Fragment Length Research Articles

Engineering a single-chain variable fragment of cetuximab for CAR T-cell therapy against head and neck squamous cell carcinomas

The monoclonal antibody cetuximab recognizes domain III of the epithelial growth factor receptor (EGFR) with high-affinity and is an important element in the treatment of several malignancies that overexpress non-mutated wild-type EGFR. In order to create an EGFR recognizing chimeric antigen receptor (CAR) for cellular immunotherapy of head and neck squamous cell carcinoma (HNSCC), we rationally designed single chain fragments of different lengths based on the cetuximab variable heavy and light chains. We then cloned the different cetuximab fragments into our second generation CAR construct, expressed CARs on primary human T-cells from healthy donors using mono- or biscistronic lentiviral vectors and tested the stability, functionality and specificity of the CARs. Our smallest CAR construct was most efficient with greatly improved vector production and T-cell transduction efficacy. Finally, we demonstrated that the new cetuximab CAR construct expressed on T-cells is highly reactive against EGFR-positive HNSCCs and also malignant cells from other solid cancer entities. In conclusion, we generated an optimized high-affinity EGFR CAR construct for the next steps in cancer immunotherapy, which need to focus on the development of armored CAR T-cells that will be more resistant and effective in the hostile microenvironment present in solid cancers.

STRipy: A graphical application for enhanced genotyping of pathogenic short tandem repeats in sequencing data.

Expansions of short tandem repeats (STRs) have been implicated as the causal variant in over 50 diseases known to date. There are several tools which can genotype STRs from high‐throughput sequencing (HTS) data. However, running these tools out of the box only allows around half of the known disease‐causing loci to be genotyped. Furthermore, the genotypes estimated at these loci are often underestimated with maximum lengths limited to either the read or fragment length, which is less than the pathogenic cutoff for some diseases. Although analysis tools can be customized to genotype extra loci, this requires proficiency in bioinformatics to set up, limiting their widespread usage by other researchers and clinicians. To address these issues, we have developed a new software called STRipy, which is able to target all known disease‐causing STRs from HTS data. We created an intuitive graphical interface for STRipy and significantly simplified the detection of STRs expansions. Moreover, we genotyped all disease loci for over two and half thousand samples to provide population‐wide distributions to assist with interpretation of results. We believe the simplicity and breadth of STRipy will increase the genotyping of STRs in sequencing data resulting in further diagnoses of rare STR diseases.

Genetic polymorphisms of catalase (rs7943316), glutathione peroxidase-1 (rs1050450), and transferrin (rs8177178) in keratoconus on a limited group of Russian patients

A pilot study of the association of single nucleotide polymorphisms in catalase (rs7943316), glutathione peroxidase-1 (rs1050450), and transferrin (rs8177178) genes with the risk of keratoconus development was conducted in a sample of Russian patients. Genotyping was performed by analyzing the polymorphism of the lengths of restriction fragments using a polymerase chain reaction. Venous blood samples from 25 patients with keratoconus treated at the Ophthalmology Clinic of the Kirov Military medical Academy in 2019 and 2020 were examined. The control group included 20 patients who had no clinical signs of keratoconus. The effect of the single nucleotide polymorphism rs7943316 of the catalase gene on the risk of keratoconus development has not been established. The T allele of the glutathione peroxidase-1 gene containing the rs1050450 polymorphism slightly increases the risk of keratoconus compared with the C allele (odds ratio = 1.91; 95% confidence interval = 0.754.85; p = 0.17). A moderate association of the A allele of the transferrin gene containing rs8177178 polymorphism with the occurrence of keratoconus and an increase in the incidence of the disease associated with the AG genotype was revealed (odds ratio = 5.67; 95% confidence interval = 1.0730; p = 0.12). Thus, when examining a limited sample of Russian patients with keratoconus, it was not possible to identify a link between the disease and single nucleotide polymorphisms of catalase rs7943316 and glutathione peroxidase-1 rs1050450. The relationship between the polymorphism of the transferrin rs8177178 gene (allele A and genotype AG) and the risk of keratoconus development was weak and not significant. Thus, expanding the study sample and further studying the polymorphisms of the transferrin gene that affect the structure of the enzyme and reduce the effectiveness of antioxidant protection of the cornea were recommended.

Disruption of the human gut microbiota affected by ulcerative colitis

Objective: The stability of the intestinal flora is an important guarantee for maintaining human health. Whether it will disturb the stability of the flora after ulcerative colitis (UC) is worth exploring.
 Methods: An observational study was performed to evaluate the disruption of the human gut microbiota affected by UC. Chromosomal DNA was extracted, and the length of DNA fragments was examined and quantified. Gene amplification and sequencing of the V3 region of 16S rRNA were subsequently performed by Illumina’s MiSeq sequencer for high-throughput sequencing.
 Results: The structure of intestinal flora in UC patients exhibited a significant increase of Proteobacteria and a remarkable decrease of Bacteroidetes compared with that of healthy controls. Among each genus in the Proteobacteria, UC patients exhibited a significant decrease of Alcaligenaceae (55.08% ± 13.90 to 0.56% ± 0.04) and a remarkable increase of Enterobacteriaceae (6.64% ± 10.22 to 98.05% ± 3.28) compared with that of healthy controls. Our results demonstrated that the disorder of the intestinal flora is associated with UC patients.
 Conclusions: Therefore, UC patients exhibited a significant shift in the dominance of the gut microbiota, and restoring the homeostasis of the intestinal flora may be an important target for the treatment of UC and alleviation of symptoms.

Mechanical properties and metallurgical features of two similar endodontic rotary instruments with different heat treatments (FireWire™ and Gold).

The aim of this study was to explain the mechanical differences between EdgeTaper Platinum (ETP) and ProTaper Gold (PTG) determining the transition temperatures and the composition of the alloy of ETP, since no data are present in literature. A total of 130 instruments were selected: 65 ETP F2 and 65 PTG F2. 20 instruments per type were submitted to each mechanical tests. The cyclic fatigue and torsional tests were performed at a pre-set temperature of 35 °C ± 1 °C. During the cyclic fatigue test, Time to fracture, number of cycles to fracture (NCF) and the fragment length (FL) were recorded. During the static torsional, Torque to Fracture (TtF) and FL were recorded. The fracture surface of 5 randomly selected fragments from each test was examined through a Scanning Electron Microscopy (SEM) and an EDX analysis was performed. 20 instruments per type were submitted to a bending test The force generated (grams) to bend each was recorded. Recorded data of mechanical and metallurgical tests were statistically analyzed using a one-way analysis of variance (ANOVA) test with significance set to a 95% confidence level. ETP F2 showed a higher cyclic fatigue resistance and bending ability than PTG F2, with a statistically significant difference (p < 0.05). PTG showed a higher torsional resistance with a statistically significant difference (p < 0.05). DSC analysis of 5 samples for each instrument type pointed out that the austenite finish temperature of PTG was higher than the ETP, respectively of 49.99 ± 3.31 (°C) and 38.92 ± 1.75 (°C). EDX analysis confirmed the near-equiatomic composition of the Ni-Ti alloys, with a presence of a third component recognized as rubidium in the ETP samples. ETP showed higher flexibility in comparison with PTG, despite the latter is characterized by a more martensitic characterization. since its Af temperature is higher than the ETP.

On the Word Fragment Length for Unambiguous Reconstruction of a Periodic Word from a Complete Multiset of Fragments of Fixed Length

We consider the problem of reconstructing a word from a multiset of its fragments of fixed length. Words consist of symbols from a finite alphabet. The word to be reconstructed is assumed to be periodic or contain a periodic word as a subword. It is shown that a periodic word with a period p can be reconstructed from a multiset of its fragments of length k, where k geqslant leftlfloor {frac{{16}}{7}sqrt p } rightrfloor + 5. For a word consisting of a q-periodic prefix repeated m times and a p-periodic suffix repeated l times, if l geqslant m{{q}^{{leftlfloor {frac{{16}}{7}sqrt P } rightrfloor + 5}}}, then the estimate becomes k geqslant leftlfloor {frac{{16}}{7}sqrt P } rightrfloor + 5, where P = {text{max(}}p,~q{text{)}}.

Исследование нелинейной цифровой фильтрации сигналов с использованием генеративно-состязательной нейронной сети

The article presents the results of the study, as well as the structural schemes and parameters of the components of the generative-adversarial neural network. Graphical images of the results of filtering radio signals are given. Conclusions are drawn about the possibilities of using these neural networks. The purpose of the study. Substantiation of the possibilities of using generative-sensory artificial neural networks to solve problems of digital processing of radio signals. Materials and methods. To evaluate the results of digital filtering of noisy signals, the method of mathematical modeling in the Matlab environment was used. As test signals, the following were taken: a sine wave, a signal in the form of a sum of sinusoids, a model of a real radio-technical information signal. White Gaussian noise is used as the noise component. Also, filtering of the signal is carried out, in which there is no fragment of a certain length. A training sample was generated for the neural network of the generator, consisting of noisy test signals. A training sample of the discriminator neural network was also generated, consisting of test signals that do not contain noise. Results. Based on the simulation, it is concluded that the generative-adversarial neural network successfully solves the problems of isolating a useful signal in a mixture of it with noise of various physical nature. Such a neural network structure is also able to restore a useful signal if any part of it is missing as a result of external interference. Conclusion. The existing methods of digital filtering of radio signals require certain labor and time costs associated with the calculation of digital filters. Also, when designing high-order filters, it becomes difficult to calculate these filters. The idea of using a neural network in filtering tasks makes it possible to significantly reduce the filter design time, thus simplifying the process of its implementation. A neural network, which is a self-learning system, can find solutions that are inaccessible to conventional digital filtering algorithms. The results of this work can find their application in the field of digital signal processing and in the development of software-configurable radio.

Genetic variation of the endangered species Halenia coreana (Gentianaceae)

Halenia coreana is an endangered, endemic species that is distributed in only a few locations in Korea, such as Mts. Hwaaksan and Daeamsan. It has been recently segregated from H. corniculata, broadly distributed in cold temperate regions that include northern Japan, the Russian Far East, northeastern China, Mongolia, and eastern Europe, where population sizes are usually large. To examine the genetic diversity of H. coreana and evaluate the level of genetic differentiation of the species compared with that of H. corniculata, we surveyed 183 candidate simple sequence repeats (SSR) motif markers for H. coreana and H. corniculata from sequence data of amplified fragments of a specific length in the genome. A total of 17 genomic-SSR markers were selected to examine the levels of genetic diversity and differentiation using 17 samples of H. coreana and 60 samples of three populations of H. corniculata. The results here suggest that the genetic diversity of H. coreana is very low with a high frequency of inbreeding within its population. We found that H. coreana is genetically differentiated from H. corniculata, supporting the recognition of the geographically isolated H. coreana as a distinct species.

Metformin and lipopolysaccharide regulate transcription of NFATc2 gene via the transcription factor RUNX2

To construct a luciferase reporter gene vector carrying human nuclear factor of activated T cells 2 (NFATc2) gene promoter and examine the effects of metformin and lipopolysaccharide (LPS) on the transcriptional activity of NFATc2 gene. The promoter sequence of human NFATc2 gene was acquired from UCSC website for PCR amplification. NFATc2 promoter fragment was inserted into pGL3-basic plasmid double cleaved with Kpn Ⅰ and Hind Ⅲ. The resultant recombinant plasmid pGL3-NFATC2-promoter was co-transfected with the internal reference plasmid pRL-TK in 293F cells, and luciferase activity in the cells was detected. Reporter gene vectors of human NFATc2 gene promoter with different fragment lengths were also constructed and assayed for luciferase activity. The changes in transcription activity of NFATc2 gene were assessed after treatment with different concentrations of metformin and LPS for 24 h. We also examined the effect of mutation in RUNX2-binding site in NFATC2 gene promoter on the regulatory effects of metformin and LPS on NFATc2 transcription. We successfully constructed pGL3-NFATc2-promoter plasmids carrying different lengths (2170 bp, 2077 bp, 1802 bp, 1651 bp, 1083 bp, 323 bp) of NFATc2 promoter sequences as verified by enzymatic digestion and sequencing. Transfection of 293F cells with the plasmid carrying a 1651 bp NFATc2 promoter (pGL3-1651 bp) resulted in the highest transcriptional activity of NFATc2 gene, and the luciferase activity was approximately 3.3 times that of pGL3-2170 bp (1.843 ± 0.146 vs 0.547 ± 0.085). Moderate (5 mmol/L) and high (10 mmol/L) concentrations of metformin significantly upregulated the transcriptional activity of pGL3-1651 bp by up to 2.5 and 3 folds, respectively. LPS at different doses also upregulated the transcriptional activity of pGL3-1651 bp by at least 1.6 folds. The mutation in the RUNX2 binding site on pGL3-1651 bp obviously reduced metformin- and LPS-induced enhancement of pGL3-1651bp transcription by 1.7 and 2 folds, respectively. pGL3-NFATc2-promoter can be transcribed and activated in 293F cells, and LPS and metformin can activate the transcription of pGL3- NFATc2-promoter in a RUNX2-dependent manner.

Associative role of polymorphism of the РТРN22 (C1858T) gene in the development of hypertension in patients with the rheumatoid arthritis

Objective. To assess the role of polymorphism of PTPN22 (C1858T) gebe in the development of hypertension (TNH) in patients with the rheumatoid arthritis (RA).Design and methods. We examined 202 patients with RA, we identified the following groups: patients with RA without HTN was identified (n = 53; 26%); patients with RA in association with HTN (n = 95; 47%), as well as patients with HTN without RA (n = 54; 27%). Healthy volunteers (n = 205) were also divided into 3 groups comparable by age, sex and size with the main groups. We applied clinical, laboratory, instrumental and molecular genetic methodsDNA isolation was performed by the standard phenol-chloroform method. Genotyping by the PTPN22 gene was carried out by the PCR-PDRF analysis method (polymerase chain reaction — polymorphism of the length of restriction fragments). PCR was performed with a set of primers to the corresponding areas of the genome. PCR products were analyzed by electrophoresis in a 4% polyacrylamide gel followed by staining with ethidium bromide.Results. The TT homozygous genotype and the T allele of the С1858Т gene polymorphism PTPN22 were predominant in the RA group and RA + HTN group compared to controls. The risk of RA without HTN is 1,7 fold higher in the TT carriers of the PTPN22 gene genotype, compared to CC and CT genotype carriers. Allele T was significantly more common in the group of patients with RA without HTN than in control group 1 [OR = 1,521 (95% confidence interval 1,0–2,324); р &lt; 0,05]. A similar distribution of genotypes and alleles is seen in the group of RA patients in association with HTN compared to control group 2. No significant difference was found in the group of patients with HTN without RA compared to control group 3.Conclusions. Our study indicates that the homozygous TT genotype and the C1858T polymorphism T allele of the PTPN22 gene are predictors of RA development alone and in association with HTN.

Analytical model and Monte Carlo simulations of polymer degradation with improved chain cut statistics

The degradation of polymers is described by mathematical models based on bond cleavage statistics including the decreasing probability of chain cuts with decreasing average chain length. We derive equations for the degradation of chains under a random chain cut and a chain end cut mechanism, which are compared to existing models. The results are used to predict the influence of internal molecular parameters. It is shown that both chain cut mechanisms lead to a similar shape of the mass or molecular mass loss curve. A characteristic time is derived, which can be used to extract the maximum length of soluble fragments l of the polymer. We show that the complete description is needed to extract the degradation rate constant k from the molecular mass loss curve and that l can be used to design polymers that lose less mechanical stability before entering the mass loss phase.Graphical abstract

Retention of viability by fragmented invasive Crassula helmsii, Elodea canadensis and Lagarosiphon major

AbstractInvasive aquatic macrophytes tend to reproduce and spread through vegetative means, often via fragmentary propagules. Dispersal among aquatic sites may occur overland via attachment to various vectors, or within river systems by directional water currents. However, for many species the relationship between fragment size and resumption of growth is unknown. Here, we assessed resumption of growth of apical and mid‐stem fragments of invasive Crassula helmsii, Elodea canadensis and Lagarosiphon major. Proportionally, apical fragments tended to more readily resume growth than mid‐stem sections, especially for E. canadensis and L. major (80–100%). However, viability did not scale linearly with increasing fragment size, which suggests that fragment size is not a singular determinant of propagule fitness. Nevertheless, longer fragments generally produced greater numbers of shoots and roots, but root production significantly differed among species and was determined through an interaction between plant section, species and fragment length. Overall, all species produced new shoots and roots from fragments as small as 10 mm. C. helmsii mid‐stem fragments standardised by node counts did not display new growth (up to 10 nodes), while E. canadensis tended to show greater shoot and root production with increasing node counts. It is evident that a medium to high proportion of small fragmentary propagules of these invasive macrophytes can retain viability. These data have clear implications for understanding the dispersal of these invasive species and their management. Specifically, cutting and dredging may increase rather than decrease infestations, especially in downstream directions. Thus, in the absence of adequate fragment containment, current short‐term control strategies may in fact be counterproductive.

Genotype Frequency of the Common TLR4 SNPs in a Kurdish Population: Global Reviews and Out-of-African Migrations.

Toll-like receptors (TLRs) are cellular innate immune receptors that explore microbial molecules. For instance, TLR4 can sense bacterial lipopolysaccharides, inducing cytokines and antimicrobial peptides against the bacteria. Single-nucleotide polymorphisms (SNPs) in TLR4 are associated with diseases such as septic shock. Therefore, investigations of common SNPs may help explain the pathogenesis of diseases and various innate immune responses to infections. This study investigated genotypic frequencies of the two common TLR4 SNPs, Asp299Gly and Thr399Ile, in a Kurdish population using restriction length fragment polymorphisms (RFLPs). Global frequencies of both TLR4 SNPs in different populations of sub-Saharan Africa, North Africa, western Asia, Eurasia, and East Asia were also used to infer human migrations and past settlements. The RFLP data demonstrate that, in the Kurdish population, the genotypic frequencies of both SNPs are similar to Iranian or other West Asian populations, which in turn are comparable to Eurasian populations, suggesting past admixture due to migrations, population intermixing, and common ancestry. Globally, the frequencies of the homozygous wild-types of TLR4 variants are prevalent, but homozygous mutants are rare or lacking in almost all global populations. Frequencies of the heterozygotes varied among populations. For instance, in sub-Saharan Africa the frequency of the Asp299Gly SNP is higher than that of Thr399Ile, whereas in the Arabian Peninsula both SNPs are present at high frequencies. In contrast, East Asian populations lack or have very low frequencies of both TLR4 SNPs of interest. Moreover, co-segregation of the TLR4 SNPs is common in some populations, which may indicate important associations with certain diseases. Future studies are required to link the TLR4 SNPs with either resistance or susceptibility to diseases.

Conserved Motifs and Domains in Members of Pospiviroidae.

In 1985, Keese and Symons proposed a hypothesis on the sequence and secondary structure of viroids from the family Pospiviroidae: their secondary structure can be subdivided into five structural and functional domains and “viroids have evolved by rearrangement of domains between different viroids infecting the same cell and subsequent mutations within each domain”; this article is one of the most cited in the field of viroids. Employing the pairwise alignment method used by Keese and Symons and in addition to more recent methods, we tried to reproduce the original results and extent them to further members of Pospiviroidae which were unknown in 1985. Indeed, individual members of Pospiviroidae consist of a patchwork of sequence fragments from the family but the lengths of fragments do not point to consistent points of rearrangement, which is in conflict with the original hypothesis of fixed domain borders.

Risk assessment of gastric cancer in the presence of Helicobacter pylori cagA and hopQII genes.

Helicobacter pylori bacterium is one of the most common bacterial infections globally and is the leading cause of indigestion, gastric and duodenal ulcers, and gastric cancer. This bacterium can escape the antibacterial effects of stomach acid by adapting to the inner layers of the stomach. It combines with the natural sugars in the gastric mucosa. The compound is so effective that it makes bacterium resistant. For genes related to the pathogenesis of H. pylori, using the existence of genes such as cagA, hopQI, and hopQII, PCR is performed on some of these genes to amplify fragments of different lengths. One of the less-studied cases is that two or more pathogenic genes are simultaneously associated with H. pylori. This study examined the frequency of diseases and healthy individuals infected with H. pylori and cagA and hopQII genotypes. To diagnose H. pylori infection in healthy and stomach cancer patients, the PCR products are electrophoresed on the agarose gel after glmM gene amplification by PCR. To this aim, stomach tissue biopsies were used for patients, and saliva was used for healthy individuals. For this purpose, 150 gastric biopsy samples from stomach cancer patients and 150 saliva samples from healthy people were collected. Data showed a significant relationship between the coexistence of two genes, cagA and hopQII, and stomach cancer. 34.2% of patients and 10.1% of healthy individuals showed two genotypes, while other healthy people (89.9%) infected with H. pylori did not have this genotype. Therefore, the simultaneous presence of these two bacterial genes in human societies can be an essential biomarker for the diagnosis and prognosis of gastric cancer.

Effect of the temperature of sodium hypochlorite on the cyclic fatigue resistance of ProTaper Gold rotary files.

Instrument fracture is one of major challenges during root canal treatment. In order to reduce such errors, it seems necessary to investigate the effects of potentially impactful factors. One of such factors could be the temperature of an agitator. This study examined the effects of different temperature of the sodium hypochlorite solution on the cyclic fatigue resistance of ProTaper Gold (PTG) rotary files. Forty-five PTG S1 rotary files were tested in a metal block that simulated a canal curvature angle of 60° and a curvature radius of 5 mm. They were randomly divided into 3 groups of 15 according to sodium hypochlorite temperatures of 22°C (group 1), 4°C (group 2) and 37°C (group 3). Files from each group were rotated at 300 rpm in the block at each temperature. The number of cycles to fracture was calculated and the fragment length was measured. The fractured surfaces were examined by means of scanning electron microscopy (SEM). The statistical analysis was completed using the Kolmogorov-Smirnov and Kruskal-Wallis tests, and the IBM SPSS Statistics for Windows software, v. 22.0, at a significance level of 5%. The cyclic fatigue resistance of the PTG rotary files was not significantly affected by the temperature of sodium hypochlorite (p > 0.05). Increasing the temperature of sodium hypochlorite to 37°C or decreasing it to 4°C did not significantly affect the cyclic fatigue resistance of PTG rotary files.

Micromechanical Tests on Natural Fibre Composites with Enzymatically Enhanced Fibre–Matrix Adhesion

Natural fibre–reinforced composites are more sustainable than other composites with respect to the raw materials. Their properties are attractive due to high specific properties, and especially so wherever high damping is valued. As the interphase between fibre and matrix is the region of highest stresses, a strong bond between fibre and matrix is essential for any composites’ properties. The present study compares two methods of determining the interfacial shear stress in natural fibre–reinforced composites: the single fibre fragmentation test and the single fibre pullout test. The studied composites are flax fibre reinforced epoxy. For a variety of fibre–matrix interaction, the fibres are treated with a laccase enzyme and dopamine, which is known to improve the fibre–matrix shear strength. In the observed samples, single fibre fragmentation test data, i.e. of fracture mode and fragment length, scatter when compared to pullout data. In single fibre pullout tests, the local interfacial shear strength showed a 30% increase in the laccase-treated samples, compared to the control samples. The method also permitted an evaluation of the frictional stress occurring after surface failure.

Towards molecular autopsies: Development of a FFPE tissue DNA extraction workflow

Sudden unexpected death (SUD) is a devastating event and forms a substantial proportion of the cases investigated at forensic mortuaries each year. Despite post-mortem investigations, the cause of death may remain undetermined. There is potential for these unresolved cases to benefit from retrospective molecular autopsies for investigation into genetic mutations which may have contributed towards death. Often, formalin fixed paraffin embedded tissues (FFPET) are the only archival sources of DNA available for retrospective analyses. However, extracting usable DNA from FFPET is challenging as current methods yield poor quality and quantity DNA. Thus, this study aimed to optimise DNA recovery from FFPET by investigating several variables within the DNA extraction workflow, including the selection of tissue type, number and thickness of tissue sections, deparaffinisation method, and DNA extraction kit. The quantity and quality of DNA recovered were assessed using spectrophotometry, real time PCR, digital capillary electrophoresis and DNA profiling. This study was the first to implement a nuclei quantification using microscopy to guide the selection of the best tissue type to use for DNA analysis. The use of a greater number of thinner tissue sections (100 sections, each 1 μm) significantly improved DNA concentration, purity and fragment length. Additionally, the combination of Deparaffinization Solution with the QIAamp® DNA FFPE Tissue Kit proved most favourable with a median DNA yield of 320 ng and 55% of DNA fragments greater than 400 bp. Isolated DNA was of single source, indicating no contamination in the workflow, and FFPET blocks that were stored for up to 3.5 years did not significantly affect DNA degradation (p = 0.1764). These results are especially informative for designing library preparation and sequencing workflows for determining cause of death in unresolved SUD cases.

Development of a method for the identification of rs6265 polymorphism in the human brain neurotrophic factor gene

The analysis and generalization of data from the literature sources characterizing the structural organization, regulation of expression, and functional activity of the neurotrophic factor of the human brain, which is one of the most common regulators of biological processes in the nervous system, is carried out. The results of numerous studies demonstrating the association of the brain-derived neurotrophic factor (BDNF) gene with the pathophysiology of the affective disorders are noted, and its contribution to the development of neuroplasticity is confirmed. The results of the design of a pair of primers and adaptation of the amplification reaction of the BDNF region with a length of 433 nucleotide pairs containing the polymorphic locus RS6265 are presented. Restriction endonuclease was selected. The sequence of primers, their localization, and correlation with the restriction site provided the separation of alternative alleles necessary for the successful identification of this marker. The use of the proposed technique made it possible to uniquely identify the genotype in 38 examined whole blood samples and identify the rare allelic variants. Also, the frequency of polymorphic variants of RS6265 of the BDNF gene was established in all the samples. There was an increase in the proportion of genotypes G/A and A/A of the RS6265 polymorphism of the BDNF gene in the group of examined systematically exposed to extreme factors. Identification of people with a rare A/A genotype of the RS6265 polymorphic locus of the BDNF gene is of a great importance for the monitoring system of long-term potentiation processes leading to the development of neuropsychic pathology. The possibility of implementing this method of genotyping in a typical laboratory using a polymerase chain reaction is proved. The proposed version of the polymerase chain reaction with the subsequent analysis of the polymorphism of the lengths of restriction fragments could be used as a fast, inexpensive, and reliable system for identifying single-nucleotide genetic polymorphisms.

Morphological analysis of posterior malleolar fractures with intra-articular impacted fragment in computed tomography scans

BackgroundIntraarticular impacted fragment (IAIF) of posterior malleolar fractures has been reported by a few studies. However its location, morphology, and the correlation of posterior malleolar fractures have not been described in detail. The aim of this study was to describe the morphology of IAIF in posterior malleolar fractures, to analyze the related factors between IAIF and posterior malleolar fragments, and explore the treatment of IAIF.Materials and methodsBetween January 2013 and December 2018, 108 consecutive patients with unilateral posterior malleolar fractures were managed in our hospital. Basic demographic and computed tomography (CT) data were collected and classified by Lauge–Hansen, OTA/AO, Haraguchi, and Mason classification. Additional radiographic data, including the length and area of posterior malleolar fragment, IAIF, and stable tibial plafond were measured. The location of IAIF was described, and involvement of the fibular notch and medial malleolus was also observed. Statistics were analyzed based on univariate analysis (Chi-square test, t-test, Mann–Whitney U test, Fisher’s test) and Spearman’s correlation test.ResultsAmong the 108 cases of posterior malleolar fractures, 75 (69.4%) were with IAIF and 33 (30.6%) cases were without. There were 74 (68.5%) females and 34 (31.5%) males, and the average age of the patients was 49 years (18–89 years). The average LIFN/(LIFN + LSFN) [length of involving fibular notch/(length of involving fibular + length of stable notch fibular notch)] was 32.9% (11.6–64.9%). The APMF/(APMF + ASTP + AIAIF) [area of posterior malleolar fragment/(area of posterior malleolar fragment + area of IAIF + area of stable tibial plafond)] and AIAIF/APMF (area of IAIF/area of posterior malleolar fragment) were 13.1% (0.8–39.7%) and 52.6% (1.2–235.4%), respectively. Involvement of medial malleolus (fracture line extended to medial malleolus, P = 0.022), involvement of fibular notch (P = 0.021), LIFN/(LIFN + LSFN) (P = 0.037), LMPMF (P = 0.004), and APMF were significantly related to the occurrence of IAIF.ConclusionOur research indicates a high incidence of IAIF in posterior malleolar fractures. All IAIFs were found in posterior malleolar, and the most common location was within the lateral area A. Posterior malleolar fracture lines that extend to medial malleolus or fibular notch herald the incidence of IAIF. LIFN/(LIFN + LSFN), LMPMF and APMF are also associated with the incidence of IAIF. CT scans are useful for posterior malleolar fractures to determine the occurrence of IAIF and make operational plans. Operation approach selection should be based on the morphology of posterior malleolar fragments and the location of IAIF.Level of evidenceLevel III, retrospective case analysis.