A meningiomatous perineurial tumour located in the mesentery. An ultrastructural and immunohistochemical study.
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Biomedical subjects
Publications and source records attributed to P Huguet.
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Prosthetic meshes are used as the standard of care in abdominal wall hernia repair. However, hernia recurrences and side effects remain unsolved problems. The demand by health care providers for increasingly efficient and cost-effective surgery encourages the development of newer strategies to improve devices and outcomes. Here, we evaluated whether l-arginine administration was able to ameliorate long-term polypropylene prostheses incorporation into the abdominal wall of Sprague-Dawley rats. Meshes were placed on-lay and continuous l-arginine was administered. In vivo biocompatibility was studied at 7, 25 and 30 days post-implantation. Effectively, l-arginine administration in combination with mesh triggered subtle changes in ECM composition that impinged on critical biochemical and structural features. Lastly, tensile strength augmented and stiffness decreased over the control condition. This could help to restructure the mechanical load transfer from the implant to the brittle surrounding tissues, i.e., impact load and fatigue load associated with mechanical tensions could be distributed between the mesh and the restored tissue in a more balanced manner, and ultimately help to reduce the incidence of loosening, recurrences, and local wound complications. Since the newly formed tissue is more mechanically stable, this approach could eventually be introduced to human hernia repair.
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Reconstruction of the burned breast poses several clinical challenges, since scarring can adversely affect the development, contour and positioning of the breast as well as the cosmetic appearance of the skin surface. Conventional management entails contracture release and thick split-thickness skin grafting. We investigated an alternative approach employing dermal regeneration template (Integra) for breast reconstruction in 12 consecutive patients who had suffered anterior chest wall burns in childhood. Integra is a bilayer material consisting of a collagen and chondroitin-6-sulfate dermal regeneration template and a temporary silicone epidermal layer. Portions of the scar contracture preventing the breast from assuming the desired shape and position were excised. Unmeshed Integra sheets were applied to the wound bed immediately following excision. Sufficient vascularization of the forming neodermis occurred within 28 days on average to enable removal of the silicone layer and placement of unmeshed 0.005in. epidermal autografts. Upon histological examination one month postoperatively, naturally-formed collagen fibres were observed in the dermal regeneration template. By one year, host collagen had typically completely replaced the Integra matrix, and elastic fibres were evident throughout the neodermis. Durable improvements in breast contour and shape were attained in all patients, and clinically-relevant recontracture of the graft site did not occur within the follow-up period. A statistically significant improvement of 6.0 (95% CI, 5.0-6.5) in Vancouver Scar Scale score was demonstrated at one year. A very high level of satisfaction in the outcome of reconstruction was expressed by 92% of the patients. Grafting with Integra provides an effective and well-tolerated alter-native to thick split-thickness grafting for breast reconstruction. Chief advantages are the availability of a biocompatible material in unlimited quantity that can be tailored to the particular wound site and the avoidance of a deep donor site wound with attendant potential for infection, scarring and permanent pigment changes.
The repair of incisional hernias has taken advantage of the strength provided by prosthetic mesh grafts, but the best position for inserting the materials has not been conclusively established. Environmental scanning electron microscopy (ESEM) provides imaging of biologic samples with minimal manipulation. We used ESEM for early imaging of the integration response to polypropylene meshes placed in two anatomic positions in the abdominal wall and correlated results with tensiometric studies. Two macroporous polypropylene prostheses were implanted in a rat model--one on the abdominal aponeurotic layer and one on the peritoneal surface--without creating a wall defect. Studies were performed over implantation intervals of 7, 15, and 30 days in strips obtained from the polypropylene fiber-receptor repair tissue interface. Microscopic appearance, tensile strength, percent elongation, and stiffness were evaluated. Meshes implanted on the abdominal aponeurotic layer showed better early tissue incorporation (higher collagen deposition, capillary density, cell accumulation) and increased tensile strength, reflecting tighter anchorage to the abdominal wall. The percent elongation increased from day 7 to day 30 after implantation, mainly in the deep stratum. The ESEM images correlated well with biomechanical results, indicating the potential of this technique as a powerful, effective tool for use in wound-healing studies.
OBJECTIVES: To study the clinical spectrum and evolution of Churg-Strauss syndrome in order to assess the clinicopathological features of the disease, the response to treatment and the long-term outcome. METHODS: Thirty-two patients with proven allergic and granulomatous angiitis (Churg-Strauss syndrome) and followed up at a single institution were evaluated. They were recruited between 1977 and 1999 from internal medicine departments. Data were obtained retrospectively from medical files in 15 cases and prospectively, using a standardized form, for the remaining patients. RESULTS: All patients had asthma and hypereosinophilia. The lungs, skin and peripheral nervous system were the organs most frequently involved. Antineutrophil cytoplasmic antibodies with antimyeloperoxidase specificity (MPO-ANCA) were detected in 77.8% of tested patients but they were not useful for monitoring disease activity. Extravascular granulomas were rarely seen in tissue biopsies. Forty per cent of the patients were treated with steroids alone. Immunosuppressive agents were added to the treatment when severe neurological, cardiac or gastrointestinal involvement was present. The outcome and long-term survival were good. Clinical relapse was rare after the first year of therapy. Dysaesthesiae of the distal limbs, neurophatic pain and cardiac failure were the most frequent sequelae. CONCLUSIONS: Churg-Strauss syndrome is a rare disorder characterized by hypereosinophilia and systemic vasculitis occurring in patients with asthma and allergic rhinitis. Vasculitis commonly affects the lungs, skin and peripheral nervous system. Outcome and long-term survival is usually good with steroids alone or in combination with immunosuppressive agents. The syndrome has a low mortality rate compared with other systemic vasculitides.
PURPOSE: To describe ocular involvement in a case of systemic indeterminate cell histiocytosis, a rare disease characterized by the proliferation of indistinct histiocytes. These histiocytes resemble Langerhans cells but lack Birbeck granules. The disease usually occurs in adults, with no predisposition for either sex. The clinical features include multiple asymptomatic nodules and cutaneous papules. There are no previous reported cases in the literature regarding ocular indeterminate cell histiocytosis and its treatment. METHODS: A patient with skin papules and hyperpigmentation associated with systemic involvement and corneal infiltration was diagnosed with systemic indeterminate cell histiocytosis after a skin biopsy. Immunohistochemical examination showed specific surface proteins of indeterminate cells, and electron microscopy showed Langerhans-like cells without typical Birbeck granules. Progressive and severe photophobia and corneal thickening made bilateral corneal transplant necessary. RESULTS: Visual acuity remained stable because of the use of systemic immunosuppressors, which decrease the recurrence of infiltration after a corneal transplant. CONCLUSION: Indeterminate cell histiocytosis is a rare disease and there is no previous description of ocular involvement. Infiltrating lesions must be treated with corneal transplant and systemic cyclosporin if they decrease visual acuity.
We have investigated the effects of high arginine (Arg) levels (7.5 mg/100 g body weight per hour) on the early integration of biocompatible mesh grafts into the rat abdominal wall. Studies were performed over implantation intervals of 6, 12, 24 or 48 hours (n=12, each). Arginine and related compounds were quantified in plasma, wound fluids and multiple tissues. Plasma nitric oxide (NO) production was studied. Strips were taken from the polypropylene fiber-host tissue interfaces (PTIs) for optical microscopic analysis and for immunohistochemical analysis using rat-specific antibodies against type I and type III collagens. Exogenous Arg was metabolized at the peripheral tissues but reliably reached the wound space. High amounts of Arg and ornithine (Orn) were detected in the specimens considered. No changes on citrulline (Ctr) or NO concentrations were observed, overall suggesting that, during the period studied, the arginase pathway predominated. The acute scarring response differed significantly in the two placements considered. The P-SS interface evidenced more extensive new tissue growth than the P-DS interface. Forty-eight hours after mesh implantation cellular infiltration, fibroblast proliferation, and mesh-surrounding angiogenesis were higher in the arginine-treated rats. Type III collagen staining was related to arginine treatment, being higher (++) in the study group. In conclusion, and independently of the site of mesh placement, supplemental Arg seemed to favorably affect early local collagen deposition. This could be potentially helpful to ameliorate the integration of biomaterials into the tissues and, consequently, to allow for the design of more selective therapeutic strategies to prevent hernia recurrence rates.
In contrast with R. B. Zajonc's (1965) classic view about social facilitation-inhibition (SFI) effects, it was found that the presence of relatively unpredictable audiences and forced social comparison with a slightly superior coactor both facilitated performance in the Stroop task while inhibiting automatic verbal processing. Not only do these findings reveal that social presence can help inhibit the emission of dominant responses, providing further support for an attentional view of SFI effects, but they also demonstrate the power of social situations over what has been thought to be invariant automatic processing. As such, they are inconsistent with the view reiterated in more than 500 articles on Stroop interference over the past 60 years and suggest that more attention should be paid to the situations in which cognition takes place.
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OBJECTIVE: To determine progressive quantitative, directional and textural changes in dermal collagen as a function of age and sex and to estimate their evolutive trend with appropriate regression models. STUDY DESIGN: Ninety-six samples of abdominal skin from autopsy cases were analyzed. The ages ranged from 3.5 months to 86 years. Picro-Sirius-stained slides were examined by polarizing microscopy, and spatial density, directional features and texture of collagen were measured by computerized image analysis. Nonlinear regression models were built to estimate evolutive changes with respect to age. The relationship between spatial orientation of collagen bundles and age was best modeled by linear regression. RESULTS: The evolutive patterns of dermal thickness and spatial density of collagen bundles correspond to a second-order polynomial model with a progressive increase from childhood to middle age and a relatively sharp decrease after the seventh decade. The evolution of textural pattern of dermal collagen, defined by gradient analysis, depicts a sort of inverted U. Its complexity is maximum in the first year of life, decreases until the period 25-50 years and increases progressively after the sixth decade. The horizontal orientation of collagen bundles with intermingled fascicles oriented in other directions, shown by young individuals, is progressively simplified with aging. In elderly subjects, collagen bundles have a horizontal orientation. No significant sex-related differences were found. CONCLUSION: Dermal collagen changes related to aging are apparently independent of sex, at least in abdominal skin, and show characteristic curvilinear evolutive trends defined by decreased dermal thickness in the elderly, decrease in the spatial density of collagen bundles and increase in textural heterogeneity of the dermis. Progressive simplification in the orientation of collagen bundles leading to a predominant horizontal disposition followed a linear trend. These changes could contribute to providing a substantial morphologic basis to age-associated biomechanical alterations in the skin.
Reactive arthritis, or Reiter's disease, characteristically affects the joints of the lower limbs in an asymmetrical pattern. Usually it does not affect the cervical spine, and atlantoaxial subluxations are the exception. This paper describes the case of an HLA-B27-positive female patient with a sexually acquired reactive arthritis where a non-reducible atlantoaxial subluxation was present. The patient was followed from age 27 to 41. By the age of 38, an anterior decompression of the cervico-medullary junction was performed by a transoral approach; in a second stage, the patient underwent an occipito-cervical posterior fusion. The pathological study revealed a non-specific and chronic inflammatory infiltrate.
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The case of a 58-year-old man with chronic paroxysmal headache and facial ecchymosis is described. The headache was pulsating, of short duration, without nausea or vomiting, and occasionally associated with flashing lights. Ecchymoses were mainly located in the middle forehead region and their appearance was associated with a reduction in intensity of the headache. Blood coagulation tests were within normal limits, and a skin biopsy of the ecchymotic lesion ruled out an underlying vasculitis. These attacks were difficult to include in any particular type of headache, although some aspects were similar to migraine headache. The possible mechanism of hemorrhages is discussed.
Angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon disorder of unknown aetiology. Clinically, it is characterized by cutaneous papules or nodules on the head and neck, and extracutaneous involvement is rare. We report a 30-year-old woman who had an asymptomatic submucosal nodule on the upper lip, which histopathologically showed features of ALHE, and review the previously described 15 cases of oral ALHE.
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