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Sample records for african scorpion androctonus

  1. Deep intraspecific divergences in the medically relevant fat-tailed scorpions (Androctonus, Scorpiones).

    PubMed

    Coelho, P; Sousa, P; Harris, D J; van der Meijden, A

    2014-06-01

    The genus Androctonus, commonly known as fat-tailed scorpions, contains 22 species distributed from Togo and Mauritania in the west, North Africa, through the Middle East and to as far east as India. With 13 species, a substantial amount of this genus' diversity occurs in North Africa, which is a major hotspot of scorpion sting incidents. Androctonus are among the most medically relevant animals in North Africa. Since venom composition within species is known to vary regionally, the improvement of therapeutic management depends on a correct assessment of the existing regional specific and sub-specific variation. In this study, we assessed the phylogeographical patterns in six species of Androctonus scorpions from North Africa using mitochondrial DNA markers. We sequenced COX1, 12S, 16S and ND1 genes from 110 individuals. Despite lacking basal resolution in the tree, we found taxonomical and geographically coherent clades. We discovered deep intraspecific variation in the widespread Androctonus amoreuxi and Androctonus australis, which consisted of several well-supported clades. Genetic distances between some of these clades are as high as those found between species. North African A. australis have a deep split in Tunisia around the Chott el-Djerid salt-lake. A novel split between A. amoreuxi scorpions was found in Morocco. We also found deep divergences in Androctonus mauritanicus, corresponding to areas attributed to invalidated subspecies. In addition we uncovered a clade of specimens from coastal south Morocco, which could not be ascribed to any know species using morphological characters. Based on these findings we recommend a reassessment of venom potency and anti-venom efficacy between these deep intraspecific divergent clades.

  2. [Scorpion envenomation in Morocco: scorpions of the genus Androctonus, Buthus and Hottentota].

    PubMed

    Aboumaâd, B; Iba, N; Dersi, N

    2014-02-01

    Around the world and especially in summer, the scorpion envenomation is a real public health problem. In Morocco, its gravity is due to the diversity of genera of the Buthidae family whose their venom is potentially lethal, mainly the genus Androctonus, Buthus and Hottentota. The areas most affected by this problematic are the central and southern of Morocco. The lethality of scorpion's venom primarily affects children. It is rich in neurotoxic polypeptides that have targeted ion channel membrane Na(+), K(+) activated or not by Ca(++). The toxins polymorphism causes pathophysiological disorders. The diversity of symptomatic treatment in the absence of immunotherapy is due to variability in clinical pictures, which depends on the species involved and the patient at risk. The objective of this review is to highlight the magnitude of the scorpion envenomation by describing its epidemiological characteristics, elucidate the pathophysiological effects of the venom of the most dangerous scorpions in Morocco the genus Androctonus, Buthus and Hottentota, and their therapeutic treatment.

  3. [Scorpion envenomation in Morocco: scorpions of the genus Androctonus, Buthus and Hottentota].

    PubMed

    Aboumaâd, B; Iba, N; Dersi, N

    2014-02-01

    Around the world and especially in summer, the scorpion envenomation is a real public health problem. In Morocco, its gravity is due to the diversity of genera of the Buthidae family whose their venom is potentially lethal, mainly the genus Androctonus, Buthus and Hottentota. The areas most affected by this problematic are the central and southern of Morocco. The lethality of scorpion's venom primarily affects children. It is rich in neurotoxic polypeptides that have targeted ion channel membrane Na(+), K(+) activated or not by Ca(++). The toxins polymorphism causes pathophysiological disorders. The diversity of symptomatic treatment in the absence of immunotherapy is due to variability in clinical pictures, which depends on the species involved and the patient at risk. The objective of this review is to highlight the magnitude of the scorpion envenomation by describing its epidemiological characteristics, elucidate the pathophysiological effects of the venom of the most dangerous scorpions in Morocco the genus Androctonus, Buthus and Hottentota, and their therapeutic treatment. PMID:24402964

  4. Structure-function relationships in scorpion neurotoxins. Identification of the supperreactive lysine residue in toxin I of Androctonus australis Hector.

    PubMed

    Sampieri, F; Habersetzer-Rochat, C

    1978-07-21

    In a previous article (Habersetzer-Rochat, C. and Sampieri, R. (1976) Biochemistry 15, 2254--2261) it was demonstrated that the toxin I of the North African Scorpion Androctonus australis Hector was inactivated after reaction with iodoacetate; the toxicity loss in mice was correlated with the carboxymethylation of one superreactive residue. In the present work, alkylation of toxin I was performed with iodo[14C]-acetate. Hence, it was possible, after reduction, S-methylation and chymotryptic hydrolysis of this toxin, to isolate the peptide containing the labelled lysine residue. By automatic Edman degradation, this residue was identified as being the penultimate lysine at position 56 in the primary sequence. Comparison of three primary structures of scorpion neurotoxins and comparison in different kinds of activity seem to indicate that this lysine residue is mainly important for toxicity in mice.

  5. Getting stung by black scorpion Androctonus crassicauda: a case report.

    PubMed

    Aghabiklooei, A; Zamani, N; Hassanian-Moghaddam, H

    2014-10-01

    Importance of the correct diagnosis in the correct early management of a scorpion stung patient by using antivenom is not emphasized, particularly when there are little evidences. A 65-year-old female was brought to our emergency department with the chief compliant of being stung by an unknown object 3 h earlier while traveling in an intercity bus. She became agitated and simultaneously experienced tachycardia, very severe generalized sweating, cold and wet extremities, bilateral diffuse crackle in the base of lungs, tachypnea, and lethargy. With the primitive diagnosis of myocardial infarction, scorpion sting was documented as the cause of this combined cholinergic and adrenergic syndrome after the scorpion was found in the patient's bed clothes. She dramatically responded to the administration of low dose of scorpion antivenom. This case dramatically responded to the antivenom administration, especially the cholinergic and sympathetic signs, pulmonary edema, and electrocardiographic changes were fully and almost immediately recovered. Scorpion antivenom may reverse life-threatening manifestations of scorpion envenomation if used early and in appropriate patients. PMID:24347298

  6. The roles of some scorpions, Hemiscorpius lepturus and Androctonus crassicauda, in a scorpionism focus in Ramhormorz, southwestern Iran.

    PubMed

    Mohseni, Alireza; Vazirianzadeh, Babak; Hossienzadeh, Mohsen; Salehcheh, Maryam; Moradi, Azra; Moravvej, Seyed Abbas

    2013-01-01

    Scorpion stings are a common and important health problem in Iran, particularly in south and southwestern Iran, including the province of Khuzestan. In the area of Khuzestan near the city of Ramhormoz, Hemiscorpius lepturus (Scorpionida: Hemiscorpioiidae) and Androctonus crassicauda (Buthidae) are present. Ramhormoz is in southwestern Iran and is one of the most important foci of the scorpion sting problem. The current study was carried out to gain both epidemiological and medical information about scorpion stings in and around the city of Ramhormoz. In total, 179 people who were admitted to the Emergency Department of Ramhormoz Imam Khomeini Hospital during 2008 and 2009 after being stung by scorpions were monitored. Epidemiological and medical parameters including sex of the victim; the part of the body stung; the month when stung; the biochemical parameters comprising blood sugar (BS), blood urea nitrogen (BUN), and creatinine (CR); hematological parameters including white blood cells (WBC), count blood cells (CBC), red blood cells (RBC), hemoglobin (Hb), hematocrit (HCT), platelet (PLT); and urine analysis including hemoglobinuria were recorded. The current study showed that most of the victims were stung by H. lepturus, while very few were stung by A. crassicaud, but in over half of the cases the species was not known. Stings were most common from May to Aguust. 73% of the victims were female. The limbs were the part of the body most likely to be stung. Hemogobinuria was very common in H. lepturus victims.

  7. Clinicopathological investigations on mice envenomed with scorpion venom (Androctonus amoreuxi).

    PubMed

    Hamedy, A F; Kilany, Omnia E; Mohallal, Mahmoud E; Soliman, Belal A; Shoukry, Nahla M; Khaled, Howayda S

    2012-12-01

    The present study assessed the toxicity of Androctonus amoreuxi crude venom on blood and biochemical serum parameters of mice. Adult male Albino mice were divided into three groups, in the control group mice were injected S.C. with saline solution. The second group and the third were injected with the venom S.C. in mice in the following doses 1/4 and 1/2 dose of LD50 respectively. Blood and serum samples were taken after 3 hours, 6 hours, 9 hours, 12 hours, 4 days and 7 days. Hematocrit (Ht), red blood cells (RBC) count, hemoglobin, MCV, MCH & MCHC were performed. Serum biochemical parameters, the levels of total proteins, albumin, globulin, glucose, cholesterol, triglycerides, ALT, AST, ALP, creatinine, uric acid and urea were measured. RBCs, Hob, PCV, MCV, MCH & MCHC showed significant increase, and increase in total protein, albumin and globulin within the experiment. Glucose and cholesterol levels were significantly increase from the beginning. Triglycerides showed significant decrease after 6 hours. Liver enzymes and kidney functions revealed significant changes post-injection. PMID:23469627

  8. Clinical comparison of scorpion envenomation by Androctonus mauritanicus and Buthus occitanus in children.

    PubMed

    Aboumaâd, Bouchra; Lahssaini, Mohammed; Tiger, Abdelaziz; Benhassain, Sidi Mohammed

    2014-11-01

    The clinical results of scorpion stings by Androctonus mauritanicus (Am) and Buthus occitanus (Bo) (main sources of scorpionism in Morocco) were evaluated in this work. The objective was to compare the clinical manifestations of envenoming from these species by investigating possible correlations among symptoms/signs and laboratory abnormalities of envenomed patients. 41 children (25 males, 18 months - 11 years) were admitted at the Provincial Hospital of El Jadida-Morocco. Their minor (18 children) or severe (23 children) systemic signs such as pallor (48.8%), pulmonary edema (APE) (36.6%), convulsion (26.8%), coma (7.3%) were more frequent in children envenomed by Am than Bo, but angioedema (Quincke's edema) (4.9%) was particularly developed in the latter group. The laboratory blood abnormalities (hyperglycemia, high levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatinine, bilirubin, leukocytes, neutrophils, monocytes, platelets and low levels of lymphocytes and hemoglobin) were significantly higher (p < 0.05) in patients envenomed by Am than Bo, and in all population in comparison to control group. The correlation among these biological analyzes and clinical status showed that higher levels of LDH and value of leukocytes ≥19 × 10(3)/mm(3) were indices of cardiac dysfunction with APE. Pallor sign was correlated with a state of shock and/or low level of hemoglobin, associated or not to bilirubin increase. Fatalities (7.3%), presenting toxic myocarditis, had lowest count of lymphocytes (≤4.2%) in comparison to survivors. This is the first report on lymphopenia which may be useful for forecast the fatal outcome in scorpion envenomation. PMID:25218169

  9. Induction of IL-12 from human monocytes after stimulation with Androctonus crassicauda scorpion venom.

    PubMed

    Saadi, Samahir; Assarehzadegan, Mohammad-Ali; Pipelzadeh, Mohammad Hassan; Hadaddezfuli, Reza

    2015-11-01

    The objective of this study was to evaluate the capacity of venom from Androctonus crassicauda to induce expression/production of interleukin (IL)-12 by isolated human monocytes. For this purpose, isolated human monocytes were exposed to different concentrations of the venom (0.16-20 μg/ml) for varying periods (6, 12, and 24 h). Apart from measures of venom cytotoxicity (i.e., lactase dehydrogenase activity [LDH] release), measures of IL-12 p40 mRNA (by Real-time PCR) of IL-12 release (by ELISA) were performed. The results showed that the venom produced significant concentration- and duration of incubation-dependent cytotoxicity. Expression of IL-12 p40 mRNA was significantly increased at all exposure timepoints relative to that in unexposed cells, but was maximal after 6 h of exposure. At that timepoint, the effect from a dose of 2.5 μg venom/ml provided the maximal increase among all doses tested. At the level of the protein itself, IL-12 production remained almost consistently elevated (vs. unexposed control values) across all exposure timepoints, with the greatest formation again occurring after 6 h of incubation at a dose of 2.5 μg venom/ml. The findings from this study demonstrated that venom from the A. crassicauda scorpion contained active constituents that could induce a sustained activation of human monocytes that was manifested, in part, as promotion of the expression/production of IL-12. PMID:26415903

  10. Diabody mixture providing full protection against experimental scorpion envenoming with crude Androctonus australis venom.

    PubMed

    di Tommaso, Anne; Juste, Matthieu O; Martin-Eauclaire, Marie-France; Dimier-Poisson, Isabelle; Billiald, Philippe; Aubrey, Nicolas

    2012-04-20

    Androctonus australis is primarily involved in envenomations in North Africa, notably in Tunisia and Algeria, and constitutes a significant public health problem in this region. The toxicity of the venom is mainly due to various neurotoxins that belong to two distinct structural and immunological groups, group I (the AahI and AahIII toxins) and group II (AahII). Here, we report the use of a diabody mixture in which the molar ratio matches the characteristics of toxins and polymorphism of the venom. The mixture consists of the Db9C2 diabody (anti-group I) and the Db4C1op diabody (anti-AahII), the latter being modified to facilitate in vitro production and purification. The effectiveness of the antivenom was tested in vivo under conditions simulating scorpion envenomation. The intraperitoneal injection of 30 μg of the diabody mixture protected almost all the mice exposed to 3 LD(50) s.c. of venom. We also show that the presence of both diabodies is necessary for the animals to survive. Our results are the first demonstration of the strong protective power of small quantities of antivenom used in the context of severe envenomation with crude venom. PMID:22375011

  11. Effect of Androctonus bicolor scorpion venom on serum electrolytes in rats: A 24-h time-course study.

    PubMed

    Al-Asmari, A; Khan, H A; Manthiri, R A

    2016-03-01

    Black fat-tailed scorpion (Androctonus bicolor) belongs to the family Buthidae and is one of the most venomous scorpions in the world. The effects of A. bicolor venom on serum electrolytes were not known and therefore investigated in this study. Adult male Wistar rats were randomly divided into seven groups with five animals in each group. One of the groups served as control and received vehicle only. The animals in the remaining groups received a single subcutaneous injection of crude A. bicolor venom (200 μg/kg bodyweight) and were killed at different time intervals including 30 min, 1 h, 2 h, 4 h, 8 h, and 24 h after venom injection. The results showed that scorpion venom caused significant increase in serum sodium levels within 30 min after injection which slightly subsided after 1 h and then persisted over 24 h. Serum potassium levels continued to significantly increase until 4 h and then slightly subsided. There were significant decreases in serum magnesium (Mg(+)) levels following scorpion venom injection, at all the time points during the course of study. Serum calcium levels were significantly increased during the entire course of study, whereas serum chloride was significantly decreased. In conclusion, A. bicolor envenomation in rats caused severe and persistent hypomagnesemia with accompanied hypernatremia, hyperkalemia, and hypercalcemia. It is important to measure serum Mg(+) levels in victims of scorpion envenomation, and patients with severe Mg(+) deficiency should be treated accordingly.

  12. Effect of Androctonus bicolor scorpion venom on serum electrolytes in rats: A 24-h time-course study.

    PubMed

    Al-Asmari, A; Khan, H A; Manthiri, R A

    2016-03-01

    Black fat-tailed scorpion (Androctonus bicolor) belongs to the family Buthidae and is one of the most venomous scorpions in the world. The effects of A. bicolor venom on serum electrolytes were not known and therefore investigated in this study. Adult male Wistar rats were randomly divided into seven groups with five animals in each group. One of the groups served as control and received vehicle only. The animals in the remaining groups received a single subcutaneous injection of crude A. bicolor venom (200 μg/kg bodyweight) and were killed at different time intervals including 30 min, 1 h, 2 h, 4 h, 8 h, and 24 h after venom injection. The results showed that scorpion venom caused significant increase in serum sodium levels within 30 min after injection which slightly subsided after 1 h and then persisted over 24 h. Serum potassium levels continued to significantly increase until 4 h and then slightly subsided. There were significant decreases in serum magnesium (Mg(+)) levels following scorpion venom injection, at all the time points during the course of study. Serum calcium levels were significantly increased during the entire course of study, whereas serum chloride was significantly decreased. In conclusion, A. bicolor envenomation in rats caused severe and persistent hypomagnesemia with accompanied hypernatremia, hyperkalemia, and hypercalcemia. It is important to measure serum Mg(+) levels in victims of scorpion envenomation, and patients with severe Mg(+) deficiency should be treated accordingly. PMID:25964378

  13. Characterization of Am IT, an anti-insect β-toxin isolated from the venom of scorpion Androctonus mauretanicus.

    PubMed

    Oukkache, Naoual; ElJaoudi, Rachid; Chgoury, Fatima; Rocha, Marisa Teixeira; Sabatier, Jean-Marc

    2015-06-25

    In the present study, a 'novel' toxin, called Am IT from the venom of scorpion Androctonus mauretanicus is isolated and characterized. A detailed analysis of the action of Am IT on insect axonal sodium currents is reported. Am IT was purified through gel filtration followed by C18 reversed-phase HPLC. Toxicity of Am IT in vivo was assessed on male German cockroach (Blattella germanica) larvae and C57/BL6 mice. Cross-reactivity of Am IT with two β-toxins was evidenced using (125)I-iodinated toxin-based radioimmunoassays with synaptosomal preparations from rat brain. The complete amino acid sequence of Am IT was finally determined by Edman sequencing. Am IT was observed to compete with AaH IT4 purified from the venom of scorpion Androctonus australis in binding assays. It was recognized by an antibody raised against a β-type toxin, which indicated some structural similarity with β-toxins (or related toxin family). The 'novel' toxin exhibited dual activity since it competed with anti-mammal toxins in binding assays as well as showed contracting activity to insect. The toxin competed with radio-labeled β-toxin Css IV by binding to Na(+) channels of rat brain synaptosomes. Analysis of toxin amino acid sequences showed that Am IT shares high structural identity (92%) with AaH IT4. In conclusion, Am IT not only reveals an anti-insect compound properties secreted by 'Old World' scorpions, paralyzing insect larvae by binding to Na(+) channels on larvae's nerve-cell membranes, but also exerts toxic activity in mice, which is similar to anti-mammal toxins from 'New World' scorpions (North and South Americas). Therefore, Am IT appears to be structurally and functionally similar to AaH IT4.

  14. Purification and cDNA cloning of a novel neurotoxic peptide (Acra3) from the scorpion Androctonus crassicauda.

    PubMed

    Caliskan, Figen; García, Blanca I; Coronas, Fredy I V; Restano-Cassulini, Rita; Korkmaz, Ferhan; Sahin, Yalcin; Corzo, Gerardo; Possani, Lourival D

    2012-09-01

    Androctonus crassicauda is one of the Southeastern Anatolian scorpions of Turkey with ethno-medical and toxicological importance. Two toxic peptides (Acra1 and Acra2) were isolated and characterized from the venom of this scorpion. In this communication, the isolation of an additional toxin (Acra3) by chromatographic separations (HPLC and TSK-gel sulfopropyl) and its chemical and functional characterization is reported. Acra3 is a 7620Da molecular weight peptide, with 66 amino acid residues crosslinked by four disulfide bridges. The gene coding for this peptide was cloned and sequenced. Acra3 is anticipated to undergo post-translational modifications at the C-terminal region, having an amidated serine as last residue. Injection of Acra3 induces severe neurotoxic events in mice, such as: excitability and convulsions, leading to the death of the animals within a few minutes after injection. Electrophysiological assays conducted with pure Acra3, using cells that specifically expressed sodium channels (Nav1.1-Nav1.6) showed no clear effect. The exact molecular target of Acra3 remained undiscovered, similar to three other scorpion peptides that clustered very closely in the phylogenetic tree included here. The exact target of these four peptides is not very clear.

  15. Scorpion (Androctonus bicolor) venom exhibits cytotoxicity and induces cell cycle arrest and apoptosis in breast and colorectal cancer cell lines

    PubMed Central

    Al-Asmari, Abdulrahman K.; Riyasdeen, Anvarbatcha; Abbasmanthiri, Rajamohamed; Arshaduddin, Mohammed; Al-Harthi, Fahad Ali

    2016-01-01

    Objectives: The defective apoptosis is believed to play a major role in the survival and proliferation of neoplastic cells. Hence, the induction of apoptosis in cancer cells is one of the targets for cancer treatment. Researchers are considering scorpion venom as a potent natural source for cancer treatment because it contains many bioactive compounds. The main objective of the current study is to evaluate the anticancer property of Androctonus bicolor scorpion venom on cancer cells. Materials and Methods: Scorpions were milked by electrical stimulation of telsons and lyophilized. The breast (MDA-MB-231) and colorectal (HCT-8) cancer cells were maintained in appropriate condition. The venom cytotoxicity was assessed by 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, and the cellular and nuclear changes were studied with propidium iodide and 4’,6-diamidino-2-phenylindole stain, respectively. The cell cycle arrest was examined using muse cell analyzer. Results: The A. bicolor venom exerted cytotoxic effects on MDA-MB-231 and HCT-8 cells in a dose- and duration-dependent manner and induced apoptotic cell death. The treatment with this venom arrests the cancer cells in G0/G1 phase of cell cycle. Conclusions: The venom selectively induces the rate of apoptosis in MDA-MB-231 and HCT-8 cells as reflected by morphological and cell cycle studies. To the best of our knowledge, this is the first scientific evidence demonstrating the induction of apoptosis and cell cycle arrest by A. bicolor scorpion venom. PMID:27721540

  16. Subtype-selective activation of K(v)7 channels by AaTXKβ₂₋₆₄, a novel toxin variant from the Androctonus australis scorpion venom.

    PubMed

    Landoulsi, Zied; Miceli, Francesco; Palmese, Angelo; Amoresano, Angela; Marino, Gennaro; El Ayeb, Mohamed; Taglialatela, Maurizio; Benkhalifa, Rym

    2013-11-01

    K(v)7.4 channel subunits are expressed in central auditory pathways and in inner ear sensory hair cells and skeletal and smooth muscle cells. Openers of K(v)7.4 channels have been suggested to improve hearing loss, systemic or pulmonary arterial hypertension, urinary incontinence, gastrointestinal and neuropsychiatric diseases, and skeletal muscle disorders. Scorpion venoms are a large source of peptides active on K⁺ channels. Therefore, we have optimized a combined purification/screening procedure to identify specific modulator(s) of K(v)7.4 channels from the venom of the North African scorpion Androctonus australis (Aa). We report the isolation and functional characterization of AaTXKβ₂₋₆₄, a novel variant of AaTXKβ₁₋₆₄, in a high-performance liquid chromatography fraction from Aa venom (named P8), which acts as the first peptide activator of K(v)7.4 channels. In particular, in both Xenopus oocytes and mammalian Chinese hamster ovary cells, AaTXKβ₂₋₆₄, but not AaTXKβ₁₋₆₄, hyperpolarized the threshold voltage of current activation and increased the maximal currents of heterologously expressed K(v)7.4 channels. AaTXKβ₂₋₆₄ also activated K(v)7.3, K(v)7.2/3, and K(v)7.5/3 channels, whereas homomeric K(v)1.1, K(v)7.1, and K(v)7.2 channels were unaffected. We anticipate that these results may prove useful in unraveling the novel biologic roles of AaTXKβ₂₋₆₄-sensitive K(v)7 channels and developing novel pharmacologic tools that allow subtype-selective targeting of K(v)7 channels. PMID:24019223

  17. Purification, synthesis and characterization of AaCtx, the first chlorotoxin-like peptide from Androctonus australis scorpion venom.

    PubMed

    Rjeibi, Ilhem; Mabrouk, Kamel; Mosrati, Hend; Berenguer, Caroline; Mejdoub, Hafedh; Villard, Claude; Laffitte, Daniel; Bertin, Denis; Ouafik, L'Houcine; Luis, José; Elayeb, Mohamed; Srairi-Abid, Najet

    2011-04-01

    AaCtx is the first chlorotoxin-like peptide isolated from Androctonus australis scorpion venom. Its amino acid sequence shares 70% similarity with chlorotoxin from Leiurus quinquestriatus scorpion venom, from which it differs by twelve amino acids. Due to its very low concentration in venom (0.05%), AaCtx was chemically synthesized. Both native and synthetic AaCtx were active on invasion and migration of human glioma cells. However, their activity was found to be lower than that of chlorotoxin. The molecular model of AaCtx shows that most of amino acids differing between AaCtx and chlorotoxin are localized on the N-terminal loop and the α-helix. Based on known compounds that block chloride channels, we suggest that the absence of negative charged amino acids on AaCtx structure may be responsible for its weak activity on glioma cells migration and invasion. This finding serves as a starting point for structure-function relationship studies leading to design high specific anti-glioma drugs.

  18. First chemical synthesis of a scorpion alpha-toxin affecting sodium channels: the Aah I toxin of Androctonus australis hector.

    PubMed

    M'Barek, Sarrah; Fajloun, Ziad; Cestèle, Sandrine; Devaux, Christiane; Mansuelle, Pascal; Mosbah, Amor; Jouirou, Besma; Mantegazza, Massimo; Van Rietschoten, Jurphaas; El Ayeb, Mohamed; Rochat, Hervé; Sabatier, Jean-Marc; Sampieri, François

    2004-11-01

    Aah I is a 63-residue alpha-toxin isolated from the venom of the Buthidae scorpion Androctonus australis hector, which is considered to be the most dangerous species. We report here the first chemical synthesis of Aah I by the solid-phase method, using a Fmoc strategy. The synthetic toxin I (sAah I) was renatured in DMSO-Tris buffer, purified and subjected to thorough analysis and comparison with the natural toxin. The sAah I showed physico-chemical (CD spectrum, molecular mass, HPLC elution), biochemical (amino-acid composition, sequence), immunochemical and pharmacological properties similar to those of the natural toxin. The synthetic toxin was recognized by a conformation-dependent monoclonal anti-Aah I antibody, with an IC50 value close to that for the natural toxin. Following intracerebroventricular injection, the synthetic and the natural toxins were similarly lethal to mice. In voltage-clamp experiments, Na(v) 1.2 sodium channel inactivation was inhibited by the application of sAah I or of the natural toxin in a similar way. This work describes a simple protocol for the chemical synthesis of a scorpion alpha-toxin, making it possible to produce structural analogues in time.

  19. In vitro and in vivo antitumor effects of the Egyptian scorpion Androctonus amoreuxi venom in an Ehrlich ascites tumor model.

    PubMed

    Salem, Mohamed L; Shoukry, Nahla M; Teleb, Wafaa K; Abdel-Daim, Mohamed M; Abdel-Rahman, Mohamed A

    2016-01-01

    Scorpion venom is a highly complex mixture of about 100-700 different components, where peptides are the major constituents with various biological and pharmacological properties including anticancer activities. In this study, anticancer efficacy of the venom of the Egyptian scorpion Androctonus amoreuxi has been evaluated. In vitro, the human breast cancer MCF-7 cell line was treated with the venom and the IC50 was estimated. In vivo studies, Ehrlich ascites carcinoma (EAC) cells were inoculated into CD-1 mice intraperitoneally to form liquid tumor or subcutaneously to form solid tumor and then treated with intraperitoneal injection with venom (0.22 mg/kg) every other day. The total tumor cells in the ascitic fluid and the size of the solid tumor were assessed after 14 and 30 days, respectively. In addition, the mean survival time (MST), body weight, tumor volume, PCV, viability of tumor cells, CBC, AST, ALP, creatinine, oxidative stress biomarkers (GSH, MDA, PCC), tumor marker Ki67, growth factor VEGF and caspase-3 were measured in normal control, EAC control and venom-treated groups (n = 6). Treatment with venom induced anti-tumor effects against liquid and in solid tumors as indicated by a significant (P < 0.05) reduction in tumor volume/size, count of viable EAC cells, expression of Ki67 and VEGF as well as by remarkable increases in MST and caspase-3 expression as compared to non-treated group. Interestingly, the venom restored the altered hematological and biochemical parameters of tumor-bearing animals and significantly increased their life span. These data indicate to (1) the cytotoxic potential effects of A. amoreuxi on tumor cells via anti-proliferative, apoptotic and anti-angiogenic activities; (2) opening a new avenue for further studies on the anti-cancer effects of this agent. PMID:27247867

  20. Characterization of Amm VIII from Androctonus mauretanicus mauretanicus: a new scorpion toxin that discriminates between neuronal and skeletal sodium channels.

    PubMed Central

    Alami, Meriem; Vacher, Hélène; Bosmans, Frank; Devaux, Christiane; Rosso, Jean-Pierre; Bougis, Pierre E; Tytgat, Jan; Darbon, Hervé; Martin-Eauclaire, Marie-France

    2003-01-01

    The venom of the scorpion Androctonus mauretanicus mauretanicus was screened by use of a specific serum directed against AaH II, the scorpion alpha-toxin of reference, with the aim of identifying new analogues. This led to the isolation of Amm VIII (7382.57 Da), which gave a highly positive response in ELISA, but was totally devoid of toxicity when injected subcutaneously into mice. In voltage-clamp experiments with rat brain type II Na+ channel rNa(v)1.2 or rat skeletal muscle Na+ channel rNa(v)1.4, expressed in Xenopus oocytes, the EC50 values of the toxin-induced slowing of inactivation were: 29+/-5 and 416+/-14 nM respectively for AmmVIII and 2.6+/-0.3 nM and 2.2+/-0.2 nM, respectively, for AaH II interactions. Accordingly, Amm VIII clearly discriminates neuronal versus muscular Na+ channel. The Amm VIII cDNA was amplified from a venom gland cDNA library and its oligonucleotide sequence determined. It shows 87% sequence homology with AaH II, but carries an unusual extension at its C-terminal end, consisting of an additional Asp due to a point mutation in the cDNA penultimate codon. We hypothesized that this extra amino acid residue could induce steric hindrance and dramatically reduce recognition of the target by Amm VIII. We constructed a model of Amm VIII based on the X-ray structure of AaH II to clarify this point. Molecular modelling showed that this C-terminal extension does not lead to an overall conformational change in Amm VIII, but drastically modifies the charge repartition and, consequently, the electrostatic dipole moment of the molecule. At last, liquid-phase radioimmunassays with poly- and monoclonal anti-(AaH II) antibodies showed the loss of conformational epitopes between AaH II and Amm VIII. PMID:12911331

  1. Histopathological changes in liver of mice after experimental envenomation with Androctonus amoreuxi scorpion venom.

    PubMed

    Fetaih, Hamdy A; Shoukry, Nahla M; Soliman, Belal A; Mohallal, Mahmoud E; Khaled, Howayda S

    2013-08-01

    A total of 78 adult male Albino mice were divided into thirteen groups (6 mice in each). One served as a control group and the other twelve groups were venom treated groups. The mice of treated groups were injected with 0.1 ml saline solution in which a particular amount of scorpion venom. The first 6 groups were subcutaneously injected with 1/2 LD50 (0.05 microg/g body weight), while the other 6 groups were injected with 1/4 LD 50 (0.025 microg/g body weight) by the same route. The animals from each group were anesthetized with ethyl ether and sacrificed at different time intervals (3, 6, 9, 12 hrs, 4 & 7days post toxin administration). The microscopic examination of liver tissue obtained from envenomed animals showed variable histopathological changes being severely increased with the time interval of envenoming. The most obvious changes in the liver were acute cellular swelling, hydropic degeneration, congestion of central veins and portal blood vessels. Besides, extramedullary hematopoiesis and invaginations in nuclei of hepatic cells, with formation of intranuclear cytoplasmic inclusions were observed. PMID:24260823

  2. In vitro studies with renal proximal tubule cells show direct cytotoxicity of Androctonus australis hector scorpion venom triggered by oxidative stress, caspase activation and apoptosis.

    PubMed

    Saidani, Chanez; Hammoudi-Triki, Djelila; Laraba-Djebari, Fatima; Taub, Mary

    2016-09-15

    Scorpion envenomation injures a number of organs, including the kidney. Mechanisms proposed to explain the renal tubule injury include direct effects of venom on tubule epithelial cells, as well as indirect effects of the autonomic nervous system, and inflammation. Here, we report direct effects of Androctonus australis hector (Aah) scorpion venom on the viability of Renal Proximal Tubule (RPT) cells in vitro, unlike distal tubule and collecting duct cells. Extensive NucGreen nuclear staining was observed in immortalized rabbit RPT cells following treatment with Aah venom, consistent with cytotoxicity. The involvement of oxidative stress is supported by the observations that 1) anti-oxidants mitigated the Aah venom-induced decrease in the number of viable RPT cells, and 2) Aah venom-treated RPT cells were intensively stained with the CellROX(®) Deep Red reagent, an indicator of Reactive Oxygen Species (ROS). Relevance to normal RPT cells is supported by the red fluorescence observed in Aah venom treated primary rabbit RPT cell cultures following their incubation with the Flica reagent (indicative of caspase activation and apoptosis), and the green fluorescence of Sytox Green (indicative of dead cells). PMID:27470530

  3. Scorpions

    MedlinePlus

    ... 222-1222) from anywhere in the United States. Poisonous Ingredient Scorpion venom contains the poison. Where Found ... most varieties of North American scorpions are NOT poisonous. The poisonous ones in the United States live ...

  4. Cationicity-enhanced analogues of the antimicrobial peptides, AcrAP1 and AcrAP2, from the venom of the scorpion, Androctonus crassicauda, display potent growth modulation effects on human cancer cell lines.

    PubMed

    Du, Qiang; Hou, Xiaojuan; Ge, Lilin; Li, Renjie; Zhou, Mei; Wang, Hui; Wang, Lei; Wei, Minjie; Chen, Tianbao; Shaw, Chris

    2014-01-01

    The non disulphide-bridged peptides (NDBPs) of scorpion venoms are attracting increased interest due to their structural heterogeneity and broad spectrum of biological activities. Here, two novel peptides, named AcrAP1 and AcrAP2, have been identified in the lyophilised venom of the Arabian scorpion, Androctonus crassicauda, through "shotgun" molecular cloning of their biosynthetic precursor-encoding cDNAs. The respective mature peptides, predicted from these cloned cDNAs, were subsequently isolated from the same venom sample using reverse phase HPLC and their identities were confirmed by use of mass spectrometric techniques. Both were found to belong to a family of highly-conserved scorpion venom antimicrobial peptides - a finding confirmed through the biological investigation of synthetic replicates. Analogues of both peptides designed for enhanced cationicity, displayed enhanced potency and spectra of antimicrobial activity but, unlike the native peptides, these also displayed potent growth modulation effects on a range of human cancer cell lines. Thus natural peptide templates from venom peptidomes can provide the basis for rational analogue design to improve both biological potency and spectrum of action. The diversity of such templates from such natural sources undoubtedly provides the pharmaceutical industry with unique lead compounds for drug discovery. PMID:25332684

  5. AaeAP1 and AaeAP2: Novel Antimicrobial Peptides from the Venom of the Scorpion, Androctonus aeneas: Structural Characterisation, Molecular Cloning of Biosynthetic Precursor-Encoding cDNAs and Engineering of Analogues with Enhanced Antimicrobial and Anticancer Activities

    PubMed Central

    Du, Qiang; Hou, Xiaojuan; Wang, Lei; Zhang, Yingqi; Xi, Xinping; Wang, Hui; Zhou, Mei; Duan, Jinao; Wei, Minjie; Chen, Tianbao; Shaw, Chris

    2015-01-01

    The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine residues, there are additional groups of peptides in the venoms that are devoid of cysteine residues. These non-disulphide bridged peptides are the subject of much research interest, and among these are peptides that exhibit antimicrobial activity. Here, we describe two novel non-disulphide-bridged antimicrobial peptides that are present in the venom of the North African scorpion, Androctonus aeneas. The cDNAs encoding the biosynthetic precursors of both peptides were cloned from a venom-derived cDNA library using 3'- and 5'-RACE strategies. Both translated precursors contained open-reading frames of 74 amino acid residues, each encoding one copy of a putative novel nonadecapeptide, whose primary structures were FLFSLIPSVIAGLVSAIRN and FLFSLIPSAIAGLVSAIRN, respectively. Both peptides were C-terminally amidated. Synthetic versions of each natural peptide displayed broad-spectrum antimicrobial activities, but were devoid of antiproliferative activity against human cancer cell lines. However, synthetic analogues of each peptide, engineered for enhanced cationicity and amphipathicity, exhibited increases in antimicrobial potency and acquired antiproliferative activity against a range of human cancer cell lines. These data clearly illustrate the potential that natural peptide templates provide towards the design of synthetic analogues for therapeutic exploitation. PMID:25626077

  6. AaeAP1 and AaeAP2: novel antimicrobial peptides from the venom of the scorpion, Androctonus aeneas: structural characterisation, molecular cloning of biosynthetic precursor-encoding cDNAs and engineering of analogues with enhanced antimicrobial and anticancer activities.

    PubMed

    Du, Qiang; Hou, Xiaojuan; Wang, Lei; Zhang, Yingqi; Xi, Xinping; Wang, Hui; Zhou, Mei; Duan, Jinao; Wei, Minjie; Chen, Tianbao; Shaw, Chris

    2015-02-01

    The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine residues, there are additional groups of peptides in the venoms that are devoid of cysteine residues. These non-disulphide bridged peptides are the subject of much research interest, and among these are peptides that exhibit antimicrobial activity. Here, we describe two novel non-disulphide-bridged antimicrobial peptides that are present in the venom of the North African scorpion, Androctonus aeneas. The cDNAs encoding the biosynthetic precursors of both peptides were cloned from a venom-derived cDNA library using 3'- and 5'-RACE strategies. Both translated precursors contained open-reading frames of 74 amino acid residues, each encoding one copy of a putative novel nonadecapeptide, whose primary structures were FLFSLIPSVIAGLVSAIRN and FLFSLIPSAIAGLVSAIRN, respectively. Both peptides were C-terminally amidated. Synthetic versions of each natural peptide displayed broad-spectrum antimicrobial activities, but were devoid of antiproliferative activity against human cancer cell lines. However, synthetic analogues of each peptide, engineered for enhanced cationicity and amphipathicity, exhibited increases in antimicrobial potency and acquired antiproliferative activity against a range of human cancer cell lines. These data clearly illustrate the potential that natural peptide templates provide towards the design of synthetic analogues for therapeutic exploitation.

  7. Two-dimensional sup 1 H nuclear magnetic resonance study of AaH IT, an anti-insect toxin from the scorpion Androctonus australis Hector. Sequential resonance assignments and folding of the polypeptide chain

    SciTech Connect

    Darbon, H. ); Weber, C.; Braun, W. )

    1991-02-19

    Sequence-specific nuclear magnetic resonance assignments for the polypeptide backbone and for most of the amino acid side-chain protons, as well as the general folding of AaH IT, are described. AaH IT is a neurotoxin purified from the venom of the scorpion Androctonus australis Hector and is specifically active on the insect nervous system. The secondary structure and the hydrogen-bonding patterns in the regular secondary structure elements are deduced from nuclear Overhauser effects and the sequence locations of the slowly exchanging amide protons. The backbone folding is determined by distance geometry calculations with the DISMAN program. The regular secondary structure includes two and a half turns of {alpha}-helix running from residues 21 to 30 and a three-stranded antiparallel {beta}-sheet including peptides 3-5, 34-38, and 41-46. Two tight turns are present, one connecting the end of the {alpha}-helix to an external strand of the {beta}-sheet, i.e., turn 31-34, and another connecting this same strand to the central one, i.e., turn 38-41. The differences in the specificity of these related proteins, which are able to discriminate between mammalian and insect voltage-dependent sodium channels of excitable tissues, are most probably brought about by the position of the C-terminal peptide with regard to a hydrophobic surface common to all scorpion toxins examined thus far. Thus, the interaction of a given scorpion toxin with its receptor might well be governed by the presence of this solvent-exposed hydrophobic surface, whereas adjacent areas modulate the specificity of the interaction.

  8. Two-dimensional 1H nuclear magnetic resonance study of AaH IT, an anti-insect toxin from the scorpion Androctonus australis Hector. Sequential resonance assignments and folding of the polypeptide chain.

    PubMed

    Darbon, H; Weber, C; Braun, W

    1991-02-19

    Sequence-specific nuclear magnetic resonance assignments for the polypeptide backbone and for most of the amino acid side-chain protons, as well as the general folding of AaH IT, are described. AaH IT is a neurotoxin purified from the venom of the scorpion Androctonus australis Hector and is specifically active on the insect nervous system. The secondary structure and the hydrogen-bonding patterns in the regular secondary structure elements are deduced from nuclear Overhauser effects and the sequence locations of the slowly exchanging amide protons. The backbone folding is determined by distance geometry calculations with the DISMAN program. The regular secondary structure includes two and a half turns of alpha-helix running from residues 21 to 30 and a three-stranded antiparallel beta-sheet including peptides 3-5, 34-38, and 41-46. Two tight turns are present, one connecting the end of the alpha-helix to an external strand of the beta-sheet, i.e., turn 31-34, and another connecting this same strand to the central one, i.e., turn 38-41. These structure elements are very similar to the secondary structure reported in single crystals for either variant 3 from the scorpion Centruroides sculpturatus Ewing (CsE V3) or toxin II from the scorpion A. australis Hector (AaH II). The differences in the specificity of these related proteins, which are able to discriminate between mammalian and insect voltage-dependent sodium channels of excitable tissues, are most probably brought about by the position of the C-terminal peptide with regard to a hydrophobic surface common to all scorpion toxins examined thus far. This surface is made of an aromatic cluster that is surrounded by long hydrophobic side-chain residues, as well as the loops protruding out of it. Thus, the interaction of a given scorpion toxin with its receptor might well be governed by the presence of this solvent-exposed hydrophobic surface, whereas adjacent areas modulate the specificity of the interaction.

  9. Taxonomical and geographical occurrence of Libyans scorpions.

    PubMed

    Zourgui, L; Maammar, M; Emetris, R

    2008-01-01

    Nine different species of scorpions can be recognized from more than 5000 samples collected from different areas in Libya: Leiurus quinquestriatus, Androctonus bicolor, Androctonus australis, Androctonus amoreuxi, Buthacus leptochelys, Buthus occitanus, Buthacus arenicola, Orthochirus innesi and Scorpio maurus. The geographical occurrence showed that Leiurus quinquestriatus seems to be restricted to the Southern areas. On the contrary, Buthus occitanus was found in the costal regions. Other species such as Androctonus were widely spread in all regions. Buthacus Leptochelys, Orthochirus innesi and Scorpio maurus were found, in the East (Aujlah, Jalu), the South (Wadi-Atbah) and the Western cost of Libya respectively. PMID:19469419

  10. Scorpion fauna and epidemiological aspects of scorpionism in southeastern Iran

    PubMed Central

    Nejati, Jalil; Mozafari, Ehsan; Saghafipour, Abedin; Kiyani, Malek

    2014-01-01

    Objective To identify the scorpion fauna and classify the epidemiological aspects of scorpionism in an endemic region, Southeast Iran. Methods Scorpionism data were collected from health centers and hospitals in Sistan-Baluchestan Province during 2010-2011. Specimens were collected at night, using UV light, between May and October 2012. Results In total, 246 scorpions were collected from two families (Buthidae and Scorpionidae). Five species including Odontobuthus odonturus, Hottentotta (Buthotus) jayakari, Compsobuthus matthiesseni, Scorpio maurus and Orthochirus scrobiculosus are reported for the first time from this area. Androctonus crassicauda was the dominant species. In total, 3 638 scorpion sting cases were recorded by health system, the majority of which were females. Stings mostly occurred in July and the age group of 15-24 years presented the highest frequency. Scorpionism decreased during 2011 compared with that in 2010 (68.2%). Conclusions Based on the results, scorpionism is a serious health problem in this area and increasing knowledge of residents regarding the prevention methods of scorpion stings is recommended. Additional research on the scorpion fauna, their ecological and molecular variety in this part of the country is needed as well as the correlation between scorpions' species and the clinical signs and symptoms. PMID:25183084

  11. Introducing Compsobuthus matthiesseni (Birula, 1905) scorpion as one of the major stinging scorpions in Khuzestan, Iran.

    PubMed

    Dehghani, Ruhollah; Djadid, Navid Dinparast; Shahbazzadeh, Dellavar; Bigdelli, Shahlla

    2009-09-01

    Khuzestan province has the highest rate of scorpion sting in Iran. This is a study to identify these scorpions in Khuzestan. In this study 418 scorpions were kept in the ethyl alcohol 70%, each being studied by stereomicroscopy and diagnosis key separately. 120 (28.7%) Androctonus crassicauda, 104 (24.9%) Hemiscorpius lepturus, 91 (21.7%) Mesobuthus eupeus, 86 (20.65%) Compsobuthus matthiesseni, 14 (3.35%) Hottentotta saulcyi, 2 (0.5%) Orthochirus scrobiculosus and 1 (0.25%) Hottentotta schach were identified. H. lepturus is in the Hemiscorpiidae family and the rest are in Buthidae. C. matthiesseni is the most frequent and O. scrobiculosus is the least frequent newly identified scorpion. This study adds two new sting scorpions to the previous list of 8 identified scorpions in Iran.

  12. [Ischemic stroke following a scorpion sting].

    PubMed

    Elkhayari, M; Hachimi, A; Ziadi, A; Abdenasser Samkaoui, M

    2013-01-01

    Scorpion envenomation is caused by an accidental scorpion sting. In its severe form, it involves life-threatening respiratory or cardiac damage; it may also cause the neurological severity of systemic manifestations. We report the case of a young 35-year-old woman stung by an Androctonus mauretanicus scorpion, who developed impaired consciousness, hemiplegia and respiratory distress. At admission, the brain computed tomography showed a hypodense area in the right parietal region; the chest radiograph revealed a bilateral alveolar syndrome. Troponin was elevated and hemostasis disorders were present. The clinical course was remarkable: cardiogenic shock with multiple organ failure followed by death on day 3. This case illustrates a rare complication of scorpion envenomation: ischemic stroke due to an undetermined mechanism, which in addition to the cardiac and respiratory injuries, led to the serious complications and fatal outcome. PMID:23648127

  13. Amino acid sequence of toxin XI of the scorpion Buthus occitanus tunetanus. Evidence of a mutation having an important effect upon neurotoxic activity.

    PubMed

    Sampieri, F; Habersetzer-Rochat, C; Martin, M F; Kopeyan, C; Rochat, H

    1987-02-01

    The complete amino acid sequence of toxin XI of the North African scorpion Buthus occitanus tunetanus has been elucidated by automatic sequencing of the reduced and alkylated toxin and of the peptides obtained after tryptic cleavage restricted to arginyl bonds. This toxin is structurally homologous to toxin II of Androctonus australis Hector, the most active among the alpha-toxins, but is far less potent, both in vivo and in vitro. This work points out 12 mutations, many of which are conservative. Nevertheless, the most striking difference is the replacement of the lysine residue at position 58, known to be important in the activity of AaH toxin II, by a valine residue. Thus, it seems that the presence of a positive charge at this location facilitates the interactions between the receptor on the sodium channel and the alpha-type toxins.

  14. [Use of medicinal plants against scorpionic and ophidian venoms].

    PubMed

    Memmi, A; Sansa, G; Rjeibi, I; El Ayeb, M; Srairi-Abid, N; Bellasfer, Z; Fekhih, A

    2007-01-01

    The scorpionic and ophidian envenomations are a serious public health problem in Tunisia especially in Southeastern regions. In these regions Artemisia campestris L is a plant well known which has a very important place in traditional medicine for its effectiveness against alleged venom of scorpions and snakes. In this work, we tested for the first time, the anti-venomous activity of Artemisia campestris L against the scorpion Androctonus australis garzonii and the viper Macrovipera lebetina venoms. Assays were conducted by fixing the dose of extract to3 mg/mouse while doses of venom are variable. The leaves of Artemisia campestris L were extracted by various organic solvents (Ether of oil, ethyl acetate, methanol and ethanol) and each extract was tested for its venom neutralizing capacity. For the ethanolic extract, a significant activity with respect to the venoms of scorpion Androctonus australis garzonii (Aag), was detected. Similarly, a significant neutralizing activity against the venom of a viper Macrovipera lebetina (Ml), was obtained with the dichloromethane extract. These results suggest the presence of two different type of chemical components in this plant: those neutralizing the venom of scorpion are soluble in ethanol whereas those neutralizing the venom of viper are soluble in dichloromethane.

  15. [Use of medicinal plants against scorpionic and ophidian venoms].

    PubMed

    Memmi, A; Sansa, G; Rjeibi, I; El Ayeb, M; Srairi-Abid, N; Bellasfer, Z; Fekhih, A

    2007-01-01

    The scorpionic and ophidian envenomations are a serious public health problem in Tunisia especially in Southeastern regions. In these regions Artemisia campestris L is a plant well known which has a very important place in traditional medicine for its effectiveness against alleged venom of scorpions and snakes. In this work, we tested for the first time, the anti-venomous activity of Artemisia campestris L against the scorpion Androctonus australis garzonii and the viper Macrovipera lebetina venoms. Assays were conducted by fixing the dose of extract to3 mg/mouse while doses of venom are variable. The leaves of Artemisia campestris L were extracted by various organic solvents (Ether of oil, ethyl acetate, methanol and ethanol) and each extract was tested for its venom neutralizing capacity. For the ethanolic extract, a significant activity with respect to the venoms of scorpion Androctonus australis garzonii (Aag), was detected. Similarly, a significant neutralizing activity against the venom of a viper Macrovipera lebetina (Ml), was obtained with the dichloromethane extract. These results suggest the presence of two different type of chemical components in this plant: those neutralizing the venom of scorpion are soluble in ethanol whereas those neutralizing the venom of viper are soluble in dichloromethane. PMID:19388583

  16. Scorpion sting in Iran: a review.

    PubMed

    Dehghani, Rouhullah; Fathi, Behrooz

    2012-10-01

    Among Middle Eastern countries, at least 52 species of scorpions, especially dangerous types, have been reported in Iran. This is more than any other country in the region. In addition, in Iran the recorded scorpion stings from 2001 to 2009 were more than 42,500 per year, of which, approximately 19.5 deaths have been reported each year, mostly in spring and summer. About 10 species are responsible for the reported envenoming which belong to the Buthidae family apart from Hemiscorpius lepturus which is a Hemiscorpiidae. The Buthidae family includes: Androctonus crassicauda, Mesobuthus eupeus, Odontobuthus doriae, Hottentotta saulcyi, Hottentotta schach, Compsobuthus matthiesseni, Orthochirus scrobiculosus, Apistobuthus pterygocercus and Olivierus caucasicus. A. crassicauda and H. lepturus are usually cited as the most dangerous species among Iranian scorpions. This article focuses on the main Iranian scorpions and their geographical distribution, especially those which are medically important and considered to be the more dangerous to human, and also attempts to demonstrate an accurate magnitude of scorpion stings in Iran.

  17. Androctonus australis hector venom contributes to the interaction between neuropeptides and mast cells in pulmonary hyperresponsiveness.

    PubMed

    Chaïr-Yousfi, Imène; Laraba-Djebari, Fatima; Hammoudi-Triki, Djelila

    2015-03-01

    Lung injury and respiratory distress syndrome are frequent symptoms observed in the most severe cases of scorpion envenomation. The uncontrolled transmigration of leukocyte cells into the lung interstitium and alveolar space and pulmonary edema may be the cause of death. Mast cells can release various inflammatory mediators known to be involved in the development of lung edema following scorpion venom injection. The present study was designed to determine the evidence of neurokinin 1 (NK1) receptor and the involvement of mast cell activation to induce pulmonary edema and to increase vascular permeability after Androctonus australis hector (Aah) venom administration. To this end, mast cells were depleted using compound 48/80 (C48/80). Furthermore, the involvement of tachykinin NK1 receptors expressed on mast cell membranes was elucidated by their blocking with an antagonist. On the other hand, the ability of Aah venom to increase vascular permeability and to induce edema was also assessed by measuring the amount of Evans blue dye (EBD) extravasation in bronchoalveolar lavage (BAL) fluid and in the lungs of mice. Pulmonary edema, as assessed by the levels of EBD extravasation, was completely inhibited in compound 48/80-treated animals. Depletion by stimuli non-immunological C48/80 component markedly reduced induced inflammatory response following the venom administration. The mast cells seem to play an important role in the development of lung injury and the increase of vascular permeability in mice following the subcutaneous administration of Aah scorpion venom through the NK1 receptor. PMID:25601496

  18. A first exploration of the venom of the Buthus occitanus scorpion found in southern France.

    PubMed

    Martin-Eauclaire, Marie-France; Bosmans, Frank; Céard, Brigitte; Diochot, Sylvie; Bougis, Pierre E

    2014-03-01

    Even though Buthus occitanus scorpions are found throughout the Mediterranean region, a lack of distinctive characteristics has hampered their classification into different subspecies. Yet, stings from this particular scorpion family are reported each year to result in pain followed by various toxic symptoms. In order to determine the toxicity origin of the rare French B. occitanus Amoreux scorpion, we collected several specimens and studied their venom composition using a nano ultra high performance liquid chromatography and matrix assisted laser desorption/ionisation time-of-flight mass spectrometry (nano UHPLC/MALDI-TOF-MS) automated workflow combined with an enzyme-linked immunosorbent assay (ELISA) approach. Moreover, we compared this dataset to that obtained from highly lethal Androctonus australis and Androctonus mauretanicus scorpions collected in North Africa. As a result, we found that the B. occitanus Amoreux venom is toxic to mice, an observation that is most likely caused by venom components that inhibit voltage-gated sodium channel inactivation. Moreover, we identified similarities in venom composition between B. occitanus scorpions living in the South of France and other Buthidae collected in Morocco and Algeria. As such, the results of this study should be taken into consideration when treating stings from the B. occitanus species living in the South of France.

  19. Polypyrazolylborates: Scorpionates

    ERIC Educational Resources Information Center

    Trofimenko, Swiatoslaw

    2005-01-01

    Scorpionate-type ligands and the original polypyrazolylborates are easy to synthesize, have good stability, and are quite user-friendly. Their thallium(I) salts are readily soluble in organic solvents that permits their use in organic media, or in two-phase aquo-organic solvent mixtures.

  20. Insects and Scorpions

    MedlinePlus

    ... gov . Workplace Safety and Health Topics Insects & Scorpions Bees, Wasps, and Hornets Fire Ants Scorpions Additional Resources ... to outdoor workers. Stinging or biting insects include bees, wasps, hornets, and fire ants. The health effects ...

  1. Emergent management of scorpion sting.

    PubMed

    Kluz-Zawadzka, Jolanta; Hartman-Ksycińska, Anna; Lewandowski, Bogumił

    2014-01-01

    Scorpionism (syndrome of scorpion stings) is an important public health problem in many regions of the world, not only in tropics and subtropics. As scorpions may be unintentionally transported to any place in the world and keeping scorpions as pets is becoming more popular, scorpion stings occur also in Poland. Therefore, health professionals should have the knowledge on the management of scorpion stings. This article discusses a case who was stung by scorpion and proposes an algorithm of management with such patients.

  2. Scorpion toxins from Centruroides noxius and Tityus serrulatus. Primary structures and sequence comparison by metric analysis.

    PubMed Central

    Possani, L D; Martin, B M; Svendsen, I; Rode, G S; Erickson, B W

    1985-01-01

    The complete primary structures of toxin II-14 from the Mexican scorpion Centruroides noxius Hoffmann and toxin gamma from the Brazilian scorpion Tityus serrulatus Lutz and Mello have been determined. Cleavage of toxin gamma after Met-6 with CNBr produced the 55-residue peptide 7-61, which maintained the four disulphide bonds but was not toxic to mice at a dose 3 times the lethal dose of native toxin gamma. Pairwise comparison by metric analysis of segment 1-50 of toxin gamma and the corresponding segments from two other South American scorpion toxins, five North American scorpion toxins, nine North African scorpion toxins and one Central Asian scorpion toxin showed that the three Brazilian toxins are intermediate between the North American and North African toxins. This result is consistent with the hypothesis that the South American and African continents were joined by a land connection in the distant past. Images Fig. 1. PMID:4052021

  3. Purification, characterization and molecular modelling of two toxin-like proteins from the Androctonus australis Hector venom.

    PubMed

    Srairi-Abid, N; Mansuelle, P; Mejri, T; Karoui, H; Rochat, H; Sampieri, F; El Ayeb, M

    2000-09-01

    Two toxin-like proteins (AahTL1 and AahTL3) were purified from the venom of the scorpion Androctonus australis Hector (Aah). AahTL1 and AahTL3 are the first non toxic proteins cross-reacting with AahI toxins group which indicates that these proteins can be used as a model of vaccins. In order to study structure-function relationships, their complete amino-acid sequences (66 residues) were determined, by automated Edman degradation. They show more than 50% of similarity with both AahI and AahIII antimammal toxins. Three-dimensional structural models of AahTL1 and AahTL3 constructed by homology suggest that the two proteins are structurally similar to antimammal scorpion alpha-toxins specific to voltage dependent Na+ channels. The models showed also that amino-acid changes between potent Aah toxins and both AahTL1 and AahTL3 disrupt the electrostatic potential gradient at their surface preventing their interaction with the receptor, which may explain their non toxicity.

  4. Erosion resistance of bionic functional surfaces inspired from desert scorpions.

    PubMed

    Zhiwu, Han; Junqiu, Zhang; Chao, Ge; Li, Wen; Ren, Luquan

    2012-02-01

    In this paper, a bionic method is presented to improve the erosion resistance of machine components. Desert scorpion (Androctonus australis) is a typical animal living in sandy deserts, and may face erosive action of blowing sand at a high speed. Based on the idea of bionics and biologic experimental techniques, the mechanisms of the sand erosion resistance of desert scorpion were investigated. Results showed that the desert scorpions used special microtextures such as bumps and grooves to construct the functional surfaces to achieve the erosion resistance. In order to understand the erosion resistance mechanisms of such functional surfaces, the combination of computational and experimental research were carried out in this paper. The Computational Fluid Dynamics (CFD) method was applied to predict the erosion performance of the bionic functional surfaces. The result demonstrated that the microtextured surfaces exhibited better erosion resistance than the smooth surfaces. The further erosion tests indicated that the groove surfaces exhibited better erosion performance at 30° injection angle. In order to determine the effect of the groove dimensions on the erosion resistance, regression analysis of orthogonal multinomials was also performed under a certain erosion condition, and the regression equation between the erosion rate and groove distance, width, and height was established.

  5. Scorpion sting: update.

    PubMed

    Bawaskar, Himmatrao Saluba; Bawaskar, Pramodini Himmatrao

    2012-01-01

    Scorpion envenomation is an important public health hazard in tropical and sub-tropical regions. Envenomation by scorpions can result in a wide range of clinical effects, including, cardiotoxicity, neurotoxicity and respiratory dysfunction. Out of 1500 scorpion species known to exist, about 30 are of medical importance. Although a variety of different scorpion species exist, majority of them produce similar cardiovascular effects. Scientists and clinicians have studied patho-physiology of scorpion envenomation by critical observations of clinical, neurotransmitters studies, radioisotope studies, echocardiography and haemodynamic patterns. Regimen including scorpion antivenom, vasodilators, intensive care management have been tried to alleviate the systemic effects of envenoming. In spite of advances in patho-physiology and therapy the mortality remains high in rural areas due to lack of access to medical facilities, moreover the medical attendee from developing tropical countries may not be aware of the advances in the treatment of scorpion sting. Since the advent of scorpion Antivenom, vasodilators, dobutamine and intensive care facilities, the fatality due to severe scorpion sting has been significantly reduced in areas where these treatment modalities are used. PMID:22715546

  6. Structure-function relationships of scorpion neurotoxins.

    PubMed

    Habersetzer-Rochat, C; Sampieri, F

    1976-06-01

    Chemical modification of some trifunctional amino acid residues in toxins I, II, and III of the scorpion Androctonus australis Hector have been performed. The results indicate: (1) Reduction and methylation of one disulfide bridge destroy toxic activity of toxin II. (2) The only tryptophan residue of toxin II (position 38) is not included in the active site of the molecule. (3) Modification of five carboxylates out of the seven contained in toxin II suppresses the toxic activity. (4) Acetylation of the lysine and tyrosine residues in toxin II leads to the loss of both toxic and antigenic activity. Treatment of the acetylated toxin by hydroxylamine restores partially the antigenic activity. In the case of toxin I, total acetylation abolishes only the toxic activity. It is concluded that at least one tyrosine residue must be involved in an antigenic site of toxin II. (5) Citraconylation of toxins II and III leads to complete loss of toxicity; decitraconylation restores full activity. (6) Guanidination of toxin II does not affect its toxicity significantly. (7) Alkylation of toxin II by iodoacetic acid affects both amino groups and histidine residues. The loss of toxicity is mainly due to the modification of the lysine residues. In the case of toxin I, the kinetics of toxicity loss closely parallel the covalent modification of one lysine residue.

  7. Scorpion image segmentation system

    NASA Astrophysics Data System (ADS)

    Joseph, E.; Aibinu, A. M.; Sadiq, B. A.; Bello Salau, H.; Salami, M. J. E.

    2013-12-01

    Death as a result of scorpion sting has been a major public health problem in developing countries. Despite the high rate of death as a result of scorpion sting, little report exists in literature of intelligent device and system for automatic detection of scorpion. This paper proposed a digital image processing approach based on the floresencing characteristics of Scorpion under Ultra-violet (UV) light for automatic detection and identification of scorpion. The acquired UV-based images undergo pre-processing to equalize uneven illumination and colour space channel separation. The extracted channels are then segmented into two non-overlapping classes. It has been observed that simple thresholding of the green channel of the acquired RGB UV-based image is sufficient for segmenting Scorpion from other background components in the acquired image. Two approaches to image segmentation have also been proposed in this work, namely, the simple average segmentation technique and K-means image segmentation. The proposed algorithm has been tested on over 40 UV scorpion images obtained from different part of the world and results obtained show an average accuracy of 97.7% in correctly classifying the pixel into two non-overlapping clusters. The proposed 1system will eliminate the problem associated with some of the existing manual approaches presently in use for scorpion detection.

  8. Scorpion Envenomation in Pregnancy.

    PubMed

    Shah, Noor; Martens, Mark G

    2016-06-01

    Scorpion envenomation affects more than 1 million people every year and represents an important public health problem worldwide. The effects of envenomation range from localized pain and paresthesias to overactivation of the sympathetic nervous system, leading to neurotoxicity and even death. Of the individuals affected by scorpion envenomation, certain populations, such as young children and older adults, are at high risk for severe disease. Substantial literature exists on the management of envenomation in children; however, scant literature exists that addresses the same phenomenon in pregnant women. This review serves to identify the effects of scorpion envenomation on pregnant women and the treatment options available to them. After thorough review of the treatment modalities that are used to treat scorpion envenomation, we developed a treatment algorithm that may help guide the management of pregnant women who present with scorpion envenomation. PMID:27255088

  9. Toxicokinetic and toxicodynamic analyses of Androctonus australis hector venom in rats: Optimization of antivenom therapy

    SciTech Connect

    Hammoudi-Triki, D.; Lefort, J.; Rougeot, C.; Robbe-Vincent, A.; Bon, C.; Laraba-Djebari, F.; Choumet, V. . E-mail: vchoumet@pasteur.fr

    2007-02-01

    This paper reports the simultaneous determination of toxicokinetic and toxicodynamic properties of Androctonus australis hector venom, in the absence and presence of antivenom (F(ab'){sub 2} and Fab), in envenomed rats. After subcutaneous injection of the venom, toxins showed a complete absorption phase from the site of injection associated with a distribution into a large extravascular compartment. The injection of Fab and F(ab'){sub 2} induced the neutralization of venom antigens in the blood compartment, as well as the redistribution of venom components from the extravascular compartment to the blood compartment. Interestingly, F(ab'){sub 2} and Fab showed distinct efficiencies depending on their route of injection. F(ab'){sub 2} induced a faster venom neutralization and redistribution than Fab when injected intravenously. Fab was more effective than F(ab'){sub 2} by the intramuscular route. The hemodynamic effects of Aah venom were further investigated. Changes in mean arterial pressure and heart rate were observed in parallel with an upper airway obstruction. Fab was more effective than F(ab'){sub 2} for preventing early symptoms of envenomation, whatever their route of administration. Intraperitoneal injection of F(ab'){sub 2} and Fab was similar for the prevention of the delayed symptoms, even after a late administration. Fab was more effective than F(ab'){sub 2} in the inhibition of airway resistance, independent of the route and time of administration. These results show that the treatment for scorpion stings might be improved by the intravascular injection of a mixture of Fab and F(ab'){sub 2}. If antivenom cannot be administered intravenously, Fab might be an alternative as they are more effective than F(ab'){sub 2} when injected intramuscularly.

  10. Assessment of immunogenic characteristics of Hemiscorpius lepturus venom and its cross-reactivity with venoms from Androctonus crassicauda and Mesobuthus eupeus.

    PubMed

    Khanbashi, Shahin; Khodadadi, Ali; Assarehzadegan, Mohammad-Ali; Pipelzadeh, Mohammad Hassan; Vazirianzadeh, Babak; Hosseinzadeh, Mohsen; Rahmani, Ali Hassan; Asmar, Akbar

    2015-01-01

    Hemiscorpius lepturus (H. lepturus), one of the most venomous scorpions in tropical and sub-tropical areas, belongs to the Hemiscorpiidae family. Studies of antibodies in sera against the protein component of the venom from this organism can be of great use for the development of engineered variants of proteins for eventual use in the diagnosis/treatment of, and prevention of reactions to, stings. In the present in vitro study, the proteins of H. lepturus venom, which could specifically activate the production of immunoglobulin G (IgG) in victims accidently exposed to the venom from this scorpion, were evaluated and their cross-reactivity with venoms from two other important scorpion species including Androctonus crassicauda and Mesobuthus eupeus assessed. H. lepturus venom was analyzed with respect to its protein composition and its antigenic properties against antibodies found in sera collected from victims exposed to the venom of this scorpion within a previous 2-month period. The cross-reactivity of the H. lepturus venom with those from A. crassicauda and M. eupeus was assessed using ELISA and immunoblotting. Electrophoretic analysis of the venom of H. lepturus revealed several protein bands with weights of 8-116 KDa. The most frequent IgG-reactive bands in the test sera had weights of 34, 50, and 116 kDa. A weak cross-reactivity H. lepturus of venom with venoms from A. crassicauda and M. eupeus was detected. The results of immunoblotting and ELISA experiments revealed that H. lepturus venom activated the host immune response, leading to the production of a high titer of antibodies. Clearly, a determination of the major immunogenic components of H. lepturus venom could be valuable for future studies and ultimately of great importance for the potential production of recombinant or hypo-venom variants of these proteins.

  11. Cardiac involvement and its complications about three cases of severe scorpion envenomation.

    PubMed

    Aboumaâd, B; Tiger, A; Khattabi, A; Soulaymani, R; Lahssaini, M; Benhassain, S M; Iba, N

    2014-02-01

    For several decades, Morocco is confronted to medico-social problem of scorpion stings and envenomations. In 2009, epidemiological data established by the Poison Control Center recorded 29,816 stung patients, with an incidence of 1.1‰ and a fatality rate of 0.18%. The neurotoxins from scorpion venom are potent activators of the autonomic nervous system resulting a physiopathological disorder of vital systems. The most serious clinical manifestations are neurotoxic effects, pulmonary edema and cardiovascular distress. This present work reports the cases of three children (4 years and 6 months, 8 months and 15 days, 4 years), hospitalized in intensive care for an envenomation by Androctonus mauritanicus (the most fatal scorpion specie). The children presented cardiac dysfunction where pulmonary edema and state of shock were complications resultants. Two cases survived after supportive and symptomatic treatment based on dobutamine as primordial treatment in cardiovascular and pulmonary correction and other drugs. The third case died. The objective of this work was to detect the limit of the effectiveness of symptomatic treatment during a severe scorpion envenomation.

  12. Cardiac involvement and its complications about three cases of severe scorpion envenomation.

    PubMed

    Aboumaâd, B; Tiger, A; Khattabi, A; Soulaymani, R; Lahssaini, M; Benhassain, S M; Iba, N

    2014-02-01

    For several decades, Morocco is confronted to medico-social problem of scorpion stings and envenomations. In 2009, epidemiological data established by the Poison Control Center recorded 29,816 stung patients, with an incidence of 1.1‰ and a fatality rate of 0.18%. The neurotoxins from scorpion venom are potent activators of the autonomic nervous system resulting a physiopathological disorder of vital systems. The most serious clinical manifestations are neurotoxic effects, pulmonary edema and cardiovascular distress. This present work reports the cases of three children (4 years and 6 months, 8 months and 15 days, 4 years), hospitalized in intensive care for an envenomation by Androctonus mauritanicus (the most fatal scorpion specie). The children presented cardiac dysfunction where pulmonary edema and state of shock were complications resultants. Two cases survived after supportive and symptomatic treatment based on dobutamine as primordial treatment in cardiovascular and pulmonary correction and other drugs. The third case died. The objective of this work was to detect the limit of the effectiveness of symptomatic treatment during a severe scorpion envenomation. PMID:24316266

  13. Scorpions: a presentation.

    PubMed

    Goyffon, Max; Tournier, Jean-Nicolas

    2014-07-21

    Scorpions, at least the species of the family Buthidæ whose venoms are better known, appear as animals that have evolved very little over time. The composition of their venoms is relatively simple as most toxins have a common structural motif that is found in other venoms from primitive species. Moreover, all the scorpion venom toxins principally act on membrane ionic channels of excitable cells. The results of recent works lead to the conclusion that in scorpions there is a close relationship between venomous function and innate immune function both remarkably efficient.

  14. Pre-clinical studies of toxin-specific nanobodies: evidence of in vivo efficacy to prevent fatal disturbances provoked by scorpion envenoming.

    PubMed

    Hmila, Issam; Cosyns, Bernard; Tounsi, Hayfa; Roosens, Bram; Caveliers, Vicky; Abderrazek, Rahma Ben; Boubaker, Samir; Muyldermans, Serge; El Ayeb, Mohamed; Bouhaouala-Zahar, Balkiss; Lahoutte, Tony

    2012-10-15

    Scorpions represent a significant threat to humans and animals in various countries throughout the world. Recently, we introduced Nanobodies (Nbs) to combat more efficiently scorpion envenoming and demonstrated the performance of NbAahIF12 and NbAahII10 to neutralize scorpion toxins of Androctonus australis hector venom. A bispecific Nb construct (NbF12-10) comprising these two Nbs is far more protective than the classic Fab'(2) based therapy and is the most efficient antivenom therapy against scorpion sting in preclinical studies. Now we investigate the biodistribution and pharmacokinetics of (99m)Tc labeled Nbs by in vivo imaging in rodents and compared these data with those of the Fab'(2) product (PAS). The pharmacodynamics of the Nbs was investigated in rats by in vivo echocardiography and it is shown that NbF12-10 prevents effectively the hemodynamic disturbances induced by a lethal dose of venom. Moreover, even a late injection of NbF12-10 restores the heart rate and brings the blood pressure to baseline values. Histology confirms that NbF12-10 prevents lung and heart lesions of treated mice after envenoming. In conjunction, in this preclinical study, we provide proof of concept that NbF12-10 prevents effectively the fatal disturbances induced by Androctonus venom, and that the Nanobody based therapeutic has a potential to substitute the classic Fab'(2) based product as immunotherapeutic in scorpion envenoming. Further clinical study using larger cohorts of animals should be considered to confirm the full protecting potential of our NbF12-10.

  15. Immunological characterization of a non-toxic peptide conferring protection against the toxic fraction (AahG50) of the Androctonus australis hector venom.

    PubMed

    Srairi-Abid, Najet; Kaabi, Hajer; Mlayah-Bellalouna, Saoussen; Mejri, Thouraya; Sampieri, François; El Ayeb, Mohamed

    2008-03-01

    KAaH1 and KAaH2 are non-toxic peptides, isolated from the venom of the Androctonus australis hector (Aah) scorpion. In a previous study, we showed these peptides to be the most abundant (approximately 10% each) in the toxic fraction (AahG50) of the Aah venom. KAaH1 and KAaH2 showed high sequence identities (approximately 60%) with birtoxin-like peptides, which likewise are the major peptidic components of Parabuthus transvaalicus scorpion venom. Here, we report the immunological characterization of KAaH1 and KAaH2. These peptides were found to be specifically recognized by polyclonal antibodies raised against AahII, the most toxic peptide of Aah venom, and represents the second antigenic group, including toxins from different scorpion species in the world. Moreover, KAaH1 partially inhibits AahII binding to its specific antibody, suggesting some common epitopes between these two peptides. The identification of possible key antigenic residues in KAaH1 was deduced from comparison of its 3-D model with the experimental structure of AahII. Two clusters of putative antigenically important residues were found at the exposed surface; one could be constituted of V3 and D53, the other of D10, T15 and Y16. Polyclonal antibodies raised against KAaH1 in mice were found to cross-react with both AahII and AahG50, and neutralizing 5LD(50)/ml of the toxic fraction. Mice vaccinated with KAaH1 were protected against a challenge of 2LD(50) of AahG50 fraction. All these data suggest that KAaH1 has clear advantages over the use of the whole or part of the venom. KAaH1 is not toxic and could produce sera-neutralizing scorpion toxins, not only from Aah venom, but also toxins of other venoms from Buthus, Leiurus, or Parabuthus scorpion species presenting antigenically related toxins.

  16. Evaluation of the lethal potency of scorpion and snake venoms and comparison between intraperitoneal and intravenous injection routes.

    PubMed

    Oukkache, Naoual; El Jaoudi, Rachid; Ghalim, Noreddine; Chgoury, Fatima; Bouhaouala, Balkiss; Mdaghri, Naima El; Sabatier, Jean-Marc

    2014-06-12

    Scorpion stings and snake bites are major health hazards that lead to suffering of victims and high mortality. Thousands of injuries associated with such stings and bites of venomous animals occur every year worldwide. In North Africa, more than 100,000 scorpion stings and snake bites are reported annually. An appropriate determination of the 50% lethal doses (LD₅₀) of scorpion and snake venoms appears to be an important step to assess (and compare) venom toxic activity. Such LD₅₀ values are also commonly used to evaluate the neutralizing capacity of specific anti-venom batches. In the present work, we determined experimentally the LD₅₀ values of reference scorpion and snake venoms in Swiss mice, and evaluated the influence of two main venom injection routes (i.e., intraperitoneal (IP) versus intravenous (IV)). The analysis of experimental LD₅₀ values obtained with three collected scorpion venoms indicates that Androctonus mauretanicus (Am) is intrinsically more toxic than Androctonus australis hector (Aah) species, whereas the latter is more toxic than Buthus occitanus (Bo). Similar analysis of three representative snake venoms of the Viperidae family shows that Cerastes cerastes (Cc) is more toxic than either Bitis arietans (Ba) or Macrovipera lebetina (Ml) species. Interestingly, the venom of Elapidae cobra snake Naja haje (Nh) is far more toxic than viper venoms Cc, Ml and Ba, in agreement with the known severity of cobra-related envenomation. Also, our data showed that viper venoms are about three-times less toxic when injected IP as compared to IV, distinct from cobra venom Nh which exhibited a similar toxicity when injected IP or IV. Overall, this study clearly highlights the usefulness of procedure standardization, especially regarding the administration route, for evaluating the relative toxicity of individual animal venoms. It also evidenced a marked difference in lethal activity between venoms of cobra and vipers, which, apart from the

  17. Evaluation of the Lethal Potency of Scorpion and Snake Venoms and Comparison between Intraperitoneal and Intravenous Injection Routes

    PubMed Central

    Oukkache, Naoual; Jaoudi, Rachid El; Ghalim, Noreddine; Chgoury, Fatima; Bouhaouala, Balkiss; Mdaghri, Naima El; Sabatier, Jean-Marc

    2014-01-01

    Scorpion stings and snake bites are major health hazards that lead to suffering of victims and high mortality. Thousands of injuries associated with such stings and bites of venomous animals occur every year worldwide. In North Africa, more than 100,000 scorpion stings and snake bites are reported annually. An appropriate determination of the 50% lethal doses (LD50) of scorpion and snake venoms appears to be an important step to assess (and compare) venom toxic activity. Such LD50 values are also commonly used to evaluate the neutralizing capacity of specific anti-venom batches. In the present work, we determined experimentally the LD50 values of reference scorpion and snake venoms in Swiss mice, and evaluated the influence of two main venom injection routes (i.e., intraperitoneal (IP) versus intravenous (IV)). The analysis of experimental LD50 values obtained with three collected scorpion venoms indicates that Androctonus mauretanicus (Am) is intrinsically more toxic than Androctonus australis hector (Aah) species, whereas the latter is more toxic than Buthus occitanus (Bo). Similar analysis of three representative snake venoms of the Viperidae family shows that Cerastes cerastes (Cc) is more toxic than either Bitis arietans (Ba) or Macrovipera lebetina (Ml) species. Interestingly, the venom of Elapidae cobra snake Naja haje (Nh) is far more toxic than viper venoms Cc, Ml and Ba, in agreement with the known severity of cobra-related envenomation. Also, our data showed that viper venoms are about three-times less toxic when injected IP as compared to IV, distinct from cobra venom Nh which exhibited a similar toxicity when injected IP or IV. Overall, this study clearly highlights the usefulness of procedure standardization, especially regarding the administration route, for evaluating the relative toxicity of individual animal venoms. It also evidenced a marked difference in lethal activity between venoms of cobra and vipers, which, apart from the nature of toxins

  18. Venomous snake bites, scorpions, and spiders.

    PubMed

    Kularatne, S A M; Senanayake, Nimal

    2014-01-01

    Neurologic dysfunction due to natural neurotoxins is an important, but neglected, public health hazard in many parts of the world, particularly in the tropics. These toxins are produced by or found among a variety of live forms that include venomous snakes, arthropods such as scorpions, spiders, centipedes, stinging insects (Hymenoptera), ticks, certain poisonous fish, shellfish, crabs, cone shells, skin secretions of dart-poison frogs, and bacterial poisons such as botulinum toxin. These toxins commonly act on neuromuscular transmission at the neuromuscular junction where acetylcholine is the neurotransmitter, but in certain situations the toxins interfere with neurotransmitters such as GABA, noradrenaline, adrenaline, dopamine, and γ-aminobutyrate. Of the toxins, α-toxins and κ-toxins (e.g., Chinese krait, Bungarus multicinctus) act on the postsynaptic membrane, blocking the receptors, whilst β-toxin (e.g., common krait, B. caeruleus) acts on the presynaptic membrane, causing impairment of acetylcholine release. Conversely, dendrotoxins of the African mamba enhance acetylcholine release. The toxins of scorpions and spiders commonly interfere with voltage-gated ion channels. Clinically, the cardinal manifestation is muscle paralysis. In severe cases respiratory paralysis could be fatal. Effective antivenoms are the mainstay of treatment of envenoming, but their lack of availability is the major concern in the regions of the globe where they are desperately needed. Interestingly, some toxins have proved to be valuable pharmaceutical agents, while some others are widely exploited to study neuromuscular physiology and pathology.

  19. The scorpion toxin Amm VIII induces pain hypersensitivity through gain-of-function of TTX-sensitive Na⁺ channels.

    PubMed

    Abbas, Najwa; Gaudioso-Tyzra, Christelle; Bonnet, Caroline; Gabriac, Mélanie; Amsalem, Muriel; Lonigro, Aurélie; Padilla, Françoise; Crest, Marcel; Martin-Eauclaire, Marie-France; Delmas, Patrick

    2013-08-01

    Voltage-gated Na(+) channels (Nav) are the targets of a variety of scorpion toxins. Here, we investigated the effects of Amm VIII, a toxin isolated from the venom of the scorpion Androctonus mauretanicus mauretanicus, on pain-related behaviours in mice. The effects of Amm VIII were compared with the classic scorpion α-toxin AaH II from Androctonus australis. Contrary to AaH II, intraplantar injection of Amm VIII at relatively high concentrations caused little nocifensive behaviours. However, Amm VIII induced rapid mechanical and thermal pain hypersensitivities. We evaluated the toxins' effects on Nav currents in nociceptive dorsal root ganglion (DRG) neurons and immortalized DRG neuron-derived F11 cells. Amm VIII and AaH II enhanced tetrodotoxin-sensitive (TTX-S) Nav currents in DRG and F11 cells. Both toxins impaired fast inactivation and negatively shifted activation. AaH II was more potent than Amm VIII at modulating TTX-S Nav currents with EC50 of 5 nM and 1 μM, respectively. AaH II and Amm VIII also impaired fast inactivation of Nav1.7, with EC50 of 6.8 nM and 1.76 μM, respectively. Neither Nav1.8 nor Nav1.9 was affected by the toxins. AaH II and Amm VIII reduced first spike latency and lowered action potential threshold. Amm VIII was less efficient than AaH II in increasing the gain of the firing frequency-stimulation relationship. In conclusion, our data show that Amm VIII, although less potent than AaH II, acts as a gating-modifier peptide reminiscent of classic α-toxins, and suggest that its hyperalgesic effects can be ascribed to gain-of-function of TTX-S Na(+) channels in nociceptors. PMID:23685008

  20. The scorpion toxin Amm VIII induces pain hypersensitivity through gain-of-function of TTX-sensitive Na⁺ channels.

    PubMed

    Abbas, Najwa; Gaudioso-Tyzra, Christelle; Bonnet, Caroline; Gabriac, Mélanie; Amsalem, Muriel; Lonigro, Aurélie; Padilla, Françoise; Crest, Marcel; Martin-Eauclaire, Marie-France; Delmas, Patrick

    2013-08-01

    Voltage-gated Na(+) channels (Nav) are the targets of a variety of scorpion toxins. Here, we investigated the effects of Amm VIII, a toxin isolated from the venom of the scorpion Androctonus mauretanicus mauretanicus, on pain-related behaviours in mice. The effects of Amm VIII were compared with the classic scorpion α-toxin AaH II from Androctonus australis. Contrary to AaH II, intraplantar injection of Amm VIII at relatively high concentrations caused little nocifensive behaviours. However, Amm VIII induced rapid mechanical and thermal pain hypersensitivities. We evaluated the toxins' effects on Nav currents in nociceptive dorsal root ganglion (DRG) neurons and immortalized DRG neuron-derived F11 cells. Amm VIII and AaH II enhanced tetrodotoxin-sensitive (TTX-S) Nav currents in DRG and F11 cells. Both toxins impaired fast inactivation and negatively shifted activation. AaH II was more potent than Amm VIII at modulating TTX-S Nav currents with EC50 of 5 nM and 1 μM, respectively. AaH II and Amm VIII also impaired fast inactivation of Nav1.7, with EC50 of 6.8 nM and 1.76 μM, respectively. Neither Nav1.8 nor Nav1.9 was affected by the toxins. AaH II and Amm VIII reduced first spike latency and lowered action potential threshold. Amm VIII was less efficient than AaH II in increasing the gain of the firing frequency-stimulation relationship. In conclusion, our data show that Amm VIII, although less potent than AaH II, acts as a gating-modifier peptide reminiscent of classic α-toxins, and suggest that its hyperalgesic effects can be ascribed to gain-of-function of TTX-S Na(+) channels in nociceptors.

  1. Immunopathologic effects of scorpion venom on hepato-renal tissues: Involvement of lipid derived inflammatory mediators.

    PubMed

    Lamraoui, Amal; Adi-Bessalem, Sonia; Laraba-Djebari, Fatima

    2015-10-01

    Scorpion venoms are known to cause different inflammatory disorders through complex mechanisms in various tissues. In the study here, the involvement of phospholipase A2 (PLA2) and cyclo-oxygenase (COX)-derived metabolites in hepatic and renal inflammation responses were examined. Mice were envenomed with Androctonus australis hector scorpion venom in the absence or presence of inhibitors that can interfere with lipid inflammatory mediator synthesis, i.e., dexamethasone (PLA2 inhibitor), indomethacin (non-selective COX-1/COX-2 inhibitor), or celecoxib (selective COX-2 inhibitor). The inflammatory response was assessed by evaluating vascular permeability changes, inflammatory cell infiltration, oxidative/nitrosative stress marker levels, and by histologic and functional analyses of the liver and kidney. Results revealed that the venom alone induced an inflammatory response in this tissues marked by increased microvascular permeability and inflammatory cell infiltration, increases in levels of nitric oxide and lipid peroxidation, and decreases in antioxidant defense. Moreover, significant alterations in the histological architecture of these organs were associated with increased serum levels of some metabolic enzymes, as well as urea and uric acid. Pre-treatment of mice with dexamethasone led to significant decreases of the inflammatory disorders in the hepatic parenchyma; celecoxib pre-treatment seemed to be more effective against renal inflammation. Indomethacin pre-treatment only slightly reduced the inflammatory disorders in the tissues. These results suggest that the induced inflammation response in liver was mediated mainly by PLA2 activation, while the renal inflammatory process was mediated by prostaglandin formation by COX-2. These findings provide additional insight toward the understanding of activated pathways and related mechanisms involved in scorpion envenoming syndrome.

  2. Scorpion envenoming in the north of Mali (West Africa): epidemiological, clinical and therapeutic aspects.

    PubMed

    Dabo, A; Golou, G; Traoré, M S; Diarra, N; Goyffon, M; Doumbo, O

    2011-08-01

    Scorpion envenomation remains a poorly known problem in sub-Saharan Africa, particularly in Mali, where the incidence is high in Northern area of the country (Sahara desert). We conducted a prospective study in two district health centers, Kidal and Tessalit (North-east of Mali), to describe the epidemiological, clinical and therapeutic features of scorpion stings. This study consisted of an exhaustive follow-up from admission to discharge of all patients stung by scorpions. Of a total of 282 cases recorded during one year, 207 (73.4%) occurred in Kidal, and the remaining 75 (26.6%) took place in Tessalit. The annual incidence was significantly higher in Tessalit (437 cases/100,000 population/year) than in Kidal (243 cases/100,000 population/year) (p < 10⁻⁶). Two hundred two (71.6%) stings occurred inside human dwellings, 142 (50.4%) during sleeping/resting, especially in August. One hundred ninety-one (67.7%) were on the lower extremities. Nocturnal stings, 168 (59.6%), occurred more often than diurnal stings, 114 (40.4%). Most patients, 163 (57.8%), were admitted less than 1 h after being stung. Local pain at the sting site was the common primary complaint. However, moderate and severe clinical signs were significantly higher in children than in adults (p < 0.05). The death rate (3.9%) was higher in children (3.5%) than in adults (0.3%) (p = 8.10⁻⁶; RR = 0.90 [IC: 0.84-0.06]). Of the 22 scorpion species identified, 13 (59.1%) were Leiurus quinquestriiatus, 8 (36.4%) were Androctonus amoreuxi, and 1 (4.5%) specimen was Buthiscus bicalcaratus. From these species, L. quinquestriiatus and A. amoreuxi were responsible of stings. The medical treatment was only symptomatic, and one hundred twenty-eight (45.3%) patients received traditional remedies before seeking medical attention. Our findings suggest that scorpion stings are common in the north of Mali and are a significant threat to human health.

  3. Scorpion envenoming in the north of Mali (West Africa): epidemiological, clinical and therapeutic aspects.

    PubMed

    Dabo, A; Golou, G; Traoré, M S; Diarra, N; Goyffon, M; Doumbo, O

    2011-08-01

    Scorpion envenomation remains a poorly known problem in sub-Saharan Africa, particularly in Mali, where the incidence is high in Northern area of the country (Sahara desert). We conducted a prospective study in two district health centers, Kidal and Tessalit (North-east of Mali), to describe the epidemiological, clinical and therapeutic features of scorpion stings. This study consisted of an exhaustive follow-up from admission to discharge of all patients stung by scorpions. Of a total of 282 cases recorded during one year, 207 (73.4%) occurred in Kidal, and the remaining 75 (26.6%) took place in Tessalit. The annual incidence was significantly higher in Tessalit (437 cases/100,000 population/year) than in Kidal (243 cases/100,000 population/year) (p < 10⁻⁶). Two hundred two (71.6%) stings occurred inside human dwellings, 142 (50.4%) during sleeping/resting, especially in August. One hundred ninety-one (67.7%) were on the lower extremities. Nocturnal stings, 168 (59.6%), occurred more often than diurnal stings, 114 (40.4%). Most patients, 163 (57.8%), were admitted less than 1 h after being stung. Local pain at the sting site was the common primary complaint. However, moderate and severe clinical signs were significantly higher in children than in adults (p < 0.05). The death rate (3.9%) was higher in children (3.5%) than in adults (0.3%) (p = 8.10⁻⁶; RR = 0.90 [IC: 0.84-0.06]). Of the 22 scorpion species identified, 13 (59.1%) were Leiurus quinquestriiatus, 8 (36.4%) were Androctonus amoreuxi, and 1 (4.5%) specimen was Buthiscus bicalcaratus. From these species, L. quinquestriiatus and A. amoreuxi were responsible of stings. The medical treatment was only symptomatic, and one hundred twenty-eight (45.3%) patients received traditional remedies before seeking medical attention. Our findings suggest that scorpion stings are common in the north of Mali and are a significant threat to human health. PMID:21605586

  4. Immunomodulatory and protective properties of tacrolimus in experimental scorpion envenomation.

    PubMed

    Kabrine, M; Laraba-Djebari, F

    2014-01-01

    Involvement of imbalance between pro- and anti-inflammatory events has been reported in the developed pathogenesis after scorpion envenomation. The immunosuppressive and anti-inflammatory properties of tacrolimus (FK-506) have been investigated: i) to better understand evolution of signaling pathways which are involved in the immune system ii) to reduce observed clinical signs while keeping a balance between pro- and anti-inflammatory cytokines. Naval Medical Research Institute (NMRI) mice received tacrolimus (1 mg/kg every 12 hours per os) for 21 days before envenomation with a sublethal dose (10 microg/20 g body weight) of Androctonus australis hector venom (Aah). Cell migration, pulmonary edema, exudation, Myeloperoxydase (MPO), Eosinophil peroxydase (EPO), C-reactive protein (CRP), C3, Creatine phosphokinase (CPK), aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), and hyperglycemia were analyzed 30 min, 3 and 24 hours after injection of Aah venom. Histological analysis of lung parenchyma was undertaken 24 hours after envenomation. Aah lethality was evaluated on mice with or without pretreatment with tacrolimus. (Fab’)2 fragments (40 mg/kg) were also used as specific treatment in all protocols. Tacrolimus significantly inhibited cell migration, pulmonary edema, exudation, CRP and hyperglycemia. It also decreased MPO and EPO activities and prevented tissue damage in lung tissue, balancing seric parameter levels (CPK, ASAT and ALAT). The pretreated animals seemed to be protected by this macrolide against the venom lethality. These findings suggest that the overactivation of the immune system is one of the causes involved in the aggravation of the pathophysiological effects induced after envenomation. The obtained results showed that the use of F(ab’)2 fragments as specific treatment cannot reduce the induced inflammatory response. PMID:24674680

  5. Pre-clinical studies of toxin-specific Nanobodies: Evidence of in vivo efficacy to prevent fatal disturbances provoked by scorpion envenoming

    SciTech Connect

    Hmila, Issam; Cosyns, Bernard; Tounsi, Hayfa; Roosens, Bram; Caveliers, Vicky; Abderrazek, Rahma Ben; Boubaker, Samir; Muyldermans, Serge; El Ayeb, Mohamed; Bouhaouala-Zahar, Balkiss; Lahoutte, Tony

    2012-10-15

    Scorpions represent a significant threat to humans and animals in various countries throughout the world. Recently, we introduced Nanobodies (Nbs) to combat more efficiently scorpion envenoming and demonstrated the performance of NbAahIF12 and NbAahII10 to neutralize scorpion toxins of Androctonus australis hector venom. A bispecific Nb construct (NbF12-10) comprising these two Nbs is far more protective than the classic Fab′{sub 2} based therapy and is the most efficient antivenom therapy against scorpion sting in preclinical studies. Now we investigate the biodistribution and pharmacokinetics of {sup 99m}Tc labeled Nbs by in vivo imaging in rodents and compared these data with those of the Fab′{sub 2} product (PAS). The pharmacodynamics of the Nbs was investigated in rats by in vivo echocardiography and it is shown that NbF12-10 prevents effectively the hemodynamic disturbances induced by a lethal dose of venom. Moreover, even a late injection of NbF12-10 restores the heart rate and brings the blood pressure to baseline values. Histology confirms that NbF12-10 prevents lung and heart lesions of treated mice after envenoming. In conjunction, in this preclinical study, we provide proof of concept that NbF12-10 prevents effectively the fatal disturbances induced by Androctonus venom, and that the Nanobody based therapeutic has a potential to substitute the classic Fab′{sub 2} based product as immunotherapeutic in scorpion envenoming. Further clinical study using larger cohorts of animals should be considered to confirm the full protecting potential of our NbF12-10. -- Highlights: ► Nanobody therapy prevents the hemodynamic disturbances induced by a lethal dose. ► Late injection of Nanobody restores hemodynamic parameters to baseline values. ► Nanobody therapy prevents lung and heart lesions of treated mice after envenoming. ► Labeled Nanobody and Fab’2 pharmacokinetics curves reach plateau in favour of Nanobody.

  6. Clinical update on scorpion envenoming.

    PubMed

    Cupo, Palmira

    2015-01-01

    Scorpion stings are currently the leading cause of venom-related injury to humans in Brazil and are a significant public health problem globally. Only scorpions of the Tityus genus are of medical importance in Brazil, and Tityus serrulatus is responsible for the most serious envenomations and deaths. The toxic effects of scorpion envenomation are due to a massive release of sympathetic and parasympathetic neurotransmitters; the severity is related to cardiac and hemodynamic changes, with cardiogenic shock and pulmonary edema contributing to the main causes of death. The pathophysiology of cardiac involvement has been discussed for decades and has been attributed to adrenergic discharge and a possible toxic effect of venom on the myocardium, while acute pulmonary edema may have a cardiogenic and/or non-cardiogenic origin. Currently, the clinical data point to catecholamine excess as the cause for reversible scorpion cardiomyopathy . These data include electrocardiographic changes, profiling of cardiac enzymes and troponin I, echocardiographic data with global or regional left ventricle dysfunction, and myocardial perfusion alterations compatible with spasm in the coronary microcirculation. Furthermore, recent data on cardiac magnetic resonance imaging findings, which are similar to those observed for stress-induced cardiomyopathy, have also been linked to catecholamine excess. The efficiency of antivenom serum treatment is controversial in the literature. Our experience in Brazil is that the management of patients with systemic manifestations of scorpion stings is based on three approaches, all of which are extremely important. These include symptomatic treatment, antivenom serum, and cardiorespiratory support. PMID:26676487

  7. SCORPION II persistent surveillance system update

    NASA Astrophysics Data System (ADS)

    Coster, Michael; Hunt, Cassandra

    2011-06-01

    This paper highlights the most recently added features and benefits available in the latest generation of Northrop Grumman SCORPION II persistent surveillance and target recognition systems. By leveraging smaller, lighter, and more power efficient SCORPION II sensor and universal gateway components, with foliage penetrating ad-hoc network communications, persistent field programmable systems that are easier to conceal can be optimized for both image capture and data exfiltration. In addition to the SCORPION II suite of sensor components, a growing list of over sixty different sensor and camera types from a variety of manufacturers have been integrated with the SCORPION Gateway family. In addition to updating several different COP systems, SCORPION and SCORPION II data can be directly processed using a common sensor status graphical user interface (GUI) that allows for viewing and analysis of images and sensor data from hundreds of SCORPION system gateways on single or multiple displays.

  8. History of study, updated checklist, distribution and key of scorpions (Arachnida: Scorpiones) from China.

    PubMed

    Di, Zhi-Yong; Yang, Zi-Zhong; Yin, Shi-Jin; Cao, Zhi-Jian; Li, Wen-Xin

    2014-01-01

    This review describes the history of taxonomic research on scorpions and provides an updated checklist and key of the scorpions currently known in China. This checklist is based on a thorough review of the extant literatures on scorpion species whose presence has been confirmed in China through field expeditions and examination of scorpion collections, excepting a few members that have no clear distribution or are currently in doubt. Totally, the scorpion fauna of China consists of 53 species and subspecies belonging to 12 genera crossing five families, with 33 species (62.3%) and one genus being recorded as endemic. Additionally, identification key and the distribution of scorpions from China are provided.

  9. Effect of cytokine antibodies in the immunomodulation of inflammatory response and metabolic disorders induced by scorpion venom.

    PubMed

    Taibi-Djennah, Zahida; Laraba-Djebari, Fatima

    2015-07-01

    Androctonus australis hector (Aah) venom and its neurotoxins may affect the neuro-endocrine immunological axis due to their binding to ionic channels of axonal membranes. This binding leads to the release of neurotransmitters and immunological mediators accompanied by pathophysiological effects. Although the hyperglycemia induced by scorpion venom is clearly established, the involved mediators in these deregulations are unknown. The strong relationship between inflammation and the wide variety of physiological processes can suggest that the activation of the inflammatory response and the massive release of IL-6 and TNF-α release induced by the venom may induce hyperglycemia and various biological disorders. We therefore investigated in this study the contribution of IL-6 and TNF-α in the modulation of inflammatory response and metabolic disorder induced by Aah venom. Obtained results revealed that Aah venom induced inflammatory response characterized by significant increase of inflammatory cells in sera and tissues homogenates accompanied by hyperglycemia and hyperinsulinemia, suggesting that the venom induced insulin resistance. It also induced severe alterations in hepatic parenchyma associated to metabolic disorders and imbalanced redox status. Cytokine antagonists injected 30 min prior to Aah venom allowed a significant reduction of inflammatory biomarker and plasma glucose levels, they also prevented metabolic disorders, oxidative stress and hepatic tissue damage induced by Aah venom. In conclusion, IL-6 and TNF-α appear to play a crucial role in the inflammatory response, hyperglycemia and associated complications to glucose metabolism disorders (carbohydrate and fat metabolism disorders, oxidative stress and hepatic damage) observed following scorpion envenoming.

  10. Anemomenotatic orientation in beetles and scorpions

    NASA Technical Reports Server (NTRS)

    Linsenmair, K. E.

    1972-01-01

    Orientation, by beetles and scorpions, according to wind direction and force are analyzed. Major efforts were made to determine: (1) which physical qualities of the air current influence anemomenotaxis, (2) which physiological mechanism is responsible for such orientation, (3) which sense organs do beetles and scorpions use to perceive wind directions, and (4) what the biological significance of anemomenotaxis in the beetle and scorpion is. Experimental results show that the trichobothria in scorpions perceives wind direction; in the beetle it is perceived by sense organs excited by pendicellus-flagellum joint movements. A compensation mechanism is suggested as the basis for anemomenotactic orientation. It was also suggested that the biological significance of anemomenotaxis in scorpions is space orientation; while in beetles it was found to be part of the appetitive behavior used to search for olfactory sign stimuli.

  11. Scorpion antivenom effect of micropropagated Aristolochia elegans.

    PubMed

    Izquierdo, Alejandro Mora; Zapata, Elsa Ventura; Jiménez-Ferrer, J Enrique; Muñoz, Crescencio Bazaldúa; Aparicio, Antonio Jiménez; Torres, Kalina Bermúdez; Torres, Lidia Osuna

    2010-08-01

    Aristolochia elegans Mast. (Aristolochiaceae) has been used to treat scorpion envenoming in Mexican traditional medicine. In vitro studies of the pharmacological activity of raw extracts from A. elegans roots have shown activity against scorpion bite. The aim of the present study was to determine for the first time the antagonistic effect of hexane and methanol extracts of the aerial parts and roots from micropropagated A. elegans plants in a model of isolated guinea-pig ileum contracted by scorpion bite. Results showed that the methanol extracts of aerial organs (74%) and roots (65%) of micropropagated plants have a similar antitoxin activity against scorpion poisoning to hexane extracts of wild plants (65%). These results suggest that using methanol extracts from the micropropagated plant material instead of wild plant root extracts from A. elegans is an alternative for treatment against scorpion bite symptoms, and will contribute to the conservation of this medicinal species.

  12. Serotonin-immunoreactive neurons in scorpion pectine neuropils: similarities to insect and crustacean primary olfactory centres?

    PubMed

    Wolf, Harald; Harzsch, Steffen

    2012-06-01

    The pectines of scorpions are a single pair of mechano- and chemosensory appendages located ventrally behind the most posterior pair of walking legs. They are used for probing the substrate in behaviours such as prey tracking and courtship. The sensory afferents on the pectines supply large segmental neuropils with a conspicuous glomerular structure. The pectine neuropils thus bear similarities to insect and crustacean deutocerebral chemosensory centres associated with the antennae, but they also possess idiosyncratic features. One characteristic property of many insect and decapod crustacean olfactory neuropils is their innervation by single, or very few, large serotonergic (inter-) neurons. This feature, among others, has been proposed to support homology of the olfactory lobes in the two arthropod groups. A possible serotonergic innervation of the scorpion pectine neuropils has not yet been studied, despite its apparent diagnostic and functional importance. We thus examined serotonin-immunoreactivity in the pectine neuropils of Androctonus australis and Pandinus imperator. Both scorpion species yielded similar results. The periphery of the neuropil and the matrix between the glomeruli are supplied by a dense network of serotonin-immunoreactive (5-HT-ir) arborisations and varicosities, while the glomeruli themselves are mostly free of 5-HT-ir fibres. The 5-HT-ir supply of the pectine neuropils has two origins. The first is a pair of neurons on each body side, up to 30 μm in diameter and thus slightly larger than the surrounding somata. These cell bodies are and associated with the neuromeres of the genital and pectine segments. The situation is reminiscent of the 5-HT supply of insect and crustacean olfactory and antennal neuropils. The second 5-HT innervation of the pectine neuropils is from a group of some 10-20 ipsilateral neuronal somata of slightly smaller size (15-20 μm). These are part of a much larger 5-HT-ir group comprising 70-90 somata. The whole

  13. Anaphylaxis to scorpion antivenin and its management following envenomation by Indian red scorpion, Mesobuthus tamulus.

    PubMed

    Bhoite, Rahul Ramesh; Bhoite, Girija Ramesh; Bagdure, Dayanand N; Bawaskar, Himmatrao S

    2015-09-01

    Mesobuthus tamulus is an Indian red scorpion that is responsible for numerous cases of scorpion stings in the Indian subcontinent. Antivenin, vasodilators, and benzodiazepines are medications of choice in the treatment of scorpion bites. Adverse reactions such as anaphylaxis to antivenin have been infrequently described in the literature. We, herein, present a case of a 42-year-old man stung by Indian red scorpion while gardening at home in India, who presented with extreme pain at the sting site and signs of cardio-toxicity. He was treated with scorpion antivenin and vasodilators but developed anaphylaxis to antivenin. We discuss management strategies. Anaphylaxis to antivenin should be on the differential during management of scorpion bites because classical signs of anaphylaxis may be absent. PMID:26430342

  14. History of study, updated checklist, distribution and key of scorpions (Arachnida: Scorpiones) from China

    PubMed Central

    DI, Zhi-Yong; YANG, Zi-Zhong; YIN, Shi-Jin; CAO, Zhi-Jian; LI, Wen-Xin

    2014-01-01

    This review describes the history of taxonomic research on scorpions and provides an updated checklist and key of the scorpions currently known in China. This checklist is based on a thorough review of the extant literatures on scorpion species whose presence has been confirmed in China through field expeditions and examination of scorpion collections, excepting a few members that have no clear distribution or are currently in doubt. Totally, the scorpion fauna of China consists of 53 species and subspecies belonging to 12 genera crossing five families, with 33 species (62.3%) and one genus being recorded as endemic. Additionally, identification key and the distribution of scorpions from China are provided. PMID:24470450

  15. Use of antibodies specific to defined regions of scorpion. cap alpha. -toxin to study its interaction with its receptor site on the sodium channel

    SciTech Connect

    Ayeb, M.E.; Bahraoui, E.M.; Granier, C.; Rochat, H.

    1986-10-21

    Five antibody populations selected by immunoaffinity chromatography for the specificity toward various regions of toxin II of the scorpion Androctonus australis Hector were used to probe the interaction of this protein with its receptor site on the sodium channel. These studies indicate that two antigenic sites, one located around the disulfide bridge 12-63 and one encompassing residues 50-59, are involved in the molecular mechanisms of toxicity neutralization. Fab fragments specific to the region around disulfide bridge 12-63 inhibit binding of the /sup 125/I-labeled toxin to its receptor site. Also, these two antigenic regions are inaccessible to the antibodies when the toxin is bound to its receptor site. In contrast, the two other antigenic sites encompassing the only ..cap alpha..-helix region (residues 23-32) and a ..beta..-turn structure (residues 32-35) are accessible to the respective antibodies when the toxin is bound to its receptor. Together, these data support the recent proposal that a region made of residues that are conserved in the scorpion toxin family is involved in the binding of the toxin to the receptor.

  16. Development and characterization of a new carrier for vaccine delivery based on calcium-alginate nanoparticles: Safe immunoprotective approach against scorpion envenoming.

    PubMed

    Nait Mohamed, Faez Amokrane; Laraba-Djebari, Fatima

    2016-05-23

    To enhance humoral defense against diseases, vaccine formulation is routinely prepared to improve immune response. Studies in nanomaterials as a carrier of vaccine delivery are promising and interesting. In this study, attenuated Androctonus australis hector (Aah) venom and its toxic fraction were encapsulated into different formulations inside calcium-alginate nanoparticles (Ca-Alg Nps), and used as a vaccine delivery system against scorpion envenomation. Ca-Alg Nps were prepared by ionic gelation and characterized. An immunization schedule was undertaken in rabbits in order to study how Aah venom entrapped in Ca-Alg Nps might induce protective immunity. Results showed the influence of different parameters on the suitable nanoparticle formation. They also showed no toxicity of free Ca-Alg Nps and a different inflammatory profile depending on the nanovaccine formulations. More interestingly, evaluation of specific IgG titer and IgG1/IgG2a isotype balance revealed a protective effect with the nanoparticles encapsulating the attenuated antigens. Challenge up to 6 LD 50 of native venom, allowed to an important immunoprotection of all immunized rabbits, with no recorded death. Taken together and with respect to the properties of nanoparticles and high immunogenicity, calcium-alginate nanoparticles could be considered as a new promising adjuvant system and a vaccine delivery against scorpion envenomation. PMID:27109567

  17. Overview of scorpion species from China and their toxins.

    PubMed

    Cao, Zhijian; Di, Zhiyong; Wu, Yingliang; Li, Wenxin

    2014-02-26

    Scorpions are one of the most ancient groups of terrestrial animals. They have maintained a steady morphology over more than 400 million years of evolution. Their venom arsenals for capturing prey and defending against predators may play a critical role in their ancient and conservative appearance. In the current review, we present the scorpion fauna of China: 53 species covering five families and 12 genera. We also systematically list toxins or genes from Chinese scorpion species, involving eight species covering four families. Furthermore, we review the diverse functions of typical toxins from Chinese scorpion species, involving Na+ channel modulators, K+ channel blockers, antimicrobial peptides and protease inhibitors. Using scorpion species and their toxins from China as an example, we build the bridge between scorpion species and their toxins, which helps us to understand the molecular and functional diversity of scorpion venom arsenal, the dynamic and functional evolution of scorpion toxins, and the potential relationships of scorpion species and their toxins.

  18. North American snake and scorpion envenomations.

    PubMed

    Wilbeck, Jennifer; Gresham, Chip

    2013-06-01

    Envenomations by snakes and scorpions in North America, although uncommon, do occur, and the victims may seek medical treatment. Combined, snake and scorpion encounters result in more than 25,000 calls a year to poison centers. Although some similarities exist with respect to general signs of envenomation and treatment, specific nuances distinguish the medical care to be anticipated and therapies available. Regardless of geographic practice area, exposures will occur that may result in a significant envenomation. This article provides critical care nurses with fundamental knowledge of varied snake and scorpion envenomation presentations and treatments to assist in optimizing patient outcomes. PMID:23692937

  19. Characterization of unique amphipathic antimicrobial peptides from venom of the scorpion Pandinus imperator.

    PubMed Central

    Corzo, G; Escoubas, P; Villegas, E; Barnham, K J; He, W; Norton, R S; Nakajima, T

    2001-01-01

    Two novel antimicrobial peptides have been identified and characterized from venom of the African scorpion Pandinus imperator. The peptides, designated pandinin 1 and 2, are alpha-helical polycationic peptides, with pandinin 1 belonging to the group of antibacterial peptides previously described from scorpions, frogs and insects, and pandinin 2 to the group of short magainin-type helical peptides from frogs. Both peptides demonstrated high antimicrobial activity against a range of Gram-positive bacteria (2.4-5.2 microM), but were less active against Gram-negative bacteria (2.4-38.2 microM), and only pandinin 2 affected the yeast Candida albicans. Pandinin 2 also demonstrated strong haemolytic activity (11.1-44.5 microM) against sheep erythrocytes, in contrast with pandinin 1, which was not haemolytic. CD studies and a high-resolution structure of pandinin 2 determined by NMR, showed that the two peptides are both essentially helical, but differ in their overall structure. Pandinin 2 is composed of a single alpha-helix with a predominantly hydrophobic N-terminal sequence, whereas pandinin 1 consists of two distinct alpha-helices separated by a coil region of higher flexibility. This is the first report of magainin-type polycationic antimicrobial peptides in scorpion venom. Their presence brings new insights into the mode of action of scorpion venom and also opens new avenues for the discovery of novel antibiotic molecules from arthropod venoms. PMID:11563967

  20. The unfulfilled promises of scorpion insectotoxins.

    PubMed

    Ortiz, Ernesto; Possani, Lourival D

    2015-01-01

    Since the description and biochemical characterization of the first insect-specific neurotoxins from scorpion venoms, almost all contributions have highlighted their potential application as leads for the development of potent bioinsecticides. Their practical use, however, has been hindered by different factors, some of which are intrinsically related to the toxins and other external determinants. Recent developments in the understanding of the action mechanisms of the scorpion insectotoxins and their bioactive surfaces, coupled with the exploration of novel bioinsecticide delivery systems have renewed the expectations that the scorpion insectotoxins could find their way into commercial applications in agriculture, as part of integrated pest control strategies. Herein, we review the current arsenal of available scorpion neurotoxins with a degree of specificity for insects, the progress made with alternative delivery methods, and the drawbacks that still preclude their practical use. PMID:26085828

  1. Epidemiological Review of Scorpion Envenomation in Iran

    PubMed Central

    Jalali, Amir; Rahim, Fakher

    2014-01-01

    This epidemiological review was carried out to display the magnitude and the geographic distribution of scorpion envenomation in Iran with focus on the southwestern region of Iran, particularly. The Iranian recognized scorpions belonging to two families, including Buthidae and Scorpionidae. Buthidae family consists of 14 genuses, 26 species, and 18 sub-species, while Scorpionidae family has three genuses and four species. The lack of basic knowledge, including the geographical distribution, clinical manifestations, and specific treatments related to scorpiofauna justifies such multidisciplinary studies. The venom of two endemic Iranian scorpions, including Hemiscorpius lepturus (H. lepturus) and Odonthubuthus doriae (O.doriae) have considered as an effective source of new neurotoxin peptides for the further development of physio-pharmacological probes and designing the clinical trials. Such epidemiological information may improve the determinants of Iranian scorpion stings in order to plan and implement effective public health intervention. PMID:25276176

  2. Epidemiological review of scorpion envenomation in iran.

    PubMed

    Jalali, Amir; Rahim, Fakher

    2014-01-01

    This epidemiological review was carried out to display the magnitude and the geographic distribution of scorpion envenomation in Iran with focus on the southwestern region of Iran, particularly. The Iranian recognized scorpions belonging to two families, including Buthidae and Scorpionidae. Buthidae family consists of 14 genuses, 26 species, and 18 sub-species, while Scorpionidae family has three genuses and four species. The lack of basic knowledge, including the geographical distribution, clinical manifestations, and specific treatments related to scorpiofauna justifies such multidisciplinary studies. The venom of two endemic Iranian scorpions, including Hemiscorpius lepturus (H. lepturus) and Odonthubuthus doriae (O.doriae) have considered as an effective source of new neurotoxin peptides for the further development of physio-pharmacological probes and designing the clinical trials. Such epidemiological information may improve the determinants of Iranian scorpion stings in order to plan and implement effective public health intervention. PMID:25276176

  3. Toxicity of scorpion venom in chick embryo and mealworm assay depending on the use of the soluble fraction versus the whole venom.

    PubMed

    van der Valk, Tom; van der Meijden, Arie

    2014-09-01

    The LD50 is an important metric for venom studies and antivenom development. It has been shown that several variables in the protocol influence the LD50 value obtained, such as venom source, extraction and treatment and administration route. These inconsistencies reduce the utility of the results of these test for comparative studies. In scorpion venom LD50 assays, often only the soluble fraction of the venom is used, whereas other studies use the whole venom. We here tested the toxicity of the soluble fraction in isolation, and of the whole venom in two different systems: chick embryos and mealworms Tenebrio molitor. Ten microliters of venom solutions from Hadrurus arizonensis, Leiurus quinquestriatus, Androctonus australis, Grosphus grandidieri and Heterometrus laoticus were applied to five day old chicken embryos at stage 25-27. Our results showed no significant differences between the LD50 based on the whole venom versus that of only the soluble fraction and in the chicken embryo assay in four of the five scorpion species tested. H. laoticus however, showed a significantly lower LD50 value for the whole venom than the soluble fraction. In assays on mealworms however, this pattern was not seen. Nonetheless, caution may be warranted when using LD50 values obtained from only the soluble fraction. The LD50 values of the five species in this study, based on the chicken embryo assay, showed good correlation with values from the literature based on mouse studies. This suggests that the chick embryo assay may be an economic alternative to rodent assays for scorpion LD50 studies. PMID:24951875

  4. Notes on the scorpions (Arachnida, Scorpiones) from Xizang with the redescription of Scorpiops jendeki Kovařík, 2000 (Scorpiones, Euscorpiidae) from Yunnan (China)

    PubMed Central

    Di, Zhiyong; Xu, Xiaobo; Cao, Zhijian; Wu, Yingliang; Li, Wenxin

    2013-01-01

    Abstract Until now, there are 26 scorpion species of 7 genera of 5 families recorded in Xizang (China). Xizang Autonomous Region (Tibet) is the scorpion biodiversity richest area in China (53 scorpion species of 12 genera of 5 families), also the highest altitude habitat of scorpions in the world. We present information of type specimens, an identification key of the scorpion species from Xizang, the distribution, updated feature pictures, and discussion on the disputed species. The redescriptions of Scorpiops jendeki Kovařík, 2000 (Yunnan) and Scorpiops tibetanus Hirst, 1911 (Xizang), comments and feature figures of species of genus Scorpiops are provided for identification. PMID:23794894

  5. Determination of the Median Lethal Dose and Electrophoretic Pattern of Hottentotta saulcyi (Scorpiones, Buthidae) Scorpion Venom

    PubMed Central

    Yağmur, Ersen Aydın; Özkan, Özcan; Karaer, K Zafer

    2015-01-01

    Background: In this study, we investigated the lethal potency, electrophoretic protein pattern and in vivo effects of Hottentotta saulcyi scorpion venom in mice. Methods: Scorpions were collected at night, by using a UV lamp from Mardin Province, Turkey. Venom was obtained from mature H. saulcyi scorpions by electrical stimulation of the telson. The lethality of the venom was determined by i.v. injections using Swiss mice. In vivo effects of the venom were assessed by using the intraperitoneal route (ip) injections into mice (20±1g) and monitored for 24 h. The protein profiles of the scorpion venom were analyzed by NuPAGE® Novex® 4–12 % gradient Bis-Tris gel followed by Coomassie blue staining. Results: The lethal assay of the venom was 0.73 mg/kg in mice. We determined the electrophoretic protein pattern of this scorpion venom to be 4, 6, 9, 31, 35, 40, 46 and 69 kDa by SDS-PAGE. Analysis of electrophoresis indicated that H. saulcyi scorpion intoxicated mice exhibited autonomic nervous system symptoms (tachypnea, restlessness, hyperexcitability, convulsions, salivation, lacrimation, weakness). Conclusions: Hottentotta saulcyi scorpion venom includes short-chain neurotoxins and long-chain neurotoxins according to the electrophoretic protein patterns. The stings of H. saulcyi scorpion must be considered of risk for humans in the southeastern region, Turkey. PMID:26623435

  6. Study of severe scorpion envenoming following subcutaneous venom injection into dogs: Hemodynamic and concentration/effect analysis.

    PubMed

    Elatrous, Souheil; Ouanes-Besbes, Lamia; Ben Sik-Ali, Habiba; Hamouda, Zineb; BenAbdallah, Saoussen; Tilouche, Nejla; Jalloul, Faten; Fkih-Hassen, Mohamed; Dachraoui, Fahmi; Ouanes, Islem; Abroug, Fekri

    2015-09-15

    To evaluate the dose-effects of Androctonus australis hector (Aah) venom injected subcutaneously on hemodynamics and neurohormonal secretions, 10 anesthetized and ventilated mongrel dogs, were split in two groups (n = 5/group). Subcutaneous injection was done with either 0.2 mg/kg or 0.125 mg/kg of the purified G50 scorpion toxic fraction. Hemodynamic parameters using right heart catheter were recorded and plasma concentrations of catecholamine, troponin, and serum toxic fraction were measured sequentially from baseline to 120 min. We identified the dose of toxic fraction evoking characteristic hemodynamic perturbation of severe envenomation, the time-lapse to envenomation, and the associated plasma level. The injection of 0.125 mg/kg toxic fraction was not associated with significant variations in hemodynamic parameters, whereas the 0.2 mg/kg dose caused envenomation characterized by significant increase in plasma catecholamines, increased pulmonary artery occluded pressure, mean arterial pressure, and systemic vascular resistance (p < 0.05), in association with sustained decline in cardiac output (p < 0.001). Envenomation occurred by the 30th minute, and the corresponding concentration of toxic fraction was 1.14 ng/ml. The current experiment allowed the identification of the sub-lethal dose (0.2 mg/kg) of the toxic fraction of Aah administered by the subcutaneous route. Two parameters with potential clinical relevance were also uncovered: the time-lapse to envenomation and the corresponding concentration of toxic fraction.

  7. Study of severe scorpion envenoming following subcutaneous venom injection into dogs: Hemodynamic and concentration/effect analysis.

    PubMed

    Elatrous, Souheil; Ouanes-Besbes, Lamia; Ben Sik-Ali, Habiba; Hamouda, Zineb; BenAbdallah, Saoussen; Tilouche, Nejla; Jalloul, Faten; Fkih-Hassen, Mohamed; Dachraoui, Fahmi; Ouanes, Islem; Abroug, Fekri

    2015-09-15

    To evaluate the dose-effects of Androctonus australis hector (Aah) venom injected subcutaneously on hemodynamics and neurohormonal secretions, 10 anesthetized and ventilated mongrel dogs, were split in two groups (n = 5/group). Subcutaneous injection was done with either 0.2 mg/kg or 0.125 mg/kg of the purified G50 scorpion toxic fraction. Hemodynamic parameters using right heart catheter were recorded and plasma concentrations of catecholamine, troponin, and serum toxic fraction were measured sequentially from baseline to 120 min. We identified the dose of toxic fraction evoking characteristic hemodynamic perturbation of severe envenomation, the time-lapse to envenomation, and the associated plasma level. The injection of 0.125 mg/kg toxic fraction was not associated with significant variations in hemodynamic parameters, whereas the 0.2 mg/kg dose caused envenomation characterized by significant increase in plasma catecholamines, increased pulmonary artery occluded pressure, mean arterial pressure, and systemic vascular resistance (p < 0.05), in association with sustained decline in cardiac output (p < 0.001). Envenomation occurred by the 30th minute, and the corresponding concentration of toxic fraction was 1.14 ng/ml. The current experiment allowed the identification of the sub-lethal dose (0.2 mg/kg) of the toxic fraction of Aah administered by the subcutaneous route. Two parameters with potential clinical relevance were also uncovered: the time-lapse to envenomation and the corresponding concentration of toxic fraction. PMID:26166304

  8. Sustained Ventricular Tachycardia and Cardiogenic Shock due to Scorpion Envenomation.

    PubMed

    Miranda, Carlos Henrique; Maio, Karina Tozatto; Moreira, Henrique Turin; Moraes, Marcos; Custodio, Viviane Imaculada do Carmo; Pazin-Filho, Antonio; Cupo, Palmira

    2014-01-01

    We describe a case of severe scorpion envenomation in an adult patient, with the presence of very rapid sustained ventricular tachycardia followed by cardiogenic shock, which was reversed by scorpion antivenom administration. Scorpion venom causes cardiac changes that can lead to an environment favoring arrhythmogenesis. PMID:24715906

  9. Beneficial effects of Androctonus australis hector venom and its non-toxic fraction in the restoration of early hepatocyte-carcinogenesis induced by FB1 mycotoxin: Involvement of oxidative biomarkers.

    PubMed

    Nadjia, Bekkari; Fatima, Laraba-Djebari

    2015-10-01

    Some venom components are known to present potential biological activities that are useful as tools in therapeutics. In this study anti-tumoral activity of Androctonus australis hector (Aah) venom and its purified fraction on early step of hepato-carcinogenesis initiated by Fumonisin (FB1), was tested. Initiated hepatic tumor was assessed in mice by decreased doses of Fumonisin B1 associated to phenobarbital. Scorpion venom was used to investigate its activity on initiated tumor by FB1. Evaluation of oxidative unbalance, enzymatic activities and DNA quantification in the liver were correlated with tissue analysis. Obtained results showed that the initiated pathogenesis by FB1 at seven months was characterized by tissue alterations and biomarker variations. These alterations were characterized by atypical lesions such as muffled nucleus, karyo- and cyto-megaly; up normal and large number of nuclei into hepatocytes. These alterations were confirmed by DNA alteration. An unbalance of oxidative status was also observed, characterized by an increased levels of respectively oxidant (NO and MDA) and antioxidant (GSH and catalase activity) mediators. Aah venom and its non-toxic fraction used at low doses seemed to be able to restore partially the hepatic altered tissue induced by FB1. Decreased levels of oxidative and anti-oxidative mediators were also observed. DNA in hepatocytes returned also to the physiological values. Structure of hepatic tissue showed restoration of some alterations such as karyo- and cyto-megaly; decrease of polyploidy hepatocytes induced by FB1. Aah venom and its non-toxic fraction seem to contain some bioactive components with anti-tumoral activity. Purification of this activity from non-toxic fraction F1 could be of interest to identify the components with anti-tumoral activities. PMID:26142225

  10. Ab initio structure determination and refinement of a scorpion protein toxin.

    PubMed

    Smith, G D; Blessing, R H; Ealick, S E; Fontecilla-Camps, J C; Hauptman, H A; Housset, D; Langs, D A; Miller, R

    1997-09-01

    The structure of toxin II from the scorpion Androctonus australis Hector has been determined ab initio by direct methods using SnB at 0.96 A resolution. For the purpose of this structure redetermination, undertaken as a test of the minimal function and the SnB program, the identity and sequence of the protein was withheld from part of the research team. A single solution obtained from 1 619 random atom trials was clearly revealed by the bimodal distribution of the final value of the minimal function associated with each individual trial. Five peptide fragments were identified from a conservative analysis of the initial E-map, and following several refinement cycles with X-PLOR, a model was built of the complete structure. At the end of the X-PLOR refinement, the sequence was compared with the published sequence and 57 of the 64 residues had been correctly identified. Two errors in sequence resulted from side chains with similar size while the rest of the errors were a result of severe disorder or high thermal motion in the side chains. Given the amino-acid sequence, it is estimated that the initial E-map could have produced a model containing 99% of all main-chain and 81% of side-chain atoms. The structure refinement was completed with PROFFT, including the contributions of protein H atoms, and converged at a residual of 0.158 for 30 609 data with F >or= 2sigma(F) in the resolution range 8.0-0.964 A. The final model consisted of 518 non-H protein atoms (36 disordered), 407 H atoms, and 129 water molecules (43 with occupancies less than unity). This total of 647 non-H atoms represents the largest light-atom structure solved to date.

  11. Optical properties of a scorpion (Centruroides limpidus)

    NASA Astrophysics Data System (ADS)

    Ullrich, Bruno; Duckworth, Robyn M.; Singh, Akhilesh K.; Barik, Puspendu; Mejía-Villanueva, Vicente O.; Garcia-Pérez, Alberto C.

    2016-04-01

    Scorpions, elusive by nature, tend to appear nocturnally and are usually not appreciated when encountered. The exoskeleton is capable of fluorescing allowing for their detection at night in order to prevent undesirable encounters. The specificity of their fluorescing suggests specialized optical features. However, despite the blue-green fluorescence, to the best of our knowledge, no further results have been published on the optical properties of scorpions. Their exoskeletal structure whose versatility provides them protection, camouflage, and flexibility has not been studied under laser excitation and monochromatic light. The experiments reveal the nonlinear optical properties, infrared photoluminescence, and photoconductivity of the epicuticle of scorpions, demonstrating that the scorpion’s outer-covering is a prototype of a semiconducting inherently integrated multifunctional polymeric film with appealing potential applications such as optical logics, photonic frequency converters, novel multiplexers handling electronic and photonic inputs, and lasers.

  12. [The threat of snake and scorpion venoms].

    PubMed

    Płusa, Tadeusz; Smędzik, Katarzyna

    2015-09-01

    Venoms of snakes and scorpions pose a significant threat to the health and life of humans. The speed and range of their actions causes damage of the organ responsible for the maintenance of vital signs. Venomous snake venoms cause blood clotting disorders, tissue necrosis and hemolysis, and the release of a number of proinflammatory cytokines and impair antibody synthesis. Availability of antitoxins is limited and in the most cases supportive treatment is recommended. In turn, the venom of scorpions beside intestinal symptoms cause significant impairment of neuromuscular conduction, causing severe respiratory disorders. Action venom poses a particular threat to sensitive patients. The degree of threat to life caused by the venom of snakes and scorpions authorizes the treatment of these substances as a potential biological weapon. PMID:26449581

  13. Assessing and managing spider and scorpion envenomation.

    PubMed

    McGhee, Stephen; Weiner, Aaron; Finnegan, Alan; Visovsky, Constance; Clochesy, John M; Graves, Brian

    2015-11-01

    Envenomation by spiders or scorpions is a public health problem in many parts of the world and is not isolated to the tropics and subtropics. Spiders and scorpions can be unintentionally transported globally, and keeping them as pets is becoming more popular, so envenomation can occur anywhere. Emergency nurses should be prepared to assess and treat patients who present with a bite or sting. This article gives an overview of the signs, symptoms and treatment of envenomation by species of arachnids that are clinically significant to humans.

  14. Assessing and managing spider and scorpion envenomation.

    PubMed

    McGhee, Stephen; Weiner, Aaron; Finnegan, Alan; Visovsky, Constance; Clochesy, John M; Graves, Brian

    2015-11-01

    Envenomation by spiders or scorpions is a public health problem in many parts of the world and is not isolated to the tropics and subtropics. Spiders and scorpions can be unintentionally transported globally, and keeping them as pets is becoming more popular, so envenomation can occur anywhere. Emergency nurses should be prepared to assess and treat patients who present with a bite or sting. This article gives an overview of the signs, symptoms and treatment of envenomation by species of arachnids that are clinically significant to humans. PMID:26542925

  15. Pseudouroctonus maidu, a new species of scorpion from northern California (Scorpiones, Vaejovidae)

    PubMed Central

    Savary, Warren E.; Bryson Jr., Robert W.

    2016-01-01

    Abstract A new species of vaejovid scorpion from northern California, Pseudouroctonus maidu sp. n., is named and described. This new species appears to be most similar to Pseudouroctonus iviei (Gertsch & Soleglad, 1972) and Pseudouroctonus glimmei (Hjelle, 1972). PMID:27199594

  16. Pseudouroctonus maidu, a new species of scorpion from northern California (Scorpiones, Vaejovidae).

    PubMed

    Savary, Warren E; Bryson, Robert W

    2016-01-01

    A new species of vaejovid scorpion from northern California, Pseudouroctonus maidu sp. n., is named and described. This new species appears to be most similar to Pseudouroctonus iviei (Gertsch & Soleglad, 1972) and Pseudouroctonus glimmei (Hjelle, 1972). PMID:27199594

  17. Autoradiographic localization of voltage-dependent sodium channels on the mouse neuromuscular junction using /sup 125/I-alpha scorpion toxin. I. Preferential labeling of glial cells on the presynaptic side

    SciTech Connect

    Boudier, J.L.; Jover, E.; Cau, P.

    1988-05-01

    Alpha-scorpion toxins bind specifically to the voltage-sensitive sodium channel in excitable membranes, and binding is potential-dependent. The radioiodinated toxin II from the scorpion Androctonus australis Hector (alpha ScTx) was used to localize voltage-sensitive sodium channels on the presynaptic side of mouse neuromuscular junctions (NMJ) by autoradiography using both light and electron microscopy. Silver grain localization was analyzed by the cross-fire method. At the light-microscopic level, grain density over NMJ appeared 6-8x higher than over nonjunctional muscle membrane. The specificity of labeling was verified by competition/displacement with an excess of native alpha ScTx. Labeling was also inhibited by incubation in depolarizing conditions, showing its potential-dependence. At the electron-microscopic level, analysis showed that voltage-sensitive sodium channels labeled with alpha ScTx were almost exclusively localized on membranes, as expected. Due to washout after incubation, appreciable numbers of binding sites were not found on the postsynaptic membranes. However, on the presynaptic side, alpha ScTx-labeled voltage-sensitive sodium channels were localized on the membrane of non-myelin-forming Schwann cells covering NMJ. The axonal presynaptic membrane was not labeled. These results show that voltage-sensitive sodium channels are present on glial cells in vivo, as already demonstrated in vitro. It is proposed that these glial channels could be indirectly involved in the ionic homeostasis of the axonal environment.

  18. Scorpionism due to Tityus neoespartanus (Scorpiones, Buthidae) in Margarita Island, northeastern Venezuela.

    PubMed

    De Sousa, Leonardo; Boadas, Jenny; Kiriakos, Demetrio; Borges, Adolfo; Boadas, Jesús; Marcano, Jenny; Turkali, Iván; De Los Ríos, Miguel

    2007-01-01

    The first two cases of scorpion envenoming caused by Tityus neoespartanus (Buthidae) are described. The accidents took place within human environments (one inside a home and the other inside a school), in the village of La Sierra, Margarita Island, State of Nueva Esparta, northeastern Venezuela. Both cases were moderately severe and developed pancreatic involvement and electrocardiographic abnormalities. This report allows inclusion of Margarita Island among the endemic areas of scorpionism in Venezuela. PMID:18200425

  19. Activity trends and movement distances in the Arizona bark scorpion (Scorpiones: Buthidae).

    PubMed

    Bibbs, Christopher Stephen; Bengston, Sarah Elizabeth; Gouge, Dawn Heather

    2014-12-01

    The bark scorpion, Centruroides sculpturatus Ewing, is a nocturnal, cryptic, nonburrowing, mobile species that is common in urban landscapes spanning the desert southwest. Bark scorpions are often found in dense localized populations in cities, but the question of whether this is because the species is metabolically movement limited or choose to aggregate has not been addressed. Field observations lead us to believe that the scorpions move very little. Their ability to move is tested here. A circular pacing ring was constructed to observe the distance individuals could move in 2 h under both dark and light conditions. Observations under light motivate the arthropods to move, and significantly greater distances were observed in light trials, the maximum travel distance being 104.37 m, while the maximum distance in dark trials was 14.63 m. To monitor movement in the field, telemetry tags were used to mark female and male scorpions over 21 d during which relocation distances were recorded daily. Additionally, 12-h and 6-h overnight observational periods took place during which, scorpion movements were recorded hourly. Overall, it was found that scorpions moved significantly more in the pacing ring than in the field, indicating that field individuals are not moving at their maximum potential. Movement limitation does not explain their distribution pattern. In both the pacing ring and field, gender and pregnancy status had significant influence on distances moved. We conclude that C. sculpturatus is capable of much greater movement than is typically observed in the field.

  20. Target-Driven Evolution of Scorpion Toxins

    PubMed Central

    Zhang, Shangfei; Gao, Bin; Zhu, Shunyi

    2015-01-01

    It is long known that peptide neurotoxins derived from a diversity of venomous animals evolve by positive selection following gene duplication, yet a force that drives their adaptive evolution remains a mystery. By using maximum-likelihood models of codon substitution, we analyzed molecular adaptation in scorpion sodium channel toxins from a specific species and found ten positively selected sites, six of which are located at the core-domain of scorpion α-toxins, a region known to interact with two adjacent loops in the voltage-sensor domain (DIV) of sodium channels, as validated by our newly constructed computational model of toxin-channel complex. Despite the lack of positive selection signals in these two loops, they accumulated extensive sequence variations by relaxed purifying selection in prey and predators of scorpions. The evolutionary variability in the toxin-bound regions of sodium channels indicates that accelerated substitutions in the multigene family of scorpion toxins is a consequence of dealing with the target diversity. This work presents an example of atypical co-evolution between animal toxins and their molecular targets, in which toxins suffered from more prominent selective pressure from the channels of their competitors. Our discovery helps explain the evolutionary rationality of gene duplication of toxins in a specific venomous species. PMID:26444071

  1. Target-Driven Evolution of Scorpion Toxins.

    PubMed

    Zhang, Shangfei; Gao, Bin; Zhu, Shunyi

    2015-10-07

    It is long known that peptide neurotoxins derived from a diversity of venomous animals evolve by positive selection following gene duplication, yet a force that drives their adaptive evolution remains a mystery. By using maximum-likelihood models of codon substitution, we analyzed molecular adaptation in scorpion sodium channel toxins from a specific species and found ten positively selected sites, six of which are located at the core-domain of scorpion α-toxins, a region known to interact with two adjacent loops in the voltage-sensor domain (DIV) of sodium channels, as validated by our newly constructed computational model of toxin-channel complex. Despite the lack of positive selection signals in these two loops, they accumulated extensive sequence variations by relaxed purifying selection in prey and predators of scorpions. The evolutionary variability in the toxin-bound regions of sodium channels indicates that accelerated substitutions in the multigene family of scorpion toxins is a consequence of dealing with the target diversity. This work presents an example of atypical co-evolution between animal toxins and their molecular targets, in which toxins suffered from more prominent selective pressure from the channels of their competitors. Our discovery helps explain the evolutionary rationality of gene duplication of toxins in a specific venomous species.

  2. [Management of scorpion sting in Morocco].

    PubMed

    Bencheikh, R Soulaymani; Khattabi, A; Faraj, Z; Semlali, I

    2008-04-01

    Scorpion stings are the first cause of poisoning, and represent between 30 and 50% of all cases reported to the Moroccan Poison Control Centre. Concerned by the size of the problem, we have paid special attention to this pathology. Through retrospective and prospective studies, it has been possible to determine the nature and the chronology of clinical stages, as well as the epidemiological, clinical and therapeutic factors of gravity. On this basis, we worked out a new management to provide support for patients. This management will standardize support provided at the national level, and will reduce the number of lethal case and rationalize spending by reviewing medication, transfer of patients and hospital care. This standardization is an essential component of the national strategy against scorpion poisoning. Other components include training of medical staff, awareness campaigns, and information systems to monitor lethal cases. A survey over five years shows a reduction in the number of lethal cases and rationalization of costs. Medical care provided rests upon the distinction between patients stung by scorpions and patients actually poisoned. The first category of patients will be monitored up to four hours after the scorpion sting, while poisoned patients will be transferred to an intensive care unit.

  3. Scorpions from Mexico: From Species Diversity to Venom Complexity.

    PubMed

    Santibáñez-López, Carlos E; Francke, Oscar F; Ureta, Carolina; Possani, Lourival D

    2015-12-24

    Scorpions are among the oldest terrestrial arthropods, which are distributed worldwide, except for Antarctica and some Pacific islands. Scorpion envenomation represents a public health problem in several parts of the world. Mexico harbors the highest diversity of scorpions in the world, including some of the world's medically important scorpion species. The systematics and diversity of Mexican scorpion fauna has not been revised in the past decade; and due to recent and exhaustive collection efforts as part of different ongoing major revisionary systematic projects, our understanding of this diversity has changed compared with previous assessments. Given the presence of several medically important scorpion species, the study of their venom in the country is also important. In the present contribution, the diversity of scorpion species in Mexico is revised and updated based on several new systematic contributions; 281 different species are recorded. Commentaries on recent venomic, ecological and behavioral studies of Mexican scorpions are also provided. A list containing the most important peptides identified from 16 different species is included. A graphical representation of the different types of components found in these venoms is also revised. A map with hotspots showing the current knowledge on scorpion distribution and areas explored in Mexico is also provided.

  4. Scorpions from Mexico: From Species Diversity to Venom Complexity.

    PubMed

    Santibáñez-López, Carlos E; Francke, Oscar F; Ureta, Carolina; Possani, Lourival D

    2016-01-01

    Scorpions are among the oldest terrestrial arthropods, which are distributed worldwide, except for Antarctica and some Pacific islands. Scorpion envenomation represents a public health problem in several parts of the world. Mexico harbors the highest diversity of scorpions in the world, including some of the world's medically important scorpion species. The systematics and diversity of Mexican scorpion fauna has not been revised in the past decade; and due to recent and exhaustive collection efforts as part of different ongoing major revisionary systematic projects, our understanding of this diversity has changed compared with previous assessments. Given the presence of several medically important scorpion species, the study of their venom in the country is also important. In the present contribution, the diversity of scorpion species in Mexico is revised and updated based on several new systematic contributions; 281 different species are recorded. Commentaries on recent venomic, ecological and behavioral studies of Mexican scorpions are also provided. A list containing the most important peptides identified from 16 different species is included. A graphical representation of the different types of components found in these venoms is also revised. A map with hotspots showing the current knowledge on scorpion distribution and areas explored in Mexico is also provided. PMID:26712787

  5. Scorpions from Mexico: From Species Diversity to Venom Complexity

    PubMed Central

    Santibáñez-López, Carlos E.; Francke, Oscar F.; Ureta, Carolina; Possani, Lourival D.

    2015-01-01

    Scorpions are among the oldest terrestrial arthropods, which are distributed worldwide, except for Antarctica and some Pacific islands. Scorpion envenomation represents a public health problem in several parts of the world. Mexico harbors the highest diversity of scorpions in the world, including some of the world’s medically important scorpion species. The systematics and diversity of Mexican scorpion fauna has not been revised in the past decade; and due to recent and exhaustive collection efforts as part of different ongoing major revisionary systematic projects, our understanding of this diversity has changed compared with previous assessments. Given the presence of several medically important scorpion species, the study of their venom in the country is also important. In the present contribution, the diversity of scorpion species in Mexico is revised and updated based on several new systematic contributions; 281 different species are recorded. Commentaries on recent venomic, ecological and behavioral studies of Mexican scorpions are also provided. A list containing the most important peptides identified from 16 different species is included. A graphical representation of the different types of components found in these venoms is also revised. A map with hotspots showing the current knowledge on scorpion distribution and areas explored in Mexico is also provided. PMID:26712787

  6. Scorpion: Close Air Support (CAS) aircraft

    NASA Technical Reports Server (NTRS)

    Allen, Chris; Cheng, Rendy; Koehler, Grant; Lyon, Sean; Paguio, Cecilia

    1991-01-01

    The objective is to outline the results of the preliminary design of the Scorpion, a proposed close air support aircraft. The results obtained include complete preliminary analysis of the aircraft in the areas of aerodynamics, structures, avionics and electronics, stability and control, weight and balance, propulsion systems, and costs. A conventional wing, twin jet, twin-tail aircraft was chosen to maximize the desirable characteristics. The Scorpion will feature low speed maneuverability, high survivability, low cost, and low maintenance. The life cycle cost per aircraft will be 17.5 million dollars. The maximum takeoff weight will be 52,760 pounds. Wing loading will be 90 psf. The thrust to weight will be 0.6 lbs/lb. This aircraft meets the specified mission requirements. Some modifications have been suggested to further optimize the design.

  7. [Epidemiological data on scorpion envenomation in Algeria].

    PubMed

    Hellal, H; Guerinik, M; Griene, L; Laid, Y; Mesbah, S; Merad, R; Alamir, B

    2012-08-01

    The scorpion envenomation is a major public health problem in Algeria. Given this fact, the Ministry of Health has developed a national strategy for prevention and control based on the training of health personnel, information, education and communication, and standardization of care on the basis of a therapeutic consensus. The monitoring and evaluation activities are carried out by epidemiological indicators through the implementation of an information system based in the services of Epidemiology, INSP (National Institute of Public Health) and Prevention Department of the Health Ministry. The information carriers are report cards implemented in different health facilities that collect data on bites and deaths from scorpion envenomation. Summaries of notifications from the wilayas are collected monthly, and processed by the Epi info software using monitoring indicators. From 1991 to 2010, there has been a stagnation in the number of stings with an average of 50,000 cases per year, but mortality decreased from more than 100 deaths in the last fifty years to 50 nowadays. The higher proportion of stings was recorded during the summer period. The most affected group is from 15 to 49 years which constitute the workforce, but children from 5 to 14 years rank first in terms of mortality. But these rates vary across years and regions. Despite all these efforts, the scorpion envenomation in Algeria remains of concern and our main challenges are to strengthen cross-sectional actions at the local level and improving the quality of care.

  8. [Epidemiological data on scorpion envenomation in Algeria].

    PubMed

    Hellal, H; Guerinik, M; Griene, L; Laid, Y; Mesbah, S; Merad, R; Alamir, B

    2012-08-01

    The scorpion envenomation is a major public health problem in Algeria. Given this fact, the Ministry of Health has developed a national strategy for prevention and control based on the training of health personnel, information, education and communication, and standardization of care on the basis of a therapeutic consensus. The monitoring and evaluation activities are carried out by epidemiological indicators through the implementation of an information system based in the services of Epidemiology, INSP (National Institute of Public Health) and Prevention Department of the Health Ministry. The information carriers are report cards implemented in different health facilities that collect data on bites and deaths from scorpion envenomation. Summaries of notifications from the wilayas are collected monthly, and processed by the Epi info software using monitoring indicators. From 1991 to 2010, there has been a stagnation in the number of stings with an average of 50,000 cases per year, but mortality decreased from more than 100 deaths in the last fifty years to 50 nowadays. The higher proportion of stings was recorded during the summer period. The most affected group is from 15 to 49 years which constitute the workforce, but children from 5 to 14 years rank first in terms of mortality. But these rates vary across years and regions. Despite all these efforts, the scorpion envenomation in Algeria remains of concern and our main challenges are to strengthen cross-sectional actions at the local level and improving the quality of care. PMID:22555670

  9. Scorpion anti-venom activity of botanicals: a pharmacological approach.

    PubMed

    Dey, Abhijit; Dey, Amrita; De, Jitendra Nath

    2013-03-01

    Scorpion bite is considered as one of the common and dangerous phenomenon throughout the world. The clinical manifestations include pulmonary edema, myocardial damage, intracerebral haemorrhage, brachial plexopathy, renal failure etc. which sometimes leads to mortality. The common antivenin therapy includes anti-scorpion venom serum or prazosin. In the vast rural areas of the third world countries phytotherapy is considered as an alternative system of medicine and scorpion sting is treated with the help of medicinal botanicals. As the safety and efficacy are considered as important aspects of anti venin therapy, conventional treatment can be supported by the herbal remedy. The present review compiles a number of medicinal plants pharmacologically evaluated in vitro and/or in vivo for scorpion antivenin properties. Considering the aspects like cost effectiveness, availability, lesser side effects and development of drug resistance, plant based anti venin therapy may be considered as a possible remedy against scorpion envenomation.

  10. Scorpion anti-venom activity of botanicals: a pharmacological approach.

    PubMed

    Dey, Abhijit; Dey, Amrita; De, Jitendra Nath

    2013-03-01

    Scorpion bite is considered as one of the common and dangerous phenomenon throughout the world. The clinical manifestations include pulmonary edema, myocardial damage, intracerebral haemorrhage, brachial plexopathy, renal failure etc. which sometimes leads to mortality. The common antivenin therapy includes anti-scorpion venom serum or prazosin. In the vast rural areas of the third world countries phytotherapy is considered as an alternative system of medicine and scorpion sting is treated with the help of medicinal botanicals. As the safety and efficacy are considered as important aspects of anti venin therapy, conventional treatment can be supported by the herbal remedy. The present review compiles a number of medicinal plants pharmacologically evaluated in vitro and/or in vivo for scorpion antivenin properties. Considering the aspects like cost effectiveness, availability, lesser side effects and development of drug resistance, plant based anti venin therapy may be considered as a possible remedy against scorpion envenomation. PMID:24175429

  11. Venom conjugated polylactide applied as biocompatible material for passive and active immunotherapy against scorpion envenomation.

    PubMed

    Ayari-Riabi, Sana; Trimaille, Thomas; Mabrouk, Kamel; Bertin, Denis; Gigmes, Didier; Benlasfar, Zakaria; Zaghmi, Ahlem; Bouhaouala-Zahar, Balkiss; Elayeb, Mohamed

    2016-04-01

    Scorpion envenoming represents a public health issue in subtropical regions of the world. Treatment and prevention need to promote antitoxin immunity. Preserving antigenic presentation while removing toxin effect remains a major challenge in toxin vaccine development. Among particulate adjuvant, particles prepared with poly (D,L-lactide) polymer are the most extensively investigated due to their excellent biocompatibility and biodegradability. The aim of this study is to develop surfactant-free PLA nanoparticles that safely deliver venom toxic fraction to enhance specific immune response. PLA nanoparticles are coated with AahG50 (AahG50/PLA) and BotG50 (BotG50/PLA): a toxic fraction purified from Androctonus australis hector and Buthus occitanus tunetanus venoms, respectively. Residual toxicities are evaluated following injections of PLA-containing high doses of AahG50 (or BotG50). Immunization trials are performed with the detoxified fraction administered alone without adjuvant. A comparative study of the effect of Freund is also included. The neutralizing capacity of sera is determined in naive mice. Six months later, immunized mice are challenged subcutaneously with increased doses of AahG50. Subcutaneous lethal dose 50 (LD50) of AahG50 and BotG50 is of 575 μg/kg and 1300 μg/kg respectively. By comparison, BotG50/PLA is totally innocuous while 50% of tested mice survive 2875 μg AahG50/kg. Alhydrogel and Freund are not able to detoxify such a high dose. Cross-antigenicity between particulate and soluble fraction is also, ensured. AahG50/PLA and BotG50/PLA induce high antibody levels in mice serum. The neutralizing capacity per mL of anti-venom was 258 μg/mL and 186 μg/mL calculated for anti-AahG50/PLA and anti-BotG50/PLA sera, respectively. Animals immunized with AahG50/PLA are protected against AahG50 injected dose of 3162 μg/kg as opposed all non-immunized mice died at this dose. We find that the detoxification approach based PLA nanoparticles, benefit

  12. Scorpion sheds 'tail' to escape: consequences and implications of autotomy in scorpions (Buthidae: Ananteris).

    PubMed

    Mattoni, Camilo I; García-Hernández, Solimary; Botero-Trujillo, Ricardo; Ochoa, José A; Ojanguren-Affilastro, Andrés A; Pinto-da-Rocha, Ricardo; Prendini, Lorenzo

    2015-01-01

    Autotomy, the voluntary shedding or detachment of a body part at a determined cleavage plane, is a common anti-predation defense mechanism in several animal taxa, including arthropods. Among arachnids, autotomy has been observed in harvestmen, mites, and spiders, always involving the loss of legs. Autotomy of the opisthosoma (abdomen) was recently reported in a single species of the Neotropical buthid scorpion genus Ananteris Thorell, 1891, but few details were revealed. Based on observations in the field and laboratory, examination of material in museum collections, and scanning electron microscopy, we document autotomy of the metasoma (the hind part of the opisthosoma, or 'tail') in fourteen species of Ananteris. Autotomy is more common in males than females, and has not been observed in juveniles. When the scorpion is held by the metasoma, it is voluntarily severed at the joints between metasomal segments I and II, II and III, or III and IV, allowing the scorpion to escape. After detachment, the severed metasoma moves (twitches) automatically, much like the severed tail of a lizard or the severed leg of a spider, and reacts to contact, even attempting to sting. The severed surface heals rapidly, scar tissue forming in five days. The lost metasomal segments and telson cannot be regenerated. Autotomy of the metasoma and telson results in permanent loss of the posterior part of the scorpion's digestive system (the anus is situated posteriorly on metasomal segment V) and the ability to inject venom by stinging. After autotomy, scorpions do not defecate and can only capture small prey items. However, males can survive and mate successfully for up to eight months in the laboratory. In spite of diminished predation ability after autotomy, survival allows males to reproduce. Autotomy in Ananteris therefore appears to be an effective, adaptive, anti-predation escape mechanism.

  13. Qualification of the scorpion helmet cueing system

    NASA Astrophysics Data System (ADS)

    Atac, Robert; Bugno, Tony

    2011-06-01

    Gentex Corporation won the Helmet Mounted Integrated Targeting (HMIT) contract with the Air National Guard and Air Force Reserve in May 2010 along with Raytheon Technical Services Corporation as the prime contractor. The HMIT program involves qualification and installation of the Scorpion HMCS Color HMD in both the A-10C and F-16C Block 30 aircraft types. Qualification tests include all aspects from ejection safety, to NVG and pilot compatibility as well as performance testing. This paper will review the qualification testing results and program status along with any lessons learned.

  14. Scorpion Biodiversity and Interslope Divergence at “Evolution Canyon”, Lower Nahal Oren Microsite, Mt. Carmel, Israel

    PubMed Central

    Raz, Shmuel; Retzkin, Sion; Pavlíček, Tomáš; Hoffman, Adam; Kimchi, Hagay; Beiles, Avigdor; Nevo, Eviatar

    2009-01-01

    Background Local natural laboratories, designated by us as the “Evolution Canyon” model, are excellent tools to study regional and global ecological dynamics across life. They present abiotic and biotic contrasts locally, permitting the pursuit of observations and experiments across diverse taxa sharing sharp microecological subdivisions. Higher solar radiation received by the “African savannah-like” south-facing slopes (AS) in canyons north of the equator than by the opposite “European maquis-like” north-facing slopes (ES) is associated with higher abiotic stress. Scorpions are a suitable taxon to study interslope biodiversity differences, associated with the differences in abiotic factors (climate, drought), due to their ability to adapt to dry environments. Methodology/Principal Findings Scorpions were studied by the turning stone method and by UV light methods. The pattern observed in scorpions was contrasted with similar patterns in several other taxa at the same place. As expected, the AS proved to be significantly more speciose regarding scorpions, paralleling the interslope patterns in taxa such as lizards and snakes, butterflies (Rhopalocera), beetles (families Tenebrionidae, Dermestidae, Chrysomelidae), and grasshoppers (Orthoptera). Conclusions/Significance Our results support an earlier conclusion stating that the homogenizing effects of migration and stochasticity are not able to eliminate the interslope intra- and interspecific differences in biodiversity despite an interslope distance of only 100 m at the “EC” valley bottom. In our opinion, the interslope microclimate selection, driven mainly by differences in insolance, could be the primary factor responsible for the observed interslope pattern. PMID:19357787

  15. Scorpion Venom and the Inflammatory Response

    PubMed Central

    Petricevich, Vera L.

    2010-01-01

    Scorpion venoms consist of a complex of several toxins that exhibit a wide range of biological properties and actions, as well as chemical compositions, toxicity, and pharmacokinetic and pharmacodynamic characteristics. These venoms are associated with high morbility and mortality, especially among children. Victims of envenoming by a scorpion suffer a variety of pathologies, involving mainly both sympathetic and parasympathetic stimulation as well as central manifestations such as irritability, hyperthermia, vomiting, profuse salivation, tremor, and convulsion. The clinical signs and symptoms observed in humans and experimental animals are related with an excessive systemic host inflammatory response to stings and stings, respectively. Although the pathophysiology of envenomation is complex and not yet fully understood, venom and immune responses are known to trigger the release of inflammatory mediators that are largely mediated by cytokines. In models of severe systemic inflammation produced by injection of high doses of venom or venoms products, the increase in production of proinflammatory cytokines significantly contributes to immunological imbalance, multiple organ dysfunction and death. The cytokines initiate a cascade of events that lead to illness behaviors such as fever, anorexia, and also physiological events in the host such as activation of vasodilatation, hypotension, and increased of vessel permeability. PMID:20300540

  16. Scorpion venom and the inflammatory response.

    PubMed

    Petricevich, Vera L

    2010-01-01

    Scorpion venoms consist of a complex of several toxins that exhibit a wide range of biological properties and actions, as well as chemical compositions, toxicity, and pharmacokinetic and pharmacodynamic characteristics. These venoms are associated with high morbility and mortality, especially among children. Victims of envenoming by a scorpion suffer a variety of pathologies, involving mainly both sympathetic and parasympathetic stimulation as well as central manifestations such as irritability, hyperthermia, vomiting, profuse salivation, tremor, and convulsion. The clinical signs and symptoms observed in humans and experimental animals are related with an excessive systemic host inflammatory response to stings and stings, respectively. Although the pathophysiology of envenomation is complex and not yet fully understood, venom and immune responses are known to trigger the release of inflammatory mediators that are largely mediated by cytokines. In models of severe systemic inflammation produced by injection of high doses of venom or venoms products, the increase in production of proinflammatory cytokines significantly contributes to immunological imbalance, multiple organ dysfunction and death. The cytokines initiate a cascade of events that lead to illness behaviors such as fever, anorexia, and also physiological events in the host such as activation of vasodilatation, hypotension, and increased of vessel permeability.

  17. Scorpion venom peptides with no disulfide bridges: a review.

    PubMed

    Almaaytah, Ammar; Albalas, Qosay

    2014-01-01

    Scorpion venoms are rich sources of biologically active peptides that are classified into disulfide-bridged peptides (DBPs) and non-disulfide-bridged peptides (NDBPs). DBPs are the main scorpion venom components responsible for the neurotoxic effects observed during scorpion envenomation as they usually target membrane bound ion channels of excitable and non-excitable cells. Several hundred DBPs have been identified and functionally characterized in the past two decades. The NDBPs represent a novel group of molecules that have gained great interest only recently due to their high diversity both in their primary structures and bioactivities. This review provides an overview of scorpion NDBPs focusing on their therapeutic applications, modes of discovery, mechanisms of NDBPs genetic diversity and structural properties. It also provides a simple classification for NDBPs that could be adopted and applied to other NDBPs identified in future studies.

  18. Applications of the Scorpion color helmet-mounted cueing system

    NASA Astrophysics Data System (ADS)

    Atac, Robert

    2010-04-01

    The innovative technology utilized in the Scorpion HMCS has broken several product and price barriers which now allow it to be used in both traditional and non-traditional applications. In particular, its bright color display provides a new dimension for informational content and vastly improved situational awareness. Users are just beginning to explore the ways that color can be used in an HMD projection display. Scorpion has also broken through price and installation cost barriers allowing, for the first time, its use on platforms that could otherwise never have afforded a helmet mounted display. Scorpion HMCS units are currently being used for both traditional cueing as well as unique new applications in both airborne and maritime platforms. These applications are further described as well as other potential roles for the Scorpion HMCS.

  19. Scorpion venom peptides with no disulfide bridges: a review.

    PubMed

    Almaaytah, Ammar; Albalas, Qosay

    2014-01-01

    Scorpion venoms are rich sources of biologically active peptides that are classified into disulfide-bridged peptides (DBPs) and non-disulfide-bridged peptides (NDBPs). DBPs are the main scorpion venom components responsible for the neurotoxic effects observed during scorpion envenomation as they usually target membrane bound ion channels of excitable and non-excitable cells. Several hundred DBPs have been identified and functionally characterized in the past two decades. The NDBPs represent a novel group of molecules that have gained great interest only recently due to their high diversity both in their primary structures and bioactivities. This review provides an overview of scorpion NDBPs focusing on their therapeutic applications, modes of discovery, mechanisms of NDBPs genetic diversity and structural properties. It also provides a simple classification for NDBPs that could be adopted and applied to other NDBPs identified in future studies. PMID:24184590

  20. Scorpion envenomation-induced acute thrombotic inferior myocardial infarction.

    PubMed

    Baykan, Ahmet Oytun; Gür, Mustafa; Acele, Armağan; Şeker, Taner; Çaylı, Murat

    2016-01-01

    The occurrence of a serious cardiac emergency following scorpion envenomation has rarely been reported and, when so, mostly presented as non-ST segment elevation myocardial infarction, cardiogenic shock, or myocarditis. Possible mechanisms include imbalance in blood pressure and coronary vasospasm caused by the combination of sympathetic excitation, scorpion venom-induced release of catecholamines, and the direct effect of the toxin on the myocardium. We report a case of a 55-year-old man who presented with acute inferior wall myocardial infarction (MI) within 2 h of being stung by a scorpion. Coronary angiogram revealed total thrombotic occlusion of the left circumflex artery, which was treated successfully with glycoprotein IIb/IIIa inhibitor, thrombus aspiration, antivenom serum, and supportive therapy. Therefore, life-threatening MI can complicate the clinical course during some types of scorpion envenomation and should be managed as an acute coronary syndrome. PMID:26875137

  1. Evidence of duplicated Hox genes in the most recent common ancestor of extant scorpions.

    PubMed

    Sharma, Prashant P; Santiago, Marc A; González-Santillán, Edmundo; Monod, Lionel; Wheeler, Ward C

    2015-01-01

    Scorpions (order Scorpiones) are unusual among arthropods, both for the extreme heteronomy of their bauplan and for the high gene family turnover exhibited in their genomes. These phenomena appear to be correlated, as two scorpion species have been shown to possess nearly twice the number of Hox genes present in most arthropods. Segmentally offset anterior expression boundaries of a subset of Hox paralogs have been shown to correspond to transitions in segmental identities in the scorpion posterior tagmata, suggesting that posterior heteronomy in scorpions may have been achieved by neofunctionalization of Hox paralogs. However, both the first scorpion genome sequenced and the developmental genetic data are based on exemplars of Buthidae, one of 19 families of scorpions. It is therefore not known whether Hox paralogy is limited to Buthidae or widespread among scorpions. We surveyed 24 high throughput transcriptomes and the single whole genome available for scorpions, in order to test the prediction that Hox gene duplications are common to the order. We used gene tree parsimony to infer whether the paralogy was consistent with a duplication event in the scorpion common ancestor. Here we show that duplicated Hox genes in non-buthid scorpions occur in six of the ten Hox classes. Gene tree topologies and parsimony-based reconciliation of the gene trees are consistent with a duplication event in the most recent common ancestor of scorpions. These results suggest that a Hox paralogy, and by extension the model of posterior patterning established in a buthid, can be extended to non-Buthidae scorpions.

  2. Scorpion Sheds ‘Tail’ to Escape: Consequences and Implications of Autotomy in Scorpions (Buthidae: Ananteris)

    PubMed Central

    Mattoni, Camilo I.; García-Hernández, Solimary; Botero-Trujillo, Ricardo; Ochoa, José A.; Ojanguren-Affilastro, Andrés A.; Pinto-da-Rocha, Ricardo; Prendini, Lorenzo

    2015-01-01

    Autotomy, the voluntary shedding or detachment of a body part at a determined cleavage plane, is a common anti-predation defense mechanism in several animal taxa, including arthropods. Among arachnids, autotomy has been observed in harvestmen, mites, and spiders, always involving the loss of legs. Autotomy of the opisthosoma (abdomen) was recently reported in a single species of the Neotropical buthid scorpion genus Ananteris Thorell, 1891, but few details were revealed. Based on observations in the field and laboratory, examination of material in museum collections, and scanning electron microscopy, we document autotomy of the metasoma (the hind part of the opisthosoma, or ‘tail’) in fourteen species of Ananteris. Autotomy is more common in males than females, and has not been observed in juveniles. When the scorpion is held by the metasoma, it is voluntarily severed at the joints between metasomal segments I and II, II and III, or III and IV, allowing the scorpion to escape. After detachment, the severed metasoma moves (twitches) automatically, much like the severed tail of a lizard or the severed leg of a spider, and reacts to contact, even attempting to sting. The severed surface heals rapidly, scar tissue forming in five days. The lost metasomal segments and telson cannot be regenerated. Autotomy of the metasoma and telson results in permanent loss of the posterior part of the scorpion’s digestive system (the anus is situated posteriorly on metasomal segment V) and the ability to inject venom by stinging. After autotomy, scorpions do not defecate and can only capture small prey items. However, males can survive and mate successfully for up to eight months in the laboratory. In spite of diminished predation ability after autotomy, survival allows males to reproduce. Autotomy in Ananteris therefore appears to be an effective, adaptive, anti-predation escape mechanism. PMID:25629529

  3. A remarkable new cave scorpion of the family Pseudochactidae Gromov (Chelicerata, Scorpiones) from Vietnam

    PubMed Central

    Lourenço, Wilson R.; Pham, Dinh-Sac

    2010-01-01

    Abstract A new genus and species of scorpion belonging to the family Pseudochactidaeare described based on four specimens collected in the Tien Son cave at the Phong Nha - Ke Bang National Park, Quang Binh Province, Vietnam. The new species represents a true troglobitic element, the first one known for the family Pseudochactidae. This represents the third known record of a pseudochactid, and the first from Vietnam. PMID:21594045

  4. Scorpion Toxin Polyptides as Therapeutic Agents: An Overview.

    PubMed

    Bhavya, Janardhan; Francois, Niyonzima N; More, Veena S; More, Sunil S

    2016-01-01

    Scorpions are distributed throughout the world and numerous biological molecules are found in their venom most importantly peptide toxins. These toxins modulate the ion channels either by blocking the pore of the channel or by altering the voltage gating. Molecules which block the pores have been useful in deciphering the structure of the ion channels. Many scorpion toxins have already been used for probing the voltage gated sodium channels and studying their activation and inactivation processes. The specialty of scorpion toxins is to discriminate between vertebrate and invertebrate channels which have led them to applications as pharmacological tools. Most of the scorpion toxin polypeptides were isolated, characterized and were shown to possess vital properties useful in the field of medicine. For instance, they show therapeutic properties such as antimicrobial activity, anticancer activity, used to treat autoimmune diseases and cardiovascular effects. Although the scorpion toxins exhibited good therapeutic effects in vitro and in vivo, no one has reached the market with success up to date. In this mini-review, the scorpion polypeptides, their interactions with ion channels and their uses as therapeutic agents are discussed. PMID:27397476

  5. Model for simulating scorpion substrate vibration and detection system

    NASA Astrophysics Data System (ADS)

    Sadiq, B. A.; Aibinu, A. M.; Joseph, E.; Salau, H. B.; Salami, M. J. E.

    2013-12-01

    Scorpion stings are vital health issues which requires prompt attention to minimize the pain inflicted on victims and avert death. A possible solution in averting the sting is the capability of detecting its presence earlier before it stings. Scorpion like other arthropods have a specific kind of movement pattern called substrate vibration, which generates a specific signal that is used in recognizing and locating mates and preys. This paper aims at developing an intelligent scorpion detection system using vibration frequency detection technique. A six step model for simulating scorpion substrate vibration and detection has been proposed. The surrounding vibrating signal is acquired and passed through a band pass filter. The resulting signal is model using autoregressive modeling technique. Resulting co-efficients are further analyzed for activity detection. The frequency response of scorpion activities for mating behaviour was simulated, detected analysed using MATLAB environment. The resulting coefficients was also compared and analysed. Results obtained shows that the proposed technique is appropriate for model and simulating scorpion substrate vibration and detection system.

  6. Scorpion sting prevention and treatment in ancient Iran

    PubMed Central

    Dehghani, Rouhullah; Arani, Mohammad Ghannaee

    2015-01-01

    Due to the medical and therapeutic importance of scorpions in Iranian traditional medicine, this review was conducted on the treatment of scorpion sting as performed by traditional healers in order to realize complications, clinical manifestations, diversities, and deficiencies in the prevention, control, and treatment as mentioned in the pertained literatures. This study tried to make known and investigate attitudes of the Iranian national and traditional medicine towards controlling these venomous animals. Keywords and articles were searched through relevant sites on the Internet. We investigated different journals and references for the Iranian traditional medicine. Based on the articles and books found, we tried to find suitable solutions to problems from the viewpoint of traditional medicine. Scorpion sting dates back to ancient Iran and has been widely reflected in the resources of Iranian traditional medicine. The traditional medicine offers various guidelines that can be beneficial in this respect. New attitude towards scorpion sting with regard to traditional medicine resources can enhance control and prevention of scorpion stings. Consequently, this attitude leads authorities and researchers to a decreased level of scorpion stings or related consequences. PMID:26151015

  7. Scorpion sting prevention and treatment in ancient Iran.

    PubMed

    Dehghani, Rouhullah; Arani, Mohammad Ghannaee

    2015-04-01

    Due to the medical and therapeutic importance of scorpions in Iranian traditional medicine, this review was conducted on the treatment of scorpion sting as performed by traditional healers in order to realize complications, clinical manifestations, diversities, and deficiencies in the prevention, control, and treatment as mentioned in the pertained literatures. This study tried to make known and investigate attitudes of the Iranian national and traditional medicine towards controlling these venomous animals. Keywords and articles were searched through relevant sites on the Internet. We investigated different journals and references for the Iranian traditional medicine. Based on the articles and books found, we tried to find suitable solutions to problems from the viewpoint of traditional medicine. Scorpion sting dates back to ancient Iran and has been widely reflected in the resources of Iranian traditional medicine. The traditional medicine offers various guidelines that can be beneficial in this respect. New attitude towards scorpion sting with regard to traditional medicine resources can enhance control and prevention of scorpion stings. Consequently, this attitude leads authorities and researchers to a decreased level of scorpion stings or related consequences. PMID:26151015

  8. Development of segments and appendages in embryos of the desert scorpion Paruroctonus mesaensis (Scorpiones: Vaejovidae).

    PubMed

    Farley, R D

    2001-10-01

    The scanning electron microscope was used to study the changing features of scorpion embryos from the blastula through early stages in the development of appendages. The earliest scorpion fossils (Silurian period) have structures more advanced than the embryos herein, so the possibility is considered that these embryos still retain and display some features indicative of evolutionary patterns in adult pre-Silurian ancestors. The blastodisc stage is followed by a knob-like germinal center that gives rise to most of the embryo body. The germinal center elongates on the ventral surface of the spherical yolk mass. The broad cephalic lobe is first delineated from the following pedipalpal segment. The limbbuds for the pedipalps and anterior walking legs appear, as additional segments are added at a growth zone at the rear of the embryo body. Initially, in the cephalic lobe there are no limbbuds; then the cheliceral buds emerge from the posterior part of the lobe. The stomodeum appears first in the anterior half of the cephalic lobe, but an oral groove forms and the mouth is displaced posteriorly within the groove. This repositioning allows space anteriorly for invagination (semilunar grooves) of epithelium for the brain and medial eyes. The mouth is directed ventrally in all stages of this study. The widespread chelicerae are initially posterior to the mouth, but later move anterior and dorsal to it. Small limbbud bulges on mesosomal segments disappear later and never become protruding appendages. Metasomal segments are produced free from the yolk surface in a ventral flexure beneath the embryo body. The telson starts as two spherical lobes, but later elongates and tapers distally, not yet developing the sharp sting (aculeus) seen in Silurian and all subsequent scorpions. The walking legs are digitigrade, as in most fossil aquatic scorpions. Segments are delineated in the appendages; the chelicerae and pedipalps are divided distally for chela (claw) formation. Bilateral

  9. Extreme diversity of scorpion venom peptides and proteins revealed by transcriptomic analysis: implication for proteome evolution of scorpion venom arsenal.

    PubMed

    Ma, Yibao; He, Yawen; Zhao, Ruiming; Wu, Yingliang; Li, Wenxin; Cao, Zhijian

    2012-02-16

    Venom is an important genetic development crucial to the survival of scorpions for over 400 million years. We studied the evolution of the scorpion venom arsenal by means of comparative transcriptome analysis of venom glands and phylogenetic analysis of shared types of venom peptides and proteins between buthids and euscorpiids. Fifteen types of venom peptides and proteins were sequenced during the venom gland transcriptome analyses of two Buthidae species (Lychas mucronatus and Isometrus maculatus) and one Euscorpiidae species (Scorpiops margerisonae). Great diversity has been observed in translated amino acid sequences of these transcripts for venom peptides and proteins. Seven types of venom peptides and proteins were shared between buthids and euscorpiids. Molecular phylogenetic analysis revealed that at least five of the seven common types of venom peptides and proteins were likely recruited into the scorpion venom proteome before the lineage split between Buthidae and Euscorpiidae with their corresponding genes undergoing individual or multiple gene duplication events. These are α-KTxs, βKSPNs (β-KTxs and scorpines), anionic peptides, La1-like peptides, and SPSVs (serine proteases from scorpion venom). Multiple types of venom peptides and proteins were demonstrated to be continuously recruited into the venom proteome during the evolution process of individual scorpion lineages. Our results provide an insight into the recruitment pattern of the scorpion venom arsenal for the first time.

  10. 78 FR 32274 - Scorpion Pier Replacement Project, Channel Islands National Park, Santa Barbara County, California

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... National Park Service Scorpion Pier Replacement Project, Channel Islands National Park, Santa Barbara... analysis process for the proposed replacement and potential relocation of the existing Scorpion Pier at..., Attn: Scorpion Pier Project, 1901 Spinnaker Drive, Ventura, CA 93001 or electronically to...

  11. The first scorpionate ligand based on diazaphosphole.

    PubMed

    Mlateček, Martin; Dostál, Libor; Růžičková, Zdeňka; Honzíček, Jan; Holubová, Jana; Erben, Milan

    2015-12-14

    The reaction of PhBCl2 with 1H-1,2,4-λ(3)-diazaphosphole in the presence of NEt3 gives a new scorpionate ligand, phenyl-tris(1,2,4-diazaphospholyl)borate (PhTdap). The coordination behaviour of this ligand toward transition and non-transition metals has been comprehensively studied. In the thallium(I) complex, Tl(PhTdap), κ(2)-N,N bonding supported with intramolecular η(3)-phenyl coordination has been observed in the solid state. Tl(PhTdap) also shows unusual intermolecular π-interactions between five-membered diazaphosphole rings and the thallium atom giving infinite molecular chains in the crystal. In the square planar complex [Pd(C,N-C6H4CH2NMe2)(PhTdap)], κ(2)-bonded scorpionate has been detected in both solution and in the solid state. For other studied compounds with the central metal ion Ti(IV), Mo(II), Mn(I), Fe(II), Ru(II), Co(II), Co(III), Ni(II) and Cd(II), the κ(3)-N,N,N coordination pattern was observed. Electronic properties of PhTdap and its ligand-field strength were elucidated from UV-Vis spectra of transition-metal species. The CH/P replacement on going from tris(pyrazolyl)borate to the ligand PhTdap causes a slight increase in electronic density rendered to the central metal atom. The following order of ligand-field strength has been established: HB(3,5-Me2pz)3 < PhB(pz)3 < HB(1,2,4-triazolyl) < HB(pz)3 < PhB(1,2,4-triazolyl) < PhTdap. The crystal structures of ten metal complexes bearing the new ligand are reported. The possibility of PhTdap coordination through the phosphorus atom is also briefly discussed. PMID:26537349

  12. Biotechnological Trends in Spider and Scorpion Antivenom Development.

    PubMed

    Laustsen, Andreas Hougaard; Solà, Mireia; Jappe, Emma Christine; Oscoz, Saioa; Lauridsen, Line Præst; Engmark, Mikael

    2016-07-23

    Spiders and scorpions are notorious for their fearful dispositions and their ability to inject venom into prey and predators, causing symptoms such as necrosis, paralysis, and excruciating pain. Information on venom composition and the toxins present in these species is growing due to an interest in using bioactive toxins from spiders and scorpions for drug discovery purposes and for solving crystal structures of membrane-embedded receptors. Additionally, the identification and isolation of a myriad of spider and scorpion toxins has allowed research within next generation antivenoms to progress at an increasingly faster pace. In this review, the current knowledge of spider and scorpion venoms is presented, followed by a discussion of all published biotechnological efforts within development of spider and scorpion antitoxins based on small molecules, antibodies and fragments thereof, and next generation immunization strategies. The increasing number of discovery and development efforts within this field may point towards an upcoming transition from serum-based antivenoms towards therapeutic solutions based on modern biotechnology.

  13. Biotechnological Trends in Spider and Scorpion Antivenom Development.

    PubMed

    Laustsen, Andreas Hougaard; Solà, Mireia; Jappe, Emma Christine; Oscoz, Saioa; Lauridsen, Line Præst; Engmark, Mikael

    2016-01-01

    Spiders and scorpions are notorious for their fearful dispositions and their ability to inject venom into prey and predators, causing symptoms such as necrosis, paralysis, and excruciating pain. Information on venom composition and the toxins present in these species is growing due to an interest in using bioactive toxins from spiders and scorpions for drug discovery purposes and for solving crystal structures of membrane-embedded receptors. Additionally, the identification and isolation of a myriad of spider and scorpion toxins has allowed research within next generation antivenoms to progress at an increasingly faster pace. In this review, the current knowledge of spider and scorpion venoms is presented, followed by a discussion of all published biotechnological efforts within development of spider and scorpion antitoxins based on small molecules, antibodies and fragments thereof, and next generation immunization strategies. The increasing number of discovery and development efforts within this field may point towards an upcoming transition from serum-based antivenoms towards therapeutic solutions based on modern biotechnology. PMID:27455327

  14. Biotechnological Trends in Spider and Scorpion Antivenom Development

    PubMed Central

    Laustsen, Andreas Hougaard; Solà, Mireia; Jappe, Emma Christine; Oscoz, Saioa; Lauridsen, Line Præst; Engmark, Mikael

    2016-01-01

    Spiders and scorpions are notorious for their fearful dispositions and their ability to inject venom into prey and predators, causing symptoms such as necrosis, paralysis, and excruciating pain. Information on venom composition and the toxins present in these species is growing due to an interest in using bioactive toxins from spiders and scorpions for drug discovery purposes and for solving crystal structures of membrane-embedded receptors. Additionally, the identification and isolation of a myriad of spider and scorpion toxins has allowed research within next generation antivenoms to progress at an increasingly faster pace. In this review, the current knowledge of spider and scorpion venoms is presented, followed by a discussion of all published biotechnological efforts within development of spider and scorpion antitoxins based on small molecules, antibodies and fragments thereof, and next generation immunization strategies. The increasing number of discovery and development efforts within this field may point towards an upcoming transition from serum-based antivenoms towards therapeutic solutions based on modern biotechnology. PMID:27455327

  15. Whole Transcriptome of the Venom Gland from Urodacus yaschenkoi Scorpion

    PubMed Central

    Juárez-González, Víctor Rivelino; Possani, Lourival D.

    2015-01-01

    Australian scorpion venoms have been poorly studied, probably because they do not pose an evident threat to humans. In addition, the continent has other medically important venomous animals capable of causing serious health problems. Urodacus yaschenkoi belongs to the most widely distributed family of Australian scorpions (Urodacidae) and it is found all over the continent, making it a useful model system for studying venom composition and evolution. This communication reports the whole set of mRNA transcripts produced by the venom gland. U. yaschenkoi venom is as complex as its overseas counterparts. These transcripts certainly code for several components similar to known scorpion venom components, such as: alpha-KTxs, beta-KTxs, calcins, protease inhibitors, antimicrobial peptides, sodium-channel toxins, toxin-like peptides, allergens, La1-like, hyaluronidases, ribosomal proteins, proteasome components and proteins related to cellular processes. A comparison with the venom gland transcriptome of Centruroides noxius (Buthidae) showed that these two scorpions have similar components related to biological processes, although important differences occur among the venom toxins. In contrast, a comparison with sequences reported for Urodacus manicatus revealed that these two Urodacidae species possess the same subfamily of scorpion toxins. A comparison with sequences of an U. yaschenkoi cDNA library previously reported by our group showed that both techniques are reliable for the description of the venom components, but the whole transcriptome generated with Next Generation Sequencing platform provides sequences of all transcripts expressed. Several of which were identified in the proteome, but many more transcripts were identified including uncommon transcripts. The information reported here constitutes a reference for non-Buthidae scorpion venoms, providing a comprehensive view of genes that are involved in venom production. Further, this work identifies new putative

  16. Whole Transcriptome of the Venom Gland from Urodacus yaschenkoi Scorpion.

    PubMed

    Luna-Ramírez, Karen; Quintero-Hernández, Verónica; Juárez-González, Víctor Rivelino; Possani, Lourival D

    2015-01-01

    Australian scorpion venoms have been poorly studied, probably because they do not pose an evident threat to humans. In addition, the continent has other medically important venomous animals capable of causing serious health problems. Urodacus yaschenkoi belongs to the most widely distributed family of Australian scorpions (Urodacidae) and it is found all over the continent, making it a useful model system for studying venom composition and evolution. This communication reports the whole set of mRNA transcripts produced by the venom gland. U. yaschenkoi venom is as complex as its overseas counterparts. These transcripts certainly code for several components similar to known scorpion venom components, such as: alpha-KTxs, beta-KTxs, calcins, protease inhibitors, antimicrobial peptides, sodium-channel toxins, toxin-like peptides, allergens, La1-like, hyaluronidases, ribosomal proteins, proteasome components and proteins related to cellular processes. A comparison with the venom gland transcriptome of Centruroides noxius (Buthidae) showed that these two scorpions have similar components related to biological processes, although important differences occur among the venom toxins. In contrast, a comparison with sequences reported for Urodacus manicatus revealed that these two Urodacidae species possess the same subfamily of scorpion toxins. A comparison with sequences of an U. yaschenkoi cDNA library previously reported by our group showed that both techniques are reliable for the description of the venom components, but the whole transcriptome generated with Next Generation Sequencing platform provides sequences of all transcripts expressed. Several of which were identified in the proteome, but many more transcripts were identified including uncommon transcripts. The information reported here constitutes a reference for non-Buthidae scorpion venoms, providing a comprehensive view of genes that are involved in venom production. Further, this work identifies new putative

  17. Treatment of scorpion envenoming syndrome -- need for scientific magnanimity.

    PubMed

    Murthy, K Radha Krishna

    2013-04-01

    Scorpion envenoming syndrome results in a severe autonomic storm with a massive release of catecholamines, increased levels of angiotensin II, an increase in glucagon, cortisol, thyroid hormones; either suppressed insulin levels or hyperinsulinaemia (insulin resistance), hyperglycaemia; increased circulating free fatty acid levels. These hormonal alterations could be responsible for the pathogenesis of a variety of clinical manifestations. Under these conditions, scorpion envenoming syndrome with myocardial damage, cardiovascular disturbances, peripheral circulatory failure, respiratory and cardiac pulmonary oedema, and many other clinical manifestations resulting in a syndrome of fuel-energy deficits and an inability to use the existing metabolic substrates by vital organs causing multisystem organ failure and death. Based on animal experiments in which insulin administration reversed the metabolic and ECG changes induced by scorpion envenoming and treating the poisonous scorpion sting victims with insulin, we consider that insulin has a primary metabolic role in preventing and reversing the cardiovascular, haemodynamic, and neurological manifestations and pulmonary oedema induced by scorpion envenoming. Administration of insulin-glucose infusion to scorpion sting victims appears to be the physiological basis for the control of the metabolic response when that has become a determinant to survival. The mordality of treatment is continuous infusion of regular crystalline insulin at the rate of 0.3 U/g glucose and glucose at the rate of 0.1g/kg body weight/hour, with supplementation of potassium as needed and maintenance of fluid, electrolytes and acid-base balance is required. This treatment should be given at the earliest on admission and continued for the next 48-72 hours. Antiscorpion serum could also be given independently or along with insulin-glucose infusion. PMID:24475558

  18. Exploration of refuge preference in the Arizona bark scorpion (Scorpiones: Buthidae).

    PubMed

    Bibbs, Christopher Stephen; Bengston, Sarah Elizabeth; Gouge, Dawn H

    2014-10-01

    The ongoing difficulty in understanding how Centruroides sculpturatus (Ewing) uses the built environment has prompted this study in exploring refuge choices in a school environment and in laboratory behavioral assays. Radio telemetry tags were used at an urban site heavily populated with C. sculpturatus to track scorpions for a period of 21 d from 1 to 21 August 2013. Complimentary laboratory work tested scorpions in refuge choice arenas targeting variables of four crevice widths--14.0, 9.3, 7.0, and 4.6 mm--or of a vertical versus horizontal orientation preference. These crevice sizes were picked as a response to crevices being naturally used in the field. Telemetry and observations tallied significant preference for artificial structural harborage. Ninety-five percent of the structure refuge use occurred in hollow block walls. Vegetative harborage, debris, and underground burrows were not selected with any significance compared with each other or structures. Generalized additive models (GAMs) indicated the strongest predictive power from individual preference. The behavioral choice assays yielded a significant preference for the largest of crevice widths offered, 14.0 mm and to a lesser extent 9.3 mm, both horizontally and vertically. GAMs for these assays indicated size as the strongest predictive factor in choices. The orientation tests and GAMs showed individual preference driving choice favoring vertical planes. Observations about negative geotaxis in assay and refuge use details from the field are also reported. PMID:25203773

  19. Scorpion Peptides: Potential Use for New Drug Development

    PubMed Central

    Hmed, BenNasr; Serria, Hammami Turky; Mounir, Zeghal Khaled

    2013-01-01

    Several peptides contained in scorpion fluids showed diverse array of biological activities with high specificities to their targeted sites. Many investigations outlined their potent effects against microbes and showed their potential to modulate various biological mechanisms that are involved in immune, nervous, cardiovascular, and neoplastic diseases. Because of their important structural and functional diversity, it is projected that scorpion-derived peptides could be used to develop new specific drugs. This review summarizes relevant findings improving their use as valuable tools for new drugs development. PMID:23843786

  20. The Cuban scorpion Rhopalurus junceus (Scorpiones, Buthidae): component variations in venom samples collected in different geographical areas

    PubMed Central

    2013-01-01

    Backgound The venom of the Cuban scorpion Rhopalurus junceus is poorly study from the point of view of their components at molecular level and the functions associated. The purpose of this article was to conduct a proteomic analysis of venom components from scorpions collected in different geographical areas of the country. Results Venom from the blue scorpion, as it is called, was collected separately from specimens of five distinct Cuban towns (Moa, La Poa, Limonar, El Chote and Farallones) of the Nipe-Sagua-Baracoa mountain massif and fractionated by high performance liquid chromatography (HPLC); the molecular masses of each fraction were ascertained by mass spectrometry analysis. At least 153 different molecular mass components were identified among the five samples analyzed. Molecular masses varied from 466 to 19755 Da. Scorpion HPLC profiles differed among these different geographical locations and the predominant molecular masses of their components. The most evident differences are in the relative concentration of the venom components. The most abundant components presented molecular weights around 4 kDa, known to be K+-channel specific peptides, and 7 kDa, known to be Na+-channel specific peptides, but with small molecular weight differences. Approximately 30 peptides found in venom samples from the different geographical areas are identical, supporting the idea that they all probably belong to the same species, with some interpopulational variations. Differences were also found in the presence of phospholipase, found in venoms from the Poa area (molecular weights on the order of 14 to 19 kDa). The only ubiquitous enzyme identified in the venoms from all five localities studied (hyaluronidase) presented the same 45 kD molecular mass, identified by gel electrophoresis analysis. Conclusions The venom of these scorpions from different geographical areas seem to be similar, and are rich in peptides that have of the same molecular masses of the peptides

  1. A second species of Euscorpiops Vachon from caves in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae). Cave Euscorpiops scorpion from Vietnam.

    PubMed

    Lourenço, Wilson R; Pham, Dinh-Sac

    2014-09-01

    Euscorpiops dakrong sp. n., belonging to the family Euscorpiidae Laurie, is described on the basis of one male and one female collected in the Dakrong Nature Reserve cave system, Dakrong District, Quang Tri Province, Vietnam. The new species presents most features exhibited by scorpions of the genus Euscorpiops, but it is characterized by a slender body and elongated pedipalps. This new scorpion taxon represents the second species of Scorpiopinae discovered in a cave system and may be yet another endemic element in the fauna of Vietnam. Some taxonomic propositions on the generic position of Scorpiops oligotrichus Fage, 1933 are also suggested.

  2. A new high-elevation scorpion species of the genus Scorpiops Peters, 1861 (Scorpiones: Euscorpiidae: Scorpiopinae) from the Himalayas, India.

    PubMed

    Zambre, Amod; Sanap, Rajesh V; Mirza, Zeeshan A

    2014-06-01

    A new high-elevation scorpion species of the genus Scorpiops is described from the Indian state of Himachal Pradesh. Scorpiops spitiensis sp. nov. is the second highest-elevation scorpion species in Asia and the first one from India occurring at elevations above 4200 m. The new species closely resembles Scorpiops petersii, but it can be distinguished from it based on a suit of characters, one of which is the presence of 16 trichobothria on the external aspect of the patella, which is unique to the new species.

  3. Evidence of duplicated Hox genes in the most recent common ancestor of extant scorpions.

    PubMed

    Sharma, Prashant P; Santiago, Marc A; González-Santillán, Edmundo; Monod, Lionel; Wheeler, Ward C

    2015-01-01

    Scorpions (order Scorpiones) are unusual among arthropods, both for the extreme heteronomy of their bauplan and for the high gene family turnover exhibited in their genomes. These phenomena appear to be correlated, as two scorpion species have been shown to possess nearly twice the number of Hox genes present in most arthropods. Segmentally offset anterior expression boundaries of a subset of Hox paralogs have been shown to correspond to transitions in segmental identities in the scorpion posterior tagmata, suggesting that posterior heteronomy in scorpions may have been achieved by neofunctionalization of Hox paralogs. However, both the first scorpion genome sequenced and the developmental genetic data are based on exemplars of Buthidae, one of 19 families of scorpions. It is therefore not known whether Hox paralogy is limited to Buthidae or widespread among scorpions. We surveyed 24 high throughput transcriptomes and the single whole genome available for scorpions, in order to test the prediction that Hox gene duplications are common to the order. We used gene tree parsimony to infer whether the paralogy was consistent with a duplication event in the scorpion common ancestor. Here we show that duplicated Hox genes in non-buthid scorpions occur in six of the ten Hox classes. Gene tree topologies and parsimony-based reconciliation of the gene trees are consistent with a duplication event in the most recent common ancestor of scorpions. These results suggest that a Hox paralogy, and by extension the model of posterior patterning established in a buthid, can be extended to non-Buthidae scorpions. PMID:26492826

  4. Seeking Refuge in Literacy from a Scorpion Bite

    ERIC Educational Resources Information Center

    Sarroub, Loukia K.

    2007-01-01

    The purpose of this study is to examine a refugee boy's experiences with literacy in and out of school in the US. Within these contexts, I explore this youth's literacy development in light of his identity as a poor Yezidi Kurdish refugee from Iraq. Central to the article are two main themes. The first, life as a scorpion sting, explicates the…

  5. Hox gene duplications correlate with posterior heteronomy in scorpions.

    PubMed

    Sharma, Prashant P; Schwager, Evelyn E; Extavour, Cassandra G; Wheeler, Ward C

    2014-10-01

    The evolutionary success of the largest animal phylum, Arthropoda, has been attributed to tagmatization, the coordinated evolution of adjacent metameres to form morphologically and functionally distinct segmental regions called tagmata. Specification of regional identity is regulated by the Hox genes, of which 10 are inferred to be present in the ancestor of arthropods. With six different posterior segmental identities divided into two tagmata, the bauplan of scorpions is the most heteronomous within Chelicerata. Expression domains of the anterior eight Hox genes are conserved in previously surveyed chelicerates, but it is unknown how Hox genes regionalize the three tagmata of scorpions. Here, we show that the scorpion Centruroides sculpturatus has two paralogues of all Hox genes except Hox3, suggesting cluster and/or whole genome duplication in this arachnid order. Embryonic anterior expression domain boundaries of each of the last four pairs of Hox genes (two paralogues each of Antp, Ubx, abd-A and Abd-B) are unique and distinguish segmental groups, such as pectines, book lungs and the characteristic tail, while maintaining spatial collinearity. These distinct expression domains suggest neofunctionalization of Hox gene paralogues subsequent to duplication. Our data reconcile previous understanding of Hox gene function across arthropods with the extreme heteronomy of scorpions.

  6. Insights into Antimicrobial Peptides from Spiders and Scorpions.

    PubMed

    Wang, Xiuqing; Wang, Guangshun

    2016-01-01

    The venoms of spiders and scorpions contain a variety of chemical compounds. Antimicrobial peptides (AMPs) from these organisms were first discovered in the 1990s. As of May 2015, there were 42 spider's and 63 scorpion's AMPs in the Antimicrobial Peptide Database (http://aps.unmc.edu/AP). These peptides have demonstrated broad or narrow-spectrum activities against bacteria, fungi, viruses, and parasites. In addition, they can be toxic to cancer cells, insects and erythrocytes. To provide insight into such an activity spectrum, this article discusses the discovery, classification, structure and activity relationships, bioinformatics analysis, and potential applications of spider and scorpion AMPs. Our analysis reveals that, in the case of linear peptides, spiders use both glycine-rich and helical peptide models for defense, whereas scorpions use two distinct helical peptide models with different amino acid compositions to exert the observed antimicrobial activities and hemolytic toxicity. Our structural bioinformatics study improves the knowledge in the field and can be used to design more selective peptides to combat tumors, parasites, and viruses. PMID:27165405

  7. Management of scorpion stings in Africa and the Mediterranean region.

    PubMed

    Chippaux, J-P

    2016-05-01

    Common in the southern and eastern Mediterranean basin, scorpion stings can develop into a severe medical emergency, especially in young children. Here we review several principles of diagnosis and treatment. The indications for antivenom and symptomatic treatment are detailed according to the symptoms and clinical severity of envenomation.

  8. Hox gene duplications correlate with posterior heteronomy in scorpions

    PubMed Central

    Sharma, Prashant P.; Schwager, Evelyn E.; Extavour, Cassandra G.; Wheeler, Ward C.

    2014-01-01

    The evolutionary success of the largest animal phylum, Arthropoda, has been attributed to tagmatization, the coordinated evolution of adjacent metameres to form morphologically and functionally distinct segmental regions called tagmata. Specification of regional identity is regulated by the Hox genes, of which 10 are inferred to be present in the ancestor of arthropods. With six different posterior segmental identities divided into two tagmata, the bauplan of scorpions is the most heteronomous within Chelicerata. Expression domains of the anterior eight Hox genes are conserved in previously surveyed chelicerates, but it is unknown how Hox genes regionalize the three tagmata of scorpions. Here, we show that the scorpion Centruroides sculpturatus has two paralogues of all Hox genes except Hox3, suggesting cluster and/or whole genome duplication in this arachnid order. Embryonic anterior expression domain boundaries of each of the last four pairs of Hox genes (two paralogues each of Antp, Ubx, abd-A and Abd-B) are unique and distinguish segmental groups, such as pectines, book lungs and the characteristic tail, while maintaining spatial collinearity. These distinct expression domains suggest neofunctionalization of Hox gene paralogues subsequent to duplication. Our data reconcile previous understanding of Hox gene function across arthropods with the extreme heteronomy of scorpions. PMID:25122224

  9. Management of scorpion stings in Africa and the Mediterranean region.

    PubMed

    Chippaux, J-P

    2016-05-01

    Common in the southern and eastern Mediterranean basin, scorpion stings can develop into a severe medical emergency, especially in young children. Here we review several principles of diagnosis and treatment. The indications for antivenom and symptomatic treatment are detailed according to the symptoms and clinical severity of envenomation. PMID:27412972

  10. [Spatial distribution of scorpion stings in Ponta Grossa, Paraná State, Brazil].

    PubMed

    Kotviski, Bianca Mayara; Barbola, Ivana de Freitas

    2013-09-01

    Among all bites and stings by venomous animals, scorpion stings have increased significantly in urban areas all over Brazil. Considering that Ponta Grossa is the city in Paraná State with the highest incidence of reported scorpion stings, the current study aimed to assess trends in scorpion stings based on notification records and complaints from January 2008 to December 2010. The geographic coordinates of addresses with reported scorpion stings were collected, digitized, and spatialized, resulting in a cartogram of the georeferenced scorpion stings in the city. The incidence coefficients for this period showed that Ponta Grossa had 113.3 cases per 100,000 inhabitants, and that Colônia Dona Luiza, Neves, and Chapada were the neighborhoods with the highest rates. Investigation of determinants of scorpion stings used visual and statistical analysis, indicating wooded or green areas, water mains, and the sewer system as the main correlated variables. PMID:24068229

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

    PubMed

    Dorce, Ana L C; Frare, Eduardo O; Paulo, Maria E F V; Dorce, Valquiria A C; Nencioni, Ana L A

    2015-09-01

    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.

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

    PubMed

    Dorce, Ana L C; Frare, Eduardo O; Paulo, Maria E F V; Dorce, Valquiria A C; Nencioni, Ana L A

    2015-09-01

    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. PMID:26140840

  13. First record of the family Pseudochactidae Gromov (Chelicerata, Scorpiones) from Laos and new biogeographic evidence of a Pangaean palaeodistribution.

    PubMed

    Lourenço, Wilson R

    2007-10-01

    A new genus and species of scorpion belonging to the recently named family Pseudochactidae is described based on two specimens collected in the Tham Xe Bangfai cave, Province of Khammouan, Laos. This new scorpion represents the second known record of a pseudochactid, and the first from Laos. The possible biogeographic consequences of this scorpion's distribution are discussed, associated with the possible Pangaean origin of pseudochactid scorpions.

  14. Transcriptome analysis of scorpion species belonging to the Vaejovis genus.

    PubMed

    Quintero-Hernández, Verónica; Ramírez-Carreto, Santos; Romero-Gutiérrez, María Teresa; Valdez-Velázquez, Laura L; Becerril, Baltazar; Possani, Lourival D; Ortiz, Ernesto

    2015-01-01

    Scorpions belonging to the Buthidae family have traditionally drawn much of the biochemist's attention due to the strong toxicity of their venoms. Scorpions not toxic to mammals, however, also have complex venoms. They have been shown to be an important source of bioactive peptides, some of them identified as potential drug candidates for the treatment of several emerging diseases and conditions. It is therefore important to characterize the large diversity of components found in the non-Buthidae venoms. As a contribution to this goal, this manuscript reports the construction and characterization of cDNA libraries from four scorpion species belonging to the Vaejovis genus of the Vaejovidae family: Vaejovis mexicanus, V. intrepidus, V. subcristatus and V. punctatus. Some sequences coding for channel-acting toxins were found, as expected, but the main transcribed genes in the glands actively producing venom were those coding for non disulfide-bridged peptides. The ESTs coding for putative channel-acting toxins, corresponded to sodium channel β toxins, to members of the potassium channel-acting α or κ families, and to calcium channel-acting toxins of the calcin family. Transcripts for scorpine-like peptides of two different lengths were found, with some of the species coding for the two kinds. One sequence coding for La1-like peptides, of yet unknown function, was found for each species. Finally, the most abundant transcripts corresponded to peptides belonging to the long chain multifunctional NDBP-2 family and to the short antimicrobials of the NDBP-4 family. This apparent venom composition is in correspondence with the data obtained to date for other non-Buthidae species. Our study constitutes the first approach to the characterization of the venom gland transcriptome for scorpion species belonging to the Vaejovidae family.

  15. Transcriptome Analysis of Scorpion Species Belonging to the Vaejovis Genus

    PubMed Central

    Quintero-Hernández, Verónica; Ramírez-Carreto, Santos; Romero-Gutiérrez, María Teresa; Valdez-Velázquez, Laura L.; Becerril, Baltazar; Possani, Lourival D.; Ortiz, Ernesto

    2015-01-01

    Scorpions belonging to the Buthidae family have traditionally drawn much of the biochemist’s attention due to the strong toxicity of their venoms. Scorpions not toxic to mammals, however, also have complex venoms. They have been shown to be an important source of bioactive peptides, some of them identified as potential drug candidates for the treatment of several emerging diseases and conditions. It is therefore important to characterize the large diversity of components found in the non-Buthidae venoms. As a contribution to this goal, this manuscript reports the construction and characterization of cDNA libraries from four scorpion species belonging to the Vaejovis genus of the Vaejovidae family: Vaejovis mexicanus, V. intrepidus, V. subcristatus and V. punctatus. Some sequences coding for channel-acting toxins were found, as expected, but the main transcribed genes in the glands actively producing venom were those coding for non disulfide-bridged peptides. The ESTs coding for putative channel-acting toxins, corresponded to sodium channel β toxins, to members of the potassium channel-acting α or κ families, and to calcium channel-acting toxins of the calcin family. Transcripts for scorpine-like peptides of two different lengths were found, with some of the species coding for the two kinds. One sequence coding for La1-like peptides, of yet unknown function, was found for each species. Finally, the most abundant transcripts corresponded to peptides belonging to the long chain multifunctional NDBP-2 family and to the short antimicrobials of the NDBP-4 family. This apparent venom composition is in correspondence with the data obtained to date for other non-Buthidae species. Our study constitutes the first approach to the characterization of the venom gland transcriptome for scorpion species belonging to the Vaejovidae family. PMID:25659089

  16. Pediatric electrocardiograph abnormalities following Centruroides limpidus tecomanus scorpion envenomation.

    PubMed

    Diaz, P; Chowell, G; Ceja, G; D'Auria, T C; Lloyd, R C; Castillo-Chavez, C

    2005-01-01

    Scorpionism is an endemic public health problem in Mexico [Hoffmann, C.C., 1936. La distribucion geografica de los alacranes peligrosos en la Republica Mexicana. Bol. Inst. Hygiene Mex. 2, 321; Hoffmann, C.C., Nieto, D.R., 1939. Segunda contribucion al conocimiento de los alacranes mexicanos. Anal. Inst. Biol. 10, 83-92; Mazzoti, L., Bravo-Becherelle, M.A., 1963. Scorpionism in the Mexican Republic. In: Keegan, H.L., McFarlane, W.V. (Eds.), Venomous and Poissonous Animals and Noxious Plants of the Pacific Area. Pergamon Press, London, pp. 119-131; Monroy-Velasco, J., 1961. Alacranes venenosos de Mexico. Rev. Mex. Cien. Med. Biol., Mex. 1, 1-23; Diaz-Najera, A., 1975. Listas y datos de distribucion geografica de los alacranes de Mexico. Rev. Inv. Salud. Publica. (Mex.) 35, 1; Velasco-Castrejon, O., Lara-Aguilera, R., Alatorre, H., 1976. Aspectos epidemiologicos y clinicos de la picadura de alacran en una area hiperendemica. Rev. Inv. Salud Publica. (Mex.) 36, 93-103; Dehesa-Davila, M., Possani, L.D., 1994. Scorpionism and serotherapy in Mexico. Toxicon 32 (9), 1015-1018]. In this prospective study, we assess cardiovascular disorders in children via electrocardiographic (ECG) recordings following envenomation by scorpion species Centruroides limpidus tecomanus found in the state of Colima, Mexico. We analyzed 113 cases between the ages of 5 and 14 years. Among the most frequent symptoms presented included local pain (99.1%) and paresthesia (75.2%), pruritus (36.3%), sialorrhoea (35.4%), and nystagmus (24.8%). Cardiovascular disorders were observed in 39.8% of cases, 71% of which were rhythm abnormalities. We find a significant association between the frequency of ECG alterations and age, whereby 8-9-year-old children are more likely to experience ECG alterations when compared with other tested age groups.

  17. Three new antimicrobial peptides from the scorpion Pandinus imperator.

    PubMed

    Zeng, Xian-Chun; Zhou, Lingli; Shi, Wanxia; Luo, Xuesong; Zhang, Lei; Nie, Yao; Wang, Jinwei; Wu, Shifen; Cao, Bin; Cao, Hanjun

    2013-07-01

    Three novel cysteine-free venom peptides, which were referred to as Pantinin-1, Pantinin-2 and Pantinin-3, respectively, have been identified from the scorpion Pandinus imperator by cDNA cloning strategy. The precursor of each peptide consists of a signal peptide, a mature peptide with no disulfide bridges, and an acidic propeptide with a typical processing signal. Each of the three peptides is an α-helical, cationic and amphipathic molecule with 13 or 14 amino acid residues. Their amino acid sequences are homologous to those of some 13-mer antimicrobial peptides isolated from scorpions. Antimicrobial assay showed that all the three peptides possess relatively strong activities against Gram-positive bacteria and a fungus, but have very weak antimicrobial activities against Gram-negative bacteria. Toxicity assay showed that the three peptides exhibit very low or mild hemolytic activities against human red blood cells. It is interesting to see that Pantinin-3 is able to potently inhibit the growth of vancomycin-resistant Enterococcus (VRE) S13, a pathogen that can cause a number of human infections; this suggests that Pantinin-3 has great potential to be applied in the treatment of VRE infections. Our findings gain new insights into the structure/function relationships of the small linear cationic antimicrobial peptides from scorpions, and provide new templates for designing of antimicrobial agents targeting antibiotic-resistant pathogenic bacteria.

  18. The "SCORPION" experiment onboard the International Space Station. Preliminary results.

    PubMed

    Borisov, V; Deshevaya, E; Grachov, E; Grigoryan, O; Tchurilo, I; Tsetlin, V

    2003-01-01

    The "SCORPION" program onboard the Russian Segment (RS) of the International Space Station (ISS) is designed to carry out complex research of the effects of the nar-Earth space parameters on the conditions under which various experiments and operations are being conducted. Special attention in this program was paid to the biological objects onboard the orbital station, e.g. it was found that variation in the number of colony forming units (micromicets and bacteria) correlates with the solar activity and the absorbed dose. The "SCORPION" experiment onboard the RS ISS started in January 2002. It was designed to measure the following parameters inside the space absorbed doses in different places inside the RS ISS, the fluxes of energetic charged particles, neutrons and gamma-quanta; the vectors of the magnetic field and low-frequency electromagnetic waves. At the same time the growth of micromicets on the samples of various materials was studied. The description of the "SCORPION" experiment and the preliminary results obtained onboard the RS ISS in 2002 are presented.

  19. A new species of the rare buthid scorpion genus Lissothus Vachon, 1948 from Central Algeria (Scorpiones, Buthidae).

    PubMed

    Lourenço, Wilson Roberto; Sadine, Salah Eddine

    2014-06-01

    Taxonomic considerations are given for the genus Lissothus Vachon, 1948 (Scorpiones, Buthidae). Two species are currently known, Lissothus bernardi Vachon, 1948 from Libya and Lissothus occidentalis Vachon, 1950 from Mauritania. In this contribution, a new species, Lissothus chaambi sp. n., is described from the desert of Central Algeria. The new species is most closely related to L. bernardi. The geographical distribution of the genus is discussed.

  20. Acute myocardial infarction following scorpion sting in a case with obstructive coronary artery disease.

    PubMed

    Patra, Soumya; Satish, K; Singla, Vivek; Ravindranath, K S

    2013-01-01

    The occurrence of an acute myocardial infarction (MI) following a scorpion sting has been very rarely reported in the previous literature. Possible pathogenetic mechanisms include severe hypotension due to hypovolaemic shock and coronary spasm with subsequent thrombosis of coronary vessels developed after the release of vasoactive, inflammatory and thrombogenic substances contained in the scorpion venom. All of the previously reported cases had normal coronary angiogram. We report a case of a 65-year-old woman who presented with severe scorpion sting and was treated with prazosin. But a few hours later, she developed acute anterior wall MI. Coronary angiogram revealed the presence of significant stenosis in coronary arteries. As acute MI owing to significant coronary artery disease can be evident after severe scorpion envenomation, so every case of acute coronary syndrome following scorpion sting needs early diagnosis, thorough cardiovascular evaluation and appropriate treatment. PMID:23715842

  1. Male and female meiosis in the mountain scorpion Zabius fuscus (Scorpiones, Buthidae): heterochromatin, rDNA and TTAGG telomeric repeats.

    PubMed

    Adilardi, Renzo Sebastián; Ojanguren-Affilastro, Andrés Alejandro; Mattoni, Camilo Iván; Mola, Liliana María

    2015-08-01

    All cytogenetically studied scorpions present male achiasmatic meiosis and lack heteromorphic sex chromosomes. In contrast, information about female meiosis in scorpions is scarce due to the difficulty of finding meiotic cells. The genus Zabius includes three described species and no chromosome studies have been performed on it until now. We analyzed the constitutive heterochromatin distribution, NORs and telomeric sequences in mitosis and meiosis of males and females of different populations of Zabius fuscus. All specimens presented 2n = 18 holokinetic chromosomes that gradually decreased in size. Male meiosis presented nine bivalents and a polymorphism for one reciprocal translocation in one population. Telomeric signals were detected at every terminal region, confirming also the presence of a (TTAGG) n motif in Buthidae. Constitutive heterochromatin was found in three chromosome pairs at a terminal region; moreover, NORs were embedded in the heterochromatic region of the largest pair. Chromosome size and landmarks allowed us to propose the chromosomes involved in the rearrangement. In four females, cells at different prophase I stages were analyzed. We describe a diffuse stage and the presence of ring-shaped bivalents. We discuss the possible origin of these bivalents in the framework of chiasmatic or achiasmatic female meiosis. These results contribute to increase the scarce evidence of female meiosis in scorpions and raise new questions about its mechanism.

  2. Scorpion Toxin, BmP01, Induces Pain by Targeting TRPV1 Channel.

    PubMed

    Hakim, Md Abdul; Jiang, Wenbin; Luo, Lei; Li, Bowen; Yang, Shilong; Song, Yuzhu; Lai, Ren

    2015-09-14

    The intense pain induced by scorpion sting is a frequent clinical manifestation. To date, there is no established protocol with significant efficacy to alleviate the pain induced by scorpion envenomation. One of the important reasons is that, little information on pain-inducing compound from scorpion venoms is available. Here, a pain-inducing peptide (BmP01) has been identified and characterized from the venoms of scorpion (Mesobuthus martensii). In an animal model, intraplantar injection of BmP01 in mouse hind paw showed significant acute pain in wild type (WT) mice but not in TRPV1 knock-out (TRPV1 KO) mice during 30 min recording. BmP01 evoked currents in WT dorsal root ganglion (DRG) neurons but had no effect on DRG neurons of TRPV1 KO mice. Furthermore, OPEN ACCESS Toxins 2015, 7 3672 BmP01 evoked currents on TRPV1-expressed HEK293T cells, but not on HEK293T cells without TRPV1. These results suggest that (1) BmP01 is one of the pain-inducing agents in scorpion venoms; and (2) BmP01 induces pain by acting on TRPV1. To our knowledge, this is the first report about a scorpion toxin that produces pain by targeting TRPV1. Identification of a pain-inducing compound may facilitate treating pain induced by scorpion envenomation.

  3. First venom gland transcriptomic analysis of Iranian yellow scorpion "Odonthubuthus doriae" with some new findings.

    PubMed

    NaderiSoorki, Maryam; Galehdari, Hamid; Baradaran, Masomeh; Jalali, Amir

    2016-09-15

    Scorpion venom contains mixture of biologic molecules including selective toxins with medical capability. Odonthubuthus doriae (O. doriae) belonged to Buthidae family of scorpions and gained more interest among Iranian dangerous scorpion since 2005. We constructed the first cDNA library to explore the transcriptomic composition of this Iranian scorpiontelson. Then by used of bioinformatic software each expression sequence taq (EST) from the library analyzed and its quiddity was clear. Analysis showed that toxins (42%) had more venom transcript than other component such as antimicrobial peptides, venom peptides and cell proteins. Over 16% of transcripts didn't have any open reading frames (ORF), however their sequences showed similarity by other scorpion sequences. One EST didn't have any similarity by known scorpion peptides. For the first time; we report a comprehensive study of an Iranian scorpion with interesting and novel findings. We characterized a new putative sodium channel modifier in scorpions by some bioinformatics software, and then predicted its structure and function. PMID:27426055

  4. Scorpion Toxin, BmP01, Induces Pain by Targeting TRPV1 Channel

    PubMed Central

    Hakim, Md Abdul; Jiang, Wenbin; Luo, Lei; Li, Bowen; Yang, Shilong; Song, Yuzhu; Lai, Ren

    2015-01-01

    The intense pain induced by scorpion sting is a frequent clinical manifestation. To date, there is no established protocol with significant efficacy to alleviate the pain induced by scorpion envenomation. One of the important reasons is that, little information on pain-inducing compound from scorpion venoms is available. Here, a pain-inducing peptide (BmP01) has been identified and characterized from the venoms of scorpion (Mesobuthus martensii). In an animal model, intraplantar injection of BmP01 in mouse hind paw showed significant acute pain in wild type (WT) mice but not in TRPV1 knock-out (TRPV1 KO) mice during 30 min recording. BmP01 evoked currents in WT dorsal root ganglion (DRG) neurons but had no effect on DRG neurons of TRPV1 KO mice. Furthermore, BmP01 evoked currents on TRPV1-expressed HEK293T cells, but not on HEK293T cells without TRPV1. These results suggest that (1) BmP01 is one of the pain-inducing agents in scorpion venoms; and (2) BmP01 induces pain by acting on TRPV1. To our knowledge, this is the first report about a scorpion toxin that produces pain by targeting TRPV1. Identification of a pain-inducing compound may facilitate treating pain induced by scorpion envenomation. PMID:26389953

  5. Camelid antivenom development and potential in vivo neutralization of Hottentotta saulcyi scorpion venom.

    PubMed

    Darvish, Maryam; Ebrahimi, Soltan Ahmad; Shahbazzadeh, Delavar; Bagheri, Kamran-Pooshang; Behdani, Mahdi; Shokrgozar, Mohammad Ali

    2016-04-01

    Scorpion envenoming is a serious health problem which can cause a variety of clinical toxic effects. Of the many scorpion species native to Iran, Hottentotta saulcyi is important because its venom can produce toxic effects in man. Nowadays, antivenom derived from hyper immune horses is the only effective treatment for sever scorpion stings. Current limitations of immunotherapy urgently require an efficient alternative with high safety, target affinity and more promising venom neutralizing capability. Recently, heavy chain-only antibodies (HC-Abs) found naturally in camelid serum met the above mentioned advantages. In this study, immuno-reactivities of polyclonal antibodies were tested after successful immunization of camel using H. saulcyi scorpion crude venom. The lethal potency of scorpion venom in C57BL/6 mice injected intraperitoneally was determined to be 2.7 mg/kg. These results were followed by the efficient neutralization of lethal activity of H. saulcyi scorpion venom by injection of antivenom and purified IgG fractions into mice intraperitonelly or intravenously, respectively. HC-Ab camelid antivenom could be considered as a useful serotherapeutics instead of present treatment for scorpion envenomation. PMID:26809016

  6. Scorpion Toxin, BmP01, Induces Pain by Targeting TRPV1 Channel.

    PubMed

    Hakim, Md Abdul; Jiang, Wenbin; Luo, Lei; Li, Bowen; Yang, Shilong; Song, Yuzhu; Lai, Ren

    2015-09-01

    The intense pain induced by scorpion sting is a frequent clinical manifestation. To date, there is no established protocol with significant efficacy to alleviate the pain induced by scorpion envenomation. One of the important reasons is that, little information on pain-inducing compound from scorpion venoms is available. Here, a pain-inducing peptide (BmP01) has been identified and characterized from the venoms of scorpion (Mesobuthus martensii). In an animal model, intraplantar injection of BmP01 in mouse hind paw showed significant acute pain in wild type (WT) mice but not in TRPV1 knock-out (TRPV1 KO) mice during 30 min recording. BmP01 evoked currents in WT dorsal root ganglion (DRG) neurons but had no effect on DRG neurons of TRPV1 KO mice. Furthermore, OPEN ACCESS Toxins 2015, 7 3672 BmP01 evoked currents on TRPV1-expressed HEK293T cells, but not on HEK293T cells without TRPV1. These results suggest that (1) BmP01 is one of the pain-inducing agents in scorpion venoms; and (2) BmP01 induces pain by acting on TRPV1. To our knowledge, this is the first report about a scorpion toxin that produces pain by targeting TRPV1. Identification of a pain-inducing compound may facilitate treating pain induced by scorpion envenomation. PMID:26389953

  7. Clinical course of bark scorpion envenomation managed without antivenom.

    PubMed

    O'Connor, Ayrn; Ruha, Anne-Michelle

    2012-09-01

    Bark scorpion envenomation is potentially life threatening in children and traditionally treated with antivenom (AV). We sought to describe the clinical course, management, complications and outcome of children with severe scorpion envenomation treated with supportive care during a period when AV was unavailable. A retrospective chart review was performed, all children presenting to a referral hospital between September 1, 2004 and July 31, 2006 with severe scorpion envenomation not receiving AV, were included. A standardized data abstraction form was used to record time of symptom onset, time to healthcare facility (HCF), clinical findings, treatment, complications, and length of stay. Eighty-eight patients were included with mean age of 3.7 years (0.33-12). Mean time to symptom onset was 20 min (0-130) and mean time to HCF was 79 min (10-240). Incidence of clinical manifestations include: neuromuscular agitation, 100 %; opsoclonus, 97 %; hypersalivation, 81 %; tachycardia, 82 %; hypertension, 49 %; vomiting, 38 %; fever, 28 %; respiratory distress, 33 %; and hypoxia, 18 %. Complications included rhabdomyolysis in 18 (20 %) and aspiration in 12 (13 %) patients. Intubation was required in 24 % of patients. The most frequently used agents to control symptoms were benzodiazepines (98 %) followed by opioids (69 %). Intravenous fluids were given to 84 %. Mean length of stay was 29 h (range, 6-73 h). There were no deaths. In addition to the classic findings of neuromuscular hyperactivity, opsoclonus, and hypersalivation, a high incidence of hyperadrenergic findings and respiratory compromise are noted in this series. A significant number of patients required mechanical ventilation. Benzodiazpines and opioids were the most common medications used to control symptoms. PMID:22562239

  8. Scorpion venoms: taking the sting out of lung disease.

    PubMed

    Rogers, D F

    1996-05-01

    Scorpion venoms contain specific toxins which block large conductance calcium-activated potassium (BKCa) channels. Use of these toxins has shown that a significant proportion of the action of bronchodilators such as beta-agonists, theophylline, and nitric oxide occurs as a result of the opening of BKCa channels. Similarly, these toxins have shown that inhibitors of airway neurotransmission also operate via BKCa channels. Drugs that open BKCa channels may be alternative bronchodilators (possibly "airway selective" and with fewer side effects) as well as inhibitors of pathophysiological neurogenic influences in asthma, chronic coughing and sneezing, and chronic bronchitis. PMID:8711688

  9. Lethal brain edema, shock, and coagulopathy after scorpion envenomation.

    PubMed

    Cavari, Yuval; Lazar, Isaac; Shelef, Ilan; Sofer, Shaul

    2013-03-01

    We report the case of a 2-year-old Bedouin boy in whom developed severe and unusual complications after being stung, most probably, by the yellow scorpion Leiurus quinquestriatus hebraeus. Five hours after arrival to the emergency department, the boy had multisystem organ failure involving the central nervous system (seizure activity followed by coma with dilated, nonreactive pupils, and severe brain edema), shock (noncardiogenic), disseminated intravascular coagulation, renal failure, hepatic failure, and watery diarrhea, causing his death. In view of the relevant literature, we discuss the pathophysiologic events ultimately leading to his death. PMID:23280335

  10. Hemprich's long-eared bat (Otonycteris hemprichii) as a predator of scorpions: whispering echolocation, passive gleaning and prey selection.

    PubMed

    Holderied, Marc; Korine, Carmi; Moritz, Thorsten

    2011-05-01

    Over 70% of the droppings of the gleaning bat Otonycteris hemprichii can contain scorpion fragments. Yet, some scorpions found in its desert habitat possess venom of the highest known toxicity, rendering them a very dangerous prey. In this study, we describe how O. hemprichii catches and handles scorpions, quantify its flight and echolocation behaviour in the field, investigate what sensory modality it uses to detect scorpions, and test whether it selects scorpions according to their size or toxicity. We confirmed that O. hemprichi is a whispering bat (approx. 80 dB peSPL) with short, multi-harmonic calls. In a flight room we also confirmed that O. hemprichii detects scorpions by their walking noises. Amplitudes of such noises were measured and they reach the flying bat at or below the level of echoes of the loess substrate. Bats dropped straight onto moving scorpions and were stung frequently even straight in their face. Stings did not change the bats' behaviour and caused no signs of poisoning. Scorpions were eaten including poison gland and stinger. Bats showed no preference neither for any of the scorpion species nor their size suggesting they are generalist predators with regard to scorpions.

  11. Prey-sensing and orientational behaviors of sand scorpions

    NASA Astrophysics Data System (ADS)

    Brownell, Philip

    2000-03-01

    Sand scorpions use exquisitely sensitive vibrational and chemosensory systems to locate prey and identify prospective mates active on the sand surface. Prey location is determined by input to a static array of 8 vibration-sensitive receptors, each responding as phase-locked accelerometers to compressional and surface waves conducted through sand. Angular orientation of the target is determined from passing surface (Rayleigh) waves, target distance possibly from the time delay between arrival of compressional and surface waves. For localization and identification of prospective mates, male scorpions use sexually dimorphic chemosensory appendages, the pectines, which are swept over a static stimulus field (chemical trail deposited on sand). These organs support a 2D array of closely-spaced (freq = 100/mm) sensilla containing more than 10^6 neurons, all projecting with great topographic precision to the central nervous system. Movement of this sensory array over a static stimulus field creates timing within the sensory signal. The potential importance of timing as a means of increasing sensitivity and selectivity of sensory response in two distinctly different modes is discussed.

  12. Scorpion envenomation in children: an analysis of 99 cases.

    PubMed

    Uluğ, Mehmet; Yaman, Yöntem; Yapici, Ferda; Can-Uluğ, Nuray

    2012-01-01

    Scorpion envenomation is a life-threatening emergency and a common public health problem in many regions of the world, particularly in children. The aim of this retrospective descriptive study was to describe the epidemiological characteristics and some common clinical symptoms and signs, laboratory findings and outcomes among humans in the southeast Anatolia region of Turkey (Mardin, Midyat). The sting cases mostly occurred in the month of July (36.4%) when the annual temperature is the highest. The majority of the cases were in the 6-10 years of age group. Most of the stings were seen in exposed extremities (92.9%), mainly in the lower limbs (58.6%). Patients in the emergency units showed signs of local and systemic effects, but no lethality occurred except one. Local and autonomic nervous system effects were most frequently characterized by local pain, hyperemia, swelling, itching, malaise, dry mouth, sweating, and thirst. Neurological, cardiovascular and respiratory disorders were uncommon. The global mortality recorded was 10 per 1000 cases. In conclusion, we propose that this information is beneficial for health education and prevention of scorpion sting cases. PMID:22734297

  13. A new mid-Silurian aquatic scorpion-one step closer to land?

    PubMed

    Waddington, Janet; Rudkin, David M; Dunlop, Jason A

    2015-01-01

    One of the oldest known fossil scorpions, a new species from the mid-Silurian Eramosa Formation (430 myr) of Ontario, Canada, exhibits several surprising features. The depositional environment and associated biota indicate a marine habitat; however, the leg morphology of this scorpion, which has a short tarsus in common with all Recent scorpions, suggests that a key adaptation for terrestrial locomotion, the ability to support its weight on a subterminal 'foot', appeared remarkably early in the scorpion fossil record. Specimens are preserved intact and undisturbed in a splayed posture typical of moults rather than carcasses. We postulate that these animals were aquatic, but occasionally ventured into extremely shallow water, or onto a transient subaerially exposed surface while moulting, before returning to deeper water. Shed exuviae were preserved in situ by rapid overgrowth of bacterial biofilm.

  14. Potassium channel blockers from the venom of the Brazilian scorpion Tityus serrulatus ().

    PubMed

    Martin-Eauclaire, Marie-France; Pimenta, Adriano M C; Bougis, Pierre E; De Lima, Maria-Elena

    2016-09-01

    Potassium (K(+)) channels are trans-membrane proteins, which play a key role in cellular excitability and signal transduction pathways. Scorpion toxins blocking the ion-conducting pore from the external side have been invaluable probes to elucidate the structural, functional, and physio-pathological characteristics of these ion channels. This review will focus on the interaction between K(+) channels and their peptide blockers isolated from the venom of the scorpion Tityus serrulatus, which is considered as the most dangerous scorpion in Brazil, in particular in Minas-Gerais State, where many casualties are described each year. The primary mechanisms of action of these K(+) blockers will be discussed in correlation with their structure, very often non-canonical compared to those of other well known K(+) channels blockers purified from other scorpion venoms. Also, special attention will be brought to the most recent data obtained by proteomic and transcriptomic analyses on Tityus serrulatus venoms and venom glands. PMID:27349167

  15. Potassium channel blockers from the venom of the Brazilian scorpion Tityus serrulatus ().

    PubMed

    Martin-Eauclaire, Marie-France; Pimenta, Adriano M C; Bougis, Pierre E; De Lima, Maria-Elena

    2016-09-01

    Potassium (K(+)) channels are trans-membrane proteins, which play a key role in cellular excitability and signal transduction pathways. Scorpion toxins blocking the ion-conducting pore from the external side have been invaluable probes to elucidate the structural, functional, and physio-pathological characteristics of these ion channels. This review will focus on the interaction between K(+) channels and their peptide blockers isolated from the venom of the scorpion Tityus serrulatus, which is considered as the most dangerous scorpion in Brazil, in particular in Minas-Gerais State, where many casualties are described each year. The primary mechanisms of action of these K(+) blockers will be discussed in correlation with their structure, very often non-canonical compared to those of other well known K(+) channels blockers purified from other scorpion venoms. Also, special attention will be brought to the most recent data obtained by proteomic and transcriptomic analyses on Tityus serrulatus venoms and venom glands.

  16. Scorpion bite prevalence and complications: report from a referral centre in southern Iran.

    PubMed

    Sagheb, Mohammad Mahdi; Sharifian, Maryam; Moini, Maryam; Sharifian, Amir Hossein

    2012-04-01

    In this study we describe the clinical features of scorpion bites in southern Iran. The records of scorpion bite victims from January 2000 to January 2009 were obtained from the record library of the Shiraz Nemazi Hospital, Shiraz, Iran. A total of 232 scorpion bite patients were included. Only 14 patients (6%) developed systemic complications. Acute renal failure (ARF) and disseminated intravascular coagulation (DIC) were the most prevalent systemic complications. The renal toxicity of scorpion envenomation is mostly due to Hemiscorpius lepturus stings and this complication is more common in younger children. This may be due to a higher ratio of venom to body mass compared with adults. H. lepturus venom is naturally cytotoxic and may bind directly to kidney tissue causing tubular injury and inducing DIC and haemolysis. PMID:22316623

  17. Un remarquable scorpion fossile dans l'ambre du Liban. Implications dans la phylogénie des Buthoidea

    NASA Astrophysics Data System (ADS)

    Lourenço, Wilson R.

    2001-05-01

    A specimen belonging to a new family, genus and species of fossil scorpion, Archaeobuthidae fam. n., Archaeobuthus estephani gen. n., sp. n., is described from the Early Cretaceous amber of Lebanon. This is the first scorpion to have been found and described from Lebanese amber (±125 Myr). In view of the fact that Lebanese amber is the oldest known amber containing a high diversity of biological inclusions, it is highly unlikely that an older scorpion specimen in amber will ever be found.

  18. Potency of insect-specific scorpion toxins on mosquito control using Bacillus thuringiensis Cry4Aa.

    PubMed

    Matsumoto, Riku; Shimizu, Yoshitaka; Howlader, Mohammad Tofazzal Hossain; Namba, Maho; Iwamoto, Aya; Sakai, Hiroshi; Hayakawa, Tohru

    2014-06-01

    Two insect-specific scorpion toxins, BjαIT and AahIT were produced as alkali-soluble protein inclusions in Escherichia coli. The inclusion bodies themselves exhibited no toxicity against Culex pipiens larvae. However, coadministration with Cry4Aa toxin enhanced the mosquitocidal activity by 2-3 fold. Insect-specific scorpion toxins can be good supplements for Cry toxin-based bioinsecticides. PMID:24508022

  19. Ecology of the scorpion, Microtityus jaumei in Sierra de Canasta, Cuba.

    PubMed

    Cala-Riquelme, Franklyn; Colombo, Marco

    2011-01-01

    An assessment of the population dynamics of Microtityus jaumei Armas (Scorpiones: Buthidae) on the slopes south of Sierra de Canasta, Guantánamo Province, Cuba show an increase in activity over the year (≤ 0.05). The activity peak is related to the reproductive period from June to November. The abundance of scorpions was significantly related to density of the canopy and thickness of the substrate.

  20. Ecology of the Scorpion, Microtityus jaumei in Sierra de Canasta, Cuba

    PubMed Central

    Cala-Riquelme, Franklyn; Colombo, Marco

    2011-01-01

    An assessment of the population dynamics of Microtityus jaumei Armas (Scorpiones: Buthidae) on the slopes south of Sierra de Canasta, Guantánamo Province, Cuba show an increase in activity over the year (≤ 0.05). The activity peak is related to the reproductive period from June to November. The abundance of scorpions was significantly related to density of the canopy and thickness of the substrate. PMID:21870972

  1. Protease inhibitor in scorpion (Mesobuthus eupeus) venom prolongs the biological activities of the crude venom.

    PubMed

    Ma, Hakim; Xiao-Peng, Tang; Yang, Shi-Long; Lu, Qiu-Min; Lai, Ren

    2016-08-01

    It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biological function of protease inhibitors in scorpion venoms remains unknown. In the present study, a trypsin inhibitor was purified and characterized from the venom of scorpion Mesobuthus eupeus, which enhanced the biological activities of crude venom components in mice when injected in combination with crude venom. This protease inhibitor, named MeKTT-1, belonged to Kunitz-type toxins subfamily. Native MeKTT-1 selectively inhibited trypsin with a Kivalue of 130 nmol·L(-1). Furthermore, MeKTT-1 was shown to be a thermo-stable peptide. In animal behavioral tests, MeKTT-1 prolonged the pain behavior induced by scorpion crude venom, suggesting that protease inhibitors in scorpion venom inhibited proteases and protect the functionally important peptide/protein toxins from degradation, consequently keeping them active longer. In conclusion, this was the first experimental evidence about the natural existence of serine protease inhibitor in the venom of scorpion Mesobuthus eupeus, which preserved the activity of venom components, suggests that scorpions may use protease inhibitors for survival. PMID:27608950

  2. Scorpion incidents, misidentification cases and possible implications for the final interpretation of results.

    PubMed

    Lourenço, Wilson R

    2016-01-01

    The aim of this contribution is to bring general information on the classification and in particular on the specific identification of scorpion species dangerous to humans. Several generic groups are taken into consideration, but the Neotropical genus Tityus C. L. Koch, 1836 is used as a major example. The content of this paper is mostly addressed to non-specialists whose research embraces scorpions in several fields such as venom toxins and public health. Although efforts have been made in the last 20 years to create better links between 'true scorpion experts' and non-specialists who use scorpions in their research, such exchanges had never led to a consensus among those different branches of biological and medical research. Consequently, many cases of species misidentification and even more serious errors concerning scorpion classification/identification are often present in the specialized literature. In conclusion, it is suggested here that the frequent cases of misidentification observed in several reports may induce mistakes in the final interpretation of results, leading only to more inefficacity in the treatment of problems caused by infamous scorpion species. PMID:27398081

  3. Broadening the neutralizing capacity of a family of antibody fragments against different toxins from Mexican scorpions.

    PubMed

    Rodríguez-Rodríguez, Everardo Remi; Olamendi-Portugal, Timoteo; Serrano-Posada, Hugo; Arredondo-López, Jonathan Noé; Gómez-Ramírez, Ilse; Fernández-Taboada, Guillermo; Possani, Lourival D; Anguiano-Vega, Gerardo Alfonso; Riaño-Umbarila, Lidia; Becerril, Baltazar

    2016-09-01

    New approaches aimed at neutralizing the primary toxic components present in scorpion venoms, represent a promising alternative to the use of antivenoms of equine origin in humans. New potential therapeutics developed by these approaches correspond to neutralizing antibody fragments obtained by selection and maturation processes from libraries of human origin. The high sequence identity shared among scorpion toxins is associated with an important level of cross reactivity exhibited by these antibody fragments. We have exploited the cross reactivity showed by single chain variable antibody fragments (scFvs) of human origin to re-direct the neutralizing capacity toward various other scorpion toxins. As expected, during these evolving processes several variants derived from a parental scFv exhibited the capacity to simultaneously recognize and neutralize different toxins from Centruroides scorpion venoms. A sequence analyses of the cross reacting scFvs revealed that specific mutations are responsible for broadening their neutralizing capacity. In this work, we generated a set of new scFvs that resulted from the combinatorial insertion of these point mutations. These scFvs are potential candidates to be part of a novel recombinant antivenom of human origin that could confer protection against scorpion stings. A remarkable property of one of these new scFvs (ER-5) is its capacity to neutralize at least three different toxins and its complementary capacity to neutralize the whole venom from Centruroides suffusus in combination with a second scFv (LR), which binds to a different epitope shared by Centruroides scorpion toxins.

  4. Evolution stings: the origin and diversification of scorpion toxin peptide scaffolds.

    PubMed

    Sunagar, Kartik; Undheim, Eivind A B; Chan, Angelo H C; Koludarov, Ivan; Muñoz-Gómez, Sergio A; Antunes, Agostinho; Fry, Bryan G

    2013-12-13

    The episodic nature of natural selection and the accumulation of extreme sequence divergence in venom-encoding genes over long periods of evolutionary time can obscure the signature of positive Darwinian selection. Recognition of the true biocomplexity is further hampered by the limited taxon selection, with easy to obtain or medically important species typically being the subject of intense venom research, relative to the actual taxonomical diversity in nature. This holds true for scorpions, which are one of the most ancient terrestrial venomous animal lineages. The family Buthidae that includes all the medically significant species has been intensely investigated around the globe, while almost completely ignoring the remaining non-buthid families. Australian scorpion lineages, for instance, have been completely neglected, with only a single scorpion species (Urodacus yaschenkoi) having its venom transcriptome sequenced. Hence, the lack of venom composition and toxin sequence information from an entire continent's worth of scorpions has impeded our understanding of the molecular evolution of scorpion venom. The molecular origin, phylogenetic relationships and evolutionary histories of most scorpion toxin scaffolds remain enigmatic. In this study, we have sequenced venom gland transcriptomes of a wide taxonomical diversity of scorpions from Australia, including buthid and non-buthid representatives. Using state-of-art molecular evolutionary analyses, we show that a majority of CSα/β toxin scaffolds have experienced episodic influence of positive selection, while most non-CSα/β linear toxins evolve under the extreme influence of negative selection. For the first time, we have unraveled the molecular origin of the major scorpion toxin scaffolds, such as scorpion venom single von Willebrand factor C-domain peptides (SV-SVC), inhibitor cystine knot (ICK), disulphide-directed beta-hairpin (DDH), bradykinin potentiating peptides (BPP), linear non-disulphide bridged

  5. Severity of Scorpion Stings in the Western Brazilian Amazon: A Case-Control Study

    PubMed Central

    Queiroz, Amanda M.; Sampaio, Vanderson S.; Mendonça, Iran; Fé, Nelson F.; Sachett, Jacqueline; Ferreira, Luiz Carlos L.; Feitosa, Esaú; Wen, Fan Hui; Lacerda, Marcus; Monteiro, Wuelton

    2015-01-01

    Background Scorpion stings are a major public health problem in Brazil, with an increasing number of registered cases every year. Affecting mostly vulnerable populations, the phenomenon is not well described and is considered a neglected disease. In Brazil, the use of anti-venom formulations is provided free of charge. The associate scorpion sting case is subject to compulsory reporting. This paper describes the epidemiology and identifies factors associated with severity of scorpions stings in the state of Amazonas, in the Western Brazilian Amazon. Methodology/Principal Findings This study included all cases of scorpion stings in the state of Amazonas reported to the Brazilian Diseases Surveillance System from January 1, 2007 to December 31, 2014. A case-control study was conducted to identify factors associated with scorpions sting severity. A total of 2,120 cases were reported during this period. The mean incidence rate in the Amazonas was 7.6 per 100,000 inhabitants/year. Scorpion stings showed a large spatial distribution in the state and represent a potential occupational health problem for rural populations. There was a positive correlation between the absolute number of cases and the altimetric river levels in the Central (p<0.001; Rs = 0.479 linear) and Southwest (p = 0.032; linear Rs = 0.261) regions of the state. Cases were mostly classified as mild (68.6%), followed by moderate (26.8%), and severe (4.6%). The overall lethality rate was 0.3%. Lethality rate among children ≤10 years was 1.3%. Age <10 years [OR = 2.58 (95%CI = 1.47–4.55; p = 0.001)], stings occurring in the rural area [OR = 1.97 (95%CI = 1.18–3.29; p = 0.033) and in the South region of the state [OR = 1.85 (95%CI = 1.17–2.93; p = 0.008)] were independently associated with the risk of developing severity. Conclusions/Significance Scorpion stings show an extensive distribution in the Western Brazilian Amazon threatening especially rural populations, children ≤10 in particular. Thus

  6. Scorpion Potassium Channel-blocking Defensin Highlights a Functional Link with Neurotoxin.

    PubMed

    Meng, Lanxia; Xie, Zili; Zhang, Qian; Li, Yang; Yang, Fan; Chen, Zongyun; Li, Wenxin; Cao, Zhijian; Wu, Yingliang

    2016-03-25

    The structural similarity between defensins and scorpion neurotoxins suggests that they might have evolved from a common ancestor. However, there is no direct experimental evidence demonstrating a functional link between scorpion neurotoxins and defensins. The scorpion defensin BmKDfsin4 from Mesobuthus martensiiKarsch contains 37 amino acid residues and a conserved cystine-stabilized α/β structural fold. The recombinant BmKDfsin4, a classical defensin, has been found to have inhibitory activity against Gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteusas well as methicillin-resistant Staphylococcus aureus Interestingly, electrophysiological experiments showed that BmKDfsin4,like scorpion potassium channel neurotoxins, could effectively inhibit Kv1.1, Kv1.2, and Kv1.3 channel currents, and its IC50value for the Kv1.3 channel was 510.2 nm Similar to the structure-function relationships of classical scorpion potassium channel-blocking toxins, basic residues (Lys-13 and Arg-19) of BmKDfsin4 play critical roles in peptide-Kv1.3 channel interactions. Furthermore, mutagenesis and electrophysiological experiments demonstrated that the channel extracellular pore region is the binding site of BmKDfsin4, indicating that BmKDfsin4 adopts the same mechanism for blocking potassium channel currents as classical scorpion toxins. Taken together, our work identifies scorpion BmKDfsin4 as the first invertebrate defensin to block potassium channels. These findings not only demonstrate that defensins from invertebrate animals are a novel type of potassium channel blockers but also provide evidence of a functional link between defensins and neurotoxins.

  7. Serrumab: a novel human single chain-fragment antibody with multiple scorpion toxin-neutralizing capacities.

    PubMed

    Pucca, Manuela Berto; Cerni, Felipe Augusto; Peigneur, Steve; Arantes, Eliane Candiani; Tytgat, Jan; Barbosa, José Elpidio

    2014-01-01

    In Brazil, scorpion envenomation is an important public health problem. The yellow scorpion, Tityus serrulatus (Ts), is considered the most dangerous species in the country, being responsible for the most severe clinical cases of envenomation. Currently, the administration of serum produced in horses is recognized and used as a treatment for accidents with scorpions. However, horse herds' maintenance is costly and the antibodies are heterologous, which can cause anaphylaxis and Serum Sickness. In the present work, a human monoclonal fragment antibody, Serrumab, has been analysed. Toxin neutralizing effects of Serrumab were evaluated using a two-electrode voltage-clamp technique. The results show that Serrumab presented a high neutralizing effect against Ts β-toxins (Ts1, 43.2% and Ts2, 68.8%) and none or low neutralizing effect against α-toxins (Ts3, 0% and Ts5, 10%). Additional experiments demonstrated that Serrumab was also able to neutralize the action of toxins from other scorpion genus (Css II, 45.96% and Lqh III, 100%/β- and α-toxins, respectively). This work indicated that Serrumab is able to neutralize many toxins in Ts venom, and could being considered as a neutralizing antibody for formulating a human anti-scorpion serum in Brazil. Additionally, this work demonstrated that Serrumab could neutralize different toxins from distinct scorpion genus. All these results reinforce the idea that Serrumab is a scFv antibody with multiple neutralizing capacities and a promising candidate for inclusion in scorpion anti-venoms against different genera. PMID:24001307

  8. Enhancement of long-lasting immunoprotective effect against Androctonus australis hector envenomation using safe antigens: Comparative role of MF59 and Alum adjuvants.

    PubMed

    Nouri, Abdelmounaim; Laraba-Djebari, Fatima

    2015-10-26

    Envenomation is a public health problem in many regions of the world. The only available treatment is the serotherapy that has limited efficiency due to the delay of its administration. The goal of this study is to provide a new and more efficient alternative to this treatment. A comparative study of the effects of two adjuvants in their ability to enhance the efficiency of the detoxified and safe antigens to produce a long lasting immunoprotection is undertaken using Aluminum Hydroxide adjuvant (Alum) or the water-in-oil MF59 adjuvant mixed with Androctonus australis hector (Aah) detoxified venom, and compare their effects on the immune system. Immunization schedule was performed with two groups of rabbits, which were injected with attenuated venom and Alum or MF59 adjuvant preparations, once a month during three months. Blood samples were collected each week for cell count, evaluation of myeloperoxidase (MPO) and eosinoperoxydase (EPO) activities and antibody titer. After four months from the last immunization, rabbits were challenged with increased doses of native Aah venom. Results showed that MF59 effect was immediate in the first 24h post-immunization by activating the recruitment of lymphocytes, monocytes and neutrophils, while Alum adjuvant effect seems to be delayed, and appeared in the second week after immunization. An important cell infiltration was observed with Alum preparation, due to its specific local depot effect. However, immunized animals with MF59 preparation challenged with the native venom showed a protective effect against its toxicity until 6 LD50 compared to those immunized with Alum preparation which are only protected at 4 LD50. One week after challenge, only immunized animals with Alum preparation present an increase in cell infiltration, MPO and EPO activities. These results are correlated with the ability of MF59 adjuvant to induce a potent immunoprotective effect against Aah venom compared to Alum adjuvant. PMID:26419199

  9. Orientation and Pore-Forming Mechanism of a Scorpion Pore-Forming Peptide Bound to Magnetically Oriented Lipid Bilayers

    PubMed Central

    Nomura, Kaoru; Corzo, Gerardo; Nakajima, Terumi; Iwashita, Takashi

    2004-01-01

    The orientation and pore-forming mechanisms of pandinin 2 (pin2), an antimicrobial peptide isolated from venom of the African scorpion Pandinus imperator, bound to magnetically oriented lipid bilayers were examined by 31P and 13C solid-state, and 15N liquid-state NMR spectroscopy. 31P NMR measurements at various temperatures, under neutral and acidic conditions, showed that membrane lysis occurred only under acidic conditions, and at temperatures below the liquid crystal-gel phase transition of the lipid bilayers, after incubation for two days in the magnet. Differential scanning calorimetry measurements showed that pin2 induced negative curvature strain in lipid bilayers. The 13C chemical shift values of synthetic pin2 labeled at Gly3, Gly8, Leu12, Phe17, or Ser18 under static or slow magic-angle spinning conditions, indicate that pin2 penetrates the membrane with its average helical axis perpendicular to the membrane surface. Furthermore, amide H-D exchange experiments of 15N-Ala4, Gly8, and Ala9 triply-labeled pin2 suggest that this peptide forms oligomers and confirms that the N-terminal region creates membrane pores. PMID:15298871

  10. Epidemiological aspect of scorpion sting in Bandar Abbas, Iran, during 2009–2011

    PubMed Central

    Moosavy, Seyed Hamid; Shahi, Mehran; Rafinejad, Javad; Zare, Shahram; Madani, Abdoulhossain; Navidpour, Shahrokh

    2016-01-01

    Introduction People in tropical and semi-tropical areas are in danger of scorpion sting, and this can be a serious problem for them. Mortality due to scorpion sting in the tropical and semi-tropical areas of Iran is about 75%, and this makes scorpion sting in these areas a serious medical problem. Because of this problem, our aim was to assess the epidemiological aspects of scorpion sting in Bandar Abbas, Iran, during 2009–2011. Methods In this cross-sectional retrospective study, epidemiologic data of 698 scorpion sting cases, who were referred to the Shahid Mohamadi Hospital of Bandar Abbas in Hormozgan Province collected from 2009 until 2011. The data included demographic and individual information, such as age, gender, geographic location, bite site, when the incident occurred, and anti-venom consumption. The required data were extracted from the patients’ recorded information in the Hospital, and we recorded data in a special checklist and imported the data into the computer for statistical analysis using of SPSS software, version 21.0. Descriptive statistics, including mean, standard deviation, frequency, and percentage, were used for data analysis. Results Two hundred and sixty-one (37.4%) of the cases were urban and 437(62.6%) were rural. Males comprised 50.1% of the cases, and women comprised 49.9% (p >0.05). Twenty-five point two percent of scorpion sting cases occurred among people in the 21 to 30 age group, and there were very few cases among people in the 51 to 60 age range (p<0.05). Most of cases were recorded in April and October, and the fewest cases were recorded in July and January (p<0.05); also 32.2% of scorpion sting cases occurred after midnight and in the early morning hours. Conclusion Our survey showed that there was a high incidence of scorpion stings in rural areas, among 21–30 age group, among housekeepers, and among students. These results indicate the need for public education programs and better sanitation services in the rural

  11. Scorpions regulate their energy metabolism towards increased carbohydrate oxidation in response to dehydration.

    PubMed

    Kalra, Bhawna; Gefen, Eran

    2012-08-01

    Scorpions successfully inhabit some of the most arid habitats on earth. During exposure to desiccating stress water is mobilized from the scorpion hepatopancreas to replenish the hemolymph and retain hydration and osmotic stability. Carbohydrate catabolism is advantageous under these conditions as it results in high metabolic water production rate, as well as the release of glycogen-bound water. Hypothesizing that metabolic fuel utilization in scorpions is regulated in order to boost body water management under stressful conditions we used a comparative approach, studying energy metabolism during prolonged desiccation in four species varying in resistance performance. We used respirometry for calculating respiratory gas exchange ratios, indicative of metabolic fuel utilization, and measured metabolic fuel contents in the scorpion hepatopancreas. We found that hydrated scorpions used a mixture of metabolic fuels (respiratory exchange rates, RER~0.9), but a shift towards carbohydrate catabolism was common during prolonged desiccation stress. Furthermore, the timing of metabolic shift to exclusive carbohydrate oxidation (RER not different from 1.0) was correlated with desiccation resistance of the respective studied species, suggesting triggering by alterations to hemolymph homeostasis.

  12. Predation among armored arachnids: Bothriurus bonariensis (Scorpions, Bothriuridae) versus four species of harvestmen (Harvestmen, Gonyleptidae).

    PubMed

    Albín, Andrea; Toscano-Gadea, Carlos A

    2015-12-01

    Natural selection shapes prey-predator relationships and their behavioral adaptations, which seek to maximize capture success in the predator and avoidance in the prey. We tested the ability of adults of the scorpion Bothriurus bonariensis (Bothriuridae) to prey on synchronous and sympatric adults harvestmen of Acanthopachylus aculeatus, Discocyrtus prospicuus, Parampheres bimaculatus and Pachyloides thorellii (Gonyleptidae). In 72.5% of the cases B. bonariensis tried to prey on the harvestmen. The most successful captures occurred in the trials against A. aculeatus and D. prospicuus. In all the successful attacks the scorpions stung the prey between the chelicerae and consumed them, starting by the anterior portion of their bodies. The harvestmen used different defensive strategies such as fleeing before or after contact with the predator, exudating of chemical substances or staying still at the scorpion's touch. When scorpions contacted the chemical substances secreted by the harvestmen, they immediately rubbed the affected appendix against the substrate. However, exudating of chemical substances did not prevent, in any case, predation on the harvestmen. This is the first study showing the ability of scorpions to prey on different species of harvestmen, as well as the capture and defensive behaviors used by the predator and the prey.

  13. Phylogenomic resolution of scorpions reveals multilevel discordance with morphological phylogenetic signal.

    PubMed

    Sharma, Prashant P; Fernández, Rosa; Esposito, Lauren A; González-Santillán, Edmundo; Monod, Lionel

    2015-04-01

    Scorpions represent an iconic lineage of arthropods, historically renowned for their unique bauplan, ancient fossil record and venom potency. Yet, higher level relationships of scorpions, based exclusively on morphology, remain virtually untested, and no multilocus molecular phylogeny has been deployed heretofore towards assessing the basal tree topology. We applied a phylogenomic assessment to resolve scorpion phylogeny, for the first time, to our knowledge, sampling extensive molecular sequence data from all superfamilies and examining basal relationships with up to 5025 genes. Analyses of supermatrices as well as species tree approaches converged upon a robust basal topology of scorpions that is entirely at odds with traditional systematics and controverts previous understanding of scorpion evolutionary history. All analyses unanimously support a single origin of katoikogenic development, a form of parental investment wherein embryos are nurtured by direct connections to the parent's digestive system. Based on the phylogeny obtained herein, we propose the following systematic emendations: Caraboctonidae is transferred to Chactoidea new superfamilial assignment: ; superfamily Bothriuroidea revalidated: is resurrected and Bothriuridae transferred therein; and Chaerilida and Pseudochactida are synonymized with Buthida new parvordinal synonymies: .

  14. [Scorpion envenomation treated in the Infectious and Tropical Diseases at the Donka National Hospital, Guinea].

    PubMed

    Sako, F B; Bangoura, E F; Traoré, F A; Soumah, M M; Tounkara, T M; Djessanglar, R; Baldé, H; Baldé, O

    2014-12-01

    A retrospective descriptive study was conducted from 1(st) October 2010 to 30 November 2012 on the records of patients admitted for scorpion envenomation in the Department of Infectious and Tropical Diseases at the Donka National Hospital. The objective of this study is to describe the epidemiological profile and clinical characteristics of scorpion envenomation in Maritime Guinea, from scorpion stings recently covered in this service. We collected 75 cases of scorpion envenomation. The median age was 21.5 with interquartile 8 and 20 and sex ratio was 1.29. The upper limbs were involved in 55% of cases, followed by the lower limbs (35%), trunk (6%), head and neck (4%). We observed 63% of patients with local signs, 30% mild and general clinical signs of 7% severe systemic symptoms. All patients received an analgesic and a heterologous antitoxin, associated with an antibiotic (87% of patients), a corticosteroid (72%), diazepam (13%) and furosemide (34.6%). The incidence of scorpion envenomation is not negligible despite underreporting of cases, most often treated in traditional medicine.

  15. Evolutionary morphology of the hemolymph vascular system in scorpions: a character analysis.

    PubMed

    Klußmann-Fricke, B-J; Prendini, L; Wirkner, C S

    2012-11-01

    Phylogenetically informative characters from the internal anatomy of scorpions were first reported more than 150 years ago, but the subject received little attention after the mid-1920s. Recent investigations, using traditional dissection, illustration and histological sectioning, microscopy, and innovative new methods for investigating complex soft tissue anatomy identified a new wealth of variation. Additionally, these investigations confirmed the phylogenetic significance of previously identified structures. Building on earlier work we present a more detailed description of the hemolymph vascular system (HVS) in scorpions, based on comparison of the vascular structures of the heart and the branching pattern of the prosomal arteries among 45 exemplar species representing most of the major scorpion lineages. Using corrosion-casting, MicroCT in combination with computer-aided 3D-reconstruction, and scanning electron microscopy, we conceptualize a series of phylogenetically informative characters for the anterior aorta system and characters of the heart and associated structures (e.g. arrangement of the ostia) of scorpions. Furthermore, we optimize the possible evolution of these new characters on a previous hypothesis of scorpion phylogeny, and discuss alternative character state transformations, their evolutionary consequences, and possible underlying evolutionary mechanisms acting on the HVS.

  16. Predation among armored arachnids: Bothriurus bonariensis (Scorpions, Bothriuridae) versus four species of harvestmen (Harvestmen, Gonyleptidae).

    PubMed

    Albín, Andrea; Toscano-Gadea, Carlos A

    2015-12-01

    Natural selection shapes prey-predator relationships and their behavioral adaptations, which seek to maximize capture success in the predator and avoidance in the prey. We tested the ability of adults of the scorpion Bothriurus bonariensis (Bothriuridae) to prey on synchronous and sympatric adults harvestmen of Acanthopachylus aculeatus, Discocyrtus prospicuus, Parampheres bimaculatus and Pachyloides thorellii (Gonyleptidae). In 72.5% of the cases B. bonariensis tried to prey on the harvestmen. The most successful captures occurred in the trials against A. aculeatus and D. prospicuus. In all the successful attacks the scorpions stung the prey between the chelicerae and consumed them, starting by the anterior portion of their bodies. The harvestmen used different defensive strategies such as fleeing before or after contact with the predator, exudating of chemical substances or staying still at the scorpion's touch. When scorpions contacted the chemical substances secreted by the harvestmen, they immediately rubbed the affected appendix against the substrate. However, exudating of chemical substances did not prevent, in any case, predation on the harvestmen. This is the first study showing the ability of scorpions to prey on different species of harvestmen, as well as the capture and defensive behaviors used by the predator and the prey. PMID:26470886

  17. Phylogenomic resolution of scorpions reveals multilevel discordance with morphological phylogenetic signal

    PubMed Central

    Sharma, Prashant P.; Fernández, Rosa; Esposito, Lauren A.; González-Santillán, Edmundo; Monod, Lionel

    2015-01-01

    Scorpions represent an iconic lineage of arthropods, historically renowned for their unique bauplan, ancient fossil record and venom potency. Yet, higher level relationships of scorpions, based exclusively on morphology, remain virtually untested, and no multilocus molecular phylogeny has been deployed heretofore towards assessing the basal tree topology. We applied a phylogenomic assessment to resolve scorpion phylogeny, for the first time, to our knowledge, sampling extensive molecular sequence data from all superfamilies and examining basal relationships with up to 5025 genes. Analyses of supermatrices as well as species tree approaches converged upon a robust basal topology of scorpions that is entirely at odds with traditional systematics and controverts previous understanding of scorpion evolutionary history. All analyses unanimously support a single origin of katoikogenic development, a form of parental investment wherein embryos are nurtured by direct connections to the parent's digestive system. Based on the phylogeny obtained herein, we propose the following systematic emendations: Caraboctonidae is transferred to Chactoidea new superfamilial assignment; superfamily Bothriuroidea revalidated is resurrected and Bothriuridae transferred therein; and Chaerilida and Pseudochactida are synonymized with Buthida new parvordinal synonymies. PMID:25716788

  18. [Scorpion envenomation treated in the Infectious and Tropical Diseases at the Donka National Hospital, Guinea].

    PubMed

    Sako, F B; Bangoura, E F; Traoré, F A; Soumah, M M; Tounkara, T M; Djessanglar, R; Baldé, H; Baldé, O

    2014-12-01

    A retrospective descriptive study was conducted from 1(st) October 2010 to 30 November 2012 on the records of patients admitted for scorpion envenomation in the Department of Infectious and Tropical Diseases at the Donka National Hospital. The objective of this study is to describe the epidemiological profile and clinical characteristics of scorpion envenomation in Maritime Guinea, from scorpion stings recently covered in this service. We collected 75 cases of scorpion envenomation. The median age was 21.5 with interquartile 8 and 20 and sex ratio was 1.29. The upper limbs were involved in 55% of cases, followed by the lower limbs (35%), trunk (6%), head and neck (4%). We observed 63% of patients with local signs, 30% mild and general clinical signs of 7% severe systemic symptoms. All patients received an analgesic and a heterologous antitoxin, associated with an antibiotic (87% of patients), a corticosteroid (72%), diazepam (13%) and furosemide (34.6%). The incidence of scorpion envenomation is not negligible despite underreporting of cases, most often treated in traditional medicine. PMID:25158841

  19. Clinico-epidemiology of stings and envenoming of Hottentotta tamulus (Scorpiones: Buthidae), the Indian red scorpion from Jaffna Peninsula in northern Sri Lanka.

    PubMed

    Kularatne, Senanayake A M; Dinamithra, Nandana P; Sivansuthan, Sivapalan; Weerakoon, Kosala G A D; Thillaimpalam, Bhanu; Kalyanasundram, Vithiya; Ranawana, Kithsiri B

    2015-01-01

    In recent years, stings of a lethal scorpion species were recorded from Jaffna Peninsula in the northern dry zone of Sri Lanka. This species was identified as Hottentotta tamulus (Scorpiones: Buthidae) which is the Indian red scorpion commonly found in Maharashtra, India. The Teaching Hospital, Jaffna recorded 84 H. tamulus stings over a year in 2012 and of them, 23 cases provided offending scorpions (proven cases). Three localities in Jaffna were recorded as hotspots of scorpion stings namely Palali, Achchuvali and Karainagar. Of the proven cases, 13 (57%) and 10 (43%) were males and females respectively and had a mean age of 30 years (SD ± 20 years). Among them, 5 (22%) were children below 12 years. In 13 (57%) patients stings occurred inside their houses including two children (40%). Six (26%) stings occurred at night when the victims were in sleep. Median time taken to arrive at the hospital from the time of stinging was 58 min (range 8-550 min). Signs of over activation of autonomic nervous system predominated the clinical picture-tachycardia in 14 (61%), high blood pressure in 11 (48%), excessive sweating in 9 (39%), excessive salivation in 5 (22%), hypotension in 4 (17%) and piloerection in 3 (13%). Children showed higher predilection to develop tachycardia - 4 (80%) and excessive salivation - 3 (60%). Priapism was not observed and 17 (74%) patients have developed intense pain at the site of sting. The commonest ECG change was tachycardia (73%) and occasional T wave inversion. Prazosin as a treatment was given to 22 (96%) patients. All patients made recovery and 13 (57%) patients left the hospital within two days. In future, there is a potential risk of spreading this species to elsewhere in the country and may disturb the ecological balance.

  20. Watch Out for Your Neighbor: Climbing onto Shrubs Is Related to Risk of Cannibalism in the Scorpion Buthus cf. occitanus

    PubMed Central

    Urbano-Tenorio, Fernando

    2016-01-01

    The distribution and behavior of foraging animals usually imply a balance between resource availability and predation risk. In some predators such as scorpions, cannibalism constitutes an important mortality factor determining their ecology and behavior. Climbing on vegetation by scorpions has been related both to prey availability and to predation (cannibalism) risk. We tested different hypotheses proposed to explain climbing on vegetation by scorpions. We analyzed shrub climbing in Buthus cf. occitanus with regard to the following: a) better suitability of prey size for scorpions foraging on shrubs than on the ground, b) selection of shrub species with higher prey load, c) seasonal variations in prey availability on shrubs, and d) whether or not cannibalism risk on the ground increases the frequency of shrub climbing. Prey availability on shrubs was compared by estimating prey abundance in sticky traps placed in shrubs. A prey sample from shrubs was measured to compare prey size. Scorpions were sampled in six plots (50 m x 10 m) to estimate the proportion of individuals climbing on shrubs. Size difference and distance between individuals and their closest scorpion neighbor were measured to assess cannibalism risk. The results showed that mean prey size was two-fold larger on the ground. Selection of particular shrub species was not related to prey availability. Seasonal variations in the number of scorpions on shrubs were related to the number of active scorpions, but not with fluctuations in prey availability. Size differences between a scorpion and its nearest neighbor were positively related with a higher probability for a scorpion to climb onto a shrub when at a disadvantage, but distance was not significantly related. These results do not support hypotheses explaining shrub climbing based on resource availability. By contrast, our results provide evidence that shrub climbing is related to cannibalism risk. PMID:27655347

  1. Study of biomechanical, anatomical, and physiological properties of scorpion stingers for developing biomimetic materials.

    PubMed

    Zhao, Zi-Long; Shu, Tao; Feng, Xi-Qiao

    2016-01-01

    Through natural selection, many animal organs have evolved superior mechanical properties and elegant hierarchical structures adaptive to their multiple biological functions. We combine experiments and theory to investigate the composition-structure-property-function relations of scorpion stingers. Their hierarchical structures and functionally gradient mechanical properties were revealed. Slow motion analysis of the penetration process of a scorpion stinger was performed to examine the refined survival skills of scorpions. An experiment-based mechanics model of the stinger was proposed, the results of which revealed an optimized range of penetration angle in an insertion event. Both theoretical and numerical results are in good agreement with our experimental measurements. The analysis method and physical insights of this work are potentially important for investigating a general class of sharp-edge biological materials, e.g., cattle horns, spider fangs, cat claws, and plant thorns.

  2. Study of biomechanical, anatomical, and physiological properties of scorpion stingers for developing biomimetic materials.

    PubMed

    Zhao, Zi-Long; Shu, Tao; Feng, Xi-Qiao

    2016-01-01

    Through natural selection, many animal organs have evolved superior mechanical properties and elegant hierarchical structures adaptive to their multiple biological functions. We combine experiments and theory to investigate the composition-structure-property-function relations of scorpion stingers. Their hierarchical structures and functionally gradient mechanical properties were revealed. Slow motion analysis of the penetration process of a scorpion stinger was performed to examine the refined survival skills of scorpions. An experiment-based mechanics model of the stinger was proposed, the results of which revealed an optimized range of penetration angle in an insertion event. Both theoretical and numerical results are in good agreement with our experimental measurements. The analysis method and physical insights of this work are potentially important for investigating a general class of sharp-edge biological materials, e.g., cattle horns, spider fangs, cat claws, and plant thorns. PMID:26478411

  3. Partial transcriptomic profiling of toxins from the venom gland of the scorpion Parabuthus stridulus.

    PubMed

    Mille, Bea G; Peigneur, Steve; Diego-García, Elia; Predel, Reinhard; Tytgat, Jan

    2014-06-01

    Since it is an apocrine secretion, scorpion venom is a complex mixture that contains a variety of low-molecular-weight basic proteins (neurotoxins), mucus, salts, as well as a large number of other constituents. Diversity of scorpion venom peptides exists also at the transcript level. Two kinds of venom peptides are typically considered: the neurotoxins and the antimicrobial peptides. We constructed a cDNA library and carried an EST (Expressed Sequence Tag) approach to overview the different peptides in the transcriptome of the telson from Parabuthus stridulus. P. stridulus are psammophilous and highly venomous scorpions endemic to Namibia (Prendini 2004) with medical relevance because of important human envenomation occurrence. We obtained 111 ESTs, 20% of them corresponding to cellular process transcripts, 7% to hypothetical proteins and 17% were sequences without good matches, but the majority of ESTs, 56%, corresponds to transcripts encoding for different venom components, including voltage-gated sodium, potassium and calcium channel toxins, antimicrobial peptides and other venom and cell proteins. To the best of our knowledge this report contains the first transcriptome analysis of genes transcribed by the venomous gland of the scorpion species P. stridulus, belonging to the family of medically important Buthidae scorpions. One hundred and eleven ESTs were analyzed, showing an important number of genes that encode for products similar to known scorpion venom components. In total, 17 unique and novel sequences were indentified. The identification and characterization of these compounds will be a good source of novel pharmacological tools for studying ion channels and the understanding of the physiological effects of toxins in P. stridulus envenomations at a molecular level.

  4. Similar burrow architecture of three arid-zone scorpion species implies similar ecological function

    NASA Astrophysics Data System (ADS)

    Adams, Amanda M.; Marais, Eugene; Turner, J. Scott; Prendini, Lorenzo; Pinshow, Berry

    2016-08-01

    Many animals reside in burrows that may serve as refuges from predators and adverse environmental conditions. Burrow design varies widely among and within taxa, and these structures are adaptive, fulfilling physiological (and other) functions. We examined the burrow architecture of three scorpion species of the family Scorpionidae: Scorpio palmatus from the Negev desert, Israel; Opistophthalmus setifrons, from the Central Highlands, Namibia; and Opistophthalmus wahlbergii from the Kalahari desert, Namibia. We hypothesized that burrow structure maintains temperature and soil moisture conditions optimal for the behavior and physiology of the scorpion. Casts of burrows, poured in situ with molten aluminum, were scanned in 3D to quantify burrow structure. Three architectural features were common to the burrows of all species: (1) a horizontal platform near the ground surface, long enough to accommodate the scorpion, located just below the entrance, 2-5 cm under the surface, which may provide a safe place where the scorpion can monitor the presence of potential prey, predators, and mates and where the scorpion warms up before foraging; (2) at least two bends that might deter incursion by predators and may reduce convective ventilation, thereby maintaining relatively high humidity and low temperature; and (3) an enlarged terminal chamber to a depth at which temperatures are almost constant (±2-4 °C). These common features among the burrows of three different species suggest that they are important for regulating the physical environment of their inhabitants and that burrows are part of scorpions' "extended physiology" ( sensu Turner, Physiol Biochem Zool 74:798-822, 2000).

  5. Broadening the neutralizing capacity of a family of antibody fragments against different toxins from Mexican scorpions.

    PubMed

    Rodríguez-Rodríguez, Everardo Remi; Olamendi-Portugal, Timoteo; Serrano-Posada, Hugo; Arredondo-López, Jonathan Noé; Gómez-Ramírez, Ilse; Fernández-Taboada, Guillermo; Possani, Lourival D; Anguiano-Vega, Gerardo Alfonso; Riaño-Umbarila, Lidia; Becerril, Baltazar

    2016-09-01

    New approaches aimed at neutralizing the primary toxic components present in scorpion venoms, represent a promising alternative to the use of antivenoms of equine origin in humans. New potential therapeutics developed by these approaches correspond to neutralizing antibody fragments obtained by selection and maturation processes from libraries of human origin. The high sequence identity shared among scorpion toxins is associated with an important level of cross reactivity exhibited by these antibody fragments. We have exploited the cross reactivity showed by single chain variable antibody fragments (scFvs) of human origin to re-direct the neutralizing capacity toward various other scorpion toxins. As expected, during these evolving processes several variants derived from a parental scFv exhibited the capacity to simultaneously recognize and neutralize different toxins from Centruroides scorpion venoms. A sequence analyses of the cross reacting scFvs revealed that specific mutations are responsible for broadening their neutralizing capacity. In this work, we generated a set of new scFvs that resulted from the combinatorial insertion of these point mutations. These scFvs are potential candidates to be part of a novel recombinant antivenom of human origin that could confer protection against scorpion stings. A remarkable property of one of these new scFvs (ER-5) is its capacity to neutralize at least three different toxins and its complementary capacity to neutralize the whole venom from Centruroides suffusus in combination with a second scFv (LR), which binds to a different epitope shared by Centruroides scorpion toxins. PMID:27212628

  6. Similar burrow architecture of three arid-zone scorpion species implies similar ecological function.

    PubMed

    Adams, Amanda M; Marais, Eugene; Turner, J Scott; Prendini, Lorenzo; Pinshow, Berry

    2016-08-01

    Many animals reside in burrows that may serve as refuges from predators and adverse environmental conditions. Burrow design varies widely among and within taxa, and these structures are adaptive, fulfilling physiological (and other) functions. We examined the burrow architecture of three scorpion species of the family Scorpionidae: Scorpio palmatus from the Negev desert, Israel; Opistophthalmus setifrons, from the Central Highlands, Namibia; and Opistophthalmus wahlbergii from the Kalahari desert, Namibia. We hypothesized that burrow structure maintains temperature and soil moisture conditions optimal for the behavior and physiology of the scorpion. Casts of burrows, poured in situ with molten aluminum, were scanned in 3D to quantify burrow structure. Three architectural features were common to the burrows of all species: (1) a horizontal platform near the ground surface, long enough to accommodate the scorpion, located just below the entrance, 2-5 cm under the surface, which may provide a safe place where the scorpion can monitor the presence of potential prey, predators, and mates and where the scorpion warms up before foraging; (2) at least two bends that might deter incursion by predators and may reduce convective ventilation, thereby maintaining relatively high humidity and low temperature; and (3) an enlarged terminal chamber to a depth at which temperatures are almost constant (±2-4 °C). These common features among the burrows of three different species suggest that they are important for regulating the physical environment of their inhabitants and that burrows are part of scorpions' "extended physiology" (sensu Turner, Physiol Biochem Zool 74:798-822, 2000). PMID:27312362

  7. A new venomous scorpion responsible for severe envenomation in Argentina: Tityus confluens.

    PubMed

    de Roodt, Adolfo R; Lago, Néstor R; Salomón, Oscar D; Laskowicz, Rodrigo D; Neder de Román, Lilia E; López, Raúl A; Montero, Teresa E; Vega, Valeria Del V

    2009-01-01

    In Argentina the scorpions of medical importance belong to the genus Tityus (T.), particularly the species T. trivittatus, the only scorpion whose sting is recognized to be associated with severe human envenoming and death. This genus is distributed from the north of the Patagonian region to the center and some provinces in the north of the country. During the period 2003-2006 four children died following scorpion stings, of which one was certainly and three were probably by T. confluens. In 2006, in the province of Tucumán, a girl died by scorpion envenoming and the scorpion responsible for the death, found in her shoe, was T. confluens. We thus studied the toxicity of venom gland homogenates from T. confluens from the provinces of Jujuy and Catamarca, and of crude venom from specimens from Catamarca and the province of La Rioja. The lethal potencies of the telson homogenates were 7.0 and 18.6microg/g for Jujuy and Catamarca, respectively, while the lethal potency of the crude venom was 0.7microg/g. Injected mice showed generalized congestion and hepatic lesions. Pancreatic damage was observed in some animals. Lungs showed congestion and foci of hemorrhage and mild edema. The heart showed injury in the muscular fibers. The venom showed high reactivity against anti-T. trivittatus antivenom and against two anti-T. serrulatus antivenoms. The anti-T. trivittatus antivenom neutralized the lethal activity of T. confluens venom. In addition, the venom reacted very slightly against an anti-Centruroides antivenom. Therefore, the stings of this scorpion must be considered of risk for humans to the same degree as the stings of T. trivittatus.

  8. Pediatric scorpion envenomation in the United States: morbidity, mortality, and therapeutic innovations.

    PubMed

    Skolnik, Aaron B; Ewald, Michele Burns

    2013-01-01

    In the Southwestern United States, the venom of the scorpion Centruroides sculpturatus (common name bark scorpion) can cause serious and potentially fatal neurotoxicity, with young children most vulnerable to its effects. Historically, advances in the quality of supportive care have made significant improvements in morbidity and mortality. In recent years, the development of effective antivenom therapies has changed the landscape of caring for these patients. This article reviews the background, pathophysiology, diagnosis, and treatment options for C. sculpturatus envenomation. Recent advances in immunotherapy and subsequent implications for pediatric emergency care providers are discussed. PMID:23283277

  9. Biochemical and electrophysiological characteristics of toxins isolated from the venom of the scorpion Centruroides sculpturatus.

    PubMed

    Meves, H; Simard, J M; Watt, D D

    1984-01-01

    Recent progress in biochemical, structural and physiological studies has revealed several interesting properties of the toxins from the American scorpion, Centruroides sculpturatus. These toxins, together with similar toxins from other species of scorpions, comprise a unique family of homologous proteins with phylogenetically related structural differences. There is now evidence from both binding and electrophysiological studies that two distinct classes of toxins are present in the venom of C. sculpturatus. One class of toxins markedly slows inactivation of the sodium permeability but has no demonstrable effect on activation, whereas the second class induces a transient shift in the voltage-dependence of activation. Both groups make inactivation incomplete.

  10. Kalium: a database of potassium channel toxins from scorpion venom.

    PubMed

    Kuzmenkov, Alexey I; Krylov, Nikolay A; Chugunov, Anton O; Grishin, Eugene V; Vassilevski, Alexander A

    2016-01-01

    Kalium (http://kaliumdb.org/) is a manually curated database that accumulates data on potassium channel toxins purified from scorpion venom (KTx). This database is an open-access resource, and provides easy access to pages of other databases of interest, such as UniProt, PDB, NCBI Taxonomy Browser, and PubMed. General achievements of Kalium are a strict and easy regulation of KTx classification based on the unified nomenclature supported by researchers in the field, removal of peptides with partial sequence and entries supported by transcriptomic information only, classification of β-family toxins, and addition of a novel λ-family. Molecules presented in the database can be processed by the Clustal Omega server using a one-click option. Molecular masses of mature peptides are calculated and available activity data are compiled for all KTx. We believe that Kalium is not only of high interest to professional toxinologists, but also of general utility to the scientific community.Database URL:http://kaliumdb.org/. PMID:27087309

  11. Peptides from the scorpion Vaejovis punctatus with broad antimicrobial activity.

    PubMed

    Ramírez-Carreto, Santos; Jiménez-Vargas, Juana María; Rivas-Santiago, Bruno; Corzo, Gerardo; Possani, Lourival D; Becerril, Baltazar; Ortiz, Ernesto

    2015-11-01

    The antimicrobial potential of two new non-disulfide bound peptides, named VpAmp1.0 (LPFFLLSLIPSAISAIKKI, amidated) and VpAmp2.0 (FWGFLGKLAMKAVPSLIGGNKSSSK) is here reported. These are 19- and 25-aminoacid-long peptides with +2 and +4 net charges, respectively. Their sequences correspond to the predicted mature regions from longer precursors, putatively encoded by cDNAs derived from the venom glands of the Mexican scorpion Vaejovis punctatus. Both peptides were chemically synthesized and assayed against a variety of microorganisms, including pathogenic strains from clinical isolates and strains resistant to conventional antibiotics. Two shorter variants, named VpAmp1.1 (FFLLSLIPSAISAIKKI, amidated) and VpAmp2.1 (FWGFLGKLAMKAVPSLIGGNKK), were also synthesized and tested. The antimicrobial assays revealed that the four synthetic peptides effectively inhibit the growth of both Gram-positive (Staphylococcus aureus and Streptococcus agalactiaea) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, with MICs in the range of 2.5-24.0 μM; yeasts (Candida albicans and Candida glabrata) with MICs of 3.1-50.0 μM; and two clinically isolated strains of Mycobacterium tuberculosis-including a multi-drug resistant one- with MICs in the range of 4.8-30.5 μM. A comparison between the activities of the original peptides and their derivatives gives insight into the structural/functional role of their distinctive residues.

  12. Kalium: a database of potassium channel toxins from scorpion venom

    PubMed Central

    Kuzmenkov, Alexey I.; Krylov, Nikolay A.; Chugunov, Anton O.; Grishin, Eugene V.; Vassilevski, Alexander A.

    2016-01-01

    Kalium (http://kaliumdb.org/) is a manually curated database that accumulates data on potassium channel toxins purified from scorpion venom (KTx). This database is an open-access resource, and provides easy access to pages of other databases of interest, such as UniProt, PDB, NCBI Taxonomy Browser, and PubMed. General achievements of Kalium are a strict and easy regulation of KTx classification based on the unified nomenclature supported by researchers in the field, removal of peptides with partial sequence and entries supported by transcriptomic information only, classification of β-family toxins, and addition of a novel λ-family. Molecules presented in the database can be processed by the Clustal Omega server using a one-click option. Molecular masses of mature peptides are calculated and available activity data are compiled for all KTx. We believe that Kalium is not only of high interest to professional toxinologists, but also of general utility to the scientific community. Database URL: http://kaliumdb.org/ PMID:27087309

  13. [A new species of Tityus (Scorpiones: Buthidae) from Turimiquire, Venezuela].

    PubMed

    De Sousa, Leonardo; Manzanilla, Jesús; Parrilla-Alvarez, Pedro

    2006-06-01

    We describe a new species of Buthid scorpion, Tityus quirogae, from the Turimiquire mountains, eastern side of the La Costa range, Monagas and Sucre States, Venezuela. It is morphologically similar to T. nematochirus and T. meridanus. It differs from these species in the distribution of the dorsal femoral trichobothria and in the following combination of characters: (1) I caudal segment with two parallel ventral keels. Caudal segments II to IV with ventral keels that are double in the extremes of the segments and single in the middle, (2) noticeable sexual dimorphism, especially in pedipalp shape; the male chelae are markedly thin and long, (3) number of pectineous teeth (male: 18 in each pecten; female: 18 in the right pecten and 19 in the left one), and (4) number of denticle rows in the movable finger of the right chela (16 in both sexes). T. quirogae is the first species of this genus, in the Northeastern region of Venezuela, with thin and elongated pedipalps. PMID:18494317

  14. Quantification of splice variants using molecular beacon or scorpion primers.

    PubMed

    Taveau, Mathieu; Stockholm, Daniel; Spencer, Melissa; Richard, Isabelle

    2002-06-15

    Uncovering the relationship between the generation of alternative transcripts and cellular processes is of crucial importance in the exploration of a gene's biology. The description and quantification of the spatiotemporal splicing pattern can be one method to select the most interesting transcripts for future studies. Fluorescence-based real-time quantitative RT-PCR has recently revolutionized the possibilities for transcriptional quantification studies. In this report, Molecular Beacon and Scorpion probes have been tested as new possibilities for determining the expression level of alternative transcripts. We validated these systems by analyzing alternative splicing of exons 6, 15, and 16 of the calpain 3 gene with tissues containing large variation in the ratio of the different transcripts. We determined conditions that demonstrated that boundary probes are useful tools and good alternatives to boundary primers, when developing a system to quantify specific transcripts. We suggest that the choice of a quantification system should depend in part on the structure and base composition of the gene and may have to be determined experimentally.

  15. Genome-wide analysis of homeobox genes from Mesobuthus martensii reveals Hox gene duplication in scorpions.

    PubMed

    Di, Zhiyong; Yu, Yao; Wu, Yingliang; Hao, Pei; He, Yawen; Zhao, Huabin; Li, Yixue; Zhao, Guoping; Li, Xuan; Li, Wenxin; Cao, Zhijian

    2015-06-01

    Homeobox genes belong to a large gene group, which encodes the famous DNA-binding homeodomain that plays a key role in development and cellular differentiation during embryogenesis in animals. Here, one hundred forty-nine homeobox genes were identified from the Asian scorpion, Mesobuthus martensii (Chelicerata: Arachnida: Scorpiones: Buthidae) based on our newly assembled genome sequence with approximately 248 × coverage. The identified homeobox genes were categorized into eight classes including 82 families: 67 ANTP class genes, 33 PRD genes, 11 LIM genes, five POU genes, six SINE genes, 14 TALE genes, five CUT genes, two ZF genes and six unclassified genes. Transcriptome data confirmed that more than half of the genes were expressed in adults. The homeobox gene diversity of the eight classes is similar to the previously analyzed Mandibulata arthropods. Interestingly, it is hypothesized that the scorpion M. martensii may have two Hox clusters. The first complete genome-wide analysis of homeobox genes in Chelicerata not only reveals the repertoire of scorpion, arachnid and chelicerate homeobox genes, but also shows some insights into the evolution of arthropod homeobox genes.

  16. Venom proteomic and venomous glands transcriptomic analysis of the Egyptian scorpion Scorpio maurus palmatus (Arachnida: Scorpionidae).

    PubMed

    Abdel-Rahman, Mohamed A; Quintero-Hernandez, Veronica; Possani, Lourival D

    2013-11-01

    Proteomic analysis of the scorpion venom Scorpio maurus palmatus was performed using reverse-phase HPLC separation followed by mass spectrometry determination. Sixty five components were identified with molecular masses varying from 413 to 14,009 Da. The high percentage of peptides (41.5%) was from 3 to 5 KDa which may represent linear antimicrobial peptides and KScTxs. Also, 155 expressed sequence tags (ESTs) were analyzed through construction the cDNA library prepared from a pair of venomous gland. About 77% of the ESTs correspond to toxin-like peptides and proteins with definite open reading frames. The cDNA sequencing results also show the presence of sequences whose putative products have sequence similarity with antimicrobial peptides (24%), insecticidal toxins, β-NaScTxs, κ-KScTxs, α-KScTxs, calcines and La1-like peptides. Also, we have obtained 23 atypical types of venom molecules not recorded in other scorpion species. Moreover, 9% of the total ESTs revealed significant similarities with proteins involved in the cellular processes of these scorpion venomous glands. This is the first set of molecular masses and transcripts described from this species, in which various venom molecules have been identified. They belong to either known or unassigned types of scorpion venom peptides and proteins, and provide valuable information for evolutionary analysis and venomics.

  17. Clinical and epidemiological aspects of scorpion stings in the northeast region of Brazil.

    PubMed

    Barros, Rafaella Moreno; Pasquino, Jackeline Araujo; Peixoto, Laisla Rangel; Targino, Isabely Tamarys Gomes; de Sousa, Jorge Alves; Leite, Renner de Souza

    2014-04-01

    Scorpion stings are a serious public health issue in tropical and subtropical countries. This is a descriptive and retrospective study of the clinical-epidemiological characteristics of scorpion sting cases registered in the Health System in the city of Campina Grande, Paraíba state, from 2007 to 2012. Data was collected from the Injury Notification Information System data banks of the Ministry of Health. A total of 2,283 records, provided by the Third Health Sector of Campina Grande, were analyzed. Data revealed that the majority of the victims are female aged between 20 and 29 years, and the highest incidence of stings was in the urban area. Victims were mostly stung on the feet and hand. Serotherapy was not administered in most cases. The majority of the victims received medical assistance within 1 to 3 hours after the sting. The most prevalent clinical manifestations were pain, edema and paresthesias. Most cases were classified as mild, though seven deaths were reported. The high incidence rate suggests that this town may be an endemic area of scorpion stings, supporting the need to develop strategies to control and prevent scorpion stings. PMID:24820610

  18. Antitoxin activity of plants used in Mexican traditional medicine against scorpion poisoning.

    PubMed

    Jiménez-Ferrer, J E; Pérez-Terán, Y Y; Román-Ramos, R; Tortoriello, J

    2005-01-01

    Scorpions, especially in urban areas of tropical and subtropical regions, present a common risk of poisoning. In Mexico, scorpion envenomation is considered a public health problem. Despite the frequency of scorpion sting cases, there are to date no uniform criteria for their treatment. In Mexican traditional medicine, different plant species have been widely used as a remedy for treating scorpion poisoning. The aim of this work was to evaluate the effect of Bouvardia ternifolia, Aristolochia elegans and Vitex mollis extracts on Centruroides limpidus limpidus venom lethality in mice, and to determine their antagonist activity on guinea pig ileum. The hexane and methanol extract from B. ternifolia modified the LD50 of C. limpidus limpidus venom from 0.750 +/- 0.08 to 1.64 +/- 0.19 and 1.16 +/- 0.14 mg/kg, respectively. The extracts of A. elegans produced lower antitoxic activity, while extracts of V. mollis did not show any protection. On in vitro test, addition of B. ternifolia and A. elegans extracts strongly inhibited, in a concentration-dependent manner, the ileum contractions induced by venom. In general, the results demonstrated the effectiveness of these two plant species in modifying the lethality of C. limpidus limpidus venom in mice.

  19. A new species of Auyantepuia González-Sponga, 1978 (Scorpiones, Chactidae) from French Guiana

    PubMed Central

    Ythier, Eric

    2015-01-01

    Abstract A new species of scorpion belonging to the genus Auyantepuia González-Sponga, 1978 (family Chactidae Pocock, 1893) is described on the basis of three specimens collected in a rainforest formation located in Saut Sabbat, South of Mana, French Guiana. This is the tenth species of the Guiano-Amazonian genus Auyantepuia, and the fifth reported from French Guiana. PMID:26798247

  20. A new species of Auyantepuia González-Sponga, 1978 (Scorpiones, Chactidae) from French Guiana.

    PubMed

    Ythier, Eric

    2015-01-01

    A new species of scorpion belonging to the genus Auyantepuia González-Sponga, 1978 (family Chactidae Pocock, 1893) is described on the basis of three specimens collected in a rainforest formation located in Saut Sabbat, South of Mana, French Guiana. This is the tenth species of the Guiano-Amazonian genus Auyantepuia, and the fifth reported from French Guiana.

  1. Aphicidal efficacy of scorpion- and spider-derived neurotoxins.

    PubMed

    Pal, Narinder; Yamamoto, Takashi; King, Glenn F; Waine, Clement; Bonning, Bryony

    2013-08-01

    Insect-specific neurotoxins that act within the insect hemocoel (body cavity) represent an untapped resource for insect pest management. On the basis of recent advances made in development of appropriate delivery systems for transport of these toxins from the insect gut, across the gut epithelium to their target site, we screened neurotoxins derived from scorpion or spider venom for efficacy against the pea aphid, Acyrthosiphon pisum, and the green peach aphid, Myzus persicae. Toxins were selected to represent different modes of electrophysiological action, including activity on voltage-gated calcium channels (ω-TRTX-Gr1a, ω-agatoxin Aa4a, ω-hexatoxin-Hv1a), calcium- and voltage-activated potassium channels (charybdotoxin, maurotoxin), chloride channels (chlorotoxin) and voltage-gated sodium channels (LqhαIT). The Bacillus thuringiensis-derived toxin Cyt1Aa was also tested as a positive control for toxicity. In per os bioassays with both aphid species, toxicity was only seen for ω-TRTX-Gr1a and Cyt1Aa. On injection into the hemocoel of A. pisum, LD₅₀ values ranged from 1 to 8 ng/mg body weight, with ω-hexatoxin-Hv1a being the most toxic (1.02 ng/mg body weight). All neurotoxins caused rapid paralysis, with charybdotoxin, maurotoxin and chlorotoxin also causing melanization of injected aphids. These data represent the first comprehensive screen of neurotoxins against aphids, and highlight the potential for practical use of the insect-specific toxin ω-hexatoxin-Hv1a in aphid management. PMID:23651761

  2. Aphicidal efficacy of scorpion- and spider-derived neurotoxins.

    PubMed

    Pal, Narinder; Yamamoto, Takashi; King, Glenn F; Waine, Clement; Bonning, Bryony

    2013-08-01

    Insect-specific neurotoxins that act within the insect hemocoel (body cavity) represent an untapped resource for insect pest management. On the basis of recent advances made in development of appropriate delivery systems for transport of these toxins from the insect gut, across the gut epithelium to their target site, we screened neurotoxins derived from scorpion or spider venom for efficacy against the pea aphid, Acyrthosiphon pisum, and the green peach aphid, Myzus persicae. Toxins were selected to represent different modes of electrophysiological action, including activity on voltage-gated calcium channels (ω-TRTX-Gr1a, ω-agatoxin Aa4a, ω-hexatoxin-Hv1a), calcium- and voltage-activated potassium channels (charybdotoxin, maurotoxin), chloride channels (chlorotoxin) and voltage-gated sodium channels (LqhαIT). The Bacillus thuringiensis-derived toxin Cyt1Aa was also tested as a positive control for toxicity. In per os bioassays with both aphid species, toxicity was only seen for ω-TRTX-Gr1a and Cyt1Aa. On injection into the hemocoel of A. pisum, LD₅₀ values ranged from 1 to 8 ng/mg body weight, with ω-hexatoxin-Hv1a being the most toxic (1.02 ng/mg body weight). All neurotoxins caused rapid paralysis, with charybdotoxin, maurotoxin and chlorotoxin also causing melanization of injected aphids. These data represent the first comprehensive screen of neurotoxins against aphids, and highlight the potential for practical use of the insect-specific toxin ω-hexatoxin-Hv1a in aphid management.

  3. A single-point mutation enhances dual functionality of a scorpion toxin.

    PubMed

    Wang, Xueli; Gao, Bin; Zhu, Shunyi

    2016-01-01

    Scorpion venom represents a tremendous, hitherto partially explored peptide library that has been proven to be useful not only for understanding ion channels but also for drug design. MeuTXKα3 is a functionally unknown scorpion toxin-like peptide. Here we describe new transcripts of this gene arising from alternative polyadenylation and its biological function as well as a mutant with a single-point substitution at site 30. Native-like MeuTXKα3 and its mutant were produced in Escherichia coli and their toxic function against Drosophila Shaker K(+) channel and its mammalian counterparts (rKv1.1-rKv1.3) were assayed by two-electrode voltage clamp technique. The results show that MeuTXKα3 is a weak toxin with a wide-spectrum of activity on both Drosophila and mammalian K(+) channels. The substitution of a proline at site 30 by an asparagine, an evolutionarily conserved functional residue in the scorpion α-KTx family, led to an increased activity on rKv1.2 and rKv1.3 but a decreased activity on the Shaker channel without changing the potency on rKv1.1, suggesting a key role of this site in species selectivity of scorpion toxins. MeuTXKα3 was also active on a variety of bacteria with lethal concentrations ranging from 4.66 to 52.01μM and the mutant even had stronger activity on some of these bacterial species. To the best of our knowledge, this is the first report on a bi-functional short-chain peptide in the lesser Asian scorpion venom. Further extensive mutations of MeuTXKα3 at site 30 could help improve its K(+) channel-blocking and antibacterial functions.

  4. Functional evolution of scorpion venom peptides with an inhibitor cystine knot fold.

    PubMed

    Gao, Bin; Harvey, Peta J; Craik, David J; Ronjat, Michel; De Waard, Michel; Zhu, Shunyi

    2013-06-27

    The ICK (inhibitor cystine knot) defines a large superfamily of polypeptides with high structural stability and functional diversity. Here, we describe a new scorpion venom-derived K+ channel toxin (named λ-MeuKTx-1) with an ICK fold through gene cloning, chemical synthesis, nuclear magnetic resonance spectroscopy, Ca2+ release measurements and electrophysiological recordings. λ-MeuKTx-1 was found to adopt an ICK fold that contains a three-strand anti-parallel β-sheet and a 310-helix. Functionally, this peptide selectively inhibits the Drosophila Shaker K+ channel but is not capable of activating skeletal-type Ca2+ release channels/ryanodine receptors, which is remarkably different from the previously known scorpion venom ICK peptides. The removal of two C-terminal residues of λ-MeuKTx-1 led to the loss of the inhibitory activity on the channel, whereas the C-terminal amidation resulted in the emergence of activity on four mammalian K+ channels accompanied by the loss of activity on the Shaker channel. A combination of structural and pharmacological data allows the recognition of three putative functional sites involved in channel blockade of λ-MeuKTx-1. The presence of a functional dyad in λ-MeuKTx-1 supports functional convergence among scorpion venom peptides with different folds. Furthermore, similarities in precursor organization, exon-intron structure, 3D-fold and function suggest that scorpion venom ICK-type K+ channel inhibitors and Ca2+ release channel activators share a common ancestor and their divergence occurs after speciation between buthidae and non-buthids. The structural and functional characterizations of the first scorpion venom ICK toxin with K+ channel-blocking activity sheds light on functionally divergent and convergent evolution of this conserved scaffold of ancient origin.

  5. Impact of hydrocortisone hemisuccinate use on outcome of severe scorpion-envenomed adult patients.

    PubMed

    Bahloul, Mabrouk; Chaari, Anis; Dammak, Hassen; Ben Algia, Najla; Medhioub, Fatma; Ben Hamida, Chokri; Chelly, Hedi; Bouaziz, Mounir

    2014-01-01

    The aim of this study is to analyze if the infusion of hydrocortisone hemisuccinate improve outcome in severe scorpion-envenomated adult patients admitted to intensive care unit (ICU). Pairwise retrospective case-control study with 1:1 matching was designed. Patients were defined as cases when they received hydrocortisone hemisuccinate (as alone steroids) during hospitalization and as controls when they did not received any steroids. Patients were matched according to age, severity factors at admission represented by the presence of pulmonary edema and grades of severity of scorpion envenomation, and scorpion antivenom administration. Eighty-four patients were included as follows: 42 patients in the cases group and 42 patients in the control group. The mean age (±SD) was 40±21 years, ranging from 16 to 90 years. Moreover, 67 (80%) patients have a systemic inflammatory response syndrome on ICU admission. The comparison between cases group and control group showed that age is not significantly different. There were the same proportions of patients with pulmonary edema in 2 groups. Moreover, 23 (54%) patients in case group and 23 (54%) in the control group received scorpion antivenom (P>0.05). The mean temperature on admission was also not significantly different. The presence of systemic inflammatory response syndrome was again not significantly different between 2 groups. The comparison of outcome of the 2 groups showed that the use of mechanical ventilation and its duration, the ICU stay length, and ICU mortality was not significantly different between the 2 groups. Although our study has some limitations, it confirms that the use of hydrocortisone hemisuccinate in severe scorpion-envenomed patients did not improve their outcome. PMID:23584312

  6. Infective endocarditis and septic pulmonary embolism following scorpion sting envenoming in an 11-year-old child.

    PubMed

    Prakash, Vellasamy; Krishnamurthy, Sriram; Mahadevan, Subramanian; Bethou, Adhisivam; Deepak Barathi, S

    2014-05-01

    Scorpion sting is one of the common paediatric toxicological problems encountered in southern India. This rural emergency often results in an autonomic storm causing peripheral circulatory failure and/or congestive cardiac failure, leading to pulmonary oedema. A rare case of scorpion sting envenoming in an 11-year-old boy that led to local cellulitis, dyspnoea and congestive heart failure is presented. This was followed by a persistent high-grade fever which lasted for more than 2 weeks and was complicated by fatal Staphylococcus aureus infective endocarditis and septic pulmonary embolism. Although infective endocarditis has been reported occasionally in adults following scorpion sting, this is the first case of infective endocarditis in a native valve in a child following scorpion sting. The literature is reviewed and the mechanisms for this association are discussed.

  7. Investigating the chemical profile of regenerated scorpion (Parabuthus transvaalicus) venom in relation to metabolic cost and toxicity.

    PubMed

    Nisani, Zia; Boskovic, Danilo S; Dunbar, Stephen G; Kelln, Wayne; Hayes, William K

    2012-09-01

    We investigated the biochemical profile of regenerated venom of the scorpion Parabuthus transvaalicus in relation to its metabolic cost and toxicity. Using a closed-system respirometer, we compared oxygen consumption between milked and unmilked scorpions to determine the metabolic costs associated with the first 192 h of subsequent venom synthesis. Milked scorpions had a substantially (21%) higher mean metabolic rate than unmilked scorpions, with the largest increases in oxygen consumption occurring at approximately 120 h, 162 h, and 186 h post-milking. Lethality tests in crickets indicated that toxicity of the regenerated venom returned to normal levels within 4 d after milking. However, the chemical profile of the regenerated venom, as evaluated by FPLC and MALDI-TOF mass spectrometry, suggested that regeneration of different venom components was asynchronous. Some peptides regenerated quickly, particularly those associated with the scorpion's "prevenom," whereas others required much or all of this time period for regeneration. This asynchrony could explain the different spikes detected in oxygen consumption of milked scorpions as various peptides and other venom components were resynthesized. These observations confirm the relatively high metabolic cost of venom regeneration and suggest that greater venom complexity can be associated with higher costs of venom production.

  8. Investigating the chemical profile of regenerated scorpion (Parabuthus transvaalicus) venom in relation to metabolic cost and toxicity.

    PubMed

    Nisani, Zia; Boskovic, Danilo S; Dunbar, Stephen G; Kelln, Wayne; Hayes, William K

    2012-09-01

    We investigated the biochemical profile of regenerated venom of the scorpion Parabuthus transvaalicus in relation to its metabolic cost and toxicity. Using a closed-system respirometer, we compared oxygen consumption between milked and unmilked scorpions to determine the metabolic costs associated with the first 192 h of subsequent venom synthesis. Milked scorpions had a substantially (21%) higher mean metabolic rate than unmilked scorpions, with the largest increases in oxygen consumption occurring at approximately 120 h, 162 h, and 186 h post-milking. Lethality tests in crickets indicated that toxicity of the regenerated venom returned to normal levels within 4 d after milking. However, the chemical profile of the regenerated venom, as evaluated by FPLC and MALDI-TOF mass spectrometry, suggested that regeneration of different venom components was asynchronous. Some peptides regenerated quickly, particularly those associated with the scorpion's "prevenom," whereas others required much or all of this time period for regeneration. This asynchrony could explain the different spikes detected in oxygen consumption of milked scorpions as various peptides and other venom components were resynthesized. These observations confirm the relatively high metabolic cost of venom regeneration and suggest that greater venom complexity can be associated with higher costs of venom production. PMID:22564718

  9. A new species of Tityus (Scorpiones, Buthidae) from El Edén Cave, Colombia.

    PubMed

    Botero-Trujillo, Ricardo; Flórez D, Eduardo

    2014-05-16

    A new scorpion species, Tityus (Tityus) grottoedensis sp. nov., is herein described based on male and female specimens collected in El Edén Cave and its vicinities (Tolima department, Colombia). The new species, which becomes the first scorpion described from a Colombian cave, is probably a eutroglophile or subtroglophile element; however, additional studies are needed to determine the degree of association of the species to the cave. Among other features, the new species is characterized by having a relatively thin body, a yellow-to-chestnut coloration, sternites IV to VI with visible lateral longitudinal carinae, and the basal piece of the middle lamella of the pectines dilated in male and female.

  10. The Scorpion Toxin Tf2 from Tityus fasciolatus Promotes Nav1.3 Opening.

    PubMed

    Camargos, Thalita S; Bosmans, Frank; Rego, Solange C; Mourão, Caroline B F; Schwartz, Elisabeth F

    2015-01-01

    We identified Tf2, the first β-scorpion toxin from the venom of the Brazilian scorpion Tityus fasciolatus. Tf2 is identical to Tb2-II found in Tityus bahiensis. We found that Tf2 selectively activates human (h)Nav1.3, a neuronal voltage-gated sodium (Nav) subtype implicated in epilepsy and nociception. Tf2 shifts hNav1.3 activation voltage to more negative values, thereby opening the channel at resting membrane potentials. Seven other tested mammalian Nav channels (Nav1.1-1.2; Nav1.4-1.8) expressed in Xenopus oocytes are insensitive upon application of 1 μM Tf2. Therefore, the identification of Tf2 represents a unique addition to the repertoire of animal toxins that can be used to investigate Nav channel function.

  11. A K⁺ channel blocking peptide from the Cuban scorpion Rhopalurus garridoi.

    PubMed

    Rodríguez-Ravelo, Rodolfo; Restano-Cassulini, Rita; Zamudio, Fernando Z; Coronas, Fredy I V; Espinosa-López, Georgina; Possani, Lourival D

    2014-03-01

    A proteomic analysis of the venom obtained from the Cuban scorpion Rhopalurus garridoi was performed. Venom was obtained by electrical stimulation, separated by high performance liquid chromatography, and the molecular masses of their 50 protein components were identified by mass spectrometry. A peptide of 3940 Da molecular mass was obtained in pure form and its primary structure determined. It contains 37 amino acid residues, including three disulfide bridges. Electrophysiological experiments showed that this peptide is capable of blocking reversibly K(+)-channels hKv1.1 with a Kd close to 1 μM, but is not effective against hKv1.4, hERG1 and EAG currents, at the same concentration. This is the first protein component ever isolated from this species of scorpion and was assigned the systematic number α-KTx 2.14.

  12. Scorpion Venom Heat-Resistant Peptide Protects Transgenic Caenorhabditis elegans from β-Amyloid Toxicity

    PubMed Central

    Zhang, Xiao-Gang; Wang, Xi; Zhou, Ting-Ting; Wu, Xue-Fei; Peng, Yan; Zhang, Wan-Qin; Li, Shao; Zhao, Jie

    2016-01-01

    Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Our previous studies found SVHRP could enhance neurogenesis and inhibit microglia-mediated neuroinflammation in vivo. Here, we use the transgenic CL4176, CL2006, and CL2355 strains of Caenorhabditis elegans which express the human Aβ1-42 to investigate the effects and the possible mechanisms of SVHRP mediated protection against Aβ toxicity in vivo. The results showed that SVHRP-fed worms displayed remarkably decreased paralysis, less abundant toxic Aβ oligomers, reduced Aβ plaque deposition with respect to untreated animals. SVHRP also suppressed neuronal Aβ expression-induced defects in chemotaxis behavior and attenuated levels of ROS in the transgenic C. elegans. Taken together, these results suggest SVHRP could protect against Aβ-induced toxicity in C. elegans. Further studies need to be conducted in murine models and humans to analyze the effectiveness of the peptide. PMID:27507947

  13. The Scorpion Toxin Tf2 from Tityus fasciolatus Promotes Nav1.3 Opening

    PubMed Central

    Camargos, Thalita S.; Bosmans, Frank; Rego, Solange C.; Mourão, Caroline B. F.; Schwartz, Elisabeth F.

    2015-01-01

    We identified Tf2, the first β-scorpion toxin from the venom of the Brazilian scorpion Tityus fasciolatus. Tf2 is identical to Tb2-II found in Tityus bahiensis. We found that Tf2 selectively activates human (h)Nav1.3, a neuronal voltage-gated sodium (Nav) subtype implicated in epilepsy and nociception. Tf2 shifts hNav1.3 activation voltage to more negative values, thereby opening the channel at resting membrane potentials. Seven other tested mammalian Nav channels (Nav1.1-1.2; Nav1.4-1.8) expressed in Xenopus oocytes are insensitive upon application of 1 μM Tf2. Therefore, the identification of Tf2 represents a unique addition to the repertoire of animal toxins that can be used to investigate Nav channel function. PMID:26083731

  14. Scorpion Venom Heat-Resistant Peptide Protects Transgenic Caenorhabditis elegans from β-Amyloid Toxicity.

    PubMed

    Zhang, Xiao-Gang; Wang, Xi; Zhou, Ting-Ting; Wu, Xue-Fei; Peng, Yan; Zhang, Wan-Qin; Li, Shao; Zhao, Jie

    2016-01-01

    Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Our previous studies found SVHRP could enhance neurogenesis and inhibit microglia-mediated neuroinflammation in vivo. Here, we use the transgenic CL4176, CL2006, and CL2355 strains of Caenorhabditis elegans which express the human Aβ1-42 to investigate the effects and the possible mechanisms of SVHRP mediated protection against Aβ toxicity in vivo. The results showed that SVHRP-fed worms displayed remarkably decreased paralysis, less abundant toxic Aβ oligomers, reduced Aβ plaque deposition with respect to untreated animals. SVHRP also suppressed neuronal Aβ expression-induced defects in chemotaxis behavior and attenuated levels of ROS in the transgenic C. elegans. Taken together, these results suggest SVHRP could protect against Aβ-induced toxicity in C. elegans. Further studies need to be conducted in murine models and humans to analyze the effectiveness of the peptide. PMID:27507947

  15. Insights into reproductive strategies of Tityus (Archaeotityus) pusillus Pocock, 1893 (Scorpiones, Buthidae).

    PubMed

    de Albuquerque, Cleide Maria Ribeiro; de Araujo Lira, André Felipe

    2016-01-01

    A remarkable diversity of life history strategies has evolved among species for achieving reproductive success, including adaptive growth, protandry, iteroparity, and extra molting. Here, we report on the reproductive strategies of the litter-dwelling scorpion, Tityus (Archaeotityus) pusillus, the most abundant and widespread scorpion species in the Atlantic Forest of northeastern Brazil. We observed both iteroparity and protandry reproductive strategies in this species. Females were competent to produce up to three broods after a single insemination, and no correlation between female size and litter size was observed. Most males reached adulthood 1 month before females following four molts, characterizing protandry. Nevertheless, an extra molt was observed to occur in some males (n=4) and females (n=1). These findings highlight the life history traits of T. (A.) pusillus, which may imply in reproductive success and adaptation to changes in environmental conditions. PMID:27083999

  16. EPIDEMIOLOGY OF SCORPION ENVENOMATION IN THE STATE OF CEARÁ, NORTHEASTERN BRAZIL

    PubMed Central

    FURTADO, Sanny da Silva; BELMINO, José Franscidavid Barbosa; DINIZ, Ana Gilza Quaresma; LEITE, Renner de Souza

    2016-01-01

    This report is a retrospective study of the epidemiology of scorpion sting cases recorded from 2007 to 2013 in the State of Ceará, Northeastern Brazil. Data were collected from the Injury Notification Information System database of the Health Department of Ceará. A total of 11,134 cases were studied and distributed across all the months of the studied period and they occurred mainly in urban areas. Victims were predominantly 20-29 years-old women. Most victims were bitten on the hand; and received medical assistance within 1-3 hours after being bitten. Cases were mostly classified as mild and progressed to cure. Scorpion envenomation in Ceará is an environmental public health problem that needs to be monitored and controlled throughout the year. PMID:27007558

  17. A remarkable new species of Alloscorpiops Vachon, 1980 from a cave in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae)

    PubMed Central

    Lourenço, Wilson R.; Pham, Dinh-Sac

    2015-01-01

    Abstract Among the genera of the subfamily Scorpiopinae Kraepelin, 1905 Alloscorpiops remains rather discrete. Only recently new species were added to this genus, increasing its number from two to five. Therefore, species of Alloscorpiops remain rare. One remarkable new species, Alloscorpiops troglodytes sp. n., is described on the basis of a single male specimen collected inside a cave from Song Thanh Nature Reserve, Cha Vanh Commune, Nam Giang District in Vietnam. The new species presents most features exhibited by scorpions of the genus Alloscorpiops, but it is characterized by reduced size, slender body and elongated pedipalps. This new scorpion taxon represents the third species of Scorpiopinae discovered in a cave system, and may be another endemic element in the fauna of Vietnam. PMID:25987872

  18. Bacterial endosymbiont infections in 'living fossils': a case study of North American vaejovid scorpions.

    PubMed

    Bryson, Robert W

    2014-07-01

    Bacterial endosymbionts are common among arthropods, and maternally inherited forms can affect the reproductive and behavioural traits of their arthropod hosts. The prevalence of bacterial endosymbionts and their role in scorpion evolution have rarely been investigated. In this study, 61 samples from 40 species of scorpion in the family Vaejovidae were screened for the presence of the bacterial endosymbionts Cardinium, Rickettsia, Spiroplasma and Wolbachia. No samples were infected by these bacteria. However, one primer pair specifically designed to amplify Rickettsia amplified nontarget genes of other taxa. Similar off-target amplification using another endosymbiont-specific primer was also found during preliminary screenings. Results caution against the overreliance on previously published screening primers to detect bacterial endosymbionts in host taxa and suggest that primer specificity may be higher in primers targeting nuclear rather than mitochondrial genes.

  19. EPIDEMIOLOGY OF SCORPION ENVENOMATION IN THE STATE OF CEARÁ, NORTHEASTERN BRAZIL.

    PubMed

    Furtado, Sanny da Silva; Belmino, José Franscidavid Barbosa; Diniz, Ana Gilza Quaresma; Leite, Renner de Souza

    2016-01-01

    This report is a retrospective study of the epidemiology of scorpion sting cases recorded from 2007 to 2013 in the State of Ceará, Northeastern Brazil. Data were collected from the Injury Notification Information System database of the Health Department of Ceará. A total of 11,134 cases were studied and distributed across all the months of the studied period and they occurred mainly in urban areas. Victims were predominantly 20-29 years-old women. Most victims were bitten on the hand; and received medical assistance within 1-3 hours after being bitten. Cases were mostly classified as mild and progressed to cure. Scorpion envenomation in Ceará is an environmental public health problem that needs to be monitored and controlled throughout the year. PMID:27007558

  20. Digestive amylase of a primitive animal, the scorpion: purification and biochemical characterization.

    PubMed

    Louati, Hanen; Zouari, Nacim; Fendri, Ahmed; Gargouri, Youssef

    2010-04-01

    Scorpion, one of the most ancient invertebrates was chosen, as a model of a primitive animal, to purify and characterize an amylase located in the hepatopancreas. The scorpion digestive amylase (SDA) was purified. Pure SDA was obtained after heat treatment followed by ammonium sulfate fractionation and three steps of chromatography. The pure amylase is not glycosylated and has a molecular mass of 59,101 Da determined by MALDI-TOF MS analysis. The maximal amylase activity was measured at pH 7.0 and 50 degrees C, in the presence of Ca2+ and using potato starch as substrate. The enzyme was able to hydrolyze also, glycogen and amylose. The 23 NH2-terminal amino acid SDA residues were sequenced. The sequence obtained is similar to those of mammalian and avian pancreatic amylases. Nevertheless, polyclonal antibodies directed against SDA failed to recognize classical digestive amylases like the porcine pancreatic one.

  1. Insights into reproductive strategies of Tityus (Archaeotityus) pusillus Pocock, 1893 (Scorpiones, Buthidae).

    PubMed

    de Albuquerque, Cleide Maria Ribeiro; de Araujo Lira, André Felipe

    2016-01-01

    A remarkable diversity of life history strategies has evolved among species for achieving reproductive success, including adaptive growth, protandry, iteroparity, and extra molting. Here, we report on the reproductive strategies of the litter-dwelling scorpion, Tityus (Archaeotityus) pusillus, the most abundant and widespread scorpion species in the Atlantic Forest of northeastern Brazil. We observed both iteroparity and protandry reproductive strategies in this species. Females were competent to produce up to three broods after a single insemination, and no correlation between female size and litter size was observed. Most males reached adulthood 1 month before females following four molts, characterizing protandry. Nevertheless, an extra molt was observed to occur in some males (n=4) and females (n=1). These findings highlight the life history traits of T. (A.) pusillus, which may imply in reproductive success and adaptation to changes in environmental conditions.

  2. Effects of Tityus stigmurus (Thorell 1876) (Scorpiones: Buthidae) venom in isolated perfused rat kidneys.

    PubMed

    Silva, Nathalia A; Albuquerque, Cleide M R; Marinho, Aline D; Jorge, Roberta J B; Silva, Antonio G; Monteiro, Helena S A; Silva, Túlio D; Silva, Márcia V; Correia, Maria Tereza S; Pereira, Ticiana P; Martins, Alice M C; Menezes, Dalgimar B; Ximenes, Rafael M; Martins, René D

    2016-01-01

    Scorpions belonging to the Tityus genus are of medical interest in Brazil. Among them, Tityus stigmurus is the main scorpion responsible for stings in the Northeast region. After a sting, the scorpion venom distributes rapidly to the organs, reaching the kidneys quickly. However, there are few studies concerning the renal pathophysiology of scorpion poisoning. In this study, we evaluated the effects of T. stigmurus venom (TsV) on renal parameters in isolated rat kidneys. Wistar rats (n = 6), weighing 250-300 g, were perfused with Krebs-Henseleit solution containing 6 g/100 mL bovine serum albumin. TsV at 0.3 and 1.0 μg/mL was tested, and the effects on perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and electrolyte excretion were analyzed. Effects were observed only at TsV concentration of 1.0 μg/mL, which increased PP (controlPP40' = 92.7 ± 1.95; TsVPP40' = 182.0 ± 4.70* mmHg, *p < 0.05), RVR (controlRVR40' = 3.28 ± 0.23 mmHg; TstRVR40' = 6.76 ± 0.45* mmHg, *p < 0.05), UF (controlUF50' = 0.16 ± 0.04; TstUF50' = 0.60 ± 0.10* mL/g/min,*p < 0.05), GFR and electrolyte excretion, with histological changes that indicate renal tubular injury. In conclusion, T. stigmurus venom induces a transient increase in PP with tubular injury, both of which lead to an augmented electrolyte excretion. PMID:27142547

  3. Effects of Tityus stigmurus (Thorell 1876) (Scorpiones: Buthidae) venom in isolated perfused rat kidneys.

    PubMed

    Silva, Nathalia A; Albuquerque, Cleide M R; Marinho, Aline D; Jorge, Roberta J B; Silva, Antonio G; Monteiro, Helena S A; Silva, Túlio D; Silva, Márcia V; Correia, Maria Tereza S; Pereira, Ticiana P; Martins, Alice M C; Menezes, Dalgimar B; Ximenes, Rafael M; Martins, René D

    2016-01-01

    Scorpions belonging to the Tityus genus are of medical interest in Brazil. Among them, Tityus stigmurus is the main scorpion responsible for stings in the Northeast region. After a sting, the scorpion venom distributes rapidly to the organs, reaching the kidneys quickly. However, there are few studies concerning the renal pathophysiology of scorpion poisoning. In this study, we evaluated the effects of T. stigmurus venom (TsV) on renal parameters in isolated rat kidneys. Wistar rats (n = 6), weighing 250-300 g, were perfused with Krebs-Henseleit solution containing 6 g/100 mL bovine serum albumin. TsV at 0.3 and 1.0 μg/mL was tested, and the effects on perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and electrolyte excretion were analyzed. Effects were observed only at TsV concentration of 1.0 μg/mL, which increased PP (controlPP40' = 92.7 ± 1.95; TsVPP40' = 182.0 ± 4.70* mmHg, *p < 0.05), RVR (controlRVR40' = 3.28 ± 0.23 mmHg; TstRVR40' = 6.76 ± 0.45* mmHg, *p < 0.05), UF (controlUF50' = 0.16 ± 0.04; TstUF50' = 0.60 ± 0.10* mL/g/min,*p < 0.05), GFR and electrolyte excretion, with histological changes that indicate renal tubular injury. In conclusion, T. stigmurus venom induces a transient increase in PP with tubular injury, both of which lead to an augmented electrolyte excretion.

  4. A new species of Euscorpius Thorell, 1876 (Scorpiones, Euscorpiidae) from south western Turkey

    PubMed Central

    Yağmur, Ersen Aydın; Tropea, Gioele; Yeşilyurt, Fatih

    2013-01-01

    Abstract A new scorpion species, Euscorpius lycius sp. n., is described based on specimens collected from Muğla and Antalya Provinces, in southwestern Turkey. It is characterized by a standard trichobothrial pattern (Pv=8/9, et=6, em=4, eb=4), small size and light brown/reddish coloration. With the description of Euscorpius lycius sp. n., the number of valid species of the genus Euscorpius in Turkey increases to 5. PMID:24294072

  5. Scorpion envenoming caused by Tityus cf. silvestris evolving with severe muscle spasms in the Brazilian Amazon.

    PubMed

    Monteiro, Wuelton Marcelo; de Oliveira, Sâmella Silva; Pivoto, Guilherme; Alves, Eliane Campos; de Almeida Gonçalves Sachett, Jacqueline; Alexandre, Cleber Nunes; Fé, Nelson Ferreira; Barbosa Guerra, Maria das Graças Vale; da Silva, Iran Mendonça; Tavares, Antonio Magela; Ferreira, Luiz Carlos de Lima; Lacerda, Marcus Vinícius Guimarães

    2016-09-01

    Scorpion stings are a public health problem in the Brazilian Amazon. However, detailed clinical characterization with the proper animal identification is scarce. Here we report a confirmed case of envenoming by Tityus cf. silvestris in the Brazilian Amazon. The case evolved with generalized muscle spasms and was treated with antivenom and supportive therapy, requiring intensive care unit admission. The patient evolved favourably and was discharged after 9 days of hospitalization. PMID:27368713

  6. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    PubMed

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity. PMID:16169172

  7. Variability in venom volume, flow rate and duration in defensive stings of five scorpion species.

    PubMed

    van der Meijden, Arie; Coelho, Pedro; Rasko, Mykola

    2015-06-15

    Scorpions have been shown to control their venom usage in defensive encounters, depending on the perceived threat. Potentially, the venom amount that is injected could be controlled by reducing the flow speed, the flow duration, or both. We here investigated these variables by allowing scorpions to sting into an oil-filled chamber, and recording the accreting venom droplets with high-speed video. The size of the spherical droplets on the video can then be used to calculate their volume. We recorded defensive stings of 20 specimens representing 5 species. Significant differences in the flow rate and total expelled volume were found between species. These differences are likely due to differences in overall size between the species. Large variation in both venom flow speed and duration are described between stinging events of single individuals. Both venom flow rate and flow duration correlate highly with the total expelled volume, indicating that scorpions may control both variables in order to achieve a desired end volume of venom during a sting.

  8. Behavioral, histopathological and biochemical impairments observed in mice envenomed by the scorpion: Hottentota gentili (Pallary, 1924).

    PubMed

    El Hidan, Moulay Abdelmonaim; Touloun, Oulaid; El Hiba, Omar; Chait, Abderrahman; Eddine Hafid, Jamal; Boumezzough, Ali

    2015-09-01

    Hottentota gentili is a black scorpion which has been considered as dangerous specie by many authors. However there are no data regarding minimal lethal dose and effects of the scorpion venom till now. We therefore aimed, by the present investigation, to assess on the one hand, the LD50 of H. gentili venom by sublethal injection and the effects on some vital organs, by a histological and a biochemical tools. On the other hand, the possible neurobehavioral impairments, in Swiss mice, 3 h, 6 h and 12 h following envenomation. The LD50 of H. gentili scorpion venom was found to be 0.46 mg/kg by subcutaneous injection route. Venom produced focal fragmentation of myocardial fibers, while lungs showed rupture of the alveolar structure. Intestines showed selective histopathological changes. Concomitantly, there was a significant rise in the serum enzymes levels, as well as hyperkalemia and a high level of plasma albumine and creatine. Proteinuria was also observed. The observed behavioral effects were a hypoactivity in the both experiments 30 min and 3 h after injection. The envenomation produced an increased immobility time only 30 min and 3 h post injection in the tail suspension test (TST).

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

    PubMed

    de Oliveira, Ursula Castro; Candido, Denise Maria; Dorce, Valquíria Abrão Coronado; Junqueira-de-Azevedo, Inácio de Loiola Meirelles

    2015-03-01

    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.

  10. Venom-spraying behavior of the scorpion Parabuthus transvaalicus (Arachnida: Buthidae).

    PubMed

    Nisani, Zia; Hayes, William K

    2015-06-01

    Many animals use chemical squirting or spraying behavior as a defensive response. Some members of the scorpion genus Parabuthus (family Buthidae) can spray their venom. We examined the stimulus control and characteristics of venom spraying by Parabuthus transvaalicus to better understand the behavioral context for its use. Venom spraying occurred mostly, but not always, when the metasoma (tail) was contacted (usually grasped by forceps), and was absent during stinging-like thrusts of the metasoma apart from contact. Scorpions were significantly more likely to spray when contact was also accompanied by airborne stimuli. Sprays happened almost instantaneously following grasping by forceps (median=0.23s) as a brief (0.07-0.30s, mean=0.18s), fine stream (<5° arc) that was not directed toward the stimulus source; however, rapid independent movements of the metasoma and/or telson (stinger) often created a more diffuse spray, increasing the possibility of venom contact with the sensitive eyes of potential scorpion predators. Successive venom sprays varied considerably in duration and velocity. Collectively, these results suggest that venom spraying might be useful as an antipredator function and can be modulated based on threat.

  11. Venom-spraying behavior of the scorpion Parabuthus transvaalicus (Arachnida: Buthidae).

    PubMed

    Nisani, Zia; Hayes, William K

    2015-06-01

    Many animals use chemical squirting or spraying behavior as a defensive response. Some members of the scorpion genus Parabuthus (family Buthidae) can spray their venom. We examined the stimulus control and characteristics of venom spraying by Parabuthus transvaalicus to better understand the behavioral context for its use. Venom spraying occurred mostly, but not always, when the metasoma (tail) was contacted (usually grasped by forceps), and was absent during stinging-like thrusts of the metasoma apart from contact. Scorpions were significantly more likely to spray when contact was also accompanied by airborne stimuli. Sprays happened almost instantaneously following grasping by forceps (median=0.23s) as a brief (0.07-0.30s, mean=0.18s), fine stream (<5° arc) that was not directed toward the stimulus source; however, rapid independent movements of the metasoma and/or telson (stinger) often created a more diffuse spray, increasing the possibility of venom contact with the sensitive eyes of potential scorpion predators. Successive venom sprays varied considerably in duration and velocity. Collectively, these results suggest that venom spraying might be useful as an antipredator function and can be modulated based on threat. PMID:25748565

  12. Variability in venom volume, flow rate and duration in defensive stings of five scorpion species.

    PubMed

    van der Meijden, Arie; Coelho, Pedro; Rasko, Mykola

    2015-06-15

    Scorpions have been shown to control their venom usage in defensive encounters, depending on the perceived threat. Potentially, the venom amount that is injected could be controlled by reducing the flow speed, the flow duration, or both. We here investigated these variables by allowing scorpions to sting into an oil-filled chamber, and recording the accreting venom droplets with high-speed video. The size of the spherical droplets on the video can then be used to calculate their volume. We recorded defensive stings of 20 specimens representing 5 species. Significant differences in the flow rate and total expelled volume were found between species. These differences are likely due to differences in overall size between the species. Large variation in both venom flow speed and duration are described between stinging events of single individuals. Both venom flow rate and flow duration correlate highly with the total expelled volume, indicating that scorpions may control both variables in order to achieve a desired end volume of venom during a sting. PMID:25911958

  13. Optimized scorpion polypeptide LMX: a pest control protein effective against rice leaf folder.

    PubMed

    Tianpei, Xiuzi; Zhu, Yingguo; Li, Shaoqing

    2014-01-01

    Lepidopteran insect pests are the main class of pests causing significant damage to crop plant yields. Insecticidal scorpion peptides exhibit toxicity specific for insects. Here, we report that a peptide LMX, optimized from the insect-specific scorpion neurotoxin LqhIT2, showed high levels of activity against rice leaf folder in vitro and in planta. Oral ingestion of LMX protein led to a significant decrease in feeding on rice leaves, repression of larval growth and development, delay in molting, and increase in larval lethality. Compared with LqhIT2 protein, the stability and insecticidal efficacy of LMX was better. Meanwhile, biochemical analysis showed that LMX protein ingestion dramatically decreased ecdysone content in rice leaf folder larvae, and down-regulated enzymatic activities of the detoxification system (α-naphthyl acetate esterase and glutathione S-transferase), the digestive system (tryptase and chymotrypsin), and the antioxidant system (catalase). These changes were tightly correlated with the dosage of LMX protein. Transgene analysis showed that the rate of leaf damage, and the number of damaged tillers and leaves in the transgenic line were greatly reduced relative to wild type plants and empty vector plants. Based on these observations, we propose that the insect-specific scorpion neurotoxin peptide LMX is an attractive and effective alternative molecule for the protection of rice from rice leaf folder. PMID:24964088

  14. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    PubMed

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity.

  15. Voltage-gated sodium channel modulation by scorpion α-toxins

    PubMed Central

    Bosmans, Frank; Tytgat, Jan

    2007-01-01

    Voltage-gated Na+ channels are integral membrane proteins that function as a gateway for a selective permeation of sodium ions across biological membranes. In this way, they are crucial players for the generation of action potentials in excitable cells. Voltage-gated Na+ channels are encoded by at least nine genes in mammals. The different isoforms have remarkably similar functional properties, but small changes in function and pharmacology are biologically well-defined, as underscored by mutations that cause several diseases and by modulation of a myriad of compounds respectively. This review will stress on the modulation of voltage-gated Na+ channels by scorpion alpha-toxins. Nature has designed these two classes of molecules as if they were predestined to each other: an inevitable ‘encounter’ between a voltage-gated Na+ channel isoform and an alpha-toxin from scorpion venom indeed results in a dramatically changed Na+ current phenotype with clear-cut consequences on electrical excitability and sometimes life or death. This fascinating aspect justifies an overview on scorpion venoms, their alpha-toxins and the Na+ channel targets they are built for, as well as on the molecular determinants that govern the selectivity and affinity of this ‘inseparable duo’. PMID:17087986

  16. Species Delimitation and Morphological Divergence in the Scorpion Centruroides vittatus (Say, 1821): Insights from Phylogeography

    PubMed Central

    Yamashita, Tsunemi; Rhoads, Douglas D.

    2013-01-01

    Scorpion systematics and taxonomy have recently shown a need for revision, partially due to insights from molecular techniques. Scorpion taxonomy has been difficult with morphological characters as disagreement exists among researchers with character choice for adequate species delimitation in taxonomic studies. Within the family Buthidae, species identification and delimitation is particularly difficult due to the morphological similarity among species and extensive intraspecific morphological diversity. The genus Centruroides in the western hemisphere is a prime example of the difficulty in untangling the taxonomic complexity within buthid scorpions. In this paper, we present phylogeographic, Ecological Niche Modeling, and morphometric analyses to further understand how population diversification may have produced morphological diversity in Centruroides vittatus (Say, 1821). We show that C. vittatus populations in the Big Bend and Trans-Pecos region of Texas, USA are phylogeographically distinct and may predate the Last Glacial Maximum (LGM). In addition, we suggest the extended isolation of Big Bend region populations may have created the C. vittatus variant once known as C. pantheriensis. PMID:23861878

  17. New Fossil Scorpion from the Chiapas Amber Lagerstätte

    PubMed Central

    Riquelme, Francisco; Villegas-Guzmán, Gabriel; González-Santillán, Edmundo; Córdova-Tabares, Víctor; Francke, Oscar F.; Piedra-Jiménez, Dulce; Estrada-Ruiz, Emilio; Luna-Castro, Bibiano

    2015-01-01

    A new species of scorpion is described based on a rare entire adult male preserved in a cloudy amber from Miocene rocks in the Chiapas Highlands, south of Mexico. The amber-bearing beds in Chiapas constitute a Conservation Lagerstätte with outstanding organic preservation inside plant resin. The new species is diagnosed as having putative characters that largely correspond with the genus Tityus Koch, 1836 (Scorpiones, Buthidae). Accordingly, it is now referred to as Tityus apozonalli sp. nov. Its previously unclear phylogenetic relationship among fossil taxa of the family Buthidae from both Dominican and Mexican amber is also examined herein. Preliminarily results indicate a basal condition of T. apozonalli regarding to Tityus geratus Santiago-Blay and Poinar, 1988, Tityus (Brazilotityus) hartkorni Lourenço, 2009, and Tityus azari Lourenço, 2013 from Dominican amber, as was Tityus (Brazilotityus) knodeli Lourenço, 2014 from Mexican amber. Its close relationships with extant Neotropic Tityus-like subclades such as ‘Tityus clathratus’ and the subgenus Tityus (Archaeotityus) are also discussed. This new taxon adds to the knowledge of New World scorpions from the Miocene that are rarely found trapped in amber. PMID:26244974

  18. Optimized Scorpion Polypeptide LMX: A Pest Control Protein Effective against Rice Leaf Folder

    PubMed Central

    Tianpei, Xiuzi; Zhu, Yingguo; Li, Shaoqing

    2014-01-01

    Lepidopteran insect pests are the main class of pests causing significant damage to crop plant yields. Insecticidal scorpion peptides exhibit toxicity specific for insects. Here, we report that a peptide LMX, optimized from the insect-specific scorpion neurotoxin LqhIT2, showed high levels of activity against rice leaf folder in vitro and in planta. Oral ingestion of LMX protein led to a significant decrease in feeding on rice leaves, repression of larval growth and development, delay in molting, and increase in larval lethality. Compared with LqhIT2 protein, the stability and insecticidal efficacy of LMX was better. Meanwhile, biochemical analysis showed that LMX protein ingestion dramatically decreased ecdysone content in rice leaf folder larvae, and down-regulated enzymatic activities of the detoxification system (α-naphthyl acetate esterase and glutathione S-transferase), the digestive system (tryptase and chymotrypsin), and the antioxidant system (catalase). These changes were tightly correlated with the dosage of LMX protein. Transgene analysis showed that the rate of leaf damage, and the number of damaged tillers and leaves in the transgenic line were greatly reduced relative to wild type plants and empty vector plants. Based on these observations, we propose that the insect-specific scorpion neurotoxin peptide LMX is an attractive and effective alternative molecule for the protection of rice from rice leaf folder. PMID:24964088

  19. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  20. "African Connection."

    ERIC Educational Resources Information Center

    Adelman, Cathy; And Others

    This interdisciplinary unit provides students in grades kindergarten through seventh grade an opportunity to understand diversity through a study of Africa as a diverse continent. The project is designed to provide all elementary students with cultural enrichment by exposing them to African music, art, storytelling, and movement. This project can…

  1. [Distribution of findings of scorpions in Buenos Aires city in the period 2001-2012 and their sanitary implications].

    PubMed

    Blanco, Guillermo; Laskowicz, Rodrigo D; Lanari, Laura C; Scarlato, Eduardo; Damin, Carlos; de Titto, Ernesto H; de Roodt, Adolfo R

    2016-02-01

    Scorpion stings and their associated mortality increased in the last years in Argentina, with a cumulative record of 73,617 cases and 30 deaths during the period 2001-2012, occurring almost all the deaths in pediatric patients. However, deaths due to severe envenoming by scorpion stings have not been recorded in Buenos Aires city and suburban regions, although the presence of scorpions in this city has been increasingly reported. We studied the temporal and geographical distribution of Tityus trivittatus findings in Buenos Aires city from the database of the Research and Development Area from the National Institute for Production of Biologics of the National Ministry of Health during the period 10/01/2001 to 31/12/2012 in order to correlate these findings with the distribution of health centers in the city. In this period 385 consults with identification of scorpions were recorded. Annual records showed a growing trend. Georeferenced data showed that findings appeared to increase in the surroundings of metro and train stations, mainly at the east of the city with expansion to the west. Although Toxicology services are geographically related to the zones with higher density of finding of scorpions, the accessibility to the centers with antivenom may hinder its application in the recommended time; some measures to avoid possible delays in the application of the treatment are suggested. PMID:26914081

  2. Scorpionism in Ecuador: First report of severe and fatal envenoming cases from northern Manabí by Tityus asthenes Pocock.

    PubMed

    Borges, Adolfo; Morales, Melva; Loor, Wilmer; Delgado, Miguel

    2015-10-01

    The presence in rural areas of western Ecuador of scorpions in the genus Tityus capable of producing pediatric mortality is hereby evidenced. The medical significance of scorpions in Ecuador has been underestimated partly because of the clinically unimportant stings delivered by Centruroides margaritatus and Teuthraustes atramentarius, which have venom with low toxicity to vertebrates. Five intra-domiciliary cases of scorpion envenoming in victims aged between 1.9 and 16 years old, including one fatality, are reported from rural settings in forest areas of Chone (n = 2) and Flavio Alfaro (n = 3) counties, northern Manabí province, western Ecuador. Three cases were graded as Class II (moderate) and two in Class III (severe) envenoming. Manifestations showed characteristic autonomic nervous system hyper-stimulation and the fatality (a 1.9-year-old boy from Flavio Alfaro) was due to cardio-respiratory failure. Marked leukocytosis in four of the cases (21,800-31,800 cells/mm(3)), with notable neutrophilia (58-82%), suggests induction of a venom-mediated systemic inflammatory response-like syndrome. Specimens responsible for cases in Flavio Alfaro County, including the fatality, were classified as Tityus asthenes Pocock, accountable for severe scorpionism in Colombia. These findings demand implementation of control and therapeutic measures in affected areas in Ecuador, including evaluation of available scorpion antivenoms.

  3. [Distribution of findings of scorpions in Buenos Aires city in the period 2001-2012 and their sanitary implications].

    PubMed

    Blanco, Guillermo; Laskowicz, Rodrigo D; Lanari, Laura C; Scarlato, Eduardo; Damin, Carlos; de Titto, Ernesto H; de Roodt, Adolfo R

    2016-02-01

    Scorpion stings and their associated mortality increased in the last years in Argentina, with a cumulative record of 73,617 cases and 30 deaths during the period 2001-2012, occurring almost all the deaths in pediatric patients. However, deaths due to severe envenoming by scorpion stings have not been recorded in Buenos Aires city and suburban regions, although the presence of scorpions in this city has been increasingly reported. We studied the temporal and geographical distribution of Tityus trivittatus findings in Buenos Aires city from the database of the Research and Development Area from the National Institute for Production of Biologics of the National Ministry of Health during the period 10/01/2001 to 31/12/2012 in order to correlate these findings with the distribution of health centers in the city. In this period 385 consults with identification of scorpions were recorded. Annual records showed a growing trend. Georeferenced data showed that findings appeared to increase in the surroundings of metro and train stations, mainly at the east of the city with expansion to the west. Although Toxicology services are geographically related to the zones with higher density of finding of scorpions, the accessibility to the centers with antivenom may hinder its application in the recommended time; some measures to avoid possible delays in the application of the treatment are suggested.

  4. Scorpionism in Ecuador: First report of severe and fatal envenoming cases from northern Manabí by Tityus asthenes Pocock.

    PubMed

    Borges, Adolfo; Morales, Melva; Loor, Wilmer; Delgado, Miguel

    2015-10-01

    The presence in rural areas of western Ecuador of scorpions in the genus Tityus capable of producing pediatric mortality is hereby evidenced. The medical significance of scorpions in Ecuador has been underestimated partly because of the clinically unimportant stings delivered by Centruroides margaritatus and Teuthraustes atramentarius, which have venom with low toxicity to vertebrates. Five intra-domiciliary cases of scorpion envenoming in victims aged between 1.9 and 16 years old, including one fatality, are reported from rural settings in forest areas of Chone (n = 2) and Flavio Alfaro (n = 3) counties, northern Manabí province, western Ecuador. Three cases were graded as Class II (moderate) and two in Class III (severe) envenoming. Manifestations showed characteristic autonomic nervous system hyper-stimulation and the fatality (a 1.9-year-old boy from Flavio Alfaro) was due to cardio-respiratory failure. Marked leukocytosis in four of the cases (21,800-31,800 cells/mm(3)), with notable neutrophilia (58-82%), suggests induction of a venom-mediated systemic inflammatory response-like syndrome. Specimens responsible for cases in Flavio Alfaro County, including the fatality, were classified as Tityus asthenes Pocock, accountable for severe scorpionism in Colombia. These findings demand implementation of control and therapeutic measures in affected areas in Ecuador, including evaluation of available scorpion antivenoms. PMID:26344916

  5. Many unique characteristics revealed by the complete mitochondrial genome of the scorpion Tityus serrulatus (Lutz e Mello 1922) (Chelicerata; Arachnida).

    PubMed

    Martins, Ana Paula Vimieiro; Carmo, Anderson Oliveira do; Mesquita, Flavia Oliveira; Pimenta, Ricardo José Gonzaga; Chagas, Aline Torres de Azevedo; Kalapothakis, Evanguedes

    2016-09-01

    This is the first complete mitochondrial genome of a Tityus species, although it is the most medically important genus in South America. Tityus serrulatus (Brazilian yellow scorpion) mtDNA revealed the same gene arrangement of three out of four other mitogenomes published by now for the same family (Centruroides limpidus, Mesobuthus gibbosus, M. martensii and Buthus occitanus). However, it presented many unique characteristics such as possession of Cox1 gene, different from all other protein-coding genes of scorpion mtDNA, starts with an atypical start codon (CTG). Moreover, no tRNA gene have complete typical secondary structure and the Tytius genome presented three non-coding regions longer than 100bp. Also, it contains the smallest scorpion 16S gene reported by now. Phylogenetic analysis using concatenated homologous genes confirmed Buthidae as a monophyletic clade and supports a monophyletic group including T. serrulatus and the other American species, C. limpidus.

  6. Cloning, sequence analysis and homology modeling of a novel phospholipase A2 from Heterometrus fulvipes (Indian black scorpion).

    PubMed

    Hariprasad, Gururao; Singh, Baskar; Das, Utpal; Ethayathulla, Abdul S; Kaur, Punit; Singh, Tej P; Srinivasan, Alagiri

    2007-06-01

    We report the cloning and sequencing of group III phospholipaseA(2) from Heterometrus fulvipes (HfPLA(2)), Indian black scorpion. The cDNA sequence codes for the mature portion of the group PLA(2) of 103 amino acids. The sequence has 85% identity with Mesobuthus tamulus (Indian red scorpion) PLA(2) and a 40% identity with bee venom PLA(2) and human group III PLA(2). Most of the essential features of group III PLA(2) like Ca(2+) binding loop and catalytic residues are conserved. Homology modeling was done with the known structure of group III bee venom PLA(2). All the secondary structural motifs and the disulfide bridges are as predicted. The variation like the replacement of aspartic acid residue with glutamic acid in the well known histidine-aspartic acid dyad is a rare feature. This is the first structural model report of an Indian black scorpion PLA(2).

  7. Obesity and African Americans

    MedlinePlus

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  8. Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions

    PubMed Central

    2013-01-01

    Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950. Results Scorpion median eye retinula cells are linked to a first and a second visual neuropil, while some fibres additionally connect the median eyes with the arcuate body. The lateral eye retinula cells are linked to a first and a second visual neuropil as well, with the second neuropil being partly shared by projections from both eyes. Conclusions Comparing these results to previous studies on the visual systems of scorpions and other chelicerates, we found striking similarities to the innervation pattern in Limulus polyphemus for both median and lateral eyes. This supports from a visual system point of view at least a phylogenetically basal position of Scorpiones in Arachnida, or even a close relationship to Xiphosura. In addition, we propose a ground pattern for the central projections of chelicerate median eyes. PMID:23842208

  9. Structure and function of the voltage sensor of sodium channels probed by a beta-scorpion toxin.

    PubMed

    Cestèle, Sandrine; Yarov-Yarovoy, Vladimir; Qu, Yusheng; Sampieri, François; Scheuer, Todd; Catterall, William A

    2006-07-28

    Voltage sensing by voltage-gated sodium channels determines the electrical excitability of cells, but the molecular mechanism is unknown. beta-Scorpion toxins bind specifically to neurotoxin receptor site 4 and induce a negative shift in the voltage dependence of activation through a voltage sensor-trapping mechanism. Kinetic analysis showed that beta-scorpion toxin binds to the resting state, and subsequently the bound toxin traps the voltage sensor in the activated state in a voltage-dependent but concentration-independent manner. The rate of voltage sensor trapping can be fit by a two-step model, in which the first step is voltage-dependent and correlates with the outward gating movement of the IIS4 segment, whereas the second step is voltage-independent and results in shifted voltage dependence of activation of the channel. Mutations of Glu(779) in extracellular loop IIS1-S2 and both Glu(837) and Leu(840) in extracellular loop IIS3-S4 reduce the binding affinity of beta-scorpion toxin. Mutations of positively charged and hydrophobic amino acid residues in the IIS4 segment do not affect beta-scorpion toxin binding but alter voltage dependence of activation and enhance beta-scorpion toxin action. Structural modeling with the Rosetta algorithm yielded a three-dimensional model of the toxin-receptor complex with the IIS4 voltage sensor at the extracellular surface. Our results provide mechanistic and structural insight into the voltage sensor-trapping mode of scorpion toxin action, define the position of the voltage sensor in the resting state of the sodium channel, and favor voltage-sensing models in which the S4 segment spans the membrane in both resting and activated states.

  10. Structure and Function of the Voltage Sensor of Sodium Channels Probed by a β-Scorpion Toxin*S

    PubMed Central

    Cestèle, Sandrine; Yarov-Yarovoy, Vladimir; Qu, Yusheng; Sampieri, François; Scheuer, Todd; Catterall, William A.

    2006-01-01

    Voltage sensing by voltage-gated sodium channels determines the electrical excitability of cells, but the molecular mechanism is unknown. β-Scorpion toxins bind specifically to neurotoxin receptor site 4 and induce a negative shift in the voltage dependence of activation through a voltage sensor-trapping mechanism. Kinetic analysis showed that β-scorpion toxin binds to the resting state, and subsequently the bound toxin traps the voltage sensor in the activated state in a voltage-dependent but concentration-independent manner. The rate of voltage sensor trapping can be fit by a two-step model, in which the first step is voltage-dependent and correlates with the outward gating movement of the IIS4 segment, whereas the second step is voltage-independent and results in shifted voltage dependence of activation of the channel. Mutations of Glu779 in extracellular loop IIS1–S2 and both Glu837 and Leu840 in extracellular loop IIS3–S4 reduce the binding affinity of β-scorpion toxin. Mutations of positively charged and hydrophobic amino acid residues in the IIS4 segment do not affect β-scorpion toxin binding but alter voltage dependence of activation and enhance β-scorpion toxin action. Structural modeling with the Rosetta algorithm yielded a three-dimensional model of the toxin-receptor complex with the IIS4 voltage sensor at the extracellular surface. Our results provide mechanistic and structural insight into the voltage sensor-trapping mode of scorpion toxin action, define the position of the voltage sensor in the resting state of the sodium channel, and favor voltage-sensing models in which the S4 segment spans the membrane in both resting and activated states. PMID:16679310

  11. Choose your weapon: defensive behavior is associated with morphology and performance in scorpions.

    PubMed

    van der Meijden, Arie; Lobo Coelho, Pedro; Sousa, Pedro; Herrel, Anthony

    2013-01-01

    Morphology can be adaptive through its effect on performance of an organism. The effect of performance may, however, be modulated by behavior; an organism may choose a behavioral option that does not fully utilize its maximum performance. Behavior may therefore be decoupled from morphology and performance. To gain insight into the relationships between these levels of organization, we combined morphological data on defensive structures with measures of defensive performance, and their utilization in defensive behavior. Scorpion species show significant variation in the morphology and performance of their main defensive structures; their chelae (pincers) and the metasoma ("tail") carrying the stinger. Our data show that size-corrected pinch force varies to almost two orders of magnitude among species, and is correlated with chela morphology. Chela and metasoma morphology are also correlated to the LD50 of the venom, corroborating the anecdotal rule that dangerously venomous scorpions can be recognized by their chelae and metasoma. Analyses of phylogenetic independent contrasts show that correlations between several aspects of chela and metasoma morphology, performance and behavior are present. These correlations suggest co-evolution of behavior with morphology and performance. Path analysis found a performance variable (pinch force) to partially mediate the relationship between morphology (chela aspect ratio) and behavior (defensive stinger usage). We also found a correlation between two aspects of morphology: pincer finger length correlates with the relative "thickness" (aspect ratio) of the metasoma. This suggests scorpions show a trade-off between their two main weapon complexes: the metasoma carrying the stinger, and the pedipalps carrying the chelae.

  12. Mass fingerprinting of the venom and transcriptome of venom gland of scorpion Centruroides tecomanus.

    PubMed

    Valdez-Velázquez, Laura L; Quintero-Hernández, Verónica; Romero-Gutiérrez, Maria Teresa; Coronas, Fredy I V; Possani, Lourival D

    2013-01-01

    Centruroides tecomanus is a Mexican scorpion endemic of the State of Colima, that causes human fatalities. This communication describes a proteome analysis obtained from milked venom and a transcriptome analysis from a cDNA library constructed from two pairs of venom glands of this scorpion. High perfomance liquid chromatography separation of soluble venom produced 80 fractions, from which at least 104 individual components were identified by mass spectrometry analysis, showing to contain molecular masses from 259 to 44,392 Da. Most of these components are within the expected molecular masses for Na(+)- and K(+)-channel specific toxic peptides, supporting the clinical findings of intoxication, when humans are stung by this scorpion. From the cDNA library 162 clones were randomly chosen, from which 130 sequences of good quality were identified and were clustered in 28 contigs containing, each, two or more expressed sequence tags (EST) and 49 singlets with only one EST. Deduced amino acid sequence analysis from 53% of the total ESTs showed that 81% (24 sequences) are similar to known toxic peptides that affect Na(+)-channel activity, and 19% (7 unique sequences) are similar to K(+)-channel especific toxins. Out of the 31 sequences, at least 8 peptides were confirmed by direct Edman degradation, using components isolated directly from the venom. The remaining 19%, 4%, 4%, 15% and 5% of the ESTs correspond respectively to proteins involved in cellular processes, antimicrobial peptides, venom components, proteins without defined function and sequences without similarity in databases. Among the cloned genes are those similar to metalloproteinases.

  13. A Scorpion Defensin BmKDfsin4 Inhibits Hepatitis B Virus Replication in Vitro

    PubMed Central

    Zeng, Zhengyang; Zhang, Qian; Hong, Wei; Xie, Yingqiu; Liu, Yun; Li, Wenxin; Wu, Yingliang; Cao, Zhijian

    2016-01-01

    Hepatitis B virus (HBV) infection is a major worldwide health problem which can cause acute and chronic hepatitis and can significantly increase the risk of liver cirrhosis and primary hepatocellular carcinoma (HCC). Nowadays, clinical therapies of HBV infection still mainly rely on nucleotide analogs and interferons, the usage of which is limited by drug-resistant mutation or side effects. Defensins had been reported to effectively inhibit the proliferation of bacteria, fungi, parasites and viruses. Here, we screened the anti-HBV activity of 25 scorpion-derived peptides most recently characterized by our group. Through evaluating anti-HBV activity and cytotoxicity, we found that BmKDfsin4, a scorpion defensin with antibacterial and Kv1.3-blocking activities, has a comparable high inhibitory rate of both HBeAg and HBsAg in HepG2.2.15 culture medium and low cytotoxicity to HepG2.2.15. Then, our experimental results further showed that BmKDfsin4 can dose-dependently decrease the production of HBV DNA and HBV viral proteins in both culture medium and cell lysate. Interestingly, BmKDfsin4 exerted high serum stability. Together, this study indicates that the scorpion defensin BmKDfsin4 also has inhibitory activity against HBV replication along with its antibacterial and potassium ion channel Kv1.3-blocking activities, which shows that BmKDfsin4 is a uniquely multifunctional defensin molecule. Our work also provides a good molecule material which will be used to investigate the link or relationship of its antiviral, antibacterial and ion channel–modulating activities in the future. PMID:27128943

  14. A Scorpion Defensin BmKDfsin4 Inhibits Hepatitis B Virus Replication in Vitro.

    PubMed

    Zeng, Zhengyang; Zhang, Qian; Hong, Wei; Xie, Yingqiu; Liu, Yun; Li, Wenxin; Wu, Yingliang; Cao, Zhijian

    2016-01-01

    Hepatitis B virus (HBV) infection is a major worldwide health problem which can cause acute and chronic hepatitis and can significantly increase the risk of liver cirrhosis and primary hepatocellular carcinoma (HCC). Nowadays, clinical therapies of HBV infection still mainly rely on nucleotide analogs and interferons, the usage of which is limited by drug-resistant mutation or side effects. Defensins had been reported to effectively inhibit the proliferation of bacteria, fungi, parasites and viruses. Here, we screened the anti-HBV activity of 25 scorpion-derived peptides most recently characterized by our group. Through evaluating anti-HBV activity and cytotoxicity, we found that BmKDfsin4, a scorpion defensin with antibacterial and Kv1.3-blocking activities, has a comparable high inhibitory rate of both HBeAg and HBsAg in HepG2.2.15 culture medium and low cytotoxicity to HepG2.2.15. Then, our experimental results further showed that BmKDfsin4 can dose-dependently decrease the production of HBV DNA and HBV viral proteins in both culture medium and cell lysate. Interestingly, BmKDfsin4 exerted high serum stability. Together, this study indicates that the scorpion defensin BmKDfsin4 also has inhibitory activity against HBV replication along with its antibacterial and potassium ion channel Kv1.3-blocking activities, which shows that BmKDfsin4 is a uniquely multifunctional defensin molecule. Our work also provides a good molecule material which will be used to investigate the link or relationship of its antiviral, antibacterial and ion channel-modulating activities in the future. PMID:27128943

  15. First divergence time estimate of spiders, scorpions, mites and ticks (subphylum: Chelicerata) inferred from mitochondrial phylogeny.

    PubMed

    Jeyaprakash, Ayyamperumal; Hoy, Marjorie A

    2009-01-01

    Spiders, scorpions, mites and ticks (chelicerates) form one of the most diverse groups of arthropods on land, but their origin and times of diversification are not yet established. We estimated, for the first time, the molecular divergence times for these chelicerates using complete mitochondrial sequences from 25 taxa. All mitochondrial genes were evaluated individually or after concatenation. Sequences belonging to three missing genes (ND3, 6, and tRNA-Asp) from three taxa, as well as the faster-evolving ribosomal RNAs (12S and 16S), tRNAs, and the third base of each codon from 11 protein-coding genes (PCGs) (COI-III, CYTB, ATP8, 6, ND1-2, 4L, and 4-5), were identified and removed. The remaining concatenated sequences from 11 PCGs produced a completely resolved phylogenetic tree and confirmed that all chelicerates are monophyletic. Removing the third base from each codon was essential to resolve the phylogeny, which allowed deep divergence times to be calculated using three nodes calibrated with upper and lower priors. Our estimates indicate that the orders and classes of spiders, scorpions, mites, and ticks diversified in the late Paleozoic, much earlier than previously reported from fossil date estimates. The divergence time estimated for ticks suggests that their first land hosts could have been amphibians rather than reptiles. Using molecular data, we separated the spider-scorpion clades and estimated their divergence times at 397 +/- 23 million years ago. Algae, fungi, plants, and animals, including insects, were well established on land when these chelicerates diversified. Future analyses, involving mitochondrial sequences from additional chelicerate taxa and the inclusion of nuclear genes (or entire genomes) will provide a more complete picture of the evolution of the Chelicerata, the second most abundant group of animals on earth.

  16. NMR sequential assignments and solution structure of chlorotoxin, a small scorpion toxin that blocks chloride channels.

    PubMed

    Lippens, G; Najib, J; Wodak, S J; Tartar, A

    1995-01-10

    The solution structure of chlorotoxin, a small toxin purified from the venom of the Leiurus quinquestriatus scorpion, has been determined using 2D 1H NMR spectroscopy. Analysis of the NMR data shows that the structure consists of a small three-stranded antiparallel beta-sheet packed against an alpha-helix, thereby adopting the same fold as charybdotoxin and other members of the short scorpion toxin family [Arseniev et al. (1984) FEBS Lett. 165, 57-62; Martins et al. (1990) FEBS Lett. 260, 249-253; Bontems et al. (1991) Science 254, 1521-1523]. Three disulfide bonds of chlorotoxin (Cys5-Cys28, Cys16-Cys33, and Cys20-Cys35), cross-linking the alpha-helix to the beta-sheet, follow the common pattern found in the other short scorpion toxins. The fourth disulfide bridge (Cys2-Cys19) links the small N-terminal beta strand to the rest of the molecule, in contrast to charybdotoxin where this disulfide bridge is absent and the first strand interacts with the rest of the molecule by several contacts between hydrophobic residues. Another structural difference between chlorotoxin and charybdotoxin is observed at the level of the alpha-beta turn. This difference is accompanied by a change in the electrostatic potential surface, which is largely positive at the level of this turn in chlorotoxin, whereas no such positive potential surface can be found at the same position in charybdotoxin. In the latter protein, the positive surface is formed by different charged residues situated on the solvent-exposed site of the C-terminal beta-sheet.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Neurological effects of venomous bites and stings: snakes, spiders, and scorpions.

    PubMed

    Del Brutto, Oscar H

    2013-01-01

    Snake and spider bites, as well as scorpion sting envenoming, are neglected diseases affecting millions of people all over the world. Neurological complications vary according to the offending animal, and are often directly related to toxic effects of the venom, affecting the central nervous system, the neuromuscular transmission, the cardiovascular system, or the coagulation cascade. Snake bite envenoming may result in stroke or muscle paralysis. Metalloproteinases and other substances (common in vipers and colubrids) have anticoagulant or procoagulant activity, and may induce ischemic or hemorrhagic strokes. The venom of elapids is rich in neurotoxins affecting the neuromuscular transmission at either presynaptic or postsynaptic levels. The clinical picture of scorpion sting envenoming is dominated by muscle weakness associated with arterial hypertension, cardiac arrythmias, myocarditis, or pulmonary edema. These manifestations occur as the result of release of catecholamines into the bloodstream or due to direct cardiac toxicity of the venom. Cerebrovascular complications have been reported after the sting of the Indian red scorpion. Intracranial hemorrhages occur in the setting of acute increases in arterial blood pressure related to sympathetic overstimulation, and cerebral infarctions are related to either cerebral hypoperfusion, consumption coagulopathy, vasculitis, or cardiogenic brain embolism. Three main syndromes result from spider bite envenoming: latrodectism, loxoscelism, and funnel-web spider envenoming. Latrodectism is related to neurotoxins present in the venom of widow spiders. Most cases present with headache, lethargy, irritability, myalgia, tremor, fasciculation, or ataxia. Loxoscelism is caused by envenoming by spiders of the family Sicariidae. It may present with a stroke due to a severe coagulopathy. The venom of funnel-web spiders also has neurotoxins that stimulate neurotransmitter release, resulting in sensory disturbances and muscle

  18. Choose Your Weapon: Defensive Behavior Is Associated with Morphology and Performance in Scorpions

    PubMed Central

    van der Meijden, Arie; Lobo Coelho, Pedro; Sousa, Pedro; Herrel, Anthony

    2013-01-01

    Morphology can be adaptive through its effect on performance of an organism. The effect of performance may, however, be modulated by behavior; an organism may choose a behavioral option that does not fully utilize its maximum performance. Behavior may therefore be decoupled from morphology and performance. To gain insight into the relationships between these levels of organization, we combined morphological data on defensive structures with measures of defensive performance, and their utilization in defensive behavior. Scorpion species show significant variation in the morphology and performance of their main defensive structures; their chelae (pincers) and the metasoma (“tail”) carrying the stinger. Our data show that size-corrected pinch force varies to almost two orders of magnitude among species, and is correlated with chela morphology. Chela and metasoma morphology are also correlated to the LD50 of the venom, corroborating the anecdotal rule that dangerously venomous scorpions can be recognized by their chelae and metasoma. Analyses of phylogenetic independent contrasts show that correlations between several aspects of chela and metasoma morphology, performance and behavior are present. These correlations suggest co-evolution of behavior with morphology and performance. Path analysis found a performance variable (pinch force) to partially mediate the relationship between morphology (chela aspect ratio) and behavior (defensive stinger usage). We also found a correlation between two aspects of morphology: pincer finger length correlates with the relative “thickness” (aspect ratio) of the metasoma. This suggests scorpions show a trade-off between their two main weapon complexes: the metasoma carrying the stinger, and the pedipalps carrying the chelae. PMID:24236075

  19. Positions under positive selection--key for selectivity and potency of scorpion alpha-toxins.

    PubMed

    Weinberger, Hagar; Moran, Yehu; Gordon, Dalia; Turkov, Michael; Kahn, Roy; Gurevitz, Michael

    2010-05-01

    Alpha-neurotoxins target voltage-gated sodium channels (Na(v)s) and constitute an important component in the venom of Buthidae scorpions. These toxins are short polypeptides highly conserved in sequence and three-dimensional structure, and yet they differ greatly in activity and preference for insect and various mammalian Na(v)s. Despite extensive studies of the structure-function relationship of these toxins, only little is known about their evolution and phylogeny. Using a broad data set based on published sequences and rigorous cloning, we reconstructed a reliable phylogenetic tree of scorpion alpha-toxins and estimated the evolutionary forces involved in the diversification of their genes using maximum likelihood-based methods. Although the toxins are largely conserved, four positions were found to evolve under positive selection, of which two (10 and 18; numbered according to LqhalphaIT and Lqh2 from the Israeli yellow scorpion Leiurus quinquestriatus hebraeus) have been previously shown to affect toxin activity. The putative role of the other two positions (39 and 41) was analyzed by mutagenesis of Lqh2 and LqhalphaIT. Whereas substitution P41K in Lqh2 did not alter its activity, substitution K41P in LqhalphaIT significantly decreased the activity at insect and mammalian Na(v)s. Surprisingly, not only that substitution A39L in both toxins increased their activity by 10-fold but also LqhalphaIT(A39L) was active at the mammalian brain channel rNa(v)1.2a, which otherwise is hardly affected by LqhalphaIT, and Lqh2(A39L) was active at the insect channel, DmNa(v)1, which is almost insensitive to Lqh2. Thus, position 39 is involved not only in activity but also in toxin selectivity. Overall, this study describes evolutionary forces involved in the diversification of scorpion alpha-toxins, highlights the key role of positions under positive selection for selectivity and potency, and raises new questions as to the toxin-channel face of interaction.

  20. The new kappa-KTx 2.5 from the scorpion Opisthacanthus cayaporum.

    PubMed

    Camargos, Thalita Soares; Restano-Cassulini, Rita; Possani, Lourival Domingos; Peigneur, Steve; Tytgat, Jan; Schwartz, Carlos Alberto; Alves, Erica Maria C; de Freitas, Sonia Maria; Schwartz, Elisabeth Ferroni

    2011-07-01

    The kappa-KTx family of peptides, which is the newest K⁺-channel blocker family from scorpion venom, is present in scorpions from the families Scorpionidae and Liochelidae. Differently from the other scorpion KTx families, the three-dimensional structure of the known kappa-KTxs toxins is formed by two parallel α-helices linked by two disulfide bridges. Here, the characterization of a new kappa-KTx peptide, designated kappa-KTx 2.5, derived from the Liochelidae scorpion Opisthacanthus cayaporum, is described. This peptide was purified by HPLC and found to be identical to OcyC8, a predicted mature sequence precursor (UniProtKB C5J89) previously described by our group. The peptide was chemically synthesized and the circular dichroism (CD) spectra of both, native and synthetic, conducted at different temperatures in water and water/trifluoroethanol (TFE), showed a predominance of α-helices. The kappa-KTx 2.5 is heat stable and was shown to be a blocker of K⁺-currents on hKv1.1, and hKv1.4, with higher affinity for Kv1.4 channels (IC₅₀= 71 μM). Similarly to the other kappa-KTxs, the blockade of K⁺-channels occurred at micromolar concentrations, leading to uncertainness about their proper molecular target, and consequently their pharmacologic effect. In order to test other targets, kappa-KTx2.5 was tested on other K⁺-channels, on Na⁺-channels, on bacterial growth and on smooth muscle tissue, a known assay to identify possible bradykinin-potentiating peptides, due to the presence of two contiguous prolines at the C-terminal sequence. It has no effect on the targets used except on hKv1.1, and hKv1.4 expressed in Chinese hamster ovary cells. Since the only plausible function found for kappa-KTx2.5 seems to be the blockade of K⁺-channels, a discussion regarding the analysis of structure-function relationships is included in this communication, based on sequence alignments of members of the kappa-KTx toxin family, and on computational simulation of a

  1. Mineral resources of the Scorpion Wilderness study area, Garfield and Kane counties, Utah

    SciTech Connect

    Bartsch-Winkler, S.; Jones, J.L.; Kilburn, J.E.; Cady, J.W.; Duval, J.S.; Cook, K.L. ); Lane, M.E.; Corbetta, P.A. )

    1989-01-01

    This paper reports on the Scorpion Wilderness Study Area which covers 14,978 acres in south- central Utah in Garfield and Kane counties. No mining claims or oil and gas leases or lease applications extend inside this study-area boundary. Demonstrated subeconomic resources of less than 30,000 tons of gypsum are in this study area. The mineral resource potential is low for undiscovered gypsum in the Carmel Formation, for undiscovered uranium in the Chinle Formation in the subsurface, and for undiscovered metals other than uranium. The energy resource potential is low for geothermal resources and is moderate for oil, gas, and carbon dioxide.

  2. Purification and characterization of chlorotoxin, a chloride channel ligand from the venom of the scorpion.

    PubMed

    DeBin, J A; Maggio, J E; Strichartz, G R

    1993-02-01

    We have previously demonstrated that the venom of the scorpion Leiurus quinquestriatus blocks small-conductance Cl- channels, derived from epithelial cells, when applied to the cytoplasmic surface. We have now purified to near homogeneity, and characterized, the component responsible for this blocking activity. It is a small basic peptide of 4,070 Da. The primary amino acid structure shows considerable homology to a class of previously described putative short insectotoxins. A brief characterization of the kinetics of Cl- channel block as well as a demonstration of toxicity to arthropods is also presented.

  3. The importance of early bedside echocardiography in children with scorpion envenomation.

    PubMed

    Sofer, Shaul; Zucker, Nili; Bilenko, Natalya; Levitas, Aviva; Zalzstein, Eli; Amichay, Doron; Cohen-Lahav, Merav; Bernstein, Tamar

    2013-06-01

    Scorpion sting may cause myocardial injury and heart failure (HF). Clinical signs of failure may develop several hours or even days after the sting, while electrocardiography (ECG) and blood examination soon after the sting may be normal. We sought to examine whether normal echocardiographic (echo) examination performed shortly after hospital arrival would exclude subsequent HF. We also sought to check if blood troponin and natriuretic peptide values measured shortly after arrival may predict or exclude subsequent HF. Natriuretic peptide activities have not been measured in scorpion sting victims. We also wanted to check if HF occurs in envenomated young infants. In a 3-year prospective study we looked at the demographic, clinical, laboratory, ECG, and echo data of all patients with general envenomation who arrived at the emergency department (ED) after scorpion sting. Clinical, laboratory, ECG, and echo results on arrival and 24 h after arrival were checked and compared between groups of patients with normal and abnormal echo on arrival. We then looked for differences in clinical course, therapy, and outcome between groups. The study included 98 children aged 80 days to 19 years (median 53.1 months), 25 were below the age of 2 years. Envenomation by the "yellow scorpion"Leiurus quinquestriatus was suspected in 74 cases. Median time between sting and ED arrival was 80 min. Echo was performed on arrival in 93 of the 98 patients, (in 5 occasions it was not performed or not recorded) 74 were normal and 19 were abnormal. Abnormal echo included hypokinesia and low fractional shortening and ejection fraction of the left ventricle. Clinical signs, abnormal ECG, and laboratory results were not discriminative between groups on arrival. Mean troponin T was higher in patients with abnormal echo, but within normal range in 13 of the 19 patients with abnormal echo and above normal in 2 of the 74 patients with normal echo-missing sensitivity and specificity. Mean N-terminal pro

  4. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  5. Therapy with African Families.

    ERIC Educational Resources Information Center

    Nwadiora, Emeka

    1996-01-01

    Informs helping professionals about the unique history and challenges of African families to guide them toward providing ethnically sensitive psychological services to African immigrant families in need. African families undergo great stress when faced with the alienation of being Black and African in a Euro-American culture. (SLD)

  6. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  7. Cooperative Exploration of Rough Martian Terrains with the "Scorpion" Legged Robot as an Adjunct to a Rover.

    NASA Technical Reports Server (NTRS)

    Colombano, Silvano P.; Kirchner, Frank; Spenneberg, Dirk; Starman, Jared; Hanratty, James; Kovsmeyer, David (Technical Monitor)

    2003-01-01

    NASA needs autonomous robotic exploration of difficult (rough and/or steep) scientifically interesting Martian terrains. Concepts involving distributed autonomy for cooperative robotic exploration are key to enabling new scientific objectives in robotic missions. We propose to utilize a legged robot as an adjunct scout to a rover for access to difficult - scientifically interesting - terrains (rocky areas, slopes, cliffs). Our final mission scenario involves the Ames rover platform "K9" and Scorpion acting together to explore a steep cliff, with the Scorpion robot rappelling down using the K9 as an anchor as well as mission planner and executive. Cooperation concepts, including wheeled rappelling robots have been proposed before. Now we propose to test the combined advantages of a wheeled vehicle with a legged scout as well as the advantages of merging of high level planning and execution with biologically inspired, behavior based robotics. We propose to use the 8-legged, multifunctional autonomous robot platform Scorpion that is currently capable of: Walking on different terrains (rocks, sand, grass, ...). Perceiving its environment and modifying its behavioral pattern accordingly. These capabilities would be extended to enable the Scorpion to: communicate and cooperate with a partner robot; climb over rocks, rubble piles, and objects with structural features. This will be done in the context of exploration of rough terrains in the neighborhood of the rover, but inaccessible to it, culminating in the added capability of rappelling down a steep cliff for both vertical and horizontal terrain observation.

  8. X-ray Structure of Native Scorpion Toxin BmBKTx1 by Racemic Protein Crystallography Using Direct Methods

    SciTech Connect

    Mandal, Kalyaneswar; Pentelute, Brad L.; Tereshko, Valentina; Kossiakoff, Anthony A.; Kent, Stephen B.H.

    2009-04-08

    Racemic protein crystallography, enabled by total chemical synthesis, has allowed us to determine the X-ray structure of native scorpion toxin BmBKTx1; direct methods were used for phase determination. This is the first example of a protein racemate that crystallized in space group I41/a.

  9. Harlem Connections: Teaching Walter Dean Myers'"Scorpions" with Paul Laurence Dunbar's "The Sport of the Gods."

    ERIC Educational Resources Information Center

    West, Mark I.

    1999-01-01

    Describes how the author, in a course titled "Literature for Adolescents" paired Walter Dean Myers' 1988 young adult novel, "Scorpions," with Paul Laurence Dunbar's 1902 novel for adults, "The Sport of the Gods." Describes student readers' responses to the pair of books, which focus on the difficulties of growing up in Harlem. (SR)

  10. Comments on Environmental and Sanitary Aspects of the Scorpionism by Tityus trivittatus in Buenos Aires City, Argentina.

    PubMed

    de Roodt, Adolfo Rafael

    2014-04-01

    Deaths by venomous animals are medical emergencies that can lead to death and thus constitute sanitary problems in some regions of the world. In the South of America, the accidents by these animals are a common sanitary problem especially in warm, tropical or subtropical regions, related with rural work in several countries. Argentina is located in the extreme South of South America and a minor part of the continental surface is in tropical or subtropical regions, where most of the accidents by venomous animals happen. However, in the big cities in the center and South of the country, with no relation to rural work, scorpionism, mostly due to the synanthropic and facultative parthenogenetic scorpion Tityus trivittatus, has become a sanitary problem in the last few decades. This scorpion is present in the biggest cities of Argentina and in the last decades has killed over 20 children in provinces of the center and north of the country, mostly in big cities. In addition, it seems that this species is growing and spreading in new regions of the cities. In this revision, some characteristics of this scorpion regarding its habitat, spreading in Buenos Aires city, combat measures and available treatments are discussed. PMID:24759176

  11. Characterization of Kbot21 Reveals Novel Side Chain Interactions of Scorpion Toxins Inhibiting Voltage-Gated Potassium Channels

    PubMed Central

    ElFessi-Magouri, Rym; Peigneur, Steve; Othman, Houcemeddine; Srairi-Abid, Najet; ElAyeb, Mohamed; Tytgat, Jan; Kharrat, Riadh

    2015-01-01

    Scorpion toxins are important pharmacological tools for probing the physiological roles of ion channels which are involved in many physiological processes and as such have significant therapeutic potential. The discovery of new scorpion toxins with different specificities and affinities is needed to further characterize the physiology of ion channels. In this regard, a new short polypeptide called Kbot21 has been purified to homogeneity from the venom of Buthus occitanus tunetanus scorpion. Kbot21 is structurally related to BmBKTx1 from the venom of the Asian scorpion Buthus martensii Karsch. These two toxins differ by only two residues at position 13 (R /V) and 24 (D/N).Despite their very similar sequences, Kbot21 and BmBKTx1 differ in their electrophysiological activities. Kbot21 targets KV channel subtypes whereas BmBKTx1 is active on both big conductance (BK) and small conductance (SK) Ca2+-activated K+ channel subtypes, but has no effects on Kv channel subtypes. The docking model of Kbot21 with the Kv1.2 channel shows that the D24 and R13 side-chain of Kbot21 are critical for its interaction with KV channels. PMID:26398235

  12. In vitro analysis of the anticancer properties of scorpion venom in colorectal and breast cancer cell lines

    PubMed Central

    AL-ASMARI, ABDULRAHMAN KHAZIM; ISLAM, MOZAFFARUL; AL-ZAHRANI, ALI MATER

    2016-01-01

    Scorpion venom contains various types of proteins and peptides that are able to act as inhibitors of neurotransmitter molecules. This is achieved primarily via the inhibition of ion channels. In addition, scorpion venom has been demonstrated to exhibit anticancer properties in prostate and breast cancer, as well as leukemia. The anticancer properties of scorpion venom are due to its inhibitory effect on matrix metalloproteinase (MMP) activity, which leads to reduced motility and invasion in tumor cells. The inhibitory effects of venom on MMPs additionally lead to a reduction in the metastatic potential of malignant tumors. In the present study, the effect of venom obtained from a local serpentarium facility was examined in colorectal and breast cancer cell lines. Cell motility and clonogenic survival assays revealed a significant decrease (60–90%) in cell motility and colony formation, two significant hallmarks of cancer survival, following treatment with various concentrations of venom. These results were in agreement with previous studies demonstrating the anticancer activity of scorpion venom. In conclusion, the venom utilized at the Research Center of Prince Sultan Military Medical City Hospital (Riyadh, Saudi Arabia) possesses significant anticancer potential against colorectal and breast cancer cell lines. PMID:26893728

  13. Characterization of Kbot21 Reveals Novel Side Chain Interactions of Scorpion Toxins Inhibiting Voltage-Gated Potassium Channels.

    PubMed

    ElFessi-Magouri, Rym; Peigneur, Steve; Othman, Houcemeddine; Srairi-Abid, Najet; ElAyeb, Mohamed; Tytgat, Jan; Kharrat, Riadh

    2015-01-01

    Scorpion toxins are important pharmacological tools for probing the physiological roles of ion channels which are involved in many physiological processes and as such have significant therapeutic potential. The discovery of new scorpion toxins with different specificities and affinities is needed to further characterize the physiology of ion channels. In this regard, a new short polypeptide called Kbot21 has been purified to homogeneity from the venom of Buthus occitanus tunetanus scorpion. Kbot21 is structurally related to BmBKTx1 from the venom of the Asian scorpion Buthus martensii Karsch. These two toxins differ by only two residues at position 13 (R /V) and 24 (D/N).Despite their very similar sequences, Kbot21 and BmBKTx1 differ in their electrophysiological activities. Kbot21 targets KV channel subtypes whereas BmBKTx1 is active on both big conductance (BK) and small conductance (SK) Ca2+-activated K+ channel subtypes, but has no effects on Kv channel subtypes. The docking model of Kbot21 with the Kv1.2 channel shows that the D24 and R13 side-chain of Kbot21 are critical for its interaction with KV channels. PMID:26398235

  14. A historical approach to scorpion studies with special reference to the 20th and 21st centuries

    PubMed Central

    2014-01-01

    This work provides historical context about scorpion studies from the end of the 19th century to the present day. The content is mainly addressed to non-zoologists, working in research fields that embrace scorpion biology, notably to those working with venoms and toxins. The historical aspects described include academic professional scholars who worked on scorpion classification and general distribution patterns; and to a lesser extent, on studies of ecology and natural history. The aim is not to provide an exhaustive description of all scholars who in one way or another became involved with scorpions, but rather of those who greatly contributed during a given period to the research of these organisms. No critical analysis of the work of previous researchers is undertaken, but some comments are proposed to bring clarification on ‘who’s who’. Since a global consensus in relation to classification and/or distribution patterns has not been reached among modern experts, these different approaches are also presented without judgment. Consequently, distinct approaches remain open for discussion. PMID:24618067

  15. Modulation of tissue inflammatory response by histamine receptors in scorpion envenomation pathogenesis: involvement of H4 receptor.

    PubMed

    Lamraoui, Amal; Adi-Bessalem, Sonia; Laraba-Djebari, Fatima

    2014-10-01

    The inflammatory response caused by scorpion venoms is a key event in the pathogenesis of scorpion envenomation. This response was assessed in the cardiac, pulmonary, and gastric tissues of envenomed mice. The results reveal an increase of permeability in cardiac, pulmonary, and gastric vessels accompanied by an edema-forming, inflammatory cell infiltration, and imbalanced redox status. These effects are correlated with severe tissue alterations and concomitant increase of metabolic enzymes in sera. Pretreatment of mice with antagonists of H1, H2, or H4 receptors markedly alleviated these alterations in the heart and lungs. Nevertheless, the blockade of the H3 receptor slightly reduced these disorders. Histamine H2 and H4 receptors were the most pharmacological targets involved in the gastric oxidative inflammation. These findings could help to better understand the role of histamine in scorpion venom-induced inflammatory response and propose new therapy using as targets the H4 receptor in addition to histamine H1 and H2 receptors to attenuate the induced inflammatory disorders encountered in scorpion envenoming. PMID:24858599

  16. Comments on Environmental and Sanitary Aspects of the Scorpionism by Tityus trivittatus in Buenos Aires City, Argentina

    PubMed Central

    de Roodt, Adolfo Rafael

    2014-01-01

    Deaths by venomous animals are medical emergencies that can lead to death and thus constitute sanitary problems in some regions of the world. In the South of America, the accidents by these animals are a common sanitary problem especially in warm, tropical or subtropical regions, related with rural work in several countries. Argentina is located in the extreme South of South America and a minor part of the continental surface is in tropical or subtropical regions, where most of the accidents by venomous animals happen. However, in the big cities in the center and South of the country, with no relation to rural work, scorpionism, mostly due to the synanthropic and facultative parthenogenetic scorpion Tityus trivittatus, has become a sanitary problem in the last few decades. This scorpion is present in the biggest cities of Argentina and in the last decades has killed over 20 children in provinces of the center and north of the country, mostly in big cities. In addition, it seems that this species is growing and spreading in new regions of the cities. In this revision, some characteristics of this scorpion regarding its habitat, spreading in Buenos Aires city, combat measures and available treatments are discussed. PMID:24759176

  17. A 454 sequencing approach for large scale phylogenomic analysis of the common emperor scorpion (Pandinus imperator).

    PubMed

    Roeding, Falko; Borner, Janus; Kube, Michael; Klages, Sven; Reinhardt, Richard; Burmester, Thorsten

    2009-12-01

    In recent years, phylogenetic tree reconstructions that rely on multiple gene alignments that had been deduced from expressed sequence tags (ESTs) have become a popular method in molecular systematics. Here, we present a 454 pyrosequencing approach to infer the transcriptome of the Emperor scorpion Pandinus imperator. We obtained 428,844 high-quality reads (mean length=223+/-50 b) from total cDNA, which were assembled into 8334 contigs (mean length 422+/-313 bp) and 26,147 singletons. About 1200 contigs were successfully annotated by BLAST and orthology search. Specific analyses of eight distinct hemocyanin sequences provided further proof for the quality of the 454 reads and the assembly process. The P. imperator sequences were included in a concatenated alignment of 149 orthologous genes of 67 metazoan taxa that covers 39,842 amino acids. After removal of low-quality regions, 11,168 positions were employed for phylogenetic reconstructions. Using Bayesian and maximum likelihood methods, we obtained strongly supported monophyletic Ecdysozoa, Arthropoda (excluding Tardigrada), Euarthropoda, Pancrustacea and Hexapoda. We also recovered the Myriochelata (Chelicerata+Myriapoda). Within the chelicerates, Pycnogonida form the sister group of Euchelicerata. However, Arachnida were found paraphyletic because the Acari (mites and ticks) were recovered as sister group of a clade comprising Xiphosura, Scorpiones and Araneae. In summary, we have shown that 454 pyrosequencing is a cost-effective method that provides sufficient data and coverage depth for gene detection and multigene-based phylogenetic analyses. PMID:19695333

  18. Genomic data reveal ancient microendemism in forest scorpions across the California Floristic Province.

    PubMed

    Bryson, Robert W; Savary, Warren E; Zellmer, Amanda J; Bury, R Bruce; McCormack, John E

    2016-08-01

    The California Floristic Province (CFP) in western North America is a globally significant biodiversity hotspot. Elucidating patterns of endemism and the historical drivers of this diversity has been an important challenge of comparative phylogeography for over two decades. We generated phylogenomic data using ddRADseq to examine genetic structure in Uroctonus forest scorpions, an ecologically restricted and dispersal-limited organism widely distributed across the CFP north to the Columbia River. We coupled our genetic data with species distribution models (SDMs) to determine climatically suitable areas for Uroctonus both now and during the Last Glacial Maximum. Based on our analyses, Uroctonus is composed of two major genetic groups that likely diverged over 2 million years ago. Each of these groups itself contains numerous genetic groups that reveal a pattern of vicariance and microendemism across the CFP. Migration rates among these populations are low. SDMs suggest forest scorpion habitat has remained relatively stable over the last 21 000 years, consistent with the genetic data. Our results suggest tectonic plate rafting, mountain uplift, river drainage formation and climate-induced habitat fragmentation have all likely played a role in the diversification of Uroctonus. The intricate pattern of genetic fragmentation revealed across a temporal continuum highlights the potential of low-dispersing species to shed light on small-scale patterns of biodiversity and the underlying processes that have generated this diversity in biodiversity hotspots. PMID:27238387

  19. Chlorotoxin: a helpful natural scorpion peptide to diagnose glioma and fight tumor invasion.

    PubMed

    Dardevet, Lucie; Rani, Dipti; Aziz, Tarek Abd El; Bazin, Ingrid; Sabatier, Jean-Marc; Fadl, Mahmoud; Brambilla, Elisabeth; De Waard, Michel

    2015-03-27

    Chlorotoxin is a small 36 amino-acid peptide identified from the venom of the scorpion Leiurus quinquestriatus. Initially, chlorotoxin was used as a pharmacological tool to characterize chloride channels. While studying glioma-specific chloride currents, it was soon discovered that chlorotoxin possesses targeting properties towards cancer cells including glioma, melanoma, small cell lung carcinoma, neuroblastoma and medulloblastoma. The investigation of the mechanism of action of chlorotoxin has been challenging because its cell surface receptor target remains under questioning since two other receptors have been claimed besides chloride channels. Efforts on chlorotoxin-based applications focused on producing analogues helpful for glioma diagnosis, imaging and treatment. These efforts are welcome since gliomas are very aggressive brain cancers, close to impossible to cure with the current therapeutic arsenal. Among all the chlorotoxin-based strategies, the most promising one to enhance patient mean survival time appears to be the use of chlorotoxin as a targeting agent for the delivery of anti-tumor agents. Finally, the discovery of chlorotoxin has led to the screening of other scorpion venoms to identify chlorotoxin-like peptides. So far several new candidates have been identified. Only detailed research and clinical investigations will tell us if they share the same anti-tumor potential as chlorotoxin.

  20. Differences in venom toxicity and antigenicity between females and males Tityus nororientalis (Buthidae) scorpions

    PubMed Central

    De Sousa, Leonardo; Borges, Adolfo; Vásquez-Suárez, Aleikar; Op den Camp, Huub JM; Chadee-Burgos, Rosa I; Romero-Bellorín, Mirna; Espinoza, Jorge; De Sousa-Insana, Leonardo; Pino-García, Oscar

    2010-01-01

    Venom from male and female specimens of the medically important Venezuelan scorpion Tityus nororientalis have been compared. Males showed a significantly higher venom yield (2.39mg/individual) compared to female scorpions (0.98mg/individual). Female venom was significantly more toxic than that of males, with a median lethal dose (LD50) in C57BL/6 mice of 9.46 μg venom protein/gm body weight [95% confidence interval (8.91-9.94)] whereas LD50 for males was 13.36(12.58-14.03) μg/gm. Mass spectral analyses by MALDI-TOF revealed differences in venom composition between males and females. From a clinical standpoint, the time course of toxicity course indicated a tendency, in the case of the female venom, to elicit the earlier occurrence of severe signs such as sialorrhea, dyspnea (bradypnea/apnea) and exophthalmus particularly in the late toxicity phase. Female venom was significantly less efficient than male venom to inhibit the binding of anti-T. discrepans antibodies to immobilized T. discrepans venom in ELISA assays, suggesting sex-related differences in the bioactive surfaces of T. nororientalis toxins. These results indicate that males and females of T. nororientalis produce venoms with different composition and activity which may have epidemiological implications. PMID:21544184

  1. Chlorotoxin: A Helpful Natural Scorpion Peptide to Diagnose Glioma and Fight Tumor Invasion

    PubMed Central

    Dardevet, Lucie; Rani, Dipti; Abd El Aziz, Tarek; Bazin, Ingrid; Sabatier, Jean-Marc; Fadl, Mahmoud; Brambilla, Elisabeth; De Waard, Michel

    2015-01-01

    Chlorotoxin is a small 36 amino-acid peptide identified from the venom of the scorpion Leiurus quinquestriatus. Initially, chlorotoxin was used as a pharmacological tool to characterize chloride channels. While studying glioma-specific chloride currents, it was soon discovered that chlorotoxin possesses targeting properties towards cancer cells including glioma, melanoma, small cell lung carcinoma, neuroblastoma and medulloblastoma. The investigation of the mechanism of action of chlorotoxin has been challenging because its cell surface receptor target remains under questioning since two other receptors have been claimed besides chloride channels. Efforts on chlorotoxin-based applications focused on producing analogues helpful for glioma diagnosis, imaging and treatment. These efforts are welcome since gliomas are very aggressive brain cancers, close to impossible to cure with the current therapeutic arsenal. Among all the chlorotoxin-based strategies, the most promising one to enhance patient mean survival time appears to be the use of chlorotoxin as a targeting agent for the delivery of anti-tumor agents. Finally, the discovery of chlorotoxin has led to the screening of other scorpion venoms to identify chlorotoxin-like peptides. So far several new candidates have been identified. Only detailed research and clinical investigations will tell us if they share the same anti-tumor potential as chlorotoxin. PMID:25826056

  2. Resistance of cervical adenocarcinoma cells (HeLa) to venom from the scorpion Centruroides limpidus limpidus

    PubMed Central

    2013-01-01

    Background The venom of Centruroides limpidus limpidus (Cll) is a mixture of pharmacologically active principles. The most important of these are toxic proteins that interact both selectively and specifically with different cellular targets such as ion channels. Recently, anticancer properties of the venom from other scorpion species have been described. Studies in vitro have shown that scorpion venom induces cell death, inhibits proliferation and triggers the apoptotic pathway in different cancer cell lines. Herein, after treating human cervical adenocarcinoma (HeLa) cells with Cll crude venom, their cytotoxic activity and apoptosis induction were assessed. Results Cll crude venom induced cell death in normal macrophages in a dose-dependent manner. However, through viability assays, HeLa cells showed high survival rates after exposure to Cll venom. Also, Cll venom did not induce apoptosis after performing ethidium bromide/acridine orange assays, nor was there any evidence of chromatin condensation or DNA fragmentation. Conclusions Crude Cll venom exposure was not detrimental to HeLa cell cultures. This may be partially attributable to the absence of specific HeLa cell membrane targets for molecules present in the venom of Centruroides limpidus limpidus. Although these results might discourage additional studies exploring the potential of Cll venom to treat human papilloma cervical cancer, further research is required to explore positive effects of crude Cll venom on other cancer cell lines. PMID:24004568

  3. Neutralizing Effects of Mimosa tenuiflora Extracts against Inflammation Caused by Tityus serrulatus Scorpion Venom

    PubMed Central

    Bitencourt, Mariana Angélica Oliveira; Lima, Maira Conceição Jerônimo de Souza; Torres-Rêgo, Manoela; da Silva-Júnior, Arnóbio Antônio; Tambourgi, Denise Vilarinho; Zucolotto, Silvana Maria

    2014-01-01

    Scorpion bite represents a significant and serious public health problem in certain regions of Brazil, as well as in other parts of the world. Inflammatory mediators are thought to be involved in the systemic and local immune response induced by Tityus serrulatus scorpion envenomation. The aim of this study was to evaluate the effect of extracts of Mimosa tenuiflora on model envenomation. In mice, the envenomation model is induced by Tityus serrulatus venom. Previous treatment of mice with fractions from M. tenuiflora was able to suppress the cell migration to the peritoneal cavity. The treatment of mice with M. tenuiflora extracts also decreased the levels of IL-6, IL-12, and IL-1β. We concluded that the administration of the extract and fractions resulted in a reduction in cell migration and showed a reduction in the level of proinflammatory cytokines. This study demonstrates, for the first time, the anti-inflammatory effect of aqueous extract from the Mimosa tenuiflora plant on T. serrulatus venom. PMID:25013776

  4. Microglial activation of p38 contributes to scorpion envenomation-induced hyperalgesia.

    PubMed

    Niu, Qing-Shan; Jiang, Feng; Hua, Li-Ming; Fu, Jin; Jiao, Yun-Lu; Ji, Yong-Hua; Ding, Gang

    2013-10-25

    Intraplantar (i.pl.) injection of BmK I, a receptor site 3-specific modulator of voltage-gated sodium channels (VGSCs) from the venom of scorpion Buthus martensi Karsch (BmK), was shown to induce long-lasting and spontaneous nociceptive responses as demonstrated through experiments utilizing primary thermal and mirror-imaged mechanical hypersensitivity with different time course of development in rats. In this study, microglia was activated on both sides of L4-L5 spinal cord by i.pl. injection of BmK I. Meanwhile, the activation of p38/MAPK in L4-L5 spinal cord was found to be co-expressed with OX-42, the cell marker of microglia. The unilateral thermal and bilateral mechanical pain hypersensitivity of rat induced by BmK I was suppressed in a dose-dependent manner following pretreatment with SB203580 (a specific inhibitor of p-p38). Interestingly, microglia activity was also reduced in the presence of SB203580, which suggests that BmK I-induced microglial activation is mediated by p38/MAPK pathway. Combined with previously published literature, the results of this study demonstrate that p38-dependent microglial activation plays a role in scorpion envenomation-induced pain-related behaviors. PMID:24064352

  5. Novel potassium channel blocker venom peptides from Mesobuthus gibbosus (Scorpiones: Buthidae).

    PubMed

    Diego-García, Elia; Peigneur, Steve; Debaveye, Sarah; Gheldof, Eveline; Tytgat, Jan; Caliskan, Figen

    2013-01-01

    In the present study, we report for the first time, the molecular, biochemical and electrophysiological characterization of the components present in the soluble venom from Mesobuthus gibbosus (Brullé, 1832). According to the epidemiological and clinical situation of scorpion envenomation cases M. gibbosus scorpion is one of the most important health-threatening species of Turkey. Despite the medical importance reported for M. gibbosus, there is no additional information on toxin peptides and venom components to clarify the toxic effect of the M. gibbosus sting. Biochemical characterization of the venom was performed using different protocols and techniques following a bioassay-guided strategy (HPLC, mass spectrometry and Edman degradation sequencing). Venom fractions were tested in electrophysiological assays on a panel of six K(+) channels (K(v)1.1-1.6) by using the two-electrode voltage clamp technique. Three new α-KTx peptides were found and called MegKTx1, MegKTx2 and MegKTx3 (M. gibbosus, K(+) channel toxin number 1-3). A cDNA library from the telson was constructed and specific screening of transcripts was performed. Biochemical and molecular characterization of MegKTx peptides and transcripts shows a relation with toxins of three different α-KTx subfamilies (α-KTx3.x, α-KTx9.x and α-KTx16.x). PMID:23142506

  6. Neutralizing effects of Mimosa tenuiflora extracts against inflammation caused by Tityus serrulatus scorpion venom.

    PubMed

    Bitencourt, Mariana Angélica Oliveira; de Souza Lima, Maira Conceição Jerônimo; Torres-Rêgo, Manoela; Fernandes, Júlia Morais; da Silva-Júnior, Arnóbio Antônio; Tambourgi, Denise Vilarinho; Zucolotto, Silvana Maria; de Freitas Fernandes-Pedrosa, Matheus

    2014-01-01

    Scorpion bite represents a significant and serious public health problem in certain regions of Brazil, as well as in other parts of the world. Inflammatory mediators are thought to be involved in the systemic and local immune response induced by Tityus serrulatus scorpion envenomation. The aim of this study was to evaluate the effect of extracts of Mimosa tenuiflora on model envenomation. In mice, the envenomation model is induced by Tityus serrulatus venom. Previous treatment of mice with fractions from M. tenuiflora was able to suppress the cell migration to the peritoneal cavity. The treatment of mice with M. tenuiflora extracts also decreased the levels of IL-6, IL-12, and IL-1β. We concluded that the administration of the extract and fractions resulted in a reduction in cell migration and showed a reduction in the level of proinflammatory cytokines. This study demonstrates, for the first time, the anti-inflammatory effect of aqueous extract from the Mimosa tenuiflora plant on T. serrulatus venom. PMID:25013776

  7. Morphofunctional changes in incubated Mauthner neurons in goldfish treated with peptides from scorpion venom.

    PubMed

    Tiras, N R; Udal'tsov, S N; Mikheeva, I B; Pakhotin, P I; Moshkov, D A

    2004-09-01

    Electron microscopy with negative contrast showed that direct interaction of one of the peptide fractions of scorpion venom with monomeric chromatographically pure actin led to polymerization of actin, transforming it from the globular form to the fibrillar form. The effects of prolonged orthodromic stimulation on the evoked electrical activity and ultrastructure of Mauthner neurons (MN) were studied in incubated slices of goldfish medulla oblongata in the presence of this actin-polymerizing venom fraction. Peptides in this fraction were found to stabilize the amplitude of the electrical response of MN to exhaustion and to protect the ultrastructure of afferent chemical synapses and the neurons themselves from damage induced by stimulation. Enhancements in morphofunctional resistance were accompanied by stabilization of actin-containing specialized synaptic structures--desmosome-like contacts. The data obtained here provide evidence that peptides of this fraction of scorpion venom have direct actions on the actin component of the MN cytoskeleton and demonstrate potential for its use as a pharmacological tool able to penetrate living cells with value for studying the role of actin in the mechanisms of adaptation and memory.

  8. As Old as the Hills: Montane Scorpions in Southwestern North America Reveal Ancient Associations between Biotic Diversification and Landscape History

    PubMed Central

    Bryson, Robert W.; Riddle, Brett R.; Graham, Matthew R.; Smith, Brian Tilston; Prendini, Lorenzo

    2013-01-01

    Background The age of lineages has become a fundamental datum in studies exploring the interaction between geological transformation and biotic diversification. However, phylogeographical studies are often biased towards lineages that are younger than the geological features of the landscapes they inhabit. A temporally deeper historical biogeography framework may be required to address episodes of biotic diversification associated with geologically older landscape changes. Signatures of such associations may be retained in the genomes of ecologically specialized (stenotopic) taxa with limited vagility. In the study presented here, genetic data from montane scorpions in the Vaejovis vorhiesi group, restricted to humid rocky habitats in mountains across southwestern North America, were used to explore the relationship between scorpion diversification and regional geological history. Results Strong phylogeographical signal was evident within the vorhiesi group, with 27 geographically cohesive lineages inferred from a mitochondrial phylogeny. A time-calibrated multilocus species tree revealed a pattern of Miocene and Pliocene (the Neogene period) lineage diversification. An estimated 21 out of 26 cladogenetic events probably occurred prior to the onset of the Pleistocene, 2.6 million years ago. The best-fit density-dependent model suggested diversification rate in the vorhiesi group gradually decreased through time. Conclusions Scorpions of the vorhiesi group have had a long history in the highlands of southwestern North America. Diversification among these stenotopic scorpions appears to have occurred almost entirely within the Neogene period, and is temporally consistent with the dynamic geological history of the Basin and Range, and Colorado Plateau physiographical provinces. The persistence of separate lineages at small spatial scales suggests that a combination of ecological stenotopy and limited vagility may make these scorpions particularly valuable indicators

  9. Species-specific diversity of novel bacterial lineages and differential abundance of predicted pathways for toxic compound degradation in scorpion gut microbiota.

    PubMed

    Bolaños, Luis M; Rosenblueth, Mónica; Castillo-Ramírez, Santiago; Figuier-Huttin, Gilles; Martínez-Romero, Esperanza

    2016-05-01

    Scorpions are considered 'living fossils' that have conserved ancestral anatomical features and have adapted to numerous habitats. However, their gut microbiota diversity has not been studied. Here, we characterized the gut microbiota of two scorpion species, Vaejovis smithi and Centruroides limpidus. Our results indicate that scorpion gut microbiota is species-specific and that food deprivation reduces bacterial diversity. 16S rRNA gene phylogenetic analysis revealed novel bacterial lineages showing a low level of sequence identity to any known bacteria. Furthermore, these novel bacterial lineages were each restricted to a different scorpion species. Additionally, our results of the predicted metagenomic profiles revealed a core set of pathways that were highly abundant in both species, and mostly related to amino acid, carbohydrate, vitamin and cofactor metabolism. Notably, the food-deprived V. smithi shotgun metagenome matched almost completely the metabolic features of the prediction. Finally, comparisons among predicted metagenomic profiles showed that toxic compound degradation pathways were more abundant in recently captured C. limpidus scorpions. This study gives a first insight into the scorpion gut microbiota and provides a reference for future studies on the gut microbiota from other arachnid species. PMID:26058415

  10. Partial Agonist and Antagonist Activities of a Mutant Scorpion β-Toxin on Sodium Channels*

    PubMed Central

    Karbat, Izhar; Ilan, Nitza; Zhang, Joel Z.; Cohen, Lior; Kahn, Roy; Benveniste, Morris; Scheuer, Todd; Catterall, William A.; Gordon, Dalia; Gurevitz, Michael

    2010-01-01

    Scorpion β-toxin 4 from Centruroides suffusus suffusus (Css4) enhances the activation of voltage-gated sodium channels through a voltage sensor trapping mechanism by binding the activated state of the voltage sensor in domain II and stabilizing it in its activated conformation. Here we describe the antagonist and partial agonist properties of a mutant derivative of this toxin. Substitution of seven different amino acid residues for Glu15 in Css4 yielded toxin derivatives with both increased and decreased affinities for binding to neurotoxin receptor site 4 on sodium channels. Css4E15R is unique among this set of mutants in that it retained nearly normal binding affinity but lost its functional activity for modification of sodium channel gating in our standard electrophysiological assay for voltage sensor trapping. More detailed analysis of the functional effects of Css4E15R revealed weak voltage sensor trapping activity, which was very rapidly reversed upon repolarization and therefore was not observed in our standard assay of toxin effects. This partial agonist activity of Css4E15R is observed clearly in voltage sensor trapping assays with brief (5 ms) repolarization between the conditioning prepulse and the test pulse. The effects of Css4E15R are fit well by a three-step model of toxin action involving concentration-dependent toxin binding to its receptor site followed by depolarization-dependent activation of the voltage sensor and subsequent voltage sensor trapping. Because it is a partial agonist with much reduced efficacy for voltage sensor trapping, Css4E15R can antagonize the effects of wild-type Css4 on sodium channel activation and can prevent paralysis by Css4 when injected into mice. Our results define the first partial agonist and antagonist activities for scorpion toxins and open new avenues of research toward better understanding of the structure-function relationships for toxin action on sodium channel voltage sensors and toward potential toxin

  11. Parameters affecting in vitro oxidation/folding of maurotoxin, a four-disulphide-bridged scorpion toxin.

    PubMed Central

    di Luccio, E; Azulay, D O; Regaya, I; Fajloun, Z; Sandoz, G; Mansuelle, P; Kharrat, R; Fathallah, M; Carrega, L; Estève, E; Rochat, H; De Waard, M; Sabatier, J M

    2001-01-01

    Maurotoxin (MTX) is a 34-mer scorpion toxin cross-linked by four disulphide bridges that acts on various K(+) channel subtypes. MTX adopts a disulphide bridge organization of the type C1-C5, C2-C6, C3-C4 and C7-C8, and folds according to the common alpha/beta scaffold reported for other known scorpion toxins. Here we have investigated the process and kinetics of the in vitro oxidation/folding of reduced synthetic L-MTX (L-sMTX, where L-MTX contains only L-amino acid residues). During the oxidation/folding of reduced L-sMTX, the oxidation intermediates were blocked by iodoacetamide alkylation of free cysteine residues, and analysed by MS. The L-sMTX intermediates appeared sequentially over time from the least (intermediates with one disulphide bridge) to the most oxidized species (native-like, four-disulphide-bridged L-sMTX). The mathematical formulation of the diffusion-collision model being inadequate to accurately describe the kinetics of oxidation/folding of L-sMTX, we have formulated a derived mathematical description that better fits the experimental data. Using this mathematical description, we have compared for the first time the oxidation/folding of L-sMTX with that of D-sMTX, its stereoisomer that contains only D-amino acid residues. Several experimental parameters, likely to affect the oxidation/folding process, were studied further; these included temperature, pH, ionic strength, redox potential and concentration of reduced toxin. We also assessed the effects of some cellular enzymes, peptidylprolyl cis-trans isomerase (PPIase) and protein disulphide isomerase (PDI), on the folding pathways of reduced L-sMTX and D-sMTX. All the parameters tested affect the oxidative folding of sMTX, and the kinetics of this process were indistinguishable for L-sMTX and D-sMTX, except when stereospecific enzymes were used. The most efficient conditions were found to be: 50 mM Tris/HCl/1.4 mM EDTA, pH 7.5, supplemented by 0.5 mM PPIase and 50 units/ml PDI for 0.1 m

  12. Solution structure of toxin 2 from centruroides noxius Hoffmann, a beta-scorpion neurotoxin acting on sodium channels.

    PubMed

    Pintar, A; Possani, L D; Delepierre, M

    1999-03-26

    We have determined the solution structure of Cn2, a beta-toxin extracted from the venom of the New World scorpion Centruroides noxius Hoffmann. Cn2 belongs to the family of scorpion toxins that affect the sodium channel activity, and is very toxic to mammals (LD50=0.4 microg/20 g mouse mass). The three-dimensional structure was determined using 1H-1H two-dimensional NMR spectroscopy, torsion angle dynamics, and restrained energy minimization. The final set of 15 structures was calculated from 876 experimental distance constraints and 58 angle constraints. The structures have a global r. m.s.d. of 1.38 A for backbone atoms and 2.21 A for all heavy atoms. The overall fold is similar to that found in the other scorpion toxins acting on sodium channels. It is made of a triple-stranded antiparallel beta-sheet and an alpha-helix, and is stabilized by four disulfide bridges. A cis-proline residue at position 59 induces a kink of the polypeptide chain in the C-terminal region. The hydrophobic core of the protein is made up of residues L5, V6, L51, A55, and by the eight cysteine residues. A hydrophobic patch is defined by the aromatic residues Y4, Y40, Y42, W47 and by V57 on the side of the beta-sheet facing the solvent. A positively charged patch is formed by K8 and K63 on one edge of the molecule in the C-terminal region. Another positively charged spot is represented by the highly exposed K35. The structure of Cn2 is compared with those of other scorpion toxins acting on sodium channels, in particular Aah II and CsE-v3. This is the first structural report of an anti-mammal beta-scorpion toxin and it provides the necessary information for the design of recombinant mutants that can be used to probe structure-function relationships in scorpion toxins affecting sodium channel activity.

  13. Scorpion toxins for the reversal of BoNT-induced paralysis.

    PubMed

    Lowery, Colin A; Adler, Michael; Borrell, Andrew; Janda, Kim D

    2013-12-15

    The botulinum neurotoxins, characterized by their neuromuscular paralytic effects, are the most toxic proteins known to man. Due to their extreme potency, ease of production, and duration of activity, the BoNT proteins have been classified by the Centers for Disease Control as high threat agents for bioterrorism. In an attempt to discover effective BoNT therapeutics, we have pursued a strategy in which we leverage the blockade of K(+) channels that ultimately results in the reversal of neuromuscular paralysis. Towards this end, we utilized peptides derived from scorpion venom that are highly potent K(+) channel blockers. Herein, we report the synthesis of charybdotoxin, a 37 amino acid peptide, and detail its activity, along with iberiotoxin and margatoxin, in a mouse phrenic nerve hemidiaphragm assay in the absence and the presence of BoNT/A. PMID:24252544

  14. [Chlorotoxin and related peptides are short insect toxins from scorpion venom].

    PubMed

    Arzamasov, A A; Vasilevskiĭ, A A; Grishin, E V

    2014-01-01

    Scorpion venom is a complex multicomponent mixture of biologically active substances, some of which possess very interesting properties and are used in quite unexpected fields. The family of chlorotoxin (CTX)-like peptides serves a good example. These toxins exhibit insecticidal activity, however, their molecular mechanism of action on insect organism remains elusive. Nevertheless, CTX-like peptides attracted considerable research effort due to their ability to specifically interact with cells of brain tumors, i.e. gliomas. In the future these compounds may considerably aid anticancer therapy. This review summarizes the results obtained during the past 40 years of CTX-like peptides investigation. Both biological function aspects and the applied field related to gliomas are considered.

  15. A toxin to nervous, cardiac, and endocrine ERG K+ channels isolated from Centruroides noxius scorpion venom.

    PubMed

    Gurrola, G B; Rosati, B; Rocchetti, M; Pimienta, G; Zaza, A; Arcangeli, A; Olivotto, M; Possani, L D; Wanke, E

    1999-05-01

    Toxins isolated from a variety of venoms are tools for probing the physiological function and structure of ion channels. The ether-a-go-go-related genes (erg) codify for the K+ channels (ERG), which are crucial in neurons and are impaired in human long-QT syndrome and Drosophila 'seizure' mutants. We have isolated a peptide from the scorpion Centruroides noxius Hoffmann that has no sequence homologies with other toxins, and demonstrate that it specifically inhibits (IC50=16+/-1 nM) only ERG channels of different species and distinct histogenesis. These results open up the possibility of investigating ERG channel structure-function relationships and novel pharmacological tools with potential therapeutic efficacy.

  16. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  17. Linguistic Imperialism: African Perspectives.

    ERIC Educational Resources Information Center

    Phillipson, Robert

    1996-01-01

    Responds to an article on aspects of African language policy and discusses the following issues: multilingualism and monolingualism, proposed changes in language policy from the Organization for African Unity and South African initiatives, the language of literature, bilingual education, and whose interests English-language teaching is serving.…

  18. Brainstem structures are primarily affected in an experimental model of severe scorpion envenomation.

    PubMed

    Guidine, Patrícia Alves Maia; Cash, Diana; Drumond, Luciana Estefani; de Souza E Rezende, Gustavo Henrique; Massensini, André Ricardo; Williams, Steve Charles Rees; Moraes-Santos, Tasso; Moraes, Márcio Flávio Dutra; Mesquita, Michel Bernanos Soares

    2014-01-01

    Severe scorpion envenoming (SSE) is more frequent in children and is characterized by systemic dysfunctions with a mortality rate of up to 9%. Recent evidence shows that the central nervous system (CNS) plays a key role in triggering the cascade of symptoms present in SSE. The age-dependent role of the CNS in SSE lethality may be summarized in 3 hypotheses: (1) the shown increased blood brain barrier permeability of infants to the toxins would especially and primarily compromise neurovegetative control areas, (2) the neurons within these areas have high affinity to the toxins, and (3) the neurovascular interaction is such that SSE metabolically compromises proper function of toxin-targeted areas. A pharmacological magnetic resonance imaging paradigm was used to evaluate localized hemodynamic changes in relative cerebral blood volume (rCBV) for 30 min after the injection of TsTX, the most lethal toxin from the venom of the Tityus serrulatus scorpion. The brainstem showed significant rCBV reduction 1 min after TsTX administration, whereas rostral brain areas had delayed increase in rCBV (confirmed by laser Doppler measurements of cortical cerebral blood flow). Moreover, metabolic activity by 14C-2-deoxyglucose autoradiography showed the highest relative increase at the brainstem. To test whether TsTX has high affinity to brainstem neurons, the lateral ventricle was injected with Alexa Fluor 568 TsTX. Although some neurons showed intense fluorescence, the labeling pattern suggests that specific neurons were targeted. Altogether, these results suggest that brainstem areas involved in neurovegetative control are most likely within the primary structures triggering the cascade of symptoms present in SSE.

  19. Active Sites of Spinoxin, a Potassium Channel Scorpion Toxin, Elucidated by Systematic Alanine Scanning.

    PubMed

    Peigneur, Steve; Yamaguchi, Yoko; Kawano, Chihiro; Nose, Takeru; Nirthanan, Selvanayagam; Gopalakrishnakone, Ponnampalam; Tytgat, Jan; Sato, Kazuki

    2016-05-31

    Peptide toxins from scorpion venoms constitute the largest group of toxins that target the voltage-gated potassium channel (Kv). Spinoxin (SPX) isolated from the venom of scorpion Heterometrus spinifer is a 34-residue peptide neurotoxin cross-linked by four disulfide bridges. SPX is a potent inhibitor of Kv1.3 potassium channels (IC50 = 63 nM), which are considered to be valid molecular targets in the diagnostics and therapy of various autoimmune disorders and cancers. Here we synthesized 25 analogues of SPX and analyzed the role of each amino acid in SPX using alanine scanning to study its structure-function relationships. All synthetic analogues showed similar disulfide bond pairings and secondary structures as native SPX. Alanine replacements at Lys(23), Asn(26), and Lys(30) resulted in loss of activity against Kv1.3 potassium channels, whereas replacements at Arg(7), Met(14), Lys(27), and Tyr(32) also largely reduced inhibitory activity. These results suggest that the side chains of these amino acids in SPX play an important role in its interaction with Kv1.3 channels. In particular, Lys(23) appears to be a key residue that underpins Kv1.3 channel inhibition. Of these seven amino acid residues, four are basic amino acids, suggesting that the positive electrostatic potential on the surface of SPX is likely required for high affinity interaction with Kv1.3 channels. This study provides insight into the structure-function relationships of SPX with implications for the rational design of new lead compounds targeting potassium channels with high potency. PMID:27159046

  20. Therapeutic potential of chlorotoxin-like neurotoxin from the Chinese scorpion for human gliomas.

    PubMed

    Fu, Yue-Jun; Yin, Li-Tian; Liang, Ai-Hua; Zhang, Chao-Feng; Wang, Wei; Chai, Bao-Feng; Yang, Jian-Yi; Fan, Xiao-Jun

    2007-01-22

    Chlorotoxin, one of the key toxins in scorpion Leiurus quinquestriatus venom, has been shown to bind specifically to glioma cell surface as a specific chloride channel blocker. In this study, a purified, recombinant chlorotoxin-like peptide from the scorpion Buthus martensii Karsch (named rBmK CTa) was characterized by in vivo and in vitro studies. The results from cell proliferation assay with human glioma (SHG-44) cells showed that rBmK CTa inhibits the growth of glioma cells in a dose-dependent manner, with an IC(50) value of approximately 0.28microM. Under the same conditions, the IC(50) value for normal astrocytes increased to 8microM. This clearly indicated that rBmK CTa had specific toxicity against glioma cells but not astrocytes. Results from whole-cell patch-clamp recording showed that chloride current in SHG-44 was inhibited by rBmK CTa in a voltage-dependent manner and percent inhibitions for the blocking action of rBmK CTa (0.07 and 0.14microM) on I(Cl) was 17.64+/-3.06% and 55.86+/-2.83%, respectively. Histological analysis of rBmK CTa treated mice showed that brain, leg muscle and cardiac muscle were the target organs of this toxin. These results suggest that rBmK CTa may have potential therapeutic application in clinical treatment of human glioma. It represents an approach for developing a novel therapeutic agent.

  1. Bothriurus bonariensis scorpion venom activates voltage-dependent sodium channels in insect and mammalian nervous systems.

    PubMed

    Dos Santos, Douglas Silva; Carvalho, Evelise Leis; de Lima, Jeferson Camargo; Breda, Ricardo Vaz; Oliveira, Raquel Soares; de Freitas, Thiago Carrazoni; Salamoni, Simone Denise; Domingues, Michelle Flores; Piovesan, Angela Regina; Boldo, Juliano Tomazzoni; de Assis, Dênis Reis; da Costa, Jaderson Costa; Dal Belo, Cháriston André; Pinto, Paulo Marcos

    2016-10-25

    Animal venoms have been widely recognized as a major source of biologically active molecules. Bothriurus bonariensis, popularly known as black scorpion, is the arthropod responsible for the highest number of accidents involving scorpion sting in Southern Brazil. Here we reported the first attempt to investigate the neurobiology of B. bonariensis venom (BBV) in the insect and mammalian nervous system. BBV (32 μg/g) induced a slow neuromuscular blockade in the in vivo cockroach nerve-muscle preparations (70 ± 4%, n = 6, p < 0.001), provoking repetitive twitches and significantly decreasing the frequency of spontaneous leg action potentials (SNCAPs) from 82 ± 3 min(-1) to 36 ± 1.3 min(-1) (n = 6, p < 0.05), without affecting the amplitude. When tested in primary cultures of rat hippocampal cells, BBV induced a massive increase of Ca(2+) influx (250 ± 1% peak increase, n = 3, p < 0.0001). The disturbance of calcium homeostasis induced by BBV on the mammalian central nervous system was not accompanied by cellular death and was prevented by the co-treatment of the hippocampal cells with tetrodotoxin, a selective sodium channel blocker. The results suggest that the biological activity of BBV is mostly related to a modulation of sodium channels function. Our biological activity survey suggests that BBV may have a promising insecticidal and therapeutic potential. PMID:27544632

  2. Brainstem structures are primarily affected in an experimental model of severe scorpion envenomation.

    PubMed

    Guidine, Patrícia Alves Maia; Cash, Diana; Drumond, Luciana Estefani; de Souza E Rezende, Gustavo Henrique; Massensini, André Ricardo; Williams, Steve Charles Rees; Moraes-Santos, Tasso; Moraes, Márcio Flávio Dutra; Mesquita, Michel Bernanos Soares

    2014-01-01

    Severe scorpion envenoming (SSE) is more frequent in children and is characterized by systemic dysfunctions with a mortality rate of up to 9%. Recent evidence shows that the central nervous system (CNS) plays a key role in triggering the cascade of symptoms present in SSE. The age-dependent role of the CNS in SSE lethality may be summarized in 3 hypotheses: (1) the shown increased blood brain barrier permeability of infants to the toxins would especially and primarily compromise neurovegetative control areas, (2) the neurons within these areas have high affinity to the toxins, and (3) the neurovascular interaction is such that SSE metabolically compromises proper function of toxin-targeted areas. A pharmacological magnetic resonance imaging paradigm was used to evaluate localized hemodynamic changes in relative cerebral blood volume (rCBV) for 30 min after the injection of TsTX, the most lethal toxin from the venom of the Tityus serrulatus scorpion. The brainstem showed significant rCBV reduction 1 min after TsTX administration, whereas rostral brain areas had delayed increase in rCBV (confirmed by laser Doppler measurements of cortical cerebral blood flow). Moreover, metabolic activity by 14C-2-deoxyglucose autoradiography showed the highest relative increase at the brainstem. To test whether TsTX has high affinity to brainstem neurons, the lateral ventricle was injected with Alexa Fluor 568 TsTX. Although some neurons showed intense fluorescence, the labeling pattern suggests that specific neurons were targeted. Altogether, these results suggest that brainstem areas involved in neurovegetative control are most likely within the primary structures triggering the cascade of symptoms present in SSE. PMID:24105889

  3. An overview of platelet indices for evaluating platelet function in children with scorpion envenomation.

    PubMed

    Konca, Capan; Tekin, Mehmet; Colak, Pinar; Uckardes, Fatih; Turgut, Mehmet

    2014-01-01

    The aim of this study was to assess the correlation between platelet indices and scorpion envenomations (SE). Medical records of 76 children who were hospitalised for scorpion stings in the paediatric intensive care unit (PICU) between February 2013 and November 2013, and 55 healthy children who were similar to the patient group in terms of age and sex, were analysed retrospectively. The leucocyte (WBC), thrombocyte (PLT), plateletcrit (PCT), platelet distribution width (PDW) and mean platelet volume (MPV) values of the 76 children with SE were recorded. These values were compared with the healthy control group. Significantly higher WBC and PDW values were noted in patients with SE in comparison to the controls. Patients with SE had significantly lower mean MPV values compared to the healthy controls (9.03 ± 1.26 compared to 10.43 ± 1.44 fL, respectively; p < 0.001). Although the mean platelet count was slightly elevated in the SE group, no statistically significant difference existed between the two groups (p = 0.097). Furthermore, the mean PCT values in the SE group compared to the control group were slightly decreased, but this decrease was not statistically significant (p = 0.141). A significant inverse correlation existed between the MPV values and the WBC (r = -0.450, p < 0.01) and PLT counts (r = -0.420, p < 0.01). The PLT values were significantly correlated with the PCT values (r = 0.687, p < 0.01). This study demonstrated that SE may lead to several alterations in platelet indices. Significantly lower values of MPV and higher values of PDW were detected in SE patients. However, the increase in the platelet counts and the decrease in the PCT values were not significant. PMID:26417303

  4. A depressant insect toxin with a novel analgesic effect from scorpion Buthus martensii Karsch.

    PubMed

    Guan, R; Wang, C G; Wang, M; Wang, D C

    2001-09-10

    A new peptide named BmK dITAP3 from scorpion Buthus martensii Karsch (BmK) has been identified to possess a dual bioactivity, a depressant neurotoxicity on insects and an analgesic effect on mice. The bioassays also showed that the peptide was definitely devoid of the neurotoxicity on mammals, which indicated that the analgesic effect of BmK dITAP3 could not be ascribed to the syndromic effects of a mammalian neurotoxicity. BmK dITAP3 exhibited 43.0% inhibition efficiency of the analgesic effect on mice at a dose of 5 mg/kg and the FPU value of 0.5 microg/body (approximately 30 mg) on the fly larvae. The pI value and the molecular mass determined by MALDI-TOF MS for dITAP3 were 6.5 and 6722.7, respectively. Its first 15 N-terminal residues were determined by Edman degradation, based on which the full amino acid sequence was deduced from the cDNA sequence encoding the peptide with 3'-RACE. Circular dichroism and sequence based prediction analyses showed dITAP3 may have a similar molecular scaffold as the most scorpion toxins but with features of the more beta structures and much less of alpha helix. The details of the purification, characterization and sequencing as well as the sequence comparison with other depressant insect toxins and the correlation between the analgesic effect and the insect toxicity will be reported and discussed, respectively.

  5. More about the geographical pattern of distribution of the genus Pseudouroplectes Lourenço, 1995 (Scorpiones: Buthidae) from Madagascar.

    PubMed

    Lourenço, Wilson R; Wilmé, Lucienne; Waeber, Patrick O

    2016-01-01

    The genus Pseudouroplectes Lourenço, 1995 (Buthidae) remains among the less speciose Malagasy genera and all the known species are extremely rare. A new species is described from the dry forests in the Tsingy formations of the National Park Bemaraha, extending the distribution of the genus further north. Once again, the single holotype specimen was obtained by extraction with the use of Berlese system. With the description of the new species, the distributional pattern of this genus is confirmed for dry forest formations from the south to the middle of the island; however, for the first time the group's distribution overlaps that of another micro-scorpion genus, Microcharmus Lourenço, 1995. The distribution patterns of the humicolous micro-scorpions endemic to Madagascar are considered to further explore the "Neogrosphus rule" as a possible explanation of global species distribution patterns in changing environments.

  6. Enzymatic properties of venoms from Brazilian scorpions of Tityus genus and the neutralisation potential of therapeutical antivenoms.

    PubMed

    Venancio, Emerson J; Portaro, Fernanda C V; Kuniyoshi, Alexandre K; Carvalho, Daniela Cajado; Pidde-Queiroz, Giselle; Tambourgi, Denise V

    2013-07-01

    Tityus scorpion stings are an important public health problem in Brazil, where the incidence of such stings exceeds the incidence of the health problems caused by other venomous animals, including snakes. In this study, we have analysed specific enzymatic activities of the venom from the Brazilian scorpions of Tityus genus, i.e., Tityus serrulatus, Tityus bahiensis and Tityus stigmurus. The data presented here revealed that Tityus spp. venoms exhibited significant hyaluronidase activity but no phospholipase activity. All the venom samples exhibited the ability to hydrolyse Abz-FLRRV-EDDnp and dynorphin 1-13 substrates. These activities were inhibited by 1,10-phenanthroline but not by PMSF, indicating the presence of metalloproteinases in the Tityus spp. venoms. The venom peptidase activity on Abz-FLRRV-EDDnp and on dynorphin 1-13 was partially inhibited by therapeutic Brazilian anti-scorpion and anti-arachnidic antivenoms. Dynorphin 1-13 (YGGFLRRIRPKLK) contains two scissile bonds between the residues Leu-Arg and Arg-Arg that are susceptible to cleavage by the Tityus venom metallopeptidase(s). Their cleavage releases leu-enkephalin, an important bioactive peptide. The detection of metalloproteinase(s) with specificity for both dynorphin 1-13 degradation and leu-enkephalin releasing can be important for the mechanistic understanding of hypotension and bradycardia induction in cases of scorpion stings, whereas hyaluronidases might contribute to the diffusion of the toxins present in these venoms. Furthermore, the limited inhibition of the toxic enzymatic activities by commercial antivenoms illustrates the necessity of improvements in current antivenom preparation.

  7. Analysis of lipid and fatty acid composition of three species of scorpions with relation to different organs.

    PubMed

    Laino, Aldana; Mattoni, Camilo; Ojanguren-Affilastro, Andrés; Cunningham, Mónica; Fernando Garcia, C

    2015-12-01

    Within arthropods most of the information related to the type of mobilization and storage of lipids is found in insects and crustaceans. Literature is scarce with relation to scorpions. This order is a remarkably important model of the biochemistry, since it is characterized as an animal with very primitive traits which have varied minimally through time. In the present study we characterize and compare lipids and fatty acids present in three species of scorpion: Timogenes elegans, Timogenes dorbignyi, and Brachistosternus ferrugineus, focusing the study on the main organs/tissues involved in the dynamics of lipids. As found in the fat body of insects, hepatopancreas of crustaceans and midgut diverticula of spiders, the hepatopancreas of the three species studied here turned out to be the organ of lipid storage (great quantity of triacylglycerides). With relation to the hemolymph and muscles, a great quantity of phospholipids was observed, which is possibly involved in membrane formation. It is important to highlight that unlike what happens in insects, in scorpions the main circulating energetic lipid is the triacylglyceride. This lipid is found in greater proportion in the hepatopancreas of females, surely for reproduction. The fatty acid of the different organs/tissues analyzed remained constant in the three species studied with certain characteristic patterns, thus observing saturated and unsaturated most abundant fatty acids of C16 and C18. Finally, it could be observed that in T. elegans, T. dorbignyi and B. ferrugineus scorpions, there is a lack of 20:4 that generates a special condition within fatty acids of arthropods.

  8. Target-Driven Positive Selection at Hot Spots of Scorpion Toxins Uncovers Their Potential in Design of Insecticides.

    PubMed

    Zhu, Limei; Peigneur, Steve; Gao, Bin; Zhang, Shangfei; Tytgat, Jan; Zhu, Shunyi

    2016-08-01

    Positive selection sites (PSSs), a class of amino acid sites with an excess of nonsynonymous to synonymous substitutions, are indicators of adaptive molecular evolution and have been detected in many protein families involved in a diversity of biological processes by statistical approaches. However, few studies are conducted to evaluate their functional significance and the driving force behind the evolution (i.e., agent of selection). Scorpion α-toxins are a class of multigene family of peptide neurotoxins affecting voltage-gated Na(+ )(Nav) channels, whose members exhibit differential potency and preference for insect and mammalian Nav channels. In this study, we undertook a systematical molecular dissection of nearly all the PSSs newly characterized in the Mesobuthus α-toxin family and a two-residue insertion ((19)AlaPhe(20)) located within a positively selected loop via mutational analysis of α-like MeuNaTxα-5, one member affecting both insect and mammalian Nav channels. This allows to identify hot-spot residues on its functional face involved in interaction with the receptor site of Nav channels, which comprises two PSSs (Ile(40) and Leu(41)) and the small insertion, both located on two spatially separated functional loops. Mutations at these hot-spots resulted in a remarkably decreased anti-mammalian activity in MeuNaTxα-5 with partially impaired or enhanced insecticide activity, suggesting the potential of PSSs in designing promising candidate insecticides from scorpion α-like toxins. Based on an experiment-guided toxin-channel complex model and high evolutionary variability in the receptor site of predators and prey of scorpions, we provide new evidence for target-driven adaptive evolution of scorpion toxins to deal with their targets' diversity. PMID:27189560

  9. OcyKTx2, a new K⁺-channel toxin characterized from the venom of the scorpion Opisthacanthus cayaporum.

    PubMed

    Schwartz, Elisabeth F; Bartok, Adam; Schwartz, Carlos Alberto; Papp, Ferenc; Gómez-Lagunas, Froylan; Panyi, Gyorgy; Possani, Lourival D

    2013-08-01

    Opisthacanthus cayaporum belongs to the Liochelidae family, and the scorpions from this genus occur in southern Africa, Central America and South America and, therefore, can be considered a true Gondwana heritage. In this communication, the isolation, primary structure characterization, and K⁺-channel blocking activity of new peptide from this scorpion venom are reported. OcyKTx2 is a 34 amino acid long peptide with four disulfide bridges and molecular mass of 3807 Da. Electrophysiological assays conducted with pure OcyKTx2 showed that this toxin reversibly blocks Shaker B K⁺-channels with a Kd of 82 nM, and presents an even better affinity toward hKv1.3, blocking it with a Kd of ∼18 nM. OcyKTx2 shares high sequence identity with peptides belonging to subfamily 6 of α-KTxs that clustered very closely in the phylogenetic tree included here. Sequence comparison, chain length and number of disulfide bridges analysis classify OcyKTx2 into subfamily 6 of the α-KTx scorpion toxins (systematic name, α-KTx6.17).

  10. Convergent evolution in the antennae of a cerambycid beetle, Onychocerus albitarsis, and the sting of a scorpion

    NASA Astrophysics Data System (ADS)

    Berkov, Amy; Rodríguez, Nelson; Centeno, Pedro

    2008-03-01

    Venom-injecting structures have arisen independently in unrelated arthropods including scorpions, spiders, centipedes, larval owlflies and antlions, and Hymenoptera (wasps, ants, and bees). Most arthropods use venom primarily as an offensive weapon to subdue prey, and only secondarily in defense against enemies. Venom is injected by biting with fangs or stinging with a specialized hypodermic structure used exclusively for the delivery of venom (usually modified terminal abdominal segments). A true sting apparatus, previously known only in scorpions and aculeate wasps, is now known in a third group. We here report the first known case of a cerambycid beetle using its antennae to inject a secretion that causes cutaneous and subcutaneous inflammation in humans. Scanning electron microscopy revealed that the terminal antennal segment of Onychocerus albitarsis (Pascoe) has two pores opening into channels leading to the tip through which the secretion is delivered. This is a novel case of convergent evolution: The delivery system is almost identical to that found in the stinger of a deadly buthid scorpion.

  11. Arachnids of medical importance in Brazil: main active compounds present in scorpion and spider venoms and tick saliva.

    PubMed

    Cordeiro, Francielle A; Amorim, Fernanda G; Anjolette, Fernando A P; Arantes, Eliane C

    2015-01-01

    Arachnida is the largest class among the arthropods, constituting over 60,000 described species (spiders, mites, ticks, scorpions, palpigrades, pseudoscorpions, solpugids and harvestmen). Many accidents are caused by arachnids, especially spiders and scorpions, while some diseases can be transmitted by mites and ticks. These animals are widely dispersed in urban centers due to the large availability of shelter and food, increasing the incidence of accidents. Several protein and non-protein compounds present in the venom and saliva of these animals are responsible for symptoms observed in envenoming, exhibiting neurotoxic, dermonecrotic and hemorrhagic activities. The phylogenomic analysis from the complementary DNA of single-copy nuclear protein-coding genes shows that these animals share some common protein families known as neurotoxins, defensins, hyaluronidase, antimicrobial peptides, phospholipases and proteinases. This indicates that the venoms from these animals may present components with functional and structural similarities. Therefore, we described in this review the main components present in spider and scorpion venom as well as in tick saliva, since they have similar components. These three arachnids are responsible for many accidents of medical relevance in Brazil. Additionally, this study shows potential biotechnological applications of some components with important biological activities, which may motivate the conducting of further research studies on their action mechanisms.

  12. [Toxicological and immunological aspects of scorpion venom (Tytius pachyurus): neutralizing capacity of antivenoms produced in Latin America].

    PubMed

    Barona, Jacqueline; Otero, Rafael; Núñez, Vitelbina

    2004-03-01

    The toxicity and immunochemical properties of Tityus pachyurus Pocock scorpion venom was characterized, as well as the neutralization capacity against it by three anti-scorpion antivenoms (Alacramyn, Instituto Bioclón, México; Suero antiescorpiónico, Instituto Butantán, Sao Paulo, Brasil; and Suero antiescorpiónico, Centro de Biotecnología, Universidad Central de Venezuela, Caracas, Venezuela). The venom yield, obtained by manual milking, 680+/-20 microg venom, a 50% lethal dose in mice was 4.8 microg/kg (90 microg for an 18-20 g mouse). The most common symptoms of venom poisoning in mice were sialorrhea, respiratory distress, profuse sweating, ataxia, behavior alterations (restlessness, somnolence) and hyperglycemia at 3 and 24 hours after subcutaneous venom injection (0.5 LD50). The neutralizing capacity of Bioclón (México City) and Butantán (Sao Paulo) antivenoms (for a 50% effective dose) was 330 and 292 microg venom/ml antivenom, respectively. The Biotecnología (Caracas) antivenom did not neutralize the lethal effect of venom. By electrophoresis (SDS-PAGE) was demonstrated that the venom contains proteins from less than 14 kd to 97 kd. The Western blots indicated immunological reactivity of the three antivenoms with most of venom components, including proteins of low molecular mass (<14 kd). The results allow to conclude that T. pachyurus venom is neutralized efficiently by anti-scorpion antivenoms produced in México and Brasil.

  13. Scorpion Venom Heat-Resistant Peptide Attenuates Glial Fibrillary Acidic Protein Expression via c-Jun/AP-1.

    PubMed

    Cao, Zhen; Wu, Xue-Fei; Peng, Yan; Zhang, Rui; Li, Na; Yang, Jin-Yi; Zhang, Shu-Qin; Zhang, Wan-Qin; Zhao, Jie; Li, Shao

    2015-11-01

    Scorpion venom has been used in the Orient to treat central nervous system diseases for many years, and the protein/peptide toxins in Buthus martensii Karsch (BmK) venom are believed to be the effective components. Scorpion venom heat-resistant peptide (SVHRP) is an active component of the scorpion venom extracted from BmK. In a previous study, we found that SVHRP could inhibit the formation of a glial scar, which is characterized by enhanced glial fibrillary acidic protein (GFAP) expression, in the epileptic hippocampus. However, the cellular and molecular mechanisms underlying this process remain to be clarified. The results of the present study indicate that endogenous GFAP expression in primary rat astrocytes was attenuated by SVHRP. We further demonstrate that the suppression of GFAP was primarily mediated by inhibiting both c-Jun expression and its binding with AP-1 DNA binding site and other factors at the GFAP promoter. These results support that SVHRP contributes to reducing GFAP at least in part by decreasing the activity of the transcription factor AP-1. In conclusion, the effects of SVHRP on astrocytes with respect to the c-Jun/AP-1 signaling pathway in vitro provide a practical basis for studying astrocyte activation and inhibition and a scientific basis for further studies of traditional medicine.

  14. A Combinational Strategy upon RNA Sequencing and Peptidomics Unravels a Set of Novel Toxin Peptides in Scorpion Mesobuthus martensii

    PubMed Central

    Luan, Ning; Shen, Wang; Liu, Jie; Wen, Bo; Lin, Zhilong; Yang, Shilong; Lai, Ren; Liu, Siqi; Rong, Mingqiang

    2016-01-01

    Scorpion venom is deemed to contain many toxic peptides as an important source of natural compounds. Out of the two hundred proteins identified in Mesobuthus martensii (M. martensii), only a few peptide toxins have been found so far. Herein, a combinational approach based upon RNA sequencing and Liquid chromatography-mass spectrometry/mass spectrometry (LC MS/MS) was employed to explore the venom peptides in M. martensii. A total of 153 proteins were identified from the scorpion venom, 26 previously known and 127 newly identified. Of the novel toxins, 97 proteins exhibited sequence similarities to known toxins, and 30 were never reported. Combining peptidomic and transcriptomic analyses, the peptide sequence of BmKKx1 was reannotated and four disulfide bridges were confirmed within it. In light of the comparison of conservation and variety of toxin amino acid sequences, highly conserved and variable regions were perceived in 24 toxins that were parts of two sodium channel and two potassium channel toxins families. Taking all of this evidences together, the peptidomic analysis on M. martensii indeed identified numerous novel scorpion peptides, expanded our knowledge towards the venom diversity, and afforded a set of pharmaceutical candidates. PMID:27782050

  15. Structural and Functional Elucidation of Peptide Ts11 Shows Evidence of a Novel Subfamily of Scorpion Venom Toxins

    PubMed Central

    Cremonez, Caroline M.; Maiti, Mohitosh; Peigneur, Steve; Cassoli, Juliana Silva; Dutra, Alexandre A. A.; Waelkens, Etienne; Lescrinier, Eveline; Herdewijn, Piet; de Lima, Maria Elena; Pimenta, Adriano M. C.; Arantes, Eliane C.; Tytgat, Jan

    2016-01-01

    To date, several families of peptide toxins specifically interacting with ion channels in scorpion venom have been described. One of these families comprise peptide toxins (called KTxs), known to modulate potassium channels. Thus far, 202 KTxs have been reported, belonging to several subfamilies of KTxs (called α, β, γ, κ, δ, and λ-KTxs). Here we report on a previously described orphan toxin from Tityus serrulatus venom, named Ts11. We carried out an in-depth structure-function analysis combining 3D structure elucidation of Ts11 and electrophysiological characterization of the toxin. The Ts11 structure is highlighted by an Inhibitor Cystine Knot (ICK) type scaffold, completely devoid of the classical secondary structure elements (α-helix and/or β-strand). This has, to the best of our knowledge, never been described before for scorpion toxins and therefore represents a novel, 6th type of structural fold for these scorpion peptides. On the basis of their preferred interaction with voltage-gated K channels, as compared to all the other targets tested, it can be postulated that Ts11 is the first member of a new subfamily, designated as ε-KTx. PMID:27706049

  16. Human bronchial epithelial cells injury and cytokine production induced by Tityus serrulatus scorpion venom: An in vitro study.

    PubMed

    Rigoni, Vera Lucia Silva; Kwasniewski, Fabio H; Vieira, Rodolfo Paula; Linhares, Ingrid Sestrem; da Silva, Joelmir Lucena Veiga; Nogueira-Pedro, Amanda; Zamuner, Stella Regina

    2016-09-15

    Tityus serrulatus is the scorpion specie responsible for the majority of scorpion sting accidents in Brazil. Symptoms of envenomation by Tityus serrulatus range from local pain to severe systemic reactions such as cardiac dysfunction and pulmonary edema. Thus, this study has evaluated the participation of bronchial epithelial cells in the pulmonary effects of Tityus serrulatus scorpion venom (Tsv). Human bronchial epithelial cell line BEAS-2B were utilized as a model target and were incubated with Tsv (10 or 50 μg/mL) for 1, 3, 6 and 24 h. Effects on cellular response of venom-induce cytotoxicity were examined including cell viability, cell integrity, cell morphology, apoptosis/necrosis as well as cell activation through the release of pro-inflammatory cytokines IL-1β, IL-6 and IL-8. Tsv caused a decrease in cell viability at 10 and 50 μg/mL, which was confirmed by lactate dehydrogenase (LDH) measurement. Flow cytometry analyses revealed necrosis as the main cell death pathway caused by Tsv. Furthermore, Tsv induced the release of IL-1β, IL-6 and IL-8. Altogether, these results demonstrate that Tsv induces cytotoxic effects on bronchial epithelial cells, involving necrosis and release of pro-inflammatory cytokines, suggesting that bronchial epithelial cells may play a role in the pulmonary injury caused by Tsv. PMID:27452928

  17. A chimeric scorpion alpha-toxin displays de novo electrophysiological properties similar to those of alpha-like toxins.

    PubMed

    Bouhaouala-Zahar, Balkiss; Benkhalifa, Rym; Srairi, Najet; Zenouaki, Ilhem; Ligny-Lemaire, Caroline; Drevet, Pascal; Sampieri, François; Pelhate, Marcel; El Ayeb, Mohamed; Ménez, André; Karoui, Habib; Ducancel, Frédéric

    2002-06-01

    BotXIV and LqhalphaIT are two structurally related long chain scorpion alpha-toxins that inhibit sodium current inactivation in excitable cells. However, while LqhalphaIT from Leiurus quinquestriatus hebraeus is classified as a true and strong insect alpha-toxin, BotXIV from Buthus occitanus tunetanus is characterized by moderate biological activities. To assess the possibility that structural differences between these two molecules could reflect the localization of particular functional topographies, we compared their sequences. Three structurally deviating segments located in three distinct and exposed loops were identified. They correspond to residues 8-10, 19-22, and 38-43. To evaluate their functional role, three BotXIV/LqhalphaIT chimeras were designed by transferring the corresponding LqhalphaIT sequences into BotXIV. Structural and antigenic characterizations of the resulting recombinant chimera show that BotXIV can accommodate the imposed modifications, confirming the structural flexibility of that particular alpha/beta fold. Interestingly, substitution of residues 8-10 yields to a new electrophysiological profile of the corresponding variant, partially comparable to that one of alpha-like scorpion toxins. Taken together, these results suggest that even limited structural deviations can reflect functional diversity, and also that the structure-function relationships between insect alpha-toxins and alpha-like scorpion toxins are probably more complex than expected.

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

    PubMed

    Bucaretchi, Fábio; Fernandes, Luciane C R; Fernandes, Carla B; Branco, Maíra M; Prado, Camila C; Vieira, Ronan J; De Capitani, Eduardo M; Hyslop, Stephen

    2014-10-01

    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

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

    PubMed

    Bucaretchi, Fábio; Fernandes, Luciane C R; Fernandes, Carla B; Branco, Maíra M; Prado, Camila C; Vieira, Ronan J; De Capitani, Eduardo M; Hyslop, Stephen

    2014-10-01

    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

  20. Two recombinant α-like scorpion toxins from Mesobuthus eupeus with differential affinity toward insect and mammalian Na(+) channels.

    PubMed

    Zhu, Limei; Peigneur, Steve; Gao, Bin; Tytgat, Jan; Zhu, Shunyi

    2013-09-01

    α-Scorpion toxins are modulators of voltage-gated Na(+) channels (Navs), which bind to the receptor site 3 to inhibit the fast inactivation of the channels. MeuNaTxα-12 and MeuNaTxα-13 are two new α-scorpion toxin-like peptides identified by cDNA cloning from the scorpion Mesobuthus eupeus with unknown functions. Here, we report their recombinant production, oxidative refolding, structural and functional features. By in vitro renaturation from bacterial inclusion bodies and further purification through reverse phase high-performance liquid chromatography, we obtained high purity recombinant products with a native-like conformation identified by circular dichroism analysis. Two-electrode voltage clamp recordings on five cloned mammalian Nav subtypes (rNav1.1, rNav1.2, rNav1.4, rNav1.5, and mNav1.6) and the insect counterpart DmNav1, all expressed in Xenopus laevis oocytes, showed that these two peptides inhibited rapid inactivation of the sensitive Na(+) channels with significant preference for DmNav1. The half maximal effective concentrations (EC50) of MeuNaTxα-12 and MeuNaTxα-13 for this channel are 19.95 ± 2.99 nM and 65.50 ± 7.28 nM, respectively, showing 45 and 38 folds higher affinities than for rNav1.1, the most sensitive mammalian channel among the five isoforms. Our functional data confirms that these two peptides belong to the α-like scorpion toxin group. A combined analysis of the site 3 sequences and the pharmacological data illuminates the importance of the loop LD4:S5-S6 of the channel in interacting with the toxins whereas affinity variations between MeuNaTxα-12 and MeuNaTxα-13 highlight a key functional role of a cationic side chain at position 28 of MeuNaTxα-12. Successful expression together with structural and functional characterization of these two new α-like scorpion toxins lays basis for further studies of their structure-function relationship.

  1. Identification and Phylogenetic Analysis of Tityus pachyurus and Tityus obscurus Novel Putative Na+-Channel Scorpion Toxins

    PubMed Central

    Guerrero-Vargas, Jimmy A.; Mourão, Caroline B. F.; Quintero-Hernández, Verónica; Possani, Lourival D.; Schwartz, Elisabeth F.

    2012-01-01

    Background Colombia and Brazil are affected by severe cases of scorpionism. In Colombia the most dangerous accidents are caused by Tityus pachyurus that is widely distributed around this country. In the Brazilian Amazonian region scorpion stings are a common event caused by Tityus obscurus. The main objective of this work was to perform the molecular cloning of the putative Na+-channel scorpion toxins (NaScTxs) from T. pachyurus and T. obscurus venom glands and to analyze their phylogenetic relationship with other known NaScTxs from Tityus species. Methodology/Principal Findings cDNA libraries from venom glands of these two species were constructed and five nucleotide sequences from T. pachyurus were identified as putative modulators of Na+-channels, and were named Tpa4, Tpa5, Tpa6, Tpa7 and Tpa8; the latter being the first anti-insect excitatory β-class NaScTx in Tityus scorpion venom to be described. Fifteen sequences from T. obscurus were identified as putative NaScTxs, among which three had been previously described, and the others were named To4 to To15. The peptides Tpa4, Tpa5, Tpa6, To6, To7, To9, To10 and To14 are closely related to the α-class NaScTxs, whereas Tpa7, Tpa8, To4, To8, To12 and To15 sequences are more related to the β-class NaScTxs. To5 is possibly an arthropod specific toxin. To11 and To13 share sequence similarities with both α and β NaScTxs. By means of phylogenetic analysis using the Maximum Parsimony method and the known NaScTxs from Tityus species, these toxins were clustered into 14 distinct groups. Conclusions/Significance This communication describes new putative NaScTxs from T. pachyurus and T. obscurus and their phylogenetic analysis. The results indicate clear geographic separation between scorpions of Tityus genus inhabiting the Amazonian and Mountain Andes regions and those distributed over the Southern of the Amazonian rainforest. Based on the consensus sequences for the different clusters, a new nomenclature for the Na

  2. Effect of clonidine in mice injected with Tityus discrepans scorpion venom.

    PubMed

    Rodríguez, A; Zerpa, H; Ruiz, A; Bermúdez, V; García, F; Silva, A; Gutiérrez, L; Villasmil, S

    2013-03-01

    A study was conducted to assess the effect of clonidine (α(2)-adrenoceptor selective agonist) on glycemia, serum and urine α-amylase, blood urea nitrogen (BUN), serum creatinine, white blood cell count, kidney histology and zymogen granule content in pancreatic acini, in mice under the effect of Tityus discrepans (Td) scorpion venom. BALB/c male mice (20 ± 2 g, n = 7-11) were intraperitoneally (ip) injected with a sublethal dose (1 μg/g) of Td venom, and were treated (ip) with 0.1 μg/g of clonidine (Catapresan(®)) or 0.9% NaCl 30 min after the venom injection, and then every 2 h. Six hours later, mice were anesthetized with diethylether and urine and blood samples were withdrawn by cystocentesis and cardiocentesis, respectively. Tissue samples were obtained and fixed immediately in buffered formalin (2%, pH 7.4) and then processed for stain H&E. Td venom did not cause hyperglycemia by itself. However, clonidine induced hyperglycemia, which was synergized by Td venom. Although the venom did not produce hyperamylasemia, clonidine significantly diminished serum α-amylase activity in envenomed mice. Td venom did not significantly increase urinary α-amylase activity, which was unaffected by clonidine. Morphometric analysis using microphotographs of pancreata from mice injected with Td venom showed a reduced zymogen granule content as judged by the acidophilic bidimensional area of acini. This effect was significantly reduced by clonidine. Kidney samples showed histological changes which were partially affected by the drug. Clonidine reduced the increase in BUN and serum creatinine concentration in envenomed mice. Td venom produced neutrophilia and lymphopenia, which were clonidine-resistant at the assayed dose. These results suggest that α(2)-adrenoceptor selective agonists would be able to reduce some scorpion venom-induced renal and pancreatic disturbances, possibly through the inhibition of neurotransmitter release from presynaptic cholinergic and

  3. The African superswell

    NASA Technical Reports Server (NTRS)

    Nyblade, Andrew A.; Robinson, Scott W.

    1994-01-01

    Maps of residual bathymetry in the ocean basins around the African continent reveal a broad bathymetric swell in the southeastern Atlantic Ocean with an amplitude of about 500 m. We propose that this region of anomalously shallow bathymetry, together with the contiguous eastern and southern African plateaus, form a superswell which we refer to as the African superswell. The origin of the African superswell is uncertain. However, rifting and volcanism in eastern Africa, as well as heat flow measurements in southern Africa and the southeastern Atlantic Ocean, suggest that the superswell may be attributed, at least in part, to heating of the lithosphere.

  4. A preliminary synopsis on amber scorpions with special reference to Burmite species: an extraordinary development of our knowledge in only 20 years.

    PubMed

    Lourenço, Wilson R

    2016-01-01

    A preliminary study on fossil scorpions found in amber, from the Lower Cretaceous through the Palaeocene and up to the Miocene is proposed. Scorpions remain rare among the arthropods found trapped in amber. Only 24 specimens are known from Cretaceous amber, representing eight families and subfamilies, ten genera and 21 species; in parallel, 10 specimens have been recorded from Baltic amber representing seven genera and ten species. A few more recent fossils from Dominican and Mexican amber have also been described. The present study of a new scorpion specimen from the Cretaceous amber of Myanmar (Burmite) resulted in the description of one new species, Betaburmesebuthus bellus sp. n. - belonging to the subfamily Palaeoburmesebuthinae Lourenço, 2015. The new description brings further elements to the clarification of the status of this subfamily, which is now raised to family level. Once again, this new Burmite element attests to the considerable degree of diversity in the Burmese amber-producing forests. PMID:27408601

  5. Variation in quantity and composition of cuticular hydrocarbons in the scorpion Buthus occitanus (Buthidae) in response to acute exposure to desiccation stress.

    PubMed

    Gefen, E; Talal, S; Brendzel, O; Dror, A; Fishman, A

    2015-04-01

    Scorpions exhibit some of the lowest recorded water loss rates among terrestrial arthropods. Evaporative water loss to the surrounding environment occurs mainly through the integument, and thus its resistance to water loss has paramount significance for the ability of scorpions to tolerate extremely dry habitats. Cuticular hydrocarbons (HCs) deposited on the outer epicuticle play an important role in determining cuticular waterproofing, and seasonal variation in both cuticular HC quantity and composition has been shown to correlate with water loss rates. Precursor incorporation rates into cuticle HCs have been observed to be extremely low in scorpions compared with insects. We therefore used adult male Buthus occitanus (Buthidae) in order to test HC profile plasticity during acute exposure to 14 d and 28 d of experimental desiccation. Cuticular HC profile of hydrated scorpions was similar to that reported for several other scorpion species, consisting of similar fractions of n-alkanes and branched alkanes, with no evidence for unsaturation. Most abundant of the n-alkanes were n-heptacosane (C27; 19±2% of total HCs), n-nonacosane (C29; 16±1%) and n-hentriacontane (C31; 11±1%). Exposure to desiccation stress resulted in a significant increase in the total amount of extracted HCs, and in the relative abundance of branched alkanes at the expense of n-alkanes. Together with an increase in HC chain lengths, these changes mimic previously-reported seasonal variation among freshly-collected specimens. This indicates that scorpions respond to water shortage by regulating the properties of their passive integumental barrier to water loss.

  6. Variation in quantity and composition of cuticular hydrocarbons in the scorpion Buthus occitanus (Buthidae) in response to acute exposure to desiccation stress.

    PubMed

    Gefen, E; Talal, S; Brendzel, O; Dror, A; Fishman, A

    2015-04-01

    Scorpions exhibit some of the lowest recorded water loss rates among terrestrial arthropods. Evaporative water loss to the surrounding environment occurs mainly through the integument, and thus its resistance to water loss has paramount significance for the ability of scorpions to tolerate extremely dry habitats. Cuticular hydrocarbons (HCs) deposited on the outer epicuticle play an important role in determining cuticular waterproofing, and seasonal variation in both cuticular HC quantity and composition has been shown to correlate with water loss rates. Precursor incorporation rates into cuticle HCs have been observed to be extremely low in scorpions compared with insects. We therefore used adult male Buthus occitanus (Buthidae) in order to test HC profile plasticity during acute exposure to 14 d and 28 d of experimental desiccation. Cuticular HC profile of hydrated scorpions was similar to that reported for several other scorpion species, consisting of similar fractions of n-alkanes and branched alkanes, with no evidence for unsaturation. Most abundant of the n-alkanes were n-heptacosane (C27; 19±2% of total HCs), n-nonacosane (C29; 16±1%) and n-hentriacontane (C31; 11±1%). Exposure to desiccation stress resulted in a significant increase in the total amount of extracted HCs, and in the relative abundance of branched alkanes at the expense of n-alkanes. Together with an increase in HC chain lengths, these changes mimic previously-reported seasonal variation among freshly-collected specimens. This indicates that scorpions respond to water shortage by regulating the properties of their passive integumental barrier to water loss. PMID:25499238

  7. Photoinduced Reactivity of the Soft Hydrotris(6-tert-butyl-3-thiopyridazinyl)borate Scorpionate Ligand in Sodium, Potassium, and Thallium Salts.

    PubMed

    Tüchler, Michael; Belaj, Ferdinand; Raber, Georg; Neshchadin, Dmytro; Mösch-Zanetti, Nadia C

    2015-09-01

    The soft scorpionate ligand hydrotris(6-tert-butyl-3-thiopyridazinyl)borate (Tn) was found to exhibit pronounced photoreactivity. Full elucidation of this process revealed the formation of 6-tert-butylpyridazine-3-thione (PnH) and 4,5-dihydro-6-tert-butylpyridazine-3-thione (H2PnH). Under exclusion of light, no solvolytic reactions occur, allowing the development of high-yield preparation protocols for the sodium, potassium, and thallium salts and improving the yield for their derived copper boratrane complex. The photoreactivity is relevant for all future studies with electron-deficient scorpionate ligands. PMID:26260148

  8. PIXE-STIM microtomography: Zinc and manganese concentrations in a scorpion stinger

    NASA Astrophysics Data System (ADS)

    Schofield, Robert M. S.; Lefevre, Harlan W.

    1992-10-01

    Microtomography using PIXE (proton induced X-ray emission) is developed and applied. Iterative algorithms for emission tomography (Donner algorithms) are modified for this purpose. STIM (scanning transmission ion microscopy) microtomography provides the required local X-ray attenuation factors and X-ray production cross sections (σ x's). The variation in σ x is treated along with X-ray attenuation in an effective attenuation factor. Several criteria for the optimal number of iterations are discussed. Element density values obtained from PIXE tomography are normalized with density values from STIM tomography to provide local concentration values. Three transverse sections of the sting of a scorpion, Hadrurus arizonensis, are reconstructed tomographically. Local zinc concentrations reaching as high as 25(± 3)% of dry mass are found. Manganese concentrations reaching 3.8(± 0.5)% of dry mass are also found. In the section manifesting high concentrations of both manganese and zinc, the zinc is found mainly in a band beneath the manganese-rich surface layer. Specimen damage during PIXE is found not to have significantly affected the results.

  9. Organization and behavior of the synaptonemal complex during achiasmatic meiosis of four buthid scorpions.

    PubMed

    Schneider, Marielle C; Mattos, Viviane F; Carvalho, Leonardo S; Cella, Doralice M

    2014-01-01

    Testicular cells of 4 buthid scorpions, Rhopalurus agamemnon (2n = 28), R. rochai (2n = 28), Tityus bahiensis (2n = 6), and T. fasciolatus (2n = 14), which show different types of chromosomal configurations in meiosis I, were subjected to cellular microspreading in order to (1) obtain knowledge about the organization and behavior of the synaptonemal complex (SC), and (2) acquire data about the mechanisms responsible for inter- and intraindividual chromosomal variation within Buthidae. Ultrastructural analysis of microspread nuclei revealed SCs with a well-preserved structure until late substages of prophase I, but did not detect kinetochore plates and recombination nodules. Pachytene cells of R. agamemnon, R. rochai and T. bahiensis exhibited single and unsynapsed axes continuous with totally synapsed SCs, indicating the occurrence of heterozygous chromosomal rearrangements. Although chromosome chains were not observed in T. fasciolatus, the presence of gaps and interlocks points out that this species also carries heterozygous rearrangements, involving a small chromosome segment. Especially in R. rochai, the cellular microspreading analysis was useful to clarify the origin of inter- and intraindividual variation in the number of bivalent-like elements and in the number of chromosomes involved in multivalent associations. It was found that more chromosomes were involved in rearrangements than previously established through investigations using light microscopy alone. PMID:25765094

  10. Serological, biochemical and enzymatic alterations in rodents after experimental envenomation with Hadruroides lunatus scorpion venom.

    PubMed

    Costal-Oliveira, F; Guerra-Duarte, C; Castro, K L P; Tintaya, B; Bonilla, C; Silva, W; Yarlequé, A; Fujiwara, R; Melo, M M; Chávez-Olórtegui, C

    2015-09-01

    Toxic effects of Peruvian Hadruroides lunatus scorpion venom on different biochemical and enzymatic parameters in blood serum of Wistar rats and Swiss mice were determined after experimental envenomation. An increase in enzymatic activities of Aspartate Aminotransferase (AST), Lactate Dehydrogenase (LDH) and levels of serum protein and albumin were observed while a decrease in creatinine level in serum was perceived after 30 min of envenomation. No alterations in urea levels and in kidney histology were detected in the envenomed rats. The global leukocytes count was diminished, with decrease in lymphocytes, eosinophils and neutrophils levels in the bloodstream, while no alterations were found in hematological parameters of red series in rats injected with H. lunatus venom. IL-2, IL-4, IL-6, INF-γ, TNF, IL-17A and IL-10 levels were evaluated 0.5, 3 and 6 h after experimental envenomation of mice with H. lunatus venom. From all the analyzed cytokines, only IL-6 showed an increase in serum levels. Taken together, these results point out that envenomation by H. lunatus can impair hematological and immunological parameters and therefore might be monitored in accidents involving this species.

  11. Fluorescent protein-scorpion toxin chimera is a convenient molecular tool for studies of potassium channels

    PubMed Central

    Kuzmenkov, Alexey I.; Nekrasova, Oksana V.; Kudryashova, Kseniya S.; Peigneur, Steve; Tytgat, Jan; Stepanov, Alexey V.; Kirpichnikov, Mikhail P.; Grishin, Eugene V.; Feofanov, Alexey V.; Vassilevski, Alexander A.

    2016-01-01

    Ion channels play a central role in a host of physiological and pathological processes and are the second largest target for existing drugs. There is an increasing need for reliable tools to detect and visualize particular ion channels, but existing solutions suffer from a number of limitations such as high price, poor specificity, and complicated protocols. As an alternative, we produced recombinant chimeric constructs (FP-Tx) consisting of fluorescent proteins (FP) fused with potassium channel toxins from scorpion venom (Tx). In particular, we used two FP, eGFP and TagRFP, and two Tx, OSK1 and AgTx2, to create eGFP-OSK1 and RFP-AgTx2. We show that these chimeras largely retain the high affinity of natural toxins and display selectivity to particular ion channel subtypes. FP-Tx are displaced by other potassium channel blockers and can be used as an imaging tool in ion channel ligand screening setups. We believe FP-Tx chimeras represent a new efficient molecular tool for neurobiology. PMID:27650866

  12. Fluorescent protein-scorpion toxin chimera is a convenient molecular tool for studies of potassium channels.

    PubMed

    Kuzmenkov, Alexey I; Nekrasova, Oksana V; Kudryashova, Kseniya S; Peigneur, Steve; Tytgat, Jan; Stepanov, Alexey V; Kirpichnikov, Mikhail P; Grishin, Eugene V; Feofanov, Alexey V; Vassilevski, Alexander A

    2016-01-01

    Ion channels play a central role in a host of physiological and pathological processes and are the second largest target for existing drugs. There is an increasing need for reliable tools to detect and visualize particular ion channels, but existing solutions suffer from a number of limitations such as high price, poor specificity, and complicated protocols. As an alternative, we produced recombinant chimeric constructs (FP-Tx) consisting of fluorescent proteins (FP) fused with potassium channel toxins from scorpion venom (Tx). In particular, we used two FP, eGFP and TagRFP, and two Tx, OSK1 and AgTx2, to create eGFP-OSK1 and RFP-AgTx2. We show that these chimeras largely retain the high affinity of natural toxins and display selectivity to particular ion channel subtypes. FP-Tx are displaced by other potassium channel blockers and can be used as an imaging tool in ion channel ligand screening setups. We believe FP-Tx chimeras represent a new efficient molecular tool for neurobiology. PMID:27650866

  13. Phylogeographic Study of Whip Scorpions (Chelicerata: Arachnida: Thelyphonida) in Japan and Taiwan.

    PubMed

    Karasawa, Shigenori; Nagata, Satomi; Aoki, Jun-ichi; Yahata, Kensuke; Honda, Masanao

    2015-08-01

    Whip scorpions (Thelyphonida), comprising an order in the class Arachnida, are distributed from tropical to temperate zones. Two species occur exclusively in Japan and Taiwan, but the border of their distributional ranges is ambiguous in the Central Ryukyus (Japan). We collected new specimens from the Central Ryukyus and revealed that the border of distribution of the two species lies between the Central and Southern Ryukyus, i.e., the Kerama Gap. Moreover, the estimated divergence time (15.8 Mya) of the two species, based on the mitochondrial COI gene, was older than the recently estimated time (1.55 Mya) of formation of the Kerama Gap. These results highlight the risks of a priori assumption solely on the basis of geological data for applying it as a calibration point to some terrestrial animals in this region. Typopeltis stimpsonii was genetically divided into four lineages, two of which turned out to be endemic to the Okinawa Islands. All specimens from the main island of Japan and Shikoku were in one lineage, which was also found in the Amami Islands and Hachijojima Island. This suggests that these specimens may have been dispersed by human activity. Typopeltis crucifer included five genetic lineages. Species collected from Ishigakijima and Iriomotejima Islands were genetically diversified not between the borders of these islands but within Ishigakijima Island. This study also suggests that phylogenetic diversity of the species in the Southern Ryukyus have increased through two times of invasions from Taiwan. PMID:26245222

  14. Tityus serrulatus Hypotensins: a new family of peptides from scorpion venom.

    PubMed

    Verano-Braga, T; Rocha-Resende, C; Silva, D M; Ianzer, D; Martin-Eauclaire, M F; Bougis, P E; de Lima, M E; Santos, R A S; Pimenta, A M C

    2008-07-01

    Using a proteomic approach, a new structural family of peptides was put in evidence in the venom of the yellow scorpion Tityus serrulatus. Tityus serrulatus Hypotensins (TsHpt) are random-coiled linear peptides and have a similar bradykinin-potentiating peptide (BPP) amino acid signature. TsHpt-I (2.7kDa), the first member of this family, was able to potentiate the hypotensive effects of bradykinin (BK) in normotensive rats. Using the C-terminal of this peptide as a template, a synthetic analog peptide (TsHpt-I([17-25])) was designed to held the BK-potentiating effect. A relevant hypotensive effect, independent on BK, was also observed on both TsHpt (native and synthetic). To better evaluate this hypotensive effect, we examined the vasorelaxation of aortic rings from male Wistar rats and the peptides were able to induce endothelium-dependent vasorelaxation dependent on NO release. Both TsHpt could not inhibit ACE activity. These peptides appear to exert their anti-hypertensive effect through NO-dependent and ACE-independent mechanisms. PMID:18445483

  15. Induction of morphological changes in model lipid membranes and the mechanism of membrane disruption by a large scorpion-derived pore-forming peptide.

    PubMed

    Nomura, Kaoru; Ferrat, Gilles; Nakajima, Terumi; Darbon, Herve; Iwashita, Takashi; Corzo, Gerardo

    2005-12-01

    The membrane disruption mechanism of pandinin 1 (pin1), an antimicrobial peptide isolated from the venom of the African scorpion, was studied using 31P, 13C, 1H solid-state and multidimensional solution-state NMR spectroscopy. A high-resolution NMR solution structure of pin1 showed that the two distinct alpha-helical regions move around the central hinge region, which contains Pro19. 31P NMR spectra of lipid membrane in the presence of pin1, at various temperatures, showed that pin1 induces various lipid phase behaviors depending on the acyl chain length and charge of phospholipids. Notably, it was found that pin1 induced formation of the cubic phase in shorter lipid membranes above Tm. Further, the 13C NMR spectra of pin1 labeled at Leu28 under magic angle spinning (MAS) indicated that the motion of pin1 bound to the lipid bilayer was very slow, with a correlation time of the order of 10(-3) s. 31P NMR spectra of dispersions of four saturated phosphatidyl-cholines in the presence of three types of pin1 derivatives, [W4A, W6A, W15A]-pin1, pin1(1-18), and pin1(20-44), at various temperatures demonstrated that all three pin1 derivatives have a reduced ability to trigger the cubic phase. 13C chemical shift values for pin1(1-18) labeled at Val3, Ala10, or Ala11 under static or slow MAS conditions indicate that pin1(1-18) rapidly rotates around the average helical axis, and the helical rods are inclined at approximately 30 degrees to the lipid long axis. 13C chemical shift values for pin1(20-44) labeled at Gly25, Leu28, or Ala31 under static conditions indicate that pin1(20-44) may be isotropically tumbling. 1H MAS chemical shift measurements suggest that pin1 is located at the membrane-water interface approximately parallel to the bilayer surface. Solid-state NMR results correlated well with the observed biological activity of pin1 in red blood cells and bacteria.

  16. Induction of Morphological Changes in Model Lipid Membranes and the Mechanism of Membrane Disruption by a Large Scorpion-Derived Pore-Forming Peptide

    PubMed Central

    Nomura, Kaoru; Ferrat, Gilles; Nakajima, Terumi; Darbon, Herve; Iwashita, Takashi; Corzo, Gerardo

    2005-01-01

    The membrane disruption mechanism of pandinin 1 (pin1), an antimicrobial peptide isolated from the venom of the African scorpion, was studied using 31P, 13C, 1H solid-state and multidimensional solution-state NMR spectroscopy. A high-resolution NMR solution structure of pin1 showed that the two distinct α-helical regions move around the central hinge region, which contains Pro19. 31P NMR spectra of lipid membrane in the presence of pin1, at various temperatures, showed that pin1 induces various lipid phase behaviors depending on the acyl chain length and charge of phospholipids. Notably, it was found that pin1 induced formation of the cubic phase in shorter lipid membranes above Tm. Further, the 13C NMR spectra of pin1 labeled at Leu28 under magic angle spinning (MAS) indicated that the motion of pin1 bound to the lipid bilayer was very slow, with a correlation time of the order of 10−3 s. 31P NMR spectra of dispersions of four saturated phosphatidyl-cholines in the presence of three types of pin1 derivatives, [W4A, W6A, W15A]-pin1, pin1(1-18), and pin1(20-44), at various temperatures demonstrated that all three pin1 derivatives have a reduced ability to trigger the cubic phase. 13C chemical shift values for pin1(1-18) labeled at Val3, Ala10, or Ala11 under static or slow MAS conditions indicate that pin1(1-18) rapidly rotates around the average helical axis, and the helical rods are inclined at ∼30° to the lipid long axis. 13C chemical shift values for pin1(20-44) labeled at Gly25, Leu28, or Ala31 under static conditions indicate that pin1(20-44) may be isotropically tumbling. 1H MAS chemical shift measurements suggest that pin1 is located at the membrane-water interface approximately parallel to the bilayer surface. Solid-state NMR results correlated well with the observed biological activity of pin1 in red blood cells and bacteria. PMID:16199510

  17. 16 Extraordinary African Americans.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    This collection for children tells the stories of 16 African Americans who helped make America what it is today. African Americans can take pride in the heritage of these contributors to society. Biographies are given for the following: (1) Sojourner Truth, preacher and abolitionist; (2) Frederick Douglass, abolitionist; (3) Harriet Tubman, leader…

  18. African Studies Computer Resources.

    ERIC Educational Resources Information Center

    Kuntz, Patricia S.

    African studies computer resources that are readily available in the United States with linkages to Africa are described, highlighting those most directly corresponding to African content. Africanists can use the following four fundamental computer systems: (1) Internet/Bitnet; (2) Fidonet; (3) Usenet; and (4) dial-up bulletin board services. The…

  19. Understanding African American Males

    ERIC Educational Resources Information Center

    Bell, Edward Earl

    2010-01-01

    The purpose of this study was to assess the socialization skills, self-esteem, and academic readiness of African American males in a school environment. Discussions with students and the School Perceptions Questionnaire provided data for this investigation. The intended targets for this investigation were African American students; however, there…

  20. Africans Away from Home.

    ERIC Educational Resources Information Center

    Clarke, John Henrik

    Africans who were brought across the Atlantic as slaves never fully adjusted to slavery or accepted its inevitability. Resistance began on board the slave ships, where many jumped overboard or committed suicide. African slaves in South America led the first revolts against tyranny in the New World. The first slave revolt in the Caribbean occurred…

  1. Keeping African Masks Real

    ERIC Educational Resources Information Center

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  2. Educating African American Males

    ERIC Educational Resources Information Center

    Bell, Edward E.

    2010-01-01

    Background: Schools across America spend money, invest in programs, and sponsor workshops, offer teacher incentives, raise accountability standards, and even evoke the name of Obama in efforts to raise the academic achievement of African American males. Incarceration and college retention rates point to a dismal plight for many African American…

  3. African horse sickness and African carnivores.

    PubMed

    Alexander, K A; Kat, P W; House, J; House, C; O'Brien, S J; Laurenson, M K; McNutt, J W; Osburn, B I

    1995-11-01

    African horse sickness (AHS) is a disease that affects equids, and is principally transmitted by Culicoides spp. that are biological vectors of AHS viruses (AHSV). The repeated spread of AHSV from sub-Saharan Africa to the Middle East, northern Africa and the Iberian peninsula indicate that a better understanding of AHS epizootiology is needed. African horse sickness has long been known to infect and cause mortality among domestic dogs that ingest virus contaminated meat, but it is uncertain what role carnivores play in transmission of the virus. We present evidence of widespread natural AHS infection among a diversity of African carnivore species. We hypothesize that such infection resulted from ingestion of meat and organs from AHS-infected prey species. The effect of AHS on the carnivores is unknown, as is their role in the maintenance cycle of the disease.

  4. Diabetes in African Americans

    PubMed Central

    Marshall, M

    2005-01-01

    African Americans have a high risk for type 2 diabetes. Genetic traits, the prevalence of obesity, and insulin resistance all contribute to the risk of diabetes in the African American community. African Americans have a high rate of diabetic complications, because of poor glycaemic control and racial disparities in health care in the USA. African Americans with diabetes may have an atypical presentation that simulates type 1 diabetes, but then their subsequent clinical course is typical of type 2 diabetes. Culturally sensitive strategies, structured disease management protocols, and the assistance of nurses, diabetic educators, and other health care professionals are effective in improving the outcome of diabetes in the African American community. PMID:16344294

  5. African bees to control African elephants

    NASA Astrophysics Data System (ADS)

    Vollrath, Fritz; Douglas-Hamilton, Iain

    2002-11-01

    Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

  6. A scorpion venom neurotoxin paralytic to insects that affects sodium current inactivation: Purification, primary structure, and mode of action

    SciTech Connect

    Eitan, M.; Fowler, E.; Herrmann, R.; Duval, A.; Pelhate, M.; Zlotkin, E. )

    1990-06-26

    A new toxin, Lqh alpha IT, which caused a unique mode of paralysis of blowfly larvae, was purified from the venom of the scorpion Leiurus quinquestriatus hebraeus, and its structural and pharmacological properties were compared to those of three other groups of neurotoxins found in Buthinae scorpion venoms. Like the excitatory and depressant insect-selective neurotoxins, Lqh alpha IT was highly toxic to insects, but it differed from these toxins in two important characteristics: (a) Lqh alpha IT lacked strict selectivity for insects; it was highly toxic to crustaceans and had a measurable but low toxicity to mice. (b) It did not displace an excitatory insect toxin, 125I-AaIT, from its binding sites in the insect neuronal membrane; this indicates that the binding sites for Lqh alpha IT are different from those shared by the excitatory and depressant toxins. However, in its primary structure and its effect on excitable tissues, Lqh alpha IT strongly resembled the well-characterized alpha scorpion toxins, which affect mammals. The amino acid sequence was identical with alpha toxin sequences in 55%-75% of positions. This degree of similarity is comparable to that seen among the alpha toxins themselves. Voltage- and current-clamp studies showed that Lqh alpha IT caused an extreme prolongation of the action potential in both cockroach giant axon and rat skeletal muscle preparations as a result of the slowing and incomplete inactivation of the sodium currents. These observations indicate that Lqh alpha IT is an alpha toxin which acts on insect sodium channels.

  7. Hot and not-so-hot females: reproductive state and thermal preferences of female Arizona Bark Scorpions (Centruroides sculpturatus).

    PubMed

    Webber, M M; Gibbs, A G; Rodríguez-Robles, J A

    2015-02-01

    For ectotherms, environmental temperatures influence numerous life history characteristics, and the body temperatures (Tb ) selected by individuals can affect offspring fitness and parental survival. Reproductive trade-offs may therefore ensue for gravid females, because temperatures conducive to embryonic development may compromise females' body condition. We tested whether reproduction influenced thermoregulation in female Arizona Bark Scorpions (Centruroides sculpturatus). We predicted that gravid females select higher Tb and thermoregulate more precisely than nonreproductive females. Gravid C. sculpturatus gain body mass throughout gestation, which exposes larger portions of their pleural membrane, possibly increasing their rates of transcuticular water loss in arid environments. Accordingly, we tested whether gravid C. sculpturatus lose water faster than nonreproductive females. We determined the preferred Tb of female scorpions in a thermal gradient and measured water loss rates using flow-through respirometry. Gravid females preferred significantly higher Tb than nonreproductive females, suggesting that gravid C. sculpturatus alter their thermoregulatory behaviour to promote offspring fitness. However, all scorpions thermoregulated with equal precision, perhaps because arid conditions create selective pressure on all females to thermoregulate effectively. Gravid females lost water faster than nonreproductive animals, indicating that greater exposure of the pleural membrane during gestation enhances the desiccation risk of reproductive females. Our findings suggest that gravid C. sculpturatus experience a trade-off, whereby selection of higher Tb and increased mass during gestation increase females' susceptibility to water loss, and thus their mortality risk. Elucidating the mechanisms that influence thermal preferences may reveal how reproductive trade-offs shape the life history of ectotherms in arid environments.

  8. Variability of Potassium Channel Blockers in Mesobuthus eupeus Scorpion Venom with Focus on Kv1.1

    PubMed Central

    Kuzmenkov, Alexey I.; Vassilevski, Alexander A.; Kudryashova, Kseniya S.; Nekrasova, Oksana V.; Peigneur, Steve; Tytgat, Jan; Feofanov, Alexey V.; Kirpichnikov, Mikhail P.; Grishin, Eugene V.

    2015-01-01

    The lesser Asian scorpion Mesobuthus eupeus (Buthidae) is one of the most widely spread and dispersed species of the Mesobuthus genus, and its venom is actively studied. Nevertheless, a considerable amount of active compounds is still under-investigated due to the high complexity of this venom. Here, we report a comprehensive analysis of putative potassium channel toxins (KTxs) from the cDNA library of M. eupeus venom glands, and we compare the deduced KTx structures with peptides purified from the venom. For the transcriptome analysis, we used conventional tools as well as a search for structural motifs characteristic of scorpion venom components in the form of regular expressions. We found 59 candidate KTxs distributed in 30 subfamilies and presenting the cysteine-stabilized α/β and inhibitor cystine knot types of fold. M. eupeus venom was then separated to individual components by multistage chromatography. A facile fluorescent system based on the expression of the KcsA-Kv1.1 hybrid channels in Escherichia coli and utilization of a labeled scorpion toxin was elaborated and applied to follow Kv1.1 pore binding activity during venom separation. As a result, eight high affinity Kv1.1 channel blockers were identified, including five novel peptides, which extend the panel of potential pharmacologically important Kv1 ligands. Activity of the new peptides against rat Kv1.1 channel was confirmed (IC50 in the range of 1–780 nm) by the two-electrode voltage clamp technique using a standard Xenopus oocyte system. Our integrated approach is of general utility and efficiency to mine natural venoms for KTxs. PMID:25792741

  9. Copper(II) Complexes of Cyclams Containing Nitrophenyl Substituents: Push-Pull Behavior and Scorpionate Coordination of the Nitro Group.

    PubMed

    Boiocchi, Massimo; Ciarrocchi, Carlo; Fabbrizzi, Luigi; Licchelli, Maurizio; Mangano, Carlo; Poggi, Antonio; Vázquez López, Miguel

    2015-11-01

    The three nitrophenyl-cyclam derivatives (nitrocyclams): 1-(4-nitrophenyl)-1,4,8,11-tetraazacyclotetradecane (2), 1-(2-nitrophenyl)-1,4,8,11-tetraazacyclotetradecane (3), and 1-(2,4-dinitrophenyl)-1,4,8,11-tetraazacyclotetradecane (4), in an MeCN solution, specifically incorporate the Cu(II) ion according to an irreversible process signaled by disappearance of the yellow color for a concentration c < 1 × 10(-4) M and by a yellow-to-red color change for c ≥ 1 × 10(-3), and must be considered efficient and specific dosimeters of copper(II) salts. When present in the ortho position of the nitrophenyl substituent, the -NO2 group coordinates the Cu(II) according to a scorpionate mode, while the metallocyclam system exhibits a trans-I configuration. In an MeCN solution the red trans-I-[Cu(II)(3)](2+) and trans-I-[Cu(II)(4)](2+) scorpionate complexes slowly convert into the violet trans-III scorpionate complexes. Kinetic aspects of the trans-I-to-trans-III configurational rearrangement were investigated in detail for the [Cu(II)(4)](2+) system. In particular, the conversion is spectacularly accelerated by catalytic amounts of Cl(-), NCO(-), and F(-). While for Cl(-) and NCO(-) the effect can be associated with the capability of the anion to stabilize through coordination a possible dissociative intermediate, the amazingly powerful effect of F(-) must be related to the preliminary deprotonation of one N-H fragment of the macrocycle, driven by the formation of the HF2(-) ion. Most of the metal complex species studied in solution were isolated in a crystalline form, and their molecular structures were elucidated through X-ray diffraction studies. This study documents the first examples of effective metal coordination by the nitro group. PMID:26468764

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

    PubMed Central

    Brites-Neto, José; Duarte, Keila Maria Roncato

    2015-01-01

    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

  11. Acute cerebellar dysfunction with neuromuscular manifestations after scorpionism presumably caused by Tityus obscurus in Santarém, Pará / Brazil.

    PubMed

    Torrez, Pasesa P Q; Quiroga, Mariana M M; Abati, Paulo A M; Mascheretti, Melissa; Costa, Walter Silva; Campos, Luciana P; França, Francisco O S

    2015-03-01

    Scorpionism is a public health problem in many tropical countries, especially in North Africa, South India, Latin America and the Middle East. In Brazil, patients with severe scorpion envenoming have mainly cardiovascular events, including acute heart failure, acute respiratory distress syndrome and shock, death is rare. We described 58 accidents presumably caused by Tityus obscurus in Brazilian Amazonia. Patients reported a sensation of "electric shocks" which could last hours. The vast majority of patients presented a clinical picture compatible with acute cerebellar dysfunction, beginning minutes and lasting up to 2 days after the accident. They presented cerebellar ataxia, dysdiadochokinesia, dysmetry, dysarthria, dyslalia, nausea and vomiting. Besides, some patients presented myoclonus and fasciculation which can also be attributed to cerebellar dysfunction or maybe the result of direct action on skeletal muscle. Two patients had evidence of intense rhabdomyolysis and acute kidney injury. The clinical picture in this scorpion envenoming is mainly characterized by an acute dysfunction of cerebellar activities and abnormal neuromuscular manifestations and in some cases muscle injury which are not described in any other region of the world. This work presents clinical, epidemiologic, laboratory and treatment aspects of this unmatched scorpion envenoming in the state of Pará, northern Brazil. PMID:25549940

  12. Venom from Opisthacanthus elatus scorpion of Colombia, could be more hemolytic and less neurotoxic than thought.

    PubMed

    Estrada-Gómez, Sebastián; Vargas Muñoz, Leidy Johana; Saldarriaga-Córdoba, Mónica; Quintana Castillo, Juan Carlos

    2016-01-01

    We report the first biochemical, biological, pharmacological and partial proteomic characterization studies of the Opisthancanthus elatus venom (Gervais, 1844) from Colombia. The Reverse Phase High-Performance Liquid Chromatography venom profile showed 28 main well-defined peaks, most eluting between 20 and 45min (18-30% of acetonitrile, respectively). High-resolution mass analysis indicates the presence of 106 components ranging from 806.59742Da to 16849.4139Da. O. elatus venom showed hemolytic activity and hydrolyzed the specific substrate BapNa suggesting the presence of proteins with serine-protease activity. Collected RP-HPLC fractions eluting at 52.6, 55.5, 55.8, 56.2, and 63.9min (PLA2 region between 33 and 40% of acetonitrile), showed hemolytic activity and hydrolyzed the synthetic substrate 4-nitro-3-octanoyloxy-benzoic acid, indicating the presence of compounds with phospholipases A2 activity. These RP-HPLC fractions, showed molecular masses values up to 13978.19546Da, corroborating the possible presence of the mentioned enzymes. Tryptic digestion and MS/MS analysis showed the presence of a phospholipase like fragment, similar to on described in other Opisthacanthus genus studies. No coagulant activity was observed. No larvicidal or antimicrobial activity was observed at concentrations evaluated. Lethal and toxic activity is expected at doses above 100mg/kg, no neurotoxic effects were detected at lower doses. In conclusion, O. elatus exhibits a venom with a predominant phospholipase A2 activity than thought; mammal's neurotoxic activity is expected above the 100mg/kg, which is very high compared to the venom from other neurotoxic scorpions.

  13. Caves as microrefugia: Pleistocene phylogeography of the troglophilic North American scorpion Pseudouroctonus reddelli

    PubMed Central

    2014-01-01

    Background Survival in microrefugia represents an important paradigm in phylogeography for explaining rapid postglacial re-colonization by species in temperate regions. Microrefugia may allow populations to persist in areas where the climatic conditions on the surface have become unfavourable. Caves generally contain stable microclimates and may represent microrefugia for species capable of exploiting both cave and surface habitats (troglophiles). We examine the phylogeography of the troglophilic North American vaejovid scorpion Pseudouroctonus reddelli using 1,993 base pairs of mitochondrial and nuclear DNA sequence data generated from 12 populations. We use (i) descriptive measures of genetic diversity and population genetics statistics, (ii) reconstructions of phylogeographical structure, spatial diffusion during diversification, and population sizes through time, and (iii) species distribution modelling to test predictions of the hypothesis that caves serve as microrefugia. We compare phylogeographical patterns in P. reddelli with other troglophilic species across the Edwards Plateau karst region of Texas. Results Results revealed high haplotype and nucleotide diversity and substantial phylogeographical structure, probably generated during the Pleistocene. Spatial diffusion occurred along the southern edge of the Edwards Plateau from multiple refugia along the Balcones Escarpment. There was little evidence for population and geographical expansion. Species distribution models predicted substantial reductions in suitable epigean habitat for P. reddelli at the Last Glacial Maximum (LGM). Conclusions High genetic diversity, strong phylogeographical structure, diffusion from multiple refugia, and unfavourable climatic conditions at the LGM collectively support the hypothesis that caves served as microrefugia for P. reddelli. Similar patterns of genetic structure in P. reddelli and other troglophilic species across the Edwards Plateau karst region of Texas suggest

  14. Chemical engineering and structural and pharmacological characterization of the α-scorpion toxin OD1.

    PubMed

    Durek, Thomas; Vetter, Irina; Wang, Ching-I Anderson; Motin, Leonid; Knapp, Oliver; Adams, David J; Lewis, Richard J; Alewood, Paul F

    2013-01-01

    Scorpion α-toxins are invaluable pharmacological tools for studying voltage-gated sodium channels, but few structure-function studies have been undertaken due to their challenging synthesis. To address this deficiency, we report a chemical engineering strategy based upon native chemical ligation. The chemical synthesis of α-toxin OD1 was achieved by chemical ligation of three unprotected peptide segments. A high resolution X-ray structure (1.8 Å) of synthetic OD1 showed the typical βαββ α-toxin fold and revealed important conformational differences in the pharmacophore region when compared with other α-toxin structures. Pharmacological analysis of synthetic OD1 revealed potent α-toxin activity (inhibition of fast inactivation) at Nav1.7, as well as Nav1.4 and Nav1.6. In addition, OD1 also produced potent β-toxin activity at Nav1.4 and Nav1.6 (shift of channel activation in the hyperpolarizing direction), indicating that OD1 might interact at more than one site with Nav1.4 and Nav1.6. Investigation of nine OD1 mutants revealed that three residues in the reverse turn contributed significantly to selectivity, with the triple OD1 mutant (D9K, D10P, K11H) being 40-fold more selective for Nav1.7 over Nav1.6, while OD1 K11V was 5-fold more selective for Nav1.6 than Nav1.7. This switch in selectivity highlights the importance of the reverse turn for engineering α-toxins with altered selectivity at Nav subtypes.

  15. An engineered scorpion toxin analogue with improved Kv1.3 selectivity displays reduced conformational flexibility

    PubMed Central

    Bartok, Adam; Fehér, Krisztina; Bodor, Andrea; Rákosi, Kinga; Tóth, Gábor K.; Kövér, Katalin E.; Panyi, Gyorgy; Varga, Zoltan

    2015-01-01

    The voltage-gated Kv1.3 K+ channel plays a key role in the activation of T lymphocytes. Kv1.3 blockers selectively suppress immune responses mediated by effector memory T cells, which indicates the great potential of selective Kv1.3 inhibitors in the therapy of certain autoimmune diseases. Anuroctoxin (AnTx), a 35-amino-acid scorpion toxin is a high affinity blocker of Kv1.3, but also blocks Kv1.2 with similar potency. We designed and produced three AnTx variants: ([F32T]-AnTx, [N17A]-AnTx, [N17A/F32T]-AnTx) using solid-phase synthesis with the goal of improving the selectivity of the toxin for Kv1.3 over Kv1.2 while keeping the high affinity for Kv1.3. We used the patch-clamp technique to determine the blocking potency of the synthetic toxins on hKv1.3, mKv1.1, hKv1.2 and hKCa3.1 channels. Of the three variants [N17A/F32T]-AnTx maintained the high affinity of the natural peptide for Kv1.3 but became more than 16000-fold selective over Kv1.2. NMR data and molecular dynamics simulations suggest that the more rigid structure with restricted conformational space of the double substituted toxin compared to the flexible wild-type one is an important determinant of toxin selectivity. Our results provide the foundation for the possibility of the production and future therapeutic application of additional, even more selective toxins targeting various ion channels. PMID:26689143

  16. Pandinus imperator scorpion venom blocks voltage-gated potassium channels in GH3 cells.

    PubMed

    Pappone, P A; Lucero, M T

    1988-06-01

    We examined the effects of Pandinus imperator scorpion venom on voltage-gated potassium channels in cultured clonal rat anterior pituitary cells (GH3 cells) using the gigohm-seal voltage-clamp method in the whole-cell configuration. We found that Pandinus venom blocks the voltage-gated potassium channels of GH3 cells in a voltage-dependent and dose-dependent manner. Crude venom in concentrations of 50-500 micrograms/ml produced 50-70% block of potassium currents measured at -20 mV, compared with 25-60% block measured at +50 mV. The venom both decreased the peak potassium current and shifted the voltage dependence of potassium current activation to more positive potentials. Pandinus venom affected potassium channel kinetics by slowing channel opening, speeding deactivation slightly, and increasing inactivation rates. Potassium currents in cells exposed to Pandinus venom did not recover control amplitudes or kinetics even after 20-40 min of washing with venom-free solution. The concentration dependence of crude venom block indicates that the toxins it contains are effective in the nanomolar range of concentrations. The effects of Pandinus venom were mimicked by zinc at concentrations less than or equal to 0.2 mM. Block of potassium current by zinc was voltage dependent and resembled Pandinus venom block, except that block by zinc was rapidly reversible. Since zinc is found in crude Pandinus venom, it could be important in the interaction of the venom with the potassium channel. We conclude that Pandinus venom contains toxins that bind tightly to voltage-dependent potassium channels in GH3 cells. Because of its high affinity for voltage-gated potassium channels and its irreversibility, Pandinus venom may be useful in the isolation, mapping, and characterization of voltage-gated potassium channels.

  17. Exploiting Cross-reactivity to Neutralize Two Different Scorpion Venoms with One Single Chain Antibody Fragment*

    PubMed Central

    Riaño-Umbarila, Lidia; Contreras-Ferrat, Gabriel; Olamendi-Portugal, Timoteo; Morelos-Juárez, Citlalli; Corzo, Gerardo; Possani, Lourival D.; Becerril, Baltazar

    2011-01-01

    We report the optimization of a family of human single chain antibody fragments (scFv) for neutralizing two scorpion venoms. The parental scFv 3F recognizes the main toxins of Centruroides noxius Hoffmann (Cn2) and Centruroides suffusus suffusus (Css2), albeit with low affinity. This scFv was subjected to independent processes of directed evolution to improve its recognition toward Cn2 (Riaño-Umbarila, L., Juárez-González, V. R., Olamendi-Portugal, T., Ortíz-León, M., Possani, L. D., and Becerril, B. (2005) FEBS J. 272, 2591–2601) and Css2 (this work). Each evolved variant showed strong cross-reactivity against several toxins, and was capable of neutralizing Cn2 and Css2. Furthermore, each variant neutralized the whole venoms of the above species. As far as we know, this is the first report of antibodies with such characteristics. Maturation processes revealed key residue changes to attain expression, stability, and affinity improvements as compared with the parental scFv. Combination of these changes resulted in the scFv LR, which is capable of rescuing mice from severe envenomation by 3 LD50 of freshly prepared whole venom of C. noxius (7.5 μg/20 g of mouse) and C. suffusus (26.25 μg/20 g of mouse), with surviving rates between 90 and 100%. Our research is leading to the formulation of an antivenom consisting of a discrete number of human scFvs endowed with strong cross-reactivity and low immunogenicity. PMID:21156801

  18. Cloning and characterization of BmK86, a novel K{sup +}-channel blocker from scorpion venom

    SciTech Connect

    Mao, Xin; Cao, Zhijian; Yin, Shijin; Ma, Yibao; Wu, Yingliang; Li, Wenxin . E-mail: liwxlab@whu.edu.cn

    2007-09-07

    Scorpion venom represents a tremendous hitherto unexplored resource for understanding ion channels. BmK86 is a novel K{sup +}-channel toxin gene isolated from a cDNA library of Mesobuthus martensii Karsch, which encodes a signal peptide of 22 amino acid residues and a mature toxin of 35 residues with three disulfide bridges. The genomic sequence of BmK86 consists of two exons disrupted by an intron of 72 bp. Comparison with the other scorpion toxins BmK86 shows low sequence similarity. The GST-BmK86 fusion protein was successfully expressed in Escherichia coli. The fusion protein was cleaved by enterokinase and the recombinant BmK86 was purified by HPLC. Using whole-cell patch-clamp recording, the recombinant BmK86 was found to inhibit the potassium current of mKv1.3 channel expressed in COS7 cells. These results indicated that BmK86 belongs to a representative member of a novel subfamily of {alpha}-KTxs. The systematic number assigned to BmK86 is {alpha}-KTx26.1.

  19. Temperature dependence of water loss rates in scorpions and its effect on the distribution of Buthotus judaicus (Buthidae) in Israel.

    PubMed

    Gefen, Eran; Ar, Amos

    2006-05-01

    Scorpions of the family Buthidae have been shown to be more desiccation resistant in comparison with sympatric Scorpionidae species. This has been attributed to the surface-dwelling existence of the former, which unlike most other scorpion species do not avoid environmental extremes by burrowing. Still, within Buthidae, the mesic Buthotus judaicus showed better osmoregulatory capacities than the xeric Leiurus quinquestriatus, largely as a result of its high resistance to water loss. However, B. judaicus exhibited poor ability to regulate its haemolymph osmolarity at 37 degrees C. In this study we report a sharp increase in water loss rates of B. judaicus at the 30-35 degrees C temperature range compared to that measured for L. quinquestriatus, which could explain the poor osmoregulatory performance of the former at higher ambient temperatures. The increase in water loss rates of B. judaicus at high temperatures is not coupled with a similar increase in respiratory rate, suggesting an increase in cuticular permeability. We suggest that this increase in cuticular permeability, which may result from a relatively low critical transition temperature, contributes to limiting the distribution of B. judaicus to habitats of moderate environmental conditions.

  20. Targeting the ion channel Kv1.3 with scorpion venom peptides engineered for potency, selectivity, and half-life.

    PubMed

    Edwards, Wilson; Fung-Leung, Wai-Ping; Huang, Chichi; Chi, Ellen; Wu, Nancy; Liu, Yi; Maher, Michael P; Bonesteel, Rachelle; Connor, Judith; Fellows, Ross; Garcia, Elena; Lee, Jerry; Lu, Lu; Ngo, Karen; Scott, Brian; Zhou, Hong; Swanson, Ronald V; Wickenden, Alan D

    2014-08-15

    Ion channels are an attractive class of drug targets, but progress in developing inhibitors for therapeutic use has been limited largely due to challenges in identifying subtype selective small molecules. Animal venoms provide an alternative source of ion channel modulators, and the venoms of several species, such as scorpions, spiders and snails, are known to be rich sources of ion channel modulating peptides. Importantly, these peptides often bind to hyper-variable extracellular loops, creating the potential for subtype selectivity rarely achieved with small molecules. We have engineered scorpion venom peptides and incorporated them in fusion proteins to generate highly potent and selective Kv1.3 inhibitors with long in vivo half-lives. Kv1.3 has been reported to play a role in human T cell activation, and therefore, these Kv1.3 inhibitor fusion proteins may have potential for the treatment of autoimmune diseases. Our results support an emerging approach to generating subtype selective therapeutic ion channel inhibitors.

  1. The gene cloning and sequencing of Bm-12, a chlorotoxin-like peptide from the scorpion Buthus martensi Karsch.

    PubMed

    Wu, J J; Dai, L; Lan, Z D; Chi, C W

    2000-05-01

    According to the known amino acid sequence of Bm-12, a short chain insect neurotoxin from the venom of the scorpion Buthus martensi Karsch (BmK) with considerable primary sequence homology to chlorotoxin, the gene specific primers were designed and synthesized for 3' and 5'RACE (Rapid Amplification of cDNA Ends). The two partial cDNA fragments obtained by 3' and 5'RACE were cloned and sequenced, and the full length cDNA sequence of Bm-12 was then completed by overlapping these two partial cDNA sequences. The predicted amino acid sequence consists of 59 amino acid residues including a putative signal peptide of 24 residues and a mature toxin of 35 residues. The predicted amino acid sequence of Bm-12 was almost consistent with the determined, different only in one residue at position 27, Lys was replaced by Gly. Based on the determined cDNA sequence, and using the total DNA isolated from the scorpion venom glands as a template, the genomic DNA of Bm-12 was also amplified by PCR and sequenced. The genomic DNA sequence revealed an intron of 93 bp present within the signal peptide region.

  2. The effects of a chactoid scorpion venom and its purified toxins on rat blood pressure and mast cells histamine release.

    PubMed

    Ettinger, Keren; Cohen, Gadi; Momic, Tatjana; Lazarovici, Philip

    2013-07-29

    The effect of the venom of the Chactoid family of scorpions on blood pressure was scantly investigated and was addressed in the present study using the venom of the Israeli scorpion, Scorpio maurus palmatus. Blood pressure in rats was monitored via cannulated femoral artery, while venom and toxins were introduced into femoral vein. Venom injection elicited a biphasic effect, expressed first by a fast and transient hypotensive response, which lasted up to 10 min, followed by a hypertensive response, which lasted up to one hour. It was found that these effects resulted from different venom components. Phospholipase A₂ produced the hypotensive effect, while a non-enzymatic neurotoxic polypeptide fraction produced the hypertensive effect. Surprisingly, the main neurotoxic polypeptide to mice had no effect on blood pressure. In vitro experiments indicated that the hypertensive factors caused histamine release from the peritoneal mast cells, but this effect is assumed to be not relevant to their in vivo effect. In spite of the cytotoxic activity of phospholipase A₂, it did not release histamine. These findings suggest that the effects of venom and isolated fractions on blood pressure parameters are mediated by different mechanisms, which deserve further pharmacological investigation.

  3. General characterization of Tityus fasciolatus scorpion venom. Molecular identification of toxins and localization of linear B-cell epitopes.

    PubMed

    Mendes, T M; Guimarães-Okamoto, P T C; Machado-de-Avila, R A; Oliveira, D; Melo, M M; Lobato, Z I; Kalapothakis, E; Chávez-Olórtegui, C

    2015-06-01

    This communication describes the general characteristics of the venom from the Brazilian scorpion Tityus fasciolatus, which is an endemic species found in the central Brazil (States of Goiás and Minas Gerais), being responsible for sting accidents in this area. The soluble venom obtained from this scorpion is toxic to mice being the LD50 is 2.984 mg/kg (subcutaneally). SDS-PAGE of the soluble venom resulted in 10 fractions ranged in size from 6 to 10-80 kDa. Sheep were employed for anti-T. fasciolatus venom serum production. Western blotting analysis showed that most of these venom proteins are immunogenic. T. fasciolatus anti-venom revealed consistent cross-reactivity with venom antigens from Tityus serrulatus. Using known primers for T. serrulatus toxins, we have identified three toxins sequences from T. fasciolatus venom. Linear epitopes of these toxins were localized and fifty-five overlapping pentadecapeptides covering complete amino acid sequence of the three toxins were synthesized in cellulose membrane (spot-synthesis technique). The epitopes were located on the 3D structures and some important residues for structure/function were identified.

  4. Isolation and molecular cloning of beta-neurotoxins from the venom of the scorpion Centruroides suffusus suffusus.

    PubMed

    Espino-Solis, Gerardo Pavel; Estrada, Georgina; Olamendi-Portugal, Timoteo; Villegas, Elba; Zamudio, Fernando; Cestele, Sandrine; Possani, Lourival D; Corzo, Gerardo

    2011-04-01

    This communication reports the identification and characterization of two new toxins from the venom of the scorpion Centruroides suffusus suffusus, named: CssVIII and CssIX, according to the original nomenclature of toxins previously described for this scorpion. The isolation was obtained by means of two chromatographic steps, and a cDNA library was used to fully identify their precursors. CssVIII and CssIX contain signal peptides of 19 and 17 amino acid residues, and mature peptides of 66 and 65 residues, respectively. Intracranial injections into mice of both purified toxins showed toxicity results similar to those found for toxins CssII and CssIV. Additionally, they compete with the parent toxin CssIV, in binding and displacement experiments, conducted with brain synaptosomes showing nanomolar affinities. These results strongly support the conclusion that they are new β-neurotoxins and certainly would be of the interest of researchers in the field of venomics for studying sodium channels.

  5. An unusual fold for potassium channel blockers: NMR structure of three toxins from the scorpion Opisthacanthus madagascariensis

    PubMed Central

    Chagot, Benjamin; Pimentel, Cyril; Dai, Li; Pil, Joost; Tytgat, Jan; Nakajima, Terumi; Corzo, Gerardo; Darbon, Hervé; Ferrat, Gilles

    2005-01-01

    The Om-toxins are short peptides (23–27 amino acids) purified from the venom of the scorpion Opisthacanthus madagascariensis. Their pharmacological targets are thought to be potassium channels. Like Csα/β (cystine-stabilized α/β) toxins, the Om-toxins alter the electrophysiological properties of these channels; however, they do not share any sequence similarity with other scorpion toxins. We herein demonstrate by electrophysiological experiments that Om-toxins decrease the amplitude of the K+ current of the rat channels Kv1.1 and Kv1.2, as well as human Kv1.3. We also determine the solution structure of three of the toxins by use of two-dimensional proton NMR techniques followed by distance geometry and molecular dynamics. The structures of these three peptides display an uncommon fold for ion-channel blockers, Csα/α (cystine-stabilized α-helix–loop–helix), i.e. two α-helices connected by a loop and stabilized by two disulphide bridges. We compare the structures obtained and the dipole moments resulting from the electrostatic anisotropy of these peptides with those of the only other toxin known to share the same fold, namely κ-hefutoxin1. PMID:15631621

  6. [Effect of polypeptides from scorpion venom on morpho-functional changes of the incubated Mauthner neurons in goldfish].

    PubMed

    Tiras, N R; Udal'tsov, S N; Mikheeva, I B; Pakhotin, P I; Moshkov, D A

    2003-01-01

    Using the electron microscopical method of negative staining it was shown that one of the fractions obtained from scorpion venom directly interacts with monomeric chromatographically pure actin causing its polymerization and transformation from globular into fibrillar form. The effect of long-term orthodromic stimulation on evoked electric activity and on the ultrastructure of Mauthner neurons (MN) in the goldfish hindbrain slices incubated in vitro was studied after the application of this venom fraction. The peptides of this fraction were shown to stabilize the amplitude of MN evoked electric responses to fatigue and to protect the ultrastructure of afferent chemical synapses and MN themselves from stimulation-induced injuries. Increase in morpho-functional resistivity is accompanied by the stabilization of specialized synaptic structures--actin-containing desmosome-like junctions. These data suggest the direct effect of peptides from scorpion venom fraction on actin component of MN cytoskeleton and show the perspective for their application as pharmacological tools capable of penetration into the living cells that may be used for investigation of the role of actin in the mechanisms of adaptation and memory.

  7. Vesicle-associated membrane protein (VAMP) cleavage by a new metalloprotease from the Brazilian scorpion Tityus serrulatus.

    PubMed

    Fletcher, Paul L; Fletcher, Maryann D; Weninger, Keith; Anderson, Trevor E; Martin, Brian M

    2010-03-01

    We present evidence that venom from the Brazilian scorpion Tityus serrulatus and a purified fraction selectively cleave essential SNARE proteins within exocrine pancreatic tissue. Western blotting for vesicle-associated membrane protein type v-SNARE proteins (or synaptobrevins) reveals characteristic alterations to venom-treated excised pancreatic lobules in vitro. Immunocytochemistry by electron microscopy confirms both the SNARE identity as VAMP2 and the proteolysis of VAMP2 as a marked decrease in secondary antibody-conjugated colloidal gold particles that are predominantly associated with mature zymogen granules. Studies with recombinant SNARE proteins were used to determine the specific cleavage site in VAMP2 and the susceptibility of VAMP8 (endobrevin). The VAMP2 cleavage site is between the transmembrane anchor and the SNARE motif that assembles into the ternary SNARE complex. Inclusion of divalent chelating agents (EDTA) with fraction nu, an otherwise active purified component from venom, eliminates SNARE proteolysis, suggesting the active protein is a metalloprotease. The unique cleavages of VAMP2 and VAMP8 may be linked to pancreatitis that develops following scorpion envenomation as both of these v-SNARE proteins are associated with zymogen granule membranes in pancreatic acinar cells. We have isolated antarease, a metalloprotease from fraction nu that cleaves VAMP2, and report its amino acid sequence.

  8. Vesicle-associated Membrane Protein (VAMP) Cleavage by a New Metalloprotease from the Brazilian Scorpion Tityus serrulatus*

    PubMed Central

    Fletcher, Paul L.; Fletcher, Maryann D.; Weninger, Keith; Anderson, Trevor E.; Martin, Brian M.

    2010-01-01

    We present evidence that venom from the Brazilian scorpion Tityus serrulatus and a purified fraction selectively cleave essential SNARE proteins within exocrine pancreatic tissue. Western blotting for vesicle-associated membrane protein type v-SNARE proteins (or synaptobrevins) reveals characteristic alterations to venom-treated excised pancreatic lobules in vitro. Immunocytochemistry by electron microscopy confirms both the SNARE identity as VAMP2 and the proteolysis of VAMP2 as a marked decrease in secondary antibody-conjugated colloidal gold particles that are predominantly associated with mature zymogen granules. Studies with recombinant SNARE proteins were used to determine the specific cleavage site in VAMP2 and the susceptibility of VAMP8 (endobrevin). The VAMP2 cleavage site is between the transmembrane anchor and the SNARE motif that assembles into the ternary SNARE complex. Inclusion of divalent chelating agents (EDTA) with fraction ν, an otherwise active purified component from venom, eliminates SNARE proteolysis, suggesting the active protein is a metalloprotease. The unique cleavages of VAMP2 and VAMP8 may be linked to pancreatitis that develops following scorpion envenomation as both of these v-SNARE proteins are associated with zymogen granule membranes in pancreatic acinar cells. We have isolated antarease, a metalloprotease from fraction ν that cleaves VAMP2, and report its amino acid sequence. PMID:20026600

  9. General characterization of Tityus fasciolatus scorpion venom. Molecular identification of toxins and localization of linear B-cell epitopes.

    PubMed

    Mendes, T M; Guimarães-Okamoto, P T C; Machado-de-Avila, R A; Oliveira, D; Melo, M M; Lobato, Z I; Kalapothakis, E; Chávez-Olórtegui, C

    2015-06-01

    This communication describes the general characteristics of the venom from the Brazilian scorpion Tityus fasciolatus, which is an endemic species found in the central Brazil (States of Goiás and Minas Gerais), being responsible for sting accidents in this area. The soluble venom obtained from this scorpion is toxic to mice being the LD50 is 2.984 mg/kg (subcutaneally). SDS-PAGE of the soluble venom resulted in 10 fractions ranged in size from 6 to 10-80 kDa. Sheep were employed for anti-T. fasciolatus venom serum production. Western blotting analysis showed that most of these venom proteins are immunogenic. T. fasciolatus anti-venom revealed consistent cross-reactivity with venom antigens from Tityus serrulatus. Using known primers for T. serrulatus toxins, we have identified three toxins sequences from T. fasciolatus venom. Linear epitopes of these toxins were localized and fifty-five overlapping pentadecapeptides covering complete amino acid sequence of the three toxins were synthesized in cellulose membrane (spot-synthesis technique). The epitopes were located on the 3D structures and some important residues for structure/function were identified. PMID:25817000

  10. Astronomy for African development

    NASA Astrophysics Data System (ADS)

    Govender, Kevindran

    2011-06-01

    In recent years there have been a number of efforts across Africa to develop the field of astronomy as well as to reap benefit from astronomy for African people. This presentation will discuss the case of the SALT (Southern African Large Telescope) Collateral Benefits Programme (SCBP) which was set up to ensure societal benefit from astronomy. With African society as the target, the SCBP has embarked on various projects from school level education to public understanding of science to socio-economic development, the latter mainly being felt in the rural communities surrounding the South African Astronomical Observatory (home to SALT). A development plan for ``Astronomy in Africa'' will also be discussed. This plan has been drawn up with input from all over Africa and themed ``Astronomy for Education''. The Africa case stands as a good example for the IYA cornerstone project ``Developing Astronomy Globally'' which focuses on developing regions.

  11. African American Health

    MedlinePlus

    ... specific health concerns. Differences in the health of groups can result from Genetics Environmental factors Access to care Cultural factors On this page, you'll find links to health issues that affect African Americans.

  12. African American Suicide

    MedlinePlus

    ... accounted for 83.8% of Caucasian elderly suicides. • Firearms were the predominant method of suicide among African ... per 100,000 annually. Source: Centers for Disease Control and Prevention. National Vital Statistics System. Mortality Data. ...

  13. Biochemical, transcriptomic and proteomic analyses of digestion in the scorpion Tityus serrulatus: insights into function and evolution of digestion in an ancient arthropod.

    PubMed

    Fuzita, Felipe J; Pinkse, Martijn W H; Patane, José S L; Juliano, Maria A; Verhaert, Peter D E M; Lopes, Adriana R

    2015-01-01

    Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

  14. Turkish scorpion Buthacus macrocentrus: general characterization of the venom and description of Bu1, a potent mammalian Na⁺-channel α-toxin.

    PubMed

    Caliskan, F; Quintero-Hernández, V; Restano-Cassulini, R; Batista, C V F; Zamudio, F Z; Coronas, F I; Possani, L D

    2012-03-01

    The venom of the scorpion Buthacus macrocentrus of Turkey was fractionated by high performance liquid chromatography (HPLC) and its mass finger print analysis was obtained by spectrometry. More than 70 different fractions were obtained, allowing the determination of the molecular masses of at least 60 peptides ranging between 648 and 44,336 Da. The venom is enriched with peptides containing molecular masses between 3200-4500 Da, and 6000-7500 Da. They very likely correspond to K⁺-channel and Na⁺-channel specific peptides, respectively, as expected from venoms of scorpions of the family Buthidae, already determined for other species. The major component obtained from HPLC was shown to be lethal to mice and was further purified and characterized. It contains 65 amino acid residues maintained closely packed by 4 disulfide bridges, and shows a molecular weight of 7263 Da. Additionally, a cDNA from the venomous glands of this scorpion was used in conjunction with sequence data from Edman degradation and mass spectrometry for cloning the gene that codes for Bu1 as we named this toxin. This gene codes for a 67 amino acid residues peptide, where the two last are eliminated post-translationally for production of an amidated C-terminal arginine. Its sequence is closely related to toxins from the species Leiurus quinquestriatus, as revealed by a phylogenetic tree analysis. Electrophysiological results conducted with Bu1 using patch-clamp techniques indicate that it modifies the Na⁺ currents, in a similar way as other well known α-scorpion toxins. These results support the conclusion that this species of scorpions is dangerous to humans, having an epidemiological interest for the country.

  15. Biochemical, transcriptomic and proteomic analyses of digestion in the scorpion Tityus serrulatus: insights into function and evolution of digestion in an ancient arthropod.

    PubMed

    Fuzita, Felipe J; Pinkse, Martijn W H; Patane, José S L; Juliano, Maria A; Verhaert, Peter D E M; Lopes, Adriana R

    2015-01-01

    Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

  16. Biochemical, Transcriptomic and Proteomic Analyses of Digestion in the Scorpion Tityus serrulatus: Insights into Function and Evolution of Digestion in an Ancient Arthropod

    PubMed Central

    Fuzita, Felipe J.; Pinkse, Martijn W. H.; Patane, José S. L.; Juliano, Maria A.; Verhaert, Peter D. E. M.; Lopes, Adriana R.

    2015-01-01

    Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

  17. Chlorotoxin, a scorpion-derived peptide, specifically binds to gliomas and tumors of neuroectodermal origin.

    PubMed

    Lyons, Susan A; O'Neal, Jeffrey; Sontheimer, Harald

    2002-08-01

    Highly migratory neuroectodermal cells share a common embryonic origin with cells of the central nervous system (CNS). They include enteric, parasympathetic, sympathoadrenal, and sensory neurons of the peripheral nervous system, Schwann cells, melanocytes, endocrine cells, and cells forming connective tissue of the face and neck. Because of their common embryologic origin, these cells and the tumors that derive from them can share genetic and antigenic phenotypes with gliomas, tumors derived from CNS glia. We recently discovered that chlorotoxin (ClTx), a 4-kD peptide purified from Leiurus quinquestriatus scorpion, is a highly specific marker for glioma cells in biopsy tissues (Soroceanu et al. Cancer Res 58:4871-4879, 1998) that can target tumors in animal models. We report on the specificity of ClTx as a marker for tumors of neuroectodermal origin that include peripheral neuroectodermal tumors (PNET) and gliomas. Specifically, we histochemically stained frozen and paraffin tissue sections of human biopsy tissues from 262 patients with a synthetically manufactured and biologically active ClTx bearing an N-terminal biotin. The vast majority (74 of 79) of primary human brain tumors investigated showed abundant binding of ClTx with greater than 90% ClTx-positive cells in each section. By comparison, 32 biopsies of uninvolved brain used for comparison were largely ClTx-negative, with only a few isolated reactive astrocytes showing some ClTx binding. However, as with gliomas, the vast majority of PNETs examined showed specific ClTx binding (31 of 34). These include medulloblastomas (4 of 4), neuroblastomas (6 of 7), ganglioneuromas (4 of 4), melanomas (7 of 7), adrenal pheochromocytomas (5 of 6), primitive PNET (1), small cell lung carcinoma (2 of 3), and Ewing's sarcoma (2 of 2). Under identical staining conditions, normal tissues from brain, skin, kidney, and lung were consistently negative for ClTx. These results suggest that chlorotoxin is a reliable and specific

  18. Synthesis and structural characterization of amido scorpionate rare earth metals complexes.

    PubMed

    Márquez-Segovia, Isabel; Lara-Sánchez, Agustín; Otero, Antonio; Fernández-Baeza, Juan; Castro-Osma, José Antonio; Sánchez-Barba, Luis F; Rodríguez, Ana M

    2014-07-01

    The reactivity of hybrid scorpionate/cyclopentadienyl ligands in the form of the protio derivatives as a mixture of two regioisomers, namely bpzcpH [1-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl}-1,3-cyclopentadiene and 2-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl}-1,3-cyclopentadiene] and bpztcpH [1-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethyl}-1,3-cyclopentadiene and 2-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethyl}-1,3-cyclopentadiene], with the tris(silylamide) precursors [M{N(SiHMe2)2}3(thf)x] of rare earth metals (including the group 3 metals scandium and yttrium) is related to the atomic radii of the metal centres. The reaction with the precursor containing the smallest ion, [Sc{N(SiHMe2)2}3(thf)], did not proceed even heating at reflux temperature in toluene. The reaction with the precursors that contain a medium-sized metal ion, i.e., [M{N(SiHMe2)2}3(thf)2] (M = Y, Lu), proceeded only at high temperature and gave good yields of the silylenediamide-containing derivatives [M{κ(2)-NN-Me2Si(NSiHMe2)2}(bpzcp)] (M = Y , Lu ) and [M{κ(2)-NN-Me2Si(NSiHMe2)2}(bpztcp)] (M = Y , Lu ) by an double activation of Si-H and Si-N bonds. However, the reaction with the precursors that contained the largest metal ions, i.e., [M{N(SiHMe2)2}3(thf)2] (M = Nd, Sm), proceeded rapidly at room temperature to afford the bis(silylamide) complexes [M{N(SiHMe2)2}2(bpzcp)] (M = Nd , Sm ) and [M{N(SiHMe2)2}2(bpztcp)] (M = Nd , Sm ). Additionally, the alkyl heteroscorpionate yttrium and lutetium complexes [M(CH2SiMe3)2(NNCp)] (M = Y, Lu) reacted with an excess of HN(SiHMe2)2 to give the mixed alkyl/amide derivatives [M{N(SiHMe2)2}(CH2SiMe3)(bpzcp)] (M = Y , Lu ) and [M{N(SiHMe2)2}(CH2SiMe3)(bpztcp)] (M = Y , Lu ). The structures of the complexes were determined by spectroscopic methods and the X-ray crystal structures of , and were also established.

  19. Characterization of the first K⁺ channel blockers from the venom of the Moroccan scorpion Buthus occitanus Paris.

    PubMed

    Martin-Eauclaire, Marie-France; Céard, Brigitte; Belghazi, Maya; Lebrun, Régine; Bougis, Pierre E

    2013-12-01

    The availability of a large variety of specific blockers, which inhibit different K(+) currents, would help to elucidate their differences in physiological function. Short peptide toxins isolated from scorpion venoms are able to block voltage-dependent or Ca(2+)-activated K(+) channels. Here, we have studied the venom of the Moroccan scorpion Buthus occitanus Paris (BoP) in order to find new peptides, which could enlarge our structure-function relationship knowledge on the Kv1.3 blocker Kaliotoxin (KTX) that belongs to the α-KTx3.1 family. Indeed and since more a decade, KTX is widely used by international investigators because it exhibits a quite sharp specificity and a high-affinity for the Kv1.3 channel, which is not only a neuronal channel but also a therapeutic target for diverse autoimmune diseases such as multiple sclerosis, type 1 diabetes, and rheumatoid arthritis. The BoP venom was first investigated using HPLC and MALDI-TOF/MS. Further, the HPLC fractions were screened by ELISA with antibodies raised against KTX. These antibodies recognized at least three components toxic in mice by intracerebroventricular injection. They were further pharmacologically characterized by competition using (125)I-KTX bound to its specific binding sites on rat brain synaptosomes. A single component (4161 Da) inhibited totally the (125)I-KTX binding and with high-affinity (IC50 = 0.1 nM), while the two other components poorly competed with (IC50 > 100 nM). These toxins were sequenced in full by Edman's degradation. The high-affinity ligand (BoPKTX) shares 86% sequence identity with KTX and was classified as toxin α-KTx3.17. The two others peptides (BoP1 and BoP2, 4093 Da and 4121 Da, respectively) only differ by a Lys/Arg mutation. Their amino acid sequences were related to Martentoxin, which has been characterized from the Chinese scorpion Buthus martenzi Karch and described as both a BKCa and Kv1.3 blocker. Accordingly, they belong to the α-KTx16 family.

  20. Comprehensive analysis of venom from the scorpion Centruroides tecomanus reveals compounds with antimicrobial, cytotoxic, and insecticidal activities.

    PubMed

    Valdez-Velazquéz, L L; Romero-Gutierrez, M T; Delgado-Enciso, I; Dobrovinskaya, O; Melnikov, V; Quintero-Hernández, V; Ceballos-Magaña, S G; Gaitan-Hinojosa, M A; Coronas, F I; Puebla-Perez, A M; Zamudio, F; De la Cruz-García, I; Vázquez-Vuelvas, O F; Soriano-Hernandez, A D; Possani, L D

    2016-08-01

    Centruroides tecomanus is a medically important scorpion of the state of Colima (Mexico). This communication reports the identification of venom components of this scorpion with biological activity over insects/crickets (Acheta domestica), crustaceans/fresh water shrimps (Cambarellus montezumae), and mammalians/mice (Mus musculus, strain CD1). It also describes the pharmacological effects on cell lines in culture (L5178Y cells, HeLa cells, HuTu cells and Jurkat E6-1 cells), as well as on several types of bacteria (see below). The soluble venom of this scorpion was fractionated by high-performance liquid chromatography (HPLC) and collected separately in twelve independent fractions collected over 60 min run (5 min time apart each other). The HPLC components of fraction VII were lethal to all three species used for assay. The IVth fraction had a toxic effect on freshwater shrimps. In this species, fractions VI, VII and VIII were all lethal. For crickets, fractions V and VI were toxic and fraction VII was lethal. In mouse, the lethal components were found in fraction VII, whereas fraction VIII was toxic, but not lethal, at the doses assayed. The molecular weight of peptides from the various group of fractions were identified by mass spectrometry determination. Components lethal to mice showed molecular weights from 7013 to 7487 Da. Two peptides were obtained in homogeneous form and shown to be lethal to the three species of animal used for assay. The soluble venom tested on L5178Y cell line survival was shown to be cytotoxic, at 10-100 μg/mL concentration, when compared to control murine splenocytes (p = 0.007). The soluble venom applied to Hela, Hutu and Jurkat cell lines did not show cytotoxic effects at these concentrations. On the contrary, it seems to have a proliferative effect. However the HPLC fractions I, III, VI and XII do have a cytotoxic effect on Jurkat E06-1 cells in culture at 200 μg/mL concentration. The antimicrobial activity of the venom

  1. Comprehensive analysis of venom from the scorpion Centruroides tecomanus reveals compounds with antimicrobial, cytotoxic, and insecticidal activities.

    PubMed

    Valdez-Velazquéz, L L; Romero-Gutierrez, M T; Delgado-Enciso, I; Dobrovinskaya, O; Melnikov, V; Quintero-Hernández, V; Ceballos-Magaña, S G; Gaitan-Hinojosa, M A; Coronas, F I; Puebla-Perez, A M; Zamudio, F; De la Cruz-García, I; Vázquez-Vuelvas, O F; Soriano-Hernandez, A D; Possani, L D

    2016-08-01

    Centruroides tecomanus is a medically important scorpion of the state of Colima (Mexico). This communication reports the identification of venom components of this scorpion with biological activity over insects/crickets (Acheta domestica), crustaceans/fresh water shrimps (Cambarellus montezumae), and mammalians/mice (Mus musculus, strain CD1). It also describes the pharmacological effects on cell lines in culture (L5178Y cells, HeLa cells, HuTu cells and Jurkat E6-1 cells), as well as on several types of bacteria (see below). The soluble venom of this scorpion was fractionated by high-performance liquid chromatography (HPLC) and collected separately in twelve independent fractions collected over 60 min run (5 min time apart each other). The HPLC components of fraction VII were lethal to all three species used for assay. The IVth fraction had a toxic effect on freshwater shrimps. In this species, fractions VI, VII and VIII were all lethal. For crickets, fractions V and VI were toxic and fraction VII was lethal. In mouse, the lethal components were found in fraction VII, whereas fraction VIII was toxic, but not lethal, at the doses assayed. The molecular weight of peptides from the various group of fractions were identified by mass spectrometry determination. Components lethal to mice showed molecular weights from 7013 to 7487 Da. Two peptides were obtained in homogeneous form and shown to be lethal to the three species of animal used for assay. The soluble venom tested on L5178Y cell line survival was shown to be cytotoxic, at 10-100 μg/mL concentration, when compared to control murine splenocytes (p = 0.007). The soluble venom applied to Hela, Hutu and Jurkat cell lines did not show cytotoxic effects at these concentrations. On the contrary, it seems to have a proliferative effect. However the HPLC fractions I, III, VI and XII do have a cytotoxic effect on Jurkat E06-1 cells in culture at 200 μg/mL concentration. The antimicrobial activity of the venom

  2. Characterization of the first K⁺ channel blockers from the venom of the Moroccan scorpion Buthus occitanus Paris.

    PubMed

    Martin-Eauclaire, Marie-France; Céard, Brigitte; Belghazi, Maya; Lebrun, Régine; Bougis, Pierre E

    2013-12-01

    The availability of a large variety of specific blockers, which inhibit different K(+) currents, would help to elucidate their differences in physiological function. Short peptide toxins isolated from scorpion venoms are able to block voltage-dependent or Ca(2+)-activated K(+) channels. Here, we have studied the venom of the Moroccan scorpion Buthus occitanus Paris (BoP) in order to find new peptides, which could enlarge our structure-function relationship knowledge on the Kv1.3 blocker Kaliotoxin (KTX) that belongs to the α-KTx3.1 family. Indeed and since more a decade, KTX is widely used by international investigators because it exhibits a quite sharp specificity and a high-affinity for the Kv1.3 channel, which is not only a neuronal channel but also a therapeutic target for diverse autoimmune diseases such as multiple sclerosis, type 1 diabetes, and rheumatoid arthritis. The BoP venom was first investigated using HPLC and MALDI-TOF/MS. Further, the HPLC fractions were screened by ELISA with antibodies raised against KTX. These antibodies recognized at least three components toxic in mice by intracerebroventricular injection. They were further pharmacologically characterized by competition using (125)I-KTX bound to its specific binding sites on rat brain synaptosomes. A single component (4161 Da) inhibited totally the (125)I-KTX binding and with high-affinity (IC50 = 0.1 nM), while the two other components poorly competed with (IC50 > 100 nM). These toxins were sequenced in full by Edman's degradation. The high-affinity ligand (BoPKTX) shares 86% sequence identity with KTX and was classified as toxin α-KTx3.17. The two others peptides (BoP1 and BoP2, 4093 Da and 4121 Da, respectively) only differ by a Lys/Arg mutation. Their amino acid sequences were related to Martentoxin, which has been characterized from the Chinese scorpion Buthus martenzi Karch and described as both a BKCa and Kv1.3 blocker. Accordingly, they belong to the α-KTx16 family. PMID:23523531

  3. Synthesis and characterization of Pi4, a scorpion toxin from Pandinus imperator that acts on K+ channels.

    PubMed

    M'Barek, Sarrah; Mosbah, Amor; Sandoz, Guillaume; Fajloun, Ziad; Olamendi-Portugal, Timoteo; Rochat, Hervé; Sampieri, François; Guijarro, J Iñaki; Mansuelle, Pascal; Delepierre, Muriel; De Waard, Michel; Sabatier, Jean-Marc

    2003-09-01

    Pi4 is a 38-residue toxin cross-linked by four disulfide bridges that has been isolated from the venom of the Chactidae scorpion Pandinus imperator. Together with maurotoxin, Pi1, Pi7 and HsTx1, Pi4 belongs to the alpha KTX6 subfamily of short four-disulfide-bridged scorpion toxins acting on K+ channels. Due to its very low abundance in venom, Pi4 was chemically synthesized in order to better characterize its pharmacology and structural properties. An enzyme-based cleavage of synthetic Pi4 (sPi4) indicated half-cystine pairings between Cys6-Cys27, Cys12-32, Cys16-34 and Cys22-37, which denotes a conventional pattern of scorpion toxin reticulation (Pi1/HsTx1 type). In vivo, sPi4 was lethal after intracerebroventricular injection to mice (LD50 of 0.2 microg per mouse). In vitro, addition of sPi4 onto Xenopus laevis oocytes heterologously expressing various voltage-gated K+ channel subtypes showed potent inhibition of currents from rat Kv1.2 (IC50 of 8 pm) and Shaker B (IC50 of 3 nm) channels, whereas no effect was observed on rat Kv1.1 and Kv1.3 channels. The sPi4 was also found to compete with 125I-labeled apamin for binding to small-conductance Ca(2+)-activated K+ (SK) channels from rat brain synaptosomes (IC50 value of 0.5 microm). sPi4 is a high affinity blocker of the Kv1.2 channel. The toxin was docked (BIGGER program) on the Kv channel using the solution structure of sPi4 and a molecular model of the Kv1.2 channel pore region. The model suggests a key role for residues Arg10, Arg19, Lys26 (dyad), Ile28, Lys30, Lys33 and Tyr35 (dyad) in the interaction and the associated blockage of the Kv1.2 channel.

  4. African-Americans and Alzheimer's

    MedlinePlus

    ... Share Plus on Google Plus African-Americans and Alzheimer's alz.org | IHaveAlz Introduction 10 Warning Signs Brain ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of ...

  5. English as an African Language.

    ERIC Educational Resources Information Center

    Desai, Gaurav

    1993-01-01

    Discusses the role of the English language in postcolonial African literature, focusing on the politics of language, "Africanized" English, and the social languages used in Chinua Achebe's novels and concludes that English today is as much an African language as a British or American one. (Contains 37 references.) (MDM)

  6. The Struggles over African Languages

    ERIC Educational Resources Information Center

    Maseko, Pam; Vale, Peter

    2016-01-01

    In this interview, African Language expert Pam Maseko speaks of her own background and her first encounter with culture outside of her mother tongue, isiXhosa. A statistical breakdown of South African languages is provided as background. She discusses Western (originally missionary) codification of African languages and suggests that this approach…

  7. The genus Hormiops Fage, 1933 (Hormuridae, Scorpiones), a palaeoendemic of the South China Sea: systematics and biogeography.

    PubMed

    Monod, Lionel

    2014-10-01

    The monotypic genus Hormiops Fage, 1933 is so far only known from two groups of granitic islands off the coasts of Peninsular Malaysia and Vietnam. Examination of newly collected material from both archipelagos and of the type series of Hormiops davidovi Fage, 1933 reveals previously disregarded morphological differences sufficient to assign the Malaysian specimens to a distinct species, described here as Hormiops infulcra sp. nov. An updated diagnosis of the genus, as well as a dichotomic key enabling the determination of Hormiops from its close relatives, Hormurus Thorell, 1876 and Liocheles Sundevall, 1833 are also provided. The phylogenetic position, distribution pattern, and ecology of these insular scorpions suggest that they are palaeoendemics, remnants of a previously more widely distributed lineage. A biogeographical model is proposed for the genus based on these observations and on a synthesis of palaeogeographical and palaeoenvironmental data currently available for Sundaland. PMID:25282174

  8. The genus Hormiops Fage, 1933 (Hormuridae, Scorpiones), a palaeoendemic of the South China Sea: systematics and biogeography.

    PubMed

    Monod, Lionel

    2014-10-01

    The monotypic genus Hormiops Fage, 1933 is so far only known from two groups of granitic islands off the coasts of Peninsular Malaysia and Vietnam. Examination of newly collected material from both archipelagos and of the type series of Hormiops davidovi Fage, 1933 reveals previously disregarded morphological differences sufficient to assign the Malaysian specimens to a distinct species, described here as Hormiops infulcra sp. nov. An updated diagnosis of the genus, as well as a dichotomic key enabling the determination of Hormiops from its close relatives, Hormurus Thorell, 1876 and Liocheles Sundevall, 1833 are also provided. The phylogenetic position, distribution pattern, and ecology of these insular scorpions suggest that they are palaeoendemics, remnants of a previously more widely distributed lineage. A biogeographical model is proposed for the genus based on these observations and on a synthesis of palaeogeographical and palaeoenvironmental data currently available for Sundaland.

  9. Synthesis and structural characterization of two half-sandwich nickel(II) complexes with the scorpionate ligands

    SciTech Connect

    Wang, G.-F. E-mail: s-shuwen@163.com; Zhang, X.; Sun, S.-W.; Sun, H.; Ma, H.-X.

    2015-12-15

    The synthesis and characterization of two new halfsandwich mononuclear nickel(II) complexes with the scorpionate ligands, [k{sup 3}-N, N',N''-Tp{sup t-Bu}, {sup Me}NiI] (1) and [k{sup 3}-N,N',N''-Tp{sup t-Bu}, {sup Me}NiNO{sub 3}] (2), are reported. These complexes have been fully characterized by elemental analyses and infrared spectra. Their molecular structures were determined by single crystal X-ray diffraction. The nickel(II) ion of complex 1 is in a four-coordinate environment, in which the donor atoms are provided by three nitrogen atoms of a hydrotris(pyrazolyl) borate ligand and one iodide atom, while that of complex 2 is in a five-coordinate environment with three nitrogen atoms from a hydrotris(pyrazolyl)borate ligand and two oxygen atoms from a nitrate ion.

  10. Tryptophan-47 rotational isomerization in variant-3 scorpion neurotoxin. A combination thermodynamic perturbation and umbrella sampling study.

    PubMed Central

    Haydock, C; Sharp, J C; Prendergast, F G

    1990-01-01

    A combination thermodynamic perturbation and umbrella sampling study predicts two free energy wells for the rotational isomerization of the variant-3 scorpion neurotoxin tryptophan-47 indole side chain. One well has the indole side chain in the crystallographic orientation; the other has the indole rotated approximately 220 degrees to form a new conformation with a relative free energy of 3 +/- 2 kcal/mol. The activation barrier is 8.5 kcal/mol from the crystallographic well, from which transition state theory predicts a rate of escape of 2 x 10(5) s-1. Correlations in the displacements of side chains neighboring tryptophan-47 and the isomerization reaction coordinate last up to 20 ps. Favorable conditions of experimental verification are discussed. PMID:2393708

  11. Structural characterization of a novel peptide with antimicrobial activity from the venom gland of the scorpion Tityus stigmurus: Stigmurin.

    PubMed

    de Melo, Edinara Targino; Estrela, Andréia Bergamo; Santos, Elizabeth Cristina Gomes; Machado, Paula Renata Lima; Farias, Kleber Juvenal Silva; Torres, Taffarel Melo; Carvalho, Enéas; Lima, João Paulo Matos Santos; Silva-Júnior, Arnóbio Antonio; Barbosa, Euzébio Guimarães; Fernandes-Pedrosa, Matheus de Freitas

    2015-06-01

    A new antimicrobial peptide, herein named Stigmurin, was selected based on a transcriptomic analysis of the Brazilian yellow scorpion Tityus stigmurus venom gland, an underexplored source for toxic peptides with possible biotechnological applications. Stigmurin was investigated in silico, by circular dichroism (CD) spectroscopy, and in vitro. The CD spectra suggested that this peptide interacts with membranes, changing its conformation in the presence of an amphipathic environment, with predominance of random coil and beta-sheet structures. Stigmurin exhibited antibacterial and antifungal activity, with minimal inhibitory concentrations ranging from 8.7 to 69.5μM. It was also showed that Stigmurin is toxic against SiHa and Vero E6 cell lines. The results suggest that Stigmurin can be considered a potential anti-infective drug.

  12. Synthesis and structural characterization of two half-sandwich nickel(II) complexes with the scorpionate ligands

    NASA Astrophysics Data System (ADS)

    Wang, G.-F.; Zhang, X.; Sun, S.-W.; Sun, H.; Ma, H.-X.

    2015-12-01

    The synthesis and characterization of two new halfsandwich mononuclear nickel(II) complexes with the scorpionate ligands, [ k 3- N, N', N''- Tp t-Bu, Me NiI] ( 1) and [ k 3- N, N', N''- Tp t-Bu, Me NiNO3] ( 2), are reported. These complexes have been fully characterized by elemental analyses and infrared spectra. Their molecular structures were determined by single crystal X-ray diffraction. The nickel(II) ion of complex 1 is in a four-coordinate environment, in which the donor atoms are provided by three nitrogen atoms of a hydrotris(pyrazolyl) borate ligand and one iodide atom, while that of complex 2 is in a five-coordinate environment with three nitrogen atoms from a hydrotris(pyrazolyl)borate ligand and two oxygen atoms from a nitrate ion.

  13. The development of the hardware for studying biological clock systems under microgravity conditions, using scorpions as animal models

    NASA Astrophysics Data System (ADS)

    Serafini, L.; Viganò, W.; Donati, A.; Porciani, M.; Zolesi, V.; Schulze-Varnholt, D.; Manieri, P.; El-Din Sallam, A.; Schmäh, M.; Horn, E. R.

    2007-02-01

    The study of internal clock systems of scorpions in weightless conditions is the goal of the SCORPI experiment. SCORPI was selected for flight on the International Space Station (ISS) and will be mounted in the European facility BIOLAB, the European Space Agency (ESA) laboratory designed to support biological experiments on micro-organisms, cells, tissue, cultures, small plants and small invertebrates. This paper outlines the main features of a breadboard designed and developed in order to allow the analysis of critical aspects of the experiment. It is a complete tool to simulate the experiment mission on ground and it can be customised, adapted and tuned to the scientific requirements. The paper introduces the SCORPI-T experiment which represents an important precursor for the success of the SCORPI on BIOLAB. The capabilities of the hardware developed show its potential use for future similar experiments in space.

  14. Do changes in body temperature following envenomation by the scorpion Leiurus quinquestriatus influence the course of toxicity?

    PubMed

    Ismail, M; Abd-Elsalam, M A; Morad, A M

    1990-01-01

    Four fatal cases following scorpion sting in children are presented. Two victims had rectal temperature above 41 degrees C, the third exhibited a temperature of 40.9 degrees C from the combined effects of scorpion sting and heat stroke, while the fourth was hypothermic. All victims developed hypothermia 48 hr following the sting. The hyperthermia was effectively treated by acetaminophen suppositories, ice packs and water sponges. All victims showed late hypotension that was refractory to dopamine infusion. This was explained by bradykinin released by the venom blocking the dopaminergic receptors. Deterioration of the cortical activity of the victims maintained on mechanical ventilation before the incidence of asystole suggests a central component in the cardiovascular manifestations of envenomation. A. amoreuxi venom was selected as a model for the pharmacokinetic and quantitative toxicological studies since it has no effect on body temperature. In hyperthermic rabbits injected with labelled lethal fraction of A. amoreuxi venom, there was a significant decrease in the elimination half-life, t1/2 beta, the apparent volume of the tissue compartment, Vt, the apparent volume of distribution, Vdss, and the intercompartmental rate constant, kCT. Hypothermic rabbits showed a significant decrease in the apparent first-order elimination rate constant, kd, and a significant increase in the elimination half-life. In both states a higher concentration of the lethal fraction in the blood was calculated. This would explain the rapidity of onset of the electrocardiographic effects and the decreased survival time in both the hyperthermic and hypothermic rabbits injected with venom when compared to normothermic animals. The s.c. LD50 in mice and the i.v. MLD in rats were significantly reduced in the hypothermic mice and hypothermic and hyperthermic rats. PMID:2087694

  15. Synthesis, structural and photo-physical studies of bismuth(III) complexes with Janus scorpionate and co-ligands.

    PubMed

    Imran, Muhammad; Mix, Andreas; Neumann, Beate; Stammler, Hans-Georg; Monkowius, Uwe; Bleckenwegner, Petra; Mitzel, Norbert W

    2014-07-28

    Some novel complexes of bismuth(III) with the Janus scorpionate ligand [HB(mtda(Me))3](-) (mtda(Me) = 2-mercapto-5-methyl-1,3,4-thiadiazolyl) were synthesised. Na[HB(mtda(Me))3] (1) was reacted with BiX3 (X = Cl, I, NO3) in the molar ratio 2 : 1 to afford the bismuth complexes {HB(mtda(Me))3}2BiCl (3), Na[{HB(mtda(Me))3}2BiI2] (4) and [{HB(mtda(Me))3}2Bi(NO3)]n (5). Two mixed complexes {HB(mtda(Me))3}Bi(phen)Cl2 (6) and {HB(mtda(Me))3}Bi(bipy)Cl2 (7) were obtained using Janus scorpionate as the primary ligand in the presence of 1,10-phenanthroline and 2,2'-bipyridyl, respectively, as co-ligands in the 1 : 1 ratio. The obtained complexes were characterised by (1)H, (13)C and diffusion NMR (DOSY), elemental analyses and mass spectrometry. Structures of the compounds NBu4[HB(mtda(Me))3] (2), 3, 4, 5, 6 and 7 were determined by single crystal X-ray diffraction. The molecular dynamic process in complex 3 was also studied by variable temperature NMR measurements. All bismuth complexes, except for the polymeric 5, are monomeric. Complexes 6 and 7 exhibit (B)H···Bi distances of 2.76(3) and 2.71(2) Å length, respectively. Compounds 2, 6 and 7 were screened for their luminescence activity. At 77 K in ethanol solution, complexes 6 and 7 exhibit phosphorescence from ligand-to-ligand charge transfer (LLCT) and the ligand-centred (LC) excited state, respectively. PMID:24906201

  16. Neuroprotection by scorpion venom heat resistant peptide in 6-hydroxydopamine rat model of early-stage Parkinson's disease.

    PubMed

    Yin, Sheng-Ming; Zhao, Dan; Yu, De-Qin; Li, Sheng-Long; An, Dong; Peng, Yan; Xu, Hong; Sun, Yi-Ping; Wang, Dong-Mei; Zhao, Jie; Zhang, Wan-Qin

    2014-12-25

    Neuroprotective effect of scorpion venom on Parkinson's disease (PD) has already been reported. The present study was aimed to investigate whether scorpion venom heat resistant peptide (SVHRP) could attenuate ultrastructural abnormalities in mitochondria and oxidative stress in midbrain neurons of early-stage PD model. The early-stage PD model was established by injecting 6-hydroxydopamine (6-OHDA) (20 μg/3 μL normal saline with 0.1% ascorbic acid) into the striatum of Sprague Dawley (SD) rats unilaterally. The rats were intraperitoneally administered with SVHRP (0.05 mg/kg per day) or vehicle (saline) for 1 week. Two weeks after 6-OHDA treatment, the rats received behavior tests for validation of model. Three weeks after 6-OHDA injection, the immunoreactivity of dopaminergic neurons were detected by immunohistochemistry staining, and the ultrastructure of neuronal mitochondria in midbrain was observed by electron microscope. In the meantime, the activities of monoamine oxidase-B (MAO-B), superoxide dismutase (SOD) and content of malondialdehyde (MDA) in the mitochondria of the midbrain neurons, as well as the inhibitory ability of hydroxyl free radical and the antioxidant ability in the serum, were measured by corresponding kits. The results showed that 6-OHDA reduced the optical density of dopaminergic neurons, induced damage of mitochondrial ultrastructure of midbrain neurons, decreased SOD activity, increased MAO-B activity and MDA content, and reduced the antioxidant ability of the serum. SVHRP significantly reversed the previous harmful effects of 6-OHDA in early-stage PD model. These findings indicate that SVHRP may contribute to neuroprotection by preventing biochemical and ultrastructure damage changes which occur during early-stage PD. PMID:25516514

  17. Venom Components of Iranian Scorpion Hemiscorpius lepturus Inhibit the Growth and Replication of Human Immunodeficiency Virus 1 (HIV-1)

    PubMed Central

    Zabihollahi, Rezvan; Bagheri, Kamran Pooshang; Keshavarz, Zohreh; Motevalli, Fatemeh; Bahramali, Golnaz; Siadat, Seyed Davar; Momen, Seyed Bahman; Shahbazzadeh, Delavar; Aghasadeghi, Mohammad Reza

    2016-01-01

    Background: During the recent years, significant progress has been achieved on development of novel anti-viral drugs. Natural products are assumed as the potential sources of novel anti-viral drugs; therefore, there are some previous studies reporting the anti-viral compounds from venomous animals. Based on the significant value for tracing of non-toxic anti-viral agents from natural resources, this study was aimed to investigate the anti-viral activity of some HPLC purified fractions derived from the venom of Iranian scorpion, Hemiscorpius lepturus, against human immunodeficiency virus 1 (HIV-1) and herpes simplex virus 1 (HSV-1). Methods: H. Lepturus crude venom was subjected to reverse phase HPLC analysis to determine its active components precisely where four dominant fractions obtained at retention time of 156-160 minutes. The phospholipase A2 and hemolytic activities of the purified fractions were first evaluated. Then the anti-viral activity was measured using single cycle HIV (NL4-3) replication and HSV (KOS) plaque reduction assays. Results: The H. lepturus crude venom inhibited HIV replication by 73% at the concentration of 200 µg/ml, while it did not show significant anti-HSV activity. It also inhibited the cell-free viral particles in a virucidal assay, while it showed no toxicity for the target cells in a proliferation assay. The four HPLC fractions purified from H. lepturus inhibited HIV with IC50 of 20 µg/ml. Conclusion: H. lepturus venom contains components with considerable anti-HIV activity insofar as it has virucidal activity that offers a novel therapeutic approach against HIV infection. Our results suggest a promising pilot for anti-HIV drug discovery with H. lepturus scorpion venom. PMID:27594443

  18. Ts8 scorpion toxin inhibits the Kv4.2 channel and produces nociception in vivo.

    PubMed

    Pucca, Manuela Berto; Cerni, Felipe Augusto; Cordeiro, Francielle Almeida; Peigneur, Steve; Cunha, Thiago Mattar; Tytgat, Jan; Arantes, Eliane Candiani

    2016-09-01

    The venom from the scorpion Tityus serrulatus (Ts) has been extensively studied mainly because of its rich cocktail of neurotoxins. Neurotoxins are the major and the most known components based on their modulation of voltage-gated ion channels. Until now, electrophysiological studies demonstrated that the Ts venom comprises toxins that affect Nav and Kv channels. However, although many studies have been conducted in this field, many peptides from Ts venom await further studies, including Ts8 toxin. Here we report the isolation and electrophysiological study of Ts8. The toxin Ts19 Frag-II was used as negative control. Ts8 demonstrates, among 20 tested channels, to be a selective modulator of Kv4.2 channels. Based on studies investigating the involvement of Kv4.2 on controlling nociception, we further investigated the modulation of pain by Ts8. Using intraplantar injections, Ts8 induced overt nociception (licking and lifting behaviors) and decreased the mechanical nociceptive threshold (hyperalgesia). Furthermore, the hyperalgesia was prolonged when intrathecal injections were performed. Independent of the severity, most of the victims stung by Ts scorpions report an intense and persistent pain as the major manifestation. The new role of Ts8 on nociception could explain, at least partially, this phenomenon. Additionally, our study also stresses the involvement of toxins specific to Nav channels and inflammatory mediators on the Ts painful sting. This work provides useful insights for a better understanding of the prolonged and intense pain associated with Ts envenoming for the development of specific therapies. PMID:27346450

  19. Molecular modeling and docking simulations of scorpion toxins and related analogs on human SKCa2 and SKCa3 channels.

    PubMed

    Andreotti, Nicolas; di Luccio, Eric; Sampieri, François; De Waard, Michel; Sabatier, Jean-Marc

    2005-07-01

    The small-conductance Ca2+-activated K+ (SKCa) channels modulate cytosolic Ca2+ concentration in excitable and non-excitable tissues by regulating the membrane potential and are responsible of slow action potential after hyperpolarization that inhibits cell firing. Among these, human SKCa2 and SKCa3 channels differ in the pore region by only two residues: Ala331 and Asn367 (human small-conductance calcium-activated potassium channel, hSKCa2) instead of Val485 and His521 (hSKCa3). To design highly selective blockers of hSKCa channels, a number of known hSKCa2 and/or hSKCa3-active peptides (i.e. scorpion toxins and analogs thereof) were analyzed for their interactions and selectivities toward these channels. Molecular models of hSKCa2 and hSKCa3 channels (S5-H5-S6 portion) were generated, and scorpion toxins/peptides of unsolved three-dimensional (3D) structures were modeled. Models of toxin-channel complexes were generated by the bimolecular complex generation with global evaluation, and ranking (BiGGER) docking software and selected by using a screening method of the docking solutions. A high degree of correlation was found to exist between docking energies and experimental Kd values of peptides that blocked hSKCa2 and/or hSKCa3 channels, suggesting it could be appropriate to predict Kd values of other bioactive peptides. The best scoring complexes were also used to identify key residues of both interacting partners, indicating that such an approach should help the design of more active and/or selective peptide blockers of targeted ion channels.

  20. The Genetic Structure and History of Africans and African Americans

    PubMed Central

    Tishkoff, Sarah A.; Reed, Floyd A.; Friedlaender, Françoise R.; Ehret, Christopher; Ranciaro, Alessia; Froment, Alain; Hirbo, Jibril B.; Awomoyi, Agnes A.; Bodo, Jean-Marie; Doumbo, Ogobara; Ibrahim, Muntaser; Juma, Abdalla T.; Kotze, Maritha J.; Lema, Godfrey; Moore, Jason H.; Mortensen, Holly; Nyambo, Thomas B.; Omar, Sabah A.; Powell, Kweli; Pretorius, Gideon S.; Smith, Michael W.; Thera, Mahamadou A.; Wambebe, Charles; Weber, James L.; Williams, Scott M.

    2010-01-01

    Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (~71%), European (~13%), and other African (~8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies. PMID:19407144

  1. The Other African Americans.

    ERIC Educational Resources Information Center

    Matory, J. Lorand

    Black North America is ethnically and culturally diverse. It contains many groups who do not call themselves or have not always called themselves "Negro,""Black,""African-American," and so forth, such as Louisiana Creoles of color and many of the Indian tribes east of the Mississippi. There are also numerous North American ethnic groups of African…

  2. African Oral Tradition Literacy.

    ERIC Educational Resources Information Center

    Green, Doris

    1985-01-01

    Presents the basic principles of two systems for notating African music and dance: Labanotation (created to record and analyze movements) and Greenotation (created to notate musical instruments of Africa and to parallel Labanotation whereby both music and dance are incorporated into one integrated score). (KH)

  3. Elective: African Literature.

    ERIC Educational Resources Information Center

    Jenkins, Kenneth V.

    The make-up of a course in African literature for high school students is discussed. It is pointed out that the course can be constructed on already familiar lines. High school students will be able to describe clearly, for example, the relationship between environment and character or the dilemma of characters caught between traditional values…

  4. The dilemma of choosing a reference character for measuring sexual size dimorphism, sexual body component dimorphism, and character scaling: cryptic dimorphism and allometry in the scorpion Hadrurus arizonensis.

    PubMed

    Fox, Gerad A; Cooper, Allen M; Hayes, William K

    2015-01-01

    Sexual differences in morphology, ranging from subtle to extravagant, occur commonly in many animal species. These differences can encompass overall body size (sexual size dimorphism, SSD) or the size and/or shape of specific body parts (sexual body component dimorphism, SBCD). Interacting forces of natural and sexual selection shape much of the expression of dimorphism we see, though non-adaptive processes may be involved. Differential scaling of individual features can result when selection favors either exaggerated (positive allometry) or reduced (negative allometry) size during growth. Studies of sexual dimorphism and character scaling rely on multivariate models that ideally use an unbiased reference character as an overall measure of body size. We explored several candidate reference characters in a cryptically dimorphic taxon, Hadrurus arizonensis. In this scorpion, essentially every body component among the 16 we examined could be interpreted as dimorphic, but identification of SSD and SBCD depended on which character was used as the reference (prosoma length, prosoma area, total length, principal component 1, or metasoma segment 1 width). Of these characters, discriminant function analysis suggested that metasoma segment 1 width was the most appropriate. The pattern of dimorphism in H. arizonensis mirrored that seen in other more obviously dimorphic scorpions, with static allometry trending towards isometry in most characters. Our findings are consistent with the conclusions of others that fecundity selection likely favors a larger prosoma in female scorpions, whereas sexual selection may favor other body parts being larger in males, especially the metasoma, pectines, and possibly the chela. For this scorpion and probably most other organisms, the choice of reference character profoundly affects interpretations of SSD, SBCD, and allometry. Thus, researchers need to broaden their consideration of an appropriate reference and exercise caution in interpreting

  5. The Dilemma of Choosing a Reference Character for Measuring Sexual Size Dimorphism, Sexual Body Component Dimorphism, and Character Scaling: Cryptic Dimorphism and Allometry in the Scorpion Hadrurus arizonensis

    PubMed Central

    Fox, Gerad A.; Cooper, Allen M.; Hayes, William K.

    2015-01-01

    Sexual differences in morphology, ranging from subtle to extravagant, occur commonly in many animal species. These differences can encompass overall body size (sexual size dimorphism, SSD) or the size and/or shape of specific body parts (sexual body component dimorphism, SBCD). Interacting forces of natural and sexual selection shape much of the expression of dimorphism we see, though non-adaptive processes may be involved. Differential scaling of individual features can result when selection favors either exaggerated (positive allometry) or reduced (negative allometry) size during growth. Studies of sexual dimorphism and character scaling rely on multivariate models that ideally use an unbiased reference character as an overall measure of body size. We explored several candidate reference characters in a cryptically dimorphic taxon, Hadrurus arizonensis. In this scorpion, essentially every body component among the 16 we examined could be interpreted as dimorphic, but identification of SSD and SBCD depended on which character was used as the reference (prosoma length, prosoma area, total length, principal component 1, or metasoma segment 1 width). Of these characters, discriminant function analysis suggested that metasoma segment 1 width was the most appropriate. The pattern of dimorphism in H. arizonensis mirrored that seen in other more obviously dimorphic scorpions, with static allometry trending towards isometry in most characters. Our findings are consistent with the conclusions of others that fecundity selection likely favors a larger prosoma in female scorpions, whereas sexual selection may favor other body parts being larger in males, especially the metasoma, pectines, and possibly the chela. For this scorpion and probably most other organisms, the choice of reference character profoundly affects interpretations of SSD, SBCD, and allometry. Thus, researchers need to broaden their consideration of an appropriate reference and exercise caution in interpreting

  6. A spider toxin that induces a typical effect of scorpion alpha-toxins but competes with beta-toxins on binding to insect sodium channels.

    PubMed

    Corzo, Gerardo; Escoubas, Pierre; Villegas, Elba; Karbat, Izhar; Gordon, Dalia; Gurevitz, Michael; Nakajima, Terumi; Gilles, Nicolas

    2005-02-01

    Delta-palutoxins from the spider Paracoelotes luctuosus (Araneae: Amaurobiidae) are 36-37 residue long peptides that show preference for insect sodium channels (NaChs) and modulate their function. Although they slow NaCh inactivation in a fashion similar to that of receptor site 3 modifiers, such as scorpion alpha-toxins, they actually bind with high affinity to the topologically distinct receptor site 4 of scorpion beta-toxins. To resolve this riddle, we scanned by Ala mutagenesis the surface of delta-PaluIT2, a delta-palutoxin variant with the highest affinity for insect NaChs, and compared it to the bioactive surface of a scorpion beta-toxin. We found three regions on the surface of delta-PaluIT2 important for activity: the first consists of Tyr-22 and Tyr-30 (aromatic), Ser-24 and Met-28 (polar), and Arg-8, Arg-26, Arg-32, and Arg-34 (basic) residues; the second is made of Trp-12; and the third is made of Asp-19, whose substitution by Ala uncoupled the binding from toxicity to lepidopteran larvae. Although spider delta-palutoxins and scorpion beta-toxins have developed from different ancestors, they show some commonality in their bioactive surfaces, which may explain their ability to compete for an identical receptor (site 4) on voltage-gated NaChs. Yet, their different mode of channel modulation provides a novel perspective about the structural relatedness of receptor sites 3 and 4, which until now have been considered topologically distinct.

  7. Scorpion venom heat-resistant peptide (SVHRP) enhances neurogenesis and neurite outgrowth of immature neurons in adult mice by up-regulating brain-derived neurotrophic factor (BDNF).

    PubMed

    Wang, Tao; Wang, Shi-Wei; Zhang, Yue; Wu, Xue-Fei; Peng, Yan; Cao, Zhen; Ge, Bi-Ying; Wang, Xi; Wu, Qiong; Lin, Jin-Tao; Zhang, Wan-Qin; Li, Shao; Zhao, Jie

    2014-01-01

    Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Although scorpions and their venom have been used in Traditional Chinese Medicine (TCM) to treat chronic neurological disorders, the underlying mechanisms of these treatments remain unknown. We applied SVHRP in vitro and in vivo to understand its effects on the neurogenesis and maturation of adult immature neurons and explore associated molecular mechanisms. SVHRP administration increased the number of 5-bromo-2'-dexoxyuridine (BrdU)-positive cells, BrdU-positive/neuron-specific nuclear protein (NeuN)-positive neurons, and polysialylated-neural cell adhesion molecule (PSA-NCAM)-positive immature neurons in the subventricular zone (SVZ) and subgranular zone (SGZ) of hippocampus. Furthermore immature neurons incubated with SVHRP-pretreated astrocyte-conditioned medium exhibited significantly increased neurite length compared with those incubated with normal astrocyte-conditioned medium. This neurotrophic effect was further confirmed in vivo by detecting an increased average single area and whole area of immature neurons in the SGZ, SVZ and olfactory bulb (OB) in the adult mouse brain. In contrast to normal astrocyte-conditioned medium, higher concentrations of brain-derived neurotrophic factor (BDNF) but not nerve growth factor (NGF) or glial cell line-derived neurotrophic factor (GDNF) was detected in the conditioned medium of SVHRP-pretreated astrocytes, and blocking BDNF using anti-BDNF antibodies eliminated these SVHRP-dependent neurotrophic effects. In SVHRP treated mouse brain, more glial fibrillary acidic protein (GFAP)-positive cells were detected. Furthermore, immunohistochemistry revealed increased numbers of GFAP/BDNF double-positive cells, which agrees with the observed changes in the culture system. This paper describes novel effects of scorpion venom-originated peptide on the stem cells and suggests the potential therapeutic values of SVHRP.

  8. Multiple actions of φ-LITX-Lw1a on ryanodine receptors reveal a functional link between scorpion DDH and ICK toxins

    PubMed Central

    Smith, Jennifer J.; Vetter, Irina; Lewis, Richard J.; Peigneur, Steve; Tytgat, Jan; Lam, Alexander; Gallant, Esther M.; Beard, Nicole A.; Alewood, Paul F.; Dulhunty, Angela F.

    2013-01-01

    We recently reported the isolation of a scorpion toxin named U1-liotoxin-Lw1a (U1-LITX-Lw1a) that adopts an unusual 3D fold termed the disulfide-directed hairpin (DDH) motif, which is the proposed evolutionary structural precursor of the three-disulfide-containing inhibitor cystine knot (ICK) motif found widely in animals and plants. Here we reveal that U1-LITX-Lw1a targets and activates the mammalian ryanodine receptor intracellular calcium release channel (RyR) with high (fM) potency and provides a functional link between DDH and ICK scorpion toxins. Moreover, U1-LITX-Lw1a, now described as φ-liotoxin-Lw1a (φ-LITX-Lw1a), has a similar mode of action on RyRs as scorpion calcines, although with significantly greater potency, inducing full channel openings at lower (fM) toxin concentrations whereas at higher pM concentrations increasing the frequency and duration of channel openings to a submaximal state. In addition, we show that the C-terminal residue of φ-LITX-Lw1a is crucial for the increase in full receptor openings but not for the increase in receptor subconductance opening, thereby supporting the two-binding-site hypothesis of scorpion toxins on RyRs. φ-LITX-Lw1a has potential both as a pharmacological tool and as a lead molecule for the treatment of human diseases that involve RyRs, such as malignant hyperthermia and polymorphic ventricular tachycardia. PMID:23671114

  9. Biochemical and physiological characterization of a new Na(+)-channel specific peptide from the venom of the Argentinean scorpion Tityus trivittatus.

    PubMed

    Coronas, Fredy I V; Diego-García, Elia; Restano-Cassulini, Rita; de Roodt, Adolfo R; Possani, Lourival D

    2015-06-01

    A new peptide with 61 amino acids cross-linked by 4 disulfide bridges, with molecular weight of 6938.12Da, and an amidated C-terminal amino acid residue was purified and characterized. The primary structure was obtained by direct Edman degradation and sequencing its gene. The peptide is lethal to mammals and was shown to be similar (95% identity) to toxin Ts1 (gamma toxin) from the Brazilian scorpion Tityus serrulatus; it was named Tt1g (from T. trivittatus toxin 1 gamma-like). Tt1g was assayed on several sub-types of Na(+)-channels showing displacement of the currents to more negative voltages, being the hNav1.3 the most affected channel. This toxin displays characteristics typical to the β-type sodium scorpion toxins. Lethality tests and physiological assays indicate that this peptide is probably the most important toxic component of this species of scorpion, known for causing human fatalities in the South American continent.

  10. Biochemical and physiological characterization of a new Na(+)-channel specific peptide from the venom of the Argentinean scorpion Tityus trivittatus.

    PubMed

    Coronas, Fredy I V; Diego-García, Elia; Restano-Cassulini, Rita; de Roodt, Adolfo R; Possani, Lourival D

    2015-06-01

    A new peptide with 61 amino acids cross-linked by 4 disulfide bridges, with molecular weight of 6938.12Da, and an amidated C-terminal amino acid residue was purified and characterized. The primary structure was obtained by direct Edman degradation and sequencing its gene. The peptide is lethal to mammals and was shown to be similar (95% identity) to toxin Ts1 (gamma toxin) from the Brazilian scorpion Tityus serrulatus; it was named Tt1g (from T. trivittatus toxin 1 gamma-like). Tt1g was assayed on several sub-types of Na(+)-channels showing displacement of the currents to more negative voltages, being the hNav1.3 the most affected channel. This toxin displays characteristics typical to the β-type sodium scorpion toxins. Lethality tests and physiological assays indicate that this peptide is probably the most important toxic component of this species of scorpion, known for causing human fatalities in the South American continent. PMID:24862827

  11. A preliminary synopsis on amber scorpions with special reference to Burmite species: an extraordinary development of our knowledge in only 20 years

    PubMed Central

    Lourenço, Wilson R.

    2016-01-01

    Abstract A preliminary study on fossil scorpions found in amber, from the Lower Cretaceous through the Palaeocene and up to the Miocene is proposed. Scorpions remain rare among the arthropods found trapped in amber. Only 24 specimens are known from Cretaceous amber, representing eight families and subfamilies, ten genera and 21 species; in parallel, 10 specimens have been recorded from Baltic amber representing seven genera and ten species. A few more recent fossils from Dominican and Mexican amber have also been described. The present study of a new scorpion specimen from the Cretaceous amber of Myanmar (Burmite) resulted in the description of one new species, Betaburmesebuthus bellus sp. n. – belonging to the subfamily Palaeoburmesebuthinae Lourenço, 2015. The new description brings further elements to the clarification of the status of this subfamily, which is now raised to family level. Once again, this new Burmite element attests to the considerable degree of diversity in the Burmese amber-producing forests. PMID:27408601

  12. The three-dimensional structural surface of two beta-sheet scorpion toxins mimics that of an alpha-helical dihydropyridine receptor segment.

    PubMed Central

    Green, Daniel; Pace, Suzi; Curtis, Suzanne M; Sakowska, Magdalena; Lamb, Graham D; Dulhunty, Angela F; Casarotto, Marco G

    2003-01-01

    An alpha-helical II-III loop segment of the dihydropyridine receptor activates the ryanodine receptor calcium-release channel. We describe a novel manipulation in which this agonist's activity is increased by modifying its surface structure to resemble that of a toxin molecule. In a unique system, native beta-sheet scorpion toxins have been reported to activate skeletal muscle ryanodine receptor calcium channels with high affinity by binding to the same site as the lower-affinity alpha-helical dihydropyridine receptor segment. We increased the alignment of basic residues in the alpha-helical peptide to mimic the spatial orientation of active residues in the scorpion toxin, with a consequent 2-20-fold increase in the activity of the alpha-helical peptide. We hypothesized that, like the native peptide, the modified peptide and the scorpion toxin may bind to a common site. This was supported by (i) similar changes in ryanodine receptor channel gating induced by the native or modified alpha-helical peptide and the beta-sheet toxin, a 10-100-fold reduction in channel closed time, with a < or = 2-fold increase in open dwell time and (ii) a failure of the toxin to further activate channels activated by the peptides. These results suggest that diverse structural scaffolds can present similar conformational surface properties to target common receptor sites. PMID:12429019

  13. Understanding traditional African healing

    PubMed Central

    MOKGOBI, M.G.

    2015-01-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists. PMID:26594664

  14. Human African trypanosomiasis.

    PubMed

    Lejon, Veerle; Bentivoglio, Marina; Franco, José Ramon

    2013-01-01

    Human African trypanosomiasis or sleeping sickness is a neglected tropical disease that affects populations in sub-Saharan Africa. The disease is caused by infection with the gambiense and rhodesiense subspecies of the extracellular parasite Trypanosoma brucei, and is transmitted to humans by bites of infected tsetse flies. The disease evolves in two stages, the hemolymphatic and meningoencephalitic stages, the latter being defined by central nervous system infection after trypanosomal traversal of the blood-brain barrier. African trypanosomiasis, which leads to severe neuroinflammation, is fatal without treatment, but the available drugs are toxic and complicated to administer. The choice of medication is determined by the infecting parasite subspecies and disease stage. Clinical features include a constellation of nonspecific symptoms and signs with evolving neurological and psychiatric alterations and characteristic sleep-wake disturbances. Because of the clinical profile variability and insidiously progressive central nervous system involvement, disease staging is currently based on cerebrospinal fluid examination, which is usually performed after the finding of trypanosomes in blood or other body fluids. No vaccine being available, control of human African trypanosomiasis relies on diagnosis and treatment of infected patients, assisted by vector control. Better diagnostic tools and safer, easy to use drugs are needed to facilitate elimination of the disease.

  15. Diversity among African Pygmies

    PubMed Central

    Ramírez Rozzi, Fernando V.; Sardi, Marina L.

    2010-01-01

    Although dissimilarities in cranial and post-cranial morphology among African pygmies groups have been recognized, comparative studies on skull morphology usually pull all pygmies together assuming that morphological characters are similar among them and different with respect to other populations. The main aim of this study is to compare cranial morphology between African pygmies and non-pygmies populations from Equatorial Africa derived from both the Eastern and the Western regions in order to test if the greatest morphological difference is obtained in the comparison between pygmies and non-pygmies. Thirty three-dimensional (3D) landmarks registered with Microscribe in four cranial samples (Western and Eastern pygmies and non-pygmies) were obtained. Multivariate analysis (generalized Procrustes analysis, Mahalanobis distances, multivariate regression) and complementary dimensions of size were evaluated with ANOVA and post hoc LSD. Results suggest that important cranial shape differentiation does occur between pygmies and non-pygmies but also between Eastern and Western populations and that size changes and allometries do not affect similarly Eastern and Western pygmies. Therefore, our findings raise serious doubt about the fact to consider African pygmies as a homogenous group in studies on skull morphology. Differences in cranial morphology among pygmies would suggest differentiation after divergence. Although not directly related to skull differentiation, the diversity among pygmies would probably suggest that the process responsible for reduced stature occurred after the split of the ancestors of modern Eastern and Western pygmies. PMID:21049030

  16. African horse sickness.

    PubMed

    Zientara, S; Weyer, C T; Lecollinet, S

    2015-08-01

    African horse sickness (AHS) is a devastating disease of equids caused by an arthropod-borne virus belonging to the Reoviridae family, genus Orbivirus. It is considered a major health threat for horses in endemic areas in sub-Saharan Africa. African horse sickness virus (AHSV) repeatedly caused large epizootics in the Mediterranean region (North Africa and southern Europe in particular) as a result of trade in infected equids. The unexpected emergence of a closely related virus, the bluetongue virus, in northern Europe in 2006 has raised fears about AHSV introduction into Europe, and more specifically into AHSV-free regions that have reported the presence of AHSV vectors, e.g. Culicoides midges. North African and European countries should be prepared to face AHSV incursions in the future, especially since two AHSV serotypes (serotypes 2 and 7) have recently spread northwards to western (e.g. Senegal, Nigeria, Gambia) and eastern Africa (Ethiopia), where historically only serotype 9 had been isolated. The authors review key elements of AHS epidemiology, surveillance and prophylaxis. PMID:26601437

  17. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  18. On the search for NNO-donor enantiopure scorpionate ligands and their coordination to group 4 metals.

    PubMed

    Otero, Antonio; Fernández-Baeza, Juan; Tejeda, Juan; Lara-Sánchez, Agustín; Sánchez-Molina, Margarita; Franco, Sonia; López-Solera, Isabel; Rodríguez, Ana M; Sánchez-Barba, Luis F; Morante-Zarcero, Sonia; Garcés, Andrés

    2009-06-15

    The preparation of new chiral bis(pyrazol-1-yl)methane-based NNO-donor scorpionate ligands in the form of the lithium derivatives [Li(bpzb)(THF)] [1; bpzb = 1,1-bis(3,5-dimethylpyrazol-1-yl)-3,3-dimethyl-2-butoxide] and [Li(bpzte)(THF)] [2; bpzte = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1-p-tolylethoxide] or the alcohol ligands (bpzbH) (3) and (bpzteH) (4) has been carried out by 1,2-addition reactions with trimethylacetaldehyde or p-tolualdehyde. The separation of a racemic mixture of the alcohol ligand 3 has been achieved and gave an enantiopure NNO alcohol-scorpionate ligand in three synthetic steps: (i) 1,2-addition of the appropriate lithium derivative to trimethylacetaldehyde, (ii) esterification and separation of diastereoisomers 5, (iii) saponification. Subsequently, the enantiopure scorpionate ligand (R,R)-bpzmmH {6; R,R-bpzmmH = (1R)-1-[(1R)-6,6-dimethylbicyclo[3.1.1]2-hepten-2-yl]-2,2-bis(3,5-dimethylpyrazol-1-yl)ethanol} was obtained with an excellent diastereomeric excess (>99% de) in a one-pot process utilizing the aldehyde (1R)-(-)-myrtenal as a chiral substrate to control the stereochemistry of the newly created asymmetric center. These new chiral heteroscorpionate ligands reacted with [MX(4)] (M = Ti, Zr; X = NMe(2), O(i)Pr, OEt, O(t)Bu) in a 1:1 molar ratio in toluene to give, after the appropriate workup, the complexes [MX(3)(kappa(3)-NNO)] (7-18). The reaction of Me(3)SiCl with [Ti(NMe(2))(3)(bpzb)] (7) or [Ti(NMe(2))(3)(R,R-bpzmm)] (11) in different molar ratios gave the halide-amide-containing complexes [TiCl(NMe(2))(2)(kappa(3)-NNO)] (19 and 20) and [TiCl(2)(NMe(2))(kappa(3)-NNO)] (21 and 22) and the halide complex [TiCl(3)(kappa(3)-NNO)] (23 and 24). The latter complexes can also be obtained by reaction of the lithium compound 1 with TiCl(4)(THF)(2) and deprotonation of the alcohol group of 6 with NaH, followed by reaction with TiCl(4)(THF)(2) in a 1:1 molar ratio, respectively. Isolation of only one of the three possible diastereoisomers of the

  19. A Teacher's Guide to African Narratives. Studies in African Literature.

    ERIC Educational Resources Information Center

    O'Brien, Sara Talis

    This guide is designed to help secondary school teachers include African literature in their classes. It furnishes English and social studies teachers with a foundation for teaching African literature by offering critical commentary on the texts themselves. A synthesis of anthropological and historical material is presented to help both teachers…

  20. African American Administrators and Staff

    ERIC Educational Resources Information Center

    Wright, Dianne; Taylor, Janice D.; Burrell, Charlotte; Stewart, Gregory

    2006-01-01

    This article explores the issues of African American participation in the administrative ranks of the academy. The authors find that African Americans tend to hold positions that are marginal in academic organizations, lacking power and influence, and that not much has changed over recent decades. Forces influencing this condition are explored,…

  1. African-American Children's Literature.

    ERIC Educational Resources Information Center

    Kline, Lucinda

    This paper examines the history of African American children's literature, the present-day status of it, and ventures predictions about its future. The paper also considers the historic and social factors of the debate about whether an author who is not African American can write a book that will/should be accepted in this category of children's…

  2. African-American Sacred Music.

    ERIC Educational Resources Information Center

    Bailey, A. Peter

    1991-01-01

    The history of African-American sacred music is traced from the time of slavery to the present interest in gospel music. The religious music of African Americans is geared toward liberation themes. It is important that this music does not dilute its power through cross-over with other music forms. (SLD)

  3. Africanization in the United States

    PubMed Central

    Pinto, M. Alice; Rubink, William L.; Patton, John C.; Coulson, Robert N.; Johnston, J. Spencer

    2005-01-01

    The expansion of Africanized honeybees from South America to the southwestern United States in <50 years is considered one of the most spectacular biological invasions yet documented. In the American tropics, it has been shown that during their expansion Africanized honeybees have low levels of introgressed alleles from resident European populations. In the United States, it has been speculated, but not shown, that Africanized honeybees would hybridize extensively with European honeybees. Here we report a continuous 11-year study investigating temporal changes in the genetic structure of a feral population from the southern United States undergoing Africanization. Our microsatellite data showed that (1) the process of Africanization involved both maternal and paternal bidirectional gene flow between European and Africanized honeybees and (2) the panmitic European population was replaced by panmitic mixtures of A. m. scutellata and European genes within 5 years after Africanization. The post-Africanization gene pool (1998–2001) was composed of a diverse array of recombinant classes with a substantial European genetic contribution (mean 25–37%). Therefore, the resulting feral honeybee population of south Texas was best viewed as a hybrid swarm. PMID:15937139

  4. Scorpion venom activates natural killer cells in hepatocellular carcinoma via the NKG2D-MICA pathway.

    PubMed

    Chen, Han; Zhidan, Wang; Xia, Ren; Zhaoxia, Wang; Qing, Jia; Qiang, Guo; Haipeng, Yin; Hengxiao, Wang

    2016-06-01

    Previous studies have demonstrated that polypeptides extracted from scorpion venom (PESV) inhibited cell proliferation in several tumors, however, the effect on dysfunctional and exhausted natural killer cells which contribute to tumor escape from immune surveillance remain to be elucidated. In this study, we determined the effect of PESV on NK infiltration into H22 cells orthotopic transplantation tumors and on the expression of MHC class I chain-related proteins A (MICA) in HepG2 cells. We found that tumor growth in mice was significantly inhibited by PESV and the survival time of tumor-bearing mice treated with PESV was significantly prolonged. Moreover, levels of tumor-infiltrating NK cells, NKG2D protein, perforin and granzyme B mRNA were significantly increased in the group treated with PESV compared with the tumor-bearing control group. In addition, In addition, up-regulation of MICA by PESV enhances the susceptibility of HepG2 cells to NK lysis in vitro. These results indicate that the inhibitory effects of PESV on hepatic carcinoma are likely mediated by up-regulation of NK cell activity via the MICA-NKG2D pathway. PMID:27089390

  5. Monoclonal immunotoxin acting on the Na/sup +/ channel, with properties similar to those of a scorpion toxin

    SciTech Connect

    Barhanin, J.; Meiri, H.; Romey, G.; Pauron, D.; Lazdunski, M.

    1985-03-01

    The authors describe the properties of a monoclonal antibody against the Na/sup +/ channel. The antibody, 72.38, competitively inhibited the binding of an /sup 125/I-labeled toxin from the Brazilian scorpion Tityus serrulatus (/sup 125/I-TiTX..gamma..) to Na/sup +/ channels of rat brain membranes. The inhibition of /sup 125/I-TiTX..gamma.. binding also was observed with the solubilized Na/sup +/ channel from rat brain membranes. Antibody 72.38 antagonized /sup 125/I-TiTX..gamma.. binding to Na/sup +/ channels from different animal species (fish, avian, and mammalian) and from different tissues (electroplax, brain, heart, and muscle). Moreover, 72.38 has been used for immunofluorescence labeling of Na/sup +/ channels in rat sciatic nodes of Ranvier and cultured dorsal root ganglion cells. Electrophysiological experiments on rat muscle cells fully confirmed the similarity between TiTX..gamma.. and 72.38 seen in binding experiments. TiTX..gamma.. and 72.38 are without effect on the ion selectivity of the Na/sup +/ channel, but they both drastically change the voltage-dependence of activation and inactivation of the Na/sup +/ channel.

  6. Sodium channel from rat brain. Reconstitution of voltage-dependent scorpion toxin binding in vesicles of defined lipid composition

    SciTech Connect

    Feller, D.J.; Talvenheimo, J.A.; Catterall, W.A.

    1985-09-25

    Purified sodium channels incorporated into phosphatidylcholine (PC) vesicles mediate neurotoxin-activated SSNa influx but do not bind the alpha-scorpion toxin from Leiurus quinquestriatus (LqTx) with high affinity. Addition of phosphatidylethanolamine (PE) or phosphatidylserine to the reconstitution mixture restores high affinity LqTx binding with KD = 1.9 nM for PC/PE vesicles at -90 mV and 36 degrees C in sucrose-substituted medium. Other lipids tested were markedly less effective. The binding of LqTx in vesicles of PC/PE (65:35) is sensitive to both the membrane potential formed by sodium gradients across the reconstituted vesicle membrane and the cation concentration in the extravesicular medium. Binding of LqTx is reduced 3- to 4-fold upon depolarization to 0 mV from -50 to -60 mV in experiments in which (Na+)out/(Na+)in is varied by changing (Na+)in or (Na+)out at constant extravesicular ionic strength. It is concluded that the purified sodium channel contains the receptor site for LqTx in functional form and that restoration of high affinity, voltage-dependent binding of LqTx by the purified sodium channel requires an appropriate ratio of PC to PE and/or phosphatidylserine in the vesicle membrane.

  7. Opposing roles of LTB4 and PGE2 in regulating the inflammasome-dependent scorpion venom-induced mortality

    PubMed Central

    Zoccal, Karina F.; Sorgi, Carlos A.; Hori, Juliana I.; Paula-Silva, Francisco W. G.; Arantes, Eliane C.; Serezani, Carlos H.; Zamboni, Dario S.; Faccioli, Lúcia H.

    2016-01-01

    Tityus serrulatus sting causes thousands of deaths annually worldwide. T. serrulatus-envenomed victims exhibit local or systemic reaction that culminates in pulmonary oedema, potentially leading to death. However, the molecular mechanisms underlying T. serrulatus venom (TsV) activity remain unknown. Here we show that TsV triggers NLRP3 inflammasome activation via K+ efflux. Mechanistically, TsV triggers lung-resident cells to release PGE2, which induces IL-1β production via E prostanoid receptor 2/4-cAMP-PKA-NFκB-dependent mechanisms. IL-1β/IL-1R actions account for oedema and neutrophil recruitment to the lungs, leading to TsV-induced mortality. Inflammasome activation triggers LTB4 production and further PGE2 via IL-1β/IL-1R signalling. Activation of LTB4-BLT1/2 pathway decreases cAMP generation, controlling TsV-induced inflammation. Exogenous administration confirms LTB4 anti-inflammatory activity and abrogates TsV-induced mortality. These results suggest that the balance between LTB4 and PGE2 determines the amount of IL-1β inflammasome-dependent release and the outcome of envenomation. We suggest COX1/2 inhibition as an effective therapeutic intervention for scorpion envenomation. PMID:26907476

  8. Opposing roles of LTB4 and PGE2 in regulating the inflammasome-dependent scorpion venom-induced mortality.

    PubMed

    Zoccal, Karina F; Sorgi, Carlos A; Hori, Juliana I; Paula-Silva, Francisco W G; Arantes, Eliane C; Serezani, Carlos H; Zamboni, Dario S; Faccioli, Lúcia H

    2016-01-01

    Tityus serrulatus sting causes thousands of deaths annually worldwide. T. serrulatus-envenomed victims exhibit local or systemic reaction that culminates in pulmonary oedema, potentially leading to death. However, the molecular mechanisms underlying T. serrulatus venom (TsV) activity remain unknown. Here we show that TsV triggers NLRP3 inflammasome activation via K(+) efflux. Mechanistically, TsV triggers lung-resident cells to release PGE2, which induces IL-1β production via E prostanoid receptor 2/4-cAMP-PKA-NFκB-dependent mechanisms. IL-1β/IL-1R actions account for oedema and neutrophil recruitment to the lungs, leading to TsV-induced mortality. Inflammasome activation triggers LTB4 production and further PGE2 via IL-1β/IL-1R signalling. Activation of LTB4-BLT1/2 pathway decreases cAMP generation, controlling TsV-induced inflammation. Exogenous administration confirms LTB4 anti-inflammatory activity and abrogates TsV-induced mortality. These results suggest that the balance between LTB4 and PGE2 determines the amount of IL-1β inflammasome-dependent release and the outcome of envenomation. We suggest COX1/2 inhibition as an effective therapeutic intervention for scorpion envenomation. PMID:26907476

  9. Scorpion venom activates natural killer cells in hepatocellular carcinoma via the NKG2D-MICA pathway.

    PubMed

    Chen, Han; Zhidan, Wang; Xia, Ren; Zhaoxia, Wang; Qing, Jia; Qiang, Guo; Haipeng, Yin; Hengxiao, Wang

    2016-06-01

    Previous studies have demonstrated that polypeptides extracted from scorpion venom (PESV) inhibited cell proliferation in several tumors, however, the effect on dysfunctional and exhausted natural killer cells which contribute to tumor escape from immune surveillance remain to be elucidated. In this study, we determined the effect of PESV on NK infiltration into H22 cells orthotopic transplantation tumors and on the expression of MHC class I chain-related proteins A (MICA) in HepG2 cells. We found that tumor growth in mice was significantly inhibited by PESV and the survival time of tumor-bearing mice treated with PESV was significantly prolonged. Moreover, levels of tumor-infiltrating NK cells, NKG2D protein, perforin and granzyme B mRNA were significantly increased in the group treated with PESV compared with the tumor-bearing control group. In addition, In addition, up-regulation of MICA by PESV enhances the susceptibility of HepG2 cells to NK lysis in vitro. These results indicate that the inhibitory effects of PESV on hepatic carcinoma are likely mediated by up-regulation of NK cell activity via the MICA-NKG2D pathway.

  10. Role of lysine and tryptophan residues in the biological activity of toxin VII (Ts gamma) from the scorpion Tityus serrulatus.

    PubMed

    Hassani, O; Mansuelle, P; Cestèle, S; Bourdeaux, M; Rochat, H; Sampieri, F

    1999-02-01

    Toxin VII (TsVII), also known as Ts gamma, is the most potent neurotoxin in the venom of the Brazilian scorpion Tityus serrulatus. It has been purified to homogeneity using a new fast and efficient method. Chemical modification of TsVII with the tryptophan-specific reagent o-nitrophenylsulfenyl chloride yielded three modified derivatives (residues Trp39, Trp50 and Trp54). Acetylation of TsVII mostly generated the monoacetylated Lys12 derivative. No side reactions were detected, as indicated by endoproteinase Lys-C peptide mapping, Edman degradation and electrospray mass spectrometry. Circular dichroism and fluorimetric measurements showed that none of the chemical modifications altered the overall structure of the derivatives. The acetylation of Lys12 or the sulfenylation of Trp39 or Trp54 led to a loss of both toxicity in mice and apparent binding affinity for rat brain and cockroach synaptosomal preparations. Sulfenylation of Trp50, however, moderately affected the toxicity of TsVII in mice and had almost no effect on its binding properties. A 3-dimensional model of TsVII was constructed by homology modeling. It suggests that the most reactive residues (Lys12 and Trp39 and Trp54) are all important in the functional disruption of neuronal sodium channels by TsVII, and are close to each other in the hydrophobic conserved region.

  11. Hemicalcin, a new toxin from the Iranian scorpion Hemiscorpius lepturus which is active on ryanodine-sensitive Ca2+ channels

    PubMed Central

    Shahbazzadeh, Delavar; Srairi-Abid, Najet; Feng, Wei; Ram, Narendra; Borchani, Lamia; Ronjat, Michel; Akbari, Abolfazl; Pessah, Isaac N.; De Waard, Michel; El Ayeb, Mohamed

    2007-01-01

    In the present work, we purified and characterized a novel toxin named hemicalcin from the venom of the Iranian chactoid scorpion Hemiscorpius lepturus where it represents 0.6% of the total protein content. It is a 33-mer basic peptide reticulated by three disulfide bridges, and that shares between 85 and 91% sequence identity with four other toxins, all known or supposed to be active on ryanodine-sensitive calcium channels. Hemicalcin differs from these other toxins by seven amino acids at positions 9 (leucine/arginine), 12 (alanine/glutamic acid), 13 (aspartic acid/asparagine), 14 (lysine/asparagine), 18 (serine/glycine), 26 (threonine/alanine) and 28 (proline/isoleucine/alanine). In spite of these differences, hemicalcin remains active on ryanodine-sensitive Ca2+ channels, since it increases [3H]ryanodine binding on RyR1 (ryanodine receptor type 1) and triggers Ca2+ release from sarcoplasmic vesicles. Bilayer lipid membrane experiments, in which the RyR1 channel is reconstituted and its gating properties are analysed, indicate that hemicalcin promotes an increase in the opening probability at intermediate concentration and induces a long-lasting subconductance level of 38% of the original amplitude at higher concentrations. Mice intracerebroventricular inoculation of 300 ng of hemicalcin induces neurotoxic symptoms in vivo, followed by death. Overall, these data identify a new biologically active toxin that belongs to a family of peptides active on the ryanodine-sensitive channel. PMID:17291197

  12. The history of African trypanosomiasis

    PubMed Central

    Steverding, Dietmar

    2008-01-01

    The prehistory of African trypanosomiasis indicates that the disease may have been an important selective factor in the evolution of hominids. Ancient history and medieval history reveal that African trypanosomiasis affected the lives of people living in sub-Saharan African at all times. Modern history of African trypanosomiasis revolves around the identification of the causative agents and the mode of transmission of the infection, and the development of drugs for treatment and methods for control of the disease. From the recent history of sleeping sickness we can learn that the disease can be controlled but probably not be eradicated. Current history of human African trypanosomiasis has shown that the production of anti-sleeping sickness drugs is not always guaranteed, and therefore, new, better and cheaper drugs are urgently required. PMID:18275594

  13. Cancer statistics for African Americans.

    PubMed

    Ghafoor, Asma; Jemal, Ahmedin; Cokkinides, Vilma; Cardinez, Cheryll; Murray, Taylor; Samuels, Alicia; Thun, Michael J

    2002-01-01

    The American Cancer Society provides estimates on the number of new cancer cases and deaths, and compiles health statistics on African Americans in a biennial publication, Cancer Facts and Figures for African Americans. The compiled statistics include cancer incidence, mortality, survival, and lifestyle behaviors using the most recent data on incidence and survival from the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) program, mortality data from the National Center for Health Statistics (NCHS), and behavioral information from the Behavior Risk Factor Surveillance System (BRFSS), Youth Risk Behavior Surveillance System (YRBSS), and National Health Interview Survey (NHIS). It is estimated that 132,700 new cases of cancer and 63,100 deaths will occur among African Americans in the year 2003. Although African Americans have experienced higher incidence and mortality rates of cancer than whites for many years, incidence rates have declined by 2.7 percent per year in African-American males since 1992, while stabilizing in African-American females. During the same period, death rates declined by 2.1 percent and 0.4 percent per year among African-American males and females, respectively. The decrease in both incidence and death rates from cancer among African-American males was the largest of any racial or ethnic group. Nonetheless, African Americans still carry the highest cancer burden among US racial and ethnic groups. Most cancers detectable by screening are diagnosed at a later stage and survival rates are lower within each stage of disease in African Americans than in whites. The extent to which these disparities reflect unequal access to health care versus other factors is an active area of research.

  14. Bioenergy and African transformation.

    PubMed

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures. PMID:25709714

  15. African oil plays

    SciTech Connect

    Clifford, A.J. )

    1989-09-01

    The vast continent of Africa hosts over eight sedimentary basins, covering approximately half its total area. Of these basins, only 82% have entered a mature exploration phase, 9% have had little or no exploration at all. Since oil was first discovered in Africa during the mid-1950s, old play concepts continue to bear fruit, for example in Egypt and Nigeria, while new play concepts promise to become more important, such as in Algeria, Angola, Chad, Egypt, Gabon, and Sudan. The most exciting developments of recent years in African oil exploration are: (1) the Gamba/Dentale play, onshore Gabon; (2) the Pinda play, offshore Angola; (3) the Lucula/Toca play, offshore Cabinda; (4) the Metlaoui play, offshore Libya/Tunisia; (5) the mid-Cretaceous sand play, Chad/Sudan; and (6) the TAG-I/F6 play, onshore Algeria. Examples of these plays are illustrated along with some of the more traditional oil plays. Where are the future oil plays likely to develop No doubt, the Saharan basins of Algeria and Libya will feature strongly, also the presalt of Equatorial West Africa, the Central African Rift System and, more speculatively, offshore Ethiopia and Namibia, and onshore Madagascar, Mozambique, and Tanzania.

  16. Bioenergy and African transformation.

    PubMed

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures.

  17. The Scorpion Toxin Analogue BmKTX-D33H as a Potential Kv1.3 Channel-Selective Immunomodulator for Autoimmune Diseases

    PubMed Central

    Ye, Fang; Hu, Youtian; Yu, Weiwei; Xie, Zili; Hu, Jun; Cao, Zhijian; Li, Wenxin; Wu, Yingliang

    2016-01-01

    The Kv1.3 channel-acting scorpion toxins usually adopt the conserved anti-parallel β-sheet domain as the binding interface, but it remains challenging to discover some highly selective Kv1.3 channel-acting toxins. In this work, we investigated the pharmacological profile of the Kv1.3 channel-acting BmKTX-D33H, a structural analogue of the BmKTX scorpion toxin. Interestingly, BmKTX-D33H, with its conserved anti-parallel β-sheet domain as a Kv1.3 channel-interacting interface, exhibited more than 1000-fold selectivity towards the Kv1.3 channel as compared to other K+ channels (including Kv1.1, Kv1.2, Kv1.7, Kv11.1, KCa2.2, KCa2.3, and KCa3.1). As expected, BmKTX-D33H was found to inhibit the cytokine production and proliferation of both Jurkat cells and human T cells in vitro. It also significantly improved the delayed-type hypersensitivity (DTH) responses, an autoreactive T cell-mediated inflammation in rats. Amino acid sequence alignment and structural analysis strongly suggest that the “evolutionary” Gly11 residue of BmKTX-D33H interacts with the turret domain of Kv1 channels; it appears to be a pivotal amino acid residue with regard to the selectivity of BmKTX-D33H towards the Kv1.3 channel (in comparison with the highly homologous scorpion toxins). Together, our data indicate that BmKTX-D33H is a Kv1.3 channel–specific blocker. Finally, the remarkable selectivity of BmKTX-D33H highlights the great potential of evolutionary-guided peptide drug design in future studies. PMID:27104568

  18. The Scorpion Toxin Analogue BmKTX-D33H as a Potential Kv1.3 Channel-Selective Immunomodulator for Autoimmune Diseases.

    PubMed

    Ye, Fang; Hu, Youtian; Yu, Weiwei; Xie, Zili; Hu, Jun; Cao, Zhijian; Li, Wenxin; Wu, Yingliang

    2016-04-01

    The Kv1.3 channel-acting scorpion toxins usually adopt the conserved anti-parallel β-sheet domain as the binding interface, but it remains challenging to discover some highly selective Kv1.3 channel-acting toxins. In this work, we investigated the pharmacological profile of the Kv1.3 channel-acting BmKTX-D33H, a structural analogue of the BmKTX scorpion toxin. Interestingly, BmKTX-D33H, with its conserved anti-parallel β-sheet domain as a Kv1.3 channel-interacting interface, exhibited more than 1000-fold selectivity towards the Kv1.3 channel as compared to other K⁺ channels (including Kv1.1, Kv1.2, Kv1.7, Kv11.1, KCa2.2, KCa2.3, and KCa3.1). As expected, BmKTX-D33H was found to inhibit the cytokine production and proliferation of both Jurkat cells and human T cells in vitro. It also significantly improved the delayed-type hypersensitivity (DTH) responses, an autoreactive T cell-mediated inflammation in rats. Amino acid sequence alignment and structural analysis strongly suggest that the "evolutionary" Gly11 residue of BmKTX-D33H interacts with the turret domain of Kv1 channels; it appears to be a pivotal amino acid residue with regard to the selectivity of BmKTX-D33H towards the Kv1.3 channel (in comparison with the highly homologous scorpion toxins). Together, our data indicate that BmKTX-D33H is a Kv1.3 channel-specific blocker. Finally, the remarkable selectivity of BmKTX-D33H highlights the great potential of evolutionary-guided peptide drug design in future studies. PMID:27104568

  19. The natural scorpion peptide, BmK NT1 activates voltage-gated sodium channels and produces neurotoxicity in primary cultured cerebellar granule cells.

    PubMed

    Zou, Xiaohan; He, Yuwei; Qiao, Jinping; Zhang, Chunlei; Cao, Zhengyu

    2016-01-01

    The scorpion Buthus martensii Karsch has been used in Traditional Chinese Medicine to treat neuronal diseases such as neuropathic pain, paralysis and epilepsy for thousands of years. Studies have demonstrated that scorpion venom is the primary active component. Although scorpion venom can effectively attenuate pain in the clinic, it also produces neurotoxic response. In this study, toxicity guided purification led to identify a mammalian toxin termed BmK NT1 comprising of 65 amino acid residues and an amidated C-terminus, a mature peptide encoded by the nucleotide sequence (GenBank No. AF464898). In contract to the recombinant product of the same nucleotide sequence, BmK AGAP, which displayed analgesic and anti-tumor effect, intravenous injection (i.v.) of BmK NT1 produced acute toxicity in mice with an LD50 value of 1.36 mg/kg. In primary cultured cerebellar granule cells, BmK NT1 produced a concentration-dependent cell death with an IC50 value of 0.65 μM (0.41-1.03 μM, 95% Confidence Intervals, 95% CI) which was abolished by TTX, a voltage-gated sodium channel (VGSC) blocker. We also demonstrated that BmK NT1 produced modest sodium influx in cerebellar granule cell cultures with an EC50 value of 2.19 μM (0.76-6.40 μM, 95% CI), an effect similar to VGSC agonist, veratridine. The sodium influx response was abolished by TTX suggesting that BmK NT1-induced sodium influx is solely through activation of VGSC. Considered these data together, we demonstrated that BmK NT1 activated VGSC and produced neurotoxicity in cerebellar granule cell cultures. PMID:26598793

  20. Involvement of Cholinergic and Adrenergic Receptors in Pathogenesis and Inflammatory Response Induced by Alpha-Neurotoxin Bot III of Scorpion Venom.

    PubMed

    Nakib, Imene; Martin-Eauclaire, Marie-France; Laraba-Djebari, Fatima

    2016-10-01

    Bot III neurotoxin is the most lethal α neurotoxin purified from Buthus occitanus tunetanus scorpion venom. This toxin binds to the voltage-gated sodium channel of excitable cells and blocks its inactivation, inducing an increased release of neurotransmitters (acetylcholine and catecholamines). This study aims to elucidate the involvement of cholinergic and adrenergic receptors in pathogenesis and inflammatory response triggered by this toxin. Injection of Bot III to animals induces an increase of peroxidase activities, an imbalance of oxidative status, tissue damages in lung parenchyma, and myocardium correlated with metabolic disorders. The pretreatment with nicotine (nicotinic receptor agonist) or atropine (muscarinic receptor antagonist) protected the animals from almost all disorders caused by Bot III toxin, especially the immunological alterations. Bisoprolol administration (selective β1 adrenergic receptor antagonist) was also efficient in the protection of animals, mainly on tissue damage. Propranolol (non-selective adrenergic receptor antagonist) showed less effect. These results suggest that both cholinergic and adrenergic receptors are activated in the cardiopulmonary manifestations induced by Bot III. Indeed, the muscarinic receptor appears to be more involved than the nicotinic one, and the β1 adrenergic receptor seems to dominate the β2 receptor. These results showed also that the activation of nicotinic receptor leads to a significant protection of animals against Bot III toxin effect. These findings supply a supplementary data leading to better understanding of the mechanism triggered by scorpionic neurotoxins and suggest the use of drugs targeting these receptors, especially the nicotinic one in order to counteract the inflammatory response observed in scorpion envenomation. PMID:27395044

  1. Zinc is incorporated into cuticular "tools" after ecdysis: the time course of the zinc distribution in "tools" and whole bodies of an ant and a scorpion.

    PubMed

    Schofield, R M S; Nesson, M H; Richardson, K A; Wyeth, P

    2003-01-01

    An understanding of the developmental course of specialized accumulations in the cuticular "tools" of arthropods will give clues to the chemical form, function and biology of these accumulations as well as to their evolutionary history. Specimens from individuals representing a range of developmental stages were examined using MeV - Ion microscopy. We found that zinc, manganese, calcium and chlorine began to accumulate in the mandibular teeth of the ant Tapinoma sessile after pre-ecdysial tanning, and the zinc mostly after eclosion; peak measured zinc concentrations reached 16% of dry mass. Accumulations in the pedipalp teeth, tarsal claws, cheliceral teeth and sting (aculeus) of the scorpion Vaejovis spinigeris also began after pre-ecdysial tanning and more than 48 h after ecdysis of the second instars. Zinc may be deposited in the fully formed cuticle through a network of nanometer scale canals that we observed only in the metal bearing cuticle of both the ants and scorpions. In addition to the elemental analyses of cuticular "tools", quantitative distribution maps for whole ants were obtained. The zinc content of the mandibular teeth was a small fraction of, and independent of, the total body content of zinc. We did not find specialized storage sites that were depleted when zinc was incorporated into the mandibular teeth. The similarities in the time course of zinc, manganese and calcium deposition in the cuticular "tools" of the ant (a hexapod arthropod) and those of the scorpion (a chelicerate arthropod) contribute to the evidence suggesting that heavy metal-halogen fortification evolved before these groups diverged.

  2. Zinc is incorporated into cuticular "tools" after ecdysis: the time course of the zinc distribution in "tools" and whole bodies of an ant and a scorpion.

    PubMed

    Schofield, R M S; Nesson, M H; Richardson, K A; Wyeth, P

    2003-01-01

    An understanding of the developmental course of specialized accumulations in the cuticular "tools" of arthropods will give clues to the chemical form, function and biology of these accumulations as well as to their evolutionary history. Specimens from individuals representing a range of developmental stages were examined using MeV - Ion microscopy. We found that zinc, manganese, calcium and chlorine began to accumulate in the mandibular teeth of the ant Tapinoma sessile after pre-ecdysial tanning, and the zinc mostly after eclosion; peak measured zinc concentrations reached 16% of dry mass. Accumulations in the pedipalp teeth, tarsal claws, cheliceral teeth and sting (aculeus) of the scorpion Vaejovis spinigeris also began after pre-ecdysial tanning and more than 48 h after ecdysis of the second instars. Zinc may be deposited in the fully formed cuticle through a network of nanometer scale canals that we observed only in the metal bearing cuticle of both the ants and scorpions. In addition to the elemental analyses of cuticular "tools", quantitative distribution maps for whole ants were obtained. The zinc content of the mandibular teeth was a small fraction of, and independent of, the total body content of zinc. We did not find specialized storage sites that were depleted when zinc was incorporated into the mandibular teeth. The similarities in the time course of zinc, manganese and calcium deposition in the cuticular "tools" of the ant (a hexapod arthropod) and those of the scorpion (a chelicerate arthropod) contribute to the evidence suggesting that heavy metal-halogen fortification evolved before these groups diverged. PMID:12770014

  3. Variation in scorpion metabolic rate and rate-temperature relationships: implications for the fundamental equation of the metabolic theory of ecology.

    PubMed

    Terblanche, J S; Janion, C; Chown, S L

    2007-07-01

    The fundamental equation of the metabolic theory of ecology (MTE) indicates that most of the variation in metabolic rate are a consequence of variation in organismal size and environmental temperature. Although evolution is thought to minimize energy costs of nutrient transport, its effects on metabolic rate via adaptation, acclimatization or acclimation are considered small, and restricted mostly to variation in the scaling constant, b(0). This contrasts strongly with many conclusions of evolutionary physiology and life-history theory, making closer examination of the fundamental equation an important task for evolutionary biologists. Here we do so using scorpions as model organisms. First, we investigate the implications for the fundamental equation of metabolic rate variation and its temperature dependence in the scorpion Uroplectes carinatus following laboratory acclimation. During 22 days of acclimation at 25 degrees C metabolic rates declined significantly (from 127.4 to 78.2 microW; P = 0.0001) whereas mean body mass remained constant (367.9-369.1 mg; P = 0.999). In field-fresh scorpions, metabolic rate-temperature (MRT) relationships varied substantially within and among individuals, and therefore had low repeatability values (tau = 0.02) and no significant among-individual variation (P = 0.181). However, acclimation resulted in a decline in within-individual variation of MRT slopes which subsequently revealed significant differences among individuals (P = 0.0031) and resulted in a fourfold increase in repeatability values (tau = 0.08). These results highlight the fact that MRT relationships can show substantial, directional variation within individuals over time. Using a randomization model we demonstrate that the reduction in metabolic rate with acclimation while body mass remains constant causes a decline both in the value of the mass-scaling exponent and the coefficient of determination. Furthermore, interspecific comparisons of activation energy, E

  4. Successfully Educating Our African-American Students

    ERIC Educational Resources Information Center

    Moncree-Moffett, Kareem

    2013-01-01

    The purpose of this empirical study was to explore the lived experiences of African American retired female teachers who have prior experience with educating urban African American students in public schools. Also explored are the experiences of active African American female teachers of urban African American students and comparisons are…

  5. Negro, Black, Black African, African Caribbean, African American or what? Labelling African origin populations in the health arena in the 21st century

    PubMed Central

    Agyemang, C.; Bhopal, R.; Bruijnzeels, M.

    2005-01-01

    Broad terms such as Black, African, or Black African are entrenched in scientific writings although there is considerable diversity within African descent populations and such terms may be both offensive and inaccurate. This paper outlines the heterogeneity within African populations, and discusses the strengths and limitations of the term Black and related labels from epidemiological and public health perspectives in Europe and the USA. This paper calls for debate on appropriate terminologies for African descent populations and concludes with the proposals that (1) describing the population under consideration is of paramount importance (2) the word African origin or simply African is an appropriate and necessary prefix for an ethnic label, for example, African Caribbean or African Kenyan or African Surinamese (3) documents should define the ethnic labels (4) the label Black should be phased out except when used in political contexts. PMID:16286485

  6. Negro, Black, Black African, African Caribbean, African American or what? Labelling African origin populations in the health arena in the 21st century.

    PubMed

    Agyemang, Charles; Bhopal, Raj; Bruijnzeels, Marc

    2005-12-01

    Broad terms such as Black, African, or Black African are entrenched in scientific writings although there is considerable diversity within African descent populations and such terms may be both offensive and inaccurate. This paper outlines the heterogeneity within African populations, and discusses the strengths and limitations of the term Black and related labels from epidemiological and public health perspectives in Europe and the USA. This paper calls for debate on appropriate terminologies for African descent populations and concludes with the proposals that (1) describing the population under consideration is of paramount importance (2) the word African origin or simply African is an appropriate and necessary prefix for an ethnic label, for example, African Caribbean or African Kenyan or African Surinamese (3) documents should define the ethnic labels (4) the label Black should be phased out except when used in political contexts. PMID:16286485

  7. African and African Caribbean users' perceptions of inpatient services.

    PubMed

    Secker, J; Harding, C

    2002-04-01

    It has been suggested that well-documented differences in African and African Caribbean people's contact with mental health services may stem from the organization, processes and practices of services themselves. This article presents the findings of a qualitative study which explored the inpatient experiences of a sample of African and African Caribbean people. Although some positive experiences were described, in the main, participants' accounts revolved around a sense of loss of control and around experiences of overt and implicit racism. Underpinning these experiences were relationships with staff that were perceived to be unhelpful. On the basis of both the positive and negative experiences described, we draw conclusions about the changes required to ensure that inpatient services more effectively meet the needs of this group.

  8. The African Millennium Villages

    PubMed Central

    Sanchez, Pedro; Palm, Cheryl; Sachs, Jeffrey; Denning, Glenn; Flor, Rafael; Harawa, Rebbie; Jama, Bashir; Kiflemariam, Tsegazeab; Konecky, Bronwen; Kozar, Raffaela; Lelerai, Eliud; Malik, Alia; Modi, Vijay; Mutuo, Patrick; Niang, Amadou; Okoth, Herine; Place, Frank; Sachs, Sonia Ehrlich; Said, Amir; Siriri, David; Teklehaimanot, Awash; Wang, Karen; Wangila, Justine; Zamba, Colleen

    2007-01-01

    We describe the concept, strategy, and initial results of the Millennium Villages Project and implications regarding sustainability and scalability. Our underlying hypothesis is that the interacting crises of agriculture, health, and infrastructure in rural Africa can be overcome through targeted public-sector investments to raise rural productivity and, thereby, to increased private-sector saving and investments. This is carried out by empowering impoverished communities with science-based interventions. Seventy-eight Millennium Villages have been initiated in 12 sites in 10 African countries, each representing a major agroecological zone. In early results, the research villages in Kenya, Ethiopia, and Malawi have reduced malaria prevalence, met caloric requirements, generated crop surpluses, enabled school feeding programs, and provided cash earnings for farm families. PMID:17942701

  9. Central African Republic.

    PubMed

    1989-11-01

    The Central African Republic contains 242,000 square miles, which rolling terrain almost 2000 feet above sea level. The climate is tropical, and it has a population of 2.8 million people with a 2.5% growth rate. There are more than 80 ethnic groups including Baya 34%, Banda 28%, Sara 10%, Mandja 9%, Mboum 9%, and M'Baka 7%. The religions are traditional African 35%, protestant 25%, Roman Catholic 25%, and Muslim 15%, and the languages are French and Sangho. The infant mortality rate is 143/1000, with expectancy at 49 years and a 40% literacy rate. The work force of 1 million is 70% agricultural, industry 6% and commerce and service 6% and government 3%. The government consists of a president assisted by cabinet ministers and a single party. Natural resources include diamonds, uranium, timber, gold, and oil, and major industries are beverages, textiles, and soap. Agricultural products feature coffee, cotton, peanuts, tobacco, food crops and livestock. Most of the population live in rural areas and most of the 80 ethnic groups have their own language. This is one of the world's least developed countries, with a per capita income of $375/year. The main problems with development are the poor transportation infrastructure, and the weak internal and international marketing systems. The US and various international organizations have aided in agriculture development, health programs, and family planning. US investment is mainly in diamond and gold mining, and although oil drilling has been successful it is not economically feasible at current prices.

  10. NMR solution structure of Cn12, a novel peptide from the Mexican scorpion Centruroides noxius with a typical beta-toxin sequence but with alpha-like physiological activity.

    PubMed

    del Río-Portilla, Federico; Hernández-Marín, Elizabeth; Pimienta, Genaro; Coronas, Fredy V; Zamudio, Fernando Z; Rodríguez de la Vega, Ricardo C; Wanke, Enzo; Possani, Lourival D

    2004-06-01

    Cn12 isolated from the venom of the scorpion Centruroides noxius has 67 amino-acid residues, closely packed with four disulfide bridges. Its primary structure and disulfide bridges were determined. Cn12 is not lethal to mammals and arthropods in vivo at doses up to 100 microg per animal. Its 3D structure was determined by proton NMR using 850 distance constraints, 36 phi angles derived from 36 coupling constants obtained by two different methods, and 22 hydrogen bonds. The overall structure has a two and half turn alpha-helix (residues 24-32), three strands of antiparallel beta-sheet (residues 2-4, 37-40 and 45-48), and a type II turn (residues 41-44). The amino-acid sequence of Cn12 resembles the beta scorpion toxin class, although patch-clamp experiments showed the induction of supplementary slow inactivation of Na(+) channels in F-11 cells (mouse neuroblastoma N18TG-2 x rat DRG2), which means that it behaves more like an alpha scorpion toxin. This behaviour prompted us to analyse Na(+) channel binding sites using information from 112 Na(+) channel gene clones available in the literature, focusing on the extracytoplasmic loops of the S5-S6 transmembrane segments of domain I and the S3-S4 segments of domain IV, sites considered to be responsible for binding alpha scorpion toxins.

  11. Brownian dynamics simulations of the recognition of the scorpion toxin maurotoxin with the voltage-gated potassium ion channels.

    PubMed Central

    Fu, Wei; Cui, Meng; Briggs, James M; Huang, Xiaoqin; Xiong, Bing; Zhang, Yingmin; Luo, Xiaomin; Shen, Jianhua; Ji, Ruyun; Jiang, Hualiang; Chen, Kaixian

    2002-01-01

    The recognition of the scorpion toxin maurotoxin (MTX) by the voltage-gated potassium (Kv1) channels, Kv1.1, Kv1.2, and Kv1.3, has been studied by means of Brownian dynamics (BD) simulations. All of the 35 available structures of MTX in the Protein Data Bank (http://www.rcsb.org/pdb) determined by nuclear magnetic resonance were considered during the simulations, which indicated that the conformation of MTX significantly affected both the recognition and the binding between MTX and the Kv1 channels. Comparing the top five highest-frequency structures of MTX binding to the Kv1 channels, we found that the Kv1.2 channel, with the highest docking frequencies and the lowest electrostatic interaction energies, was the most favorable for MTX binding, whereas Kv1.1 was intermediate, and Kv1.3 was the least favorable one. Among the 35 structures of MTX, the 10th structure docked into the binding site of the Kv1.2 channel with the highest probability and the most favorable electrostatic interactions. From the MTX-Kv1.2 binding model, we identified the critical residues for the recognition of these two proteins through triplet contact analyses. MTX locates around the extracellular mouth of the Kv1 channels, making contacts with its beta-sheets. Lys23, a conserved amino acid in the scorpion toxins, protrudes into the pore of the Kv1.2 channel and forms two hydrogen bonds with the conserved residues Gly401(D) and Tyr400(C) and one hydrophobic contact with Gly401(C) of the Kv1.2 channel. The critical triplet contacts for recognition between MTX and the Kv1.2 channel are Lys23(MTX)-Asp402(C)(Kv1), Lys27(MTX)-Asp378(D)(Kv1), and Lys30(MTX)-Asp402(A)(Kv1). In addition, six hydrogen-bonding interactions are formed between residues Lys23, Lys27, Lys30, and Tyr32 of MTX and residues Gly401, Tyr400, Asp402, Asp378, and Thr406 of Kv1.2. Many of them are formed by side chains of residues of MTX and backbone atoms of the Kv1.2 channel. Five hydrophobic contacts exist between residues Pro

  12. Two conserved arginine residues from the SK3 potassium channel outer vestibule control selectivity of recognition by scorpion toxins.

    PubMed

    Feng, Jing; Hu, Youtian; Yi, Hong; Yin, Shijin; Han, Song; Hu, Jun; Chen, Zongyun; Yang, Weishan; Cao, Zhijian; De Waard, Michel; Sabatier, Jean-Marc; Li, Wenxin; Wu, Yingliang

    2013-05-01

    Potassium channel functions are often deciphered by using selective and potent scorpion toxins. Among these toxins, only a limited subset is capable of selectively blocking small conductance Ca(2+)-activated K(+) (SK) channels. The structural bases of this selective SK channel recognition remain unclear. In this work, we demonstrate the key role of the electric charges of two conserved arginine residues (Arg-485 and Arg-489) from the SK3 channel outer vestibule in the selective recognition by the SK3-blocking BmP05 toxin. Indeed, individually substituting these residues with histidyl or lysyl (maintaining the positive electric charge partially or fully), although decreasing BmP05 affinity, still preserved the toxin sensitivity profile of the SK3 channel (as evidenced by the lack of recognition by many other types of potassium channel-sensitive charybdotoxin). In contrast, when Arg-485 or Arg-489 of the SK3 channel was mutated to an acidic (Glu) or alcoholic (Ser) amino acid residue, the channel lost its sensitivity to BmP05 and became susceptible to the "new" blocking activity by charybdotoxin. In addition to these SK3 channel basic residues important for sensitivity, two acidic residues, Asp-492 and Asp-518, also located in the SK3 channel outer vestibule, were identified as being critical for toxin affinity. Furthermore, molecular modeling data indicate the existence of a compact SK3 channel turret conformation (like a peptide screener), where the basic rings of Arg-485 and Arg-489 are stabilized by strong ionic interactions with Asp-492 and Asp-518. In conclusion, the unique properties of Arg-485 and Arg-489 (spatial orientations and molecular interactions) in the SK3 channel account for its toxin sensitivity profile. PMID:23511633

  13. Effects of Tityus serrulatus scorpion venom and its toxin TsTX-V on neurotransmitter uptake in vitro.

    PubMed

    Cecchini, Alessandra L; Vasconcelos, Flávio; Amara, Susan G; Giglio, José Roberto; Arantes, Eliane Candiani

    2006-12-01

    Scorpion neurotoxins targeting the Na(v) channel can be classified into two classes: alpha- and beta-neurotoxins and are reported as highly active in mammalian brain. In this work, we evaluate the effects of Tityus serrulatus venom (Ts venom) and its alpha-neurotoxin TsTX-V on gamma-aminobutyric acid (GABA), dopamine (DA) and glutamate (Glu) uptake in isolated rat brain synaptosomes. TsTX-V was isolated from Ts venom by ion exchange chromatography followed by reverse-phase (C18) high-performance liquid chromatography. Neither Ts venom nor TsTX-V was able to affect (3)H-Glu uptake. On the other hand, Ts venom (0.13 microg/mg) significantly inhibited both (3)H-GABA and (3)H-DA uptake ( approximately 50%). TsTX-V showed IC(50) values of 9.37 microM and 22.2 microM for the inhibition of (3)H-GABA and (3)H-DA uptake, respectively. These effects were abolished by pre-treatment with tetrodotoxin (TTX, 1 microM), indicating the involvement of voltage-gated Na(+) channels in this process. In the absence of Ca(2+), and at low Ts venom concentrations, the reduction of (3)H-GABA uptake was not as marked as in the presence of Ca(2+). TsTX-V did not reduce (3)H-GABA uptake in COS-7 cells expressing the GABA transporters GAT-1 and GAT-3, suggesting that this toxin indirectly reduces the transport. The reduced (3)H-GABA uptake by synaptosomes might be due to rapid cell depolarization as revealed by confocal microscopy of C6 glioma cells. Thus, TsTX-V causes a reduction of (3)H-GABA and (3)H-DA uptake in a Ca(2+)-dependent manner, not directly affecting GABA transporters, but, in consequence of depolarization, involving voltage-gated Na(+) channels.

  14. The myosin interacting-heads motif is present in the relaxed thick filament of the striated muscle of scorpion.

    PubMed

    Pinto, Antonio; Sánchez, Fredi; Alamo, Lorenzo; Padrón, Raúl

    2012-12-01

    Electron microscopy (EM) studies of 2D crystals of smooth muscle myosin molecules have shown that in the inactive state the two heads of a myosin molecule interact asymmetrically forming a myosin interacting-heads motif. This suggested that inactivation of the two heads occurs by blocking of the actin-binding site of one (free head) and the ATP hydrolysis site of the other (blocked head). This motif has been found by EM of isolated negatively stained myosin molecules of unregulated (vertebrate skeletal and cardiac muscle) and regulated (invertebrate striated and vertebrate smooth muscle) myosins, and nonmuscle myosin. The same motif has also been found in 3D-reconstructions of frozen-hydrated (tarantula, Limulus, scallop) and negatively stained (scallop, vertebrate cardiac) isolated thick filaments. We are carrying out studies of isolated thick filaments from other species to assess how general this myosin interacting-heads motif is. Here, using EM, we have visualized isolated, negatively stained thick filaments from scorpion striated muscle. We modified the iterative helical real space reconstruction (IHRSR) method to include filament tilt, and band-pass filtered the aligned segments before averaging, achieving a 3.3 nm resolution 3D-reconstruction. This reconstruction revealed the presence of the myosin interacting-heads motif (adding to evidence that is widely spread), together with 12 subfilaments in the filament backbone. This demonstrates that conventional negative staining and imaging can be used to detect the presence of the myosin interacting-heads motif in helically ordered thick filaments from different species and muscle types, thus avoiding the use of less accessible cryo-EM and low electron-dose procedures. PMID:22982253

  15. Investigation of in vivo potential of scorpion venom against skin tumorigenesis in mice via targeting markers associated with cancer development

    PubMed Central

    Al Asmari, Abdulrahman K; Khan, Abdul Quaiyoom

    2016-01-01

    Cancer is the leading cause of morbidity and mortality all over the world in spite of the advances made in its management. In this study, we investigated the in vivo anti-tumorigenic potential of the venom obtained from a medically important scorpion species Leiurus quinquestriatus on chemically induced skin cancer in mice. Animals were divided into five groups, with 13 animals in each group. All the treatments were given topically on the shaved dorsal surface of the skin. Animals in Group 1 received vehicle only (0.2 mL acetone). Moreover, 7,12-dimethylbenz[a]anthracene (DMBA, 400 nmol per mouse) was applied to all the animals in the remaining four groups. After 1 week, different concentrations of venom (17.5 μg, 35 μg, and 52.5 μg per animal) were applied to each animal in the Groups III–V. Thirty minutes after the application of venom, croton oil was applied on the same position where venom was administered to the animals of Groups III–V. Animals in Group II were treated as the positive control (without venom) and received croton oil as in Groups III–V. The findings of this study revealed that venom extract of L. quinquestriatus inhibits DMBA + croton oil-induced mouse skin tumor incidence and tumor multiplicity. Venom treatment also decreased the expression of proinflammatory cytokines. Immunohistochemistry results showed a downregulation of the expression of molecular markers such as Ki-67, nuclear factor kappa-B, cyclooxygenase-2, B-cell lymphoma-2, and vascular endothelial growth factor, in venom-treated animals. Our findings suggest that the venom of L. quinquestriatus possesses in vivo anticancer potential and may be used in the development of anticancer molecules. PMID:27799739

  16. Purification and N-terminal partial sequence of anti-epilepsy peptide from venom of the scorpion Buthus martensii Karsch.

    PubMed Central

    Zhou, X H; Yang, D; Zhang, J H; Liu, C M; Lei, K J

    1989-01-01

    An anti-epilepsy peptide (AEP) was isolated and purified from venom of the scorpion Buthus martensii Karsch. The purification procedure included CM-Sephadex C-50 chromatography, gel filtration on Sephadex G-50 and DEAE-Sephadex A-50 chromatography. Its homogeneity was demonstrated by pH 4.3 polyacrylamide-disc-gel electrophoresis, focusing electrophoresis and SDS/polyacrylamide-disc-gel electrophoresis. The Mr of this peptide, calculated from measurements in SDS/15%-polyacrylamide-disc-gel and SDS/20%-polyacrylamide-disc-gel electrophoresis, is 8300. The isoelectric point is 8.52 by pH 8-9.5-range isoelectric focusing. No haemorrhagic or toxic activities were found. No toxicity was found even after the dose reached 28 mg/kg. The pharmacological tests showed that the AEP had no effect on heart rate, blood pressure or electrocardiogram, but strongly inhibited epilepsy induced by coriaria lactone and cephaloridine. The fluorescence spectrum showed that the peptide has a strong emission peak at 337 nm. Amino acid analysis suggested that the AEP is composed of 66 residues from 18 amino acids and has an Mr of 8290. The sequence of the first 50 N-terminal residues is as follows: Asp-Gly-Tyr-Ile-Arg-Gly-Ser-Asp-Asn-Cys-Lys-Val-Ser-Cys-Leu-Leu-Gly-Asn- Glu-Gly - Cys-Asn-Lys-Glu-Cys-Arg-Ala-Tyr-Gly-Ala-Ser-Tyr-Gly-Tyr-Cys-Trp-Thr-Val- Lys-Leu - Ala-Gln-Asp-Cys-Glu-Gly-Leu-Pro-Asp-Thr-. Images Fig. 4. PMID:2930463

  17. The pathological effects of Heminecrolysin, a dermonecrotic toxin from Hemiscorpius lepturus scorpion venom are mediated through its lysophospholipase D activity.

    PubMed

    Borchani, Lamia; Sassi, Atfa; Ben Gharsa, Haifa; Safra, Ines; Shahbazzadeh, Delavar; Ben Lasfar, Zakaria; El Ayeb, Mohamed

    2013-06-01

    We have previously identified Heminecrolysin, a sphingomyelinase D (SMaseD), as the major protein responsible for the main pathological effects observed following Hemiscorpius (H.) lepturus scorpion envenomation. We aimed herein to further investigate the kinetics and molecular mechanisms triggered by Heminecrolysin to initiate hematological disorders and inflammatory reaction. We show that Heminecrolysin highly hydrolyzes lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA) and choline, with a Vmax = 1481 ± 51 μmol/min/mg and a Km = 97 ± 16.78 μM, at a much lesser extend sphingomyelin but not phosphatidylcholine substrates. Its lysophospholipase D (lysoPLD) catalytic efficiency, up to three orders of magnitude higher, comparatively to spider's SMaseDs (newly referred as phospholipases D; PLDs), could explain its strong hemolytic capacity. Chelating agents such as EDTA, EGTA, and 1, 10-phenantroline blocked Heminecrolysin-induced LPC hydrolysis at 98, 48, and 70% respectively. Hemolysis blockade occurs only when the toxin is added to erythrocytes in the presence of serum, source of LPC and complement, indicating that the production of LPA and the presence of complement are mandatory for hemolysis. Moreover, we show that Heminecrolysin efficiently binds to erythrocyte's membrane and provokes phosphatidylserine (PS) translocation without cleavage of glycophorin A, suggesting that, unlike spider's PLDs, complement was activated only via the classical pathway. Interestingly, Heminecrolysin was found to induce PS exposure on human nucleated Jurkat T cells, to stimulate secretion of the pro-inflammatory (TNF-α, IL-6), and anti-inflammatory (IL-10) cytokines by human monocytes, and to provoke a disseminated intravascular coagulation on chick embryo chorioallantoic membrane model system. Taken together, our results indicate that Heminecrolysin evokes the major characteristic clinical features of H. lepturus envenomation by using mainly its lyso

  18. Early African Hominids: Pedagogic Patterns.

    ERIC Educational Resources Information Center

    Newman, James L.

    1984-01-01

    By studying early African hominids, students can learn about the interactive testing and creative aspects of scientific thinking and sharpen their geographical skills. It is impossible to study this topic without giving prominence to space and time. (RM)

  19. Influence of post-starvation extraction time and prey-specific diet in Tityus serrulatus scorpion venom composition and hyaluronidase activity.

    PubMed

    Pucca, Manuela Berto; Amorim, Fernanda Gobbi; Cerni, Felipe Augusto; Bordon, Karla de Castro Figueiredo; Cardoso, Iara Aimê; Anjolette, Fernando Antonio Pino; Arantes, Eliane Candiani

    2014-11-01

    The role of diet in venom composition has been a topic of intense research interest. This work presents evidence that the variation in the venom composition from the scorpion Tityus serrulatus (Ts) is closely associated with post-starvation extraction time and prey-specific diet. The scorpions were fed with cockroach, cricket, peanut beetle or giant Tenebrio. The venoms demonstrated a pronounced difference in the total protein and toxins composition, which was evaluated by electrophoresis, reversed-phase chromatography, densitometry, hyaluronidase activity and N-terminal sequencing. Indeed, many toxins and peptides, such as Ts1, Ts2, Ts4, Ts5, Ts6, Ts15, Ts19 frag. II, hypotensins 1 and 3, PAPE peptide and peptide 9797 (first described in Ts venom), were all identified in different proportions in the analyzed Ts venoms. This study is pioneer on assessing the influence of the starvation time and the prey diet on hyaluronidase activity as well as to describe a modification of Tricine-gel-electrophoresis to evaluate this enzyme activity. Altogether, this study reveal a large contribution of the extraction time and diet on Ts venom variability as well as present a background to recommend the cockroach diet to obtain higher protein content and the cricket diet to obtain higher hyaluronidase specific activity.

  20. Vietnamese Heterometrus laoticus scorpion venom: evidence for analgesic and anti-inflammatory activity and isolation of new polypeptide toxin acting on Kv1.3 potassium channel.

    PubMed

    Hoang, Anh N; Vo, Hoang D M; Vo, Nguyen P; Kudryashova, Kseniya S; Nekrasova, Oksana V; Feofanov, Alexey V; Kirpichnikov, Mikhail P; Andreeva, Tatyana V; Serebryakova, Marina V; Tsetlin, Victor I; Utkin, Yuri N

    2014-01-01

    The scorpion Heterometrus laoticus (Scorpionidae) inhabits Indochinese peninsula and is widely distributed in South-West Vietnam. Since no human fatalities caused by H. laoticus stings were reported, no systematic characterization of the venom was earlier done. In this study we report on biological activity of the venom from H. laoticus caught in Vietnamese province An Giang. The venom manifested a very low acute toxicity with LD50 of about 190 mg/kg body weight in mice at subcutaneous (s.c.) injection and 12 mg/kg at intravenous injection. The venom analgesic effects using tail immersion and writhing tests as well as anti-inflammatory effect using carrageenan test were analyzed at doses of 9.5 and 19 mg/kg at s.c. injections. It was found that at two doses tested H. laoticus venom showed both anti-nociceptive and anti-inflammatory activity. The venom was fractionated by means of gel-filtration and reversed-phase HPLC. As a result several polypeptide toxins were isolated and new toxin hetlaxin was identified. Its amino acid sequence was determined and binding to the extracellular vestibule of the K⁺-conducting pore of Kv1.1 and Kv1.3 potassium channels was studied. Hetlaxin belongs to the scorpion alpha-toxin family and is the first toxin isolated from H. laoticus venom which possesses high affinity (K(i) 59 nM) to Kv1.3 potassium channel.

  1. A novel cysteine-free venom peptide with strong antimicrobial activity against antibiotics-resistant pathogens from the scorpion Opistophthalmus glabrifrons.

    PubMed

    Bao, Aorigele; Zhong, Jie; Zeng, Xian-Chun; Nie, Yao; Zhang, Lei; Peng, Zhao Feng

    2015-10-01

    Antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, pose serious threat to human health. The outbreak of antibiotic-resistant pathogens in recent years emphasizes once again the urgent need for the development of new antimicrobial agents. Here, we discovered a novel antimicrobial peptide from the scorpion Opistophthalmus glabrifrons, which was referred to as Opisin. Opisin consists of 19 amino acid residues without disulfide bridges. It is a cationic, amphipathic, and α-helical molecule. Protein sequence homology search revealed that Opisin shares 42.1-5.3% sequence identities to the 17/18-mer antimicrobial peptides from scorpions. Antimicrobial assay showed that Opisin is able to potently inhibit the growth of the tested Gram-positive bacteria with the minimal inhibitory concentration (MIC) values of 4.0-10.0 μM; in contrast, it possesses much lower activity against the tested Gram-negative bacteria and a fungus. It is interesting to see that Opisin is able to strongly inhibit the growth of methicillin- and vancomycin-resistant pathogens with the MICs ranging from 2.0 to 4.0 μM and from 4.0 to 6.0 μM, respectively. We found that at a concentration of 5 × MIC, Opisin completely killed all the cultured methicillin-resistant Staphylococcus aureus. These results suggest that Opisin is a promising therapeutic candidate for the treatment of the antibiotic-resistant bacterial infections.

  2. Sex-Linked Chromosome Heterozygosity in Males of Tityus confluens (Buthidae): A Clue about the Presence of Sex Chromosomes in Scorpions

    PubMed Central

    Adilardi, Renzo Sebastián; Ojanguren-Affilastro, Andrés Alejandro; Mola, Liliana María

    2016-01-01

    Scorpions of the genus Tityus show holokinetic chromosomes, achiasmatic male meiosis and an absence of heteromorphic sex chromosomes, like all Buthidae. In this work, we analysed the meiotic behaviour and chromosome rearrangements of a population of the scorpion Tityus confluens, characterising the cytotypes of males, females and embryos with different cytogenetic techniques. This revealed that all the females were structural homozygotes, while all the males were structural heterozygotes for different chromosome rearrangements. Four different cytotypes were described in males, which differed in chromosome number (2n = 5 and 2n = 6) and meiotic multivalent configurations (chains of four, five and six chromosomes). Based on a detailed mitotic and meiotic analysis, we propose a sequence of chromosome rearrangements that could give rise to each cytotype and in which fusions have played a major role. Based on the comparison of males, females and a brood of embryos, we also propose that the presence of multivalents in males and homologous pairs in females could be associated with the presence of cryptic sex chromosomes, with the male being the heterogametic sex. We propose that the ancestral karyotype of this species could have had homomorphic XY/XX (male/female) sex chromosomes and a fusion could have occurred between the Y chromosome and an autosome. PMID:27783630

  3. The first description of cardiac magnetic resonance findings in a severe scorpion envenomation: Is it a stress-induced (Takotsubo) cardiomyopathy like?

    PubMed

    Miranda, Carlos H; Braggion-Santos, Maria F; Schmidt, André; Pazin-Filho, Antônio; Cupo, Palmira

    2015-06-01

    There are more than 1 million cases of scorpion envenomation worldwide. Severe complications due to myocardial depression can happen in some patients, mainly children. A catecholamine-induced myocarditis probably causes this cardiac dysfunction. We describe a case of a 7-year-old boy with a severe scorpion envenomation complicated by pulmonary edema in which the cardiac magnetic resonance (CMR)was performed during the acute phase. The CMR showed an apical ballooning in the left ventricle associated with a left ventricle ejection fraction of 29% and a global edema of the midmyocardium and apical myocardiumin the T2-weighted triple inversion recovery images. The CMR was repeated after 7 months and showed complete recovery of the wall motion in the apical region and of the myocardial function (left ventricle ejection fraction, 60%) associated with normalization of the signal in the T2-weighted triple inversion recovery images. These clinical and laboratory findings, mainly the CMR images, are similar to those observed in stress-induced cardiomyopathy (Takotsubo) reinforcing the hypothesis that the catecholamine's excess has a pivotal function in the pathophysiology of the cardiac dysfunction in these 2 conditions. PMID:25601163

  4. Hepatitis C in African Americans.

    PubMed

    Saab, Sammy; Jackson, Christian; Nieto, Jose; Francois, Fritz

    2014-10-01

    The care of hepatitis C virus (HCV) in African Americans represents an opportunity to address a major health disparity in medicine. In all facets of HCV infection, African Americans are inexplicably affected, including in the prevalence of the virus, which is higher among them compared with most of the racial and ethnic groups. Ironically, although fibrosis rates may be slow, hepatocellular carcinoma and mortality rates appear to be higher among African Americans. Sustained viral response (SVR) rates have historically significantly trailed behind Caucasians. The reasons for this gap in SVR are related to both viral and host factors. Moreover, low enrollment rates in clinical trials hamper the study of the efficacy of anti-viral therapy. Nevertheless, the gap in SVR between African Americans and Caucasians may be narrowing with the use of direct-acting agents. Gastroenterologists, hepatologists, primary care physicians, and other health-care providers need to address modifiable risk factors that affect the natural history, as well as treatment outcomes, for HCV among African Americans. Efforts need to be made to improve awareness among health-care providers to address the differences in screening and referral patterns for African Americans.

  5. The African Pediatric Fellowship Program: Training in Africa for Africans.

    PubMed

    Wilmshurst, Jo M; Morrow, Brenda; du Preez, Avril; Githanga, David; Kennedy, Neil; Zar, Heather J

    2016-01-01

    Africa has a significant burden of childhood disease, with relatively few skilled health care professionals. The African Paediatric Fellowship Programme was developed by the Department of Pediatrics and Child Health at the University of Cape Town to provide relevant training for African child health professionals, by Africans, within Africa. Trainees identified by partner academic institutions spend 6 months to 2 years training in the Department of Pediatrics and allied disciplines. They then return to their home institution to build practice, training, research, and advocacy. From 2008 to 2015, 73 physicians have completed or are completing training in general pediatrics or a pediatric subspecialty. At 1 year posttraining, 98% to 100% are practicing back in their home institution. The impact of the returning fellows is evident from their practice interventions, research collaborations, and positions as stakeholders who can change health care policies. Thirty-three centers in 13 African countries are partners with the program, and the program template is now followed by other partner sites in Africa. Increasing and retaining the skills pool of African child health specialists is building a network of motivated, highly skilled clinicians who are equipped to advance child health in Africa. PMID:26659458

  6. The African Pediatric Fellowship Program: Training in Africa for Africans.

    PubMed

    Wilmshurst, Jo M; Morrow, Brenda; du Preez, Avril; Githanga, David; Kennedy, Neil; Zar, Heather J

    2016-01-01

    Africa has a significant burden of childhood disease, with relatively few skilled health care professionals. The African Paediatric Fellowship Programme was developed by the Department of Pediatrics and Child Health at the University of Cape Town to provide relevant training for African child health professionals, by Africans, within Africa. Trainees identified by partner academic institutions spend 6 months to 2 years training in the Department of Pediatrics and allied disciplines. They then return to their home institution to build practice, training, research, and advocacy. From 2008 to 2015, 73 physicians have completed or are completing training in general pediatrics or a pediatric subspecialty. At 1 year posttraining, 98% to 100% are practicing back in their home institution. The impact of the returning fellows is evident from their practice interventions, research collaborations, and positions as stakeholders who can change health care policies. Thirty-three centers in 13 African countries are partners with the program, and the program template is now followed by other partner sites in Africa. Increasing and retaining the skills pool of African child health specialists is building a network of motivated, highly skilled clinicians who are equipped to advance child health in Africa.

  7. East African Rift

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Places where the earth's crust has formed deep fissures and the plates have begun to move apart develop rift structures in which elongate blocks have subsided relative to the blocks on either side. The East African Rift is a world-famous example of such rifting. It is characterized by 1) topographic deep valleys in the rift zone, 2) sheer escarpments along the faulted walls of the rift zone, 3) a chain of lakes within the rift, most of the lakes highly saline due to evaporation in the hot temperatures characteristic of climates near the equator, 4) voluminous amounts of volcanic rocks that have flowed from faults along the sides of the rift, and 5) volcanic cones where magma flow was most intense. This example in Kenya displays most of these features near Lake Begoria.

    The image was acquired December 18, 2002, covers an area of 40.5 x 32 km, and is located at 0.1 degrees north latitude, 36.1 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  8. An African ethic for nursing?

    PubMed

    Haegert, S

    2000-11-01

    This article derives from a doctoral thesis in which a particular discourse was used as a 'paradigm case'. From this discourse an ethic set within a South African culture arose. Using many cultural 'voices' to aid the understanding of this narrative, the ethic shows that one can build on both a 'justice' and a 'care' ethic. With further development based on African culture one can take the ethic of care deeper and reveal 'layers of understanding'. Care, together with compassion, forms the foundation of morality. Nursing ethics has followed particular western moral philosophers. Often nursing ethics has been taught along the lines of Kohlberg's theory of morality, with its emphasis on rules, rights, duties and general obligations. These principles were universalistic, masculine and noncontextual. However, there is a new ethical movement among Thomist philosophers along the lines to be expounded in this article. Nurses such as Benner, Bevis, Dunlop, Fry and Gadow--to name but a few--have welcomed the concept of an 'ethic of care'. Gilligan's work gave a feminist view and situated ethics in the everyday aspects of responsiveness, responsibility, context and concern. Shutte's search for a 'philosophy for Africa' has resulted in finding similarities in Setiloane and in Senghor with those of Thomist philosophers. Using this African philosophy and a research participant's narrative, an African ethic evolves out of the African proverb: 'A person is a person through other persons', or its alternative rendering: 'I am because we are: we are because I am.' This hermeneutic narrative reveals 'the way affect imbues activity with ethical meaning' within the context of a black nursing sister in a rural South African hospital. It expands upon the above proverb and incorporates the South African constitutional idea of 'Ubuntu' (compassion and justice or humanness).

  9. African American Males. A Critical Link in the African American Family.

    ERIC Educational Resources Information Center

    Jones, Dionne J., Ed.

    African Americans are experiencing extreme stress in the United States, and African-American males appear to suffer the most. The chapters in this volume examine some of the issues confronting African-American men today. They include: (1) "Introduction" (Dionne J. Jones); (2) "Reaffirming Young African American Males: Mentoring and Community…

  10. African American Preschoolers' Language, Emergent Literacy Skills, and Use of African American English: A Complex Relation

    ERIC Educational Resources Information Center

    Connor, Carol McDonald; Craig, Holly K.

    2006-01-01

    Purpose: This study examined the relation between African American preschoolers' use of African American English (AAE) and their language and emergent literacy skills in an effort to better understand the perplexing and persistent difficulties many African American children experience learning to read proficiently. Method: African American…

  11. African horse sickness.

    PubMed

    Mellor, Philip Scott; Hamblin, Christopher

    2004-01-01

    African horse sickness virus (AHSV) causes a non-contagious, infectious insect-borne disease of equids and is endemic in many areas of sub-Saharan Africa and possibly Yemen in the Arabian Peninsula. However, periodically the virus makes excursions beyond its endemic areas and has at times extended as far as India and Pakistan in the east and Spain and Portugal in the west. The vectors are certain species of Culicoides biting midge the most important of which is the Afro-Asiatic species C. imicola. This paper describes the effects that AHSV has on its equid hosts, aspects of its epidemiology, and present and future prospects for control. The distribution of AHSV seems to be governed by a number of factors including the efficiency of control measures, the presence or absence of a long term vertebrate reservoir and, most importantly, the prevalence and seasonal incidence of the major vector which is controlled by climate. However, with the advent of climate-change the major vector, C. imicola, has now significantly extended its range northwards to include much of Portugal, Spain, Italy and Greece and has even been recorded from southern Switzerland. Furthermore, in many of these new locations the insect is present and active throughout the entire year. With the related bluetongue virus, which utilises the same vector species of Culicoides this has, since 1998, precipitated the worst outbreaks of bluetongue disease ever recorded with the virus extending further north in Europe than ever before and apparently becoming endemic in that continent. The prospects for similar changes in the epidemiology and distribution of AHSV are discussed.

  12. African N Assessment

    NASA Astrophysics Data System (ADS)

    Bekunda, M.; Galford, G. L.; Hickman, J. E.; Palm, C.

    2011-12-01

    Africa's smallholder agricultural systems face unique challenges in planning for reducing poverty, concurrent with adaptation and mitigation to climate change. At continental level, policy seeks to promote a uniquely African Green Revolution to increase crop yields and food production, and improve local livelihoods. However, the consequences on the environment and climate are not clear; these pro-economic development measures should be linked to climate change adaptation and mitigation measures, and research is required to help achieve these policy proposals by identifying options, and testing impacts. In particular, increased nitrogen (N) inputs are essential for increasing food production in Africa, but are accompanied by inevitable increases in losses to the environment. These losses appear to be low at input levels promoted in agricultural development programs, while the increased N inputs both increase current food production and appear to reduce the vulnerability of food production to changes in climate. We present field and remote sensing evidence from Malawi that subsidizing improved seed and fertilizers increases resilience to drought without adding excess N to the environment. In Kenya, field research identified thresholds in N2O losses, where emissions are very low at fertilization rates of less than 200 kg ha-1. Village-scale models have identified potential inefficiencies in the food production process where the largest losses of reactive N occur, and which could be targeted to reduce the amount of N released to the environment. We further review some on-going research activities and progress in Africa that compare different methods of managing resources that target resilience in food production and adaptation to climate change, using nutrient N as an indicator, while evaluating the effects of these resource management practices on ecosystems and the environment.

  13. Effects of Tityus serrulatus scorpion venom and its toxin TsTX-V on neurotransmitter uptake in vitro

    SciTech Connect

    Cecchini, Alessandra L.; Vasconcelos, Flavio; Giglio, Jose Roberto; Arantes, Eliane Candiani . E-mail: ecabraga@fcfrp.usp.br

    2006-12-01

    Scorpion neurotoxins targeting the Na{sub v} channel can be classified into two classes: {alpha}- and {beta}-neurotoxins and are reported as highly active in mammalian brain. In this work, we evaluate the effects of Tityus serrulatus venom (Ts venom) and its {alpha}-neurotoxin TsTX-V on {gamma}-aminobutyric acid (GABA), dopamine (DA) and glutamate (Glu) uptake in isolated rat brain synaptosomes. TsTX-V was isolated from Ts venom by ion exchange chromatography followed by reverse-phase (C18) high-performance liquid chromatography. Neither Ts venom nor TsTX-V was able to affect {sup 3}H-Glu uptake. On the other hand, Ts venom (0.13 {mu}g/mg) significantly inhibited both {sup 3}H-GABA and {sup 3}H-DA uptake ({approx} 50%). TsTX-V showed IC{sub 5} values of 9.37 {mu}M and 22.2 {mu}M for the inhibition of {sup 3}H-GABA and {sup 3}H-DA uptake, respectively. These effects were abolished by pre-treatment with tetrodotoxin (TTX, 1 {mu}M), indicating the involvement of voltage-gated Na{sup +} channels in this process. In the absence of Ca{sup 2+}, and at low Ts venom concentrations, the reduction of {sup 3}H-GABA uptake was not as marked as in the presence of Ca{sup 2+}. TsTX-V did not reduce {sup 3}H-GABA uptake in COS-7 cells expressing the GABA transporters GAT-1 and GAT-3, suggesting that this toxin indirectly reduces the transport. The reduced {sup 3}H-GABA uptake by synaptosomes might be due to rapid cell depolarization as revealed by confocal microscopy of C6 glioma cells. Thus, TsTX-V causes a reduction of {sup 3}H-GABA and {sup 3}H-DA uptake in a Ca{sup 2+}-dependent manner, not directly affecting GABA transporters, but, in consequence of depolarization, involving voltage-gated Na{sup +} channels.

  14. Very small and soft scorpionates: water stable technetium tricarbonyl complexes combining a bis-agostic (k(3)-H, H, S) binding motif with pendant and integrated bioactive molecules.

    PubMed

    Maria, Leonor; Paulo, António; Santos, Isabel C; Santos, Isabel; Kurz, Philipp; Spingler, Bernhard; Alberto, Roger

    2006-11-15

    The novel trihydro(mercaptoazolyl)borates Na[H(3)B(tim(Me))] (L(1)) (tim(Me) = 2-mercapto-1-methylimidazolyl), Na[H(3)B(tim(Bupip))] (L(2)) (tim(Bupip) = 1-[4-((2-methoxyphenyl)-1-piperazinyl)butyl]-2-mercaptoimidazolyl), and Na[H(3)B(bzt)] (L(3)) (bzt = 2-mercaptobenzothiazolyl) were synthesized by reaction of NaBH(4) with the corresponding azole. Ligands L(1)-L(3) represent a new class of light and soft scorpionates that stabilizes the [M(CO)(3)](+) core (M = (99)Tc, Re) by formation of the complexes fac-[M{kappa(3)-H(mu-H)(2)B(tim(Me))}(CO)(3)] (M = (99)Tc (1), Re (2)), fac-[Re{kappa(3)-H(mu-H)(2)B(tim(Bupip))}(CO)(3)] (3), and fac-[Re{kappa(3)-H(mu-H)(2)B(bzt)}(CO)(3)] (4), respectively. The soft scorpionates are coordinated to the metal in unique (kappa(3)-H, H', S) fashion, as confirmed by X-ray crystallography of 1, 2, and 4. These complexes with bis-agostic hydride coordination are formed in aqueous solution with the two hydrides replacing two coordinating aquo ligands. The agostic hydrogen atoms were located directly, confirming an unprecedented donor atom set combining one sulfur and two hydrogen atoms. Preliminary studies have shown the possibility of preparing some of these complexes at the no carrier added level ((99m)Tc), under conditions as required in radiopharmaceutical preparation. Due to their lipophilicity, small-size, and easy functionalization with adequate biomolecules, the trihydro(mercaptoazolyl)borate technetium tricarbonyl complexes are suitable for the design of CNS receptor ligand radiopharmaceuticals as exemplified with 3, comprising a pendant serotonergic 5-HT(1A) ligand. The integrated design of radiopharmaceuticals involving a bis-agostic scorpionate ligand is demonstrated by the synthesis of 4, with an integrated benzothiazolyl fragment for the recognition of beta-amyloid plaques.

  15. African Perceptions of Female Attractiveness

    PubMed Central

    Coetzee, Vinet; Faerber, Stella J.; Greeff, Jaco M.; Lefevre, Carmen E.; Re, Daniel E.; Perrett, David I.

    2012-01-01

    Little is known about mate choice preferences outside Western, educated, industrialised, rich and democratic societies, even though these Western populations may be particularly unrepresentative of human populations. To our knowledge, this is the first study to test which facial cues contribute to African perceptions of African female attractiveness and also the first study to test the combined role of facial adiposity, skin colour (lightness, yellowness and redness), skin homogeneity and youthfulness in the facial attractiveness preferences of any population. Results show that youthfulness, skin colour, skin homogeneity and facial adiposity significantly and independently predict attractiveness in female African faces. Younger, thinner women with a lighter, yellower skin colour and a more homogenous skin tone are considered more attractive. These findings provide a more global perspective on human mate choice and point to a universal role for these four facial cues in female facial attractiveness. PMID:23144734

  16. Plio-pleistocene African climate

    SciTech Connect

    deMenocal, P.B.

    1995-10-06

    Marine records of African climate variability document a shift toward more arid conditions after 2.8 million years ago (Ma), evidently resulting from remote forcing by cold North Atlantic sea-surface temperatures associated with the onset of Northern Hemisphere glacial cycles. African climate before 2.8 Ma was regulated by low-latitude insolation forcing of monsoonal climate due to Earth orbital precession. Major steps in the evolution of African hominids and other vertebrates are coincident with shifts to more arid, open conditions near 2.8 Ma, 1.7 Ma, and 1.0 Ma, suggesting that some Pliocene (Plio)-Pleistocene speciation events may have been climatically mediated. 65 refs., 6 figs.

  17. Plio-Pleistocene African Climate

    NASA Astrophysics Data System (ADS)

    Demenocal, Peter B.

    1995-10-01

    Marine records of African climate variability document a shift toward more arid conditions after 2.8 million years ago (Ma), evidently resulting from remote forcing by cold North Atlantic sea-surface temperatures associated with the onset of Northern Hemisphere glacial cycles. African climate before 2.8 Ma was regulated by low-latitude insolation forcing of monsoonal climate due to Earth orbital precession. Major steps in the evolution of African hominids and other vertebrates are coincident with shifts to more arid, open conditions near 2.8 Ma, 1.7 Ma, and 1.0 Ma, suggesting that some Pliocene (Plio)-Pleistocene speciation events may have been climatically mediated.

  18. West African crude production diversifies

    SciTech Connect

    Aalund, L.

    1983-06-01

    Nigeria, with its seven crude-oil export streams, dominated West African production and accounted for over 70% of the depressed 1.8 million b/d output from the region last year. However, during the 1970s a flurry of new producing fields, primarily off the African coast, diversified production among a number of countries and touched off a wave of oil activity. The Journal takes a close look at the quality of West African oil in this installment of assays on world export crudes. This issue covers, in alphabetical order, Bonny Light (Nigeria) to Espoir (Ivory Coast). A following issue will wrap up West Africa by presenting assays on crudes from Forcados Blend (Nigeria) to Zaire Crude (Zaire).

  19. The African Cultural Astronomy Project

    NASA Astrophysics Data System (ADS)

    Urama, Johnson O.; Holbrook, Jarita C.

    2011-06-01

    Indigenous, endogenous, traditional, or cultural astronomy focuses on the many ways that people and cultures interact with celestial bodies. In most parts of Africa, there is very little or no awareness about modern astronomy. However, like ancient people everywhere, Africans wondered at the sky and struggled to make sense of it. The African Cultural Astronomy Project aims to unearth the body of traditional knowledge of astronomy possessed by peoples of the different ethnic groups in Africa and to consider scientific interpretations when appropriate for cosmogonies and ancient astronomical practices. Regardless of scientific validity, every scientist can relate to the process of making observations and creating theoretical mechanisms for explaining what is observed. Through linking the traditional and the scientific, it is believed that this would be used to create awareness and interest in astronomy in most parts of Africa. This paper discusses the vision, challenges and prospects of the African Cultural Astronomy Project in her quest to popularize astronomy in Africa.

  20. The African American Image in American Cinema.

    ERIC Educational Resources Information Center

    Bourne, St. Clair

    1990-01-01

    Political conditions have influenced the screen images of U.S. cinema, and the images of African Americans have reflected prevailing social stereotypes. The history of African-American representation in films is traced, and it is noted that the tendency to portray African Americans stereotypically has not changed. (SLD)