OBJECTIVE: The perineal body connects muscles from the pelvic floor and is critical for support of the lower part of the vagina and proper function of the anal canal. We determined mechanical parameters and volume fractions of main components of the human female postmenopausal perineal body. METHODS: The specimens were taken from 15 fresh female cadavers (age 74 ± 10, mean ± standard deviation). Seventy-five specimens from five regions of the perineal body were processed histologically to assess volume fractions of tissue components using stereological point testing grid. Fifteen specimens taken from the midline region were loaded uniaxially with 6 mm/min velocity until tissue rupture to determine Young's modulus of elasticity, ultimate stresses, and strains. RESULTS: The perineal body was composed of collagen (29%), adipose cells (27%), elastin (7%), smooth muscle (11%), and skeletal muscle (3%). The residual tissue (19%) constituted mostly peripheral nerves, lumina of blood vessels, fibroblasts, and fibrocytes. Young's modulus of elasticity at midline region was 18 kPa (median) at small and 232 kPa at large deformations, respectively. The ultimate stress was 172 kPa and the ultimate strain was 1.4. CONCLUSIONS: We determined the structural and mechanical parameters of the perineal body. The resultant data could be used as input for models simulating pelvic floor prolapse or dysfunction.
- MeSH
- anální kanál MeSH
- biomechanika fyziologie MeSH
- elastin analýza MeSH
- hladké svalstvo anatomie a histologie MeSH
- kolagen analýza MeSH
- kosterní svaly anatomie a histologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mrtvola MeSH
- pánevní dno anatomie a histologie fyziologie chirurgie MeSH
- perineum anatomie a histologie fyziologie chirurgie MeSH
- postmenopauza fyziologie MeSH
- prolaps pánevních orgánů patofyziologie MeSH
- pružnost fyziologie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- tuková tkáň anatomie a histologie MeSH
- vagina MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aim: This study evaluates the effect of electrospun dressings in critical sized full-thickness skin defects in rabbits. Materials & methods: Electrospun poly-ε-caprolactone (PCL) and polyvinyl alcohol (PVA) nanofibers were tested in vitro and in vivo. Results: The PCL scaffold supported the proliferation of mesenchymal stem cells, fibroblasts and keratinocytes. The PVA scaffold showed significant swelling, high elongation capacity, limited protein adsorption and stimulation of cells. Nanofibrous dressings improved wound healing compared with the control group in vivo. A change of the PCL dressing every 7 days resulted in a decreased epithelial thickness and type I collagen level in the adhesive group, indicating peeling off of the newly formed tissue. In the PVA dressings, the exchange did not affect healing. Conclusion: The results demonstrate the importance of proper dressing exchange.
- MeSH
- buňky 3T3 MeSH
- hojení ran účinky léků MeSH
- králíci MeSH
- kůže * zranění metabolismus patologie MeSH
- myši MeSH
- nanovlákna chemie MeSH
- obvazy * MeSH
- polyestery * chemie farmakologie MeSH
- polyvinylalkohol chemie farmakologie MeSH
- prasata MeSH
- tkáňová adheziva * chemie farmakologie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
One of the main aims of bone tissue engineering, regenerative medicine and cell therapy is development of an optimal artificial environment (scaffold) that can trigger a favorable response within the host tissue, it is well colonized by resident cells of organism and ideally, it can be in vitro pre-colonized by cells of interest to intensify the process of tissue regeneration. The aim of this study was to develop an effective tool for regenerative medicine, which combines the optimal bone-like scaffold and colonization technique suitable for cell application. Accordingly, this study includes material (physical, chemical and structural) and in vitro biological evaluation of scaffolds prior to in vivo study. Thus, porosity, permeability or elasticity of two types of bone-like scaffolds differing in the ratio of collagen type I and natural calcium phosphate nanoparticles (bCaP) were determined, then analyzes of scaffold interaction with mesenchymal stem cells (MSCs) were performed. Simultaneously, dynamic seeding using a perfusion bioreactor followed by static cultivation was compared with standard static cultivation for the whole period of cultivation. In summary, cell colonization ability was estimated by determination of cell distribution within the scaffold (number, depth and homogeneity), matrix metalloproteinase activity and gene expression analysis of signaling molecules and differentiation markers. Results showed, the used dynamic colonization technique together with the newly-developed collagen-based scaffold with high content of bCaP to be an effective combined tool for producing bone grafts for bone implantology and regenerative medicine.
- MeSH
- buněčná diferenciace MeSH
- fosforečnany vápenaté metabolismus MeSH
- kolagen chemie MeSH
- kosti a kostní tkáň chemie MeSH
- kultivované buňky MeSH
- mezenchymální kmenové buňky metabolismus MeSH
- nanočástice MeSH
- osteogeneze účinky léků MeSH
- prasata MeSH
- regenerativní lékařství MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- transplantace mezenchymálních kmenových buněk metody MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The aortic and pulmonary allograft heart valves (AHV) are used in the cardiac surgery for replacing the impaired semilunar valves. They are harvested from donor hearts and cryostored in tissue banks. The expiration period was set to 5 years arbitrarily. We hypothesized that their mechanical and structural properties do not deteriorate after this period. A total of 64 human AHV (31 aortic and 33 pulmonary) of different length of cryopreservation (fresh, 0-5, 5-10, over 10 years) were sampled to different tissue strips (artery, leaflet, ventriculo-arterial junction) and tested by tensile test with loading velocity 10 mm/min until tissue rupture. Neighbouring regions of tissue were processed histologically and evaluated for elastin and collagen area fraction. The results were evaluated statistically. In aortic AHV, the physical deformation response of wall samples to stress did not changed significantly neither during the process of cryopreservation nor during the first 10 years of storage. In pulmonary AHV, the ultimate strain dropped after 5 years of cryopreservation indicating that pulmonary artery was significantly less deformable at the time of rupture. On the other hand, the ultimate stress was equal during the first 10 years of cryostorage. The changes in collagen and elastin amount in the tissue samples were not associated with mechanical impairment. Neither elasticity, stiffness and solidity nor morphology of aortic and pulmonary AHV did not change reasonably with cryopreservation and in the first 10 years of cryostorage. This evidence suggests that the expiration period might be extended in the future.
- MeSH
- aortální chlopeň transplantace MeSH
- dospělí MeSH
- elastin analýza MeSH
- homologní transplantace MeSH
- kolagen analýza MeSH
- kryoprezervace metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- plicní chlopeň transplantace MeSH
- tkáňové banky * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Publikační typ
- abstrakt z konference MeSH
To provide basic data on the local differences in density of microvessels between various parts of the human brain, including representative grey and white matter structures of the cerebral hemispheres, the brain stem and the cerebellum, we quantified the numerical density NV and the length density LV of microvessels in two human brains. We aimed to correlate the density of microvessels with previously published data on their preferential orientation (anisotropy). Microvessels were identified using immunohistochemistry for laminin in 32 samples harvested from the following brain regions of two adult individuals: the cortex of the telencephalon supplied by the anterior, middle, and posterior cerebral artery; the basal ganglia (putamen and globus pallidus); the thalamus; the subcortical white matter of the telencephalon; the internal capsule; the pons; the cerebellar cortex; and the cerebellar white matter. NV was calculated from the number of vascular branching points and their valence, which were assessed using the optical disector in 20-μm-thick sections. LV was estimated using counting frames applied to routine sections with randomized cutting planes. After correction for shrinkage, NV in the cerebral cortex was 1311±326mm-3 (mean±SD) and LV was 255±119mm-2. Similarly, in subcortical grey matter (which included the basal ganglia and thalamus), NV was 1350±445mm-3 and LV was 328±117mm-2. The vascular networks of cortical and subcortical grey matter were comparable. Their densities were greater than in the white matter, with NV=222±147mm-3 and LV=160±96mm-2. NV was moderately correlated with LV. In parts of brain with greater NV, blood vessels lacked a preferential orientation. Our data were in agreement with other studies on microvessel density focused on specific brain regions, but showed a greater variability, thus mapping the basic differences among various parts of brain. To facilitate the planning of other studies on brain vascularity and to support the development of computational models of human brain circulation based on real microvascular morphology; stereological data in form of continuous variables are made available as supplements.
Currently, titanium endosseous implants represent the standard in dental implantology. To improve their mechanical properties, biocompatibility and osseointegration, the concept of bulk nanostructured titanium with variously textured surface is being developed. Different animal species, mostly pigs, minipigs and rabbits, are used for the osseointegration assessment. The selection of implantation site in the target bone is also important, because various types of bones have different ratio between the compact and the trabecular bone tissue. After finishing the in vivo experiment, the implant position and orientation is verified by X-ray imaging. The part of the bone with the implant is surgically removed, cut into tissue blocks, and histologically processed using technique of undemineralized ground sections. This includes embedding the samples into resin followed by sawing, grinding, and polishing of transparent histological sections. A subsequent staining provides information on the formation and mineralization of the bone matrix in close proximity of the implant. Osseointegration is evaluated using a bone-implant contact (BIC) expressed as the ratio of the implant length in contact with bone tissue and total length of the implant. Additional information about the newly formed bone in regions surrounding the implant may be also provided by a double tetracycline test. According to our own experiments, this methodology is simple to perform, highly reproducible, and gives consistent results.
- MeSH
- lidé MeSH
- nanostruktury MeSH
- titan MeSH
- zubní implantáty * MeSH
- zubní materiály MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
The study involved the electrospinning of the copolymer poly(L-lactide-co-ε-caprolactone) (PLCL) into tubular grafts. The subsequent material characterization, including micro-computed tomography analysis, revealed a level of porosity of around 70%, with pore sizes of 9.34 ± 0.19 μm and fiber diameters of 5.58 ± 0.10 μm. Unlike fibrous polycaprolactone, the electrospun PLCL copolymer promoted fibroblast and endothelial cell adhesion and proliferation in vitro. Moreover, the regeneration of the vessel wall was detected following implantation and, after six months, the endothelialization of the lumen and the infiltration of arranged smooth muscle cells producing collagen was observed. However, the degradation rate was found to be accelerated in the rabbit animal model. The study was conducted under conditions that reflected the clinical requirements-the prostheses were sutured in the end-to-side fashion and the long-term end point of prosthesis healing was assessed. The regeneration of the vessel wall in terms of endothelialization, smooth cell infiltration and the presence of collagen fibers was observed after six months in vivo. A part of the grafts failed due to the rapid degradation rate of the PLCL copolymer.
- MeSH
- aorta patologie MeSH
- arteriae carotides patologie MeSH
- buněčná adheze MeSH
- buňky 3T3 MeSH
- cévní protézy * MeSH
- endoteliální buňky pupečníkové žíly (lidské) MeSH
- endoteliální buňky MeSH
- fibroblasty cytologie MeSH
- kolagen metabolismus MeSH
- králíci MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- myocyty hladké svaloviny cytologie MeSH
- myši MeSH
- polyestery chemie MeSH
- polymery chemie MeSH
- poréznost MeSH
- prasata MeSH
- psi MeSH
- regenerace MeSH
- rentgenová mikrotomografie MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury MeSH
- transplantace cév * MeSH
- zobrazování trojrozměrné MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- myši MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This study evaluated the subacute morphologic alterations in renal artery wall and renal nerves in response to catheter-based renal denervation (RDN) in sheep and also compared the efficiency of single-point and multiple-point ablation catheters. Effect of each ablation catheter approved for the clinical use (Symplicity Flex(TM), Medtronic, Inc., or EnligHTN(TM), St. Jude Medical, INC.) was compared to intact contralateral renal artery in 12 sheep by histopathology and immunohistochemistry evaluation after a 10-day period post-RDN procedure. The safety was verified by extensive evaluation of kidney morphology. Vascular wall lesions and nerve injuries were more pronounced in those animals treated with multi-point EnligHTN catheter when compared with animals treated with single-point Symplicity Flex catheter. However, neither RDN procedure led to complete renal nerve ablation. Both systems, tested in the present study, provided only incomplete renal nerve ablation in sheep. Moreover, no appreciable progression of the nerve disintegration in subacute phase post-RDN procedure was observed. This study further supports the notion that the effectiveness remains fully dependent on anatomical inter-individual variability of the sympathetic nerve plexus accompanying the renal artery. Therefore, new systems providing deeper penetrance to targeted perivascular structure would be more efficient.
- MeSH
- arteria renalis * cytologie inervace MeSH
- katetrizační ablace * přístrojové vybavení metody MeSH
- katétry MeSH
- ledviny * krevní zásobení cytologie inervace MeSH
- náhodné rozdělení MeSH
- ovce MeSH
- sympatektomie * přístrojové vybavení metody MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- srovnávací studie MeSH
The aim of this study was to compare data on the volume fraction of bone and the thickness of the cortical compact bone acquired during microcomputed tomography (micro-CT) analysis with data acquired from identical samples using stereological analysis of either decalcified paraffin sections or ground sections. Additionally, we aimed to compare adjacent tissue samples taken from the major trochanter of the porcine femur to map the basic biological variability of trabecular bone. Fifteen pairs of adjacent tissue blocks were removed from the major trochanter of the proximal epiphyses of porcine femurs (female pigs aged 24-39 months, weight=59.16±8.15kg). In each sample, the volume of the cortical compact bone, the volume of the trabecular bone, and the thickness of the cortical compact bone was assessed using micro-CT. Afterwards, half of the samples were decalcified and processed using paraffin histological sections. Another half was processed into ground sections. The volume and thickness of bone was assessed in histological sections using stereological techniques. There were no significant differences in the bone volumes and thicknesses measured by micro-CT and the corresponding values quantified in decalcified sections. Similarly, there were no differences between the results from micro-CT and the analysis of the corresponding ground sections. Histomorphometric studies based on relatively low numbers of undecalcified ground sections or demineralized paraffin sections of bone yield data on bone volume and the thickness of cortical compact bone that is comparable with three-dimensional micro-CT examination. The pilot data on the variability of cortical compact bone and trabecular bone volumes in the porcine major trochanter provided in this study aim for planning experiments in the field of bone healing and implantology.
- MeSH
- anatomie průřezová MeSH
- dekalcifikace (technika) MeSH
- femur anatomie a histologie diagnostické zobrazování MeSH
- fixace tkání metody MeSH
- kosti a kostní tkáň anatomie a histologie diagnostické zobrazování MeSH
- prasata MeSH
- rentgenová mikrotomografie MeSH
- Sus scrofa MeSH
- zalévání tkání do parafínu metody MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
