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Brown recluse spider bites occur commonly in the Southern United States but eyelid bites are rare. Management of eyelid bites is difficult because the initial spider bite is frequently unnoticed, surgical and medical treatments are ineffective, and even a small area of necrosis affects the appearance and function of the eyelid.
A new neurotoxin (JSTX) was separated from spider (Nephila clavata, Joro spider) venom. JSTX irreversibly suppressed the excitatory postsynaptic potential (EPSP) and the glutamate potential in the lobster neuromuscular junction with high degree of specificity. The threshold concentration for suppressing EPSPs corresponds to a small fraction of the toxin in a venom gland, roughly estimated as low as 10(-10) M/l. 10(-10) M/l. In the giant synapse of squid stellate ganglion JSTX suppressed EPSPs without affecting the antidromic response. Glutamate-induced membrane depolarization was blocked by JSTX. In mammalian brain slice preparation, JSTX suppressed the orthodromic spike response but failed to affect on the antidromic spike in the hippocampal pyramidal neuron of CA1 and CA3 region. The above results strongly support the view that the squid giant synapse and synapses in the hippocampal pyramidal neuron are mediated by glutamate.
Venom from the poisonous brown recluse spider (Loxosceles reclusa) catalyses the lysis of dithiothreitol-treated human erythrocytes when incubated with serum complement but not in heat inactivated serum, a characteristic of complement system activation via the alternate pathway. This activity of the venom was shown to reside in a Sephadex G-75 fraction of the venom which also contains the dermonecrotoxin. Isoelectric focusing of this fraction identified the complement inactivating molecules(s) in the region near pH=6. Analysis of complement after interaction with venom indicated a loss of haemolytic C3. Immunoelectrophoretic development of venom-complement mixtures with anti C3 proactivator revealed the appearance of the C3 activator. These data indicate that recluse spider venom activates the alternate complement pathway.
Most species of spiders leave their egg-sacs in a sheltered place. However, some of them look after or carry their egg-sacs until the spiderlings hatch. Others extend their maternal behaviour to feeding their young by regurgitation or by the distribution of prey. The adaptative aspect of this maternal behaviour is shown by a reduced rate of reproduction in the species whose care of progeny is the most sophisticated. The maternal care of the egg-sac depends on the physiological state of the female, that state, in turn, being maintained by the presence of the egg-sac. The tolerance exhibited by the mother towards her offspring implies at least two mechanisms: (i) inhibition of predatory behaviour in response to the movements of an offspring at a distance, (ii) inhibition of cannibalism when in contact with an offspring. The parental relationship can be complemented by cooperation between the young that involves a tolerance mechanism probably close to that of social spiders.
OBJECTIVES: To demonstrate and define normal lymphatic transit times by lymphoscintigraphy and to evaluate the efficacy of the currently recommended first-aid measures for the management of snake or spider envenomation. SETTING: The nuclear medicine department of a major teaching hospital. PARTICIPANTS AND DESIGN: Twenty-four subjects received either intradermal or subcutaneous injections of 99mtechnetium antimony sulfur colloid (0.1 mL) in both hands/forearms and feet/legs. This simulated a snake or spider bite. Fifteen of the subjects had first-aid in the form of firm bandages and splints applied to an upper and a lower limb immediately after injection. MAIN OUTCOME MEASURES: The progress of the radiotracer was followed with a large field of view gamma camera. If no egress of radiotracer was seen in the bandaged limbs, the subject walked until radioactivity was detected. RESULTS: The mean (+/- SEM) periphery-to-systemic circulation transit time after subcutaneous injection was 58 (+/- 7) minutes. The first-aid was found to be very effective when applied with bandage pressures ranging from 40 to 70 mmHg (5.3-9.3 kPa) in the upper limb and 55 to 70 mmHg (7.3-9.3 kPa) in the lower limb. Lower and higher bandage pressures were ineffective. However, despite first-aid measures, egress of radiotracer, even in the upper limbs, was seen in all subjects who walked for 10 minutes or more. CONCLUSIONS: Firm pressure bandaging is an effective means of restricting the lymphatic flow of toxins after envenomation, provided the bandage is applied within the defined pressure range. Strict limb immobilisation is necessary to minimise lymphatic flow, and walking after upper or lower limb envenomation will inevitably result in systemic envenomation despite first-aid measures.
Accumulate experience, from 1955 to 1995, in an outpatient university parasitology clinic in Santiago, with 1,384 patients referred from diverse public and private medical institutions because of a probable spider bite or insect stings, is presented. It is noteworthy that only 618 (44.7%) of consultations corresponded to clinical conditions originated by arthropods, whereas from the remaining 766, 612 (44.2%) were due to a bacterial, viral or parasitic etiology and 154 (11.1%) were caused by physical or chemical agents. Frequency of diagnosis was: loxoscelism 16.6%, spider bites (excluded Loxosceles laeta) 1.3%, scorpion sting 0.9%, tick stings 2.2%, insect bites 23.7%, impetigo 6.6%, folliculitis 11.3%, boil 22.7%, erysipelas 0.1%, pustula maligna 0.3%, herpes simplex 2.5, palpebral herpes zoster 0.3%, acute Chagas' disease 0.4%, angioneurotic edema 0.1%, ecchymosis 3.0, contact dermitis 7.8% and chemical dermitis 0.2%. These frequencies do not indicate the real occurrence of the diagnosed nosologies, but what happened in a specialized outpatient clinic dealing cheaply with parasitic diseases and arthropod envenomations. Description of relevant clinical features and epidemiological considerations of pathology observed, conjointly with differential diagnosis are presented.
The mechanosensory organs of arachnids receive diverse peripheral inputs. Little is known about the origin, distribution, and function of these chemical synapses, which we examined in lyriform slit sense organ VS-3 of the spider Cupiennius salei. The cuticular slits of this organ are each associated with two large bipolar mechanosensory neurons with different adaptation rates. With intracellular recording, we have now been able to correlate directly the staining intensity of a neuron for acetylcholinesterase with its adaptation rate, thus allowing us simply to stain a neuron to identify its functional type. All rapidly adapting neurons stain more heavily than slowly adapting neurons. Immunostaining of whole-mount preparations reveals GABA-like immunoreactive fibers forming numerous varicosities at the surface of all sensory neurons in VS-3; peripheral GABA-like immunoreactive somata are lacking. Sectioning the leg nerve procures rapid degeneration of most fiber profiles, confirming that the fibers are efferent. Punctate synapsin-like immunoreactivity colocalizes to these varicosities, although some synapsin-like immunoreactive puncta are GABA-immunonegative. Fibers with similar immunoreactivities are also associated with trichobothria, tactile hairs, internal joint receptors, i.e. other types of spider mechanosensory organs. In organ VS-3, immunoreactivity is most dense across the initial axon segment. The exact distribution of peripheral synapses was reconstructed from a 10-microm-long electron micrograph series of the dendritic, somatic, and initial axon regions of acetylcholinesterase-stained VS-3 neurons. These reveal a pattern similar to that of the synapsin-like immunoreactivity. Two different types of synapse were distinguished on the basis of their presynaptic vesicle populations. Many peripheral synapses thus appear to derive from efferent GABA-like immunoreactive fibers and probably provide centrifugal inhibitory control of primary mechanosensory activities.
Latrodectus mactans has now invaded towns and cities. The spider's venom is a neurotoxin that causes little local reaction but produces pain and spasm in large skeletal muscle groups within 30 minutes to three hours after the bite. Severe envenomation may result in respiratory failure and coma. First aid is of no value. Muscle relaxants are useful in treatment, as is calcium gluconate. Antivenin is indicated for high-risk victims, such as those with hypertension and persons younger than 16 or older than 60 years of age.
We described genetically engineered syntheses of tandem repetitive polypeptides consisting of glycine-rich sequence, GlyLeuGlyGlyGlnGlyGlyGlyAlaGlyGlnGlyGlyTyrGly, designated SCAP(1), in spidroin 1 of spider dragline silk from Nephila clavipes and the secondary conformational analyses in the solid state by Fourier transform ir measurements. The polypeptides composed of 4, 5, 6, 7, 11, 12, or 13 repeats of SCAP(1) were expressed in Escherichia coli, purified by nickel chelate affinity chromatography, and then cleaved with cyanogen bromide to release N- and C-terminal extensions. Typical yields were from 1.2 to 5.2 mg of lyophilized uncleaved polypeptides per liter of fermentation medium at an absorbance of 2.0 at 600 nm, and the production levels increased with decreasing the molecular weight of the expressed polypeptides. The lyophilized powder of cleaved SCAP(13) adopted the random coil, whereas the cast film from formic acid formed the beta-sheet structure. The conformational results might indicate that the glycine-rich sequence formed beta-sheet structure in spidroin I. Cleaved SCAP(13) started to decompose under nitrogen at ca. 230 degrees C, which was in agreement with the decomposition temperature of the spider dragline silk from N. clavipes.
Members of the population of black-handed spider monkeys (Ateles geoffroyi) on Barro Colorado Island, Panama, use the leaves of three Rutaceae species in a behavior that resembles fur rubbing in the white faced capuchin (Cebus capucinus). This behavior has not been reported from other sites where Ateles has been studied. During more than 1,200 hours of observation, 30 episodes of this behavior were recorded ad libitum. Adult males engage in this behavior more than adult females. Season did not impact the frequency of the behavior. The behavior described here differs in many respects from that reported for Cebus capucinus, and does not fit the hypotheses that the behavior functions in repelling insects or other antiseptic purposes. It is proposed that fur rubbing in this group of spider monkeys is a modification of a behavior previously recorded in Ateles and may function in scent marking.
Data are presented regarding the habitat use and ranging behavior of a spider monkey (Ateles chamek) community at Lago Caiman in northeastern Bolivia. Habitat use was driven primarily by fruit availability and distribution across the community home range. Strong seasonal variations occurred in fruit availability within all five of the floristically and phenologically distinct habitat types identified within the study site, and the spider monkeys dramatically shifted their ranging according to which habitat was richest in fleshy fruits. This use of local habitat diversity resulted in an unusually elongated shape for the home range that was otherwise typical of previous Ateles studies in terms of size. Ranging behavior was clumped and community core areas shifted seasonally across the focal community home range. Individual core areas were not relevant to the study due to dramatic community-wide shifts in ranging patterns. Day journey lengths were highly variable (460-5,690 m) and the distribution and abundance of fleshy fruit resources explained 81% of the monthly variations in mean day journey length. Keystone habitats for forest frugivores are identified and results are discussed with reference to previous studies on this genus, and the importance of considering keystone habitats and local habitat diversity within the management of forestry concessions in the region. Results are also discussed with reference to the behavioral ecology of the genus Ateles.
I report three cases of coalitionary aggression by adult male black-handed spider monkeys (Ateles geoffroyi) against subadult males within their community on Barro Colorado Island (BCI), Panama. Two of these cases were followed by the disappearance and presumed death of the victim. Similar behavior was recently reported by Valero et al. [in press], who suggested that this behavior may be the result of intense male reproductive competition. Like the single instance they reported, the cases I report all occurred when the operational sex ratio was approximately 1:1, which suggests that intense competition among males for access to reproductively viable females may be a contributing factor. Additionally the very low density of spider monkeys on BCI may play a significant role in the occurrence of this lethal aggression. Large numbers of adult males are not necessary to protect a territorial boundary against neighboring groups, and additional males may act merely as mating competition.
A recent study suggests that differing populations of woolly spider monkeys exhibit a substantial degree of morphological, cytogenetic, and behavioral variation. We re-evaluate the differences between populations in the degree of canine tooth height sexual dimorphism and in the frequency of thumbs. Statistical analysis of variation in the degree of canine sexual dimorphism between these populations fails to provide strong evidence for subspecific variation: differences in the degree of canine dimorphism cannot be considered statistically significant. Differences between populations in the frequency of thumbs are, however, statistically significant. The lack of clear distinctions between populations in the degree of canine dimorphism complicates assessments of behavioral variation between these populations. We suggest that the level of geographic variation in woolly spider monkey canine dimorphism is not consistent with subspecific status.
Using a conditioning paradigm, the olfactory sensitivity of five spider monkeys for homologous series of aliphatic 1-alcohols (1-propanol to 1-octanol) and n-aldehydes (n-butanal to n-nonanal) was investigated. With the exception of 1-propanol, the animals significantly discriminated concentrations below 1 ppm from the odorless solvent, and in several cases, individual monkeys even demonstrated detection thresholds below 10 ppb. The results showed 1) spider monkeys to have a well-developed olfactory sensitivity for both substance classes, which for the majority of alcohols tested matches or even is better than that of the rat, and 2) a significant negative correlation between perceptibility in terms of olfactory detection thresholds and carbon chain length of the alcohols, but not of the aldehydes tested. These findings lend further support to the growing body of evidence suggesting that between-species comparisons of the number of functional olfactory receptor genes or of neuroanatomical features are poor predictors of olfactory performance, and that general labels such as "microsmat" or "macrosmat" (which are usually based on allometric comparisons of olfactory brain structures) are inadequate to describe a species' olfactory capabilities.
In this study we assess the effect of pyrrolizidine alkaloids (PAs) extracted from Lithospermum canescens on the biology of the two-spotted spider mite (Tetranychus urticae Koch). Lithospermum canenscens (Michaux) Lehm. (Boraginaceae) is a common prairie plant also known as Indian paint or hoary puccoon. A mixture of seven PAs with known chemical structures was used in this investigation. Mites treated with PAs showed a high mortality of juveniles, a decrease in female fecundity and a shortened longevity. The intrinsic rate of population increase (r(m)) was used as an indicator of T. urticae population performance after treatment with PAs. The r(m) value obtained with alkaloid-treated leaves was lower than that for mites developing on untreated leaves, which indicates that the mite population would develop much slower on treated plants. The results suggest that further studies should be performed to assess the possible use of PA extracts for spider mite control.
BACKGROUND AND OBJECTIVES: Lower-extremity spider veins are a cosmetic problem that poses formidable clinical difficulty for laser removal. They are significantly harder to remove than facial telangiectasias. A new-generation, pulsed-dye laser (PDL), capable of administering pulses that clinically behave like true 40-millisecond pulses has been developed, by doubling the number of sub-pulses comprising each laser pulse. STUDY DESIGN/MATERIALS AND METHODS: Fifteen subjects with Fitzpatrick skin types I-III were enrolled in the study and treated to 35 sites. Subjects were treated three times at 6-week intervals using an average fluence of 20.4 J/cm(2), a 3 x 10 mm spot, and a dynamic cooling device to protect the epidermis. Digital photographs were taken before initiating treatment and 8 weeks following the final treatment. RESULTS: Mean improvement scores using a 4-point scale as rated subjectively by the treating physician were 0.92 (<25%), 2.7 (approximately 40-50%), and 3.6 (approximately 65-75%), 6 weeks following 1st and 2nd treatments and 8 weeks following the 3rd and final treatment, respectively. Improvement was also determined by three physicians, rating digital photographs and blinded as to which photographs were pre- or post-treatment. They rated improvement as mild (0-25%) in 10.5% of photographs, moderate (26-50%) in 15.2%, marked (51-75%) in 38.1%, and excellent (76-100%) in 6.3%. There was no textural change in any treatment site. CONCLUSIONS: The new-generation, high-energy, 595 nm, long pulse-duration, PDL effectively removes lower-extremity spider veins in subjects with skin types I-III.
We compared the influence of recent feeding history on locomotory behaviour in two species of wolf spiders, Hogna helluo (Walckenaer) and Pardosa milvina Hentz, in the laboratory. Both species are cursorial hunters. We maintained the spiders in the laboratory on satiation and stringent feeding regimes and measured their locomotory activity levels for 1 h using a digital activity recording device. We subjected H. helluo to either ad libitum feeding for 14 days or no food for 14 days. We subjected P. milvina to ad libitum feeding or fasting treatments for 7 and 14 days. We found that H. helluo showed a shift in locomotory activity depending on feeding regime, whereas P. milvina did not. Food-limited H. helluo travelled further than satiated H. helluo, and did so by moving more frequently. Pardosa milvina was in general much more active than H. helluo. We propose that P. milvina is an active forager compared with the sit-and-wait strategy of H. helluo. This difference in foraging strategy is correlated with differences in body size and habitat use. Copyright 1999 The Association for the Study of Animal Behaviour.
Phylogenetic relationships based on DNA sequence variation for the aldolase A intron V nuclear genomic region were evaluated and compared to phylogenies based on mitochondrial DNA sequence variation among spider monkeys (Ateles). Samples of Ateles ranging from Central America throughout the Amazon Basin were sequenced to determine phylogenetic relationships among geographically widely distributed populations. Analysis of nuclear DNA sequences using parsimony, maximum-likelihood, and genetic distance analyses produced similar phylogenies. Four previously proposed monophyletic species of spider monkeys were: (1) Ateles paniscus, composed of haplotypes from the northeastern Amazon Basin; (2) A. belzebuth, found in the western and southern Amazon Basin; (3) A. hybridus, located primarily along the Magdalena River valley of Colombia; and (4) A. geoffroyi, including all haplotypes found in the Choco region of South America and throughout Central America. The nuclear phylograms were analyzed based on associated bootstrap support and confidence probabilities. Support from the nuclear DNA genome was less robust than support from the mitochondrial DNA data, most likely due to a level of sequence variation, which was 90% less than that of the mitochondrial DNA genome. Nuclear DNA congruencies with mitochondrial DNA-based phylogenies, as supported by the incongruence length difference and winning sites tests, provide further support for the suggested revisions in Ateles taxonomy that are contradictory to long-held taxonomies based on pelage variation.