Bone Activity Biomarkers and Bone Mineral Density in Children with Chronic Kidney Disease

Introduction: Chronic kidney disease - mineral and bone disorder (CKD-MBD) is a spectrum of bone minerals changes that range from high turnover lesions of secondary hyperparathyroidism to the low turnover lesions of adynamic bone disease. Bone biopsy is the gold standard for the diagnosis, but it is not routinely performed because it is invasive technique. Methods: Fifteen CKD children on regular hemodialysis (group I) and 15 CKD children on conservative management (group II) were selected from the nephrology clinics of Zagazig University Hospitals along with 15 age and sex-matched healthy controls. Participants were subjected to biochemical assessment that included osteocalcin (OC), total and bone-specific alkaline phosphatase (tALP and bALP), isomerized beta form of type I collagen cross-linked telopeptide (β-Crosslaps) and intact parathyroid hormone (iPTH) levels. Patients with CKD also had their bone mineral density (BMD) measured using dual energy X-ray absorptiometry (DEXA) at lumbar spine and femoral neck. Results: Serum β-Crosslaps, OC and bALP were significantly higher in patient groups than controls and in group I compared to group II .There was a negative significant correlation between mean Z-score at lumbar spines and bALP, OC and iPTH in group I and with β-Crosslaps in both patient groups. The mean Z-score at femoral neck correlated negatively with bALP in group I, with OC in group II and with iPTH and β-Crosslaps in both groups. Conclusion: Biochemical bone markers and assessment of BMD in patients with CKD may have a role in the early detection of CDK-MBD. Keywords: chronic kidney disease; bone mineral density; bone biomarker

Atrial arrhythmogenicity of KCNJ2 mutations in short QT syndrome: Insights from virtual human atria

Gain-of-function mutations in KCNJ2-encoded Kir2.1 channels underlie variant 3 (SQT3) of the short QT syndrome, which is associated with atrial fibrillation (AF). Using biophysically-detailed human atria computer models, this study investigated the mechanistic link between SQT3 mutations and atrial arrhythmogenesis, and potential ion channel targets for treatment of SQT3. A contemporary model of the human atrial action potential (AP) was modified to recapitulate functional changes in IK1 due to heterozygous and homozygous forms of the D172N and E299V Kir2.1 mutations. Wild-type (WT) and mutant formulations were incorporated into multi-scale homogeneous and heterogeneous tissue models. Effects of mutations on AP duration (APD), conduction velocity (CV), effective refractory period (ERP), tissue excitation threshold and their rate-dependence, as well as the wavelength of re-entry (WL) were quantified. The D172N and E299V Kir2.1 mutations produced distinct effects on IK1 and APD shortening. Both mutations decreased WL for re-entry through a reduction in ERP and CV. Stability of re-entrant excitation waves in 2D and 3D tissue models was mediated by changes to tissue excitability and dispersion of APD in mutation conditions. Combined block of IK1 and IKr was effective in terminating re-entry associated with heterozygous D172N conditions, whereas IKr block alone may be a safer alternative for the E299V mutation. Combined inhibition of IKr and IKur produced a synergistic anti-arrhythmic effect in both forms of SQT3. In conclusion, this study provides mechanistic insights into atrial proarrhythmia with SQT3 Kir2.1 mutations and highlights possible pharmacological strategies for management of SQT3-linked AF

Brucella abortus Induces the Premature Death of Human Neutrophils through the Action of Its Lipopolysaccharide

Most bacterial infections induce the activation of polymorphonuclear neutrophils (PMNs), enhance their microbicidal function, and promote the survival of these leukocytes for protracted periods of time. Brucella abortus is a stealthy pathogen that evades innate immunity, barely activates PMNs, and resists the killing mechanisms of these phagocytes. Intriguing clinical signs observed during brucellosis are the low numbers of Brucella infected PMNs in the target organs and neutropenia in a proportion of the patients; features that deserve further attention. Here we demonstrate that B. abortus prematurely kills human PMNs in a dose-dependent and cell-specific manner. Death of PMNs is concomitant with the intracellular Brucella lipopolysaccharide (Br-LPS) release within vacuoles. This molecule and its lipid A reproduce the premature cell death of PMNs, a phenomenon associated to the low production of proinflammatory cytokines. Blocking of CD14 but not TLR4 prevents the Br-LPS-induced cell death. The PMNs cell death departs from necrosis, NETosis and classical apoptosis. The mechanism of PMN cell death is linked to the activation of NADPH-oxidase and a modest but steadily increase of ROS mediators. These effectors generate DNA damage, recruitments of check point kinase 1, caspases 5 and to minor extent of caspase 4, RIP1 and Ca++ release. The production of IL-1β by PMNs was barely stimulated by B. abortus infection or Br-LPS treatment. Likewise, inhibition of caspase 1 did not hamper the Br-LPS induced PMN cell death, suggesting that the inflammasome pathway was not involved. Although activation of caspases 8 and 9 was observed, they did not seem to participate in the initial triggering mechanisms, since inhibition of these caspases scarcely blocked PMN cell death. These findings suggest a mechanism for neutropenia in chronic brucellosis and reveal a novel Brucella-host cross-talk through which B. abortus is able to hinder the innate function of PMN.Fondo Especial de la Educación Superior/[0500-13]/FEES/Costa RicaFondo Especial de la Educación Superior/[0504-13]/FEES/Costa RicaFondo Especial de la Educación Superior/[0505-13]/FEES/Costa RicaFondo Especial de la Educación Superior/[0248-13]/FEES/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

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

Pattern of congenital malformations in newborn: a hospital-based study

Background: Birth defects, encountered frequently by pediatricians, are important causes of childhood morbidity and mortality. Birth defects can be classified based on their severity, pathogenic mechanism or whether they involve a single system or multiple systems. This hospital based prospective descriptive study highlights the prevalence of congenital anomalies (CAs) in one year, among liveborn neonates delivered in a university hospital. Design and methods: All women giving birth to babies were included. Demographic details, associated risk factors and the type of CAs in babies were recorded. Diagnosis of CAs was based on clinical evaluation, radiographic examination and chromosomal analysis of newborn whenever recommended. Results: The overall incidence of CAs among liveborn neonates was 2.5%, as most of the cases were referred to Zagazig University Hospital for delivery. The musculoskeletal system (23%) was the most commonly involved; followed by central nervous system (20.3%). Involvement of more than one system was observed in (28.6%) cases. Out of the maternal and fetal risk factors, parental consanguinity, maternal undernutrition and obesity, positive history of an anomaly in the family, low birth weight(LBW), and prematurity were significantly associated with higher frequency of CAs(p <0.05), with non-significant differences for maternal age and the sex of the neonates. Conclusion : The current study highlighted the point prevalence of congenital anomalies in one year in zagazig university hospital in Egypt. The present study revealed a high prevalence of congenital anomalies in our locality and stressed upon the importance of carrying out a thorough clinical examination of all neonates at birth

A PROSPECTIVE STUDY OF BRUCELLOSIS IN CHILDREN: RELATIVE FREQUENCY OF PANCYTOPENIA

Hematological complications in brucellosis are common. Pancytopenia, although mainly reported in adults has also been described in children with brucellosis. This investigation was conducted to estimate the relative frequency of pancytopenia in children with brucellosis. This study was carried out in Al-Khafji region, Saudi Arabia. Sixty patients with brucellosis, were enrolled in the study. At enrollment, the following investigations were performed: CBC, blood culture and BM, aspiration was carried out in all patients with pancytopenia, to exclude malignancy. Obtained results revealed that: out of 60 children with brucellosis, 50 (83%) ingested raw animal milk and 45% had a positive family history of brucellosis. The commonly presenting symptoms and signs included; excessive sweating (68%), bone aches (62%), chills (55%), arthritis (32%), and hepatosplenomegaly. The most commonly detected hematological manifestations included; anemia (in 43%), leukopenia (in 38%) and leukocytosis (in 20%). Meanwhile, pancytopenia was detected in 11 patients (18%). Positive blood culture for brucella was seen in 38% (23 patients). melitensis from 21 patients was cultured in vitro. Out of 9 BM cultures, 3 were positive for B. melitensis and 6 cultures were negative. Out of 11 patients with pancytopenia, 9 patients (82%) presented with bone aches and weakness, 7(64%) presented with sweating and chills, 6(55%) of patients had petechiea and purpura, 5 (46%) had splenomegaly and 5 (46%) had hepatomegal

Impact of maternal vitamin D status during pregnancy on the prevalence of neonatal vitamin D deficiency

Maternal vitamin D deficiency is not uncommon. The lack of vitamin D during pregnancy may result in poor fetal growth and altered neonatal development that may persist into later life. Recognition of risk factors and early detection of vitamin D deficiency during pregnancy is important in order to prevent neonatal vitamin D deficiency and related complications. The aim of the current study is to assess the effect of maternal vitamin D status on the neonatal vitamin D stores. A total of 92 pregnant women at the end of the 3rd trimester and their newborns were recruited from Al Khafji Joint Operation Hospital, Saudi Arabia, during the year 2011. Maternal and cord blood samples were taken for determination of serum levels of circulating 25-hydroxyvitamin D3 [25(OH)D3] concentration, serum calcium (Ca++), phosphorus (PO4) and alkaline phosphatase (ALP). Compared with pregnant women with adequate vitamin D levels, women deficient in vitamin D had infants with vitamin D deficiency (X±SD 33.44±18.33 nmol/L vs 55.39±17.37 nmol/L, P=0.01). Maternal and neonatal serum 25(OH)D3 levels showed a positive correlation with serum Ca++ and negative correlation with serum PO4 and ALP. Neonatal 25(OH)D was related to maternal 3rd trimester levels (r=0.89, P=0.01). The newborn serum 25(OH)D3 concentrations rely on maternal vitamin D status. Poor maternal vitamin D status may adversely affect neonatal vitamin D status and, consequently, calcium homeostasis

Pattern of Congenital Anomalies in Newborn: A Hospital-Based Study

Birth defects, encountered frequently by pediatricians, are important causes of childhood morbidity and mortality. Birth defects can be classified according to their severity, pathogenic mechanism, or whether they are involving a single system or multiple systems. This hospital-based prospective descriptive study highlights the prevalence of Congenital Anomalies (CAs) in one year among live born neonates delivered in Zagazig University Hospital (Egypt). All women giving birth to viable babies were included. Demographic details, associated risk factors and the type of CAs in all babies were recorded. Diagnosis of CAs was based on clinical evaluation, radiographic examination, ultrasonography, echocardiography and chromosomal analysis of the newborn whenever recommended. The overall incidence of CAs among live born neonates was 2.5%, as most of the cases were referred to Zagazig University Hospital (Egypt) for delivery. The musculoskeletal system (23%) was the most commonly involved followed by the central nervous system (20.3%). Involvement of more than one system was observed in (28.6%) cases. Among maternal and fetal risk factors; parental consanguinity, maternal under nutrition and obesity, positive history of an anomaly in the family, low birth weight, and prematurity were significantly associated with higher frequency of CAs (P<0.05), with non-significant differences for maternal age and the sex of the neonates. The current study highlights the prevalence of congenital anomalies in one year in Zagazig University Hospital. It revealed a high prevalence of congenital anomalies in our locality and stressed the importance of carrying out a thorough clinical examination of all neonates at birth