Forms Of Aberrations Research Articles

Gain-Type Aneuploidies Influence the Burden of Selective Long Non-Coding Transcripts in Colorectal Cancer.

Chromosomal instability is a hallmark of colorectal carcinogenesis and produces an accumulation of different forms of aneuploidies or broad copy number aberrations. Colorectal cancer is characterized by gain-type broad copy number aberrations, specifically in Chr20, Chr8q, Chr13 and Chr7, but their roles and mechanisms in cancer progression are not fully understood. It has been suggested that broad copy number gains might contribute to tumor development through the so-called caricature transcriptomic effect. We intend to investigate the impact of broad copy number gains on long non-coding RNAs' expression in colorectal cancer, given their well-known role in oncogenesis. The influence of such chromosomal aberrations on lncRNAs' transcriptome profile was investigated by SNP and transcriptome arrays in our series of colorectal cancer samples and cell lines. The correlation between aneuploidies and transcriptomic profiles led us to obtain a class of Over-UpT lncRNAs, which are transcripts upregulated in CRC and further overexpressed in colon tumors bearing specific chromosomal aberrations. The identified lncRNAs can contribute to a wide interaction network to establish the cancer driving effect of gain-type aneuploidies.

An analytic expression for the field dependence of three-order Zernike aberrations in decentered and/or tilted optical systems

The double Zernike polynomials can describe the aperture dependence and field dependence of non-coaxial optical system aberrations simultaneously, and characterize the complex optical aberrations, which are of great value in the optical system design and alignment. In this paper, the specific analytic forms of all third-order double Zernike aberrations in decentered and/or tilted optical systems are derived based on the nodal aberration theory. This paper realizes the orthogonalization of the third-order aberrations with different aperture dependence and field dependence. The calculation process of the third-order double Zernike aberrations is presented. The ray tracing of the Cassegrain telescope verifies the analytic derivation of the double Zernike aberrations.

Influence of Aberrations on Modal Decomposition for LMA Fiber Laser Systems

Understanding the mode components is of great importance to manipulate the optical modes and to improve the optical system performance. However, various forms of aberrations, stemming from misalignment and imperfect optical components and system design, degrade the performance of the modal decomposition (MD) system. Here we analyze the influence of various Zernike aberrations on MD performance in large-mode-area fiber laser systems. Using computer-generated optical correlation filter together with angular multiplexing technique, we can simultaneously measure multi-modal contents. Among the common aberrations, we find that the MD results are least sensitive to vertical astigmatism aberration. However, the vertical coma aberration and horizontal coma aberration have a large impact on MD results under the same aberration strength, which show a rather large change in modal weight and intermodal phase. Our analysis is useful to construct a precise MD system applicable for high-power optical fiber modal analysis and mode control.

Carbamazepine adversely altered the pituitary-testicular axis with resultant reproductive dysfunctions than levetiracetam or carbamazepine-levetiracetam adjuvant treatment in male Wistar rat.

This study investigated the on-toward reactions of individual or adjunctive treatment with carbamazepine (CBZ) and levetiracetam (LEV) on the pituitary-testicular axis in male rats. Twenty-four male Wistar rats were randomised into 4 groups (n=6) and received daily intraperitoneal (i.p) treatment of normal saline (0.1ml/day); CBZ (25mg/kg i.p); LEV (50mg/kg i.p); or combination of CBZ (12.5mg/kg) and LEV (25mg/kg) for 4weeks. The serum concentration of luteinising hormone (LH), follicle-stimulating hormone (FSH), and testosterone was determined. Also, the seminal profile and histomorphological status of the testis were determined. Data were analysed using descriptive and inferential statistics. The control and test groups were compared using Student's t test, analysis of variance (ANOVA), and Student-Newman-Keuls post hoc analysis where appropriate, while the results presented as mean±SEM in graphs or tables. The level of significance was taken at p<.05. The percentage motility, viability, and concentration of FSH decreased significantly in all the treatment groups, while the testis was presented with various forms of histomorphological aberrations. This study concludes that CBZ, and CBZ+LEV adjunctive treatments alter the pituitary-testicular axis with evidence of hormonal deregulation and alteration in the reproductive functions' indices, while LEV treatment remains the safest.

Destruction of Sound Signal Structure in a Peripheral Population (as Exemplified by the Gray Marmot Marmota baibacina).

The variability of the alarm call of the gray marmot (Marmota baibacina) in the peripheral population in the valley of the Arpa River (Kyrgyzstan) is described. It was earlier reported that this population lived together with the red marmot (M. caudata). The authors did not find the red marmot there. Two forms of aberrations were found in the edge population of the gray marmot: amplitude modulation and no pause between the components. The destruction of the signal structure that is typical of the species is probably associated with the disruption of gene flow and does not contain clear signs of hybridization. The material was collected under the field conditions.

Genotoxicity study of nano Al2O3, TiO2 and ZnO along with UV-B exposure: An Allium cepa root tip assay

The present effort aims to investigate the cytotoxic and genotoxic impact of three widely used nanoparticles (ZnO, TiO2 and Al2O3) on root cells of Allium cepa as a test organism. The root tip of Allium cepa were treated with three different concentrations (0.1 10 and 100 mg/L) of the above-mentioned NPs and the observations were recorded after proper growth of root under both nanoparticle solutions and UV-B exposure in combined conditions and separately. The parameters such as mitotic index, various forms of chromosomal aberrations, various reactive oxygen species (ROS) generation such as superoxide radical (O−2·), hydrogen peroxide, hydroxyl radical (·OH), lipid peroxidation and bio-uptake of nanoparticles were assessed. The results revealed that for all the three nanoparticles, mitotic index (MI) was highly reduced in comparison to control. Among the three nanoparticles, the MI value of TiO2 was 59.5% at 0.1 mg/L. Chromosomal aberration data suggest that nano Al2O3 exhibited disturbed metaphase at 0.1 mg/L, and abnormal anaphase and sticky metaphase at 10 and 100 mg/L, respectively. Similarly, lagged metaphase and anaphase with multiple chromatin bridges were recorded for both nano ZnO and nano TiO2 at 0.1 mg/L. But, nonsignificant (p > 0.05) results were recorded between only nano metal oxide and UV-B along with nano metal oxide. ROS generation data revealed that ZnO is more active under UV-B than TiO2 and Al2O3. The cellular deformation and the existence of metal in A. cepa under nano ZnO, TiO2 and Al2O3 treatment were evaluated by Scanning Electron Micrograph (SEM) and X-ray fluorescence (XRF) study, respectively. It may safely be concluded that with respect to chromosomal aberration and mitotic index, out of the three nanoparticles, Al2O3 is the most severe at higher concentrations and nano ZnO shows lowest mitotic index under UV-B exposure.

A study on coronary artery anomalies in adult patients undergoing coronary angiography for various indications

Introduction: As variations in coronary artery anatomy is very common, the term “coronary artery anomaly” (CAA) applies only to the rarer forms of anatomic aberrations seen in the general population. CAAs are usually detected incidentally during coronary angiography (CAG) or autopsy. Some hemodynamically significant anomalies cause symptoms at young age and can cause sudden death. Knowledge of CAA is necessary to suspect them in appropriate clinical setting for early diagnosis and management that may be lifesaving. Subjects and Methods: Over a period of 1 year, we studied coronary anatomy of 1000 adult patients attending a tertiary cardiac center for coronary artery disease, valvular heart disease planning valve surgery, etc., where CAG was required. The absolute prevalence of different CAAs was recorded. Results: In our study, 3.6% of the patients had CAA. Most common of them were “right coronary artery arising from the left sinus” and “separate origin of the left anterior descending artery and left circumflex artery from the left sinus.” A significant coronary artery fistula was the next common. Conclusion: Some CAAs made coronary intervention technically challenging. There were hemodynamic implications in some, namely myocardial ischemia resulting from significant myocardial bridge and “coronary steal phenomenon” related to large coronary artery fistula. A high index of suspicion is required for early diagnosis, and the management of most serious forms can abort serious consequences. Information regarding CAAs is also helpful to overcome procedural difficulty during coronary and cardiothoracic interventions and avoid complications.

An Evaluation of Hepatotoxicity, Nephrotoxicity, and Genotoxicity Induced by Acute Toxicity of Hexavalent Chromium and Comparison of the Possible Protective Role of Selenium and Vitamin E on These Effects

Introduction Hexavalent chromium Cr (VI) is a strong oxidizing toxic agent. It penetrates cell membrane and quickly reduced with production of reactive intermediates and reactive oxygen species that react with the DNA causing anomalies in the cell structure. Vitamin E (vit. E) is a lipid soluble antioxidant preventing damage to membranes also selenium (Se) is an essential micronutrient with an antioxidant activity. Aim of the present study was to evaluate the hepatotoxicity, nephrotoxicity, and genotoxicity induced by acute Cr (VI) toxicity. Also, to evaluate and compare the possible protective role of vit. E and Se against that toxicity. Methodology: This study was carried out on 60 adult male albino rats divided into 10 rats of six groups, negative control group, selenium control group (0.5 mg/kg IP for 5 consecutive days), vitamin E control group (125 mg/kg orally for 14 days), Cr (VI) group (10 mg/kg single dose IP), Cr (VI) + Selenium group and hexavalent chromium + Vitamin E group. Liver and kidney function tests, total protein, oxidative stress, antioxidant markers and genotoxic analysis were done to all groups. Result: Acute Cr(VI) toxicity resulted in increased levels of the studied liver, kidney , oxidative stress markers, all forms of chromosomal aberrations and elevation of DNA damage. It decreased levels of total protein and antioxidant markers. Treatment with Se or vit. E resulted in improvement in all these effects. Conclusion& recommendation: Cr (VI) is a hepatotoxic, nephrotoxic, and genotoxic. Se or vit. E has the ability for reduction of these deleterious effects. So it is recommended to do regular medical examination of workers exposed to hexavalent chromium for early detection of any health problem and afford dietary supplementation with vitamin E and selenium.

A Novel Method for Identifying the Potential Cancer Driver Genes Based on Molecular Data Integration.

The identification of the cancer driver genes is essential for personalized therapy. The mutation frequency of most driver genes is in the middle (2-20%) or even lower range, which makes it difficult to find the driver genes with low-frequency mutations. Other forms of genomic aberrations, such as copy number variations (CNVs) and epigenetic changes, may also reflect cancer progression. In this work, a method for identifying the potential cancer driver genes (iPDG) based on molecular data integration is proposed. DNA copy number variation, somatic mutation, and gene expression data of matched cancer samples are integrated. In combination with the method of iKEEG, the "key genes" of cancer are identified, and the change in their expression levels is used for auxiliary evaluation of whether the mutated genes are potential drivers. For a mutated gene, the concept of mutational effect is defined, which takes into account the effects of copy number variation, mutation gene itself, and its neighbor genes. The method mainly includes two steps: the first step is data preprocessing. First, DNA copy number variation and somatic mutation data are integrated. Then, the integrated data are mapped to a given interaction network, and the diffusion kernel is used to form the mutation effect matrix. The second step is to obtain the key genes by using the iKGGE method, and construct the connection matrix by means of the gene expression data of the key genes and mutation impact matrix of the mutated genes. Experiments on TCGA breast cancer and Glioblastoma multiforme datasets demonstrate that iPDG is effective not only to identify the known cancer driver genes but also to discover the rare potential driver genes. When measured by functional enrichment analysis, we find that these genes are clearly associated with these two types of cancers.

FEN1-mediated α-segment error editing during Okazaki fragment maturation

DNA-replication-repair machinery determines the non-random occurrence of variations across the genome. During eukaryotic nuclear-genome replication, most parts of the leading and lagging strand are synthesized by high fidelity DNA polymerase ϵ and δ respectively. However, a third enzyme polymerase (Pol) α-primase initiates each synthesis event. During Okazaki fragment, down-stream of the RNA primer and synthesis, DNA fragment synthesized by proofreading-deficient Pol-α, which we termed as α-segment, provide major source of mutations and undergo DNA repair process to remove the incorporated errors.1 The α-segment contributes ∼1.5% of total genome. A series of the very recent papers made available by Nature press indicates that despite Okazaki fragment processing, DNA synthesized by Pol α is retained in vivo.2-5 DNA-binding proteins including histones and transcription factors that rapidly re-associate, post-replication, to act as partial barriers to Pol-δ-mediated displacement of the α-segment, resulting increased mutation rates in the region. What is the cellular mechanism that minimizes the mutation frequency in the alpha-segment? Limited evidence is available. Pol α variant strains have mild mutator phenotypes, resulting from DNA replication errors generated by Pol α, and their mutation rates are synergistically increased by loss of MSH2-dependent mismatch repair (MMR). Thus, MSH2-dependent MMR in yeast plays a major role in correcting mismatches in the α-segment.1 Additional study indicated that some mismatches generated by yeast Pol α are excised by exonuclease 1 (EXO1), a 5′ exonuclease involved in MMR.6 Interestingly, the loss of MMR resulting from deleting EXO1 is mild compared to the loss of MMR from deleting MSH2, implying the existence of a MSH2-dependent but EXO1-independent mechanism that removes mismatches from the α-segment. In our paper currently in press with EMBO Journal,7 we investigated the molecular mechanism mediated by FEN1 and MSH2 functional complex to edit the errors in the α-segment. Our unique substrate designing strategy segregates the RNA primer removal (RPR) and α-segment error editing (AEE) activities of FEN1 and characterize efficiency of functional enzymatic component of nuclear extract (NEs). Interestingly, besides its well-characterized RNA primer removl function, FEN1 was able to go on in an exonuclease fashion in presence of the mis-paired nucleotides in the α-segment and remove them within a limited distance (12 nts) from the nick MSH2 interacts with FEN1 and facilitates its nuclease activity to remove mismatches near the 5′ ends of DNA substrates. Mouse cells and mice encoding FEN1 AEE defective mutations display a strong mutator phenotype, enhanced cellular transformation, and increased cancer susceptibility.7 The proposed AEE mechanism is significant because it effectively removes replication errors while concomitantly maturing Okazaki fragments, which is a rate-limiting step in DNA replication.7 However, if a mutation occurs in AEE components that deregulates the process and leads to constitutive editing and futile cycles, it could affect DNA ligation and result in spontaneous DNA strand breaks and consequently, various forms of chromosome aberrations. Such a mutation would be different from the ones due to defects in RPR process, of which the major form is the duplication mutation. Both the mutations that result in DNA strand breaks and aneuploidy and the duplication mutation, are hallmarks of human cancer. The current study identifies a novel role of FEN1 in a specialized mismatch repair pathway and a new cancer etiological mechanism.

Third-order aberration analysis of tilted-pupil optical systems

The aberration field of an optical system with a tilted pupil is explored through expanding the vector expressions of the third-order wavefront aberrations. First, the vector forms of the wavefront aberrations are modified to obtain the aberration expressions with the pupil tilted; full field displays of coma and astigmatism in this situation are given. Then, the third-order aberration formulas with the pupil decentered and tilted simultaneously are derived and discussed. Finally, an example is taken to certify the validity of aberration distribution properties.

English

Most industries are sited with little or no consideration for environmental and social consequences, especially in developing countries. This has led to the discharge of genotoxic chemicals used for many purposes in the manufacturing processes into environmental compartments such as air, water, soil and sediments. Results of the cytotoxic and genotoxic assays of these wastewaters on&nbsp;Allium cepa&nbsp;root tip meristem showed significant reduction of mitotic indices and diverse forms of chromosomal aberrations, cytokinetic failures, micro and multiple nuclei. In Nigeria, the results of diverse assessments of industrial effluents have shown that they are environmental risks and potential mutagenic agents, problems still exist in the enforcement of on ground sound legislative by Federal Ministry of Environment and Federal Environmental Protection Agency. Failure in implementation of sound policies has been identified to be caused by weakness and poor enforcement by the necessary arms of the government, public awareness of international, national and local environmental laws. Legislation and standards that apply to existing and proposed projects are grossly lacking, the absence of mandatory disclosure of information by industries hinders monitoring which is a major problem to compliance and enforcement. Furthermore, there is absence of a legal framework which would ensure that industries comply with the requirement of standing environmental legislation. Any development that does not respect the environment cannot be said to be sustainable. There is therefore the need to integrate the environmental legislatives and environmental impact assessment (EIA) reports in the establishment and consequent monitoring of industries and industrial activities for the establishment and promotion of sustainable development and sound technologies. &nbsp; Key words:&nbsp;Genotoxic,&nbsp;Allium&nbsp;test, industry, legislation, wastewater.

Okazaki fragment maturation: nucleases take centre stage

Completion of lagging strand DNA synthesis requires processing of up to 50 million Okazaki fragments per cell cycle in mammalian cells. Even in yeast, the Okazaki fragment maturation happens approximately a million times during a single round of DNA replication. Therefore, efficient processing of Okazaki fragments is vital for DNA replication and cell proliferation. During this process, primase-synthesized RNA/DNA primers are removed, and Okazaki fragments are joined into an intact lagging strand DNA. The processing of RNA/DNA primers requires a group of structure-specific nucleases typified by flap endonuclease 1 (FEN1). Here, we summarize the distinct roles of these nucleases in different pathways for removal of RNA/DNA primers. Recent findings reveal that Okazaki fragment maturation is highly coordinated. The dynamic interactions of polymerase δ, FEN1 and DNA ligase I with proliferating cell nuclear antigen allow these enzymes to act sequentially during Okazaki fragment maturation. Such protein-protein interactions may be regulated by post-translational modifications. We also discuss studies using mutant mouse models that suggest two distinct cancer etiological mechanisms arising from defects in different steps of Okazaki fragment maturation. Mutations that affect the efficiency of RNA primer removal may result in accumulation of unligated nicks and DNA double-strand breaks. These DNA strand breaks can cause varying forms of chromosome aberrations, contributing to development of cancer that associates with aneuploidy and gross chromosomal rearrangement. On the other hand, mutations that impair editing out of polymerase α incorporation errors result in cancer displaying a strong mutator phenotype.

Aberrations theory of a time dependent magnetic field lens

We analyze new forms of aberrations affecting a time dependent magnetic field lens recently proposed. The lens consist of an axially symmetric ellipsoidal solenoid producing a spatially uniform but time pulsating homogeneous field. The dynamics of electrons emitted by some object and injected into this coil shows that this system is capable of focusing a parallel beam or produce images free of geometrical aberrations. The cardinal elements of this lens change periodically in positions and therefore to obtain a stationary image it is necessary to employ a chopped electron beam. Two forms of aberrations originate from the finite duration of the electron pulse and the energy dispersion of the incoming beam (chromatic aberration). Their image degradation effects are quite similar and result from recording different axially displaced images at some fixed stationary plane. We show how, by adjusting the parameters characterizing the magnetic pulse and introducing small apertures that increase the depth of focus, their effects can be reduced or in some cases eliminated. Other forms of instrumental aberrations characteristic of this time dependent magnetic field lens are briefly discussed.

Aberrations theory of a time dependent magnetic field lens

We analyze new forms of aberrations affecting a time dependent magnetic field lens recently proposed. The lens consist of an axially symmetric ellipsoidal solenoid producing a spatially uniform but time pulsating homogeneous field. The dynamics of electrons emitted by some object and injected into this coil shows that this system is capable of focusing a parallel beam or produce images free of geometrical aberrations. The cardinal elements of this lens change periodically in positions and therefore to obtain a stationary image it is necessary to employ a chopped electron beam. Two forms of aberrations originate from the finite duration of the electron pulse and the energy dispersion of the incoming beam (chromatic aberration). Their image degradation effects are quite similar and result from recording different axially displaced images at some fixed stationary plane. We show how, by adjusting the parameters characterizing the magnetic pulse and introducing small apertures that increase the depth of focus, their effects can be reduced or in some cases eliminated. Other forms of instrumental aberrations characteristic of this time dependent magnetic field lens are briefly discussed.

Monochromatic aberrations and characteristics of retinal image quality

Background:Patients use a wide variety of terms to describe the characteristics of their vision. These descriptions encompass the effects of their eyes' monochromatic aberrations. Methods:To illustrate the effect of monochromatic aberrations on the quality of the retinal image, we mathematically reconstructed the image falling on the retina. This has been achieved by combining the properties of various scenes with the optical characteristics of the eye. Results:The effects of some common monochromatic aberrations are illustrated. We also show examples of the retinal image characteristics for two eyes, one with a decentred corneal apex and a second with a decentred refractive surgery ablation. Conclusions:The image reconstruction technique provides a powerful tool for investigating the quality of the retinal image. It provides the capacity for clinicians to better understand a patient's visual performance. The image reconstruction technique can also broaden our knowledge of the effects of various forms of aberrations on retinal image quality for complex real‐world scenes.

Radiation-Induced Chromosomal Aberrations in Simulated Internal Contamination with Radioactive Caesium

Human blood samples were treated with various amounts of dissolved 137 Cs and incubated for one hour, then washed with culture medium. The doses received by lymphocytes were calculated and the cells were cultivated for chromosomal aberration assay. It was found that the unstable forms of chromosomal aberrations, taken separately or collectively, were distributed in a non-Poisson manner among the irradiated cells. The data were fitted to the linear and linear quadratic models. In accidents involving internal contamination with radioactive caesium, this approach may be used for dose assessment as an adjunct to physical measurements by whole-body counter and bioassay

Maternal and fetal chromosomal aberrations in mice following prenatal exposure to subembryotoxic doses of lead nitrate.

Maternal exposure to low levels of lead nitrate (12.5, 25, 50 mg/kg body weight), administered on the 9th day of gestation, did not cause embryonic resorption and fetal lethality, but induced chromosomal deletions and other forms of aberrations in fetal liver and maternal bone marrow cells.

Invariant aberrations I Preliminaries

In this paper I begin the investigation, in the context of Lagrangian aberration theory, of the existence and the explicit forms of aberrations of any order that are invariant, possibly only when ancillary conditions are satisfied, under displacements of the plane of the entrance pupil or of that of the object or both simultaneously, i.e., under p-variations, l-variations, or s-variations. Much of the formal work revolves about the effects of infinitesimal linear transformations of coordinates on linear combinations of homologous aberration coefficients. Generically, any invariant is the product of a scale factor with such a linear combination, and recurrence relations are found for the numerical multipliers that enter into it.

Significance of keratosis and dyskeratosis for classifying hyperplastic aberrations of laryngeal mucosa

Retrospective study of 325 tissue samples of hyperplastic aberrations of the laryngeal mucosa by means of light and electron microscopy and immunohistochemical methods has demonstrated that superficial keratinization is not important for determining changes into precancerosis or "risky epithelium" or even for the progress from hyperplastic aberrations to carcinoma. The degree of keratinization of the epithelial surface in all three forms of hyperplastic aberrations is almost the same. In grouping the hyperplastic aberrations into "precanceroses" or "risky epithelium," the following morphologic changes have to be considered as extremely important factors: the occurrence of dyskeratotic cells, the basalification of the epithelium, and the response of the organism in the form of infiltration of immunocompetent cells in the subepithelial stroma.