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Biomedical subjects

J O Schmidt

Publications and source records attributed to J O Schmidt.

28 records · Page 2Linked to original sources
PubMed1986

Hornet venoms: lethalities and lethal capacities.

The i.v. LD50 values to mice of pure venoms of Vespa mandarinia japonica, V. simillima xanthoptera, V. tropica deusta and V. l. luctuosa were, respectively, 4.1, 3.1, 2.8 and 1.6 mg/kg. The LD50 value of 1.6 mg/kg distinguishes the venom of V. luctuosa as the most lethal known wasp venom. To measure the absolute lethality of a single sting, a new index, called lethal capacity, based on the amount of venom possessed by an individual and its lethality is presented. V. mandarinia and V. tropica are the most venomous known insects, with a lethal capacity of one sting from V. mandarinia delivering an LD50 (i.v.) dosage of venom to 270 g of mouse. The lethal capacity for an entire hornet colony, called colony lethal capacity, for V. tropica is 84 kg of mouse/colony.

Animals↗
PubMed1985

Lipophorin of the larval honeybee, Apis mellifera L.

Most insects have a major lipoprotein species in the blood (hemolymph) that serves to transport fat from the midgut to the storage depots in fat body cells and from the fat body to peripheral tissues. The generic name lipophorin is used for this lipoprotein. In larvae of the honeybee, Apis mellifera, a lipophorin has been found with properties that correlate well with those of the only other lipophorin reported for an immature insect, that of the tobacco hornworm, Manduca sexta. The honeybee lipophorin (Mr = 530,000) has a density of 1.13 g/ml, contains approximately 41% lipid and 59% protein, and contains two apoproteins, apoLp-I, Mr = 250,000 and apoLp-II, Mr = 80,000, both of which are glycosylated. The lipids consist predominantly of polar lipids, of which phospholipids and diacylglycerols represent 60% of the total. When the intact lipophorin is treated with trypsin, apoLp-I is rapidly proteolyzed, while apoLp-II is resistant, indicating a difference in exposure of the two apoproteins to the aqueous environment. Honeybee apoLp-II cross-reacts with antibodies to M. sexta apoLp-II, but not to anti-M. sexta apoLp-I. No cross-reactivity of honeybee apoLp-I to anti-M. sexta apoLp-I was observed.

Amino Acids↗
PubMed1982

Proteins in venoms of two wasps, Polistes comanchus navajoe and Vespa orientalis.

1. By means of gel electrophoresis the basic proteins in venoms of Polistes comanchus navajoe and Vespa orientalis were resolved into 6 and 5 proteins respectively, all of molecular weights greater than 15,000. 2. Several proteins appeared to be similar in both venoms. 3. The main component of P. comanchus venom responsible for hemolysis was isolated, and data concerning its thermolability, molecular weight (approximately 26,000) and amino acid composition show that unlike the cytolytic components of bee and ant venoms which are small peptides, the corresponding functional entity of P. comanchus venom (polistin) is a protein having the characteristics of an enzyme.

Amino Acids↗
PubMed1978

A harvester ant venom: chemistry and pharmacology.

The mammalian toxicity of the potently algogenic venom of the ant Pogonomyrmex badius is greater than that reported for any other insect venom. This enzyme-rich venom contains high concentrations of phospholipase A2 and B, hyaluronidase, acid phosphatase, lipase, and esterases. This hemolytic secretion from the poison gland products unusual symptoms in mammals and appears to have been evolved as a deterrent for vertebrate predators.

Acid Phosphatase↗