Diffusive vs. convective therapy: effects on mediators of inflammation in patient with severe systemic inflammatory response syndrome

OBJECTIVE: To compare two forms of continuous renal replacement therapy, continuous venovenous hemofiltration (CVVH) vs. continuous venovenous hemodialysis (CVVHD), in terms of the removal of inflammatory mediators from the blood of patients with systemic inflammatory response syndrome and acute renal failure. DESIGN: Randomized crossover, clinical study. SETTING: University teaching hospital. PATIENTS: Thirteen patients with systemic inflammatory response syndrome and acute renal failure receiving continuous renal replacement therapy. INTERVENTION: Patients were randomized to receive either convective clearance using CVVH or diffusive clearance using CVVHD for the first 24 hrs, followed by the other modality for 24 hrs. All treatments utilized AN69 hemofilters. CVVH was performed with an ultrafiltration rate of 2 L/hr and CVVHD with a dialysis outflow rate of 2 L/hr. MEASUREMENTS AND MAIN RESULTS: Plasma and ultrafiltrate concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-10, and sL-selectin were measured at 0, 1, 3, 6, 12, and 24 hrs by radioimmunoassay. Plasma endotoxin concentrations were also measured at 0, 12, and 24 hrs by chromogenic assay. CVVH was associated with a 13% decrease in plasma TNF-alpha concentrations compared with a 23% increase while on CVVHD (p < .05). Mean plasma concentrations of IL-6, IL-10, and sL-selectin were unchanged over time and between therapies. Only minimal amounts of mediators were recovered in the effluents with either therapy except for IL-6. The clearances for IL-6 were different between therapies, 1.9+/-0.8 (SD) mL/min for CVVHD and 3.3+/-1.5 mL/min for CVVH, (p< .01). Plasma endotoxin concentrations were not different between therapies. CONCLUSION: CVVH resulted in a decrease in plasma TNF-alpha concentrations as compared with CVVHD, while the type of transport mechanism used did not influence plasma concentrations of IL-6, IL-10, soluble L-selectin, or endotoxin. Differences in clearance for IL-6 between CVVH and CVVHD did not translate into significant changes in circulating IL-6 concentrations.     

Comprehensive analysis of risk factors for acquisition of Pseudomonas aeruginosa in young children with cystic fibrosis

Racial differences in insulin secretion and insulin sensitivity in healthy children were studied by administering a 2-hour hyperglycemic clamp (225 mg/dL) to 14 black and 16 white healthy adolescents (Tanner II-V), and 12 black and 11 white prepubertal children, matched for age, body mass index, and Tanner I pubertal development. In prepubertal children, fasting and first-phase insulin concentrations were higher in blacks compared with whites (14.7+/-1.3 vs 10.4+/-1.2, P=0.02, and 76.9+/-6.8 vs 52.1+/-6.4 microu/mL, P=0.016). There were no differences in second-phase insulin levels and insulin sensitivity index. In pubertal adolescents, first-phase and second-phase insulin concentrations were higher in blacks compared with whites (first-phase: 157.3+/-18.3 vs 77.0+/-8.7 microu/mL, P=0.0003; second-phase: 175.0+/-24.3 vs 108.7+/-8.8 microu/mL, P=0.012). Insulin sensitivity index was 35% lower in black adolescents compared with whites (P=0.02). These findings indicate that significant differences in insulin secretion and sensitivity are detectable early in childhood in healthy African-American vs American whites. However, genetic (race) vs environmental factors (physical activity/fitness, energy balance) should be carefully scrutinized as potential factors responsible for such differences.     

Expression of peroxisome proliferator activated receptor mRNA in normal and tumorigenic rodent mammary glands

PURPOSE: To evaluate the usefulness of Doppler ultrasonography (US) in the diagnosis of hyperfiltration in patients with insulin-dependent diabetes mellitus (IDDM). MATERIALS AND METHODS: Eighty-one consecutive patients with IDDM were studied. All patients were normotensive and had normal creatinine and blood urea nitrogen levels. The glomerular filtration rate (GFR) was evaluated by means of plasma clearance of chromium-51 ethylenediaminetetraacetic acid, urinary albumin excretion, US evaluation of renal volume, and Doppler evaluation of resistance index (RI) in the renal interlobar arteries. The patients were divided according to GFR into the following groups: those with hyperfiltering kidneys (group 1, n = 40) and those with normofiltering kidneys (group 2, n = 41). RESULTS: The median renal volume was 351 mL (95% CI = 337 mL, 379 mL) in group 1 and 318 mL (95% CI = 300 mL, 335 mL) in group 2 (P = .005). The number of patients with microalbuminuria was significantly lower in group 1 than in group 2 (P = .02). The median RI was significantly lower in group 1 (0.55; 95% CI = 0.53, 0.57) than in group 2 (0.57; 95% CI = 0.56, 0.59) (P = .04). An RI of less than 0.5, a renal volume greater than 410 mL/m2, and the absence of microalbuminuria were independent predictors of hyperfiltration. An RI of less than 0.5 and a renal volume greater than 410 mL/m2 showed high specificity (98% and 95%, respectively) and poor sensitivity (25% and 23%, respectively) in the diagnosis of hyperfiltration in IDDM patients. CONCLUSION: Both RI and renal volume showed correlation with GFR, but neither parameter is sufficiently sensitive in screening for hyperfiltration in IDDM patients.     

Action of pure ethanol and some alcoholic beverages on the gastric mucosa in healthy humans: a descriptive endoscopic study

A method for the simultaneous determination of residues of 17 beta-trenbolone and 17 beta, 19-nortestosterone and their epimers in animal tissues is described, involving immunoaffinity chromatography clean-up and high-performance liquid chromatography with dual-wavelength UV detection. The method has been validated at 2 micrograms/kg in pig and cattle liver and corned beef with recoveries of 41% upwards. The method has been applied to the determination of incurred residues of 19-nortestosterone and trenbolone. Various alternative extraction steps for incurred trenbolone have been investigated, including direct extraction, protease digestion, heating and ultrasonic probe treatment. Glucuronidase digestion has been shown to be the most effective method for this analyte.     

Cerebral microembolism in patients with retinal ischemia

BACKGROUND AND PURPOSE: We investigated the frequency of cerebral microembolism detected by transcranial Doppler ultrasonography in patients with clinical evidence of retinal ischemia, including transient monocular blindness, central and branch retinal artery infarction, and ischemic oculopathy, and assessed its correlation with carotid artery stenosis. METHODS: Records of 331 consecutive patients examined during a 47-month period at the Neurovascular Laboratory were reviewed. Of the original 453 intracranial arteries, 186 middle cerebral arteries (MCAs) satisfied qualifying criteria that excluded patients with cardiac embolic sources. Forty-five MCAs ipsilateral to the symptomatic eye constituted the study group. The control group consisted of 141 asymptomatic MCAs. Microembolus detection studies were performed on transcranial Doppler instruments equipped with special software, and the degree of carotid artery stenosis was measured by cerebral or MR angiography or by color duplex studies. RESULTS: Microembolism was detected in 40.0% of study MCAs and 9.2% of controls (P < 0.001). In the study group, microembolic signals were detected in 61.9% of MCAs tested within a week of symptom onset and 20.8% of those tested afterward (P < 0.001). Severe (> or = 70%) carotid stenosis or occlusion was more frequent in the study group (P < 0.001). Microembolic signals were detected in 25.3% and 11.2%, respectively, of MCAs distal to carotid arteries with 70% to 100% and 0% to 69% stenosis (P = 0.013). CONCLUSIONS: In patients without cardiac embolic sources, cerebral microembolism is frequently present on the side of retinal ischemia, particularly during the week after onset of symptoms. It is often associated with severe stenosis or occlusion of the ipsilateral carotid artery.