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Richard S. Vetter - One of the best experts on this subject based on the ideXlab platform.
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Distribution of the Brown Recluse Spider (Araneae: Sicariidae) in Illinois and Iowa.
Journal of medical entomology, 2014Co-Authors: Kenneth L Cramer, Richard S. VetterAbstract:The medical importance of the Brown Recluse Spider, Loxosceles reclusa Gertsch and Mulaik, is well known, but there is a need for more accurate information about the distribution of the Spider in North America. We gathered information via an Internet offer to identify Spiders in Illinois and Iowa that were thought to be Brown Recluses. We also mined Brown Recluse locality information from other agencies that kept such records. In Iowa, the Brown Recluse is unknown from its northern counties and rare in southern counties. In Illinois, Brown Recluse Spiders are common in the southern portion of the state and dwindle to almost nonexistence in a transition to the northern counties. Although there were a few finds in the Chicago, IL area and its suburbs, these are surmised to be human-transported specimens and not part of naturally occurring populations. Considering the great human population density and paucity of Brown Recluses in the Chicago area, medical personnel therein should obtain patient geographic information and be conservative when diagnosing loxoscelism in comparison with southern Illinois, where the Spiders are plentiful and bites are more likely.
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Scavenging by Spiders (Araneae) and Its Relationship to Pest Management of the Brown Recluse Spider
Journal of economic entomology, 2011Co-Authors: Richard S. VetterAbstract:Experiments reported in Sandidge (2003; Nature 426: 30) indicated that the Brown Recluse Spider, Loxosceles reclusa Gertsch & Mulaik, preferred to scavenge dead prey over live prey and that the Spiders were not detrimentally affected when fed insecticide-killed crickets. Extrapolations made in subsequent media coverage disseminating the results of this research made counterintuitive statements that pesticide treatment in houses would increase Brown Recluse populations in homes. This information was presented as if the scavenging behavior was specialized in the Brown Recluse; however, it was more likely that this behavior has not been well studied in other species. To provide a comparison, the current laboratory study examined the likelihood of non-Loxosceles Spiders to scavenge dead prey. Of 100 non-Loxosceles Spiders that were tested (from 11 families, 24 genera, and at least 29 species from a variety of Spider hunting guilds), 99 scavenged dead crickets when offered in petri dishes. Some of the Spiders were webspinners in which real-world scavenging of dead prey is virtually impossible, yet they scavenge when given the opportunity. Therefore, scavenging is a flexible opportunistic predatory behavior that is spread across a variety of taxa and is not a unique behavior in Brown Recluses. These findings are discussed in relation to pest management practices.
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periodicity of molting and resumption of post molt feeding in the Brown Recluse Spider loxosceles reclusa araneae sicariidae
Journal of the Kansas Entomological Society, 2010Co-Authors: Richard S. Vetter, Michael K RustAbstract:The periodicity of molting and resumption of feeding after molting was investigated in the Brown Recluse Spider, Loxosceles reclusa Gertsch and Mulaik (Sicariidae). Spiders molted almost every hour of the day but there was a tendency to molt more frequently between 8 A.M. and 1 A.M. Spiderlings resumed feeding after 20 hrs post-molt with feeding occuring more frequently around the 43rd hour and well-established after 48 hrs. The Brown Recluse Spider, Loxosceles reclusa Gertsch and Mulaik (Sicariidae), is one of the best known Spiders in North America, being familiar outside of the arachnological world due to its ability to cause necrotic skin lesions and the propensity of humans to exaggerate this capability. Even though the toxicological aspects of its venom and the medical consequences that ensue are well researched, there is comparatively little information regarding aspects of its life history. Molting in arthropods is a period of extreme change. In Spiders, a few days before molting, the legs darken as new setae become evident under the old cuticle (Peck and Whitcomb, 1970; Foelix, 1996) so the onset of molting is obvious. Feeding ceases and does not resume until some degree of exoskeletal hardening occurs. Molting can consume a significant amount of energy. In six Spider species studied by Celerier (1986) (theraphosid, four lycosids, ctenid), exuvia production represented 5 to 16% of the growth production for the entire post-embryonic development . Various developmental life history traits in Loxosceles Spiders have been documented. The length of individual instars, time from egg to maturity, and overall longevity have been rigorously investigated for L. reclusa (Hite et al., 1966; Horner and Stewart, 1967), L. laeta (Nicolet) (Galiano, 1967), L. gaucho Gertsch (Rinaldi et al., 1997), L. hirsuta Mello-Leitao (Fischer and da Silva, 2001) and L. intermedia Mello-Leitao (Fischer and Vasconcellos-Neto, 2005). However, other aspects, such as molting periodicity and resumption of feeding post-molt in Loxosceles Spiders, have not been researched to our knowledge and, hence, we present our research herein.
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Brown Recluse Spider loxosceles reclusa envenomation in small animals
Journal of Veterinary Emergency and Critical Care, 2009Co-Authors: Lonny B Pace, Richard S. VetterAbstract:Objective – To provide a comprehensive review of relevant literature regarding the Brown Recluse Spider (BRS) and to define those criteria that must be satisfied before making a diagnosis of Brown Recluse envenomation. Etiology – The complex venom of the BRS contains sphingomyelinase D, which is capable of producing all the clinical signs in the human and some animal models. Diagnosis – There is no current commercially available test. In humans there are many proposed guidelines to achieve a definitive diagnosis; however, there are no established guidelines for veterinary patients. Therapy – Currently, no consensus exists for treatment of BRS envenomation other than supportive care, which includes rest, thorough cleaning of the site, ice, compression, and elevation. Prognosis – Prognosis varies based on severity of clinical signs and response to supportive care.
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Distribution of the Brown Recluse Spider (Araneae: Sicariidae) in Georgia with comparison to poison center reports of envenomations.
Journal of medical entomology, 2009Co-Authors: Richard S. Vetter, Nancy C. Hinkle, Lisa M. AmesAbstract:Georgia is on the southeastern margin of the native range of the Brown Recluse Spider, Loxosceles reclusa Gertsch and Mulaik. The Brown Recluse is not a common Georgia Spider and has limited distribution in the state. Using recent submissions, previously published records, and examination of museum specimens, we document the Spider's presence in 31 (19.5%) of Georgia's 159 counties, with almost all being found in the northern portion. The Spider was collected almost exclusively north of the Fall Line (a transition zone separating the Piedmont and the Coastal Plain geological provinces). Only two locations in the southern Coastal Plain province produced L. reclusa specimens; these southern finds are considered Spiders that were transported outside their range. There were six finds of the non-native world tramp species, L. rufescens (Dufour), three south of the Fall Line. In conspicuous contrast, over a 5-yr period, a Georgia poison center database recorded 963 reports of Brown Recluse Spider bites from 103 counties. These figures greatly outnumber the historic verifications of Brown Recluses in the state for both specimen quantity and county occurrence, indicating improbable Spider involvement and the overdiagnosis of bites. In the southern half of the state, medical diagnoses of Brown Recluse Spider bites have virtually zero probability of being correct. Bite diagnoses should be made with caution in north Georgia given the Spider's spotty distribution with low frequency of occurrence.
Pampee P Young - One of the best experts on this subject based on the ideXlab platform.
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Brown Recluse Spider bite mediated hemolysis clinical features a possible role for complement inhibitor therapy and reduced rbc surface glycophorin a as a potential biomarker of venom exposure
PLOS ONE, 2013Co-Authors: Eric A Gehrie, Hui Nian, Pampee P YoungAbstract:Background The venom of Loxosceles reclusa (Brown Recluse Spider) can cause a severe, life-threatening hemolysis in humans for which no therapy is currently available in the USA beyond supportive measures. Because this hemolysis is uncommon, relatively little is known about its clinical manifestation, diagnosis, or management. Here, we aimed to clarify the clinical details of envenomation, to determine the efficacy of the complement inhibitor eculizumab to prevent the hemolysis in vitro, and to investigate markers of exposure to Brown Recluse venom. Study Design and Methods We performed a 10-year chart review of cases of Brown Recluse Spider bite-mediated hemolysis at our institution. We also designed an in vitro assay to test the efficacy of eculizumab to inhibit hemolysis of venom exposed red blood cells. Finally, we compared levels of CD55, CD59 and glycophorin A on venom exposed versus venom-naive cells. Results Most victims of severe Brown Recluse Spider mediated hemolysis at our institution are children and follow an unpredictable clinical course. Brown Recluse Spider bite mediated hemolysis is reduced by 79.2% (SD=18.8%) by eculizumab in vitro. Erythrocyte glycophorin A, but not CD55 or CD59, is reduced after red blood cells are incubated with venom in vitro. Conclusion Taken together, our laboratory data and clinical observations indicate that L. reclusa venom exposure results in non-specific antibody and complement fixation on red blood cells, resulting in complement mediated hemolysis that is curtailed by the complement inhibitor eculizumab in vitro. Glycophorin A measurement by flow cytometry may help to identify victims of L. reclusa envenomation.
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Brown Recluse Spider bite mediated hemolysis: clinical features, a possible role for complement inhibitor therapy, and reduced RBC surface glycophorin A as a potential biomarker of venom exposure.
Public Library of Science (PLoS), 1Co-Authors: Eric A Gehrie, Hui Nian, Pampee P YoungAbstract:The venom of Loxosceles reclusa (Brown Recluse Spider) can cause a severe, life-threatening hemolysis in humans for which no therapy is currently available in the USA beyond supportive measures. Because this hemolysis is uncommon, relatively little is known about its clinical manifestation, diagnosis, or management. Here, we aimed to clarify the clinical details of envenomation, to determine the efficacy of the complement inhibitor eculizumab to prevent the hemolysis in vitro, and to investigate markers of exposure to Brown Recluse venom.We performed a 10-year chart review of cases of Brown Recluse Spider bite-mediated hemolysis at our institution. We also designed an in vitro assay to test the efficacy of eculizumab to inhibit hemolysis of venom exposed red blood cells. Finally, we compared levels of CD55, CD59 and glycophorin A on venom exposed versus venom-naïve cells.Most victims of severe Brown Recluse Spider mediated hemolysis at our institution are children and follow an unpredictable clinical course. Brown Recluse Spider bite mediated hemolysis is reduced by 79.2% (SD=18.8%) by eculizumab in vitro. Erythrocyte glycophorin A, but not CD55 or CD59, is reduced after red blood cells are incubated with venom in vitro.Taken together, our laboratory data and clinical observations indicate that L. reclusa venom exposure results in non-specific antibody and complement fixation on red blood cells, resulting in complement mediated hemolysis that is curtailed by the complement inhibitor eculizumab in vitro. Glycophorin A measurement by flow cytometry may help to identify victims of L. reclusa envenomation
Collis R Geren - One of the best experts on this subject based on the ideXlab platform.
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sphingomyelinase d activity of Brown Recluse Spider loxosceles reclusa venom as studied by 31p nmr effects on the time course of sphingomyelin hydrolysis
Toxicon, 1998Co-Authors: Michael L Merchant, J F Hinton, Collis R GerenAbstract:Abstract M. L. Merchant, J. F. Hinton and C. R. Geren. Sphingomyelinase D activity of Brown Recluse Spider (Loxosceles reclusa) venom as studied by 31P-NMR: effects on the time-course of sphingomyelin hydrolysis. Toxicon 36, 537–545, 1998.—The time-course for the hydrolysis of the D linkage of chicken egg yolk sphingomyelin in a Triton X-100 mixed micelle and of lysophosphotidylcholine micelles, as catalyzed by Brown Recluse Spider venom and Brown Recluse Spider toxin, was followed by phosphorous-31 nuclear magnetic resonance spectroscopy. The overall rate of hydrolysis of sphingomyelin in mixed micelles was found to be an order of magnitude faster than the hydrolysis of lysophosphotidylcholine. Incorporation of lysophosphotidylcholine into mixed micelles with Triton X-100 inhibited the lipase activity of Brown Recluse Spider venom and Brown Recluse Spider venom toxin. The effects of increased rates of overall reaction were observed with increased temperature and also with decreased ionic strength. The presence of divalent calcium ions was found to be necessary for hydrolytic activity, but only in catalytic amounts (less than 1 mM).
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effect of hyperbaric oxygen on sphingomyelinase d activity of Brown Recluse Spider loxosceles reclusa venom as studied by 31p nuclear magnetic resonance spectroscopy
American Journal of Tropical Medicine and Hygiene, 1997Co-Authors: Michael L Merchant, J F Hinton, Collis R GerenAbstract:Hyperbaric oxygen (HBO) has been reported by some to be therapeutic for necrotic lesions induced by the venom of the Brown Recluse Spider, Loxosceles reclusa. Others have reported no efficacy for this treatment. In this study, the effect of high pressure oxygen on an enzymatic activity of the toxin of this venom is reported. The time course for the hydrolysis of the phosphocholine ester bond of chicken egg yolk sphingomyelin, as catalyzed by Brown Recluse Spider venom (BRSV) and venom treated with extended HBO (12 hr at 10 atmospheres), was followed by phosphorus-31 nuclear magnetic resonance spectroscopy. The venom and HBO-pretreated venom demonstrated sphingomyelinase D activity. Phospholipase C activity was not detected. The sphingomyelinase D activity of BRSV in three separate experiments was not altered by HBO. The HBO-pretreated venom, in all cases, did not exhibit an altered time course in the overall hydrolysis of the D linkage of sphingomyelin.
Eric A Gehrie - One of the best experts on this subject based on the ideXlab platform.
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Brown Recluse Spider bite mediated hemolysis clinical features a possible role for complement inhibitor therapy and reduced rbc surface glycophorin a as a potential biomarker of venom exposure
PLOS ONE, 2013Co-Authors: Eric A Gehrie, Hui Nian, Pampee P YoungAbstract:Background The venom of Loxosceles reclusa (Brown Recluse Spider) can cause a severe, life-threatening hemolysis in humans for which no therapy is currently available in the USA beyond supportive measures. Because this hemolysis is uncommon, relatively little is known about its clinical manifestation, diagnosis, or management. Here, we aimed to clarify the clinical details of envenomation, to determine the efficacy of the complement inhibitor eculizumab to prevent the hemolysis in vitro, and to investigate markers of exposure to Brown Recluse venom. Study Design and Methods We performed a 10-year chart review of cases of Brown Recluse Spider bite-mediated hemolysis at our institution. We also designed an in vitro assay to test the efficacy of eculizumab to inhibit hemolysis of venom exposed red blood cells. Finally, we compared levels of CD55, CD59 and glycophorin A on venom exposed versus venom-naive cells. Results Most victims of severe Brown Recluse Spider mediated hemolysis at our institution are children and follow an unpredictable clinical course. Brown Recluse Spider bite mediated hemolysis is reduced by 79.2% (SD=18.8%) by eculizumab in vitro. Erythrocyte glycophorin A, but not CD55 or CD59, is reduced after red blood cells are incubated with venom in vitro. Conclusion Taken together, our laboratory data and clinical observations indicate that L. reclusa venom exposure results in non-specific antibody and complement fixation on red blood cells, resulting in complement mediated hemolysis that is curtailed by the complement inhibitor eculizumab in vitro. Glycophorin A measurement by flow cytometry may help to identify victims of L. reclusa envenomation.
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Brown Recluse Spider bite mediated hemolysis: clinical features, a possible role for complement inhibitor therapy, and reduced RBC surface glycophorin A as a potential biomarker of venom exposure.
Public Library of Science (PLoS), 1Co-Authors: Eric A Gehrie, Hui Nian, Pampee P YoungAbstract:The venom of Loxosceles reclusa (Brown Recluse Spider) can cause a severe, life-threatening hemolysis in humans for which no therapy is currently available in the USA beyond supportive measures. Because this hemolysis is uncommon, relatively little is known about its clinical manifestation, diagnosis, or management. Here, we aimed to clarify the clinical details of envenomation, to determine the efficacy of the complement inhibitor eculizumab to prevent the hemolysis in vitro, and to investigate markers of exposure to Brown Recluse venom.We performed a 10-year chart review of cases of Brown Recluse Spider bite-mediated hemolysis at our institution. We also designed an in vitro assay to test the efficacy of eculizumab to inhibit hemolysis of venom exposed red blood cells. Finally, we compared levels of CD55, CD59 and glycophorin A on venom exposed versus venom-naïve cells.Most victims of severe Brown Recluse Spider mediated hemolysis at our institution are children and follow an unpredictable clinical course. Brown Recluse Spider bite mediated hemolysis is reduced by 79.2% (SD=18.8%) by eculizumab in vitro. Erythrocyte glycophorin A, but not CD55 or CD59, is reduced after red blood cells are incubated with venom in vitro.Taken together, our laboratory data and clinical observations indicate that L. reclusa venom exposure results in non-specific antibody and complement fixation on red blood cells, resulting in complement mediated hemolysis that is curtailed by the complement inhibitor eculizumab in vitro. Glycophorin A measurement by flow cytometry may help to identify victims of L. reclusa envenomation
Michael L Merchant - One of the best experts on this subject based on the ideXlab platform.
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sphingomyelinase d activity of Brown Recluse Spider loxosceles reclusa venom as studied by 31p nmr effects on the time course of sphingomyelin hydrolysis
Toxicon, 1998Co-Authors: Michael L Merchant, J F Hinton, Collis R GerenAbstract:Abstract M. L. Merchant, J. F. Hinton and C. R. Geren. Sphingomyelinase D activity of Brown Recluse Spider (Loxosceles reclusa) venom as studied by 31P-NMR: effects on the time-course of sphingomyelin hydrolysis. Toxicon 36, 537–545, 1998.—The time-course for the hydrolysis of the D linkage of chicken egg yolk sphingomyelin in a Triton X-100 mixed micelle and of lysophosphotidylcholine micelles, as catalyzed by Brown Recluse Spider venom and Brown Recluse Spider toxin, was followed by phosphorous-31 nuclear magnetic resonance spectroscopy. The overall rate of hydrolysis of sphingomyelin in mixed micelles was found to be an order of magnitude faster than the hydrolysis of lysophosphotidylcholine. Incorporation of lysophosphotidylcholine into mixed micelles with Triton X-100 inhibited the lipase activity of Brown Recluse Spider venom and Brown Recluse Spider venom toxin. The effects of increased rates of overall reaction were observed with increased temperature and also with decreased ionic strength. The presence of divalent calcium ions was found to be necessary for hydrolytic activity, but only in catalytic amounts (less than 1 mM).
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effect of hyperbaric oxygen on sphingomyelinase d activity of Brown Recluse Spider loxosceles reclusa venom as studied by 31p nuclear magnetic resonance spectroscopy
American Journal of Tropical Medicine and Hygiene, 1997Co-Authors: Michael L Merchant, J F Hinton, Collis R GerenAbstract:Hyperbaric oxygen (HBO) has been reported by some to be therapeutic for necrotic lesions induced by the venom of the Brown Recluse Spider, Loxosceles reclusa. Others have reported no efficacy for this treatment. In this study, the effect of high pressure oxygen on an enzymatic activity of the toxin of this venom is reported. The time course for the hydrolysis of the phosphocholine ester bond of chicken egg yolk sphingomyelin, as catalyzed by Brown Recluse Spider venom (BRSV) and venom treated with extended HBO (12 hr at 10 atmospheres), was followed by phosphorus-31 nuclear magnetic resonance spectroscopy. The venom and HBO-pretreated venom demonstrated sphingomyelinase D activity. Phospholipase C activity was not detected. The sphingomyelinase D activity of BRSV in three separate experiments was not altered by HBO. The HBO-pretreated venom, in all cases, did not exhibit an altered time course in the overall hydrolysis of the D linkage of sphingomyelin.
