Envenoming by king cobras (Ophiophagus hannah) in Vietnam with cardiac complications and necrotizing fasciitis

King Cobra (Ophiophagus hannah) bite is well-known for its potentially fatal neurotoxicity. However, fatalities still occur, despite specific antivenom and respiratory support. Cardiovascular disturbances, which have attracted little attention in published reports of O. hannah envenoming, could contribute to fatality. We present two cases of confirmed O. hannah envenoming in Southern Vietnam in which there were cardiac abnormalities including arrhythmias and electrocardiographic changes, as well as elevated markers of myocardial damage. Cardiac pacing was required. One patient developed critical multi-organ dysfunctions partly explained by extensive necrotizing fasciitis/myositis originating from an Aeromonas sobria wound infection. This resulted in rhabdomyolysis, disseminated intravascular coagulation and acute kidney injury. Specific antivenom reversed neurotoxic effects of envenoming. Additional therapeutic interventions included antibiotics, surgical debridement, continuous renal replacement therapy and therapeutic plasma exchange. Both patients eventually made full recoveries. Apart from the critical problem of rapidly evolving and severe neurotoxicity, our case reports also emphasises the risk of cardiotoxic envenoming, and the complications of an overwhelming secondary bacterial wound infection. We suggest a practical approach to diagnosis and management.

Phylogenetic relationships of Hemiuridae (Digenea: Hemiuroidea) with new morphometric and molecular data of Aphanurus mugilis Tang, 1981 (Aphanurinae) from mullet fish of Vietnam

Adult Aphanurus mugilis Tang, 1981 worms were detected in the intestine of Moolgarda engeli in the shallow waters off Cat Ba Island, Vietnam. Tang (1981) first described this species in Mugil cephalus off China. The worms in Vietnamese mullet were identical to Chinese specimens in a number of morphometric characteristics, with the exception of body and ovary size. In the present study, morphological characteristics, and the first molecular data for A. mugilis are provided. Additionally, molecular phylogenetic analysis of the family Hemiuridae was performed. The results of our molecular phylogenetic study indicate that the presence or absence of an ecsoma was not associated with molecular data for hemiurid subfamilies differentiation. The basal position of Bunocotylinae on the molecular-based phylogenetic tree indicated a primordial nature of ecsoma of hemiurid trematodes. Considerable molecular differentiation of Bunocotylinae from other hemiurids indicated the possibility of the recognition of the family Bunocotylidae Dollfus, 1950. Assuming that Machidatrema chilostoma is considered within the Bunocotylinae, the paraphyly of the Lecithasterinae was supported.

[Molecular genetic characterization of the Far Eastern trematode Skrjabino lecithum spasskii Belous, 1954 (Digenea: Haploporidae)), a parasite of mullets]

Intraspecific genetic differentiation of the trematode Skrjabinolecithum spasskii and its phylogenetic relationships with other species of the family Haploporidae were studied by comparing the nucleotide sequences of a part of the 28S rRNA gene and the ITS1-5.8S-ITS2 rDNA region. Trematodes were isolated from so-iuy mullet Liza haematocheila fishes collected in rivers of Primorye and flathead grey mullet Mugil cephalus fishes collected in water bodies of Vietnam (27 fishes in total). A phylogenetic analysis showed that S. spasskii is close to species of the genus Capitimitta of the subfamily Waretrematinae. By intraspecific variation of rDNA sequences, trematodes were divided into three groups with tree different genotypes, which had fixed nucleotide substitutions. Genotype I was found in trematodes from fishes collected in Primorye. Genotype II was detected in trematodes from M. cephalus fishes collected in the Tonkin Bay, Cat Ba Island, Vietnam. Genotype III was found in five trematodes from L. haematocheila collected in the Kievka River, Primorye. The genetic distances between genotypes I and III from Primorye were 0.4 and 0.65% by 28S and ITS rDNA sequences, respectively. The lowest genetic distances were observed between genotypes II (Vietnam) and III (Primorye), 0.1 and 0.33% by 28S and ITS rDNA sequences, respectively. Possible causes of genetic differentiation of S. spasskii from different geographic locations and different definitive host species are discussed.

Characterization of network parameters for UHMWPE by plane strain compression

Ultra-high molecular weight polyethylene (PE) is used as a bearing material for total joint replacement prostheses since it is a tough, wear-resistant semicrystalline polymer. Despite its high resistance to wear, PE components have shown measureable wear in vivo, which can cause wear-particle induced osteolysis. Crosslinking of PE using ionizing radiation has been shown to increase wear resistance since both chemical crosslinks and physical entanglements provide high resistance to wear. Molecular characterization of crosslinked PEs is usually conducted using equilibrium swelling or by quantifying gel content. In this study, we compared crosslink densities and molecular weight between crosslinks derived from equilibrium swelling to those obtained by applying the Gaussian and Eight-Chain model to describe plane strain compression of the PE melt. The latter approach has the advantage of accounting for contributions of entanglements to the overall crosslink density, which solvent-based techniques largely neglect. As expected, the crosslink density calculated from model fitting increased monotonically with increase in radiation dose in a 0-200kGy dose range, with a corresponding monotonic decrease in molecular weight between crosslinks, but provided higher values of crosslink density and correspondingly lower values of molecular weight between crosslinks compared to the equilibrium swelling technique.