Composite prostheses for the repair of abdominal wall defects: effect of the structure of the adhesion barrier component

The component of a composite prosthesis, which makes contact with the visceral peritoneum, can be reabsorbable or non-reabsorbable, and laminar or reticular. This study was designed to determine whether the composition of this second, barrier component could improve its behavior at this interface. Abdominal wall defects in rabbits were repaired using a polypropylene prosthesis (PP), or the composites Sepramesh (PP+h) or Vicryl (PP+v). Fourteen days after surgery, the implants were evaluated by light and scanning electron microscopy, and immunohistochemistry. Prosthetic areas occupied by adhesions (PP: 71.08±5.09, PP+h: 18.55±4.96, P+v: 69.69±16.81%), neoperitoneal thickness (PP: 256.17±21.68, PP+h: 83.11±19.63, PP+v:213.72±35.90 μm) and macrophage counts (PP: 8.73±1.16, PP+h: 27.33±4.13, PP+v: 31.24±3.08%) showed significant differences (P<0.05). The tested biomaterials induced an optimal recipient tissue infiltration. Least adhesion formation was observed on the PP+h implants. This suggests that the second component, although reabsorbable, should be smooth in structure.     

The incidence of endocarditis caused by a prosthetic valve and its risk factors

To study the incidence and risk factors of prosthetic valve endocarditis (PVE) we followed 99.5% of 912 patients who had valve replacement from January 1, 1981 through December 31, 1985, for 1 to 6 (mean 3) years. PVE occurred in 27 patients (2.96% or 0.98% per patient-year). The incidence of PVE in the aortic position (3.9%) was significantly higher than in the mitral position (1.5%): p less than 0.25. PVE developed in 19 out of 329 patients with bioprostheses (5.8%) and in 8 out of 583 patients with mechanical valves (1.4%): p less than 0.005. Actuarially at 5 years follow-up 90.7% of the bioprosthetic group and 98.4% of the mechanical valve group was free of PVE (p less than 0.01). Bioprosthetic valve replacement in infective endocarditis further increased the risk of PVE compared to valve replacement by mechanical prostheses. In conclusion: in order of importance antecedent endocarditis, bioprostheses, male sex and aortic position are risk factors in the development of PVE. In patients requiring operation for infective endocarditis, mechanical valves are recommended. As the outcome of PVE is still very grave, authors stress the importance of prophylaxis, early diagnosis and timely operation.     

Effect of dithranol therapy on membrane, basement membrane and nuclear markers in psoriasis lesions

We investigated the effects of anti-psoriatic therapy with dithranol (1/20-1%) in salicylic acid (0.5%) in white petrolatum on lesional skin. FITC-labeled lectins and pemphigus vulgaris antibodies (PV) served as analytical means to study the glycocalyx. Antibodies of bullous pemphigoid (BP) were used as basal membrane markers. Nuclear antigens were recorded according to the binding of speckled, anti-nuclear antibodies (ANA) as well as antibodies to dsDNA. With some lectins, dithranol therapy resulted in pronounced fluorescence of the lower parts of the basal cells. ConA was fixed by the basal cell layer. To a lesser degree, ANA were fixed by nuclei of keratinocytes. PV antibodies were not fixed at all.     

Studies of the blood lipid peroxide status and vitamin E levels in patients with chronic active hepatitis and alcoholic liver disease

As free radicals and lipid peroxidation are involved in the pathogenesis of different inflammatory diseases of the liver, the blood malondialdehyde content, the activity or quantity of free radical eliminating enzymes and the natural antioxidant, vitamin E serum level has been studied in ten patients with chronic active hepatitis and in six subjects with alcoholic liver disease. Thirty healthy volunteers served as controls. The serum malondialdehyde/thiobarbituric acid reactive substance and its concentrations increased significantly in both hepatitis groups. The superoxide dismutase content was also raised in the patients' sera. The serum glutathione peroxidase (GSH-Px) activity was decreased in both groups, while the red blood cell GSH-Px showed a significantly lower activity in the alcoholic hepatitis patients. Serum catalase activity and vitamin E levels in both types of chronic hepatitis were not significantly different from the healthy controls.     

Conventional and experimental drug therapy in myelofibrosis with myeloid metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is currently classified as a classic (ie, BCR-ABL-negative) myeloproliferative disorder characterized by anemia, multiorgan extramedullary hematopoiesis, constitutional symptoms, and premature death from either leukemic transformation or other disease complications. Stem cell transplantation can be curative, but many patients either are not appropriate candidates or do not choose to accept the significant risks associated with transplantation. Current pharmacologic therapy has been beneficial mainly in terms of palliating disease-associated cytopenias, constitutional symptoms, splenomegaly, and other organ damage from excess myeloproliferation. Novel treatment strategies are under investigation, including targeted inhibition of JAK2^V617F, the activating tyrosine kinase point mutation present in about half of patients with MMM. In this article, we review both the old and new pharmacologic options for MMM.     

Estado actual del valor pronóstico de los marcadores moleculares en pacientes con cáncer colorrectal y la predicción de respuesta al tratamiento adyuvante

Colorectal cancer is one of the best studied of all malignant diseases interms of genetics and/or molecular prognostic factors. These factors, and relationships with prognosis, may have important implications especially in the design of surgical and adjuvant chemo-radiotherapy options. However, the true prognostic significance of all known factors has yet to be realised. We have reviewed the literature with specific focus on the role of molecular markers involved in prognosis and the prediction of response to adjuvant treatment.