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1.
J Hand Surg Am ; 44(4): 341.e1-341.e6, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30170887

RESUMO

PURPOSE: Grayson ligament has been described as a common pathway for digital contracture in Dupuytren disease. Its anatomical descriptions in the literature are, however, inconsistent. METHODS: We have performed a microsurgical dissection study in 20 fresh-frozen and thawed digits to revisit the anatomy of Grayson ligaments. We also performed dissections in Thiel-preserved hands to be able to study the changes in tension of the ligaments during flexion and extension of the finger. RESULTS: We found the ligaments originally described by Grayson to be the best developed part of a trabecular network of fibers, originating in continuity with the outer adventitial layer of the flexor tendon sheath and running toward their insertions into the skin in multiple planes, all volar to the neurovascular bundle. The most dorsal fibers, which cover the neurovascular bundles, form a chevron shape with its midline apex pointing distally in an extended finger. During flexion, the fibers become more transversely oriented. CONCLUSIONS: We found Grayson ligament comprises a trabecular network of fibers, instead of a ligament, with a dynamic fiber orientation on the volar side of the finger. The main function of this network of fibers seems to be the stabilization of the skin and fat pad in digit extension while the relaxation in flexion allows the skin and volar fat pad to adapt optimally to the form of the object that is held. CLINICAL RELEVANCE: The new insights in the anatomy of Grayson trabecular network of fibers may be of importance in the understanding of the pathological anatomy of Dupuytren disease.


Assuntos
Dedos/anatomia & histologia , Ligamentos/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Dedos/fisiologia , Humanos , Ligamentos/fisiologia , Masculino , Pessoa de Meia-Idade
2.
Int J Surg ; 109(3): 481-490, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36912691

RESUMO

BACKGROUND: This review aims to identify publications on quantitative biomechanical testing of surgical knot security and the physical factors that determine knot security and failure. MATERIALS AND METHODS: An electronic literature search was performed in accordance with PRISMA guidelines in January 2022 utilizing the PubMed and Google Scholar databases to look for objective biomechanical studies on knot security in surgery using the primary terms 'knot security' and 'biomechanical testing'. RESULTS: Thirty-six articles were included. Twenty-four configurations of surface, laparoscopic, and arthroscopic knots were studied. Biomechanical tensile testing was used to evaluate knot security in vitro . Load to failure (N) and elongation at knot failure (mm) were quantified by static and cyclic testing to evaluate the knot holding capacity and failure mechanism of slippage or rupture. CONCLUSION: This review reassures that the knot configuration, suture materials, suture sizes, and number of throws are key factors in determining the knot's security. Knot configuration has to be simple for laparoscopic and arthroscopic knots due to the confined space of the operating site. With the advent of stronger suture materials for high-tension surgical reconstructive procedures, there is an unmet need to understand the physical behavior of the knot and the factors that determine its resistance to slippage or rupture.Level of Evidence: Level IV.


Assuntos
Procedimentos de Cirurgia Plástica , Técnicas de Sutura , Humanos , Fenômenos Biomecânicos , Resistência à Tração , Teste de Materiais , Suturas , Artroscopia/métodos
3.
Tech Hand Up Extrem Surg ; 27(4): 220-224, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37282887

RESUMO

Septic arthritis of the metacarpophalangeal joint (MCPJ) compromises 9% of hand infections in Singapore. Common surgical treatment is open arthrotomy and joint washout. The wound is often left open for drainage postoperatively. Repeated debridement and secondary closure are frequently needed after the index surgery. We describe a method of continuous catheter irrigation of septic MCPJ joint using an infant feeding catheter. This method provides great infection clearance to avoid repeated debridement and allows primary closure of the wound to avoid secondary closure. This method also significantly reduces postoperative pain so that to facilitate early mobilization of the joint, which is crucial for functional recovery. We illustrate the techniques of this procedure and key points of postoperative management in the ward with case examples to demonstrate its simplicity, safety, and efficacy in treating MCPJ septic arthritis.


Assuntos
Artrite Infecciosa , Humanos , Desbridamento/métodos , Artrite Infecciosa/cirurgia , Drenagem , Articulação Metacarpofalângica/cirurgia , Catéteres , Estudos Retrospectivos
4.
J Hand Surg Eur Vol ; 48(9): 930-935, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37125756

RESUMO

This study aimed to compare the torsional resistance of three fixation techniques for spiral metacarpal fractures: screw-only fixation, screw plus neutralization plate fixation, and a locking plate construct. A spiral fracture was created on 18 cadaveric metacarpal bones by applying an axial and torsional loading force using an Instron 3343 mechanical tester. The failure strength was defined as the native torque strength. The fractures were divided into three groups and fixed using each of the three techniques. The repaired bones were loaded to failure to determine the post-repair strength. The neutralization plate group conferred a post-repair torque (278.6 Nmm) that was similar to the native torque (292 Nmm) with a diminution of only 4.5% and appeared to provide the best resistance to torsion.

5.
Clin Dev Immunol ; 2012: 863264, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23320020

RESUMO

Since the start of the clinical vascularized composite allotransplantation (VCA) era over a decade ago this field has witnessed significant developments in both basic and translational research. Transplant tolerance, defined as rejection-free acceptance of transplanted organs or tissues without long-term immunosuppression, holds the potential to revolutionize the field of VCA by removing the need for life-long immunosuppression. While tolerance of organ and vascularized composite transplants may be induced in small animal models by a variety of protocols, only mixed-chimerism-based protocols have successfully bridged the gap to preclinical study and to clinical trial in solid organ transplantation to date. In this paper we review the mixed-chimerism approach to tolerance induction, with specific reference to the field of VCA transplantation, and provide an overview of some novel cellular therapies as potential adjuvants to mixed chimerism in the development of tolerance induction protocols for clinical vascularized composite allotransplantation.


Assuntos
Quimeras de Transplante/imunologia , Imunologia de Transplantes , Tolerância ao Transplante/imunologia , Transplante Homólogo/imunologia , Animais , Humanos
6.
J Hand Surg Eur Vol ; 46(8): 852-856, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33175646

RESUMO

We performed a detailed dynamic high-resolution ultrasound examination of the flexor tendons in trigger fingers and compared this with normal contralateral digits. There was a loss of defined linear tendon margins and/or traction of the flexor tendons on the surrounding soft tissue during passive flexion of the distal interphalangeal joint in 17 out of 20 trigger fingers, which indicated adherence to the surrounding tissues. The differential motion between the flexor digitorum profundus tendon and the flexor digitorum superficialis tendons was also lost in ten trigger fingers, which suggested adherence between the tendons. No signs of peritendinous or intertendinous adhesions were found in the healthy control fingers. We conclude that tendon adhesions are present in the majority of trigger fingers. We could not determine a relationship between the severity of triggering and the presence of adherence due to limited sample size.Level of evidence: II.


Assuntos
Dedo em Gatilho , Dedos/diagnóstico por imagem , Humanos , Amplitude de Movimento Articular , Tendões/diagnóstico por imagem , Dedo em Gatilho/diagnóstico por imagem , Ultrassonografia
7.
Am J Pathol ; 175(5): 1938-51, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19834058

RESUMO

Intrasynovial flexor tendon injuries of the hand can frequently be complicated by tendon adhesions to the surrounding sheath, limiting finger function. We have developed a new tendon injury model in the mouse to investigate the three-dimensional cellular biology of intrasynovial flexor tendon healing and adhesion formation. We investigated the cell biology using markers for inflammation, proliferation, collagen synthesis, apoptosis, and vascularization/myofibroblasts. Quantitative immunohistochemical image analysis and three-dimensional reconstruction with cell mapping was performed on labeled serial sections. Flexor tendon adhesions were also assessed 21 days after wounding using transmission electron microscopy to examine the cell phenotypes in the wound. When the tendon has been immobilized, the mouse can form tendon adhesions in the flexor tendon sheath. The cell biology of tendon healing follows the classic wound healing response of inflammation, proliferation, synthesis, and apoptosis, but the greater activity occurs in the surrounding tissue. Cells that have multiple "fibripositors" and cells with cytoplasmic protrusions that contain multiple large and small diameter fibrils can be found in the wound during collagen synthesis. In conclusion, adhesion formation occurs due to scarring between two damaged surfaces. The mouse model for flexor tendon injury represents a new platform to study adhesion formation that is genetically tractable.


Assuntos
Traumatismos dos Tendões , Tendões , Aderências Teciduais , Animais , Biomarcadores/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Traumatismos dos Dedos/patologia , Traumatismos dos Dedos/fisiopatologia , Humanos , Inflamação/metabolismo , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão , Modelos Animais , Pericitos/citologia , Pericitos/metabolismo , Traumatismos dos Tendões/patologia , Traumatismos dos Tendões/fisiopatologia , Tendões/patologia , Tendões/fisiologia , Aderências Teciduais/patologia , Aderências Teciduais/fisiopatologia , Articulação do Dedo do Pé/patologia , Articulação do Dedo do Pé/fisiopatologia , Cicatrização/fisiologia
8.
J Hand Surg Eur Vol ; 45(10): 1051-1054, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32437222

RESUMO

We tested the tensile strength of the proximal juncture of tendon grafts with Pulvertaft tendon repairs in 18 cadaveric digital flexor tendons. These tendons were divided into three groups of six: single, two, or three weaves. Each of the interlacing weaves was secured with eight anchoring sutures. The specimens were loaded in a biomechanical tester until failure. The ultimate tensile strength did not show any significant differences across all three groups with statistical power of 0.77. The mean tendon elongation before repair failure showed significant difference at 10 mm (standard deviation (SD) 2), 16 mm (SD 3), and 15 mm (SD 3), respectively. All specimens failed by intra-tendinous pull-out of the weaves. We conclude that the two-weave Pulvertaft construct demonstrated comparable tensile strength to three weaves and tendon elongation was similar when two or three weaves were used.


Assuntos
Técnicas de Sutura , Tendões , Fenômenos Biomecânicos , Humanos , Suturas , Tendões/cirurgia , Resistência à Tração
9.
J Hand Surg Am ; 34(3): 423-31, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19258138

RESUMO

PURPOSE: Longitudinal scars on the radial quadrant of the distal forearm skin envelope are typically observed to be wider than those on the ulnar quadrant and have an increased incidence of hypertrophic change. Forearm rotation movements may produce differential skin tensions within the forearm skin envelope, and this may lead to differential scarring patterns. This study was designed to measure skin tension changes in the forearm as a result of rotational position to see if these would be consistent with the hypothesis that greater tension changes are observed on the radial aspect of the forearm. METHODS: The effect of forearm position on the magnitude and direction of skin tension was measured on human volunteers. Standardized circles were marked in circumferential fashion at specified intervals on forearm skin, and the angular and dimensional distortion of these circles that occurred with forearm rotation was measured with caliper and goniometer. Data were analyzed for statistical significance using paired t-test. RESULTS: Pronation and supination resulted in marked angular rotation of the lines of maximal skin tension at all sites on the forearm. Supination resulted in a greater angular deviation of the lines of maximal skin tension from the longitudinal line of usual surgical incision, particularly on the radial aspect of the forearm. In supination, the magnitude of ellipsoid deformation at the distal forearm was greater on the radial aspect compared with that of the ulnar. Similar significant changes were also demonstrated at the mid-forearm and proximal forearm levels. CONCLUSIONS: This study systematically maps the effects of pronation and supination on skin tension within the forearm skin envelope. The significant changes occurring in both the ellipsoid deformation and ellipsoid orientation support our hypothesis that the magnitude of skin tension changes significantly with forearm rotation. The radial aspect of the distal forearm experiences the greatest changes, particularly as the forearm supinates.


Assuntos
Antebraço/fisiologia , Pronação/fisiologia , Fenômenos Fisiológicos da Pele , Supinação/fisiologia , Humanos , Masculino , Rotação , Tensão Superficial
10.
Burns ; 34(4): 474-86, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17980970

RESUMO

In the management of partial thickness burns, it is difficult to balance between conservative management and surgical intervention. Our hypothesis was that a triangular relationship exists between protease/anti-protease profile at the burn wound surface, angiogenesis and re-epithelialisation. By manipulation of the biochemical profile at the wound level, we determined to affect the nature and extent of angiogenesis and resulting re-epithelialisation. We performed a randomised longitudinal observational study on partial thickness burns in adult patients presenting to two regional burns units. Our results demonstrated that a high-protease wound environment is associated with lower levels of the angiogenic factor VEGF, a lower more uniform change in wound bloodflow and a uniform well healed wound with an architecturally normal epidermis. In addition, we found that a low protease wound environment is associated with higher levels of the angiogenic factor VEGF, a higher wound bloodflow throughout the wound healing period and a more chaotic, hypercellular, overkeratinised, and chaotic thickened epidermis.


Assuntos
Queimaduras/enzimologia , Neovascularização Fisiológica/fisiologia , Peptídeo Hidrolases/metabolismo , Pele/irrigação sanguínea , Cicatrização/fisiologia , Adolescente , Adulto , Idoso , Curativos Hidrocoloides , Queimaduras/terapia , Contagem de Células , Células Epiteliais/fisiologia , Humanos , Imuno-Histoquímica , Fluxometria por Laser-Doppler , Pessoa de Meia-Idade , Tratamento de Ferimentos com Pressão Negativa , Adulto Jovem
11.
J Biomed Mater Res A ; 105(2): 389-397, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27649836

RESUMO

The functional replacement of tendon represents an unmet clinical need in situations of tendon rupture, tendon grafting, and complex tendon reconstruction, as usually there is a finite source of healthy tendon to use as donors. The microfibrous architecture of tendon is critical to the function of tendon. This study investigates the use of electrospun poly(ɛ-caprolactone) scaffolds as potential biomaterial substitutes for tendon grafts. We assessed the performance of two electrospinning manufacturers (small- and large-scale) and the effect of two sterilization techniques-gamma irradiation and ethanol submersion-on cell response to these electrospun scaffolds after their implantation into a murine tendon model. Cell infiltration and proliferation analyses were undertaken to determine the effect on cell response within the implant over a 6-week period. Immunohistochemical analysis was performed to characterize inflammatory response and healing characteristics (proliferation, collagen deposition, myofibroblast activity, and apoptosis). Neither the sterilization techniques nor the manufacturer was observed to significantly affect the cell response to the scaffold. At each time point, cell response was similar to the autograft control. This suggests that ethanol submersion can be used for research purposes and that the scaffold can be easily reproduced by a large-scale manufacturer. These results further imply that this electrospun scaffold may provide an alternative to autograft, thus eliminating the need for sourcing healthy tendon tissue from a secondary site. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 389-397, 2017.


Assuntos
Teste de Materiais , Poliésteres/química , Regeneração , Traumatismos dos Tendões/cirurgia , Tendões/fisiologia , Alicerces Teciduais/química , Animais , Masculino , Camundongos , Traumatismos dos Tendões/metabolismo , Traumatismos dos Tendões/patologia , Fatores de Tempo
12.
Plast Reconstr Surg ; 109(2): 566-72; discussion 573-5, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11818837

RESUMO

The anatomy and function of Cleland's ligaments--thought by the authors to require clarification because of the conflicting anatomic descriptions in the literature--are reviewed. A statistical representation of the structure of these ligamentous bundles was derived from the study of 16 fixed human cadaveric digits and five fresh cadaveric digits, all from different patients. The results demonstrate a large variation in anatomy. However, this anatomic heterogeneity is not indicative of an equally varied function. In general, it was found that the majority of Cleland's ligaments traversed a great distance adherent to the skin before actually inserting in the dermis. Over one-third of the dorsal fibers demonstrated a multiplanar organization, fanning out before inserting into the skin. In contrast, the ventral fibers did not fan out before inserting into the skin. Excision of these ventral fibers revealed a separate "ledgelike" plane of fibers arising from the fibrous flexor sheath and running in a straight line perpendicular to the long axis of the digit. A branch of the digital nerve was found to pierce this ligamentous layer in the majority of digits studied. Unlike those of previous reports, the results of the present study suggest that the ligaments have a constant function of anchoring the skin of the digit on both the dorsal and ventral aspects, thereby preventing the displacement of skin during flexion of the digits. All previous studies failed to make this conclusion. The anatomic relationship to the digital neurovascular bundle also suggests that Cleland's ligaments may stabilize the digital vessels during flexion. In conclusion, Cleland's ligaments are highly functional structures and are essential for normal cutaneous stability during digital movements.


Assuntos
Dedos/anatomia & histologia , Ligamentos/anatomia & histologia , Pele/anatomia & histologia , Feminino , Humanos , Masculino
13.
Curr Med Res Opin ; 30(4): 733-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24397625

RESUMO

OBJECTIVE: The efficacy and safety of collagenase clostridium histolyticum (CCH) in patients with Dupuytren's contracture (DC) was demonstrated in a program including two pivotal phase 3 clinical trials (CORD I and II) which included patients with a broad range of disease severity. This analysis assessed the efficacy and safety of CCH in the subpopulation of DC patients with up to two joints affected and moderate disease according to British Society of Surgery of the Hand classification. This was in support of a resubmission to the Scottish Medicines Consortium. RESEARCH DESIGN AND METHODS: A post-hoc analysis that included data from patients with up to two joints affected and moderate disease treated with CCH during the randomized and open-label phases of CORD I and II. RESULTS: Of 362 patients who received CCH during the two trials, 58 had one or two joints affected and moderate disease. Sixty-seven joints were treated; 49 patients received treatment for one joint, and 9 patients received treatment for two joints. Each patient received an average of 1.62 injections of CCH per joint. Of 65 evaluable joints, 82% met the primary endpoint of clinical success (reduction in contracture to ≤5° of full extension 30 days after the last injection). This was similar if only primary joints were considered (81% achieved clinical success). Recurrence at 12 months (increase in joint contracture to ≥20° in the presence of a palpable cord in joints that had attained clinical success) was observed in 3.8% of joints. Reported adverse events were mild to moderate in intensity; none resulted in discontinuation. CONCLUSIONS: CORD I and II show that CCH is well tolerated and effective in the treatment of DC in a broad population. The present analysis suggests that CCH has particular value in patients with moderate severity disease and up to two joints affected. STUDY LIMITATIONS: This analysis used data from both the randomized and open-label phases of CORD I and II; therefore, it is not possible to present comparative data for this subpopulation. As this was a post-hoc analysis in a relatively small patient subpopulation, statistical comparisons with the full population were not considered appropriate. Furthermore, the small sample size means that additional subgroup analyses, for example of patients by previous treatment or number of injections administered, are not appropriate. Nevertheless, the data presented demonstrate that CCH is both well tolerated and effective in this population when managed by appropriately trained individuals.


Assuntos
Clostridium histolyticum/enzimologia , Contratura de Dupuytren/tratamento farmacológico , Colagenase Microbiana/uso terapêutico , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Colagenase Microbiana/efeitos adversos , Pessoa de Meia-Idade , Estudos Prospectivos
14.
PLoS One ; 9(11): e112672, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25383548

RESUMO

Repaired tendons may be complicated by progressive fibrosis, causing adhesion formation or tendon softening leading to tendon rupture and subsequent reduced range of motion. There are few therapies available which improve the gliding of damaged tendons in the hand. We investigate the role of Mannose 6-phosphate (M6P) in a 600 mM hypertonic solution (Adaprev) on tendon adhesion formation in vivo using a mouse model of severed tendon in conjunction with analysis of collagen synthesis, cellular proliferation and receptors involved in TGF beta signalling. Cytotoxicity was assessed by measuring tissue residency, mechanical strength and cell viability of tendons after treatment with Adaprev. To elicit potential modes of action, in vitro and ex vivo studies were performed investigating phosphorylation of p38, cell migration and proliferation. Adaprev treatment significantly (p<0.05) reduced the development of adhesions and improved collagen organisation without reducing overall collagen synthesis following tendon injury in vivo. The bioavailability of Adaprev saw a 40% reduction at the site of administration over 45 minutes and tendon fibroblasts tolerated up to 120 minutes of exposure without significant loss of cell viability or tensile strength. These favourable effects were independent of CI-MPR and TGF-ß signalling and possibly highlight a novel mechanism of action related to cellular stress demonstrated by phosphorylation of p38. The effect of treatment reduced tendon fibroblast migration and transiently halted tendon fibroblast proliferation in vitro and ex vivo. Our studies demonstrate that the primary mode of action for Adaprev is potentially via a physical, non-chemical, hyperosmotic effect.


Assuntos
Manosefosfatos/administração & dosagem , Traumatismos dos Tendões/tratamento farmacológico , Traumatismos dos Tendões/fisiopatologia , Aderências Teciduais/prevenção & controle , Aderências Teciduais/fisiopatologia , Cicatrização/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Proliferação de Células , Células Cultivadas , Colágeno/metabolismo , Modelos Animais de Doenças , Humanos , Soluções Hipertônicas , Manosefosfatos/uso terapêutico , Camundongos , Coelhos , Transdução de Sinais/efeitos dos fármacos , Traumatismos dos Tendões/metabolismo , Resistência à Tração/efeitos dos fármacos , Aderências Teciduais/metabolismo , Fator de Crescimento Transformador beta/metabolismo
15.
Transplantation ; 95(3): 403-9, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23114532

RESUMO

Vascularized composite allotransplantation has become established as a clinical specialty since the first successful hand transplant was performed in 1998. Data now available indicate that hand and face transplants offer patients good functional outcomes and significant improvements in quality of life. Despite the debilitating nature of the injuries treated by such transplants, the defects are generally not life threatening, making it difficult for physicians to recommend life-long immunosuppression that can itself have grave consequences. One potential solution to this dilemma is the induction of immunologic tolerance of the tissue transplants because tolerance would eliminate the need for such immunosuppression. Transplant tolerance may also prevent chronic rejection, a significant source of late graft loss after organ transplantation.Induction of mixed hematopoietic chimerism is a robust approach to establishing such transplant tolerance, which recently led to the first clinical application of a tolerance induction protocol for kidney transplantation. In this manuscript, we review the current status of VCA and of research directed toward bringing a tolerance approach to the VCA field. We also discuss the potential clinical significance of these studies and outline the remaining obstacles to introduction of a tolerance induction protocol to clinical practice in hand or face transplantation.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Terapia de Imunossupressão/métodos , Quimeras de Transplante/imunologia , Tolerância ao Transplante/imunologia , Animais , Rejeição de Enxerto/prevenção & controle , Terapia de Imunossupressão/efeitos adversos , Modelos Animais , Transplante de Tecidos , Transplante Homólogo
16.
J Orthop Res ; 31(2): 328-34, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22987740

RESUMO

Matrix metalloproteinases (MMPs) are expressed in Dupuytren's contracture and play a role in matrix remodeling. We tested the role of tension on contractility and MMP expression in Dupuytren's nodule and cord cells. Cells were subjected to pre-determined loading patterns of known repeatable magnitudes (static load, unloading, and overloading) and tested for MMP gene expression (MMP-1, -2, -9, -13, and TIMP-1, -2) and force generation using a tension-culture force monitor. Matrix remodeling was assessed by addition of cytochalasin D and residual matrix tension was quantified. Nodule compared to cord and control cells demonstrate greater force generation and remodeling (p < 0.05). Nodule cells subjected to a reduced load and overloading led to threefold increase of MMP-1, -2, and -9 compared to static load, whilst cord and control cells only showed a twofold increase of MMP-9. Nodule cells subjected to overloading showed a twofold increase in TIMP-2 expression, whilst cord and control cells showed a twofold increase in TIMP-1 expression. Nodule cells differ from cord cells by increased force generation in response to changes in the mechanical environment and related MMP/TIMP-mediated matrix remodeling. In turn this may lead to permanent matrix shortening and digital contracture. Interventional therapies should be aimed at nodule cells to prevent contraction and subsequent permanent matrix remodeling.


Assuntos
Contratura de Dupuytren/fisiopatologia , Metaloproteinases da Matriz/biossíntese , Idoso , Células Cultivadas , Citocalasina D/farmacologia , Fibroblastos/citologia , Fibroblastos/fisiologia , Expressão Gênica , Humanos , Pessoa de Meia-Idade , Contração Muscular , Estresse Mecânico , Inibidor Tecidual de Metaloproteinase-1/biossíntese , Inibidor Tecidual de Metaloproteinase-2/biossíntese
17.
Eur J Plast Surg ; 35(9): 673-682, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22904603

RESUMO

A high incidence of associated infection with the use of transcutaneous metal devices has been widely reported. The aims of this study were: (1) to record the incidence of pin site infection in a Plastic Surgery department, (2) to compare the infection rate in our department with published literature and (3) to identify factors that contribute to infection. A prospective cohort study was performed including all patients presenting to the plastic surgery unit with any type of transcutaneous metal in situ over a 3-month period. Patients and staff were questioned on wound hygiene and whether they had been provided with specific protocols. Our study revealed an infection rate of 24%. Patients and staff were not aware of preventive protocols. From this study, the following conclusions are made: (1) pin site infection is a major problem, and no consensus has been reached on the best way to manage pin sites, (2) there is variable knowledge of pin-site care, (3) there is a need for a clearer definition of pin-site infection and a standardised system of assessment, classification and treatment and (4) there is a need for more innovative technology in pin-site manufacture as studies reveal that the type of material used in the pins does affect infection rates.

18.
Plast Reconstr Surg ; 127(2): 689-702, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21285773

RESUMO

BACKGROUND: This study is a clinical characterization of keloid scars in an African population comprising three rural tribes with familial keloids. Site distribution, morphologic features, and other characteristics of the scars were studied to assess whether each tribe had a specific scar phenotype. METHODS: Keloid scar clinics were set up at Soba Hospital in Khartoum, Sudan, for patient recruitment and management. In addition, familial keloid cases were recruited from rural tribal populations during field trips. A database including clinical and demographic data and digital photographs of all keloid cases was established. Statistical analysis was conducted using SPSS and SAS software. RESULTS: One hundred eleven individuals with keloid scarring (67 male subjects and 44 female subjects) were recruited. Patients were predominantly from three multigenerational pedigrees (total of 38 nuclear families) afflicted with keloid scars residing in different rural regions of Sudan. Two distinct morphologic phenotypes of keloid scarring were observed. The first phenotype has been designated "superficial spreading" (horizontal) keloid and the second has been designated "raised" (vertical) keloid. Clinically significant features and statistically measurable morphologic parameters were compared among these phenotypes (p = 0.001). Furthermore, linear claw-like extensions of keloid (transgression) were noted to be significantly higher in the superficial spreading keloid phenotype (p = 0.03). CONCLUSIONS: There is strong evidence of different phenotypes of keloid scarring. Two distinct phenotypes have been observed, described, and statistically verified. Each tribe demonstrated one particular phenotype, with two being superficial spreading and one being raised. Other significant clinical characteristics have been described. This is of significance in understanding both the clinical basis and the genetic basis of keloid scarring.


Assuntos
População Negra/genética , Queloide/genética , Fenômenos Biomecânicos , População Negra/etnologia , Feminino , Humanos , Queloide/patologia , Queloide/fisiopatologia , Masculino , Fenótipo , Sudão
19.
PLoS One ; 6(1): e16337, 2011 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-21298098

RESUMO

The ability of tendons to glide smoothly during muscle contraction is impaired after injury by fibrous adhesions that form between the damaged tendon surface and surrounding tissues. To understand how adhesions form we incubated excised tendons in fibrin gels (to mimic the homeostatic environment at the injury site) and assessed cell migration. We noticed cells exiting the tendon from only the cut ends. Furthermore, treatment of the tendon with trypsin resulted in cell extravagation from the shaft of the tendons. Electron microscopy and immunolocalisation studies showed that the tendons are covered by a novel cell layer in which a collagen type IV/laminin basement membrane (BM) overlies a keratinised epithelium. PCR and western blot analyses confirmed the expression of laminin ß1 in surface cells, only. To evaluate the cell retentive properties of the BM in vivo we examined the tendons of the Col4a1(+/Svc) mouse that is heterozygous for a G-to-A transition in the Col4a1 gene that produces a G1064D substitution in the α1(IV) chain of collagen IV. The flexor tendons had a discontinuous BM, developed fibrous adhesions with overlying tissues, and were acellular at sites of adhesion formation. In further experiments, tenotomy of wild-type mice resulted in expression of laminin throughout the adhesion. In conclusion, we show the existence of a novel tendon BM-epithelium that is required to prevent adhesion formation. The Col4a1(+/Svc) mouse is an effective animal model for studying adhesion formation because of the presence of a structurally-defective collagen type IV-containing BM.


Assuntos
Membrana Basal/química , Movimento Celular , Tendões/anatomia & histologia , Animais , Colágeno Tipo IV/análise , Epitélio/fisiologia , Técnicas In Vitro , Queratinas/análise , Laminina/análise , Camundongos , Modelos Animais , Tendões/fisiologia , Aderências Teciduais/prevenção & controle
20.
Plast Reconstr Surg ; 128(1): 163-172, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21701333

RESUMO

BACKGROUND: Skin scarring is associated with psychosocial distress and has a negative effect on quality of life. The transforming growth factor (TGF)-ß family of cytokines plays a key role in scarring. TGF-ß3 improves scar appearance in a range of mammalian species. This study was performed to assess the efficacy of intradermal avotermin (TGF-ß3) for the improvement of scar appearance following scar revision surgery. METHODS: Sixty patients (35 men and 25 women; age, 19 to 78 years; 53 Caucasians; scar length, 5 to 21 cm) received intradermal avotermin (200 ng/100 µl/linear cm wound margin) and placebo to outer wound segments immediately after, and again 24 hours after, complete (group 1) or staged (group 2) scar revision surgery. A within-patient design was chosen to control for interindividual factors that affect scarring. The primary efficacy variable was a total scar score derived from a visual analogue scale, scored by a lay panel from standardized photographs from months 1 through 7 following treatment. RESULTS: : Primary endpoint data from the combined surgical groups showed that avotermin significantly improved scar appearance compared with placebo (total scar score difference, 21.93 mm; p = 0.04). Profilometry showed a greater reduction in scar surface area from baseline with avotermin treatment compared with placebo, significant in group 2 at months 7 and 12 (difference, 41.99 mm and 25.85 mm, respectively; p = 0.03 for both comparisons). Histologic analysis from group 2 showed that, compared with placebo treatment, collagen organization in avotermin-treated scars more closely resembled normal skin in 14 of 19 cases. Avotermin was well tolerated. CONCLUSION: Avotermin administration following scar revision surgery is well tolerated and significantly improves scar appearance compared with placebo. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.(Figure is included in full-text article.).


Assuntos
Cicatriz/prevenção & controle , Fator de Crescimento Transformador beta3/uso terapêutico , Adulto , Idoso , Cicatriz/cirurgia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação , Adulto Jovem
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