RESUMO
Despite their evolutionary novelty, lizard venoms are much less studied in comparison to the intense research on snake venoms. While the venoms of helodermatid lizards have long been assumed to be for defensive purposes, there is increasing evidence of toxic activities more useful for predation than defence (such as paralytic neurotoxicity). This study aimed to ascertain the effects of Heloderma, Lanthanotus, and Varanus lizard venoms on the coagulation and cardiovascular systems. Anticoagulant toxicity was demonstrated for the Varanus species studied, with the venoms prolonging clotting times in human and bird plasma due to the destructive cleavage of fibrinogen. In contrast, thromboelastographic analyses on human and bird plasmas in this study demonstrated a procoagulant bioactivity for Heloderma venoms. A previous study on Heloderma venom using factor-depleted plasmas as a proxy model suggested a procoagulant factor was present that activated either Factor XI or Factor XII, but could not ascertain the precise target. Our activation studies using purified zymogens confirmed FXII activation. Comparisons of neonate and adult H. exasperatum, revealed the neonates to be more potent in the ability to activate FXII, being more similar to the venom of the smaller species H. suspectum than the adult H. exasperatum. This suggests potent FXII activation a basal trait in the genus, present in the small bodied last common ancestor. This also indicates an ontogenetic difference in prey preferences in the larger Heloderma species paralleing the change in venom biochemistry. In addition, as birds lack Factor XII, the ability to clot avian plasma suggested an additional procoagulant site of action, which was revealed to be the activation of Factor VII, with H. horridum being the most potent. This study also examined the effects upon the cardiovascular system, including the liberation of kinins from kininogen, which contributes to hypotension induction. This form of toxicity was previously described for Heloderma venoms, and was revealed in this study was to also be a pathophysiological effect of Lanthanotus and Varanus venoms. This suggests that this toxic activity was present in the venom of the last common ancestor of the anguimorph lizards, which is consistent with kallikrein enzymes being a shared toxin trait. This study therefore uncovered novel actions of anguimorph lizard venoms, not only contributing to the evolutionary biology body of knowledge but also revealing novel activities to mine for drug design lead compounds.
Assuntos
Coagulação Sanguínea , Lagartos , Animais , Lagartos/fisiologia , Coagulação Sanguínea/efeitos dos fármacos , Humanos , Anticoagulantes/toxicidade , Aves , Peçonhas/toxicidade , Cardiotoxinas/toxicidade , Tromboelastografia , CardiotoxicidadeRESUMO
Epilepsy affects around 50 million people worldwide and 30% of patients have difficulty controlling the disease. The search for substances that can fill the existing gaps in the treatment of epilepsy is of great importance. Arthropod venoms are promising sources for this purpose due to the presence of small peptides that modulate the activity of ion channels and neuron receptors. The aim of this study was to investigate dinoponeratoxins from the Dinoponera quadriceps ant venom (M-PONTX-Dq3a, M-PONTX-Dq3b and M-PONTX-Dq3c) as potential anticonvulsants. We evaluated them in a seizure model induced by pentylenetetrazole (PTZ) in male swiss mice. Interestingly, intraperitoneal treatment with each peptide increased the time until the first seizure and the percentage of survival, with M-PONTX-Dq3b showing the best results. M-PONTX-Dq3a was discarded due to the appearance of some signs of toxicity with the increase in malondialdehyde (MDA) levels in the striatum. Both, M-PONTX-Dq3b and M-PONTX-Dq3c decreased iNOS and TNF-α in the hippocampus. Notably, M-PONTX-Dq3c treatment decreased the levels of MDA and nitrite in the cortex and hippocampus. Our results indicate that, M-PONTX-Dq3b and M-PONTX-Dq3c have anticonvulsant activity and exhibit anti-inflammatory effects in epilepsy, offering new perspectives for biopharmaceutical development.
Assuntos
Formigas , Epilepsia , Humanos , Camundongos , Animais , Masculino , Peptídeos Antimicrobianos , Pentilenotetrazol/toxicidade , Peçonhas/toxicidade , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Convulsões/prevenção & controle , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Peptídeos/químicaRESUMO
For millennia, scientists, researchers, and the general public have been intrigued by animal venoms due to their potent effects and paradoxical ability to both harm and heal [...].
Assuntos
Peçonhas , Animais , Peçonhas/toxicidade , ChinaRESUMO
Aculeate hymenopterans use their venom for a variety of different purposes. The venom of solitary aculeates paralyze and preserve prey without killing it, whereas social aculeates utilize their venom in defence of their colony. These distinct applications of venom suggest that its components and their functions are also likely to differ. This study investigates a range of solitary and social species across Aculeata. We combined electrophoretic, mass spectrometric, and transcriptomic techniques to characterize the compositions of venoms from an incredibly diverse taxon. In addition, in vitro assays shed light on their biological activities. Although there were many common components identified in the venoms of species with different social behavior, there were also significant variations in the presence and activity of enzymes such as phospholipase A2s and serine proteases and the cytotoxicity of the venoms. Social aculeate venom showed higher presence of peptides that cause damage and pain in victims. The venom-gland transcriptome from the European honeybee (Apis mellifera) contained highly conserved toxins which match those identified by previous investigations. In contrast, venoms from less-studied taxa returned limited results from our proteomic databases, suggesting that they contain unique toxins.
Assuntos
Himenópteros , Toxinas Biológicas , Animais , Abelhas , Peçonhas/toxicidade , Proteômica , TranscriptomaRESUMO
The evolution of venom and the selection pressures that act on toxins have been increasingly researched within toxinology in the last two decades, in part due to the exceptionally high rates of diversifying selection observed in animal toxins. In 2015, Sungar and Moran proposed the 'two-speed' model of toxin evolution linking evolutionary age of a group to the rates of selection acting on toxins but due to a lack of data, mammals were not included as less than 30 species of venomous mammal have been recorded, represented by elusive species which produce small amounts of venom. Due to advances in genomics and transcriptomics, the availability of toxin sequences from venomous mammals has been increasing. Using branch- and site-specific selection models, we present the rates of both episodic and pervasive selection acting upon venomous mammal toxins as a group for the first time. We identified seven toxin groups present within venomous mammals, representing Chiroptera, Eulipotyphla and Monotremata: KLK1, Plasminogen Activator, Desmallipins, PACAP, CRiSP, Kunitz Domain One and Kunitz Domain Two. All but one group (KLK1) was identified by our results to be evolving under both episodic and pervasive diversifying selection with four toxin groups having sites that were implicated in the fitness of the animal by TreeSAAP (Selection on Amino Acid Properties). Our results suggest that venomous mammal ecology, behaviour or genomic evolution are the main drivers of selection, although evolutionary age may still be a factor. Our conclusion from these results indicates that mammalian toxins are following the two-speed model of selection, evolving predominately under diversifying selection, fitting in with other younger venomous taxa like snakes and cone snails-with high amounts of accumulating mutations, leading to more novel adaptions in their toxins.
Assuntos
Quirópteros , Toxinas Biológicas , Animais , Toxinas Biológicas/genética , Toxinas Biológicas/toxicidade , Mamíferos/genética , Peçonhas/genética , Peçonhas/toxicidade , Serpentes , Perfilação da Expressão Gênica , Evolução MolecularRESUMO
Bites from venomous marine annelid 'bloodworms' (e.g., Glycera spp.) do not appear to have been described in the medical literature despite being seemingly well-known to bait diggers and fishermen. The few laboratory study reports describe their venom composition and physiological effects in vitro to be primarily proteolytic enzymes and neurotoxins apparently used for predation and defense. Herein, we present the report of a symptomatic envenoming suffered by a marine ecologist bitten while performing her field research. The local effects included a rapid onset of pain, swelling, and numbness at the bite site "as if injected with local anesthetic". Additional signs and symptoms appearing over a two-week period were consistent with both delayed venom effects and potentially secondary infection. The late signs and symptoms resolved during a course of antibiotic treatment with doxycycline prescribed as a precaution and lack of resources to consider a wound culture. Comments about annelid bites sporadically appear in the popular literature, especially pertaining to the fishing industry, under names such as 'bait-diggers hand'. While these bites are not known to be dangerously venomous, they seem to produce painful local symptoms and possibly increase the risk of marine bacterial infections that could be associated with more serious outcomes. More cases need to be formally described to better understand the natural history of these types of envenomation.
Assuntos
Poliquetos , Mordeduras de Serpentes , Animais , Antivenenos , Feminino , Neurotoxinas , Mordeduras de Serpentes/terapia , Peçonhas/toxicidadeRESUMO
A hundred and twenty years ago, the Butantan Institute was founded by the Brazilian physician and scientist Vital Brazil, combining, in the same institution, medical research, and the transfer of results to society in the form of health products [...].
Assuntos
Academias e Institutos/história , Toxicologia/história , Peçonhas/toxicidade , Animais , Brasil , História do Século XX , História do Século XXI , Humanos , Internacionalidade/históriaRESUMO
Among the vast repertoire of animal toxins and venoms selected by nature and evolution, mankind opted to devote its scientific attention-during the last century-to a restricted group of animals, leaving a myriad of toxic creatures aside. There are several underlying and justifiable reasons for this, which include dealing with the public health problems caused by envenoming by such animals. However, these studies became saturated and gave rise to a whole group of animals that become neglected regarding their venoms and secretions. This repertoire of unexplored toxins and venoms bears biotechnological potential, including the development of new technologies, therapeutic agents and diagnostic tools and must, therefore, be assessed. In this review, we will approach such topics through an interconnected historical and scientific perspective that will bring up the major discoveries and innovations in toxinology, achieved by researchers from the Butantan Institute and others, and describe some of the major research outcomes from the study of these neglected animals.
Assuntos
Desenvolvimento de Medicamentos , Toxinas Biológicas/toxicidade , Peçonhas/toxicidade , Animais , HumanosRESUMO
Bites from helodermatid lizards can cause pain, paresthesia, paralysis, and tachycardia, as well as other symptoms consistent with neurotoxicity. Furthermore, in vitro studies have shown that Heloderma horridum venom inhibits ion flux and blocks the electrical stimulation of skeletal muscles. Helodermatids have long been considered the only venomous lizards, but a large body of robust evidence has demonstrated venom to be a basal trait of Anguimorpha. This clade includes varanid lizards, whose bites have been reported to cause anticoagulation, pain, and occasionally paralysis and tachycardia. Despite the evolutionary novelty of these lizard venoms, their neuromuscular targets have yet to be identified, even for the iconic helodermatid lizards. Therefore, to fill this knowledge gap, the venoms of three Heloderma species (H. exasperatum, H. horridum and H. suspectum) and two Varanus species (V. salvadorii and V. varius) were investigated using Gallus gallus chick biventer cervicis nerve-muscle preparations and biolayer interferometry assays for binding to mammalian ion channels. Incubation with Heloderma venoms caused the reduction in nerve-mediated muscle twitches post initial response of avian skeletal muscle tissue preparation assays suggesting voltage-gated sodium (NaV) channel binding. Congruent with the flaccid paralysis inducing blockage of electrical stimulation in the skeletal muscle preparations, the biolayer interferometry tests with Heloderma suspectum venom revealed binding to the S3-S4 loop within voltage-sensing domain IV of the skeletal muscle channel subtype, NaV1.4. Consistent with tachycardia reported in clinical cases, the venom also bound to voltage-sensing domain IV of the cardiac smooth muscle calcium channel, CaV1.2. While Varanus varius venom did not have discernable effects in the avian tissue preparation assay at the concentration tested, in the biointerferometry assay both V. varius and V. salvadorii bound to voltage-sensing domain IV of both NaV1.4 and CaV1.2, similar to H. suspectum venom. The ability of varanid venoms to bind to mammalian ion channels but not to the avian tissue preparation suggests prey-selective actions, as did the differential potency within the Heloderma venoms for avian versus mammalian pathophysiological targets. This study thus presents the detailed characterization of Heloderma venom ion channel neurotoxicity and offers the first evidence of varanid lizard venom neurotoxicity. In addition, the data not only provide information useful to understanding the clinical effects produced by envenomations, but also reveal their utility as physiological probes, and underscore the potential utility of neglected venomous lineages in the drug design and development pipeline.
Assuntos
Canais de Cálcio/metabolismo , Lagartos , Neurotoxinas/toxicidade , Canais de Sódio/metabolismo , Peçonhas/toxicidade , Animais , Galinhas , Técnicas In Vitro , Masculino , Junção Neuromuscular/efeitos dos fármacos , Junção Neuromuscular/fisiologia , Ligação ProteicaRESUMO
Animal venoms comprise numerous toxin families, consisting mainly of peptides and proteins [...].
Assuntos
Peptídeos , Peçonhas , Animais , Humanos , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Peptídeos/toxicidade , Peçonhas/farmacologia , Peçonhas/uso terapêutico , Peçonhas/toxicidadeRESUMO
This Special Issue of Toxins aims to increase the profile and understanding of how ecology shapes the evolution of venom systems, and also how venom influences the ecological attributes of and interactions among species [...].
Assuntos
Ecologia , Evolução Molecular , Peçonhas/genética , Animais , Peçonhas/toxicidadeRESUMO
Snakes of the genera Pseudocerastes and Eristicophis (Viperidae: Viperinae) are known as the desert vipers due to their association with the arid environments of the Middle East. These species have received limited research attention and little is known about their venom or ecology. In this study, a comprehensive analysis of desert viper venoms was conducted by visualising the venom proteomes via gel electrophoresis and assessing the crude venoms for their cytotoxic, haemotoxic, and neurotoxic properties. Plasmas sourced from human, toad, and chicken were used as models to assess possible prey-linked venom activity. The venoms demonstrated substantial divergence in composition and bioactivity across all experiments. Pseudocerastes urarachnoides venom activated human coagulation factors X and prothrombin and demonstrated potent procoagulant activity in human, toad, and chicken plasmas, in stark contrast to the potent neurotoxic venom of P. fieldi. The venom of E. macmahonii also induced coagulation, though this did not appear to be via the activation of factor X or prothrombin. The coagulant properties of P. fieldi and P. persicus venoms varied among plasmas, demonstrating strong anticoagulant activity in the amphibian and human plasmas but no significant effect in that of bird. This is conjectured to reflect prey-specific toxin activity, though further ecological studies are required to confirm any dietary associations. This study reinforces the notion that phylogenetic relatedness of snakes cannot readily predict venom protein composition or function. The significant venom variation between these species raises serious concerns regarding antivenom paraspecificity. Future assessment of antivenom is crucial.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Junção Neuromuscular/efeitos dos fármacos , Comportamento Predatório , Proteínas de Répteis/toxicidade , Mordeduras de Serpentes/metabolismo , Peçonhas/toxicidade , Viperidae/metabolismo , Animais , Anuros , Linhagem Celular Tumoral , Galinhas , Humanos , Masculino , Junção Neuromuscular/fisiopatologia , Proteoma , Proteômica , Proteínas de Répteis/metabolismo , Mordeduras de Serpentes/sangue , Mordeduras de Serpentes/fisiopatologia , Especificidade da Espécie , Peçonhas/metabolismoRESUMO
In this paper, I draw an analogy between the use of electricity by electric eels (Electrophorus electricus) to paralyze prey muscles and the use of venoms that paralyze prey by disrupting the neuromuscular junction. The eel's strategy depends on the recently discovered ability of eels to activate prey motor neuron efferents with high-voltage pulses. Usually, eels use high voltage to cause brief, whole-body tetanus, thus preventing escape while swallowing prey whole. However, when eels struggle with large prey, or with prey held precariously, they often curl to bring their tail to the opposite side. This more than doubles the strength of the electric field within shocked prey, ensuring maximal stimulation of motor neuron efferents. Eels then deliver repeated volleys of high-voltage pulses at a rate of approximately 100 Hz. This causes muscle fatigue that attenuates prey movement, thus preventing both escape and defense while the eel manipulates and swallows the helpless animal. Presumably, the evolution of enough electrical power to remotely activate ion channels in prey efferents sets the stage for the selection of eel behaviors that functionally "poison" prey muscles.
Assuntos
Electrophorus/fisiologia , Fenômenos Eletrofisiológicos , Comportamento Predatório , Peçonhas/toxicidade , AnimaisRESUMO
Phyllomedusa bicolor or Kambo is a frog that lives in the Amazon rainforest. It can release through its skin a substance used in healing rituals that are common among South-American tribes, as well as in urban people of America and Europe. We report a 41-year-old female patient who, during a healing ritual consumed ayahuasca (a drink obtained from the mixture of Banisteriopsis caapi, Psychotria viridis and Mimosa hostilis) and 12 hours later received the poison of Kambo Frog (Phyllomedusa bicolor) on superficial right shoulder skin burns. The ritual included a minimum of six-liter water intake over a few hours period. She evolved with clouding of sensorium, motor agitation, frequent vomiting, and generalized tonic-clonic seizures. She presented lethargic to the emergency room, with a weak pupillary light reflex, generalized stiffness, moving all four limbs. Laboratory showed severe hyponatremia (120 mEq/L) and a creatine kinase level of 8,479 UI/L, that increased 107,216 IU/L within few days. An admission CT Brain scan was normal. The toxicological screening did not identify the presence of other substances. During hospitalization the patient developed severe psychomotor agitation controlled by a dexmedetomidine infusion, hyponatremia, low plasma osmolality (248 mOsm/kg), and disproportionately high urinary osmolality (448 mOsm/kg), suggestive of inappropriate antidiuretic hormone secretion syndrome (SIADH). With correction of hyponatremia, the patient gradually recovered consciousness. Rhabdomyolysis was assumed to be secondary to seizure and managed by volume and bicarbonate infusions with a positive response.
Assuntos
Anuros , Hiponatremia/induzido quimicamente , Peçonhas/toxicidade , Adulto , Animais , Comportamento Ritualístico , Feminino , Humanos , Índice de Gravidade de DoençaRESUMO
Phyllomedusa bicolor or Kambo is a frog that lives in the Amazon rainforest. It can release through its skin a substance used in healing rituals that are common among South-American tribes, as well as in urban people of America and Europe. We report a 41-year-old female patient who, during a healing ritual consumed ayahuasca (a drink obtained from the mixture of Banisteriopsis caapi, Psychotria viridis and Mimosa hostilis) and 12 hours later received the poison of Kambo Frog (Phyllomedusa bicolor) on superficial right shoulder skin burns. The ritual included a minimum of six-liter water intake over a few hours period. She evolved with clouding of sensorium, motor agitation, frequent vomiting, and generalized tonic-clonic seizures. She presented lethargic to the emergency room, with a weak pupillary light reflex, generalized stiffness, moving all four limbs. Laboratory showed severe hyponatremia (120 mEq/L) and a creatine kinase level of 8,479 UI/L, that increased 107,216 IU/L within few days. An admission CT Brain scan was normal. The toxicological screening did not identify the presence of other substances. During hospitalization the patient developed severe psychomotor agitation controlled by a dexmedetomidine infusion, hyponatremia, low plasma osmolality (248 mOsm/kg), and disproportionately high urinary osmolality (448 mOsm/kg), suggestive of inappropriate antidiuretic hormone secretion syndrome (SIADH). With correction of hyponatremia, the patient gradually recovered consciousness. Rhabdomyolysis was assumed to be secondary to seizure and managed by volume and bicarbonate infusions with a positive response.
Assuntos
Humanos , Animais , Feminino , Adulto , Anuros , Peçonhas/toxicidade , Hiponatremia/induzido quimicamente , Índice de Gravidade de Doença , Comportamento RitualísticoRESUMO
Animals that specialise in blood feeding have particular challenges in obtaining their meal, whereby they impair blood hemostasis by promoting anticoagulation and vasodilation in order to facilitate feeding. These convergent selection pressures have been studied in a number of lineages, ranging from fleas to leeches. However, the vampire bat (Desmondus rotundus) is unstudied in regards to potential vasodilatory mechanisms of their feeding secretions (which are a type of venom). This is despite the intense investigations of their anticoagulant properties which have demonstrated that D. rotundus venom contains strong anticoagulant and proteolytic activities which delay the formation of blood clots and interfere with the blood coagulation cascade. In this study, we identified and tested a compound from D. rotundus venom that is similar in size and amino acid sequence to human calcitonin gene-related peptide (CGRP) which has potent vasodilatory properties. We found that the vampire bat-derived form of CGRP (i.e., vCGRP) selectively caused endothelium-independent relaxation of pre-contracted rat small mesenteric arteries. The vasorelaxant efficacy and potency of vCGRP were similar to that of CGRP, in activating CGRP receptors and Kv channels to relax arteriole smooth muscle, which would facilitate blood meal feeding by promoting continual blood flow. Our results provide, for the first time, a detailed investigation into the identification and function of a vasodilatory peptide found in D. rotundus venom, which provides a basis in understanding the convergent pathways and selectivity of hematophagous venoms. These unique peptides also show excellent drug design and development potential, thus highlighting the social and economic value of venomous animals.
Assuntos
Quirópteros , Artérias Mesentéricas/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Peçonhas/toxicidade , Animais , Comportamento Alimentar , Masculino , Artérias Mesentéricas/fisiologia , Ratos Sprague-DawleyRESUMO
AIM: To study the epidemiology and outcome of acute kidney injury (AKI) caused by venomous animals. METHODS: A retrospective study of patients admitted at Indira Gandhi Medical College Hospital, Shimla, with AKI due to venomous animals over a period of 15 years (January 2003-December 2017). Medical records were evaluated for patient information on demographic factors, clinical characteristics, complications, and outcome. Outcomes of requirement for intensive care unit (ICU) support, treatment with dialysis, survival, and mortality were analyzed. The survival and non-survival groups were compared to see the difference in the demographic factors, laboratory results, clinical characteristics, and complications. RESULTS: One hundred and eighty-one patients were diagnosed with AKI caused by venomous creatures. Mean age was 44 ± 15.4 years, and the majority (54.1%) was women. Snakebite (77.9%) and wasp stings (19.9%) were the leading causes of AKI. Clinical details were available in 148 patients. The median duration of arrival at hospital was two days. 81.8% had oliguria, and 54.7% had a history of hematuria or having passed red or brown colored urine. The hematological and biochemical laboratory abnormalities were as follows: anemia (75%), leukocytosis (75.7%), hyperkalemia (35.8%), severe metabolic acidosis (46.6%), hepatic dysfunction (54.7%), hemolysis (85.8%), and rhabdomyolysis (65.5%). Main complications were as follows: gastrointestinal bleed (9.5%), seizure/encephalopathy (10.8%), and pneumonia/acute respiratory distress syndrome (ARDS) (11.5%). 82.3% of the patients required dialysis. 154 (85.1%) patient survived, and 27 (14.9%) patients died. As compared to the survival group, the white blood cell count, serum bilirubin, aspartate aminotransferase, alanine aminotransferase, creatine kinase, and lactate dehydrogenase were significantly higher, and serum albumin levels were significantly lower in patients who died. The proportion of patients with leukocytosis, hyperkalemia, metabolic acidosis, pneumonia/ARDS, seizure/encephalopathy, need for ICU support, and dialysis was significantly higher in patients who died. CONCLUSIONS: Snakebite and multiple Hymenoptera stings (bees and wasps) were the leading causes of AKI due to venomous animals. AKI was severe, a high proportion required dialysis, and the mortality was high.
Assuntos
Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/terapia , Peçonhas/toxicidade , Injúria Renal Aguda/mortalidade , Adulto , Animais , Feminino , Humanos , Índia/epidemiologia , Mordeduras e Picadas de Insetos/complicações , Mordeduras e Picadas de Insetos/epidemiologia , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Diálise Renal , Estudos Retrospectivos , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/epidemiologia , Resultado do TratamentoRESUMO
The insects are a hyperdiverse class containing more species than all other animal groups combined-and many employ venom to capture prey, deter predators and micro-organisms, or facilitate parasitism or extra-oral digestion. However, with the exception of those made by Hymenoptera (wasps, ants and bees), little is known about insect venoms. Here, we review the current literature on insects that use venom for prey capture and predator deterrence, finding evidence for fourteen independent origins of venom usage among insects, mostly among the hyperdiverse holometabolan orders. Many lineages, including the True Bugs (Heteroptera), robber flies (Asilidae), and larvae of many Neuroptera, Coleoptera and Diptera, use mouthpart-associated venoms to paralyse and pre-digest prey during hunting. In contrast, some Hymenoptera and larval Lepidoptera, and one species of beetle, use non-mouthpart structures to inject venom in order to cause pain to deter potential predators. Several recently published insect venom proteomes indicate molecular convergence between insects and other venomous animal groups, with all insect venoms studied so far being potently bioactive cocktails containing both peptides and larger proteins, including novel peptide and protein families. This review summarises the current state of the field of entomo-venomics.
Assuntos
Insetos/química , Peçonhas/química , Animais , Evolução Molecular , Insetos/anatomia & histologia , Insetos/genética , Peçonhas/genética , Peçonhas/toxicidadeRESUMO
BACKGROUND: Anaphylaxis is a potentially life-threatening allergic reaction with a strong risk of recurrence. OBJECTIVE: To assess risk factors associated with recurrent anaphylaxis-related emergency department (ED) visits within 1 year of an ED visit for anaphylaxis in a large observational cohort study. METHODS: We used an administrative claims database to identify patients seen from 2008 through 2012 in the ED for anaphylaxis based on an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code algorithm. Patients with at least 2 years of continuous enrollment in a health plan were included. Multivariable logistic regression analysis was used to determine associations with recurrence of anaphylaxis within 1 year. RESULTS: During the 5-year study period, 7,367 patients (median age, 42 years; <18 years old, 23.3%) met the inclusion criteria. The most common anaphylaxis trigger was unspecified (56.2%), followed by food (25.3%), medication (14.6%), and venom (3.9%). Overall, 3.0% of patients had an additional anaphylaxis-related ED visit within 1 year (3.61 episodes per 100 patient-years). On multivariable analysis, risk factors associated with anaphylaxis recurrence were food trigger (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.34-3.99), history of asthma (OR, 1.30; 95% CI, 1.13-1.51), and intensive care unit admission at the index anaphylaxis event (OR, 1.95; 95% CI, 1.41-2.69). CONCLUSION: In this contemporary cohort study, history of asthma, food trigger, and greater index anaphylaxis severity, as measured by intensive care unit admission, were associated with a higher likelihood of a recurrent anaphylaxis-related ED visit within 1 year.
Assuntos
Anafilaxia/epidemiologia , Hipersensibilidade a Drogas/epidemiologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Hipersensibilidade Alimentar/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anafilaxia/diagnóstico , Criança , Pré-Escolar , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Estados Unidos/epidemiologia , Peçonhas/toxicidade , Adulto JovemRESUMO
The growing world population is placing an increasing demand on food production. In addition, abuse and misuse of chemical insecticides has led to the evolution of resistance in insect pests as well as environmental damage. Together, these developments have created a demand for new insecticidal compounds to facilitate global food production. Arachnid venom peptides provide an environmentally-friendly alternative as potential bioinsecticides given their advantages of being fully biodegradable, highly potent, and phyletically selective. However, the use of arachnid venom peptides as bioinsecticides has been questioned due to their presumed lack of oral toxicity. Thus, the aim of this work was to develop screens for oral insecticidal activity. Based on the high susceptibility of dipterans to venom peptides, fruit flies (Drosophila melanogaster) and sheep blowflies (Lucilia cuprina) were selected for screening 56 arachnid venoms. 71.4% of these venoms caused 50% or higher mortality in Drosophila, whereas 30.4% were lethal to blowflies at oral doses of 1 or 30 µg/fly, respectively. We used these assays to compare the oral and injection activity of four well-known spider venom peptides (Hv1a, Hv1c, Dc1a and Ta1a). Hv1c and Ta1a only showed weak or no oral activity in both species, while Hv1a and Dc1a showed higher oral activity in blowflies than Drosophila. Overall, we have established screens for oral toxicity in two dipteran insects. Our results indicate that oral insecticidal activity is more widespread in arachnid venoms than expected, and that some arachnid venoms and venom peptides exhibit phyletic differences in oral toxicity.