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G Laing

Publications and source records attributed to G Laing.

8 recordsLinked to original sources
PubMed1994

Detection and neutralization of B. jararaca venom in mice.

1. Bothrops jararaca venom was detected by ELISA at different times in the skin, muscle, blood, liver, lung, heart, kidney and spleen of mice injected with venom i.m. or i.d. 2. The results showed that even 10 min after i.m. injection the venom is detected mostly in skin rather than in the muscle of the venom injection site. A small amount of venom was detected in the kidney up to 12 h after im venom injection, and none was detected in tissues of lung, heart, liver or spleen. 3. However, in mice injected i.d., the venom could be detected in the skin up to 24 h after injection. Local necrosis and haemorrhage could be neutralized by antivenom injected by the i.d. or i.v. routes only if the antivenom was given a short time after venom injection, even when antivenom is administered in high concentration. 4. In contrast, experiments performed in mice receiving venom i.d. and treated by i.d. or i.v. routes with antivenom injected at different times after envenoming showed that the effect of venom on blood coagulation could be counteracted by antivenom administered by either route up to 2 h after venom injection. 5. We suggest that a feasible amount of antivenom administered i.d. could be given as a first aid measure after a snake bite accident. However, further experimental studies using the i.d. route for antivenom administration are essential to confirm this possibility.

Animals↗
PubMed1992

Comparison of the purity and efficacy of affinity purified avian antivenoms with commercial equine crotalid antivenoms.

Antivenoms were raised in laying hens by repeated immunizations with detoxified crotalid snake venoms and purified from egg yolks by affinity chromatography. While the affinity purified avian antivenoms were essentially pure IgG, commercial equine (Wyeth) and W.H.O. international reference antivenoms (Trimeresurus flavoviridis) contained several non-immunoglobulin contaminants. In standard mouse protection assays, the purified avian Crotalus atrox and T. flavoviridis antivenoms were 6.3 and 2.0 times as potent, respectively, as these equine antivenoms in neutralizing venom lethality. The purity, efficacy, and ease of manufacture of avian antivenoms, and their inability to fix mammalian complement, make them an attractive alternative to equine and other mammalian antivenoms.

Animals↗
PubMed1992

An affinity purified ovine antivenom for the treatment of Vipera berus envenoming.

A novel antivenom for treating patients with Vipera berus bite has been developed. Sheep are immunised monthly with relatively small amounts of Vipera berus (common adder) venom and the resultant antisera pooled. The immunoglobulin fraction is precipitated with sodium sulphate then cleaved with papain to produce Fab fragments. Finally, those Fab fragments that are directed specifically against components in the venom are purified by affinity chromatography on columns comprising V. berus venom coupled to cyanogen bromide activated Sepharose 4B. The resultant product is some three times more effective than the non-purified Fab in protecting mice against the lethal venom effects.

Animals↗
PubMed1991

Isolation and comparison of myotoxins isolated from venoms of different species of Bothrops snakes.

Venoms of nine different snake species of the genus Bothrops were fractionated using fast protein liquid chromatography (FPLC). Basic proteins with phospholipase A2 and/or myotoxic activities were isolated from venoms of B. jararacussu, B. moojeni, B. neuwiedi and B. pradoi. B. jararaca venom possessed very low concentrations of these proteins, which were undetectable in venoms of B. atrox, B. alternatus, B. cotiara and B. erythromelas. Basic proteins from B. moojeni and B. pradoi venoms were isolated in pure form. All active fractions possessed a common band of 15,000 mol. wt which caused a rise in serum creatine phosphokinase levels and histopathological changes in muscle cells following i.m. injection into mice. Levels of phospholipase A2 activity were variable. The implications of the possession of varying levels of myotoxins and phospholipase A2 in these venoms are discussed.

Animals↗
PubMed1989

Use of liposomes for protective immunisation against Crotalus durissus (tropical rattlesnake) venom.

Crotalus durissus venom has been described as a weak antigen when injected in combination with Freund's complete adjuvant during the course of traditional methods of equine immunisation. Antibody production is slow and unpredictable, with a wide variation in individual responses. In this experimental study, C. durissus venom was incorporated into stabilised sphingomyelin-cholesterol liposomes both in the presence and absence of lipopolysaccharide immunostimulant and injected by both i.v. and s.c. routes into mice and rabbits. A rapid, sustained and protective immune response was obtained following a single injection of these preparations in mice. Antibody levels were estimated using enzyme-linked immunosorbent assay (ELISA), and the protective effect was evaluated by subsequent challenge with a subcutaneous minimum lethal dose of the venom. Results indicated that the immune response was significantly potentiated by the presence of immunostimulant in the venom liposomes. The use of C. durissus venom liposomes should be a useful tool for the immunisation of animals both in experimental and commercial procedures.

Animals↗