Specific and nonspecific immune factors in dental plaque fluid and saliva from young and old populations.

Separate samples of supragingival dental plaque overtly free of blood were centrifuged to obtain the free fluid phase (plaque fluid). Bound protein was eluted from the plaque bacteria and matrix by washing the plaque with a low-pH buffer. The plaque fluid, low pH eluate, and whole saliva were assayed for immunoglobulins A, G, and M, the third component of complement, lysozyme, lactoferrin, and lactoperoxidase. Concentrations of total protein and albumin were also determined. Antibody reactive with specific plaque bacteria was detected by indirect immunofluorescent microscopy. Specific and nonspecific immune proteins were present in plaque fluid from adult subjects at significantly greater concentrations than in their saliva, which suggests that these proteins are concentrated in dental plaque. The results indicate that both saliva and gingival exudate contribute to the immunological proteins found in the free fluid phase of dental plaque. The observation that immunoglobulin A antibody reactive with plaque bacteria could be detected in plaque fluid suggests that a wide variety of immunological reactions may occur in the dental plaque. These potential interactions between host, plaque bacteria, and their products could serve to influence the plaque flora and its ability to induce disease.     

Participation of serum and membrane lectins on the oxidative burst regulation in Macrobrachium rosenbergii hemocytes

Using a spectrophotometric NBT reduction assay and phagocytosis, we identified that production of superoxide anions and phagocytic activity of hemocytes from Macrobrachium rosenbergii were significantly higher in the presence of rat, rabbit, and chicken erythrocytes than with human, pig, or horse erythrocytes. Hemocytes stimulated with MrL, MrLMab, or PMA increased 4.7, 5.1, and 6.1 fold, respectively, the oxidative response as compared to non-stimulated hemocytes. MrLMab together with MrL increased 5.7 fold the oxidative capacity of hemocytes as compared to non-stimulated cells. These effects were inhibited with 100 mM GalNAc, GlcNAc, or Neu5Ac and 0.2 microM of sialylated submaxillary gland mucin and fetuin. Piroxicam inhibited (P < 0.05) the production of O(2)(-) induced by MrL, whereas iodoacetamide inhibited the effect of MrLMAb (P < 0.05) in a dose-dependent manner. Our results suggest that MrLMab might activate the oxidative burst through the metabolism of glucose as opposed to MrL which utilizes NADPH-independent mechanisms, very probably through pro-inflammatory metabolites.     

Metabolic polymorphisms and the micronucleus frequency in buccal epithelium of adolescents living in an urban environment

Micronuclei and other biomarkers were evaluated in oral cells from 11- to 16-year-old girls living in a foster home in the central area of México City. Variables analyzed for possible association with these biomarkers include smoking habits, body mass index, metabolic polymorphisms for NAT1 and GSTM1 and whether the cells were obtained from the cheek or pharynx. The results indicated that individuals having the NAT1*10 homozygous genotype showed a significant increase in chromatin buds and binucleated cells. When the damage in the cheek was compared with damage in the pharynx, a significant increase in micronuclei and binucleated cells was found for the latter tissue in all the individuals analyzed.     

Using Bayesian networks in the construction of a bi-level multi-classifier. A case study using intensive care unit patients data

Combining the predictions of a set of classifiers has shown to be an effective way to create composite classifiers that are more accurate than any of the component classifiers. There are many methods for combining the predictions given by component classifiers. We introduce a new method that combine a number of component classifiers using a Bayesian network as a classifier system given the component classifiers predictions. Component classifiers are standard machine learning classification algorithms, and the Bayesian network structure is learned using a genetic algorithm that searches for the structure that maximises the classification accuracy given the predictions of the component classifiers. Experimental results have been obtained on a datafile of cases containing information about ICU patients at Canary Islands University Hospital. The accuracy obtained using the presented new approach statistically improve those obtained using standard machine learning methods.     

Impaired signal transduction in mitogen activated rat splenic lymphocytes during aging

Mitogen activated protein kinases (MAPK) are activated by a wide variety of signals leading to cell proliferation and differentiation in different cell types. With aging, there is a marked decrease in proliferation of T-lymphocytes in response to a variety of mitogens. Several age-related changes in the activation of MAPK pathways in T-lymphocytes activated via the T-cell receptor (TCR) have been described in different species. This way, some TCR proximal defects in tyrosine kinase activity have been delineated. In this study, we have used rat splenic lymphocytes to measure the effect of aging on the activation of two MAP kinase families: ERK and JNK. In order to bypass the receptor-proximal age-dependent defects previously described, we used phorbol ester (PMA) and Ca2+ ionophore (A23187) as co-mitogens. Our results demonstrate that splenic lymphocytes from old rats have a disturbance in the activation of the ERK and JNK MAPK signal transduction pathways, that are located downstream of the receptor-proximal events. At least part of the age-related defect leading to decreased ERK activity appears to be located upstream of ERK itself, since activation of MEK is also impaired. On the other hand, the observed defects in MAPK activation do result in decreased activation of downstream events, such as c-Jun phosphorylation. Thus, we conclude that aging of splenic lymphocytes results in a functional decline in signal transduction, and at least some of these defects are located downstream of the receptor-proximal events previously described by others. The impaired activity of these two MAP kinase pathways is likely to play a role in the diminished lymphoproliferation observed in old individuals.     

Assessment of bioequivalence after subcutaneous and intramuscular administration of urinary gonadotrophins

The objective was to demonstrate bioequivalence between s.c. and i.m. administration of Humegon (FSH/LH ratio 1:1) and Normegon (FSH/LH ratio 3:1). In two randomized, single-centre, cross-over studies, 18 healthy volunteers on each formulation were assigned to one of the two administration sequences. Subjects were given single doses of one of the above gonadotrophins after endogenous gonadotrophin production had first been suppressed using high-dose oral contraceptive. Subsequently, rate (Cmax, tmax) and extent (AUC) of absorption of follicle stimulating hormone (FSH) and luteinizing hormone (LH) were determined for 14 days. For Cmax and AUC, analysis of variance (ANOVA) was performed on log-transformed data and for tmax ANOVA was performed on ranks. Intramuscular and s.c. injections of Humegon were bioequivalent with respect to the main pharmacokinetic parameters, being AUC and Cmax of FSH absorption. Intramuscular and s.c. injections of Normegon were bioequivalent with respect to the AUC of FSH and not bioequivalent with respect to the Cmax of FSH. For tmax of FSH as well as for most LH variables of both preparations, bioequivalence could not be proven due to the high intra- and interindividual variability and/or concentrations being close to the detection limit. Thus, the main pharmacokinetic FSH variables after i.m. and s.c. administration of Humegon and Normegon were bioequivalent.