Epidermoid cysts are one of the uncommon slow growing lesions. There is some amount of controversy prevailing in the uniform understanding of these among the researchers regarding the nomenclature of ...these lesions. With a critical review of reported cases, author demarcated four different anatomical types of brain stem epidermoids and proposed a new classification system for a better understanding of the natural history.Four years female child presented with insidious onset left sixth and seventh cranial nerve palsy with right hemiparesis. Radiological evaluation revealed a pure intrinsic brain stem cystic lesion. Surgical decompression of the cyst was done, and the child recovered well. Histopathological examination was an epidermoid cyst.Brain stem epidermoids are uncommon, and there is no age or sex predilection. Based on the epicenter these tumors could be classified into four different types. Adequate surgical excision is the hallmark in the treatment. Nepal Journal of Neuroscience, Volume 14, Number 3, 2017, page: 33-41
Obesity is a significant factor related to metabolic disturbances that can lead to metabolic syndrome (MetS). Metabolic dysregulation causes oxidative stress, which affects telomere structure. The ...current study aimed to evaluate the relationships between telomere length, oxidative stress and the metabolically healthy and unhealthy phenotypes in healthy young men. Ninety-eight participants were included in the study (49 healthy slim and 49 obese patients). Study participants were divided into three subgroups according to body mass index and metabolic health. Selected oxidative stress markers were measured in serum. Relative telomere length (rTL) was measured using quantitative polymerase chain reaction. The analysis showed associations between laboratory markers, oxidative stress markers and rTL in metabolically healthy and unhealthy participants. Total oxidation status (TOS), total antioxidant capacity (TAC) and rTL were significantly connected with metabolically unhealthy obesity. TAC was associated with metabolically healthy obesity. Telomeres shorten in patients with metabolic dysregulation related to oxidative stress and obesity linked to MetS. Further studies among young metabolically healthy and unhealthy individuals are needed to determine the pathways related to metabolic disturbances that cause oxidative stress that leads to MetS.
V sodobni kulturi se srečujemo z vrsto zamenjav paradigem, ki usmerjajo pozornost h kulturnim vsebinam s poudarjenimi vizualnimi, kinetičnimi, taktilnimi in performativnimi učinki. Te izrazito ...demonstrira umetniški performans, ki kot avdiovizualen, taktilen, proprioceptičen in motoričen investira uprizorjena telesa v gibanju, je časoven in procesualen. Čeprav je performans v jedru performativnega obrata od kulture teksta (ki predstavlja literarno paradigmo) h kulturi performansa (ki vpliva tudi na neumetniška področja), sodi danes tudi tekst v performans, in sicer v tisti modalnosti, ki vključuje tako napisane/izgovorjene črke in besede kot druge besedilne sestavine: praznine, »belo pisavo«, prečrtane črke in besede, odsotnost, izginjanje in bralčevo telesnost vključujoče aranžmaje. V tem eseju obravnavamo projekta Bit.Fall in CyberSpaceLand, ki funkcionirata kot performansa hitrega pojavljanja besed in njihovega izginjanja ter kot uprizoritvi vizualnih besedilnih aranžmajev. Prav tako pa se v teh projektih vzpostavlja igra verbalnih in neverbalnih označevalcev, ki sodi k razširjenem konceptu teksta, razumljenega kot besedilna storitev; ta igra spodbuja ne-samo-branje kot novo modalnost kompleksnega izkušanja teksta.
Several ligands can bind to the non-canonical G-quadruplex DNA structures thereby stabilizing them. These molecules can act as effective anticancer agents by stabilizing the telomeric regions of DNA ...or by regulating oncogene expression. In order to better interact with the quartets of G-quadruplex structures, G-binders are generally characterized by a large aromatic core involved in π-π stacking. Some natural flexible cyclic molecules from Traditional Chinese Medicine have shown high binding affinity with G-quadruplex, such as berbamine and many other alkaloids. Using the structural information available on G-quadruplex structures, we performed a high throughput in silico screening of commercially available alkaloid derivative databases by means of a structure-based approach based on docking and molecular dynamics simulations against the human telomeric sequence dAG3(T2AG3)3 and the c-myc promoter structure. We identified 69 best hits reporting an improved theoretical binding affinity with respect to the active set. Among them, a berberine derivative, already known to remarkably inhibit telomerase activity, was related to a better theoretical affinity versus c-myc.
The cytogenomics-based methodology of Directional Genomic Hybridization (dGH™) emerged from the concept of strand-specific hybridization, first made possible by Chromosome Orientation FISH (CO-FISH), ...the utility of which was demonstrated in a variety of early applications, often involving telomeres. Similar to standard whole chromosome painting (FISH), dGH™ is capable of identifying inter-chromosomal rearrangements (translocations between chromosomes), but its distinctive strength stems from its ability to detect intra-chromosomal rearrangements (inversions within chromosomes), and to do so at higher resolution than previously possible. dGH™ brings together the strand specificity and directionality of CO-FISH with sophisticated bioinformatics-based oligonucleotide probe design to unique sequences. dGH™ serves not only as a powerful discovery tool-capable of interrogating the entire genome at the megabase level-it can also be used for high-resolution targeted detection of known inversions, a valuable attribute in both research and clinical settings. Detection of chromosomal inversions, particularly small ones, poses a formidable challenge for more traditional cytogenetic approaches, especially when they occur near the ends or telomeric regions. Here, we describe Telo-dGH™, a strand-specific scheme that utilizes dGH™ in combination with telomere CO-FISH to differentiate between terminal exchange events, specifically terminal inversions, and an altogether different form of genetic recombination that often occurs near the telomere, namely sister chromatid exchange (SCE).
In the past few decades, non-coding RNAs (ncRNAs) have emerged as important regulators of gene expression in eukaryotes. Most studies of ncRNAs in plants have focused on the identification of ...silencing microRNAs (miRNAs) and small interfering RNAs (siRNAs). Another important family of ncRNAs that has been well characterized in plants is the small nucleolar RNAs (snoRNAs) and the related small Cajal body-specific RNAs (scaRNAs). Both target chemical modifications of ribosomal RNAs (rRNAs) and small nuclear RNAs (snRNAs). In plants, the snoRNA genes are organized in clusters, transcribed by RNA Pol II from a common promoter and subsequently processed into mature molecules. The promoter regions of snoRNA polycistronic genes in plants are highly enriched in two conserved cis-regulatory elements (CREs), Telo-box and Site II, which coordinate the expression of snoRNAs and ribosomal protein coding genes throughout the cell cycle.
In order to identify novel ncRNA genes, we have used the snoRNA Telo-box/Site II motifs combination as a functional promoter indicator to screen the Arabidopsis genome. The predictions generated by this process were tested by detailed exploration of available RNA-Seq and expression data sets and experimental validation. As a result, we have identified several snoRNAs, scaRNAs and 'orphan' snoRNAs. We also show evidence for 16 novel ncRNAs that lack similarity to any reported RNA family. Finally, we have identified two dicistronic genes encoding precursors that are processed to mature snoRNA and miRNA molecules. We discuss the evolutionary consequences of this result in the context of a tight link between snoRNAs and miRNAs in eukaryotes.
We present an alternative computational approach for non-coding RNA detection. Instead of depending on sequence or structure similarity in the whole genome screenings, we have explored the properties of promoter regions of well-characterized ncRNAs. Interestingly, besides expected ncRNAs predictions we were also able to recover single precursor arrangement for snoRNA-miRNA. Accompanied by analyses performed on rice sequences, we conclude that such arrangement might have interesting functional and evolutionary consequences and discuss this result in the context of a tight link between snoRNAs and miRNAs in eukaryotes.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is expressed in germinal-center-derived, mononuclear Hodgkin (H) and multinuclear, diagnostic Reed-Sternberg (RS) cells in classical ...EBV-positive Hodgkin's lymphoma (cHL). LMP1 expression in EBV-negative H-cell lines results in a significantly increased number of RS cells. In a conditional, germinal-center-derived B-cell in vitro system, LMP1 reversibly down-regulates the shelterin proteins, telomeric repeat binding factor (TRF)1, TRF2, and protection of telomeres (POT)1. This down-regulation is associated with progressive 3D shelterin disruption, resulting in telomere dysfunction, progression of complex chromosomal rearrangements, and multinuclearity. TRF2 appears to be the key player. Thus, we hypothesize that the 3D interaction of telomeres and TRF2 is disrupted in H cells, and directly associated with the formation of H and RS cells. Using quantitative 3D co-immuno-TRF2-telomere fluorescent in situ hybridization (3D TRF2/Telo-Q-FISH) applied to monolayers of primary H and RS cells, we demonstrate TRF2-telomere dysfunction in EBV-positive cHL. However, in EBV-negative cHL a second molecular mechanism characterized by massive up-regulation of TRF2, but attrition of telomere signals, is also identified. These facts point towards a shelterin-related pathogenesis of cHL, where two molecularly disparate mechanisms converge at the level of 3D Telomere-TRF2 interactions, leading to the formation of RS cells.
Trisomies 18 and 21 are genetic disorders in which cells possess an extra copy of each of the relevant chromosomes. Individuals with these disorders who survive birth generally have a shortened life ...expectancy. As telomeres are known to play an important role in the maintenance of genomic integrity by protecting the chromosomal ends, we conducted a study to determine whether there are differences in telomere length at birth between individuals with trisomy and diploidy, and between trisomic chromosomes and normal chromosomes. We examined samples of peripheral blood lymphocytes (PBLs) from 31 live neonates (diploidy: 10, trisomy 18: 10, trisomy 21: 11) and estimated the telomere length of each chromosome arm using Q-FISH. We observed that the telomeres of trisomic chromosomes were neither shorter nor longer than the mean telomere length of chromosomes as a whole among subjects with trisomies 18 and 21 (intra-cell comparison), and we were unable to conclude that there were differences in telomere length between 18 trisomy and diploid subjects, or between 21 trisomy and diploid subjects (inter-individual comparison). Although it has been reported that telomeres are shorter in older individuals with trisomy 21 and show accelerated telomere shortening with age, our data suggest that patients with trisomies 18 and 21 may have comparably sized telomeres. Therefore, it would be advisable for them to avoid lifestyle habits and characteristics such as obesity, cigarette smoking, chronic stress, and alcohol intake, which lead to marked telomere shortening.
•The first data of telomere length of 18 and 21 trisomy patients at chromosomal level•The telomere length in trisomies was not significantly shorter than that in controls.•The telomere lengths were very variable within the same cell, and individual at birth.•The telomere of the p-arm was longer than that of the q-arm in 32.3% of the subjects.•No specifically short telomeres on either arm of trisomic chromosomes at birth
The 3D nuclear architecture is closely related to cellular functions and chromosomes are organized in distinct territories. Quantitative 3D telomere FISH analysis (3D Q-FISH) and 3D super-resolution ...imaging (3D-SIM) at a resolution up to 80 nm as well as the recently developed combined quantitative 3D TRF2-telomere immune FISH technique (3D TRF2/Telo-Q-FISH) have substantially contributed to elucidate molecular pathogenic mechanisms of hematological diseases. Here we report the methods we applied to uncover major molecular steps involved in the pathogenesis of EBV-associated Hodgkin's lymphoma. These methods allowed us to identify the EBV-encoded oncoprotein LMP1 as a key element in the formation of Hodgkin (H-cell) and multinucleated Reed-Sternberg cells (RS-cell), the diagnostic tumor cell of classical Hodgkin's lymphoma (cHL). LMP1 mediates multinuclearity through downregulation of shelterin proteins, in particular telomere repeat binding factor 2 (TRF2).
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