bluuebunny/crossref_metadata_2025_split huggingface dataset:
Important Factors in the Healing of a Pressure Ulcer in the Ischium of a Spinal Cord‐Injury Patient Whose Pressure Ulcers Recurred Over 26 Years
Authors: Sugai Ayumi , Yamamoto Hiromasa 
Published: January 2005

Objectives:  Pressure ulcers in the ischium of spinal cord‐injury patients are caused by their wheelchair‐bound lifestyle. Such injuries are intractable and limit a patient's activities of daily life for long periods. Here, we report our experience with a patient whose pressure ulcer was healed without limitation of her daily activities.Subject:  A woman aged 56, who had injured her thoracic spinal cord 26 years earlier, developed a pressure ulcer in the right ischium. The injury healed and then recurred over 10 admissions for treatment, and the maximum period over which the patient stayed at home without a pressure ulcer was only two months over the past several decades. In June 2002, she was healed and discharged, but the pressure ulcer recurred in the same region only one month later.Course:  She was treated in the outpatient department, but the affected area expanded and the condition aggravated and invaded the subcutaneous tissue. The causes were considered to be a body posture leaning to the right, rubbing during decompression, and pressure on the lesion exerted by a cushion of the wheelchair. Treatment of the patient began from a consideration of daily activities, including work and housekeeping. The cushion was changed to a new one that helped the patient maintain a good posture and prevented rubbing. In addition, the patient was instructed to develop a decompressing action that dispersed the body pressure to the posterior thigh, and was shown how to sit during monthly visits to the outpatient department. The affected lesion was washed every day in the shower, and was treated with sugar and povidone‐iodine.Results:  The patient observed changes in the affected lesion of the pressure ulcer, and reported changes that occurred in her daily life. In April 2003, the pressure ulcer had healed and has yet to recur 8 months later.Conclusions:  (1) For pressure ulcers in the ischium of a spinal cord‐injury patient, it is of importance for healing and prevention of recurrence to find the cause of the pressure and to improve the condition, rather than to treat the affected lesion. (2) Instructions regarding adoption of the correct sitting position, i.e., a major factor in daily life, and continuous care intervention improved the patient's self‐care ability.
symposium i‐1. pathophysiology and treatment of pressure ulcer Moderated by Koicki Hirata: The Study of Clinical Usefulness of Basic FGF
Authors: Hamanoue Masahiro , Nakajo Tetuhiro , Kijima Fumio , Nisijima Hiro , Maenohara Sigeho 
Published: January 2005

Recently, basic FGF (fibroblast growth factor) has been made clinical use for wound cure. We studied clinical usefulness of basic FGF.Cases:  Nine cases took wound necrosis by infection. Two cases took burn after mastectomy. One case took abscess in pelvic space.Methods:  We investigated healing rate of wound by healing area per day. And we evaluated histological wound healing by HE staining, labeling index of Ki64 staining, CD34 staining for index of neovascularization, and α‐smooth muscle actin staining for differentiation of fibroblasts.Result:  Healing rate of nine cases with wound necrosis by infection was 5 cm2/day and that of two cases with burn after mastectomy was 0.5 cm2/day. Labeling index was more than 10%. CD34 staining showed increasing neovascularization of healing tissues with treatment of bFGF, compaired with that recieved other treatments. But the case with abscess did not recover and took the reoperation for treatment.Conclusion:  We concluded that bFGF was efficacious against tissue damage and useful for wound cure. But basic FGF was not useful for the infectious focus without control.
Microscopical Characterization of Poly‐L/D‐Lactide (PLDLA) 96/4 Sutures in the Achilles Tendon of Rabbits
Authors: Kangas J , Pajala A , Leppilahti J , Ryhänen J , Länsman S , Törmälä P , Waris T , Ashammakhi N 
Published: January 2005

Common Achilles tendon ruptures are usually not fixed by absorbable sutures due to limitations in their strength properties. Modern technology has made it possible to develop bioabsorbable sutures with prolonged strength retention. To evaluate histologically tissue reactions and biodegradation of poly‐L/D‐lactide (PLDLA) sutures implanted in Achilles tendon of rabbits. Fifteen rabbits were operated on and killed within a time schedule of 2, 6 and 12 weeks, with five rabbits in per period. PLDLA monofilament sutures (Tampere University of Technology, Tampere, Finland) were implanted inside the rabbit medial gastrocnemius tendon for biocompatibility testing. Polyglyconate (4.0) monofilament sutures (Maxon®, Cyanamid of Great Britain Ltd., Gosport, UK) with the same diameter were implanted in the contralateral tendon. The histology was studied in hard‐resin embedded samples and the thickness of the encapsule membrane was determined histomorphometrically.PLDLA have significantly smaller capsule formation around each fiber in tendon than Maxon® sutures. The mean capsule thicknesses around PLDLA sutures was 5.26, 11.66, and 10.63 after 2, 6, and 12 weeks respectively. The mean capsule thicknesses around Maxon® sutures was 13.22, 80.97, and 17.59 after 2, 6, and 12 weeks, respectively. In conclusion, by 12 weeks the PLDLA sutures implanted intratendineously formed thinner fibrous capsule than Maxon® sutures of same diameter. The suture materials were not degraded by 12 weeks.Acknowledgments:  Research funds from the Technology Development Center in Finland (TEKES, Biowaffle Project 40274/03 and MFM Project 424/31/04), the European Commission (EU Spare Parts Project QLK6‐CT‐2000‐00487), the Academy of Finland (Project 73948) and the Ministry of Education (Graduate School of Biomaterials and Tissue Engineering) are greatly appreciated.
Smooth Muscle Cells of Fatal Coronary Artery Lesions Exhibit a Myofibroblastic Phenotype
Authors: Hao H , Gabbiani G , Camenzind E , Virmani R , Bochaton‐Piallat ML 
Published: January 2005

Objectives:  Characterize the phenotypic features of smooth muscle cells (SMCs) of erosions, stable plaques and in stent restenosis causing sudden death, in order to verify the possibility that they have modulated into myofibroblasts.Methods and Results:  Expression of α‐SM actin (α‐SMA), SM myosin heavy chains (SMMHCs) and smoothelin was investigated by immunohistochemistry followed by morphometrical quantification in the media and intima of coronary lesions. The expression of all cytoskeletal proteins was lower in the media of restenotic lesions and, to a lesser extent, of stable plaques compared to that of erosions demonstrating a significant medial atrophy in the two first conditions. An important expression of α‐SMA was detected in the intima of the different lesions; moreover, the area of α‐SMA staining was significantly larger in erosions and restenotic lesions compared to stable plaques. In the same location a striking decrease of SMMHCs and a disappearance of smoothelin was observed in all situations.Conclusions:  Intimal SMCs of erosions and restenotic lesions as well as, to a lesser extent, of stable plaques, exhibit a phenotypic profile suggesting that they have modulated into myofibroblasts. The high accumulation of α‐SMA‐positive cells in erosions correlates with the higher appearance of thrombotic complications in this situation compared to the two other situations. (Supported by the Swiss National Science Foundation grant No 32‐068034.02.)
PDGF‐Stimulated Fibroblast Matrix Contraction is Mediated Through Direct Stimulation of Cell Protrusion and Ruffling Activity
Authors: Dahlmann AH , Bailly M , Khaw PT 
Published: January 2005

Scarring of the cornea, the transparent tissue at the front of the eyeball, is an important cause of visual impairment. A major chemokine upregulated in tear fluid after corneal injury is platelet‐derived growth factor (PDGF), which induces the stromal cells of the cornea (keratocytes) to assume a fibroblastic phenotype. We have investigated the role of PDGF in matrix contraction by human corneal fibroblasts (HCF) using the standard three‐dimensional (3D) fibroblast‐populated collagen matrix model (FPCM).When stimulated with PDGF, HCF in monolayer (2D) display circular ruffles (CR) on their dorsal surface. Using immunolabeling, we found that CR contain proteins of the Arp2/3 complex, which is required for the assembly of filamentous actin during protrusive activity. This PDGF‐mediated ruffling ability is altered by antibodies or blocking peptides that specifically interfere with the Arp2/3‐mediated pathway of actin polymerization, as well as by the myosin light chain kinase inhibitor, ML9. Preincubation with anti‐PDGF‐BB antibody or with the tyrosine kinase inhibitor, AG1295, also inhibits CR. While PDGF efficiently stimulates HCF‐mediated cell protrusive activity and macroscopic collagen gel contraction in the 3D model, this effect is directly inhibited by all the substances which inhibit CR in 2D, demonstrating a direct involvement of the PDGF‐mediated CR pathway in tissue contraction. Thus, 3D PDGF‐induced matrix contraction by HCF involves the same players as CR, a phenomenon observed in 2D cell cultures: PDGF‐BB receptor, receptor tyrosine kinase, the machinery for filamentous actin assembly (Arp 2/3 complex, Scar and Wasp proteins), and myosin. The functional role of circular ruffling or its equivalent in three‐dimensional fibroblast‐populated collagen matrices seems to be a rapid reorganization of the actin cytoskeleton in preparation for cell‐matrix interaction.
Cytoplasmic Actins β and γ are Differentially Distributed in Stationary and Motile Cells
Authors: Dugina V , Gabbiani G , Chaponnier C 
Published: January 2005

We have compared the distribution of β‐ and γ‐cytoplasmic actins in highly motile cells using laser confocal microscopy and newly developed β‐ and γ‐cytoplasmic actins monoclonal antibodies as well as the commercially available β‐actin antibody (clone Ac74).When fibroblastic, epithelial or endothelial cells attach on a substrate, divide, move into a wound, they have to organize their actin cytoskeleton in different types of structures such as in cell protrusions, in stress fibers or in circular bundles, e.g., during spreading. Interestingly, β‐ and γ‐cytoplasmic actins get organized in a complete different way, spatially and structurally. γ‐Cytoplasmic actin is mainly organized as a network under the dorsal membrane and in motile part of the cell (e.g., in lamellipodia); on the other hand, β‐actin is detected in the basal but not in the dorsal portion of the cell, is organized in radial cables at the cell‐cells contact in epithelial cells, in stress fibers in fibroblastic and endothelial cells and in circular bundles during cell spreading.It is known that the only sequence differences between the two cytoplasmic actins concern four amino acids located at the N‐terminus nonapeptide. Our results suggest that the N‐terminal domain of cytoplasmic actins are of major importance in allowing their differential cellular organisation in distinct cell activities, probably through an interaction with specific actin binding proteins.
Thrombin Inhibits the Migration of Human Liver Myofibroblasts
Authors: Gillibert‐Duplantier J , Neaud V , Desmoulière A , Bioulac‐Sage P , Rosenbaum J 
Published: January 2005

Liver myofibroblasts are the key cells of liver fibrogenesis. Recent data show that the serine proteinase thrombin is involved in fibrogenesis through a mitogenic effect on myofibroblasts. The aim of this study was to evaluate the effects of thrombin on the migration of human liver myofibroblasts; another major parameter in fibrogenesis.In a Boyden chamber assay, thrombin dose‐dependently (10−10–10−7 M) decreased spontaneous myofibroblast migration down to 49 ± 1% of control values (p = 5.10−10) without affecting cell adhesion or viability. Thrombin effect was blocked by its specific catalytic inhibitor hirudin and could be reproduced by using the proteinase‐activated receptor‐1 (PAR‐1) agonist SFLLRNP. Thrombin also completely inhibited migration when induced by the chemotactic agent platelet‐derived growth factor‐BB. We then investigated the signaling mechanisms involved. The COX‐2 inhibitor NS398 dose‐dependently (2.5–10 μM) blunted the inhibitory effect of thrombin on spontaneous migration. However, NS398 did not reverse the inhibitory effect of thrombin on PDGF‐BB‐induced migration. Phosphatidylinositol 3‐kinase (PI3‐K) is a major determinant of chemotaxis induced by PDGF. Whereas thrombin did not itself induce PI3‐K activity, as shown by the lack of detectable phosphorylation of Akt‐1, it inhibited PDGF‐BB‐induced Akt‐1 phosphorylation. This effect was dependent of the Rho/ROCK pathway since it was abolished in the presence of the ROCK inhibitor Y‐27632.In summary, thrombin, acting via a proteinase‐activated receptor, inhibits human liver myofibroblasts migration. Inhibition of basal migration is dependent on COX‐2, while inhibition of PDGF‐BB‐induced migration involves decreased PI3‐K activation via a Rho/ROCK mechanism. We suggest that thrombin could thus stabilize activated myofibroblasts on the site of active fibrogenesis.
Myofibroblasts in Dense Model Collagen Matrices: Migration, Proliferation, Apoptosis
Authors: Helary C , Ovtracht L , Godeau G , Coulomb B , Giraud Guille MM 
Published: January 2005

Fibrillar collagen matrices, that mimic the supramolecular organization of collagen in tissues, are obtained by using acid soluble collagen concentrated at 40 mg/ml and then forming fibrils at neutral pH. They present mechanical properties close to that of human dermis (1). We have previously shown that 150.000 human dermal fibroblasts seeded at the surface of collagen matrices migrate and attain a density of 5500 cells/mm3 after 28 days (2).The present work studies the phenotype of the cells migrating into dense, compared to loose (5 mg/ml) collagen networks. We demonstrate that cell migration is associated to matrix hydrolysis by MT1‐MMP on the cell front and gelatinase A (MMP2) that allow a migration distance of 350 μm after 28 days. Immunodetection of alpha‐smooth muscle actin evidences a myofibroblast phenotype for all cells penetrating both 40 and 5 mg/ml matrices. In parallel, we observe collagen I and fibronectin synthesis, typical of myofibroblasts. The TUNEL test reveals 43% of apoptotic cells in dense matrices after 28 days and a total absence of apoptosis in loose matrices. BrdU incorporation in myofibroblasts shows an intense proliferation in the dense collagen matrices that compensates cell death. Indeed the number of cells after one month of culture represents three times the number initially seeded.To conclude, in our culture conditions using 10% foetal calf serum, the stiffness of the matrix seems to be a stimulus of apoptosis; futhermore cells which express alpha‐SM actin are both able to proliferate and migrate.
Comparison of Different Wound Dressings on Cultured Human Fibroblasts and Collagen Lattices
Authors: Humbert P , Viennet J , Bride J , Gabiot AC 
Published: January 2005

Introduction:  The cellular phases (granulation, reepithelialization, and dermal remodelling) of the healing process involve many cell types. Fibroblasts and myofibroblasts are the key cells in granulation tissue formation and wound contraction.Objective:  To compare the effects on cultured human fibroblasts of a new nonadhesive lipidocolloid wound dressing, Urgotul®, with five other wound dressings including impregnated gauzes and some other modern wound dressings.Method:  Cultures in monolayer were used to study the morphology and growth of fibroblasts. The Bell model of cultured dermis equivalents was used to investigate myofibroblast differentiation. These cultures were labelled α‐SM actin and F‐actin.Results:  Two of the tested dressings induced cytotoxic effects on the fibroblasts. They were found to inhibit cell growth (greater than 60%) and to disturb cell shape and cytoskeletal differentiation. Urgotul® and the remaining three dressings showed no effect on proliferation. However some of them modified fibroblast morphology and affected F‐actin distribution.Conclusion:  Depending on their nature and components, wound dressings may respect or affect in vitro fibroblast behaviour (proliferation, morphology, and α‐SM actin and F‐actin distribution). The observed in vitro findings require further investigations.
Differential Response of Fibroblasts from Type I Diabetics to Proliferative and Migratory Signals
Authors: Vallury M , Zaher H , Lindblad WJ 
Published: January 2005

Type I diabetics experience significant morbidity from failure of lower extremity injuries to heal. This impaired healing response leads to chronic ulceration, infection and potential amputation of the extremity. Numerous hypotheses have been proposed to explain this impaired healing response, but little is known about intrinsic differences in the fibroblasts populating the diabetic extremity prior to wounding.Nontransformed fibroblast cell lines from type I diabetics were obtained from the NIGMS‐NIH cell repository at the Coriell Institute. Cells were maintained in Dulbecco's modified Eagle's medium containing 10% fetal calf serum, penicillin, streptomycin and either 450 mg/dL (high) or 100 mg/dL (low) glucose. Cell migration was measured over 72 hr by movement of cells away from a circular source of cells, deposited within cloning rings, under high or low glucose conditions. The initial (0, 6, 24 and 48 hr) proliferative response of cells was measured by 3H‐thymidine incorporation into confluent cell monolayers following partial scraping of the cell layer. Growth curves were obtained by seeding 50,000 cells into 6‐well plates and counting cells at 24, 48, 72, and 168 hrs.Fibroblasts from diabetic individuals showed impaired migration compared to nondiabetic cells (34% vs. 67% increase in diameter) in high glucose over an initial 72 hrs. This difference was minimized if the cells were cultured and tested in low glucose medium. In contrast, diabetic derived cells proliferated more rapidly at early times (13.5%[24 hr], 97%[48 hr], 209%[72 hr] diabetic vs. 4%, 52.5%, 156% increase in cell number) when cultured under high glucose conditions. This trend continued under low glucose conditions, although the magnitude difference was diminished. These results suggest that the fibroblast population present in the type I diabetic connective tissue possesses a phenotype distinctly different from normal cells, characterized by a reduced capacity to migrate, but a normal or heightened proliferative response. This may indicate that injury to this connective tissue fails to produce the required influx of fibroblasts to deposit new matrix.
The Role of Fibroblasts in Skin Substitutes
Authors: Middelkoop E , Van Den Bogaerdt A , Ulrich M 
Published: January 2005

Skin substitutes are slowly finding a position in the treatment of burns, scar reconstructions and chronic wounds. Some of the substitutes consist of extracellular matrix replacement material only, such as Integra and Alloderm; some include allogeneic cells (Dermagraft, Appligraf). The ideal skin substitute has not been developed yet, since none of the presently available products can ultimately prevent scar formation.Study of the role of autologous fibroblasts in the healing process might give further insight into the scarring process and eventually lead to improved skin substitutes.We compared wound reepithelialization of experimental wounds treated with proliferating keratinocytes and a dermal substitute with either dermal fibroblasts, adipose tissue derived fibroblasts or no fibroblasts. We also investigated the rate of keratinocyte migration of human skin equivalents cultured in vitro in the presence of dermal or adipose tissue derived fibroblasts.We reached successful wound closure in 8 days with transfer of proliferating keratinocytes on a dermal substitute seeded with dermal fibroblasts. However, the wounds treated with substitutes which contained adipose tissue derived fibroblasts or no fibroblasts at all were not closed even after 21 days.Keratinocytes seeded onto collagen lattices populated with either dermal or fat‐derived fibroblasts showed similar findings: a retarded migration and/or proliferation of keratinocytes on the collagen lattices with fat‐derived fibroblasts. The collagen lattices populated with fat‐derived fibroblasts also showed a marked contraction, up till 50% of the original area.In both models, more alpha‐smooth muscle actin positive cells were found in the fibroblast population from adipose origin.We conclude that epidermal regeneration is negatively influenced by the presence of fat‐derived fibroblasts in a dermal matrix; possibly, myofibroblasts play a role in this.
The Glasbox®: A New System for Measurement of Contractile Forces Developed by Fibroblasts in Collagen Lattices
Authors: Viennet C , Armbruster V , Gharbi T , Humbert P 
Published: January 2005

Cellular contraction, defined as the force cells exhibit on the extracellular matrix, plays a significant role in dermal tissue. To study the contractility of cells in vitro, we have developed a new patented device named GlaSbox®“Growing Lattice Study Box”. It consists of a cell chamber composed with 8 rectangular wells (26 × 33 mM) in which lattices develop. Two opposite silicon beams hang down into each well. The lattice is attached to this sensor through a grid directly etched on the lower part of the beams. A strain gauge is deposited at the beam surface, and connected to form a Wheastone bridge. The strain gauges signal output is amplified then converted and collected by a computer which includes an acquisition card and a specific program giving directly the forces in real time. The significant advantages of the GlaSbox® are:

the absence of any interface between the collagen lattice and the beams which maintain it stretched,
its ability to test eight lattices simultaneously,
the low volumes of cells and collagen required.

To demonstrate the applicability of this system, contractile forces of human fibroblasts from different skin conditions were measured such as chronic venous leg ulcers and striae distensae. These fibroblasts were found to produce an average force of 1.10−8 N/cell and have greater contractile capacity than normal fibroblasts (Viennet et al., J Wound Care 2004, in press). The GlaSbox® is a useful tool to study the contractility of dermis equivalent composed of various fibroblast lines and, the effect of different active principles or even growth factors (e.g., TGF‐β) on cellular contraction. In addition, it can be used to examine the relationship between cellular contraction, cell proliferation, and collagen production, which is important for the understanding of the mechanism of scar tissue formation.