The Experts below are selected from a list of 30 Experts worldwide ranked by ideXlab platform

Kevin D. Welch - One of the best experts on this subject based on the ideXlab platform.

  • Geographical and seasonal variation in water hemlock (Cicuta maculata) toxins
    Biochemical Systematics and Ecology, 2020
    Co-Authors: Clinton A. Stonecipher, Kevin D. Welch, Stephen T. Lee, Daniel Cook, James A. Pfister
    Abstract:

    Abstract Water hemlock (Cicuta spp.) plants are typically found in wet areas and are toxic to all species of livestock. The toxic components in water hemlock are C17 polyacetylenes, with Cicutoxin being the most studied. The objective of this study was to evaluate the variation in Cicutoxin and total C17 polyacetylene compounds in water hemlock populations across western North America. Cicutoxin and total C17 polyacetylene concentrations varied among the six collection locations and among plant parts. Tubers contained the highest Cicutoxin and total C17 polyacetylene concentrations of all plant parts. Green seeds contained the second most abundant total C17 polyacetylene concentrations. Total C17 polyacetylene and Cicutoxin concentrations were also compared in different plant parts at several different phenological stages over the growing season. Cicutoxin and total C17 polyacetylene concentrations in the tubers increased until the green seed stage whereupon the concentrations decreased as the seeds matured and the plant began to senesce. Concentrations of secondary compounds in the stems were consistent with the optimal defense theory in which secondary compounds were higher in stems in earlier development stages compared to later stages and concentrations in seeds were higher than other above ground parts. The toxic compounds are found in all plant parts, with tubers posing the most significant risk of livestock poisoning. Results presented in this study suggest that the toxic risk to livestock likely does not differ between water hemlock (Cicuta maculata) populations across western North America under similar circumstances of ingestion.

  • Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause
    Toxicon : official journal of the International Society on Toxinology, 2010
    Co-Authors: Kip E. Panter, Kevin D. Welch, Dale R. Gardner, Bryan L. Stegelmeier, Dirk M. Holstege
    Abstract:

    It is well understood that water hemlock tubers are highly toxic to animals and to humans. However, this is the first time that immature seed from (Cicuta maculata) has been implicated in livestock poisoning. Nine mature Hereford cows from a herd of 81 died in northwestern Utah after ingesting immature seed heads of water hemlock (Cicuta maculata) in late summer. No obvious signs of poisoning were reported as all nine were found dead near the banks of the stream where water hemlock was found. Upon discovery of the dead cows, the remaining 72 cows were immediately removed from the pasture and no further losses occurred. Field necropsy of 3 of the dead cows and follow-up serology and histopathological examination of selected tissues did not identify any bacterial or viral causes. History of ingestion of large quantities of water hemlock seed, the acute nature of the deaths, chemical comparison of seed with toxic tubers and follow-up mouse bioassay testing supported the diagnosis of water hemlock poisoning. Seed heads collected from the neighboring pasture upstream and across the fence from the poisoned cattle and tubers collected from grazed plants were chemically analyzed and found to contain Cicutoxin, and high levels of two cicutol-like derivatives (cicutol-#1 and #2) as well as other unidentified polyacetylene compounds. Seeds and tubers from suspected plants were semi-quantified and compared to archive samples of highly toxic tubers used in previous experiments. The immature hemlock seed contained less Cicutoxin (0.01 times), but 9.5 and 22.5 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Tubers from the grazed plants contained 4.6 times more Cicutoxin and 9.8 and 18.8 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Mouse bioassays with water extracts of immature seed and tubers from grazed plants demonstrated both were highly toxic and of greater toxicity when compared to archived sample.

Dirk M. Holstege - One of the best experts on this subject based on the ideXlab platform.

  • Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause
    Toxicon : official journal of the International Society on Toxinology, 2010
    Co-Authors: Kip E. Panter, Kevin D. Welch, Dale R. Gardner, Bryan L. Stegelmeier, Dirk M. Holstege
    Abstract:

    It is well understood that water hemlock tubers are highly toxic to animals and to humans. However, this is the first time that immature seed from (Cicuta maculata) has been implicated in livestock poisoning. Nine mature Hereford cows from a herd of 81 died in northwestern Utah after ingesting immature seed heads of water hemlock (Cicuta maculata) in late summer. No obvious signs of poisoning were reported as all nine were found dead near the banks of the stream where water hemlock was found. Upon discovery of the dead cows, the remaining 72 cows were immediately removed from the pasture and no further losses occurred. Field necropsy of 3 of the dead cows and follow-up serology and histopathological examination of selected tissues did not identify any bacterial or viral causes. History of ingestion of large quantities of water hemlock seed, the acute nature of the deaths, chemical comparison of seed with toxic tubers and follow-up mouse bioassay testing supported the diagnosis of water hemlock poisoning. Seed heads collected from the neighboring pasture upstream and across the fence from the poisoned cattle and tubers collected from grazed plants were chemically analyzed and found to contain Cicutoxin, and high levels of two cicutol-like derivatives (cicutol-#1 and #2) as well as other unidentified polyacetylene compounds. Seeds and tubers from suspected plants were semi-quantified and compared to archive samples of highly toxic tubers used in previous experiments. The immature hemlock seed contained less Cicutoxin (0.01 times), but 9.5 and 22.5 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Tubers from the grazed plants contained 4.6 times more Cicutoxin and 9.8 and 18.8 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Mouse bioassays with water extracts of immature seed and tubers from grazed plants demonstrated both were highly toxic and of greater toxicity when compared to archived sample.

Beasley, Michael D. G. - One of the best experts on this subject based on the ideXlab platform.

  • Poisoning due to water hemlock
    'Informa UK Limited', 2009
    Co-Authors: Schep, Leo J., Slaughter, Robin J., Becket Gordon, Beasley, Michael D. G.
    Abstract:

    Introduction. Water hemlock, which encompasses a range of species divided across two genera (Cicuta and Oenanthe), are regarded as being among the most poisonous plants both in North America and in the United Kingdom. Despite their toxicity, the literature consists almost entirely of case reports.  Aim. The aim of this review is to summarize this literature by covering all aspects of taxonomy and botanical characterization, principal toxins, basic pharmacology including mechanisms of toxicity, and the clinical features, diagnosis, and management of poisoning. Mechanisms of toxicity. The principal toxins, Cicutoxin and oenanthotoxin, belong to a group of C17 conjugated polyacetylenes. They act as (noncompetitive) gamma-aminobutyric acid antagonists in the central nervous system (CNS), resulting in unabated neuronal depolarization that can lead to seizures. Ingestion of even a small amount of plant matter may result in severe intoxication.  Features. After ingestion, the patient is most likely to experience CNS stimulatory effects including seizures that, in the absence of aggressive supportive care, can result in death. Other features include nausea, vomiting, diarrhea, tachycardia, mydriasis, rhabdomyolysis, renal failure, coma, respiratory impairment, and cardiac dysrhythmias.  Management. Treatment consists mainly of prompt airway management and seizure control, plus decontamination if achieved early and after stabilization. In the event of renal failure, the use of hemodialysis has been employed successfully.  Conclusions.  The ingestion of water hemlock can lead to serious complications that may be fatal. Prognosis is good, however, if prompt supportive care is provided

Kip E. Panter - One of the best experts on this subject based on the ideXlab platform.

  • Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause
    Toxicon : official journal of the International Society on Toxinology, 2010
    Co-Authors: Kip E. Panter, Kevin D. Welch, Dale R. Gardner, Bryan L. Stegelmeier, Dirk M. Holstege
    Abstract:

    It is well understood that water hemlock tubers are highly toxic to animals and to humans. However, this is the first time that immature seed from (Cicuta maculata) has been implicated in livestock poisoning. Nine mature Hereford cows from a herd of 81 died in northwestern Utah after ingesting immature seed heads of water hemlock (Cicuta maculata) in late summer. No obvious signs of poisoning were reported as all nine were found dead near the banks of the stream where water hemlock was found. Upon discovery of the dead cows, the remaining 72 cows were immediately removed from the pasture and no further losses occurred. Field necropsy of 3 of the dead cows and follow-up serology and histopathological examination of selected tissues did not identify any bacterial or viral causes. History of ingestion of large quantities of water hemlock seed, the acute nature of the deaths, chemical comparison of seed with toxic tubers and follow-up mouse bioassay testing supported the diagnosis of water hemlock poisoning. Seed heads collected from the neighboring pasture upstream and across the fence from the poisoned cattle and tubers collected from grazed plants were chemically analyzed and found to contain Cicutoxin, and high levels of two cicutol-like derivatives (cicutol-#1 and #2) as well as other unidentified polyacetylene compounds. Seeds and tubers from suspected plants were semi-quantified and compared to archive samples of highly toxic tubers used in previous experiments. The immature hemlock seed contained less Cicutoxin (0.01 times), but 9.5 and 22.5 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Tubers from the grazed plants contained 4.6 times more Cicutoxin and 9.8 and 18.8 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Mouse bioassays with water extracts of immature seed and tubers from grazed plants demonstrated both were highly toxic and of greater toxicity when compared to archived sample.

Schep, Leo J. - One of the best experts on this subject based on the ideXlab platform.

  • Poisoning due to water hemlock
    'Informa UK Limited', 2009
    Co-Authors: Schep, Leo J., Slaughter, Robin J., Becket Gordon, Beasley, Michael D. G.
    Abstract:

    Introduction. Water hemlock, which encompasses a range of species divided across two genera (Cicuta and Oenanthe), are regarded as being among the most poisonous plants both in North America and in the United Kingdom. Despite their toxicity, the literature consists almost entirely of case reports.  Aim. The aim of this review is to summarize this literature by covering all aspects of taxonomy and botanical characterization, principal toxins, basic pharmacology including mechanisms of toxicity, and the clinical features, diagnosis, and management of poisoning. Mechanisms of toxicity. The principal toxins, Cicutoxin and oenanthotoxin, belong to a group of C17 conjugated polyacetylenes. They act as (noncompetitive) gamma-aminobutyric acid antagonists in the central nervous system (CNS), resulting in unabated neuronal depolarization that can lead to seizures. Ingestion of even a small amount of plant matter may result in severe intoxication.  Features. After ingestion, the patient is most likely to experience CNS stimulatory effects including seizures that, in the absence of aggressive supportive care, can result in death. Other features include nausea, vomiting, diarrhea, tachycardia, mydriasis, rhabdomyolysis, renal failure, coma, respiratory impairment, and cardiac dysrhythmias.  Management. Treatment consists mainly of prompt airway management and seizure control, plus decontamination if achieved early and after stabilization. In the event of renal failure, the use of hemodialysis has been employed successfully.  Conclusions.  The ingestion of water hemlock can lead to serious complications that may be fatal. Prognosis is good, however, if prompt supportive care is provided