SALIVARY GLAND PDF
The salivary glands are exocrine glands that produce saliva. Anatomy of the Salivary Glands: the Parotid Gland (1), the Submandibular Gland (2) and the. It is constituted by the secretions of the three paired major salivary glands; the salivary glands, of which there are hundreds contained within the submucosa of. The salivary glands include paired major glands (pa- rotid, submandibular and sublingual) and minor glands throughout the upper aerodigestive tract.
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It is not our intent to cover anatomy during this course. However, you should know the locations and characteristics of the salivary glands. The fine anatomical . PDF | Salivary glands are essential organs that produce and secrete saliva to the oral cavity. During gland morphogenesis, many. Salivary glands are a group of organs secreting a watery substance that is of where, when and how major salivary glands develop in the lower jaw of the.
Here we identify a vector protein by mass spectrometry, with similarity to the human gamma interferon inducible thiol reductase GILT , that is associated with saliva sporozoites of infected Anopheles mosquitoes and has a negative impact on the speed and cell traversal activity of Plasmodium.
This protein, referred to as mosquito GILT mosGILT represents an example of a protein found in mosquito saliva that may negatively influence sporozoite movement in the host and could lead to new approaches to prevent malaria. Introduction Malaria remains one of the deadliest diseases worldwide 1.
The key step during the initiation of malaria is for the Plasmodium parasite to infect the host liver.
After insertion of the proboscis from an infected female Anopheles mosquito, Plasmodium parasites, in the form of sporozoites, are injected together with mosquito saliva into the skin of an animal host. Sporozoites within the dermis must migrate to a blood vessel that will transport them to the liver.
Once at the liver, sporozoites invade hepatic cells and develop into exoerythrocytic forms EEFs containing thousands of merozoites, which are released into the circulation and establish a blood-stage infection 1 , 2 , 3 , 4. Motility is essential for Plasmodium to properly navigate through both the host skin and hepatic microenvironments.
Sporozoites utilize substrate-dependent gliding motility and cell traversal in both locations as they travel toward the host hepatocytes 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , Within the skin, sporozoites are able to switch from an initial rapid motility to a more restricted movement around the dermal blood vessels 7.
In addition, as sporozoites move towards the liver, they can enter and exit host cells within transient vacuoles, which are molecularly distinct from the parasitophorous vacuole membrane used during a productive hepatocyte infection This process, known as cell traversal, allows the sporozoites to cross cellular barriers and evade the host immune response 5 , 8 , 13 , 15 , Numerous sporozoite proteins involved in cell traversal and gliding motility have been identified 6 , 8 , 14 , 15 , 17 , 18 , 19 , 20 , 21 , However, many additional signals and environmental factors regulating sporozoite motility in the host still remained to be determined.
Mosquito saliva contains numerous proteins that work as efficient immunomodulators, in addition to molecules with anti-hemostatic and vasodilatory functions 23 , The main purpose of these saliva components is to facilitate blood feeding, but they could also have an influence on pathogen transmission.
Saliva proteins can have an impact on a microorganism indirectly, by altering the microenvironment and enhancing transmission 24 , 25 , As one of several examples, maxadilan, a vasodilator and immunomodulator in sandfly saliva, exacerbates Leishmania major infection 26 , 27 , 28 , 29 , Other proteins in vector saliva can directly interact with pathogens and influence transmission.
As one example, the tick saliva protein, Salp15, binds the surface of Borrelia burgdorferi and inhibits complement-mediated killing 31 , Studies have examined proteins in mosquito salivary glands SGs that are important for the survival of Plasmodium within the vector, such as saglin In addition, a recent study described that immunization against an abundant Anopheles specific SG protein, AgTRIO, can reduce the parasite burden in the host after mosquito-borne transmission However, investigators have not characterized proteins in mosquito saliva that directly interact with Plasmodium during movement out of the vector.
Therefore, we examined Plasmodium sporozoites purified from mosquito saliva in an effort to identify targets that may be manipulated to interfere with the malaria transmission. Here we show a mosquito SG protein with homology to the human gamma interferon inducible thiol reductase GILT that interacts with the surface of Plasmodium sporozoites as they are expelled from Anopheles mosquito SGs.
We found that this mosquito GILT-like protein can partially reduce the speed and cell traversal activity of both human and rodent Plasmodium sporozoites.
The partial inhibition of these critical motility components modestly influences the ability of the sporozoites to migrate to the liver and establish a normal hepatic infection. Results Mass spectrometry of sporozoites from vector saliva To identify mosquito proteins in saliva that may interact with Plasmodium, sporozoites were collected directly from the saliva of infected Anopheles gambiae mosquitoes Fig.
Saliva from age-matched naive mosquitoes was collected in the same manner as a control. After washing the sporozoites, liquid chromatography tandem mass spectrometry LC MS-MS was utilized to identify potential mosquito proteins that might be strongly associated with the sporozoites in saliva.
A complete list of all of the A. One mosquito protein, AGAP, was detected in all three independent biological replicates associated with Plasmodium berghei sporozoites Fig. Three other mosquito proteins were also identified in two of the sporozoite replicates—a histone 2B-like protein, a protein with homology to papilin, and an unknown protein with a predicted signal peptide Fig.
Immunity in the salivary gland
In an additional study, to extend this observation to a Plasmodium species that infects humans, we utilized a colony of Anopheles stephensi mosquitoes infected with the human malaria parasite, Plasmodium falciparum. ASTE, the A. Three independent biological replicates were used. Each Venn diagram represents the A. The numbers in red indicate proteins that were only present in the samples from Plasmodium-infected mosquitoes.
Pathology of Salivary Gland Disease
The proteins identified in two of the independent experiments are highlighted in blue and green, respectively Full size image AGAP is expressed in Anopheles gambiae SGs A. Benign tumors Pleomorphic adenomas are the most common benign tumors and have a broad histologic spectrum.
These tumors can recur if incompletely excised and may rarely metastasize without having histologic features of malignancy. Basal cell adenomas are benign tumors with specific histologic patterns. The membranous type is associated with cylindromatosis gene CYLD1 mutations, cutaneous syndromes, and can be multifocal and is more likely to undergo malignant transformation. Canalicular adenomas are minor salivary tumors that are clinicopathologically distinct from basal cell adenomas.
Myoepitheliomas also have varied patterns and should show at most a few ducts. Morphologically it has a characteristic lymphoid stroma resembling a lymph node. Oncocytoma and oncocytosis are benign tumors and tumor-like lesions comprised of solid nests of large polygonal cells with abundant granular eosinophilic cytoplasm that may occasionally mimic metastatic renal cell carcinoma.
Sclerosing polycystic adenosis is a rare clonal proliferation that resembles fibrocystic disease of the breast, and though benign, may show changes resembling salivary duct carcinoma.
Malignant tumors Adenoid cystic carcinoma is a slow growing but relentless malignancy for which stage, histologic grade based on solid component, and p53 expression are important prognosticators.
These characteristically overexpress c-kit. Mucoepidermoid carcinoma is the most common salivary malignancy with three cell types mucous, intermediate, and epidermoid. Most grading systems are three tiered and generally correlate with prognosis; mucoepidermoid carcinomas of the submandibular gland appear more aggressive than those of the parotid gland. Malignant mixed tumors can be subcategorized into carcinoma ex-pleomorphic adenoma, true malignant mixed tumor carcinosarcoma , and metastasizing mixed tumor.
Acinic cell carcinoma is a low-grade tumor that can rarely dedifferentiate into an aggressive high grade tumor. Epithelial-myoepithelial carcinoma is a rare biphasic low-grade neoplasm characterized by clear myoepithelial cells and small ducts and may mimic other clear cell lesions of the head and neck.
Introduction to Salivary Glands: Structure, Function and Embryonic Development
Basal cell adenocarcinoma resembles its benign counterpart, basal cell adenoma, and is distinguished mainly by the presence of invasion, though ancillary studies such as immunoperoxidase stains for Ki 67, p53, bc, and epidermal growth factor receptor may help in diagnosis.
Myoepithelial carcinoma also resembles its benign counterpart and is separated mainly by the presence of invasion, mitoses, and necrosis. Nuclear pleomorphism may be a poor prognostic sign. Salivary duct carcinoma is a high grade carcinoma that expresses androgen receptor and herneu.
It can be confused with low-grade cribriform cystadenocarcinoma, a recently characterized entity that resembles a lowgrade mammary type ductal carcinoma. Rare malignant tumors include cystadenocarcinomas, large cell carcinoma, small cell carcinoma, and primary squamous cell carcinomas; all but cystadenocarcinomas behave in an aggressive fashion. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Abbondanzo SL Extranodal marginal-zone Bcell lymphoma of the salivary gland. A clinicopathologic study of twenty cases. A disease simulating malignancy.
Report of a case. A case report. Allen MS Jr. Report of a case with immunohistochemical study.References 1. Milne-Edwards H: Forgot Password? Key mechanisms involved in this process are discussed, including reciprocal tissue interactions between epithelial and mesenchymal cells, epithelial branching morphogenesis and coordinated cell deathand cell proliferation.
Surgical management of the neck metastases Therapeutic neck dissection is indicated for lymph node involvement. April 20, Cover Date: