Reduction of serum antioxidative capacity during hemodialysis

Background Hemodialysis (HD) is thought to exacerbate oxidative stress (OS). The purpose of this study was to assess patients' oxidative status during and after HD, and to clarify the relation between oxidative status and antioxidant solutes such as uric acid (UA) and ascorbic acid (AsA). Methods Serum diacron-reactive oxygen metabolites (d-ROM), and biological antioxidant potential (BAP), as well as serum concentrations of UA, AsA, urea nitrogen (UN), and creatinine (Cre) were measured in eight HD patients at six time points during and after HD. Inflow and outflow dialyzer blood was evaluated during HD or sham HD (no dialysate flow). Further, BAP was evaluated by adding UA or AsA to post-HD serum. Results No changes were found in d-ROM over time, whereas BAP was significantly decreased by HD. No differences were found in d-ROM during HD or sham HD, or between inflow and outflow blood. During HD, significantly lower BAP levels were found in outflow blood than in inflow blood. Serum UA and AsA levels were decreased by HD; however, no increases were obserbed in BAP levels after the addition of these molecules to post-HD serum. Conclusion These data indicate that HD reduces serum antioxidative capacity, and the loss of dialyzable molecules may be involved. However, this reduction in capacity does not seem to be caused by the loss of UA or AsA.     

Alpha-oxoaldehydes in haemodialysis solution.

Sir, In patients on chronic dialysis treatment, factors that enhanceoxidative stress include the uraemic milieu, bio-incompatibilityof the dialysis apparatus, and loss of anti-oxidants throughdialysis. Furthermore, in peritoneal dialysis (PD) treatment,the PD solution per se has oxidative capacity due to the presenceof glucose-derived -oxoaldehydes, such as methylglyoxal (MG)and glyoxal (GO). Indeed, recent reports indicate that, in PDpatients,      

Case of rhabdomyolysis induced by the approved daily dose of a traditional Chinese medicine

We report a case of a 67-year-old woman with hypokalemic rhabdomyolysis induced by pseudohyperaldosteronism. The pseudohyperaldosteronism in this case was caused by the administration of a traditional Chinese medicine, which contained 2.0 g of licorice in the approved daily dose. She started to suffer from hypertension and general fatigue after taking the medication, but continued it for two years until admission after an episode of diarrhea and vomiting. On admission, severe hypokalemia (1.6 mEq/L) and increased serum creatinine kinase (8,778 IU/L) was noted. With the findings of a high transtubular potassium concentration gradient (TTKG) in spite of low plasma renin activity and a low plasma aldosterone concentration, we suspected licorice-induced pseudohyperaldosteronism as the cause of her hypokalemic rhabdomyolysis. The Chinese medicine was terminated, and she received appropriate hydration and potassium replacement therapy as judged by the value of TTKG with the result that her serum potassium and creatinine kinase levels were normalized without any more adverse events. Since it was only a low dose of licorice (2.0 g/day) that induced hypokalemic rhabdomyolysis in this case, serum electrolytes should be examined in all cases under the possible consumption of licorice.     

Pathophysiology of cardiorenal interaction

In the renal circulation, the afferent arterioles leading to juxtamedullary glomeruli are anatomically under high pressure load in order to reduce the high arterial pressure and keep the pressure of the following glomeruli at about 50 mmHg. Because of the pressure overload, it is possible that vascular injury begins in the afferent arterioles of juxtamedullary glomeruli. We call such high pressure-loaded vessels branching directly from relatively large vessels 'strain vessels'. Coronary arteries and penetrating cerebral arteries are also strain vessels. They are also susceptible to pressure-induced injury. This review presents a hypothesis that microalbuminuria reflects the early stage of vascular injury, especially strain vessels' injury, and that strain vessels' injury connects chronic kidney disease with the risk of cardiovascular disease.     

Evidence for differential regulation of lactate metabolic properties in aged and unloaded rat skeletal muscle

Skeletal muscles of elderly individuals show fatigue resistance and reduced lactate accumulation compared with those of young subjects during activities that recruit a small amount of muscle mass. To explore the mechanism underlying the functional changes in aged muscle, we focused on lactate metabolic properties, including monocarboxylate transporter (MCT) 1 and MCT4, in muscles from old and young control rats and hindlimb-suspended young rats. MCT1 expression was lower in soleus (SOL) of old rats than in SOL of young control rats, but was similar in young control and hindlimb-suspended rats. MCT4 expression was lower in extensor digitorum longus (EDL) of old rats than in that of young control rats, but did not differ between young control and hindlimb-suspended rats. The ratio of lactate dehydrogenase to citrate synthase activities was higher in SOL of hindlimb-suspended and old rats than in SOL of young control rats, and was lower in EDL of old rats than in those of young control and hindlimb-suspended rats. Our data suggest that aging causes metabolic changes that can reduce lactate accumulation during exercise and increase fatigue resistance in skeletal muscle, and that these changes result from aging rather than from inactivity.     

Angiographic index for angioplasty-treatable atheromatous renal artery stenosis

The relative reduction of the lumen diameter by an atheromatous lesion (% diameter reduction) is generally used as an angiographic index for atheromatous renal artery stenosis (ARAS), but its association with the clinical outcome of angioplasty has not been sufficiently evaluated. This study aimed to identify an angiographic index(ices) that can be used to identify angioplasty-treatable ARAS. We evaluated the clinical outcome of angioplasty in 27 patients who had unilateral ARAS without renal insufficiency by assessing the reduction in systemic arterial blood pressure (BP) after angioplasty and examined its association with various angiographic indices. In the receiver operating characteristic analysis for BP reduction, the area under the curve was larger for the absolute value of the lumen diameter at the narrowest part of its constriction (the narrowest diameter), an angiographic index introduced in this study, than for % diameter reduction (0.770 vs. 0.731). At a 3-mm maximum threshold, the narrowest diameter identified cases with BP reduction; the sensitivity/specificity was 0.89/0.75 (p < 0.001). Furthermore, the narrowest diameter correlated better than % diameter reduction with hemodynamic indices of ARAS. In conclusion, the narrowest diameter is an angiographic index that can effectively identify angioplasty-treatable ARAS in patients without renal insufficiency.     

Methylmercury inhibits type II 5'-deiodinase activity in NB41A3 neuroblastoma cells

Methylmercury (MeHg) is a well-known neurotoxicant and prenatal exposure to MeHg results in severe brain damage. Since MeHg has a high affinity for thiol groups, we sought to determine whether MeHg inhibited type II iodothyronine deiodinase (D2) activity, by which prohormone thyroxine (T4) is converted to active thyroid hormone, 3,5,3'-triiodothyronine (T3) in the brain, using NB41A3 mouse neuroblastoma cells. In MeHg-treated cells, D2 activity was inhibited in a dose- and time-dependent manner; relatively low concentrations of MeHg (30 nM) inhibited D2. Kinetic analysis using a double reciplocal plot of D2 activity revealed competitive inhibition by MeHg. DTT protected D2 from MeHg when cells were incubated with both MeHg and DTT or when MeHg was added to the assay buffer containing DTT and cell sonicates from untreated cells. Removal of MeHg from culture medium did not recover D2 activity. These results demonstrate that MeHg inhibited D2 activity in NB41A3 cells and the selenocysteine in the catalytic subunit of D2 may be involved in the inhibitory action of MeHg. Further our results suggest that T3 deficiency due to D2 inhibition in the brain may be involved in the neurotoxicity of MeHg.     

Efficacy of inactivated trivalent influenza vaccine in alleviating the febrile illness of culture-confirmed influenza in children in the 2000-2001 influenza season

During the 2000/2001 influenza season in Japan, children ranging in age from 6 months to 13 years with fever exceeding 37.5 degrees C were recruited. Vaccine efficacy was evaluated by comparing the rates of pre-seasonal vaccination between groups stratified by fever severity. Seven hundred and sixty one patients (33.1%), culture positive for influenza were enrolled for analysis. The numbers of patients for A/H1N1 and A/H3N2 were insufficient for statistical analysis. For influenza B the odds ratio for vaccinated children to have a maximum fever exceeding 39.5 degrees C was 0.52 (95% CI, 0.30-0.92) Our findings suggest modest impact of influenza vaccination on limiting severity of disease symptoms.     

Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2002 and March 2003

Tendency of isolated bacteria from infections in general surgery during the period from April 2002 to March 2003 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 334 strains were isolated from 131 (75.3%) of 174 patients with surgical infections. One hundred and seventy-one strains were isolated from primary infections, and 163 strains were isolated from post-operative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. Among aerobic Gram-positive bacteria, although the isolation rate of Staphylococcus aureus was the highest, followed by that of Enterococcus faecalis from primary infections, the isolation rate of E. faecalis was the highest from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, E. coli was the most predominantly isolated, followed by P. aeruginosa, Enterobacter cloacae, and Citobacter freundii. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. The isolation rate of aerobic Gram-negative bacteria from primary infections and that of aerobic Gram-positive bacteria from postoperative infections were high in the last several years. We noticed no vancomycin-resistant Gram-positive cocci nor P. aeruginosa producing metallo-beta-lactamase. But we noticed cefazolin-resistant E. coli probably producing extended spectrum beta-lactamase.