Microbiota-immune-brain interactions: A new vision in the understanding of periodontal health and disease.

This review highlights the significance of interactions between the microbiota, immune system, nervous and hormonal systems, and the brain on periodontal health and disease. Microorganisms in the microbiota, immune cells, and neurons communicate via homeostatic nervous and hormonal systems, regulating vital body functions. By modulating pro-inflammatory and anti-inflammatory adaptive immune responses, these systems control the composition and number of microorganisms in the microbiota.

A 4-year follow-up of non-freezing cold injury with cold allodynia and neuropathy in 26 naval soldiers.

Background and aims Non-freezing cold injuries (NFCI), which typically may occur in military personnel, may result from exposure to cold, at temperatures around 0 °C or above, and worsened by wind and moisture. The injury is due to cooling but not freezing of tissue like in frostbite. NFCI may result in in chronic neuropathy and cold hypersensitivity.

Soldier Health Habits and the Metabolically Optimized Brain.

Human performance enhancement was the subject of a NATO workshop that considered the direct benefits of individual soldier health and fitness habits to brain health and performance. Some of the important health and fitness include physical activity and purposeful exercise, nutritional intake, sleep and rest behaviors, psychological outlook and mindfulness, and other physiologically based systemic challenges such as thermal exposure. These influences were considered in an integrated framework with insights contributed by each of five participating NATO member countries using representative research to highlight relevant interrelationships.

Plasma Cytokine Profiles in Long-Term Strenuous Exercise.

The open window theory indicates altered immunity 3 to 72 hours after exercise. The J-curve describes the risk of illness in response to exercise. The aim of this study was to examine the secretion of proinflammatory and anti-inflammatory cytokines before and after long-term strenuous exercise.

Effects of long-term exposure of 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy") on neuronal transmitter transport, brain immuno-regulatory systems and progression of experimental periodontitis in rats.

The present study was designed to investigate the effects of long-term exposure (4 weeks) to the widely used narcotic drug and putative neurotoxicant 3,4-methylenedioxymetamphetamine (MDMA; "ecstasy") on neuronal transmitter transport and progression of experimental periodontitis in male Wistar rats. The rats were exposed to MDMA (10mg/kg/day i.p.

Effect of short- and long-term physical activities on circulating granin protein levels.

Background: The classic chromogranin-secretogranin (granin) proteins are produced in the myocardium and throughout the neuroendocrine system, but while chromogranin (Cg) A and B levels are high in the adrenal medulla, secretogranin (Sg) II production is higher in the pituitary gland. Whether these differences may influence the response to physical activity is not known.

Methods: We measured circulating granin proteins during (1) a short-term maximal bicycle exercise stress test and (2) a 7 day military ranger course of continuous physical activity and sleep and energy deprivation.

One week of multifactorial high-stress military ranger training affects Gram-negative signalling.

Background: Toll-like receptor 4 (TLR4), especially expressed on monocytes/macrophages, connects microbial and sterile innate immune activation. Lipopolysaccharide (LPS) from Gram-negative bacteria and several endogenous molecules, among others saturated fatty acids (SFAs), are able to induce signalling through this receptor. Downstream inflammatory cytokines orchestrate the immune response.

Moderate temperature alterations affect Gram-negative immune signalling in ex vivo whole blood.

Background: Alterations in body temperature may influence immune system function and consequently affect the risk of infection and inflammatory diseases. Lipopolysaccharide (LPS) from gram-negative bacteria induces production of inflammatory cytokines after ligand binding to Toll-like receptor 4 (TLR4) on immune cells (especially monocytes/ macrophages). Our aim was to explore how clinically relevant hypo- and hyperthermia affect this signalling in an ex vivo whole blood model, and investigate if the cytokine response was correlated with monocyte TLR4 expression level.

Systemic chemical desensitization of peptidergic sensory neurons with resiniferatoxin inhibits experimental periodontitis.

Background And Objective: The immune system is an important player in the pathophysiology of periodontitis. The brain controls immune responses via neural and hormonal pathways, and brain-neuro-endocrine dysregulation may be a central determinant for pathogenesis. Our current knowledge also emphasizes the central role of sensory nerves.

Calprotectin (S100A8/S100A9) and myeloperoxidase: co-regulators of formation of reactive oxygen species.

INFLAMMATORY MEDIATORS TRIGGER POLYMORPHONUCLEAR NEUTROPHILS (PMN) TO PRODUCE REACTIVE OXYGEN SPECIES (ROS: O(2) (-), H(2)O(2), ∙OH). Mediated by myeloperoxidase in PMN, HOCl is formed, detectable in a chemiluminescence (CL) assay. We have shown that the abundant cytosolic PMN protein calprotectin (S100A8/A9) similarly elicits CL in response to H(2)O(2) in a cell-free system.

LeuCAM and reactive oxygen species during long-term exercise combined with sleep and energy deficiency.

Introduction: During the Norwegian military ranger-training course, cadets are exposed to prolonged physical exercise combined with sleep-, energy-, and food deficiency. The open-window postexercise hypothesis indicates that after hard physical activity, there is an increased risk of contracting infectious diseases.

Purpose: The purpose of the present study was to determine leukocyte reactive oxygen species (ROS) levels, total antioxidant status (TAS), leukocyte expression of the cell adhesion molecules CD62L and CD11b, and plasma levels of soluble adhesion molecule L-selectin before, during, and in the recovery phase of a military ranger-training course.

Enhanced susceptibility to periodontitis in an animal model of depression: reversed by chronic treatment with the anti-depressant tianeptine.

Objective: To test the hypothesis that the olfactory bulbectomy model of depression in rats could influence susceptibility to ligature-induced periodontitis, and that chronic treatment with the anti-depressant drug tianeptine could attenuate this effect.

Material And Methods: Tianeptine was given twice daily (10 mg/kg, i.p.

Negative energy balance in male and female rangers: effects of 7 d of sustained exercise and food deprivation.

Background: A challenging 7-d ranger field exercise (FEX) by cadets in the Norwegian Military Academy provided a venue in which to study the effects of negative energy balance.

Objective: We quantified total energy expenditure (TEE), food intake, and changes in body composition in male and female cadets.

Design: TEE (measured by doubly labeled water), food intake, activity patterns (measured by accelerometry), and body composition (measured by dual-energy X-ray absorptiometry) were measured in 16 cadets (10 men and 6 women aged 21-27 y).

Seven days' around the clock exhaustive physical exertion combined with energy depletion and sleep deprivation primes circulating leukocytes.

Both exhaustive physical exertion and starvation have been reported to induce depression of immune function. The aim of the present study was to investigate the inflammatory environment and state of activation and mediator-producing potential of circulating leukocytes during prolonged physical activity with concomitant energy and sleep deprivation. Eight well-trained males were studied during 7 days of semi-continuous physical activity.

Neonatal dexamethasone and chronic tianeptine treatment inhibit ligature-induced periodontitis in adult rats.

Objective: The responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis has been found to play a significant role for susceptibility and resistance to periodontal disease. In the present study we have investigated the effects of two different treatment strategies, which have been found to down-regulate the HPA axis, on ligature-induced periodontitis.

Methods: In experiment 1, newborn rats were treated with the synthetic glucocorticoid hormone dexamethasone-21-phosphate, which permanently down-regulates HPA axis responsiveness.

[Brominated flame retardants may cause brain injuries in the fetus and the newborn].

Background: Brominated flame retardants are incorporated into an ever-increasing number of ordinary consumer goods, which has lead to pollution of the environment, wildlife, food of animal origin, and human blood, adipose tissue, and mother's milk. This group of chemicals has a striking structural similarity with the thyroid hormones and may constitute a potential health risk by interfering with thyroid hormone homeostasis.

Material And Methods: We focus on these features and discuss possible clinical consequences, on the basis of Medline searches and our own experience.

Chemical sympathectomy inhibits periodontal disease in Fischer 344 rats.

Objective: The responsiveness of the sympathetic nervous system (SNS) and the hypothalamic--pituitary--adrenal (HPA) axis plays a major role in immune regulation and for the outcome of infections and inflammatory disorders. This study was designed to investigate whether chemical SNS denervation with the noradrenaline-selective neurotoxic drug 6-hydroxydopamine (6-OHDA), which destroys peripheral noradrenaline terminals, would influence immune responses to Gram-negative bacterial lipopolysaccharide (LPS) stimulation, and the progression of ligature-induced periodontal disease in Fischer 344 rats.

Material And Methods: 6-OHDA (40--60 microg/kg) or vehicle was injected intraperitoneally (i.

Soluble beta-1,3/1,6-glucan from yeast inhibits experimental periodontal disease in Wistar rats.

Objective: We have investigated whether a purified immunomodulatory water soluble beta-1,3/1,6-glucan isolated from the cell wall of Bakers yeast, Saccharomyces cerevisiae, would influence the progression of ligature-induced periodontal disease, and to modulate accompanying cytokine and hypothalamic-pituitary-adrenal (HPA) axis responses to a lipopolysaccharide (LPS) challenge.

Material And Methods: beta-1,3/1,6-glucan (10 mg/kg/day) was given in the drinking water to Wistar rats during the entire experiment, starting 14 days before disease induction, while control rats were given tap water only. Periodontal disease was assessed when the ligatures had been in place for 35 days.

N-Acetylcysteine administered as part of the immediate post-traumatic resuscitation regimen does not significantly influence initiation of inflammatory responses or subsequent endotoxin hyporesponsiveness.

Polytrauma and resuscitative efforts induce extensive alterations in the host's internal environment and cellular responses that may be a serious threat to these patients. Administration of exogenous thiols has been recommended to modulate the post-traumatic inflammatory responses. In this study, we have investigated the effect of N-acetylcysteine (NAC) on the early markers of leukocyte activation and subsequent endotoxin hyporesponsiveness.

Chronic glycine treatment inhibits ligature-induced periodontal disease in Wistar rats.

Objective: Dysregulation of immune and stress responses plays a significant role for the development and progression of inflammatory diseases, including periodontal disease. The non-essential amino acid glycine modulates immune and central nervous system (CNS) responses, and has been shown to beneficially affect tissue destructive inflammatory conditions. The purpose of this study was to test the ability of orally administered glycine to influence periodontal disease progression, as well as immune and hypothalamic-pituitary-adrenal (HPA) responses following lipopolysaccharide stimulation.

Chronic treatment with the glutamate receptor antagonist MK-801 alters periodontal disease susceptibility.

Objective: Previous experiments in rats suggest that hypothalamic-pituitary-adrenal (HPA) axis over-responsiveness, which leads to increased secretion of immunoregulatory glucocorticoid hormones, increases periodontal disease susceptibility, whereas HPA axis under-responsiveness is associated with increased resistance to the disease. The present study was designed to investigate whether MK-801 (dizocilipine malate), an antagonist of the glutamate receptor N-methyl-D-aspartate (NMDA) in the brain, which has been found to play an important role in the regulation of the HPA axis, would influence the outcome of experimental ligature-induced periodontal disease in a rat model.

Methods: Experimental periodontal disease was induced in periodontal disease susceptible and HPA axis high-responding Fischer 344 rats 2 days before chronic treatment with MK-801(1 mg/kg intraperitoneally).

Effects of a 3-month endurance event on physical performance and body composition: the G2 trans-Greenland expedition.

Objective: Prolonged physical exertion with inadequate time for recuperation may result in an overtraining phenomenon characterized by reduced physical strength and endurance capacity. We tested the hypothesis that highly motivated men pushed to the limits of their endurance capacity for 3 months would suffer physical breakdown characterized by loss of lean mass and reduced physical performance capacity.

Methods: Two well-trained men (VO2max > 60 mL/kg/min), aged 25 years, completed an unsupported, 2928-km, south-to-north ski trek across Greenland in 86 days.

Rapid rewarming after mild hypothermia accentuates the inflammatory response after acute volume controlled haemorrhage in spontaneously breathing rats.

Accidental hypothermia is a common companion of trauma/haemorrhage, and several clinical studies have identified reduced body temperature as an independent risk predisposing to increased morbidity and mortality. Accordingly, the majority of trauma care guidelines prescribe early and aggressive rewarming of hypothermic patients. Enzyme reactions are generally downregulated at temperatures below 37 degrees C, including most of those responsible for the inflammatory response.

Effect of immune modulation on TT virus (TTV) and TTV-like-mini-virus (TLMV) viremia.

The present study was designed to investigate how two chronically replicating viruses, TT virus (TTV) and TTV-like mini virus (TLMV), interact with host defence systems. Successive serum samples from three groups of subjects, undergoing modifications of their antiviral defence, were tested by real-time PCR to measure changes in viral titers, and by sequence analyses to indicate whether increases in viremia could be attributed to infection with an unfamiliar strain: 1) in patients receiving immunosuppressants subsequent to kidney transplantation, viral titers tended to increase; 2) in soldiers undergoing extreme training known to cause immunosuppression, insignificant increases in titers were observed; and 3) interferon treatment of patients with hepatitis C virus caused a temporary decrease in TTV and TLMV titers. Increases in viremia were associated only occasionally with the appearance of novel strains.

Hydrocortisone and the mitogen-activated protein kinase inhibitor U0126 acutely suppress reactive oxygen species generation from circulating granulocytes after gunshot injuries in the pig.

Objective: Several external stimuli, including trauma, increase the endogenous production of reactive oxygen species that spontaneously attack vital biological molecules. In addition to their direct toxic effects, several secondary messenger systems are induced. To forestall a subsequent organ dysfunction, a short-term posttraumatic down-regulation of granulocyte function has been advocated.