Sodium Bicarbonate versus Sodium Chloride and Oral N‐Acetylcysteine for the Prevention of Contrast‐Induced Nephropathy in Advanced Chronic Kidney Disease

Introduction: Contrast‐induced acute kidney injury (CI‐AKI) is one of the leading causes of hospital‐acquired acute kidney injury. Multiple clinical studies have proposed several preventive strategies. Aims: To examine the efficacy of sodium bicarbonate compared with sodium chloride and oral N‐acetylcysteine (NAC) for preventive hydration after cardiac catheterization. Methods: We conducted a prospective, single‐center trial. Patients with chronic kidney disease (CKD) stage III–IV undergoing cardiac catheterization were allocated to receive either an infusion of 0.9% sodium chloride and oral NAC or 154 mEq/L sodium bicarbonate. Main: Outcome measure CI‐AKI, defined as an increase of 25% or 0.3 mg/dL or more in plasma creatinine within 2 days of contrast administration. Results: Ninety‐three patients were allocated to one of the two groups: 42 patients in the saline plus NAC group and 51 patients in the bicarbonate group. There were no statistically significant differences between the groups in the most important clinical and procedural characteristics. Baseline plasma creatinine levels, estimated glomerular filtration rate, incidence of diabetes mellitus, hypertension, congestive heart failure, and contrast medium volume were similar. Mean plasma creatinine concentration was 1.76 ± 0.54 mg/dL in the saline and NAC group and 1.9 ± 1 mg/dL in the bicarbonate group (P = 0.23). The rate of CI‐AKI was 9.8% in the bicarbonate group and 8.4% in the saline plus NAC group. No patient required renal replacement therapy. Conclusion: Hydration with sodium bicarbonate is not more effective than hydration with sodium chloride and oral NAC for prophylaxis of CI‐AKI in patients with CKD stage III–IV undergoing cardiac catheterization.     

M. tuberculosis-Complex Specific T-Cell Stimulation and DTH Reactions Induced With a Peptide from the 38-kDa Protein

An immunodominant T-cell-stimulatory epitope located near the carboxy terminus of the 38-kDa antigen from M. tuberculosis (38.G, residues 350-369) was found to be M. tuberculosis-complex specific. This was demonstrated by the presence of proliferative and delayed type hypersensitivity (DTH) responses in mice immunized with Mycobacterium tuberculosis and Mycobacterium bovis BCG, whereas mice immunized with M. avium or other non-tuberculous species of mycobacteria showed no such responses. Peptide 38.G stimulated the proliferation of peripheral blood lymphocytes from healthy purified protein derivative (PPD)-positive individuals but not from PPD-negative individuals. It also elicited DTH responses in M. tuberculosis sensitized mice and in PPD-positive healthy human volunteers. Peptide 38.G could therefore prove to be an important component in any new molecularly defined reagent used in the immunodiagnosis of tuberculous infection.     

Immune response and in vivo production of cytokines in patients with liver hydatidosis

Cytokines play an important role in the human immunological response, but the exact role of cytokines in the human immune response against parasites, especially against Echinococcus granulosus, remains unclear. IL-1, IL-2, IL-4 and tumour necrosis factor (TNF) levels in peripheral blood of 21 patients with liver hydatidosis were evaluated before surgical treatment, and the levels of IgA, IgM, IgG, IgE, specific IgE against E. granulosus, C3, C4 and BF complement fractions and CD20, CD3, CD4, CD8 and CD16 cell percentages were also determined, as was the relationship between these variables and cytokine levels. Data from hydatid patients were compared with data obtained from 21 healthy volunteers. Hydatid patients showed increases of IgG, IgE, IgEs and IL-2 (P< 0.01), and decreases of IL-1 and TNF levels (P< 0.001), but these variables (respectively) increased in patients showing cysts in the central area of the liver or with a wide opening of cysts in the biliary tract. The increase of IL-1, IL-2 and IL-4 showed a close relationship with the number, characteristics and above all the location of cysts within the liver itself. IgG and IL-4 levels and also IgG and IgE levels showed a significant correlation (P< 0.05).     

Relaxation by Calcium Antagonists of Potassium-contracted Trachea from Normal and Sensitized Guinea-pigs: Influence of Epithelium and the Surface of Drug Entry

Abstract— A technique by which drug access was restricted to either the mucosal or the adventitial surface of tracheal rings, isolated from normal (unsensitized) or sensitized guinea-pigs, was used to study the role of the epithelium in the relaxation produced by calcium antagonists (verapamil, nifedipine, cinnarizine and flunarizine) of K⁺-induced contraction. In trachea from normal guinea-pigs, the relaxation to verapamil for unrestricted or mucosal drug entry was reduced in the absence of epithelium, whereas the relaxation produced by nifedipine, cinnarizine or flunarizine was unchanged. In sensitized trachea, the relaxation elicited by the calcium antagonists tested was similar in intact and epithelium-denuded tracheal rings irrespective of the surface of drug entry. These results confirm that the epithelium influences the relaxation to verapamil. This modulatory effect is absent in sensitized trachea and is not shared by other calcium antagonists.