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1.
J Child Health Care ; : 13674935241242156, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38556616

RESUMO

Previous studies have demonstrated that Buzzy® is effective for pain reduction during vaccination. This study aimed to determine if Buzzy® would have an effect on either duration of vaccine administration and/or patient satisfaction. Pediatric patients aged birth to 18 years old receiving a vaccination were randomized to either a control group receiving no intervention, or the experimental group, utilizing Buzzy®. Time of administration was measured by the number of seconds required by nursing to administer vaccines. Patient satisfaction was measured with a survey given to guardians. Time required was reduced by almost 2 min when utilizing Buzzy®, with median time dropping to 190, 95% CI [26.99, 415.92] seconds from 333, 95% CI [51.35, 627.21] seconds. Patient satisfaction surveys showed positive impacts of using the device, with 100% that used the device reporting that it "made a difference in the pain level experienced," but did not demonstrate statistical significance. This study shows that use of Buzzy® increases efficiency of appointments with possible positive effect on patient satisfaction.

2.
Toxins (Basel) ; 15(10)2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37888629

RESUMO

A field biologist was bitten by a female Nikolsky's viper (Vipera berus nikolskii) in Kharkiv Oblast, Ukraine. Two months later, the patient began to experience cold-induced vasospasm of the affected digit diagnosed as acquired Raynaud phenomenon. The patient had more than 30 occurrences during the single winter following the bite, but the signs and symptoms of Raynaud phenomenon disappeared with the end of winter. This report describes the case and puts it into context with the literature on the topic of toxin-induced peripheral vasospastic disorders and their potential importance in snakebite envenoming.


Assuntos
Doença de Raynaud , Mordeduras de Serpentes , Viperidae , Animais , Humanos , Feminino , Mordeduras de Serpentes/complicações , Venenos de Víboras/toxicidade , Extremidade Superior , Doença de Raynaud/diagnóstico , Doença de Raynaud/etiologia , Antivenenos
3.
Pediatrics ; 152(5)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37800272

RESUMO

BACKGROUND: Reducing child mortality in low-income countries is constrained by a lack of vital statistics. In the absence of such data, verbal autopsies provide an acceptable method to determining attributable causes of death. The objective was to assess potential causes of pediatric postdischarge mortality in children younger than age 5 years (under-5) originally admitted for suspected sepsis using verbal autopsies. METHODS: Secondary analysis of verbal autopsy data from children admitted to 6 hospitals across Uganda from July 2017 to March 2020. Structured verbal autopsy interviews were conducted for all deaths within 6 months after discharge. Two physicians independently classified a primary cause of death, up to 4 alternative causes, and up to 5 contributing conditions using the Start-Up Mortality List, with discordance resolved by consensus. RESULTS: Verbal autopsies were completed for 361 (98.6%) of the 366 (5.9%) children who died among 6191 discharges (median admission age: 5.4 months [interquartile range, 1.8-16.7]; median time to mortality: 28 days [interquartile range, 9-74]). Most deaths (62.3%) occurred in the community. Leading primary causes of death, assigned in 356 (98.6%) of cases, were pneumonia (26.2%), sepsis (22.1%), malaria (8.5%), and diarrhea (7.9%). Common contributors to death were malnutrition (50.5%) and anemia (25.7%). Reviewers were less confident in their causes of death for neonates than older children (P < .05). CONCLUSIONS: Postdischarge mortality frequently occurred in the community in children admitted for suspected sepsis in Uganda. Analyses of the probable causes for these deaths using verbal autopsies suggest potential areas for interventions, focused on early detection of infections, as well as prevention and treatment of underlying contributors such as malnutrition and anemia.


Assuntos
Anemia , Desnutrição , Sepse , Recém-Nascido , Criança , Humanos , Lactente , Adolescente , Pré-Escolar , Autopsia , Causas de Morte , Uganda/epidemiologia , Assistência ao Convalescente , Alta do Paciente , Sepse/diagnóstico , Anemia/diagnóstico
4.
Toxins (Basel) ; 15(9)2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37755983

RESUMO

Antivenom is currently the standard-of-care treatment for snakebite envenoming, but its efficacy is limited by treatment delays, availability, and in many cases, species specificity. Many of the rapidly lethal effects of envenoming are caused by venom-derived toxins, such as phospholipase A2 (sPLA2); therefore, small molecule direct toxin inhibitors targeting these toxins may have utility as initial and adjunct therapies after envenoming. Varespladib (intravenous, IV) and varespladib-methyl (oral) have been shown to potently inhibit sPLA2s from snake venoms in murine and porcine models, thus supporting their further study as potential treatments for snakebite envenoming. In this pilot study, we tested the ability of these compounds to reverse neurotoxic effects of venom from the Australian and Papuan taipan (Oxyuranus scutellatus) subspecies in juvenile pigs (Sus domesticus). The mean survival time for control animals receiving Australian taipan venom (0.03 mg/kg, n = 3) was 331 min ± 15 min; for those receiving Papuan taipan venom (0.15 mg/kg, n = 3) it was 178 ± 31 min. Thirteen pigs received Australian taipan venom and treatment with either IV or oral varespladib (or with IV to oral transition) and all 13 survived the duration of the study (≥96 h). Eight pigs received Papuan taipan venom followed by treatment: Briefly: Two animals received antivenom immediately and survived to the end of the study. Two animals received antivenom treatment delayed 45 min from envenoming and died within 4 h. Two animals received similarly delayed antivenom treatment and were rescued by varespladib. Two animals were treated with varespladib alone after a 45-min delay. Treatment with varespladib only was effective but required repeat dosing over the course of the study. Findings highlight both the importance of early treatment and, as well, a half-life for the investigational inhibitors now in Phase II clinical trials for snakebite. Varespladib rapidly reversed weakness even when administered many hours post-envenoming and, overall, our results suggest that varespladib and varespladib-methyl could be efficacious tools in the treatment of sPLA2-induced weakness from Oxyuranus envenoming. Further clinical study as initial therapy and as potential method of rescue from some types of antivenom-resistant envenomings are supported by these data.


Assuntos
Fosfolipases A2 Secretórias , Mordeduras de Serpentes , Animais , Suínos , Camundongos , Antivenenos/farmacologia , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Projetos Piloto , Austrália , Venenos Elapídicos/toxicidade
5.
Prenat Diagn ; 43(10): 1344-1354, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37674263

RESUMO

OBJECTIVE: Carrier screening with reflex to single-gene noninvasive prenatal testing (sgNIPT) is an alternative approach for identifying pregnancies at risk for inherited autosomal recessive conditions without the need for a sample from the reproductive partner. This study is the largest clinical validation of this approach in a general population setting. METHODS: The clinical performance of carrier screening with reflex to sgNIPT for cystic fibrosis, spinal muscular atrophy, alpha thalassemias, and beta hemoglobinopathies was assessed by collecting pregnancy outcome data on patients who underwent this testing and comparing the neonatal outcome to the assay-predicted fetal risk. RESULTS: Of 42,067 pregnant individuals who underwent screening, 7538 carriers (17.9%) had reflex sgNIPT, and neonatal or fetal outcomes were obtained for 528 cases, including 25 affected pregnancies. Outcomes demonstrated high concordance with sgNIPT, for example, all pregnancies with 9 in 10 personalized fetal risk results were affected (positive predictive value (PPV) of 100% for the sub-group) and the sgNIPT assay showed a sensitivity of 96.0% (95% CI: 79.65%-99.90%), specificity of 95.2% (95% CI: 92.98%-96.92%), average PPV of 50.0% (95% CI: 35.23%-64.77%), and negative predictive value (NPV) of 99.8% (95% CI: 98.84%-99.99%). The end-to-end performance of carrier screening with reflex to sgNIPT was calculated to have a sensitivity of 92.4% and specificity of 99.9%, which are unaffected by partner carrier screening or misattributed paternity unlike a traditional carrier screening workflow, which has a 35% sensitivity and a maximum of 25% PPV (1 in 4) in a real-life setting. CONCLUSION: This study builds upon earlier findings to confirm that carrier testing with reflex to sgNIPT is highly accurate for general population screening. Given this high accuracy and an NPV of 99.8%, this workflow should be considered as an option for most of the general pregnant population. When the biological partner sample is unavailable, this workflow should be recommended as the first-line approach.


Assuntos
Fibrose Cística , Hemoglobinopatias , Teste Pré-Natal não Invasivo , Recém-Nascido , Feminino , Humanos , Gravidez , Feto , Padrões de Herança
6.
BMJ Case Rep ; 16(7)2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37474144

RESUMO

A late preterm infant with intrauterine growth restriction developed respiratory distress, tachypnoea and hypoxia after birth, requiring supplemental oxygen. Chest radiographs demonstrated persistent elevation of the right hemidiaphragm. Chest ultrasound initially demonstrated symmetrical bilateral diaphragm motion, but subsequent ultrasounds showed asymmetrical excursion with weaker movement of the right hemidiaphragm. Placental pathology demonstrated chronic infectious villitis secondary to cytomegalovirus (CMV), and subsequent CMV testing on the infant was positive. The infant was microcephalic and head imaging revealed intracranial calcifications, consistent with congenital CMV infection.CMV is the most common congenital infection and has a wide array of clinical manifestations. This report highlights the rarely described association between congenital CMV infection and respiratory distress due to underlying diaphragm dysfunction. In neonates with respiratory distress and features of congenital CMV infection, clinicians should have a high index of suspicion for diaphragm dysfunction.


Assuntos
Infecções por Citomegalovirus , Complicações Infecciosas na Gravidez , Síndrome do Desconforto Respiratório , Lactente , Recém-Nascido , Humanos , Gravidez , Feminino , Diafragma/diagnóstico por imagem , Recém-Nascido Prematuro , Placenta , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus , Retardo do Crescimento Fetal , Taquipneia/complicações , Síndrome do Desconforto Respiratório/complicações
8.
JAMA Oncol ; 9(4): 552-555, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36729480

RESUMO

Importance: Ibrutinib has been associated with serious cardiotoxic arrhythmias. In preclinical models, these events are paralleled or proceeded by diffuse myocardial injury (inflammation and fibrosis). Yet whether this is seen in patients or has implications for future cardiotoxic risk is unknown. Objective: To assess the incidence and outcomes of myocardial injury among patients with ibrutinib-related cardiotoxicity. Design, Setting, and Participants: This cohort study included consecutive patients treated with ibrutinib from 2012 to 2019, phenotyped using cardiovascular magnetic resonance (CMR) from a large US Comprehensive Cancer Center registry. Exposures: Ibrutinib treatment for cancer control. Main Outcomes and Measures: The primary outcome was the presence of late gadolinium enhancement (LGE) fibrosis. The secondary outcome was the occurrence of major adverse cardiac events (MACE), defined as atrial fibrillation, heart failure, symptomatic ventricular arrhythmias, and sudden death of probable or definite ibrutinib association after CMR. We also assessed parametric-mapping subclinical fibrosis (native-T1, extracellular volume fraction) and inflammation/edema (max-T2) measures. Cardiovascular magnetic resonance measures were compared with those obtained in similar consecutive patients with cancer without ibrutinib treatment (pretreatment controls). Observed measures were also compared with similar-aged broad population rates (general-population controls) and a broader pool of cardiovascular disease (CVD) risk-matched cancer controls. Multivariable regression was used to assess the association between CMR measures and MACE. Results: Overall, 49 patients treated with ibrutinib were identified, including 33 imaged after treatment initiation (mean [SD] age, 65 [10] years, 9 [27%] with hypertension, and 23 [69.7%] with index-arrhythmias); median duration of ibrutinib-use was 14 months. The mean (SD) pretreatment native T1 was 977.0 (73.0) ms, max-T2 56.5 (4.0) ms, and 4 (13.3%) had LGE. Posttreatment initiation, mean (SD) native T1 was 1033.7 (48.2) ms, max-T2 61.5 (4.8) ms, and 17 (54.8%) had LGE (P < .001, P = .01, and P < .001, respectively, pre- vs post-ibrutinib treatment). Native T12SDs was elevated in 9 (28.6%), and max-T22SDs in 21 (63.0%), respectively. Cardiovascular magnetic resonance measures were highest in those with suspected toxic effects (P = .01 and P = .01, respectively). There was no association between traditional CVD-risk or cancer-treatment status and abnormal CMR measures. Among those without traditional CVD, 16 (58.6%) had LGE vs 38 (13.3%) in matched-controls (relative-risk, 4.8; P < .001). Over a median follow-up of 19 months, 13 (39.4%) experienced MACE. In multivariable models inclusive of traditional CVD risk factors, LGE (hazard ratio [HR], 4.9; P = .04), and native-T12SDs (HR, 3.3; P = .05) associated with higher risks of MACE. Conclusions and Relevance: In this cohort study, myocardial injury was common in ibrutinib users, and its presence was associated with higher cardiotoxic risk.


Assuntos
Meios de Contraste , Miocárdio , Humanos , Idoso , Miocárdio/patologia , Estudos de Coortes , Cardiotoxicidade/etiologia , Imagem Cinética por Ressonância Magnética , Gadolínio , Imageamento por Ressonância Magnética/métodos , Fibrose , Inflamação , Valor Preditivo dos Testes , Função Ventricular Esquerda , Prognóstico , Volume Sistólico
9.
Cancers (Basel) ; 15(3)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36765943

RESUMO

The purpose of the study was to characterize a detection system based on inorganic scintillators and determine its suitability for dosimetry in preclinical radiation research. Dose rate, linearity, and repeatability of the response (among others) were assessed for medium-energy X-ray beam qualities. The response's variation with temperature and beam angle incidence was also evaluated. Absorbed dose quality-dependent calibration coefficients, based on a cross-calibration against air kerma secondary standard ionization chambers, were determined. Relative output factors (ROF) for small, collimated fields (≤10 mm × 10 mm) were measured and compared with Gafchromic film and to a CMOS imaging sensor. Independently of the beam quality, the scintillator signal repeatability was adequate and linear with dose. Compared with EBT3 films and CMOS, ROF was within 5% (except for smaller circular fields). We demonstrated that when the detector is cross-calibrated in the user's beam, it is a useful tool for dosimetry in medium-energy X-rays with small fields delivered by Image-Guided Small Animal Radiotherapy Platforms. It supports the development of procedures for independent "live" dose verification of complex preclinical radiotherapy plans with the possibility to insert the detectors in phantoms.

10.
Cancer Med ; 12(1): 297-305, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35633055

RESUMO

BACKGROUND: Contemporary therapies improve breast cancer (BC) outcomes. Yet, many of these therapies have been increasingly linked with serious cardiotoxicity, including reports of profound hypertension. Yet, the incidence, predictors, and impacts of these events are largely unknown. METHODS: Leveraging two large U.S.-based registries, the National Inpatient Sample (NIS) and the Food and Drug Administration Adverse Event Reporting System (FAERS) databases, we assessed the incidence, factors, and outcomes of hypertensive events among BC patients from 2007 to 2015. Differences in baseline characteristics, hypertension-related discharges, and complications were examined over time. Further, we performed a disproportionality analysis using reporting-odds-ratios (ROR) to determine the association between individual BC drugs and hypertensive events. Utilizing an ROR cutoff of >1.0, we quantified associations by drug-class, and individual drugs with the likelihood of excess hypertension. RESULTS: Overall, there were 5,464,401 BC-admissions, of which 46,989 (0.8%) presented with hypertension. Hypertensive BC patients were older, and saw initially increased in-hospital mortality, which equilibrated over time. The mean incidence of hypertension-related admissions was 732 per 100,000 among BC patients, versus 96 per 100,000 among non-cancer patients (RR 7.71, p < 0.001). Moreover, in FAERS, those with hypertension versus other BC-treatment side-effects were more frequently hospitalized (40.1% vs. 36.7%, p < 0.001), and were most commonly associated with chemotherapy (45.9%). Outside of Eribulin (ROR 3.36; 95% CI 1.37-8.22), no specific drug was associated with a higher reporting of hypertension; however, collectively BC drugs were associated with a higher odds of hypertension (ROR 1.66; 95% CI 1.09-2.53). CONCLUSIONS: BC therapies are associated with a substantial increase in limiting hypertension.


Assuntos
Neoplasias da Mama , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Hipertensão , Estados Unidos/epidemiologia , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/epidemiologia , Sistemas de Notificação de Reações Adversas a Medicamentos , Cardiotoxicidade , Hipertensão/induzido quimicamente , Hipertensão/epidemiologia , Bases de Dados Factuais
11.
Toxins (Basel) ; 14(12)2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36548733

RESUMO

The African viperid snake genera Atheris, Cerastes, and Proatheris are closely related, similar in size, but occupy extremely divergent ecological niches (arboreal in tropical rainforests, fossorial in deserts, and swamp-dwelling, respectively). Their venoms have not previously been subjected to comparative analyses for their action upon the coagulation of blood, most notably with significant data deficiencies from Atheris and Proatheris. In contrast, the closely related genus Echis is well-documented as capable of producing potent procoagulant effects. In light of this, we set out to compare the coagulotoxic actions of Atheris ceratophora, A. chlorechis, A. desaixi, A. nitschei, A. squamigera, C. cerastes, C. cerastes gasperettii, C. vipera, and Proatheris superciliaris and explore potential pharmacological interventions to reestablish normal blood coagulation. All venoms displayed extremely potent procoagulant effects, over twice as fast as the most potent Echis reported to date. Although Cerastes is used in the immunising mixture of two different regionally available antivenoms (Inoserp-MENA with C. cerastes, C. cerastes gasperettii, C. vipera and Saudi Arabian polyvalent with C. cerastes), none of the other species in this study are included in the immunising mixture of any antivenom. Notably, all the Cerastes species were only neutralised by the Inoserp-MENA antivenom. C. cerastes venom was not neutralised well by the Saudi Arabian antivenom, with the low levels of recognition for any of the Cerastes venoms suggesting a strong regional variation in the venom of this species, as the C. cerastes venom tested was of African (Tunisian) origin versus Saudi locality used in that antivenom's production. The other antivenoms (Micropharm EchiTAbG, ICP EchiTAb-Plus-ICP, Inosan Inoserp Pan-Africa, Premium Serums PANAF Sub-Sahara Africa, South African Vaccine Producers Echis, South African Vaccine Producers Polyvalent) all displayed trivial-to-no ability to neutralise the procoagulant toxicity of any of the Atheris, Cerastes, or Proatheris venoms. Comparative testing of the enzyme inhibitors DMPS, marimastat, and prinomastat, revealed a very potent neutralising capacity of marimastat, with prinomastat showing lower but still significant potency at the same molar concentration, while a 5× molar concentration of DMPS had no apparent effect on procoagulant venom effects normalized by the other inhibitors. These results and methods contribute to the body of knowledge of potential clinical effects and data necessary for evidence-based advancement of clinical management strategies.


Assuntos
Mordeduras de Serpentes , Viperidae , Animais , Humanos , Antivenenos/farmacologia , Arábia Saudita , Venenos de Víboras/toxicidade , África Subsaariana , Inibidores Enzimáticos , População Africana , Mordeduras de Serpentes/tratamento farmacológico
12.
Toxins (Basel) ; 14(11)2022 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-36422958

RESUMO

The availability of effective, reliably accessible, and affordable treatments for snakebite envenoming is a critical and long unmet medical need. Recently, small, synthetic toxin-specific inhibitors with oral bioavailability used in conjunction with antivenom have been identified as having the potential to greatly improve outcomes after snakebite. Varespladib, a small, synthetic molecule that broadly and potently inhibits secreted phospholipase A2 (sPLA2s) venom toxins has renewed interest in this class of inhibitors due to its potential utility in the treatment of snakebite envenoming. The development of varespladib and its oral dosage form, varespladib-methyl, has been accelerated by previous clinical development campaigns to treat non-envenoming conditions related to ulcerative colitis, rheumatoid arthritis, asthma, sepsis, and acute coronary syndrome. To date, twenty-nine clinical studies evaluating the safety, pharmacokinetics (PK), and efficacy of varespladib for non-snakebite envenoming conditions have been completed in more than 4600 human subjects, and the drugs were generally well-tolerated and considered safe for use in humans. Since 2016, more than 30 publications describing the structure, function, and efficacy of varespladib have directly addressed its potential for the treatment of snakebite. This review summarizes preclinical findings and outlines the scientific support, the potential limitations, and the next steps in the development of varespladib's use as a snakebite treatment, which is now in Phase 2 human clinical trials in the United States and India.


Assuntos
Mordeduras de Serpentes , Humanos , Mordeduras de Serpentes/tratamento farmacológico , Antivenenos/uso terapêutico , Disponibilidade Biológica , Índia
13.
Toxicon ; 218: 19-24, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36057394

RESUMO

Venoms are evolutionary novelties that have real-world implications due to their impact upon human health. However, relative to the abundant studies of elapid and viperid snake venoms, fewer investigations have been undertaken on those of rear-fanged snakes as they are more problematic for obtaining venom. While most rear-fanged venomous snakes are not considered to be of great medical importance, several species are capable of producing fatalities. Most notable among these are snakes from the genus Rhabdophis, the Asian "keelback" snakes. Prior work have described potent procoagulant toxicity suggesting Factor X and prothrombin activation, but did not investigate the ability to activate other clotting factors. Here we show that in addition to activating both Factor X and prothrombin (with prothrombin twice that of FX), the venom of Rhabdophis subminiatus is able to more potently activate Factor VII (ten times that of prothrombin), while also activating FXII and FIX equipotently to prothrombin, and with FXI also activated but at a much lower level. The ability to activate FVII represents a third convergent evolution of this trait. The Australian elapid clade of [Oxyuranus (taipans) + Pseudonaja (brown snakes)] was the first identified to have evolved this trait. and only recently was it shown to be independently present in another lineage (the Central American viperid species Porthidium volcanicum). In addition, the abilities to activate FXI and FXII are also convergent between R. subminiatus and P. volcanicum, but with R. subminiatus being much more potent. By testing across amphibian, avian, and mammalian plasmas we demonstrate that the venom is potently procoagulant across diverse plasma types. However, consistent with dietary preference, R. subminiatus venom was most potent upon amphibian plasma. While a Rhabdophis antivenom is produced in Japan to treat R. tigrinus envenomings, it is scarce even within Japan and is not exported. As this genus is very wide-ranging in Asia, alternate treatment options are in need of development. Hence we tested the ability of candidate, broad-spectrum enzyme inhibitors to neutralize R. subminiatus venom: marimastat was more effective than prinomastat but both marimastat and prinomastat were significantly more effective than DMPS (2,3-Dimercapto-1-propanesulfonic acid). The findings of this study shed light on the evolution of these fascinating rear-fanged snakes as well as explored their systemic effects upon blood coagulation and point to potential treatment options for the rare, but potentially lethal encounters.


Assuntos
Antivenenos , Colubridae , Animais , Antivenenos/farmacologia , Austrália , Coagulação Sanguínea , Fatores de Coagulação Sanguínea/metabolismo , Fatores de Coagulação Sanguínea/farmacologia , Elapidae/metabolismo , Fator VII/metabolismo , Fator VII/farmacologia , Fator X/metabolismo , Fator X/farmacologia , Humanos , Ácidos Hidroxâmicos , Mamíferos , Compostos Orgânicos , Protrombina , Venenos de Serpentes/farmacologia , Unitiol/metabolismo , Unitiol/farmacologia
14.
Toxicol Lett ; 366: 26-32, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35788045

RESUMO

Snakebite remains a worldwide public health burden and a severely neglected tropical disease. Recent research has begun to focus on the potential use of repurposed small-molecule enzyme-inhibitors as early treatments to neutralise the effects of snake venoms. Black snakes (Pseudechis spp.) are a widespread and dangerously venomous group found throughout Australia and New Guinea. Utilising validated coagulation assays, our study assessed the efficacy of two chemically different small molecule inhibitors, a phospholipase A2 inhibitor (varespladib) and a metalloproteinase inhibitor (prinomastat), in vitro neutralisation of the anticoagulant prothrombinase-inhibiting activity of venom from seven species within the Pseudechis genus (P. australis, P. butleri, P. coletti, P. guttatus, P. papuanus, P.rossignolii, P. sp (NT).). Varespladib was shown to be highly effective at neutralising this anticoagulant activity for all seven species, but with P. coletti notably less so than the others. In contrast, prinomastat showed strong neutralisation for five out of the seven species, but was ineffective at neutralising the activity of P. coletti or P. rossignolii venoms. This suggests that varespladib binds to a highly conserved site but that prinomastat binds to a more variable site. These results build upon recent literature indicating that metalloproteinase inhibitors have cross-neutralising potential towards snake venom phospholipase A2 toxins, but with higher degrees of variability that PLA2-specific inhibitors. An important caveat is that these are in vitro tests and while suggestive of potential clinical utility, in vivo animal testing and clinical trials are required as future work.


Assuntos
Antivenenos , Venenos Elapídicos , Animais , Anticoagulantes/farmacologia , Antivenenos/farmacologia , Venenos Elapídicos/metabolismo , Elapidae/metabolismo , Inibidores Enzimáticos/metabolismo , Metaloproteases/metabolismo , Fosfolipases A2/metabolismo , Venenos de Serpentes/toxicidade
15.
Toxins (Basel) ; 14(8)2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35893753

RESUMO

Within Neotropical pit-vipers, the Mexican/Central-American clade consisting of Atropoides, Cerrophidion, Metlapilcoatlus, and Porthidium is a wide-ranging, morphologically and ecologically diverse group of snakes. Despite their prevalence, little is known of the functional aspects of their venoms. This study aimed to fill the knowledge gap regarding coagulotoxic effects and to examine the potential of different therapeutic approaches. As a general trait, the venoms were shown to be anticoagulant but were underpinned by diverse biochemical actions. Pseudo-procoagulant activity (i.e., thrombin-like), characterized by the direct cleavage of fibrinogen to form weak fibrin clots, was evident for Atropoides picadoi, Cerrophidiontzotzilorum, Metlapilcoatlus mexicanus, M. nummifer, M. occiduus, M. olmec, and Porthidium porrasi. In contrast, other venoms cleaved fibrinogen in a destructive (non-clotting) manner, with C. godmani and C. wilsoni being the most potent. In addition to actions on fibrinogen, clotting enzymes were also inhibited. FXa was only weakly inhibited by most species, but Cerrophidion godmani and C. wilsoni were extremely strong in their inhibitory action. Other clotting enzymes were more widely inhibited by diverse species spanning the full taxonomical range, but in each case, there were species that had these traits notably amplified relatively to the others. C. godmani and C. wilsoni were the most potent amongst those that inhibited the formation of the prothrombinase complex and were also amongst the most potent inhibitors of Factor XIa. While most species displayed only low levels of thrombin inhibition, Porthidium dunni potently inhibited this clotting factor. The regional polyvalent antivenom produced by Instituto Picado Clodomiro was tested and was shown to be effective against the diverse anticoagulant pathophysiological effects. In contrast to the anticoagulant activities of the other species, Porthidium volcanicum was uniquely procoagulant through the activation of Factor VII and Factor XII. This viperid species is the first snake outside of the Oxyuranus/Pseudonaja elapid snake clade to be shown to activate FVII and the first snake venom of any kind to activate FXII. Interestingly, while small-molecule metalloprotease inhibitors prinomastat and marimastat demonstrated the ability to prevent the procoagulant toxicity of P. volcanicum, neither ICP antivenom nor inhibitor DMPS showed this effect. The extreme variation among the snakes here studied underscores how venom is a dynamic trait and how this can shape clinical outcomes and influence evolving treatment strategies.


Assuntos
Venenos de Crotalídeos , Crotalinae , Viperidae , Animais , Anticoagulantes/farmacologia , Antivenenos/farmacologia , Venenos de Crotalídeos/química , Venenos Elapídicos , Elapidae , Fibrinogênio , Venenos de Serpentes , Trombina
18.
Molecules ; 27(5)2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35268832

RESUMO

Snakebite remains a significant public health burden globally, disproportionately affecting low-income and impoverished regions of the world. Recently, researchers have begun to focus on the use of small-molecule inhibitors as potential candidates for the neutralisation of key snake venom toxins and as potential field therapies. Bitis vipers represent some of the most medically important as well as frequently encountered snake species in Africa, with a number of species possessing anticoagulant phospholipase A2 (PLA2) toxins that prevent the prothrombinase complex from inducing clot formation. Additionally, species within the genus are known to exert pseudo-procoagulant activity, whereby kallikrein enzymatic toxins cleave fibrinogen to form a weak fibrin clot that rapidly degrades, thereby depleting fibrinogen levels and contributing to the net anticoagulant state. Utilising well-validated coagulation assays measuring time until clot formation, this study addresses the in vitro efficacy of three small molecule enzyme inhibitors (marimastat, prinomastat and varespladib) in neutralising these aforementioned activities. The PLA2 inhibitor varespladib showed the greatest efficacy for the neutralisation of PLA2-driven anticoagulant venom activity, with the metalloproteinase inhibitors prinomastat and marimastat both showing low and highly variable degrees of cross-neutralisation with PLA2 anticoagulant toxicity. However, none of the inhibitors showed efficacy in neutralising the pseudo-procoagulant venom activity exerted by the venom of B. caudalis. Our results highlight the complex nature of snake venoms, for which single-compound treatments will not be universally effective, but combinations might prove highly effective. Despite the limitations of these inhibitors with regards to in vitro kallikrein enzyme pseudo-procoagulant venom activity, our results further support the growing body of literature indicating the potential use of small molecule inhibitors to enhance first-aid treatment of snakebite envenoming, particularly in cases where hospital and thus antivenom treatment is either unavailable or far away.


Assuntos
Viperidae , Animais
19.
Nat Cancer ; 3(2): 173-187, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35221334

RESUMO

Radiotherapy is one of the most effective approaches to achieve tumor control in cancer patients, although healthy tissue injury due to off-target radiation exposure can occur. In this study, we used a model of acute radiation injury to the lung, in the context of cancer metastasis, to understand the biological link between tissue damage and cancer progression. We exposed healthy mouse lung tissue to radiation before the induction of metastasis and observed a strong enhancement of cancer cell growth. We found that locally activated neutrophils were key drivers of the tumor-supportive preconditioning of the lung microenvironment, governed by enhanced regenerative Notch signaling. Importantly, these tissue perturbations endowed arriving cancer cells with an augmented stemness phenotype. By preventing neutrophil-dependent Notch activation, via blocking degranulation, we were able to significantly offset the radiation-enhanced metastases. This work highlights a pro-tumorigenic activity of neutrophils, which is likely linked to their tissue regenerative functions.


Assuntos
Neoplasias Pulmonares , Exposição à Radiação , Animais , Humanos , Pulmão/patologia , Neoplasias Pulmonares/patologia , Camundongos , Ativação de Neutrófilo , Neutrófilos/patologia , Microambiente Tumoral
20.
Adv Radiat Oncol ; 7(2): 100888, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35198835

RESUMO

PURPOSE: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in cancer survivors, particularly after chest radiation therapy (RT). However, the extent to which CVD events are consistently reported in contemporary prospective trials is unknown. METHODS AND MATERIALS: From 10 high-impact RT, oncology, and medicine journals, we identified all latter phase trials from 2000 to 2019 enrolling patients with breast, lung, lymphoma, mesothelioma, or esophageal cancer wherein chest-RT was delivered. The primary outcome was the report of major adverse cardiac events (MACEs), defined as incident myocardial infarction, heart failure, coronary revascularization, arrhythmia, stroke, or CVD death across treatment arms. The secondary outcome was the report of any CVD event. Multivariable regression was used to identify factors associated with CVD reporting. Pooled annualized incidence rates of MACEs across RT trials were compared with contemporary population rates using relative risks (RRs). RESULTS: The 108 trials that met criteria enrolled 59,070 patients (mean age, 58.0 ± 10.2 years; 46.0% female), with 273,587 person-years of available follow-up. During a median follow-up of 48 months, 468 MACEs were reported (including 96 heart failures, 75 acute coronary syndrome, 1 revascularization, 94 arrhythmias, 28 strokes, and 20 CVD deaths; 307 occurred in the intervention arms vs 144 in the control arms; RR, 1.96; P < .001). Altogether, 50.0% of trials did not report MACEs, and 37.0% did not report any CVD. The overall weighted-trial incidence was 376 events per 100,000 person-years compared with 1408 events per 100,000 person-years in similar nontrial patients (RR, 0.27; P < .001). There were no RT factors associated with CVD reporting. CONCLUSION: In contemporary chest RT-based clinical trials, reported CVD rates were lower than expected population rates.

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