ANTIMICROBIAL ACTIVITY OF EXTRACTS FROM ECUADORIAN LICHENS.

Antimicrobial activity of the ethanolic, isopropanolic, acetone, DMSO and aqueous extracts of the two lichen species from Ecuadorian highland, Usnea sp. and Stereocaulon sp. were explored in vitro against bacteria Bacillus subtilis, Escherichia coli and Staphylococcus aureus by the disc-diffusion method. Also the minimal inhibitory concentration (MIC) was determined. The strongest antimicrobial activity was found in DMSO extract of Usnea sp. compared to antibacterial activity of ciprfloxacin and cefazolin antibiotics. The inhibition zone was 28 mm, 30 mm, 31mm (DMSO extract, ciprfloxacin and cefazolin respectively) in case of B. subtilis usage as the test bacteria. MIC value for Usnea sp. and Stereocaulon sp. DMSO extracts was 0.4 mg/ml. E. coli was resistant to all kinds of extracts. The S. aureus sensitivity to lichen DMSO extracts was comparable to sensitivity of these microorganisms to tetracycline and vancomycin. Thereby, most kinds of extracts (ethanol, isopropanol, hexane, DMSO and acetone solvents) from Ecuadorian lichens Usnea sp. and Stereocaulon sp. with the exception of aqueous Stereocaulon sp. extracts possessed antibacterial activity against B. subtilis. DMSO lichen extracts had also antimicrobial activity against S. aureus. At the same time the extracts studied didn't demonstrate antibacterial activity against the representatives of the most common and harmful phytopathogenic bacteria tested. Further investigations of Ecuadorian lichens especially study of plants collected from extremal highland biotops can be very important in study of possibility of treatment of numerous diseases caused by pathogenic microorganisms.

Current trials of interventions to prevent radiocontrast-induced nephropathy.

Radiocontrast administration is a common cause of hospital-acquired acute renal failure. It is associated with significant in-hospital and long-term morbidity and mortality and increases the costs of medical care by at least extending the hospital stay. A variety of therapeutic interventions, including saline hydration, diuretics, mannitol, calcium channel antagonists, theophylline, endothelin receptor antagonists, and dopamine, have been employed to prevent radiocontrast-induced acute renal failure. Recent advances have examined the impact of fenoldopam (dopamine-1 receptor agonist), N-acetylcysteine (antioxidant), iso-osmolar contrast agents, hemodialysis, and hemofiltration on ameliorating radiocontrast-induced acute renal failure. Although hydration with half-normal saline had remained the gold standard for the prevention of radiocontrast-induced nephropathy, recent data have revealed the superiority of hydration with normal saline over half-normal saline. This review focuses on the most recent studies of interventions to ameliorate radiocontrast-induced acute renal failure and provides a critical analysis of some of the recent studies conducted to prevent radiocontrast-induced nephropathy.

Predictors of alkalosis after liver transplantation.

BACKGROUND: Metabolic alkalosis (MA) is common after orthotopic liver transplantation (OLT). METHODS: The study was conducted to identify factors associated with MA after 285 OLTs. MA, defined as total carbon dioxide content of 30 mEq/L or greater, developed in 115 patients (40%) within the first 3 postoperative days. RESULTS: By univariate analysis, patients with MA had a greater preoperative carbon dioxide content (24.4 +/- 3 versus 22.9 +/- 2.9 mEq/L; P < 0.0001) and hematocrit (35% +/- 5% versus 33% +/- 6%; P < 0.02), but lower creatinine (0.9 +/- 0.5 versus 1.2 +/- 1.2 mg/dL; P < 0.001) and blood urea nitrogen levels (15 +/- 12 versus 19 +/- 17 mg/dL; P < 0.001) compared with controls. Patients with MA were administered more citrate intraoperatively compared with controls (6.2 +/- 5.2 versus 4.5 +/- 3.6 mEq/kg of body weight; P < 0.02). Patients with MA had a lower postoperative potassium level (3.7 +/- 0.4 versus 4 +/- 0.5 mEq/L; P < 0.0001) and cumulative fluid balance (-0.66 +/- 1.87 versus +0.003 +/- 3.9 L; P < 0.007) compared with controls. By multivariate analysis, preoperative carbon dioxide content (odds ratio, 1.19; 95% confidence interval [CI], 1.08 to 1.31 per mEq/L), creatinine level (odds ratio, 0.61; 95% CI, 0.39 to 0.96 per mg/dL), intraoperative administered citrate (odds ratio, 3.35; 95% CI, 1.71 to 6.53 per 10 mEq/kg body weight), and postoperative potassium level (odds ratio, 0.32; 95% CI, 0.18 to 0.57 per mEq/L) were independently associated with MA. MA was not associated with increased hospital mortality (7.8% versus 8.2%, MA versus controls). However, patients with MA spent more time on mechanical ventilation than controls (5 +/- 0.8 versus 3 +/- 0.6 days; P < or = 0.03). CONCLUSION: Preoperative total carbon dioxide content, renal function, intraoperative administered citrate, and postoperative potassium level are independently associated with MA after primary OLT.

An epidemiologic study of early renal replacement therapy after orthotopic liver transplantation.

The preoperative impairment of renal function is associated with the need for postoperative renal replacement therapy (RRT) in patients undergoing liver transplantation. The principal goal of this investigation was to identify other factors apparent before or during transplant that were independently associated with the need for RRT in the early posttransplant period. A total of 260 consecutive adult patients who received a primary liver transplant were studied. Twenty-eight patients required early RRT (RRT initiated within 1 wk of transplant); 23 for control of volume overload. Preoperative blood urea nitrogen (odds ratio [95% CI], 1.52 [1.15 to 2.01] per 10 mg/dl), serum creatinine (1.91 [1.06 to 3.44] per 1 mg/dl), and urine output (0.12 [0.03 to 0.44] L/d) were independently predictive of the need for early RRT and in combination formed a parsimonious model that discriminated well (area under the receiver operating characteristic curve, 0.877) and had excellent fit (P = 0.699 to reject model fit). No other potential predictors meaningfully improved predictions of which patients would require early RRT. Patients requiring early RRT consumed more healthcare resources than patients who did not require early RRT, spending more time in intensive care (15 +/- 13 d versus 7 +/- 11 d; P < 0.001) and in the hospital (34 +/- 27 d versus 19 +/- 20 d; P < 0.001). The need for early RRT was strongly associated with death before hospital discharge (29% mortality versus 4% mortality among all others; P < 0.001). The data demonstrate that dependency on RRT in the first week after orthotopic liver transplantation stems almost entirely from preoperative renal dysfunction.