Structural and functional characterisation of isolated puff adder (Bitis arietans) venom serine proteases

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  Structural and functional characterisation of isolated puff adder (Bitis arietans) venom serine proteases Abstract Serine proteases (SVSPs) are known to play a major role in the haemotoxic actions of viper venom, but compared with those from other medically important vipers, the serine proteases of puff adder venoms have not been extensively characterised. To address this, we isolated, identified and characterised the bioactivity of the serine proteases within the venom of the Nigerian puff adder, which we had previously shown to be especially rich in this class of toxin. Two distinct groups were identified, each with different protein substrate specificities. Both had similar molecular weights of 52-62 kDa, with 4-6 N-glycans, but one group consisted of trypsin-like acidic SVSPs and the other of non-trypsin-like basic SVSPs with a specificity for aliphatic amino acids at the P 1 position. Each acted differently on fibrinogen: the acidic SVSPs showed thrombin-like alpha/beta-fib...

Toxic myocarditis following scorpion sting in a child: a case report and pediatric management approach

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Toxic myocarditis following scorpion sting in a child: a case report and pediatric management approach

Case presentation

A 3.5-year-old girl with no prior medical history was brought to the emergency department of a hospital in Birjand, Iran, at 23:50 by ambulance following a scorpion sting by a Hemiscorpius lepturus scorpion (locally known as “Gadim”). The sting occurred on the dorsal surface of her right upper limb. The patient presented with decreased levels of consciousness, hypotension, and anaphylactic shock. She complained of severe pain at the sting site and had experienced one episode of non-projectile, bilious, and non-bloody vomiting.

At the sting site, which appeared as a visible dot adjacent to a vein, erythema, edema, and mild tenderness were observed. Neurovascular examination of the affected hand was reported as normal. Neurologically, the patient was neither conscious nor oriented, with closed eyes, no response to verbal stimuli, and only localization to painful stimuli. The attending nurse documented an initial Glasgow Coma Scale (GCS) score of 10. Spontaneous and normal breathing was noted, and the pupils were bilaterally equal and reactive to light.


The patient was promptly placed under cardiopulmonary monitoring. Upon admission, her vital signs were as follows: respiratory rate (RR) of 30 breaths/min, heart rate (HR) of 150 beats/min, temperature (T) of 34.7 °C, oxygen saturation (SpO2) of 89%, and blood pressure (BP) of 70/42 mmHg. An emergency medicine specialist evaluated the patient, who was instructed to remain NPO, and an intravenous line was established. At the time of admission, she received two intramuscular doses of epinephrine (0.1 mg/kg, 1:1000), and 5 mg of intravenous chlorpheniramine (equivalent to 0.5 cc from the 10 mg/ml ampoule available in the Iranian pharmacopeia), and three vials of scorpion antivenom, along with intravenous normal saline (approximately 1 L over one hour) as part of fluid resuscitation to correct severe hypotension (BP 70/42 mmHg) and anaphylactic shock. Initial laboratory tests, including CBC, Diff, BUN, Cr, Bs, Na, K, Mg, Troponin I, Creatine Phosphokinase (CPK), N-terminal pro–B-type natriuretic peptide (NT-proBNP), and liver enzymes, were performed and sent for analysis. Based on clinical and paraclinical findings, no evidence of hemolysis or rhabdomyolysis was observed throughout the hospital stay. Chest X-ray (CXR) performed as part of the diagnostic evaluation, showing normal results (Fig. 1).

Akbari, A., Niksefat, F., Mirshahi, A. et al. Toxic myocarditis following scorpion sting in a child: a case report and pediatric management approach. BMC Pediatr 25, 900 (2025). https://doi.org/10.1186/s12887-025-06266-4