Unraveling and profiling Tityus bahiensis venom: Biochemical analyses of the major toxins.

Among the scorpions found in Brazil, Tityus bahiensis is one of the species that causes most of the reported human accidents. In spite of this important constatation, the venom composition description is not available in the literature. Thus, this venom remains not properly studied, segregating this particular species into an abandoned, forgotten condition. In the present study, chromatographic separation (RP-HPLC-C18) and proteomic analyses were employed to unravel the diversity, complexity, and proportional distribution of the main peptides and proteins found in the scorpion venom. Moreover, sequence analyses and the presence of new isoforms and toxins are discussed based on a database comparison with other Tityus toxins. Our results show the presence of a wide diversity of potassium and sodium channel toxins and enzymes, such as metallopeptidases and hyaluronidases, as previously described for other species. However, the current work also describes for the first time, at the protein level, phospholipase, angiotensin-converting enzyme, cysteine-rich proteins, serine peptidase inhibitors peptides, and antimicrobial peptides. Finally, thorough data analyses allowed the description of the venom toxins distribution regarding their diversity and relative quantity. SIGNIFICANCE: The work presents the first Tityus bahiensis proteome. We have focused on describing the neurotoxin variability in terms of their isoforms/amino acid substitutions. Understanding the natural variations in the toxins' sequences is essential, once the affinity of these peptides to their respective receptors/ionic channels will vary depending on the specific peptide sequences. Moreover, the current study describes some proteins present in the venom, including enzymes being described for the first time in scorpion venoms, such as PLA2 and ACE. Moreover, we describe the individual relative quantity distribution for the different protein classes identified, as well as their variability in the T.bahiensis venom. Finally, this study also reports the development of a simple straightforward chromatographic method for scorpion venom fractionation.

Unraveling and profiling Tityus bahiensis venom: biochemical analyses of the major toxins

Among the scorpions found in Brazil, Tityus bahiensis is one of the species that causes most of the reported human accidents. In spite of this important constatation, the venom composition description is not available in the literature. Thus, this venom remains not properly studied, segregating this particular species into an abandoned, forgotten condition. In the present study, chromatographic separation (RP-HPLC-C18) and proteomic analyses were employed to unravel the diversity, complexity, and proportional distribution of the main peptides and proteins found in the scorpion venom. Moreover, sequence analyses and the presence of new isoforms and toxins are discussed based on a database comparison with other Tityus toxins. Our results show the presence of a wide diversity of potassium and sodium channel toxins and enzymes, such as metallopeptidases and hyaluronidases, as previously described for other species. However, the current work also describes for the first time, at the protein level, phospholipase, angiotensin-converting enzyme, cysteine-rich proteins, serine peptidase inhibitors peptides, and antimicrobial peptides. Finally, thorough data analyses allowed the description of the venom toxins distribution regarding their diversity and relative quantity. Significance: the work presents the first Tityus bahiensis proteome. We have focused on describing the neurotoxin variability in terms of their isoforms/amino acid substitutions. Understanding the natural variations in the toxins' sequences is essential, once the affinity of these peptides to their respective receptors/ionic channels will vary depending on the specific peptide sequences. Moreover, the current study describes some proteins present in the venom, including enzymes being described for the first time in scorpion venoms, such as PLA2 and ACE. Moreover, we describe the individual relative quantity distribution for the different protein classes identified, as well as their variability in the T.bahiensis venom. Finally, this study also reports the development of a simple straightforward chromatographic method for scorpion venom fractionation.

Dopaminergic metabolism is affected by intracerebral injection of Tb II-I isolated from Tityus bahiensis scorpion venom.

Tb II-I isolated from Tityus bahiensis venom causes epileptic-discharges when injected into the hippocampus of rats. The involvement of neurotransmitters in this activity was investigated. Our results demonstrated that Tb II-I increases the concentrations of dopamine metabolite but does not alter other neurotransmitters. Thus, dopaminergic system seems to be partially responsible for the convulsive process. Specific action on particular neurotransmitter can make this toxin a useful tool to better understand the functioning of the system.

Dopaminergic metabolism is affected by intracerebral injection of Tb II-I isolated from Tityus bahiensis scorpion venom

Tb II-I isolated from Tityus bahiensis venom causes epileptic-discharges when injected into the hippocampus of rats. The involvement of neurotransmitters in this activity was investigated. Our results demonstrated that Tb II-I increases the concentrations of dopamine metabolite but does not alter other neurotransmitters. Thus, dopaminergic system seems to be partially responsible for the convulsive process. Specific action on particular neurotransmitter can make this toxin a useful tool to better understand the functioning of the system.

Peripheral mechanisms involved in Tityus bahiensis venom-induced pain.

Scorpionism is a public health burden in Brazil. Tityus bahiensis is responsible for most accidents in the Southeastern region of Brazil. Here, the hyperalgesic mechanisms of Tityus bahiensis venom were investigated, focusing on the role of pro-inflammatory cytokines (tumor necrosis factor alpha [TNF-α] and interleukin 1 beta [IL-1ß]) and activation of the transcription factor NFκB. Intraplantar (i.pl.) administration of Tityus bahiensis venom (0.2, 0.6, 1.2 and 2.4 µg/20 µL i.pl.) induced mechanical hyperalgesia and thermal hyperalgesia. The 2.4 µg dose of Tityus bahiensis venom induced overt pain-like behavior and increased myeloperoxidase (MPO) and N-acetyl-beta-D-glucosaminidase (NAG) activities, TNF-α and IL-1ß levels in the paw tissue. Systemic pre-treatment with etanercept (soluble TNF-α receptor; 10 mg/kg), IL-1ra (IL-1 receptor antagonist; 30 mg/kg) and pyrrolidine dithiocarbamate (PDTC, nuclear factor kappa B [NFκB] inhibitor; 100 mg/kg) inhibited Tityus bahiensis venom-induced mechanical and thermal hyperalgesia, MPO and NAG activity and overt pain-like behavior. These data demonstrate the involvement of TNF-α and IL-1ß signaling as well as NFκB activation in Tityus bahiensis venom-induced mechanical and thermal hyperalgesia, overt pain-like behavior, and MPO activity and NAG activity, indicating thus, that targeting these mechanisms might contribute to reducing the pain in this scorpionism.

Peripheral mechanisms involved in Tityus bahiensis venom-induced pain

Scorpionism is a public health burden in Brazil. Tityus bahiensis is responsible for most accidents in the Southeastern region of Brazil. Here, the hyperalgesic mechanisms of Tityus bahiensis venom were investigated, focusing on the role of pro-inflammatory cytokines (tumor necrosis factor alpha [TNF-α] and interleukin 1 beta [IL-1β]) and activation of the transcription factor NFκB. Intraplantar (i.pl.) administration of Tityus bahiensis venom (0.2, 0.6, 1.2 and 2.4 μg/20 μL i.pl.) induced mechanical hyperalgesia and thermal hyperalgesia. The 2.4 μg dose of Tityus bahiensis venom induced overt pain-like behavior and increased myeloperoxidase (MPO) and N-acetyl-beta-D-glucosaminidase (NAG) activities, TNF-α and IL-1β levels in the paw tissue. Systemic pre-treatment with etanercept (soluble TNF-α receptor; 10 mg/kg), IL-1ra (IL-1 receptor antagonist; 30 mg/kg) and pyrrolidine dithiocarbamate (PDTC, nuclear factor kappa B [NFκB] inhibitor; 100 mg/kg) inhibited Tityus bahiensis venom-induced mechanical and thermal hyperalgesia, MPO and NAG activity and overt pain-like behavior. These data demonstrate the involvement of TNF-α and IL-1β signaling as well as NFκB activation in Tityus bahiensis venom-induced mechanical and thermal hyperalgesia, overt pain-like behavior, and MPO activity and NAG activity, indicating thus, that targeting these mechanisms might contribute to reducing the pain in this scorpionism.

Scorpion venom increases acetylcholine release by prolonging the duration of somatic nerve action potentials.

Scorpionism is frequently accompanied by a massive release of catecholamines and acetylcholine from peripheral nerves caused by neurotoxic peptides present in these venoms, which have high specificity and affinity for ion channels. Tityus bahiensis is the second most medically important scorpion species in Brazil but, despite this, its venom remains scarcely studied, especially with regard to its pharmacology on the peripheral (somatic and autonomic) nervous system. Here, we evaluated the activity of T. bahiensis venom on somatic neurotransmission using myographic (chick and mouse neuromuscular preparations), electrophysiological (MEPP, EPP, resting membrane potentials, perineural waveforms, compound action potentials) and calcium imaging (on DRG neurons and muscle fibres) techniques. Our results show that the major toxic effects of T. bahiensis venom on neuromuscular function are presynaptically driven by the increase in evoked and spontaneous neurotransmitter release. Low venom concentrations prolong the axonal action potential, leading to a longer depolarization of the nerve terminals that enhances neurotransmitter release and facilitates nerve-evoked muscle contraction. The venom also stimulates the spontaneous release of neurotransmitters, probably through partial neuronal depolarization that allows calcium influx. Higher venom concentrations block the generation of action potentials and resulting muscle twitches. These effects of the venom were reversed by low concentrations of TTX, indicating voltage-gated sodium channels as the primary target of the venom toxins. These results suggest that the major neuromuscular toxicity of T. bahiensis venom is probably mediated mainly by α- and ß-toxins interacting with presynaptic TTX-sensitive ion channels on both axons and nerve terminals.

Scorpion venom increases acetylcholine release by prolonging the duration of somatic nerve action potentials

Scorpionism is frequently accompanied by a massive release of catecholamines and acetylcholine from peripheral nerves caused by neurotoxic peptides present in these venoms, which have high specificity and affinity for ion channels. Tityus bahiensis is the second most medically important scorpion species in Brazil but, despite this, its venom remains scarcely studied, especially with regard to its pharmacology on the peripheral (somatic and autonomic) nervous system. Here, we evaluated the activity of T. bahiensis venom on somatic neurotransmission using myographic (chick and mouse neuromuscular preparations), electrophysiological (MEPP, EPP, resting membrane potentials, perineural waveforms, compound action potentials) and calcium imaging (on DRG neurons and muscle fibres) techniques. Our results show that the major toxic effects of T. bahiensis venom on neuromuscular function are presynaptically driven by the increase in evoked and spontaneous neurotransmitter release. Low venom concentrations prolong the axonal action potential, leading to a longer depolarization of the nerve terminals that enhances neurotransmitter release and facilitates nerve-evoked muscle contraction. The venom also stimulates the spontaneous release of neurotransmitters, probably through partial neuronal depolarization that allows calcium influx. Higher venom concentrations block the generation of action potentials and resulting muscle twitches. These effects of the venom were reversed by low concentrations of TTX, indicating voltage-gated sodium channels as the primary target of the venom toxins. These results suggest that the major neuromuscular toxicity of T. bahiensis venom is probably mediated mainly by a- and ß-toxins interacting with presynaptic TTX-sensitive ion channels on both axons and nerve terminals.

Effect of maternal exposure to Tityus bahiensis scorpion venom during lactation on the offspring of rats.

Scorpion stings are a public health problem in Brazil and lactating women may be affected. We aimed to study the effects of Tityus bahiensis venom in the offspring of rats treated during lactation. Mothers received a subcutaneous injection of saline (1.0ml/kg) or venom (2.5mg/kg) or an intraperitoneal injection of LPS (lipopolysaccharide) (100µg/kg) on postnatal (PN) days 2 (PN2), 10 (PN10) or 16 (PN16). The offspring were evaluated during the childhood and adulthood. Pups showed a delay in physical and reflexological development, and a decrease in motor activity. Adults displayed low anxiety. There was an increase in the number of viable neuronal cells in hippocampal areas CA1 and CA4. The levels of IFN-γ (interferon-gamma) increased in the experimental groups. Several of the parameters analyzed showed important differences between the sexes. Thus, the scorpion venom affects the development in the offspring of mothers envenomed during the lactation.

Tityus bahiensis scorpion venom injected to dams during pregnancy affects some cytokines of fetuses.

Due to the high incidence of scorpion stings in Brazil, pregnant women are among the possible victims. Cytokines are important during the pregnancy, and scorpion venoms can change their release. We evaluated the levels of some cytokines in the fetuses after the treatment of pregnant rats with the Tityus bahiensis scorpion venom. The concentration of some of them is altered and can be responsible for the effects previously observed on innate reflexes, and the physical and behavioral development of the offspring.

The transcriptome recipe for the venom cocktail of Tityus bahiensis scorpion.

Scorpion venom is a mixture of peptides, including antimicrobial, bradykinin-potentiating and anionic peptides and small to medium proteins, such as ion channel toxins, metalloproteinases and phospholipases that together cause severe clinical manifestation. Tityus bahiensis is the second most medically important scorpion species in Brazil and it is widely distributed in the country with the exception of the North Region. Here we sequenced and analyzed the transcripts from the venom glands of T. bahiensis, aiming at identifying and annotating venom gland expressed genes. A total of 116,027 long reads were generated by pyrosequencing and assembled in 2891 isotigs. An annotation process identified transcripts by similarity to known toxins, revealing that putative venom components represent 7.4% of gene expression. The major toxins identified are potassium and sodium channel toxins, whereas metalloproteinases showed an unexpected high abundance. Phylogenetic analysis of deduced metalloproteinases from T. bahiensis and other scorpions revealed a pattern of ancient and intraspecific gene expansions. Other venom molecules identified include antimicrobial, anionic and bradykinin-potentiating peptides, besides several putative new venom components. This report provides the first attempt to massively identify the venom components of this species and constitutes one of the few transcriptomic efforts on the genus Tityus.

Modeling of spatial distribution for scorpions of medical importance in the São Paulo State, Brazil.

AIM: In this work, we aimed to develop maps of modeling geographic distribution correlating to environmental suitability for the two species of scorpions of medical importance at São Paulo State and to develop spatial configuration parameters for epidemiological surveillance of these species of venomous animals. MATERIALS AND METHODS: In this study, 54 georeferenced points for Tityus serrulatus and 86 points for Tityus bahiensis and eight environmental indicators, were used to generate species distribution models in Maxent (maximum entropy modeling of species geographic distributions) version 3.3.3k using 70% of data for training (n=38 to T. serrulatus and n=60 to T. bahiensis) and 30% to test the models (n=16 for T. serrulatus and n=26 for T. bahiensis). The logistic threshold used to cut models in converting the continuous probability model into a binary model was the "maximum test sensitivity plus specificity," provided by Maxent, with results of 0.4143 to T. serrulatus and of 0.3401 to T. bahiensis. The models were evaluated by the area under the curve (AUC), using the omission error and the binomial probability. With the data generated by Maxent, distribution maps were produced using the "ESRI(®) ArcGIS 10.2.2 for Desktop" software. RESULTS: The models had high predictive success (AUC=0.7698±0.0533, omission error=0.2467 and p<0.001 for T. serrulatus and AUC=0.8205±0.0390, omission error=0.1917 and p<0.001 for T. bahiensis) and the resultant maps showed a high environmental suitability in the north, central, and southeast of the state, confirming the increasing spread of these species. The environmental variables that mostly contributed to the scorpions species distribution model were rain precipitation (28.9%) and tree cover (28.2%) for the T. serrulatus and temperature (45.8%) and thermal amplitude (12.6%) for the T. bahiensis. CONCLUSION: The distribution model of these species of medical importance scorpions in São Paulo State revealed a higher environmental suitability of these species in the regions north, central, and southeast of the state, warning to emergencies actions for prevention and surveillance from scorpion stings in several counties. There is also a need to best conservation strategies related to neighboring territories, with the implementation of new environmental protected areas and measures of spread control of these species in urban areas of several counties.

Clinical consequences of Tityus bahiensis and Tityus serrulatus scorpion stings in the region of Campinas, southeastern Brazil.

Scorpion stings account for most envenomations by venomous animals in Brazil. A retrospective study (1994-2011) of the clinical consequences of Tityus scorpion stings in 1327 patients treated at a university hospital in Campinas, southeastern Brazil, is reported. The clinical classification, based on outcome, was: dry sting (no envenoming), class I (only local manifestations), class II (systemic manifestations), class III (life-threatening manifestations, such as shock and/or cardiac failure requiring inotropic/vasopressor agents, and/or respiratory failure), and fatal. The median patient age was 27 years (interquartile interval = 15-42 years). Scorpions were brought for identification in 47.2% of cases (Tityus bahiensis 27.7%; Tityus serrulatus 19.5%). Sting severity was classified and each accounted for the following percentage of cases: dry stings - 3.4%, class I - 79.6%, class II - 15.1%, class III - 1.8% and fatal - 0.1%. Pain was the primary local manifestation (95.5%). Systemic manifestations such as vomiting, agitation, sweating, dyspnea, bradycardia, tachycardia, tachypnea, somnolence/lethargy, cutaneous paleness, hypothermia and hypotension were detected in class II or class III + fatal groups, but were significantly more frequent in the latter group. Class III and fatal cases occurred only in children <15 years old, with scorpions being identified in 13/25 cases (T. serrulatus, n = 12; T. bahiensis, n = 1). Laboratory blood abnormalities (hyperglycemia, hypokalemia, leukocytosis, elevations in serum total CK, CK-MB and troponin T, bicarbonate consumption and an increase in base deficit and blood lactate), electrocardiographic changes (ST segment) and echocardiographic alterations (ventricular ejected fraction <54%) were frequently detected in class III patients. Seventeen patients developed pulmonary edema, 16 had cardiac failure and seven had cardiogenic shock. These results indicate that most scorpion stings involved only local manifestations, mainly pain; the greatest severity was associated with stings by T. serrulatus and in children <15 years old.

Mild reproductive effects of the Tityus bahiensis scorpion venom in rats

Scorpion envenoming is a public health problem in Brazil, where Tityus serrulatus and T. bahiensis are considered the most dangerous scorpions. They are well adapted to urbanized environments, and there is an increasing probability of human exposure to these venoms, including during pregnancy. Not much is known about the effects of prenatal exposure to the venom, and no information is available to aid in the rational treatment of victims stung during pregnancy. Thus, this study aimed to investigate whether venom from the scorpion T. bahiensis administered once to pregnant female rats at a dose that causes a moderate envenomation may lead to deleterious effects on the reproductive performance of the dams and on the development of their offspring. This is the first work demonstrating that T. bahiensis venom, when administered experimentally to rats, alters maternal reproductive performance and the morphological development of fetuses. The venom was given to dams on the 5th (GD5) or on the 10th (GD10) gestational day. After laparotomy, on GD21, fetuses and placentas were counted, weighed and externally analyzed. The corpora lutea were counted. The sex and vitality of fetuses were evaluated, and each litter was then randomly divided for visceral or skeletal analyses. Data were analyzed by ANOVA followed by the Tukey-Kramer test and Fisher's exact test. The significance level for all tests was set at p < 0.05.

Mild reproductive effects of the Tityus bahiensis scorpion venom in rats

Scorpion envenoming is a public health problem in Brazil, where Tityus serrulatus and T. bahiensis are considered the most dangerous scorpions. They are well adapted to urbanized environments, and there is an increasing probability of human exposure to these venoms, including during pregnancy. Not much is known about the effects of prenatal exposure to the venom, and no information is available to aid in the rational treatment of victims stung during pregnancy. Thus, this study aimed to investigate whether venom from the scorpion T. bahiensis administered once to pregnant female rats at a dose that causes a moderate envenomation may lead to deleterious effects on the reproductive performance of the dams and on the development of their offspring. This is the first work demonstrating that T. bahiensis venom, when administered experimentally to rats, alters maternal reproductive performance and the morphological development of fetuses. The venom was given to dams on the 5th (GD5) or on the 10th (GD10) gestational day. After laparotomy, on GD21, fetuses and placentas were counted, weighed and externally analyzed. The corpora lutea were counted. The sex and vitality of fetuses were evaluated, and each litter was then randomly divided for visceral or skeletal analyses. Data were analyzed by ANOVA followed by the Tukey-Kramer test and Fisher's exact test. The significance level for all tests was set at p < 0.05.

Avaliação dos efeitos neurotóxicos da injeção intrahipocampal de três toxinas isoladas do veneno do escorpião Tityus bahiensis / Assessment of the neurotoxic effects the intrahippocampal injection of three toxins isolated from Tityus bahiensis scorpion venom

In Brazil, the scorpions of the genus Tityus belonging to the Buthidae family are the main responsible for serious accidents. Among them there are Tityus serrulatus and Tityus bahiensis; due to the high number of accidents they cause, they are considered of greater clinical importance. However, there are few studies on the action of the venom of T. bahiensis mainly in the central nervous system, even this venom presenting an important neurotoxic action. The neurotoxins are considered the main toxic elements of the venom, and among those already described, ion channels (sodium, potassium, calcium and chloride) are considered their main targets of action. The action of some of these toxins produces behavioral, electrographic and histopathological changes due to the alteration in the brain concentration of neurotransmitters. Therefore, the aim of our study was to evaluate the possible neurotoxic effects of three toxins from the venom of the scorpion on the hippocampus of rats, by evaluating the behavioral and electroencephaographic activity, and to evaluate possible changes on the levels of neurotransmitters and integrity of hippocampal neurons after intrahippocampal injection of the toxins. Thus, T. bahiensis scorpion venom was fractionated by gel filtration (Sephadex G25) into 5 fractions. The fraction that showed a higher activity on the tested model was chromatographed on HPLC generating 3 peaks (toxins Tb II-I, Tb II-II and Tb II-III), which had tested their activities on experimental models. Male Wistar rats used as experimental subjects were submitted to a stereotactic surgery for the implantation of cannulae and / or electrodes in the hippocampus. The animals were evaluated for behavioral activity, brain and neuronal integrity (histological sections of hippocampal tissue examined by an optical microscope for quantification of cells in the CA1, CA3 and CA4 areas) after injection of toxins. Microdialysis samples were collected for measurement of neurotransmitters that were performed on HPLC. The results show that the toxins induced behavioral (prostration, respiratory difficult, limited mobility, increased secretion, myoclonus and wet dog shake) electroencephalographic spikes and discharges) and histological alterations (cell death in the hippocampal CA1, CA3 and CA4 regions). More specifically in relation to Tb II-II, it was able to alter the levels of the neurotransmitters glutamate and GABA. Administration of glutamatergic antagonists AP-5 and MK-801 prior of injection of Tb II-II showed that this toxin acts on glutamate receptors, more effectively on non-NMDA type receptors, since the action of MK-801 in relation Tb II-II was more effective at blocking the onset of some behavioral, electroencephalographic and histopathological changes in comparison to the AP-5. With these results we can conclude that the three toxins were able to make changes on behavioral, electroencephalographic and histopathological parameters, and the action of Tb II-II is primarily a result of increased release of glutamate that generally seems to be more strongly linked to its action on glutamatergic non-NMDA -type receptors.

No Brasil, os escorpiões do gênero Tityus pertencentes à família Buthidae são os principais causadores de acidentes graves. Entre eles destacam-se o Tityus serrulatus e o Tityus bahiensis devido ao alto número de acidentes que causam tornando-os os de maior importância médica. Contudo, poucos são os estudos sobre a ação do veneno do T. bahiensis principalmente no sistema nervoso central, mesmo esse veneno apresentando uma importante ação neurotóxica. As neurotoxinas são consideradas os principais elementos tóxicos desses venenos, sendo que entre as já descritas, os canais iônicos (sódio, potássio, cálcio e cloreto) são considerados os seus principais alvos de ação. A ação de algumas dessas toxinas produz alterações comportamentais, eletrográficas e histopatológicas por alterar as concentrações cerebrais de neurotransmissores. Portanto, o objetivo do nosso trabalho foi avaliar os possíveis efeitos neurotóxico de três toxinas isoladas do veneno do escorpião Tityus bahiensis sobre o hipocampo de ratos, por meio da avaliação das atividades comportamentais e elétrica cerebral, além de avaliar possíveis alterações sobre os níveis de neurotransmissores e a integridade dos neurônios hipocampais, após injeção intrahipocampal das toxinas. Para tanto, o veneno do escorpião T. bahiensis foi fracionado por Gel Filtração (Sephadex G25) formando 5 frações. A fração que apresentou maior atividade sobre o modelo testado foi cromatografada em HPLC gerando 3 picos isolados (toxina Tb II-I, Tb II-II e Tb II-III), os quais tiveram suas atividades testadas sobre os modelos experimentais. Como sujeitos experimentais utilizamos ratos Wistar machos, submetidos à cirurgia estereotáxica para a implantação de cânulas ou/e eletrodos no hipocampo. Os animais foram avaliados quanto à atividade comportamental, elétrica cerebral e integridade neuronal (cortes histológico do tecido hipocampal analisados em microscópio óptico para quantificação das células nas áreas CA1, CA3 e CA4), após injeção das toxinas. Por microdiálise foram coletadas as amostras para dosagem de neurotransmissores que foram realizadas em HPLC. Os resultados demonstram que as três toxinas promoveram alterações sobre parâmetros comportamentais (prostração, dificuldade respiratória e locomotora, mioclonia, “wet dog shake” e convulsão), eletrográficos (espículas e descargas epileptiformes) e histopatológicos (morte de células nas regiões CA1, CA3 e CA4). Em relação à Tb IIII, essa foi capaz de alterar os níveis dos neurotransmissores Glutamato e GABA. O uso dos antagonistas de glutamato AP-5 e MK-801 antes da injeção da Tb II-II mostrou que essa age em receptores glutamatérgico, de maneira mais efetiva sobre os receptores do tipo não NMDA, já que a ação do MK-801 em relação a Tb II-II foi mais efetiva em bloquear o surgimento de algumas alterações comportamentais, eletrográficas e histopatológicas em comparação com o AP-5. Com esses resultados podemos concluir que as três toxinas foram capazes de promover alterações sobre parâmetros comportamentais, eletrográficos e histopatológicos, sendo que a ação da Tb II-II é resultado prioritariamente do aumento da liberação de glutamato que de maneira geral parece estar mais intensamente ligado a sua ação sobre receptores glutamatérgicos do tipo não NMDA.

Posterior reversible encephalopathy syndrome following a scorpion sting.

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity not yet understood, that is present with transient neurologic symptoms and particular radiological findings. The most common imaging pattern in PRES is the presence of edema in the white matter of the posterior portions of both cerebral hemispheres. The cause of PRES is unclear. We report a case of 13-year-old male who was stung by a scorpion and developed a severe headache, visual disturbance, and seizures and had the diagnosis of PRES with a good outcome. Numerous factors can trigger this syndrome, most commonly: acute elevation of blood pressure, abnormal renal function, and immunosuppressive therapy. There are many cases described showing the relationship between PRES and eclampsia, transplantation, neoplasia and chemotherapy treatment, systemic infections, renal disease acute, or chronic. However, this is the first case of PRES following a scorpion sting.

Participação de fatores de crescimento e de citosinas nas alterações observadas na prole de ratas tratadas com o veneno do escorpião Tityus Bahiensis no período gestacional / Participation of growth factors and citokynes in alterations observed in offspring of rats treated with Tityus bahiensis scorpion venom during the pregnancy

No Brasil, o escorpionismo é um problema de saúde pública. O escorpião T. serrulatus é considerado o mais perigoso, mas um grande número de acidentes também acontece com o T. bahiensis. O objetivo do estudo foi verificar possíveis efeitos do veneno do escorpião T. bahiensis no desempenho reprodutivo materno e nos níveis de citocinas e fatores de crescimento em embriões de mães tratadas durante a gestação. Para os parâmetros reprodutivos foram utilizadas fêmeas prenhes injetadas com uma dose de 2,5mg/Kg (s.c.) do veneno no 5º (GD5) ou no 10º (GD10) dia gestacional. O grupo controle foi injetado com salina a 1,46% (1ml/Kg) em ambos os dias. No 21º dia gestacional, os filhotes foram retirados por laparotomia e divididos em dois grupos que receberam tratamento específico para a análise visceral e esquelética. Para avaliação dos níveis de citocinas e de fatores de crescimento, as fêmeas prenhes foram injetadas com salina (1ml/Kg), LPS (100μg/kg) ou veneno (2,5mg/Kg) no 10º (GD10) ou 16º (GD16) dia gestacional. Os filhotes foram removidos por laparotomia 6, 12 ou 24 horas após o tratamento materno. As amostras foram maceradas em um homogenizador de tecido e centrifugadas. Os níveis de citocinas e fatores de crescimento foram determinados por ensaios imunoenzimáticos. Nos parâmetros reprodutivos não houve alterações no peso materno durante a gestação, no número de corpos lúteos, número de filhotes, peso do útero e dos filhotes. Houve diminuição no número de implantações e reabsorções no grupo GD5. Houve aumento no peso das placentas em GD5 e GD10. No desenvolvimento dos filhotes foram observadas aumento no peso do coração e pulmão em GD5 e GD10 e no peso do fígado em GD10. Não foram observadas anomalias e malformações internas ou externas nos filhotes de ambos os grupos experimentais. Em GD10 não foram observadas alterações nos níveis de citocinas 6 horas após a aplicação do veneno, mas verificou-se diminuição do nível de INF-γ 24 horas depois...

In Brazil scorpionism is a public health problem. The scorpion T. serrulatus is considered the most dangerous, but a large number of accidents also occur with T. bahiensis. The objective of this work was to verify the possible effects of the T. bahiensis scorpion venom on the maternal reproductive parameters and on the cytokines levels and growth factors in embryos after the treatment of pregnancy females. To the reproductive parameters it was used pregnant females injected with a dose of 2.5mg/Kg (s.c.) of the venom. The experimental groups were injected with venom on the 5th (GD5) or on the 10th (GD10) gestational day. The control group was injected with NaCl 1.46% on both days. On the 21st gestational day, the pups were taken out by laparotomy and were divided into two groups that received specific treatments for skeletal or visceral analyses. To evaluate the cytokines levels, pregnant females were injected with saline (1ml/kg), LPS (100μg/kg) or crude venom (2.5mg/kg) on the 10th (GD10) or 16th (GD16) gestational day. The pups were removed by laparotomy 6, 12 or 24 hours after the mother’s treatment. The samples (embryo/placenta) were macerated by a tissue homogenizer and centrifuged. The cytokine levels were determined by enzyme immunoassays. In the reproductive parameters no changes were observed in the maternal weight during the gestational period, corpora lutea, number of pups, uterus weight and pups weight. There was a decrease on the number of implantation and resorption in GD5 There was alteration on the placenta’s weight in GD5 and GD10. In pups development there were observed alterations in the heart and lung weight on GD5 and GD10 and on the liver weight on GD10. There were not observed external or internal anomalies and malformations in the offspring of both experimental groups. The cytokines levels were not alterated after 6 hours in GD10. In GD16 there was an increase in the IL-1α levels...