Anti-Inflammatory and Immunomodulatory Properties of a Crude Polysaccharide Derived from Green Seaweed Halimeda tuna: Computational and Experimental Evidences

In this study, we investigated for the first time the anti-inflammatory and immunomodulatory properties of crude polysaccharide (PSHT) extracted from green marine algae Halimeda tuna. PSHT exhibited anti-oxidant activity in vitro through scavenging 1, 1-diphenyl-2-picryl hydroxyl free radical, reducing Fe3+/ferricyanide complex, and inhibiting nitric oxide. PSHT maintained the erythrocyte membrane integrity and prevented hemolysis. Our results also showed that PSHT exerted a significant anti-edematic effect in vivo by decreasing advanced oxidation protein products and malondialdehyde levels and increasing the superoxide dismutase and glutathione peroxidase activities in rat's paw model and erythrocytes. Interestingly, PSHT increased the viability of murine RAW264.7 macrophages and exerted an anti-inflammatory effect on lipopolysaccharide-stimulated cells by decreasing pro-inflammatory molecule levels, including nitric oxide, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-α). Our findings indicate that PSHT could be used as a potential immunomodulatory, anti-inflammatory, anti-hemolytic, and anti-oxidant agent. These results could be explained by the computational findings showing that polysaccharide building blocks bound both cyclooxygenase-2 (COX-2) and TNF-α with acceptable affinities.

The Potential Effect of Polysaccharides Extracted from Red Alga Gelidium spinosum against Intestinal Epithelial Cell Apoptosis

Gut injury is a severe and unpredictable illness related to the increased cell death of intestinal epithelial cells (IECs). Excessive IEC apoptotic cell death during the pathophysiological state entails chronic inflammatory diseases. This investigation was undertaken to assess the cytoprotective action and underlying mechanisms of polysaccharides from Tunisian red alga, Gelidium spinosum (PSGS), on H2O2-induced toxicity in IEC-6 cells. The cell viability test was initially carried out to screen out convenient concentrations of H2O2 and PSGS. Subsequently, cells were exposed to 40 µM H2O2 over 4 h in the presence or absence of PSGS. Findings revealed that H2O2 caused oxidative stress manifested by over 70% cell mortality, disturbed the antioxidant defense, and increased the apoptotic rate in IEC-6 cells (32% than normal cells). Pretreatment of PSGS restored cell viability, especially when used at 150 µg/mL and normal cell morphology in H2O2-callenged cells. PSGS also equally sustained superoxide dismutase and catalase activities and hindered the apoptosis induced by H2O2. This protection mechanism of PSGS may be associated with its structural composition. The ultraviolet visible spectrum, Fourier-transformed infrared (FT-IR), X-ray diffraction (XRD), and high-performance liquid chromatography (HPLC) demonstrated that PSGS is mainly sulfated polysaccharides. Eventually, this research work provides a deeper insight into the protective functions and enhances the investment of natural resources in handling intestinal diseases.

Anxiety among healthcare professionals during the COVID-19 pandemic: Predictive role of social support

Introduction

The COVID-19 pandemic may cause elevated levels of anxiety in healthcare professionals (HCP). Identifying factors that could help maintain mental health especially social support could be helpful in facing this stressful situation.

Objectives

The aim of this study was to asses the relationship between the trait-anxiety and perceived social support among Tunisian HCP in the current pandemic wave of COVID-19.

Methods

A cross- sectional descriptive and analytic study conducted among Tunisian HCP during November and December 2020. The data were collected by an online questionnaire. The trait-anxiety was assessed using the “General Anxiety questionnaire of Spielberger” (STAI-Y-B). We used the “Social Support Questionnaire” to measure availability and satisfaction regarding perceived social support.

Results

Participants were 135 HCP, and aged from 24 to 61 years old (average age 31.98 years). The sex ratio was 1.1 (71 males and 64 females). Of HCP involved in the study, 61.5% were single, 36.3% were married and 2.2% were divorced. The average scores of availability and satisfaction regarding perceived social were 7.79 (SD=3.56) and 28.41 (SD=6.75), respectively. Seventy-two of the HCP had a trait-anxious. Analysis showed that social support satisfaction scores were significantly lower in trait-anxious HCP (p<0.001). However, there was no significant difference in the score of availability according to trait-anxiety (p=0.49).

Conclusions

Our study highlighted the existence of a deficit on perceived social support satisfaction among trait-anxious Tunisian HCP. Perceived social support as a determinant of trait anxiety should be the focus of social work in this period.

Disclosure

No significant relationships.

Trait-anxiety among healthcare professionals in COVID-19 pandemic

Introduction

Factors causing anxiety among healthcare professionals (HCP) are increasing, and psychosocial causes are the most common. During the COVID-19 pandemic, HCP are exposed to additional stressful factors.

Objectives

The aim of this study was to assess the prevalence of trait-anxiety and its associated factors towards the COVID-19 outbreak among Tunisian HCP.

Methods

A cross-sectional descriptive and analytical study conducted among Tunisian HCP during November and December 2020. The data were collected by an online questionnaire including the sociodemographic information and the “General anxiety questionnaire of Spielberger” (STAI-Y-B) which was used to assess the trait-anxiety.

Results

A total of 135 HCP participated in this study (47.4% female and 52.6% male). The average age was 31.98 years (SD=6.59). Of the participants, 3% were nurses, 8.1% were interns, 48.1% were residents, 34.8% were specialist doctors and 5.9% were generalist doctors. Concerning marital status, 61.5% were single, 36.3% were married and 2.2% were divorced. Of HCP involved in the study, 13.3% of the participants had a history of chronic somatic-disorder and 11.9 % of them had a history of a psychiatric disorder. The prevalence of trait-anxiety in HCP was 53.3%. The analysis showed that anxious HCP were more younger (p=0.002) and had history of a psychiatric disorder (p=0.017) compared to non-anxious HCP. However, no significant difference was found by gender, marital status and professional degree according to trait-anxiety.

Conclusions

In our study, we found that more than the half of HCP were anxious and these one were more younger and had history of psychiatric disorders.

Disclosure

No significant relationships.

Dress syndrome following carbamazepine exposure: A very early onset

Introduction

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe cutaneous drug reaction characterised by both systemic and cutaneous clinical manifestation with a mean latency period of 3.9 weeks.

Objectives

To underline the importance of an early diagnosis of DRESS SYNDROME.

Methods

We reported a case of carbamazepine induced DRESS syndrome with atypical chronology of manifestations.

Results

A 43-year-old man with no previous known medical history was admitted in psychiatry. He experienced a relapse of schizoaffective symptoms. In the last three years, the patient was treated by Valproic acid as a mood stabilizer. Because of the unavailability of this molecule, carbamazepine was prescribed in combination with antipsychotics. Three days later, the patient developed a high fever, hypotension, a pruritus, a facial oedema, a skin rash associated to lymphadenopathy. Laboratory findings showed a lymphopenia, eosinophilia and elevated liver chemistries. In order to define the case, RegiSCAR scoring system was used, and our case is categorized as probable with a score of five. Carbamazepine was discontinued upon clinical manifestationsand the patient was treated with systemic antihistaminic treatment associated to methylprednisolone with a good outcome. After 3 weeks, clinical and biological improvement were noted.

Conclusions

Despite the absence of a delayed onset, typically between 3 weeks and 3months, we can diagnose dress syndrome 3 days after carbamazepine intake. This case highlights that psychiatrists should be aware of the risk of early onset dress syndrome associated with carbamazepine and they should monitor for warning symptoms from treatment initiation.

Disclosure

No significant relationships.

Trait anxiety and coping strategies among healthcare professionals during the COVID-19 pandemic

Introduction

The current pandemic wave of COVID-19 has become a global threat. Healthcare professionals (HCP), by being on the front line in managing this pandemic, confronted high levels of stress and traumatic experiences.

Objectives

The aims of our study were to evaluate the trait-anxiety among Tunisian HCP and its impact on coping strategies.

Methods

A cross- sectional descriptive and analytic study conducted among Tunisian HCP during November and December 2020. The data was collected by an online questionnaire distributed through social media. The trait-anxiety was assessed using the “General Anxiety questionnaire of Spielberger” (STAI-Y-B) and the “Ways of coping checklist revised (WCC-R) questionnaire” identified three types of coping (problem-focused, emotion-focused and social-support seeking).

Results

Participants were 135 HCP (71 males and 64 females) and aged from 24 to 61 years old (average age 31.98 years; SD 6.59 years). Of HCP involved in the study, 61.5% were single, 36.3% were married and 2.2% were divorced. Seventy-two of them had a trait-anxious. As a coping style, 85.2% of participants used problem-focused style, 88.9% of them used emotion-focused style and 63% of them used social support seeking style. The analysis of WCC-R showed that anxious HCP used emotion-focused coping more than non anxious HCP (p= 0.028). However, there was no significant difference in problem-focused or social support seeking coping styles and presence of trait-anxiety.

Conclusions

In our study, we find that the most anxious Tunisian HCP focused on emotions strategies. Personality traits play on attitudes of coping strategies.

Disclosure

No significant relationships.

Assessment of ochratoxin A stability following gamma irradiation: experimental approaches for feed detoxification perspectives

The present study evaluated the effect of gamma irradiation on the stability of ochratoxin A (OTA) under various conditions. The effects of the physical state of OTA (solid vs aqueous), initial OTA concentration, irradiation dose and dose rate as well as the presence of model substances simulating food matrix compounds on OTA radiostability were investigated. First, pure OTA with and without food model compounds including α-D-glucose (monosaccharide), Methyl α-D-glucopyranoside (starch) and the amino acid derivatives N-α-acetyl-L-lysine methyl ester and N-α-acetyl-L-cysteine methyl ester (protein models) were irradiated with doses of 2, 4 and 8 kGy applied at 15.117 and 108.24 Gy/min. Secondly, artificially OTA-contaminated wheat with different moisture content (11, 14 and 16%) was irradiated with doses of 2, 4 and 8 kGy applied at 63.39 Gy/min. Residual OTA levels were analysed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Solid OTA (50 and 3,200 ng/ml)showed great irradiation stability, even with irradiation doses up to 8 kGy. Under dry conditions, the presence of food model components did not affect OTA radiostability. However, in an aqueous solution, complete reduction was achieved at the initial OTA concentration of 50 ng/ml and irradiation dose of 2 kGy. Applying gamma irradiation to cereal-based food model systems produced a significant OTA reduction (5,000 µg/kg) of 47.2% in moistened wheat kernels (16%) with an absorbed dose of 8 kGy but failed to reduce the OTA content of low moisture content wheat (11%). These model experiments offered a useful tool to assess the main key factors affecting gamma irradiation-induced OTA reduction. Gamma irradiation is promising since the irradiation doses applied could partially reduce OTA contamination. Nevertheless, its efficacy was largely affected by initial moisture content and could be dangerous if toxic by-products are produced or nutritive quality is lost and needs further study.

Certified reference materials and reference methods for nuclear safeguards and security

Confidence in comparability and reliability of measurement results in nuclear material and environmental sample analysis are established via certified reference materials (CRMs), reference measurements, and inter-laboratory comparisons (ILCs). Increased needs for quality control tools in proliferation resistance, environmental sample analysis, development of measurement capabilities over the years and progress in modern analytical techniques are the main reasons for the development of new reference materials and reference methods for nuclear safeguards and security. The Institute for Reference Materials and Measurements (IRMM) prepares and certifices large quantities of the so-called "large-sized dried" (LSD) spikes for accurate measurement of the uranium and plutonium content in dissolved nuclear fuel solutions by isotope dilution mass spectrometry (IDMS) and also develops particle reference materials applied for the detection of nuclear signatures in environmental samples. IRMM is currently replacing some of its exhausted stocks of CRMs with new ones whose specifications are up-to-date and tailored for the demands of modern analytical techniques. Some of the existing materials will be re-measured to improve the uncertainties associated with their certified values, and to enable laboratories to reduce their combined measurement uncertainty. Safeguards involve the quantitative verification by independent measurements so that no nuclear material is diverted from its intended peaceful use. Safeguards authorities pay particular attention to plutonium and the uranium isotope (235)U, indicating the so-called 'enrichment', in nuclear material and in environmental samples. In addition to the verification of the major ratios, n((235)U)/n((238)U) and n((240)Pu)/n((239)Pu), the minor ratios of the less abundant uranium and plutonium isotopes contain valuable information about the origin and the 'history' of material used for commercial or possibly clandestine purposes, and have therefore reached high level of attention for safeguards authorities. Furthermore, IRMM initiated and coordinated the development of a Modified Total Evaporation (MTE) technique for accurate abundance ratio measurements of the "minor" isotope-amount ratios of uranium and plutonium in nuclear material and, in combination with a multi-dynamic measurement technique and filament carburization, in environmental samples. Currently IRMM is engaged in a study on the development of plutonium reference materials for "age dating", i.e. determination of the time elapsed since the last separation of plutonium from its daughter nuclides. The decay of a radioactive parent isotope and the build-up of a corresponding amount of daughter nuclide serve as chronometer to calculate the age of a nuclear material. There are no such certified reference materials available yet.

Characterizing uranium oxide reference particles for isotopic abundances and uranium mass by single particle isotope dilution mass spectrometry

Uranium and plutonium particulate test materials are becoming increasingly important as the reliability of measurement results has to be demonstrated to regulatory bodies responsible for maintaining effective nuclear safeguards. In order to address this issue, the Institute for Reference Materials and Measurements (IRMM) in collaboration with the Institute for Transuranium Elements (ITU) has initiated a study to investigate the feasibility of preparing and characterizing a uranium particle reference material for nuclear safeguards, which is finally certified for isotopic abundances and for the uranium mass per particle. Such control particles are specifically required to evaluate responses of instruments based on mass spectrometric detection (e.g. SIMS, TIMS, LA-ICPMS) and to help ensuring the reliability and comparability of measurement results worldwide. In this paper, a methodology is described which allows quantifying the uranium mass in single micron particles by isotope dilution thermal ionization mass spectrometry (ID-TIMS). This methodology is characterized by substantial improvements recently achieved at IRMM in terms of sensitivity and measurement accuracy in the field of uranium particle analysis by TIMS. The use of monodisperse uranium oxide particles prepared using an aerosol generation technique developed at ITU, which is capable of producing particles of well-characterized size and isotopic composition was exploited. The evidence of a straightforward correlation between the particle volume and the mass of uranium was demonstrated in this study. Experimental results have shown that the uranium mass per particle can be measured via the ID-TIMS method to a relative expanded uncertainty of about 10% (coverage factor k=2). The availability of reliable and validated methods for the characterization of uranium particles is considered to be essential for the establishment of SI-traceable measurement results. It is therefore expected that the method developed in this study is valuable for the certification of particulate materials in which the isotopic composition and the content of uranium must be accurately known.