Radiopaque marker colonic transit study in the pediatric population BSPGHAN Motility Working Group consensus statement

Functional constipation (FC) is a common condition in childhood in the United Kingdom and worldwide. Various radiological approaches have been established for diagnostic purposes. The radiopaque marker study (ROMS) is universally accepted and used to assess colonic transit time (CTT) in children with FC. Despite being widely used, there is a lack of standardization with various technical protocols, reproducibility of different populations, the purpose for using investigation, variance in the number of markers used, the amount of study days and calculations, the need to empty the colon before performing the test, and whether to perform on medication or off, or the use of specific diets. As part of the British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) motility working group (MWG), we decided to explore further into the evidence, in order to provide guidance regarding the use of ROMS in dealing with FC in the pediatric population.

Targeted therapies for glioblastoma treatment

Glioblastoma, the most common and aggressive type of brain tumor in adults, poses significant challenges in terms of treatment. Conventional approaches including surgery, chemotherapy, and radiotherapy have yielded limited success, with a median survival of approximately 15 months. However, extensive research into the biology of glioblastoma has identified molecular targets that can be exploited by newly developed drugs, leading to the emergence of precise personalized therapies. Several innovative treatment strategies are currently under development, aiming to enhance effectiveness while minimizing side effects. Clinical trials are underway to evaluate the efficacy of monoclonal antibodies that target glioblastoma cells, either by blocking specific receptors or by modifying molecular interactions that impede cell proliferation. Another promising avenue involves the use of oncolytic viruses designed to selectively infect glioblastoma cells. Additionally, the review explores the utilization of nanocarriers capable of surmounting the formidable obstacle of the blood-brain barrier, enabling efficient drug delivery. Cell therapies represent another promising approach, with dendritic cells, chimeric antigen receptor-T cells, and macrophages emerging as potential treatment modalities. By summarizing recent advances in targeted therapies against glioblastoma, this review aims to provide a comprehensive overview of ongoing efforts to discover effective and safe methods for treating glioblastoma patients. The ultimate goal is to improve patient outcomes and transform the landscape of glioblastoma treatment.

From the original SARS-CoV-2 strain to the Omicron variant: predictors of COVID-19 in ambulatory symptomatic children

OBJECTIVES

To determine the predictors of a positive SARS-CoV-2 test in a pediatric ambulatory setting.

PATIENTS AND METHODS

We performed a cross-sectional prospective study (November 2020-February 2022) of 93 ambulatory settings in France. We included symptomatic children < 15 years old tested for SARS-CoV-2. For each period corresponding to the spread of the original strain and its variants (period 1: original strain; period 2: Alpha, period 3: Delta; period 4: Omicron), we used a multivariate analysis to estimate adjusted odds ratios (aORs) associated with COVID-19 among age, signs, symptoms or contact, and 95 % confidence intervals (95CIs).

RESULTS

Of 5,336 children, 13.9 % (95CI 13.0-14.8) had a positive test. During the first three periods, the positivity rate ranged from 5.6 % (95CI 4.6-6.7) to 12.6 % (95CI 10.8-14.6). The main factors associated with a positive test were contact with an infected adult at home or outside the home (aOR 11.5 [95CI 4.9-26.9] to 38.9 [95CI 19.3-78.7]) or an infected household child (aOR 15.0 [95CI 4.8-47.1] to 28.4 [95CI 8.7-92.6]). By contrast, during period 4, aORs for these predictors were substantially lower (2.3 [95CI 1.1-4.5] to 5.5 [95CI 3.2-7.7]), but the positivity rate was 45.7 % (95CI 42.3-49.2).

CONCLUSIONS

In pediatric ambulatory settings, before the Omicron period, the main predictor of a positive test was contact with an infected person. During the Omicron period, the odds of these predictors were substantially lower while the positivity rate was higher. An accurate diagnostic strategy should only rely on testing and not on age, signs, symptoms or contact.

Sialidase Attenuates Epidermal Growth Factor Response and Abolishes Antiproliferative Effects of Erlotinib in A549Alveolar Epithelial Cells

Erlotinib is a widely used, reversible tyrosine kinase inhibitor (TKI), targeting pro-proliferative signaling of epidermal growth factor receptor (EGFR). The drug is approved for the first-line treatment of patients with metastatic non-small cell lung cancer with EGFR mutations. Extracellular glycans can affect EGFR expression, dimerization, phosphorylation, and EGF binding. In this study we investigated the effects of EGF and erlotinib on the cell cycle of naive and sialidase (alpha-neuraminidase)-pretreated human A549 alveolar epithelial cells. A549 cells were labeled with propidium iodide, and fractions of cells in different phases of cycle were quantified by flow cytometry. We found that neither did desialilation nor EGF, as well as erlotinib treatment, increase the number of damaged cells (subG0/G1 cell fraction), while erlotinib did significantly increase the number of G0/G1 cells and decrease S + G2/M cell fractions. In naive cells, EGF increased proliferating cell numbers by more than 40%, and this effect was blocked by erlotinib. In desialylated cells, however, proliferation was significantly decreased by about 29%, and EGF and erlotinib did not exert significant effects. We conclude that changes in alveolar epithelial cell membrane glycosylation may affect function of growth-promoting receptors and erlotinib effectiveness.

Cigarette Smoke-Induced Oxidative Stress and Autophagy in Human Alveolar Epithelial Cell Line (A549 Cells)

Chronic exposure to cigarette smoke (CS) causes structural and functional changes in the respiratory tract. It is a major risk factor for cardiovascular and systemic pulmonary diseases. The aim of this study was to investigate the effect of acute CS exposure (2 h) on oxidative stress, heat shock protein 70 (HSP70) expression, autophagy (LC3 expression), and oxidative stress (DCF fluorescence) in human alveolar epithelial cell line A549. Cell culture medium was conditioned with CS using commercial cigarettes, and A549 cells were grown in modified media for 2 h. In some experiments, A549 cells were pretreated with 100 μM of L-buthionine-sulfoximine (BSO) for 24 h to induce glutathione (GSH) depletion. In the cells grown in CS-conditioned medium, GSH was depleted by more than 30%, and reactive oxygen species were increased. Moreover, there was a considerable overexpression of HSP70 and a substantial accumulation of LC3. Similar changes were found when the cells were pretreated with BSO. We conclude that the short-term exposure of epithelial cells to CS increases oxidative stress that entails enhanced autophagy activity.

The succession of the plant community on a decontaminated radioactive meadow site

Long-term observation of the succession in a plant community is considered a fundamental unit used to investigate the expected consequences of soil contamination by radionuclides and to understand restoration of technogeneously disturbed ecosystems. The development of arboreal willow meadow under remediation of a radioactively contaminated site has been studied for half a century. Succession stages in the formation of the de novo community were noted. Changes in the floristic composition, soil structure as well as radionuclide activity concentrations in topsoil were registered on each step. Technical recultivation of the area including covering radioactive wastes with a mixture of sand and gravel led to lower the radiation levels and was suitable for decontamination during first 5-8 years. This allowed the community to develop with maximal effectiveness on the initial steps. Than the covering layer lost its barrier functions but no adverse effects at dose rates up to 150 μGy/h on completion of the community formation were registered. Radioecological conditions and changes in the plant community development were registered simultaneously on the area studied that makes possible to follow main doseforming radionuclides migration and to determine main steps of the succession. The study results is a practical demonstration that edaphic niches, climatic conditions and сoenotic relationships between plants play a more important role in the evolution of the studied community than the contamination type and radiation exposure levels.

Sequential incremental doses of bisacodyl increase the diagnostic accuracy of colonic manometry

BACKGROUND

Colonic manometry is the standard diagnostic modality for evaluating colonic motility in children. Intraluminal bisacodyl is routinely used to trigger high-amplitude propagating contractions (HAPCs), a feature of normal colonic motility. Usually, only a single dose (0.2 mg/kg) is suggested. We retrospectively explored whether the use of an additional higher (0.4 mg/kg) dose of bisacodyl increases the yield of colonic manometry.

METHODS

In 103 children (median age: 8.8 years, range 3.2-15.7 years) with a diagnosis of slow transit constipation, colonic motility was recorded for 1 h before and 1 h after each of two incremental doses of bisacodyl (low, L, dose: 0.2 mg/kg, max 10 mg; high, H, dose: 0.4 mg/kg, max 20 mg) and the characteristics of HAPCs analyzed.

KEY RESULTS

High-amplitude propagating contractions were seen in 85 children. H dose significantly increased the proportion of patients with fully propagated HAPCs (H dose: 57/103 [55%], L dose: 27/103 [26%], p < 0.001), paralleling the significant decrease in the proportion with partially propagated HAPCs (H dose: 29/103 [28%], L dose: 47/103 [46%], p < 0.01). Mean HAPC number significantly increased throughout the colon at H compared to L dose (7.2 ± 5.05 vs 5.6 ± 5.1, p < 0.05). Finally, the proportion of patients with normal pressure wave morphology of HAPCs significantly increased with higher dose (H dose: 55/85 [65%], L dose: 27/85 [32%], p < 0.001).

CONCLUSIONS & INTERFERENCES

An additional higher dose of bisacodyl during colonic manometry improves colonic neuromuscular function suggesting its use might improve interpretation and decision making in children with slow transit constipation.

An unconventional role for miRNA: let-7 activates Toll-like receptor 7 and causes neurodegeneration

Activation of innate immune receptors by host-derived factors exacerbates CNS damage, but the identity of these factors remains elusive. We uncovered an unconventional role for the microRNA let-7, a highly abundant regulator of gene expression in the CNS, in which extracellular let-7 activates the RNA-sensing Toll-like receptor (TLR) 7 and induces neurodegeneration through neuronal TLR7. Cerebrospinal fluid (CSF) from individuals with Alzheimer’s disease contains increased amounts of let-7b, and extracellular introduction of let-7b into the CSF of wild-type mice by intrathecal injection resulted in neurodegeneration. Mice lacking TLR7 were resistant to this neurodegenerative effect, but this susceptibility to let-7 was restored in neurons transfected with TLR7 by intrauterine electroporation of Tlr7(−/−) fetuses. Our results suggest that microRNAs can function as signaling molecules and identify TLR7 as an essential element in a pathway that contributes to the spread of CNS damage.

Extracellularly delivered single-stranded viral RNA causes neurodegeneration dependent on TLR7

Innate immune receptors represent an evolutionarily ancient system that allows organisms to detect and rapidly respond to pathogen- and host-derived factors. TLRs are predominantly expressed in immune cells and mediate such a response. Although this class of pattern recognition receptors is involved in CNS disorders, the knowledge of ligands leading to activation of TLRs and to subsequent CNS damage is limited. We report in this study that ssRNA causes neurodegeneration and neuroinflammation dependent on TLR7 in the CNS. TLR7 is not only expressed in microglia, the major immune cells of the brain, but also in neurons of the CNS. Extracellularly delivered ssRNA40, an oligoribonucleotide derived from HIV and an established ligand of TLR7, induces neuronal cell death dependent on TLR7 and the central adapter molecule MyD88 in vitro. Activation of caspase-3 is involved in neuronal damage mediated by TLR7. This cell-autonomous neuronal cell death induced by ssRNA40 is amplified in the presence of microglia that mount an inflammatory response to ssRNA40 through TLR7. Intrathecal administration of ssRNA40 causes widespread neurodegeneration in wild-type but not in TLR7(-/-) mice, confirming that neuronal cell death induced by ssRNA40 through TLR7 occurs in vivo. Our results point to a possible mechanism through which extracellularly delivered ssRNA contributes to CNS damage and determine an obligatory role for TLR7 in this pathway.

Gene expression of pluripotency determinants is conserved between mammalian and planarian stem cells

Freshwater planaria possess extreme regeneration capabilities mediated by abundant, pluripotent stem cells (neoblasts) in adult animals. Although planaria emerged as an attractive in vivo model system for stem cell biology, gene expression in neoblasts has not been profiled comprehensively and it is unknown how molecular mechanisms for pluripotency in neoblasts relate to those in mammalian embryonic stem cells (ESCs). We purified neoblasts and quantified mRNA and protein expression by sequencing and shotgun proteomics. We identified ∼4000 genes specifically expressed in neoblasts, including all ∼30 known neoblast markers. Genes important for pluripotency in ESCs, including regulators as well as targets of OCT4, were well conserved and upregulated in neoblasts. We found conserved expression of epigenetic regulators and demonstrated their requirement for planarian regeneration by knockdown experiments. Post-transcriptional regulatory genes characteristic for germ cells were also enriched in neoblasts, suggesting the existence of a common ancestral state of germ cells and ESCs. We conclude that molecular determinants of pluripotency are conserved throughout evolution and that planaria are an informative model system for human stem cell biology.

De novo assembly and validation of planaria transcriptome by massive parallel sequencing and shotgun proteomics

Freshwater planaria are a very attractive model system for stem cell biology, tissue homeostasis, and regeneration. The genome of the planarian Schmidtea mediterranea has recently been sequenced and is estimated to contain >20,000 protein-encoding genes. However, the characterization of its transcriptome is far from complete. Furthermore, not a single proteome of the entire phylum has been assayed on a genome-wide level. We devised an efficient sequencing strategy that allowed us to de novo assemble a major fraction of the S. mediterranea transcriptome. We then used independent assays and massive shotgun proteomics to validate the authenticity of transcripts. In total, our de novo assembly yielded 18,619 candidate transcripts with a mean length of 1118 nt after filtering. A total of 17,564 candidate transcripts could be mapped to 15,284 distinct loci on the current genome reference sequence. RACE confirmed complete or almost complete 5' and 3' ends for 22/24 transcripts. The frequencies of frame shifts, fusion, and fission events in the assembled transcripts were computationally estimated to be 4.2%-13%, 0%-3.7%, and 2.6%, respectively. Our shotgun proteomics produced 16,135 distinct peptides that validated 4200 transcripts (FDR ≤1%). The catalog of transcripts assembled in this study, together with the identified peptides, dramatically expands and refines planarian gene annotation, demonstrated by validation of several previously unknown transcripts with stem cell-dependent expression patterns. In addition, our robust transcriptome characterization pipeline could be applied to other organisms without genome assembly. All of our data, including homology annotation, are freely available at SmedGD, the S. mediterranea genome database.

MiRNA need a TRIM regulation of miRNA activity by Trim-NHL proteins

Trim-NHL proteins are defined by RING, B-Box and Coiled-coil protein motifs (referred to collectively as the Trim domain) coupled to an NHL domain. The C. elegans, D. melanogaster, mouse and human Trim-NHL proteins are potential and in several cases confirmed, E3 ubiquitin ligases. Current research is focused on identifying targets and pathways for Trim-NHL-mediated ubiquitination and in assessing the contribution of the NHL protein-protein interactiondomain for function and specificity. Several Trim-NHL proteins were discovered in screens for developmental genes in model organisms; mutations in one of the family members, Trim32, cause developmental disturbances in humans. In most instances, mutations that alter protein function map to the NHL domain. The NHL domain is a scaffold for the assembly of a translational repressor complex by the Brat proto-oncogene, a well-studied family member in Drosophila. The link to translational control is common to at least four Trim-NHLs that associate with miRNA pathway proteins. So far, two have been shown to repress (Mei-P26 and Lin41) and two to promote (NHL-2, Trim32) miRNA-mediated gene silencing. In this chapter we will describe structure-function relations for each of the proteins and then focus on the lessons being learned from these proteins about miRNA functions in development and in stem cell biology.

Substituted 2-aminothiopen-derivatives: a potential new class of GluR6-antagonists

In the course of search for new therapeutic agents against epilepsy new inhibitors for the kainate receptor subtypes GluR5 and GluR6 were synthesized. We were able to synthesize new substituted thieno[2,3-d]pyrimidines 3a,b, 4a,b, 5a,b as well as thiophene-3-carboxamides 2a-d and a multitude of substituted 4-methyl-5-phenylthiophene-3-carboxylic acids. All compounds described herein were tested for their antagonistic effect towards the kainate receptor subtypes GluR5 and GluR6. The highest activity was observed for ethyl 2-amino-4-methyl-5-phenylthiophene-3-carboxylate 1c with an IC50=0.75 microM at the GluR6 receptor.

Synthesis of thieno[2,3-d]oxazines and thieno[2,3-d]thiazines as subtype specific kainate receptor antagonists

For the development of new antiepileptics the kainate receptors GluR6 and GluR5 are important targets. Based on the anticonvulsant effects of chinazolines and thieno[2,3-d]pyrimidines that are known from the literature, thieno[2,3-d][1.3]oxazines were synthesized and studied for their inhibitory properties at GluR6 and GluR5 receptors. The strongest inhibitor activity was observed with 5-methyl-6-phenyl-thieno[2,3-d][1.3]oxazines with C1 or C3-substituents in position 2 (3b-f). The 2-trihalide-methyl-substituted compounds 3c and 3d were the most active inhibitors at the GluR5-receptor (IC50=23.4 micromol, 16 microl). The 2-isopropyl-substituted compound 3f displayed the strongest activity at the GluR6-receptor (IC(50)=8.7 micromol). A number of thieno[2,3-d][1.3]thiazines and thieno[2,3-d] pyrimidines that were synthesized from the thieno[2,3][1.3]oxazines did not show any activity.

[Thieno[2,3-d]pyrimidines as antagonists of the glutamate receptors]

Although the function of the kainate receptors in the brain is still not clear, they are increasingly defined as targets in the development of new classes of anti-epileptics. The thienopyrimidines described in this report were tested for their antagonistic effect at the kainate receptor subtypes GluR5 and GluR6. The highest effectiveness was obtained by a 4-ethoxy-thieno[2,3-d]pyrimidin with an IC50 = 68 microM at the GluR6 receptor.

Post-transcriptional regulation of the let-7 microRNA during neural cell specification

The let-7 miRNA regulates developmental timing in C. elegans and is an important paradigm for investigations of miRNA functions in mammalian development. We have examined the role of miRNA precursor processing in the temporal control and lineage specificity of the let-7 miRNA. In situ hybridization (ISH) in E9.5 mouse embryos revealed early induction of let-7 in the developing central nervous system. The expression pattern of three let-7 family members closely resembled that of the brain-enriched miRNAs mir-124, mir-125 and mir-128. Comparison of primary, precursor, and mature let-7 RNA levels during both embryonic brain development and neural differentiation of embryonic stem cells and embryocarcinoma (EC) cells suggest post-transcriptional regulation of let-7 accumulation. Reflecting these results, let-7 sensor constructs were strongly down-regulated during neural differentiation of EC cells and displayed lineage specificity in primary cells. Neural differentiation of EC cells was accompanied by an increase in let-7 precursor processing activity in vitro. Furthermore, undifferentiated and differentiated cells contained distinct precursor RNA binding complexes. A neuron-enhanced binding complex was shown by antibody challenge to contain the miRNA pathway proteins Argonaute1 and FMRP. Developmental regulation of the processing pathway correlates with differential localization of the proteins Argonaute, FMRP, MOV10, and TNRC6B in self-renewing stem cells and neurons.

[Protected mercaptoalkylpyrimidinones: synthesis and test for immunostimulating activity]

Protected mercaptoalkylpyrimidinones: synthesis and test for immunostimulating activity 3-Hydroxyalkyl-pyrimidine 1 reacts with phosphoroxychloride and thioglycolic acid or thiourea to yield pyrimidin-3-ylalkylthioacetic acids 3 or pyrimidin-3-ylalkylthiouroniumsalts 5 respectively. Some of the pyrimidines 3 and 5 showed immunomodulatory activity.

[Procalcitonin in diagnosis of purulent and aseptic meningitis in children]

Procalcitonin (PCT) is a new indicator of the systemic response to severe infections. To evaluate clinical usefulness of serum procalcitonin measurements in the differential diagnosis of purulent versus aseptic meningitis in children was the aim of the study. Fifteen children (aged 1 month-14 years) with purulent meningitis and 12 children (aged 6 months-12 years) with aseptic meningitis were included into the study. Serum PCT concentration was measured on admission by immunoluminometric assay. Thirty healthy controls (aged 3 months-14 years) were also enrolled into the study. Serum PCT concentration was above 0.5 ng/ml in 14 out of 15 children with purulent meningitis (range 0.0-95.2 ng/ml; arrhythmetic mean--28.2 ng/ml). In all children with aseptic meningitis (range 0.0-0.3 ng/ml; mean--0.1 ng/ml) as well as in healthy controls (range 0.0-0.3 ng/ml; mean--0.1 ng/ml) serum PCT was below 0.5 ng/ml.

CONCLUSION

Elevated serum PCT concentration in child with meningitis suggests bacterial aetiology.

[Level of magnesium in blood serum in children from the province of Rzesz'ow]

In 142 girls and 107 boys aged 5-15 years serum magnesium level was determined by the colorimetric method. Decreased values were found in 24 children including 7 boys and 17 girls. In 21 of them neurotic reactions or concentration disturbances were observed.

Formation of prostacyclin-sensitive platelet aggregates in human whole blood in vitro. Part I. The occurrence of the phenomenon in healthy male volunteers

When unstirred citrated blood of young males was left to stand at 21 degrees C, the number of free platelets decreased as measured with a whole blood platelet counter. This decrease indicated spontaneous platelet aggregation (SPA) since it was accompanied by the time-dependent increase in platelet micro-aggregates and plasma beta-thromboglobulin while lactate dehydrogenase level did not change significantly. Addition of PGI2 to whole blood increased free platelet count and decreased the number of platelet micro-aggregates. The de-aggregatory effect of PGI2 (measured as a percentage increase in free platelet number) was correlated with the initial amount of platelet micro-aggregates. Blood storage enhanced SPA and de-aggregatory effect of prostacyclin. Immediately after blood collection de-aggregatory effect of prostacyclin was absent. Our results favour an assumption that prostacyclin-sensitive platelet aggregates in blood of young volunteers are formed in vitro rather than in vivo.