Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Colubridae”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1992

The secretion of Duvernoy's gland of Malpolon monspessulanus induces haemorrhage in the lungs of mice.

A toxic protein that induces death of mice with profuse bleeding from the nostrils was isolated from the secretion of Duvernoy's gland of Malpolon monspessulanus (Colubridae). The toxic protein, referred to as CM-b, showed mainly one band on SDS-PAGE corresponding to a mol. wt of 24,000. Its intravenous LD50 in mice was 1 microgram/g and i.v. injections of lethal or sublethal doses induced haemorrhage in the lungs. When injected into the skin of mice, however, the toxin was not haemorrhagic. CM-b showed no proteolytic or procoagulant activity. The nature of this and other components from Duvernoy's secretion of colubrids that cause similar effects remains to be established.

Animals↗
PubMed1984

Xanthine:NAD+ oxidoreductase in the liver of grass snake Natrix natrix.

The enzyme hydroxylating oxypurines in the liver of grass snake (Natrix natrix, Colubridae) was found to be a stable xanthine:NAD+ oxidoreductase (EC 1.2.1.37). The Michaelis constants for NAD+ and xanthine amounted to 14.4 and 12.3 microM, respectively. The enzyme affinity to hypoxanthine is lower than that to xanthine, but the former substrate is hydroxylated faster than the latter. The enzyme is only slowly and slightly (up to 22%) inhibited by NADH accumulating during xanthine hydroxylation. The above data and the time-course of hypoxanthine----xanthine----uric acid hydroxylation indicated that the kinetic properties of the snake liver enzyme provide in this uricotelic animal fast elimination of superfluous nitrogen derived from protein catabolism.

Animals↗
PubMed2005

Isolation and characterization of two disintegrins inhibiting ADP-induced human platelet aggregation from the venom of Crotalus scutulatus scutulatus (Mohave Rattlesnake).

Disintegrins and disintegrin-like proteins are molecules found in the venom of four snake families (Atractaspididae, Elapidae, Viperidae, and Colubridae). The disintegrins are nonenzymatic proteins that inhibit cell-cell interactions, cell-matrix interactions, and signal transduction, and may have potential in the treatment of strokes, heart attacks, cancers, and osteoporosis. Prior to 1983, the venom of Crotalus scutulatus scutulatus (Mohave Rattlesnake) was known to be only neurotoxic; however, now there is evidence that these snakes can contain venom with: (1) neurotoxins; (2) hemorrhagins; and (3) both neurotoxins and hemorrhagins. In this study, two disintegrins, mojastin 1 and mojastin 2, from the venom of a Mohave rattlesnake collected in central Arizona (Pinal County), were isolated and characterized. The disintegrins in these venoms were identified by mass-analyzed laser desorption ionization/time-of-flight/time-of-flight (MALDI/TOF/TOF) mass spectrometry as having masses of 7.436 and 7.636 kDa. Their amino acid sequences are similar to crotratroxin, a disintegrin isolated from the venom of the western diamondback rattlesnake (C. atrox). The amino acid sequence of mojastin 1 was identical to the amino acid sequence of a disintegrin isolated from the venom of the Timber rattlesnake (C. horridus). The disintegrins from the Mohave rattlesnake venom were able to inhibit ADP-induced platelet aggregation in whole human blood both having IC50s of 13.8 nM, but were not effective in inhibiting the binding of human urinary bladder carcinoma cells (T24) to fibronectin.

Adenosine Diphosphate↗
PubMed2001

Identification and molecular characterization of 18 paramyxoviruses isolated from snakes.

Viral agents from 18 different snake species (families Colubridae, Viperidae, and Crotalidae) showing respiratory symptoms and neuronal disease were identified as paramyxoviruses by typical cytopathogenic effect (CPE), electron microscopy, and hemagglutination inhibition. Detailed molecular characterization of the viruses was performed by partial L- and F-gene-specific reverse transcription polymerase chain reaction (RT-PCR) and sequencing, nucleotide and amino acid sequence alignment, and phylogenetic analysis (PHYLIP). RT-PCR of the partial L-gene (566 nt) was successful for all 18 viruses; amplicons of the partial F-gene (918 nt) could be obtained in 16 cases. F- and L-sequence alignment revealed similarities to Fer de Lance virus (FDLV) ranging from 79 to 88% on a nucleotide basis, and 94 to 99% on an amino acid basis. Phylogenetic analysis of the ophidian paramyxoviruses resulted in three clusters for the L-gene sequence and corresponding clusters for the F-gene sequence, indicating no species specificity. We analyzed the F-protein of the snake paramyxoviruses, which proved to have an identical conserved motif of heptad repeat A and predicted a furin cleavage site. This uniformity distinguishes the snake virus group from the other type species of the subfamily Paramyxovirinae. For further classification, we aligned the sequences of the ophidian paramyxoviruses and members of the Paramyxoviridae, such as Sendai virus (genus Respirovirus), mumps virus (genus Rubulavirus), measles virus (genus Morbillivirus), human respiratory syncytial virus (genus Pneumovirus) (Van Regenmortel and 10 co-authors, 2000) and Hendra virus, which have recently been suggested as type species of the genus Henipavirus (Wang et al., 2000). Maximum sequence similarity was found to the partial L-gene of Sendai virus, with 56% nucleotide and 61% amino acid identity. The FDLV and Sendai virus cluster in the phylogenetic analysis of L- and F-protein regarding the Paramyxovirus type species and Hendra virus and show the closest relationship. Regarding the biological properties, the antigenic distance, and particularly the low homology of available sequences, we propose a new genus for the reptilian paramyxoviruses within the Paramyxoviridae.

Amino Acid Sequence↗
PubMed2001

Snake inhibitors of phospholipase A(2) enzymes.

Phospholipase A(2) (PLA(2)) enzymes consist of a large family of proteins which share the same enzymatic function and display considerable sequence homology. These enzymes have been identified and characterised in mammalian tissue and snake venoms. Numerous physiological functions have been attributed to mammalian PLA(2)s and they are nontoxic. In comparison, venom PLA(2)s are toxic and induce a variety of pharmacological effects that are probably mediated via membrane receptors. Snake PLA(2) inhibitors (PLIalpha), with a similar structure to the M-type receptor, have been identified as soluble complexes in the serum of viperinae and crotalinae snakes. These inhibitors showed selective binding to crotalid group II PLA(2)s and appeared to be restricted to the serum of this snake family. Analysis of PLA(2) binding to recombinant fragments of PLIalpha indicated that the CRD region was most likely responsible for enzyme inhibition. A second type of inhibitor, PLIbeta, has been identified in serum from one viperid snake and consists of a leucine-rich structure. The third type of inhibitor, PLIgamma, was found in the serum of five snake families and contains a pattern of cysteine residues that define a three-finger structure. PLIgamma inhibitors isolated from the serum of Elapidae, Hydrophidae, Boidae and Colubridae families were able to inhibit a broad range of enzymes including the nontoxic mammalian group IB and IIA PLA(2)s, and bee venom group III PLA(2). However, differences in the binding affinities indicated specificity for particular PLA(2)s. A different representation has emerged for crotalid and viperid snakes. Their PLIgammas did not inhibit bee venom group III, mammalian group IB and IIA enzymes. Furthermore, inhibition data for the gamma-type inhibitor from Crotalus durissus terrificus (CICS) showed that this inhibitor was specific for viperid beta-neurotoxins and did not inhibit beta-neurotoxins from elapids [1]. Further studies are required to determine if this phenomenon is true for all gamma-type inhibitors from Crotalidae snakes. The relative distribution of these inhibitors, their specificities and the structural features involved in binding are discussed in this review.

Animals↗
PubMed1995

Higher-level snake phylogeny inferred from mitochondrial DNA sequences of 12S rRNA and 16S rRNA genes.

Portions of two mitochondrial genes (12S and 16S ribosomal RNA) were sequenced to determine the phylogenetic relationships among the major clades of snakes. Thirty-six species, representing nearly all extant families, were examined and compared with sequences of a tuatara and three families of lizards. Snakes were found to constitute a monophyletic group (confidence probability [CP] = 96%), with the scolecophidians (blind snakes) as the most basal lineages (CP = 99%). This finding supports the hypothesis that snakes underwent a subterranean period early in their evolution. Caenophidians (advanced snakes), excluding Acrochordus, were found to be monophyletic (CP = 99%). Among the caenophidians, viperids were monophyletic (CP = 98%) and formed the sister group to the elapids plus colubrids (CP = 94%). Within the viperids, two monophyletic groups were identified: true vipers (CP = 98%) and pit vipers plus Azemiops (CP = 99%). The elapids plus Atractaspis formed a monophyletic clade (CP = 99%). Within the paraphyletic Colubridae, the largely Holarctic Colubrinae was found to be a monophyletic assemblage (CP = 98%), and the Xenodontinae was found to be polyphyletic (CP = 91%). Monophyly of the henophidians (primitive snakes) was neither supported nor rejected because of the weak resolution of relationships among those taxa, except for the clustering of Calabaria with a uropeltid, Rhinophis (CP = 94%).

Animals↗
PubMed1978

Behavior and phylogeny: constriction in ancient and modern snakes.

Comparative analyses of behavior have an underappreciated potential for revealing the role of ethoecological factors in the origins of higher taxa. Twenty-seven species (13 genera) in the advanced family Colubridae exhibited 19 patterns of coil application; one or two patterns were usually consistent within a genus. Forty-eight species (26 genera) in the primitive families Acrochordidae, Aniliidae, Boidae, and Xenopeltidae usually used a single pattern, despite differences in age, size, shape, habitat, and diet. This implies the shared retention of an action pattern used by their common ancestor no later than the early Paleocene. Constriction must have been used as a prey-killing tactic very early in the history of snakes and might have been a behavioral "key innovation" in the evolution of their unusual jaw mechanism.

Animals↗
PubMed2000

A survey of hemoparasite infections in free-ranging mammals and reptiles in French Guiana.

Blood smears of 1,353 free-ranging mammals (35 species) and 112 reptiles (31 species) from French Guiana were examined for hemoparasites. Parasites from 3 major groups were recorded: Apicomplexa (including hemogregarines, piroplasms, and Plasmodium spp.), Trypanosomatidae, and Filaroidea. Fifty percent of the individuals (86% of the species) were infected by parasites from at least 1 group. Hemogregarines, identified as Hepatozoon sp., infected numerous snakes with high prevalences (30-100%); infection is reported for the first time in 5 host genera of snakes: Clelia, Oxybelis, Pseustes, Rhinobotryum, and Bothriopsis. Infections were also observed in 4 marsupial species and 1 rodent. Hepatozoon spp. recorded in Didelphis albiventris (Marsupialia) and Coendou prehensilis (Rodentia) may be new species. Plasmodium sp. were observed in 2 snake species, Dipsas indica (Colubridae) and Bothrops atrox (Viperidae). Plasmodium brasilianum was recorded in all 5 primate species examined. Piroplasms were observed in all mammal orders except primates. Large terrestrial rodents were the main hosts of members of the Babesidae; 42% of Myoprocta acouchy, 36% of Dasyprocta agouti, and 44% of Agouti paca were infected. Trypanosomes were common in mammals and were recorded in 70% of the examined genera. Trypanosoma cruzi-like infections were reported in 21 mammal species, including sloths, rodents, carnivores, and primates. Microfilariae were also widespread, with higher prevalences in sloths, anteaters, and porcupines (>40% of the individuals infected) and in tamarins (95% infected). This survey highlights some potential anthropozoonotic risks due to the recent further evidence of Plasmodium brasilianum and P. malariae as a single species and to the increased diversity of hosts for Trypanosoma cruzi.

Animals↗
PubMedDate not supplied

Reptile envenomations.

Venomous reptiles are distributed in select habitats in temperate and tropical areas of the world with few geographical exceptions, and have adapted to not only terrestial existence, but to arboreal and aquatic environments as well. Venomous snakes are found in the families Colubridae (fixed and rear fanged snakes), Elapidae (fixed and front fang snakes), Hydrophiidae (sea snakes), Viperidae (Old World vipers) and Crotalidae (pit vipers). Venomous lizards are found in the United States and Mexico, and comprise the family Helodermatidae. Venom delivery systems and venom components show diversity, and greater appreciation of interspecies clinical effect is apparent in modern literature. First aid care for the bitten individual remains controversial, but most authorities now tend to minimize field procedures, especially those endeavors which may potentially damage tissue. The weight of evidence in the area of definitive therapy lies with the use of antivenin, although proponents of primary surgical intervention in crotalid envenomations have followings, particularly in the United States. Recent developments in "purification" of existing antivenins are promising, and attention to species-specific antivenin production, especially to the venoms of the crotalid species of the New World, is encouraged. Due to a growing international traffic in venomous animals for the purposes of research and supply of zoos and private reptile collections, knowledge of resources for assistance in bites of non-indigenous reptiles is a growing consideration.

Animals↗
PubMed2000

[Reptiles from Cerro Colorado and its surroundings, Cumana, Sucre State, Venezuela].

An inventory of the reptiles that inhabit in Cerro Colorado and its surroundings, was performed from March, 1994 to March, 1995. There were reported 8 species of snakes and 7 of lizards enclosed in 4 and 5 families repectively. Aspects observed were ecolology as habitat, activity, reproduction and relative abundance. The more abundant species of lizards were: Cnemidophorus femniscatus, Ameiva bifrontata, (Teiidae), Tropidurus hispidus (Tropiduridae), Gonatodes vittatus and Hemidactylus mabouia (Gekkonidae) and the ophidians: Leptodeira annulata and Mastigodryas amarali (Colubridae). It is believed that the changes occurred in the zone influenced the increase of the relative abundance of the species Leptotyphlops goudotii (Leptotyphlopidae) arid Gymnophthalmus speciosus(Gymnophthalmidae) and perhaps in the disappearance of others that have been reported at the xerophitic or semixerophitic zones of the Sucre State of Venezuela.

Animals↗
PubMed2001

[Inventory of reptiles in 2 semi-arid zones from Northeastern of the Peninsula de Araya, Sucre State, Venezuela].

The fauna of reptiles in two localities from Northeastern Peninsula de Araya (Guayacán and El Morahal), Sucre State, Venezuela, was evaluated. Both zones are characterized by a vegetation of thorny tropical mount type, and semiarid climate of scarce precipitations (less than 700 mm). Field trips were made between june 1997 and june 1998. The samples were collected both during day and night, with the aid of conventional accessories. The information was complemented with visual registrations and bibliography revision. A total of 21 species were captured and/or observed, distributed in 10 families belonging to 2 of the 3 orders present in Venezuela. The most important families from the point of view of the diversity of species, were the Gekkonidae (2.00 bits/species) for the lizards and the Colubridae (2.33 bits/species) among the snakes. It was also reported one species of tortoises and three of cinegetic interest, being Cnemidophorus lemniscatus, Ameiva bifrontata y Tropidurus hispidus the only species of constant presence during the study.

Animals↗
PubMed2000

Evolution and phylogenetic information content of mitochondrial genomic structural features illustrated with acrodont lizards.

DNA sequences from 195 squamate reptiles indicate that mitochondrial gene order is the most reliable phylogenetic character establishing monophyly of acrodont lizards and of the snake families Boidae, Colubridae, and Viperidae. Gene order shows no evidence of evolutionary parallelisms or reversals in these taxa. Derived secondary structures of mitochondrial tRNAs also prove to be useful phylogenetic characters showing no reversals. Parallelisms for secondary structures of tRNAs are restricted to deep lineages that are separated by at least 200 million years of independent evolution. Presence of a stem-and-loop structure between the genes encoding tRNA(Asn) and tRNA(Cys), where the replication origin for light-strand synthesis is typically located in vertebrate mitochondrial genomes, is found to undergo at least three and possibly as many as seven evolutionary shifts, most likely parallel losses. This character is therefore a less desirable phylogenetic marker than the other structural changes examined. Sequencing regions that contain multiple genes, including tRNA genes, may be preferable to the common practice of obtaining single-gene fragments for phylogenetic inference because it permits observation of major structural changes in the mitochondrial genome. Such characters may occasionally provide phylogenetic information on relatively short internal branches for which base substitutional changes are expected to be relatively uninformative.

Animals↗
PubMed2002

[Action of venoms on blood coagulation: diagnosis of hemorrhagic syndromes].

Venoms from Viperidae, Crotalidae, some Australian Elapidae and few Colubridae are a mixture of enzymes which impact on blood coagulation in several ways. These proteins can be classified as haemorragins which induce disorders of the capillary permeability, disintegrins and related proteins which disturb the clotting time while acting on plate adhesion, and proteases which cleave peptides. Venoms contain molecules directed against several targets of the coagulation system. The same molecule may present different activities. Components of snake venoms are used in diagnostic coagulation tests, fundamental research and as drugs against infectious agents, cancer or haematological disorders. The structural differences between proteins from snake venoms and natural coagulation factors and the target diversity of the venom components explain why it remains illusory to treat bleedings when acting just at symptom level. Conversely, antivenom, whose components are directed against the venom proteins, is the only aetiological therapy effective against snake envenomations.

Animals↗
PubMed2001

Snake bite in Nigeria.

Four families of venomous snakes are found in Nigeria--Viperidae, Elapidae, Colubridae and Actraspididae but three species carpet viper (Echis ocellatus), black-necked spitting cobra (Naja nigricollis) and puff adder (Bitis arietans), belonging to the first two families, are the most important snakes associated with envenoming in Nigeria. The incidence of bites has been reported as 497 per 100,000 population per year with a 12 percent natural mortality, with Echis ocellatus accounting for at least 66 percent in certain foci. Bites occur more often while victims were farming, herding or walking although the spitting cobra may bite victims who roll upon it in their sleep. Carpet viper venom contains a prothrombin activating procoagulant, haemorrhagin and cytolytic fractions which cause haemorrhage, incoagulable blood, shock and local reactions/ necrosis. The spitting cobra bite manifests with local tissue reaction and occassionally with bleeding from the site of bite, but no classic neurotoxic feature has been observed except following Egyptian cobra (N. haje) bites. Cardiotoxicity and renal failure may occassionally occur following bites by the carpet viper and the puff adder. In the laboratory, haematological and other features are noted and immunodiagnosis has a role in species identification. Immobilisation of the bitten limb is probably the single most important first aid measure. Antivenom should be used cautiously when indicated. As only 8.5 percent of snake bite victims attend hospitals in Nigeria, health education should be the main preventive measure, mean-while, the study of immunisation of occupationally predisposed individuals in endemic areas should be intensified. A new Fab fragment antivenom specific to Nigerian Echis ocellatus was investigated clinically, just as the local herbs-Aristolochia spp, Guiera spp and Schummaniophyton spp are investigated experimentally.

Animals↗
PubMed2006

Snakebite.

The five families of poisonous snakes are: Viperidae, elapidae, colubridae, hydrophidae, atractaspididae. The commonly seen snakes in India are saw scaled viper, Russell's viper, common cobri and common crait. The venom of a single snake contains all the toxins. The venom of viperidae is haemotoxic. It may complicate with acute renal failure if left untreated. The venom of elapidae is neurotoxic. Management consists in two parts-general and specific. Supportive treatment is done with the use of antibiotics and tetanus immunoglobulin/toxoid. Specific therapy for viper bite is elaborated in this article. Elapid bite and hydrophidae bites are also discussed. Prevention of snakebite is done with avoidance of contact with a snake by using protective knee length footwear and thick gloves. Venom toxoids are used for secondary prevention among the farmers of Japan.

Animals↗
PubMedDate not supplied

[Conserved and variable segments of the snake phospholipase A2 amino acid domain].

Homologous amino acid sequences of phospholipases A2 of snakes belonging to families Elapidae, Viperidae and Colubridae were considered in order to study the location of conservative and variable regions. To identify significant conservative and variable regions a comparison between two groups of aligned sequences of snake phospholipases A2 was successfully applied. The phospholipases A2 sequences were divided into two groups (taxons) according to the phylogenetic tree reconstructed from the pair distance matrix. Results of the comparison were plotted to facilitate the identification of significant conservative and variable regions. It was shown, that the results of the comparison between two phylogenetic groups of snake phospholipases A2 didn't depend much on the number of each group representatives, and the location of conservative and variable regions didn't significantly change if one of the groups was represented by the single sequence. It should be mentioned, that the more the phylogenetic difference between groups of phospholipases A2 the more was the number of significant conservative and variable regions. The knowledge of the number and location of conservative and variable regions and their dependence on phylogenetic relations between the compared taxons can be used to predict the synthetic peptide structure to obtain antibodies of various specificity. These antibodies may have either a wide range of cross-reactivity against all of phospholipases A2 or a limited range of cross-reactivity against phospholipases A2 of one taxon.

Amino Acid Sequence↗
PubMed1978

Plasmodium pessoai sp. n. from two Costa Rican snakes.

A unique malaria parasite species was found in 1/1 Spilotes pullatus (Colubridae) and 1/70 Lachesis muta (Crotalidae) from the moist Atlantic lowland forests of eastern Costa Rica. It is distinguished by small, sausage-shaped gametocytes (x 10.4 by 4.6 mu), growing schizonts that often contain a noticeable digestive vacuole with the contents partially visible, and striking spherical or bouquet-shaped segmenters whose precise merozoite numbers are difficult to discern (about 22-32) because of an intensely staining magenta or rose-colored substance in the matrix of the surrounding vacuole.

Animals↗