Antimicrobial Peptide immunity protects human nasal and auricular cartilage against infection

The effect of perichondrium on cartilage graft properties

PURPOSE OF REVIEW

The role of perichondrium in cartilage graft survival has been long debated. Although the innate function of perichondrium in providing mechanical and regenerative support to cartilage in its native position is relatively undisputed, studies continue to vacillate over how the perichondrium effects cartilage grafts once transplanted. This review evaluates historical and recent experiments showing how perichondrium may or may not impact graft survival.

RECENT FINDINGS

Experimental studies in animal models have more recently evaluated macroscopic and microscopic properties of diced cartilage grafts with and without perichondrium, finding that in general grafted cartilage with perichondrial components retains greater weight and mechanical strength compared with cartilage without perichondrial components. However, these findings have not been replicated in humans. Solid pieces of rib cartilage have most recently been used without perichondrium to prevent warping, though no studies have evaluated whether retaining perichondrium with oblique and concentric cutting techniques may effect overall resorption.

SUMMARY

Although historical opinions and more recent animal studies suggest a role of perichondrium in cartilage graft survival, randomized controlled human studies are still lacking on whether retaining perichondrium truly effects graft survival and ultimate surgical outcomes.

Glycosaminoglycan, Antimicrobial Defence Molecule and Cytokine Appearance in Tracheal Hyaline Cartilage of Healthy Humans

Hyaline cartilage is an important tracheal structure, yet little is known about its molecular composition, complicating investigation of pathologies and replacement options. Our aim was to research tracheal hyaline cartilage structure, protective tissue factors and variations in healthy humans. The tissue material was obtained from 10 cadavers obtained from the Riga Stradins University Institute of Anatomy and Anthropology archive. Tissues were stained with Bismarck brown and PAS for glycosaminoglycans, and immunohistochemistry was performed for HBD-2, HBD-3, HBD-4, IL-10 and LL-37. The slides were inspected by light microscopy and Spearman's rank correlation coefficient was calculated. The extracellular matrix was positive across hyaline cartilage for PAS, yet Bismarck brown marked positive proliferation and growth zones. Numerous positive cells for both factors were found in all zones. All of the antimicrobial defence molecules and cytokines were found in a moderate number of cells, except in the mature cell zone with few positive cells. Spearman's rank correlation coefficient revealed strong and moderate correlations between studied factors. Hyaline cartilage is a tracheal defence structure with a moderate number of antimicrobial defence protein and cytokine immunoreactive cells as well as numerous glycosaminoglycan positive cells. The extracellular matrix glycosaminoglycans provide structural scaffolding and intercellular signalling. The correlations between the studied factors confirm the synergistic activity of them.

A reliable method to avoid contamination during cartilage graft preparation in septorhinoplasty

PURPOSE

The aim of the study is to determine the risk of contamination in the cartilage graft materials prepared on the swester table and those prepared in a sterile package, and to reveal a more reliable method by performing the microbiological examination of these materials.

METHODS

Cartilages removed from the nasal septum were divided into four pieces. The first part (Sample A) was directly placed into the medium. Sample B was prepared by being crushed in a sterile package. Sample C was prepared on the auxiliary swester table, and Sample D was prepared on the main swester table actively used by surgery team. All samples were transferred in a 1 ml brain heart(BH) liquid medium. From each BH medium, 100 µl culture was performed on blood agar, eosin-methylene blue-lactose-sucrose agar and chocolate agar.

RESULTS

Bacterial growth was detected in 2 of the samples A, in 4 of the samples B, in 24 of the samples C, and in 36 of the samples D. The number of patients with bacterial growth in the samples C and/or D despite no growth in the sample B was 35. When the samples A/B and C/D were compared in terms of bacterial growth, a significant difference was found in all matchings (p < 0.001 for all comparisons).  CONCLUSION: These findings showed that preparation of the cartilage grafts on the swester table was extremely risky for microbiological contamination. Arslan and his colleagues suggest that preparing a graft material in a sterile package is extremely simple, cheap, and it also reduces contamination risk significantly.

Successful Posterior Canal Wall Reconstruction with Tissue-Engineered Cartilage

Difficulties are associated with reconstruction of middle ear bony structures in surgery for destructive lesions, including cholesteatoma. Although autologous cartilage appears to be the optimal choice because of its resistance to infection, the harvesting of sufficient volumes may be challenging. Therefore, regenerative medicine techniques to obtain sufficient material for reconstruction are awaited. We herein present a case of middle ear surgery for cholesteatoma with a sufficient volume of stick-shaped tissue-engineered cartilage produced from a piece of autologous auricular cartilage and autologous serum, with sufficient firmness to reconstruct bony structures. During surgery, sections of tissue-engineered cartilage were placed side by side to reconstruct the posterior canal wall. The postoperative course was uneventful. This is the first-in-human report of reconstructing middle ear bony structures with tissue-engineered cartilage. The results suggest a promising future for the satisfactory reconstruction of middle ear structures with minimal morbidity at the donor site.

Effect of chlorhexidine pretreatment on bacterial contamination at rhinoplasty field

BACKGROUND

This study investigated on bacterial contamination of the rhinoplasty field. The effect of preoperative chlorhexidine treatment on decreasing bacterial contamination in the rhinoplasty field is examined.

METHODS

Thirty patients who underwent rhinoplasty were block randomized into a chlorhexidine, regular-soap, or control group comprising ten participants each. The chlorhexidine group was subjected to chlorhexidine showering, shampooing, and facial-cleansing 12 h prior to the operation. The regular-soap group was subjected to cleansing with regular soap, and the control group did not have any skin pretreatment. Bacterial cultures were done 12 h preoperatively from nasal cavity and perinasal skin, immediately preoperatively from perinasal skin and at 1 and 2 h intraoperatively from operation field. Culture results were compared between the three groups, according to operation time, or whether infection-prone procedure was performed.

RESULTS

The bacterial species and colony-forming unit numbers at preoperative nasal cavity and perinasal skin were similar. In all three groups, Coagulase-negative staphylococcus was the most common bacteria found in the rhinoplasty field. The numbers of Staphylococcus aureus and Corynebacterium decreased rapidly after preoperative chlorhexidine treatment. The infection-prone procedure was associated with increased bacterial numbers over time during the operation. In all three groups, there was no postoperative infection in a follow-up period of 6 months.

CONCLUSION

Rhinoplasty is confirmed as a clean contaminated operation with skin flora consistently found in the operation field. Chlorhexidine pretreatment in rhinoplasty patients has a tendency to decrease the numbers of Staphylococcus aureus and Corynebacterium on the perinasal skin.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I.

Treatment of recurrent anal fistula using an autologous cartilage plug: a pilot study

BACKGROUND

The aim of the present study was to assess a novel autologous cartilage plug technique used to treat anal fistula in ten patients.

METHODS

All ten patients had undergone at least two prior operations for recurrent fistulas. The plugs were prepared using the patients' own cartilage, which was obtained from either the nose or the ear, diced into pieces, and wrapped with oxidized regenerated cellulose. During the same session, fistula tracts were curetted using cytology brushes, and then, the cartilage plug was inserted into the tract. Routine postoperative examinations were performed at 2, 4, 8, 12, and 24 weeks after surgery. Magnetic resonance imaging was performed before surgery and at 3 and 6 months postoperatively. Relief of symptoms, radiological healing, recurrence, and continence were evaluated.

RESULTS

The ten patients included six males and four females, with a median age of 39 years (range 25-70 years) and a median of three previous fistula operations (range 2-7 operations). Nine patients had cryptoglandular abscess, and one patient had Crohn's disease. The majority of the patients had transsphincteric fistulas with substantial anal sphincter involvement. The cartilage donor site was the nose for one patient and the ear for nine patients. The median follow-up time was 24 months (range 10-32 months). Of the ten patients, nine had fistula treatment without any short-term complications. The fistula failed to heal in one patient. Among the nine patients whose operations were initially successful, two late recurrences were observed.

CONCLUSIONS

The cartilage plug seems to be a promising alternative for anal fistula treatment.

Construction of eukaryotic expression vector with mBD1-mBD3 fusion genes and exploring its activity against influenza A virus

Influenza (flu) pandemics have exhibited a great threat to human health throughout history. With the emergence of drug-resistant strains of influenza A virus (IAV), it is necessary to look for new agents for treatment and transmission prevention of the flu. Defensins are small (2–6 kDa) cationic peptides known for their broad-spectrum antimicrobial activity. Beta-defensins (β-defensins) are mainly produced by barrier epithelial cells and play an important role in attacking microbe invasion by epithelium. In this study, we focused on the anti-influenza A virus activity of mouse β-defensin 1 (mBD1) and β defensin-3 (mBD3) by synthesizing their fusion peptide with standard recombinant methods. The eukaryotic expression vectors pcDNA3.1(+)/mBD1-mBD3 were constructed successfully by overlap-PCR and transfected into Madin-Darby canine kidney (MDCK) cells. The MDCK cells transfected by pcDNA3.1(+)/mBD1-mBD3 were obtained by G₄₁₈ screening, and the mBD1-mBD3 stable expression pattern was confirmed in MDCK cells by RT-PCR and immunofluorescence assay. The acquired stable transfected MDCK cells were infected with IAV (A/PR/8/34, H1N1, 0.1 MOI) subsequently and the virus titers in cell culture supernatants were analyzed by TCID₅₀ 72 h later. The TCID₅₀ titer of the experimental group was clearly lower than that of the control group (p < 0.001). Furthermore, BALB/C mice were injected with liposome-encapsulated pcDNA3.1(+)/mBD1-mBD3 through muscle and then challenged with the A/PR/8/34 virus. Results showed the survival rate of 100% and lung index inhibitory rate of 32.6% in pcDNA3.1(+)/mBD1-mBD3group; the TCID₅₀ titer of lung homogenates was clearly lower than that of the control group (p < 0.001). This study demonstrates that mBD1-mBD3 expressed by the recombinant plasmid pcDNA3.1(+)/mBD1-mBD3 could inhibit influenza A virus replication both in vitro and in vivo. These observations suggested that the recombinant mBD1-mBD3 might be developed into an agent for influenza prevention and treatment.

Ubiquitous presence of piscidin-1 in Atlantic cod as evidenced by immunolocalisation

Background

Antimicrobial peptides (AMPs), the natural antibiotics bestowed upon all forms of life, consist of small molecular weight proteins with a broad spectrum antimicrobial activity against a variety of pathogenic microorganisms. Piscidins are one of the AMP families that are imperative for the innate defence mechanisms of teleosts. Atlantic cod, a basal fish belonging to the superorder Paracanthopterygii also possesses multiple piscidin peptides. Two piscidin paralogues (pis1 and pis2) and a novel alternative splice variant of pis2 of this fish were previously described by us. To shed light on other potent roles of these molecules, now we have mapped the distribution of piscidin 1 (Pis1), in different tissues and organs of cod through immunohistochemistry (IHC) employing an affinity purified polyclonal antibody specific to Pis1.

Results

Various cell types and tissues of Atlantic cod including those from the immune organs of naïve fish are armed with Pis1 peptide. Different types of the blood leucocytes and phagocytic cells among the leucocytes examined gave a relatively strong indication of Pis1 immunopositivity. In addition, other cell types such as hematopoietic cells, epithelial cells and multi-granular cells located in the mucosal and hematopoietic tissues were also Pis1-immunoreactive. More interestingly, chondrocytes appear to produce Pis1 and this is the first report on the presence of an AMP in cartilage tissue of fish. Furthermore, Pis1 immunopositivity was detected in other tissues and organs of naïve fish including neural tissues, exocrine and endocrine glands, compound gland cells, excretory kidney, intestinal and respiratory epithelial cells, swim bladder, skin and hypodermis layer, myosepta, liver, heart, eye and oocytes.

Conclusions

Pis1 peptide is produced by various cell types located in different tissues and organs of Atlantic cod. It is present in all immune-related organs of naïve fish and the elevated peptide expression following phagocytosis strongly suggest their involvement in innate defence. Further, its widespread occurrence in non-immune tissues and organs of apparently healthy fish implies that piscidin may have other functions in addition to its role as an immune effector molecule.