Evaluation of the impact of two C5 genetic variants on C5-eculizumab complex stability at the molecular level

Complement C5 is the target of the monoclonal antibody eculizumab, used in complement dysregulating disorders, like the rare disease Paroxysmal Nocturnal Hemoglobinuria (PNH). PNH is an acquired hematopoietic stem cell condition characterized by aberrant destruction of erythrocytes, chronic hemolytic anemia, and thromboembolism propensity. C5 is a protein component of the complement system which is part of the immune system of the body and plays a prominent role in the destruction of red blood cells, misidentifying them as a threat. This work describes the application of molecular dynamics simulations to the study of the underlying interactions between complement C5 and eculizumab. This study also reveals the importance of single nucleotide polymorphisms on C5 protein concerning the effective inhibition of the mAB, involving the mechanistic events taking place at the interface spots of the complex. The predicted conformational change in the C5 Arg885/His/Cys mutation has implications on the protein's interaction with eculizumab, compromising their compatibility. The acquired insights into the conformational changes, dynamics, flexibility, and interactions shed light on the knowledge of the function of this biomolecule providing answers about the poor response to the treatment in PNH patient carriers of the mutations. By investigating the intricate dynamics, significant connections between C5 and eculizumab can be uncovered. Such insights may aid in the creation of novel compounds or lead to the enhancement of eculizumab's efficacy.Communicated by Ramaswamy H. Sarma.

Perinatal outcome of fetuses predicted to be large-for-gestational age on universal third-trimester ultrasound in non-diabetic pregnancy

OBJECTIVE

To describe the perinatal outcome of fetuses predicted to be large-for-gestational age (LGA) on universal third-trimester ultrasound in non-diabetic pregnancies of women attempting vaginal delivery.

METHODS

This was a prospective population-based cohort study of patients from a single tertiary maternity unit in the UK offering universal third-trimester ultrasound and practicing expectant management of suspected LGA until 41-42 weeks. All women with a singleton pregnancy and an estimated due date between January 2014 and September 2019 were included. Women delivering before 37 weeks, those having a planned Cesarean delivery, those with pre-existing or gestational diabetes, those with fetal abnormalities and those who did not undergo a third-trimester scan were excluded from the assessment of perinatal outcome of cases with LGA predicted on ultrasound after implementation of the universal scan period. Association of LGA on universal third-trimester ultrasound screening and perinatal adverse outcome was assessed, with the exposures of interest being estimated fetal weight (EFW) at the 90th -95th , > 95th and > 99th percentile. The reference group was composed of fetuses with EFW at the 30th -70th percentile. Analysis was performed using multivariate logistic regression. The evaluated adverse perinatal outcomes included a composite outcome of admission to neonatal intensive care unit, Apgar score < 7 at 5 min and arterial cord pH < 7.1 (CAO1) and a composite outcome of stillbirth, neonatal death and hypoxic ischemic encephalopathy (CAO2). Secondary maternal outcomes were induction of labor, mode of delivery, postpartum hemorrhage, shoulder dystocia and obstetric anal sphincter injury.

RESULTS

Cases with EFW > 95th percentile on universal third-trimester scan were at increased risk of CAO1 (adjusted odds ratio (aOR), 2.18 (95% CI, 1.69-2.80)) and CAO2 (aOR, 2.58 (95% CI, 1.05-6.34)). Cases with EFW at the 90th -95th percentile had a less pronounced increase in the risk of CAO1 (aOR, 1.35 (95% CI, 1.02-1.78)) and were not at increased risk of CAO2. All pregnancies with a fetus predicted to be LGA were at increased risk of all of the evaluated secondary maternal outcomes except for obstetric anal sphincter injury. The risk of adverse maternal outcome was typically higher with increasing EFW. Post-hoc exploration of data suggested that shoulder dystocia had a limited contribution to composite adverse perinatal outcomes in LGA cases (population attributable fraction of 10.8% for CAO1 and 29.1% for CAO2).

CONCLUSIONS

Cases with EFW > 95th percentile are at increased risk of severe adverse perinatal outcome, such as death and hypoxic ischemic encephalopathy. These findings should aid antenatal counseling regarding the associated risk and delivery options. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Stalling the Course of Neurodegenerative Diseases: Could Cyanobacteria Constitute a New Approach toward Therapy?

Neurodegenerative diseases (NDs) are characterized by progressive and irreversible neuronal loss, accompanied by a range of pathological pathways, including aberrant protein aggregation, altered energy metabolism, excitotoxicity, inflammation, and oxidative stress. Some of the most common NDs include Alzheimer's Disease (AD), Parkinson's Disease (PD), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), and Huntington's Disease (HD). There are currently no available cures; there are only therapeutic approaches that ameliorate the progression of symptoms, which makes the search for new drugs and therapeutic targets a constant battle. Cyanobacteria are ancient prokaryotic oxygenic phototrophs whose long evolutionary history has resulted in the production of a plethora of biomedically relevant compounds with anti-inflammatory, antioxidant, immunomodulatory, and neuroprotective properties, that can be valuable in this field. This review summarizes the major NDs and their pathophysiology, with a focus on the anti-neurodegenerative properties of cyanobacterial compounds and their main effects.

Tracing the Path between Mushrooms and Alzheimer's Disease-A Literature Review

Alzheimer's disease (AD) is well-known among neurodegenerative diseases for the decline of cognitive functions, making overall daily tasks difficult or impossible. The disease prevails as the most common form of dementia and remains without a well-defined etiology. Being considered a disease of multifactorial origin, current targeted treatments have only managed to reduce or control symptoms, and to date, only two drugs are close to being able to halt its progression. For decades, natural compounds produced by living organisms have been at the forefront of research for new therapies. Mushrooms, which are well-known for their nutritional and medicinal properties, have also been studied for their potential use in the treatment of AD. Natural products derived from mushrooms have shown to be beneficial in several AD-related mechanisms, including the inhibition of acetylcholinesterase (AChE) and β-secretase (BACE 1); the prevention of amyloid beta (Aβ) aggregation and neurotoxicity; and the prevention of Tau expression and aggregation, as well as antioxidant and anti-inflammatory potential. Several studies in the literature relate mushrooms to neurodegenerative diseases. However, to the best of our knowledge, there is no publication that summarizes only AD data. In this context, this review aims to link the therapeutic potential of mushrooms to AD by compiling the anti-AD potential of different mushroom extracts or isolated compounds, targeting known AD-related mechanisms.

Boat noise impacts early life stages in the Lusitanian toadfish: A field experiment

Marine traffic is the most common and chronic source of ocean noise pollution. Despite the evidence of detrimental effects of noise exposure on fish, knowledge about the effects on the critical early life stages - embryos and larvae - is still scarce. Here, we take a natural habitat-based approach to examine potential impacts of boat noise exposure in early life stages in a wild fish population of the Lusitanian toadfish (Halobatrachus didactylus). In-situ experiments were carried out in the Tagus estuary, an estuary with significant commercial and recreational boat traffic. Nests with eggs were exposed to either ambient (control) or boat noise (treatment), for 1 fortnight. Eggs were photographed before being assigned to each treatment, and after exposure, to count number of eggs and/or larvae to assess survival, and sampled to study development and oxidative stress and energy metabolism-related biomarkers. Data concerns 4 sampling periods (fortnights) from 2 years. Results indicate that offspring survival did not differ between treatments, but boat noise induced a detrimental effect on embryos and larvae stress response, and on larvae development. Embryos showed reduced levels of electron transport system (ETS), an energy metabolism-related biomarker, while larvae showed higher overall stress responses, with increased levels of superoxide dismutase (SOD) and DNA damage (oxidative stress related responses), ETS, and reduced growth. With this study, we provided the first evidence of detrimental effects of boat noise exposure on fish development in the field and on stress biomarker responses. If these critical early stages are not able to compensate and/or acclimate to the noise stress later in the ontogeny, then anthropogenic noise has the potential to severely affect this and likely other marine fishes, with further consequences for populations resilience and dynamics.

63 The “Brighton Connector”: A Simple, Reproducible and Cost-Effective Technique for Bilateral Antegrade Cerebral Perfusion During Aortic Arch Surgery

Aim

Surgery of the aortic arch presents significant technical and physiological challenges. Selective antegrade cerebral perfusion (SACP) during arch surgery has been shown to improve mortality and neurological outcomes in these patients. At our centre, we aimed to develop a safe, reliable, and cost-effective technique to provide bilateral antegrade cerebral perfusion without the need of another pump head.

Method

We developed our system using equipment that is included in the accessory packaging for the Sorin Xtra cell saver system, which is readily available in cardiac surgical units nationwide, but often discarded as it is not required. An EOPA arterial return cannula and the TRUE FLOW RDB SACP cannula were joined using our novel connection.

Results

A single surgeon has used the “Brighton Connector” for 6 patients in the last two years. All patients made a satisfactory recovery with a 0% rate of mortality or permanent neurological deficit.

Conclusions

All components in our circuit are already approved for use in cardiac theatres, and the connection tubing would normally be discarded, making our method cost neutral. We demonstrate through a case series that mortality and neurological outcomes are good and comparable with other techniques.

POS0055 SARS-COV-2 OUTBREAK IN AUTOIMMUNE DISEASES: THE EURO-COVIMID STUDY

Background:

Coronavirus disease 2019 (COVID-19), has raised several questions in patients with immune-mediated inflammatory diseases (IMID). Whether the seroprevalence and factors associated with symptomatic COVID-19 are similar in IMID patients and in the general population is still unknown.

Objectives:

To assess the serological and clinical prevalence of COVID-19 in European IMID patients, along with the factors associated with its risk and the impacts the pandemic had on the IMID management.

Methods:

Prospective multicentre cross-sectional study among patients with five IMID (i.e. systemic lupus erythematous, Sjögren’s syndrome, rheumatoid arthritis, axial spondylarthritis or giant cell arteritis) from six tertiary-referral centers from France, Germany, Italy, Portugal, Spain and United Kingdom. Demographics, comorbidities, IMID, treatments, flares and COVID-19 details were collected. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests were systematically performed.

Results:

Between June 7 and December 8, 2020, 3028 patients were included (median age 58 years, 73.9% females). SARS-CoV-2 antibodies were detected in 166 (5.5%) patients. Symptomatic COVID-19 was seen in 122 patients (prevalence: 4.0%, 95% CI 3.4-4.8%); 23 (24.2%) of them were hospitalized and four (3.2%) died. In multivariate logistic regression analysis, symptomatic COVID-19 was more likely to be observed in patients with higher levels of C-reactive protein (OR: 1.18; 95% CI 1.05-1.33; p = 0.006), and increased with the number of IMID flares (OR: 1.27; 95% CI 1.02-1.58; p = 0.03). Conversely, it was less likely to occur in patients treated with biological therapy (OR: 0.51; 95% CI 0.32-0.82; p = 0.006). During the pandemic, at least one self-reported disease flare was seen in 654 (21.6%) patients. Also, 519 (20.6%) patients experienced changes in their treatment, with 125 of these (24.1%) being due to COVID-19.

Conclusion:

The SARS-CoV-2 prevalence in IMID patients over the study period seems to be similar to that of the general population1. The IMID inflammatory status seems to be independently associated with the development of COVID-19.

References:

[1]Pollán M, Pérez-Gómez B, Pastor-Barriuso R, Oteo J, Hernán MA, Pérez-Olmeda M, et al. Prevalence of SARS-CoV-2 in Spain (ENE-COVID): a nationwide, population-based seroepidemiological study. Lancet Lond Engl. 2020 Aug 22;396(10250):535–44.

Disclosure of Interests:

None declared.

Nursing diagnoses: what about NANDA-I syndromes?

AIM

The aim of this paper is to propose a label structure for nursing diagnosis syndromes from NANDA-I.

BACKGROUND

Worldwide changes and human needs seem to get more complex, offering challenging opportunities for nursing care and to nursing knowledge. Nursing classifications represent nursing knowledge and are critical in guiding clinical practice and patient-centred care.

SOURCES OF EVIDENCE

This discussion paper is based on the analysis of NANDA-I Taxonomy II and related literature.

DISCUSSION/CONCLUSION

A total of 13 diagnoses comprise the term 'syndrome'; however, the labels are not consistent with the multiaxial system within the NANDA-I model of a nursing diagnosis. Syndromes require a more specific approach and definition when compared to other type of nursing diagnoses. A new format for describing the label is provided and would be useful in improving current syndromes and in reflecting a more individualized and patient-centred nursing care.

IMPLICATIONS FOR NURSING POLICY AND PRACTICE

The proposal provided in this paper could raise the quality of nurses' assessment, increase accuracy of NANDA-I nursing diagnoses, promote nurses' clinical reasoning and the adequacy of care. Ultimately, changes should be not only perceived in nurses´ practice but also in nursing education as curricula should promote a critical thinking. Nurse leaders and policymakers could additionally use this in the development of advanced programmes and protocols that could manage and monitorize implementation of advanced care.

Oxidative Stress Modulation and Radiosensitizing Effect of Quinoxaline-1,4-Dioxides Derivatives

Background:

Quinoxaline-1,4-dioxide (QNX) derivatives are synthetic heterocyclic compounds with multiple biological and pharmacological effects.

Objective:

In this study, we investigated the oxidative status of quinoxaline-1,4-dioxides derivatives in modulating melanoma and glioma cell lines, based on previous results from the research group and their capability to promote cell damage by the production of Reactive Oxygen Species (ROS).

Methods:

Using in vitro cell cultures, the influence of 2-amino-3-cyanoquinoxaline-1,4-dioxide (2A3CQNX), 3- methyl-2-quinoxalinecarboxamide-1,4-dioxide (3M2QNXC) and 2-hydroxyphenazine-1,4-dioxide (2HF) was evaluated in metabolic activity, catalase activity, glutathione and 3-nitrotyrosine (3-NT) quantitation by HPLC in malignant melanocytes (B16-F10, MeWo) and brain tumor cells (GL-261 and BC3H1) submitted to radiotherapy treatments (total dose of 6 Gy).

Results:

2HF increased the levels of 3-NT in non-irradiated MeWo and glioma cell lines and decreased cell viability in these cell lines with and without irradiation.

Conclusions:

Quinoxaline-1,4-dioxides derivatives modulate the oxidative status in malignant melanocytes and brain tumor cell lines and exhibited a potential radiosensitizer in vitro action on the tested radioresistant cell lines.

The INTERNATIONAL MISSION study: minimally invasive surgery in ovarian neoplasms after neoadjuvant chemotherapy

OBJECTIVES

The aim of this retrospective multicenter study was to investigate the extent, feasibility, and outcomes of minimally invasive surgery at the time of interval debulking surgery in different gynecological cancer centers.

METHODS/MATERIALS

In December 2016, 20 gynecological cancer centers were contacted by e-mail, to participate in the INTERNATIONAL MISSION study. Seven centers confirmed and five were included, with a total of 127 patients diagnosed with advanced epithelial ovarian cancer after neoadjuvant chemotherapy and minimally invasive interval surgery. Only women with a minimum follow-up time of 6 months from interval surgery or any cancer-related event before 6 months were included in the survival analysis. Baseline characteristics, chemotherapy, and operative data were evaluated. Survival analysis was evaluated using the Kaplan-Meier method. RESULTS : All patients had optimal cytoreduction at the time of interval surgery: among them, 122 (96.1%) patients had no residual tumor. Median operative time was 225 min (range 60 - 600) and median estimated blood loss was 100 mL (range 70 - 1320). Median time to discharge was 2 days (1-33) and estimated median time to start chemotherapy was 20 days (range 15 - 60). Six (4.7%) patients experienced intraoperative complications, with one patient experiencing two serious complications (bowel and bladder injury at the same time). There were six (4.7%) patients with postoperative short-term complications: among them, three patients had severe complications. The conversion rate to laparotomy was 3.9 %. Median follow-up time was 37 months (range 7 - 86): 74 of 127 patients recurred (58.3%) and 31 (24.4%) patients died from disease. Median progression-free survival was 23 months and survival at 5 years was 52 % (95% CI: 35 to 67).

CONCLUSIONS

Minimally invasive surgery may be considered for the management of patients with advanced ovarian cancer who have undergone neoadjuvant chemotherapy, when surgery is limited to low-complexity standard cytoreductive procedures.

P1278 Budget impact of global longitudinal strain for the early detection of cardiotoxicity incorporation in the brazilian private healthcare system

Funding Acknowledgements

Department of Cardiovascular Imaging / Brazilian Society of Cardiology

Objective

To estimate the budget impact of incorporating global longitudinal strain (GLS) for the early detection of cardiotoxicity in patients under cancer treatment, compared to conventional echocardiographic measurements (ECO) in the Brazilian Private Healthcare System (PHS). Methods: The BI was calculated based on a Markov constructed with the following health states: no changes, cardiotoxicity, heart failure, reversibility and death, with annual cycles. Eligible population was estimated through an epidemiological approach, based on the prevalence of cancer, proportion of cancer patients treated with anthracyclines and proportion of patients covered by health plans. The time horizon was 5 years, with perspective of the PHS. One scenario was built considering only the cost of GLS and ECO, whereas the other scenario included direct medical costs related to the management of cardiotoxicity and heart failure. Probabilistic sensitivity analyses were performed to explore uncertainties. Results: The initial eligible population was estimated in 209,657 patients. The scenario considering only GLS and ECO procedures costs resulted in a positive BI, from BRL3.6 million in the first year to R$ 59 million in the fifth year. Considering total costs, the incorporation of GLS has the potential to result in savings to PHS from the fourth year of incorporation. In the fifth year the economy reaches about R$ 9 million. Deterministic results are corroborated by the probabilistic analyses. Conclusion: Cardiotoxicity has a major impact in cancer patients treated with anthracyclines, being associated with increased risk of heart failure and mortality. Since GLS has the potential of early detection of cardiotoxicity, allowing the rapid onset of treatment, the use of GLS has the potential to promote savings for the private healthcare system.

Abstract P1278 Figure. budget impact of GLS

Prevalence of eosinophilic esophagitis: A multicenter study on a pediatric population evaluated at thirty-six Latin American gastroenterology centers

INTRODUCTION AND OBJECTIVE

Eosinophilic esophagitis is a chronic, immune-mediated disease described in case series and publications worldwide. Over the past twenty years, the authors of different studies have attempted to evaluate its incidence and prevalence. The objetive of the present study was to estimate the prevalence of eosinophilic esophagitis in a group of children seen at 36 pediatric gastroenterology centers in ten Latin American countries.

MATERIALS AND METHODS

A multicenter, observational, and cross-sectional study was conducted that estimated the period prevalence of eosinophilic esophagitis in children seen at outpatient consultation and that underwent diagnostic upper gastrointestinal endoscopy for any indication at 36 centers in 10 Latin American countries, within a 3-month time frame.

RESULTS

Between April and June 2016, 108 cases of eosinophilic esophagitis were evaluated. Likewise, an average of 29,253 outpatient consultations and 4,152 diagnostic upper gastrointestinal endoscopies were carried out at the 36 participating centers. The period prevalence of eosinophilic esophagitis in the population studied (n=29,253) was 3.69 cases×1,000 (95% CI: 3.04 to 4.44), and among the children that underwent routine upper gastrointestinal endoscopy (n=4,152), it was 26x1,000 (95% CI: 22.6 to 29.4).

CONCLUSIONS

The general period prevalence of eosinophilic esophagitis in a group of children evaluated at 36 Latin American pediatric gastroenterology centers was 3.69×1,000, and in the children that underwent endoscopy, it was 26×1,000. There was important prevalence variability between the participating countries and centers. The present analysis is the first study conducted on the prevalence of pediatric eosinophilic esophagitis in Latin America.

Severe asthma in obese patients: Improvement of lung function after treatment with omalizumab

INTRODUCTION

Asthma and obesity have a considerable impact on public health and their prevalence is increasing. Obesity is a known risk factor for asthma and can make it more difficult to control. Omalizumab is recommended in patients with severe allergic persistent asthma. The aim of this study was to assess the impact of omalizumab treatment in obese asthmatic patients with poorly controlled severe persistent asthma.

METHODOLOGY

A non-interventional, prospective study was conducted, in an outpatient asthma clinic. All patients with severe asthma who started treatment with omalizumab were included and followed over 12 months. The study population was divided into two groups (obese and non-obese) for statistical analysis (descriptive and comparative analysis).

RESULTS

Thirty-two patients (19 obese) were followed. After 12 months of omalizumab treatment, there was a statistically significant improvement in body mass index, number of exacerbations in the previous year, rescue medication, disease control and lung function, in the whole population. At the end of the study obese patients had a significantly better lung function (FEV₁) than non-obese.

DISCUSSION

As described in the literature, there was a significant reduction in the number of exacerbations in the previous year, rescue medication and better disease control, in the whole population. In relation to lung function, about which published data are inconsistent, treatment with omalizumab significantly improved it in obese patients.

CONCLUSION

Our study showed that omalizumab significantly improved asthma control, reduced rescue medication and asthma exacerbations in all the population; and for the first time showed that obese patients achieved significantly improved lung function.

Localized salt-dependent aquagenic urticaria, a rare subtype of urticaria: a case report

Summary

Aquagenic urticaria (AU) is a rare form of chronic inducible urticaria elicited by water at any temperature. We describe the case of a 25-year-old atopic woman who presented to our unit with a 4-year history of recurrent urticarial rashes, highly pruritic, confined to the neck and lower part of the face, occurring solely on contact with sea water. The lesions were reproduced by challenge tests with aqueous 3.5% NaCl and other hypertonic aqueous solutions but not with 20% glucose neither tap water. Our case supports the existence of a distinct salt-dependent subtype of aquagenic urticaria (SDAU), which seems to be triggered mostly by sea bathing, affects young women and has a characteristic localization on the inferior facial contours and neck. To the best of our knowledge, only eight cases of SDAU have been reported in the literature.

Polyphenolic characterisation and bioactivity of an Oxalis pes-caprae L. leaf extract

The present work is focused on the characterisation of the polyphenolic content of an Oxalis pes-caprae L. leaf extract and on the evaluation of its bioactivity with particular interest on its vascular activity and antioxidant potential. The polyphenolic content was characterised by HPLC-DAD and LC-MS/MS. The vascular activity was evaluated according to the influence on the serotonergic and adrenergic systems of the human internal mammary artery (HIMA). Antioxidant and neuroprotective studies were also conducted. Several luteolin and apigenin derivatives were identified as main constituents of the extract, which did not present any contractile effect nor had any effect on the serotonergic system of HIMA. However, it showed antagonistic effect on the adrenergic system, inhibiting the contraction to noradrenaline (reduction of 58.44% of maximum contraction). The extract showed antioxidant activity and standardised luteolin and apigenin derivatives showed neuroprotective potential, particularly homoorientin.

Reversible drug-induced antiphospholipid syndrome

We report an original case of reversible antiphospholipid syndrome (APS) due to minocycline in a young male patient who experienced recurrent strokes while taking minocycline. He started minocycline therapy (50 mg twice daily) at 15 years old for acne. After three years of treatment, the patient experienced a lateral medullary syndrome. He was treated with aspirin while minocycline was continued. Eighteen months later, the patient complained about horizontal binocular diplopia. MRI revealed an infarct of the oculomotor nerve nucleus. Laboratory investigations revealed high titers of anti-beta 2 glycoprotein 1 (antiβ2GP1) antibodies of 470 U/ml (normal range <15 U/ml) and antiphosphatidylethanolamine antibodies of 137.4 U/ml (normal range <18 U/ml). Other laboratory tests were normal. Six weeks after discontinuation of minocycline, anti-β2GP1 antibodies decreased to 335 U/ml and to 36 U/ml at six months and then remained negative for six years. Many drugs have been considered as possibly causing APS but only in a limited number of patients. To our knowledge this is the first case of drug-induced APS with complete disappearance of high titers of anti-β2GP1 antibodies after minocycline withdrawal. This case also illustrates the need to monitor the levels of antiphospholipid antibodies, even though initial values are high and confirmed after 12 weeks.

3-Nitrotyrosine quantification methods: Current concepts and future challenges

BACKGROUND

Measurement of 3-nitrotyrosine (3-NT) in biological samples can be used as a biomarker of nitrosative stress, since it is very stable and suitable for analysis. Increased 3-NT levels in biological samples have been associated with several physiological and pathological conditions. Different methods have been described for the detection and quantification of this molecule, such as (i) immunological methods; (ii) liquid chromatography, namely high-pressure liquid chromatography (HPLC)-based methods that use ultraviolet-visible (UV/VIS) absorption, electrochemical (ECD) and diode array (DAD) detection, liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS); (iii) gas chromatography, such as gas chromatography-mass spectrometry (GC-MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS).

METHODS

A literature review on nitrosative stress, protein nitration, as well as 3-NT quantification methods was carried out.

RESULTS

This review covers the different methods for analysis of 3-NT that have been developed during the last years as well as the latest advances in this field. Overall, all methods present positive and negative aspects, although it is clear that chromatography-based methods present good sensitivity and specificity. Regarding this, GC-based methods exhibit the highest sensibility in the quantification of 3-NT, although it requires a prior time consuming derivatization step. Conversely, HPLC does not require such derivatization step, despite being not as accurate as GC.

CONCLUSION

It becomes clear that all the methods described during this literature review, although accurate for 3-NT quantification, need to be improved regarding both sensitivity and specificity. Moreover, optimization of the protocols that have been described is clearly needed.

Quinoxaline, its derivatives and applications: A State of the Art review

Quinoxaline derivatives are an important class of heterocycle compounds, where N replaces some carbon atoms in the ring of naphthalene. Its molecular formula is C8H6N2, formed by the fusion of two aromatic rings, benzene and pyrazine. It is rare in natural state, but their synthesis is easy to perform. In this review the State of the Art will be presented, which includes a summary of the progress made over the past years in the knowledge of the structure and mechanism of the quinoxaline and quinoxaline derivatives, associated medical and biomedical value as well as industrial value. Modifying quinoxaline structure it is possible to obtain a wide variety of biomedical applications, namely antimicrobial activities and chronic and metabolic diseases treatment.

Quinoxaline, its derivatives and applications: A State of the Art review

Quinoxaline derivatives are an important class of heterocycle compounds, where N replaces some carbon atoms in the ring of naphthalene. Its molecular formula is C8H6N2, formed by the fusion of two aromatic rings, benzene and pyrazine. It is rare in natural state, but their synthesis is easy to perform. In this review the State of the Art will be presented, which includes a summary of the progress made over the past years in the knowledge of the structure and mechanism of the quinoxaline and quinoxaline derivatives, associated medical and biomedical value as well as industrial value. Modifying quinoxaline structure it is possible to obtain a wide variety of biomedical applications, namely antimicrobial activities and chronic and metabolic diseases treatment.