Increased phagocytic capacity of the blood,but decreased phagocytic activity per individual circulating neutrophil after an ultradistance run

The effect of a long strenuous endurance exercise on the phagocytic function of neutrophils was examined. 9 athletes [7 males, 2 females, age: 36–68 years, body mass: 64 (SD 10) kg, height: 175 (SD 10) cm] completed a competetive 100 km run in 8:07 (median value; range: 7:29–9:50 hours). In a whole blood assay the phagocytosis of opsonized E. coli, the receptor density of the Fc receptor 3 (CD16) and the complement receptor 3 (CD11b, direct immunofluorescence) of neutrophils were measured on a per cell basis by flow cytometry before and up to 3 hours after the race. The phagocytic rate (percentage of neutrophils incorporating bacteria) was unchanged after exercise, whereas the phagocytic activity (number of incorporated bacteria per cell) was significantly reduced by –34 (SD 8) % (Wilcoxon test, P<0.001). The total phagocytic capacity of the blood increased 2-3fold post exercise. The surface antigen expressions of CD11b and CD16 were unaffected by the ultradistance run. The results indicate either a reduced phagocytic function of neutrophils on a single cell basis or the mobilization of neutrophils of the marginal pool with a lower phagocytic activity. However, after a long endurance exercise the phagocytotic capacity of the blood was enhanced due to increased cell concentrations.     

Mutagenicity,antioxidant potential,and antimutagenic activity against hydrogen peroxide of cashew (Anacardium occidentale) apple juice and cajuina

Fresh and processed cashew (Anacardium occidentale) apple juice (CAJ) are among the most popular drinks in Brazil. Besides their nutritional benefits, these juices have antibacterial and antitumor potential. The chemical constituents of both the fresh juice and the processed juice (cajuina) were analyzed and characterized as complex mixtures containing high concentrations of vitamin C, various carotenoids, phenolic compounds, and metals. In the present study, these beverages exhibited direct and rat liver S9-mediated mutagenicity in the Salmonella/microsome assay with strains TA97a, TA98, and TA100, which detect frameshifts and base pair substitution. No mutagenicity was observed with strain TA102, which detects oxidative and alkylating mutagens and active forms of oxygen. Both CAJ and cajuina showed antioxidant activity as determined by a total radical-trapping potential assay. To test whether this antioxidant potential might result in antimutagenesis, we used a variation of the Salmonella/microsome assay that included pre-, co-, and posttreatment of hydrogen peroxide-exposed Salmonella typhimurium strain TA102 with the juices. CAJ and cajuina protected strain TA102 against mutation by oxidative damage in co- and posttreatments. The antimutagenic effects during cotreatment with hydrogen peroxide may be due to scavenging free radicals and complexing extracellular mutagenic compounds. The protective effects in posttreatment may be due to stimulation of repair and/or reversion of DNA damage. The results indicate that CAJ and cajuina have mutagenic, radical-trapping, antimutagenic, and comutagenic activity and that these properties can be related to the chemical constituents of the juices.     

Mobilization and oxidative burst of neutrophils are influenced by carbohydrate supplementation during prolonged cycling in humans

Prolonged, strenuous exercise may lead to suppressive effects on the immune system, which might be responsible for a greater susceptibility to opportunistic infections. The aim of this study was to examine the influence of carbohydrate substitution (CHS) during prolonged, strenuous exercise on neutrophil granulocytes and their oxidative burst (intracellular oxidation of dihydrorhodamine₁₂₃ to rhodamine₁₂₃ after induction by formylized 1-methionyl-1-leucyl-1-phenylalanin) using flow cytometry. In three trials different concentrations of CHS (placebo compared to 6% and 12% CHS; 50 ml·kg^–1) were given randomly to 14 endurance trained cyclists [mean (SD) age 25 (5) years, maximal oxygen uptake 67 (6) ml·min^–1·kg^–1] cycling for 4 h in a steady state at 70% of their individual anaerobic threshold. Blood samples were taken before, immediately after cessation, 1 h and 19 h after exercise. A significant rise in neutrophil counts was observed immediately after cessation and 1 h after exercise with a return to normal rest values 19 h after exercise for all three conditions (P<0.001). The relative proportions of rhodamine₁₂₃+ neutrophils were significantly diminished in all three conditions 1 h after exercise (P<0.01), while the mean fluorescence intensity was lowest in the placebo trial and differed significantly to the 12% CHS trial (P=0.024) and almost significantly to the 6% CHS trial (P=0.052). In conclusion, these data suggest a beneficial effect of CHS on the neutrophil oxidative burst and a possible attenuation of the susceptibility to infections, presumably due to the reduction of metabolic stress in prolonged, strenuous exercise. Electronic Publication     

Comparative pharmacokinetics of ciprofloxacin,ofloxacin and pefloxacin in human aqueous humour

Eighty-five patients undergoing cataract surgery were given for prophylaxis of intraocular infection two intravenous doses each of 200 mg, 300 mg or 400 mg ciprofloxacin (35 patients), 400 mg or 800 mg pefloxacin (30 patients), or 400 mg ofloxacin (20 patients). Ciprofloxacin levels in aqueous humour ranged from 0.02 to 0.50 µg/ml, pefloxacin levels from 1.04 to 7.80 µg/ml, and ofloxacin levels from 0.44 to 2.27 µg/ml with ratios of aqueous humour to serum levels ranging from 3.8 % to 25 %, 21 % to 48.1 % and 44 % to 88.4 %, respectively. It is concluded that the quinolones studied might be suitable for surgical prophylaxis or treatment of anterior chamber infections due toEnterobacteriaceae, while ciprofloxacin at high doses is preferable forPseudomonas aeruginosa infections.     

Polarized ion transport during migration of transformed Madin-Darby canine kidney cells

Epithelial cells lose their usual polarization during carcinogenesis. Although most malignant tumours are of epithelial origin little is known about ion channels in carcinoma cells. Previously, we observed that migration of transformed Madin-Darby canine kidney (MDCK-F) cells depended on oscillating K⁺ channel activity. In the present study we examined whether periodic K⁺ channel activity may cause changes of cell volume, and whether K⁺ channel activity is distributed in a uniform way in MDCK-F cells. After determining the average volume of MDCK-F cells (2013±270 m³; n=8) by means of atomic force microscopy we deduced volume changes by calculating the K⁺ efflux during bursts of K⁺ channel activity. Therefore, we measured the membrane conductance of MDCK-F cells which periodically rose by 22.3±2.5 nS from a resting level of 6.5±1.4 nS (n=12), and we measured the membrane potential which hyperpolarized in parallel from –35.4±1.2 mV to –71.6±1.8 mV (n=11). The distribution of K⁺ channel activity was assessed by locally superfusing the front or rear end of migrating MDCK-F cells with the K⁺ channel blocker charybdotoxin (CTX). Only exposure of the rear end to CTX inhibited migration providing evidence for horizontal polarization of K⁺ channel activity in transformed MDCK-F cells. This is in contrast to the vertical polarization in parent MDCK cells. We propose that the asymmetrical distribution of K⁺ channel activity is a prerequisite for migration of MDCK-F cells.     

Hormonal substitution during menopause: what are we treating?

OBJECTIVES: It is suggested that during menopausal transition, women with vasomotor symptoms benefit from HRT, (hormone replacement therapy) whereas, the use of HRT for other cognitive-vegetative symptoms is questionable. METHODS: The occurrence of menopausal complaints and depressive symptoms was assessed cross-sectionally in 5896 Dutch Caucasian women (47-54 years) of a large community sample in the city of Eindhoven, The Netherlands. Menopausal complaints were assessed using a 22 items self-rating scale (consisting of a vasomotor, uro-genital and a cognitive-vegetative subscale). Depressive symptoms were assessed using the Edinburgh depression scale (EDS). Differences in mean scores were analysed between groups using ANOVA. The independent relationship of depressive symptoms to the intensity of menopausal complaints was assessed, by multiple linear regression analysis. RESULTS: Women using HRT showed the highest scores on all subscales. Oral contraceptive users had significantly lower scores on the vasomotor subscale compared to HRT users and to non users. Depressive symptoms contributed the most, to the explained variance on scores on the menopausal subscales. CONCLUSIONS: Women during menopause presenting several complaints, other than vasomotor origin might be suffering from underlying depression which makes it questionable to prescribe HRT for the latter symptoms.     

Role of Intestinal Epithelial Cells in Immune Effects Mediated by Gram-Positive Probiotic Bacteria: Involvement of Toll-Like Receptors

The mechanisms by which probiotic bacteria exert their effects on the immune system are not completely understood, but the epithelium may be a crucial player in the orchestration of the effects induced. In a previous work, we observed that some orally administered strains of lactic acid bacteria (LAB) increased the number of immunoglobulin A (IgA)-producing cells in the small intestine without a concomitant increase in the CD4⁺ T-cell population, indicating that some LAB strains induce clonal expansion only of B cells triggered to produce IgA. The present work aimed to study the cytokines induced by the interaction of probiotic LAB with murine intestinal epithelial cells (IEC) in healthy animals. We focused our investigation mainly on the secretion of interleukin 6 (IL-6) necessary for the clonal expansion of B cells previously observed with probiotic bacteria. The role of Toll-like receptors (TLRs) in such interaction was also addressed. The cytokines released by primary cultures of IEC in animals fed with Lactobacillus casei CRL 431 or Lactobacillus helveticus R389 were determined. Cytokines were also determined in the supernatants of primary cultures of IEC of unfed animals challenged with different concentrations of viable or nonviable lactobacilli and Escherichia coli, previously blocked or not with anti-TLR2 and anti-TLR4. We concluded that the small intestine is the place where a major distinction would occur between probiotic LAB and pathogens. This distinction comprises the type of cytokines released and the magnitude of the response, cutting across the line that separates IL-6 necessary for B-cell differentiation, which was the case with probiotic lactobacilli, from inflammatory levels of IL-6 for pathogens.