Scar Tissue (scar + tissue)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Osteogenesis induced by extracorporeal shockwave in treatment of delayed osteotendinous junction healing

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2010
Ling Qin
Abstract Healing at the osteotendinous junction (OTJ) is challenging in orthopedic surgery. The present study aimed to test extracorporeal shockwave (ESW) in treatment of a delayed OTJ healing. Twenty-eight rabbits were used for establishing a delayed healing (DH) model at patella-patellar-tendon (PPT) complex after partial patellectomy for 4 weeks and then were divided into DH and ESW groups. In the ESW group, a single ESW treatment was given at postoperative week 6 to the PPT healing complex. The samples were harvested at week 8 and 12 for radiographic and histological evaluations with seven samples for each group at each time point. Micro-CT results showed that new bone volume was 1.18 ± 0.61,mm3 in the ESW group with no measurable new bone in the DH group at postoperative week 8. Scar tissue formed at the OTJ healing interface of the DH group, whereas ESW triggered high expression of VEGF in hypertrophic chondrocytes at week 8 and regeneration of the fibrocartilage zone at week 12 postoperatively. The accelerated osteogenesis could be explained by acceleration of endochondral ossification. In conclusion, ESW was able to induce osteogenesis at OTJ with delayed healing with enhanced endochondral ossification process and regeneration of fibrocartilage zone. These findings formed a scientific basis to potential clinical application of ESW for treatment of delayed OTJ healing. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:70,76, 2010 [source]


Intricacies of the Single-Scar Technique for Donor Harvesting in Hair Transplantation Surgery

DERMATOLOGIC SURGERY, Issue 6 2004
Dominic A. Brandy MD
Background. Although single-scar techniques have been published and are used by approximately half of all surgeons, this approach is not as common as one might suspect. Objective. The objective is to demonstrate several surgical gems that make the single-scar donor technique a viable method that can be performed by the vast majority of hair restoration surgeons. Methods. The author presents various techniques such as postauricular skin elevation, subcutaneous undermining of the nape scalp, debulking of underlying scar tissue, temporary staple closure, and permanent double-layered closure using magnification (preferably 2.5 × or greater). All of these contribute to a loose closure with an aesthetically pleasing single donor scar after multiple surgeries. Results. Utilizing the various techniques described in this article, the author has been able to achieve a cosmetically attractive single scar after multiple surgeries in the vast majority of patients. Conclusion. An aesthetically pleasing single, thin donor scar is preferable to multiple scars or a thick single scar at the donor area after multiple hair restoration surgical procedures. The author presents several methods that help hair restoration surgeons conquer some of the obstacles that have deterred them from performing a single-scar technique with consistently excellent results. [source]


Left Ventricular Pseudoaneurysm Developing as a Late Complication of Coronary Artery Bypass Grafting with Apicoseptal Plication

ECHOCARDIOGRAPHY, Issue 8 2005
Ozcan Ozeke M.D.
Left ventricular pseudoaneurysm is a false aneurysm, which results from a left ventricle rupture contained by adherent pericardium or scar tissue. The most common etiology of left ventricular pseudoaneurysm is acute myocardial infarction but one-third of pseudoaneurysms develop following surgery. We present a case report of a patient who developed a false aneurysm of the left ventricle 2 months following surgical repair of a left ventricular aneurysm with a concomitant coronary bypass. [source]


Cardiac regeneration by progenitor cells , bedside before bench?

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2005
J. Bauersachs
Abstract Recent experimental and clinical trials give rise to the hope that progenitor cells could replace scar tissue after myocardial infarction with healthy functional myocardium. However, while a significant increase in left ventricular ejection fraction has been described after progenitor cell transplantation in several clinical trials, long-term results are lacking, and the mechanisms underlying the improvement of ejection fraction are unclear. Therefore, the efficacy of progenitor cell transplantation after myocardial infarction has not been established, and potential problems may have been underestimated. In-depth laboratory and animal studies are needed to determine the best cell type, optimal amount of cells, and time point for transplantation. Treatment of patients with progenitor cells outside well controlled prospective trials should be avoided. [source]


Centrally necrotizing carcinoma of the breast: clinicopathological analysis of 33 cases indicating its basal-like phenotype and poor prognosis

HISTOPATHOLOGY, Issue 2 2010
Lin Yu
Yu L, Yang W, Cai X, Shi D, Fan Y & Lu H (2010) Histopathology,57, 193,201 Centrally necrotizing carcinoma of the breast: clinicopathological analysis of 33 cases indicating its basal-like phenotype and poor prognosis Aims:, To investigate the clinicopathological features and immunophenotype of centrally necrotizing carcinoma (CNC) of the breast to ascertain its relationship to basal-like phenotype and its prognosis. Methods and results:, The clinical and pathological characteristics of 33 CNCs were reviewed. Immunohis-tochemical study of oestrogen receptor, progesterone receptor, HER2, cytokeratin (CK) 8/18, high-molecular-weight CK (34,E12), CK5/6, CK14, CK17, smooth muscle antigen, p63, vimentin and epidermal growth factor receptor was performed. The striking feature of CNC was a central, necrotic or acellular zone surrounded by a ring-like area of viable tumour cells. The central zone showed three morphological types: predominance of coagulative necrosis (21 cases), predominance of fibrosis and scar tissue (nine cases) and infarction (three cases). Tumour cells displayed invasive ductal carcinoma of high grade. The expression rate of basal-like markers was higher than that of myoepithelial markers (87.9% versus 46.2%). Basal-like subtype was shown by 63.6% of cases. The expression rate of CK5/6 (90.5%) was highest among basal-like markers. Follow-up data of 19 patients were available. Median progression-free survival was 15.5 months. In 12 patients (63.2%), local recurrence and/or distant metastasis developed (median time to recurrence and/or metastasis, 14.0 months). Conclusions:, CNC has distinctive morphological features, which mostly exhibit a basal-like immunophenotype and poor prognosis. CNC is a typical representative of basal-like breast cancer. [source]


The ethics of cloning and creating embryonic stem cells as a source of tissue for transplantation: time to change the law in Australia

INTERNAL MEDICINE JOURNAL, Issue 4 2000
J. Savulescu
Abstract Every day, people die because there are insufficient tissues available for transplantation. The development of cloning and embryonic stem (ES) cell line technologies offers real hope for developing better sources of tissues for transplantation. Moreover, these new technologies may mean that damaged tissue (for example, after a stroke or heart attack) can be replaced with normal functioning tissue rather than scar tissue. Research into ,therapeutic cloning' and the development of ES cell lines is illegal in several States in Australia. It is time to review that legislation in order to allow destructive embryo research. My argument is that at least research should be allowed on spare embryos from assisted reproduction; that it is only one moral view (of several plausible ones) of the status of the embryo which precludes producing embryos for research; that this view is mistaken and so it is morally permissible to produce embryos for research into therapeutic cloning. [source]


A case of mucosal leishmaniasis: beneficial usage of polymerase chain reaction for diagnosis

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 12 2001
Hironori Onuma MD
A 36-year-old woman, who had emigrated from Japan to Paraguay as a 4-year-old child before returning to Japan in 1991, visited our clinic on November 10, 1997. She had suffered from a persistent ulcer on her forearm as a 6-year-old child and received intravenous injections for a few months, although she did not remember the details of therapy. Since May 1997, she had been aware of redness and swelling on her nose and had been treated with topical corticosteroid, but no improvement had been noted. Physical examination revealed erythematous plaque with crust from the left internal naris to nasolabial region (Fig. 1a). The atrophic plaque that had resulted from prolonged ulceration was found on the right forearm (Fig. 1b). In a biopsy specimen from the erythematous plaque on the nasolabial region, mononuclear dermal infiltrate, consisting of lymphocytes and histiocytes, was seen (Fig. 2a). The histiocytes were filled with Leishman-Donovan (L-D) bodies on a Giemsa staining sample (Fig. 2b). Fiberscopic examination revealed white plaque in the pharynx. The biopsy from the affected mucosa showed the same histopathological finding as with the skin. Figure 1. (a) Erythematous plaque with crust from the left internal naris to nasolabial region. (b) Atrophic plaque on the right forearm Figure 2. (a) In the biopsy specimen from the erythematous plaque on the nasolabial region, a mononuclear dermal infiltrate consisting of lymphocytes and histiocytes was seen. (Hematoxylin-Eosin stain, × 100) (b) The histiocytes were filled with Leishman-Donovan bodies. (Giemsa staining, × 400) Total DNA was purified from the skin biopsy specimen for polymerase chain reaction (PCR) analysis using a specific primer for L (V) braziliensis.1,2 A 70-bp product was amplified (Fig. 3a); furthermore, the specificity of the PCR product was confirmed by Southern hybridization with the probe for L (V) braziliensis (Fig. 3b) and DNA sequence analysis (data not shown). From December 2, 1997, the patient received 20 mg/kg/day sodium stibogluconate (PentostamTM) intravenously for 20 days. After 5 days of treatment, the redness and swelling of the skin lesion was improved, and faint erythema remained at the end of 20 days' treatment. After a 2-week interval, since the erythema remained, another 20-day treatment was performed. All of the skin lesion became scar tissue and L-D bodies could not be found in a skin biopsy specimen. However, L-D bodies were still found in a biopsy from the pharyngeal mucosa that had a normal appearance. Though another additional treatment was planned, the patient refused it. Figure 3. (a) The results of PCR. 70-bps bands appear in lanes 2 and 6. Lane 1, a size marker (pUC19/HapII); lane 2, DNA extracted from the formalin-fixed patient's sample; lane 3, DNA extracted from a formalin-fixed control sample; lane 4, DNA (,); lane 5, DNA extracted from L (V) tropica; lane 6, DNA extracted from L (V) braziliensis. (b) Results of Southern blotting using the PCR products. The PCR products were transferred from agarose gel as shown in Fig. 3 (a). Specific probes were hybridized with 70-bps bands on lanes 2 and 6 [source]


Expression of phospholipase D isozymes in scar and viable tissue in congestive heart failure due to myocardial infarction

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2004
Melissa R. Dent
Abstract The phospholipase D (PLD) associated with the cardiac sarcolemmal (SL) membrane hydrolyses phosphatidylcholine to produce phosphatidic acid, an important phospholipid signaling molecule known to influence cardiac function. The present study was undertaken to examine PLD isozyme mRNA expression, protein contents and activities in congestive heart failure (CHF) subsequent to myocardial infarction (MI). MI was induced in rats by occlusion of the left anterior descending coronary artery. At 8 weeks after the surgical procedure, hemodynamic assessment revealed that these experimental rats were at a moderate stage of CHF. Semi-quantitative reverse transcriptase-polymerase chain reaction revealed that PLD1 and PLD2 mRNA amounts were unchanged in viable left ventricular (LV) tissue of the failing heart. Furthermore, this technique demonstrated the presence of PLD1 and PLD2 mRNA in the scar tissue. While SL PLD1 and PLD2 protein contents were elevated in the viable LV tissue of the failing heart, SL PLD1 activity was significantly decreased, whereas SL PLD2 activity was significantly increased. On the other hand, although PLD1 protein was undetectable, PLD2 protein and activity were detected in the scar tissue. Our findings suggest that differential changes in PLD isozymes may contribute to the pathophysiology of CHF and may also be involved in the processes of scar remodeling. [source]


Use of intense pulsed light in the treatment of scars

JOURNAL OF COSMETIC DERMATOLOGY, Issue 1 2005
H Cartier
Summary Background, Reducing erythema and infiltration of inflamed, hypertrophic, and colloidal scars have been a challenge for healthcare providers. Peer-reviewed scientific data for intense pulsed light systems are lacking. Objective, A chronicle of three patients who have participated in the treatment of inflamed, hypertrophic, and colloidal scars, using intense pulsed light. Methods, Intense pulsed light with a selection of wavelengths, pulse durations, and energy densities was used on patients with inflamed, hypertrophic, and colloidal scars. Results, A definite improvement in scar tissue was observed and achieved in all the cases. Conclusion, Intense pulsed light source with the correct outputs is an effective tool for the treatment and improvement of inflamed, hypertrophic, and colloidal scars. [source]


Periarticular ligament changes following ACL/MCL transection in an ovine stifle joint model of osteoarthritis

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 8 2007
Yusei Funakoshi
Abstract Anterior cruciate ligament (ACL) injuries often lead to significant functional impairment, and are associated with increased risk for induction of degenerative joint disease. However, few studies have described the effect of ligament transection on the remaining intact knee ligaments. This study sought to determine specifically what impact combined ACL/medial collateral ligament (MCL) transection had on the remaining intact knee ligaments, particularly from the histological, biochemical, and molecular perspectives. Twenty weeks post-ACL/MCL transection, the cut ends of sheep MCLs were bridged by scar, while the posterior cruciate ligaments (PCLs) and lateral collateral ligaments (LCLs) seemed gross morphologically normal. Water content and cell density increased significantly in the MCL scars and the intact PCLs but were unchanged in the LCLs. Collagen fibril diameter distribution was significantly altered in both MCL scar tissue and uninjured PCLs from transected joints. MMP-13 mRNA levels in MCL scars and PCLs from ligament transected joints were increased, while TIMP-1 mRNA levels were significantly decreased in the PCLs only. This study has shown that some intact ligaments in injured joints are impacted by the injury. The joint appears to behave like an integrated organ system, with injury to one component affecting the other components as the "organ" attempts to adapt to the loss of integrity. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:997,1006, 2007 [source]


Decorin antisense gene therapy improves functional healing of early rabbit ligament scar with enhanced collagen fibrillogenesis in vivo

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2000
Norimasa Nakamura
Injured ligaments heal with scar tissue, which has mechanical properties inferior to those of normal ligament, potentially resulting in re-injury, joint instability, and subsequent degenerative arthritis. In ligament scars, normal large-diameter collagen fibrils have been shown to be replaced by a homogenous population of small collagen fibrils. Because collagen is a major tensile load-bearing matrix element and because the proteoglycan decorin is known to inhibit collagen fibrillogenesis, we hypothesized that the restoration of larger collagen fibrils in a rabbit ligament scar, by down-regulating the proteoglycan decorin, would improve the mechanical properties of scar. In contrast to sense and injection-treated controls, in vivo treatment of injured ligament by antisense decorin oligodeoxynucleotides led to an increased development of larger collagen fibrils in early scar and a significant improvement in both scar failure strength (83,85% improvement at 6 weeks; p < 0.01) and scar creep elongation (33,48% less irrecoverable creep; p < 0.03) under loading. This is the first report that in vivo manipulation of collagen fibrillogenesis improves tissue function during repair processes with gene therapy. These findings not only suggest the potential use of this type of approach to improve the healing of various soft tissues (skin, ligament, tendon, and so on) but also support the use of such methods to better understand specific structure-function relationships in scars. [source]


Compressive compared with tensile loading of medial collateral ligament scar in vitro uniquely influences mRNA levels for aggrecan, collagen type II, and collagenase

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2000
Tokifumi Majima
To test the hypothesis that loading conditions can be used to engineer early ligament scar behaviors, we used an in vitro system to examine the effect that cyclic hydrostatic compression and cyclic tension applied to 6-week rabbit medial collateral ligament scars had on mRNA levels for matrix molecules, collagenase, and the proto-oncogenes c-fos and c-jun. Our specific hypothesis was that tensile stress would promote more normal mRNA expression in ligament whereas compression would lead to higher levels of mRNA for cartilage-like molecules. Femur (injured medial collateral ligament)-tibia complexes were subjected to a hydrostatic pressure of 1 MPa or a tensile stress of 1 MPa of 0.5 Hz for 1 minute followed by 14 minutes of rest. On the basis of a preliminary optimization experiment, this 15-minute testing cycle was repeated for 4 hours. Semiquantitative reverse transcription-polymerase chain reaction analysis was performed for mechanically treated medial collateral ligament scars with use of rabbit specific primer sets for types I, II, and III collagen, decorin, biglycan, fibromodulin, versican, aggrecan, collagenase, c-fos, c-jun, and a housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase. Cyclic hydrostatic compression resulted in a statistically significant increase in mRNA levels of type-II collagen (171% of nonloaded values) and aggrecan (313% of nonloaded values) but statistically significant decreases in collagenase mRNA levels (35% of nonloaded values). Cyclic tension also resulted in a statistically significant decrease in collagenase mRNA levels (66% of nonloaded values) and an increase in aggrecan mRNA levels (458% of nonloaded values) but no significant change in the mRNA levels for the other molecules. The results show that it is possible to alter mRNA levels for a subset of genes in scar tissue by supplying unique mechanical stimuli in vitro and thus that further investigation of scar engineering for potential reimplantation appears feasible. [source]


SEXUAL DIMORPHISM AND BODY SCARRING IN THE BOTO (AMAZON RIVER DOLPHIN) INIA GEOFFRENSIS

MARINE MAMMAL SCIENCE, Issue 1 2006
A. R. Martin
Abstract Measurements and quantitative descriptions of a large sample of live adult botos (Inia geoffrensis) were obtained from the Mamirauá Reserve in the central Amazon. Males were on average 16% longer and weighed 55% more than females, demonstrating that this species is one of the most sexually dimorphic of all cetaceans for size. Males were also pinker than females, more heavily scarred by intraspecific tooth rakes, and had more life-threatening injuries. Some larger males had areas of modified skin that may simply be scar tissue, but may also be a heritable characteristic used as a shield or weapon. As in sperm whales, sexual size dimorphism and male-male aggression appear to be linked in botos, suggesting fierce competition for a resource,probably mating opportunities. The boto is unique among river dolphins in that males are larger than females. This distinction implies long evolutionary separation and fundamental differences in social behavior. [source]


Nontransmural Scar Detected by Magnetic Resonance Imaging and Origin of Ventricular Tachycardia in Structural Heart Disease

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009
MIKI YOKOKAWA M.D.
Background: Contrast-enhanced magnetic resonance imaging (CMR) identifies scar tissue as an area of delayed enhancement (DE). The scar region might be the substrate for ventricular tachycardia (VT). However, the relationship between the occurrence of VT and the characteristics of scar tissue has not been fully studied. Methods: CMR was performed in 34 patients with monomorphic, sustained VT and dilated cardiomyopathy (DCM, n = 18), ischemic cardiomyopathy (ICM, n = 10), or idiopathic VT (IVT, n = 6). The VT exit site was assessed by a detailed analysis of the QRS morphology, including bundle branch block type, limb lead polarity, and precordial R-wave transition. On CMR imaging, the transmural score of each of the 17 segments was assigned, using a computer-assisted, semiautomatic technique, to measure the DE areas. Segmental scars were classified as nontransmural when DE was 1,75% and transmural when DE was 76,100% of the left ventricular mass in each segment. Results: A scar was detected in all patients with DCM or ICM. Nontransmural scar tissue was often found at the VT exit site, in patients with DCM or ICM. In contrast, no scar was found in patients with IVT. Conclusions: CMR clarified the characteristics and distribution of scar tissue in patients with structural heart disease, and the presence and location of scar tissue might predict the VT exit site in these patients. [source]


Magnetic Resonance Imaging is Superior to Cardiac Scintigraphy to Identify Nonresponders to Cardiac Resynchronization Therapy

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009
MIKI YOKOKAWA M.D.
Background: Left ventricular (LV) postero-lateral scar and total scar burden are factors responsible for a poor response to cardiac resynchronization therapy (CRT). Contrast-enhanced magnetic resonance imaging (CMR) and 99mTc-2-methoxy isobutyl isonitrile single photon emission computed tomography (SPECT) perfusion imaging are widely used to detect myocardial scar tissue; however, their ability to detect regional scars and predict a positive response to CRT has not been fully evaluated. Methods: CMR and SPECT were performed in 17 patients with dilated cardiomyopathy (DCM) and seven patients with ischemic cardiomyopathy (ICM) before CRT. All images were scored, using a 17-segment model. To analyze the LV scar regions by CMR, we assessed the transmural delayed enhancement extent as the transmural score in each segment (0 = no scar, 4 = transmural scar). Similarly, a perfusion defect score was assigned to each segment by SPECT (0 = normal uptake, 4 = defect). Results: By both SPECT and CMR imaging, the total scar score was significantly higher in the ICM than in the DCM group. An LV postero-lateral wall scar region was detected using both imaging modes. By SPECT imaging, the percentage of regional scar score in the LV inferior wall was significantly higher in the DCM than in the ICM group. Conclusions: By SPECT imaging in the DCM group, severe perfusion defects, due to attenuation artifacts, were frequently observed in the LV inferior wall, resulting in the overestimation of scar tissue. CMR identified nonresponders to CRT more reliably than SPECT in patients with DCM. [source]


Posttransplant Bronchiolitis Obliterans Syndrome Is Associated with Bronchial Epithelial to Mesenchymal Transition

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009
S. Hodge
Bronchiolitis obliterans syndrome (BOS) compromises lung transplant outcomes and is characterised by airway epithelial damage and fibrosis. The process whereby the normal epithelial configuration is replaced by fibroblastic scar tissue is poorly understood, but recent studies have implicated epithelial mesenchymal transition (EMT). The primary aim of this study was to assess the utility of flow cytometry in detecting and quantifying EMT in bronchial epithelial cells. Large airway brushings were obtained at 33 bronchoscopies in 16 BOS-free and 6 BOS grade 1,3 patients at 2,120 months posttransplant. Flow cytometry was used to assess expression of the mesenchymal markers ,SMA, S100A4 and ED-A FN and HLA-DR. TGF ,1 and HGF were measured in Bronchoalveolar lavage (BAL). Expression of all three mesenchymal markers was increased in BOS, as was HLA-DR. BAL HGF, but not TGF ,1 was increased in BOS. Longitudinal investigation of one patient revealed a 100% increase in EMT markers concurrent with a 6-fold increase in BAL TGF ,1 and the diagnosis of BOS at 17 months posttransplant. Flow cytometric evaluation of bronchial epithelium may provide a novel and rapid means to assess lung allografts at risk of BOS. [source]


Pseudoxanthoma elasticum: biopsy of clinically normal skin in the investigation of patients with angioid streaks

BRITISH JOURNAL OF DERMATOLOGY, Issue 4 2007
S.J. Brown
Summary Background Pseudoxanthoma elasticum (PXE) is a genetic disorder characterized by fragmentation and calcification of elastic fibres with resultant pathological changes in the dermis, Bruch's membrane and blood vessels. Defects in Bruch's membrane produce angioid streaks on the retina but this appearance is not pathognomonic of PXE. Biopsy of clinically normal skin or scar tissue in patients with angioid streaks may show the histological features of PXE. Objectives To test the hypothesis that biopsy of clinically normal skin is a useful investigation in patients with angioid streaks. Methods This prospective study investigated 18 consecutive patients with angioid streaks. Each patient underwent a full dermatological examination and was investigated for diseases known to be associated with angioid streaks. Axillary skin biopsies were taken from 14 consenting patients. Results Typical PXE was found in 11 patients. No other diseases associated with angioid streaks were identified. Five patients had angioid streaks in the absence of systemic disease. Two patients had nondiagnostic dermatological features which were not clarified by histology. Two of the 11 patients with PXE showed histological evidence of PXE from clinically normal axillary skin. However, in both cases flexural skin elsewhere showed the typical clinical and histological features of PXE. Conclusions This study demonstrates the association between angioid streaks and PXE. However, it does not support the hypothesis that biopsy of normal-looking skin is helpful in the investigation of adult patients with angioid streaks. [source]


Aberrant serum hyaluronan and hyaluronidase levels in scleroderma

BRITISH JOURNAL OF DERMATOLOGY, Issue 3 2004
B.A. Neudecker
Summary Background Scleroderma, or systemic sclerosis, is characterized by aberrations of extracellular matrix deposition. These changes parallel early stages of wound healing when increased deposition of hyaluronan (HA) and collagen occur. Both processes result ultimately in the formation of fibrotic scar tissue. Activities of HA synthase and hyaluronidase, the enzymes that synthesize and degrade HA, are critical in HA turnover. Both become elevated whenever increased matrix deposition occurs. HA deposition occurs early in wound healing, and increases are documented in the circulation of scleroderma patients. We postulated that elevated HA and hyaluronidase may both be indicators of early-stage disease in scleroderma, in parallel with early changes observed in wound healing. In an attempt to reduce HA accumulation and the associated fibrosis in scleroderma tissues, topical and intravenous hyaluronidase administrations have been used in the past as treatment modalities, with occasional success. This also suggested that hyaluronidase enzyme activity is involved in the disease process. It is now recognized that the hyaluronidases constitute an enzyme family. The somatic hyaluronidase Hyal-1 is the only activity present in human serum. Objectives To determine levels of HA and Hyal-1 in the sera of scleroderma patients at various stages of their disease. Methods Levels of HA and Hyal-1 activity were determined in 25 scleroderma patients. Subjects were separated into two groups, those in the early stage with duration of disease of 2 years or less, and late-stage patients with disease duration of more than 2 years. Results In early-stage scleroderma, levels of HA were elevated significantly, as predicted, in comparison with late-stage patients and controls. Late-stage levels of HA were comparable with those found in control sera. By contrast, levels of Hyal-1 activity were normal in early-stage patients, similar to those in controls, but were decreased in late-stage patients, falling even below those of controls. Conclusions We have confirmed that circulating levels of HA are elevated in scleroderma, but show for the first time that such elevations occur predominantly in early-stage disease. Patients with late-stage disease have decreased serum Hyal-1 activity, perhaps reflecting decreased levels of HA turnover. This study also represents the first time that hyaluronidase activity levels have been determined in scleroderma patients. [source]


3422: Sources of straylight in the human eye

ACTA OPHTHALMOLOGICA, Issue 2010
D DE BROUWERE
Purpose Besides refractive aberrations, ocular light scattering is a major parameter affecting image quality on the retina in healthy eyes. Several pathologies in the anterior segment such as corneal scarring and cataract cause significant increase of straylight in the eye. In this study, we link morphologic changes addressed to corneal scarring to a scattering function. Methods Excised rabbit corneas with different grades of scarring following photorefractive keratectomy were optically evaluated for their forward light scattering distribution and consecutively prepared for histology. An absolute parameter for forward scattering was calculated based on the readings in the optical device. We compared this parameter to the relative thickness of the scar tissue observed in the histological data. Results The histological data showed a wide variation of thickness a scar tissue layer in the anterior stroma. The scattering ratio measured using the optical device measuring forward light scattering correlated strongly with the relative thickness of the scar tissue layer with (0.63, Pearson's coefficient), as well as a standard haze exam (measuring backscattered light) (0.51, Pearson's coefficient). The light scattering distribution is narrowly forward peaked (FWHM 30 arcmin), suggesting this light scattering is caused by large particles such as myofibroblasts, oedema or irregular scar tissue in the ablated zone. Conclusion Corneal light scattering associated with the increased amount of haze after excimer laser ablation has a narrowly forward distribution that can be attributed to the subepithelial structures observed in treated corneas. This is in contrast to the origin of scatterers linked to cataract, as small protein aggregates and multilamellar bodies that are scattering over wider angles. [source]


4135: Matrix metalloproteinase 14 overexpression reduces corneal scarring

ACTA OPHTHALMOLOGICA, Issue 2010
S GALIACY
Purpose Corneal wound healing is an everyday preoccupation for ophthalmologists.Corneal transparency depends on the scarring quality after a traumatic corneal wound, but also after refractive corneal surgery. Cicatrisation and fibrosis formation involve epithelial/fibroblast interactions via paracrin signals inducing extracellular matrix (ECM) remodelling. The major event is fibroblast activation and differentiation into myofibroblasts. These cells have a key role in the fibrotic response. They acquire contractile properties, and synthetise a new ECM, mainly composed of type III collagen. This scar tissue is less organised than the regular stroma, thus explaining corneal opacity. ECM remodelling is a critical step which aims to digest the excess of ECM by proteolysis of type III collagen. MMP14 is a membrane-bound fibrillar collagenase from the Matrix Metalloprotease family. We hypothesised that its overexpression in the corneal stroma during wound repair will increase ECM remodelling and thus prevent collagen deposition in the scar tissue. Methods We developed an adeno-associated virus-based vector expressing murine MMP14 under the control of the CMV promoter. We evaluated MMP14 overexpression after viral transfection in a murine model of corneal wound healing. We characterised several parameters: clinical observation, histology, and wound healing markers. Results Our preliminary results showed a decreased in oedema and corneal scar formation, associated with a decreased expression of alpha smooth actin and type III collagen. Conclusion These results represent proof of concept that gene transfer of MMP14 can reduce scar formation, which could have therapeutic applications after corneal trauma. [source]


Inflammatory infiltrate of chronic periradicular lesions: an immunohistochemical study

INTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2003
S. Liapatas
Abstract Aim, To determine the cellular profile of human chronic periradicular lesions using immunohistochemical methods in order to study the differences in the cell infiltrate of periradicular granulomas and cysts. Methodology, The study population consisted of 45 individuals without any systemic disease. Biopsies were obtained during periradicular surgery. Paraffin-embedded sections were stained by the avidin,biotin complex method (ABC), whilst cryostat tissue sections were stained using the alkaline phosphatase antialkaline phosphatase assay (APAAP). These methods are highly valid and sensitive using a panel of specific monoclonal antibodies: CD4, CD8, CD3, CD10, HLADR, CD20, CD45RO, CD68 and CD57. The 45 specimens were characterized by the use of both techniques. Results, The 45 specimens were histologically diagnosed as: 25 periradicular granulomas, 17 periradicular cysts and 3 scar tissues. No statistically significant differences were detected in the inflammatory infiltrate between periradicular granulomas and cysts. Observation of the sections showed that the majority of inflammatory cells consisted of T and B lymphocytes and macrophages. T and B lymphocytes were equally distributed in 60% of the cases. The T4/T8 ratio ranged approximately from 1 to 3 and greater, being consistent with inflammation of periradicular tissues. The final differentiation of B lymphocytes to plasma cells was also detected, whilst natural killer (NK) cells were found in only 10 cases (22%). Moreover, antigen presenting cells and T suppressor/cytotoxic cells were found to be associated with both pre-existing and newly formed epithelium. Conclusions, Periradicular granulomas and cysts represent two different stages in the development of chronic periradicular pathosis as a normal result of the process of immune reactions that cannot be inhibited. [source]