North American poisonous bites and stings

Cryotherapy as a coadjuvant in crotaline snakebite management with F(ab')2 antivenom: A randomized pilot study

INTRODUCTION

Local cryotherapy induces vasoconstriction, which leads to a reduction in the inflammatory process. However, the effectiveness of local cryotherapy as a coadjuvant in the treatment of snakebite with F(ab')₂ antivenom is unknown.

OBJECTIVE

To describe the clinical effectiveness of local cryotherapy as a coadjuvant in patients with snakebite treated with F(ab')₂ antivenom therapy at the Hospital Juárez de Mexico.

MATERIAL AND METHODS

Patients with grade II snakebite envenomation according to the Christopher-Rodning classification system were enrolled from the Clinical Toxicology Service of the Hospital Juárez de México. One group of patients received F(ab')₂ antivenom therapy (Antivipmyn®) plus local cryotherapy, and the other group received only F(ab')₂ antivenom therapy.

RESULTS

Thirty-eight patients were included, of whom 86.8 % were male (n = 33). Approximately 81.5 % of the subjects were injured in an upper extremity, while 18.5 % were injured in a lower extremities; 47.3 % of the subjects reported treatment of the snakebite prior to hospitalization (suction, the application of a tourniquet, incision of the bite site, or the application of traditional medicine). No differences were found concerning edema, swelling, and pain between the groups. The group that received local cryotherapy as a coadjuvant to F(ab')₂ antivenom therapy had a shorter hospital stay (Cohen's d = 1.33; 95 % confidence interval [95 % CI] = 0.74-1.62; p < 0.01) and received fewer doses of F(ab')₂ antivenom therapy (Cohen's d = 0.69; 95 % CI = 0.19-3.80; p = 0.03).

CONCLUSIONS

The use of adequate local cryotherapy as a coadjuvant to F(ab')₂ antivenom therapy reduces the length of hospital stay and the number of doses of F(ab')₂ antivenom therapy used.

Managing collapsed or seriously ill participants of ultra-endurance events in remote environments

Increasing participation in ultramarathons and other ultra-endurance events amplifies the potential for serious medical issues during and immediately following these competitions. Since these events are often located in remote settings where access may be extremely limited; the diagnostic capabilities, treatment options, and expectations of medical care may differ from those of urban events. This work outlines a process for assessment and treatment of athletes presenting for medical attention in remote environments, with a focus on potentially serious conditions such as major trauma, acute coronary syndrome, exertional heat stroke, hypothermia, hypoglycemia, exercise-associated hyponatremic encephalopathy, severe dehydration, altitude illness, envenomation, anaphylaxis, and bronchospasm. A list of suggested medical supplies is provided and discussed. But, given that diagnostic and treatment options may be extremely limited in remote settings, it is important for medical providers to understand how to assess and manage the most common serious medical issues with limited resources, and to be prepared to make presumptive diagnoses when necessary.

AaeAP1 and AaeAP2: novel antimicrobial peptides from the venom of the scorpion, Androctonus aeneas: structural characterisation, molecular cloning of biosynthetic precursor-encoding cDNAs and engineering of analogues with enhanced antimicrobial and anticancer activities

The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine residues, there are additional groups of peptides in the venoms that are devoid of cysteine residues. These non-disulphide bridged peptides are the subject of much research interest, and among these are peptides that exhibit antimicrobial activity. Here, we describe two novel non-disulphide-bridged antimicrobial peptides that are present in the venom of the North African scorpion, Androctonus aeneas. The cDNAs encoding the biosynthetic precursors of both peptides were cloned from a venom-derived cDNA library using 3'- and 5'-RACE strategies. Both translated precursors contained open-reading frames of 74 amino acid residues, each encoding one copy of a putative novel nonadecapeptide, whose primary structures were FLFSLIPSVIAGLVSAIRN and FLFSLIPSAIAGLVSAIRN, respectively. Both peptides were C-terminally amidated. Synthetic versions of each natural peptide displayed broad-spectrum antimicrobial activities, but were devoid of antiproliferative activity against human cancer cell lines. However, synthetic analogues of each peptide, engineered for enhanced cationicity and amphipathicity, exhibited increases in antimicrobial potency and acquired antiproliferative activity against a range of human cancer cell lines. These data clearly illustrate the potential that natural peptide templates provide towards the design of synthetic analogues for therapeutic exploitation.

Acute kidney injury after massive attack of Africanised bees

Acute kidney injury (AKI) is a well-documented complication of massive attack by Africanised bees and can be observed 48-72 h after the accident. We report a case of Africanised bees attack followed by severe and lethal AKI. A 56-year-old man was admitted to emergency department after a massive attack of Africanised bees (>1000 bee stings). He was unconscious, presenting with hypotension and tachycardia. Mechanical ventilation, volume expansion and care for anaphylaxis were instituted. The patient was transferred to the intensive care unit (ICU) and after 48 h he developed rhabdomyolysis, oliguria, increased creatinine levels, hyperkalaemia and refractory acidosis. A diagnosis of AKI secondary to rhabdomyolysis and shock was made. The patient was treated with a prolonged course of haemodialysis. However, he progressed to refractory shock and died 5 days after admission.