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A case of volvulus of stomach complicating left phrenic interruption and left lower lobectomy

YOUNG CK

Med J Malaya, 1957 Sep;12(1):384-5.
PMID: 13492810
Matched MeSH terms: Phrenic Nerve/surgery*
Neuromuscular effects of candoxin, a novel toxin from the venom of the Malayan krait (Bungarus candidus)

Nirthanan S, Charpantier E, Gopalakrishnakone P, Gwee MC, Khoo HE, Cheah LS, et al.

Br J Pharmacol, 2003 Jun;139(4):832-44.
PMID: 12813007

1 Candoxin (MW 7334.6), a novel toxin isolated from the venom of the Malayan krait Bungarus candidus, belongs to the poorly characterized subfamily of nonconventional three-finger toxins present in Elapid venoms. The current study details the pharmacological effects of candoxin at the neuromuscular junction. 2 Candoxin produces a novel pattern of neuromuscular blockade in isolated nerve-muscle preparations and the tibialis anterior muscle of anaesthetized rats. In contrast to the virtually irreversible postsynaptic neuromuscular blockade produced by curaremimetic alpha-neurotoxins, the neuromuscular blockade produced by candoxin was rapidly and completely reversed by washing or by the addition of the anticholinesterase neostigmine. 3 Candoxin also produced significant train-of-four fade during the onset of and recovery from neuromuscular blockade, both, in vitro and in vivo. The fade phenomenon has been attributed to a blockade of putative presynaptic nicotinic acetylcholine receptors (nAChRs) that mediate a positive feedback mechanism and maintain adequate transmitter release during rapid repetitive stimulation. In this respect, candoxin closely resembles the neuromuscular blocking effects of d-tubocurarine, and differs markedly from curaremimetic alpha-neurotoxins that produce little or no fade. 4 Electrophysiological experiments confirmed that candoxin produced a readily reversible blockade (IC(50) approximately 10 nM) of oocyte-expressed muscle (alphabetagammadelta) nAChRs. Like alpha-conotoxin MI, well known for its preferential binding to the alpha/delta interface of the muscle (alphabetagammadelta) nAChR, candoxin also demonstrated a biphasic concentration-response inhibition curve with a high- (IC(50) approximately 2.2 nM) and a low- (IC(50) approximately 98 nM) affinity component, suggesting that it may exhibit differential affinities for the two binding sites on the muscle (alphabetagammadelta) receptor. In contrast, curaremimetic alpha-neurotoxins have been reported to antagonize both binding sites with equal affinity.

Matched MeSH terms: Phrenic Nerve/drug effects; Phrenic Nerve/physiology
Neuromuscular effects of four phospholipases A2 from the venom of Pseudechis australis, the Australian king brown snake

Geh SL, Rowan EG, Harvey AL

Toxicon, 1992 Sep;30(9):1051-7.
PMID: 1440642

Four homologous single chain phospholipases A2 (Pa-1G, Pa-5, Pa-12C and Pa-15) were tested for neuromuscular effects on chick biventer cervicis and mouse hemidiaphragm nerve-muscle preparations. The four isozymes blocked directly elicited (mouse hemidiaphragm) and indirectly elicited (mouse and chick nerve-muscle preparations) twitch responses in concentrations of 1-30 micrograms/ml. The order of potency seen in both types of preparations was Pa-1G = Pa-5 greater than Pa-12C much greater than Pa-15. All four isozymes caused slow-onset, sustained contractures and reduction of muscle membrane potentials. In the chick preparation, responses to acetylcholine, carbachol and KCl were reduced by exposure to the toxins. It is concluded that the toxins act primarily postsynaptically to depress muscle contractility, perhaps by directly damaging muscle fibres. The order of potency agrees with their phospholipase A2 activity. Pa-1G is unusual because it is an acidic molecule, most toxic phospholipases being basic.

Matched MeSH terms: Phrenic Nerve/drug effects
Immediate selective laryngeal reinnervation in vagal paraganglioma patients

Mat Baki M, Clarke P, Birchall MA

J Laryngol Otol, 2018 Sep;132(9):846-851.
PMID: 30180919 DOI: 10.1017/S0022215118000476

OBJECTIVE: This prospective case series aimed to present the outcomes of immediate selective laryngeal reinnervation.
METHODS: Two middle-aged women with vagal paraganglioma undergoing an excision operation underwent immediate selective laryngeal reinnervation using the phrenic nerve and ansa cervicalis as the donor nerve. Multidimensional outcome measures were employed pre-operatively, and at 1, 6 and 12 months post-operatively.
RESULTS: The voice handicap index-10 score improved from 23 (patient 1) and 18 (patient 2) at 1 month post-operation, to 5 (patient 1) and 1 (patient 2) at 12 months. The Eating Assessment Tool 10 score improved from 20 (patient 1) and 24 (patient 2) at 1 month post-operation, to 3 (patient 1) and 1 (patient 2) at 12 months. There was slight vocal fold abduction observed in patient one and no obvious abduction in patient two.
CONCLUSION: Selective reinnervation is safe to perform following vagal paraganglioma excision conducted on the same side. Voice and swallowing improvements were demonstrated, but no significant vocal fold abduction was achieved.

Matched MeSH terms: Phrenic Nerve/transplantation*
The absence of antagonism between extracts of Clinacanthus nutans Burm. and Naja naja siamensis venom

Cherdchu C, Poopyruchpong N, Adchariyasucha R, Ratanabanangkoon K

Southeast Asian J. Trop. Med. Public Health, 1977 Jun;8(2):249-54.
PMID: 199949

Clinacanthus nutans Burm, a herb reputed in Thailand and Malaysia to be "snakebite antidote" has been tested in vitro and in vivo for antivenin activity. The aqueous extract of C. nutans leaves has been found to have no effect on the inhibition of neuromuscular transmission produced by purified Naja naja siamensis neurotoxin in isolated rat phrenic-nerve diaphragm preparations. The extract of C. nutans, when given orally or intraperitoneally, are ineffective in prolonging the survival time of experimental mice receiving lethal doses of N.n. siamensis crude venom. Oral administrations of the herb extracts pretreated with alpha-amylase or beta-amylase also fail to protect the animal. It is concluded that the extract of C. nutans can not antagonize the action of cobra venom.

Matched MeSH terms: Phrenic Nerve