Lactoferrin in Gingival Crevicular Fluid and Peripheral Blood during Experimental Gingivitis

Objectives Lactoferrin (LF) is an iron binding protein and stored in the specific granules of granulocytes. It is released by degranulation following granulocyte activation. A positive correlation was previously reported between periodontitis and LF titers of gingival crevicular fluid (GCF) and blood. The purpose of this study was to examine alterations of GCF and blood levels of LF (LF-GCF and LF-BL, respectively), employing the experimental gingivitis model. Methods Twelve systemically healthy volunteers, aged 19–21, were selected. Pre-experimental phase of hygiene was followed by a 14-day experimental gingivitis phase in which subjects refrained from all oral hygiene procedures. After that subjects resumed optimal plaque control for 21 days of recovery period. At days 0 (baseline), 14 and 35 gingival crevicular fluid (GCF) and blood samples were collected and plaque index (PI), gingival index (GI), bleeding on probing (BOP) and probing pocket depth scores were recorded. LF levels were measured with commercial enzyme-linked immunosorbent assay (ELISA) kit. Results PI, GI, BOP and LF-GCF increased significantly after 14 days of experimental gingivitis period and decreased significantly after reinstitution of oral hygiene measures (P<.05). LF-BL appeared to follow the same pattern. Significant negative correlation was detected between the level of LF-BL and BOP at day 14 (P<.05), whereas significant positive correlation was noticed between LF-BL and clinical scores PI, GI and BOP at day 35 (P<.05). Conclusions LF-BL followed the same pattern with LF-GCF and clinical scores during the experimental gingivitis and recovery periods, although alterations of the LF-BL appeared statistically insignificant.PubMe

Concurrent occurrence of human and equine West Nile virus infections in Central Anatolia, Turkey: the first evidence for circulation of lineage 1 viruses

SummaryBackgroundWest Nile fever is an important zoonotic infection caused by West Nile virus (WNV), a member of the Flaviviridae. Previous serological data from Turkey suggest widespread WNV circulation. This report includes cases of human and equine WNV infections occurring concurrently, and manifesting as central nervous system infections, in two neighboring provinces of Central Anatolia, Turkey. A partial phylogenetic analysis of the causative virus is given for the first time.MethodsThe cases were reported in February (horses) and March (human). Symptoms of the disease were similar in the two species, characterized by neurological manifestations suggesting meningoencephalitis. Real-time/nested PCRs and commercial immunoassays and a plaque reduction neutralization assay were employed for the detection of viral RNA and specific antibodies, respectively.ResultsWNV RNAs were detected in buffy coat (horses) and cerebrospinal fluid (human) samples. Partial nucleotide sequences of the E-gene coding region revealed that the strains are closely related to viruses of lineage 1, clade 1a. Accompanying equine serosurveillance demonstrated WNV-specific antibodies in 31.6% of the samples.ConclusionsThis is the first report of acute WNV infections caused by lineage 1 strains from Turkey, in concordance with previous reports from some European and North African countries

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND: Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori. OBJECTIVES: To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started. SEARCH METHODS: We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively. SELECTION CRITERIA: We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as13C or14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities. MAIN RESULTS: We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons. AUTHORS' CONCLUSIONS: In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions

New, Newer, Newest Human Polyomaviruses: How Far?

Polyomaviruses, classified in Polyomaviridae family, are non-enveloped small (40-45 nm) viruses with icosahedral symmetry and circular double-stranded DNA genome. Polyomaviruses can infect a variety of vertebrates including birds, rodents, cattle, monkeys and humans. The characteristics such as establishment of latent infections, reactivations during immunosuppression and oncogenic potencies render the human polyomaviruses (HPyVs) of considerable importance for public health. The first polyomavirus (Mouse polyomavirus) has been identified in 1953 as filterable tumor-causing agents in mice, followed by Simian vacuolating virus (SV40) isolated from rhesus monkey kidney cells that had been used for poliovirus vaccine preparation in 1960. Due to the known transforming capacity of SV40, it was initially thought that the incidence of cancer could increase following the administration of SV40-contaminated polio vaccines, however advanced studies yielded inconsistent results, without any evidence to conclude whether or not the contaminated polio vaccine caused cancer. Several studies have reported the detection of SV40 genome in some of the human tumors, as well as in the clinical samples of healthy subjects. In addition SV40 seropositivity was reported in human populations although in low rates (2-10%). These data have raised the possibility that SV40 infects humans and circulates in human populations unrelated to being exposed to the vaccine. The discovery of the first human polyomaviruses was in 1971 independently from eachother, one was BK virus (BKPyV) isolated from the urine sample of a renal transplant patient, and the other was JC virus (JCPyV) isolated from the brain tissue of a petient with progressive multifocal leukoencephalopathy, and both were named after the patients' initials. BK and JC viruses were the only well-known human polyomaviruses throughout 36 years, however dramatical increase in number of newly identified human polyomaviruses was recorded in the last six years due to the use of sophisticated molecular methods and new-generation sequencing technologies. In 2007, two new HPyVs were identified independently from nasopharyngeal aspirates of children with acute respiratory tract infections; one was KI (Karolinska Institute) and the other was WU (Washington University) polyomaviruses, named after the initials of institutes which they were first described. In 2008, the fifth HPyV namely Merkel cell polyomavirus (MCPyV) was isolated from the skin tumor sample of a patient with Merkel cell carcinoma. In 2010, three other novel human polyomaviruses were discovered, two were from skin samples of healthy subjects (HPyV-6 and HPyV-7), and one (Trichodysplasia Spinulosa-associated virus; TSPyV) from keratotic spicule sample of a heart-transplanted patient. Another new HPyV was identified in 2011 named HPyV-9, from the blood and urine samples of an asymptomatic patient with kidney transplant. Most recently, three new HPyVs have been sequentially discovered during the last quarter of 2012. The 10th HPyV (HPyV10) was identified in condyloma samples of an immunocompromised patient with WHIM syndrome (Wart, Hypogammaglobulinemia, Infections, Myelokathexis), 11th virus was isolated from stool sample of a healthy child from Malawi (Malawi polyomavirus; MWPyV), and 12th was described from fecal sample of a diarrheal child from Mexico (Mexico polyomavirus; MXPyV). The whole genome sequence analysis of HPyV10, MWPyV and MXPyV pointed out that they are closely related viruses. The last novel polyomavirus, namely Saint Louis polyomavirus (STLPyV) has been reported in a study published on February 2013, identified from the stool sample of a healthy child. Seroepidemiological studies indicated that most of the novel HPyVs are highly prevalent (average rate: 40-80%) worldwide and likely acquired asymptomatically during childhood, similar to the old ones, BKPyV and JCPyV. However data about HPyV10, MWPyV, MXPyV and STLPyV are not enough as they have been discovered most recently. Similarly, little is known about the pathogenesis, route of infection and the relationship with clinical diseases of novel HPyVs except MCPyV and TSPyV which are known to be responsible for Merkel cell carcinoma and trichodysplasia spinulosa, respectively. The expanding repertoire of human polyomaviruses made us think that many others will be uncovered in the future thanking to the advances in molecular methods. In this review, recent developments subjecting new human polyomaviruses have been summarized.WoSScopu

Viral Superantigens

Superantigens (SAgs) are microbial proteins produced by various microorganisms that elicit excessive and strong stimulation of T cells via an unconventional mechanism. They cause polyclonal activation of T cells in a non-specific manner, by binding to a particular variable-beta (V beta) chain of T-cell receptor (TCR) and MHC class II molecule, in unprocessed form and outside of peptide-binding cleft, forming a bridge between the antigen presenting cell and the T cell. SAgs are classified into three groups, namely 1) exogenous (soluble proteins and exotoxins secreted by microorganisms), 2) endogenous (transmembrane proteins encoded by viruses which are integrated into the genome) and 3) B-cell SAgs (proteins which stimulate predominantly B cells). The best characterized and mostly studied SAgs are staphylococcal and streptococcal exotoxins, however it is well-known that many other microorganisms also possess SAg activities. Despite the presence of several viruses that cause severe infections in humans, the number of viruses that have proteins identified with SAg property in their pathogenesis, is relatively low. To date, the defined viruses that encoded SAgs are as follows; mouse mammary tumor virus (MMTV) (Marrack, et al. 1991), rabies virus (Lafon, et al. 1992), Epstein-Barr virus (EBV) (Sutkowski, et al. 1996), human endogenous retrovirus (HERV) (Conrad, et al. 1997), human immunodeficiency virus (HIV) (Posnett, et al. 1995; Torres, et al. 1996; Townsley-Fuchs, et al. 1997) and Ebola virus (Leroy, et al. 2011). SAgs were first described in the MMTV, a polymorphic B-type retrovirus that is either contained in the genome as an endogenous provirus (germline transmission) or exogenous infectious virus that transmits vertically via breast milk. Both MMTV forms encode SAgs. The SAg-mediated massive T cell activation is required for the spread of exogenous MMTV from intestines to mammary glands, facilitating the transmission of infectious virus. On the other hand, expression of endogenous SAgs leads to thymic deletion of responding T cells (bearing V beta 6-9(+) TCR) due to self-tolerance induction during the fetal life, and protects the host against future exogenous MMTV infections. The SAg of rabies virus is the N protein found in nucleocapsid structure and stimulates V beta 8(+) TCR-bearing T cells. The SAg-induced polyclonal activation of T cells leads to turn-off the specific immune response, to enhance the immunopathogenesis and facilitates viral transmission from the initial site of infection (the muscle tissue) to the nerve endings. In case of EBV-associated SAg that activates V beta 13(+) TCR-bearing T cells, it was detected that the SAg activity was not encoded by EBV itself, but instead was due to the transactivation of HERV-K18 by EBV latent membrane proteins, whose env gene encodes the SAg (Sutkowski, et al. 2001). It has been denoted that EBV-induced SAg expression plays a role in the long-term persistence and latency of virus in memory B cells, in the development of autoimmune diseases and in the oncogenesis mechanisms. The proteins which are identified as SAgs of HIV are Nef and gp120. It is believed that, the massive activation of CD4(+) T cells (selectively with V beta-12(+), V beta-5.3(+) and V beta-18(+) TCRs) in early stages of infection and clonal deletion, anergy and apoptosis of bystander T cells in the late stages may be due to SAg property of Nef protein, as well as the other mechanisms. However there are some studies indicating that Nef does not act as a SAg (Lapatschek, et al. 2001). HIV gp120 glycoprotein is a B-cell SAg that binds to VH3-expressing B cell receptors and causes polyclonal B cell activation. In addition, binding of gp120 to IgE on the surface of basophiles and mast cells causes activation of those cells, secretion of high level proinflammatory mediators leading to allergic reactions and tissue damage. In a recent study, the depletion (anergy or deletion) of T cell populations bearing V beta 12(+), V beta 13(+) and V beta 17(+) TCR have been shown, in patients infected with Zaire Ebola virus, whatever the clinical outcome (death or recovery), these results also suggest the presence of SAg activity. In this review article, following a brief description of the general characteristics of SAgs, virus-encoded SAgs and their roles in the diseases have been discussed.WoSScopusTr-Dizi

Multicentre evaluation of central nervous system infections due to Flavi and Phleboviruses in Turkey

Objectives: Flavi- and Phleboviruses associated with central nervous system (CNS) infections including West Nile Virus (WNV), Tick-borne Encephalitis Virus (TBEV) and Toscana Virus (TOSV) cause significant morbidity and mortality in humans. In this study, the impact of these agents have been investigated in CNS infections at referral hospitals in two provinces in Turkey, where circulation of these viruses have previously been recognized