Different kinds of forces can be applied to the biological tissue. The analysis of the applied force is highly important to explain the mechanism of cellular response. In this study, the applied force to the collagen gel was analyzed by the finite elements analysis. The model received two different kinds of static force (compression and tension). The force range was 50g to 400g. In results, von Mises stress was concentrated in the peripheral region in the compression model. It was concentrated in the central area in the tension model. However, the compressive force was high in the peripheral area of the compression model and the tensional force was also high in the same area of the tension model. In conclusion, the applied force could be different to the region and it should be considered in the experiment to analyze the effects of the mechanical force on the cells.
Cell Culture Techniques ; Collagen ; Finite Element Analysis

Different kinds of forces can be applied to the biological tissue. The analysis of the applied force is highly important to explain the mechanism of cellular response. In this study, the applied force to the collagen gel was analyzed by the finite elements analysis. The model received two different kinds of static force (compression and tension). The force range was 50g to 400g. In results, von Mises stress was concentrated in the peripheral region in the compression model. It was concentrated in the central area in the tension model. However, the compressive force was high in the peripheral area of the compression model and the tensional force was also high in the same area of the tension model. In conclusion, the applied force could be different to the region and it should be considered in the experiment to analyze the effects of the mechanical force on the cells.
Cell Culture Techniques ; Collagen ; Finite Element Analysis

A material for ridge preservation should have dimensional stability to resist bio-degradation. This study was designed to compare bio-degradation of ridge preservation materials. Collagen plug was used as a positive control. Untreated, ethanol-treated, and 4-hexylresorcinol (4HR)-treated silk plugs were used for the experimental group. Each material underwent a scanning electron microscopic exam and a Fourier transform infrared (FT-IR) spectroscopic exam. Bio-degradation was evaluated by analyzing cylindrical bony defects in rabbit tibias. There were no prominent differences in microstructure among the silk plug groups. FT-IR exam demonstrated that the ethanol- and 4HR-treated silk plug groups had enhanced β-sheet structure. All silk plug groups exhibited significantly higher residual graft than the collagen plug group 4 weeks postoperative (p<0.05). In conclusion, silk fibroin-based ridge preservation material was less bio-degradable than a collagen plug until at least 4 weeks after grafting.
Collagen* ; Fourier Analysis ; Hexylresorcinol ; Silk* ; Tibia ; Transplants*

OBJECTIVETo investigate the correlation and anatomic association of benign hyperplastic nodules in the peripheral zone (PZ) with those in the transition zone (TZ) of the prostate, and to compare the histological components of the two kinds of nodules.

METHODSWe obtained benign hyperplastic nodules specimens from the PZ and TZ by autopsy, measured the distance between the outer surface of the nodules and the inner gland, observed the integrity of the surgical envelope of the prostate, and determined the histological components of the two kinds of nodules by HE staining, immunohistochemistry and automatic quantitative image analysis.

RESULTSThe surgical envelope of the prostate was integrated and the distance between the nodules of the PZ and the outer surface of the inner gland was about 2.5 to 5 mm ([3.9 +/- 0.8] mm), with no signs of anatomic connection in between. The stromata and epithelia in the nodules accounted for (69.32 +/- 8.35)% and (16.08 +/- 5.36)% in the PZ and (74.58 +/- 8.95)% and (15.82 +/- 6.41)% in the TZ.

CONCLUSIONBenign hyperplastic nodules may originate from the PZ of the prostate and not correlate with the inner gland hyperplasia in the TZ, but with no statistical difference between the histological components of the two kinds of nodules.

Aged ; Aged, 80 and over ; Autopsy ; Collagen Type I ; analysis ; Collagen Type II ; analysis ; Collagen Type III ; analysis ; Collagen Type IV ; analysis ; Fibronectins ; analysis ; Humans ; Hyperplasia ; Immunohistochemistry ; Laminin ; analysis ; Male ; Prostate ; chemistry ; pathology ; Prostatic Hyperplasia ; metabolism ; pathology

BACKGROUND: The purpose of this study is to investigate differences of chemical composition between subchondral bone in advanced osteoarthritic (OA) and non-OA distal femur. METHODS: Twenty femurs were harvested, respectively. The subchondral trabeculae were obtained from the middle of medial articular surface of distal femurs. A 10 mm diameter cylindrical saw was used to harvest. Raman spectroscopy, a non-destructive technique, was employed to determine the chemical information of the trabecular bones in the human distal femurs. RESULTS: The maximum intensity of the phosphate peak was 2,376.51+/-954.6 for the non-OA group and 1,936.3+/-831.75 for the OA group. The maximum intensity of the phosphate peak observed between the two groups was significantly different (P=0.017). The maximum intensity of the amide I peak were 474.17+/-253.42 for the nonOA group and 261.91+/-205.61 for the OA group. The maximum intensity of the amide I peak were significantly different between the two groups (P=0.042). Also, among other chemical and matrix components (Hydroxyproline,Carbonate, Amide IIIdisordered;ordered, and CH2), the spectrums showed similar significant differences in the intensity (P=0.027, P=0.014, P=0.012; P=0.038, P=0.029). Area integration were performed to determine disorder in collagen's secondary structure via amide III (alpha helix/random coil). The value of the alpha helix to random coil band area are significantly different (P=0.021) and result showing that there was a trend toward higher collagen maturity for the nonosteoarthritic bone specimens. CONCLUSIONS: The result suggested that OA may affect the chemical compositions of trabecular bone, and such distinctive chemical information may be.
Cartilage ; Collagen ; Femur ; Humans ; Osteoarthritis* ; Spectrum Analysis, Raman

OBJECTIVETo study the indexes for evaluating intervertebral disc degeneration in rats during the aging process.

METHODSNine SD rats were fed for 6 months and 12 for 22 months as the young and aged groups, respectively. The Miyamoto's grade of the rats was calculated, and the quantity and relative area of the vascular buds as well as the thickness of the calcified and non-calcified layers of the cartilage endplate were measured using the stereoscopic method. Immunohistochemistry with monoclonal antibodies was used to determine the expressions of collagens II and X in the endplate.

RESULTSThe quantity and relative area of the vascular buds, non-calcified layer/calcified layer ratio, type II collagen expression in the calcified layer and nucleus pulposus of the cartilage endplate were all significantly decreased in the aged rats as compared with those of the youth rats (P<0.05), but the collagen X expression in the non-calcified layer was significantly higher in the aged rats (P=0.003). No significant difference was found in the Miyamoto's grade between the aged and young rats (P=1.130).

CONCLUSIONThe relative area of the vascular buds, non-calcified layer/calcified layer ratio, phenotypic expressions of collagens II and X in the cartilage endplate, but not the Miyamoto's grade, are sensitive indexes for evaluating intervertebral disc degeneration in rats during the aging process.

Aging ; Animals ; Cartilage ; pathology ; Collagen Type II ; analysis ; Collagen Type X ; analysis ; Intervertebral Disc Degeneration ; pathology ; Rats ; Rats, Sprague-Dawley

Collagen Type I ; analysis ; Collagen Type III ; analysis ; Fluorescent Antibody Technique, Indirect ; Humans ; Liver ; chemistry ; Microscopy, Confocal

This study was undertaken to localize fibronectin and type IV collagen in the cultured retinal pigment epithelial cell by means of immunofluorescent staining and immunocytochemical methods. Immunofluorescent staining and immunocytochemical methods revealed fibronectin and type IV collagen localized on the extracellular membrane of the cultured retinal pigment epithelial cell. Ultrastructural immunocytochemical technique also revealed fibronectin associated with extracellular tissue. This study demonstrated that fibronectin and type IV collagen are an integral component of the extracellular matrix of the human retinal pigment epithelial cell in vitro.
Cells, Cultured ; Collagen/*analysis ; Extracellular Matrix/*analysis/immunology ; Fibronectins/*analysis ; Fluorescent Antibody Technique ; Humans ; Immunohistochemistry ; Pigment Epithelium of Eye/*analysis

A method for quantitation of collagen was established by detecting marker peptide with high performance liquid chromatography-mass spectrometry (HPLC-MS). Theoretical marker peptides were selected by sequence comparison. Bovine collagen type I was digested with trypsin. Marker peptides typical for collagen type I were identified with HPLC-MS. The relationship between the abundance of marker peptides and collagen concentration was established. The results show that GEAGPSGPAGPTGAR and the other 5 peptides showed high resolution during chromatographic separation and high signal intensity during MS analysis. Peptide signal intensity and collagen concentration showed a good linear relationship in the range from 0.1 to 3 mg/mL. Bovine tendon and collagen sponge were used as actual samples and collagen contents were determined as 90.2% and 93.4% respectively. Quantitation of marker peptides of collagen was a feasible method to identify and quantify collagens in medical device research and development.
Animals ; Cattle ; Chromatography, High Pressure Liquid ; Collagen Type I ; analysis ; Mass Spectrometry ; Peptides ; analysis

OBJECTIVETo describe the methods which were used to develop collagen-based materials for wound dressing.

METHODSFresh frozen bovine tendon was treated with 0.05 mol/L acetic acid at pH 3.2 for 48-72 hours, homogenized, filtered, mixed with 8% chondroitin sulphate, for creating a deaerated 1.5%-2.5% collagen solution. The solution was lyophilized in either a pre-frozen or non-pre-frozen mould. The collagen sponge was then cross-linked with 0.25% glutaraldehyde for 24 hours. Three other types of wound dressings were developed using a similar method: collagen membrane with a polyurethane membrane onlay, polyurethane-coated collagen membrane and collagen membrane on gauze.

RESULTSIt was demonstrated that the use of frozen bovine tendon was stable, and that the prepared collagen sponge contained pores of 50-400 microm in diameter.

CONCLUSIONSCollagen could be used as wound dressing.

Amino Acids ; analysis ; Animals ; Biological Dressings ; Cattle ; Collagen ; analysis ; chemistry ; isolation & purification ; Freeze Drying ; Polyurethanes