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Parascaris Univalens
''Parascaris univalens'' is a parasitic ascaridoid nematode that infects the gastrointestinal tracts of equines. Taxonomy ''P. univalens'' is morphologically identical to ''Parascaris equorum'', the only other species in the genus. The species are distinguished by the number of chromosomes. Karyotyping is the only way to differentiate between the two: ''P. univalens'' has one pair of chromosomes and ''P. equorum'' has two pairs. However, new genomic research suggests that both ''Parascaris'' species could be the same species. Both species are model organisms for chromosome organization and cell division. Description The species is yellow-white in color, with adults having a long body and a broad anterior end that has three shamrock-like lips. Adult females can reach up to 50 cm in length and be 1–2 cm round. As with other ascarid worms, ''P. univalens'' is known to increase in size as it ages. These worms are host-specific to equines and cannot infect humans or ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascarididae
The Ascarididae are a family of the large intestinal roundworms. Members of the family are intestinal parasites, infecting all classes of vertebrates. It includes a number of genera,Anderson RC (2000)''Nematode Parasites of Vertebrates. Their Development and Transmission, 2nd ed.''CAB International, Wallingford, Oxon, UK, pp. 245-315. the most well known of which are: *'' Amplicaecum'' *'' Angusticaecum'' *''Ascaris'' *†'' Ascarites'' (fossil)Poinar Jr, G. and Boucot, A. J. (2006) Evidence of intestinal parasites of dinosaurs. ''Parasitology'', 133: 245-249. *''Baylisascaris'' *'' Crossophorus'' *'' Dujardinascaris'' *''Hexametra'' *'' Lagochilascaris'' *'' Ophidascaris'' *''Parascaris'' *'' Polydelphis'' *'' Seuratascaris'' *''Toxascaris'' *''Toxocara'' *'' Travassoascaris'' ''Ascaris lumbricoides'' is the main ascarid parasite of humans, causing ascariasis Ascariasis is a disease caused by the parasitic roundworm ''Ascaris lumbricoides''. Infections have no sympto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broad range of environments. Less formally, they are categorized as Helminths, but are taxonomically classified along with Arthropod, arthropods, Tardigrade, tardigrades and other moulting animalia, animals in the clade Ecdysozoa, and unlike platyhelminthe, flatworms, have tubular digestion, digestive systems with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species described to date vary by author and may change rapidly over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equus (genus)
''Equus'' , is a genus of mammals in the family Equidae, which includes horses, donkeys, and zebras. Within the Equidae, ''Equus'' is the only recognized extant genus, comprising seven living species. Like Equidae more broadly, ''Equus'' has numerous extinct species known only from fossils. The genus most likely originated in North America and spread quickly to the Old World. Equines are odd-toed ungulates with slender legs, long heads, relatively long necks, manes (erect in most subspecies), and long tails. All species are herbivorous, and mostly grazers, with simpler digestive systems than ruminants but able to subsist on lower-quality vegetation. While the domestic horse and donkey (along with their feral descendants) exist worldwide, wild equine populations are limited to Africa and Asia. Wild equine social systems are in two forms; a harem system with tight-knit groups consisting of one adult male or stallion, several females or mares, and their young or foals; and a terr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parascaris Equorum
''Parascaris equorum'' is a species of ascarid that is the equine roundworm. Amongst horse owners, the parasites are colloquially called "Ascarids". This is a host-specific helminth intestinal parasite that can infect horses, donkeys, and zebras. Horses up to six months of age are the most susceptible to infection. After this time, infection rates begin to decline and is extremely uncommon in horses over twelve months of age. It cannot infect humans or other animals. It is yellow-white in color, and females can become as large as in length. Found worldwide, ''P. equorum'' is one of the most difficult equine parasites to kill, requiring larger doses of more powerful anthelmintic medications than are needed for other equine parasites. Life cycle ''P. equorum'' is sexually dimorphic, the females are significantly larger than males. While males only grow up to 15–28 cm in length, the females can grow up to 50 cm in length. They are a white colored, cylindrical worm a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyotype
A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model Organism
A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Model organisms are widely used to research human disease when human experimentation would be unfeasible or unethical. This strategy is made possible by the common descent of all living organisms, and the conservation of metabolic and developmental pathways and genetic material over the course of evolution. Studying model organisms can be informative, but care must be taken when generalizing from one organism to another. In researching human disease, model organisms allow for better understanding the disease process without the added risk of harming an actual human. The species chosen will usually meet a determined taxonomic equivalency to humans, so as to react to disease or its treatment in a way that resembles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatin Diminution
Theodor Heinrich Boveri (12 October 1862 – 15 October 1915) was a German zoologist, comparative anatomist and co-founder of modern cytology. He was notable for the first hypothesis regarding cellular processes that cause cancer, and for describing ''chromatin diminution in nematodes''. Boveri was married to the American biologist Marcella O'Grady (1863–1950). Their daughter Margret Boveri (1900–1975) became one of the best-known journalists in post-World War II Germany. Work Using an optical microscope, Boveri examined the processes involved in the fertilization of the animal egg cell; his favorite research objects were the nematode ''Parascaris'' and sea urchins. Boveri's work with sea urchins showed that it was necessary to have all chromosomes present in order for proper embryonic development to take place. This discovery was an important part of the Boveri–Sutton chromosome theory. He also discovered, in 1888, the importance of the centrosome for the formation of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parenchyma
Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word παρέγχυμα ''parenchyma'' meaning 'visceral flesh', and from παρεγχεῖν ''parenchyma'' meaning 'to pour in' from παρα- ''para-'' 'beside' + ἐν ''en-'' 'in' + χεῖν ''chyma'' 'to pour'. Originally, Erasistratus and other anatomists used it to refer to certain human tissues. Later, it was also applied to plant tissues by Nehemiah Grew. Structure The parenchyma is the ''functional'' parts of an organ (anatomy), organ, or of a structure such as a tumour in the body. This is in contrast to the Stroma (animal tissue), stroma, which refers to the ''structural'' tissue of organs or of structures, namely, the connective tissues. Brain The brain parenchyma refers to the functional tissue in the brain that is made up of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Alveolus
A pulmonary alveolus (plural: alveoli, from Latin ''alveolus'', "little cavity"), also known as an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where oxygen is exchanged for carbon dioxide. Alveoli make up the functional tissue of the mammalian lungs known as the lung parenchyma, which takes up 90 percent of the total lung volume. Alveoli are first located in the respiratory bronchioles that mark the beginning of the respiratory zone. They are located sparsely in these bronchioles, line the walls of the alveolar ducts, and are more numerous in the blind-ended alveolar sacs. The acini are the basic units of respiration, with gas exchange taking place in all the alveoli present. The alveolar membrane is the gas exchange surface, surrounded by a network of capillaries. Across the membrane oxygen is diffused into the capillaries and carbon dioxide released from the capillaries into the alveoli to be breathed out. Alveoli are pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthelmintic
Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. They may also be called vermifuges (those that stun) or vermicides (those that kill). Anthelmintics are used to treat people who are infected by helminths, a condition called helminthiasis. These drugs are also used to treat infected animals. Pills containing anthelmintics are used in mass deworming campaigns of school-aged children in many developing countries. The drugs of choice for soil-transmitted helminths are mebendazole and albendazole; for schistosomiasis and tapeworms it is praziquantel. Types Antiparasitics that specifically target worms of the genus ''Ascaris'' are called ascaricides. * Benzimidazoles: ** Albendazole – effective against threadworms, roundworms, whipworms, tapeworms, hookworms ** Mebendazole – effective against v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrantel
Pyrantel is a medication used to treat a number of parasitic worm infections. This includes ascariasis, hookworm infections, enterobiasis (pinworm infection), trichostrongyliasis, and trichinellosis. It is taken by mouth. Side effects include nausea, headache, dizziness, trouble sleeping, and rash. A lower dose should be used in people with liver disease. While it does not appear to be harmful during pregnancy, it has not been studied for this use. It is unclear if it is safe for use during breastfeeding. It is in the antihelmintic family of medications. It works by paralyzing worms. Pyrantel was initially described in 1965. It is on the World Health Organization's List of Essential Medicines. Pyrantel is available as a generic medication. It may also be used to treat worms in a number of other animals. Pregnancy and breastfeeding Pyrantel pamoate is considered a pregnancy category C drug for use during pregnancy for humans, but is in category A for canines and felines. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivermectin
Ivermectin (, '' EYE-vər-MEK-tin'') is an antiparasitic drug. After its discovery in 1975, its first uses were in veterinary medicine to prevent and treat heartworm and acariasis. Approved for human use in 1987, today it is used to treat infestations including head lice, scabies, river blindness (onchocerciasis), strongyloidiasis, trichuriasis, ascariasis and lymphatic filariasis. It works through many mechanisms to kill the targeted parasites, and can be taken orally, or applied to the skin for external infestations. It belongs to the avermectin family of medications. William Campbell and Satoshi Ōmura won the 2015 Nobel Prize in Physiology or Medicine for its discovery and applications. It is on the World Health Organization's List of Essential Medicines, and is approved by the U.S. Food and Drug Administration as an antiparasitic agent. In 2018, it was the 420th most commonly prescribed medication in the United States, with more than 100,000 prescriptions. It is availab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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