Seroprevalence of Toxoplasmosis and associated risk factors in pregnant women at the Protestant Hospital, Mbouo-Bandjoun, Cameroon

Background: Toxoplasmosis is a common worldwide infection caused by the protozoan Toxoplasma gondii. In Cameroon, several recent studies have reported high seroprevalence of this parasitosis in various hospitals (Douala, Limbe, Njinikom and Yaoundé). The aim of this study was to determine whether this high prevalence of toxoplasmosis might occur in other regions of the country.Methodology: Serological tests by the indirect Enzyme Linked Immunosorbent Assay (ELISA) for IgG and IgM were carried out on 200 pregnant women (36 HIV-positive and 164 HIV-negative) at the Protestant Hospital of Mbouo-Bandjoun in western Cameroon to determine the presence of Toxoplasma gondii infection and to identify the risk factors associated with seropositivity of the subjects.Results: The overall seroprevalence of anti-Toxoplasma antibodies was 45.5%. The prevalence rate was 80.5% in the HIV-positive group (47.2% IgG, 22.2% IgM and 11.1% IgG + IgM) and 37.8% in the HIV-negative group (25.6%, 9.7% and 2.4% respectively). Using a multivariate logistic regression analysis, the secondary level of educational, presence of HIV infection, and frequency of close contacts with cats were significantly associated with the prevalence of IgG and/or IgM antibodies.Conclusion: Compared with previous reports of human toxoplasmosis in Cameroon, the prevalence in our study showed a decrease in the disease occurrence. Further studies are needed to determine whether this decrease is localised to our study or a general phenomenon currently affecting the country.Keywords: Cameroon, IgG, IgM, pregnant women, seroprevalence, Toxoplasma gondi

Decoding the Components of Dynamics in Three-Domain Proteins

In this study we examine the feasibility and limitations of describing the motional behavior of three-domain proteins in which the domains are linearly connected. In addition to attempting a determination of both the internal and overall re-orientational correlation times, we investigate the existence of correlations in the motions between the three domains. Since in linearly arranged three-domain proteins there are typically no experimental data that can directly report on motional correlation between the first and third domain, we address this question by dynamics simulations. Two limiting cases occur: 1) for weak repulsive potentials and 2) when strong repulsive potentials are applied between sequential domains. The motions of the first and third domains become correlated in the case of strong inter-domain repulsive potentials when these potentials do not allow the angle between the sequential domains to be smaller than about 60°. Although various modeling approaches are available, we chose to use the model-free and extended model-free formalisms of Lipari and Szabo due to their widespread application in the study of protein dynamics. We find that the motional behavior can be separated into two components; the first component represents the concerted overall motion of the three domains, and the second describes the independent component of the motion of each individual domain. We find that this division of the motional behavior of the protein is maintained only when their timescales are distinct and can be made when the angles between sequential domains remain between 60° and 160°. In this work, we identify and quantify inter-domain motional correlations

HpARI protein secreted by a helminth parasite suppresses interleukin-33

Infection by helminth parasites is associated with amelioration of allergic reactivity, but mechanistic insights into this association are lacking. Products secreted by the mouse parasite Heligmosomoides polygyrus suppress type 2 (allergic) immune responses through interference in the interleukin-33 (IL-33) pathway. Here, we identified H. polygyrus Alarmin Release Inhibitor (HpARI), an IL-33-suppressive 26-kDa protein, containing three predicted complement control protein (CCP) modules. In vivo, recombinant HpARI abrogated IL-33, group 2 innate lymphoid cell (ILC2) and eosinophilic responses to Alternaria allergen administration, and diminished eosinophilic responses to Nippostrongylus brasiliensis, increasing parasite burden. HpARI bound directly to both mouse and human IL-33 (in the cytokine's activated state) and also to nuclear DNA via its N-terminal CCP module pair (CCP1/2), tethering active IL-33 within necrotic cells, preventing its release, and forestalling initiation of type 2 allergic responses. Thus, HpARI employs a novel molecular strategy to suppress type 2 immunity in both infection and allergy. Osbourn et al identified HpARI, a protein secreted by a helminth parasite that is capable of suppressing allergic responses. HpARI binds to IL-33 (a critical inducer of allergy) and nuclear DNA, preventing the release of IL-33 from necrotic epithelial cells

The role of the complement system in traumatic brain injury: a review

Traumatic brain injury (TBI) is an important cause of disability and mortality in the western world. While the initial injury sustained results in damage, it is the subsequent secondary cascade that is thought to be the significant determinant of subsequent outcomes. The changes associated with the secondary injury do not become irreversible until some time after the start of the cascade. This may present a window of opportunity for therapeutic interventions aiming to improve outcomes subsequent to TBI. A prominent contributor to the secondary injury is a multifaceted inflammatory reaction. The complement system plays a notable role in this inflammatory reaction; however, it has often been overlooked in the context of TBI secondary injury. The complement system has homeostatic functions in the uninjured central nervous system (CNS), playing a part in neurodevelopment as well as having protective functions in the fully developed CNS, including protection from infection and inflammation. In the context of CNS injury, it can have a number of deleterious effects, evidence for which primarily comes not only from animal models but also, to a lesser extent, from human post-mortem studies. In stark contrast to this, complement may also promote neurogenesis and plasticity subsequent to CNS injury. This review aims to explore the role of the complement system in TBI secondary injury, by examining evidence from both clinical and animal studies. We examine whether specific complement activation pathways play more prominent roles in TBI than others. We also explore the potential role of complement in post-TBI neuroprotection and CNS repair/regeneration. Finally, we highlight the therapeutic potential of targeting the complement system in the context of TBI and point out certain areas on which future research is needed

Virulence of Group A Streptococci Is Enhanced by Human Complement Inhibitors

Streptococcus pyogenes, also known as Group A Streptococcus (GAS), is an important human bacterial pathogen that can cause invasive infections. Once it colonizes its exclusively human host, GAS needs to surmount numerous innate immune defense mechanisms, including opsonization by complement and consequent phagocytosis. Several strains of GAS bind to human-specific complement inhibitors, C4b-binding protein (C4BP) and/or Factor H (FH), to curtail complement C3 (a critical opsonin) deposition. This results in diminished activation of phagocytes and clearance of GAS that may lead to the host being unable to limit the infection. Herein we describe the course of GAS infection in three human complement inhibitor transgenic (tg) mouse models that examined each inhibitor (human C4BP or FH) alone, or the two inhibitors together (C4BPxFH or 'double' tg). GAS infection with strains that bound C4BP and FH resulted in enhanced mortality in each of the three transgenic mouse models compared to infection in wild type mice. In addition, GAS manifested increased virulence in C4BPxFH mice: higher organism burdens and greater elevations of pro-inflammatory cytokines and they died earlier than single transgenic or wt controls. The effects of hu-C4BP and hu-FH were specific for GAS strains that bound these inhibitors because strains that did not bind the inhibitors showed reduced virulence in the 'double' tg mice compared to strains that did bind; mortality was also similar in wild-type and C4BPxFH mice infected by non-binding GAS. Our findings emphasize the importance of binding of complement inhibitors to GAS that results in impaired opsonization and phagocytic killing, which translates to enhanced virulence in a humanized whole animal model. This novel hu-C4BPxFH tg model may prove invaluable in studies of GAS pathogenesis and for developing vaccines and therapeutics that rely on human complement activation for efficacy

Morphological and structural characteristics of orthodontic mini-implants [Morphologische und strukturelle Merkmale kieferorthopädischer Mini-Implantate]

Aim. The purpose of this study was to investigate the geometric characteristics, composition, microstructure, and pullout strength of commercially available orthodontic mini-implants. Material and methods. The mini-implants used were AbsoAnchor®, Dual-Top™ JA, Spider Screws® K1, and Vector-TAS™. The geometric features were measured by optical microscopy. Surface texture and elemental composition were examined by scanning electron microscopy and energy dispersive X-ray microanalysis. Surface 3D roughness was estimated by optical profilometry, and pullout strength measured in artificial bone blocks with two bone densities. Results. The AbsoAnchor® showed the highest intra-osseous surface area, followed by the Dual-Top™, Spider Screw®, and Vector-TAS™. The mini-implants were composed of a Ti6Al4V alloy. The Vector-TAS™ had the highest oxygen and phosphorus content with the most homogeneous surface texture. No significant differences were detected in amplitude surface roughness parameters (Sa, Sz) between the implants. However, differences existed in hybrid (Sdr, Sds) and functional (Sci) parameters. AbsoAnchor® achieved the highest pullout strength, followed by the Dual- Top™, Spider Screw®, and Vector-TAS™, with highest values in the high density group. The intra-osseous surface area of mini-implants showed a positive correlation with pullout strength, especially in the high density group. Conclusion. All the mini-implants tested were made of Ti6Al4V alloy. Significant differences were found in the surface area of the threaded parts. The significant differences documented in 3D surface roughness parameters (hybrid and functional) and pullout strength may anticipate variations in their clinical performance. © Springer-Verlag

Satisfaction with orthodontic care provided in a university orthodontic clinic

Objective: To evaluate patients’ satisfaction with their orthodontic care at the Department of Orthodontics of University of Athens. Materials and Methods: The study sample comprised of 100 individuals whose orthodontic treatment had been completed during the period May to October 2010. A questionnaire was designed and piloted before the telephone interviews were carried out. Questions concerned socio-demographic characteristics, reason for seeking care at the Dental School, level of satisfaction with treatment outcome, fees paid for treatment, and various aspects of organisation of care provision, assessed on 1-very dissatisfied to 5-very satisfied Likert type items. Results: Satisfaction score was particularly high as far as treatment outcome (53% were “very satisfied” and 31% were “satisfied”), dentist’s response to an emergency (81% were “very satisfied”), and personnel’s behavior at initial examination (81% were “very satisfied”) were concerned. Factors appearing to require improvement were the waiting time from initial examination to the beginning of treatment, the waiting room and the duration of treatment. Overall satisfaction was found to be significantly associated with total duration of treatment, fees paid by patients, treatment outcome, the behaviour of personnel who conducted first clinical examination, and dentist’s response to an emergency. Overall satisfaction was confirmed as the vast majority of patients (97%) would recommend the Orthodontic Clinic. Conclusion: While the Orthodontics Clinic enjoys overall highly satisfied patients, there is scope for improvement of organizational aspects of care provision like the waiting time between the initial examination and the beginning of treatment, the waiting room and the duration of treatment. © 2019 Ioannis et al

Corrigendum: Satisfaction with orthodontic care provided in a university orthodontic clinic (The Open Dentistry Journal, (2019), 13, (67-75), 10.2174/1874210601913010067)

The correct list of authors' names is provided and replaced online which is mentioned as under: Ioannis Lyros1,*, Elpida Pavi2, Apostolos I. Tsolakis1, Margarita Makou1, John Kyriopoulos2 The published list of authors was: Ioannis Lyros1,*, Pavi Elpida2, Apostolos I. Tsolakis1, Makou Margarita1, Kyriopoulos John1. © 2019 Lyros et al

Adhesion of porphyromonas gingivalis and biofilm formation on different types of orthodontic brackets

Objectives. To examine the interaction between Porphyromonas gingivalis and 3 different orthodontic brackets in vitro, focusing on the effect of an early salivary pellicle and other bacteria on the formation of biofilms. Material and Methods. Mono- and multi-species P. gingivalis biofilms were allowed to form in vitro, on 3 different bracket types (stainless steel, ceramic and plastic) with and without an early salivary pellicle. The brackets were anaerobically incubated for 3 days in Brain Heart Infusion Broth to form biofilms. Bacteria were quantified by trypsin treatment and enumeration of the total viable counts of bacteria recovered. Results. Saliva was found to significantly affect (P<0.001) adhesion and biofilm formation of P. gingivalis, with higher numbers for the coated brackets. No significant effect was detected for the impact of the type of biofilm, although on stainless steel and plastic brackets there was a tendency for higher numbers of the pathogen in multi-species biofilms. Bracket material alone was not found to affect the number of bacteria. Conclusions. The salivary pellicle seems to facilitate the adhesion of P. gingivalis and biofilm formation on orthodontic brackets, while the material comprising the brackets does not significantly impact on the number of bacteria. © 2012 William Papaioannou et al