Antioxidant and oxidative stress indices in dialysis-dependent acute renal failure

BACKGROUND: Experimental animal models and in vitro studies have established a role for reactive oxygen species and the therapeutic potential for free radical scavengers in acute renal failure (ARF). Little is known of the effects of hemodialysis and other clinical variables on antioxidant defenses and oxidative stress among patients with ARF. METHODS: We examined antioxidant defenses and oxidative stress status in 24 patients with ARF requiring hemodialysis (HD). Blood samples were drawn prior to the first dialysis session (baseline), as well as before and after the third and sixth dialysis sessions. At each time point, the following parameters were measured: plasma alpha-tocopherol (vitamin E), plasma glutathione peroxidase (GSH-Px), serum total oxygen radical absorbance capacity (ORAC), plasma thiobarbituric acid reactive substances (TBARS), plasma tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10). Multivariate linear regression analyses were performed to examine clinical/laboratory variables associated with antioxidant/oxidative stress indices. The changes in antioxidant/oxidative stress indices over time after initiation of hemodialysis was evaluated in a subgroup of patients (n = 11) who completed six dialysis sessions. Intradialytic changes in antioxidant/oxidative stress indices and the differential impact of cellulose acetate vs. polysulfone dialyzers were also evaluated. RESULTS: Factors associated with alpha-tocopherol level were serum albumin (301 microg/dl upward arrow for each 1 g/dl upward arrow in albumin) and ORAC (188 microg/dl upward arrow for each 1,000 micromol Trolox Eq/l upward arrow in ORAC). Age was independently associated with plasma GSH-Px levels (55 U/l downward arrow for each 10-year age upward arrow ). Factors associated with ORAC were alpha-tocopherol (85 micromol Trolox Eq/l upward arrow for each 100 microg/dl upward arrow in alpha-tocopherol) and total bilirubin (30 micromol Trolox Eq/l downward arrow for each 1 mg/dl upward arrow in total bilirubin). Total bilirubin was independently associated with TBARS (0.2 microM upward arrow for each 1 mg/dl upward arrow in total bilirubin). GSH-Px and ORAC levels declined over time between baseline and the sixth dialysis session (p < 0.05 for both). Finally, there was a significant intradialytic decline in ORAC levels, which appeared to be more pronounced with use of cellulose acetate compared with polysulfone dialyzer membranes (p < 0.05). CONCLUSIONS: These observations indicate that antioxidant and oxidative stress indices in ARF patients are associated with several clinical and laboratory variables as well as the dialysis procedure. Further studies are needed to investigate the therapeutic role of anti-oxidant therapy in these patients.     

The change in allograft function among long-term kidney transplant recipients

Long-term kidney allograft survival continues to remain an elusive goal. Kidney transplant recipients are believed to be at high risk for loss of allograft function, and new, potentially non-nephrotoxic immunosuppressive medications are advocated to improve long-term allograft survival. To evaluate the efficacy of such therapeutic interventions, information regarding the change in GFR among kidney transplant recipients with long-term allograft survival is needed. We studied 40,963 transplant recipients between 1987 and 1996 with allograft survival of at least 2 yr in the United States Renal Data System. Linear regression methods were applied to serial GFR estimates after transplantation. The baseline mean GFR at 6 mo after transplantation was 49.6 +/- 15.4 ml/min per 1.73 m(2). During the mean follow-up of 5.7 +/- 2.3 yr, the mean +/- standard error of the change in GFR was -1.66 +/- 6.51 ml/min per 1.73 m(2) per year (median, -0.94 L/min per 1.73 m(2) per year). A total of 12,583 (30%) of patients had improvement in GFR, 8133 (20%) patients had no change in GFR, and 20,247 (50%) patients had decline in GFR. It is concluded that, although most patients had significant impairment of GFR at baseline, the decline in GFR was slow and many patients had either no change or improvement in GFR. Strategies to improve long-term kidney allograft survival that increase baseline allograft function may be more effective than strategies to slow the decline in GFR.     

A whole genome association study in multiple sclerosis patients from north Portugal

Genetic factors are known to influence susceptibility to multiple sclerosis (MS) but the genes involved are largely undefined. Here, we report an association study based on 200 patients and 200 controls from the Porto region in Portugal. A total of 3974 markers were successfully typed from which we have identified 46 markers showing evidence of association. When compared to a physical map three regions were found with two of these markers less than 1.5 Mb apart: chromosomes 6p21.3 (the MHC region), 6q14.1 and 7q34.     

Three-wall decompression technique using transpalpebral and endonasal approach in patients with Graves' ophthalmopathy

PURPOSE: To evaluate the effects of the three-wall decompression technique using transpalpebral and endonasal approach in patients suffering from Graves' ophthalmopathy. METHODS: In this prospective study, we present a consecutive series of 15 subjects (17 eyes) who were submitted to orbital decompression by removing the inferior and lateral walls using transpalpebral incision combined with a transnasal endoscopic resection of the medial wall. The surgical technique involved the preservation of the bone structure between the lamina papyracea of the ethmoid and the maxillary orbital floor. MAIN RESULTS: The mean ocular recession based on Hertel measurements was 6.00 mm (range, 4-9 mm). None of the patients presented pre-operation diplopia, and one developed post-operation diplopia. Visual acuity was preserved in all cases. CONCLUSION: It is safe and efficient to perform three-wall decompression, combining transpalpebral and endoscopic transnasal approach, with preservation of the bone structure and the bone lateral to the infraorbital canal with fixation by two titanium plates on the lateral edge and removal of intraorbital fat, which results in significant proptosis reduction and minimal complications.     

Applications of videolaparoscopic surgery in children

OBJECTIVES: To present the videolaparoscopies performed by the Childreńs Surgery Service, and study the main indications for pediatric laparoscopic surgeries, considering advantages and disadvantages over conventional open procedures. METHODS: Retrospective analysis of 612 videolaparoscopies in children aged between 8 days and 17 years treated from November/95 to 2000. Basic principles of videolaparoscopy and the postoperative management of several pediatric diseases are described. The results, advantages, and complications were analyzed after a 5-year follow-up period. RESULTS: Laparoscopic surgery allowed for a wide series of abdominal procedures conventionally carried out through open surgery, mainly for the treatment of gastroesophageal reflux disease, inflammatory acute abdomen, adhesive intestinal obstruction, biliary lithiasis, tumors, cryptorchidism, ovarian diseases, splenectomies, aganglionosis, trauma and others. Morbidity was low (1%), and mortality due to laparoscopy was nonexistent. Conversion to laparotomy occurred in only 14 cases (2.3%), mainly because of trauma. The principal advantages included minimal surgical trauma, pain and reflex ileum, short hospital stay, almost no incisional hernias and better cosmetic scars. CONCLUSIONS: Videolaparoscopy seems to be a great advance in modern pediatric surgery, allowing safer and less invasive treatment of a wide series of abdominal diseases at all pediatric ages.