Preparation and in vitro characterization of chitosan nanoparticles containing Mesobuthus eupeus scorpion venom as an antigen delivery system

Hydrophilic nanoparticles have been widely investigated in recent years as delivery systems for therapeutic macromolecules such as antigens. In the present study Mesobuthus eupeus venom-loaded chitosan nanoparticles were prepared via ionic gelation of tripolyphosphate (TPP) and chitosan. The optimum encapsulation efficiency (91.1 percent) and loading capacity (76.3 percent) were obtained by a chitosan concentration of 2 mg/mL, chitosan-to-TPP mass ratio of 2 and M. eupeus venom concentration of 500 µg/mL. The average nanoparticle size at optimum conditions was determined by Zetasizer (Malvern Instruments, UK). The nanoparticle size was about 370 nm (polydispersity index: 0.429) while the zeta potential was positive. Transmission electron microscope (TEM) imaging showed a spherical, smooth and almost homogenous structure for nanoparticles. Fourier transform infrared (FTIR) spectroscopy confirmed tripolyphosphoric groups of TPP linked with ammonium groups of chitosan in the nanoparticles. The in vitro release of nanoparticles showed an initial burst release of approximately 60 percent in the first ten hours, followed by a slow and much reduced additional release for about 60 hours. It is suggested that the chitosan nanoparticles fabricated in our study may provide a suitable alternative to traditional adjuvant systems.(AU)

Epidemiological aspects of scorpion stings in Al-Jouf Province, Saudi Arabia

Information on scorpion stings is available for many parts of Saudi Arabia, but not for Al-Jouf Province. We reviewed and analyzed 1449 cases of scorpion stings that presented to the emergency department of the hospitals and medical centers in Al-Jouf Province during a 2-year period [2005-2006]. The majority of patients [92.7%] manifested class I envenomation with local pain at the sting site as the primary complaint. Systemic toxicity was noticed in 7.3% of cases but no deaths were reported. Scorpion stings were recorded throughout the year with the highest seasonal incidence in the summer [64.3%] and the lowest during the winter [10.6%]. The highest monthly incidence was in June [21.5%] and the lowest in December [1.5%]. Most of the patients were male [77.3%] and the age of 44.2% of victims ranged between 15 to 30 years. Diurnal stings exceeded the nocturnal ones with a ratio of 3:2, and most of the stings were located mainly on the exposed limbs [88.6%], especially the lower limbs [51.7%]. Leiurus quinquestriatus and Androctonus crassicc cauda were incriminated in most recorded cases. Our findings indicate that scorpion stings are common in Al-Jouf Province, especially during the summer. The overall threat to human health was found to be low

Utility of scorpion antivenin vs prazosin in the management of severe Mesobuthus tamulus (Indian red scorpion) envenoming at rural setting.

BACKGROUND : Scorpion antivenom (SAV) is specific antidote to scorpion venom..SAV did not prevent the cardiovascular morbidity and mortality (autonomic storm), hence its utility in the management for severe scorpion envenomingmay be limited. Since 1983 the advent of prazosin revolutionized the management of severe scorpion sting. Since 2002 SAV against Indian red scorpion (IRS) for the treatment of scorpion sting cases is available at primary health centers. We compared the effects of SAV Vs Prazosin (PRA) in the management of severe scorpion stung cases at rural setting in a non-randomised open label manner. METHODS : From January 2002 to December 2004, 53 patients accidentally stung by scorpion were admitted in hospital at Mahad. Of these 25 patients received intravenous SAV at primary health centers and were referred to Mahad for further management. 28 patients directly reported to Mahad were treated with oral prazosin (PRA). Time interval between sting and hospitalization, the total dose of SAV and PRA administered was noted. Clinical manifestations were noted in a standard protocol. Details of SAV patients were noted from referred letters or in case of a doubt, details were obtained by direct communication with the medical officer who first saw and examined the case. All 53 cases were evaluated clinically for improvement, deterioration or fatal outcome. RESULTS : SAV Vs PRA ( 25 Vs 28) cases reported to hospital within 11/2 -3 (1.4) Vs 1/2-4 (1.3) hours after stung. On arrival 21 (84%) Vs 26 (92%) had hypertension, 2 (8%) Vs 1 (3.5%) had hypotension, 2 (8%)Vs 1 (3.5%) had normal blood pressure. Heart rate 58-102 (82) Vs 48-120 (80.2) respectively. 9 cases received 20 ml, 1 case 30 ml and remaining 15 cases were given 10 ML of SAV on arrival to PHC, while 28 cases received oral prazosin. 20 (80%) Vs 2 (7.5%) had acute pulmonary edema, 5 (20%) Vs 8 (30%) had persistent raised blood pressure. 4 (16%) Vs 0% died. Recovery time was 11-4 (2.26) Vs 1-2 (1.25) days respectively. CONCLUSION : We found that SAV is no more effective to alleviate or reverse the cardiovascular effects of scorpion venom actions in severe case as against prazosin prevents and cures the cardiovascular manifestations in a severe scorpion envenomation. Therefore role of SAV in severe scorpoin venomation needs to be relooked and prazosin needs to be a standard of care in such cases to overcome the autonomic storm.

O íon magnésio no tratamento de acidentes causados pelos escorpiöes Tityus serrulatus, T. bahiensis e Centruroides sculpturatus: estudo experimental / Magnesium in the treatment of accidents caused by the scorpions Tityus serrulatus, T. bahiensis and Centruroides sculpturatus: an experimental study

Os efeitos produzidos pelas peçonhas escorpiônicas säo consequentes, em sua maioria, à liberaçäo de acetilcolina (ACh) e catecolaminas. A verificaçäo de que o magnésio (Mg2+) inibe a liberaçäo de ACh em razäo de bloquear o influxo de cálcio nas terminaçöes nervosas, levou-nos a investigar a açäo deste cátion sobre os distúrbios produzidos pelas peçonhas escorpiônicas. Relatamos na presente comunicaçäo a açäo do Mg2+ sobre os efeitos induzidos pelas peçonhas dos escorpiöes Tityus serrulatus, T. bahiensis e Centruroides sculpturatus nas preparaçöes isoladas nervo frênico-diafragma, íleo, canal deferente e átrios de rato e in vivo, em ratos anestesiados com registro da pressäo arterial e do eletrocardiograma. Os efeitos da peçonha dos escorpiöes nas preparaçöes isoladas foram abolidos ou muito atenuados pelo Mg2+. O Mg2+, no entanto, somente antagonizou os efeitos da peçonha de C. sculpturatus no íleo de rato. Em ratos anestesiados, a hipertensäo e arritmias provocadas pela peçonha de T. serrulatus foram revertidas com exclusäo de bradicardia pela injeçäo do Mg2+. A peçonha de C. sculpturatus na maioria das experiências causou hipotensäo e arritmias de pequena gravidade. O Mg2+ reverteu as arritmias, mas causou quedas acentuadas da pressäo arterial. Os resultados da pesquisa sugerem o emprego do Mg2+ em acidentes graves na ausência de hipotensäo e bradicardia, produzidos por T. serrulatus e T. bahiensis. Parece contra-indicado nos acidentes causados por C. sculpturatus em vista de seu efeito acima referido na pressäo arterial.

Preparation of a potent anti-scorpion-venom-serum against the venom of red scorpion (Buthus tamalus).

A number of children and adults, especially pregnant women succumb to the sting by red Scorpion (Buthus tamalus) in Konkan region--particularly on the coastal line. No specific antiserum or any other antidote is available to treat a victim of scorpion bite and hence the need to prepare a potent antiserum. Red Scorpion (B. tamalus) venom is a mixture of a number of protein moieties and neurotoxins of low molecular weight. Therefore, the venom is poor in antigenic composition and it is difficult to get antibodies specific to neutralise lethal factor/factors. Using Bentonite as an adjuvant and extending the period of immunization a potent antiserum has been prepared capable of neutralising the lethal factor/factors. In vivo testing carried out in albino mice, guinea pigs, dogs and langurs confirms this finding and shows that the antiserum is quite effective in neutralising the scorpion venom to save the life of envenomated animals.

A comparative study of severe scorpion envenomation in children caused by Tityus bahiensis and Tityus serrulatus

No periodo de janeiro de 1984 a maio de 1994, de 239 criancas com ate 15 anos de idade, picadas por escorpioes pertencentes as especies T. bahiensis (84,9 por cento) e T. serrulatus (15,1 por cento), 17 apresentaram envenenamento grave...

Insulin administration reverses the metabolic and electrocardiographic changes in acute myocarditis induced by Indian red scorpion (Buthus tamulus) venom in experimental dogs.

Acute myocarditis was produced by injection of 4 mg/kg Indian red scorpion (Buthus tamulus) venom in dogs. Several rhythm changes, conduction defects, infarction-like pattern and many other ECG abnormalities; hyperglycemia, reduced insulin secretion, rise in free fatty acids along with fall in triglycerides; depletion of glycogen content of atria, ventricles, liver and skeletal muscles was noticed within 20-30 minutes after scorpion envenomation. Ten units of crystalline insulin was given i.v. at this time. All the arrhythmias, conduction defects and other ECG abnormalities disappeared after intervention with insulin. The sinus rhythm persisted for a duration of 120 minutes till the animals were sacrificed. Reduction in free fatty acids along with a rise in triglycerides; glycogenesis in liver, cardiac and skeletal muscles was observed at the time when ECG tracing was normal. It is suggested that catecholamines released during autonomic storm in scorpion poisoning suppress insulin secretion. These in turn result in glycogenolysis; lipolysis resulting in increased free fatty acids and produce arrhythmias. Insulin administration results in glycogenesis; lipogenesis and stops arrhythmias.

Comparative detoxification and protection of scorpion (Heterometrus bengalensis) venom by toxoid antiserum.

Comparative detoxification of scorpion venom by using different chemical agents was investigated. Detoxification by formalin showed the best optimum detoxifying agent. The formalin treatment resulted in 2.3% protein loss with 6-fold detoxification. This formal toxoid was immunogenic in rabbit giving high neutralizing antibodies as revealed from indirect haemagglutination test. Toxoid antiserum protected mice against the lethal action of venom. It also effectively antagonized the smooth muscle contractile response of venom, and venom-induced neuromuscular paralysis. This toxoid antiserum also protected the venom-induced cardiac arrest. The possibility of using this formal toxoid for antisera production and immunization for therapeutic use needs to be explored.