Granulation Tissue

Objectives/Hypothesis: The use of self-expanding metallic airway stents has been extended in recent years in inoperable patients with malignant and benign airway diseases. The risk of granulation tissue formation in the stent is a major concern. The objective of the present study was to determine whether immunosuppression modulates granulation tissue formation in airway stents, as seen in coronary stents.Study Design: The study included 19 patients with benign airway obstructions and 11 recipients of lung transplants with anastomotic obstructions who were receiving immunosuppression therapy.Methods: The degree of in-stent granulation tissue formation was evaluated (score range, 0–3) every 3 months for 2 years.Results: Granulation tissue formation was significantly lower in the transplant recipients than in the nontransplant patients at 3 months (score 0.7 vs. 1.6, P = .031), 15 months (score 0 vs. 1.1, P = .026), and 18 months (score 0 vs. 1.8, P = .020). During the 2 years of follow-up, the transplant recipients underwent significantly fewer laser resections and brachytherapy treatments for in-stent granulation.Conclusions: The immunosuppression given to lung transplant recipients may have an inhibitory effect on granulation tissue formation in metallic airway stents. Further studies are needed to evaluate the effect of systemic therapy or coated stents with drugs such as sirolimus.

Discontinuous Atrial Ablations. Introduction: Linear atrial ablations are thought to he necessary to accomplish successful catheter ablation of atrial fibrillation. In order to investigate the conduction characteristics of atrial myocardium in regions of linear lesion discontinuity gaps), we performed activation sequence mapping in gap regions during atrial pacing and atrial fibrillation.Methods and Results. In seven dogs, a linear epicardial ablation was created on the right atrial free wall with a discontinuous segment (gap) in the mid-portion of the lesion. A plaque electrode was used to measure conduction across the gap. Conduction was assessed during (1) atrial pacing from the edge of the plaque electrode during sinus rhythm, and (2) during atrial fibrillation. After each series of measurements, the lesion gap was decreased by creating additional radiofrequency ablations and repeat conduction maps were obtained. The process was repeated until conduction block was observed during atrial pacing. Gap lengths ranged from 0 to 25 mm. During atrial pacing, gaps as narrow as 2 mm demonstrated normal conduction and gaps as large as 5 mm demonstrated block during pacing. Although conduction block was never present across gaps greater than 5 mm, the ability to predict conduction block as a function of gap width was difficult for lesions ≤ 5 mm due to a significant degree of overlap between normal conduction and conduction block in this gap range. During atrial fibrillation, 1/175 (0.6%) mapped wavelets conducted across gaps that demonstrated block during pacing; whereas, 411/600 (68.5%; P < 0.0001) wavelets conducted across gaps that did not demonstrate block during pacing (P = NS compared to preablation measurements). Histologically normal atrial myocytes were observed within gaps exhibiting conduction block.Conclusions: Visible gaps > 5 mm rarely demonstrate conduction block during atrial pacing and atrial fibrillation; whereas, gaps ≤ 5 mm in length may demonstrate block. Lesion gaps that do not demonstrate conduction block during atrial pacing have no higher rate of functional conduction block during atrial fibrillation than fibrillating atria without ablation lesions.

Maggot debridement therapy has been widely used for treating a variety of scarred-over soft-tissue wounds. Published accounts record several illnesses in which treatment with larval therapy has promoted injury healing in conjunction with infection by bacterial pathogens resistant to conventional antibiotics. An initial test of the maggot therapy was developed for cutaneous injuries produced by Leishmania amazonensis. An experimental design based on an animal model with three replicates in Mesocricetus aureatus (Rodentia: Muridae) was used to evaluate size variation lesion before and after after larval therapy with Lucilia sericata maggots . The criteria used for therapy evaluation were lesion size, maggot application time, and presence or absence of edema and secretions. Effective scarring and wound healing was observed after therapy with L. sericata larvae, i.e. 80% to 100% lesion area reduction after 12 hours. The preliminary results suggest that fly maggots of L. sericata have a ...

Background. Airway complications are a significant cause of morbidity after lung transplantation. Effective treatment reduces the impact of these complications.Methods. Data from 123 lung (99 single, 24 bilateral) transplants were reviewed. Potential risk factors for airway complications were analyzed. Stenoses were treated with expanding metal (Gianturco) stents.Results. Mean follow-up was 749 days. Thirty-five complications developed in 28 recipients (complication rate: 23.8%/anastomosis). Mean time to diagnosis was 47 days. Only Aspergillus infection and airway necrosis were significantly associated with development of complications (p < 0.00001 and p < 0.03, respectively). Stenosis was diagnosed an average of 42 days posttransplant. Average decline in forced expiratory volume in 1 second (FEV1) was 39%. Eighteen patients (13 single and 5 bilateral) required stent insertion. Mean increase in FEV1 poststenting was 87%. Two stent patients died from infectious complications. Six patients required further intervention. Long-term survival and FEV1 did not differ from nonstented patients.Conclusions. Aspergillus and airway necrosis are associated with the development of airway complications. Expanding metal stents are an effective long-term treatment.

Contraction is an important phenomenon in wound repair and hypertrophic scarring. Studies indicate that wound contraction involves a specialized cell known as the myofibroblast, which has morphologic characteristics of both smooth muscle and fibroblastic cells. In order to better characterize the myofibroblast, the authors have examined its cytoskeleton and surrounding extracellular matrix (ECM) in human burn granulation tissue, human hypertrophic scar, and rat granulation tissue by indirect immunofluorescence. Primary antibodies used in this study were directed against 1) smooth muscle myosin and 2) nonmuscle myosin, components of the cytoskeleton in smooth muscle and nonmuscle cells, respectively, and 3) laminin and 4) fibronectin, extracellular glycoproteins mediating cell-matrix attachment in smooth muscle and nonmuscle cells, respectively. Myofibroblasts can be identified by their intense staining of actin bundles with either anti-actin antibody or NBD-phallacidin. Myofibroblas...

This paper reports on the development of a dentigerous cyst associated with a lower permanent incisor following intrusion of two lower primary incisors. The small root remnant of one of the traumatized primary incisors was associated with granulation tissue, while the second incisor was discolored and suspected of being non-vital. The associated permanent incisor and other adjacent incisors were apically and laterally dislocated from their natural site of eruption. The conservative treatment included extraction of the involved primary discolored incisor, as well as the root remnant, followed by removal of the granulation tissue. After 18 months of follow-up, the permanent incisors were erupting in normal position, without pathological signs of the dentigerous cyst. Following severe traumatic injury to a primary tooth, periodic radiographic follow-up, until eruption of the correspondent permanent tooth, is recommended.

The histologic characteristics of air space enlargement with fibrosis (AEF) are compared with usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP) and centrilobular emphysema (CLE) to determine similarities and differences. Lung specimens from 39 patients were studied; 9 with AEF, 13 with UIP and 5 with CLE identified in lobectomy specimens for cancer and 12 NSIP cases identified on surgical lung biopsies. We determined the characteristics of cystic structures (i.e. abnormal airspace), degree of inflammation and severity of pneumocyte injury semi-quantitatively. In AEF, the wall thickness of the cystic lesions (0.8 mm) was thinner than in UIP (2.1 mm) and thicker than in CLE (0.07 mm). The degree of inflammation and granulation tissue were milder in AEF than in UIP and NSIP and CLE showed milder inflammatory cells than AEF. As for pneumocyte injury, AEF had fewer erosions (0.1/case) and fewer ubiquitin-positive pneumocytes than UIP (4.8 cells/slide) and NSIP (9.8 cells/slide). Our data suggested that the histological characteristics of AEF differed significantly from UIP, NSIP and CLE.

Ulcer healing process is an intricate and active process including reconstruction process of mucosa through formation of granulation tissue. Granulation tissue formation takes place by means of formation of ulcer base, formation of blood vessel (angiogenesis) and re-establishment of glandular architecture. The process of granulation tissue formation on the ulcer base takes place 48-72 hours after ulceration process occurs. These three phases involve various genes grouped according to their activated time, i.e. the initial response genes, intermediate response gene and late response genes. Initial response genes are activated in 30 minutes to 2 hours time, e.g EGF-R, c-fos, c-jun, egr-1, Sp-1, TFF-2/SP. Intermediate response genes are activated for 6 hours to 2 days, eg EGF, bFGF, PDGF and VEGF. Late response genes are activated for 14 days, e.g. HGF, ITF, c-met/HGF-R.

Granulation-tissue fibroblasts are phenotypically unique cells that play an important role in wound repair and the development of chronic inflammatory lesions in connective tissue. In the present study, we compared proteoglycan, type I, and type III procollagen gene expression by granulation-tissue fibroblasts from wound and chronically inflamed tissues with normal gingival fibroblasts. We also analyzed the effect of TGF-beta 1 on proteoglycan mRNA levels and macromolecule production by these cells. One granulation-tissue fibroblast strain that was composed exclusively of alpha-smooth-muscle actin-positive cells (myofibroblasts) expressed strongly elevated basal levels of biglycan, fibromodulin, and versican (the large chondroitin sulphate proteoglycan), as well as type I and III procollagen mRNA. TGF-beta 1 enhanced more potently the expression of types I and III procollagen, biglycan, and versican mRNA by these cells as compared with normal fibroblasts. Other granulation-tissue fibroblast strains, in which about half of the cells expressed alpha-smooth-muscle actin, also showed enhanced proteoglycan and types I and III procollagen expression as compared with normal fibroblasts. These results suggest that alterations in matrix composition during inflammation and wound healing are regulated partly by altered phenotypes of the cells that produce the matrix, and partly by altered responses of these cells to TGF-beta 1.

Inhibition of tumor angiogenesis represents a promising new approach for the treatment of human cancers. It has remained unclear, however, whether inhibition of tumor angiogenesis may also result in impaired wound healing, a process thought to be angiogenesis dependent. To determine the effects of the angiogenesis inhibitor vasostatin, a 180 amino acid calreticulin fragment, on wound healing at tumor inhibiting