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Pharmaceutics Oct 2021Actinium-225 (Ac) is a promising radionuclide used in targeted alpha therapy (TAT). Although Ac labeling of bifunctional chelating ligands is effective, previous in vivo...
Evaluation of Aminopolycarboxylate Chelators for Whole-Body Clearance of Free Ac: A Feasibility Study to Reduce Unexpected Radiation Exposure during Targeted Alpha Therapy.
Actinium-225 (Ac) is a promising radionuclide used in targeted alpha therapy (TAT). Although Ac labeling of bifunctional chelating ligands is effective, previous in vivo studies reported that free Ac can be released from the drugs and that such free Ac is predominantly accumulated in the liver and could cause unexpected toxicity. To accelerate the clinical development of Ac TAT with a variety of drugs, preparing methods to deal with any unexpected toxicity would be valuable. The aim of this study was to evaluate the feasibility of various chelators for reducing and excreting free Ac and compare their chemical structures. Nine candidate chelators (D-penicillamine, dimercaprol, Ca-DTPA, Ca-EDTA, CyDTA, GEDTA TTHA, Ca-TTHA, and DO3A) were evaluated in vitro and in vivo. The biodistribution and dosimetry of free Ac were examined in mice before an in vivo chelating study. The liver exhibited pronounced Ac uptake, with an estimated human absorbed dose of 4.76 Sv/MBq. Aminopolycarboxylate chelators with five and six carboxylic groups, Ca-DTPA and Ca-TTHA, significantly reduced Ac retention in the liver (22% and 30%, respectively). Significant Ac reductions were observed in the heart and remainder of the body with both Ca-DTPA and Ca-TTHA, and in the lung, kidney, and spleen with Ca-TTHA. In vitro interaction analysis supported the in vivo reduction ability of Ca-DTPA and Ca-TTHA. In conclusion, aminopolycarboxylate chelators with five and six carboxylic groups, Ca-DTPA and Ca-TTHA, were effective for whole-body clearance of free Ac. This feasibility study provides useful information for reducing undesirable radiation exposure from free Ac.
PubMed: 34683999
DOI: 10.3390/pharmaceutics13101706 -
Science Translational Medicine May 2020Snakebite envenoming causes 138,000 deaths annually, and ~400,000 victims are left with permanent disabilities. Envenoming by saw-scaled vipers (Viperidae: ) leads to...
Snakebite envenoming causes 138,000 deaths annually, and ~400,000 victims are left with permanent disabilities. Envenoming by saw-scaled vipers (Viperidae: ) leads to systemic hemorrhage and coagulopathy and represents a major cause of snakebite mortality and morbidity in Africa and Asia. The only specific treatment for snakebite, antivenom, has poor specificity and low affordability and must be administered in clinical settings because of its intravenous delivery and high rates of adverse reactions. This requirement results in major treatment delays in resource-poor regions and substantially affects patient outcomes after envenoming. Here, we investigated the value of metal ion chelators as prehospital therapeutics for snakebite. Among the tested chelators, dimercaprol (British anti-Lewisite) and its derivative 2,3-dimercapto-1-propanesulfonic acid (DMPS) were found to potently antagonize the activity of Zn-dependent snake venom metalloproteinases in vitro. Moreover, DMPS prolonged or conferred complete survival in murine preclinical models of envenoming against a variety of saw-scaled viper venoms. DMPS also considerably extended survival in a "challenge and treat" model, where drug administration was delayed after venom injection and the oral administration of this chelator provided partial protection against envenoming. Last, the potential clinical scenario of early oral DMPS therapy combined with a delayed, intravenous dose of conventional antivenom provided prolonged protection against the lethal effects of envenoming in vivo. Our findings demonstrate that the safe and affordable repurposed metal chelator DMPS can effectively neutralize saw-scaled viper venoms in vitro and in vivo and highlight the promise of this drug as an early, prehospital, therapeutic intervention for hemotoxic snakebite envenoming.
Topics: Africa; Animals; Asia; Chelating Agents; Humans; Mice; Snake Bites; Viper Venoms
PubMed: 32376771
DOI: 10.1126/scitranslmed.aay8314 -
Journal of Veterinary Internal Medicine 2023Nonbronchoscopic bronchoalveolar lavage (nBAL) is routinely performed in calves, and airway cytology has great potential in airway disease diagnostics. A good reference...
BACKGROUND
Nonbronchoscopic bronchoalveolar lavage (nBAL) is routinely performed in calves, and airway cytology has great potential in airway disease diagnostics. A good reference framework for nBAL cytology is lacking.
OBJECTIVES
To distinguish different cytological profiles in nBAL from grouped housed calves using cluster analysis, and characterize these profiles on individual and herd levels.
ANIMALS
Three hundred thirty-eight group-housed calves from 60 herds (mainly dairy and beef ).
METHODS
Cross-sectional study. Differential counts of white blood cells were determined on nBAL fluid, followed by differentiation of cytological profiles by K-means-based cluster analysis. These profiles were characterized by reference values, decision tree analysis, and associations with clinical, ultrasonographic, bacteriological, and cytological features.
RESULTS
A normal (55.9%), a neutrophilic (41.1%), and an eosinophilic profile (3.0%) were identified. The normal profile was characterized by reference values of 2.3% to 47.4% neutrophils, 35.1% to 95.1% macrophages, 0.4 to 22.9% lymphocytes, and 0.0% to 0.9% eosinophils. The neutrophilic profile was characterized by ≥44.5% neutrophils, <1.6% eosinophils, and <11.5% lymphocytes. This profile was associated with the isolation of Pasteurella multocida, the presence of neutrophils with toxic granulation, and the presence of phagocytosed bacteria in neutrophils. The eosinophilic profile was characterized by eosinophils ≥1.6% (neutrophilia present) or ≥2.4% (neutrophilia absent), and associated with the presence of mast cells. On herd level, the neutrophilic and eosinophilic profiles were present in 85.0% and 15.0% of the herds, respectively.
CONCLUSIONS AND CLINICAL IMPORTANCE
This study provides a first step in the development of cytological guidelines, aiding the assessment of airway health and inflammation in calves through nBAL fluid cytology.
Topics: Animals; Cattle; Bronchoalveolar Lavage Fluid; Cross-Sectional Studies; Bronchoalveolar Lavage; Inflammation; Cluster Analysis; Dimercaprol; Cattle Diseases
PubMed: 37731196
DOI: 10.1111/jvim.16855 -
The American Journal of Case Reports Jul 2023BACKGROUND ThinPrep Cytolyt is a methanol-based cell preservation solution frequently used to fix tissue samples immediately following endobronchial ultrasound-guided...
BACKGROUND ThinPrep Cytolyt is a methanol-based cell preservation solution frequently used to fix tissue samples immediately following endobronchial ultrasound-guided fine-needle aspiration. Currently, no published reports describe an iatrogenic exposure to Cytolyt. We report the only known case of an accidental intraoperative administration of a methanol solution, with corresponding plasma concentrations, and successful treatment with fomepizole. CASE REPORT A 70-year-old woman with a history of stage IIIA rectal adenocarcinoma was referred for evaluation of a newly identified lung mass. During the procedure, a bronchoalveolar lavage (BAL) of the right upper lobe was performed. After BAL, the proceduralist was informed that the syringe used to instill fluid for the BAL contained Cytolyt rather than saline. The Department of Medical Toxicology was contacted immediately, and the patient received a 15 mg/kg dose of fomepizole. The first plasma methanol level, before fomepizole administration, was elevated to 21 mg/dL. The methanol level was 13 mg/dL 3 h after fomepizole treatment and even lower thereafter; therefore, no additional fomepizole was required. The patient did not develop signs of systemic toxicity and was discharged on hospital day 3. CONCLUSIONS Following methanol exposures, patients can exhibit metabolic acidosis, with potential for blindness, hemodynamic instability, and possibly death if untreated. Fomepizole (4-methylpyrazole) inhibits alcohol dehydrogenase and is a mainstay of treatment. Preventing medical errors is key in ensuring optimal patient care and decreasing adverse events. Providers using CytoLyt and any similar products should be aware of this potential error and approach the possibility of methanol toxicity as they would other routes of methanol exposure.
Topics: Female; Humans; Aged; Fomepizole; Methanol; Antidotes; Pyrazoles; Dimercaprol; Iatrogenic Disease
PubMed: 37461205
DOI: 10.12659/AJCR.937247 -
Annals of the American Thoracic Society May 2023Bronchoscopy for research purposes is a valuable tool to understand lung-specific biology in human participants. Despite published reports and active research protocols...
Bronchoscopy for research purposes is a valuable tool to understand lung-specific biology in human participants. Despite published reports and active research protocols using this procedure in critically ill patients, no recent document encapsulates the important safety considerations and downstream applications of this procedure in this setting. The objectives were to identify safe practices for patient selection and protection of hospital staff, provide recommendations for sample procurement to standardize studies, and give guidance on sample preparation for novel research technologies. Seventeen international experts in the management of critically ill patients, bronchoscopy in clinical and research settings, and experience in patient-oriented clinical or translational research convened for a workshop. Review of relevant literature, expert presentations, and discussion generated the findings presented herein. The committee concludes that research bronchoscopy with bronchoalveolar lavage in critically ill patients on mechanical ventilation is valuable and safe in appropriately selected patients. This report includes recommendations on standardization of this procedure and prioritizes the reporting of sample management to produce more reproducible results between laboratories. This document serves as a resource to the community of researchers who endeavor to include bronchoscopy as part of their research protocols and highlights key considerations for the inclusion and safety of research participants.
Topics: Humans; Bronchoscopy; Critical Illness; Bronchoalveolar Lavage; Dimercaprol; Patient Selection
PubMed: 37125997
DOI: 10.1513/AnnalsATS.202302-106ST -
Biomedicines Aug 2020Animal-derived antivenoms are the only specific therapies currently available for the treatment of snake envenoming, but these products have a number of limitations...
Animal-derived antivenoms are the only specific therapies currently available for the treatment of snake envenoming, but these products have a number of limitations associated with their efficacy, safety and affordability for use in tropical snakebite victims. Small molecule drugs and drug candidates are regarded as promising alternatives for filling the critical therapeutic gap between snake envenoming and effective treatment. In this study, by using an advanced analytical technique that combines chromatography, mass spectrometry and bioassaying, we investigated the effect of several small molecule inhibitors that target phospholipase A (varespladib) and snake venom metalloproteinase (marimastat, dimercaprol and DMPS) toxin families on inhibiting the activities of coagulopathic toxins found in snake venoms. The venoms of , , and , which are known for their potent haemotoxicities, were fractionated in high resolution onto 384-well plates using liquid chromatography followed by coagulopathic bioassaying of the obtained fractions. Bioassay activities were correlated to parallel recorded mass spectrometric and proteomics data to assign the venom toxins responsible for coagulopathic activity and assess which of these toxins could be neutralized by the inhibitors under investigation. Our results showed that the phospholipase A-inhibitor varespladib neutralized the vast majority of anticoagulation activities found across all of the tested snake venoms. Of the snake venom metalloproteinase inhibitors, marimastat demonstrated impressive neutralization of the procoagulation activities detected in all of the tested venoms, whereas dimercaprol and DMPS could only partially neutralize these activities at the doses tested. Our results provide additional support for the concept that combinations of small molecules, particularly the combination of varespladib with marimastat, serve as a drug-repurposing opportunity to develop new broad-spectrum inhibitor-based therapies for snakebite envenoming.
PubMed: 32825484
DOI: 10.3390/biomedicines8090297 -
BMC Pharmacology & Toxicology May 2021There are no reports on the incidence of chronic mercury poisoning in a large population in China. This study investigated the epidemiology, clinical manifestations,...
BACKGROUND
There are no reports on the incidence of chronic mercury poisoning in a large population in China. This study investigated the epidemiology, clinical manifestations, treatment, and follow-up of Chinese patients with chronic mercury poisoning.
METHODS
Data for 288 mercury poisoning patients were collected at our hospital from July 2014 to September 2019, including sex, age, admission time, blood mercury content, urine mercury content, creatinine, urinary mercury/creatinine ratio, 24-h urinary protein levels, electromyography (EMG) findings, renal biopsy, and follow-up. Patient characteristics were evaluated by statistical and correlation analyses.
RESULTS
First, mercury poisoning in China mainly occurred through occupational exposure and the inappropriate use of mercury-containing cosmetics and Chinese folk remedies (CFRs). Second, the most common symptoms were nervous system (50.3 %), kidney (16.4 %) and breathing (8.0 %). Mercury poisoning-induced Nephrotic syndrome (NS) and peripheral neuropathy are common long-term complications. The complications of occupational and cosmetics-induced mercury poisoning are consistent with international belief. However, the NS caused by CFRs is mainly membranous nephropathy and the probability of peripheral neuropathy caused by CFRs is higher than other pathogens. Third, follow-up data shows that 13 patients with EMG-confirmed neurological injury, 10 showed full recovery after 38.50 ± 8.03 months. Furthermore, among 18 patients with NS, 15 had normal urine protein and serum albumin levels after 22.67 ± 10.26 months.
CONCLUSIONS
Regulation of skin-lightening cosmetic products, safety surveillance of CFRs, and prevention and control of occupational exposure must be improved to decrease the incidence of mercury poisoning in China.
Topics: Adolescent; Adult; Aged; Anti-Inflammatory Agents; Chelating Agents; Child; Child, Preschool; China; Chronic Disease; Cosmetics; Drugs, Chinese Herbal; Female; Follow-Up Studies; Humans; Male; Mercury; Mercury Poisoning; Middle Aged; Occupational Diseases; Occupational Exposure; Prednisone; Retrospective Studies; Unithiol; Young Adult
PubMed: 33941274
DOI: 10.1186/s40360-021-00493-y -
Physiological Reports Sep 2023The circadian rhythm system regulates lung function as well as local and systemic inflammations. The alteration of this rhythm might be induced by a change in the eating...
The circadian rhythm system regulates lung function as well as local and systemic inflammations. The alteration of this rhythm might be induced by a change in the eating rhythm. Peroxisome proliferator-activated receptor gamma (PPARG) is a key molecule involved in circadian rhythm regulation, lung functions, and metabolic processes. We described the effect of the PPARG agonist pioglitazone (PZ) on the diurnal mRNA expression profile of core circadian clock genes (Arntl, Clock, Nr1d1, Cry1, Cry2, Per1, and Per2) and metabolism- and inflammation-related genes (Nfe2l2, Pparg, Rela, and Cxcl5) in the male murine lung disrupted by reversed feeding (RF). In mice, RF disrupted the diurnal expression pattern of core clock genes. It decreased Nfe2l2 and Pparg and increased Rela and Cxcl5 expression in lung tissue. There were elevated levels of IL-6, TNF-alpha, total cells, macrophages, and lymphocyte counts in bronchoalveolar lavage (BAL) with a significant increase in vascular congestion and cellular infiltrates in male mouse lung tissue. Administration of PZ regained the diurnal clock gene expression, increased Nfe2l2 and Pparg expression, and reduced Rela, Cxcl5 expression and IL-6, TNF-alpha, and cellularity in BAL. PZ administration at 7 p.m. was more efficient than at 7 a.m.
Topics: Animals; Male; Mice; Dimercaprol; Inflammation; Interleukin-6; Lung; Pioglitazone; PPAR gamma; RNA, Messenger; Tumor Necrosis Factor-alpha
PubMed: 37704580
DOI: 10.14814/phy2.15823 -
Frontiers in Immunology 2021Palearctic vipers are medically significant snakes in the genera , and which occur throughout Europe, Central Asia, Near and Middle East. While the ancestral condition... (Comparative Study)
Comparative Study
Palearctic vipers are medically significant snakes in the genera , and which occur throughout Europe, Central Asia, Near and Middle East. While the ancestral condition is that of a small-bodied, lowland species, extensive diversification has occurred in body size, and niche specialization. Using 27 venom samples and a panel of coagulation assays, we evaluated the relative coagulotoxic potency of Palearctic viper venoms and compared their neutralization by three antivenoms (Insoserp Europe, VIPERFAV and ViperaTAb) and two metalloprotease inhibitors (prinomastat and DMPS). We show that variation in morphology parallels variation in the Factor X activating procoagulant toxicity, with the three convergent evolutions of larger body sizes ( genus, genus, and uniquely within the genus) were each accompanied by a significant increase in procoagulant potency. In contrast, the two convergent evolutions of high altitude specialization (the genus and uniquely within the genus) were each accompanied by a shift away from procoagulant action, with the species being particularly potently anticoagulant. Inoserp Europe and VIPERFAV antivenoms were both effective against a broad range of species, with Inoserp able to neutralize additional species relative to VIPERFAV, reflective of its more complex antivenom immunization mixture. In contrast, ViperaTAb was extremely potent in neutralizing but, reflective of this being a monovalent antivenom, it was not effective against other species. The enzyme inhibitor prinomastat efficiently neutralized the metalloprotease-driven Factor X activation of the procoagulant venoms. In contrast, DMPS (2,3-dimercapto-1-propanesulfonic acid), which as been suggested as another potential treatment option in the absence of antivenom, DMPS failed against all venoms tested. Overall, our results highlight the evolutionary variations within Palearctic vipers and help to inform clinical management of viper envenomation.
Topics: Animals; Antivenins; Blood Coagulation; Blood Coagulation Tests; Evolution, Molecular; Humans; Immunoglobulin Fab Fragments; Matrix Metalloproteinase Inhibitors; Organic Chemicals; Snake Bites; Species Specificity; Time Factors; Unithiol; Viper Venoms; Viperidae
PubMed: 34177943
DOI: 10.3389/fimmu.2021.688802 -
Journal of Medical Toxicology :... Jul 2021
Topics: Antidotes; Brain Diseases; Dimercaprol; Humans; Lead; Pharmaceutical Preparations; United States
PubMed: 33687652
DOI: 10.1007/s13181-021-00830-x