Probiotics, immunity and exercise : a review

Nutritional practices that promote good health and optimal athletic performance are of interest to athletes, coaches, exercise scientists and dietitians. Probiotic supplements modulate the intestinal microbial flora and offer promise as a practical means of enhancing gut and immune function. The intestinal microbial flora consists of diverse bacterial species that inhabit the gastrointestinal tract. These bacteria are integral to the ontogeny and regulation of the immune system, protection of the body from injection, and maintenance of intestinal homeostasis. The interaction of the gut microbial flora with intestinal epithelial cells and immune cells exerts beneficial effects on the upper respiratory tract, skin and uro-genital tract. The capacity for probiotics to modulate perturbations in immune function after exercise highlight their potential for use in individuals exposed to high degrees of physical and environment stress. Future studies are required to address issues of dose-response in various exercise settings, the magnitude of species-specific effects, mechanisms of action and clinical outcomes in terms of health and performance.

Using the collaborative evidence based practice model : a systematic review and uptake of chlorhexidine-impregnated sponge dressings on central venous access devices in a tertiary cancer centre

Background: Greater research utilisation in cancer nursing practice is needed, in order to provide well-informed and effective nursing care to people affected by cancer. This paper aims to report on the implementation of evidence-based practice in a tertiary cancer centre. Methods: Using a case report design, this paper reports on the use of the Collaborative Model for Evidence Based Practice (CMEBP) in an Australian tertiary cancer centre. The clinical case is the uptake of routine application of chlorhexidine-impregnated sponge dressings for preventing centrally inserted catheter-related bloodstream infections. In this case report, a number of processes that resulted in a service-wide practice change are described. Results: This model was considered a feasible method for successful research utilisation. In this case report, chlorhexidine-impregnated sponge dressings were proposed and implemented in the tertiary cancer centre with an aim of reducing the incidence of centrally inserted catheter-related bloodstream infections and potentially improving patient health outcomes. Conclusion: The CMEBP is feasible and effective for implementing clinical evidence into cancer nursing practice. Cancer nurses and health administrators need to ensure a supportive infrastructure and environment for clinical inquiry and research utilisation exists, in order to enable successful implementation of evidence-based practice in their cancer centres.

Experimental observations of rapid maize streak virus evolution reveal a strand-specific nucleotide substitution bias

Background. Recent reports have indicated that single-stranded DNA (ssDNA) viruses in the taxonomic families Geminiviridae, Parvoviridae and Anellovirus may be evolving at rates of ∼10-4 substitutions per site per year (subs/site/year). These evolution rates are similar to those of RNA viruses and are surprisingly high given that ssDNA virus replication involves host DNA polymerases with fidelities approximately 10 000 times greater than those of error-prone viral RNA polymerases. Although high ssDNA virus evolution rates were first suggested in evolution experiments involving the geminivirus maize streak virus (MSV), the evolution rate of this virus has never been accurately measured. Also, questions regarding both the mechanistic basis and adaptive value of high geminivirus mutation rates remain unanswered. Results. We determined the short-term evolution rate of MSV using full genome analysis of virus populations initiated from cloned genomes. Three wild type viruses and three defective artificial chimaeric viruses were maintained in planta for up to five years and displayed evolution rates of between 7.4 × 10-4 and 7.9 × 10-4 subs/site/year. Conclusion. These MSV evolution rates are within the ranges observed for other ssDNA viruses and RNA viruses. Although no obvious evidence of positive selection was detected, the uneven distribution of mutations within the defective virus genomes suggests that some of the changes may have been adaptive. We also observed inter-strand nucleotide substitution imbalances that are consistent with a recent proposal that high mutation rates in geminiviruses (and possibly ssDNA viruses in general) may be due to mutagenic processes acting specifically on ssDNA molecules. © 2008 Walt et al; licensee BioMed Central Ltd.

More men than women make mucosal IgA antibodies to human papillomavirus type 16 (HPV-16) and HPV-18: A study of oral HPV and oral HPV antibodies in a normal healthy population

Background: We have previously shown the high prevalence of oral anti-human papillomavirus type 16 (HPV-16) antibodies in women with HPV-associated cervical neoplasia. It was postulated that the HPV antibodies were initiated after HPV antigenic stimulation at the cervix via the common mucosal immune system. The present study aimed to further evaluate the effectiveness of oral fluid testing for detecting the mucosal humoral response to HPV infection and to advance our limited understanding of the immune response to HPV. Methods: The prevalence of oral HPV infection and oral antibodies to HPV types 16, 18 and 11 was determined in a normal, healthy population of children, adolescents and adults, both male and female, attending a dental clinic. HPV types in buccal cells were determined by DNA sequencing. Oral fluid was collected from the gingival crevice of the mouth by the OraSure method. HPV-16, HPV-18 and HPV-11 antibodies in oral fluid were detected by virus-like particle-based enzyme-linked immunosorbent assay. As a reference group 44 women with cervical neoplasia were included in the study. Results: Oral HPV infection was h ighest in children (9/114, 7.9%), followed by adolescents (4/78, 5.1%), and lowest in normal adults (4/116, 3.5%). The predominant HPV type found was HPV-13 (7/22, 31.8%) followed by HPV-32 (5/22, 22.7%). The prevalence of oral antibodies to HPV-16, HPV-18 and HPV-11 was low in children and increased substantially in adolescents and normal adults. Oral HPV-16 IgA was significantly more prevalent in women with cervical neoplasia (30/44, 68.2%) than the women from the dental clinic (18/69, 26.1% P = 0.0001). Significantly more adult men than women displayed oral HPV-16 IgA (30/47 compared with 18/69, OR 5.0, 95% CI 2.09-12.1, P < 0.001) and HPV-18 IgA (17/47 compared with 13/69, OR 2.4, 95% CI 0.97-6.2, P = 0.04). Conclusion: The increased prevalence of oral HPV antibodies in adolescent individuals compared with children was attributed to the onset of sexual activity. The increased prevalence of oral anti-HPV IgA in men compared with women was noteworthy considering reportedly fewer men than women make serum antibodies, and warrants further investigation. © 2006 Marais et al; licensee BioMed Central Ltd.