Fab Antivenom Reversal of Neurotoxicity Caused by a Juvenile Crotalus horridus Lacking Canebrake Toxin.

We present a case of neurotoxic effects in a pediatric patient after envenomation by a timber rattlesnake (Crotalus horridus) in the Appalachian upstate of South Carolina. Though some members of this species are capable of primarily neurotoxic envenomation, there is heterogeneity in venom composition, and neurotoxic timber rattlesnakes are not endemic to the Appalachian region. However, neurotoxic effects caused by C horridus species lacking typical neurotoxins have been suspected, though not previously confirmed in the medical literature. This case presents a patient who was envenomated by a genotypically confirmed non-neurotoxic C horridus but who nevertheless presented with symptoms consistent with primary neurotoxicity. Neurotoxic effects can be variable in their response to traditional antivenom, though this patient demonstrated rapid response to treatment, representing a novel case in the literature of neurotoxic effects from a snake lacking typical neurotoxins with documented improvement with traditional antivenom.

A Photographic Case of Frostbite Treated with Delayed Hyperbaric Oxygen Therapy.

Davis, Ashlee, Brent Sinopoli, Nathaniel Mann, and Antine E. Stenbit. A photographic case of frostbite treated with delayed hyperbaric oxygen therapy. High Alt Med Biol. 23:194-197, 2022.-A 50-year-old female presented to the emergency department in June 2019 5 days after summiting Denali. Temperature on summit day was -25°F, and she developed frostbite on multiple digits of both hands. Eight digits demonstrated severe frostbite based on the grading set forth by Cauchy et al. Five of these had grade III injuries. She received three hyperbaric dives in Alaska before flying to her home state. On day 5 she received aspirin, aloe wraps, and underwent twenty-seven 90-minute dives at 2 atmospheres absolute. Unique in current literature, each dive was accompanied by photographs detailing clinical progression, which may assist providers in providing expectations in care. She eventually underwent amputation at, or distal to, the distal interphalangeals of bilateral third and fourth digits and the left fifth digit. By January 2020, she had returned to near-normal range of motion. Hyperbaric oxygen therapy represents a potential adjunct therapeutic option for frostbite, even in delayed manner, but its use as a treatment modality warrants further prospective analysis.

Molecular taxonomy in the dark: evolutionary history, phylogeography, and diversity of cave crayfish in the subgenus Aviticambarus, genus Cambarus.

Freshwater crayfish species in the subgenus Aviticambarus (Cambaridae: Cambarus) are restricted to caves along the Cumberland Plateau, the Sequatchie Valley, and the Highland Rim which extend along the Tennessee River in southcentral Tennessee and northern Alabama. Historically, three stygobitic species, Cambarus jonesi, Cambarus hamulatus, and Cambarus veitchorum, comprise this subgenus. We examine species' boundaries and phylogeographic structure of this imperiled Southern Appalachian assemblage to shed light on patterns of cave colonization. We also provide estimates of genetic diversity for conservation status assessment. Using geologic evidence, phylogeographic analyses, and sequence data from five gene regions (two nuclear: Histone H3 and GAPDH and three mitochondrial: 12S, 16S, and CO1 totaling almost 2700 base pairs), we identify two well-supported cryptic species in addition to the three currently recognized taxa. Four of these taxa exhibit low levels of genetic variation both currently and historically, which may indicate local extirpation events associated with geological and river basin changes. Our results also support other recent findings that pre-Pleistocene paleodrainages may best explain the current patterns of aquatic faunal biodiversity in the Southern Appalachians.