Mechanical non-surgical treatment of peri-implantitis: a single-blinded randomized longitudinal clinical study. II. Microbiological results

BACKGROUND: Peri-implantitis is common in patients with dental implants. We performed a single-blinded longitudinal randomized study to assess the effects of mechanical debridement on the peri-implant microbiota in peri-implantitis lesions. MATERIALS AND METHODS: An expanded checkerboard DNA-DNA hybridization assay encompassing 79 different microorganisms was used to study bacterial counts before and during 6 months following mechanical treatment of peri-implantitis in 17 cases treated with curettes and 14 cases treated with an ultrasonic device. Statistics included non-parametric tests and GLM multivariate analysis with p<0001 indicating significance and 80% power. RESULTS: At selected implant test sites, the most prevalent bacteria were: Fusobacterium nucleatum sp., Staphylococci sp., Aggregatibacter actinomycetemcomitans, Helicobacter pylori, and Tannerella forsythia. 30 min. after treatment with curettes, A. actinomycetemcomitans (serotype a), Lactobacillus acidophilus, Streptococcus anginosus, and Veillonella parvula were found at lower counts (p<0.001). No such differences were found for implants treated with the ultrasonic device. Inconsistent changes occurred following the first week. No microbiological differences between baseline and 6-month samples were found for any species or between treatment study methods in peri-implantitis. CONCLUSIONS: Both methods failed to eliminate or reduce bacterial counts in peri-implantitis. No group differences were found in the ability to reduce the microbiota in peri-implantitis.

The impact of the stone age diet on gingival conditions in the absence of oral hygiene

BACKGROUND: The objective of this study was to assess the oral microbiota and clinical data in subjects without access to traditional oral hygiene methods and who ate a diet available in the Stone Age. METHODS: Ten subjects living in an environment replicating the Stone Age for 4 weeks were enrolled in this study. Bleeding on probing (BOP), gingival and plaque indices, and probing depth (PD) were assessed at baseline and at 4 weeks. Microbiologic samples were collected at the mesio-buccal subgingival aspects of all teeth and from the dorsum of the tongue and were processed by checkerboard DNA-DNA hybridization methods. RESULTS: No subject had periodontitis. Mean BOP decreased from 34.8% to 12.6% (P <0.001). Mean gingival index scores changed from 0.38 to 0.43 (not statistically significant) and mean plaque scores increased from 0.68 to 1.47 (P <0.001). PD at sites of subgingival sampling decreased (mean difference: 0.2 mm; P <0.001). At week 4, the total bacterial count was higher (P <0.001) for 24 of 74 species, including Bacteroides ureolyticus, Eikenella corrodens, Lactobacillus acidophilus, Capnocytophaga ochracea, Escherichia coli, Fusobacterium nucleatum naviforme, Haemophilus influenzae, Helicobacter pylori, Porphyromonas endodontalis, Staphylococcus aureus (two strains), Streptococcus agalactiae, Streptococcus anginosis, and Streptococcus mitis. Bacterial counts from tongue samples were higher at baseline (P <0.001) for 20 species, including Tannerella forsythia (previously T. forsythensis), Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans; serotype a), and Streptococcus spp. CONCLUSIONS: The experimental gingivitis protocol is not applicable if the diet (e.g., Stone Age) does not include refined sugars. Although plaque levels increased, BOP and PD decreased. Subgingival bacterial counts increased for several species not linked to periodontitis, whereas tongue bacterial samples decreased during the study period.

Cluster of Bacteria Associated with Peri-Implantitis.

BACKGROUND Information on the microbiota in peri-implantitis is limited. We hypothesized that neither gender nor a history of periodontitis/smoking or the microbiota at implants differ by implant status. MATERIALS AND METHODS Baseline microbiological samples collected at one implant in each of 166 participants with peri-implantitis and from 47 individuals with a healthy implant were collected and analyzed by DNA-DNA checkerboard hybridization (78 species). Clinical and radiographic data defined implant status. RESULTS Nineteen bacterial species were found at higher counts from implants with peri-implantitis including Aggregatibacter actinomycetemcomitans, Campylobacter gracilis, Campylobacter rectus, Campylobacter showae, Helicobacter pylori, Haemophilus influenzae, Porphyromonas gingivalis, Staphylococcus aureus, Staphylococcus anaerobius, Streptococcus intermedius, Streptococcus mitis, Tannerella forsythia, Treponema denticola, and Treponema socranskii (p < .001). Receiver operating characteristic curve analysis identified T. forsythia, P. gingivalis, T. socranskii, Staph. aureus, Staph. anaerobius, Strep. intermedius, and Strep. mitis in peri-implantitis comprising 30% of the total microbiota. When adjusted for gender (not significant [NS]), smoking status (NS), older age (p = .003), periodontitis history (p < .01), and T. forsythia (likelihood ratio 3.6, 95% confidence interval 1.4, 9.1, p = .007) were associated with peri-implantitis. CONCLUSION A cluster of bacteria including T. forsythia and Staph. aureus are associated with peri-implantitis.

Identification and analysis of a nickel-inducible cation diffusion facilitator-NiCoT combined system in Rhizobium leguminosarum bv. viciae

Nickel, like other transition metals, can be toxic to cells even at moderate concentration (low microM range) by displacing essential metals from their native binding sites or by generating reactive oxygen species that cause oxidative DNA damage. For this reason, cells have evolved mechanisms to deal with excess nickel. Efflux systems include members of the Resistance-Nodulation-cell Division (RND) protein family, P-type ATPases, cation diffusion facilitators (CDF) and other resistance factors. Nickel-specific exporters have been characterized in Cupravidus metallidurans, Helicobacter pylori, Achromobacter xylosoxidans, Serratia marcenses and Escherichia coli.

Diagnosis and management of nonvariceal upper gastrointestinal hemorrhage: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). It addresses the diagnosis and management of nonvariceal upper gastrointestinal hemorrhage (NVUGIH). Main Recommendations MR1. ESGE recommends immediate assessment of hemodynamic status in patients who present with acute upper gastrointestinal hemorrhage (UGIH), with prompt intravascular volume replacement initially using crystalloid fluids if hemodynamic instability exists (strong recommendation, moderate quality evidence). MR2. ESGE recommends a restrictive red blood cell transfusion strategy that aims for a target hemoglobin between 7 g/dL and 9 g/dL. A higher target hemoglobin should be considered in patients with significant co-morbidity (e. g., ischemic cardiovascular disease) (strong recommendation, moderate quality evidence). MR3. ESGE recommends the use of the Glasgow-Blatchford Score (GBS) for pre-endoscopy risk stratification. Outpatients determined to be at very low risk, based upon a GBS score of 0 - 1, do not require early endoscopy nor hospital admission. Discharged patients should be informed of the risk of recurrent bleeding and be advised to maintain contact with the discharging hospital (strong recommendation, moderate quality evidence). MR4. ESGE recommends initiating high dose intravenous proton pump inhibitors (PPI), intravenous bolus followed by continuous infusion (80 mg then 8 mg/hour), in patients presenting with acute UGIH awaiting upper endoscopy. However, PPI infusion should not delay the performance of early endoscopy (strong recommendation, high quality evidence). MR5. ESGE does not recommend the routine use of nasogastric or orogastric aspiration/lavage in patients presenting with acute UGIH (strong recommendation, moderate quality evidence). MR6. ESGE recommends intravenous erythromycin (single dose, 250 mg given 30 - 120 minutes prior to upper gastrointestinal [GI] endoscopy) in patients with clinically severe or ongoing active UGIH. In selected patients, pre-endoscopic infusion of erythromycin significantly improves endoscopic visualization, reduces the need for second-look endoscopy, decreases the number of units of blood transfused, and reduces duration of hospital stay (strong recommendation, high quality evidence). MR7. Following hemodynamic resuscitation, ESGE recommends early (≤ 24 hours) upper GI endoscopy. Very early (< 12 hours) upper GI endoscopy may be considered in patients with high risk clinical features, namely: hemodynamic instability (tachycardia, hypotension) that persists despite ongoing attempts at volume resuscitation; in-hospital bloody emesis/nasogastric aspirate; or contraindication to the interruption of anticoagulation (strong recommendation, moderate quality evidence). MR8. ESGE recommends that peptic ulcers with spurting or oozing bleeding (Forrest classification Ia and Ib, respectively) or with a nonbleeding visible vessel (Forrest classification IIa) receive endoscopic hemostasis because these lesions are at high risk for persistent bleeding or rebleeding (strong recommendation, high quality evidence). MR9. ESGE recommends that peptic ulcers with an adherent clot (Forrest classification IIb) be considered for endoscopic clot removal. Once the clot is removed, any identified underlying active bleeding (Forrest classification Ia or Ib) or nonbleeding visible vessel (Forrest classification IIa) should receive endoscopic hemostasis (weak recommendation, moderate quality evidence). MR10. In patients with peptic ulcers having a flat pigmented spot (Forrest classification IIc) or clean base (Forrest classification III), ESGE does not recommend endoscopic hemostasis as these stigmata present a low risk of recurrent bleeding. In selected clinical settings, these patients may be discharged to home on standard PPI therapy, e. g., oral PPI once-daily (strong recommendation, moderate quality evidence). MR11. ESGE recommends that epinephrine injection therapy not be used as endoscopic monotherapy. If used, it should be combined with a second endoscopic hemostasis modality (strong recommendation, high quality evidence). MR12. ESGE recommends PPI therapy for patients who receive endoscopic hemostasis and for patients with adherent clot not receiving endoscopic hemostasis. PPI therapy should be high dose and administered as an intravenous bolus followed by continuous infusion (80 mg then 8 mg/hour) for 72 hours post endoscopy (strong recommendation, high quality evidence). MR13. ESGE does not recommend routine second-look endoscopy as part of the management of nonvariceal upper gastrointestinal hemorrhage (NVUGIH). However, in patients with clinical evidence of rebleeding following successful initial endoscopic hemostasis, ESGE recommends repeat upper endoscopy with hemostasis if indicated. In the case of failure of this second attempt at hemostasis, transcatheter angiographic embolization (TAE) or surgery should be considered (strong recommendation, high quality evidence). MR14. In patients with NVUGIH secondary to peptic ulcer, ESGE recommends investigating for the presence of Helicobacter pylori in the acute setting with initiation of appropriate antibiotic therapy when H. pylori is detected. Re-testing for H. pylori should be performed in those patients with a negative test in the acute setting. Documentation of successful H. pylori eradication is recommended (strong recommendation, high quality evidence). MR15. In patients receiving low dose aspirin for secondary cardiovascular prophylaxis who develop peptic ulcer bleeding, ESGE recommends aspirin be resumed immediately following index endoscopy if the risk of rebleeding is low (e. g., FIIc, FIII). In patients with high risk peptic ulcer (FIa, FIb, FIIa, FIIb), early reintroduction of aspirin by day 3 after index endoscopy is recommended, provided that adequate hemostasis has been established (strong recommendation, moderate quality evidence).

Isolation and characterization of microorganisms with probiotic potential

Tese de mestrado em Microbiologia Aplicada, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2016

Active membrane transport and receptor proteins from bacteria

A general strategy for the expression of bacterial membrane transport and receptor genes in Escherichia coli is described. Expression is amplified so that the encoded proteins comprise 5-35% of E. coli inner membrane protein. Depending upon their topology, proteins are produced with RGSH6 or a Strep tag at the C-terminus. These enable purification in mg quantities for crystallization and NMR studies. Examples of one nutrient uptake and one multidrug extrusion protein from Helicobacter pylori are described. This strategy is successful for membrane proteins from H. pylori, E. coli, Enterococcus faecalis, Bacillus subtilis, Staphylococcus aureus, Microbacterium liquefaciens, Brucella abortus, Brucella melitensis, Campylobacter jejuni, Neisseria meningitides, Streptomyces coelicolor and Rhodobacter sphaeroides. ©2005 Biochemical Society.

Paracellular permeability is increased by basal lipopolysaccharide in a primary culture of colonic epithelial cells; an effect prevented by an activator of Toll-like receptor-2

Lipopolysaccharide (LPS), which generally activates Toll-like receptor 4 (TLR4), is expressed on commensal colonic bacteria. In a number of tissues, LPS can act directly on epithelial cells to increase paracellular permeability. Such an effect in the colon would have an important impact on the understanding of normal homeostasis and of pathology. Our aim was to use a novel primary culture of colonic epithelial cells grown on Transwells to investigate whether LPS, or Pam(3)CSK( 4), an activator of TLR2, affected paracellular permeability. Consequently, [(14)C]-mannitol transfer and transepithelial electrical resistance (TEER) were measured. The preparation consisted primarily of cytokeratin-18 positive epithelial cells that produced superoxide, stained for mucus with periodic acid-Schiff reagent, exhibited alkaline phosphatase activity and expressed TLR2 and TLR4. Tight junctions and desmosomes were visible by transmission electron microscopy. Basally, but not apically, applied LPS from Escherichia coli increased the permeability to mannitol and to a 10-kDa dextran, and reduced TEER. The LPS from Helicobacter pylori increased paracellular permeability of gastric cells when applied either apically or basally, in contrast to colon cells, where this LPS was active only from the basal aspect. A pan-caspase inhibitor prevented the increase in caspase activity caused by basal E. coli LPS, and reduced the effects of LPS on paracellular permeability. Synthetic Pam(3)CSK(4) in the basal compartment prevented all effects of basal E. coli LPS. In conclusion, LPS applied to the base of the colonic epithelial cells increased paracellular permeability by a mechanism involving caspase activation, suggesting a process by which perturbation of the gut barrier could be exacerbated. Moreover, activation of TLR2 ameliorated such effects.

Relação da doença periodontal com o cancro do pâncreas: diagnóstico do cancro do pâncreas com recurso a testes salivares

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Cáncer de vesícula biliar en Chile y factores nutricionales de riesgo

El cáncer de vesícula biliar es la neoplasia maligna más común en el tracto biliar. Chile presenta la tercera prevalencia más alta de cáncer de vesícula en el continente americano, siendo las mujeres chilenas de la ciudad de Valdivia las que presentan la prevalencia más alta. Los principales factores que se han asociado al cáncer de vesícula son: ser mujer, colelitiasis, obesidad, etnia, inflamación crónica, historia de enfermedades infecciones, como H. pylori y Salmonella e historia familiar de cáncer. En Chile la mortalidad por cáncer de vesícula es cercana al nivel de prevalencia. Esto se debe en parte a que el cáncer de vesícula es una enfermedad silenciosa y sin síntomas específicos en primeras instancias. Presentar obesidad y ser portador de agentes infecciosos, como Helicobacter pylori, son dos de los factores de riesgo más importantes para desarrollar cáncer de vesícula en Chile, ya que existe y una prevalencia de obesidad cercana al 30%. El objetivo de esta revisión literaria es informar y resumir los factores de riesgo de cáncer de vesícula prevalentes en Chile, para así enfocarse en la prevención y cuidado de estos, con el propósito de reducir la prevalencia de esta letal enfermedad.

Effect of Metronidazole on Halitosis of 2 to 10 Years Old Children

Background: Regarding the fact that halitosis has social and personal aspects which can lead to social embarrassment and consequently low self-esteem and self-confidence in subjects suffering from the problem, especially children, its proper treatment is an important issue. Objectives: The aim of this study was to evaluate the effect of metronidazole as a nonspecific antimicrobial agent in the treatment of halitosis in children. Materials and Methods: In this study, 2-10 years old children with oral halitosis were enrolled. Children without H. pylori infection and parasitic infection were randomized in two interventional and control groups. Metronidazole was given 5mg/kg/day for one week. Information regarding the demographic characteristics of studied population and halitosis (duration and time of day with more halitosis and its severity) before and after intervention was recorded using a questionnaire Results: 77 children with halitosis were studied in two interventional (40 children) and control (37 children) groups. There was no significant difference between two groups before intervention. After intervention, halitosis improvement rate - according to the reports of mothers of studied children - was higher significantly in intervention group (P < 0.05). Conclusions: The results support the effectiveness of metronidazole in the treatment of halitosis. Moreover, it supports recent findings regarding the participation of specific bacteria specially unculturable ones in the pathogenesis of the disease.

Estado del arte sobre estrés laboral entre los años 2005 y 2016

El propósito de este estudio es realizar un estado del arte sobre estrés laboral entre los años 2005 y 2016 utilizando artículos publicados en las bases de datos Ebsco, Apa-Psychnet, Proquest, Psycodoc, Pubmed, Redalyc y Scielo las cuales están abaladas por la Universidad del Rosario. Se hallaron en total 2674 artículos utilizando 6 palabras claves como criterios de búsqueda los cuales fueron Estrés Laboral, Estrés ocupacional, Estrés en el Trabajo, Job Stress, Work Stress y Occupational Stress. El instrumento de recolección de información fue una ficha bibliográfica modificada la cual permitió sistematizar los datos de los artículos encontrados en diferentes dimensiones para así poder utilizar los artículos encontrados como unidades de análisis para la investigación. El análisis de los artículos arrojó una diferencia significativa entre el volumen de publicaciones hechas en español versus las hechas en inglés tanto de artículos empíricos como teóricos. También se encontraron indicadores que permiten ver como el estudio del estrés laboral ha aumentado desde el año 2012 hasta la actualidad, siendo este el lapso en el cual el 59% de los artículos han sido arbitrados y subidos a las diferentes bases de datos.

Immunization of BALB/c mice with Helicobacter urease B induces a T helper 2 response absent in Helicobacter infection.

BACKGROUND & AIMS: Infection with Helicobacter induces a T helper type 1 response in mice and humans. Mice can be cured or protected from infection with Helicobacter by mucosal immunization with recombinant H. pylori urease B subunit (rUreB). This study characterizes the immune response of infected mice immunized with rUreB. METHODS: BALB/c mice were infected with H. felis. Two weeks later, they were orally immunized four times with rUreB and cholera toxin (CT) at weekly intervals. Controls were only infected or sham-immunized with CT. Animals were killed at various times after immunization. Splenic CD4(+) cells were obtained and cultured in vitro with rUreB to evaluate antigen-specific proliferation and induction of interferon gamma and interleukin 4 secretion. RESULTS: All rUreB-immunized mice (n = 8) were cured from infection 3 weeks after the fourth immunization. Immunization induced a proliferative response of splenic CD4(+) cells, a progressive decrease in interferon gamma secretion, and a concomitant increase in interleukin 4 secretion after each immunization. A simultaneous increase in rUreB specific serum immunoglobulin G1 levels was observed in infected/immunized mice. CONCLUSIONS: In BALB/c mice, therapeutic mucosal immunization with rUreB induces progressively a Th2 CD4(+) T cell response resulting in the elimination of the pathogen.

Reduction of Helicobacter infection in IL-10-/- mice is dependent on CD4+ T cells but not on mast cells.

BACKGROUND: In contrast to wild type, interleukin-10-deficient (IL-10(-/-)) mice are able to clear Helicobacter infection. In this study, we investigated the immune response of IL-10(-/-) mice leading to the reduction of Helicobacter infection. MATERIALS AND METHODS: We characterized the immune responses of Helicobacter felis-infected IL-10(-/-) mice by studying the systemic antibody and cellular responses toward Helicobacter. We investigated the role of CD4(+) T cells in the Helicobacter clearance by injecting H. felis-infected IL-10(-/-) mice with anti-CD4 depleting antibodies. To examine the role of mast cells in Helicobacter clearance, we constructed and infected mast cells and IL-10 double-deficient mice. RESULTS: Reduction of Helicobacter infection in IL-10(-/-) mice is associated with strong humoral (fivefold higher serum antiurease antibody titers were measured in IL-10(-/-) in comparison to wild-type mice, p < .008) and cellular (urease-stimulated splenic CD4(+) T cells isolated from infected IL-10(-/-) mice produce 150-fold more interferon-gamma in comparison to wild-type counterparts, p < .008) immune responses directed toward Helicobacter. Depletion of CD4(+) cells from Helicobacter-infected IL-10(-/-) mice lead to the loss of bacterial clearance (rapid urease tests are threefold higher in CD4(+) depleted IL-10(-/-) in comparison to nondepleted IL-10(-/-) mice, p < .02). Mast cell IL-10(-/-) double-deficient mice clear H. felis infection, indicating that mast cells are unnecessary for the bacterial eradication in IL-10(-/-) mice. CONCLUSION: Taken together, these results suggest that CD4(+) cells are required for Helicobacter clearance in IL-10(-/-) mice. This reduction of Helicobacter infection is, however, not dependent on the mast cell population.