Biomedical subjects

M W J Ferguson

Publications and source records attributed to M W J Ferguson.

18 recordsLinked to original sources

PubMed2006

The cellular effect of a single interrupted suture on tendon.

The effects on cell and matrix morphology of a single interrupted suture are described in rabbit (vascular) and mouse (avascular) digital flexor tendons. This model of tendon injury is reproducible and suitable for quantitative histological analysis. Tendons analysed at day 1, 3, 5, 7 and 14 after wounding demonstrated a well-demarcated "acellular zone" around the suture within 24 hours and persisting over 14 days. The placement of an untied suture in tendon did not produce this effect but tying and releasing the tied knot did. The rapidity of onset suggests that cells move from the zone of injury into less mechanically strained tissue. The acellular zone was apparent in rabbit hind paw flexor tendon which is vascularised and the corresponding tendon in mouse which has no intrinsic blood vessels. This phenomenon highlights biological events that must be considered in parallel with the current trend for multistrand locking flexor tendon suture repairs.

Animals↗

PubMed2005

Keloid disease: clinical relevance of single versus multiple site scars.

Much of our current understanding of keloid disease (KD) is based on anecdote rather than objective observation and statistical analysis. To elucidate further the aetiology of KD, we compared the profiles of patients with single versus multiple anatomical site keloid scars. We studied the clinical characteristics of 211 cases of keloid scarring, 137 (65%) females and 74 (35%) males. There were 122 cases with scars in single anatomical site and 89 cases with 369 scars in multiple anatomical sites entered into the study. Patients were of Afrocaribbean origin that presented to the department of Plastic and Reconstructive Surgery at the University of West Indies in Kingston, Jamaica. A total number of 491 keloid scars (single and multiple sites) were evaluated in the study. Data were collected on multiple parameters. The association of age of onset, anatomical area, cause of scarring, sex of the patient, presence or absence of family and medical history in patients with single as opposed to multiple site keloid scars were examined in detail and statistically evaluated. The formation of keloid scars in multiple anatomical sites was found to be statistically significant in that it was more common in younger age groups (p < 0.001) and in females (p < 0.001). Previous medical history, including other fibrotic disorders, was not statistically associated with development of keloid scars in multiple anatomical sites (p > 0.05). More than 50% (111) of all keloid cases had a positive family history of keloid scarring, and family history was strongly associated with the formation of keloid scars in multiple sites as opposed to a single anatomical site (p < 0.002). We conclude that in this particular study group female sex, younger age at presentation and the presence of a positive family history were associated with the development of keloid scars in multiple anatomical sites in Afrocaribbean individuals. This knowledge further emphasizes the need for genetic studies in KD, which may lead to better diagnostic and therapeutic regimes.

Adolescent↗

PubMed2005

Genetic susceptibility to keloid disease: mutation screening of the TGFbeta3 gene.

Keloid disease (KD) is a fibroproliferative dermal tumour of unknown aetiology. The increased familial clustering in KD, its increased prevalence in certain races and its presence in identical twins suggest a strong genetic predisposition to keloid formation. Transforming growth factor beta isoforms (TGFbeta) play a central role in wound healing and fibrosis and have been implicated in KD pathogenesis. Recent data has suggested that TGFbeta(3) has an important role in scar formation. There is little known about the genetic variation present within the TGFbeta(3) gene, which contains seven exons and six introns spanning 43,000 base pairs of the human genome. Exons one to seven and the promoter region (1000 bp upstream from exon 1 in the 5'-flanking regions) were screened in 95 Caucasian KD cases and 95 Caucasian controls for the presence of novel mutations using a high throughput DHPLC mutation detection technology. There were no mutations identified in any of the exonic regions, however, multiple nondisease associated mutations were found in the promoter region of the TGFbeta(3) gene. These data demonstrate that there is no association between the exonic and promoter regions of TGFbeta(3) gene and keloid scarring in our cohort of Caucasian patients.

Adolescent↗

PubMed2005

Harnessing wound healing and regeneration for tissue engineering.

Biomedical science has made major advances in understanding how cells grow into functioning tissue and the signalling mechanisms used to achieve this are slowly being dissected. Tissue engineering is the application of that knowledge to the building or repairing of organs, including skin, the largest organ in the body. Generally, engineered tissue is a combination of living cells and a supporting matrix. Besides serving as burn coverings, engineered skin substitutes can help patients with diabetic foot ulcers. Today, most of these ulcers are treated with an approach that includes antibiotics, glucose control, special shoes and frequent cleaning and bandaging. The results of such treatments are often disappointing and ineffectual, and scarring remains a major problem, mechanically, cosmetically and psychologically. Within our group we are attempting to address this by investigating novel approaches to skin tissue engineering. We are identifying novel therapeutic manipulations to improve the degree of integration between a tissue engineered dermal construct and the host by both molecular manipulation of growth factors but also by understanding and harnessing mechanisms of regenerative biology. For the purpose of this summary, we will concentrate primarily on the latter of these two approaches in that we have identified a novel mouse mutant that completely and perfectly regenerates skin and cartilaginous components following ear injury. This experimental animal will allow us to characterize not only novel genes involved in the regeneration process but also to utilize cells from such animals in artificial skin equivalents to assess their behaviour compared with normal cells. This approach should allow us to create a tissue-engineered substitute, which more closely resembles the normal regional microanatomy and physiology of the skin, allowing better integration to the host with minimal or no scarring.

Animals↗

PubMed2005

Mitochondrial mutation detection using enhanced multiplex denaturing high-performance liquid chromatography.

In this study, we investigated the presence of mutations within the mitochondrial genome in 40 Caucasian subjects using an enhanced multiplex denaturing high-performance liquid chromatography (DHPLC) approach. The enhanced DHPLC approach has increased sensitivity and throughput, and reduced analysis time per individual sample compared to conventional methods. This technique involved amplifying the mitochondrial genome in 18 fragments ranging in size from 300 to 2000 bp using a novel proofreading polymerase (Optimase, Transgenomic Inc., Omaha, NE) with a low misincorporation rate. Fourteen of these fragments underwent subsequent restriction digestion using a combination of five restriction enzymes to enable multiplex DHPLC analysis; the remaining four underwent conventional DHPLC. Using this complete mitochondrial genome-screening approach, we confirmed a number of previously reported mutations and additionally identified a large number of novel mutations using an enhanced DHPLC technique.

Adult↗

PubMed2004

Description of site-specific morphology of keloid phenotypes in an Afrocaribbean population.

By examining the keloid scars of 211 Afrocaribbean patients presenting to the Plastic Surgery unit in Kingston, Jamaica, we have described site-specific morphologies of scarring; keloid disease is not a homogenous biological entity. All cases conformed to clinical criteria for diagnosis of keloid scarring: 369 keloid scars were present in 137 females (2-83 years; mean 29.6 years; SD+/-14.9 years) and 74 males (5-90 years, mean 29.5 years; SD+/-15.0 years). Morphologies were specific to each anatomical site: trunk scars (n=45,12.1%) were geometrically shaped with clear margins or irregular in outline, surface and margin; back single scars were well-demarcated botryoid but multiple scars were butterfly-shaped, spheroidal and irregular; chest scars (n=72,20.1%) were butterfly or nonbutterfly shaped found most commonly in the midsternal line; upper limb scars (n=57,15.3%) mostly in the deltoid region (propeller shaped) or elsewhere nodular, linear to irregular; ear (n=85,23%) commonest site being the lobe, having reniform to bulbous shape; face and neck (n=60,16.2%) scars were firm nodular to hard; posterior auricular scars were either horizontal and oblong-shaped or vertical and reniform in outline; scalp scars (n=11,2.8%) were commonest in the occipital area varying from small papules to large plaques; lower limb scars (n=39,10.5%) varied from propeller, butterfly, petalloid to dum-bell-shaped. Three plantar and eight pubic keloids were rare findings. Recognition of different morphological phenotypes is necessary in understanding genotypic predisposition and aiding diagnosis, treatment and prognosis of keloid scars.

Adolescent↗

PubMed2004

Genetic susceptibility to keloid disease: transforming growth factor beta receptor gene polymorphisms are not associated with keloid disease.

Keloid disease (KD) is an abnormal form of scarring with a familial predisposition. Genetic studies have yet to identify the genes involved in KD. Transforming growth factor beta (TGF-beta) has multiple cellular activities including cellular proliferation, differentiation and extracellular matrix production. TGF-beta family members such as TGF-beta(1) and TGF-beta(2) are known to be involved in KD formation. However, we previously demonstrated a lack of association between common TGF-beta(1) and TGF-beta(2) polymorphisms and KD. Other studies have implicated TGF-beta receptors in KD pathogenesis. TGF-beta receptors were therefore selected as candidate-susceptibility genes for this condition. Single-nucleotide polymorphisms (SNPs) in TGF-beta receptors I, II and III (TGF-betaRI, TGF-betaRII and TGF-betaRIII) were identified and investigated for association with the risk of developing KD. A polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping novel and known TGF-beta receptor polymorphisms. DNA samples from 92 KD cases and 181 controls were examined. There were no statistically significant differences in genotype or allele frequency distributions between cases and controls for the TGF-beta receptor SNPs. Therefore, these TGF-beta receptor polymorphisms are unlikely to be associated with keloid scarring. It is possible that other SNPs in other TGF-beta family members are associated with KD. To our knowledge, this is the first report of a case-control association study with KD and TGF-beta receptor gene polymorphisms.

Case-Control Studies↗

PubMed2003

Skin scarring.

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Cicatrix↗

PubMed2003

Genetic susceptibility to Dupuytren's disease: transforming growth factor beta receptor (TGFbetaR) gene polymorphisms and Dupuytren's disease.

Dupuytren's disease (DD) is a benign fibroproliferative disease of unknown cause. It is a familial condition that commonly affects Caucasians. Genetic studies have yet to identify the genes involved in DD. Transforming growth factor beta (TGFbeta) family members are multifunctional; some play a central role in wound healing and fibrosis. Previous studies have implicated TGFbeta cytokines and receptors in DD. In the light of this evidence, TGFbeta receptors represent candidate susceptibility genes for this condition. In this study, we investigated the association of single nucleotide polymorphisms (SNPs) in TGFbeta receptors one, two and three (TGFbetaRI, RII and RIII) with the risk of DD formation. A polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping novel and known TGFbeta receptor polymorphisms. DNA samples from 183 DD patients and 181 controls were examined. There was a statistically significant difference (p<0.05) in genotype frequency distributions between cases and controls for TGFbetaRI polymorphisms in the recessive model. However, there were no significant difference in genotype or allele frequency distributions between cases and controls for the TGFbetaRII and TGFbetaRIII SNPs.

Adult↗

PubMed2003

Rapid denaturing high-performance liquid chromatography (DHPLC) for mutation scanning of the transforming growth factor beta3 gene using a novel proof-reading polymerase.

We have utilized a novel variation on the conventional denaturing high-performance liquid chromatography (DHPLC) technology, which we term rapid DHPLC, combining changes in instrumentation, cartridge technology and analysis conditions to enable significant increases in throughput to be achieved. In addition, the use of a novel proof-reading polymerase for sample amplification with a low misincorporation rate enables simplification of the DHPLC patterns and hence enhanced mutation detection recognition. This scheme for increasing DHPLC throughput has been tested by scanning the transforming growth factor (TGF) beta3 gene for the presence of mutations for which there is limited published or on-line data available regarding the presence of gene polymorphisms. TGFbeta isoforms have multiple roles in cell division, growth, proliferation, transformation and differentiation. TGFbeta3 is a TGFbeta cytokine isoform, and has an important role in embryogenesis, cell differentiation and wound healing. The TGFbeta3 gene consists of seven exons and six introns spanning 43 000 bp of the human genome on chromosome 14q23-24. The rapid DHPLC approach enabled scanning of all seven exons and part of the promoter region (1000 bp upstream from exon 1 in the 5'-flanking regions) of the TGFbeta3 gene in 95 Caucasian individuals in only 8 days, in comparison to the 17 days it would have previously taken. Mutations were clearly identified in the promoter region of the TGFbeta3 gene but were absent from the exonic regions. Understanding the genetic variations affecting the TGFbeta3 gene is important as this molecule has multiple regulatory functions on a variety of cell types.

Adult↗

PubMed2002

TGF-beta(3)-induced chondroitin sulphate proteoglycan mediates palatal shelf adhesion.

In mammals, the adhesion and fusion of the palatal shelves are essential mechanisms in the development of the secondary palate. Failure of any of these processes leads to the formation of cleft palate. The mechanisms underlying palatal shelf adhesion are poorly understood, although the presence of filopodia on the apical surfaces of the superficial medial edge epithelial (MEE) cells seems to play an important role in the adhesion of the opposing MEE. We demonstrate here the appearance of chondroitin sulphate proteoglycan (CSPG) on the apical surface of MEE cells only immediately prior to contact between the palatal shelves. This apical CSPG has a functional role in palatal shelf adhesion, as either the alteration of CSPG synthesis by beta-D-Xyloside or its specific digestion by chondroitinase AC strikingly alters the in vitro adhesion of palatal shelves. We also demonstrate the absence of this apical CSPG in the clefted palates of transforming growth factor beta 3 (TGF-beta(3)) null mutant mice, and its induction, together with palatal shelf adhesion, when TGF-beta(3) is added to TGF-beta(3) null mutant palatal shelves in culture. When chick palatal shelves (that do not adherein vivo nor express TGF-beta(3), nor CSPG in the MEE) are cultured in vitro, they do not express CSPG and partially adhere, but when TGF-beta(3) is added to the media, they express CSPG and their adhesion increases strikingly. We therefore conclude that the expression of CSPG on the apical surface of MEE cells is a key factor in palatal shelf adhesion and that this expression is regulated by TGF-beta(3).

Animals↗

PubMed2002

Scar wars.

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Adolescent↗

PubMed2002

Novel single nucleotide polymorphisms in the 3'-UTR of the TGFbetaRI and TGFbetaRIII genes.

Transforming growth factor beta (TGFbeta) family members are multifunctional cytokines that play a key role in cellular growth, proliferation and differentiation. Transmembrane signalling by TGFbeta occurs via a complex of the serine/threonine kinases TGFbeta type 1 (TGFbetaRI), type 2 (TGFbetaRII), and type 3 (TGFbetaRIII) receptors. Previous studies have implicated TGFbeta receptors (TGFbetaR) in a variety of important hereditary clinical disorders. Mutations of the TGFbetaR genes have been observed in several human cancers. The aim of this study was to identify and confirm novel single nucleotide polymorphisms (SNPs) in TGFbetaRI and RIII and to determine the relative allele and genotype frequencies of these SNPs. SNPs were identified from the examination of sequence alignments held in databases and were confirmed by DNA sequencing. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was devised for genotyping TGFbeta receptor polymorphisms. DNA samples from 91 controls were examined. The observed heterozygosities of TGFbetaRI and TGFbetaRIII gene polymorphisms in the control population were 43 and 33%, respectively, suggesting these SNPs could be useful markers in disease association studies.

3' Untranslated Regions↗

PubMed2002

Transforming growth factor-beta 1, 2, 3 and receptor type I and II in diabetic foot ulcers.

AIMS: To study the distribution of transforming growth factor-beta (TGF-beta) 1, 2 and 3, and TGF-beta receptor types I and II in diabetic foot ulcers, diabetic skin and normal skin by immunohistochemistry, immunofluorescence and Western blotting. We also compared the TGF-betas with those of chronic venous ulcers. METHODS: Skin biopsies were obtained from the leg or the foot of non-diabetic and diabetic subjects, and from the edge of diabetic foot ulcers and chronic venous ulcers. Distribution (by immunofluorescence and immunocytochemistry) of TGF-beta 1, 2 and 3 and TGF-beta receptors (RI and RII) was done by staining 8-microm skin sections using appropriate antibodies. Protein levels of TGF-beta were measured by Western blot analysis. RESULTS: TGF-beta3 expression was increased in the epithelium at the edge of diabetic foot ulcers, being more intense than diabetic and normal skin (P = 0.03, 0.02, respectively), as was its expression in venous ulcers compared with normal skin. However, TGF-beta1 expression was not increased in diabetic foot ulcers and chronic venous ulcers, and was comparable to diabetic and normal skin. There was also no increase for the receptors in diabetic foot ulcers. CONCLUSION: The lack of TGF-beta1 up-regulation in both diabetic foot ulcers and venous ulcers may explain the impaired healing in these chronic wounds, and could represent a general pattern for chronicity.

Activin Receptors, Type I↗

PubMed2002

Genetic susceptibility to keloid disease and transforming growth factor beta 2 polymorphisms.

Keloid disease (KD) is a benign fibroproliferative scarring condition of unknown aetiopathogenesis. There is a familial predisposition to keloid scarring. The genes involved in the pathogenesis of abnormal dermal scarring have yet to be identified. Transforming growth factor beta (TGF beta) is a family of multifunctional cytokines, which play a central role in wound healing and fibrosis. The TGF beta 2 isoform is a member of this cytokine family and has previously been implicated in KD pathogenesis. We tested for an association between KD and two novel polymorphisms within the TGF beta 2 gene: an insertion polymorphism within the 59-untranslated region, 109 base pairs away from the initiation codon, and a single nucleotide polymorphism in exon one. We examined DNA samples from 101 patients with KD and 187 ethnically matched controls. No statistically significant differences in TGF beta 2 genotype or allele frequency distribution were observed between the patients and the controls. We believe this to be the first report of a case-control association study in KD and TGF beta 2 polymorphisms.

Cicatrix, Hypertrophic↗

PubMed2002

Genetic susceptibility in Dupuytren's disease: lack of association of a novel transforming growth factor beta(2) polymorphism in Dupuytren's disease.

The genes involved in the pathogenesis of Dupuytren's disease have yet to be identified. In this study, we tested for an association between Dupuytren's disease (DD) and a novel insertion polymorphism within the 5'-untranslated region (5'-UTR), of the TGFbeta(2) gene. DNA samples from 179 DD patients and 187 ethnically matched controls were examined. There was no statistically significant difference in TGFbeta(2) allele frequency distributions between cases and controls for the TGFbeta(2) polymorphism.

Adult↗

PubMed2002

Genetic susceptibility in Dupuytren's disease. TGF-beta1 polymorphisms and Dupuytren's disease.

Dupuytren's disease is a benign fibroproliferative disease of unknown aetiology. It is often familial and commonly affects Northern European Caucasian men, but genetic studies have yet to identify the relevant genes. Transforming growth factor beta one (TGF-beta1) is a multifunctional cytokine which plays a central role in wound healing and fibrosis. It stimulates the proliferation of fibroblasts and the deposition of extracellular matrix. Previous studies have implicated TGF-beta1 in Dupuytren's disease, suggesting that it may represent a candidate susceptibility gene for this condition. We have investigated the association of four common single nucleotide polymorphisms in TGF-beta1 with the risk of developing Dupuytren's disease. A polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping TGF-beta1 polymorphisms. DNA samples from 135 patients with Dupuytren's disease and 200 control subjects were examined. There was no statistically significant difference in TGF-beta1 genotype or allele frequency distributions between the patients and controls for the codons 10, 25, -509 and -800 polymorphisms. Our observations suggest that common TGF-beta1 polymorphisms are not associated with a risk of developing Dupuytren's disease. These data should be interpreted with caution since the lack of association was shown in only one series of patients with only known, common polymorphisms of TGF-beta1. To our knowledge, this is the first report of a case-control association study in Dupuytren's disease using single nucleotide polymorphisms in TGF-beta1.

Adult↗

PubMedDate not supplied

Spatial distribution of mast cells in chronic venous leg ulcers.

Chronic venous leg ulcers (CVUs) show chronic inflammation but different pathological changes occur in different parts of the ulcer. There is a lack of re-epithelialisation and defective matrix deposition in the ulcer base but epidermal hyperproliferation and increased matrix deposition in the surrounding skin. The role of mast cells in wound healing, inflammation, fibrosis and epidermal hyperproliferation has been extensively studied but less is known about their role in CVUs. In the present study, we investigated the distribution of mast cells in CVUs with specific consideration of the differences between the ulcer base and the skin surrounding the ulcer. Both histochemical and immunohistological methods were used to detect the mast cell marker tryptase in frozen sections of CVU biopsies. Mast cells were counted in the dermis of normal skin, in the ulcer base and in the skin surrounding the ulcer. Double immunofluorescence staining was used to study the location of mast cells in relation to blood vessels. In normal skin few mast cells were seen in the dermis but none in the epidermis. However in CVUs there was a significant increase in intact and degranulated mast cells in the surrounding skin and ulcer edge (184 per field, p<0.003) of CVUs and a significant reduction in the ulcer base (20.5 per field p<0.05) in comparison to normal skin (61 per field). In CVUs mast cells showed a characteristic location near the epithelial basement membrane whilst mast cell granules and phantom cells (mast cells devoid of granules) were predominantly seen in the epidermis. In the dermis, mast cells were seen associated with blood vessels. The marked increase in mast cells in the surrounding skin of CVUs and depletion of mast cells in the ulcer base could implicate mast cell mediators in the pathological changes in CVUs particularly in the epidermal and vascular changes occurring in the surrounding skin.

Cell Count↗