10 research outputs found
Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU
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Phytoplankton-pigment signatures and their relationship to spring–summer stratification in the Gulf of Gabes
International audienceWe investigated the phytoplankton dynamics (determined by CHEMTAX analysis of HPLC pigment data) and its relationships with nutrients and water column structure, during two oceanographic cruises in May–June and September 2006 in the Gulf of Gabes (south-eastern Mediterranean). The May–June cruise coincided with the beginning of the summer stratification, while a strong stratification occurred in September with a more than 30 m deepening of the thermocline, and a reduction of the euphotic depth. This strong stratification resulted in a shift in nitrogen sources from nitrates to ammonium as well as phosphate depletion (0.2 mM) and a decrease in silicate concentrations (<2 mM). With the exception of chlorophyll a, pigment concentrations were higher in September than in May–June samplings. The picoand nanophytoplankton were the major contributors to phytoplankton total biomass, accounting for 90% and 87% of total chlorophyll a in May–June and September, respectively. Picoplankton persisted throughout the entire survey, occupying different depth layers. Chlorophytes were present at substantial amounts (average 23% of total chlorophyll a) during May–June; however, they declined in September (average 5%). Diatoms were overall poorly represented in this study (2% of total chlorophyll a), due probably to silicate shortage. Apparently, the nutrient availability, but also the water column stability seemed to be among the major factors determining phytoplankton dynamics. Indeed, cyanobacteria were prominent in surface samples during the period of strong stratification, whereas the relative contribution of chlorophytes decreased, probably due to low phosphate availability
Environmental microplastic accumulation exacerbates liver ischemia-reperfusion injury in rat: Protective effects of melatonin
Ischemia-reperfusion (IR) injury is an inevitable complication of liver transplantation and partial hepatectomy. Although the hazards of environmental microplastics (EMPs) have been well explored, data underlying their impact on IR-induced hepatotoxicity and how to alleviate these damages remain largely undefined. In this study, the involvement of melatonin (MT) in modulating EMPs toxicity in the liver undergoing ischemia-reperfusion injury was investigated. Male Wistar rats were exposed to MPs for 7 days and then subjected to 1 h of partial warm ischemia (70 %) followed by 24 h of reperfusion. We analyzed some parameters as the oxidative stress, the stability of cytoskeleton as well as inflammation, and autophagy. Our data suggested that EMPs elicited liver injury in ischemic animals. Data revealed several histological alterations caused by EMP and IRI, including cellular disorientation, cell necrosis, and microvacuolar steatosis, as well as inflammatory cell infiltration. EMPs increased blood transaminase (AST and ALT) and oxidative stress levels in the ischemic liver. In addition, RT-qPCR, immunofluorescence, and western blot analyses highlighted an increased expression of α-tubulin, IL-18, NFkB, and LC3. However, the ability of MT to reduce MPs and IRI toxicity was consistent with a significant decrease in the evaluated markers. The combined data not only document that melatonin is an effective agent to protect against hepatic IRI but also reduces cellular dysfunction caused by EMPs
Exploring the Therapeutic Potential of <i>Ammodaucus leucotrichus</i> Seed Extracts: A Multi-Faceted Analysis of Phytochemical Composition, Anti-Inflammatory Efficacy, Predictive Anti-Arthritic Properties, and Molecular Docking Insights
Ammodaucus leucotrichus exhibits promising pharmacological activity, hinting at anti-inflammatory and anti-arthritic effects. This study investigated seed extracts from Ammodaucus leucotrichus using methanol and n-hexane, focusing on anti-inflammatory and anti-arthritic properties. The methanol extract outperformed the n-hexane extract and diclofenac, a reference anti-inflammatory drug, in trypsin inhibition (85% vs. 30% and 64.67% at 125 μg/mL). For trypsin inhibition, the IC50 values were 82.97 μg/mL (methanol), 202.70 μg/mL (n-hexane), and 97.04 μg/mL (diclofenac). Additionally, the n-hexane extract surpassed the methanol extract and diclofenac in BSA (bovine serum albumin) denaturation inhibition (90.4% vs. 22.0% and 51.4% at 62.5 μg/mL). The BSA denaturation IC50 values were 14.30 μg/mL (n-hexane), 5408 μg/mL (methanol), and 42.30 μg/mL (diclofenac). Gas chromatography–mass spectrometry (GC–MS) revealed 59 and 58 secondary metabolites in the methanol and n-hexane extracts, respectively. The higher therapeutic activity of the methanol extract was attributed to hydroxyacetic acid hydrazide, absent in the n-hexane extract. In silico docking studies identified 28 compounds with negative binding energies, indicating potential trypsin inhibition. The 2-hydroxyacetohydrazide displayed superior inhibitory effects compared to diclofenac. Further mechanistic studies are crucial to validate 2-hydroxyacetohydrazide as a potential drug candidate for rheumatoid arthritis treatment
Phytoplankton dynamics related to water mass properties in the Gulf of Gabes: Ecological implications
International audienceThe spatial distribution of chlorophylls and carotenoids was recorded throughout the Gulf of Gabes (South Ionian Sea) in March 2007, and was related to patterns of the physical structure and the nutrient concentrations. Two distinctwater masseswere identified based on the temperature and salinity (T–S) analysis: a cool and less salty Modified Atlantic Water (MAW) and a saltier Mediterranean Mixed Water (MMW). There was no significant difference in the mean nitrogen and phosphate concentrations between MMW and MAW, although the silica values were significantly higher in MAW. The Integrated chlorophyll a mean value was about 4 mg m−2, with a maximum of 13 mg m−2 at MAW stations. Higher Chlorophyll a records in typical MAW stations were mainly due to chlorophytes, which contributed up to 58% of the pigments concentrations in the MAWand about 46% in theMMW. The contribution of chlorophytes to total Chlorophyll a was found to be relatively stable throughout the water column. The contribution of diatoms, which were twofold higher in the MMW than in the MAW, did not exceed 17% of chlorophyll a and was mainly due to subsurface maxima. The chlorophytes, pelagophytes, prymnesiophytes and cryptophytes all together accounted for more than 77% of total chlorophyll a in the MAWand about 67% in the MMW. There were statistically significant differences between MMW and MAW in the pigment contribution of cyanobacteria and pelagophytes. These two taxa accounted for 13% and 24% of chlorophyll a respectively in the MAWand MMW indicating that these differences concerned phytoplankton classes at relatively low contributions to total chlorophyll a
Zinc mitigates renal ischemia-reperfusion injury in rats by modulating oxidative stress, endoplasmic reticulum stress, and autophagy
Oxidative stress is a major factor involved in the pathogenesis of renal ischemia/reperfusion (I/R). Exogenous zinc (Zn) was suggested as a potent antioxidant; however, the mechanism by which it strengthens the organ resistance against the effects of reactive oxygen species (ROS) is not yet investigated. The present study aims to determine whether acute zinc chloride (ZnCl2) administration could attenuate endoplasmic reticulum (ER) stress, autophagy, and inflammation after renal I/R. Rats were subjected to either sham operation (Sham group, n = 6), or 1 hr of bilateral ischemia followed by 2 hr of reperfusion (I/R groups, n = 6), or they received ZnCl2 orally 24 hr and 30 min before ischemia (ZnCl2 group, n = 6). Rats were subjected to 1 hr of bilateral renal ischemia followed by 2 hr of reperfusion (I/R group, n = 6). Our results showed that ZnCl2 enhances renal function and reduces cytolysis (p < 0,05). In addition, it increased significantly the activities of antioxidant enzymes (SOD, CAT, and GPX) and the level of GSH in comparison to I/R (p < 0,05). Interestingly, ZnCl2 treatment resulted in significant decreased ER stress, as reflected by GRP78, ATF‐6,p‐eIF‐2α, XPB‐1, and CHOP downregulaion. Rats undergoing ZnCl2 treatment demonstrated a low expression of autophagy parameters (Beclin‐1 and LAMP‐2), which was correlated with low induction of apoptosis (caspase‐9, caspase‐3, and p‐JNK), and reduction of inflammation (IL‐1ß, IL‐6, and MCP‐1) (p < 0,05). In conclusion, we demonstrated the potential effect of Zn supplementation to modulate ER pathway and autophagic process after I/R.The Tunisian Ministry of Higher Education
and Scientific Research, Tunisia,
Grant number: UR12ES11; Plan Nacional de I
+D, Spain, Grant numbers: SAF-2014-57674-
R, SAF-2015-69944-R; The Generalitat de
Catalunya, Spain, Grant number: 2014-
SGR785; NIAAA/NIH, Grant number:
P50AA011999Peer reviewe
The effect of zinc acexamate on oxidative stress, inflammation and mitochondria induced apoptosis in rat model of renal warm ischemia
Aim: Zinc has proved its efficacy in many models of ischemia reperfusion (I/R) injury. In this study, we used zinc
acexamate (ZAC) as an exogenous source of zinc against renal I/R injury and we investigated whether its protective effects are mediated by the decrease of oxidative stress, inflammation, and mitochondria inducedapoptosis. Methods: Rats were orally pretreated with vehicle or ZAC (10 or 100 mg/kg) 24 h and 30 min prior to
1 h of bilateral renal warm ischemia and 2 h of reperfusion. Results: Our data showed that 10 mg/kg of ZAC, but
not 100 mg/kg, improved renal architecture and function. Also, the low dose of ZAC up-regulated antioxidant
enzymes activities and glutathione level and decreased lipids and proteins oxidation. Interestingly, the use of
ZAC resulted in a significant reduce of pro-inflammatory cytokines (IL-1ß, IL-6 and MCP-1), enhanced mitochondria integrity and decreased expression of the pro-apoptotic protein caspase-9. Conclusion: We conclude
that renal I/R induced oxidative stress, inflammation and apoptosis and that the use of ZAC at 10 mg/kg, but not
100 mg/kg, protects rat kidneys from I/R injury by down-regulating these processes.This work was supported by grants from: The Tunisian Ministry of
Higher Education and Scientific Research (UR12ES11); SAF-2014-
57674-R, SAF-2015-69944-R from Plan Nacional de I + D, Spain and
CIBEREHD; the center grant P50AA011999 Southern California
Research Center for ALPD and Cirrhosis funded by NIAAA/NIH; and
AGAUR of the Generalitat de Catalunya2014-SGR785.Peer reviewe
Flow cytometry-based diagnostic approach for inborn errors of immunity: experience from Algeria
PurposeIn this study, we retrospectively reviewed the use of flow cytometry (FCM) in the diagnosis of inborn errors of immunity (IEIs) at a single center in Algeria. Sharing insights into our practical experience, we present FCM based diagnostic approaches adapted to different clinical scenarios.MethodsBetween May 2017 and February 2024, pediatric and adult patients presenting with clinical features suggestive of immunodeficiency were subjected to FCM evaluation, including lymphocyte subset analysis, detection of specific surface or intracellular proteins, and functional analysis of immune cells.ResultsOver a nearly seven-year period, our laboratory diagnosed a total of 670 patients (372 (55.5%) males and 298 (44.5%) females), distributed into 70 different IEIs belonging to 9 different categories of the International Union of Immunological Societies classification. FCM was used to diagnose and categorize IEI in 514 patients (76.7%). It provided direct diagnostic insights for IEIs such as severe combined immunodeficiency, Omenn syndrome, MHC class II deficiency, familial hemophagocytic lymphohistiocytosis, and CD55 deficiency. For certain IEIs, including hyper-IgE syndrome, STAT1-gain of function, autoimmune lymphoproliferative syndrome, and activated PI3K delta syndrome, FCM offered suggestive evidence, necessitating subsequent genetic testing for confirmation. Protein expression and functional assays played a crucial role in establishing definitive diagnoses for various disorders. To setup such diagnostic assays at high and reproducible quality, high level of expertise is required; in house reference values need to be determined and the parallel testing of healthy controls is highly recommended.ConclusionFlow cytometry has emerged as a highly valuable and cost-effective tool for diagnosing and studying most IEIs, particularly in low-income countries where access to genetic testing can be limited. FCM analysis could provide direct diagnostic insights for most common IEIs, offer clues to the underlying genetic defects, and/or aid in narrowing the list of putative genes to be analyzed