77tyus serrulatus venom contains two classes of toxins (77tyus gamma toxin is a new tool with a very highaffinity for studying the Na' channel) . J. biol. Chem . 257, 12553 (1982) .THEiNTERAcrtoN of TiTxy, the major toxin in the venom of the scorpion 77tyus serrulatus, with its receptor inexcitable membranes was studied with the use of "sI-TiTxy. This derivative retains biological activity, and itsspecific binding to both brain synaptosomes and electroplaque membranes from FJectrophorus elertricus ischaracterized by a dissociation constant equal to that of the native toxin-receptor complex, about 2-5 pm.This very high affinity results mainly from a very slow rate of dissociation, equivalent to a half-life longer than10 hr at 4°C. There is a 1:1 stoichiometry between TiTxy binding and tetrodotoxin binding to the membranes,but neither tetrodotoxin nor any of 7 other neurotoxins that are representative of 4 different classes of effectorsof theNa* channel interfere with Titxy binding. Similarly, local anesthetics and other molecules that affect othertypes of ionic channels Or neurotransmitter receptors have no effect on Titxy binding . However, toxin II fromCentruroides syffusus sgffusus does compete with TiTxy, though its affinity for the receptor is much lower.Since the Centruroldf toxin II is known to affect Na* channel function, these two scorpion toxins must be putinto a fifth class of Na' channel effectors.

H. P. KOLM

BAR-SELA, S. and LEvo, Y. (Allergy Unit, Department of Medicine A, Hadassah University Hospital,Jerusalem, Israel) Insect-sting allergy in Israel : immunotherapy with pure venoms . Israel J. med. Sci. 18, 487(1982) .DEMOGRAPHIC, atopic and other clinical characteristics of 25 patients with insect-sting allergy are reported . Allpatients were skin tested by pure venoms (PVs) or whole body extracts obtained from bees and several vespids.PVs were found to be extremely useful and highly superior to whole body extracts in the diagnosis of insectallergy. Immunotherapy was indicated in 15 patients, 12 ofwhom completeda 12-wk PV desensitization course .Immunization was associated with minimal side effects and proved to be highly effective against a live-insectchallenge.

H. P. KoLM

HErLAND, 0., WARHuus, K., GiERcKscy, K. E., AAsLID, R. and PRYDz, H. (Research Institute for InternalMedicine, Rikahospitalet, Oslo, Department of Surgery, Institute for Clinical Medicine, University of Tromsd,Tromsd, and Department of Biochemical Engineering Rikshospitalet, Oslo, Norway) Toxicity of phospholipaseC in rabbits. Scand. J. clip. Lab. Invest . 42, 239 (1982).TissuE thromboplastin is the most potent physiological trigger of blood coagulation and is probably involved inthe pathogenesis of several forms of intravascular coagulation . Phospholipase C from Bacilhis cereus is aneffective inhibitor of thromboplastin . As part of an investigation into the possible use of phospholipase C as atherapeutic or prophylactic agent in thrombosis and other forms of intravascular coagulation, we havepreviously studied its effect in rats . We now report on the toxicity in rabbits (along with some data on cats andmonkeys). Estimated LDb for rabbits was about 0.45-0.65 mg/kg (as compared to 1.70 mg/kg for rats). Norespiratory or circulatory changes were observed, but phospholipase C caused a significant increase of severalplasma enzymes in rabbits.

H. P. KOLM

REtsm", R. E., WYPYCH, J. I., MumrizR , U. R. and GRANT, J. A. (Allergy Research Laboratory, BuffaloGeneral Hospital, State University ofNewYork, Buffalo, New York, and University of Texas Medical Branch,Adult Allergy Section, Galveston, Texas, U.S.A .) Comparison of the allergenicity and andgenicity of Polistesvenom and other vespid venoms . J. Allergy clin . Immun. 70, 281 (1982).THE'cRossAxnGEmctry of Polistes venom with other vespid venoms was examined with rabbit and humanantisera. Venom preparations from various Polistes species were obtained by electrical stimulation ofindividualinsects and venom sacdissection . Rabbit antibodies were raised to the venom(P. apachus) and venom sac extract(P, exclamans) . Human antisera were obtained from patients allergic to Polistes and other vespid venoms . Thevenom appeared to bemore potent than the venom sac preparations in reactionswith rabbit IgG and human ISEantibodies. Among the Polistes species, P. ezdamans, P. instablis andP. apachus venoms showed several linesof precipitation with rabbit antisera, and P. annularis and P. fuscatus venoms only one line, suggestingquantitative or qualitative antigenic differences. In RAST analysis, most sera reacted equally to all Polistesspecies, but occasional exceptions were noted, again suggesting differences in venom allergens. P. eaclamans,-coupled discsgave themost consistent results . In gel diffusion experiments, there wasno crossreactivity betweenPolistes and yellow jacket venomsand only limited crosareactivitybetweenPolistes andhornet venoms. Patientssensitive to Polistes venom showed varying degrees of reactivity to yellow jacket and hornet venoms in RASTanalysis. Patients sensitive to other vespid venoms also showed varying degrees of sensitivity to Polistes venom.Polistes venom appears to contain a genus-unique antigen (allergen). In addition, there appear to be somecross<eacdng antigens in Polistes and other vespidvenoms, but to a much lesser degreethan found previously inthe analysis of the relationship of yellow jacket and hornet venoms .

H. P. KoLM