Comparison of the failure rate, bonding time and ARI score of two orthodontic bonding systems: Self-Etch Primer and Conventional Etching Primer: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the failure incidence of brackets with at least six months follow-up between self-etch primer and conventional etch/primer, as well as to investigate the clinical duration of the bonding process and the amount of adhesive remnant index (ARI).

METHODS

Electronic search was conducted in databases including PubMed, Scopus, Web of Science, ProQuest, ClinicalTrials.gov, and ICTRP (International Clinical Trials Registry Platform). The electronic search targeted only randomized clinical trials and was limited from January 2000 to June 2021. Delphi list is used to evaluate the risk of bias and Stata Version14.2 software was used. This systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and recorded on the Ethics Committee of Research Institute of Dental Sciences, SBMU (IR.SBMU.DRC.REC.1398.240).

RESULTS

Out of 2288 extracted studies, 30 of them entered the full-text evaluation process. According to the inclusion criteria, 15 studies entered this systematic review. Containing 607 participants and 10,563 brackets/teeth. All the included studies were of randomized clinical trials (RCT) design with either parallel or split-mouth design. Comparing the two groups, the risk difference effect (RD)=0.007 CI 95% (-0.004,0.018) indicated a neglectable difference in the risk of bracket failure during treatment between the two groups. The index I²=53.9% indicated moderate heterogeneity in the results. Furthermore, the P-value=0.007 indicated statistical insignificance between the two interventions in terms of failure rate. The clinical duration of bonding time analysis were equal to SMD _Cohen=-2.67 CI95% (-3.49, -1.85), which indicated a statistically significant reduction in clinical process time, using the self-etch primer. Data synthesis for adhesive remnant index could not be conducted due to heterogeneity among included studies.

CONCLUSIONS

There was no difference between the self-etch primer and conventional etch/primer in bracket debonding at a medium level of evidence, However, there was statistically significant reduction in clinical bonding time using self-etch primer.

Upregulated miR-410 is linked to poor prognosis in colorectal cancer

BACKGROUND

Although miR-410 acts as a cancer inducer in colorectal cancer, there is limited data on the clinical implications of miR-410 expression levels in patients. We hypothesized a link between miR-410 expression and its potential clinical values in patients with colorectal cancer.

MATERIAL AND METHODS

120 colorectal cancer tissue specimens and 120 adjacent non-tumour tissues were obtained. Quantification of miR-410 expression levels was determined by, quantitative RT-PCR. Expression was analysed by clinical features.

RESULTS

miR-410 was up-regulated in malignant tissues compared with corresponding normal tissues (P < 0.01), with TNM stage and lymph node metastasis (P = 0.03, P = 0.004, respectively), and with worse overall survival (P = 0.002). Multivariate survival analysis identified it as an independent risk factor for outcome (P = 0.021, HR = 2.19; 95% CI = 1.12-4.25).

CONCLUSION

Compared to normal non-cancerous tissues, miR-410 was overexpressed in tumour tissues and is independently associated with the unfavourable outcome. Levels of MiR-410 might a useful laboratory tool in managing and predicting the prognosis of colorectal cancer.

Objective assessment of dermal fibrosis in cutaneous scarring, using optical coherence tomography, high-frequency ultrasound and immunohistomorphometry of human skin

Background

Noninvasive quantitative assessment of dermal fibrosis remains a challenge. Optical coherence tomography (OCT) and high‐frequency ultrasound (HFUS) can accurately measure structural and physiological changes in skin.

Objectives

To perform quantitative analysis of cutaneous fibrosis.

Methods

Sixty‐two healthy volunteers underwent multiple sequential skin biopsies (day 0 and 1–8 weekly thereafter), with OCT and HFUS measurements at each time point supported with immunohistomorphometry analysis.

Results

HFUS and OCT provided quantitative measurements of skin thickness, which increased from uninjured skin (1·18 and 1·2 mm, respectively) to week 1 (1·28 mm, P = 0·01; 1·27 mm, P = 0·02), and compared favourably with haematoxylin and eosin. Spearman correlation showed good agreement between techniques (P < 0·001). HFUS intensity corresponded to dermal density, with reduction from uninjured skin (42%) to week 8 (29%) (P = 0·02). The OCT attenuation coefficient linked with collagen density and was reduced at week 8 (1·43 mm, P < 0·001). Herovici analysis showed that mature collagen levels were highest in uninjured skin (72%) compared with week 8 (42%, P = 0·04). Fibronectin was greatest at week 4 (0·72 AU) and reduced at week 8 (0·56 AU); and α‐smooth muscle actin increased from uninjured skin (11·5%) to week 8 (67%, P = 0·003).

Conclusions

Time‐matched comparison images between haematoxylin and eosin, OCT and HFUS demonstrated that epidermal and dermal structures were better distinguished by OCT. HFUS enabled deeper visualization of the dermis including the subcutaneous tissue. Choice of device was dependent on the depth of scar type, parameters to be measured and morphological detail required in order to provide better objective quantitative indices of the quality and extent of dermal fibrosis.

What's already known about this topic?

Objective studies of the progression of scar formation and the properties of mature scars are necessary in order to evaluate clinical treatment, and for research focused on developing novel methods for management of dermal fibrosis.

Optical coherence tomography (OCT) and high‐frequency ultrasound (HFUS) are two known noninvasive techniques that are used effectively for measuring structural and physiological changes in cutaneous tissue.

What does this study add?

OCT and HFUS are useful tools for noninvasive monitoring of cutaneous fibrosis, enabling quantitative sequential temporal measurements of cutaneous thickness similarly to histology.

OCT attenuation coefficient (better in resolution) and HFUS intensity (better in depth) provide an indication of collagen deposition in skin over the course of healing, supported by immunohistochemical analysis.

Choice of device is dependent upon wound and scar type, the parameters to be measured and the morphological detail required.

https://doi.org/10.1111/bjd.18394 available online

https://www.bjdonline.com/article/Objective-assessment-of-dermal-fibrosis-in-cutaneous-scarring-using-optical-coherence-tomography-high-frequency-ultrasound-and-immunohistomorphometry-of-human-skin/

Functional biocompatibility testing of silicone breast implants and a novel classification system based on surface roughness

PURPOSE

Increasing numbers of women undergo breast implantation for cosmetic and reconstructive purposes. Contracture of the fibrous capsule, which encases the implant leads to significant pain and reoperation. Texture, wettability and the cellular reaction to implant surfaces are poorly understood determinants of implant biocompatibility. The aim of this study was to evaluate the in-vitro characteristics of a range of commercial available implants using a macrophage based assay of implant biocompatibility and a quantitative assessment of wettability and texture.

METHODS

Thirteen commercially available surfaces were subjected to wettability and texture characterisation using scanning and laser confocal microscopy. THP-1 macrophages were cultured on their surfaces and assessed using Integrin αV immunocytochemistry, SEM and RT-PCR for the expression of TNF-Alpha, IL-6, IL-10 and a cytokine array for the production of TNF-alpha, IL-10, IL-1RA and IL1β; important indicators of inflammation and macrophage polarization.

RESULTS

Textured surfaces can be accurately sub-categorized dependent upon roughness and re-entrant features into four main types (macro, micro, meso and nano-textured surfaces). Significant (P < 0.0001) differences in implant hydrophobicity and texture exist. Certain surfaces promoted poor macrophage polarization and an innate potential to foster a proinflammatory response. A subgroup analysis showed that texture had a variable effect on markers of inflammation in these surfaces.

CONCLUSIONS

We propose a classification of implant surfaces based on roughness and present a macrophage based assay of breast implant biocompatibility with a quantitative assessment of implant wettability and texture. The breast implant surface-cell interaction is variable and sufficient to alter healing response and capsular contracture fate in-vivo.

Site-specific gene expression profiling as a novel strategy for unravelling keloid disease pathobiology

Keloid disease (KD) is a fibroproliferative cutaneous tumour characterised by heterogeneity, excess collagen deposition and aggressive local invasion. Lack of a validated animal model and resistance to a multitude of current therapies has resulted in unsatisfactory clinical outcomes of KD management. In order to address KD from a new perspective, we applied for the first time a site-specific in situ microdissection and gene expression profiling approach, through combined laser capture microdissection and transcriptomic array. The aim here was to analyse the utility of this approach compared with established methods of investigation, including whole tissue biopsy and monolayer cell culture techniques. This study was designed to approach KD from a hypothesis-free and compartment-specific angle, using state-of-the-art microdissection and gene expression profiling technology. We sought to characterise expression differences between specific keloid lesional sites and elucidate potential contributions of significantly dysregulated genes to mechanisms underlying keloid pathobiology, thus informing future explorative research into KD. Here, we highlight the advantages of our in situ microdissection strategy in generating expression data with improved sensitivity and accuracy over traditional methods. This methodological approach supports an active role for the epidermis in the pathogenesis of KD through identification of genes and upstream regulators implicated in epithelial-mesenchymal transition, inflammation and immune modulation. We describe dermal expression patterns crucial to collagen deposition that are associated with TGFβ-mediated signalling, which have not previously been examined in KD. Additionally, this study supports the previously proposed presence of a cancer-like stem cell population in KD and explores the possible contribution of gene dysregulation to the resistance of KD to conventional therapy. Through this innovative in situ microdissection gene profiling approach, we provide better-defined gene signatures of distinct KD regions, thereby addressing KD heterogeneity, facilitating differential diagnosis with other cutaneous fibroses via transcriptional fingerprinting, and highlighting key areas for future KD research.

Development, fabrication and evaluation of a novel biomimetic human breast tissue derived breast implant surface

Breast implant use has tripled in the last decade with over 320,000 breast implant based reconstructions and augmentations performed in the US per annum. Unfortunately a considerable number of women will experience capsular contracture, the irrepressible and disfiguring, tightening and hardening of the fibrous capsule that envelops the implant. Functionalising implant surfaces with biocompatible tissue-specific textures may improve in vivo performance. A novel biomimetic breast implant is presented here with anti-inflammatory in vitro abilities. Topographical assessment of native breast tissue facilitated the development of a statistical model of adipose tissue. 3D grayscale photolithography and ion etching were combined to successfully replicate a surface modelled upon the statistics of breast tissue. Pro-inflammatory genes ILβ1, TNFα, and IL6 were downregulated (p<0.001) and anti-inflammatory gene IL-10 were upregulated on the novel surface. Pro-inflammatory cytokines Gro-Alpha, TNFα and neutrophil chemoattractant IL8 were produced in lower quantities and anti-inflammatory IL-10 in higher quantities in culture with the novel surface (p<0.01). Immunocytochemistry and SEM demonstrated favourable fibroblast and macrophage responses to these novel surfaces. This study describes the first biomimetic breast tissue derived breast implant surface. Our findings attest to its potential translational ability to reduce the inflammatory phase of the implant driven foreign body reaction.

STATEMENT OF SIGNIFICANCE

Breast implants are still manufactured using outdated techniques and have changed little since their inception in the 1960's. Breast implants can cause a medical condition, capsular contracture which often results in disfigurement, pain, implant removal and further surgery. This condition is due to the body's reaction to these breast implants. This article describes the successful development and testing of a novel breast implant surface inspired by the native shapes present in breast tissue. Results show that this novel implant surface is capable of reducing the negative reaction of human cells to these surfaces which may help reduce capsular contracture formation. This work represents the first steps in producing a biocompatible breast implant.

Synthesis of N, N-dimethyl N-ethyl Chitosan as a Carrier for Oral Delivery of Peptide Drugs

N, N-dimethyl N-ethyl chitosan (DMEC), a quanternized derivative of chitosan was synthesized based on a modified two-step method via a 22 factorial design to optimize the preparative conditions. The degree of deacetylation of the starting chitosan was determined by FTIR and NMR methods and was 95%. In the first step of the synthesis, mono-ethyl chitosan was prepared by introducing an ethyl group onto the amine group of chitosan via a Schiff base and in the next step methyl iodide was added to produce DMEC which was water soluble in a pH range of 4-8. The DMEC polymers with different degrees of quaternization were obtained and fully characterized using FTIR and 1H-NMR spectroscopic methods. Based on 1H-NMR calculations, the degree of quaternization was 52% by optimizing the two-step process.

Platinum nanoparticles with superacid-doped polyvinylpyrrolidone coated carbon nanotubes: electrocatalyst for oxygen reduction reaction in high-temperature proton exchange membrane fuel cell

In order to improve the catalytic activity and durability of proton-exchange-membrane-fuel-cells (PEMFCs), Nafion-free Pt-based catalyst using the superacid-doped polymer coated multiwall carbon nanotubes (MWCNTs) was investigated.

Fabrication and surface stochastic analysis of enhanced photoelectrochemical activity of a tuneable MoS2–CdS thin film heterojunction

CdS/MoS₂(t)/ITO thin films were prepared via a facile method with controllable surface properties, and a model was proposed to describe the enhancement of photoelectrochemical activity from a stochastic view point.

Mutational and phenotypical spectrum of phenylalanine hydroxylase deficiency in Denmark

We describe the genotypes of the complete cohort, from 1967 to 2014, of phenylketonuria (PKU) patients in Denmark, in total 376 patients. A total of 752 independent alleles were investigated. Mutations were identified on 744 PKU alleles (98.9%). In total, 82 different mutations were present in the cohort. The most frequent mutation c.1315+1G>A (IVS12+1G>A) was found on 25.80% of the 744 alleles. Other very frequent mutations were c.1222C>T (p.R408W) (16.93%) and c.1241A>G (p.Y414C) (11.15%). Among the identified mutations, five mutations; c.532G>A (p.E178K), c.730C>T (p.P244S), c.925G>A (p.A309T), c.1228T>A (p.F410I), and c.1199+4A>G (IVS11+4A>G) have not been reported previously. The metabolic phenotypes of PKU are classified into four categories; 'classical PKU', 'moderate PKU', 'mild PKU' and 'mild hyperphenylalaninemia'. In this study, we assigned the phenotypic outcome of three of the five novel mutations and furthermore six not previously classified mutations to one of the four PKU categories.

Topical management of striae distensae (stretch marks): prevention and therapy of striae rubrae and albae

Striae distensae (SD) are common dermal lesions, with significant physical and psychological impact. Many therapeutic modalities are available but none can completely eradicate SD. The most common therapy is the application of topicals used both therapeutically and prophylactically. Even though there are many commercially available topical products, not all have sufficient level of evidence to support their continued use in SD. The aim here was to assess the evidence for the use of topicals in SD and to propose a structured approach in managing SD. A systematic search of published literature and manufacturer website information for topicals in SD was carried out. The results showed that there are few studies (n = 11) which investigate the efficacy of topicals in management of SD. Trofolastin and Alphastria creams demonstrated level-2 evidence of positive results for their prophylactic use in SD. Additionally, tretinoin used therapeutically showed varying results whilst cocoa butter and olive oil did not demonstrate any effect. Overall, there is a distinct lack of evidence for each topical formulation. The majority of topicals failed to mention their effect on early vs. later stages of SD (striae rubrae compared to striae albae) and their role in both prevention and treatment. In conclusion, there is no topical formulation, which is shown to be most effective in eradicating or improving SD. A structured approach in identification and targeted management of symptoms and signs with the appropriate topical is required. Randomized controlled trials are necessary to assess the efficacy of topical products for treatment and prevention of different stages of SD.

A comprehensive evidence-based review on the role of topicals and dressings in the management of skin scarring

Wound healing after dermal injury is an imperfect process, inevitably leading to scar formation as the skin re-establishes its integrity. The resulting scars have different characteristics to normal skin, ranging from fine-line asymptomatic scars to problematic scarring including hypertrophic and keloid scars. Scars appear as a different colour to the surrounding skin and can be flat, stretched, depressed or raised, manifesting a range of symptoms including inflammation, erythema, dryness and pruritus, which can result in significant psychosocial impact on patients and their quality of life. In this paper, a comprehensive literature review coupled with an analysis of levels of evidence (LOE) for each published treatment type was conducted. Topical treatments identified include imiquimod, mitomycin C and plant extracts such as onion extract, green tea, Aloe vera, vitamin E and D, applied to healing wounds, mature scar tissue or fibrotic scars following revision surgery, or in combination with other more established treatments such as steroid injections and silicone. In total, 39 articles were included, involving 1703 patients. There was limited clinical evidence to support their efficacy; the majority of articles (n = 23) were ranked as category 4 LOE, being of limited quality with individual flaws, including low patient numbers, poor randomisation, blinding, and short follow-up periods. As trials were performed in different settings, they were difficult to compare. In conclusion, there is an unmet clinical need for effective solutions to skin scarring, more robust long-term randomised trials and a consensus on a standardised treatment regime to address all aspects of scarring.

An abnormality in glucocorticoid receptor expression differentiates steroid responders from nonresponders in keloid disease

Background

Glucocorticoids (GCs) are first‐line treatment for keloid disease (KD) but are limited by high incidence of resistance, recurrence and undesirable side‐effects. Identifying patient responsiveness early could guide therapy.

Methods

Nineteen patients with KD were recruited at week 0 (before treatment) and received intralesional steroids. At weeks 0, 2 and 4, noninvasive imaging and biopsies were performed. Responsiveness was determined by clinical response and a significant reduction in vascular perfusion following steroid treatment, using full‐field laser perfusion imaging (FLPI). Responsiveness was also evaluated using (i) spectrophotometric intracutaneous analysis to quantify changes in collagen and melanin and (ii) histology to identify changes in epidermal thickness and glycosaminoglycan (GAG) expression. Biopsies were used to quantify changes in glucocorticoid receptor (GR) expression using quantitative reverse transcriptase polymerase chain reaction, immunoblotting and immunohistochemistry.

Results

At week 2, the FLPI was used to separate patients into steroid responsive (n = 12) and nonresponsive groups (n = 7). All patients demonstrated a significant decrease in GAG at week 2 (P < 0·05). At week 4, responsive patients exhibited significant reduction in melanin, GAG, epidermal thickness (all P < 0·05) and a continued reduction in perfusion (P < 0·001) compared with nonresponders. Steroid‐responsive patients had increased GR expression at baseline and showed autoregulation of GR compared with nonresponders, who showed no change in GR transcription or protein.

Conclusions

This is the first demonstration that keloid response to steroids can be measured objectively using noninvasive imaging. FLPI is a potentially reliable tool to stratify KD responsiveness. Altered GR expression may be the mechanism gating therapeutic response.

What's already known about this topic?

Steroids are used as first‐line treatment for keloid disease, but response is variable with apparent steroid responders and nonresponders.

It remains unclear whether steroid responsiveness is due to an intrinsic difference in the mechanism of the glucocorticoid receptor (GR) action or reduced sensitivity to the steroid itself.

What does this study add?

We show for the first time the utility of noninvasive imaging techniques in stratifying steroid responsiveness in patients treated with steroids.

GR expression increased significantly in keloid tissue. Increased GR expression also correlated with an increased response to steroid treatment.

Steroid responders show a significant decrease in GR transcript and protein 2 weeks after steroid treatment (P < 0·05), which was not evident in steroid‐resistant patients.

Psychometric properties of the Sexual Adjustment Questionnaire (SAQ) in the Iranian population with spinal cord injury

STUDY DESIGN

This is a cross-sectional study.

OBJECTIVES

The objective of this study was to examine the psychometric properties of the Sexual Adjustment Questionnaire (SAQ) for Iranian people with spinal cord injury.

SETTING

This study was conducted in the brain and Spinal Cord Injury Research Center, Tehran University of Medical Sciences, Tehran, Iran.

METHODS

We assessed the psychometric properties of the SAQ, with 200 participants (men=146, women=54) completing the scale. An evaluation of its test-retest reliability was performed over a 2-weeks period, on a subsample of 30 patients recruited from the overall group. Cronbach's α-coefficient was computed for assessment of internal consistency reliability. In addition, content and face validity were examined by an expert committee. Construct validity was assessed by examining convergent and discriminant validity. Finally, exploratory factor analysis was used to extract the factor structure of the questionnaire.

RESULTS

The Cronbach's α and intraclass correlation coefficient were 0.77 and 0.72 retrospectively. With regard to construct validity, there was a significant (P=0.009) negative correlation (r=-0.28) between the SAQ score and age. Those with lower levels of educations scored significantly lower on the SAQ (P=0.04). The exploratory factor analysis indicated a four-factor structure for the questionnaire, accounting for 68.9% of the observed variance. The expert committee approved the face and content validity of the developed measure.

CONCLUSION

The SAQ is a valid measure for assessing sexual adjustment in people with spinal cord injury. The evaluation of sexual well-being may be useful in clinical trials and practical settings.

Functional histopathology of keloid disease

Keloid disease is a benign, yet locally aggressive and recurrent cutaneous fibroproliferative condition characterised by excessive scarring. Unique to humans, keloids represent the end-point of a spectrum of abnormal wound healing, are aesthetically disfiguring and can cause major functional impairment. Its heterogeneous phenotype can confound clinical diagnosis leading to mismanagement. This review examines the histological morphology of keloid disease relative to the underlying pathobiology, places it in the context of other cutaneous fibroses and highlights gaps within the literature that hinder differential diagnosis. The pathological similarity to hypertrophic scarring, dermatofibrosarcoma protuberans, dermatofibroma and scleroderma emphasise the importance of detailing the architectural and cellular components of this unique entity. In the papillary dermis keloid tumours show a tongue-like advancing edge that resembles invasive tumour growth. A thickened but flattened epidermis, hyalinised haphazardly arranged collagen bundles that dominate the dermis with subsequent obliteration of the papillary-reticular boundary along with displacement and eventually destruction of skin appendages, exemplify additional hallmark findings associated with keloid disease. Compared to healthy skin, keloid scars show an increased type I/III collagen ratio, decreased fibrillin-1 and decorin expression, increased dermal cellularity and increased expression of fibronectin, versican, elastin and tenascin in the reticular dermis and hyaluronan and osteopontin in the epidermis. We illustrate these "pathognomonic" features of keloid disease by representative micrographs and discuss them in the context of inflammation, hypoxia and tension--as key elements of keloid disease. Finally, we highlight deficits within the keloid research literature as well as discuss important areas for future research in keloid histology.

Conversion of canola oil and canola oil methyl ester (CME) to green aromatics over a HZSM-5 catalyst: a comparative study

The catalytic conversions of canola oil and canola oil methyl ester (CME) for the production of green aromatics over a HZSM-5 catalyst were investigated.

Strategic management of keloid disease in ethnic skin: a structured approach supported by the emerging literature

Keloid disease (KD) is a common, benign, dermal fibroproliferative growth of unknown aetiology. Lesions tend to grow over time; they often recur following therapy and do not regress spontaneously. KD causes considerable discomfort due to pain, pruritus and inflammation, and a significant psychosocial impact with reduced quality of life. It is unique to humans and occurrence is higher in individuals with dark, pigmented, ethnic skin. There is a strong familial heritability, with a high ethnic predisposition in individuals of African, Asian and Hispanic descent. High recurrence rates and unknown resolution rates present a major problem for both the patient and clinician. Many treatment modalities exist; however, there is no single advocated therapy. Therefore, the aim of this review was to explore the most current literature regarding the range of treatment options for KD and to offer a structured approach in the management of KD, based on evidence and experience, to aid clinicians in their current practice. A focused history involving careful evaluation of the patient's symptoms, signs, quality of life and psychosocial well-being should direct targeted therapy, complemented with regular follow-up and re-evaluation. Many treatment modalities, such as intralesional steroid injection, silicone gel application, cryotherapy, lasers, 5-fluorouracil and, relatively recently, photodynamic therapy, are currently being used in clinical practice for the management of KD. Combination therapies have also been shown to be beneficial. However, there is a lack of robust, randomized, level-one, evidence-controlled trials evaluating these treatment options. Management of KD in ethnic pigmented skin remains a clinical challenge. Thus, a strategic approach with structured assessment, targeted therapy and focus on prevention of recurrence is highly recommended. Quality evidence is essential in order to tailor treatment effectively for the ethnic patient presenting with KD.

Site-specific immunophenotyping of keloid disease demonstrates immune upregulation and the presence of lymphoid aggregates

BACKGROUND

Keloid disease (KD) is a common fibroproliferative disorder of unknown aetiology. T cells and macrophages are increased in KD and are thought to contribute to its pathogenesis. However, while a link between inflammation and fibrotic disorders is well known for other disorders, it remains undetermined in KD.

OBJECTIVES

Systematically to immunophenotype the inflammatory infiltrate of KD in situ in a site-specific manner, and to compare this with normal skin and scar tissue.

METHODS

Sixty-eight keloid cases were screened for the presence of all three (intralesional, perilesional and extralesional) keloid-associated specific tissue sites. Subsequently, a complete set of 25 keloid biopsies (from different patients) was compared with normal skin (n = 11) and normal scar (n = 11) samples and subjected to systematic, site-specific quantitative immunohistomorphometry and histochemistry, using a range of immunological markers of B cells, T cells, macrophages, mast cells (MCs) and Langerhans cells.

RESULTS

T cells, B cells, degranulated and mature MCs (coexpressing OX40 ligand) and alternative macrophages (M2) were all significantly increased in intralesional and perilesional KD sites compared with normal skin and scar tissue (P < 0·05). Additionally, 10 of 68 KD cases (15%) showed the presence of distinctive lymphoid aggregates, which resembled mucosa-associated lymphoid tissue (MALT).

CONCLUSIONS

The increased number and activity of MCs and M2 may implicate inflammation in the fibrotic process in KD. The distinct KD-associated lymphoid aggregate resembles MALT, for which we propose the term 'keloid-associated lymphoid tissue' (KALT). It may perpetuate inflammatory stimuli that promote KD growth. KALT, MCs and M2 are promising novel targets for future KD therapy.

Whole genome and global expression profiling of Dupuytren's disease: systematic review of current findings and future perspectives

Dupuytren's disease (DD) is a common fibroproliferative disorder affecting the palmar fascia, which may lead to permanent contracture of the affected digit. Profiling studies investigating DD at whole-genomic, transcriptomic and proteomic levels have been carried out, from which large numbers of candidate genes potentially involved in DD have been reported. This review focuses on identifying genes reported by multiple studies or validated by multiple experimental techniques, as well as signalling pathways suggested to contribute to DD. Meta-analysis was also carried out on three microarray datasets. Twenty-one genes were found to be reported as dysregulated in multiple gene expression microarrays, seven of which have been further validated by other experimental methods. Sixty-four genes determined to be dsyregulated by meta-analysis correlate to those reported by published microarray studies. In addition, several pathways have been proposed to be involved in DD by whole-genome or global expression profiling. Further investigation in these genes and pathways, and correlating them to genotypes or environmental factors for DD, may aid in further elucidation of mechanisms involved in DD pathogenesis.

New technologies for studying the complexity of oral diseases

Several new technologies are providing useful diagnostic tools and new information related to the pathogenesis of certain oral diseases. In this review, we describe several of these technologies including gene and microRNA arrays, proteomics, and antigen arrays as they relate to the study of Sjögren's syndrome and head and neck cancer. A common theme is the systematic analysis of large-scale inventories of RNAs, proteins, and autoantibody biomarkers revealing information not previously recognized. We also discuss metagenomic approaches that characterize the many different microorganisms present in the oral cavity that may impact oral and human health. Lastly, we describe applications of a new type of antibody-profiling technology termed Luciferase Immunoprecipitation Systems (LIPS), which has a wide dynamic range of detection of both linear and conformational epitopes needed for optimum diagnostics and biomarker discovery. We propose that the information offered by these technologies will enhance our ability to diagnose, treat, and further understand the pathogenesis of multiple oral diseases.

Extracellular matrix molecules implicated in hypertrophic and keloid scarring

Tissue regeneration repairs the fabric of the skin to maintain homeostasis after injury. The expression and proliferation of extracellular matrix (ECM) molecules in the dermis, mediated by a range of growth factors and cytokines, is a fundamental element of wound repair. Previous work focused on how these complex molecular mechanisms relate to the formation of raised dermal scars, including keloid and hypertrophic scars, characterized by excessive deposition of ECM molecules. However, the mechanisms in the wound repair pathway which lead to the differential expression and organization of ECM molecules observed in different types of scar tissue are not fully understood. To summarize what is known about the expression and composition of ECM molecules in abnormal scarring, an extensive search of the literature was conducted, focusing on keywords connected to skin scarring, hypertrophic scars and keloid disease. The transcription and translation of collagen I and III, fibronectin, laminin, periostin and tenascin are all increased in raised dermal scar tissue. However, hyaluronic acid, dermatopontin and decorin are decreased, and the expression and localisation of fibrillin and elastin fibres in the dermis are altered compared with normal skin and scars. Recent whole genome profiling and proteomic studies have led to the identification of regulatory elements with different expression profiles in hypertrophic and keloid tissue. If the mechanisms of raised dermal scar formation are to be elucidated and effective therapeutic treatments developed, an integrated approach to research is required, focussing on the interactions between ECM molecules, regulatory elements and pathways.

Exploring the application of mesenchymal stem cells in bone repair and regeneration

Failure of bone repair is a challenging problem in the management of fractures. There is a limited supply of autologous bone grafts for treating nonunions, with associated morbidity after harvesting. There is need for a better source of cells for repair. Mesenchymal stem cells (MSCs) hold promise for healing of bone because of their capacity to differentiate into osteoblasts and their availability from a wide variety of sources. Our review aims to evaluate the available clinical evidence and recent progress in strategies which attempt to use autologous and heterologous MSCs in clinical practice, including genetically-modified MSCs and those grown on scaffolds. We have compared various procedures for isolating and expanding a sufficient number of MSCs for use in a clinical setting. There are now a number of clinical studies which have shown that implantation of MSCs is an effective, safe and durable method for aiding the repair and regeneration of bone.

Characterization of hyaluronan and TSG-6 in skin scarring: differential distribution in keloid scars, normal scars and unscarred skin

Background Hyaluronan (HA) is a major component of the extracellular matrix (ECM) with increased synthesis during tissue repair. Tumour necrosis factor-stimulated gene-6 (TSG-6) is known to catalyze the covalent transfer of heavy chains (HC1 and HC2) from inter-α-inhibitor (IαI) onto HA, and resultant HC•HA complexes have been implicated in physiological and pathological processes related to remodelling and inflammation.

Objective The aims of this study were to determine the expression of HA, TSG-6 and the IαI polypeptides in unscarred skin, normal scars and keloid scars.

Methods Formalin-fixed paraffin-embedded sections of unscarred skin, normal scars and keloid scars were prepared from patient samples collected during scar revision surgery. Haematoxylin and eosin, as well as immunofluorescent staining for HA, TSG-6 and the three polypeptide chains of IαI (i.e. HC1, HC2 and bikunin) were performed.

Results All skin types stained positive for TSG-6, HC1, HC2 and bikunin, associated with keratinocytes, fibroblasts and skin appendages all in close proximity to HA. Keloid lesions showed altered HA organization patterns compared with unscarred skin and normal scars. TSG-6 staining was significantly more intense in the epidermis compared with the dermis of all sample types. There was a significant reduction in TSG-6 levels within keloid lesions compared with the dermis of unscarred skin (P = 0.017).

Conclusion TSG-6 is expressed in unscarred skin, where its close association with HA and IαI could give rise to TSG-6-mediated HC•HA formation within this tissue. A reduction in the beneficial effects of TSG-6, caused by diminished protein levels in keloid lesions, could contribute to this abnormal scarring process.

Dermal substitute-assisted healing: enhancing stem cell therapy with novel biomaterial design

The use of dermal substitutes is increasingly widespread but the outcomes of substitute-assisted healing remain functionally deficient. Presently, the most successful scaffolds are acellular polymer matrices, prepared through lyophilization and phase separation techniques, designed to mimic the dermal extracellular matrix. The application of scaffolds containing viable cells has proven to be problematic due to short shelf-life, high cost and death of transplanted cells as a result of immune rejection and apoptosis. Recent advances in biomaterial science have made new techniques available capable of increasing scaffold complexity, allowing the creation of 3D microenvironments that actively control cell behaviour. Importantly, it may be possible through these sophisticated novel techniques, including bio-printing and electrospinning, to accurately direct stem cell behaviour. This complex proposal involves the incorporation of cell-matrix, cell-cell, mechanical cues and soluble factors delivered in a spatially and temporally pertinent manner. This requires accurate modelling of three-dimensional stem cell interactions within niche environments to identify key signalling molecules and mechanisms. The application of stem cells within substitutes containing such environments may result in greatly improved transplanted cell viability. Ultimately this may increase cellular organization and complexity of skin substitutes. This review discusses progress made in improving the efficacy of cellular dermal substitutes for the treatment of cutaneous defects and the potential of evolving new technology to improve current results.

Characterization of stem cells in Dupuytren's disease

BACKGROUND

Dupuytren's disease (DD) is a common fibroproliferative disease of unknown origin. The source of abnormal cells leading to DD formation remains underexplored. In addition to fascia, palmar skin and fat-derived cells may be a potential source of cells causing DD. This study aimed to profile haematopoietic and mesenchymal stem cells in different DD tissue components compared with tissue removed at carpal tunnel surgery (control).

METHODS

Biopsies were taken from the diseased cord, nodule, perinodular fat and skin overlying the nodule of ten patients with DD and compared with control tissue from seven patients having surgery for carpal tunnel syndrome. Fluorescence-activated cell sorting (FACS), immunohistochemistry and quantitative real-time polymerase chain reaction (QRT-PCR) were used to identify expression of selected stem cell markers.

RESULTS

FACS and QRT-PCR analysis identified the highest RNA expression and number of cells positive for adipocyte stem cell markers (CD13 and CD29) in the DD nodule in comparison with carpal tunnel control tissue (P = 0·053). CD34 RNA was overexpressed, and a higher percentage of these cells was present in DD skin compared with carpal tunnel skin (P = 0·001).

CONCLUSION

Each structural component of DD (cord, nodule, perinodular fat and skin) had distinct stem cell populations. These findings support the hypothesis that DD may result from mesenchymal progenitor cell expansion.

Treatment of symptomatic abnormal skin scars with electrical stimulation

OBJECTIVE

To evaluate the effect of non-invasive biofeedback electrical stimulation on symptomatic abnormal skin scars.

METHOD

Thirty patients with over 140 scars with long-term pain and itch were recruited into the study. Patients monitored the intensity of symptoms (pain and itching) on a numerical rating scale. In addition, a modified Manchester scar scale was used to objectively assess digital photographs of each scar in terms of colour, contour, distortion and texture, while a non-invasive spectrophotometric intracutaneous analysis was used to monitor the scars' physical characteristics.

RESULTS

The electrical stimulation device resulted in a clinically and statistically significant (p < 0.05) reduction of symptoms and scar scores. Pain and itch scores were both reduced to a median score of 0 by 2 months, from a baseline of 7 and 6 respectively. Scar scores were reduced from a baseline of 14 to a median score of 11 by 2 months.

CONCLUSION

These results give a preliminary indication of the potential role of non-invasive biofeedback electrical stimulation in the management of chronic scar pain and itch. However, further large scale controlled studies are warranted to elucidate its overall efficacy and mechanistic action.

CONFLICT OF INTEREST

Funding was provided from Fenzian Ltd for this study.

Tumour necrosis factor-α expression is associated with increased severity of periprosthetic breast capsular contracture

BACKGROUND

The pathogenesis of periprosthetic capsular contracture following breast implant surgery is unclear. The aim of this study was to identify the expression of tumour necrosis factor-α (TNF-α), collagen type III α(1) (COL3A1), transforming growth factor-β(1) (TGF-β(1)) and connective tissue growth factor (CTGF) in different Baker grades of breast capsular contracture.

METHODS

Seven periprosthetic breast capsule specimens were collected from 6 patients. TNF-α, COL3A1, TGF-β(1) and CTGF gene expression were analysed using real-time quantitative polymerase chain reaction. Immunohistolocalisation of TNF-α was performed on paraffin-embedded sections. Significant correlations were analysed using the Pearson correlation coefficient.

RESULTS

TNF-α expression was associated with increased Baker grade of capsular contracture (Pearson correlation, r = 0.558; p = 0.02). COL3A1 gene expression was reduced with increasing severity of contracture (r = -0.490; p = 0.05). There were no significant correlations between TGF-β(1) and CTGF expression with Baker grade. Positive TNF-α staining in breast capsules was localised to fibroblasts, macrophages, and extracellularly close to the prosthesis.

CONCLUSION

The increased expression of TNF-α may play a key role in the inflammatory response associated with capsular contracture. The corresponding decrease in COL3A1 may contribute to the change in capsular physical properties seen in capsular contracture.

Patterning of novel breast implant surfaces by enhancing silicone biocompatibility, using biomimetic topographies

INTRODUCTION AND AIMS

Silicone biocompatibility is dictated by cell-surface interaction and its understanding is important in the field of implantation. The role of surface topography and its associated cellular morphology needs investigation to identify qualities that enhance silicone surface biocompatability. This study aims to create well-defined silicone topographies and examine how breast tissue-derived fibroblasts react and align to these surfaces.

METHODS

Photolithographic microelectronic techniques were modified to produce naturally inspired topographies in silicone, which were cultured with breast tissue-derived human fibroblasts. Using light, immunofluorescent and atomic force microscopy, the cytoskeletal reaction of fibroblasts to these silicone surfaces was investigated.

RESULTS

Numerous, well-defined micron-sized pillars, pores, grooves, and ridges were manufactured and characterized in medical grade silicone. Inimitable immunofluorescent microscopy represented in our high magnification images of vinculin, vimentin, and the actin cytoskeleton highlights the differences in fibroblast adhesion between fabricated silicone surfaces. These unique figures illustrate that fibroblast adhesion and the reactions these cells have to silicone can be manipulated to enhance biointegration between the implant and the breast tissue. An alteration of fibroblast phenotype was also observed, exhibiting the propensity of these surfaces to induce categorical remodeling of fibroblasts.

CONCLUSIONS

This unique study shows that fibroblast reactions to silicone topographies can be tailored to induce physiological changes in cells. This paves the way for further research necessary to develop more biocompatible constructs capable of eliminating capsular contracture by subverting the foreign body response.

Current implant surface technology: an examination of their nanostructure and their influence on fibroblast alignment and biocompatibility

Systematic reviews indicate that breast implant texture confers a protective effect on capsular contracture. Fibroblasts are affected by micro- and nanotopographies. Few previous studies have investigated the inherent topographies of existing breast implants and the surfaces with which body tissue is exposed.

AIMS

To examine currently available breast implant surfaces at high resolution and evaluate features within their surface that have been demonstrated to influence fibroblast alignment.

METHODS

Using scanning electron and light microscopy, 5 distinct smooth and textured silicone implants including the Mentor Siltex (Mentor Corporation, Santa Barbara, Calif) and Allergan Biocell (Allergan Medical Corporation, Santa Barbara, Calif) surfaces were investigated at high magnification to illustrate their intrinsic surface topographies.

RESULTS

The images obtained illustrate remarkable micro- and nanoscale topographies. Each surface produced a distinctive microenvironment capable of influencing cell shape and thus biointegration. These features are illustrated by our unique, high-magnification images. The smooth surface exhibits a shallow, regular, 5-microm period rippled texture that may explain higher reported contracture rates, while the Biocell and Siltex surfaces show 100- to 200-microm deep but random features that have been shown to anchor the implant to breast tissue and reduce contracture. Results allow a cell's eye view of these implants, with an explanation of why these types of topographies influence the success of these implants.

CONCLUSIONS

We assessed commonly available silicone implants and offer a unique overview into their surface topographies and how they are manufactured. We conclude that these surfaces require modernization. Our findings provide further insight into potential interactions between cellular assemblies and artificial surfaces and may contribute to the development of improved implant surfaces.

Genetic susceptibility to raised dermal scarring

Raised skin scars, such as keloid and hypertrophic scars mostly occur post-wounding in the human dermis. There is compelling evidence for a genetic component to these conditions, given the familial predisposition, varied incidence in different ethnic populations and the presence in twins. The aim of this study was to perform a systematic review of the literature regarding genetic susceptibility to raised dermal scarring. We identified relevant articles by a systematic search of relevant search engines. Key search terms included: keloid disease, hypertrophic scarring, fibrosis, linkage analysis, gene expression, human leucocyte antigen system (HLA), twins, families, case-control association study and congenital syndromes. Numerous candidate genes have been identified, along with potential linkage regions on different chromosomes. Recent data also suggest that carriers of specific major histocompatibility complex (MHC) alleles, in particular HLA-DRB1*15, HLA-DQA1*0104, DQB1*0501 and DQB1*0503, are at increased risk of developing keloid scarring. In addition, distinct immunophenotypical profiles can distinguish between keloid and hypertrophic scars. Keloid and hypertrophic scars are multifaceted aberrations of the healing process with as yet incompletely understood aetiologies. Current data suggest a genetic susceptibility with a strong immunogenic component to dermal fibrosis with MHC genes being implicated. It appears unlikely that a single gene is responsible for the development of raised dermal scars. A likely scenario may involve the interaction of several gene pathways in addition to environmental factors. The ability to assess accurately an individual's potential genetic susceptibility to raised scarring may lead to a more personalized approach to their management in the future.

Positive association of HLA-DRB1*15 with Dupuytren's disease in Caucasians

Dupuytren's disease (DD) is a permanent nodular condition affecting the palms and digits of the hands, leading to progressive shortening and contractures of the digits often resulting in diminished function and severe deformity. DD is thought to be one of the most common hereditary connective tissue disorders in Caucasians. To elucidate further the aetiology of DD, we compared the HLA-DRB1 phenotype frequencies of DD patients (n=67) against the HLA-DRB1 phenotype frequencies observed in a control population (n=537). HLA-DRB1*15 phenotype frequency was higher in DD positive Caucasoids (37.3%) when compared with control data (20.9%) (corrected P=0.029): we conclude that in Caucasoids of European origin, HLA-DRB1*15 is associated with risk of developing DD.

The hidden cost of skin scars: quality of life after skin scarring

BACKGROUND

Surprisingly little is known about how skin scars affect patients' lives, though specialist clinical impressions suggest their impact is related to both their physical and psychosocial effects. Facial scars have been shown to cause high levels of anxiety and self-consciousness, but further work has been neglected. We aimed to explore the influence of skin scars on patients' quality of life (QoL) and identify potential implications for clinical practice.

METHODS

We adopted a needs-based approach to QoL and conducted semi-structured interviews with scar patients at a specialist clinic. Transcribed data underwent interpretative phenomenological analysis to identify common themes in individuals' personal experiences.

RESULTS

Thirty-four scar patients (24 women; aged 14-70 years, mean=35.7 years, SD=17.9 years) with a wide range of scar type, severity and onset were recruited. Five hundred and seventy-three statements were identified from interview transcripts relating to need impairment by skin scars. These were subsequently classified into 44 themes covering five main areas: physical comfort and functioning; acceptability to self and others; social functioning; confidence in the nature and management of the condition; emotional well-being. The majority of respondents were unhappy with their scar's appearance due to their perceived stigma and psychological associations, and thus adopted different coping behaviours to hide or compensate for them. Often this made them unsociable and interfered with their communication skills, personal relationships, work life and leisure activities. Concerns about the diagnosis and persistent nature of scars were common, whilst unempathic management by general physicians and frustrations of current treatment compounded distress.

CONCLUSIONS

There are five main areas of impact on the needs of scar patients that should be addressed in their management, which are greater and more complex than previously considered. Support services should be made available, along with clinician and public education to improve management and help reduce patient distress. A need for a carefully designed measure of scar-related QoL is also indicated, for use in clinical settings and trials.

Permeation enhancer effect of chitosan and chitosan derivatives: comparison of formulations as soluble polymers and nanoparticulate systems on insulin absorption in Caco-2 cells

In this study four quaternized derivatives of chitosan: trimethyl chitosan (TMC), dimethylethyl chitosan (DMEC), diethylmethyl chitosan (DEMC) and triethyl chitosan (TEC) with degree of substitution of approximately 50+/-5% were synthesized and their effect on the permeability of insulin across intestinal Caco-2 monolayers was studied and compared with chitosan both in free-soluble form and in nanoparticulate systems. Transepithelial electrical resistance (TEER) studies revealed that all four chitosan derivatives in free-soluble forms were able to decrease the TEER value in the following order TMC>DMEC>DEMC=TEC>chitosan, indicating their abilities to open the tight junctions. Recovery studies on the TEER showed that the effect of the polymers on Caco-2 cell monolayer is reversible and proves the viability of cells after incubation with all polymers. A similar rank order was also observed when measuring the zeta-potentials of the various polymers in solution form. Transport studies of insulin together with the soluble polymers across Caco-2 cell layers showed the following ranking: TMC>DMEC>DEMC>TEC>chitosan which is in agreement with the strength of the cationic charge of the polymer. In comparison to the free-soluble polymers, the nanoparticles prepared by ionic gelation of the chitosan and its quaternized derivatives had much lower effect on decreasing the TEER by opening of the tight junctions. This can be explained by the reduced available amount of positive charge at the surface of the nanoparticles. In accordance with these results, the insulin loaded nanoparticles showed much less permeation across the Caco-2 cell monolayer in comparison to the free-soluble polymers. Mass balance transport studies revealed that a substantial amount of the nanoparticles has been entrapped into the Caco-2 monolayer or attached to the cell surface. It can thus be stated that while free-soluble polymers can reversibly open the tight junctions and increase the permeation of insulin, the nanoparticles had basically only a low effect on the opening of the tight junction and the paracellular transport of insulin across the Caco-2 cell monolayer. These data convincingly show that nanoparticles consisting of chitosan and its quaternary ammonium derivatives loaded with insulin are less effective in facilitating paracellular transport across Caco-2 cell monolayers than the corresponding free polymers.