Browsing by Author "Pacheco, D"

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    Clinical features of Wegener granulomatosis and microscopic polyangiitis in Chilean patients
    (SOC MEDICA SANTIAGO, 2005) Cisternas, M; Soto, L; Jacobelli, S; Marinovic, MA; Vargas, A; Sobarzo, E; Saavedra, J; Chauan, K; Melendez, G; Foster, C; Pacheco, D; Wainstein, E; Sociedad Chilena de Reumatologia
    Background Systemic vasculitis are a group of heterogeneous diseases characterized by inflammation and necrosis of blood vessel walls. The etiology is not known, but geographic and environmental, factors are implicated. Aim: To describe the clinical features of microscopic polyangiitis (MPA) and Wegener's granulomatosis (WG) in a Chilean cohort of patients. Patients and methods: Retrospective review of the medical records of 123 patients with the diagnosis of systemic vasculitis (65 MPA and 58 WG), seen from 1990 to 2001. The diagnosis were made based on the American College of Rheumatology and Chapel Hill criteria. Results: The mean follow-up for MPA was 15 months (1-120) and for WG, 20 months (1-120). The median age (years) at diagnosis for MPA was 61 (19-82) and WG 50 (20-82). Gender distribution was similar in both groups (male: 68% and 57% respectively). The main clinical features in the MPA group were renal involvement (68%), peripheral nervous system involvement (57%), pulmonary hemorrhage (28%), and skin disease (32%). In the WG group were alveolar hemorrhage (62%), renal involvement (78%); paranasal sinus involvement (57%); and ocular disease (26%). In both, creatinine levels above 2.0 mg/dl were associated with a higher mortality (p < 0.01). ANCA by immunofluorescence was performed in 56 MPA patients (75% had pANCA, 4% had cANCA and 21% were ANCA negative) and in 55 WG patients (17%, had pANCA, 79% had cANCA and 4% were ANCA negative). Global mortality was 18% and 17% respectively, and the most causes of death were infections. Conclusions: The clinical features of our patients are similar to other-published data. In our WG and MPA patients the main predictor for death was a serum creatinine above 2 mg/dl.
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    Oncogenic hypophosphatemic osteomalacia associated with a nasal hemangiopericytoma
    (LIPPINCOTT WILLIAMS & WILKINS, 2003) Fuentealba, C; Pinto, D; Ballesteros, F; Pacheco, D; Boettiger, O; Soto, N; Fernandez, W; Gabler, F; Gonzales, G; Reginato, AJ
    We report a patient with a nasal hemangiopericytoma associated with an oncogenic hypophosphartemic osteomalacia (OHO). This syndrome results from tumor products that decrease renal tubular phosphate resorption, leading to the osteomalacia. This patient presented with classic bone manifestations of osteomalacia and a nasal tumor. Laboratory studies performed before the first resection of the tumor included normal serum calcium, hypophosphatemia due to decreased tubular reabsorption of phosphate, and an undetectable serum 1,25 dihydroxy vitamin D level. Serum parathormone level was normal. Anterior iliac crest bone biopsy showed characteristic signs of osteomalacia that included increased osteoid and delayed mineralization. A partial resection of the nasal tumor was performed. After the first surgery the patient showed detectable serum level of 1,25 dihydroxy vitamin D, and transient normalization of the tubular reabsorption of phosphate. The patient was also treated with phosphate supplements and vitamin D with transient control of her clinical manifestations and improvement of the radiographic signs of osteomalacia.
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    Visible light-induced photooxidation of glucose sensitized by riboflavin
    (ELSEVIER SCIENCE INC, 1999) Silva, E; Edwards, AM; Pacheco, D
    Ne conducted this study to evaluate the oxidation of glucose induced by visible light in the presence of sensitizers such as methylene blue and flavins (i.e., flavin mononucleotide and riboflavin). The concentration of the sensitizers was similar to that of flavin in parenteral nutrients. The photooxidation of glucose sensitized by flavin mononucleotide or riboflavin was greater than that which was observed in the presence of methylene blue, whereas the isotopic effect of deuterium oxide (D2O) was enhanced more substantially in the presence of methylene blue than in the presence of flavins. These results show that methylene blue exerts its action through singlet oxygen and that at a high substrate concentration las was used in this work flavin mononucleotide and riboflavin act preferentially, as type I sensitizers. In the flavin photosensitized processes, the presence of hydrogen peroxide, superoxide anion, and hydroxyl radical was demonstrated. The photooxidation of glucose is favored by an increase in PH, and it also depends on the energy absorbed by the system. By using a specific reagent for glucose (i.e., o-toluidine), it was possible to quantify the photoconversion of glucose. The results obtained in this work should be considered in the management of glucose-containing parenteral nutrients that are exposed to risible light in the presence of a multivitamin complex containing flavin mononucleotide. (C) Elsevier Science Inc. 1999. All rights reserved.