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PubMed2007

Differential chemokine response of fibroblast subtypes to complement C1q.

BACKGROUND AND OBJECTIVE: The pathogenesis of periodontitis includes an inappropriate activation of the classical complement cascade (C') with accumulation of inflammatory C' products in fluids and tissues. Our hypothesis is that in vivo the C' product, C1q, may act as a regulatory component of the innate immune response of distinct matrix fibroblasts to the inflammatory environment. This study analyzed the C1q induction of pro-inflammatory cytokine secretion in fibroblast subtypes derived from distinct periodontal tissues, and identified a mechanism of the cell response. MATERIAL AND METHODS: Primary human gingival fibroblast, periodontal ligament fibroblast, and granulation tissue fibroblast cultures were treated for 24 h with C1q. Protein arrays assessed the secretory profile of constitutive and C1q-inducible pro-inflammatory cytokines, and enzyme-linked immunosorbent assays were used to quantify the kinetics of each inducible cytokine. RESULTS: Granulation tissue fibroblast cultures were unresponsive to C1q challenge. In contrast, periodontal ligament fibroblasts responded with a release of monocyte chemoattractant protein (MCP)-1, interleukin-6, interleukin-8, and macrophage inflammatory protein (MIP)-1beta higher than the basal level by 8.2-, 7.0-, 3.8-, and 7.2-fold, respectively. Human gingival fibroblast cultures increased secretion of these chemokines by 5.2-, 4.5-, 3.0-, and 9.8-fold, respectively. Inhibitor studies revealed that C1q-inducible release of chemokines by the human gingival fibroblast and periodontal ligament cultures was contingent upon p38 mitogen-activated protein kinase activity. CONCLUSION: The ability of C1q to stimulate secretion of pro-inflammatory chemokines depends upon which specific fibroblast subtype is involved. Targeting C1q-activated intracellular signaling pathways may be an effective means to inhibit the production of chemokines that promote inflammatory cell infiltration into gingival and periodontal ligament tissues.

Cells, Cultured↗

PubMed1969

The effect of scurvy on hexosamine-containing substances in healing wounds in guinea pigs.

1. Granulation tissue from healing tendonectomy wounds in guinea pigs was analysed and the effects of inanition and ascorbic acid deficiency on this tissue were investigated. 2. Inanition produced no significant effect on either the glucosamine or the galactosamine content of the tissue. Ascorbic acid deficiency decreased the galactosamine content without affecting the glucosamine content. 3. Fractionation of papain-digested granulation tissue gave three major fractions, which behaved respectively as glycopeptide, hyaluronic acid and a sulphated glycosaminoglycan mixture. At least half of the sulphated glycosaminoglycan mixture behaved as dermatan sulphate. 4. Inanition produced no consistent effect on the fractions examined. In ascorbic acid deficiency, a decrease in the sulphated glycosaminoglycan fraction was observed, which accounted for the decreased galactosamine content of the tissue. This was accompanied by a decrease in hyaluronic acid and a slight increase in the glycopeptide fraction.

Animals↗

PubMed1979

Effect of SiO2-liberated macrophage factor on protein synthesis in connective tissue in vitro.

1. To elucidate the role of macrophages in fibrosis the effect of the SiO2-liberated macrophage factor was assessed on protein synthesis in granulation-tissue slices. SiO2 could be replaced by chrysotile asbestos. The active factor is found in the 45/55% sucrose interface of macrophage homogenate. 2. There is no evidence of the involvement of collagenase. 3. The SiO2 effect is not influenced by the addition of yeast RNA to the incubation medium. 4. At a small concentration of polyvinylpyridine-N-oxide (PVNO) protein synthesis in the granulation tissue slices is stimulated, but at higher concentrations PVNO prevented the liberation of the fibrogenic factor from macrophages by SiO2. 5. Phospholipase C and trypsin inhibited the effect of SiO2, which was partially abolished also by heating, and by repeated freezing and thawing. 6. The macrophage RNAse, its inhibitors and fibroblast mRNA are suggested as key factors in the development of fibrosis.

Animals↗

PubMed1984

Competence of nerve tissue as distal insert promoting nerve regeneration in a silicone chamber.

A new peripheral nerve forms across a 10 mm gap within a silicone chamber regeneration model when the distal segment of a transected sciatic nerve, connected to its end organs, is sutured into the distal end of the chamber. We have tested the ability of other tissue inserts to support axonal regeneration in the chamber. When an isolated 2 mm piece of sciatic nerve was sutured into the distal end, fibrin matrix formation, cell immigration and axonal regeneration were identical to those occurring in the control. When the distal nerve insert was replaced with a 2 mm piece of skin or a ligation, a matrix did not form and subsequent cell immigration and axonal regeneration did not occur. When a 2 mm piece of tendon was inserted, a matrix did form at 1 week, but a structure across the gap was observed at later time periods in only 2 out of 7 chambers. The matrix either dissolved before cells could enter the chamber or did not promote cellular immigration and subsequent axonal regeneration. When the distal end was left open, a matrix formed and cells from the reactive tissue outside the chamber entered the matrix and formed a granulation tissue bridge across the gap. This tissue failed to support axonal regeneration; at 3 weeks, axons stopped 1 mm beyond the proximal stump at the interface with the granulation tissue. Thus, matrix formation and a cellular bridge are necessary but not sufficient to ensure regeneration. Successful regeneration across the silicone chamber gap requires humoral and/or cellular contributions available from peripheral nervous tissue and not from the other tested tissues.

Animals↗

PubMed2003

Semiquantitative analysis of the histopathological features of the neuropathic foot ulcer: effects of pressure relief.

OBJECTIVE: This study was designed to evaluate the histopathology of neuropathic ulcers and whether pressure relief could change such histological patterns. RESEARCH DESIGN AND METHODS: We compared neuropathic plantar ulcers tissue excised from 10 diabetic patients (group A) with those taken from 10 patients with comparable lesions and glycemic control after 20 days in a total contact cast (group B). Tissue specimens were blindly examined by two independent pathologists for hyperkeratosis, fibrosis, cutaneous annexes, capillaries, inflammation, cellular debris, and granulating tissue. For each parameter, quantification was obtained according to an arbitrary score: 0, absent; 1, present in <33%; 2, present in 34-66%; and 3, present in >67% of the lesion. RESULTS: Patients in group B showed a marked reduction in ulcer size after 20 days of casting (P < 0.01). The histopathological features of the two groups markedly differed. Group A patients showed a predominance of inflammatory elements as well as matrix alterations, vessel disruptions, inflammation, and debris. Group B ulcers showed a shift toward a reparative pattern with prevalence of neoformed capillaries and fibroblasts. Semiquantitative analysis confirmed the prevalence of hyperkeratosis, fibrosis, inflammation, and cellular debris in group A patients (P < 0.05), whereas cutaneous annexes, capillaries, and granulating tissue were more prevalent in group B lesions (P < 0.01). CONCLUSIONS: These results indicate that pressure relief with a total contact cast is associated with changes in the histology of neuropathic foot ulcers, indicating reduction of inflammatory and reactive components and acceleration of reparative processes.

Aged↗

PubMed1982

[Obliteration of the bulla of the guinea pig with a Kieler bone chip].

The obliteration of the sinus frontalis after removal of the chronically inflamed and irreversibly transformed mucous is a common surgical treatment. There is no definite answer to the question of the most suitable material for obliteration. The suitability of the Kieler Knochenspan was, therefore, tested in animal experiments. After trepanation and removal of the mucous of the bulla of 30 guinea pigs, the cave was filled up with Kieler Knochenspan. The animals were killed 2 weeks, 1, 2, 3, and 4 months after implantation. The implanted nonvital spongy substance of the Kieler Knochenspan was first enclosed in granulation tissue. Then, depending on the duration of implantation, this granulation tissue turns into bony substance first peripherically and then centrally. Immunologically conditioned reactions were never observed. Thus, the transformation of the Kieler Knochenspan in the pneumatic system of the guinea pig is the same as in human tubular bones. So the conclusion is drawn that Kieler Knochenspan might be used in the obliteration of the human frontal sinus.

Animals↗

PubMedDate not supplied

Treatment of chronic nonhealing leg ulceration with gaseous nitric oxide: a case study.

BACKGROUND: Despite the best clinical practice, chronic nonhealing ulcers of the lower extremities present a significant challenge. Nitric oxide (NO) has been shown to play a significant role in biological functions including wound healing and as an antimicrobial agent in nonspecific immune response. OBJECTIVE: Our goal was to study the effect of gaseous NO (gNO) administered directly to a two-year-old nonhealing chronic venous ulcer in a 55-year-old male presenting with a 30-year history of severe venous disease. METHODS: gNO (200 ppm) was applied to the lower extremity using a delivery system connected to a "single patient use" plastic boot, at 1.0 L/min. RESULTS: The patient received an average of 8.1-h treatments for 14 consecutive nights. On day 0 the wound was malodorous and covered by bacterial biofilm with little healthy granulation tissue present. Following 3 days of gNO treatment, healthy granulation tissue was noted with absence of malodorous odor. At day 14, the ulcer was significantly reduced in size (p = 0.014) and almost completely reepithelialized. Day 10 post-treatment did not reveal any deterioration in healing. Six weeks later, the wound was 90% healed. At 26 weeks post gNO discontinuation, the ulcer was completely healed. CONCLUSIONS: This single case study demonstrated that gNO as a topical agent was well tolerated by the patient without any report of discomfort or side effect. The result of wound healing was very promising and warrants future exploration.

Administration, Topical↗

PubMed1991

TGF-beta 1 accelerates wound healing: reversal of steroid-impaired healing in rats and rabbits.

TGF-beta modulates events of normal wound healing through multiple pathways that influence cell infiltration, proliferation, angiogenesis, extracellular matrix synthesis and remodeling. The effects of topically applied TGF-beta 1 on wound healing in two models of healing were evaluated when the healing response was impaired by the administration of methylprednisolone to rats or rabbits. TGF-beta 1 increased the healing of linear incision wounds on rats, as measured by breaking strength, to that of normal rats. Full thickness open wounds were also created on the inner ears of rabbits to simulate a non-contracting wound with limited blood supply. Healing was further impaired by the administration of methylprednisolone. The single application of TGF-beta 1 improved the healing of open wounds. TGF-beta 1 stimulated increased granulation tissue formation, as well as reepithelialization. The amount of granulation tissue and epithelialization were similar to wounds from normal-healing control rabbits. The delayed healing caused by methylprednisolone permitted the evaluation of multiple applications of TGF-beta 1 to wounds. Two applications of TGF-beta 1 spaced 7 days apart further improved the healing response when compared to a single application. Thus, single or multiple topical applications of TGF-beta 1 reversed impaired healing conditions secondary to methylprednisolone when used on incisional or open wounds. These observations support the hypothesis that growth factors, such as TGF-beta 1, may be useful as accelerators of wound repair in patients with impaired healing conditions.

Animals↗

PubMed1993

Cellular components of microvascular proliferation in human glial and metastatic brain neoplasms. A light microscopic and immunohistochemical study of formalin-fixed, routinely processed material.

Since the origin of cells contributing to microvascular proliferation (MVP) in glial neoplasms is unsettled, a light microscopic and immunohistochemical study for vascular smooth muscle cells and endothelial cells was performed in formalin-fixed, routinely processed brain tumor biopsy material. MVP in glial neoplasms was compared with that in intracerebral metastatic carcinomas and in intracranial granulation tissue. On the basis of the degree of hyperplasia of hypertrophic cells in the microvascular wall, MVP was subjectively divided into mild, moderate, and glomeruloid (marked) proliferation. The relative contribution of vascular smooth muscle cells and endothelial cells to different degrees of MVP was estimated immunohistochemically using antibodies against alpha-smooth muscle actin and von Willebrand factor, respectively. Glomeruloid MVP occurred in 50% of the malignant glial neoplasms. Moderate MVP was found in most malignant gliomas and in some pilocytic astrocytomas. Glomeruloid MVP was present in peritumoral glial tissue in 4 out of 15 intracerebral metastatic carcinomas, while only mild to moderate MVP was found within these tumors. In granulation tissue MVP was mild. In glomeruloid and moderate MVP vascular smooth muscle cells were more hypertrophic and more numerous than endothelial cells. The contribution of hypertrophic vascular smooth muscle cells to mild MVP was variable. MVP in glial neoplasms was generally not accompanied by a matrix of fibrous stroma but was directly embedded in glial tissue. The architecture of this MVP suggested "in situ" proliferation of microvascular cells without migration of these cells into the surrounding tissue.

Actins↗

PubMed1999

Myocardial scarring after transmyocardial laser revascularization: A potential mechanism of clinical improvement?

BACKGROUND AND OBJECTIVE: The morphological evolution of transmyocardial laser channels was analyzed in a pig model. MATERIALS AND METHODS: Five channels were created in the lateral wall of the left ventricle of 12 animals, using a Ho:YAG laser. In half of the animals, an additional infarction was induced in the same area. Animals were sacrificed at one-week intervals until week 5 and the critical regions of the left ventricular wall were subjected to microscopic computed morphometrical analysis. RESULTS: There was no clearly patent lumen at any stage. Cross-sectional area of the channels fell from 8.5 +/- 1.2 mm(2) at day 0 to 2.1 +/- 0.1 mm(2) at day 35. From day 7 onward, the channel area was gradually replaced by granulation tissue and the proportion of the channel occupied by granulation scar tissue increased from 37 +/- 2% at day 7 to 100% at day 28. In the subgroup with concomitant infarction, granulation tissue of both channel and infarction became indistinguishable from day 14 onward. CONCLUSIONS: These results suggest strongly that channel patency is not the mechanism of angina relief after transmyocardial laser revascularization with Ho:YAG laser.

Animals↗

PubMed1985

A study of calcergy in the rat induced by the implantation of polyurethane sponges soaked in lead acetate.

Polyurethane sponges were soaked in a 5 mg/ml solution of lead acetate, dried, and implanted subcutaneously in rats. Sponges soaked in distilled water were implanted as controls. The reaction to the sponges was studied from 5 h to 140 days after implantation, utilising sponge dry weight gain, rate of ingrowth of granulation tissue, histology and electron microscopy. Five hours after implantation, test sponges showed lead phosphate deposits in the central sponge zone and by one day the deposits stained positively for calcium. Transmission electron microscopy (TEM) showed needle-shaped crystals of hydroxyapatite. Ingrowth of granulation tissue into test sponges was delayed. Breakdown of the sponge matrix was observed in control sponges after 140 days. This model highlighted the physicochemical nature of the calcergic reaction, implicating fluid transudates/exudates in the initial stages.

Animals↗

PubMedDate not supplied

Localization of interleukin-1 in human cholesteatoma.

Recent studies by other investigators have shown that interleukin-1 (IL-1) promotes bone resorption by stimulating various cells. Interleukin-1 not only stimulates collagenase production by fibroblasts and macrophages, but also acts as an osteoclast-activating factor. In this study, IL-1 was localized in human cholesteatoma tissues using both immunoperoxidase and immunofluorescent-staining methods with specific monoclonal antibodies. Highly concentrated IL-1 was found in the epithelial layer and granulation tissue. More specifically, intense staining was seen in basal and spinous cells of the epithelial layer, and in fibroblasts and macrophages of the granulation layer. We also located IL-1 in the normal external ear canal skin; however, the intensity of the staining in the cholesteatoma epithelium was found to be stronger. The presence of IL-1 in the epithelial layer and granulation tissue of the cholesteatoma suggests that IL-1 from the stimulated keratinocytes of the cholesteatoma could be one factor responsible for the markedly increased bone resorption observed in cholesteatoma patients.

Bone Resorption↗

PubMed1997

Acoustic properties of dialysed kidney by scanning acoustic microscopy.

BACKGROUND: A correlation between acquired renal cysts in the dialysed kidney and renal cancer has long been debated, but no changes in the physical properties of kidneys at the microscopic level have been reported. The purpose of the present study was to classify the physical properties of the kidneys of patients undergoing haemodialysis at several stages of pathology by use of the scanning acoustic microscope. METHODS: Sixteen surgically excised kidneys of dialysis patients were investigated. Tissues were fixed in 10% formalin, frozen in acetone, and cut 10 microns thick on a cryostat. We used a scanning acoustic microscope operated in the frequency range of 100-200 MHz. Attenuation constant and sound speed were measured on a two-dimensional distribution. RESULTS: The attenuation constant for inflammatory granulation tissue was significantly higher than that for hyaline degeneration tissue (P < 0.001). Sound speed was high for granulation tissue, but tended to diminish gradually for hyaline degeneration. Sound speed increased again with progression to cystic degeneration (P < 0.001), but the attenuation constant remained low. When a cystic kidney contained a malignant lesion, the previously low attenuation constant rose at that site (P < 0.001), and the previously high sound speed was diminished (P < 0.001). CONCLUSION: Our data suggest that the physical properties of dialysed kidneys at different stages of pathology can be classified by their acoustic properties. Simultaneous evaluation of attenuation constant and sound speed is considered applicable to determining whether tissues contain malignant elements.

Acoustics↗

PubMed1990

The effect of platelet releasate on wound healing in animal models.

The alpha granules of platelets contain growth factors that are important in wound healing. We found that a major effect of thrombin-induced human platelet releasates in animal models of wound healing is to enhance the development of granulation tissue and new connective tissue matrix. These studies provide further evidence that platelet-derived protein factors may be useful in treating full-thickness dermal wounds by increasing the rate of granulation tissue formation.

Animals↗

PubMed2000

The effects of mitomycin-C and stenting on airway wound healing after laryngotracheal reconstruction in a pig model.

OBJECTIVE: To assess the effects of mitomycin-C (MTC) and endoscopic stenting on airway wound healing after laryngotracheal reconstruction. DESIGN: A prospective, blinded, randomized controlled animal study. SUBJECTS: Twenty-six domestic pigs (Sus scrofula) divided into four groups. INTERVENTIONS: Each animal underwent single-stage laryngotracheal reconstruction (SSLTR) with auricular cartilage grafts and stenting. Group 1 animals were sacrificed on postoperative day 3, and group 2 animals on postoperative day 7. On postoperative day 7, groups 3 and 4 underwent endoscopy, stent removal, and application of MTC (0.5 mg/ml) or placebo (normal saline). Group 3 animals were sacrificed on postoperative day 14, group 4 animals on day 21. Two additional animals from each experimental group were prepared for election microscopy studies. Segments of reconstructed airway were evaluated grossly and histologically for all animals. Additional tonometric evaluation was performed on two stents to determine their compressive strength. MAIN OUTCOME MEASURES: Healing, reepithelization, graft incorporation, and airway diameter. RESULTS: Two-thirds of the animals demonstrated some degree of stent collapse on endoscopy. Granulation tissue formation was seen in all animals, and resolved with stent removal. No animal experienced airway compromise due to granulation tissue formation. Stenting was seen to induce a submucosal fibroproliferative response and scarring, with loss of normal glandular architecture, in all animals. MTC did not affect the acute inflammatory response, reepithelization of the graft site, or formation of the subepithelial fibroproliferative response. MTC treated animals, however, demonstrated better graft incorporation with fibrocartilage proliferation of the graft. Untreated animals demonstrated liquefactive necrosis of the graft, without evidence of neochondrification of the graft. CONCLUSIONS: The pig airway is an adequate model of wound healing following SSLTR and stenting. Metallic ballon expandable stents can be successfully used following SSLTR, allowing for immediate postoperative extubation. However, the formation of a submucosal fibroproliferative response and mucosal scarring seen in our study raises some concerns with the current stent design. Before stenting is widely clinically applied, the optimum stent design needs to be developed. Finally, MTC seems to prevent the liquefactive necrosis of SSLTR grafts and promote neochondrification, allowing improved graft incorporation. Further studies are needed to asses the long-term effects of MTC on healing and restenosis, and its effects on cartilage growth and formation, following SSLTR.

Animals↗

PubMed2003

Immunohistochemical analysis of a cerebral arteriovenous malformation obliterated by radiosurgery and presenting with re-bleeding. Case report.

The purpose of this study was to analyze immunohistochemical characteristics of the cell population in a radiosurgically obliterated cerebral arteriovenous malformation (AVM) after recurrent hemorrhage. Immunohistochemical reactions were carried out on paraffin-embedded histological sections for von Willebrand factor (FVIII), CD34 endothelial antigen (CD34), vimentin and alpha-smooth-muscle actin (SMA) cytoskeletal proteins. Histopathological analysis revealed that the majority of AVM channels were replaced by hypocellular scar tissue. However some of them still disclosed thrombus organization by granulation tissue seven years after radiosurgery. FVIII and CD34 reactions revealed vessel neoformation in thromboses. Proliferating spindle-shaped cells with SMA and vimentin expression were identified in the granulation tissue. These histopathological findings suggest the role of re-canalization in recurrence of hemorrhage following radiosurgical obliteration of the AVM. Contribution of myofibroblastic elements in the vessels' occlusion after radiosurgery is also demonstrated.

Adult↗

PubMed1994

[A tracheal prosthesis made from P(AEMA)--a further step toward tracheal replacement].

In animal experiments (5 dogs) the authors tested a material for the construction of tracheal prostheses so far not used in other countries. P(AEMA), the polymer 2-acetoxy-ethylmethacrylate is well tolerated, it did not produce a rejection reaction. The inner wall of the prosthesis was throughout the experiment patent, smooth and secretion did not adhere to it. Macroscopic examination did not reveal cumulation of mucus and signs of infection. The self-cleansing capacity was not impaired and the dog was able to expectorate mucus over a 5 cm length of the prosthesis. The solid ends of the prosthesis, however, caused mechanical irritation of the site of anastomosis and after cca 4 weeks of the experiment granulation tissue began to form. The experiments were terminated on account of complete occlusion of the lumen of the airways by granulation tissue 4-6 weeks after operation. The authors' efforts to design a suitable tracheal prosthesis led to a change of strategy of subsequent research. They started experiments with a heterologous portion of the pig trachea devoid of antigenicity; this will be the subject of a subsequent paper.

Animals↗

PubMed1985

Biomechanical properties and collagen formation in subcutaneously implanted cellulose sponges treated with fibrin sealant.

Cellulose sponges were cut into two pieces and fibrin sealant was applied to the opposing surfaces, which were held together with sutures. In each rat two sets of sponges, one with and one without fibrin sealant, were implanted subcutaneously for 10 days. The tensile strength and energy absorption of the granulation tissue bridging the incision of the sponges were not influenced by the fibrin sealant. The formation of collagen in fibrin-sealed sponges did not differ from that in ordinary sponges. The results indicated that fibrin sealant does not influence the collagen formation and the mechanical strength after 10 days of healing. At this time the tissue possesses pronounced mechanical strength. The initial strength of sealed sponges possessed considerable mechanical strength (maximum stress 25% and failure energy 12% compared to values achieved after 10 days of implantation). This indicates that the sealant gives mechanical strength in the first days of healing, where the granulation tissue itself only provides minimal strength.

Animals↗