Background: For patients with head and neck squamous cell carcinoma (HNSCC), failure of definitive radiation combined with cisplatin nearly universally results in death. Although hyperactivation of the Nrf2 pathway can drive radiation and cisplatin resistance along with suppressed anti-tumor immunity, treatment-refractory HNSCC tumors may retain sensitivity to targeted agents secondary to synergistic lethality with other oncogenic drivers (e.g.
View Article and Find Full Text PDFWe compared the enzymatic, coagulant, and neuromuscular activities of two variants (yellow-CDRy and white-CDRw) of venom with a sample of (CDT) venom and examined their neutralization by antivenom against CDT venom. The venoms were screened for enzymatic and coagulant activities using standard assays, and electrophoretic profiles were compared by SDS-PAGE. Neutralization was assessed by preincubating venoms with crotalic antivenom and assaying the residual activity.
View Article and Find Full Text PDFThe venom of Colombian specimens of the rear-fanged snake Pseudoboa neuwiedii contains proteolytic and phospholipase A (PLA) activities, but is devoid of esterases. Mass spectrometric analysis of electrophoretic bands indicated that this venom contains C-type lectins (CTL), cysteine-rich secretory proteins (CRiSP), PLA, snake venom metalloproteinases (SVMP), and snake venom matrix metalloproteinases (svMMP). In this investigation, we extended our characterization of P.
View Article and Find Full Text PDFNeonicotinoid insecticides (NNI) are agonists of insect nicotinic acetylcholine receptors (nAChR) that induce non-elucidate mechanisms of abnormal behavior in insects. In this work, we investigated the effects of sublethal doses of the neonicotinoid thiamethoxam (TMX) on neurochemical and physiological parameters in cockroaches. Sublethal doses of TMX (0.
View Article and Find Full Text PDFDespite the wide range of institutions that maintain venomous snakes in captivity in Brazil there are no comprehensive data on the occurrence of snakebites and envenomations in these places. We examined the range of native and exotic species of venomous snakes kept by Brazilian zoos and serpentaria (scientific and commercial) and assessed the frequency of snakebites in workers handling these snakes during a 10-year period (2012-2021). Twenty-two (73.
View Article and Find Full Text PDFFipronil, a pesticide widely used to control agricultural and household insect pests, blocks insect GABA and glutamate (GluCl) ionotropic receptors, resulting in uncontrolled hyperexcitation and paralysis that eventually leads to death. The use of fipronil is controversial because unintentional exposure to this compound may contribute to the ongoing global decline of insect pollinator populations. Although the sublethal effects of fipronil have been linked to aberrant behavior and impaired olfactory learning in insects, the precise mechanisms involved in these responses remain unclear.
View Article and Find Full Text PDFTumors typically lack canonical danger signals required to activate adaptive immunity and also frequently employ substantial immunomodulatory mechanisms that downregulate adaptive responses and contribute to escape from immune surveillance. Given the variety of mechanisms involved in shielding tumors from immune recognition, it is not surprising that single-agent immunomodulatory approaches have been largely unsuccessful in generating durable antitumor responses. Here we report a unique combination of immunomodulatory and cytostatic agents that recondition the tumor microenvironment and eliminate complex and/or poor-prognosis tumor types including the non-immunogenic 4T-1 model of TNBC, the aggressive MOC-2 model of HNSCC, and the high-risk MYCN-amplified model of neuroblastoma.
View Article and Find Full Text PDFCoralsnakes ( spp.) are the only elapids found throughout the Americas. They are recognized for their highly neurotoxic venom, which is comprised of a wide variety of toxins, including the stable, low-mass toxins known as three-finger toxins (3FTx).
View Article and Find Full Text PDFIn this work, we compared the biochemical and toxicological profiles of venoms from an adult female specimen of Lachesis muta rhombeata (South American bushmaster) and her seven offspring born in captivity, based on SDS-PAGE, RP-HPLC, enzymatic, coagulant, and hemorrhagic assays. Although adult and juvenile venoms showed comparable SDS-PAGE profiles, juveniles lacked some chromatographic peaks compared with adult venom. Adult venom had higher proteolytic (caseinolytic) activity than juvenile venoms (p < 0.
View Article and Find Full Text PDFInt J Circumpolar Health
December 2024
In this work, we examined the neuromuscular blockade caused by venoms from four South-American coralsnakes (Micrurus altirostris - MA, M. corallinus - MC, M. spixii - MS, and M.
View Article and Find Full Text PDFFipronil (Fpl), an insecticide belonging to the class of phenylpyrazoles, is associated with the widespread mortality of pollinator insects worldwide. Based on studies carried out on residual concentrations of Fpl commonly found in the environment, in this study, we evaluated the sublethal effects of Fpl on behavior and other neurophysiological parameters using the cockroach Nauphoeta cinerea as a biological model. Sublethal doses of Fpl (0.
View Article and Find Full Text PDFPhoneutrism (bites by wandering spiders of the genus Phoneutria) frequently results in local pain. We describe a retrospective cohort study of a case series of phoneutrism admitted to our Emergency Department (ED), in which we used the Numeric Pain Rating Scale (NPRS 0-10) to assess the intensity of local pain upon admission, and recorded the analgesic measures used to control this pain. Other criteria for inclusion were: (1) An age ≥8 years, (2) Treatment exclusively at our ED, and (3) Visualization or photographing the spider at the time of the bite and/or bringing the spider for identification.
View Article and Find Full Text PDFIn this work, we examined the action of two South American coralsnake (Micrurus corallinus and Micrurus dumerilii carinicauda) venoms on rat heart function in the absence and presence of treatment with Brazilian coralsnake antivenom (CAV) and varespladib (VPL), a potent phospholipase A inhibitor. Anesthetized male Wistar rats were injected with saline (control) or a single dose of venom (1.5 mg/kg, i.
View Article and Find Full Text PDFPlatelets have been shown to enhance the survival of lymphoma cell lines. However, it remains unclear whether they play a role in lymphoma. Here, we investigated the potential role of platelets and/or megakaryocytes in the progression of Eμ-myc lymphoma.
View Article and Find Full Text PDFSerological markers are a promising tool for surveillance and targeted interventions for Plasmodium vivax malaria. P. vivax is closely related to the zoonotic parasite P.
View Article and Find Full Text PDFThe venom of the South American rattlesnake Crotalus durissus terrificus causes an irreversible neuromuscular blockade in isolated preparations due to action of the presynaptically-acting heterodimeric phospholipase A (PLA) crotoxin. Some populations of this subspecies contain, in addition to crotoxin, the toxin crotamine, which acts directly on muscle fibers. In this study we used C.
View Article and Find Full Text PDFBackground: Although loxoscelism (bites by brown spiders of the genus Loxosceles) frequently results in dermonecrosis, no previous clinical reports have provided detailed temporal photodocumentation of the evolution of dermonecrotic lesions in a case series.
Methods: This was a retrospective cohort study involving a case series of loxoscelism. Only cases of dermonecrosis with photodocumentation of lesion evolution (from admission until complete or almost complete healing) were included.
Varespladib (VPL) was primarily developed to treat inflammatory disturbances associated with high levels of serum phospholipase A (PLA). VPL has also demonstrated to be a potential antivenom support agent to prevent PLA-dependent effects produced by snake venoms. In this study, we examined the action of VPL on the coagulant, haemorrhagic and enzymatic activities of (South-American bushmaster) venom.
View Article and Find Full Text PDFTargeted modulation of the immune system against tumors can achieve responses in otherwise refractory cancers, which has spurred efforts aimed at optimizing such strategies. To this end, we have previously investigated cancer immunotherapy approaches using recombinant adenovirus vectors, as well as via modulation of the self-ligand receptor SLAMF7. Here, we present a gene transfer-based immunotherapy approach using targeted expression of a SLAMF7-Fc fusion construct directly into tumors at high concentrations via a recombinant adenoviral vector (Ad-SF7-Fc).
View Article and Find Full Text PDFToxins (Basel)
November 2021
Systemic envenomation by (South American rattlesnake) can cause coagulopathy, rabdomyolysis, acute kidney injury, and peripheral neuromuscular blockade, the latter resulting in flaccid paralysis. Previous studies have shown that plant products such as tannic acid and theaflavin can protect against the neuromuscular blockade caused by venom in vitro. In this work, we used mouse-isolated phrenic nerve-diaphragm preparations to examine the ability of caffeic acid, chlorogenic acid, and quercetin to protect against venom-induced neuromuscular blockade in vitro.
View Article and Find Full Text PDFSerology tests are extremely useful for assessing whether a person has been infected with a pathogen. Since the onset of the COVID-19 pandemic, measurement of anti-SARS-CoV-2-specific antibodies has been considered an essential tool in identifying seropositive individuals and thereby understanding the extent of transmission in communities. The Luminex system is a bead-based technology that has the capacity to assess multiple antigens simultaneously using very low sample volumes and is ideal for high-throughput studies.
View Article and Find Full Text PDFPurpose: The purpose of this study was to explore adolescents' experiences and knowledge of type 2 diabetes (T2D) and identify appropriate T2D education and prevention interventions for this population.
Design And Methods: This interpretive description study was conducted at two urban high schools in midwestern Canada. Participants had been previously screened and considered at high risk for T2D, prediabetes, or as having T2D.