Gingival crevicular fluid levels of interferon-γ, but not interleukin-4 or -33 or thymic stromal lymphopoietin, are increased in inflamed sites in patients with periodontal disease.

OBJECTIVE: To investigate the hypothesis that levels of interferon (IFN)-γ and interleukin (IL)-4, as well as the newer cytokines IL-33 and thymic stromal lymphopoietin (TSLP), in gingival crevicular fluid (GCF) samples differ from sites of patients at various clinical stages of periodontal disease and controls. BACKGROUND: Periodontal diseases result from the complex interplay between pathogenic bacteria and the host's immune responses. Several inflammatory mediators, such as IFN-γ and IL-4, have been detected in GCF samples in patients with periodontitis, but the results are mostly contradicting due to the lack of uniformity and collection of sites and methods of analysis. MATERIAL AND METHODS: GCF samples were collected from sites with different clinical characteristics (healthy, gingivitis and periodontitis sites) from periodontally healthy ( n = 14), plaque-induced gingivitis (n = 17) and chronic periodontitis (n = 11) subjects. The GCF samples were analyzed for the frequency of detection and levels of IFN-γ, IL-4, IL-33 and TSLP using a multiplex bead immunoassay. RESULTS: Inflamed sites in both patients with plaque-induced gingivitis and chronic periodontitis showed statistically significantly higher volume of GCF compared to non-inflamed sites in all patients. IFN-γ could be detected in about 50-70% of the samples analyzed and at significantly higher levels in sites with periodontitis compared to healthy sites in patients with chronic periodontitis (p = 0.035). We also show a statistically significant decrease of IFN-? in healthy sites of patients with chronic periodontitis as compared to gingivitis sites in patients with plaque-induced gingivitis (p = 0.047). Only some of the GCF samples showed detectable levels for IL-4 and TSLP, while IL-33 was below the detection level in all samples collected. CONCLUSIONS: These results suggest that IFN-γ levels in GCF depend on the clinical stage of the site and not on the disease stage of the patient, but need to be expanded to a greater number of subjects and additional analysis of corresponding gingival tissue biopsies for cytokine gene expression.

New trends in computational modeling: a Neuroid-based retina model.

It is thought that using detailed neuron-models could lead to a better understanding of how the nervous system works. However, neural networks preserve their collective computational properties, regardless of the level of description used for modeling the main building block. In this paper, we built a Neuroid-based retina model. As a result of the implementation, the Neuroid was able to reproduce the essential features of the photoreceptor response to light. Likewise, the retina model responded to specific visual effects such as simultaneous contrast, Mach bands and Hermann grid. All of these suggest that the Neuroid comprises enough functional characteristics, such that we could focus not only on the most relevant computational aspects of nerve cells, but also in the collective capabilities of large-scale neural networks.

Development of a linear induction motor based artificial muscle system.

We present the design of a linear induction motor based on electromagnetic interactions. The engine is capable of producing a linear movement from electricity. The design consists of stators arranged in parallel, which produce a magnetic field sufficient to displace a plunger along its axial axis. Furthermore, the winding has a shell and cap of ferromagnetic material that amplifies the magnetic field. This produces a force along the length of the motor that is similar to that of skeletal muscle. In principle, the objective is to use the engine in the development of an artificial muscle system for prosthetic applications, but it could have multiple applications, not only in the medical field, but in other industries.

The Neuroid: A novel and simplified neuron-model.

In this paper we introduce a novel computational neuron-model, the Neuroid, which is based on three basic operations that are carried out by nerve cells to process the incoming information, such as comparison, and frequency pulse modulation-demodulation. The model was implemented using LabVIEW 10.0, in order to assign to each of these operations, an execution block (Virtual Instrument). The results of its implementation showed a very similar behavior to that exhibited by real neurons. Furthermore, due to its simplicity and low computational requirements, it is expected that the Neuroid can be used to create several software models of biological neural systems, either for research or teaching purposes.

Clinical and microbiological changes associated with the use of combined antimicrobial therapies to treat "refractory" periodontitis.

BACKGROUND: The present investigation examined clinical and microbial changes after a combined aggressive antimicrobial therapy in subjects identified as "refractory" to conventional periodontal therapy. METHOD: Fourteen subjects were identified as "refractory" based on full-mouth mean attachment loss and/or >3 sites with attachment loss > or =3 mm following scaling and root planing (SRP), periodontal surgery and systemic antibiotics. After baseline monitoring, subjects received SRP, locally delivered tetracycline at pockets > or =4 mm, systemically administered amoxicillin (500 mg, t.i.d. for 14 days)+metronidazole (250 mg, t.i.d. for 14 days) and professional removal of supragingival plaque weekly for 3 months. Subjects were monitored clinically every 3 months post-therapy for 2 years. Subgingival plaque samples were taken at the same time points from the mesial aspect of each tooth and the levels of 40 subgingival taxa were determined using checkerboard DNA-DNA hybridization. Mean levels of each species were averaged within a subject at each visit. Significance of changes in clinical and microbiological parameters over time were evaluated using the Friedman or Wilcoxon signed ranks test. RESULTS: On average, subjects showed significant improvements in all clinical parameters after therapy. Mean (+/-SEM) full-mouth pocket depth reduction was 0.83+/-0.13 mm and mean attachment level "gain" was 0.44+/-0.12 at 24 months. Clinical improvement was accompanied by major reductions in multiple subgingival species during the first 3 months of active therapy that were maintained for most species to the last monitoring visit. Reductions occurred for three Actinomyces species, "orange complex" species including Campylobacter showae, Eubacterium nodatum, three Fusobacterium nucleatum subspecies, Peptostreptococcus micros, Prevotella intermedia as well as the "Streptococcus milleri" group, Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedus. Subjects differed in their response to therapy; six modest response subjects exhibited less attachment level gain and were characterized by reductions in the microbiota from baseline to 3 months, but re-growth of many species thereafter. CONCLUSIONS: The combined antibacterial therapy was successful in controlling disease progression in 14 "refractory" periodontitis subjects for 2 years.

Controlling the plaque biofilm.

AIM: To examine the effect of supragingival plaque removal in conjunction with different periodontal therapies on subgingival plaque composition in different subject populations. METHOD: Four different studies are presented which examined the effect of repeated removal of supragingival plaque performed by professionals or by tooth brushing on subgingival plaque composition. The studies were performed in different populations including chronic periodontitis, periodontal maintenance and refractory subjects. For all studies, each subject was examined for clinical parameters at up to 168 sites and subgingival plaque samples were taken from the mesial aspect of each tooth and examined for their content of specific bacterial species using checkerboard DNA-DNA hybridisation techniques. RESULTS: Repeated supragingival plaque removal used in conjunction with scaling and root planing only or combined with other periodontal therapies resulted in improvements in clinical parameters as well as significant decreases in the counts of subgingival species, including those associated with periodontal disease aetiology. Meticulous tooth brushing provided similar clinical and microbial improvements. CONCLUSIONS: Meticulous removal of supragingival plaque has beneficial effects on clinical parameters of periodontal disease and on the nature of the microbiota that colonises both above and below the gingival margin and appropriately has been a major focus in the prevention and control of dental diseases, particularly periodontal disease.

[Serum concentration of calcium and calcitonin in hyperthyroidism caused by Graves' disease]. / Concentraciones séricas de calcio y calcitonina en hipertiroidismo por enfermedad de Graves.

Serum calcium and calcitonin were determined in 13 patients (12 women and 1 man), ages ranging from 30 to 40 years, with clinical diagnosis of hyperthyroidism due to Graves' Disease, confirmed by serum determinations of T3 and T4, with the purpose of establishing the relationship that these two substances may have in this pathology. The results obtained showed a decrease in seric calcium concentration in relation to a control group (10.02 +/-) 0.48 vs 11.49 +/- 0.28 mg/dl; p less than 0.005) and an increase in calcitonin concentration (193.6 +/- 8.62 vs 116.7 +/- 7.61 pg/ml; p less than 0.0001). We also found a significative negative association (r = -0.69; p less than 0.01) between these two compounds in the group of patients with hyperthyroidism, not being found in the control group.

Comparative clinical evaluation of imipenem/cilastatin vs. cefotaxime in treatment of severe bacterial infections.

Adult patients with severe bacterial infections caused by organisms susceptible to imipenem and cefotaxime were given either imipenem/cilastatin sodium (MK0787/MK0791) or cefotaxime as a part of a multiclinic randomized study to evaluate the effectiveness, safety, and tolerability of imipenem/cilastatin. Clinical diagnoses included bacteremia, urinary tract infection, osteomyelitis, mediastinitis, lower respiratory tract infection, and soft tissue infection. Efficacy was evaluated for 10 patients given imipenem/cilastatin and for 10 patients given cefotaxime. Major pathogens isolated included Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella species, Streptococcus pneumoniae, Bacteroides fragilis, and Peptostreptococcus species. Satisfactory clinical responses were noted in 90% of the patients in both treatment groups. Eradication of the pathogen was achieved in nine of 10 patients treated with imipenem/cilastatin and in 10 of 10 patients treated with cefotaxime. No major adverse effects were found in patients in each treatment group. The results of this study suggest that imipenem/cilastatin sodium is a relatively safe and effective antibiotic for the treatment of adult patients with severe infections caused by susceptible organisms.