Half-life Estimation of Pertussis-Specific Maternal Antibodies in (Pre)Term Infants After In-Pregnancy Tetanus, Diphtheria, Acellular Pertussis Vaccination.

BACKGROUND: To reduce the risk of pertussis-related morbidity and mortality in early life, an increasing number of countries recommend maternal pertussis vaccination. However, there is limited knowledge about half-lives of vaccine-induced pertussis-specific maternal antibodies, especially in preterm infants, and factors potentially influencing them. METHODS: We compared 2 different approaches to provide estimates of the half-lives of pertussis-specific maternal antibodies in infants and explored potential effects on the half-life in 2 studies. In the first approach, we estimated the half-lives per child and used these estimates as responses in linear models. In the second approach, we used linear mixed effect models on a log2 transformed scale of the longitudinal data to use the inverse of the time parameter as an estimate for the half-lives. RESULTS: Both approaches provided similar results. The identified covariates partly explain differences in half-life estimates. The strongest evidence we observed was a difference between term and preterm infants, with the preterm infants showing a longer half-life. Among others, a longer interval between vaccination and delivery increases the half-life. CONCLUSIONS: Several variables influence the decay speed of maternal antibodies. Both approaches have advantages and disadvantages, while the choice is secondary when assessing the half-life of pertussis-specific antibodies. CLINICAL TRIALS REGISTRATION: NCT02408926 and NCT02511327.

Effectiveness of computer-based interventions for community-dwelling people with cognitive decline: a systematic review with meta-analyses.

BACKGROUND: Cognitive deficits arise with age and can increase the risk for subjective cognitive decline (SCD) and mild cognitive impairment (MCI), which may result in dementia, leading to health problems, care dependency and institutionalization. Computer-based cognitive interventions (CCIs) have the potential to act as important counteraction functions in preserving or improving cognition concomitant to available pharmacological treatment. The aim was to assess the effectiveness of CCIs performed individually with a personal or tablet computer, game console, virtual, augmented, or mixed reality application on cognition in community-dwelling people with SCD, MCI and dementia. METHODS: A systematic review with meta-analyses of randomized controlled trials (RCTs) was performed. The systematic literature search was conducted in MEDLINE, CINAHL, Embase, Cochrane CENTRAL, IEEE Xplore Digital Library, Web of Science, Scopus and PsycINFO. In addition, a search for gray literature and backward citation searching were carried out. To judge on the evidence, two reviewers independently used the Cochrane Risk of Bias Tool. The standardized mean difference (SDM) for pooling comparable studies using the random-effects model was applied. RESULTS: Twenty-four RCTs were identified, of which 1 RCT examined CCIs in individuals with SCD, 18 RCTs with MCI, and 6 RCTs with dementia. Most interventions were conducted with personal computers. Meta-analyses with 12 RCTs showed significant effects of computer-based cognitive interventions for people with MCI in the domains memory, working memory, attention/concentration/processing speed and executive functioning, but no significant improvements in global cognition and language. Regarding dementia a meta-analysis pooled with 4 RCTs demonstrated a tendency towards, but no significant increase of memory functions (SMD 0.33, CI 95% [-0.10, 0.77]). One RCT regarding SCD reported significant improvements in memory functions for participants conducting a cognitive training on a personal computer. CONCLUSIONS: The results demonstrated that CCIs have beneficial effects on domain-specific cognition in people with MCI but no significant effects on people with dementia. In terms of SCD, one study showed significant improvements in memory functions. It seems that the beneficial effect for cognitive preservation or improvement due to CCIs occurs at the earliest intervention state. However, more research on SCD is needed. TRIAL REGISTRATION: PROSPERO International Prospective Register of Systematic Reviews CDR42020184069.

Modelling longitudinal binary outcomes with outcome dependent observation times: an application to a malaria cohort study.

BACKGROUND : In spite of the global reduction of 21% in malaria incidence between 2010 and 2015, the disease still threatens many lives of children and pregnant mothers in African countries. A correct assessment and evaluation of the impact of malaria control strategies still remains quintessential in order to eliminate the disease and its burden. Malaria follow-up studies typically involve routine visits at pre-scheduled time points and/or clinical visits whenever individuals experience malaria-like symptoms. In the latter case, infection triggers outcome assessment, thereby leading to outcome-dependent sampling (ODS). Commonly used methods to analyze such longitudinal data ignore ODS and potentially lead to biased estimates of malaria-specific transmission parameters, hence, inducing an incorrect assessment and evaluation of malaria control strategies. METHODS : In this paper, a new method is proposed to handle ODS by use of a joint model for the longitudinal binary outcome measured at routine visits and the clinical event times. The methodology is applied to malaria parasitaemia data from a cohort of [Formula: see text] Ugandan children aged 0.5-10 years from 3 regions (Walukuba-300 children, Kihihi-355 children and Nagongera-333 children) with varying transmission intensities (entomological inoculation rate equal to 2.8, 32 and 310 infectious bites per unit year, respectively) collected between 2011-2014. RESULTS : The results indicate that malaria parasite prevalence and force of infection (FOI) increase with age in the region of high malaria intensity with highest FOI in age group 5-10 years. For the region of medium intensity, the prevalence slightly increases with age and the FOI for the routine process is highest in age group 5-10 years, yet for the clinical infections, the FOI gradually decreases with increasing age. For the region with low intensity, both the prevalence and FOI peak at the age of 1 year after which the former remains constant with age yet the latter suddenly decreases with age for the clinically observed infections. CONCLUSION : Malaria parasite prevalence and FOI increase with age in the region of high malaria intensity. In all study sites, both the prevalence and FOI are highest among previously asymptomatic children and lowest among their symptomatic counterparts. Using a simulation study inspired by the malaria data at hand, the proposed methodology shows to have the smallest bias, especially when consecutive positive malaria parasitaemia presence results within a time period of 35 days were considered to be due to the same infection.

Sex-specific evaluation and redevelopment of the GRACE score in non-ST-segment elevation acute coronary syndromes in populations from the UK and Switzerland: a multinational analysis with external cohort validation.

BACKGROUND: The Global Registry of Acute Coronary Events (GRACE) 2.0 score was developed and validated in predominantly male patient populations. We aimed to assess its sex-specific performance in non-ST-segment elevation acute coronary syndromes (NSTE-ACS) and to develop an improved score (GRACE 3.0) that accounts for sex differences in disease characteristics. METHODS: We evaluated the GRACE 2.0 score in 420 781 consecutive patients with NSTE-ACS in contemporary nationwide cohorts from the UK and Switzerland. Machine learning models to predict in-hospital mortality were informed by the GRACE variables and developed in sex-disaggregated data from 386 591 patients from England, Wales, and Northern Ireland (split into a training cohort of 309 083 [80·0%] patients and a validation cohort of 77 508 [20·0%] patients). External validation of the GRACE 3.0 score was done in 20 727 patients from Switzerland. FINDINGS: Between Jan 1, 2005, and Aug 27, 2020, 400 054 patients with NSTE-ACS in the UK and 20 727 patients with NSTE-ACS in Switzerland were included in the study. Discrimination of in-hospital death by the GRACE 2.0 score was good in male patients (area under the receiver operating characteristic curve [AUC] 0·86, 95% CI 0·86-0·86) and notably lower in female patients (0·82, 95% CI 0·81-0·82; p<0·0001). The GRACE 2.0 score underestimated in-hospital mortality risk in female patients, favouring their incorrect stratification to the low-to-intermediate risk group, for which the score does not indicate early invasive treatment. Accounting for sex differences, GRACE 3.0 showed superior discrimination and good calibration with an AUC of 0·91 (95% CI 0·89-0·92) in male patients and 0·87 (95% CI 0·84-0·89) in female patients in an external cohort validation. GRACE 3·0 led to a clinically relevant reclassification of female patients to the high-risk group. INTERPRETATION: The GRACE 2.0 score has limited discriminatory performance and underestimates in-hospital mortality in female patients with NSTE-ACS. The GRACE 3.0 score performs better in men and women and reduces sex inequalities in risk stratification. FUNDING: Swiss National Science Foundation, Swiss Heart Foundation, Lindenhof Foundation, Foundation for Cardiovascular Research, and Theodor-Ida-Herzog-Egli Foundation.

Pertussis Immunization During Pregnancy: Assessment of the Role of Maternal Antibodies on Immune Responses in Term and Preterm-Born Infants.

BACKGROUND: Limited data exist on the impact of maternal tetanus, diphtheria, acellular pertussis (Tdap) vaccination for preterm born infants. We report its effect at birth and on antibody-mediated immune responses to a DTaP-IPV-HB-PRP~T vaccine in preterm compared with term infants. METHODS: Women delivering at term or prematurely were either vaccinated with a Tdap vaccine (Boostrix; GSK) during pregnancy or not vaccinated in the last 5 years. Cord and maternal blood were collected at delivery. Infants were vaccinated with DTaP-IPV-HB-PRP~T vaccine (Hexyon; Sanofi Pasteur) and blood collected before and 1 month after primary (8-12-16 weeks) and before and 1 month after booster vaccination (13 or 15 months for preterm and term, respectively). Immunoglobulin G antibodies against all antigens included in DTaP-IPV-HB-PRP~T vaccine were measured (NCT02511327). RESULTS: Cord blood geometric mean concentrations (GMCs) in preterm infants from Tdap-vaccinated women were significantly higher than in term and preterm infants from unvaccinated women. A longer time interval between maternal vaccination and delivery resulted in higher cord blood GMCs in preterm infants. Equal GMCs in term and preterm infants from Tdap-vaccinated women were observed after primary vaccination. After boosting, significantly lower GMCs were seen for pertussis toxin, filamentous hemagglutinin, and tetanus toxoid in preterm compared with term infants from Tdap-vaccinated women, yet still comparable to GMCs in both term and preterm infants from unvaccinated women. CONCLUSIONS: Preterm infants profit from maternal Tdap vaccination. Prematurity did not influence primary immune responses in the presence of maternal antibodies but was associated with a lower booster immune response.

Clinical, serological and epidemiological features of hepatitis A in León, Nicaragua.

BACKGROUND AND OBJECTIVES: To monitor and document the endemicity and disease burden of acute hepatitis A in the area of an ongoing vaccine effectiveness study in León, Nicaragua. METHODS: At community health centres in León, all children, adolescents and young adults presenting with jaundice and/or other clinical signs of hepatitis were offered free serologic screening (hepatitis A, B and C) and blood tests for liver enzymes and bilirubin. Clinical and socioeconomic data were collected with a structured questionnaire. Diagnosis of acute hepatitis A was confirmed by anti-HAV IgM testing. Using logistic regression we compared the characteristics and living conditions of acute hepatitis A cases with those of non-cases. RESULTS: Of 557 eligible subjects enrolled between May 2006 and March 2010, 315 (56.6%) were diagnosed with hepatitis A, 80.6% of them ≤10 years and five >18 years of age. No severe cases were encountered. Apart from jaundice (95.6%) and other signs of hepatitis A (fever, pale stool, dark urine, nausea, vomiting, anorexia), two thirds of patients had moderately raised liver enzymes. Cases occurred throughout the year, with highest incidences from August to March. Poor sanitary conditions and crowding were the main risk factors. CONCLUSIONS: In the study area, hepatitis A is still highly endemic in young and school age children living in low socioeconomic conditions. There are, however, first indications that the endemicity level is shifting from high to high-intermediate.

A data-driven metapopulation model for the Belgian COVID-19 epidemic: assessing the impact of lockdown and exit strategies.

BACKGROUND: In response to the ongoing COVID-19 pandemic, several countries adopted measures of social distancing to a different degree. For many countries, after successfully curbing the initial wave, lockdown measures were gradually lifted. In Belgium, such relief started on May 4th with phase 1, followed by several subsequent phases over the next few weeks. METHODS: We analysed the expected impact of relaxing stringent lockdown measures taken according to the phased Belgian exit strategy. We developed a stochastic, data-informed, meta-population model that accounts for mixing and mobility of the age-structured population of Belgium. The model is calibrated to daily hospitalization data and is able to reproduce the outbreak at the national level. We consider different scenarios for relieving the lockdown, quantified in terms of relative reductions in pre-pandemic social mixing and mobility. We validate our assumptions by making comparisons with social contact data collected during and after the lockdown. RESULTS: Our model is able to successfully describe the initial wave of COVID-19 in Belgium and identifies interactions during leisure/other activities as pivotal in the exit strategy. Indeed, we find a smaller impact of school re-openings as compared to restarting leisure activities and re-openings of work places. We also assess the impact of case isolation of new (suspected) infections, and find that it allows re-establishing relatively more social interactions while still ensuring epidemic control. Scenarios predicting a second wave of hospitalizations were not observed, suggesting that the per-contact probability of infection has changed with respect to the pre-lockdown period. CONCLUSIONS: Contacts during leisure activities are found to be most influential, followed by professional contacts and school contacts, respectively, for an impending second wave of COVID-19. Regular re-assessment of social contacts in the population is therefore crucial to adjust to evolving behavioral changes that can affect epidemic diffusion.

Triage of human papillomavirus infected women by methylation analysis in first-void urine.

Host cell DNA methylation analysis in urine provides promising triage markers for women diagnosed with a high-risk (HR) human papillomavirus (HPV) infection. In this study, we have investigated a panel of six host cell methylation markers (GHSR, SST, ZIC1, ASCL1, LHX8, ST6GALNAC5) in cervicovaginal secretions collected within the first part of the urine void (FVU) from a referral population. Cytology, histology, and HPV DNA genotyping results on paired FVU and cervical samples were available. Urinary median methylation levels from HR-HPV (n = 93) positive women were found to increase for all markers with severity of underlying disease. Significantly elevated levels were observed for GHSR and LHX8 in relation to high-grade cervical intraepithelial neoplasia (CIN2 +; n = 33), with area under de curve values of 0.80 (95% Confidence Interval (CI) 0.59-0.92) and 0.76 (95% CI 0.58-0.89), respectively. These findings are the first to support the assertion that methylation analysis of host cell genes is feasible in FVU and holds promise as molecular, triage strategy to discern low- from high-grade cervical disease in HR-HPV positive women. Molecular testing on FVU may serve to increase cervical cancer screening attendance in hard-to-reach populations whilst reducing loss to follow-up and await further optimization and validation studies.

Modelling the early phase of the Belgian COVID-19 epidemic using a stochastic compartmental model and studying its implied future trajectories.

Following the onset of the ongoing COVID-19 pandemic throughout the world, a large fraction of the global population is or has been under strict measures of physical distancing and quarantine, with many countries being in partial or full lockdown. These measures are imposed in order to reduce the spread of the disease and to lift the pressure on healthcare systems. Estimating the impact of such interventions as well as monitoring the gradual relaxing of these stringent measures is quintessential to understand how resurgence of the COVID-19 epidemic can be controlled for in the future. In this paper we use a stochastic age-structured discrete time compartmental model to describe the transmission of COVID-19 in Belgium. Our model explicitly accounts for age-structure by integrating data on social contacts to (i) assess the impact of the lockdown as implemented on March 13, 2020 on the number of new hospitalizations in Belgium; (ii) conduct a scenario analysis estimating the impact of possible exit strategies on potential future COVID-19 waves. More specifically, the aforementioned model is fitted to hospital admission data, data on the daily number of COVID-19 deaths and serial serological survey data informing the (sero)prevalence of the disease in the population while relying on a Bayesian MCMC approach. Our age-structured stochastic model describes the observed outbreak data well, both in terms of hospitalizations as well as COVID-19 related deaths in the Belgian population. Despite an extensive exploration of various projections for the future course of the epidemic, based on the impact of adherence to measures of physical distancing and a potential increase in contacts as a result of the relaxation of the stringent lockdown measures, a lot of uncertainty remains about the evolution of the epidemic in the next months.

The impact of contact tracing and household bubbles on deconfinement strategies for COVID-19.

The COVID-19 pandemic caused many governments to impose policies restricting social interactions. A controlled and persistent release of lockdown measures covers many potential strategies and is subject to extensive scenario analyses. Here, we use an individual-based model (STRIDE) to simulate interactions between 11 million inhabitants of Belgium at different levels including extended household settings, i.e., "household bubbles". The burden of COVID-19 is impacted by both the intensity and frequency of physical contacts, and therefore, household bubbles have the potential to reduce hospital admissions by 90%. In addition, we find that it is crucial to complete contact tracing 4 days after symptom onset. Assumptions on the susceptibility of children affect the impact of school reopening, though we find that business and leisure-related social mixing patterns have more impact on COVID-19 associated disease burden. An optimal deployment of the mitigation policies under study require timely compliance to physical distancing, testing and self-isolation.

Breast Milk Antibody Levels in Tdap-Vaccinated Women After Preterm Delivery.

BACKGROUND: Enrichment of breast milk (BM) with immunoglobulin (Ig) A and IgG through maternal vaccination could help infants combat targeted pathogens. However, evidence on this effect after preterm delivery is lacking. In this study, we investigated the total and anti-pertussis toxin (anti-PT)-specific IgA and IgG production in BM after term and preterm delivery in the presence of maternal Tdap (tetanus, diphtheria, acellular pertussis) vaccination. METHODS: Serum and BM samples of lactating women who delivered at term or prematurely and did or did not receive Tdap vaccine (Boostrix, GSK Biologicals) during pregnancy were collected as part of a clinical study (N = 234). Anti-PT IgA/IgG (IBL assay; Meso Scale Discovery assay) and total IgA/IgG (Thermofisher, on BM samples only) immunosorbent assays were performed on all samples collected at 72 hours and 4, 8, and 12 weeks postpartum. RESULTS: BM after preterm delivery contained anti-PT IgA and IgG geometric mean concentrations (GMCs) comparable to those after term delivery (eg, colostrum anti-PT IgA, 5.39 IU/mL vs 6.69 IU/mL, respectively). Maternal Tdap vaccination induced significantly higher anti-PT IgG GMCs in colostrum of vaccinated compared with unvaccinated women who delivered at term (0.110 IU/mL vs 0.027 IU/mL, P = .009). Anti-PT antibodies persisted up to 12 weeks postpartum. CONCLUSIONS: This study provides evidence that maternal Tdap vaccination induces high Ig levels in BM after both term and preterm delivery and that these antibodies remain abundantly present throughout lactation, possibly offering additional mucosal protection during the most vulnerable period in early life. CLINICAL TRIAL REGISTRATION: NCT02511327.

Stable HEV IgG seroprevalence in Belgium between 2006 and 2014.

Recent European studies suggest an emergence of hepatitis E virus (HEV) infection. We evaluated trends in birth cohort-specific HEV seroprevalence and regional differences in Belgium. HEV IgG seroprevalence was analysed on national serum banks (1579 and 2087 samples for 2006 and 2014, respectively. Hepatitis E virus antigen was tested on positive samples. Observed data were modelled using a generalized additive model with a complementary log-log link. No significant differences between birth cohorts or sexes were found. Modelling identified the individual's age and province as relevant factors. The probability of HEV seropositivity increases significantly with age. An estimated total of 434 819 (yearly rate of 54,352) (sero-)infections were found between 2006 and 2014. Overall, HEV IgG seroprevalences were 4.1% (64/1579, 95% CI 3.1-5.1) and 5.8% (121/2087, CI 4.8-6.9) in 2006 and 2014, respectively. Observed HEV antigen seroprevalence was 0.027% (1/3666) for the entire cohort. These results show stable HEV IgG seroprevalence in Belgium.

How nasopharyngeal pneumococcal carriage evolved during and after a PCV13-to-PCV10 vaccination programme switch in Belgium, 2016 to 2018.

BackgroundThe current carriage study was set up to reinforce surveillance during/after the PCV13-to-PCVC10 switch in Belgium.AimThis observational study monitored carriage of Streptococcus pneumoniae (Sp) serotypes, particularly those no longer covered (3, 6A, 19A), as well as Haemophilus influenzae (Hi), because PCV10 contains the non-typeable Hi protein D.MethodsA total of 2,615 nasopharyngeal swabs from children (6-30 months old) attending day care were collected in three periods over 2016-2018. Children's demographic and clinical characteristics and vaccination status were obtained through a questionnaire. Sp and Hi were identified by culture and PCR. Pneumococcal strains were tested for antimicrobial (non-)susceptibility by disc diffusion and serotyped by Quellung-reaction (Quellung-reaction and PCR for serotypes 3, 6A, 19A).ResultsThe carriage prevalence of Sp (> 75%) remained stable over the successive periods but that of Hi increased (87.4%, 664 Hi-carriers/760 in 2016 vs 93.9%, 895/953 in 2017-2018). The proportion of non-PCV13 vaccine serotypes decreased (94.6%, 438 isolates/463 in 2016 vs 89.7%, 599/668 in 2017-2018) while that of PCV13-non-PCV10 vaccine serotypes (3 + 6A + 19A) increased (0.9%, 4 isolates/463 in 2016 vs 7.8%, 52/668 in 2017-2018), with serotype 19A most frequently identified (87.9%, 58/66 isolates). Non-susceptibility of pneumococci against any of the tested antibiotics was stable over the study period (> 44%).ConclusionsDuring and after the PCV13-to-PCV10 vaccine switch, the proportion of non-PCV13 serotypes decreased, mainly due to a serotype 19A carriage prevalence increase. These results complement invasive pneumococcal disease surveillance data, providing further basis for pneumococcal vaccination programme policy making.

Androgen and Anti-Mullerian Hormone Concentrations at Term in Newborns and Their Mothers with and without Polycystic Ovary Syndrome.

Objectives: The aetiology of polycystic ovary syndrome (PCOS) is not particularly mapped; however, a complex interaction of various factors, such as genetic, environmental and intrauterine factors, can be assumed. Experimental animal studies and clinical observations support the hypothesis that developmental programming by excess intrauterine steroid is relevant. The aim of the study was to investigate whether mothers with and without PCOS exhibit different androgen and anti-Mullerian hormone (AMH) levels at the end of pregnancy and how maternal hormone levels are reflected in their offspring. Methods: Between March 2013 and December 2015, we performed a prospective cross-sectional study at the Medical University of Graz. We included 79 women with PCOS according to the ESHRE/ASRM 2003 definition and 354 women without PCOS, both with an ongoing pregnancy ≥37 + 0 weeks of gestation, who gave birth in our institution. Primary outcome parameters were the levels of maternal and neonatal androgens (testosterone, free testosterone, androstenedione) and AMH at delivery. Results: Androgen levels in female offspring of PCOS and non-PCOS women at birth did not differ, while maternal hormone levels differed significantly. Androgen levels in PCOS boys were significantly higher when compared to levels in PCOS girls. Discussion: Our findings do not support the hypothesis that maternal androgen excess contributes to elevated androgen concentrations in the female offspring. Nevertheless, the effects of the increased androgen concentrations in mothers on their offspring have to be investigated in future studies.

Comparison of early postoperative pain after partial tumour nephrectomy by flank, transabdominal or laparoscopic access.

AIM: To explore whether the total pain experience differs after (partial) kidney tumour nephrectomies via flank, transabdominal or laparoscopic access. MATERIALS AND METHODS: We analyzed retrospectively 107 patients with flank, 12 with transabdominal and 21 with laparoscopic interventions. For pain treatment, conventional analgesics (A) or intravenous patient-controlled analgesia (PCIA) or thoracic peridural analgesia (tPDA) were used. Self-reported pain was measured with a Visual Analogue Scale three times daily. The area under the curve (AUC) at rest (R) and during a standardized body movement (M) were calculated from the intervention till the end of the second T(0-2) and seventh postoperative day T(0-7), respectively. RESULTS: The median AUC for T(0-2) at R was more intense for laparoscopy (13) than for flank incision (A, 9) and approximately the same during M. For flank incisions (A), the median AUC at R rises from 9 for T(0-2) to 22 for T(0-7) and at M the median AUC increases from 18 to 37. In contrast, laparoscopy did not cause further pain after the second postoperative day. Furthermore, with flank incision for T(0-2), at R, tPDA was superior to A (median AUC: 5 versus 9, p = 0.02) and at M again tPDA (median AUC: 12) had a better pain-control as A (18) or even as PCIA (19, p = 0.005). CONCLUSION: Laparoscopic nephrectomies cause a relatively intense mean cumulative pain for T(0-2) and a subsequent absence of pain. However, flank incisions went on to increased pain levels until the seventh postoperative day with tPDA as most effective therapy.

Sample size calculation for estimating key epidemiological parameters using serological data and mathematical modelling.

BACKGROUND: Our work was motivated by the need to, given serum availability and/or financial resources, decide on which samples to test in a serum bank for different pathogens. Simulation-based sample size calculations were performed to determine the age-based sampling structures and optimal allocation of a given number of samples for testing across various age groups best suited to estimate key epidemiological parameters (e.g., seroprevalence or force of infection) with acceptable precision levels in a cross-sectional seroprevalence survey. METHODS: Statistical and mathematical models and three age-based sampling structures (survey-based structure, population-based structure, uniform structure) were used. Our calculations are based on Belgian serological survey data collected in 2001-2003 where testing was done, amongst others, for the presence of Immunoglobulin G antibodies against measles, mumps, and rubella, for which a national mass immunisation programme was introduced in 1985 in Belgium, and against varicella-zoster virus and parvovirus B19 for which the endemic equilibrium assumption is tenable in Belgium. RESULTS: The optimal age-based sampling structure to use in the sampling of a serological survey as well as the optimal allocation distribution varied depending on the epidemiological parameter of interest for a given infection and between infections. CONCLUSIONS: When estimating epidemiological parameters with acceptable levels of precision within the context of a single cross-sectional serological survey, attention should be given to the age-based sampling structure. Simulation-based sample size calculations in combination with mathematical modelling can be utilised for choosing the optimal allocation of a given number of samples over various age groups.

Blockade of prostaglandin E2 receptor 4 ameliorates nephrotoxic serum nephritis.

Prostaglandin E2 (PGE2) signaling is known to modulate inflammation and vascular resistance. Receptors of PGE2 [E-type prostanoid receptors (EP)] might be an attractive pharmacological target in immune-mediated diseases such as glomerulonephritis. We hypothesized that selective EP4 antagonism improves nephrotoxic serum nephritis (NTS) by its anti-inflammatory properties. Mice were subjected to NTS and treated with the EP4 antagonist ONO AE3-208 (10 mg·kg body wt-1·day-1] or vehicle starting from disease initiation. In one set of experiments, treatment was started 4 days after NTS induction. Tubular epithelial cells were evaluated in vitro under starving conditions. EP4 antagonist treatment significantly improved the NTS phenotype without affecting blood pressure levels. Remarkably, the improved NTS phenotype was also observed when treatment was started 4 days after NTS induction. EP4 antagonism decreased tubular chemokine (C-X-C motif) ligand ( Cxcl) 1 and Cxcl-5 expression and thereby subsequently reduced interstitial neutrophil infiltration into the kidney. In vitro, tubular epithelial cells increasingly expressed Cxcl-5 mRNA and Cxcl-5 protein when treated with PGE2 or an EP4 agonist under starving conditions, which was blunted by EP4 antagonist treatment. Together, EP4 antagonism improves the NTS phenotype, probably by decreasing mainly Cxcl-5 production in tubular cells, thereby reducing renal neutrophil infiltration.

Endothelial indoleamine 2,3-dioxygenase-1 regulates the placental vascular tone and is deficient in intrauterine growth restriction and pre-eclampsia.

Indoleamine 2,3-dioxygenase-1 (IDO1) mediates the degradation of L-tryptophan (L-Trp) and is constitutively expressed in the chorionic vascular endothelium of the human placenta with highest levels in the microvasculature. Given that endothelial expression of IDO1 has been shown to regulate vascular tone and blood pressure in mice under the condition of systemic inflammation, we asked whether IDO1 is also involved in the regulation of placental blood flow and if yes, whether this function is potentially impaired in intrauterine growth restriction (IUGR) and pre-eclampsia (PE). In the large arteries of the chorionic plate L-Trp induced relaxation only after upregulation of IDO1 using interferon gamma and tumor necrosis factor alpha. However, ex vivo placental perfusion of pre-constricted cotyledonic vasculature with L-Trp decreases the vessel back pressure without prior IDO1 induction. Further to this finding, IDO1 protein expression and activity is reduced in IUGR and PE when compared to gestational age-matched control tissue. These data suggest that L-Trp catabolism plays a role in the regulation of placental vascular tone, a finding which is potentially linked to placental and fetal growth. In this context our data suggest that IDO1 deficiency is related to the pathogenesis of IUGR and PE.

Mathematical models used to inform study design or surveillance systems in infectious diseases: a systematic review.

BACKGROUND: Mathematical models offer the possibility to investigate the infectious disease dynamics over time and may help in informing design of studies. A systematic review was performed in order to determine to what extent mathematical models have been incorporated into the process of planning studies and hence inform study design for infectious diseases transmitted between humans and/or animals. METHODS: We searched Ovid Medline and two trial registry platforms (Cochrane, WHO) using search terms related to infection, mathematical model, and study design from the earliest dates to October 2016. Eligible publications and registered trials included mathematical models (compartmental, individual-based, or Markov) which were described and used to inform the design of infectious disease studies. We extracted information about the investigated infection, population, model characteristics, and study design. RESULTS: We identified 28 unique publications but no registered trials. Focusing on compartmental and individual-based models we found 12 observational/surveillance studies and 11 clinical trials. Infections studied were equally animal and human infectious diseases for the observational/surveillance studies, while all but one between humans for clinical trials. The mathematical models were used to inform, amongst other things, the required sample size (n = 16), the statistical power (n = 9), the frequency at which samples should be taken (n = 6), and from whom (n = 6). CONCLUSIONS: Despite the fact that mathematical models have been advocated to be used at the planning stage of studies or surveillance systems, they are used scarcely. With only one exception, the publications described theoretical studies, hence, not being utilised in real studies.

Cancer Stem Cell Gene Variants in CD44 Predict Outcome in Stage II and Stage III Colon Cancer Patients.

BACKGROUND/AIM: Growing evidence suggests that human cancers are stem cell diseases and recent data support the existence of cancer stem cells (CSCs) in a variety of malignancies, including colon cancer. These CSCs were shown to be capable of initiating tumor development and progression. Several studies have suggested CD133, CD26 and CD44 as markers of tumor-initiating cells of colon cancer. The purpose of the present study was to assess the impact of single-nucleotide polymorphisms (SNPs) in stem cell-related genes on clinical outcome in a large cohort of colon cancer patients with clinical stage II and III. PATIENTS AND METHODS: Data from 599 consecutive patients with colon cancer stage II and III, treated between 1995 and 2011 at a single centre, were retrospectively evaluated. Genomic DNA was extracted from paraffin-embedded normal tissue distant from the tumor to obtain germline DNA. Allelic distribution of polymorphisms was tested for deviation from Hardy-Weinberg equilibrium using χ2-test. The association of polymorphisms with time to recurrence (TTR) and overall survival (OS) was analyzed using Kaplan-Meier curves and compared by the log-rank test. Case-wise deletion for missing polymorphisms was used in univariable and multivariable analyses. RESULTS: CD44 rs187115 showed a statistically significant association with TTR; patients carrying at least one G allele had a significant reduced risk of recurrence compared to patients with the homozygous A/A variant (hazard ratio (HR)=0.67, 95% confidence interval (CI)=0.48-0.94, p=0.019). CD44 rs13347 showed a statistically significant association with OS. Patients carrying at least one T allele in rs13347 had a significantly reduced risk of death compared to patients with the homozygous C/C variant (HR=0.61, 95% CI=0.41-0.92, p=0.019). None of the other investigated polymorphisms (CD44 rs187116, CD44 rs7116432, CD44 rs353639, DPP4 rs2268889, DPP4 rs3788979, DPP4 rs7608798 and CD133 rs2240688) were associated with either TTR or OS. CONCLUSION: Germline variants rs13347 and rs187115 in the stem cell gene CD44 are prognostically relevant in stage II and III colon cancer patients.