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PubMedDate not supplied

[Mortality from contact with poisonous snakes and lizards in Mexico from 1979 to 2003].

OBJECTIVE: To describe the trend of standardized mortality by contact with poisonous snakes and lizards in Mexico from 1979 to 2003. MATERIAL AND METHODS: We describe the standardized mortality trend by contact with poisonous snakes and lizards occurring in Mexico from 1979 to 2003, and report the mortality data bases from the INEGI (Instituto Nacional de Estadística, Geografía e Informática). We determined frequencies, percentages, mortality rates, standardized mortality rates and mortality relative risks with 95% confidence intervals. RESULTS: The general trend shows a statistically significant descent of 63.8%. The highest mortality rate within the 2000-2003 period was reported in Quintana Roo (7.47/1,000,000), Oaxaca (4.01/1,000,000), Veracruz (1.56/1,000,000), Chiapas (1.48/1,000,000), Campeche (1.43/1,000,000) and Yucatan (1.29/1,000,000). The groups with the highest risk are those older than 60 years and males. CONCLUSIONS: In spite of the detected decrease in mortality, the contact with poisonous snakes and lizards still is a public health problem in Mexico. As timely treatment saves lives, it is necessary to include and offer treatment in all emergency units of the country.

Adolescent↗
PubMed1991

Snake venom constituents: biochemistry and toxicology (Part 1).

Complicated and mystifying as the snake envenomation process may appear, the toxic principles of snake venoms are biochemical entities that could be isolated, purified and characterized. In this review, the toxicological process of envenomation and the biochemical basis of venom toxicity are presented for those not directly involved in venom research but who nevertheless have an interest in snake venom poisoning.

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↗
PubMed1991

Characterization and immunological comparison of isoenzymes of phospholipases A2 from snake venoms of different genera and families.

Phospholipases A2 (PLA2) were isolated and purified from the Taiwan cobra (Naja naja atra) and several snake species of the same or different genera by semipreparative cation-exchange and reversed-phase HPLC. They were shown to possess different enzymatic activity toward the synthetic substrate L-alpha-lecithin by the fatty-acid titration method. The immunological cross-reactivity of these structurally similar isotoxins was investigated using immunodiffusion, precipitin reaction and enzyme-linked immunosorbent assay (ELISA). PLA2 from the venoms of the same species such as the Taiwan cobra (Naja naja atra) and the Indian cobra (Naja naja naja) showed a high degree of antigenic resemblance whereas no immunoreactivity was observed among those PLA2 from different genera. Quantitative immunoreactivity assays by ELISA revealed the partial cross-reactivity between the antibody against PLA2 of Taiwan cobra and those isoenzymes from snakes of remotely-related species. The immunological relatedness between PLA2 of the representative snake species of different genera and families is shown to be correlated with the extent of sequence homology among these enzymes.

Amino Acid Sequence↗
PubMedDate not supplied

[Epidemiology and clinical picture of accidents by adult and young snakes Bothrops jararaca].

Four hundred and fifteen cases of bites by adult Bothrops jararaca (group A) were admitted to the Hospital Vital Brasil between 1981 and 1987. These cases were compared to 562 cases of bites by young snakes of the same species (group B) during the same period and at the same hospital. In group B blood incoagulability was more frequent when compared to group A. However in group A bites in the leg, use of tourniquet, tecidual damage (blister, necroses and abscess), were more frequent when compared to group B. The doses of sero given for the group A was greater when compared to group B. Accidents month distribution, dates available were for the patients admitted between 1975 and 1988. The accidents were more frequent in the first and at the end of the year. In the first months of the year for the young snakes and mainly at the end of the year for the adult snakes.

Adolescent↗
PubMed1985

Mixed leucocyte reaction (MLR) in the snake Psammophis sibilans.

In spring, spleen cells (SC) derived from outbred adult snakes, Psammophis sibilans, proliferated vigorously in mixed leucocyte cultures (MLC), thus indicating that reptiles are endowed with the subset(s) of lymphocytes capable of recognizing and responding to alloantigens. Sephadex G-10- or nylon wool-adherent latex-ingesting cells provided accessory, rather than stimulatory, function in MLC. The data, based on numerous one- and two-way MLR studies, showed that the snake P. sibilans possesses strong lymphocyte-activating determinants (LAD) which, however, appeared not to be extensively diverse, as mutually or unilaterally unresponsive SC combinations were quite often observed. Furthermore, seasonal investigations revealed that the lymphoproliferative response in MLR is considerable only in some months of spring and autumn, being abrogated during the rest of the year. These findings suggest that antigen sharing and environmental conditions greatly restrict the cell-mediated immune potential of snakes.

Animals↗
PubMed1988

The effect of certain topical medications on healing of cutaneous wounds in the common garter snake (Thamnophis sirtalis).

The effects of four topical medications on the rate and character of healing of cutaneous wounds were studied in six common garter snakes (Thamnophis sirtalis) held at an ambient temperature of 30 degrees C. Two sets of five 6 to 8 mm round excisional wounds, four test and one control site in each set, were created on the dorsolateral body wall of each snake. Wounds were examined daily and treated for ten days, then the snakes were killed and sections of all wounds were examined by light microscopy. Composite scores, derived by ranking each treatment group in relation to the control group (control score = 0) for each of 22 characteristics associated with wound healing, were used to compare the overall effects of each treatment. Statistical comparisons were made between groups for 20 characteristics. Wounds treated with a polyurethane film merited a score of +12 and had significantly more advanced healing than untreated controls for three characteristics. Wounds treated with an ointment containing scarlet red scored +6 but healing was not significantly greater than controls. Wounds treated with an antibacterial spray powder and an antibacterial ointment healed more slowly than controls and had scores of -6 and -12 respectively.

Administration, Topical↗
PubMed1985

Social dynamics of group courtship behavior in male red-sided garter snakes (Thamnophis sirtalis parietalis).

Mating in red-sided garter snakes is characterized by the formation of mating balls. Up to 100 males simultaneously court single females. The social dynamics of the formation of these mating balls was examined to determine whether the mating balls are formed simply because of a common attraction to the female or whether males are stimulated by the mating balls themselves. A sexually attractive female garter snake appears to be even more attractive to a male when she is being courted by other males than when she is alone. Male garter snakes courted females more actively when other males were also courting the female than when they were alone with her. There is a positive correlation between the number of additional males present and the amount of courtship activity shown by the test male toward the stimulus female. The extent to which the courtship activity of the test males was stimulated by the presence of additional courting males was not influenced by how actively the additional males courted.

Animals↗
PubMed1984

Preliminary study on the use of ceftazidime, a broad spectrum cephalosporin antibiotic, in snakes.

Ceftazidime, a broad spectrum cephalosporin antibiotic with an enhanced anti-pseudomonal activity, was tested in vitro against a variety of reptilian bacterial isolates. Blood concentrations of this antibiotic were determined in clinically ill snakes following an intramuscular injection at a dose rate of 20 mg kg-1. Peak plasma levels of up to 70.5 micrograms ml-1 were reached one to eight hours after the injection and therapeutic plasma levels were maintained for at least 96 hours. A series of snakes treated with ceftazidime at a dose rate of 20 mg kg-1 every 72 hours showed a rapid and obvious clinical response to treatment. The snakes were maintained at 30 degrees C during treatment and the effect of environmental temperature on antibiotic half-life is discussed. Ceftazidime proved to be a highly active antibiotic against the bacteria known to cause disease in reptiles, with no obvious adverse effects having been so far described.

Animals↗
PubMed1984

Carcinogenic activity of N-nitrosodiethylamine in snakes (Python reticulatus, Schneider).

Fourteen snakes of the species Python reticulatus were randomized after one year's adaptation in our laboratory, i.e., at the age of 18 months. Groups of three animals (average body weight, 1 kg) were subjected to lifelong administration of 24, 12 or 6 mg/kg body weight of N-nitrosodiethylamine (NDEA) at fortnightly intervals. The NDEA-containing aqueous solution (0.3 ml/kg body weight) was administered by gavage. Five untreated animals served as controls. Snakes receiving 24 mg/kg NDEA died from toxic liver and kidney damage within the first year of experimentation. The three snakes receiving 12 mg/kg NDEA died within the last three months of the second year of treatment. These animals had developed multiple benign and malignant tumours in the liver and the kidney. The two animals that died last also developed tumours in the oral cavity and the trachea. Animals treated with 6 mg/kg NDEA died from tumours in the trachea.

Animals↗
PubMed1980

Lymphosarcoma associated with virus-like intranuclear inclusions in a California king snake (Colubridae: Lampropeltis).

A laboratory-bred and laboratory-reared male California king snake was submitted for clinical evaluation, and a mass was palpated caudal to the stomach and within the abdominal cavity. The snake was anesthetized and the mass was excised. A constricted atonic section of adjacent small intestine was removed and the ends were subsequently reanastomosed. The snake died 2 days post surgery; after histopathologic examination of all major organs (except muscle and brain), lymphosarcoma was diagnosed. Lymphocytes, approximately 70% of which contained small to large eosinophilic intranuclear inclusions, had infiltrated all major organs. By electron microscopic examination these inclusions were found to be large electron-dense granular structures. Aggregates of circular structures that measured 50 nm were seen in the cytoplasm of several cells.

Abdominal Neoplasms↗
PubMed1995

[Snake bites].

Snake bites are a rare occurrence in Belgium. Nevertheless, all doctors should know how to react to this potentially very dangerous emergency. A snakebite does not necessarily result in poisoning: the effects can range from a little local discomfort to a severe systemic reaction with multiple organ failure. Therefore, all snake bites must be treated as serious and should receive adequate treatment. At the same time, hysterical over reaction must be avoided for this risks complications. This article reviews the principal elements of snake bite treatment: from the emergency stage through to stabilization in the hospital. Key points raised are the necessity to immobilize the affected region, to establish adequate perfusion and to anticipate infectious complications. Serum therapy indications are reviewed together with adjuvant interventions such as corticotherapy and heparin therapy.

Adrenal Cortex Hormones↗
PubMed1994

Intravenous immunoglobulin in the treatment of snake bite envenoming: a pilot study.

The standard treatment for snake bite envenoming is with snake antivenon (AVS). Reports to date on the efficacy of AVS have been equivocal. Some studies have shown a beneficial effect on the coagulopathy, while its effect on neurotoxicity is questionable. AVS therapy is also associated with a high incidence of reactions. We conducted a pilot study to compare the standard AVS therapy, with AVS plus intravenous immunoglobulin (IVIG), in the treatment of snake bite evenoming. Our study indicates that the addition of IVIG to the standard AVS regimen, eliminates the need to repeat AVS for envenoming associated with coagulopathy.

Antivenins↗
PubMedDate not supplied

[Snake bites in the state of São Paulo, Brazil].

From 1986 to 1989, 8,721 accidents caused by poisonous snakes have been notified to the Government of the State of São Paulo (Brazil), Health Department, which represented the average annual incidence rate of 6.8 to 7.4/100,000 persons. The classification of the snake genus had been possible in 6,834 cases and the distribution was: Bothrops (85.6%), Crotalus (13.3%) and Micrurus (1.1%). The vast majority of cases (5,807) occurred from November to April. The age distribution shows that 74.4% of the accidents had been suffered by people from 10 to 49 year old people with great predominance in males (77.0%). The anatomical areas more frequently bitten were feet and ankles (52.8%), hands (20.5%) and legs (17.2%). At the health center 67.5% of the patients had been treated within the first, second and third sixth hour after the accident. The distribution according to the severity of poisoning was: light (53.5%), moderate (38.3%) and severe (8.2%). The case fatality rate was 0.4%, 60,954 vials of various anti-venoms were used (an average of 7.0 vials per patient). Accidents owing to poisonous snakes are frequent in the State of São Paulo; the most important genus is Bothrops; the young male population is more often attacked; they are an important cause of death.

Adolescent↗
PubMed1998

Colonic adenocarcinoma in a corn snake (Elaphe guttata guttata).

Colonic adenocarcinoma was diagnosed by surgical biopsy in a domestically raised 3-yr-old male corn snake (Elaphe guttata guttata). The snake presented with a history of constipation. Several masses were palpated in the distal coelomic cavity. On proctoscopy, a nodular firm white mass encircled the distal colon proximal to the cloaca. The histologic diagnosis was transmural mucinous colonic adenocarcinoma with scirrhous reaction. Resection of the affected region alleviated intestinal obstruction for at least 4 mo, after which the snake was lost to follow-up.

Adenocarcinoma, Mucinous↗
PubMed1997

[Pedicled thoraco-abdominal skin flap applied in early repair of deep ulcer of upper extremity resulting from snake-bite injury].

The ulcer resulting from snake-bite injury was characterized by deep and wide tissue necrosis and secondary infection. The patient was at high risk of loss of function of his extremity. From 1989 to 1996, 16 cases with deep ulcer of the upper extremity resulting from snake-bite injury were treated with different types of axial thoraco-abdominal skin flaps, depending on the location of the ulcer. Thoraco-umbilical skin flap was used in 2 cases, lateral thoracoabdominal skin flap in 1 case, iliolumbar skin flaps in 5 cases, lower abdominal skin flaps in 6 cases, lower abdominal divided foliated skin flap in 1 case and Y-shaped hypogastric skin flap in 1 case. Reparative operation was carried out within 3 weeks after injury and primary repair were undertaken in 6 of them. The pedicles were divided in 17 to 24 days after operation. Twelve flaps survived. Three of the 6 flaps had mild signs of inflammation which disappeared after administration of antibiotics. One had necrosis of the distal part of the flap, and was healed with split skin graft. This type of skin flap was an ideal method for the treatment of snake-bite injury of the upper extremity.

Adolescent↗
PubMed2026

The genomic alchemist's arsenal: A comprehensive review of gene recruitment, regulatory rewiring, and the evolutionary arms race in snake envenomation.

Snake venom represents a striking example of evolutionary innovation, in which ancestral physiological gene networks have been co-opted into potent biochemical weapons. Advances in multi-omics, single-cell genomics, and structural bioinformatics have catalyzed a conceptual shift from descriptive toxin cataloging to a systems-level understanding of venom evolution, regulation, and function. This Review integrates genomic, cellular, and structural perspectives to delineate the molecular architecture underpinning venom diversification and target-site co-evolution. Emphasis is placed on regulatory mechanisms driving rapid expression plasticity, including super-enhancer activity, transposable element insertion, spatial heterogeneity within the venom gland, and non-coding RNA-mediated modulation. At the protein level, the review examines how hypervariable toxins engage in structural arms races with prey targets, and how multi-toxin complex formation, functional synergy, and molecular dynamics simulations inform models of lethality and resistance. A comparative framework is provided by contrasting high-potency predatory snake venoms with low-potency defensive venoms of hymenopterans such as bees and wasps, revealing how ecological selective pressures shape toxin potency, composition, and target specificity across taxa. Finally, current translational strategies are evaluated, with a focus on the relative merits of recombinant human monoclonal antibodies versus catalytic-site small-molecule inhibitors as deployable interventions for snakebite. By synthesizing evolutionary genomics, structural biology, comparative toxinology, and synthetic antivenomics, this Review outlines a predictive framework for anticipating venom evolutionary trajectories and for designing broad-spectrum, next-generation therapeutics.

Animals↗
PubMed1992

Venomous snakes of southwest Asia.

This report provides a brief description of the venomous snakes encountered in Southwest Asia, as well as a brief review of the clinical implications of envenomation from each animal. Specific therapy for snake envenomation in the United States is somewhat controversial, and it is no less controversial with animals from this region. The most logical approach probably combines medical management with antivenom when available, and surgical intervention when clearly indicated due to elevated compartment pressure or massive tissue necrosis. Antivenom is available for all species except W aegyptia (in vitro only) and Atractaspis species. Antivenom for V palaestinae may be used for Atractaspis envenomation (Tables 2 and 3).

Animals↗