Second Line Of Defense Research Articles

An Analysis of Intrusion Detection Classification using Supervised Machine Learning Algorithms on NSL-KDD Dataset

From the past few years, Intrusion Detection Systems (IDS) are employed as a second line of defence and have shown to be a useful tool for enhancing security by detecting suspicious activity. Anomaly based intrusion detection is a type of intrusion detection system that identifies anomalies. Conventional IDS are less accurate in detecting anomalies because of the decision taking based on rules. The IDS with machine learning method improves the detection accuracy of the security attacks. To this end, this paper studies the classification analysis of intrusion detection using various supervised learning algorithms such as SVM, Naive Bayes, KNN, Random Forest, Logistic Regression and Decision tree on the NSL-KDD dataset. The findings reveal which method performed better in terms of accuracy and running time.

Construction of elliptic curve cryptography‐based authentication protocol for internet of things

AbstractThe advancement in the internet of things (IoT) is bringing changes in our daily lives. The widespread adoption of the IoT in a variety of areas sets the basis for smart living while also posing privacy and security concerns. Authentication and key agreement (AKA) protocol provides identity authentication for participants in a communication system and generates a temporary session key for participants to securely transmit messages. In addition to this, the adoption of smart cards adds a second line of defense in AKA protocols for IoT. To enhance the security of AKA protocols for IoT, many AKA protocols are proposed, but the majority of them fail to manage the balance between security and efficiency. To achieve both security and efficiency together for IoT, based on the elliptic curve public‐key cryptography, we design a three‐factor AKA protocol. We follow security analysis and efficiency analysis to analyze the security and efficiency. By comparing with related existing protocols, it is found that this protocol achieves security and efficiency attributes. The investigation shows that the protocol can meet key security requirements, consumes less computing resources, and is especially suitable for IoT scenarios with high security and efficiency.

Ofeleein i mi Vlaptin-Volume II: Immunity Following Infection or mRNA Vaccination, Drug Therapies and Non-Pharmacological Management at Post-Two Years SARS-CoV-2 Pandemic.

The persistence of the coronavirus disease 2019 (COVID-19) pandemic has triggered research into limiting transmission, morbidity and mortality, thus warranting a comprehensive approach to guide balanced healthcare policies with respect to people’s physical and mental health. The mainstay priority during COVID-19 is to achieve widespread immunity, which could be established through natural contact or vaccination. Deep knowledge of the immune response combined with recent specific data indicates the potential inferiority of induced immunity against infection. Moreover, the prevention of transmission has been founded on general non-pharmacological measures of protection, albeit debate exists considering their efficacy and, among other issues, their socio-psychological burden. The second line of defense is engaged after infection and is supported by a plethora of studied agents, such as antibiotics, steroids and non-steroid anti-inflammatory drugs, antiviral medications and other biological agents that have been proposed, though variability in terms of benefits and adverse events has not allowed distinct solutions, albeit certain treatments might have a role in prevention and/or treatment of the disease. This narrative review summarizes the existing literature on the advantages and weaknesses of current COVID-19 management measures, thus underlining the necessity of acting based on the classical principle of “ofeleein i mi vlaptin”, that is, to help or not to harm.

Integrative Genomics Sheds Light on Evolutionary Forces Shaping the Acidithiobacillia Class Acidophilic Lifestyle.

Extreme acidophiles thrive in environments rich in protons (pH values <3) and often high levels of dissolved heavy metals. They are distributed across the three domains of the Tree of Life including members of the Proteobacteria. The Acidithiobacillia class is formed by the neutrophilic genus Thermithiobacillus along with the extremely acidophilic genera Fervidacidithiobacillus, Igneacidithiobacillus, Ambacidithiobacillus, and Acidithiobacillus. Phylogenomic reconstruction revealed a division in the Acidithiobacillia class correlating with the different pH optima that suggested that the acidophilic genera evolved from an ancestral neutrophile within the Acidithiobacillia. Genes and mechanisms denominated as “first line of defense” were key to explaining the Acidithiobacillia acidophilic lifestyle including preventing proton influx that allows the cell to maintain a near-neutral cytoplasmic pH and differ from the neutrophilic Acidithiobacillia ancestors that lacked these systems. Additional differences between the neutrophilic and acidophilic Acidithiobacillia included the higher number of gene copies in the acidophilic genera coding for “second line of defense” systems that neutralize and/or expel protons from cell. Gain of genes such as hopanoid biosynthesis involved in membrane stabilization at low pH and the functional redundancy for generating an internal positive membrane potential revealed the transition from neutrophilic properties to a new acidophilic lifestyle by shaping the Acidithiobacillaceae genomic structure. The presence of a pool of accessory genes with functional redundancy provides the opportunity to “hedge bet” in rapidly changing acidic environments. Although a core of mechanisms for acid resistance was inherited vertically from an inferred neutrophilic ancestor, the majority of mechanisms, especially those potentially involved in resistance to extremely low pH, were obtained from other extreme acidophiles by horizontal gene transfer (HGT) events.

Distribution of antimicrobial resistance among clinical and food Listeria monocytogenes isolated in Moscow in 2019–2021

Objective. To determine the current state-of-art of acquired resistance to antimicrobial drugs among L. monocytogenes strains associated with listeriosis in humans and food contamination in Moscow. Materials and Methods. We used 39 L. monocytogenes strains isolated in Moscow in 2019–2021 from clinical material (n = 24) and food (n = 15). Resistance to 12 antibiotics of the first and second lines of defense was studied using disk-diffusion method. The parameters recommended for L. monocytogenes were used to interpret the results; in the absence of recommendations for L. monocytogenes, the criteria for Staphylococcus aureus and/or Enterococcus spp. were used. Results. All strains were susceptible to ampicillin, benzylpenicillin, erythromycin, vancomycin, imipenem, linezolid, and the amoxicillin/clavulanic acid. Resistance was observed to gentamicin (23%) as well as to meropenem, trimethoprim/sulfamethoxazole and ciprofloxacin (5%, 74% and 28% of strains, respectively). A total of 15 strains with multiple antibiotic resistance were identified (13 and 2 isolates were resistant to three and four antibiotics, respectively). Simultaneous resistance to trimethoprim/sulfamethoxazole, ciprofloxacin and levofloxacin was observed in 9 strains, 6 strains were resistant to gentamicin and trimethoprim/sulfamethoxazole, including 3 strains – to gentamicin, trimethoprim/sulfamethoxazole, levofloxacin, and 2 strains – to gentamicin, trimethoprim/sulfamethoxazole, ciprofloxacin. Comparison of the growth inhibition zones by ampicillin and benzylpenicillin in the studied strains with historical data on the strains isolated in Russia in 1950–1980 showed a significant downward shift in the size of growth inhibition zones. Comparison of the distribution of strains with different diameters of growth inhibition zones depending on the source of isolation did not show significant differences between clinical strains and strains of food origin isolated in 2019–2021. Conclusions. A wide spread of acquired resistance was shown among L. monocytogenes strains of clinical and food origin isolated in Moscow in 2019–2021. Despite the fact that all strains were susceptible to penicillins, the distribution of growth inhibition zone diameters showed a significant shift towards decreasing sensitivity to ampicillin and benzylpenicillin in strains isolated in 2019–2021 compared with L. monocytogenes strains isolated in Russia before 1980.

Macromodeling Approach and Robustness Enhancement Strategies for Steel Frame Buildings with Composite Slabs against Column Loss

This study presents a numerical assessment of the behavior of seismically designed steel frame buildings against ground floor column loss. In the designed prototype buildings, moment frames with beam-to-column rigid connections and concentric X-bracing frames resist the lateral force, whereas the steel-concrete composite floor slabs resist the gravity load. Macromodels are used to capture the building response when removing ground floor columns. The macromodels are built with a reduced modeling approach, in which the concrete damage and the local steel fracture behavior are accurately considered. The macromodeling approach is calibrated by high-fidelity models and validated by composite floor test. The validated macromodels are used to investigate the effect of column loss location, total number of floors, floor slab, beam-to-column connection type, adjacent span, and steel brace on the collapse resistance of prototype buildings. To account for sudden column failure, an energy-based approach is used to convert the quasi-static response curves to dynamic response curves. The structural robustness is derived by comparing each column failure case’s dynamic ultimate capacities with corresponding design requirements. Structural robustness enhancement strategies for steel frame buildings under progressive collapse scenarios are summarized and discussed. Moreover, a retrofitted moment-resisting connection with steel strands is proposed to enhance the steel frame buildings’ robustness by providing a second line of defense.

How the Quest for Huge Returns by Financial Institutions Trumps Prudent Risk Management: The Archegos Saga

Competition in the financial services sector has always been fierce. In many respects financial services is a sophisticated borrower’s market. Sophisticated borrowers with a proven track record are able to mobilise significant amounts of financial resources as they pursue complex and innovative financial strategies which are regarded by the various lenders as so likely to be profitable, that the risk is worth taking. The risk is attached to a specific instrument, real or synthetic such as a total return swap, and is a bet on the direction of the value of the instrument. In the quest for business, especially “aggressive deal makers” like Bill Hwang of Archegos, securities financing institutions can and do compromise their own due diligence and risk management processes and procedures. Often, tension arises within firms when the dealmakers pushing hard to take on business come up against resistance from cautious risk managers. In a profit driven industry, risk managers are often overruled by management, in favour of deal makers. This case had an impact across borders. When the implosion eventually occurred securities financing firms were shown to have disregarded prudent risk management practices. The failure of Archegos compelled regulators to act in order to prevent similar possibly worse collapses in the future. Remedial measures included a direction to securities financing institutions to demonstrate a commitment to safe practices by adopting a risk based approach to their supervisory activities. The failure of Archegos highlights the importance of an understanding of the key inherent risks faced by entities offering equity financing transactions, and also the supervisor’s expectation for the mitigation of these risks. In the operational sphere, it is evident that risk mitigation can be enhanced by a clear demarcation and understanding of the roles of the first line of defense, second line of defense, senior management and the board.

ROBUSTNESS ASSESSMENT OF PRECAST REINFORCED CONCRETE STRUCTURAL SYSTEMS IN AN ACCIDENTAL DESIGN SITUATION

The article presents the simplified implementation of the method of alternative load paths based on the energy balance approach. This methodshould be used to checking the global resistance of a damaged structural system after the occurrence of an accidental event. It is necessary to provide(reserve) enough ties with the required continuity and ductility in the original prefabricated structural system to ensure the integrity of the damaged system.We consider the system of ties as the “second line of defense” of the structural system after the exhaustion of the flexural resistance of its elements.The continuity and ductility of the tie elements provide a resistance of the damaged structural system under an accidental combination of actionsby mobilizing alternative load paths after the support or key element has been removed. Ductility is the ability of the tie to obtain significant plastic bondelongation before rupture. The ductility is important properties of the ties for redistributing internal forces and getting large deflections. It is necessary for the realization of the chain (membrane) effect, as well as a measure that provides energy absorption (damping) during the dynamic application of anaccidental action after the vertical support losing. The article presents analytical solutions and the working example for the design of horizontal ties in precast hollow-core slabs floor, which areobtained based on the energy approach.

Reactive Oxygen Species: Do They Play a Role in Adaptive Immunity?

The immune system protects the host from a plethora of microorganisms and toxins through its unique ability to distinguish self from non-self. To perform this delicate but essential task, the immune system relies on two lines of defense. The innate immune system, which is by nature fast acting, represents the first line of defense. It involves anatomical barriers, physiological factors as well as a subset of haematopoietically-derived cells generically call leukocytes. Activation of the innate immune response leads to a state of inflammation that serves to both warn about and combat the ongoing infection and delivers the antigenic information of the invading pathogens to initiate the slower but highly potent and specific second line of defense, the adaptive immune system. The adaptive immune response calls on T lymphocytes as well as the B lymphocytes essential for the elimination of pathogens and the establishment of the immunological memory. Reactive oxygen species (ROS) have been implicated in many aspects of the immune responses to pathogens, mostly in innate immune functions, such as the respiratory burst and inflammasome activation. Here in this mini review, we focus on the role of ROS in adaptive immunity. We examine how ROS contribute to T-cell biology and discuss whether this activity can be extrapolated to B cells.

About the Calculation of the Compliance Value and its Practical Relevance

Corporate investment in compliance in general and compliance management systems (CMS) in particular, follow the cardinal management obligation to always obey the law (so-called “management duty to legality”). But does the compliance function as any other corporate investment really add value favoring all shareholders? The socially desired answer should be probably “yes”, but the business reality shows a different picture: the measurement of the compliance value is a “blind spot” in the scientific theory and research as well as in the corporate practice. This paper analyzes reasons for that “blind spot” and explores the systematization of the compliance value drivers setting up a practical model that monetarizes these effects as well as calculating the added value and ROI of compliance. The author concludes that this quantification is particularly relevant to practice, as the compliance function must be able to measure the quantified impact(s) of the compliance function in order to demonstrate its value to management, shareholders, as well as all interested parties, and to justify and strengthen its role increasing the effectiveness of the CMS as part of the company’s “second line of defense”.

The tumor suppression theory of aging

Despite continued increases in human life expectancy, the factors determining the rate of human biological aging remain unknown. Without understanding the molecular mechanisms underlying aging, efforts to prevent aging are unlikely to succeed. The tumor suppression theory of aging introduced here proposes somatic mutation as the proximal cause of aging, but postulates that oncogenic transformation and clonal expansion, not functional impairment, are the relevant consequences of somatic mutation. Obesity and caloric restriction accelerate and decelerate aging due to their effect on cell proliferation, during which most mutations arise. Most phenotypes of aging are merely tumor-suppressive mechanisms that evolved to limit malignant growth, the dominant age-related cause of death in early and middle life. Cancer limits life span for most long-lived mammals, a phenomenon known as Peto’s paradox. Its conservation across species demonstrates that mutation is a fundamental but hard limit on mammalian longevity. Cell senescence and apoptosis and differentiation induced by oncogenes, telomere shortening or DNA damage evolved as a second line of defense to limit the tumorigenic potential of clonally expanding cells, but accumulating senescent cells, senescence-associated secretory phenotypes and stem cell exhaustion eventually cause tissue dysfunction and the majority, if not most, phenotypes of aging.

Interplay between Gut Lymphatic Vessels and Microbiota.

Lymphatic vessels play a distinctive role in draining fluid, molecules and even cells from interstitial and serosal spaces back to the blood circulation. Lymph vessels of the gut, and especially those located in the villi (called lacteals), not only serve this primary function, but are also responsible for the transport of lipid moieties absorbed by the intestinal mucosa and serve as a second line of defence against possible bacterial infections. Here, we briefly review the current knowledge of the general mechanisms allowing lymph drainage and propulsion and will focus on the most recent findings on the mutual relationship between lacteals and intestinal microbiota.

The Study from the Perspective of Engineering History about the Battle of Bacca Forts between China and Britain Armies

By February 1841, there had a very important battle between the Chinese and British armies at Bocca Tigris Forts. Six forts on the second line of defense of its fell only one day, and the "escape" of the garrison soldiers became the main theme. Admial Kwan died of a bullet wound, and his chest was fought with bayonet. The Chinese and British armies were engaged in artillery warfare here. The Qing court essentially let a naval force with the main function of "controlling thieves and preventing barbarians" , using the "decaying" weapon compared with the British army, to resist the invasion of the strongest European navy in the world, the failure was inevitable. The essence of the war was so, Originally the Qing dynasty built it for coastal defense and piracy, but during the canton system, it was reduced to the Huangpu port’s gateway.The reason why the Qing army as a side of justice was powerless to resist aggression in this war can be explained from the three aspects of engineering thought, national system and comprehensive national strength.

A progressive collapse modelling strategy coupling the yield design theory with non-linear analysis

Several examples of structures have been severely damaged, or even reached the total collapse, after the propagation of some local failure, resulting from an accidental or exceptional event. These catastrophic events highlight the importance of not limiting safety assessment in structural design under identified conditions, but also to investigate how much the structural integrity can be preserved so that progressive collapse is avoided under an exceptional event unidentified at the design stage.The main objective of this work is to propose a progressive collapse modelling approach in order to characterize structural robustness. Considering the occurrence of some exceptional event, the yield design theory is used to identify the part of the structure concerned by a failure mechanism. As the yield design theory is based on the infinitesimal strain assumption, an iterative coupling between the yield design approach and a non-linear analysis of the directly affected part is proposed to (i) better analyze the structural response of the part concerned by the failure mechanism, (ii) consider the development of materials and geometrical non-linearities, and (iii) model progressive collapse within the structure. The successive iterations of the yield design approach including the deformed geometrical configuration allow to check the potential ability of the structure to develop a second line of defence. This coupling strategy is applied to a steel framed structure for illustration of the proposed concepts.

Ascidians as Bioresources: An Anti-inflammatory Activity of Colonial Ascidians Eudistoma ovatum and Didemnum perlucidum

Carrageenan-induced rat paw edema is a prominent inflammatory model to evaluate the anti-inflammatory effect of compounds of biological origin. In animals pretreated with Eudistoma ovatum (EO) and Didemnum perlucidum (DP) drugs, there was significant and dose-dependent inhibition of Carrageenan-induced posterior paw edema. A variety of antioxidant enzymes, such as Superoxide dismutase (SOD), Glutathione peroxidase (GPx), and Glutathione reductase (GRd) can scavenge and minimize the formation of reactive oxygen species (ROS). SOD protects cells against the damages of ROS. GPx in the presence of glutathione (GSH) accelerates the reduction of H2O2 or other organic hydroperoxides and serves as a second line of defense against hydroperoxides. The amount of platelets is affected by the increased plasma concentration of active proteins in the acute response to inflammation. Anti-inflammatory activity in carrageenan-induced paw edema in rat model was found in the extract of both ascidians E. ovatum and D. perlucidum. But the methanolic extract of E. ovatum showed more significant anti-inflammatory activity. The study includes the investigation on the effects of EO and DP on some oxidative parameters such as lipid peroxidation (LPO), SOD and GSH level, hematological parameters (RBC, WBC and Platelets, cytokines (IL 6 and TNF α), hepatic enzymes (Acid phosphatase - ACP and Alkaline phosphatase - ALP) and membrane-bound glycoproteins (hexose, hexosamine, sialic acid, and fucose). This study provided the finely tuned of the extracts in inflammatory diseases. Thus, a pharmacological basis is achieved for use of the ascidians against rheumatism and other associated diseases.

A large-scale computational screen identifies strong potential inhibitors for disrupting SARS-CoV-2 S-protein and human ACE2 interaction

SARS-CoV-2 has infected millions of individuals across the globe and has killed over 2.7 million people. Even though vaccines against this virus have recently been introduced, the antibody generated in the process has been reported to decline quickly. This can reduce the efficacy of vaccines over time and can result in re-infections. Thus, drugs that are effective against COVID-19 can provide a second line of defence and can prevent occurrence of the severe form of the disease. The interaction between SARS-CoV2 S-protein and human ACE2 (hACE2) is essential for the infection of the virus. Thus, drugs that block this interaction could potentially inhibit SARS-CoV-2 infection into the host cells. To identify such drugs, we first analyzed the recently published crystal structure of S-protein-hACE2 complex and identified essential residues of both S-protein and hACE2 for this interaction. We used this knowledge to virtually dock a drug library containing 4115 drug molecules against S-protein for repurposing drugs that could inhibit binding of S-protein to hACE2. We identified several potential inhibitors based on their docking scores, pharmacological effects and ability to block residues of S protein required for interaction with hACE2. The top inhibitors included drugs used for the treatment of hepatitis C (velpatasvir, pibrentasvir) as well as several vitamin D derivatives. Several molecules obtained from our screen already have good experimental support in published literature. Thus, we believe that our results will facilitate the discovery of an effective drug against COVID-19. Communicated by Ramaswamy H. Sarma

Segmented intravaginal ring for the combination delivery of hydroxychloroquine and anti-CCR5 siRNA nanoparticles as a potential strategy for preventing HIV infection

Vaginal drug delivery has been shown to be a promising strategy for the prevention of sexually transmitted infections. Therapy delivered at the site of infection has many advantages including improved therapeutic efficacy, reduction in systemic toxicity, and reduced potential for development of drug resistance. We developed a “smart” combination intravaginal ring (IVR) that will (1) provide continuous release of hydroxychloroquine (HCQ) to induce T cell immune quiescence as the first-line of defense and (2) release nanoparticles containing anti-CCR5 siRNA only during sexual intercourse when triggered by the presence of seminal fluid as the second-line of defense. The IVR was capable of releasing HCQ over 25 days with a mean daily release of 31.17 ± 3.06 µg/mL. In the presence of vaginal fluid simulant plus seminal fluid simulant, over 12 × more nanoparticles (5.12 ± 0.9 mg) were released over a 4-h period in comparison to IVR segments that were incubated in the presence of vaginal fluid simulant alone (0.42 ± 0.19 mg). Anti-CCR5 siRNA nanoparticles were able to knockdown 83 ± 5.1% of CCR5 gene expression in vitro in the CD4+ T cell line Sup-T1. The IVR system also demonstrated to be non-cytotoxic to VK2/E6E7 vaginal epithelial cells.Graphical abstract

In silico investigation of binding affinities between human leukocyte antigen class I molecules and SARS-CoV-2 virus spike and ORF1ab proteins

Aim: The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019, a global pandemic. There is hence an urgent need for effective approaches to understand the mechanism of viral interaction with immune cells that lead to viral elimination and subsequent long-term immunity. The first, immediate response to the viral infection involves mobilization of native immunity and human leukocyte antigen (HLA) class I mechanisms to kill infected cells and eliminate the virus. The second line of defense involves the activation of HLA class II system for the production of antibodies against the virus which will add to the elimination of the virus and prevent future infections. In a previous study, investigated the relations between SARS-CoV-2 spike glycoprotein (S protein) and HLA class II alleles were investigaed; here report on the relations of the S protein and the open reading frame 1ab (ORF1ab) of SARS-CoV-2 to HLA class I alleles. Methods: An in silico sliding window approach was used to determine exhaustively the binding affinities of linear epitopes of 10 amino acid length (10-mers) to each of 61 common (global frequency ≥ 0.01) HLA class I molecules (17, 24 and 20 from gene loci A, B and C, respectively). A total of 8,354 epitopes were analyzed; 1,263 from the S protein and 7,091 from ORF1ab. Results: HLA-A genes were the most effective at binding SARS-CoV-2 epitopes for both spike and ORF1ab proteins. Good binding affinities were found for all three genes and were distributed throughout the length of the S protein and ORF1ab polyprotein sequence. Conclusions: Common HLA class I molecules, as a population, are very well suited to binding with high affinity to SARS-CoV-2 spike and ORF1ab proteins and hence should be effective in aiding the early elimination of the virus.

Self-Verification Program in bp: Success Story of Major Accident Risk Management via Bowtie Barrier Model

Summarybp’s (“the company’s”) wells organization manages its operational risks through what is known as the “three lines of defense” model. This is a three-tiered approach; the first line of defense is self-verification, which wells assets apply to prevent or mitigate operational risks. The second line of defense is conducted by the safety and operational risk function using deep technical expertise. The third line of defense is provided by group audit. In this paper, we discuss the wells self-verification program evolution from its first implementation and share case studies, results, impact, lessons learned, and further steps planned as part of the continuous improvement cycle.The company’s wells organization identified nine major accident risks that have the potential to result in significant health, safety, and environment (HSE) impacts. Examples include loss of well control (LoWC), offshore vessel collision, and dropped objects. The central risk team developed bowties for these risks, with prevention barriers on cause legs and mitigation barriers on consequence legs. Detailed risk bowties are fundamental to wells self-verification, adding technical depth to allow more focused verification to be performed when compared with the original bowties, because verification is now conducted using checklists targeting barriers at their component level, defined as critical tasks and equipment. Barriers are underpinned by barrier enablers (underlying supporting systems and processes) such as control of work, safe operating limits, inspection and maintenance, etc. Checklists are standardized and are available through a single, global digital application. This permits the verifiers, typically wellsite leaders, to conduct meaningful verification conversations, record the resulting actions, track them to closure within the application, and gain a better understanding of any cumulative impacts, ineffective barriers, and areas to focus on.Self-verification results are reviewed at rig, region, wells, and upstream levels. Rigs and regions analyze barrier effectiveness and gaps and implement corrective actions with contractors at the rig or region level. Global insights are collated monthly and presented centrally to wells leadership. Common themes and valuable learnings are then addressed at the functional level, shared across the organization, or escalated by the leadership.The self-verification program at the barrier component level proved to be an effective risk management tool for the company’s wells organization. It helps to continuously identify risks, address gaps, and learn from them. Recorded assessments not only provide the wells organization with barrier performance data but also highlight opportunities to improve. Leadership uses the results from barrier verification to gain a holistic view of how major accident risks are managed. Program evolution has also eliminated duplicate reviews, improved clarity of barrier components, and improved sustainability through applying a systematic approach, standardization, digitization, and procedural discipline.

The association of glutathione S-transferase T1 and M1 deletions with myocardial infarction

Glutathione S-transferases (GSTs) are the family of enzymes involved in the second line of defense against oxidative stress (OS). The lack of GSTT1/GSTM1 enzyme quantity or activity, due to the presence of homozygous deletion compromises antioxidative defense resulting in OS. OS is the critical mechanism in the pathophysiology of atherosclerosis, coronary artery disease, and myocardial infarction (MI). The increase in reactive oxygen species together with the process of apoptosis plays a role in left ventricular remodeling (LVR) after MI. The associations of GSTT1 and GSTM1 gene polymorphisms with the risk of MI are inconsistent. The aim was to analyze the association of GSTT1/GSTM1 null genotypes with first MI and LVR 8 months after the MI. The study involved 330 controls and 438 consecutive patients with symptoms and signs of first MI. The subgroup of 150 MI patients was prospectively followed up for 6 months. Evidence of maladaptive LVR was obtained by 2D Doppler echocardiography 3–5 days and 6 months after the MI. A multiplex polymerase chain reaction was used to detect the deletion in GSTT1 and GSTM1 genes. GSTM1 null genotype was significantly and independently associated with first MI (adjusted OR = 1.45 95% CI 1.03–2.03, p = 0.03). Association of double null genotypes with maladaptive LVR in patients 6 months after the first MI was no longer significant after adjustment for factors that differed significantly between patients with and without maladaptive LVR. This study demonstrated the association of GSTM1 null genotypes with the risk of MI in the Serbian population.