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We hypothesized that teats with a teat apex score (TAS) of 4 on a 4-point scale would exhibit elevated levels of denatured collagen compared with teats with lower TAS. We procured keratin layer and smooth muscle samples from Holsteins with TAS ranging from 1 to 4, as well as from crossbred heifers (Japanese Black male and Holstein female) with TAS of 1. Teats with a TAS of 4 demonstrated increased total collagen content, higher amounts of type I collagen (the harder, thicker variant), and reduced amounts of type III collagen (the softer, thinner variant) compared with teats with lower TAS. Teats with TAS of 3 and 4 exhibited evidence of damaged collagen in smooth muscle layers compared with teats with TAS of 1. Additionally, we identified 47-kDa heat shock protein-positive fibroblasts in the smooth muscles of teats with TAS of 3 and 4. Therefore, the smooth muscle of teats with a TAS of 4 exhibited increased amounts of denatured collagen in comparison to teats with lower TAS., (© 2024 Japanese Society of Animal Science.)

Purpose: To assess collagen content and types in the rectus abdominis muscle of cadavers of different ages., Methods: Forty fresh adult male cadavers within 24 h of death were obtained from an Institute of Legal Medicine and divided by age at death into Group 1 (mean age, 23.3 years; range, 18-30 years; n = 20) and Group 2 (mean age, 46.2 years; range, 31-60 years; n = 20). From each cadaver, samples of the rectus abdominis muscle measuring 1 cm(2) were collected 3 cm superiorly and 2 cm inferiorly to the umbilicus. Histological sections were prepared and stained with picrosirius red and Masson's trichrome stain for visualization of total collagen fibers, and immunohistochemical analysis was performed to distinguish types I, II, III, IV and V collagen., Results: No significant differences in total collagen were found between groups by Masson's trichrome staining. However, picrosirius red staining revealed a significantly greater amount and higher concentration of total collagen and types I and III collagen in Group 1 than in Group 2 (P < 0.05). All but type II collagen were detected by immunohistochemistry in both groups. No significant difference in type IV collagen was found between groups. Type V collagen was detected by immunohistochemistry in both groups, but quantification was not possible due to background staining., Conclusion: The amounts of types I and III collagen in the rectus abdominis muscle were significantly smaller in older subjects.

Objectives: Collagen-based nanocomposite incorporating nanobioactive glass (Col/nBG) was developed as a scaffolding matrix for dentin-pulp regeneration. The effects of the novel matrix on the proliferation of human dental pulp cells (hDPCs) and their differentiation into odontoblastic lineage were investigated., Methods: Nanocomposite scaffold was prepared by incorporating nBG within the Col solution and then reconstituting them into a membrane form. Cell growth by MTS assay, adhesion by scanning electron microscopy (SEM), and odontoblastic differentiation by alkaline phosphatase (ALP) activity, mineralization, and the mRNA expression of differentiation-related genes of DPCs on each scaffold were evaluated., Results: The introduction of nBG significantly improved the bone mineral-like apatite formation in the simulated body fluid, suggesting excellent acellular bone-bioactivity. The hDPCs cultured on the Col/nBG nanocomposite have shown active growth behavior during culture for 14 days. The mRNA levels of major organic extracellular matrix of dentin, collagen type I and III were highly expressed in the Col/nBG matrix. Moreover, the alkaline phosphatase (ALP) activity and the mineralized nodule formation were increased in the Col/nBG nanocomposite compared to those in Col. Odontoblatic differentiation genes, including dentin sialophosphoprotein, dentin matrix protein I, ALP, osteopontin and osteocalcin were significantly stimulated in the Col containing nBG. Moreover, the key adhesion receptor integrin components α2 and β1, specifically binding to collagen molecule sequence, were upregulated in Col/nBG compared to Col, suggesting that odontogenic stimulation was closely related to the integrin-mediated process., Significance: In our study, the nanocomposite Col/nBG matrix induced the growth and odontogenic differentiation more effectively than Col alone, providing a promising scaffold condition for regeneration of dentin-pulp complex tissue., (Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Objective: To evaluate the action of conjugated equine estrogen, raloxifene and isolated or combined genistein-rich soy extracts on collagen fibers in the bones of oophorectomized rats., Materials and Methods: Seventy female rats received testosterone propionate (0.1 µg/g) on the 9th day after birth. At 6 months of age, the rats were administered the vehicle (propylene glycol, 0.5 ml/day), and ten of the rats were randomly chosen to comprise the non-oophorectomized control group (GI). The other 60 rats were ovariectomized and randomized into six groups of ten as follows: GII, vehicle; GIII, conjugated equine estrogen (CEE), 50 µg/kg/day; GIV, raloxifene (RAL), 0.75 mg/kg/day; GV, genistein-rich soy extract (GSE), 300 mg/kg/day; GVI, CEE + GSE, 50 µg/kg/day + 300 mg/kg/day; and GVII, CEE + RAL, 50 µg/kg/day + 0.75 mg/kg/day. Three months after surgery, the drugs were administered for 60 consecutive days. All rats were euthanized, and their left tibiae were removed for histological routine. The histological sections were stained with hematoxylin-eosin, and picrosirius for evaluating bone microarchitecture. Types I and II collagen fibers were analyzed by immunofluorescence. Data analysis was carried out with ANOVA and Tukey's test., Results: Collagen reduction was significant in the GIII animals when compared to the other groups (p < 0.05). There was no significant difference in the thickness of collagen fibers among the groups. There was a greater quantity of type III collagen in GVI than in the other groups., Conclusion: Our data indicate that conjugated equine estrogen improves bone quality because it increases the quantity of type I collagen while reducing the quantity of thin collagen fibers. In addition, the combination of CEE and raloxifene or genistein-rich soy extract is not as efficient as CEE itself to improve bone quality.

Based on previous studies showing that interleukin-1 (IL-1) significantly increased after stress shielding, this article reports further research into the possible therapeutic applications of IL-1 receptor antagonist (IL-1Ra). Forty rats whose left Achilles tendons were denervated and completely stress shielded were divided into 5 groups: 2-week phosphate-buffered saline (PBS); 4-week PBS; 2-week IL-1Ra; 4-week IL-1Ra; and normal control. The Achilles tendons were tested morphologically, and the changes in collagen I and III, matrix metalloproteinases (MMP)-1 and -3, and tissue inhibitors of metalloproteinase (TIMP)-1 were determined. The collagen fibrils in the IL-1Ra groups were morphologically more similar to those in the control group than to those in the PBS groups. The collagen I levels increased in the 2-week groups. Significant differences existed between the PBS and IL-1Ra groups at 4 weeks. The MMP-1 level increased dramatically after stress shielding and increased less in the 2-week IL-1Ra group than in the 2-week PBS group. The degree of decrease of MMP-3 in the IL-1Ra groups was significantly less than that in the PBS groups. The collagen III and TIMP-1 levels continued to increase, and no difference was found between the PBS and IL-1Ra groups. Interleukin-1 receptor antagonist prevented morphological deterioration and collagen metabolism of the denervated Achilles tendons after stress shielding, likely by inhibiting the decline of MMP-3 and increasing MMP-1 levels at an early stage., (Copyright 2012, SLACK Incorporated.)

Purpose: We hypothesize that Permacol™ may allow controlled integration over time while providing long-term mechanical stability and native tissue remodeling. The purpose of this report is to investigate these properties in an explanted piece of Permacol™ after 2 years in vivo., Methods: A 62-year-old female presented with a complex abdominal wall history having undergone a transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstruction 10 years ago, followed by an abdominal wall repair with Marlex™ mesh for weakness 3 years later. Two years ago, she developed an abdominal bulge repaired with a Permacol™ overlay. Twenty-three months postoperatively, she presented with abdominal distension. Computed tomography (CT) scanning demonstrated a fluid collection behind the Permacol™. She underwent incision and drainage of the hematoma/bursa and quilting repair of the abdominal wall. A 1 × 6-cm Permacol™ section was resected as part of closure. Histology, immunohistochemistry, and mechanical testing of the Permacol™ explant were performed., Results: Histology showed fibroblast and blood vessel ingrowth with no cellular infiltrates reflective of inflammation. Immunohistochemistry for human-specific collagen types I and III and elastin detected staining throughout. Sections stained with non-specific control antibody exhibited no discernable staining. Elastin highlighted blood vessels. Native Permacol™ had a breaking strength of ~20 N, while for explanted Permacol™, it was ~33 N., Conclusions: Permacol™ maintained durability while allowing vascular ingrowth without residual inflammation. Explant demonstrated integration with human collagen and elastin remodeling throughout. Increase in mechanical strength may reflect newly synthesized collagen and elastin. These histologic findings and clinical result support the use of Permacol™ in complex abdominal wall reconstruction.

Objective: The cause of haemorrhoidal disease is unknown, epidemiological data and histopathological findings support the hypothesis that reduced connective tissue stability is associated with the incidence of haemorrhoids. Therefore the aim of this study was to analyse the quantity and quality of collagen formation in the corpus cavernosum recti in patients with III°/IV° haemorrhoids in comparison with persons without haemorrhoids., Method: Haemorrhoidectomy specimens of 31 patients with III°/IV° haemorrhoids were examined. The specimens of 20 persons who died a natural death and who had no haemorrhoidal disease served as the controls. The amount of collagen was estimated photometrically by calculating the collagen/protein ratio. The collagen I/III ratio served as parameter for the quality of collagen formation and was calculated using cross polarization spectroscopy., Results: Patients with haemorrhoids had a significantly reduced collagen/protein ratio (42.2 ± 16.2μg/mg vs 72.5±31.0μg/mg; P= 0.02) and a significantly reduced collagen I/III ratio (2.0±0.1 vs 4.6±0.3; P<0.001) compared with persons without haemorrhoidal disease. There was no correlation with patients' age or gender., Conclusions:  There is a fundamental disorder of collagen metabolism in patients with haemorrhoidal disease. It remains unclear whether this is due to exogenous or endogenous influences., (© 2010 The Authors. Colorectal Disease © 2010 The Association of Coloproctology of Great Britain and Ireland.)

Objectives: Control of hyperplastic and invasively growing gingival tissue is crucial for maintaining normal oral function and for successful bone regenerative therapy. We tested the hypothesis that materials containing N-acetyl cysteine (NAC), an antioxidant cysteine derivative, can control proliferation and function of oral mucosal cells., Methods: Oral mucosal cells derived from the rat palatal tissue were cultured with or without NAC at different concentrations (2.5-10.0mM). To simulate inflammatory conditions, cultures were treated with hydrogen peroxide. NAC was also applied via collagen materials in membrane and sponge forms to explore the clinical applicability. The redox balance inside the cells was evaluated by measuring the concentration of intracellular glutathione (GSH)., Results: Adding NAC into cultures of oral mucosal cells reduced their proliferation, transcriptional expression, and collagen production in an NAC-concentration-dependent manner without cytotoxic effects. Furthermore, NAC substantially reduced the hydrogen peroxide-induced elevation of cellular proliferation and collagen production. The controlling effects of NAC were also demonstrated in cells cultured on NAC-containing collagen materials and were associated with an increase in intracellular glutathione (GSH) reserves and a decrease in the oxidized form of glutathione (GSSG)., Significance: These results indicate that NAC may abrogate inflammation- or oxidative-stress-induced hyperfunction of oral mucosal cells and that it can be delivered effectively via biodegradable materials. This study provides a basis to explore NAC-containing biomaterials that are functionalized to control oral soft tissue growth and function without cytotoxicity.

Purpose: To compare polyester with absorbable layer prosthesis with collagen-elastin/polypropylene prosthesis in the repair of abdominal wall defects., Methods: The 16 studied rabbits were divided in groups A and B (euthanized on the 30th and 60th days, after the implant of the mesh). The animals underwent laparotomy and received a 2 cm wall 'defect' on each side of the Alba linea. The repair was made with the suture of a polyester mesh with absorbable film on the left side of the Alba Linea and with collagen-elastin/polypropylene mesh on the right side. Adherences were classified according to Nair Score and microscopic evaluation observing types I and III collagen formation and other immunohistochemical analyses., Results: There were no significant differences in adhesion formation. The collagen type I showed higher deposition in polyester with absorbable layer. In group B, the difference between the meshes was significant, with higher collagen III deposition in polyester with absorbable layer (60 masculine P.O.). About the metalloproteinases, the presence of MMP -1 and MMP-8 were about the same; the expression of MMP-13 increased near to the 60th day., Conclusions: There is no significant difference between the two meshes in adhesion formation and immunohistochemical evaluation. The polyester mesh resorbable film presented a higher deposition of collagen.

Purpose: This study assessed the collagen deposition and correlated it with local inflammatory responses to evaluate the length of time required for fibroplasia when polypropylene meshes are used to repair incisional abdominal wall hernias in rats., Methods: Thirty-six male Wistar rats underwent longitudinal resection of a peritoneal and musculoaponeurotic tissue segment (3x2 cm) of the abdominal wall followed by defect reconstruction with polypropylene mesh bridging over aponeurosis. The animals were divided into 6 groups according to the time points for the analysis of fibroplasia: 1, 2, 3, 7, 21 and 30 days post-implantation. Animals were sacrificed at each time point, and the site where the polypropylene mesh was implanted was evaluated histologically to assess inflammatory response and percentage of collagen using computer-assisted videomorphometry., Results: Total collagen was found at the mesh site on the 3rd day post-implantation, and increased progressively on all subsequent days up to the 21st day, when it reached its highest percentage (p<0.001). Type III collagen increased progressively from the 3rd to the 21st days, when it reached its highest percentage (p<0.001); on the 30th day, it decreased significantly (p>0.001). Type I collagen was first found between the 7th and 21st days; it reached its highest percentage on the 21st day and then remained stable until the 30th day. The type I to type III collagen ratio increased significantly and progressively up to the 30th day (p<0.001). Neutrophils were found at the mesh site from the 1st to the 21st day post-implantation. Macrophages, giant cells and lymphocytes were seen on the 2nd day. Thirty days after mesh implantation, neutrophils disappeared, but the percentages of macrophages, giant cells and lymphocytes remained stable (p<0.001)., Conclusions: This study showed that total collagen was first seen on the 3rd day post-implantation, with a higher percentage of type I collagen at the last observational time point. The prolonged healing inflammatory response and the persistence of chronic inflammation surrounding to the mesh did not affect the length of time required for fibroplasia.

Objective: To investigate the dynamics of the cartilage matrix in the articular condyle after removal of a side shift plate; Emergence of type I, II, and III collagen in the matrix as well as changes in levels of matrix metalloproteinase (MMP)-1, -8, and -13 that degrade collagen were studied histopathologically and immunohistochemically., Design: Lateral displacement of the mandible was achieved by attaching a side shift plate to the anterior teeth of the maxilla in male rats at 6 weeks. The wearing period of the side shift plate was 8 weeks. Observations were made at 0, 1, 2, 4 and 8 weeks after removal., Results: In histopathological findings, the timing of proliferation of the layer of hypertrophy varied between the bilateral sides. In immunohistochemical findings a significant decline in the expression of type II collagen in the displacement side was observed immediately after removal. Moreover, the expressions of MMPs were elevated in both sides on 0 weeks. At 1 week after removal, a significant elevated in the expression of type II collagen, MMPs was decline in both sides., Conclusions: After removal, the levels of MMP-1, -8, and 13 were reduced and the emergence of type II collagen increased. Thus, cellular outgrowth was initiated to trigger intracartilaginous ossification to restore the cartilage matrix.

Tissue shortage complicates the surgery of cleft palate (CP) anomalies. The healing of defects on the palate impairs growth of the dento-maxillary complex due to scar tissue formation. Implantation of grafts into the wound area might reduce this adverse effect of surgery. The aim of this study was to evaluate a cultured autologous mucosal substitute, which can be used as a graft material. Two different types of cultured mucosal substitutes composed of skin-derived substrates (unprocessed dermis and AlloDerm) and autologous oral keratinocytes were implanted in palatal wounds in six beagle dogs (1-1.5 years of age). The cultured substitutes were compared with a sham and a control group. The animals were sacrificed in pairs 1, 3, and 12 weeks after surgery. Epithelial regeneration, inflammatory response (leucocyte protein L1), ingrowth of (myo-) fibroblasts, collagen type III, and formation of a basal membrane (JM 403) were evaluated. The results demonstrated that all cultured substitutes possessed a multilayered epithelium, closely resembling normal palatal epithelium. After implantation, however, the epithelium was lost and an inflammatory response was observed in the first week. After 3 and 12 weeks, the implanted substitutes had completely disappeared and epithelial migration occurred from the wound margins. It is possible to culture an autologous epithelium on a skin-derived substrate and implant it as an oral mucosal substitute in palatal wounds. However, these substitutes do not improve the healing of palatal wounds. It is suggested that the revascularization of the wound area is too slow to allow survival and integration of the substitutes.

The development of a sarcomatoid morphotype is recognized as an extreme form of dedifferentiation in renal cell carcinoma and is associated with a poor prognosis. Although sarcomatoid renal cell carcinoma shows pronounced spindle cell morphology, clear cell renal cell carcinoma may show early spindle cell change with cellular elongation, and the prognostic significance of this is debated. To determine the relationship between sarcomatoid renal cell carcinoma and clear cell renal cell carcinoma showing early spindle cell change, we have investigated collagen expression using immunohistochemistry in these 2 tumor types. Both sarcomatoid renal cell carcinoma and early spindle cell change tumors showed pericellular interstitial expression of collagen types I and III, whereas sarcomatoid renal cell carcinoma also showed cytoplasmic expression of these collagen types. Expression of these collagen types in typical clear cell renal cell carcinoma was, in occasional cases, limited to faint and patchy staining in a pericellular interstitial distribution. Tumor cells did not stain for collagen type IV in sarcomatoid renal cell carcinoma, early spindle cell change, or typical clear cell renal cell carcinoma. In sarcomatoid renal cell carcinoma, there was diffuse pericellular expression of collagen type V and patchy pericellular expression of collagen type VI, whereas early spindle cell change tumors showed patchy pericellular staining with antibodies to collagen type V. Collagen type VI expression in early spindle cell change was largely confined to the vascular adventitia and areas of scarring, although very occasional foci of faint interstitial staining were also seen. In typical clear cell renal cell carcinoma, staining of collagen types V and VI was limited to the vascular adventitia and foci of desmoplasia, whereas no staining of tumor cell cytoplasm were seen. This study has shown that collagen expression of sarcomatoid renal cell carcinoma differs from that of early spindle cell change and provides validating evidence that these 2 morphotypes should not be considered together for classification purposes.

Incisional hernias represent one of the most common complications of laparotomies. Previous investigations have suggested that a disorder in collagen fiber structure and production level may be an important pathologic cause of abdominal wall hernias. We hypothesized that a cross-examination of multiple extracellular matrix biomarkers might identify underlying defects contributing to the development of hernias. We examined two patient populations: patients with incisional hernias (presenting for hernia repair) and patients with no hernia after previous laparotomy (undergoing a second laparotomy). Patients with previous wound infections, open abdomens, or on steroids were excluded. Fascia samples were obtained from all patients at the time of their second operation and they were studied. Western blots and reverse transcriptase-polymerase chain reaction were used to determine the ratio of type I, III, and IV collagens, as well as matrix metalloproteinase 1 (MMP1) and MMP2 in both groups. Values of P < 0.05 were considered statistically significant. At the protein level, collagen I/III ratio was slightly decreased in patients with incisional hernias compared with those with no hernia, whereas it was significantly decreased at the mRNA transcript level (0.49 vs 1.03, P < 0.01, respectively). The MMP-1 mRNA transcripts were not different in incisional hernia (IH) versus nonincisional hernia, but the MMP-2 level was significantly increased in patients with IH. Reduced collagen I/III and MMP-1/MMP-2 ratios in IH might be consequence of the biological activities between key elements participating in the development of IH after laparotomies. The potential role of MMP-2-specific inhibitors in preventing IH is of significance for future studies.

The extracellular matrix (ECM) performs a very important role in growth regulation and tissue differentiation and organization. In view of this, the purpose of this study was to analyze the collagen, the major organic component of dental pulp ECM, in papillae of human tooth germs in different developmental phases. The maxillas and mandibles of 9 human fetuses ranging from 10 to 22 weeks of intrauterine life were removed and 16 tooth germs (1 in the cap stage, 8 in the early bell stage and 7 in the late bell stage) were obtained. The pieces were processed for histological analysis and stained with hematoxylin-eosin, Masson's Trichrome and picrosirius staining technique. Both types of collagen in the dental papilla were only detected by the picrosirius staining technique under polarized light microscopy. Type III collagen was detected in all specimens. Type I collagen was present in focal areas of the dental papilla only in some specimens. In conclusion, the findings of this study showed that type III collagen is a regular component of the papillae of human tooth germs whereas type I collagen is present in a significantly lesser amount.

The tenosynovium within the carpal tunnel consists of a single layer of synovial cells, which lines the bursae within the carpal tunnel, and the subsynovial connective tissue (SSCT), which contains the tendon vasculature and other structural elements. In this study, we used immunogold labeling to localize collagen types within the SSCT in three cadaver specimens and three patients with carpal tunnel syndrome. Positive labeling for collagen types I, III and VI was found with immunoelectron microscopy. Collagen types I and III were codistributed within the SSCT. Type VI was primarily located in microfibrillar structures between collagen bundles, between elastin and collagen bundles and between collagen bundles and cells. There was no difference in the distribution of collagen types when comparing cadaver specimens and carpal tunnel patients.

Background: Topical corticosteroids decrease collagen synthesis during short-term treatment and can induce skin atrophy when applied over the long term. In contrast, short-term tacrolimus ointment therapy does not affect collagen synthesis., Objectives: Our aim was to evaluate the long-term effects of 0.1% tacrolimus ointment on collagen synthesis and on skin thickness in adults with moderate to severe atopic dermatitis (AD) and to compare the findings with the effects of conventional steroid-based therapy., Methods: Fifty-six patients with AD were treated with 0.1% tacrolimus ointment in a 1-year, open-label, prospective clinical trial. Thirty-six patients with AD applied conventional steroid-based therapy and 27 healthy subjects were recruited as controls. The primary endpoint was the change in levels of procollagen propeptides I and III measured by radioimmunoassay between baseline and month 12. Additional endpoints included the change in skin thickness measured by ultrasound between baseline and month 12., Results: Procollagen propeptide baseline values were significantly lower in the group to be treated with tacrolimus ointment than in healthy controls. One-year treatment with tacrolimus ointment was associated with an increase in collagen synthesis; the median increase in combined procollagen propeptide levels was 272 micro g L-1 (+ 140.9%, P < 0.001) and was accompanied by a significant increase in skin thickness. In three patients with visible skin atrophy, this condition ameliorated. Corticosteroid-based therapy had no significant effect on collagen synthesis; the median increase in combined procollagen propeptide levels was 11 micro g L-1 (+ 3.9%). A significant reduction in skin thickness was demonstrated., Conclusions: Long-term tacrolimus ointment therapy in patients with AD is nonatrophogenic and reverses corticosteroid-induced skin atrophy.

Objective(s): To investigate whether the quantity of collagen types I and III in the pubocervical fascia of women with genuine stress incontinence (GSI) affects the efficacy of the tension-free vaginal tape (TVT) procedure., Methods: Sixty-three patients participated in the study and were divided in 2 groups as follows: 37 patients with GSI and pelvic organ prolapse stage I (group 1), and 26 patients with pelvic organ prolapse stage I but not GSI (control group). Urodynamic studies confirmed the diagnosis of GSI. Biopsies were obtained during surgery from the pubocervical fascia., Results: The quantity of collagen types I and III was statistically significantly reduced in patients with GSI compared to the control group. The efficacy of the TVT procedure in patients with a significant reduction in collagen type I was an 82.1% cure. In patients with a significant reduction in collagen type III, the TVT efficacy was an 85.1% cure. The efficacy of the TVT procedure was not statistically significantly different between patients with GSI and a significant reduction in collagen types I and III, and patients with no reduction in collagen types I and III., Conclusions: The significantly reduced quantity of collagen types I and III in the pubocervical fascia of women with GSI does not affect the efficacy of the TVT procedure at an average of 25 months of follow-up., (Copyright 2004 S. Karger AG, Basel)

Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the expression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein (microg/mg) showed significant differences comparing different mesh materials (sham controls 38.44 +/- 16.33 microg/mg, PE 68.5 +/- 23.8 microg/mg, PP 101.6 +/- 32.3 microg/mg, PG 49.6 +/- 11.6 microg/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated (r =.95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material.

We have previously reported that the fragility of skin, tendon and bone from the oim mouse is related to a significant reduction in the intermolecular cross-linking. The oim mutation is unlikely to affect the efficacy of the lysyl oxidase, suggesting that the defect is in the molecule and fibre. We have therefore investigated the integrity of both the oim collagen molecules and the fibre by differential scanning calorimetry. The denaturation temperature of the oim molecule in solution and the fibre from tail tendon were found to be higher than the wild-type by 2.6deg.C and 1.9deg.C, respectively. With the loss of the alpha2 chain, the hydroxyproline content of the homotrimer is higher than the heterotrimer, which may account for the increase. There is a small decrease in the enthalpy of the oim fibres but it is not significant, suggesting that the amount of disorder of the triple-helical molecules and of the fibres is small and involves only a small part of the total bond energy holding the helical structure together. The difference in denaturation temperature of the skin collagen molecules (t(m)) and fibres (t(d)) is significantly lower for the oim tissues, 19.9deg.C against 23.1deg.C, indicating reduced molecular interactions and hence packing of the molecules in the fibre. Computation of the volume fraction of the water revealed that the interaxial separation of the oim fibres was indeed greater, increasing from 19.6A to 21.0A. This difference of 1.4A, equivalent to a C-C bond, would certainly decrease the ability of the telopeptide aldehyde to interact with the epsilon -amino group from an adjacent molecule and form a cross-link. We suggest, therefore, that the reduction of the cross-linking is due to increased water content of the fibre rather than a distortion of the molecular structure. The higher hydrophobicity of the alpha2 chain appears to play a role in the stabilisation of heterotrimeric type I collagen, possibly by increasing the hydrophobic interactions between the heterotrimeric molecules, thereby reducing the water content and increasing the binding of the molecules in the fibre.

Objective: To find a simple method to detect the collagens in human hypertrophic scars., Methods: The content and distribution of collagen in human hypertrophic scars were observed with both conventional light and polarization microscopy combined with image analysis of hypertrophic scar sections stained with picrosiriusred., Results: Polarization microscopy revealed closely packed thick fibrils of type I collagen fibers that showed either red or yellow intense birefringence in the hypertropic tissue, whereas type III collagen fibers consisted mainly of green thin fibril with weak greenish birefringence. The hypertrophic scar, as indicated by image analysis, contained (73.95+/-3.22)% type I collagen and (21.13+/-3.57)% type III collagen., Conclusion: Polarization microscopy and sirius red staining is an ideal method in analyzing the distribution and arrangement of the collagen in hypertrophic scars.

Collagen is one of the chief components of the extracellular matrix of gingival connective tissue, where five different types have been identified to date. The molecular mechanism of collagen loss in periodontitis still needs to be explored. In the present study total collagen content was investigated in gingival connective tissue of adult periodontitis (AP) as well as early onset periodontitis patients (EOP) and clinically healthy subjects. Furthermore, collagen type I, III, IV, V andVI content was evaluated in gingival biopsies obtained from periodontitis patients. There was a statistically significant difference between AP (25.1 +/- 8.1 microg/mg) and EOP (15.6 +/- 4.0microg/mg) groups with regard to the total collagen content (P < 0.05). In the clinically healthy control group the total collagen content was 20.7 +/- 4.6microg/mg. Moreover, the distribution of collagen types exhibited variations in pooled homogenates of each periodontitis group. The total collagen loss seemed to be greater in the EOP patients than in the AP patients. When the ratio of fibril forming collagens to nonfibrillar collagens was evaluated, it seems to be decreased in AP patients in comparison to EOP patients. The findings of the present study suggest that different collagen types present in various periodontitis categories may be related with diverse pathogenic mechanisms acting in these diseases.