Ciguatera toxicity

322 glycaemic control or body wt. When insulin treatment was reduced and discontinued, Xiaoke failed to prevent the progression of severe hy~rgly~emia and weight loss. The results suggest that the slowly generated antihyperglycaemic effect of Xiaoke in streptozotocin diabetic mice may involve an extra-pancreatic effect on food intake, glucose production or glucose clearance. However, as evidenced in BB/E rats, Xiaoke does not substitute for insulin in the absence of endogenous insulin secretion. Inhibition of natural killer celI function by marijuana components Klein TW; Newton C; Friedman H J. TOXICOL. ENVIRON. HEALTH; 2914(321-3321119871 The extent of modulation of host resistance mechanisms by marijuana components is not fully understood. Natural killer (NKI cells are a subpopulation of lymphoid cells and are irn~r~nt in host resistance mechanisms against malignant cells, virus-infected cells, and possibly pathogenic bacteria and fungi. We report that the marijuana component delta-9tetrahydrocannabinol (THC!) injected into mice results in a suppression of splenic NK activity. Furthermore, THC and the hydroxylated metabolite 11-hydroxy-delta-9tetrahydrocannabinol (ll-hydroxy-THC) suppress the NK activity of cultured murine splenocytes in a dose-dependent manner (range 1 x 10” to 3.2 X 10” Ml without diminishing NK ceI1viability. The hydroxytated derivative appears to possess a more potent suppressive effect, in that it suppresses at lower concentrations than THC does and requires a shorter incubation time with the effector cells for its suppressive action. Purification of NK cells by Percoli density-gradient centrifugation suggests that both cannabinoids act directly on the natural killer cell population, resulting in suppression. Studies involving target binding analysis and calcium ionophore experiments suggest that cannabinoids do not suppress NK cell killing by the inhibition of effectorltarget binding or by disruption of calcium ion flux. These results suggest that two principal psychoactive cannabinoids can suppress natural killer cell function by interacting directly with the killer cells and disrupting cellular events postbinding and during the programming for lysis. Furthermore, the data suggest different modes of action for THC and the hydroxylated metabolite. Hemlock water dropwort poisoning Ball MJ; Flather ML: Forfar JC POSTGRAD. MED. J.; 63,‘7391363- 3651/19871 Seven plant poisoning is relativeiy uncommon in adults. We report two adults who ingested hemlock water dropwort roots, having mistaken them for wild parsnip. One developed prolonged convulsions, severe metabolic acidosis and respiratory distress requiring mechanical ventilation. The toxin - oenanthotoxin - was detected in the gastric aspirate and measured by high performance liquid chromatography. Ciguatera toxicity Lange WR AM. FAM. PHYS.; 3514(177- ~82~~~987/ Ciguatera poisoning is the most common foodborne illness caused by a chemical toxin in the United States and is endemic in the Caribbean and InduPacific. Ci~atoxin, produced by a marine dinoflagellate that attaches to algae, is passed up the food chain to large fish and, finally, to humans. The toxin has anticholinesterase activity. The clinical picture is characterized by a variety of gastrointestinal, neurologic and cardiovascular symptoms, usually self-limited. Amitriptyline is reported to be beneficial. Effects of tobacco smoke inhalation on capillary blood flow in human skin Richardson D ARCH. ENVIRON. HEALTH; 42/l (19- 25111987/