Expression profile of viability and stress response genes as a result of resveratrol supplementation in vitrified and in vitro produced cattle embryos.

BACKGROUND: Resveratrol, a potent antioxidant, is known to induce the up-regulation of the internal antioxidant system. Therefore, it holds promise as a method to mitigate cryopreservation-induced injuries in bovine oocytes and embryos. This study aimed to (i) assess the enhancement in the quality of in vitro produced bovine embryos following resveratrol supplementation and (ii) monitor changes in the expression of genes associated with oxidative stress (GPX4, SOD, CPT2, NFE2L2), mitochondrial function (ATP5ME), endoplasmic reticulum function (ATF6), and embryo quality (OCT4, DNMT1, CASP3, ELOVL5). METHODS AND RESULTS: Three groups of in vitro bovine embryos were cultured with varying concentrations of resveratrol (0.01, 0.001, and 0.0001 µM), with a fourth group serving as a control. Following the vitrification process, embryos were categorized as either good or poor quality. Blastocysts were then preserved at - 80 °C for RNA isolation, followed by qRT-PCR analysis of selected genes. The low concentrations of resveratrol (0.001 µM, P < 0.05 and 0.0001 µM, P < 0.01) significantly improved the blastocyst rate compared to the control group. Moreover, the proportion of good quality vitrified embryos increased significantly (P < 0.05) in the groups treated with 0.001 and 0.0001 µM resveratrol compared to the control group. Analysis of gene expression showed a significant increase in OCT4 and DNMT1 transcripts in both good and poor-quality embryos treated with resveratrol compared to untreated embryos. Additionally, CASP3 expression was decreased in treated good embryos compared to control embryos. Furthermore, ELOVL5 and ATF6 transcripts were down-regulated in treated good embryos compared to the control group. Regarding antioxidant-related genes, GPX4, SOD, and CPT2 transcripts increased in the treated embryos, while NFE2L2 mRNA decreased in treated good embryos compared to the control group. CONCLUSIONS: Resveratrol supplementation at low concentrations effectively mitigated oxidative stress and enhanced the cryotolerance of embryos by modulating the expression of genes involved in oxidative stress response.

Oxidative DNA Damage and Zinc Status in Patients With Rheumatoid Arthritis in Duhok, Iraq.

Background In patients with rheumatoid arthritis, oxidative DNA damage is increased by deficient zinc levels as well as increasing disease activity. However, the relationship between zinc levels, disease activity, and oxidative DNA damage remains unclear. In this study, we investigated serum zinc levels and disease activity and their association with 8-hydroxy-2-deoxyguanosine (8-OHdG). Methodology This case-control study was conducted among rheumatoid arthritis patients (n = 264) and healthy individuals (n = 192). Oxidative DNA damage was assessed by measuring serum 8-OHdG using enzyme-linked immunosorbent assay. Colorimetry was used to measure serum zinc levels. Disease activity was assessed using the Disease Activity Score-28 (DAS-28) score. Results Significantly higher 8-OHdG levels (p < 0.00) were found in the test group compared to the control group. Moreover, significantly lower serum zinc levels (p < 0.001) were noted in patients with rheumatoid arthritis compared to the control group. In addition, higher 8-OHdG levels were found in patients with low serum zinc levels compared to those with normal mean serum zinc levels. Lower levels of DNA oxidative damage were found in patients with moderate and low disease activity compared to those with high disease activity. A significant negative correlation was noted between serum zinc levels and DAS-28 scores and oxidative DNA damage marker (r = - 0.30, p = 0.038 and r = - 0.26, p = 0.043, respectively), while a significant positive correlation was observed between body mass index and 8-OHdG (r = 0.22, p = 0.02) in healthy individuals. Conclusions High serum 8-OHdG levels and high disease activity with low mean serum zinc levels may indicate a high degree of oxidative DNA damage in patients with rheumatoid arthritis.

Unraveling the Chemosensing Mechanism by the 7-(Diethylamino)coumarin-hemicyanine Hybrid: A Ratiometric Fluorescent Probe for Hydrogen Peroxide.

The hemicyanine hybrid containing the 7-(diethylamino)coumarin (ACou) donor attached to the cationic indolenium (Ind) acceptor through a vinyl linkage (ACou-Ind) represents a classic ratiometric fluorescent probe for detecting nucleophilic analytes, such as cyanide and reactive sulfur species (RSS), through addition reactions that disrupt dye conjugation to turn off red internal charge transfer (ICT) fluorescence and turn on blue coumarin emission. The chemosensing mechanism for RSS detection by ACou-Ind suggested in the literature has now been revised. Our studies demonstrate that thiolates react with ACou-Ind through conjugate addition to afford C4-SR adducts that lack coumarin fluorescence due to photoinduced electron transfer quenching by the electron-rich enamine intermediate. Thus, ACou-Ind serves as a turn-off probe through loss of red ICT fluorescence upon RSS addition. The literature also suggests that blue coumarin emission of thiolate adducts is enhanced in the presence of reactive oxygen species (ROS) due to ROS-mediated cellular changes. Our studies predict that such a scenario is unlikely and that thiolate adducts undergo oxidative deconjugation in the presence of H2O2, the pervasive ROS. Under basic conditions, H2O2 also reacts directly with ACou-Ind to generate intense coumarin fluorescence through an epoxidation process. The relevance of our chemosensing mechanism for ACou-Ind was assessed within live zebrafish, and implications for the utility of ACou-Ind for unraveling the interplay between RSS and ROS are discussed.

Bibenzyl synthesis in Cannabis sativa L.

This study focuses on the biosynthesis of a suite of specialized metabolites from Cannabis that are known as the 'bibenzyls'. In planta, bibenzyls accumulate in response to fungal infection and various other biotic stressors; however, it is their widely recognized anti-inflammatory properties in various animal cell models that have garnered recent therapeutic interest. We propose that these compounds are synthesized via a branch point from the core phenylpropanoid pathway in Cannabis, in a three-step sequence. First, various hydroxycinnamic acids are esterified to acyl-coenzyme A (CoA) by a member of the 4-coumarate-CoA ligase family (Cs4CL4). Next, these CoA esters are reduced by two double-bond reductases (CsDBR2 and CsDBR3) that form their corresponding dihydro-CoA derivatives from preferred substrates. Finally, the bibenzyl backbone is completed by a polyketide synthase that specifically condenses malonyl-CoA with these dihydro-hydroxycinnamoyl-CoA derivatives to form two bibenzyl scaffolds: dihydropiceatannol and dihydroresveratrol. Structural determination of this 'bibenzyl synthase' enzyme (CsBBS2) indicates that a narrowing of the hydrophobic pocket surrounding the active site evolved to sterically favor the non-canonical and more flexible dihydro-hydroxycinnamoyl-CoA substrates in comparison with their oxidized relatives. Accordingly, three point mutations that were introduced into CsBBS2 proved sufficient to restore some enzymatic activity with an oxidized substrate, in vitro. Together, the identification of this set of Cannabis enzymes provides a valuable contribution to the growing 'parts prospecting' inventory that supports the rational metabolic engineering of natural product therapeutics.

Glucan and glycogen exist as a covalently linked macromolecular complex in the cell wall of Candida albicans and other Candida species.

The fungal cell wall serves as the interface between the organism and its environment. Complex carbohydrates are a major component of the Candida albicans cell wall, i.e., glucan, mannan and chitin. ß-Glucan is a pathogen associated molecular pattern (PAMP) composed of ß-(1 â†’ 3,1 â†’ 6)-linked glucopyranosyl repeat units. This PAMP plays a key role in fungal structural integrity and immune recognition. Glycogen is an α-(1 â†’ 4,1 â†’ 6)-linked glucan that is an intracellular energy storage carbohydrate. We observed that glycogen was co-extracted during the isolation of ß-glucan from C. albicans SC5314. We hypothesized that glucan and glycogen may form a macromolecular species that links intracellular glycogen with cell wall ß-(1 â†’ 3,1 â†’ 6)-glucan. To test this hypothesis, we examined glucan-glycogen extracts by multi-dimensional NMR to ascertain if glycogen and ß-glucan were interconnected. 1H NMR analyses confirmed the presence of glycogen and ß-glucan in the macromolecule. Diffusion Ordered SpectroscopY (DOSY) confirmed that the ß-glucan and glycogen co-diffuse, which indicates a linkage between the two polymers. We determined that the linkage is not via peptides and/or small proteins. Our data indicate that glycogen is covalently linked to ß-(1 â†’ 3,1 â†’ 6) glucan via the ß -(1 â†’ 6)-linked side chain. We also found that the glucan-glycogen complex was present in C. dublinensis, C. haemulonii and C. auris, but was not present in C. glabrata or C. albicans hyphal glucan. These data demonstrate that glucan and glycogen form a novel macromolecular complex in the cell wall of C. albicans and other Candida species. This new and unique structure expands our understanding of the cell wall in Candida species.

Synthesis and hyperglycemic, biochemical and histopathological evaluation of novel sulfonylbiguanide and sulfonylurea derivatives as potent anti-diabetic agents.

New sulfonylbiguanide hydrochloride salts and sulfonylurea derivatives containing two sulfonyl groups were synthesized through the reaction of arylsulfonohydrazides with cyanoguanidine and p-tolylsulfonylisocyanate, respectively. Oral treatment of hyperglycemic rats with the synthesized sulfonylbiguanide derivatives 2 and sulfonylurea derivatives 3 revealed that sulfonylurea derivatives 3a and 3c possessed significant decrease of the elevated glucose in compression with the anti-diabetic standard drugs. Effects of the synthesized sulfonylurea derivatives 3a and 3c on the diabetic properties towards α-amylase, liver function enzyme levels (AST, ALT, ALP, TB and γ-GT), kidney functions (urea and creatinine), lipids profiles (TG, TL, TC and HDL-C) were studied. Also, the effect of sulfonylurea derivatives 3a and 3c as antioxidants (reduced glutathione and lipid peroxide) was evaluated. Histopathological examination of hepatic and pancreatic tissues was investigated. The obtained results suggested that the most potent sulfonylurea derivatives 3a and 3c might be possible used as novel diabetic inhibitor agents.

Variants of SARS-CoV-2, their effects on infection, transmission and neutralization by vaccine-induced antibodies.

OBJECTIVE: The current study reviewed Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) variants for their effects on infection, transmission and neutralization by vaccine-induced antibodies. MATERIALS AND METHODS: The research articles for the current study were searched over PubMed, Google Scholar, EMBASE and Web of Science online databases. The keywords used were: (("SARS-CoV-2" OR "COVID-19") AND ("mutation" OR "variant") AND ("death" OR "hospitalization" OR "infection" OR "transmission") AND ("antibody" OR "neutralize" OR "vaccine")). A total of 333 research articles were retrieved through online-database search. These articles were further scrutinized for their relevancy. Additionally, searches were performed to find the latest relevant information over Google search engine and relevant news browsers. Finally, around 35 germane articles were considered for scripting the current report. RESULTS: The mutations have changed amino acids at key positions in spike protein viz. S477N, E484K, Q677H, E484Q, L452R, K417T, K417N and N501Y. These mutations are relevant for different characteristics and are present in newly evolved strains of SARS-CoV-2 like E484K in B.1.526, B.1.525, P.2, B.1.1.7, P.1 and B.1.351. Mutations have increased the immune escape potential leading to 3.5-6.5-folds decrease in neutralization of antibodies (Pfizer and Moderna vaccines). The variant, B.1.617 circulating in India and many other countries (double variant) having E484Q and L452R mutations, has raised the infection rate and decreased the neutralization capacity of the vaccine-induced antibodies. Deadly K417N+E484K+N501Y triplet mutations found in B.1.351 and P.1 have increased the transmission ability of these strains by 50% leading to greater COVID-19 hospitalization, ICU admissions and deaths. CONCLUSIONS: The new SARS-CoV-2 variants have compromised the neutralization potential of the currently used vaccines, but still, they have considerable efficacy to reduce infection and mortality. GRAPHICAL ABSTRACT: https://www.europeanreview.org/wp/wp-content/uploads/Graphical_Abstract.jpg.

Perturbing dimer interactions and allosteric communication modulates the immunosuppressive activity of human galectin-7.

The design of allosteric modulators to control protein function is a key objective in drug discovery programs. Altering functionally essential allosteric residue networks provides unique protein family subtype specificity, minimizes unwanted off-target effects, and helps avert resistance acquisition typically plaguing drugs that target orthosteric sites. In this work, we used protein engineering and dimer interface mutations to positively and negatively modulate the immunosuppressive activity of the proapoptotic human galectin-7 (GAL-7). Using the PoPMuSiC and BeAtMuSiC algorithms, mutational sites and residue identity were computationally probed and predicted to either alter or stabilize the GAL-7 dimer interface. By designing a covalent disulfide bridge between protomers to control homodimer strength and stability, we demonstrate the importance of dimer interface perturbations on the allosteric network bridging the two opposite glycan-binding sites on GAL-7, resulting in control of induced apoptosis in Jurkat T cells. Molecular investigation of G16X GAL-7 variants using X-ray crystallography, biophysical, and computational characterization illuminates residues involved in dimer stability and allosteric communication, along with discrete long-range dynamic behaviors involving loops 1, 3, and 5. We show that perturbing the protein-protein interface between GAL-7 protomers can modulate its biological function, even when the overall structure and ligand-binding affinity remains unaltered. This study highlights new avenues for the design of galectin-specific modulators influencing both glycan-dependent and glycan-independent interactions.

The Antidepressant-Like and Analgesic Effects of Kratom Alkaloids are accompanied by Changes in Low Frequency Oscillations but not ΔFosB Accumulation.

Mitragyna speciosa ("kratom"), employed as a traditional medicine to improve mood and relieve pain, has shown increased use in Europe and North America. Here, the dose-dependent effects of a purified alkaloid kratom extract on neuronal oscillatory systems function, analgesia, and antidepressant-like behaviour were evaluated and kratom-induced changes in ΔFosB expression determined. Male rats were administered a low or high dose of kratom (containing 0.5 or 1 mg/kg of mitragynine, respectively) for seven days. Acute or repeated low dose kratom suppressed ventral tegmental area (VTA) theta oscillatory power whereas acute or repeated high dose kratom increased delta power, and reduced theta power, in the nucleus accumbens (NAc), prefrontal cortex (PFC), cingulate cortex (Cg) and VTA. The repeated administration of low dose kratom additionally elevated delta power in PFC, decreased theta power in NAc and PFC, and suppressed beta and low gamma power in Cg. Suppressed high gamma power in NAc and PFC was seen selectively following repeated high dose kratom. Both doses of kratom elevated NAc-PFC, VTA-NAc, and VTA-Cg coherence. Low dose kratom had antidepressant-like properties whereas both doses produced analgesia. No kratom-induced changes in ΔFosB expression were evident. These results support a role for kratom as having both antidepressant and analgesic properties that are accompanied by specific changes in neuronal circuit function. However, the absence of drug-induced changes in ΔFosB expression suggest that the drug may circumvent this cellular signaling pathway, a pathway known for its significant role in addiction.

Crosstalk of Cyclin-dependent kinase inhibitor 1A (CDKN1A) gene polymorphism with p53 and CCND1 polymorphism in breast cancer.

OBJECTIVE: Mutations and polymorphisms in genes of cell- cycle and apoptosis regulatory pathway influence the breast cancer risk. Analysis of single low penetrance mutant alleles may not reflect the precise risk association when analyzed alone. PATIENTS AND METHODS: A total of 115 DNA samples extracted from breast cancer patients and an equal number of age and sex-matched normal controls were used for polymorphic analysis. Genotyping for p21 rs1801270 and CCND1 rs603965 was done by PCR-RFLP method while AFLP method was used for p53 rs1042522 single nucleotide polymorphism detection. Statistical methods included simple mean±SD and correlation coefficient to analyze the risk of association of p21, p53 and CCND1 SNPs and breast cancer. RESULTS: Individuals harboring SNPs in p21, p53 and CCND1 genes namely rs1801270, rs1042522 and rs603965, respectively were rendered increasingly susceptible to developing breast cancer when compared with normal controls. CONCLUSIONS: Our report emphasizes the need of combinational analysis of low-penetrance mutant alleles to assess accurately their association with breast cancer risk. Future case-control studies analyzing gene-environment interactions across different populations may confirm reported risk associations of studied polymorphisms with developing breast cancer.

Porous carboxymethyl cellulose carbon of lignocellulosic based materials incorporated manganese oxide for supercapacitor application.

The present work developed porous carboxymethyl cellulose (CMC) carbon film from lignocellulosic based materials as supercapacitor electrode. Porous CMC carbon films of bamboo (B) and oil palm empty fruit bunch (O) were prepared through simple incipient wetness impregnation method followed by calcination process before incorporation with manganese oxide (Mn2O3). The carbonization produced porous CMC carbon whereby CMCB exhibited higher surface area than CMCO. After Mn2O3 incorporation, the crystallite size of CMCB and CMCO were calculated as 50.09 nm and 42.76 nm, respectively whereas Mn2O3/CMCB and Mn2O3/CMCO composite films were revealed to be 26.71 nm and 35.60 nm in size, respectively. Comparatively, the Mn2O3/CMCB composite film exhibited higher electrochemical performance which was 31.98 mF cm-2 as compared to 24.15 mF cm-2 by Mn2O3/CMCO composite film and both CMC carbon films with fairly stable cycling stability after 1000 charge-discharge cycles. Therefore, it can be highlighted that Mn2O3/CMC composite film as prepared from bamboo and oil palm fruit can potentially become the new electrode materials for supercapacitor application.

Temperature Sensing of Thiolate Addition by Phenolate Merocyanine Dyes: Importance of the Quinone Methide Resonance Structure.

Merocyanine (MC) dyes containing an aromatic donor vinyl linked to a cationic acceptor serve as chemosensors for analyte detection. Their electrophilicity permits anion detection through addition reactions that disrupt dye conjugation. Herein, we demonstrate the temperature influence on thiolate addition to MCs containing the N-methylbenzothiazolium (Btz) acceptor. The zwitterionic phenolate dye (PhOBtz) displays impressive temperature sensitivity to thiolate addition, with the brightly colored phenolate favored upon heating and the colorless thiolate adduct favored upon cooling. In contrast, MC dyes containing neutral donors (PhOMeBtz and PhNMe2Btz) display only moderate temperature sensitivity to thiolate capture and release. Extraction of thermodynamic parameters demonstrates a strong enthalpic driving force for thiolate addition to PhOBtz that is absent for PhOMeBtz and PhNMe2Btz. Variable temperature 1H NMR studies demonstrate that PhOBtz adopts the para-quinone methide (p-QM) resonance structure. Thus, thiolate addition to PhOBtz resembles 1,6-conjugate addition to p-QMs which is accompanied by a large increase in the π-stabilization energy upon adduct formation. Manipulation of PhOBtz electrophilicity by attaching chlorine substituents to the phenolate caused the thiolate adducts to dissipate over time for p-QM regeneration. Our work provides new design ideas for the utility of phenolate MC dyes, given that they are carriers of the p-QM electrophile.

Impact of COVID-19 on the cerebrovascular system and the prevention of RBC lysis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) uses Angiotensin- converting enzyme 2 (ACE2) receptors to infect host cells which may lead to coronavirus disease (COVID-19). Given the presence of ACE2 receptors in the brain and the critical role of the renin-angiotensin system (RAS) in brain functions, special attention to brain microcirculation and neuronal inflammation is warranted during COVID-19 treatment. Neurological complications reported among COVID-19 patients range from mild dizziness, headache, hypogeusia, hyposmia to severe like encephalopathy, stroke, Guillain-Barre Syndrome (GBS), CNS demyelination, infarcts, microhemorrhages and nerve root enhancement. The pathophysiology of these complications is likely via direct viral infection of the CNS and PNS tissue or through indirect effects including post- viral autoimmune response, neurological consequences of sepsis, hyperpyrexia, hypoxia and hypercoagulability among critically ill COVID-19 patients. Further, decreased deformability of red blood cells (RBC) may be contributing to inflammatory conditions and hypoxia in COVID-19 patients. Haptoglobin, hemopexin, heme oxygenase-1 and acetaminophen may be used to maintain the integrity of the RBC membrane.

1D 1 H NMR as a Tool for Fecal Metabolomics.

Metabolomic studies allow a deeper understanding of the processes of a given ecological community than nucleic acid-based surveys alone. In the case of the gut microbiota, a metabolic profile of, for example, a fecal sample provides details about the function and interactions within the distal region of the gastrointestinal tract, and such a profile can be generated in a number of different ways. This unit elaborates on the use of 1D 1 H NMR spectroscopy as a commonly used method to characterize small-molecule metabolites of the fecal metabonome (meta-metabolome). We describe a set of protocols for the preparation of fecal water extraction, storage, scanning, measurement of pH, and spectral processing and analysis. We also compare the effects of various sample storage conditions for processed and unprocessed samples to provide a framework for comprehensive analysis of small molecules from stool-derived samples. © 2020 Wiley Periodicals LLC Basic Protocol 1: Extracting fecal water from crude fecal samples Alternate Protocol 1: Extracting fecal water from small crude fecal samples Basic Protocol 2: Acquiring NMR spectra of metabolite samples Alternate Protocol 2: Acquiring NMR spectra of metabolite samples using Bruker spectrometer running TopSpin 3.x Alternate Protocol 3: Acquiring NMR spectra of metabolite samples by semiautomated process Basic Protocol 3: Measuring sample pH Support Protocol 1: Cleaning NMR tubes Basic Protocol 4: Processing raw spectra data Basic Protocol 5: Profiling spectra Support Protocol 2: Spectral profiling of sugars and other complex metabolites.

Bibliometric analysis of manuscript characteristics that influence citations: A comparison of ten major dermatology journals.

BACKGROUND: The number of citations an article receives is a reassuring marker for its influence in the academic world. OBJECTIVE: We aimed to discover characteristics of dermatology articles that may impact their citation. METHODS: This cross-sectional study collected and analyzed articles published between January and June 2013 from ten highest impact dermatology journals. The study included manuscript characteristics i.e. the length of an article, the presence of visual aids, accessibility, originality, and clarity. Citation analysis statistics required multiple tools such as linear regression, point-biserial correlation, Spearman's rank-order correlation, and Kruskal-Wallis to determine the association between these study variables and the number of citations of articles. RESULTS: Of 748 articles included in our study, the number of citations ranged from 0 to 814 (median: 18), with weak positive correlations to the length of manuscript (word count: rs 0.3, p<0.001; pages: rs 0.3, p<0.001). Having a structured abstract (rpb -0.15, p<0.001) and increasing number of references (rs -0.26, p<0.001) showed a negative correlation. Studies originating in North America were associated with higher citations, followed by Europe and Asia (p<0.001). Review articles had a higher number of citations (p<0.001). CONCLUSIONS: We found that the number of words and the number of pages within a dermatology manuscript had the strongest positive correlation for a higher citation count. The results of this study can benefit authors who may improve the citation of their articles by utilizing this bibliometric study when assembling their manuscript.

Identifying lipids tightly bound to an integral membrane protein.

Anabaena Sensory Rhodopsin (ASR) is a microbial photosensor from the cyanobacterium Anabaena sp. PCC 7120. It was found in previous studies that ASR co-purifies with several small molecules, although their identities and structural or functional roles remained unclear. Here, we use solid-state nuclear magnetic resonance (SSNMR) spectroscopy and mass spectrometry to characterize these molecules. Numerous correlations atypical for protein amino acids were found and assigned in the SSNMR spectra. The chemical shift patterns correspond to N-acetyl-d-glucosamine, N-acetyl-d-mannosaminuronic acid, and 4-acetamido-4,6-dideoxy-d-galactose which are part of the Enterobacterial Common Antigen (ECA). These sugars undergo rapid anisotropic motions and are likely linked flexibly to a rigid anchor that tightly binds ASR. Phosphorus NMR reveals several signals that are characteristic of monophosphates, further suggesting phosphatidylglyceride as the ECA lipid carrier which is anchored to ASR. In addition, NMR signals corresponding to common phospholipid phosphatidylethanolamine (PE) have been detected. The presence of PE tightly interacting with ASR was confirmed using liquid chromatography-mass spectrometry. This article commemorates Professor Michèle Auger and her contributions to membrane biophysics and Nuclear Magnetic Resonance.

Structure of an Unusual Tetracyclic Deoxyguanosine Adduct: Implications for Frameshift Mutagenicity of ortho-Cyano Nitroanilines.

Nitroaromatic compounds represent a major class of industrial chemicals that are also found in nature. Polycyclic derivatives are regarded as potent mutagens and carcinogens following bioactivation to produce nitrenium electrophiles that covalently modify DNA to afford N-linked C8-2'-deoxyguanosine (C8-dG) lesions that can induce frameshift mutations, especially in CpG repeat sequences. In contrast, their monocyclic counterparts typically exhibit weak mutagenicity or a lack thereof, despite also undergoing bioactivation to afford N-linked C8-dG adducts. Recently, it has been reported that cyano substitution can greatly increase the mutagenicity of nitroaniline derivatives that are components of azo dyes. The basis of this "cyano effect" may be rooted in the formation of a novel polycyclic adduct arising from initial formation of the N-linked C8-dG adduct followed by a cyclization process involving N7 of dG and the ortho-CN group of the attached C8-aryl moiety to generate a quinazolinimine ring as part of a fused tetracyclic C8,N7-dG adduct structure. The present work structurally characterizes this novel cyclic adduct using a combination of optical spectroscopies, NMR analysis, density functional theory (DFT) calculations, and molecular dynamics (MD) simulations. Our data indicate that this highly fluorescent cyclic adduct adopts the promutagenic syn conformation and can stabilize the slipped mutagenic intermediate (SMI) within the CpG repeat of the NarI sequence, which is a hotspot for frameshift mutagenesis mediated by polycyclic N-linked C8-dG adducts. In contrast, the open para-CN (4-aminobenzontrile-derived) N-linked C8-dG adduct is less likely to disrupt the canonical B-form. Together, our results provide a rationale for the potent mutagenicity of cyano-substituted nitroaniline derivatives recently reported in frameshift-sensitive tester strains.

Long-Term Results of Multiple Anterior Cervical Discectomy with Cage Fusion Technique: Results of Multiple Centre Study.

BACKGROUND: Cervical herniation is commonly treated by anterior cervical discectomy and fusion (ACDF) if conservative management has failed in relief of the patient's symptoms. Disc fusion is needed after ACDF as anterior longitudinal ligament will be absent after doing the operation, especially if multiple levels are needed. The occurrence of complications as cage subsidence and adjacent segment failure related to the length of follow up as they are increasing in percentage is directly proportional to the length of follow up. AIM: Analysis of the results for patients who underwent 3 levels of ACDF with cage fusion for short term and long term follow up in multiple centres as the visual analogue score for neck pain & brachialgia. METHODS: This retrospective cohort series of 68 patients selected out of 136 patients suffering from 3 levels of degenerative cervical disc disease who were unresponsive to adequate conservative therapy. All cases were treated at one of the neurosurgery departments of 3 different hospitals (Naser institute for research and treatment hospital, Haram hospital for research and treatment and Misr university for science and technology) by the same surgical team in the period from February 2012 to February 2017. RESULTS: We found in this study;68 patients fulfilling the inclusion criteria, of the 29 patients underwent 3 levels of ACDF starting from C3-4 (42.65%) and 39 patients who underwent 3 levels of ACDF starting from C4-5 (57.35%). Clinical assessment for VAS pain score for both neck pain and radiculopathy were done before the surgery and immediately post-operative and during each time follow up visit and we found statistically significant immediate postoperative improvement. (P < 0.05). CONCLUSION: Stand-alone three levels of an anterior cervical discectomy with cage fusion technique improved the clinical outcomes on long term follow up.