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Antibody development in garter snakes (Thamnophis spp.) experimentally infected with western equine encephalitis virus.

Garter snakes (Thamnophis spp.) have been considered to possibly play an important role in the ecology of western equine encephalitis (WEE) virus. Serological tests (hemagglutination-inhibition, complement-fixation, neutralization test in mice, and plaque neutralization) to detect antibody in these reptiles following laboratory exposure t this virus have, in our experience, been unsatisfactory. A new test, the snake globulin precipitation (SGP) test, has been developed and we consider it to be reliable in detecting antibody in WEE virus-infected garter snakes. Antibody has been detected in these snakes over 4.5 years following inoculation with WEE virus. The SGP test should be a valuable tool in obtaining further information regarding the possible role of these cold-blooded vertebrates in the ecology of this important arbovirus.

Animals↗

An epidemiological study of snake bite envenomation in Papua New Guinea.

We report a study of 347 patients with snake bite envenomation in Papua New Guinea. The male: female ratio of the victims was 1.6:1 and their mean age was 24.5 years; 26% were children less than 15 years old. In all cases in which the bite site was known (334) the snake had bitten the extremities of the victim, with 71.3% of these bites being on the ankle or below. The patients came from three regions: urban Papua, rural Papua and (mostly rural) New Guinea. Snake bites occurred more frequently during the daytime in all regions, but this pattern was less obvious in New Guinea (P = 0.004), reflecting the predominance of the death adder (Acanthophis antarcticus) in New Guinea and of the taipan (Oxyuranus scutellatus canni) in Papua. Bites were commoner in the rainy season (November to April) in all groups, but this was less noticeable in rural Papua and New Guinea (P = 0.004). This may relate to seasonal activities of the rural population. The female:male ratio for patients from rural areas was higher for those 30 years of age and over than for those under 30 (P = 0.034), probably reflecting the increased gardening workload of older women. The incidence of envenomation and mortality rates after snake bite in Papua appear to have changed little over 25 years. However, increased relative numbers of taipans seem to be occurring in central Papua possibly related to the cane toad (Bufo marinus) and deforestation. We calculate the annual incidence of envenomation and the mortality rate per 100,000 to be 81.8 and 4.3, respectively, for rural central Papua, 21.8 and 2.1 for urban central Papua, and 3.0 and less than 1.0 for the Madang region of New Guinea. The importance of a standard management protocol and of improved first aid are emphasised.

Adolescent↗

Fatal cerebral haemorrhage after tiger snake (Notechis scutatus) envenomation.

OBJECTIVE: This case report illustrates the threat to life posed by tiger snake venom-induced coagulopathy, the importance of first-aid, precautions with antivenom administration, the dose of antivenom and the necessity to monitor the coagulation status. CASE SUMMARY: An 11-year-old child was envenomated several times by a tiger snake (Notechis scutatus). Despite administration of three ampoules (9000 units) of tiger snake antivenom, fatal cerebral haemorrhage occurred. Inadequate first-aid had been applied. The bite site was covered with a loose bandage instead of a pressure-immobilisation bandage. In hospital, facilities to monitor coagulation status were unavailable. CONCLUSIONS: More public education is required in first-aid management of snake envenomation. Frequent monitoring of coagulation status is necessary to optimise antivenom and coagulation factor therapy.

Blood Coagulation↗

Successful resuscitation after cardiac arrest following massive brown snake envenomation.

We report a 44-year-old Western Australian man who suffered a cardiac arrest several hours after a bite by a brown snake. He was successfully resuscitated after bolus administration of undiluted brown snake antivenom. We suggest that an initial bolus dose of at least five ampoules (5000 units) of undiluted brown snake antivenom should be given as primary therapy for cardiac arrest following brown snake envenomation in Western Australia.

Adult↗

[Viper (Vipera berus) snake bites].

Cases of snake bites (Vipera berus) have as compared with past years a rising trend in the Czech Republic. This ensues among other factors from a higher prevalence of snakes due to the improving ecological situation. The morbidity of snake bites is of no epidemiological importance, the frequency of snake bites amounts to several tens per year and in some clinically manifest intoxication does not develop. Nevertheless in individual cases, in children weakened subjects, a viper bite may be manifested by a serious and in exceptional instances fatal affection. Within the framework of first aid the authors do not recommend application of a tourniquet or dissecting of the wound because of undesirable potentiation of tissue traumatization. Non-specific treatment involves the administration of corticoids and antihistaminics. Specific immunotherapy, administration of horse antiserum (Ipser Europe, Pasteur Mérieux, France) is indicated only in case of systemic or very severe local symptoms and is associated with the risk of a severe allergic reaction. In case of severe systemic symptoms, symptomatic treatment in a health institution of the appropriate type is of fundamental importance. In all cases observation of the affected subject is recommended to rule out intoxication or the development of possible complications.

Adult↗

Dose and frequency of anti-snake venom injection in treatment of Echis carinatus (saw-scaled viper) bite.

OBJECTIVES: To assess the adequacy of initial standard dose of 100 ml of polyvalent anti-snake venom (ASV) and subsequent doses of 50 ml in correcting coagulation dysfunction in cases of viperine bite and to find the incidence of recurrence of coagulation dysfunction. The other objective was to correlate total requirement of ASV with initial coagulation profile. METHODS: Forty two adult patients of Echis carinatus bite with features of systemic envenomation, admitted over a period of 18 months, were monitored every six hours with bed-side clotting time (CT) and were given an initial standard dose of 100 ml of ASV intravenously. Further doses of 50 ml were administered six hourly until coagulation profile normalised or whenever a recurrence of coagulation dysfunction observed. RESULTS: Twenty one (50%) of 42 patients who received initial standard dose of 100 ml of ASV required a subsequent 50 ml of ASV. Ten (23.8%) of them required a further 50 ml on subsequent test (making the total requirement at least 200 ml). Sixteen (72.7%) of 22 patients who had incoagulable blood at entry required further dose of anti-snake venom (after initial 100 ml), six required 150 ml and ten 200 ml or more before CT returned to normal. Recurrence of venom antigenemia as evidenced by prolonged clotting time was noticed in 15 patients (35.7%). The mean dose requirement of anti-snake venom was 179.2 ml. CONCLUSIONS: Total requirement of anti-snake venom correlated positively with degree of coagulation dysfunction at entry. Hence patients having incoagulable blood at entry should be administered higher initial dose of ASV i.e., 150-200 ml. If needed as judged by CT, subsequent dose of ASV in patients having still incoagulable blood should be 100 ml (and those having mild dysfunction 50 ml) until total correction occurs Recurrence of coagulation dysfunction was observed in approximately one-third of patients and thus, CT should be monitored even after total correction.

Adult↗

Preparation and chemical characterization of the three chains of the major hemoglobin of the sea snake, Pelamis platurus.

One of the 2 main hemoglobins of the sea snake Pelamis platurus, (the Yellow-bellied sea snake) comprising about 70% of the total hemoglobin, was separated by DEAE-Sephadex column chromatography. From results of gel filtration and iron content determination, both intact sea snake hemoglobin, and the isolated major hemoglobin, were concluded to be composed of 4 subunits with a molecular weight of 66,000-67,000 daltons. Separation of the chains of globin of the major hemoglobin by CM 52 column chromatography gave 3 peaks, named, chains a, b, and c. The approximate molecular weights of chains a, b, and c were deduced by SDS gel electrophoresis to be 14,000, 16,000, and 20,000 daltons, respectively. The peptide maps and amino acid compositions of the three chains were distinctly different. N-Terminal and C-terminal amino acid sequence studies reveal that chains a, b, and c represented the alpha-chain, beta-chain, and beta'-chain differing from the normal beta-chain in having a C-terminal sequence of -Arg-Leu-His-Tyr. From the peak areas of the 3 chains obtained by CM 52 column chromatography, and the peak sizes of the 3 bands separated by SDS gel electrophoresis, it was concluded that the sea snake hemoglobin is composed of a hybrid tetramer, alpha2betabeta'.

Amino Acid Sequence↗

[Identification of seven snake-drugs by iso-electric point].

This paper deals with the identification of seven snake-drugs by means of iso-electric point of protein. The experimental results show that different species of snake-drugs have different iso-electric points. The experimental data are accurate and easily reproducible (CV less than 0.5%). The difference of the averages of iso-electric points of the seven snake-drugs (P less than 0.01%) is extremely significant and thus provides a scientific criterion for the identification of peeled or powdered snake-drugs.

Animals↗

Liquid chromatographic determination of 4,4'-dinitrocarbanilide, the active component of the infertility agent nicarbazin, in chicken, duck, goose, and snake eggs.

4,4'-Dinitrocarbanilide (DNC) was extracted from chicken, duck, goose, and snake eggs and isolated by reversed-phase liquid chromatography. DNC was detected by ultraviolet absorbance at 347 nm and quantitated by comparison with a calibration standard. Recoveries of DNC from fortified control chicken, duck, goose, and snake egg samples were determined for DNC levels of 0.16, 10, and 16 microg/g. The mean recoveries from chicken, duck, goose, and snake eggs were 92 +/- 4, 88 +/- 9, 87 +/- 7, and 95 +/- 6%, respectively. The method limits of detection for DNC in chicken, duck, goose, and snake eggs ranged from 0.015 to 0.035 microg/g. The reported method is much simpler than and equally efficient as previous methods developed for the determination of DNC residues in egg contents.

Animals↗

Limited proteolysis of human and rabbit immunoglobulins by snake venoms produces Fab-like fragments.

Rabbit and, to a lesser extent, human immunoglobulins (IgGs) are cleaved by snake venoms. The snake venom proteases active on IgGs release fragments which behave on SDS-PAGE like Fab units similar to those released by the thiol-activated enzymes. However, in contrast to the cysteine proteases, the activity of snake venom proteases on IgGs is not only blocked by metal chelating agents but is also inhibited by thiol compounds. The snake enzymes active on IgG are metalloproteases.

Animals↗

Profile of cardiac complications of snake bite.

The present study was conducted in 30 cases of snake bite to understand fully the intricacies of the cardiac profile and to render help in the management of the problem arising out of them. All were subjected to routine and specific investigations (ECG, X-ray Chest, SGOT). The present study concluded that 57 per cent of patients of snake bite were in 2nd and 3rd decades of life. Viperine snake bite occurred in 93 per cent and elapide snake bite in 7 per cent of cases. Cardiotoxicity was seen in only 25 per cent patients with viperine bite. Seventy-six per cent of the patients presented within 24 hours of the bite. Seventy per cent of patients had haemorrhagic manifestations and 30 per cent had cardiotoxicity. The disturbance in heart rate was seen in 47 per cent, rhythm disturbance in 6.7 per cent, tachycardia in 36.7 per cent and bradycardia in 10 per cent cases. Hypertension was found in 6.7 per cent, hypotension in 16.7 per cent. Thirty per cent of patients had gallop rhythm and it persisted in 16.6 per cent patients till discharge. One patient had evidence of pulmonary edema and one had basal congestion. Cardiomegaly on chest X-ray was found in one patient and elevated SGOT titres were found in ten per cent. Common electrocardiographic changes were sinus tachycardia, sinus arrhythmia (6.6%), sinus bradycardia (10%), tall T-wave in V2 (3.3%), pattern suggestive of acute anterior wall infarction with reciprocal changes (3.3%), myocardial ischemia (10%), non-specific ST-T changes (16.7%) and atrioventricular block (3.3%). The mortality rate was 10 per cent and all these patients had bleeding manifestations and abnormal electrocardiograms.

Adult↗

[Snake venom proteins in hemostasis: new results].

Biological features of venomous snakes as well as biochemical properties and actions of their venoms which serve for prey acquisition, indicate the vertebrates' haemostasis system as a vulnerable target for snake venom actions. Components exerting a specific, either stimulating or inactivating effect on basal membrane or endothelial cells of the vascular wall, on platelets, on almost every step of plasma coagulation or fibrinolysis respectively, have been isolated and purified from snake venoms. Snake venom proteins acting with a defined specificity on cellular or plasmatic components of the human haemostatic system are being used in coagulation and aggregation tests, in photometric assays in conjunction with chromogenic substrates as well as in immunological systems as biochemical tools for research and diagnostic purposes.

Blood Coagulation↗

Thrombocytopenia after brown snake envenomation.

The marked coagulation disturbances in patients after severe envenomation by brown snakes (genus Pseudonaja) were examined with particular emphasis on the sequential platelet counts. The common finding (in almost half the studied patients) of a progressive depletion in platelet numbers leading to thrombocytopenia, which in one case was severe, suggests that thrombocytopenia should be considered as a possible complicating factor in the management of these patients. This trend was not a feature of the cases that involved bites by tiger snakes. The finding of this study in relation to envenomation by brown snakes is in contrast to the widely held opinion that thrombocytopenia is not an outcome of snake-bites in Australia.

Australia↗

The effect of ambient temperature and type of wound on healing of cutaneous wounds in the common garter snake (Thamnophis sirtalis).

The effects of ambient temperature (13.5 degrees C, 21 degrees C, 30 degrees C) and type of wound on healing of skin wounds were evaluated in common garter snakes (Thamnophis sirtalis). Linear unsutured incisions and circular excisional wounds were evaluated grossly and microscopically in three snakes held at each temperature at each of two, five and ten days after surgery. Linear sutured and unsutured incisions and circular and square excisional wounds were similarly evaluated three and six weeks after wound production in groups of six snakes held at each temperature. The rates of stabilization of wound margins, scab formation, migration and maturation of the regenerating epithelium, resolution of dermal inflammation, and fibroplasia varied directly with temperature. The inflammatory reaction to wounding was similar in character and intensity in snakes held at all three temperatures two days after surgery. Unsutured linear incisions, compared to sutured incisions, tended to have more rapid epithelial maturation and a less intense inflammatory response. Healing of square and circular excisional wounds was similar; contraction of round wounds was slightly more irregular and, at a few observations, dermal maturation was slower and inflammation more widespread. It was concluded that healing of skin wounds can be accelerated by holding reptiles at the upper end of their voluntary temperature range. Wounds, if possible, should be created along the axis of lines of skin tension. Suturing small incisional wounds may not be advantageous.

Animals↗

Effects of ambient temperature on the half-life and dosage regimen of amikacin in the gopher snake.

Eight gopher snakes were given amikacin (5 mg/kg of body weight IM) and were housed at ambient temperatures of 25 C or 37 C. Snakes housed at 37 C had a larger volume of distribution, and a more rapid body clearance of amikacin while the apparent half-life was not changed significantly. The minimum inhibitory concentrations of amikacin against isolated snake pathogens were determined at both temperatures. Bacteria were twice as sensitive at 37 C than at 25 C. The data indicated that amikacin should be given IM at a dose schedule of 5 mg/kg (loading dose) followed by 2.5 mg/kg every 72 hours, and that snakes should be housed near the high end of their preferred optimum ambient temperature during treatment.

Amikacin↗

Antibody against Western equine encephalitis virus occurring in the serum of garter snakes (Colubridae: Thamnophis) in Saskatchewan.

A study was made of feeding and temperature as factors affecting the appearance of western equine encephalitis (WEE) virus-neutralizing serum (VNS) antibodies in the serum of garter snakes (Thamnophis spp). Eighty snakes were collected in the field, held in captivity under controlled conditions, and bled at frequent intervals. The sera were examined by standard procedures for the presence of WEE VNS-antibodies. It was found that snakes held between 10-28 degrees C showed conversion and intermittent WEE VNS-antibody appearance, whereas snakes held at 6 degrees C showed a decline in titre. The appearance of WEE VNS-antibody was related to environmental temperature, or a temperature-controlled factor, and not to feeding.

Animals↗

Evaluation of a bait trap for Habu, the venomous snake, Trimeresurus flavoviridis.

The box trap for the venomous snake, Trimeresurus flavoviridis, 25 X 45 cm and 15 cm high, was made of a sheet of polypropylene board, and involved the use of a small rodent in a wire mesh cage as bait. The efficacy of this trap was evaluated in the field on Tokunoshima Island, one of the southern-most islands of Japan. The catch rate of the trap was expressed by the probability of snakes caught in trap-days, a product of the number of traps set and the period of set days. In one experiment, a result was successfully achieved by setting the boxes for almost 2,000 trap-days each for 2 different test materials in a limited geographical area. The one-way entrance made of flexible polyethylene sticks arranged conically allowed significantly more invasion of snakes than that of a swinging hinged door as shown by the catch rates of 12 snakes/1721 trap-days to 0/1682, respectively. Using traps with a conical entrance, the catch rate with the albino rat, Ratus norvegicus, was 6/2324 which was significantly higher than 0/2450 using rat feces as attractant. The catch rate with the field rat, Ratus rattus, at 31/2402 was significantly about 6 times higher than 5/2446 with the albino rat, whereas an albino rat was about 5 times more attractive than 2 albino mice at significantly different rates of 17/2455 and 3/2284, respectively. The box trap baited with a small rodent proved attractive to snakes and attractiveness differed with the species of bait animals.

Animals↗

Complement in the serum and venom of Brazilian snakes (Crotalidae).

Proteins antigenically related to CoF, the anticomplementary protein of the venom of the Indian hooded cobra (Naja naja), were found in a variety of elapid and viper venoms but not in the venom of Brazilian crotalids . In keeping with this finding was the weak ability of Brazilian snake venom to convert C3 in human serum. All snake serums tested, including Brazilian crotalids , contained a beta-globulin antigenically related to CoF. This serum protein in Brazilian snake serum had a number of characteristics of mammalian C3, including conversion on storage or on incubation of this serum with endotoxin, zymosan or mammalian antigen-antibody precipitates. The serum protein did not, however, convert on incubation with hydrazine. Brazilian crotalid serum did not, as did cobra serum, have the ability to inactivate CoF's ability to activate complement in normal human serum. The crotalid serum had hemolytic activity for rabbit antibody-sensitized and unsensitized sheep red blood cells that was active in the presence of Ca++ and Mg++ or Mg++ alone but greater with Ca++ present, suggesting the presence of both classical and alternative pathways of complement activation. This activity was maximal at 37 degrees C, but was destroyed or inactive after heating at 50 degrees C for 1 hr, incubation with hydrazine or by addition of EDTA. A marked reduction of hemolytic activity of Bothrops serum occurred after removal of the CoF-like protein. These findings suggest that Brazilian snake venom has little CoF-like material, but its serum contains a CoF-like protein with many characteristics of C3.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗