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Biomedical subjects

G V Odell

Publications and source records attributed to G V Odell.

At least 19 recordsLinked to original sources
PubMed2000

The venomous hair structure, venom and life cycle of Lagoa crispata, a puss caterpillar of Oklahoma.

The presence of a unique population of Lagoa crispata, puss caterpillar, in western Oklahoma is reported. A detailed microscopic examination shows the structure of the L. crispata spines resemble the type 4 spines described by [Kawamoto, F., Kumada, N., 1984. Biology and venoms of lepidoptera. In: Tu, A.T. (Ed.), Handbook of Natural Toxins, Insect Poisons, Allergens and other invertebrate venoms, vol. 2, pp. 291-332 (ch. 9)]. The major food source of L. crispata are the leaves of oak (shin oak). The high tannin content of this food source results in spine extracts high in oak tannins. These extracts have activity but enzyme and toxin activity is lost with time. The gel filtration protein fractions are colored from brown to yellow and are inactive as enzymes or toxins. No hyaluronidase, protease or phosphohydrolase activity is detected in these protein fractions. The life cycle shows these caterpillars have 6 instars. Characterizations and annual emerging times of each instar are included.

Adenosine Triphosphatases↗
PubMed1998

Citrate inhibition of snake venom proteases.

Thirty snake venoms had a citrate content of 2.3 to 12.9%, dry basis, by an aconitase isocitric dehydrogenase coupled enzyme assay. This is a venom concentration range of approximately 30 to 150 mM citrate assuming 25% venom solids content. Inhibition of snake venom protease activity by the addition of exogenous citrate was obtained using azure blue hide powder and azocasein as substrates. Protease inhibitions of 7.5% for Crotalus atrox venom to 78% for Bothrops picadoi venom were observed with citrate. Complete inhibition of snake venom protease activity by citrate was not observed. Bothrops asper (Pacifico) venom showed a 41% protease inhibition by citrate with azocasein as the substrate and 46% inhibition of Bothrops asper (Alantico) venom protease with azure blue hide power as a substrate. Trypsin was not inhibited in this system. Citrate may inhibit some venom protease activity by forming a complex with the zinc of zinc-dependent enzymes. reserved.

Animals↗
PubMed1995

Arthropod venom citrate inhibits phospholipase A2.

Citrate has been identified as a major component of honey bee (Apis mellifera) venom by gas liquid chromatography-mass spectrometry. A citrate concentration of 9% was found for dried bee venom by a coupled enzyme assay, aconitase-isocitric dehydrogenase. A liquid honey bee venom would contain 140 mM citrate concentration (if the solids content were 30%). Bee venom phospholipase was inhibited at a 43% level with a citrate concentration of 20 mM and calcium ion at 3 mM with the enzyme assay. Citrate was also found in the venoms of bumble bee, Bombus fervidus, 7%; yellow jacket, Vespula maculifrons, 4%; scorpion, Centruroides sculpturatus, 8%; tarantula, Grammastola cala, 8% and brown recluse spider venom gland extract, Loxoceles reclusa, 1.5% based on dried venom solids. Citrate may serve as an endogenous inhibitor of divalent metal ion-dependent enzymes in arthropod venoms as described by Francis et al. (1992, Toxicon 30, 1239-1246). Many arthropod venoms contain calcium-dependent phospholipases. A direct effect of citrate as a venom component may be possible. The presence of citrate in venoms must be considered in research on receptors, ion channels and divalent ion-dependent toxins.

Aconitate Hydratase↗
PubMed1994

Primary structures of two proteins from the venom of the Mexican red knee tarantula (Brachypelma smithii).

Venom of the Mexican red knee tarantula (Brachypelma smithii) was fractionated by gel filtration over Sephadex G-50 Fine. Small polypeptides present in the second and third peaks were subfractionated by cation exchange and reversed-phase FPLC. One major, basic protein was isolated and sequenced from each G-50 fraction using a gas-phase protein sequencer. Primary structures were completed and confirmed using tandem mass spectrometry and carboxypeptidase digestions. Protein 1 contains 39 residues, including six cysteine residues in three disulfide bonds. It is identical to one of the isoforms of ESTX from the venom of the tarantula Eurypelma californicum. Brachypelma smithii Protein 5 contains 34 residues, including six cysteine residues in three disulfide bonds. Disulfide bond assignments for both proteins are provided. Protein 5 shows most similarity with toxin Tx2-9 from the Brazilian 'armed' spider, but only displays 41% sequence identity. Similarities with other proteins are lower. Proteins 1 and 5 appear unrelated to each other.

Alkylation↗
PubMed1992

Citrate is a major component of snake venoms.

Citrate has been identified as a major component of snake venoms by gas liquid chromatography and mass spectrometry. The venoms of Bothrops asper, Crotalus atrox, Crotalus viridis viridis, Crotalus adamanteus, Sistrurus miliarius barbouri, Crotalus horridus horridus, Agkistrodon contortrix mokasen, Agkistrodon contortrix contortrix and Agkistrodon piscivorus piscivorus contain citrate at concentration levels which can serve as effective buffers. Calcium, magnesium, zinc, iron, sodium and potassium salts of citrate would be constituents of venom.

Animals↗
PubMed1990

The amino acid sequence of a myotoxic phospholipase from the venom of Bothrops asper.

A myotoxic, basic phospholipase A2 (pI greater than 9.5) with anticoagulant activity has been purified from the venom of Bothrops asper, and its amino acid sequence determined by automated Edman degradation. It is distinct from the B. asper phospholipase A2 known as myotoxin I [Lomonte, B. and Gutierrez, J. M., 1989, Toxicon 27, 725] but cross-reacts with myotoxin I rabbit antisera, suggesting that the proteins are closely related isoforms. To our knowledge, this is the first myotoxic phospholipase to be sequenced that lacks presynaptic neurotoxicity (iv LD50 approximately equal to 8 micrograms/g in mice). The protein appears to exist as a monomer, contains 122 amino acids, and fits with subgroup IIA of other sequenced phospholipase A2 molecules. Its primary sequence shows greatest identity with ammodytoxin B (67%), a phospholipase A2 presynaptic neurotoxin from Vipera ammodytes ammodytes venom. Hydropathy profiles of B. asper phospholipase and the ammodytoxins also show great similarities. In contrast, even though the amino acid sequence identities between B. asper phospholipase and the basic subunit of crotoxin remain high (64%), their hydropathy profiles differ substantially. Domains and residues that may be responsible for neurotoxicity are discussed.

Amino Acid Sequence↗
PubMed1988

[Characteristics of the venoms and digestive secretions of Aphonopelma seemanni and Sphaerobothria hoffmanni (Araneae: Theraphosidae) of Costa Rica].

A comparison of some components of the venoms of two Costa Rican tarantulas, Aphonopelma seemanni (Cambridge) and Sphaerobothria hoffmanni (Karsch) by polyacrylamide gel electrophoresis shows patterns similar to those of Dugesiella hentzi (Girard), a North American tarantula. The digestive secretions have proteins that do not enter the 15% gels; thus no bands are observed. The method used by the tarantulas to consume their prey involves the action of both the venom and the digestive secretions. The percent protein, pH, proteolytic activity and hemolytic activity of venom and digestive secretions of both species were determined, and a high proteolytic activity for digestive secretions was found.

Animals↗
PubMed1986

In vivo ability of antimyotoxin a serum plus polyvalent (Crotalidae) antivenom to neutralize prairie rattlesnake (Crotalus viridis viridis) venom.

A mixture of antimyotoxin a serum and polyvalent (Crotalidae) antivenom was injected i.v. in mice either 5 min before or 5 min, 30 min, 1 hr or 3 hr after i.m. injection of venom. Neutralization of the local myotoxicity of a sublethal dose (1.5 micrograms/g) of C. v. viridis venom occurred if the antisera were injected 5 min before or 5 or 30 min after venom, but not if injected 1 or 3 hr after the venom. Hemorrhage was neutralized when the mixture was injected either 5 min before or 5 min after injection of venom, but not when injected 30 min after injection of venom. Previous results showed that the mixture of antisera neutralized the same amount of venom (1.5 micrograms/g) when mixed with the venom prior to injection. Thus it is not possible with these two antisera to neutralize myonecrosis if the time interval between injections is greater than 30 min.

Animals↗
PubMed1985

Ability of a mixture of antimyotoxin a serum and polyvalent (Crotalidae) antivenin to neutralize myonecrosis, hemorrhage and lethality induced by prairie rattlesnake (Crotalus viridis viridis) venom.

Mixtures containing polyvalent (Crotalidae) antivenin and antimyotoxin a serum were tested for their ability to neutralize the myotoxic, hemorrhagic and lethal activities of crude C. v. viridis venom when mixed with the venom prior to injection into white mice. A light microscopic method was used to measure the local myotoxic activity of the venom, i.e. myonecrosis index. The results show that the neutralizing ability of a 1:1 mixture of antisera for myonecrosis was 16 times that of antimyotoxin a serum alone and 63 times that of antivenin alone. There was no difference in neutralizing ability of the three ratios (2:1, 1:1, 1:2) of antivenin: antimyotoxin serum tested. Hemorrhage was measured by a new method in which the amount of hemoglobin in a muscle extract was measured after i.m. injection of test solution. The results show that the ability of a 1:1 mixture to neutralize hemorrhage was comparable to that of antivenin alone. There was no difference in hemorrhage neutralizing ability of the three ratios tested. In its ability to neutralize lethality, the 1:1 mixture was again comparable to antivenin. However, when the three different ratios of antisera were tested for neutralization of lethality the 2:1 and 1:1 ratios were as effective as antivenin alone, whereas the 1:2 ratio (antivenin: antimyotoxin serum) was less effective than antivenin alone. Thus the addition of antimyotoxin a serum to antivenin in equal proportions greatly improves the neutralization of the myotoxic activity of C. v. viridis venom and does not decrease the ability of antivenin to neutralize hemorrhage and lethality.

Animals↗
PubMed1984

Pathogenesis of myonecrosis induced by crude venom and a myotoxin of Bothrops asper.

The pathogenesis of skeletal muscle necrosis induced by crude Bothrops asper venom and isolated myotoxic phospholipase was studied using light and electron microscopy. White mice were injected intramuscularly with a dose of 2.5 micrograms/g and tissue samples were taken at 30 min and 1, 3, 6, 12, 24, and 48 hr. Toxin-injected muscle showed localized wedge-shaped lesions ("delta lesions") by 30 min, which included disrupted plasma membranes. At 1 and 3 hr the predominant type of necrotic cell contained clumped myofibrils in which individual myofilaments were indistinguishable. At later time periods there was a relaxation and redistribution of myofilaments resulting in a more homogeneous and hyaline appearance of necrotic cells. Some mitochondria were swollen and had flocculent densities, and most of them were disrupted, having only one membrane and vesiculated cristae. The basal lamina was intact at all time intervals. Phagocytosis of muscle cell debris started at 3 hr and was prominent by 24-48 hr. In crude venom-injected muscle many cells showed pathologic features identical to those observed after myotoxin injection. Crude venom also induced hemorrhage which was evident 30 min after injection, reaching its highest level by 12 hr. At 3, 6, and 12 hr some cells were undergoing different pathologic changes which appeared to be due to ischemia. Although these cells were irreversibly damaged, as indicated by ruptured plasma membrane, their myofibrillar structure was better preserved than that of toxin-affected cells. The Z line was absent, but A, I, H, and M bands were intact. As a result of Z line loss, sarcomeres were disoriented. It is proposed that the myotoxin induces myonecrosis by first altering the integrity of the plasma membrane, thereby increasing the permeability to calcium, other ions, and molecules which leads to death of the cell. Crude venom affects muscle cells in two ways: by direct action of myotoxin (s) and by ischemia due to hemorrhage.

Animals↗
PubMed1984

A new method for quantitating hemorrhage induced by rattlesnake venoms: ability of polyvalent antivenom to neutralize hemorrhagic activity.

Polyvalent (Crotalidae) antivenin was tested for its ability to neutralize the hemorrhagic activity of two crotaline venoms when mixed with them prior to injection. Hemorrhage was measured by two methods. In the first method an intradermal injection of venom produced a hemorrhagic spot which was quantitated by measuring diameters. In the second method the amount of hemoglobin in a muscle extract was measured after i.m. injection of venom. The results show that both methods are useful for quantitating hemorrhage induced by Crotalus viridis viridis and Crotalus atrox venoms. Antivenin neutralized the hemorrhagic activity of 240 micrograms C. v. viridis venom and 120 micrograms C. atrox venom per 0.05 ml. The question remains, can antivenin neutralize this amount of venom when injected independently of venom.

Animals↗
PubMed1984

In vivo test of the ability of antiserum to myotoxin a from prairie rattlesnake (Crotalus viridis viridis) venom to neutralize local myonecrosis induced by myotoxin a and homologous crude venom.

Antiserum to myotoxin a was tested for its ability to prevent local myonecrosis induced by myotoxin a and C. v. viridis venom. Antiserum was injected i.v. either 5 min before or immediately, 15 min, 30 min, 1 hr or 3 hr after i.m. injection of toxin or venom. A light microscopic method was used to measure the effects of myotoxin a, i.e. vacuolation index, and whole venom, i.e. myonecrosis index. The results show that antimyotoxin a serum neutralizes the myotoxicity of a sublethal amount of myotoxin a if injected 56 min before or immediately after toxin, but not if injected 15 min after the toxin. Its neutralizing ability for crude C. v. viridis venom was considerably better, neutralizing a dose of 0.75 microgram/g even if injection of antiserum was delayed for 30 min after venom injection. Thus, antimyotoxin a serum might be useful in treating myonecrosis resulting from prairie rattlesnake (C. v. viridis) venom poisoning.

Animals↗
PubMed1984

Isolation of a myotoxin from Bothrops asper venom: partial characterization and action on skeletal muscle.

A myotoxic phospholipase has been isolated from Bothrops asper venom by ion-exchange chromatography on CM-Sephadex followed by gel filtration on Sephadex G-75. The toxin is a basic polypeptide with an estimated molecular weight of 10,700. It has both phospholipase A and indirect hemolytic activities, but is devoid of proteolytic, direct hemolytic and hemorrhagic effects. When injected i.m. into mice the toxin induces a rapid increase in plasma creatine kinase levels and a series of degenerative events in skeletal muscle which lead to myonecrosis. The toxin induces an increase in intracellular calcium levels and is able to hydrolyze muscle phospholipids in vivo. Pretreatment with the calcium antagonist verapamil failed to prevent the myotoxic activity. It is proposed that B. asper myotoxin causes cell injury by disrupting the integrity of skeletal muscle plasma membrane and that myotoxicity is at least partially due to the phospholipase A activity of the toxin.

Animals↗
PubMed1984

Skeletal muscle regeneration after myonecrosis induced by crude venom and a myotoxin from the snake Bothrops asper (Fer-de-Lance).

Skeletal muscle regeneration was studied following injections of Bothrops asper venom and a myotoxin isolated from the crude venom. In toxin-injected muscle regeneration proceeded normally. By 4 days there were myotubes and small regenerating cells. The size of the cells increased by 1 and 2 weeks, and by 4 weeks regenerating cells were fully developed. The regenerated cells retained centrally located nuclei. The regenerative process in venom-injected muscle was not completely normal--by 1 and 2 weeks four main areas, based on the predominant cell type present, were observed in the tissue: (a) necrotic muscle cells; (b) regenerating muscle cells; (c) fibroblasts and collagen; (d) adipocytes. Furthermore, some nerve fibers were demyelinated. Samples obtained 4 weeks after venom injection showed an almost complete regeneration in many areas, whereas in other areas nests of small regenerating cells were surrounded by portions of adipose tissue and collagen. At four weeks regenerating cells in venom-injected muscle were significantly smaller than cells in toxin-injected and saline-injected muscles. There was a significant reduction in capillary/muscle cell ratio in areas of the muscle where hemorrhage and myonecrosis were present 30 min after injection of B. asper venom. Since B. asper venom drastically affects the microvasculature, it is proposed that impairment of regeneration after injection of crude venom is a consequence of diminished blood supply to some areas of the muscle.

Animals↗
PubMed1983

Pathogenesis of skeletal muscle necrosis induced by tarantula venom.

The pathogenesis of myonecrosis induced by venoms of the Arkansas tarantula (Dugesiella hentzi, Girard) and the Honduran tarantula (Aphonopelma spp.) was studied using light and electron microscopy, scanning electron microscopy and x-ray microprobe analysis, and histochemistry. White mice were injected intraperitoneally with a sublethal dose of tarantula venom. Gross examination 24 hr after injection revealed white areas of apparent calcification in the diaphragm muscle. Light microscopic examination at 15 min revealed hypercontracted muscle cells, and necrotic masses containing areas of condensed myofibrils and clumps of mitochondria. By 12 hr numerous phagocytic cells were present around degenerated muscle cells. Electron microscopic examination revealed a myonecrosis of rapid onset with plasma membrane rupture and contraction bands 15 min after injection. At 3 hr only small patches of plasma membrane remained and mitochondrial changes such as swelling, dense intracristal spaces, partitioning, and flocculent densities were prominent. By 12 and 24 hr very dark spicular densities were present in mitochondria and numerous phagocytic cells were located within the intact basal lamina of necrotic cells. X-ray analysis and histochemistry of 24 hr samples showed that necrotic cells contained very high levels of calcium and phosphate. These two tarantula venoms caused a rapid onset myonecrosis in which the primary injury was rupture of the plasma membrane followed by inability of mitochondria and sarcoplasmic reticulum to maintain normal levels of calcium in the cytoplasm leading to cell death.

Animals↗
PubMed1983

Detection of antibodies to myotoxin a and prairie rattlesnake (Crotalus viridis viridis) venom in three antisera using enzyme-linked immunosorbent assay and immunodiffusion.

Immunodiffusion and enzyme-linked immunosorbent assay (ELISA) were used to compare three antisera for their content of antibodies against myotoxin a and C. v. viridis venom. No antibodies were detected in Wyeth's polyvalent (Crotalidae) antivenin against myotoxin a using immunodiffusion, whereas ELISA indicated a low titer of such antibodies. However, antimyotoxin a serum and anti-C. v. viridis venom both had higher titers than antivenin when tested against myotoxin a and crude venom in the ELISA. These results correlate well with previous data which indicated that antiserum to myotoxin a was more effective than antivenin in neutralizing the myotoxicity of C. v. viridis venom. The high content of antibodies to myotoxin a in anti-C. v. viridis venom supports the hypothesis that this monovalent antiserum might be effective in neutralizing rattlesnake (C. v. viridis) venom-induced myonecrosis.

Animals↗