophage counts were higher for Bio-A than for the biologic meshes. CONCLUSIONS: Greater mesothelial cover was observed in vitro for St. In vivo, adhesion formation and the macrophage response induced by Bio-A were greater than those elicited by the biologic materials. Bio-A and Tuto showed substantial biodegradation compared with St.

Intraperitoneal behaviour of a new composite mesh (Parietex™ Composite Ventral Patch) designed for umbilical or epigastric hernia repair.

INTRODUCTION: The most common treatment option for ventral and umbilical hernias is the implant of a prosthetic mesh. This study compares the behaviour of a new mesh, Parietex™ Composite Ventral Patch (Ptx), with two commercially available meshes, Ventralex™ ST Hernia Patch and Proceed™ Ventral Patch. MATERIALS AND METHODS: The following meshes were tested in a umbilical-hernia repair model using 54 rabbits: Ventralex™ ST Hernia Patch (Vent) (Bard Davol Inc., USA); Proceed™ Ventral Patch (PVP) (Ethicon, USA) and Ptx (Covidien, Sofradim, France) (n = 18 each). At 3, 7 and 14 days postimplantation, peritoneal behaviour and adhesion formation were assessed by sequential laparoscopy. Adhesions were scored for consistency and quantified by image analysis. The animals were euthanized at 2 (n = 27) and 6 weeks (n = 27) postsurgery. Mesothelial cover of meshes and tissue ingrowth were determined by scanning and light microscopy. RESULTS: Seroma was observed in 1/18 Vent, 7/18 PVP and 4/18 Ptx, mainly between the implant and subcutaneous tissue. Firm omental adhesions between the mesh and parietal peritoneum were noted in 2/9 Vent, 6/9 PVP and 3/9 Ptx at 2 weeks and in 3/9 Vent, 5/9 PVP and 1/9 Ptx at 6 weeks. Three (out of 9) encapsulated PVP implants showed "tissue-integrated" adhesions affecting the intestinal loops. No differences between implants were detected in the surface area occupied by adhesions at 2 weeks, though at 6 weeks, percentages were significantly higher (p < 0.01; Mann-Whitney U test) for PVP compared to Ptx or Vent. At this time point, Ptx and Vent showed good host tissue incorporation and optimal mesothelialization. CONCLUSIONS: The PVP implants showed greater adhesion formation than the other materials. Postimplantation behaviour was comparable for Ptx and Vent including scarce adhesion formation and optimal mesothelialization. Regarding tissue integration, Ptx showed greater long-term collagenization of the neoformed tissue.

[Large-scale imaging of corneal nerve fibres by guided eye movements]. / Großflächige Abbildung kornealer Nervenfasern durch geführte Augenbewegungen.

BACKGROUND: The high resolution of corneal confocal microscopy (CCM) allows in vivo imaging of the corneal sub-basal nerve plexus (SNP). The field of view of a single CCM image (0.16 mm²) is not sufficient for the reliable morphometric characterisation of the SNP. Therefore we are developing a highly automated mosaicking technique for large-area imaging of the SNP using CCM image sequences. METHODS: In order to acquire an image sequence of a larger area of the SNP, the view direction of the patient is guided by a computer-controlled moving fixation target on a display in front of the non-examined eye. The CCM image sequence is recorded with 30 fps. An online calculated mosaic image allows the medical operator to observe the acquisition process and assess the quality and size of the resulting image during the CCM recording process. Remaining image artefacts are corrected in an automated post-processing step. RESULTS: Using a first prototype system and an appropriate fixation target trajectory, a mean growth of the covered SNP area of 0.18 mm²/s could be achieved. CONCLUSION: Using the presented technology, large-area images of the SNP can be generated. The technology is characterized by a high degree of automation and short examination times.

Mechanical characterization of nanoporous materials by use of atomic force acoustic microscopy methods.

We have used the atomic force acoustic microscopy (AFAM) method to determine the indentation modulus of nanoporous thin-film materials with ultralow values of dielectric permittivity (dielectric constant k < 2.4). The AFAM method is based on the contact mode of atomic force microscopy (AFM) and as such is able to characterize materials with high spatial resolution. The tested material was porous organosilicate glass with nominal porosity ranging from 27% to 40%. The values obtained for the indentation modulus varied from 4 to 7 GPa depending on the pore concentration. The values obtained for the indentation modulus by use of the AFAM method were in very good agreement with those determined by nanoindentation. In addition, a part of the AFAM results obtained for the sample with the highest porosity content showed dependence of the effective indentation modulus on the applied load. Preliminary data analysis suggests that the stress rate is the critical factor in triggering this particular mechanical response of the porous material.

Mutans streptococci and caries prevalence in children after early maternal caries prevention: a follow-up at 19 years of age.

AIM: The efficacy of early maternal caries prevention was evaluated. Furthermore, the difference between children colonised with mutans streptococci (MS) at an early or late stage with regard to the prevalence of carious lesions was determined. METHODS: The children of first-time mothers selected on the basis of high salivary levels of MS for participation in a caries prevention programme were recalled at the age of 19 years. They were examined for salivary MS, lesion prevalence (decayed and filled surfaces, DFS) and MS in plaque from 12 selected proximal surfaces. RESULTS: The recall rate was 70% for the children of both the high-control and interventional groups. All high-control children and 67% of the interventional children were colonised by MS. All the children with non-detectable MS in saliva were also negative in all plaque samples. No statistically significant difference was found between the groups in terms of DFS, although more interventional children were caries free than in the control group. Early-colonised children, irrespective of group identity, had higher salivary MS levels and DFS than later MS-colonised children. CONCLUSION: The results indicate that it is possible to remain negative for MS into adulthood if non-colonised at an early age and this affects the development of carious lesions. Strategies for the prevention of dental caries in early childhood should, therefore, include measures to prevent or delay early colonisation by cariogenic bacteria.

Role of lysyl oxidases in neointima development in vascular allografts.

BACKGROUND: Extracellular matrix deposition is the main factor inducing stenotic lesions in arterial grafts. Lysyl oxidases (LOX) play a key role in stabilizing collagen and elastin. OBJECTIVE: To examine the repair response to arterial allografts in terms of LOX expression and collagen/elastin deposition using LOX inhibitors. METHODS: Lewis/Fisher-344 rats were used as donors/recipients. Donor segments were grafted to the right iliac artery of recipients and retrieved 14/30 (short-term) or 90/180 days (long-term) after surgery. One group of animals was injected with a potent irreversible LOX inhibitor daily for 30 days. RESULTS: Intimal hyperplasia increased in thickness until 90/180 days postsurgery. Elastin showed great expression in the neointima at 14/30 days and in the media at 90/180 days. LOX/LOXL1 were similarly expressed in the arterial wall during the first month. In the long term, their overexpression was confined to neointimal layers. At 14 days, collagen types I/III were identified in the grafts. The neointima acquired collagen I over time. In the group of animal treated with the LOX inhibitor, intimal hyperplasia was significantly inhibited. CONCLUSION: LOX were overexpressed in late stages of intimal hyperplasia in the allografts. LOX inhibitors prevented the development of the neointimal layer, such that their modulation could reduce the excessive extracellular matrix deposition that leads to stenosis.

[Image reconstruction of the corneal subbasal nerve plexus with extended field of view from focus image stacks of a confocal laser scanning microscope]. / Bildrekonstruktion des subbasalen Nervenplexus der Kornea mit erweitertem Bildfeld aus Fokusserien eines konfokalen Laser-Scanning-Mikroskops.

BACKGROUND: Confocal laser scanning microscopy (CLSM) allows the in vivo analysis of nerve structures of the human cornea. In this way, pathological alterations of the peripheral nervous system that also affect the corneal subbasal nerve plexus (SNP) can be diagnosed non-invasively and possibly earlier than with other methods. The field of view of in vivo CLSM images of the cornea (ca. 0.4 × 0.4 mm²) is not sufficient for a reliable assessment. Two phenomena make the image assessment difficult: the presence of ridge-like tissue deformations in the neighbourhood of the SNP and image distortions that are induced by involuntary and unavoidable eye movements during image acquisition. This paper presents an image processing method for generating undistorted images of the SNP with an extended field of view. METHODS: The presented method has been tested on five volunteers. Eight focus image stacks have been taken and processed from each subject using a Heidelberg Retina Tomograph with Rostock Cornea Module (HRT). An image registration scheme specifically adapted to the image acquisition system corrects the non-linear motion-induced image distortions and reconstructs a volume from each focus image stack. The epithelial basal boundary surface including the SNP appears as a distinctive hyper-reflective layer inside the reconstructed volume. Extracting this continuous layer generates a depth map and finally a two-dimensional image of the SNP. A final fusion step of the single reconstructed SNP images leads to laterally extended images. RESULTS: Out of 40 focus image stacks, 34 have been fully processed into two-dimensional SNP reconstruction images. Six focus image stacks could not be transformed into volumes because of extremely fast eye movements during the image acquisition that prevented the complete image registration of the stacks. The 34 SNP reconstruction images depict an average area of 94.7 % ( ±â€Š6.2 %) with respect to the field of view of a single HRT image. The final fusion of the reconstructed images resulted in an average increase of the image area by a factor of 2.6 (ranging from 2.2 to 3.1). CONCLUSION: The presented image processing algorithms are capable of correcting the motion-induced image distortions and of generating larger two-dimensional images of the SNP even in presence of severe tissue deformations. These images provide the basis for a more reliable assessment of the corneal nerve fibres.

Carious lesions and caries risk predictors in a group of Swedish children 2 to 3 years of age. One year observation.

AIM: Identification of potential carious risk criteria, retrospectively at 2 years of age, for developing carious lesions at 3 years of age. Study design Longitudinal observations from 2 until 3 years of age. Cross-sectional observations of two cohorts of 3- year-olds with different approaches. MATERIALS AND METHODS: The study group consisted of 78 three- year- olds from a previous study at age 2 years. Clinical examination, diet history, questions regarding breastfeeding and salivary sampling for mutans streptococci (MS) were performed at both ages. The previous study on 124 three-year-olds was used as a control group for comparison of the 3-year-olds in the longitudinal study group. RESULTS: The examinations suggested the following risk predictors: carious lesions, frequent intake of selected sugar-containing products, breastfeeding at night and MS, which covered all children with lesions at 3 years of age, resulting in a positive predictive value of 32% and a negative predictive value of 100%. The only statistically significant difference between the two groups of 3-year-olds was the reported intake of sugar-containing items. Statistics Student's t-test and chi square test, completed by Fischer's exact test. CONCLUSION: The combination of the suggested risk criteria was predictive of carious lesions. In spite of individual parental information, new lesions developed after one year. Based on observations, a more structured and monitored preventive approach is suggested.

Update--steroidogenic factor 1 (SF-1, NR5A1).

Steroidogenic factor 1 (SF1, NR5A1, Ad4BP) is a nuclear receptor and regulator of multiple genes involved in adrenal and gonadal development, steroidogenesis, and the reproductive axis. Complete deletion of Nr5a1 in XY mice results in adrenal and gonadal agenesis, female external genitalia and presence of Müllerian structures. These findings were first reported in the early 1990s. Subsequently, NR5A1 mutations were found in two 46,XY phenotypic females with Müllerian structures and adrenal failure and in one 46,XX female with adrenal failure. More recently, heterozygous NR5A1 mutations have been identified in a substantial proportion of patients with 46,XY disorders of sex development (46,XY DSD) without adrenal insufficiency. Most of these individuals display severe underandrogenization with ambiguous genitalia at birth, partial gonadal dysgenesis, and absence of Müllerian structures or remnants. Some of the patients have a milder phenotype such as hypospadias and cryptorchidism, due to less severe defects in androgen synthesis. Testosterone, inhibin B and AMH are usually low indicating a partial (or sometimes progressive) form of gonadal dysgenesis in most cases. However, normal testosterone production at birth might also be present. The frequency of NR5A1 mutations in otherwise unexplained 46,XY DSD with underandrogenization and partial testicular dysgenesis has been estimated to be about 15%. Furthermore, NR5A1 mutations have now been found in women with familial and sporadic 46,XX primary ovarian insufficiency without adrenal failure. These human phenotypes associated with NR5A1 mutations show that SF-1 is a key factor involved in both human testis and ovarian development, but that human adrenal development seems to be more resistant to the effects of SF-1 haploinsufficiency than gonadal development. Patients with 46,XY DSD and mild underandrogenization due to partial testicular dysgenesis should possibly be assigned to the male sex, as small testes with Leydig, Sertoli and germ cells are present in almost all cases. Additionally, spontaneous virilization in puberty might be possible in patients with NR5A1 mutations. However, fertility options and the risk of testicular malignancy and adrenal insufficiency in adulthood are unknown and need to be investigated in long-term outcome studies.

Mutans streptococci and caries prevalence in children after early maternal caries prevention: a follow-up at eleven and fifteen years of age.

AIM: The efficacy of early maternal caries prevention in children was evaluated. METHODS: First-time mothers selected on the basis of a high level of salivary mutans streptococci (MS) and mothers excluded at screening due to a low level of MS ('low') were recalled when their children were 11 years old. The salivary MS level was determined in the mothers. Their children were examined for salivary MS and lesion prevalence (decayed and filled surfaces, DFS) at the ages of 11 and 15 years. RESULTS: More 'high control' mothers displayed ≥106 MS than the 'high interventional' and 'low control' mothers and, vice versa, more 'interventional' and 'low control' mothers had MS counts of <3 × 105 than 'high control' mothers. More of 'interventional' and 'low control' children had <105 MS/ml as compared with the 'high control' children. All the 'high control' children had detectable MS. MS were undetected in 5 'interventional' and 5 'low control' children at 15 years. Significantly fewer 'high control' than 'interventional' and 'low control' children were caries free at 11 and 15 years of age. Non-MS-colonised children at 3 years of age, irrespective of group identity, displayed statistically lower MS counts and less DFS at 15 years than those colonised at 3 years of age. Children with clinical caries/fillings at 15 years had had a significantly higher level of MS at 11 years of age than those without clinical caries/fillings. CONCLUSION: The clinical trial, focusing on the mothers, resulted in long-term benefits for their children. Children colonised by MS at an early stage developed more caries than those colonised at a later stage.

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.

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.

Stromal vascular fraction cells as biologic coating of mesh for hernia repair.

BACKGROUND: The interest in non-manipulated cells originating from adipose tissue has raised tremendously in the field of tissue engineering and regenerative medicine. The resulting stromal vascular fraction (SVF) cells have been successfully used in numerous clinical applications. The aim of this experimental work is, first to combine a macroporous synthetic mesh with SVF isolated using a mechanical disruption process, and to assess the effect of those cells on the early healing phase of hernia. METHODS: Human SVF cells combined with fibrin were used to coat commercial titanized polypropylene meshes. In vitro, viability and growth of the SVF cells were assessed using live/dead staining and scanning electron microscopy. The influence of SVF cells on abdominal wall hernia healing was conducted on immunodeficient rats, with a focus on short-term vascularization and fibrogenesis. RESULTS: Macroporous meshes were easily coated with SVF using a fibrin gel as temporary carrier. The in vitro experiments showed that the whole process including the isolation of human SVF cells and their coating on PP meshes did not impact on the SVF cells' viability and on their capacity to attach and to proliferate. In vivo, the SVF cells were well tolerated by the animals, and coating mesh with SVF resulted in a decrease degree of vascularity compared to control group at day 21. CONCLUSIONS: The utilization of SVF-coated mesh influences the level of angiogenesis during the early onset of tissue healing. Further long-term animal experiments are needed to confirm that this effect correlates with a more robust mesh integration compared to non-SVF-coated mesh.

Mammary tumor virus antigen: sensitive immunoassay.

A rapid, sensitive immuno-assay for mammary tumor virus antigen based on inhibition of passive hemagglutination has been developed. The method permits measurement of this antigen in mouse milk from which the fat has been removed.

Graphene on insulating crystalline substrates.

We show that it is possible to prepare and identify ultra-thin sheets of graphene on crystalline substrates such as SrTiO(3), TiO(2), Al(2)O(3) and CaF(2) by standard techniques (mechanical exfoliation, optical and atomic force microscopy). On the substrates under consideration we find a similar distribution of single layer, bilayer and few-layer graphene and graphite flakes as with conventional SiO(2) substrates. The optical contrast C of a single graphene layer on any of those substrates is determined by calculating the optical properties of a two-dimensional metallic sheet on the surface of a dielectric, which yields values between C = -1.5% (G/TiO(2)) and C = -8.8% (G/CaF(2)). This contrast is in reasonable agreement with experimental data and is sufficient to make identification by an optical microscope possible. The graphene layers cover the crystalline substrate in a carpet-like mode and the height of single layer graphene on any of the crystalline substrates as determined by atomic force microscopy is d(SLG) = 0.34 nm and thus much smaller than on SiO(2).