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Sicarius Ornatus
''Sicarius ornatus'' is a species of venomous spider found in South America (Brazil). It has a highly toxic venom like the other South American sicariid, ''Loxosceles laeta'' and the African '' Hexophthalma hahni'', but there are few human bites recorded. Its venom has active sphingomyelinase D, and can lead to a severe pathology. The venom of ''Sicarius ornatus'' contains active sphingomyelinase D, the main toxin responsible for local and systemic effects, the venom of ''S. ornatus'' is endowed with all toxic properties in vitro and ex vivo, and like ''Loxosceles'', it is capable and hydrolyzes sphingomyelin , induce cell death of keratinocytes and complement-dependent hemolysis Hemolysis or haemolysis (), also known by several other names, is the rupturing ( lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo ..., harmful events that have been associated with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venomous Spider
A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain. Most spiders do not cause bites that are of importance. For a bite to be significant, substantial envenomation is required. Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism. Symptoms may include pain which may be at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others. Bites from the recluse spiders cause the condition loxoscelism, in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur. Headaches, vomiting and a mild fever may also occur. Other spiders that can cause significant bites include the Australian funnel-web spider and South American wandering spider. Efforts to preven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency of Norway), Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area and the seventh most populous. Its capital is Brasília, and its most populous city is São Paulo. The federation is composed of the union of the 26 States of Brazil, states and the Federal District (Brazil), Federal District. It is the largest country to have Portuguese language, Portuguese as an List of territorial entities where Portuguese is an official language, official language and the only one in the Americas; one of the most Multiculturalism, multicultural and ethnically diverse nations, due to over a century of mass Immigration to Brazil, immigration from around the world; and the most populous Catholic Church by country, Roman Catholic-majority country. Bounded by the Atlantic Ocean on the east, Brazil has a Coastline of Brazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loxosceles Laeta
The Chilean recluse spider, ''Loxosceles laeta'', is a highly venomous spider of the family Sicariidae. In Spanish, it (and other South American recluse spiders) is known as ', or "corner spider"; in Brazilian Portuguese, as ' or "brown spider". It is considered by many to be the most dangerous of recluse spiders, and its bites often result in serious systemic reactions, up to and including death. Description The Chilean recluse is one of the larger species of recluse spiders, generally ranging from 8–40 mm in size (including legs). Like most recluses, it is brown and usually has markings on the dorsal side of its thorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider resulting in the nickname "fiddleback spider" or "violin spider" in English-speaking areas. Coloring varies from light tan to brown and the violin marking may not be visible. Since the "violin pattern" is not diagnostic, it is far mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexophthalma Hahni
''Hexophthalma hahni'' ( synonyms ''Sicarius hahni'' and ''Sicarius testaceus''), known along with other members of the genus as the six-eyed sand spider, is a member of the family Sicariidae, found in deserts and other sandy places in southern Africa. Due to their flattened stance and laterigrade legs, they are also sometimes known as six-eyed crab spiders. Its specific name honours Carl Wilhelm Hahn. Venom All species of ''Hexophthalma'' produce venom that can have necrotic (dermonecrotic) effects, capable of causing serious or even life-threatening wounds, particularly if the wound becomes infected or the venom spreads in the body. The necrotic effects are caused by a family of proteins related to sphingomyelinase D Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, res ..., present i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingomyelinase D
Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, resulting in the formation of ceramide 1-phosphate and choline: : sphingomyelin + H2O \rightleftharpoons ceramide 1-phosphate + choline or the hydrolysis of 2-lysophosphatidylcholine to give choline and 2-lysophosphatidate. Sphingomyelin phosphodiesterase D activity is shared by enzymes with a wider substrate range, classified as phospholipases D or lipophosphodiesterase II . Sphingomyelinases D are produced by some spiders in their venoms, specifically the brown recluse (''Loxosceles reclusa''), by arthropods such as ticks, or pathogenic bacteria and fungi. Pathogenicity is expressed through different mechanisms, such as membrane destabilization, cell penetration, inflammation of the lungs and cutaneous lesions, common following brown rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loxosceles
The recluse spiders (''Loxosceles'' (), also known as brown spiders, fiddle-backs, violin spiders, and reapers, is a genus of spiders that was first described by R. T. Lowe in 1832. They are venomous spiders known for their bite, which sometimes produces a characteristic set of symptoms known as loxoscelism. Recluse spiders are now identified as members of the family Sicariidae, having formerly been placed in their own family, the Loxoscelidae. Although recluse spiders are feared, they are usually not aggressive. Relation with other spiders Sicariidae are of the superfamily Scytodoidea. Other families in the Scytodoidea include Drymusidae, Scytodidae, and Periegopidae. Habitat and appearance ''Loxosceles'' is distributed nearly worldwide in warmer areas. All have six eyes arranged in three groups of two (dyads) and some are brownish with a darker brown characteristic violin marking on the cephalothorax. However, the "violin marking" cannot be used as a reliable way to identif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratinocytes
Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells. Basal cells in the basal layer (''stratum basale'') of the skin are sometimes referred to as basal keratinocytes. Keratinocytes form a barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, and viruses. A number of structural proteins, enzymes, lipids, and antimicrobial peptides contribute to maintain the important barrier function of the skin. Keratinocytes differentiate from epidermal stem cells in the lower part of the epidermis and migrate towards the surface, finally becoming corneocytes and eventually be shed off, which happens every 40 to 56 days in humans. Function The primary function of keratinocytes is the formation of a barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, and viruses. Pathogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemolysis
Hemolysis or haemolysis (), also known by several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo or in vitro. One cause of hemolysis is the action of hemolysins, toxins that are produced by certain pathogenic bacteria or fungi. Another cause is intense physical exercise. Hemolysins damage the red blood cell's cytoplasmic membrane, causing lysis and eventually cell death. Etymology From hemo- + -lysis, from , "blood") + , "loosening"). Inside the body Hemolysis inside the body can be caused by a large number of medical conditions, including some parasites (''e.g.'', ''Plasmodium''), some autoimmune disorders (''e.g.'', autoimmune haemolytic anaemia, drug-induced hemolytic anemia, atypical hemolytic uremic syndrome (aHUS)), some genetic disorders (''e.g.'', Sickle-cell disease or G6PD deficiency), or blood with too low a solute conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sicarius Tropicus
''Sicarius tropicus'' is a species of six-eyed sand spider ('' Sicarius'') endemic in South American caatinga in Brazil. Like related spiders, it is venomous, but only one medically-significant bite has been recorded, causing dermonecrotic lesions in a 17-year-old boy. Venom A 2021 study compared the venom with that of ''Loxosceles laeta'', considered the most toxic species in the genus. The venom of ''S. tropicus'' contains Sphingomyelinase D, capable of causing dependent ''hemolysis Hemolysis or haemolysis (), also known by several other names, is the rupturing ( lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo ...''; the hemolysis mechanisms were found to differ between the two species. References {{Taxonbar, from=Q2401348 Sicariidae Spiders described in 1936 Spiders of Brazil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sicariidae
Sicariidae is a family of six-eyed venomous spiders known for their potentially necrotic bites. The family consists of three genera and about 160 species. Well known spiders in this family include the brown recluse spider and the six-eyed sand spider. Description ''Loxosceles'', commonly known as "recluse spiders" or "violin spiders", is distributed nearly worldwide in warmer areas. ''Hexophthalma'' and '' Sicarius'', commonly known as "sand spiders" or "assassin spiders", live in the deserts of southern Africa and South to Central America, respectively. They are known for their self-burying behavior and the ability to go for long periods without food or water. All members have six eyes arranged in three groups of two (dyads). Violin spiders are usually brownish with a darker brown characteristic violin marking on the cephalothorax. They are also haplogyne, meaning the females possessing unsclerotised genitals. ''Hexophthalma'' and ''Sicarius'' resemble crab spiders and lack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiders Of Brazil
Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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