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PubMed2004

Phylogenetic placement of the spider genus Nephila (Araneae: Araneoidea) inferred from rRNA and MaSp1 gene sequences.

The family status of the genus Nephila, which belongs to Tetragnathidae currently but Araneidae formerly, was reexamined based on molecular phylogenetic analyses. In the present study, 12S and 18S rRNA gene fragments of eight species of spiders were amplified and sequenced. In addition, 3'-end partial cDNA of major ampullate spidroin-1 (MaSp1) gene of Argiope amoena was cloned and sequenced, and the 3'-end non-repetitive region's cDNA sequence of MaSp1 gene and the predicted amino acid sequence of C-terminal non-repetitive region of MaSp1 were aligned with some previously known sequences. The resulting phylogeny showed that Araneidae and Tetragnathidae are not a sister group in the superfamily Araneoidea, and the genus Nephila is closer to the genera of the family Araneidae rather than to those of Tetragnathidae. We suggest that the genus Nephila should be transferred back to Araneidae. Or the subfamily Nephilinae might be elevated to family level after it was redefined and redelimited. Furthermore, the study showed that 3'-end non-repetitive region's cDNA sequence of MaSp1 gene and C-terminal non-repetitive region's amino acid sequence of MaSp1 are useful molecular markers for phylogenetic analysis of spiders.

Amino Acid Sequence↗
PubMed2005

Spider silk proteins--mechanical property and gene sequence.

Spiders spin up to seven different types of silk and each type possesses different mechanical properties. The reports on base sequences of spider silk protein genes have gained importance as the mechanical properties of silk fibers have been revealed. This review aims to link recent molecular data, often translated into amino acid sequences and predicted three dimensional structural motifs, to known mechanical properties.

Animals↗
PubMed2005

Pharmacological characterisation of spider antimicrobial peptides.

Most spider antimicrobial peptides share a common mechanism of membrane permeabilisation and the innate immune systems of the pathogen. In this review, we present recent accounts of the application at the preclinical level that should be tried and the range of bioactivities and their particular structure can be harnessed for molecular engineering applications and in drug design. Structural analyses such as amino acid sequence and circular dichroism are described. Conductance measurements and pharmacological studies of the action on the inner or outer membranes of anti-microbe will reveal more about the mode of action of the antimicrobial peptides of spider.

Amino Acid Sequence↗
PubMed1989

Beliefs and inferences: a test of a rational-emotive hypothesis: 2. On the prospect of seeing a spider.

96 subjects were asked to imagine that they were about to enter a room in which there may have been one or more spiders. They were also asked to imagine that (a) they either held a rational or an irrational belief about spiders, (b) they were about to enter the room either alone or with someone, and (c) that the room was either dark or light. Having absorbed their assigned role, the subjects were then asked to make inferences about various elements of their situation. The results supported the hypothesis that holding an irrational belief leads to more negative inferences. It was also found that the lighting conditions in the room and whether the subject was alone or with someone affected the negativity of the inferences made. In addition, there were several two-way and three-way interactions between the independent variables which indicated that entering a light room or being with someone else tended to moderate the negativity of inferences made by those holding a rational belief rather than the opposite, amplifying the negativity of inferences made by those holding an irrational belief. The results supported Ellis's (1985) recent formulation concerning the complex relationship between events and inferences (A), beliefs (B), and emotional and behavioral consequences of beliefs (C).

Adolescent↗
PubMed1980

Funnelweb-spider venom antagonist.

It was found in a series of experiments on anaesthetized monkeys that rat plasma and rat euglobulin fractions contain a substance which could offer some protection against funnelweb-spider envenomation when administered before envenomation or simultaneously with the funnelweb-spider venom. Further work to isolate, identify, and purify this substance is needed.

Animals↗
PubMedDate not supplied

Delayed diagnosis of red-back spider envenomation: a timely reminder.

A case of the delayed diagnosis of envenomation by the redback spider (Latrodectus mactans hasselti) is reported. The common and more unusual presentations then are discussed, together with treatment guide-lines, and comparison is made with the management of latrodectism in the United States as a result of envenomation by the black-widow spider.

Adult↗
PubMed1999

Brown recluse spider bites.

The bite of the brown recluse spider (BRS) is the most severe arthropod cause of necrotic skin lesions. The severity of cutaneous injury due to BRS bites vary from mild erythema to severe necrosis. Rarely, severe systemic reactions occur. Diagnosis may be difficult, since the victim may not feel the bite or see the spider. Treatment must be individually tailored. Proper treatment, reassurance, and rapid followup are helpful in reducing the cutaneous and psychologic discomfort associated with BRS bites.

Animals↗
PubMedDate not supplied

Comparison of skin test results obtained with different dust, Dermatophagoides; Acarus siro and spider extracts.

The authors describe the comparative analysis of skin tests performed in 87 asthmatic children with extracts of house dust, grain dust and different arthropodes beloging to the Arachidaegenus. Most of these patients were living in traditional agricultural environment. Reactions to the Acarus siro and grain dust (Sevac) extracts gave significant correlation, whereas house dust did not show this agreement. Extracts from spiders (Aranidae) caused often, in 40% of asthmatic children, positive skin reaction; that was the same frequency as with Dermatophagoides, nevertheless the correlation was only partial. The authours conclude that Acarus siro and antigenically related mites are the main allergizing component of grain dust; excretes of spiders display a comparable allergizing factor in house dust as do Pyroglyphid mites in this area.

Allergens↗
PubMed2003

Automatic processing in spider phobia: implicit fear associations over the course of treatment.

This study evaluates the cognitive model of anxiety by investigating treatment-related changes in automatic associations to evaluate schematic processing. Spider-phobic participants (n = 31) and healthy controls (n = 30) completed fear-based Implicit Association Tests (IATs), which are reaction-time measures that tap implicit associations without requiring conscious introspection. The specific tasks involved classifying pictures of snakes and spiders along with semantic categorizations (good vs.bad, afraid vs. unafraid, danger vs. safety, and disgusting vs. appealing). Phobic individuals were assessed before and after group-based exposure treatment and 2 months later, controls were assessed at matched time points. Results supported clinical applications for implicit fear associations, including prediction of phobic avoidance, and treatment sensitivity of the fear- and disgust-specific automatic associations.

Adolescent↗
PubMed1976

Spiders of the genus Loxosceles in Australia.

A previous report of the presence of loxoscelid spiders in Australia is confirmed by a further finding of Loxosceles rufescens at a second suburban locality in Adelaide, South Australia. There is thus a third genus of potentially lethal spiders in Australia.

Animals↗
PubMedDate not supplied

[Construction of the synthetic genes for protein analogs of spider silk carcass spidroin 1 and their expression in tobacco plants].

To obtain transgenic tobacco plants expressing recombinant analogs of spider dragline silk spidroin 1, artificial 1f5 and 1f9 coding for spidroin 1 analogs were 3'-fused in-frame with the reporter lichenase gene. The Tr2' weak constitutive promoter of Agrobacterium tumefaciens T-DNA and the strong constitutive promoter of the cauliflower mosaic virus 35S RNA gene were used as regulatory elements. The expression cassettes were used to transform agrobacteria and then introduced in tobacco leaf disks. On evidence of Southern hybridization, transgenic plants each carried a single copy of a hybrid gene, which corresponded in size to the constructed one. Zymography and Western blotting revealed full-length hybrid proteins in leaf extracts of transgenic plants. The results testified that plants can maintain and express synthetic genes for spider silks and, consequently, may be used as a convenient producer of recombinant silk analogs.

Agrobacterium tumefaciens↗
PubMed2004

Coombs-positive hemolytic anemia secondary to brown recluse spider bite: a review of the literature and discussion of treatment.

The bite of the brown recluse spider (Loxosceles reclusa) typically results in local, dermonecrotic skin lesions. Rarely, these bites may precipitate systemic disturbances of varying severity collectively known as systemic loxoscelism. The more severe systemic alterations attributed to the venom of this arachnid include hemolytic anemia, multiorgan failure, disseminated intravascular coagulation, or even death. Coombs-positive hemolysis associated with brown recluse spider bites has rarely been documented in the literature. We report 2 cases of systemic loxoscelism in young women associated with severe Coombs-positive hemolytic anemia and systemic symptoms requiring hospitalization. Both patients were treated with aggressive wound care, hematologic monitoring with blood transfusion, and intravenous fluid replacement. Recovery was excellent in both cases. We review the literature and discuss the controversies surrounding the treatment of more severe brown recluse bite reactions.

Adult↗
PubMed1991

Spider toxin and the glutamate receptors.

A neurotoxin (JSTX) was isolated from the venom of spider (Nephila clavata). JSTX blocked both the excitatory postsynaptic (EPSPs) and glutamate-induced potentials in lobster neuromuscular synapse and squid giant synapse. In mammalian central nervous system, JSTX blocked the EPSPs in CA1 pyramidal neurons resulting from stimulation of Schaffer collateral/commissure input. Pharmacological investigation showed that JSTX preferentially suppressed quisqualate/kainate receptor subtypes but was much less effective on NMDA receptor. Using synthesized spider toxins we studied the structure-activity relationship and found that the 2,4 dihydroxyphenylacetyl asparagine in the toxin structure was responsible for suppressive action, while the remaining part containing a polyamine was related to the agonist binding site with the polycationic part enhancing the toxic activity. Labeling of synthesized JSTX was used for histochemical as well as biochemical studies. Using autoradiography, 125I-JSTX-3 was found to bind at the lobster neuromuscular synapse. Histochemical study utilizing the interaction of biotinylated JSTX-3 with avidin showed specific binding of the toxin in rat cerebellum and hippocampus. JSTX-3-binding protein was purified from rat brain by affinity chromatography. SDS-PAGE of the affinity purified protein showed at least 4 bands ranging from 40 to 70 kDa.

Animals↗
PubMedDate not supplied

Efficacy of funnel-web spider antivenom in human envenomation by Hadronyche species.

We describe the envenomation of three patients by Hadronyche versuta, Hadronyche infensa and Hadronyche cerberea (which all are species of funnel-web spider) and the reversal of symptoms by funnel-web spider antivenom. The importance of continuing to administer antivenom until symptoms are reversed is emphasized; all three patients required further doses of antivenom to reverse the symptoms completely. None of the patients had received first aid.

Aged↗
PubMed1989

Pulmonary oedema from a widow spider bite. A case report.

The clinical course of a patient bitten by a widow spider (Latrodectus indistinctus Pickard-Cambridge (Araneae: Theridiidae] is described. Although this spider is common in southern Africa, case reports are rare. To date details of the development of pulmonary oedema after a bite have not been published in South Africa.

Adult↗
PubMed1988

[The action of the venom of the spider Eresus niger on the neuromuscular synapses of the frog].

The effect of Eresus niger spider venom on frog neuromuscular preparations has been studied using the intracellular microelectrodes. The spider venom has been found to block both spontaneous and elicited transmitter release and possesses the phospholipase activity. It has been suggested that the venom blocking synaptic transmission results from its phospholipase activity by analogy with the action of snake presynaptic neurotoxins.

Animals↗
PubMed1987

The management of snake and spider bites in the southeastern United States.

Of all snake bites reported in the United States of America each year, 75 per cent occur in the states that form the Southeastern Surgical Congress. Pit vipers, coral snakes, and exotic imported snakes are all found in that area. Deaths from those snake bites are rare, but morbidity is high and it is often due to overtreatment rather than undertreatment. Treatment in the field is rarely necessary for the victim who is less than 1 hour away from definitive care. The type and size of the snake and the age, size, and health of the patient are important guides to therapy. Envenomation may not occur. When envenomation occurs from pit viper bites, antivenom is not always necessary, and its inherent dangers (serum sickness and possible hypersensitivity) must be weighed against the severity of systemic and local manifestations. All coral snake bites resulting in envenomation must be treated vigorously with coral snake antivenom. The Oklahoma City Poison Control Center can guide the treatment of bites from exotic snakes. The most frequently encountered toxic spider bites in the Southeast are those of the black widow and brown recluse spiders. The symptoms of black widow envenomation are best controlled with calcium gluconate or a muscle relaxant. Antivenom should be reserved for severe reactions. Brown recluse necrotic lesions are best controlled with dapsone.

Humans↗
PubMed1987

The bite of Lactrodectus indistinctus (button spider). A case report.

Lactrodectus indistinctus (button spider) is widely distributed in South Africa. However, the incidence of lactrodectism is unknown and no case reports have appeared recently. The importance of the recognition of this syndrome is stressed since a history or evidence of the spider bite may be absent or overlooked.

Adult↗