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Biomedical subjects

D Mebs

Publications and source records attributed to D Mebs.

At least 37 records · Page 2Linked to original sources

[Jellyfish poisoning].

While bathing in the Indian Ocean a 31-year-old German woman came into contact with a jelly-fish, probably of the species Chrysaora quinquecirrha. Initial signs were inflammatory cutaneous changes on the upper trunk, and both arms and feet. Over the next few days massive edematous swelling developed over the trunk, in addition to signs of arterial underperfusion in the hands and legs. Under treatment with urokinase and prostaglandin E1 the circulatory disorder in the feet completely disappeared. But the edema on the arms and hands got worse and huge bullae developed. On the assumption of a compartment syndrome a bilateral fasciotomy was performed. Wound healing proceeded normally. However, even after six months there remained extensive sensory and motor defects in both hands and arms.

Adult

Tannins occurring in the toxic Brazilian plant Thiloa glaucocarpa.

Four tannins were isolated from dried leaves of Thiloa glaucocarpa, which is one of the plants causing poisoning of cattle in Brazil. These four tannins were determined from spectrometric and chemical evidence to be the ellagic C-glucosyl tannins vescalagin, castalagin, stachyurin and casuarinin. The main components, vescalagin and castalagin, are also known as constituents of oak (Quercus spp.), the toxicity of which for cattle is supposed to be due to tannins. Suggestions concerning the resemblance of the symptoms of poisoning by Thiloa glaucocarpa and by oak are supported by the presence of the constituents in both plants.

Acetylation

Myotoxic activity of phospholipases A2 isolated from cobra venoms: neutralization by polyvalent antivenoms.

Phospholipases A2 which produce myonecrosis when injected i.m. into mice were isolated from venoms of Naja nigricollis, N.h.haje and N.nivea by gel filtration, ion-exchange chromatography on SP-Sephadex C-25 and CM-cellulose and by hydrophobic interaction chromatography on Phenyl-Sepharose CL-4B. Basic polypeptides of the cardio/cytotoxin-type were essentially free of myotoxic activity. Polyvalent antivenoms were tested for their ability to neutralize the myotoxic activity of the phospholipases A2 when mixed with them prior to injection. Antivenoms from Behringwerke (Orient, Central Africa, North Africa) and from the South African Institute for Medical Research, but not habu (Trimeresurus flavoviridis) monovalent antivenom, neutralized the myotoxic activity of the phospholipases A2.

Animals

Isolation and characterization of myotoxic phospholipases A2 from crotalid venoms.

Phospholipases A2 producing myonecrosis when injected i.m. into mice were isolated from venoms of Trimeresurus flavoviridis, Agkistrodon bilineatus, A. c. contortrix, A. c. mokeson, A. p. piscivorus and Bothrops asper by gels filtration on Sephadex G-75 followed by ion-exchange chromatography on CM-cellulose. They are basic enzymes with molecular weights between 14,000 and 15,000 containing 120-129 amino acid residues and exhibit relatively low enzymatic activity when tested on egg yolk suspension. Local myonecrosis is induced even at doses of 1.25 micrograms per mouse.

Amino Acids

Experimental studies on the spitting cobra ophthalmia (Naja nigricollis).

Experimental studies were conducted to investigate the clinical and morphological effects of various doses of Naja nigricollis venom (0.1-5.0 mg) on the eyes of rabbits. Our findings suggest that in the early stage of the ophthalmia caused by the spitting cobra, specific fractions of the venom are responsible for the nitrogen mustardlike effect. However, the further course seems to be determined by liberated inflammation mediators like prostaglandins and leukotrienes.

Animals

Macrocyclic trichothecenes: cause of livestock poisoning by the Brazilian plant Baccharis coridifolia.

Nine macrocyclic trichothecenes, thought to cause toxic effects in herbivors, were isolated from the Brazilian shrub Baccharis coridifolia. The structures of two new components, named miophytocene A and B, are described. Structure analysis was mainly accomplished by application of two-dimensional Fourier transform NMR techniques. The trichothecenes are most likely produced by the soil fungus Myrothecium verrucaria, which was isolated from soil samples around B. coridifolia. It is concluded that the plant is able to absorb and accumulate these mycotoxins. Histopathological studies on rabbits which received roridin E and A per os revealed mainly necrosis and hemorrhages of the mucosa of the colon and in the case of roridin A also of the caecum. Lethality in mice was generally low, intoxication proceeding slowly. It has to be considered, however, that all trichothecenes tested are practically insoluble in aqueous solutions and were applied as emulsions (i.p. and per os application). No trichothecenes or other toxic substances were detected from the Brazilian species Baccharis dracunculifolia, although slight toxic effects have been reported in cattle.

Animals

Bioactive proteins from marine sponges: screening of sponge extracts for hemagglutinating, hemolytic, ichthyotoxic and lethal properties and isolation and characterization of hemagglutinins.

Aqueous extracts of 48 sponge species from the Red Sea, the Australian Barrier Reef and the Florida Keys were screened for hemagglutinating, hemolytic, ichthyotoxic and lethal activities. Forty two per cent of the sponge species exhibited agglutinating properties to human erythrocytes of ABO groups. From four species (Haliclona sp., Cinachyra tenuifolia, Callyspongia viridis, Terpios zeteki) the hemagglutinating factors were isolated by gel filtration and affinity chromatography. A molecular weight of 24,000 was determined for the pure hemagglutinin from Haliclona sp. by SDS electrophoresis and of 22,000 for the semipure hemagglutinin from Cinachyra tenuifolia by gel filtration. These hemagglutinins were inhibited by D-lactose, but not by D-melibiose or other oligosaccharides, indicating that they may react with terminal D-galactose beta 1----4 residues. The other semipure hemagglutinins were not inhibited by various sugars tested. Hemolytic activity to human erythrocytes was present in about 15% of the sponge extracts, showing a close relationship to ichthyotoxic activity. More than half of the sponge extracts caused toxic symptoms in mice when injected i.p. Using various concentrations death occurred within 12-48 hr. The lethal factors seem to be related to components of low molecular weight in the sponge extracts.

Animals

A toxin from the sea urchin Tripneustes gratilla.

A heat labile toxic protein of 25,000 molecular weight was isolated (LD50 0.85 mg/kg. i.p. injection into mice) from the pedicellariae of the sea urchin Tripneustes gratilla. Pretreatment of the mice with antihistaminics did not prevent the toxic effects.

Animals

Lack of toxins in alcoholic extracts of the sponge Tedania ignis.

Alcoholic extracts of the sponge Tedania ignis collected on the coast of the Florida Key's (U.S.A.) were essentially free of toxins which had been found in specimens from the Venezuelan coast, supporting the assumption of planktonic origin of these toxins.

Animals

Intraspecific variation in content of a basic toxin in eastern diamondback rattlesnake (Crotalus adamanteus) venom.

Venom samples from four specimens of Crotalus adamanteus from the same litter were analyzed for the content of a basic toxin by gel filtration. Whereas the venoms of two snakes were essentially free of the toxin, two other contained about 5% and 11% toxin (w/w). The individual absence or presence of the toxin in the venom was constant, suggesting a genetically determined variation.

Amino Acids

Hemolysins and proteinase inhibitors from sea anemones of the Gulf of Aqaba.

Bioactive polypeptides have been isolated from three sea anemone species by gel filtration and ion-exchange chromatography: hemolysins from Gyrostoma helianthus and Radianthus koseirensis and proteinase inhibitors from the latter species and from Rhodactis rhodostoma. The hemolysins (molecular weight about 10,000) are free of phospholipase A activity, possess considerable ichthyotoxicity, and hemolysis is inhibited by sphingomyelin. The main proteinase inhibitor from Rhodactis rhodostoma is composed of 48 amino acids and inhibits trypsin, kallikrein and chymotrypsin, whereas the semipure inhibitor from Rhadianthus koseirensis has very low affinity for serine proteases and does not inhibit chymotrypsin.

Animals