TRANSFORMATION OF EFFUSION AND FORMATION OF GRANULATION TISSUE IN PATHOLOGIC PROCESS OF OTITIS MEDIA WITH EFFUSION

Objective To explore the diversity of stagnant effusions and the pathologic processes leading to granulation tissue formation in otitis media with effusion(OME). Methods Temporal bone slides from 306 ears with OME were studied histopathologically under the light microscope. Results Results of this study revealed a pathologic process in witch the type and the condition of stagnant effusion in the middle ear cleft was a variable in the dynamics of OME progression from an early stage to an advanced stage. The location of granulation tissue and retentive effusion were found to be closely related. Conclusion Early stage granulation tissue formation exhibited a pathologic process in which granulation tissue formation occurred only in areas where effusion had stagnated or was absorbed. The incidence of the retentive effusion and formation of granulation tissue was much higher and the pathologic changes most extensive in the area around the ossicular chain.

Effects of platelet-rich plasma on in vitro proliferation and migration of fibroblasts from human chronic refractory wound granulation tissue

Objective:To observe the effects of platelet-rich plasma(PRP)on in vitro proliferation and migration of fibroblasts from human chronic refractory wound granulation tissue.Methods:Fibroblasts were separated from human chronic refractory wound granulation tissue and then were identified.The obtained fibroblasts were divided into fetal bovine serum(FBS)group,hydrogel group and PRP group,and the three groups were cultured with culture mediums containing FBS,hydrogel and PRP respectively,in order to observe the growth of fibroblasts.The wound scratch assay was used to observe the migration of fibroblasts.Results:PRP group had more fibroblasts than FBS group and hydrogel group since Day 5 of culture,and exhibited greater fibroblast scratch migration area than FBS group on 48 h and 72 h of wound scratch assay(all p<.05).Conclusions:Compared with FBS,human fibroblasts cultured by PRP can more effectively promote the proliferation and migration of fibroblasts.

Effect of three interventional bronchoscopic methods on tracheal stenosis and the formation of granulation tissues in dogs

Background Therapeutic approaches for tracheal stenosis caused by the formation of exuberant granulation tissues usually include electrocautery, mechanical dilation, laser therapy, argon plasma coagulation （APC）, cryotherapy and stent placement. However, restenosis after stent insertion remains a significant limitation. We examined the efficacy of three different approaches, including induction of mechanical lesions, APC performed with different powers or durations and cryotherapy, to identify the method that limited the formation of granulation tissue. Methods Twelve specially bred research mongrel dogs were divided into three groups. In group 1 （four dogs） mild （procedure 1; two dogs） or moderate （procedure 2; two dogs） damage was induced mechanically. Group 2 （six dogs） received APC at different powers or durations （procedure 3：30 W, 1 cm/s; procedure 4：30 W, 2 cm/s; procedure 5：25 W, 3 cm/s）. Group 3 （two dogs） received cryotherapy （procedure 6： two freeze-thaw cycles of 30 seconds）. Uncovered self-expandable metallic stents were inserted in all dogs to maintain a continuous stimulus to the trachea mucosa. Dogs were monitored for 4 weeks and the relationship between granulation tissue proliferation and method used was analyzed. Results In group 1, granulation tissue growth increased with more severe mechanical damage. The growth of granulation tissue in group 2 was more pronounced than in group 1, and both dogs in procedure 3 died because of severe stenosis. In this group, the formation of granulation tissue decreased with decreasing power and duration. In group 3, no obvious granulation tissue was found at week 4. Conclusions Lesions and stimuli from a foreign body （the stent） are two important factors that lead to overgrowth of granulation tissue. Thermal lesions, such as APC, seem to induce greater granulation tissue growth and cartilage damage compared with mechanical and cryotherapy lesions. Cryotherapy in combination with mechanical dilation may be a safe and effective treatment method for managing tracheal stenosis caused by the formation of granulation tissue.

P311 promotes typeⅡtransforming growth factor-βreceptor mediated fibroblast activation and granulation tissue formation in wound healing

Background:P311,a highly conserved 8 kDa intracellular protein,has recently been reported to play an important role in aggravating hypertrophic scaring by promoting the differentiation and secretion of fibroblasts.Nevertheless,how P311 regulates the differentiation and function of fibroblasts to affect granulation tissue formation remains unclear.In this work,we studied the underlying mechanisms via which P311 affects fibroblasts and promotes acute skin wound repair.Methods:To explore the role of P311,both in vitro and in vivo wound-healing models were used.Full-thickness skin excisional wounds were made in wild-type and P311−/−C57 adult mice.Wound healing rate,re-epithelialization,granulation tissue formation and collagen deposition were measured at days 3,6 and 9 after skin injury.The biological phenotypes of fibroblasts,the expression of target proteins and relevant signaling pathways were examined both in vitro and in vivo.Results:P311 could promote the proliferation and differentiation of fibroblasts,enhance the ability of myofibroblasts to secrete extracellular matrix and promote cell contraction,and then facilitate the formation of granulation tissue and eventually accelerate skin wound closure.Importantly,we discovered that P311 acts via up-regulating the expression of type II transforming growth factor-βreceptor(TGF-βRII)in fibroblasts and promoting the activation of the TGF-βRII-Smad signaling pathway.Mechanistically,the mammalian target of rapamycin signaling pathway is closely implicated in the regulation of the TGF-βRII-Smad pathway in fibroblasts mediated by P311.Conclusions:P311 plays a critical role in activation of the TGF-βRII-Smad pathway to promote fibroblast proliferation and differentiation as well as granulation tissue formation in the process of skin wound repair.

Obstruction of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice

Background:Delayed wound healing remains a common but challenging problem in patients with acute or chronic wound following accidental scald burn injury.However,the systematic and detailed evaluation of the scald burn injury,including second-degree deep scald(SDDS)and thirddegree scald(TDS),is still unclear.The present study aims to analyze the wound-healing speed,the formation of granulation tissue,and the healing quality after cutaneous damage.Methods:In order to assess SDDS and TDS,the models of SDDS and TDS were established using a scald instrument in C57BL/6 mice.Furthermore,an excisional wound was administered on the dorsal surface in mice(Cut group).The wound-healing rate was first analyzed at days 0,3,5,7,15 and 27,with the Cut group as a control.Then,on the full-thickness wounds,hematoxylin and eosin(H&E)staining,Masson staining,Sirius red staining,Victoria blue staining and immunohistochemistry were performed to examine re-epithelialization,the formation of granulation tissue,vascularization,inflammatory infiltration and the healing quality at different time points in the Cut,SDDS and TDS groups.Results:The presented data revealed that the wound-healing rate was higher in the Cut group,when compared with the SDDS and TDS groups.H&E staining showed that re-epithelialization,formation of granulation tissue and inflammatory infiltration were greater in the Cut group,when compared with the SDDS and TDS groups.Immunohistochemistry revealed that the number of CD31,vascular endothelial growth factor A,transforming growth factor-βandα-smooth muscle actin reached preferential peak in the Cut group,when compared with other groups.In addition,Masson staining,Sirius red staining,Victoria blue staining,Gordon-Sweets staining and stress analysis indicated that the ratio of collagen I to III,reticular fibers,failure stress,Young’s modulus and failure length in the SDDS group were similar to those in the normal group,suggesting that healing quality was better in the SDDS group,when compared with the Cut and TDS groups.Conclusion:Overall,the investigators first administered a comprehensive analysis in the Cut,SDDS and TDS groups through in vivo experiments,which further proved that the obstacle of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice.

Hemoglobin expression in rat experimental granulation tissue

The general opinion that hemoglobin is only a carrier protein for oxygen and carbon dioxide has been challenged by several recent studies showing hemoglobin expression in other cells than those of the erythroid series,for example,in macrophages.We discovered b-globin expression in rat experimental granulation tissue induced by subcutaneously implanted cellulose sponges.Closer investigation revealed also a-globin expression.The first peak of the biphasic globin expression noticed during granulation tissue formation correlated with the invasion of monocytes/macrophages,whereas the second one seemed to be connected to the appearance of hematopoietic progenitors.Data presented in this study indicate globin expression both in macrophages and in immature erythroid cells as validated by erythroid-specific markers.

Comparative Evaluation of Different Treatment for Purulent Wounds in Dogs

To compare the healing of purulent wounds with Shilajit dressing vs. Vishnevsky dressing in dogs with purulent wounds of >2 weeks of duration, eight dogs were chosen from same ages in two groups i.e., Shilajit and Vishnevsky dressing group. Dressing was done on every day basis for more than two weeks of follow up period. Main outcome of healing measure was completed at three weeks. Wound healing status was assessed at three days intervals till end of three weeks. Shilajit treated achieved complete decrease in the wound surface area, effect of healing score in Shilajit dressing group in comparison to the Vishnevsky dressing group at p > 0.05 level of significance. Shilajit is highly effective in achieving a characteristic feature of regenerative and granulation healing of purulent wounds as compared to Vishnevsky dressing group in dogs.

Preparation and characterization of paclitaxel-loaded poly lactic acid-co-glycolic acid coating tracheal stent

Background In-stent restenosis caused by airway granulation poses a challenge due to the high incidence of recurrence after treatment.Weekly applications of anti-proliferative drugs have potential value in delaying the recurrence of airway obstruction.However,it is not practical to subject patients to repeated bronchoscopy and topical drug applications.We fabricated novel pacilitaxel-eluting tracheal stents with sustained and slow pacilitaxel release,which could inhibit the formation of granulation tissue.And we assessed the quality and drug release behaviors of drug-eluting stents （DESs） in vitro.Methods Stents were dipped vertically into a coating solution prepared by dissolving 0.5 g （2％ w/v） of poly lactic acid-coglycolic acid （PLGA） and 0.025 g （0.1％ w/v） of pacilitaxel in 25 ml of dichloromethane.DES morphology was examined by scanning electron microscopy （SEM）.Pacilitaxel release kinetics from these DESs was investigated in vitro by shaking in PBS buffer followed by high performance liquid chromatography （HPLC）.Results Using an orthogonal experimental design,we fabricated numerous pacilitaxel/PLGA eluting tracheal stents to assess optimum coating proportions.The optimum coating proportion was 0.1％ （w/v） pacilitaxel and 2％ （w/v） PLGA,which resulted in total pacilitaxel loading of （16.380 6±0.002 1） mg/stent.By SEM the coating was very smooth and uniform.Pacilitaxel released from DES was at （0.376 3±0.003 8） mg/d,which is a therapeutic level.There was a prolonged,sustained release of pacilitaxel of ＞40 days.Conclusions Paclitaxel-loaded PLGA coating tracheal stents were successfully developed and evaluated.Quality assessments demonstrated favorable surface morphology as well as sustained and effective drug release behavior,which provides an experimental reference for clinical practitioners.

Role of angiogenesis and angiogenic factors in acute and chronic wound healing

Angiogenesis plays a crucial role in wound healing by forming new blood vessels from preexisting vessels by invading the wound clot and organizing into a microvascular network throughout the granulation tissue.This dynamic process is highly regulated by signals from both serum and the surrounding extracellular matrix environment.Vascular endothelial growth factor,angiopoietin,fibroblast growth factor and transforming growth factor-beta are among the potent angiogenic cytokines in wound angiogenesis.Specific endothelial cell ECM receptors are critical for morphogenetic changes in blood vessels during wound repair.In particular integrin(αvβ3)receptors for fibrin and fibronectin,appear to be required for wound angiogenesis:αvβ3 is focally expressed at the tips of angiogenic capillary sprouts invading the wound clot,and any functional inhibitors ofαvβ3 such as monoclonal antibodies,cyclic RGD peptide antagonists,and peptidomimetics rapidly inhibit granulation tissue formation.In spite of clear knowledge about influence of many angiogenic factors on wound healing,little progress has been made in defining the source of these factors,the regulatory events involved in wound angiogenesis and in the clinical use of angiogenic stimulants to promote repair.

Histopathological study of chronic wounds modulated by intermittent negative pressure therapy under limited access dressing

Aim:Negative pressure wound therapy(NPWT)has achieved widespread success in the treatment of chronic wounds.However,its effects have been only partially explored,and investigations have generally concentrated on the wound-dressing interface;a detailed histopathological description of the evolution of wounds under NPWT is still lacking.The present study was performed to investigate the effect of a limited access dressing(LAD)which exerts intermittent NPWT in a moist environment on chronic wounds.Methods:A total of 140 patients were randomized into 2 groups:LAD group(n=64)and conventional dressing group(n=76).By histopathological analysis of the granulation tissue,the amount of inflammatory infiltrate,necrotic tissue,angiogenesis,and extracellular matrix(ECM)deposition was studied and compared to determine healing between the 2 groups.Results:After 10 days of treatment,histopathological analysis showed a significant decrease in necrotic tissue with LAD compared to the conventional dressing group(mean±standard error,11.5±0.48 vs.10.1±0.30,P=0.007),the number of inflammatory cells(12.6±0.60 vs.8.63±0.35,P=0.018),a significant increase in new blood vessels(12.8±0.58 vs.9.3±0.29,P=0.005)and ECM deposit(13.3±0.50 vs.9.6±0.24,P=0.001).Conclusion:LAD exerts its beneficial effects on chronic wound healing by decreasing the amount of necrotic tissue and inflammatory cells while increasing the amount of ECM deposition and angiogenesis.