ABSTRACT
BACKGROUND: Pneumococcal urinary antigen test is a valuable tool for diagnosing pneumococcal pneumonia and meningitis in adults. Its use in children is generally not accepted because of nonspecificity at this age. It is frequently positive in asymptomatic nasopharyngeal carriers. The aim of our study was to assess the age limit from which the test is no longer positive in asymptomatic healthy carriers. METHODS: A total of 197 children aged 36-83 months attending 9 day care centers in Prague were enrolled during February and March 2010. Nasopharyngeal swab specimens were collected from each participant and selectively cultivated. The presence of pneumococcal antigen in urine was detected by BinaxNOW® S. pneumoniae kit. RESULTS: Streptococcus pneumoniae was cultivated in 53.3 % of healthy children with the highest colonization rate (59.3 %) in children aged 48-59 months. The most frequently colonizing serotypes were: 19F, 23F, 3, 19A, 6B and 4. The presence of pneumococcal antigen in urine decreased with age from 39.0 % in 36-47 months to 17.9 % in 72-83 months old (p = 0.031). The antigen positivity was serotype-dependent and more frequent in nonvaccinated children. CONCLUSION: We demonstrated age-dependent linear decrease of pneumococcal antigen excretion into urine in healthy children. The positivity rate of the test in children aged 72-83 months was similar to that referred in healthy adults, irrespective of colonization. To confirm this age limit for use of this test in diagnostics of pneumococcal diseases, further study in school-age children is justified.
Subject(s)
Aging/immunology , Antigens, Bacterial/urine , Colony Count, Microbial/statistics & numerical data , Nasopharynx/immunology , Nasopharynx/microbiology , Streptococcus pneumoniae/immunology , Streptococcus pneumoniae/isolation & purification , Age Distribution , Child , Child, Preschool , Czech Republic/epidemiology , Female , Humans , Male , Reference Values , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
BACKGROUND: ß-Glucans are well-established immunomodulators. Recently, glucans have been found to influence stress-related immunosuppression. AIM: The aim of this study was to compare the effects of four different types of ß-glucans on immune reactions suppressed by cold- or restrain-induced stress. METHODS: Mice were subjected to restraint and cold stress for various time intervals. The ability of individual glucans to overcome stress-related changes was evaluated after 14 days of feeding. RESULTS: First, we showed that cold stress caused 38% decrease in phagocytic activity. While all glucans showed some ability to inhibit stress-related inhibition, only glucan #300 was able to return the phagocytosis to a normal level. In the control group, feeding with glucans did not alter the level of corticosterone. On the other hand, both types of stress resulted in a significant increase in corticosterone which was blocked to some extent by feeding with glucan. Both types of stress reduced IL-6 secretion but only glucan #300 managed to keep IL-6 secretion above control levels. The same results were obtained in the case of IL-12. CONCLUSION: From our data, we can conclude that, even when all orally-administered glucans helped to restore the stress-related decrease in immune reaction, the level of activity varied widely among individual glucans. In addition, the results suggest that glucans might work via inhibition of corticosterone levels and/or stimulation of cytokine production.
Subject(s)
Immune Tolerance/drug effects , Immunologic Factors/administration & dosage , Stress, Physiological/immunology , beta-Glucans/administration & dosage , Administration, Oral , Animals , Cold Temperature , Corticosterone/blood , Cytokines/biosynthesis , Female , Immunologic Factors/pharmacology , Mice , Mice, Inbred BALB C , Restraint, Physical , beta-Glucans/pharmacologyABSTRACT
BACKGROUND: Recent data showing that glucan elicited defense responses in grapevine and induced protection via induction of resveratrol production led us to evaluate the possible synergetic effects of glucan and resveratrol complex on immune reactions. METHODS: We measured phagocytosis using HEMA particles, expression of cell surface markers via fl ow cytometry, expression of cytokines using ELISA, recovery after fluorouracil-induced leucopenia and effects on gene expression via RT-PCR. RESULTS: Our results showed that both glucan and resveratrol complex stimulated phagocytosis of blood leukocytes, caused increase in surface expression of CD(+) splenocytes and showed higher restoration of spleen recovery after experimentally induced leucopenia. In all these cases, strong synergetic effects were observed. When we measured the effects of these substances on expression level of NF-kappaB2, Cdc42 and Bcl-2 in breast cancer cells, upregulation of Cdc42 expression was evident only using both immunomodulators in combination. CONCLUSIONS: In conclusion, our data suggest significant synergy in stimulation of immune reactions and support further studies of these natural immunomodulators.
