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PubMed2002

The venom optimisation hypothesis: a spider injects large venom quantities only into difficult prey types.

The spider Cupiennius salei needs 0.01-10 microl venom to kill a prey item. Since its venom glands contain only 10 microl and regeneration requires 8-16 days C. salei should use its venom very economically. By a monoclonal antibody we measured, for the first time, the amounts of venom injected by a spider into different prey types. Crickets and stick insects, as victims without special defence mechanism, received only the minimum amount of venom which is not significantly different from the LD(50). Blowflies and ground beetles received considerably more venom because they are difficult to overwhelm or even endanger the spider by their defence behaviour. These results support our venom optimisation hypothesis which supposes that spiders use their venom as economically as possible.

Animals↗
PubMed1998

Pharmacokinetics of 125I-labelled Walterinnesia aegyptia venom and its distribution of the venom and its toxin versus slow absorption and distribution of IGG, F(AB')2 and F(AB) of the antivenin.

A three-compartment open pharmacokinetic model best fitted the data obtained following the i.v. injection of the venom, toxin and the immunoglobulin fractions into either rabbits or mice. The venom and toxin, however, possessed pharmacokinetic characteristics that were significantly different from the immunoglobulin fractions. The venom and toxin had very highly significantly greater disposition rate constants to the shallow and deep tissue compartments and overall elimination rate constant from the central compartment than any of the immunoglobulin fractions. This was reflected in other pharmacokinetic parameters, including highly significantly smaller areas under the curve (AUC) and highly significantly greater volumes of the central compartment (Vc), shallow tissue compartment (Vt shallow), deep tissue compartment (Vt deep) and total body clearance (TBC). In rabbits, F(ab')2 possessed the fastest disposition rate constants and the shortest distribution half-lives, while Fab showed the slowest disposition rate constants and the longest distribution half-lives. The same picture occurred in mice except that the values for Fab were between those of F(ab')2 and IgG. The time needed by the venom and toxin to reach maximum tissue concentration (tmax) ranged between 7 and 15 min and 60 and 180 min for the shallow and deep tissue compartments, respectively. The immunoglobulin fractions required 8-26-fold these times to attain tmax; F(ab')2 was the fastest to achieve its maximal concentration. Following i.m. injection, very fast absorption of venom and toxin took place, with the toxin reaching tmax within 5-20 min and 90% of the injected dose absorbed within 60 min. The bioavailability factor (F) was 0.82 and 0.88 for the venom and toxin, respectively. Fab had an F-value of 0.36 and required 4.3 and 47.4-fold the time taken by the venom and toxin to achieve tmax. The calculated values of F for F(ab')2 and IgG were 0.25 and 0.26, respectively. In the physiologically based pharmacokinetics (PBPK), the venom and toxin reached tmax in the different organs studied very rapidly while the immunoglobulin fractions required several-fold this time to attain tmax. F(ab')2 possessed the highest CPmax, the smallest AUC and the shortest t1/2 beta in the different tissues; Fab had values between F(ab)2 and IgG. It is concluded that F(ab')2 possesses pharmacokinetic characteristics that render it most suitable for use in serotherapy of snake and scorpion envenoming. It should be injected i.v. in doses higher than calculated neutralizing doses to compensate for the slow rate of distribution. Because of slow and incomplete absorption, the i.m. injection of the immunoglobulin fractions would be of little value in serotherapy.

Absorption↗
PubMed1999

Antibodies against Tityus discrepans venom do not abolish the effect of Tityus serrulatus venom on the rat sodium and potassium channels.

Anti-(Tityus serrulatus + Tityus bahiensis) and anti-Tityus discrepans venom polyclonal antisera were used to investigate whether antigenic differences exist between the venoms of the Brazilian T. serrulatus and the Venezuelan T. discrepans scorpions. Both antisera recognised the toxin-containing electrophoretic fractions of their cognate venoms and also those from Tityus zulianus and Tityus trinitatis venoms on Western blots. The anti-T. discrepans antiserum reacted only weakly with T. serrulatus toxic polypeptides. The effect of T. serrulatus alpha- or beta-toxins on rat skeletal muscle Na+ channels expressed in Xenopus laevis oocytes was abolished by pre-incubating the venom with anti-(T. serrulatus + T. bahiensis) serum but not with anti-T. discrepans serum. Nor did the Brazilian or the Venezuelan sera prevent the reduction in K+ currents by T. serrulatus venom in X. laevis oocytes expressing the rat brain delayed rectifying Shaker K+ channel (Kv1.2). These results indicate that toxins from T. serrulatus and T. discrepans venoms, which primarily target mammalian Na+ channels, are antigenically distinct, although they probably share common epitopes. Our results also suggest that Na+ channel-active toxins are the immunodominant antigens of the T. serrulatus venom.

Animals↗
PubMed2000

Detection of nerve growth factor (NGF) in venoms from diverse source: isolation and characterization of NGF from the venom of honey bee (Apis melifera).

Pearce (1973) reported the absence of NGF in the venoms of bees, scorpions, spiders, and toads. Contrary to the negative findings in the past, results of this research prove the presence of NGF in bee and scorpion venoms. Venoms from various species of snake, bee, scorpion, and toad were screened by two methods: immunological test ELISA using antibodies versus mouse NGF and venom NGF and the biological test of neurite outgrowth, the characteristic of NGF on PC cells. The presence of NGF was detected in snake, bee, and scorpion venoms, but not in toad venom by these tests. NGF was isolated from bee venom by HPLC fractionation using ion exchange chromatography. The molecular weight of bee NGF was found to be 14.0 kDa resolving into a single band by PAGE. The biological activity of bee NGF on PC12 cells was found to be 1/10 of the venom NGF.

Animals↗
PubMed2026

Venomous Lepidoptera: defensive toxin systems, venom composition, and clinical significance.

Venomous Lepidoptera constitute an underrecognized yet medically significant group of toxin-producing arthropods that employ contact-mediated defensive envenomation through specialized integumentary structures such as setae, spines, and scoli. Unlike actively stinging arthropods, these insects deliver venom passively upon contact, eliciting a diverse spectrum of clinical manifestations collectively termed lepidopterism. Clinical outcomes range from localized pain and dermatitis to severe systemic effects, including hemorrhagic syndromes, complement activation, and chronic inflammatory disorders. Recent advances in proteomic and transcriptomic technologies have transformed our understanding of lepidopteran venoms, revealing unexpectedly complex toxin repertoires comprising serine proteases, phospholipases, pore-forming proteins, disulfide-rich peptides, neuroactive RF-amide peptides, and immune-modulating components. These findings have provided new insights into the molecular basis of toxicity, host-pathogen interactions, and the evolutionary diversification of venom systems within Lepidoptera. This review synthesizes current knowledge on the morphology of venom-delivery structures, venom composition, mechanisms of action, and associated clinical manifestations, while highlighting medically important taxa, particularly species of the genus Lonomia. The successful development of antivenom against Lonomia envenomation underscores the translational relevance of lepidopteran toxin research and its potential for therapeutic innovation. By integrating molecular, clinical, and evolutionary perspectives, this review repositions venomous Lepidoptera as a legitimate and important component of arthropod toxinology. Furthermore, it identifies critical methodological limitations and key knowledge gaps, providing a framework for future investigations aimed at advancing our understanding of toxin biology, immunopathology, and the development of novel biomedical applications.

Animals↗
PubMed1989

Inhibition of human platelet aggregation and secretion by ant venom and a compound isolated from venom.

Venom from the tropical ant, Pseudomyrmex triplarinus, has activity against rheumatoid arthritis. Since platelets are involved in inflammatory responses, they were employed to study the effects of venom on prostaglandin-dependent human platelet aggregation and secretion. The assay is very sensitive and uses microliter volumes, which makes it useful as a screen during isolation and characterization of venom components. Whole venom inhibited arachidonic acid- and U46619-induced platelet aggregation with IC50s of 45 and 39 micrograms/ml, respectively. This suggested that venom prevented the action of prostaglandins. Pure venom was fractionated by gel filtration and at least three materials with antiplatelet activity were detected. The smallest component (factor F) was most active and was purified by additional molecular filtration and characterized by UV absorbance, thin-layer chromatography, nuclear magnetic resonance spectra, and activity to platelets. Factor F was identified as adenosine, which is known to stimulate platelet adenylate cyclase and has not been previously reported to be a component of insect venom.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1992

Immunotherapy with honeybee venom and yellow jacket venom is different regarding efficacy and safety.

Venom immunotherapy (VIT) for Hymenoptera allergy is accepted as safe and effective. However, widely varying success rates and frequencies of side effects are reported. Differences between various Hymenoptera species could account for these diverging results. We therefore analyzed 205 patients with a history of systemic allergic reactions to either honeybee (148 patients) or yellow jacket stings (57 patients) during VIT. All patients had a positive skin test to the respective venom before VIT, were monitored for side effects of VIT, and submitted to a sting challenge while they were receiving VIT. Patients with honeybee-venom allergy had a higher sensitivity in both skin tests (p less than 0.05) and RAST (p less than 0.001) than patients with yellow jacket-venom allergy. They developed systemic side effects to VIT injections significantly more often (41% versus 25%; p less than 0.01) and also reacted more frequently to the sting challenge (23% versus 9%; p less than 0.01) than patients with yellow jacket-venom allergy. We conclude that results obtained from studies on the allergy to one Hymenoptera venom cannot be extrapolated to allergies to other Hymenoptera venoms.

Acute Disease↗
PubMed1989

Kinins in ant venoms--a comparison with venoms of related Hymenoptera.

1. Venom preparations have been made of six ant, one pompilid wasp, two mutillid wasp, and four social wasp species. 2. The venoms were analysed pharmacologically in order to detect kinin-like activity. 3. Due to the small amounts of venoms available only a cascade of smooth muscle preparation could be used. 4. Kinin activities have been found in five ant venoms and in four social wasp venoms. 5. No kinin activity has been found in the venoms of the pompilid and mutillid wasps. 6. All ant venoms also contain unidentified agonists for vertebrate smooth muscle preparations.

Animals↗
PubMed1998

A study on the venom yield of venomous snake species from Argentina.

A study on the venom yield of snakes from Argentina over a three year period was carried out on adult specimens of Bothrops alternatus (n = 74); Bothrops neuwiedii (n = 127); Bothrops ammodytoides (n = 30); Bothrops moojeni (n = 14); Bothrops jararaca (n = 14); B. jararacussu (n = 6); Crotalus durissus terrificus (n = 120) and Micrurus spp. (n = 6) as well as with 12 specimens of newborn C. d. terrificus kept in captivity. While for each species there was a positive correlation between venom yield and number of snakes milked, the correlation with the snake's body weights after individual milkings was even better, suggesting that the size of the snakes is more important in determining the venom yield than the number of snakes milked or the specimen's sex. Individual milkings indicated that, in addition to the snake size, when the amount of venom is normalized per 100 g body weight there is a species specific difference in venom yield. It follows the order B. jararacussu > B. moojeni approximately = B. jararaca approximately = B. alternatus > B. neuwiedii> Micrurus spp approximately = B. ammodytoides> C. d. terrificus. Although the venom yield per 100 g body weight of newborn C. d. terrificus specimens is 2-fold higher than that of adults, no correlation was observed between venom yield and body weight.

Age Factors↗
PubMed1992

Clinical correlation of the venom-specific IgG antibody level during maintenance venom immunotherapy.

Allergen immunotherapy is associated with a significant increase of specific IgG antibodies that have been suggested as a mechanism of action and as a marker of efficacy for immunotherapy. The value of venom-specific IgG antibody determinations as a measure of clinical protection against sting anaphylaxis has been difficult to prove in individual patients. We performed 211 insect sting challenges in 109 patients over a 4-year period to determine the significance of venom IgG levels 3 micrograms/ml or lower. Systemic symptoms occurred in only 1.6% of those with venom IgG more than 3 micrograms/ml, but in 16% of those with less than 3 micrograms/ml IgG, and notably in 26% of patients with low venom IgG who had received less than 4 years of treatment. The venom IgG level had no predictive value in patients who had received more than 4 years of therapy. Honeybee sting data were inconclusive because of the small number of subjects. We conclude that low venom-specific IgG levels are associated with an elevated risk of treatment failure during the first 4 years of immunotherapy with yellow jacket or mixed vespid venoms.

Adult↗
PubMed2005

Proteome analysis of brown spider venom: identification of loxnecrogin isoforms in Loxosceles gaucho venom.

Brown spiders of the Loxosceles genus are distributed worldwide. In Brazil, eight species are found in Southern states, where the envenomation by Loxosceles venom (loxoscelism) is a health problem. The mechanism of the dermonecrotic action of Loxosceles venom is not totally understood. Two isoforms of dermonecrotic toxins (loxnecrogins) from L. gaucho venom have been previously purified, and showed sequence similarities to sphingomyelinase. Herein we employed a proteomic approach to obtain a global view of the venom proteome, with a particular interest in the loxnecrogin isoforms' pattern. Proteomic two-dimensional gel electrophoresis maps for L. gaucho, L. intermedia, and L. laeta venoms showed a major protein region (30-35 kDa, pI 3-10), where at least eight loxnecrogin isoforms could be separated and identified. Their characterization used a combined approach composed of Edman chemical sequencing, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and electrospray ionization-quadropole-time of flight tandem mass spectrometry leading to the identification of sphingomyelinases D. The venom was also pre-fractionated by gel filtration on a Superose 12 fast protein liqiud chromatography column, followed by capillary liquid chromatography-mass spectrometry. Eleven possible loxnecrogin isoforms around 30-32 kDa were detected. The identification of dermonecrotic toxin isoforms in L. gaucho venom is an important step towards understanding the physiopathology of the envenomation, leading to improvements in the immunotherapy of loxoscelism.

Amino Acid Sequence↗
PubMed2005

Snake venomics: comparative analysis of the venom proteomes of the Tunisian snakes Cerastes cerastes, Cerastes vipera and Macrovipera lebetina.

The protein composition of the crude venoms of the three most important vipers of Tunisia was analyzed by RP-HPLC, N-terminal sequence analysis, MALDI-TOF mass determination, and in-gel tryptic digestion followed by PMF and CID-MS/MS of selected peptide ions in a quadrupole-linear IT instrument. Our results show that the venom proteomes of Cerastes cerastes, Cerastes vipera, and Macrovipera lebetina are composed of proteins belonging to a few protein families. However, each venom showed distinct degree of protein composition complexity. The three venoms shared a number of protein classes though the relative occurrence of these toxins was different in each snake species. On the other hand, the venoms of the Cerastes species and Macrovipera lebetina each contained unique components. The comparative proteomic analysis of Tunisian snake venoms provides a comprehensible catalogue of secreted proteins, which may contribute to a deeper understanding of the biological effects of the venoms, and may also serve as a starting point for studying structure-function correlations of individual toxins.

Amino Acid Sequence↗
PubMed2005

Direct vs. mediated effects of scorpion venom: an experimental study of the effects of a second challenge with scorpion venom.

OBJECTIVE: To assess the respective roles of venom and of catecholamines following scorpion envenomation and to verify whether a second challenge with scorpion venom induces the same consequences than a first one. DESIGN AND SETTING: Controlled animal study in a university research laboratory. SUBJECTS: Anesthetized and ventilated dogs. INTERVENTIONS: Fifteen dogs received intravenously a sublethal dose of scorpion venom (0.05 mg/kg). In the reenvenomated group (n=5) a second venom challenge with one-half sublethal venom dose was performed 30 min after the first one. The control group (n=10) received saline. Five additional animals served as sham. MEASUREMENTS AND RESULTS: Plasma toxin and catecholamine levels and a set of usual hemodynamic measurements were repeatedly measured in the first hour following envenomation. In the reenvenomated group another set of measurements was performed 5 min after the second challenge. Changes in toxin, catecholamines, and the main hemodynamic parameters were compared between the study groups. Initial peak toxin levels were similar in the two groups. They induced a striking increase in circulating catecholamines, a fall in heart rate, and an increase in mean arterial and pulmonary artery occluded pressures and in systemic vascular resistance. In the reenvenomated group the second challenge with scorpion venom achieved a toxin blood level similar to the first peak. However, it was not associated with a significant effect either on catecholamines release or on hemodynamics. Subsequent trends in hemodynamic changes were similar to those observed in the control group. CONCLUSIONS: These data emphasize the limited role of direct effects of scorpion venom on the cardiovascular system and the key role of catecholamines.

Animals↗
PubMed1992

The use of enzyme-linked immunosorbent assay for the quantitation of Calloselasma rhodostoma (Malayan pit viper) venom and venom antibodies.

The specificity and sensitivity of an indirect and two (an 'ordinary' and a 'rapid') double sandwich enzyme-linked immunosorbent assay (ELISA) procedures for the quantitation of Calloselasma rhodostoma (Malayan pit viper) venom were examined. The three assays were equally sensitive and the accuracy of the assays was not substantially affected by individual variation in the venom composition. The specificity of the assays was examined against 26 venoms from snakes of the families Viperidae and Elapidae. While the double sandwich ELISA procedures were sufficiently specific to be used in the clinical immunodiagnosis of C. rhodostoma bite in Malaysia, the indirect ELISA procedure exhibited extensive cross-reactivity with other Malaysian pit viper venoms. Attempts were made to improve the specificity of the indirect ELISA procedure for the quantitation of C. rhodostoma venom. A 'low ELISA cross-reactivity' venom fraction (termed VF52) was isolated from C. rhodostoma venom by repeated Sephadex G-100 gel filtration chromatography. The indirect ELISA procedure using antibodies to VF52 as immunoreagent showed an improvement in specificity. The use of the indirect ELISA procedure for the detection of C. rhodostoma antibodies was also examined and the results show that the assay was sufficiently specific to be used for retrospective diagnosis of C. rhodostoma bite in Malaysia, in particular when VF52 was used as the coating antigen.

Antibody Specificity↗
PubMed1986

Evaluation of decline in serum venom-specific IgE as a criterion for stopping venom immunotherapy.

During a 7-year period, venom immunotherapy has been stopped in 57 patients because of a fall in IgE antibody titers to insignificant levels (RAST less than 10% STD). All patients had a history of venom anaphylaxis and elevated venom-specific IgE before therapy. Maintenance doses of 50 micrograms were administered every 4 to 6 weeks; 30 patients received yellow jacket venom, and 16 patients received honeybee venom only. Therapy was stopped after treatment from 1 to 8 years (mean 2.8 years). Repeat skin tests demonstrated an average two-log decrease in sensitivity; 35 of 55 tests remained positive at venom concentrations of less than or equal to 0.1 micrograms/ml. There were 55 re-stings in 24 patients, occurring from 3 months to 5 years after cessation of therapy, resulting in three systemic reactions. One patient, previously treated with bee venom, reacted to a yellow jacket sting. These re-sting reactors also had tolerated several other stings after therapy was stopped. Thus, the two actual reactions represent a "failure" rate of 8% per patient and 4% per sting, compared to reaction rates of 27% and 17% in patients who stopped therapy without physician advice. These data suggest that this criterion may be reliable for stopping therapy. However, subsequent tolerated re-stings may require continued patient evaluation.

Adolescent↗
PubMed2005

Neutralisation of venom-induced haemorrhage by IgG from camels and llamas immunised with viper venom and also by endogenous, non-IgG components in camelid sera.

Envenoming by snakes results in severe systemic and local pathology. Intravenous administration of antivenom, prepared from IgG of venom immunised horses or sheep, is the only effective treatment of systemic envenoming. Conventional antivenoms, formulated as intact IgG, papain-cleaved (Fab) or pepsin-cleaved F(ab')2 fragments, are however ineffective against the local venom effects because of their inability to penetrate the blood/tissue barrier. We have embarked on a new research program to examine (i) whether the unusually small (15 kDa) antigen-binding fragment of camelid heavy chain IgG (V(H)H) can be exploited to neutralise the local effects of envenoming and (ii) whether a novel antivenom to treat both the systemic and local effects of envenoming can be formulated by combining anti-snake venom V(H)H and conventional F(ab')2. In this preliminary study, we demonstrate that camels and llamas respond to immunisation with Echis ocellatus venom with high antibody titres and broad antigen specificity. These encouraging immunological results were matched by the successful elimination of venom-induced haemorrhage by IgG from the venom-immunised camels and llamas. Unexpectedly, we report for the first time that camelid serum contains a non-IgG, highly potent inhibitor of venom-induced haemorrhage.

Animals↗
PubMed1990

The Hymenoptera venom study. III: Safety of venom immunotherapy.

One thousand four hundred ten (44%) of the 3236 subjects in the Hymenoptera venom study accepted venom immunotherapy (VIT). Time to maintenance averaged 95 days, and the largest number achieved maintenance (147 subjects, 10.4%) at day 56. Ninety-two percent of the treated subjects achieved maintenance, and 84% continued therapy, most subjects (91%) until the study was terminated. One hundred seventy-one subjects (12%) experienced 327 treatment systemic reactions (Srs). The incidence of pruritus and angioedema/urticaria was similar with mild, moderate, or severe SRs. The SR severity did not correlate with the severity of the most recent sting before entry into the Hymenoptera-venom study, the most severe historical sting SR, the most severe SR during venom skin tests, the total dose of venom, the degree of skin test reactivity, or the lowest concentration yielding a positive skin test. Most SRs occurred between 1 and 50 micrograms and at maintenance; honeybee or wasp venoms were most likely to produce SR. This study, the largest of its kind with the use of standardized extracts, demonstrates (1) that there was good compliance, (2) that various historical and diagnostic criteria did not predict SRs to VIT, (3) that SRs to VIT were most likely to occur between 1 and 50 micrograms and at maintenance, (4) that honeybee or wasp venoms were most likely to produce an SR, and (5) that VIT is relatively safe.

Animals↗
PubMed1998

Evolution of lymphocyte transformation to wasp venom antigen during immunotherapy for wasp venom anaphylaxis.

BACKGROUND: Venom immunotherapy (VIT) has proven to be safe and effective in wasp venom anaphylaxis. However, there are no good parameters to indicate when to stop venom immunotherapy. OBJECTIVE: To evaluate the relationship of the lymphocyte transformation test (LTT) to history and specific IgE determination, and to address the time course of lymphocyte transformation responses to wasp (Vespula) venom during VIT and the possible utility of LTT to determine the duration of therapy. METHODS: Peripheral blood mononuclear cells (PBMCs) of 18 individuals with a history of wasp sting anaphylaxis and a positive serum-venom-specific IgE, were stimulated with wasp venom before immunotherapy, at the end of a 5-day semi-rush immunotherapy and at 24 months during venom immunotherapy. Results, expressed as stimulation index (SI), were compared with the SI in seven asymptomatic stung controls. RESULTS: In controls the median (minimum-maximum) of the SI were 2.39 (0.52-3.39) before therapy and 2.39 (1.12-6.02) when repeated after 24 months. For patients the median (minimum-maximum) of the SI were 10.13 (1.19-44.88) before immunotherapy (d0), 2.73 (0.67-12.03) at the end of the build-up immunotherapy (d5) and 4.21 (0.88-14.66) at the end of 24 months of maintenance therapy (m24). The proliferation responses in vespid-allergic patients were significantly higher than in stung controls (P = 0.006) but only 13/18 patients showed a positive LTT result before the start of immunotherapy (sensitivity of the LTT 72%). When the LTT was repeated after a 5 day build-up hyposensitization course the SI significantly dropped as compared to the pre-treatment levels (P = 0.002). The SI of the LTT was negative in eight out of 18 patients at 24 months and the median values were significantly lower than before therapy (P = 0.03). CONCLUSIONS: Although, in the absence of sting challenge data it is not possible to draw conclusions about the predictive value of the LTT, our data may suggest that abolition of the LTT during VIT might indicate clinical insensitivity. Further studies, comparing the results of sting challenges, with the results of lymphocyte transformation will be necessary in order to evaluate the role of LTT in stopping immunotherapy.

Adolescent↗