Incidence, predictors and criteria for the diagnosis of giardiasis in children

Background. The prevalence of giardiasis among children is 355 cases per 100,000, with 80 % of cases of infestation occurring in children under the age of 14 years. The urgency of the high prevalence of protozoal pathology in children is determined by the fact that its manifestations are often masked under various pathological conditions. The purpose was to study the incidence, predictors and criteria for the diagnosis of giardiasis in children. Materials and methods. Research design is a controlled randomized trial. The study included children suffering from giardiasis (n = 55), aged 3 to 17 years. The comparison group consisted of 30 apparently healthy children. A survey of patients and collection of material performed at the outpatient and gastroenterology departments of the MHI “Chernivtsi Regional Clinical Hospital” during 2014–2016. Laboratory and instrumental investigations were conducted in Ukrainian-German laboratory “Bukintermed” and children’s gastroenterology center “Digest”. Indirect (serological one, macroscopy of the duodenal mucosa in endoscopic examination, indirect signs of giardiasis in duodenal biopsy samples) and direct methods were used (microscopy of the feces, duodenal contents, detection of vegetative forms of lamblia in duodenal biopsy samples during histological examination). A parent survey was conducted. Results. A positive result was obtained in 29 out of 565 subjects surveyed for lamblia (5.1 %). More often, additional examination was required for the presence of giardiasis in children suffering from chronic diseases of the upper gastrointestinal and hepatobiliary system, allergic reactions, intestinal dysbiosis and persistent eosinophilia. Children affected with giardiasis were more likely to have a concomitant illness than the children of the comparison group (p < 0.05). In 41.4 % of cases, children lived in conditions that were not satisfactory, did not always follow the rules of sanitary hygiene. We have established antenatal (health during pregnancy, the course of pregnancy, the presence of occupational hazards), intranatal (premature birth, stimulation of labor and cesarean section, birth trauma and asphyxia in children) and postnatal adverse factors (duration of breastfeeding, concomitant pathology). All histological features can be used as possible criteria for giardiasis in children, but with the highest probability, the following sign can be used — the presence of villous epithelium desquamation areas with simultaneous dominance of eosinophils and mast cells in the infiltrate. Conclusions. The incidence of giardiasis in children and adolescents is 5.1 %. Anamnestic factors (social, hygienic, medical and biological ones) established by us can be considered as predictors for the development of giardiasis in children. In the clinical picture of giardiasis, the defeat of the digestive tract dominates — in 96.3 % of children. To improve the accuracy of giardiasis diagnosis in children, it is necessary to use a set of direct and indirect methods of the diagnosis

Incidence, predictors and criteria for the diagnosis of giardiasis in children

Мета. Вивчення частоти, предикторів і критеріїв діагностики лямбліозу в дітей. Висновки. Частота лямбліозу у дітей і підлітків дорівнює 5,1 %. Встановлені нами анамнестичні фактори (соціальні, гігієнічні, медико-біологічні) можна розглядати як предиктори розвитку лямбліозу в дітей. У клініці лямбліозу домінує ураження травного тракту – у 96,3 % дітей. Для підвищення точності діагностики лямбліозу в дітей необхідно використовувати комплекс прямих і непрямих методів діагностики. Цель. Изучение частоты, предикторов и критериев диагностики лямблиоза у детей. Выводы. Частота лямблиоза у детей и подростков составляет 5,1 %. Анамнестические факторы (социальные, гигиенические, медико-биологические) можно рассматривать как предикторы развития лямблиоза у детей. В клинике лямблиоза доминируют поражения пищеварительного тракта (у 96,3 % детей). Для повышения точности диагностики лямблиоза у детей необходимо использовать комплекс прямых и косвенных методов диагностики. The purpose was to study the incidence, predictors and criteria for the diagnosis of giardiasis in children. Conclusions. The incidence of giardiasis in children and adolescents is 5.1 %. Anamnestic factors (social, hygienic, medical and biological ones) established by us can be considered as predictors for the development of giardiasis in children. In the clinical picture of giardiasis, the defeat of the digestive tract dominates – in 96.3 % of children. To improve the accuracy of giardiasis diagnosis in children, it is necessary to use a set of direct and indirect methods of the diagnosis

The Functions of RNA-Dependent RNA Polymerases in Arabidopsis

One recently identified mechanism that regulates mRNA abundance is RNA silencing, and pioneering work in Arabidopsis thaliana and other genetic model organisms helped define this process. RNA silencing pathways are triggered by either self-complementary fold-back structures or the production of double-stranded RNA (dsRNA) that gives rise to small RNAs (smRNAs) known as microRNAs (miRNAs) or small-interfering RNAs (siRNAs). These smRNAs direct sequence-specific regulation of various gene transcripts, repetitive sequences, viruses, and mobile elements via RNA cleavage, translational inhibition, or transcriptional silencing through DNA methylation and heterochromatin formation. Early genetic screens in Arabidopsis were instrumental in uncovering numerous proteins required for these important regulatory pathways. Among the factors identified by these studies were RNA-dependent RNA polymerases (RDRs), which are proteins that synthesize siRNA-producing dsRNA molecules using a single-stranded RNA (ssRNA) molecule as a template. Recently, a growing body of evidence has implicated RDR-dependent RNA silencing in many different aspects of plant biology ranging from reproductive development to pathogen resistance. Here, we focus on the specific functions of the six Arabidopsis RDRs in RNA silencing, their ssRNA substrates and resulting RDR-dependent smRNAs, and the numerous biological functions of these proteins in plant development and stress responses