Spiders
Spider Venoms
Bites and Stings
Brown Recluse Spider
Dapsone
Expert Testimony
Snake Bites
Phosphoric Diester Hydrolases
Silk
Necrosis
Isolation, identification, and molecular characterization of strains of Photorhabdus luminescens from infected humans in Australia. (1/54)
We describe the isolation of Photorhabdus (Xenorhabdus) luminescens from four Australian patients: two with multiple skin lesions, one with bacteremia only, and one with disseminated infection. One of the patients had multiple skin lesions following the bite of a spider, while the lesions in the other patient were possibly associated with a spider bite. The source of infection for the remaining two patients is unknown. As a member of the family Enterobacteriaceae, P. luminescens is unusual in that it fails to reduce nitrate and ferments only glucose and mannose. It gives negative reactions for lysine decarboxylase, arginine dihydrolase, and ornithine decarboxylase (Moeller). The species is motile, utilizes citrate, hydrolyzes urea, and usually produces a unique type of annular hemolysis on sheep blood agar plates incubated at 25 degrees C. A weak bioluminescence is the defining characteristic. P. luminescens is an insect pathogen and is symbiotically associated with entomopathogenic nematodes. Its isolation from human clinical specimens has been reported previously from the United States. Restriction fragment length polymorphism-PCR analysis of the 16S rRNA gene demonstrated a high level of similarity among the Australian clinical strains and significant differences between the Australian clinical strains and the U.S. clinical strains. However, numerical analyses of the data suggest that the two groups of clinical strains are more similar to each other than they are to the symbiotic strains found in nematodes. This is the first report of the isolation of P. luminescens from infected humans in Australia and the second report of the isolation of this species from infected humans worldwide. (+info)A clinico-epidemiological study of bites by spiders of the genus Phoneutria. (2/54)
From January, 1984 to December, 1996, 422 patients (ages 9 m-99 y, median 29 y) were admitted after being bitten by spiders which were brought and identified as Phoneutria spp. Most of the bites occurred at March and April months (29.2%), in the houses (54.5%), during the day (76.5%), and in the limbs (feet 40.9%, hands 34.3%). Upon hospital admission, most patients presented only local complaints, mainly pain (92.1%) and edema (33.1%) and were classified as presenting mild (89.8%), moderate (8.5%) and severe (0.5%) envenomation. Few patients (1.2%) did not present signs of envenomation. Severe accidents were only confirmed in two children (9 m, 3 y). Both developed acute pulmonary edema, and the older died 9 h after the accident. Patients more than 70 year-old had a significantly greater (p<0.05) frequency of moderate envenomations compared to the 10-70-year-old individuals. Proceedings to relief local pain were frequently performed (local anesthesia alone 32.0%, local anesthesia plus analgesics 20.6% and oral analgesics alone 25. 1%). Only 2.3% of the patients (two cases classified as severe and eight as moderate, eight of them in children) were treated with i.v. antiarachnid antivenom. No antivenom early reaction was observed. In conclusion, accidents involving the genus Phoneutria are common in the region of Campinas, with the highest risk groups being children under 10 years of age and adults over 70 years of age. Cases of serious envenomation are rare (0.5%). (+info)Black widow bites in children. (3/54)
While seldom lethal, the bite of the black widow spider causes serious systemic symptoms that appear suddenly and progress rapidly. Children are more vulnerable to these complications; therefore, early hospitalization and aggressive therapy must be considered. General information about the widow spider genus is presented, and an illustrative case and treatment options are discussed. (+info)A new assay for the detection of Loxosceles species (brown recluse) spider venom. (4/54)
STUDY OBJECTIVE: Dermal lesions from unrelated arthropod species and medical causes appear similar to Loxosceles species (brown recluse spider) bites. This may result in delayed diagnosis and treatment. We developed a sensitive Loxosceles species venom enzyme-linked immunosorbent assay (ELISA) and characterized the specificity of the assay by evaluating antigenic cross-reactivity from a variety of North American arthropod venoms. METHODS: North American arthropod (14 spiders, 2 scorpions, and 1 bee) venoms were studied. Three venom amounts (diluted in 100 microL of ELISA buffer) were assayed: 16,000 ng, 2,000 ng, and 40 ng. The latter quantity was selected because this is the observed maximum amount of venom we detect when inoculating dermis with amounts likely to be deposited by a spider bite. The larger venom amounts are overwhelming quantities designed to test the limits of the assay for arthropod venom cross-reactivity. Similar amounts of Loxosceles species venom and bovine albumin served as positive and negative controls, respectively. RESULTS: At the lowest amount of venom tested (40 ng), the ELISA detected only the Loxosceles species positive control. When 2,000 ng was assayed, only Scytodes fusca and Kukulcania hibernalis arachnid venoms (in addition to Loxosceles species) cross-reacted to the assay. Finally, at 16,000 ng, the ELISA assay modestly detected Diguetia canities, Heteropoda venatoria, Tegenaria agrestis, Plectreurys tristes, Dolomedes tenebrosus, and Hadrurus arizonensis arachnid venoms. CONCLUSION: Cross-reactivity was observed in 8 of 17 North American arthropod venoms when large venom amounts were assayed with a Loxosceles species ELISA. By using a relevant quantity of venom, 40 ng, the assay was specific for Loxosceles species venom. The venom specificity of the ELISA may allow clinical application in Loxosceles species endemic regions of North America. (+info)Reports of presumptive brown recluse spider bites reinforce improbable diagnosis in regions of North America where the spider is not endemic. (5/54)
Envenomations by the brown recluse spider have been reported throughout North America, despite the fact that the spider's range is limited to the South and central Midwest of the United States. Several of these medical reports have originated from regions of nonendemicity where the spider has never or rarely been documented and brown recluse spider populations are unknown. In most of these reports, no spider is positively identified in association with the dermonecrotic wound, and diagnosis has been based on clinical examination findings. Considering the extreme rarity of brown recluse spiders in areas of nonendemicity, the diagnosis of a presumptive bite is a misdiagnosis that reinforces the assumption that brown recluse spiders are common local etiologic agents of necrosis. There are many medical conditions of diverse origin that have been misdiagnosed as brown recluse spider bites, some of which can be fatal or debilitating. Physicians' awareness of these conditions will increase diagnostic accuracy in areas of North America where bites from brown recluse spiders are improbable. (+info)Clinical and epidemiological features of definitive and presumed loxoscelism in Sao Paulo, Brazil. (6/54)
A retrospective study analysed 359 proven or presume cases of loxoscelism seen at the Hospital Vital Brazil, Instituto Butantan, Sao Paulo, Brazil, between 1985 and 1996. The spider was identified in 14%. The bites occurred predominantly in the urban areas (73%) between September and February. Patients > 14 years were commonest inflicted (92%) and 41% were bitten while getting dressed. Only 11% sought medical care within the first 12 hours post bite. Cutaneous loxoscelism was the commonest form presenting (96%); commonest manifestations were: pain (76%), erythema (72%), edema with enduration (66%), ecchymosis (39%). Skin necrosis occurred in 53% of patients, most frequently seen on trunk, thigh and upper arm, and when patients seek medical care more than 72 hours after bite. Local infection was detected in 12 patients (3%). Hemolysis was confirmed in 4 cases (1.1%). Generalised cutaneous rash, fever and headache were also observed in 48% of the total of patients. None of them had acute renal failure or died. Treatment usually involved antivenom administration (66%), being associated with corticosteroids (47%) or dapsone (30%). Presumptive diagnosis of loxoscelism may be established based on clinical and epidemiological findings. Further investigations are required to prove the value of antivenom and other treatment schedules. (+info)A prospective study of 750 definite spider bites, with expert spider identification. (7/54)
BACKGROUND: Spider bite is a subject of much medical mythology with prevalent fears that spiders cause severe envenoming, with neurotoxic effects or necrotic ulcers. Clinical experience and small studies suggest otherwise, but this has not been confirmed by prospective studies of bites by identified spiders. AIM: To describe the clinical effects of bites by accurately identified spiders, and determine whether early clinical features and circumstances can predict spider type. DESIGN: Prospective follow-up study. METHODS: Patients were recruited from admissions to two emergency departments (n=48) and referrals from three state poison information centres (n=1426), over 27 months. Overall, there were 750 people with definite spider bites where the spiders were immediately collected and expertly identified. RESULTS: Significant effects occurred in 44 bites (6%), including 37 (of 56) redback spider bites (Latrodectus hasselti) with significant pain lasting >24 h. Of these, only 6 (11%) received antivenom. One severe neurotoxic envenoming by an Australian funnelweb spider required antivenom. No definite spider bites resulted in necrotic ulcers (0%, 99%CI 0-0.7%). There were no early allergic reactions and secondary infection occurred in seven cases (0.9%, 95%CI 0.4-1.9%). Circumstances and early clinical effects were strongly associated with taxonomic spider identification, with positive predictive values >0.95 for common groups of spiders. CONCLUSIONS: Australian spider bite caused minor effects in most cases and is unlikely to cause necrotic ulcers, allergic reactions or infection. Redback spider bite (widow spider) caused prolonged pain, and antivenom could have been used more frequently. The circumstances and early clinical features of spider bites may allow early appropriate advice and treatment of spider bite without taxonomic identification. (+info)Histopathological findings in rabbits after experimental acute exposure to the Loxosceles intermedia (brown spider) venom. (8/54)
Loxoscelism, the term used to describe envenomation with brown spiders, is characterized by a dermonecrotic lesion at the bite site. In the present investigation we submitted albino rabbits to an acute experimental envenomation protocol using Loxosceles intermedia (brown spider) venom, with in order to determine the pathogenesic features of the lesion induced by this spider, which is the cause of several accidents throughout the world. Rabbits received intradermal injections of the venom and were monitored over the first 4 h, and then at 12 h and 1, 2 and 5 days after envenomation. Histological specimens from 3 rabbits per time point were collected from euthanized animals and processed for histological examination by light microscopy. Major findings observed during the first 4 h were oedema, haemorrhage, degeneration of blood vessel walls, plasma exudation, thrombosis, neutrophil accumulation in and around blood vessels with an intensive diapedesis, a diffuse collection of inflammatory cells (polymorphonuclear leucocytes) in the dermis, and subcutaneous muscular oedema. Over the following hours and up to 5 days after envenomation the changes progressed to massive neutrophil infiltration (with no other leucocytes) into the dermis and even into subcutaneous muscle tissue, destruction of blood vessels, thrombosis, haemorrhage, myonecrosis, and coagulative necrosis on the 5th day. (+info)A spider bite is not a medical condition in and of itself, but rather an injury caused by the puncture of the skin by the fangs of a spider. Not all spiders are capable of penetrating human skin, and only a small number of species found in certain parts of the world have venom that can cause harmful reactions in humans.
The symptoms of a spider bite can vary widely depending on the species of spider, the amount of venom injected, the sensitivity of the person bitten, and the location of the bite. Some common symptoms include redness, swelling, pain, itching, and formation of a blister at the site of the bite. In more severe cases, symptoms such as muscle cramps, nausea, vomiting, fever, chills, and difficulty breathing can occur.
It is important to note that many skin reactions that are attributed to spider bites may actually be caused by other factors such as bacterial infections or allergic reactions. Accurate identification of the spider responsible for a bite is often difficult, and in most cases, treatment is directed at relieving symptoms and preventing complications.
I'm sorry for any confusion, but "spiders" is not a term that has a specific medical definition. It is a common name used to refer to arachnids of the order Araneae, characterized by having two main body parts (the cephalothorax and abdomen), eight legs, and fangs that inject venom.
However, in a medical context, "spider" or "spider bite" may be used to describe skin lesions or reactions resulting from the bite of certain spiders, particularly those with medically significant venoms. For example, necrotic arachnidism is a condition caused by the bite of some spider species, such as recluse spiders (Loxosceles spp.). The bites can cause skin necrosis and other systemic symptoms in severe cases.
If you are looking for information on a specific medical topic or condition, please provide more details so I can offer a more accurate response.
Spider venoms are complex mixtures of bioactive compounds produced by the specialized glands of spiders. These venoms are primarily used for prey immobilization and defense. They contain a variety of molecules such as neurotoxins, proteases, peptides, and other biologically active substances. Different spider species have unique venom compositions, which can cause different reactions when they bite or come into contact with humans or other animals. Some spider venoms can cause mild symptoms like pain and swelling, while others can lead to more severe reactions such as tissue necrosis or even death in extreme cases.
Antivenins, also known as antivenoms, are medications created specifically to counteract venomous bites or stings from various creatures such as snakes, spiders, scorpions, and marine animals. They contain antibodies that bind to and neutralize the toxic proteins present in venom. Antivenins are usually made by immunizing large animals (like horses) with small amounts of venom over time, which prompts the animal's immune system to produce antibodies against the venom. The antibody-rich serum is then collected from the immunized animal and purified for use as an antivenin.
When administered to a victim who has been envenomated, antivenins work by binding to the venom molecules, preventing them from causing further damage to the body's tissues and organs. This helps minimize the severity of symptoms and can save lives in life-threatening situations. It is essential to seek immediate medical attention if bitten or stung by a venomous creature, as antivenins should be administered as soon as possible for optimal effectiveness.
"Bites and stings" is a general term used to describe injuries resulting from the teeth or venomous secretions of animals. These can include:
1. Insect bites: The bite marks are usually small, punctate, and may be accompanied by symptoms such as redness, swelling, itching, and pain. Examples include mosquito, flea, bedbug, and tick bites.
2. Spider bites: Some spiders possess venomous fangs that can cause localized pain, redness, and swelling. In severe cases, systemic symptoms like muscle cramps, nausea, vomiting, and difficulty breathing may occur. The black widow and brown recluse spiders are notorious for their venomous bites.
3. Snake bites: Venomous snakes deliver toxic saliva through their fangs, which can lead to local tissue damage, swelling, pain, and potentially life-threatening systemic effects such as paralysis, bleeding disorders, and respiratory failure.
4. Mammal bites: Animal bites from mammals like dogs, cats, and wild animals can cause puncture wounds, lacerations, and crush injuries. They may also transmit infectious diseases, such as rabies.
5. Marine animal stings: Stings from jellyfish, sea urchins, stingrays, and other marine creatures can result in localized pain, redness, swelling, and systemic symptoms like difficulty breathing, muscle cramps, and altered heart rhythms. Some marine animals' venoms can cause severe allergic reactions or even death.
Treatment for bites and stings varies depending on the type and severity of the injury. It may include wound care, pain management, antibiotics to prevent infection, and in some cases, antivenom therapy to counteract the effects of venom. Seeking immediate medical attention is crucial in severe cases or when systemic symptoms are present.
The black widow spider (Latrodectus mactans) is a species of venomous spider known for the distinctive, hourglass-shaped marking on its abdomen. It is found throughout North America and in parts of Europe, Africa, Asia, and South America. The female black widow spider is typically black or dark brown with a red or orange hourglass-shaped marking on the underside of her abdomen. She is larger than the male, measuring about 1/2 inch in length, while the male is smaller and usually light brown or grayish in color.
The black widow spider's venom contains a neurotoxin called alpha-latrotoxin, which can cause muscle pain, rigidity, and severe cramping. Bites from this spider are rarely fatal to healthy adults but can be dangerous to young children, the elderly, and those with compromised immune systems. Symptoms of a black widow bite may include nausea, sweating, and difficulty breathing.
Black widow spiders build irregular, tangled webs in dark, secluded areas such as woodpiles, sheds, and outdoor toilets. They are not aggressive by nature but will bite if they feel threatened or disturbed. It is essential to seek medical attention immediately if you suspect a black widow spider bite. Treatment may include pain medication, muscle relaxants, and in severe cases, antivenin therapy.
The brown recluse spider (Loxosceles reclusa) is a species of venomous spider that is native to North America. It is also known as the fiddleback spider or violin spider due to the distinctive violin-shaped marking on its cephalothorax. The brown recluse spider is a medium-sized spider, with adults ranging in size from 6 to 20 millimeters in body length. It is characterized by its light to dark brown coloration and lack of conspicuous markings on the abdomen.
The brown recluse spider is known for its necrotic bite, which can cause significant tissue damage and scarring. The venom of the brown recluse spider contains a number of different proteins, including sphingomyelinase D, which is thought to be responsible for the necrotic effects of the bite. The severity of the reaction to a brown recluse spider bite can vary widely, ranging from mild localized reactions to severe systemic reactions that can be life-threatening.
Brown recluse spiders are typically found in the central and southern United States, particularly in the states of Texas, Oklahoma, Kansas, Arkansas, Missouri, Mississippi, Louisiana, Alabama, Georgia, Florida, Tennessee, Kentucky, Ohio, and Indiana. They prefer to live in warm, dry environments and are often found in woodpiles, sheds, barns, and other outbuildings. Inside homes, they can be found in closets, attics, crawl spaces, and underneath furniture.
It is important to note that brown recluse spiders are not aggressive and will only bite if they feel threatened or cornered. If you think you may have been bitten by a brown recluse spider, it is important to seek medical attention as soon as possible. Treatment for a brown recluse spider bite typically involves wound care, pain management, and in some cases, the use of antibiotics to prevent infection.
Dapsone is a medication that belongs to a class of drugs called sulfones. It is primarily used to treat bacterial skin infections such as leprosy and dermatitis herpetiformis (a skin condition associated with coeliac disease). Dapsone works by killing the bacteria responsible for these infections.
In addition, dapsone has anti-inflammatory properties and is sometimes used off-label to manage inflammatory conditions such as vasculitis, bullous pemphigoid, and chronic urticaria. It is available in oral tablet form and topical cream or gel form.
Like all medications, dapsone can cause side effects, which may include nausea, loss of appetite, and headache. More serious side effects, such as methemoglobinemia (a blood disorder that affects the body's ability to transport oxygen), peripheral neuropathy (nerve damage that causes pain, numbness, or weakness in the hands and feet), and liver damage, can occur but are less common.
It is important for patients taking dapsone to be monitored by a healthcare provider to ensure safe and effective use of the medication.
Expert testimony is a type of evidence presented in court by a qualified expert who has specialized knowledge, education, training, or experience in a particular field that is relevant to the case. The expert's role is to provide an objective and unbiased opinion based on their expertise to assist the judge or jury in understanding complex issues that are beyond the knowledge of the average person.
In medical cases, expert testimony may be presented by healthcare professionals such as doctors, nurses, or other medical experts who have specialized knowledge about the medical condition or treatment at issue. The expert's testimony can help establish the standard of care, diagnose a medical condition, evaluate the cause of an injury, or assess the damages suffered by the plaintiff.
Expert testimony must meet certain legal standards to be admissible in court. The expert must be qualified to testify based on their education, training, and experience, and their opinion must be based on reliable methods and data. Additionally, the expert's testimony must be relevant to the case and not unduly prejudicial or misleading.
Overall, expert testimony plays a critical role in medical cases by providing objective and unbiased evidence that can help judges and juries make informed decisions about complex medical issues.
A snake bite is a traumatic injury resulting from the puncture or laceration of skin by the fangs of a snake, often accompanied by envenomation. Envenomation occurs when the snake injects venom into the victim's body through its fangs. The severity and type of symptoms depend on various factors such as the species of snake, the amount of venom injected, the location of the bite, and the individual's sensitivity to the venom. Symptoms can range from localized pain, swelling, and redness to systemic effects like coagulopathy, neurotoxicity, or cardiotoxicity, which may lead to severe complications or even death if not treated promptly and appropriately.
'Human bites' refer to wounds or injuries resulting from the human mouth coming into contact with another person's body tissue. These bites can occur during fights, accidents, or intentional acts and can cause damage ranging from minor abrasions to serious tissue injury or infection. Human bite wounds may also pose a risk of transmission for various pathogens, including bacteria like Streptococcus and Staphylococcus species, hepatitis B and C viruses, and herpes simplex virus. Proper evaluation, wound care, and potential antibiotic treatment are crucial to prevent complications associated with human bites.
Insect bites and stings refer to the penetration of the skin by insects, such as mosquitoes, fleas, ticks, or bees, often resulting in localized symptoms including redness, swelling, itching, and pain. The reaction can vary depending on the individual's sensitivity and the type of insect. In some cases, systemic reactions like anaphylaxis may occur, which requires immediate medical attention. Treatment typically involves relieving symptoms with topical creams, antihistamines, or in severe cases, epinephrine. Prevention measures include using insect repellent and protective clothing.
Bite force refers to the amount of force or pressure that can be exerted by the teeth and jaw when biting down or clenching together. It is a measure of an individual's maximum biting strength, typically expressed in units such as pounds (lb) or newtons (N). Bite force is an important factor in various biological and medical contexts, including oral health, nutrition, and the study of animal behavior and evolution.
In humans, bite force can vary widely depending on factors such as age, sex, muscle strength, and dental health. On average, a healthy adult human male may have a maximum bite force of around 150-200 pounds (670-890 newtons), while an adult female may have a bite force of around 100-130 pounds (445-578 newtons). However, these values can vary significantly from person to person.
Abnormalities in bite force can be indicative of various medical conditions or injuries, such as temporomandibular joint disorders (TMD), muscle weakness, or neurological disorders affecting the facial muscles. Assessing and measuring bite force may also be useful in evaluating the effectiveness of dental treatments or appliances, such as dentures or orthodontic devices.
Phosphoric diester hydrolases are a class of enzymes that catalyze the hydrolysis of phosphoric diester bonds. These enzymes are also known as phosphatases or nucleotidases. They play important roles in various biological processes, such as signal transduction, metabolism, and regulation of cellular activities.
Phosphoric diester hydrolases can be further classified into several subclasses based on their substrate specificity and catalytic mechanism. For example, alkaline phosphatases (ALPs) are a group of phosphoric diester hydrolases that preferentially hydrolyze phosphomonoester bonds in a variety of organic molecules, releasing phosphate ions and alcohols. On the other hand, nucleotidases are a subclass of phosphoric diester hydrolases that specifically hydrolyze the phosphodiester bonds in nucleotides, releasing nucleosides and phosphate ions.
Overall, phosphoric diester hydrolases are essential for maintaining the balance of various cellular processes by regulating the levels of phosphorylated molecules and nucleotides.
I'm sorry for any confusion, but "Silk" is not a medical term. Silk is a natural protein fiber, mainly composed of fibroin and produced by certain insect larvae to form cocoons. It's commonly used in textiles and other industries for its softness, smoothness, and strength. If you have any questions related to medical terminology or health-related topics, I'd be happy to help with those instead!
Necrosis is the premature death of cells or tissues due to damage or injury, such as from infection, trauma, infarction (lack of blood supply), or toxic substances. It's a pathological process that results in the uncontrolled and passive degradation of cellular components, ultimately leading to the release of intracellular contents into the extracellular space. This can cause local inflammation and may lead to further tissue damage if not treated promptly.
There are different types of necrosis, including coagulative, liquefactive, caseous, fat, fibrinoid, and gangrenous necrosis, each with distinct histological features depending on the underlying cause and the affected tissues or organs.
An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.