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Critical Care (London, England) Sep 2023No univocal recommendation exists for microbiological diagnosis of ventilator-associated pneumonia (VAP). Sampling of either proximal or distal respiratory tract likely...
Incidence, microbiological and immunological characteristics of ventilator-associated pneumonia assessed by bronchoalveolar lavage and endotracheal aspirate in a prospective cohort of COVID-19 patients: CoV-AP study.
BACKGROUND
No univocal recommendation exists for microbiological diagnosis of ventilator-associated pneumonia (VAP). Sampling of either proximal or distal respiratory tract likely impacts on the broad range of VAP incidence between cohorts. Immune biomarkers to rule-in/rule-out VAP diagnosis, although promising, have not yet been validated. COVID-19-induced ARDS made VAP recognition even more challenging, often leading to overdiagnosis and overtreatment. We evaluated the impact of different respiratory samples and laboratory techniques on VAP incidence and microbiological findings in COVID-19 patients.
METHODS
Prospective single-centre cohort study conducted among COVID-19 mechanically ventilated patients in Policlinico Hospital (Milan, Italy) from January 2021 to May 2022. Microbiological confirmation of suspected VAP (sVAP) was based on concomitant endotracheal aspirates (ETA) and bronchoalveolar lavage (BAL). Conventional and fast microbiology (FILMARRAY® Pneumonia Panel plus, BAL) as well as immunological markers (immune cells and inflammatory cytokines) was analysed.
RESULTS
Seventy-nine patients were included. Exposure to antibiotics and steroid therapy before ICU admission occurred in 51/79 (64.6%) and 60/79 (65.9%) patients, respectively. Median duration of MV at VAP suspicion was 6 (5-9) days. Incidence rate of microbiologically confirmed VAP was 33.1 (95% CI 22.1-44.0) and 20.1 (95% CI 12.5-27.7) according to ETA and BAL, respectively. Concordance between ETA and BAL was observed in 35/49 (71.4%) cases, concordance between BAL and BAL in 39/49 (79.6%) cases. With BAL as reference standard, ETA showed 88.9% (95% CI 70.8-97.7) sensitivity and 50.0% (95% CI 28.2-71.8) specificity (Cohen's Kappa 0.40, 95% CI 0.16-0.65). BAL showed 95.0% (95% CI 75.1-99.9) sensitivity and 69% (95% CI 49.2-84.7) specificity (Cohen's Kappa 0.60, 95% CI 0.39-0.81). BAL IL-1β differed significantly between VAP (135 (IQR 11-450) pg/ml) and no-VAP (10 (IQR 2.9-105) pg/ml) patients (P = 0.03).
CONCLUSIONS
In COVID-19 ICU patients, differences in microbial sampling at VAP suspicion could lead to high variability in VAP incidence and microbiological findings. Concordance between ETA and BAL was mainly limited by over 20% of ETA positive and BAL negative samples, while BAL showed high sensitivity but limited specificity when evaluating in-panel targets only. These factors should be considered when comparing results of cohorts with different sampling. BAL IL-1β showed potential in discriminating microbiologically confirmed VAP.
CLINICAL TRIAL REGISTRATION
NCT04766983, registered on February 23, 2021.
Topics: Humans; COVID-19; Pneumonia, Ventilator-Associated; Cohort Studies; Incidence; Prospective Studies; Bronchoalveolar Lavage; Dimercaprol
PubMed: 37749631
DOI: 10.1186/s13054-023-04658-5 -
Toxicon: X Jun 2022Snakebite envenoming affects more than 250,000 people annually in sub-Saharan Africa. Envenoming by (boomslang) results in venom-induced consumption coagulopathy...
Snakebite envenoming affects more than 250,000 people annually in sub-Saharan Africa. Envenoming by (boomslang) results in venom-induced consumption coagulopathy (VICC), whereby highly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogen. The only available treatment for envenoming is the monovalent SAIMR Boomslang antivenom. Treatment options are urgently required because this antivenom is often difficult to source and, at US$6000/vial, typically unaffordable for most snakebite patients. We therefore investigated the and preclinical efficacy of four SVMP inhibitors to neutralise the effects of venom; the matrix metalloproteinase inhibitors marimastat and prinomastat, and the metal chelators dimercaprol and DMPS The venom of exhibited an SVMP-driven procoagulant phenotype . Marimastat and prinomastat demonstrated equipotent inhibition of the SVMP-mediated procoagulant activity of the venom , whereas dimercaprol and DMPS showed considerably lower potency. However, when tested in preclinical murine models of envenoming using mixed sex CD1 mice, DMPS and marimastat demonstrated partial protection against venom lethality, demonstrated by prolonged survival times of experimental animals, whereas dimercaprol and prinomastat failed to confer any protection at the doses tested. The preclinical results presented here demonstrate that DMPS and marimastat show potential as novel small molecule-based therapeutics for snakebite envenoming. These two drugs have been previously shown to be effective against VICC in preclinical models, and thus we conclude that marimastat and DMPS should be further explored as potentially valuable early intervention therapeutics to broadly treat VICC following snakebite envenoming in sub-Saharan Africa.
PubMed: 35321116
DOI: 10.1016/j.toxcx.2022.100118 -
BMJ Case Reports Sep 2021A 38-year-old man presented at the emergency department with abdominal pain, vomiting, generalised weakness and altered consciousness. He had been ingesting opioids for...
A 38-year-old man presented at the emergency department with abdominal pain, vomiting, generalised weakness and altered consciousness. He had been ingesting opioids for over 5 years and had several past hospital admissions for abdominal pain. His investigations showed deranged liver function tests, anaemia and basophilic stippling on the peripheral blood smear. Further investigations revealed a significant increase in the serum lead level. We started chelation with peroral penicillamine 250 mg every 6 hours for 2 days and switched to intramuscular dimercaprol 4 mg/kg every 12 hours and intravenous calcium ethylenediamine tetraacetic acid 50 mg/kg in two divided doses daily for the next 5 days. We then discharged him home; he had become clinically stable by that time. We repeated his lead level and followed him up in the clinic. In this report, we emphasise the consideration of lead toxicity in opioid abusers and bring to attention a rare way of lead chelation in resource-limited settings.
Topics: Abdominal Pain; Adult; Analgesics, Opioid; Brain Diseases; Humans; Lead; Lead Poisoning; Male
PubMed: 34544696
DOI: 10.1136/bcr-2020-240977 -
Translational Neurodegeneration Apr 2021The mechanisms underlying lesions of dopaminergic (DA) neurons, an essential pathology of Parkinson's disease (PD), are largely unknown, although oxidative stress is...
BACKGROUND
The mechanisms underlying lesions of dopaminergic (DA) neurons, an essential pathology of Parkinson's disease (PD), are largely unknown, although oxidative stress is recognized as a key factor. We have previously shown that the pro-oxidative aldehyde acrolein is a critical factor in PD pathology, and that acrolein scavenger hydralazine can reduce the elevated acrolein, mitigate DA neuron death, and alleviate motor deficits in a 6-hydroxydopamine (6-OHDA) rat model. As such, we hypothesize that a structurally distinct acrolein scavenger, dimercaprol (DP), can also offer neuroprotection and behavioral benefits.
METHODS
DP was used to lower the elevated levels of acrolein in the basal ganglia of 6-OHDA rats. The acrolein levels and related pathologies were measured by immunohistochemistry. Locomotor and behavioral effects of 6-OHDA injections and DP treatment were examined using the open field test and rotarod test. Pain was assessed using mechanical allodynia, cold hypersensitivity, and plantar tests. Finally, the effects of DP were assessed in vitro on SK-N-SH dopaminergic cells exposed to acrolein.
RESULTS
DP reduced acrolein and reversed the upregulation of pain-sensing transient receptor potential ankyrin 1 (TRPA1) channels in the substantia nigra, striatum, and cortex. DP also mitigated both motor and sensory deficits typical of PD. In addition, DP lowered acrolein and protected DA-like cells in vitro. Acrolein's ability to upregulate TRPA1 was also verified in vitro using cell lines.
CONCLUSIONS
These results further elucidated the acrolein-mediated pathogenesis and reinforced the critical role of acrolein in PD while providing strong arguments for anti-acrolein treatments as a novel and feasible strategy to combat neurodegeneration in PD. Considering the extensive involvement of acrolein in various nervous system illnesses and beyond, anti-acrolein strategies may have wide applications and broad impacts on human health.
Topics: Acrolein; Animals; Behavior, Animal; Cerebral Cortex; Dimercaprol; Dopaminergic Neurons; Hydroxydopamines; Male; Motor Activity; Neostriatum; Neuroprotective Agents; Pain; Pain Measurement; Parkinson Disease, Secondary; Rats; Rats, Sprague-Dawley; Substantia Nigra; TRPA1 Cation Channel
PubMed: 33910636
DOI: 10.1186/s40035-021-00239-0 -
Heliyon Apr 2024Mercury's neurotoxic effects have prompted the development of advanced control and remediation methods to meet stringent measures for industries with high-mercury... (Review)
Review
Mercury's neurotoxic effects have prompted the development of advanced control and remediation methods to meet stringent measures for industries with high-mercury feedstocks. Industries with significant Hg emissions, including artisanal and small-scale gold mining (ASGM)-789.2 Mg year, coal combustion-564.1 Mg year, waste combustion-316.1 Mg year, cement production-224.5 Mg year, and non-ferrous metals smelting-204.1 Mg year, use oxidants and adsorbents capture Hg from waste streams. Oxidizing agents such as O, Cl, HCl, CaBr, CaCl, and NHCl oxidize Hg to Hg for easier adsorption. To functionalize adsorbents, carbonaceous ones use S, SO, and NaS, metal-based adsorbents use dimercaprol, and polymer-based adsorbents are grafted with acrylonitrile and hydroxylamine hydrochloride. Adsorption capacities span 0.2-85.6 mg g for carbonaceous, 0.5-14.8 mg g for metal-based, and 168.1-1216 mg g for polymer-based adsorbents. Assessing Hg contamination in soils and sediments uses bioindicators and stable isotopes. Remediation approaches include heat treatment, chemical stabilization and immobilization, and phytoremediation techniques when contamination exceeds thresholds. Achieving a substantially Hg-free ecosystem remains a formidable challenge, chiefly due to the ASGM industry, policy gaps, and Hg persistence. Nevertheless, improvements in adsorbent technologies hold potential.
PubMed: 38571637
DOI: 10.1016/j.heliyon.2024.e28253 -
Neurotoxicity Research Oct 2022Ferroptosis is a necrotic cell death caused by lipid oxidation that may be responsible for neural degeneration in Parkinson's disease. We assessed whether three neuronal...
Ferroptosis is a necrotic cell death caused by lipid oxidation that may be responsible for neural degeneration in Parkinson's disease. We assessed whether three neuronal cell lines are sensitive to killing by ferroptosis. Ferroptosis inducer erastin killed LUHMES neurons at sub-micromolar concentrations, whereas neuronal cells derived from SH-SY5Y cells or neural stem cells were at least 50-fold less sensitive. LUHMES differentiated neurons were likewise sensitive to killing by RSL3 or ML210, inhibitors of the glutathione peroxidase 4 enzyme (GPX4) that consumes GSH to detoxify lipid peroxides. Additional assays showed that erastin, RSL3, and ML210 increased lipid peroxide levels, and that LUHMES neurons were protected from both peroxide accumulation and cell death by ferrostatin-1. A possible role of iron was assessed by evaluating the effects of five metal chelators on cytotoxicity of erastin and RSL3. LUHMES neurons were protected from RSL3 by three of the chelators, 2,3-dimercapto-1-propanesulfonic acid (DMPS), deferoxiprone (DFX), and deferiprone (DFP). Collectively, these results demonstrate the vulnerability of LUHMES neurons to ferroptosis by chemical treatments that disrupt glutathione synthesis, lipid peroxide detoxification, or iron metabolism. The same vulnerabilities may occur in CNS neurons, which reportedly generate low levels of GSH and metallothioneins, limiting their ability to neutralize oxidative stresses and toxic metals. These results suggest a rationale and methods to search for environmental toxicants that may exploit these vulnerabilities and promote neurodegenerative diseases.
Topics: Humans; Carbolines; Chelating Agents; Deferiprone; Dopaminergic Neurons; Ferroptosis; Glutathione; Iron; Lipid Peroxides; Neuroblastoma; Phospholipid Hydroperoxide Glutathione Peroxidase; Unithiol
PubMed: 35922689
DOI: 10.1007/s12640-022-00538-y -
Journal of Trace Elements in Medicine... 2015In the present review we provide an update of the appropriate use of chelating agents in the treatment of intoxications with compounds of mercury, lead and copper. The... (Review)
Review
In the present review we provide an update of the appropriate use of chelating agents in the treatment of intoxications with compounds of mercury, lead and copper. The relatively new chelators meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-propanesulphonate (DMPS) can effectively mobilize deposits of mercury as well as of lead into the urine. These drugs can be administered orally and have relatively low toxicity compared to the classical antidote dimercaptopropanol (BAL). d-Penicillamine has been widely used in copper overload, although 2,3-dimercaptosuccinic acid or tetrathiomolybdate may be more suitable alternatives today. In copper-toxicity, a free radical scavenger might be recommended as adjuvant to the chelator therapy.
Topics: Administration, Oral; Animals; Chelating Agents; Chelation Therapy; Copper; Drug Therapy, Combination; Evidence-Based Medicine; Free Radical Scavengers; Humans; Infusions, Parenteral; Lead Poisoning; Mercury Poisoning; Penicillamine; Succimer; Trientine; Unithiol
PubMed: 24894443
DOI: 10.1016/j.jtemb.2014.04.010 -
Immunity, Inflammation and Disease Aug 2023A systemic and local inflammatory immune imbalance is thought to be the cause of traumatic tracheal stenosis (TS). However, with CD4 T lymphocytes being the predominant...
A systemic and local inflammatory immune imbalance is thought to be the cause of traumatic tracheal stenosis (TS). However, with CD4 T lymphocytes being the predominant immune cells in TS, the mechanism of action and recruitment has not been described. In our research, using flow cytometry, ELISA, immunofluorescence, and Transwell chamber assays, the expression, distribution, and potential chemotactic function of CD4 T cells in TS patients were examined before and after treatment. The results showed that the untreated group had significantly more CD4 T cells and their secreted TGF-β1 than the treated group. Additionally, the untreated group's CD4 T cells showed a significant rise in CCL22 and CCL1, as well as a larger proportion of CCR4 and CCR8. CD4 T cells and CD68 macrophages located in TS also expressed CCL1 and CCL22. In vitro, anti-CCL1 and anti-CCL22 can partially block the chemoattractant effect of TS bronchoalveolar lavage (BAL) on purified CD4 T cells. The findings of this study indicated that TS contained unbalanced CD4 immune cells that were actively recruited locally by CCR4/CCL22 and CCR8/CCL1. As a result, it is anticipated that CD4 immune rebalancing can serve as a novel treatment for TS.
Topics: Humans; Tracheal Stenosis; Biological Assay; CD4-Positive T-Lymphocytes; Dimercaprol; Enzyme-Linked Immunosorbent Assay
PubMed: 37647429
DOI: 10.1002/iid3.916 -
Prague Medical Report 2023Acute eosinophilic pneumonia (AEP) is a rare cause of respiratory failure. It is primarily a disease of smokers, either a new smoker or an existing one with a recent...
Acute eosinophilic pneumonia (AEP) is a rare cause of respiratory failure. It is primarily a disease of smokers, either a new smoker or an existing one with a recent increase in cigarette consumption. Other risk factors include toxic gas exposure, inhalational illicit drugs, and smoking marijuana. AEP has also been reported in patients with e-cigarette or vaping associated lung injury (EVALI). We present the case of a 20-year-old male who presented to the hospital with acute respiratory failure. The patient has been vaping heavily for the past three months and started smoking three days before presenting to the emergency department. He was hypertensive, tachycardic, tachypneic, and required high-flow nasal cannula to maintain SpO2 > 92%. His condition deteriorated in the first 24 hours following hospitalization requiring noninvasive positive pressure ventilation. Bronchoalveolar lavage revealed an eosinophil count of 36%. Bronchoalveolar lavage (BAL) cytology revealed lipid-laden macrophages. He was diagnosed with AEP due to EVALI, and the patient was treated with high dose corticosteroid with subsequent improvement. Before the bronchoscopic evaluation, the clinical and radiologic findings were consistent with COVID-19, and the patient was tested twice for SARS-CoV-2 PCR. In the appropriate clinical setting, AEP should be considered in the differential diagnoses of community-acquired pneumonia, acute respiratory distress syndrome (ARDS), and COVID-19, especially in this pandemic era.
Topics: Male; Humans; Young Adult; Adult; COVID-19; Pulmonary Eosinophilia; Vaping; Electronic Nicotine Delivery Systems; Lung Injury; SARS-CoV-2; Dimercaprol
PubMed: 37736951
DOI: 10.14712/23362936.2023.22 -
Journal of Neurochemistry Jun 2017Acrolein is one of the most toxic byproducts of lipid peroxidation, and it has been shown to be associated with multiple pathological processes in trauma and diseases,...
Acrolein is one of the most toxic byproducts of lipid peroxidation, and it has been shown to be associated with multiple pathological processes in trauma and diseases, including spinal cord injury, multiple sclerosis, and Alzheimer's disease. Therefore, suppressing acrolein using acrolein scavengers has been suggested as a novel strategy of neuroprotection. In an effort to identify effective acrolein scavengers, we have confirmed that dimercaprol, which possesses thiol functional groups, could bind and trap acrolein. We demonstrated the reaction between acrolein and dimercaprol in an abiotic condition by nuclear magnetic resonance spectroscopy. Specifically, dimercaprol is able to bind to both the carbon double bond and aldehyde group of acrolein. Its acrolein scavenging capability was further demonstrated by in vitro results that showed that dimercaprol could significantly protect PC-12 cells from acrolein-mediated cell death in a dose-dependent manner. Furthermore, dimercaprol, when applied systemically through intraperitoneal injection, could significantly reduce acrolein contents in spinal cord tissue following a spinal cord contusion injury in rats, a condition known to have elevated acrolein concentration. Taken together, dimercaprol may be an effective acrolein scavenger and a viable candidate for acrolein detoxification.
Topics: Acrolein; Animals; Body Weight; Cell Death; Dimercaprol; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Free Radical Scavengers; L-Lactate Dehydrogenase; Magnetic Resonance Spectroscopy; Male; PC12 Cells; Rats; Spinal Cord; Spinal Cord Injuries
PubMed: 28301040
DOI: 10.1111/jnc.14025