Telocytes of Fascial Structures.

Currently, the exact role of telocytes within fascial structures is unknown. The morphology, distribution and behaviour of fascial telocytes as well as the mutual relationship between telocytes and other cellular fascia constituents should be definitely a subject of further studies. It will contribute to better understanding of the role of the fascial system in health and diseases, may shed light on the regeneration potential of these tissues and may help to find targets for future treatments for locomotor disorders, including fascial diseases. Last but not least, confirmation of the presence of telocytes within fascia may contribute to optimise the use of fascia as a graft material.

A preliminary technical study on sodium dodecyl sulfate-induced changes of the nano-structural and macro-mechanical properties in human iliotibial tract specimens.

INTRODUCTION: Acellular scaffolds are frequently used for the surgical repair of ligaments and tendons. Even though data on the macro-mechanical properties related to the acellularization process exist, corresponding data on the nano-structural properties are still lacking. Such data would help identify target proteins of the formed extracellular matrix that are chemically altered by the acellularization. In this study we examined the altered structure by comparing molecular properties of collagens from native and acellular iliotibial tract samples to the macroscopic stress-strain behavior of tract samples. MATERIAL AND METHODS: Matched pairs of five human iliotibial tract samples were obtained from five donors (mean age 28.2±4.7 years). One of each pair was acellularized using 1vol% sodium dodecyl sulfate (SDS) for 7 days. (13)C magic angle spinning nuclear magnetic resonance spectroscopy ((13)C CP MAS NMR) was utilized to compare the collagen overall secondary structure and internal dynamics of collagen-typical amino acid proteins. The resulting data was compared to age-matched stress-strain data of tract samples obtained in an uniaxial tensile setup and histologically. RESULTS: Typical and nearly identical collagen (13)C CP MAS NMR spectra were found in the tract samples before and after acellularization with SDS. The characteristic collagen backbone remained intact in the native and acellular samples. Collagen molecular composition was largely unaltered in both conditions. Furthermore, a similar dynamic behavior was found for the amino acids Hyp γ, Pro α/Hyp α, Ala α, Gly α and Ala ß. These minute alterations in the collagens' molecular properties related to acellularization with SDS were in line with the similarly minute changes in the macro-mechanical tensile behavior, such as the elastic modulus and ultimate stress. Histology showed intact type I collagens, minute amounts of elastins before and after acellularization and evidence for acellularization-induced reductions of proteoglycans. DISCUSSION: Nano-structural properties of collagens are minutely affected by SDS treatment for acellularization, indicated by the molecular composition and dynamics. The lacking acellularization-related changes in the molecular structure properties of collagens in iliotibial tract samples are in line with the small alterations in their macro-mechanical tensile behavior. Though the given setup approaches soft tissue mechanics from both scaling extremes of mechanical testing, further structural analyzes are needed in a larger sample size to substantiate these findings.

Long-Term Comparison of Rib and Ear Cartilage Grafts in Autologous and Allogenic Fascia Lata: An Experimental Study in a White Rabbit Model.

BACKGROUND: Diced cartilage in fascia has become the graft material of choice for dorsal grafts in rhinoplasty. Allogenic fascia lata has not yet been investigated as an isolated fascial graft or as a combined graft with ear and rib cartilage, especially in comparison with autologous fascia and over a long implantation period. METHODS: Ten different grafts were built from either autologous or allogenic fascia lata alone or as diced cartilage in fascia grafts with diced costal or ear cartilage and implanted into the dorsal skin of 15 rabbits. After 3 or 9 months, the grafts were explanted and analyzed histologically. Chondrocytes and cartilage matrix characteristics, including calcification, ossification, formation of bone marrow, fibrosis ingrowth and fibrotic transformation, the presence of immune reactions, vascular ingrowth, regenerative capacity, and capsule formation, were examined in a semiquantitative manner. RESULTS: All grafts were vital and without inflammatory response. The cartilage showed regular nuclei, a normal matrix, and regenerative capacity. A higher grade of calcification and ossification was observed in the fascia/cartilage grafts than in isolated cartilage grafts, and was more pronounced for costal cartilage. Both types of fascia were shown to be equally stable and without degradation. There were no significant differences in the diced cartilage in fascia grafts built with autologous compared to allogenic fascia. CONCLUSIONS: This study shows the equivalency of diced cartilage in fascia grafts and isolated fascial grafts using allogenic fascia lata compared to autologous fascia. The type of cartilage used accounts for different long-term characteristics of diced cartilage in fascia grafts.

Electron microscopy of human fascia lata: focus on telocytes.

From the histological point of view, fascia lata is a dense connective tissue. Although extracellular matrix is certainly the most predominant fascia's feature, there are also several cell populations encountered within this structure. The aim of this study was to describe the existence and characteristics of fascia lata cell populations viewed through a transmission electron microscope. Special emphasis was placed on telocytes as a particular interstitial cell type, recently discovered in a wide variety of tissues and organs such as the heart, skeletal muscles, skin, gastrointestinal tract, uterus and urinary system. The conducted study confirmed the existence of a telocyte population in fascia lata samples. Those cells fulfil main morphological criteria of telocytes, namely, the presence of very long, thin cell processes (telopodes) extending from a relatively small cell body. Aside from telocytes, we have found fibroblasts, mast cells and cells with features of myofibroblastic differentiation. This is the first time it has been shown that telocytes exist in human fascia. Currently, the exact role of those cells within the fascia is unknown and definitely deserves further attention. One can speculate that fascia lata telocytes likewise telocytes in other organs may be involved in regeneration, homeostasis and intracellular signalling.

The ultrastructure of the fascia lata in hernia patients and healthy controls.

BACKGROUND: Current research data indicate that a hernia is a manifestation of a generalized polyethiological connective tissue pathology. The goal of this study was to demonstrate ultrastructural differences in tissues distant from the hernial defect. MATERIALS AND METHODS: Biopsy specimens harvested upon thigh surgery from 12 males aged 25-65 y were compared. Seven of these men had an inguinal hernia or a history thereof. Scanning electron microphotograms taken at a magnification of 50× were analyzed with the use of Image J software. For every patient, 100 thickness measurements were performed of the fibrous elements (cross-sections) visible in five consecutive photograms. The person performing the measurements had no means of identifying the patient from whom the specimen had been harvested. RESULTS: The authors have found the thickness of the fibers to fall in the range from 23.441 u (ImageJ intrinsic units) to 94.878 u in the hernia group and 22.067 u to 303.681 u for the control group. A statistically significant difference was found between the mean values of thickness measurements of the fibrous elements in the study and control groups. CONCLUSIONS: The study has shown that in patients with an inguinal hernia, the mean diameter of fibers within the fascia lata is significantly smaller. This appears to indicate that the process is generalized and that one can expect the structural alterations to occur within the connective tissue of the entire organism. The authors speculate that they may result from a combination of external and internal factors.

Nanostructural investigation of frontalis sling biomaterial surfaces.

This study examined the nanostructural surface of three frontalis sling biomaterials: autogenous fascia lata, preserved fascia lata and silicone rod. The morphological characteristics of the sling biomaterial surfaces were examined qualitatively and quantitatively by scanning electron microscopy and atomic force microscopy, respectively. The autogenous fascia lata showed well-arranged nanostructures of parallel fascia collagen fibrils with clear 67 nm axial periodicity, whereas the preserved fascia lata showed tangled nanostructures of damaged collagen fibril bundles. The silicone rod showed a substantial amount of debris with some scratches and the smoothest roughness compared with the other sling biomaterials, followed by preserved fascia lata. Autogenous fascia lata showed the highest surface roughness. The association between the roughness and cell adhesion suggests that the nanostructure of autogenous fascia lata biomaterials is the best for frontalis sling and that of the silicone rod biomaterials is the worst.

Regional variability, processing methods, and biophysical properties of human fascia lata extracellular matrix.

This study aims to assess the regional variability, processing methods, mechanical, biochemical, and cellular properties of human fascia lata as a scaffold for soft tissue repair and tissue engineering applications. Ten pairs of fascia lata (donor age 18-55) were used. One fascia patch from each pair was used to assess the geometric and biomechanical variability of fresh fascia. The other from each pair was subjected to 1 of 2 allograft processing methods: antibiotic soak alone or acellularization plus antibiotic soak. Stiffness, modulus, hydroxyproline, chondroitin/dermatan sulfate glycosaminoglycan (CSDS GAG), and DNA content were quantified in fascia from fresh and treated groups. The effect of location was not significant for thickness or stiffness within a 6 x 12 cm2 region of the iliotibial tract of fresh human fascia lata. Processing did not significantly change the stiffness, modulus, or CSDS GAG content of fascia ECM. However, hydroxyproline (collagen) content is significantly reduced in acellularized fascia, probably reflecting a removal of soluble collagen during the treatment (p < 0.02). Processing reduced the DNA content of fresh fascia approximately 10-fold (p < 0.001). The mechanical, chemical and ultrastructural similarities between fascia lata and tendon may make fresh or processed fascia an attractive ECM scaffold for soft tissue, particularly tendon, repair.

pN collagen type III within tendon grafts used for anterior cruciate ligament reconstruction.

This study measured the amount of immature collagen type III present in tendon rafts obtained from anterior cruciate ligament (ACL) reconstructions. These values were compared with those obtained from control grafts typically used for reconstruction--Achilles, patellar, and fascia lata--and also to the normal ACL. Analyses were performed using a commercially available radioimmunoassay (RIA). The RIA made use of a rabbit polyclonal antibody specific to the amino terminus of procollagen type III. The specificity of the Ab was confirmed by a western blot. Fibril diameter of each of the above samples was measured by transmission electron microscopy (TEM). We thus were able to determine if there was a relationship between pN collagen III content and fibril diameter. The mean amount of pN collagen type III in the normal tendon control group was 0.8 +/- 0.3 ng/microg total protein (range 0.0-2.5 ng/microg). There was significantly greater pN collagen III (16 +/- 3.7 ng/microg total protein) in the grafts containing an average fibril diameter <55 nm than in the normal tendons or ACL (P < 0.05). Grafts with an average fibril diameter >55 nm had similar levels of pN collagen III (1.0 +/- 0.79 ng/microg) as the controls. There was also significantly less pN-collagen III within the functional grafts (5.3 +/- 1.9 ng/microg) as compared to failed grafts, (21.6 +/- 5.1 ng/microg, P < 0.05). These results indicate that incomplete processing of procollagen III may be responsible for some of the ultrastructural alterations seen in tendon grafts. Since ultrastructural organization is believed to influence mechanical properties of these tissues. pN collagen III levels may be a possible indicator of ligament or tendon weakness.

Detailed evaluation of 2959 allogeneic and xenogeneic dense connective tissue grafts (fascia lata, pericardium, and dura mater) used in the course of 20 years for duraplasty in neurosurgery.

Surgical experience with 2959 allogeneic and xenogeneic dense connective tissue grafts (1767 of fascia lata, 909 of pericardium, and 283 of dura mater), used in 2665 neurosurgical operations performed in the course of 20 years (1976 to 1995) is reported. Duraplasty using either allogeneic or xenogeneic grafts has had a similar, and favourable clinical outcome. Nevertheless, the pliable deep frozen fascia lata grafts, which could be used in any location, have been reserved for sella turcica plugging, anterior cranial base plasty, aneurysmal wrapping, and surgery of lipomyelomeningocele. Pericardium and dura mater grafts were in the majority of cases used over the brain convexity and posterior cranial fossa. Ovine pericardium proved to be superior to bovine and allogeneic pericardia because of its workability, flexibility, reduced thickness, and better transparency. Postsurgical complications occurred in 7.3%, and they were: 1) cerebrospinal fluid fistulas in 2.8%; 2) meningites in 2.3% (aseptic 1.4%, bacterial 0.8%, and tumoural 0.1% meningites); 3) pseudomeningoceles in 2.2%; 4) wound infections in 0.6%; 5) malresorptive hydrocephalus in 0.5%; and 6) adhesions to nerve tissue in 0.5%. The majority of complications healed without surgery. Forty-eight grafts (1.6%) failed to fulfil the requirements of the surgeon, and 46 of them were re-operated upon. Though another thirty-nine grafts healed successfully, 39 shunts (1.5%) had to be performed for malresorptive hydrocephalus (0.9%), and/or for a big pseudomeningocele (0.6%). So, the pure complication rate in 2665 duraplasties was 3.1%. The complex evaluation of the allogeneic and xenogeneic grafts (fascia, pericardium, and dura mater), used for duraplasty in neurosurgery during the last 20 years proved them, as remarkably good, with a success rates of 96.9%.

Immunolocalization of the costameres in human skeletal muscle fibers: confocal scanning laser microscope investigations.

BACKGROUND: The costameres in skeletal muscle fibers were first described by Pardo et al. (1983a) and have been defined as transverse circumferential elements of the cytoskeleton associated to the sarcolemma. Specific immunostaining for vinculin shows that the costameres overlie I bands. However, an exact correlation between the costameres and the Z line is uncertain, although approximately 10 proteins so far have been localized in the costameres. To define the exact localization of costameres in human skeletal muscle fibers, we carried out an immunofluorescence study using confocal scanning laser microscopy on the fascia lata muscle of adult males. METHODS: Samples were fixed in 3% paraformaldehyde; frozen sections were treated with antivinculin, antitalin, antidesmin, and anti-alpha-actinin, then immunostained with TRITC. For double localization, the TRITC-streptavidin, as a marker for vinculin and FITC-streptavidin a marker for desmin, were used. RESULTS: The distance between two subsequent transverse lines of actininf indicated that muscle fibers were well stretched. Processing, with different software functions of the images obtained using CLSM, shows that vinculin and talin are only present in the sarcolemmal lattice. Immunostaining for vinculin and double immunostaining for vinculin and desmin demonstrate that costameres superimpose underlying I bands without interruption at the Z line. Immunostaining for talin showed that the protein is located in correspondence with the I band and M line. CONCLUSIONS: We believe that costameres are "proteic machinery." The findings of the present study suggest that it is possible to determine the width and the period of each proteic component. In addition, we indicate that costameres are present in correspondence with M line.

Structural studies on bovine bioprosthetic tissues and their in vivo calcification: prevention via drug delivery.

Cardiovascular calcification, the formation of calcium phosphate deposits in cardiovascular tissue, is a common end-stage phenomenon affecting a wide variety of bioprostheses. To study the process of calcification in tissue prosthetics, glutaraldehyde-treated bovine pericardium, dura mater and fascialata were implanted subcutaneously in rats and retrieved 21 days later and thereby morphological findings were correlated with biochemically determined levels of calcium. Transmission electron microscopy showed that calcification primarily involved the surface of collagen fibrils and the interfibrillar spaces. The deposition of calcium was higher with dura and fascia prostheses compared to pericardium. However, the release of Fe3+ ions from chitosan matrix had substantially inhibited the deposits of calcium in all implanted tissues. It seems that the structural and anatomical features of the tissue is one of the important factors for tissue-associated calcification. It is also confirmed that glutaraldehyde-preserved pericardium is the most suitable material for the development of cardiac prosthesis, with an appropriate drug combination therapy for prevention of pathological calcification.

[Scanning electron microscopy study of autologous vein and fascia lata before and one year after implantation into the arterial blood stream]. / Rasterelektronenmikroskopische Bilder von autologer Vene und Fascia lata vor und ein Jahr nach Implantation in die arterielle Strombahn.

The present communication deals with scanning electronmicroscopical changes of autologous vein and autologous fascia lata, which were used as arterial implants. We examined material, which could be removed during reoperation for vascular occlusion. After one year, the surface exposed to the blood stream shows a homogenous layer of fibrin. Whilst the elastic fibers of fascia lata-transplants have nearly completely disappeared, we can still find them in the vein. This might be the essential reason for the longer survival of venous implants into the arterial blood stream.

[Scanning electron microscopy study of autologous fascia lata and bovine xenograft as arterial prosthesis. An experimental study]. / Rasterelektronenmikroskopische Untersuchungen von autologer Fascia lata und bovinem Xenograft als Arterienersatz. Eine tierexperimentelle Untersuchung.

The present communication deals with the decomposition of thrombi and the formation of an endothelium in two different vascular prothesis. Devitalized bovine arteries which were enzymatically reduced to a collagen reticulum, and tubes made of autologous fascia lata were implanted into the arterial bloodstream of dogs. The implants were left in place for a time ranging between 30 min and four months. They were examined by scanning electronmicroscope with the cortical point method. This enabled us to reach the following conclusions: unprepared autologous fascia lata implanted into the arterial bloodstream has much more thrombogenous qualities than solcograft. The decomposition of thrombi and the formation of an endothelium is much faster accomplished in fascia lata than in the devitalized bovine artery. It is not possible to distinguish solcograft and fascia lata by the formation of endothelium only.