|
Leydig Cell Tumour
Leydig cell tumour, also Leydig cell tumor (US spelling), (testicular) interstitial cell tumour and (testicular) interstitial cell tumor (US spelling), is a member of the sex cord-stromal tumour group of ovarian and testicular cancers. It arises from Leydig cells. While the tumour can occur at any age, it occurs most often in young adults. A Sertoli–Leydig cell tumour is a combination of a Leydig cell tumour and a Sertoli cell tumour from Sertoli cells. Presentation The majority of Leydig cell tumors are found in males, usually at 5–10 years of age or in middle adulthood (30–60 years). Children typically present with precocious puberty. Due to excess testosterone secreted by the tumour, one-third of female patients present with a recent history of progressive masculinization. Masculinization is preceded by anovulation, oligomenorrhea, amenorrhea and ''defeminization''. Additional signs include acne and hirsutism, voice deepening, clitoromegaly, temporal hair recession, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H&E Stain
Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin-eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagnosis and is often the gold standard. For example, when a pathologist looks at a biopsy of a suspected cancer, the histological section is likely to be stained with H&E. H&E is the combination of two histological stains: hematoxylin and eosin. The hematoxylin stains cell nuclei a purplish blue, and eosin stains the extracellular matrix and cytoplasm pink, with other structures taking on different shades, hues, and combinations of these colors. Hence a pathologist can easily differentiate between the nuclear and cytoplasmic parts of a cell, and additionally, the overall patterns of coloration from the stain show the general layout and distribution of cells and provides a general overview of a tissue sample's structure. Thus, pattern recogniti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clitoromegaly
Clitoromegaly (or macroclitoris) is an abnormal enlargement of the clitoris that is mostly congenital or acquired, though deliberately induced clitoris enlargement as a form of genital body modification is achieved through various uses of anabolic steroids, including testosterone. Clitoromegaly is not the same as normal enlargement of the clitoris seen during sexual arousal. Presentation The different grade of genital ambiguity is commonly measured by the Prader classification, which ranges, in ascending order of masculinisation, from 1: ''female external genitalia with clitoromegaly'' through 5: ''pseudo-phallus looking like normal male external genitalia''. Causes Clitoromegaly is a rare condition and can be either present by birth or acquired later in life. If present at birth, congenital adrenal hyperplasia can be one of the causes, since in this condition the adrenal gland of the female fetus produces additional androgens and the newborn baby has ambiguous genitalia whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imatinib
Imatinib, sold under the brand names Gleevec and Glivec (both marketed worldwide by Novartis) among others, is an oral chemotherapy medication used to treat cancer. Imatinib is a small molecule inhibitor targeting multiple receptor tyrosine kinases such as CSF1R, ABL, c-KIT, FLT3, and PDGFR-β. Specifically, it is used for chronic myelogenous leukemia (CML) and acute lymphocytic leukemia (ALL) that are Philadelphia chromosome-positive (Ph+), certain types of gastrointestinal stromal tumors (GIST), hypereosinophilic syndrome (HES), chronic eosinophilic leukemia (CEL), systemic mastocytosis, and myelodysplastic syndrome. Common side effects include vomiting, diarrhea, muscle pain, headache, and rash. Severe side effects may include fluid retention, gastrointestinal bleeding, bone marrow suppression, liver problems, and heart failure. Use during pregnancy may result in harm to the baby. Imatinib works by stopping the Bcr-Abl tyrosine-kinase. This can slow growth or result in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melan-A
Protein melan-A also known as melanoma antigen recognized by T cells 1 or MART-1 is a protein that in humans is encoded by the ''MLANA'' or "MALENA" gene. A fragment of the protein, usually consisting of the nine amino acids 27 to 35, is bound by MHC class I complexes which present it to T cells of the immune system. These complexes can be found on the surface of melanoma cells. Decameric peptides (26-35) are being investigated as cancer vaccines. Discovery and nomenclature The names MART-1 and melan-A were coined by two groups of researchers who independently sequenced the gene for this antigen in 1994. Both names are currently in common use. Kawakami et al. at the National Cancer Institute coined the term MART-1, which stands for "melanoma antigen recognized by T-cells." Coulie et al. of Belgium called the gene melan-A, presumably an abbreviation for "melanocyte antigen." Clinical significance MART-1/melan-A is a protein antigen that is found on the surface of melanoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calretinin
Calretinin, also known as calbindin 2 (formerly 29 kDa calbindin), is a calcium-binding protein involved in calcium signaling. In humans, the calretinin protein is encoded by the ''CALB2'' gene. Function This gene encodes an intracellular calcium-binding protein belonging to the troponin C superfamily. Members of this protein family have six EF-hand domains which bind calcium. This protein plays a role in diverse cellular functions, including message targeting and intracellular calcium buffering. Calretinin is abundantly expressed in neurons including retina (which gave it the name) and cortical interneurons. Expression was found in different neurons than that of the similar vitamin D-dependent calcium-binding protein, calbindin-28kDa. Calretinin has an important role as a modulator of neuronal excitability including the induction of long-term potentiation. Loss of expression of calretinin in hippocampal interneurons has been suggested to be relevant in temporal lobe epilep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinke Crystals
Reinke crystals are rod-like cytoplasmic inclusions which can be found in Leydig cells of the testes. Occurring only in adult humans and wild bush rats, their function is unknown. Ovarian stromal tumors having a predominant pattern of fibroma or thecoma but also containing cells typical of steroid hormone-secreting cells were reported. Some of the tumors were classified as luteinized thecomas because the steroid cells resembled lutein cells and lacked crystalloids of Reinke. But others were classified as stromal Leydig cell tumors as seen in tumors of the testes because Reinke crystalloids were identified in the steroid cells. The Stromal Leydig tumors occurred at an average age of 61 years and were associated with Ovarian hyperandrogenism which led to virilization in some cases, endometrial hyperplasia in other cases, and endometrial hyperplasia with carcinoma in the rest of the cases. Luteinized thecomas and stromal Leydig cell tumors are indistinguishable except for the presence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histology
Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into ''organology'', the study of organs, ''histology'', the study of tissues, and ''cytology'', the study of cells, modern usage places all of these topics under the field of histology. In medicine, histopathology is the branch of histology that includes the microscopic identification and study of diseased tissue. In the field of paleontology, the term paleohistology refers to the histology of fossil organisms. Biological tissues Animal tissue classification There are four basic types of animal tissues: muscle tissue, nervous tissue, connective tissue, and epithelial tissue. All animal tissues are considered to be subtypes of these four principal tissue types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leydig Cell Tumour1
Leydig cells, also known as interstitial cells of the testes and interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle and produce testosterone in the presence of luteinizing hormone (LH). They are polyhedral in shape and have a large, prominent nucleus, an eosinophilic cytoplasm, and numerous lipid-filled vesicles. Structure The mammalian Leydig cell is a polyhedral epithelioid cell with a single eccentrically located ovoid nucleus. The nucleus contains one to three prominent nucleoli and large amounts of dark-staining peripheral heterochromatin. The acidophilic cytoplasm usually contains numerous membrane-bound lipid droplets and large amounts of smooth endoplasmic reticulum (SER). Besides the abundance of SER with scattered patches of rough endoplasmic reticulum, several mitochondria are also prominent within the cytoplasm. Reinke crystals have lipofuscin pigment and rod-shaped crystal-like structures 3 to 20 micrometres in diameter. Adu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thecoma
Thecomas or theca cell tumors are benign Ovarian cancer, ovarian neoplasms composed only of theca cells. Histogenetically they are classified as sex cord-stromal tumours. They are typically estrogen-producing and they occur in older women (mean age 59; 84% after menopause). (They can, however, appear before menopause.) 60% of patients present with abnormal uterine bleeding, and 20% have endometrial carcinoma. Pathologic features Grossly, the tumour is solid and yellow. Grossly and microscopically, it consists of the ovarian cortex. Microscopically, the tumour cells have abundant lipid-filled cytoplasm. References External links Gynaecological neoplasia {{oncology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granulosa Cell Tumour
Granulosa cell tumours are tumours that arise from granulosa cells. They are estrogen secreting tumours and present as large, complex, ovarian masses. These tumours are part of the sex cord-gonadal stromal tumour or non-epithelial group of tumours. Although granulosa cells normally occur only in the ovary, granulosa cell tumours occur in both ovaries and testicles (see ovarian cancer and testicular cancer). These tumours should be considered malignant and treated in the same way as other malignant tumours of ovary. The ovarian disease has two forms, juvenile and adult, both characterized by indolent growth, and therefore has high recovery rates. The staging system for these tumours is the same as for epithelial tumours and most present as stage I.Gynaecology. 3rd Ed. 2003. Churchill Livingstone, pp. 690-691. The peak age at which they occur is 50–55 years, but they may occur at any age. Juvenile granulosa cell tumour is a similar but distinct rare tumour. It too occurs in bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorooctanoic Acid
Perfluorooctanoic acid (PFOA; conjugate base perfluorooctanoate; also known colloquially as C8, for its 8 carbon chain structure) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes and as a material feedstock. PFOA is considered a surfactant, or fluorosurfactant, due to its chemical structure, which consists of a perfluorinated, ''n''-octyl "tail group" and a carboxylate "head group". The head group can be described as hydrophilic while the fluorocarbon tail is both hydrophobic and lipophobic. The tail group is inert and does not interact strongly with polar or non-polar chemical moieties; the head group is reactive and interacts strongly with polar groups, specifically water. The "tail" is hydrophobic due to being non-polar and lipophobic because fluorocarbons are less susceptible to the London dispersion force than hydrocarbons. PFOA is one of many synthetic organofluorine compounds collectively known as per- and po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
