Acute Generalized Exanthematous Pustulosis (AGEP) Triggered by a Spider Bite

BackgroundAcute generalized exanthematous pustulosis (AGEP) is a rare and severe cutaneous reaction usually triggered by drugs. Other causative factors such as viral infections are rarely involved. In this study, we report a case of AGEP caused by a spider bite.Case SummaryA 56-year-old woman was referred to the allergy unit after a spider bite at the left popliteal fossa, while gardening, 5 days earlier. The offending spider was captured and identified by an entomologist as belonging to the Loxosceles rufescens species. No acute reaction was observed; however, after 24 hours, due to the occurrence of typical dermonecrotic skin lesions associated with erythema and edema, Cefuroxime and Clindamycin were administered intramuscularly after medical advice was given. Almost 72 hours after the spider bite, an erythematous and partly edematous eruption appeared locally in the gluteus area bilaterally, which progressively expanded to the trunk, arms and femors. Within 24 hours dozens of small, pinhead sized, non- follicular pustules were present, mainly in the folds. The patient complained of a burning sensation of the skin in addition to pruritus; and simultaneously had a fever of 38-39 °C as the eruption expanded.DiscussionA spider bite may represent a possible causative factor of AGEP. A spider's venom contains sphingomyelinase that stimulates the release of IL8 and GM-CSF, which are involved in AGEP pathogenesis. Whether or not the con-current use of antibiotics has an effect in AGEP appearance when combined with a spider's venom, cannot be excluded.     

From the Cover: Fossil evidence for the origin of spider spinnerets, and a proposed arachnid order

Silk production from opisthosomal glands is a defining characteristic of spiders (Araneae). Silk emerges from spigots (modified setae) borne on spinnerets (modified appendages). Spigots from Attercopus fimbriunguis, from Middle Devonian (386 Ma) strata of Gilboa, New York, were described in 1989 as evidence for the oldest spider and the first use of silk by animals. Slightly younger (374 Ma) material from South Mountain, New York, conspecific with A. fimbriunguis, includes spigots and other evidence that elucidate the evolution of early Araneae and the origin of spider silk. No known Attercopus spigots, including the original specimen, occur on true spinnerets but are arranged along the edges of plates. Spinnerets originated from biramous appendages of opisthosomal somites 4 and 5; although present in Limulus, no other arachnids have opisthosomal appendage homologues on these segments. The spigot arrangement in Attercopus shows a primitive state before the reexpression of the dormant genetic mechanism that gave rise to spinnerets in later spiders. Enigmatic flagellar structures originally described as Arachnida incertae sedis, are shown to be Attercopus anal flagella, as found in Permarachne, also originally described as a spider. An arachnid order, Uraraneida, is erected for a plesion, including these two genera, based on this combination of characters. The inability of Uraraneida precisely to control silk weaving suggests its original use as a wrapping, lining, or homing material.     

Spray aiming in the bombardier beetle: photographic evidence.

Bombardier beetles, when physically assaulted, eject a hot quinonoid spray from the tip of the abdomen. Photographic evidence is presented demonstrating that the African bombardier beetle, Stenaptinus insignis, can aim its spray in virtually any direction. It can target its individual legs, and even the individual segments of its legs. Moreover, in aiming at a leg, it takes into account the postural orientation of that leg. The beetle is able even to target sites on its back. It is postulated that the ability to aim helps the beetle mainly in defense against ants.     

Supermodeled sabercat, predatory behavior in Smilodon fatalis revealed by high-resolution 3D computer simulation

The American sabercat Smilodon fatalis is among the most charismatic of fossil carnivores. Despite broad agreement that its extraordinary anatomy reflects unique hunting techniques, after >150 years of study, many questions remain concerning its predatory behavior. Were the “sabers” used to take down large prey? Were prey killed with an eviscerating bite to the abdomen? Was its bite powerful or weak compared with that of modern big cats? Here we quantitatively assess the sabercat''s biomechanical performance using the most detailed computer reconstructions yet developed for the vertebrate skull. Our results demonstrate that bite force driven by jaw muscles was relatively weak in S. fatalis, one-third that of a lion (Panthera leo) of comparable size, and its skull was poorly optimized to resist the extrinsic loadings generated by struggling prey. Its skull is better optimized for bites on restrained prey where the bite is augmented by force from the cervical musculature. We conclude that prey were brought to ground and restrained before a killing bite, driven in large part by powerful cervical musculature. Because large prey is easier to restrain if its head is secured, the killing bite was most likely directed to the neck. We suggest that the more powerful jaw muscles of P. leo may be required for extended, asphyxiating bites and that the relatively low bite forces in S. fatalis might reflect its ability to kill large prey more quickly, avoiding the need for prolonged bites.     

A clinical and epidemiological study on spider bites in Turkey

ObjectiveTo classify and characterize spider bites among inquiries to the National Poison Information Center (NPIC) between 1995 and 2004, in terms of the epidemiology and clinical symptomatology.MethodsClinical and epidemiological data were obtained from the NPIC's patient records. The following information was recorded for each spider bite: demographics, circumstances of the bite, and local and systemic effects.ResultsA total of 82 cases were reported. The accidents were mostly seen during August. The gender distribution was 59.76% male, 37.20% female, and 2.44% unknown and the 20–29 age group presented more spider bites. Most of the cases were in the Central Anatolia, Marmara, Mediterranean, and Black Sea regions. Local symptoms were observed in 60.87% of the cases, including local pain, edema, redness, itching, debris, burning, and numbness. Systemic symptoms were observed such as nausea, vomiting, abdominal pain, lethargy, anxiety, weakness, somnolence, dyspnea, hypertension, hypotension, and hyperthermia.ConclusionsIn conclusion, these findings emphasize the presence of medically important spider species in Turkey. All patients and especially pediatric patients should be admitted to the hospital. Identification of spider species may be considered a useful clinical and epidemiological tool in determining the incidence and risk of spider bites.     

Transient Reverse Takotsubo Cardiomyopathy Following a Spider Bite in Greece: A Case Report

Black widow spider is endemic in the Mediterranean area and although envenomations are rare, may occasionally lead to death.We present a case of a 64-year-old female developing a rare variant of takotsubo, stress-induced, cardiomyopathy after a spider bite. This resulted in acute heart failure within 24 hours of the bite. With medical treatment and supportive care, the patient''s clinical condition improved.Reverse takotsubo cardiomyopathy was diagnosed by echocardiography, which was transient. Clinical and echocardiographic findings have been completely resolved on follow-up 46 days later.Reverse takotsubo cardiomyopathy has not been yet described following a spider bite. Doctors in the emergency department of endemic countries should be familiar with this potential complication.     

A systematic review and meta-analysis on the role of omental or falciform ligament wrapping during pancreaticoduodenectomy

BackgroundThe role of wrapping in the setting of pancreaticoduodenectomy (PD) is controversial. This study aimed to assess whether the use of omental or falciform ligament wrapping of pancreatic anastomosis and/or vessels could reduce the rate of POPF and postpancreatectomy hemorrhage (PPH) after PD.MethodsStudies comparing PD with (PD-W) and without wrapping (PD-nW) were included. Primary outcomes were POPF and extraluminal PPH. Dichotomous variables were analyzed for risk ratios (RR) with 95% Confidence Intervals.ResultsNine studies involving 4384 patients were considered. The risk of POPF and clinically relevant POPF (CR-POPF) was similar between patients with and without omental wrapping of pancreatic anastomosis when considered as overall. A significant benefit from wrapping in terms of CR-POPF (RR 0.14, P = 0.002) was reported for patients who underwent PD with pancreaticojejunostomy (PJ). The risk of extraluminal PPH was slightly lower in patients who underwent vessels wrapping compared to those who did not (RR 0.58, P = 0.020). Similar extraluminal PPH rates were reported for patients with and without wrapping of pancreatic anastomosis (P = 0.620).DiscussionData from low-evidence studies suggest that omental wrapping of PJ may reduce the incidence of CR-POPF, whereas vessels wrapping may have a slight effect for preventing extraluminal PPH.     

DNA wrapping is required for DNA damage recognition in the Escherichia coli DNA nucleotide excision repair pathway

Localized DNA melting may provide a general strategy for recognition of the wide array of chemically and structurally diverse DNA lesions repaired by the nucleotide excision repair (NER) pathway. However, it is not clear what causes such DNA melting and how it is driven. Here, we show a DNA wrapping–melting model supported by results from dynamic monitoring of the key DNA–protein and protein–protein interactions involved in the early stages of the Escherichia coli NER process. Using an analytical technique involving capillary electrophoresis coupled with laser-induced fluorescence polarization, which combines a mobility shift assay with conformational analysis, we demonstrate that DNA wrapping around UvrB, mediated by UvrA, is an early event in the damage-recognition process during E. coli NER. DNA wrapping of UvrB was confirmed by Förster resonance energy transfer and fluorescence lifetime measurements. This wrapping did not occur with readily denaturable damaged DNA substrates (“bubble” DNA), suggesting that DNA wrapping of UvrB plays an important role in the induction of DNA melting around the damage site. Analysis of DNA wrapping of mutant UvrB Y96A further suggests that a cooperative interaction between DNA wrapping of UvrA₂B and contact of the β-hairpin of UvrB with the bulky damage moiety may be involved in the local DNA melting at the damage site.     

Evolutionary history predicts plant defense against an invasive pest

It has long been hypothesized that invasive pests may be facilitated by the evolutionary naïveté of their new hosts, but this prediction has never been examined in a phylogenetic framework. To address the hypothesis, we have been studying the invasive viburnum leaf beetle (Pyrrhalta viburni), which is decimating North American native species of Viburnum, a clade of worldwide importance as understory shrubs and ornamentals. In a phylogenetic field experiment using 16 species of Viburnum, we show that old-world Viburnum species that evolved in the presence of Pyrrhalta beetles mount a massive defensive wound response that crushes eggs of the pest insect; in contrast, naïve North American species that share no evolutionary history with Pyrrhalta beetles show a markedly lower response. This convergent continental difference in the defensive response of Viburnum spp. against insect oviposition contrasts with little difference in the quality of leaves for beetle larvae. Females show strong oviposition preferences that correspond with larval performance regardless of continental origin, which has facilitated colonization of susceptible North American species. Thus, although much attention has been paid to escape from enemies as a factor in the establishment and spread of nonnative organisms, the colonization of undefended resources seems to play a major role in the success of invasive species such as the viburnum leaf beetle.     

Brown recluse spider bites: a complex problem wound. A brief review and case study

Brown recluse spiders (Loxosceles reclusa) are responsible for virtually all documented cases of spider bites leading to significant necrosis. The actual spider bite often goes unnoticed for as long as 4 to 6 hours, which makes diagnosis and, therefore, appropriate treatment, difficult. The spider bite generally results in either a necrotic wound or systemic symptoms that can lead to hemolysis. The patient described in this article experienced both complications. Dapsone and hyperbaric oxygen therapy brought the adverse response to the bite under control. The patient was hospitalized for 7 days during treatment for hemolysis and an extensive, necrotic wound. Efforts are underway to develop an assay to provide a definitive diagnosis for the brown recluse spider bite, but none is yet commercially available. Antivenom is scarce; capture of the offending spider appears to be most helpful in the diagnosis and proper treatment of spider bites.     

Lignin degradation in wood-feeding insects

The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut community analysis of A. glabripennis identified a single species of fungus in the Fusarium solani/Nectria haematococca species complex. This is a soft-rot fungus that may be contributing to wood degradation. These results transform our understanding of lignin degradation by wood-feeding insects.     

‘Bobo-Newton syndrome’: An unwanted gift from man’s best friend

Capnocytophaga canimorsus is a facultative Gram-negative bacillus that is typically a constituent of the oral flora of dogs and cats. It was first isolated by Bobo and Newton in 1976 from a man presenting with meningitis following a dog bite. Transmission to humans follows various animal-related injuries, which may be gross or subtle. C canimorsus can cause a spectrum of syndromes ranging from skin and soft tissue infection to invasive disease such as meningitis or endocarditis. The present article reports a case of C canimorsus meningitis in a patient with the classic risk factor of alcoholic liver cirrhosis. Clinical suspicion was confirmed by culture and genetic identification of the blood isolate. The present article reviews the Capnocytophaga genus, the clinical syndromes most commonly associated with this zoonotic organism, its laboratory identification and treatment.     

Leptinotarsin: A presynaptic neurotoxin that stimulates release of acetylcholine

Leptinotarsin, a toxin found in the hemolymph of the beetle Leptinotarsa haldemani, can stimulate release of acetylcholine from synaptic termini. Leptinotarsin causes an increase in the frequency of miniature end plate potentials (mepps) of the rat phrenic nerve-diaphragm preparation. The increase in the frequency of mepps induced by leptinotarsin is biphasic: about 10% of the total mepps are released in an initial burst that lasts about 90 sec, after which the remaining mepps are released over a period of 10-20 min. Tetrodotoxin has no effect upon the release induced by leptinotarsin, but low-Ca²⁺ conditions abolish the first phase. The two phases of release may represent two presynaptic pools of acetylcholine, both of which can be released in quantized form. In a second study, rat brain synaptosomes were incubated with [³H]choline and were immobilized on Millipore filters. Leptinotarsin induced release of [³H]acetylcholine from this preparation, confirming the release seen by using neurophysiological methods. The ability of leptinotarsin to induce release from either intact nerve terminals or synaptosomes was abolished when the toxin was heated. The releasing activity of leptinotarsin from synaptosomes was also partially dependent upon the presence of Ca²⁺ in the perfusing solution. Release from synaptosomes followed first-order kinetics, and was not inhibited by commercial antibodies to black widow spider antigens. The data suggest that leptinotarsin acts as a presynaptic neurotoxin and may be of value as a mechanistic probe in understanding the storage and release of neurotransmitters.     

Envenomation by a spider, Agelenopsis aperta (Family: Agelenidae) Previously Considered Harmless

This is the first report of clinically significant bites by the grass spider (Agelenopsis aperta ). Two cases of envenomation in southern California are presented. In the more serious case, a child exhibited several envenomation symptoms. Although this spider may be generally innocuous, it should be considered as a creature of occasional medical importance. Many skin lesions are attributed to spider bites despite insufficient incriminating evidence, and bites that are clinically significant may often erroneously be attributed to the brown recluse spider. Misidentification can lead to undue anxiety in a patient’s family. [Vetter RS: Envenomation by a spider, Agelenopsis aperta (Family: Agelenidae) previously considered harmless. Ann Emerg Med December 1998;32:739-741.]     

Lyme disease masquerading as brown recluse spider bite

We report a case of Lyme disease with clinical features resembling those described from brown recluse spider bites. The most striking manifestation was a necrotic skin wound. Brown recluse spider bites may be overdiagnosed in some geographic regions. Tick bite and infection with Borrelia burgdorferi should be considered in the differential diagnosis of necrotic arachnidism in regions endemic for Lyme disease.     

Emergency department death from systemic loxoscelism

Systemic loxoscelism is a constitutional illness resulting from the bite of the brown recluse spider. In severe form, it may cause hemolysis, acute renal failure, and disseminated intravascular coagulation. More rarely, it may result in death. We report an unusual case of systemic loxoscelism resulting in death less than one day following envenomation. We also discuss screening algorithms and contemporary management of systemic loxoscelism.     

Whiteflies interfere with indirect plant defense against spider mites in Lima bean

Plants under herbivore attack are able to initiate indirect defense by synthesizing and releasing complex blends of volatiles that attract natural enemies of the herbivore. However, little is known about how plants respond to infestation by multiple herbivores, particularly if these belong to different feeding guilds. Here, we report the interference by a phloem-feeding insect, the whitefly Bemisia tabaci, with indirect plant defenses induced by spider mites (Tetranychus urticae) in Lima bean (Phaseolus lunatus) plants. Additional whitefly infestation of spider-mite infested plants resulted in a reduced attraction of predatory mites (Phytoseiulus persimilis) compared to attraction to plants infested by spider mites only. This interference is shown to result from the reduction in (E)-β-ocimene emission from plants infested by both spider mites and whiteflies. When using exogenous salicylic acid (SA) application to mimic B. tabaci infestation, we observed similar results in behavioral and chemical analyses. Phytohormone and gene-expression analyses revealed that B. tabaci infestation, as well as SA application, inhibited spider mite-induced jasmonic acid (JA) production and reduced the expression of two JA-regulated genes, one of which encodes for the P. lunatus enzyme β-ocimene synthase that catalyzes the synthesis of (E)-β-ocimene. Remarkably, B. tabaci infestation concurrently inhibited SA production induced by spider mites. We therefore conclude that in dual-infested Lima bean plants the suppression of the JA signaling pathway by whitefly feeding is not due to enhanced SA levels.     

Case report: compartment syndrome after a suspected black widow spider bite

Widow spider envenomations generally produce systemic neurologic syndromes without significant local injury. We report a patient who sustained a black widow spider bite to the left forearm and presented to the emergency department with rhabdomyolysis and compartment syndrome. We documented a decrease in symptoms and compartment pressure after administration of antivenom. No surgical intervention was performed. We believe this report to be the first documenting compartment syndrome associated with black widow spider bite.     

Immunometabolic Effect of Cholesterol in Hepatitis C Infection: Implications in Clinical Management and Antiviral Therapy

Hepatitis C virus (HCV) is a lipid-enveloped virion particle that causes infection to the liver, and as part of its life cycle, it disrupts the host lipid metabolic machinery, particularly the cholesterol synthesis pathway. The innate immune response generated by liver resident immune cells is responsible for successful viral eradication. Unfortunately, most patients fail to eliminate HCV and progress to chronic infection. Chronic infection is associated with hepatic fat accumulation and inflammation that triggers fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Despite that the current direct-acting antiviral agents have increased the cure rate of HCV infection, viral genotype and the host genetic background influence both the immune response and lipid metabolism. In this context, recent evidence has shown that cholesterol and its derivatives such as oxysterols might modulate and potentialize the hepatic innate immune response generated against HCV. The impairment of the HCV life cycle modulated by serum cholesterol could be relevant for the clinical management of HCV-infected patients before and after treatment. Alongside, cholesterol levels are modulated either by genetic variations in IL28B, ApoE, and LDLR or by dietary components. Indeed, some nutrients such as unsaturated fatty acids have demonstrated to be effective against HCV replication. Thus, cholesterol modifications may be considered as a new adjuvant strategy for HCV infection therapy by providing a biochemical tool that guides treatment decisions, an improved treatment response and favoring viral clearance. Herein, the mechanisms by which cholesterol contributes to the immune response against HCV infection and how genetic and environmental factors may affect this role are reviewed.     

NMR-spectroscopic screening of spider venom reveals sulfated nucleosides as major components for the brown recluse and related species

Extensive chemical analyses of spider venoms from many species have revealed complex mixtures of biologically active compounds, of which several have provided important leads for drug development. We have recently shown that NMR spectroscopy can be used advantageously for a direct structural characterization of the small-molecule content of such complex mixtures. Here, we report the application of this strategy to a larger-scale analysis of a collection of spider venoms representing >70 species, which, in combination with mass spectrometric analyses, allowed the identification of a wide range of known, and several previously undescribed, small molecules. These include polyamines, common neurotransmitters, and amino acid derivatives as well as two additional members of a recently discovered family of natural products, the sulfated nucleosides. In the case of the well studied brown recluse spider, Loxosceles reclusa, sulfated guanosine derivatives were found to comprise the major small-molecule components of the venom.