|
Aplasia
Aplasia (; from Greek ''a'', "not", "no" + ''plasis'', "formation") is a birth defect where an organ or tissue is wholly or largely absent. It is caused by a defect in a developmental process. Aplastic anemia is the failure of the body to produce blood cells. It may occur at any time, and has multiple causes. __TOC__ Examples * Acquired pure red cell aplasia * Aplasia cutis congenita * Aplastic anemia * Germ cell aplasia, also known as Sertoli cell-only syndrome * Radial aplasia * Thymic aplasia, which is found in DiGeorge syndrome and also occurs naturally as part of the gradual loss of function of the immune system later in life See also * Atrophy * Hyperplasia * Hypoplasia * Neoplasia * List of biological development disorders References Bibliography * Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. Campbell Biology (10th ed.). Addison Wesley Longman; 2014. {{DEFAULTSORT:Biological development disorders Lists of diseases Disability-related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acquired Pure Red Cell Aplasia
Pure red cell aplasia (PRCA) or erythroblastopenia refers to a type of aplastic anemia affecting the precursors to red blood cells but usually not to white blood cells. In PRCA, the bone marrow ceases to produce red blood cells. There are multiple etiologies that can cause PRCA. The condition has been first described by Paul Kaznelson in 1922. Signs and symptoms Signs and symptoms may include: * Pale appearance * Rapid heart rate * Fatigue Causes Causes of PRCA include: Treatment PRCA is considered an autoimmune disease as it will respond to immunosuppressant treatment such as cyclosporin in many patients, though this approach is not without risk. It has also been shown to respond to treatments with rituximab and tacrolimus. See also * Diamond–Blackfan anemia (genetic red cell aplasia) * Aplastic anemia Aplastic anemia is a cancer in which the body fails to make blood cells in sufficient numbers. Blood cells are produced in the bone marrow by stem cells that reside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Aplasia
Radial aplasia is a congenital defect which affects the formation of the radius bone in the arm. The radius is the lateral bone (thumb side) which connects the humerus of the upper arm to the wrist via articulation with the carpal bones. A child born with this condition has either a short or absent radius bone in one or both of his or her arms. Radial aplasia also results in the thumb being either partly formed or completely absent from the hand, which can result in difficulties performing activities of daily living. Radial aplasia is connected with the condition VACTERL association The VACTERL association (also VATER association, and less accurately VACTERL syndrome) refers to a recognized group of birth defects which tend to co-occur (see below). This pattern is a recognized association, as opposed to a syndrome, because th ..., under the 'L' for limb malformations. Radial aplasia is not inherited. The cause for radial aplasia is unknown, but it widely believed to occur within ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Biological Development Disorders
References Bibliography * Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. Campbell Biology (10th ed.). Addison Wesley Longman; 2014. {{DEFAULTSORT:Biological development disorders Lists of diseases Disability-related lists Biological nomenclature Medical terminology Lists of biology lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplastic Anemia
Aplastic anemia is a cancer in which the body fails to make blood cells in sufficient numbers. Blood cells are produced in the bone marrow by stem cells that reside there. Aplastic anemia causes a deficiency of all blood cell types: red blood cells, white blood cells, and platelets. It occurs most frequently in people in their teens and twenties but is also common among the elderly. It can be caused by heredity, immune disease, or exposure to chemicals, drugs, or radiation. However, in about half of cases, the cause is unknown. Aplastic anemia can be definitively diagnosed by bone marrow biopsy. Normal bone marrow has 30–70% blood stem cells, but in aplastic anemia, these cells are mostly gone and are replaced by fat. First-line treatment for aplastic anemia consists of immunosuppressive drugs—typically either anti-lymphocyte globulin or anti-thymocyte globulin—combined with corticosteroids, chemotherapy, and ciclosporin. Hematopoietic stem cell transplantation is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sertoli Cell-only Syndrome
Sertoli cell-only syndrome (a.k.a. Del Castillo syndrome and germ cell aplasia ) is a disorder characterized by male sterility without sexual abnormality. It describes a condition of the testes in which only Sertoli cells line is present in seminiferous tubules. Presentation Sertoli cell-only syndrome patients normally have normal secondary male features and have normal or small-sized testes. Pathophysiology Sertoli cell-only syndrome is likely multifactorial, and is characterized by severely reduced or absent spermatogenesis; because of the presence of Sertoli cells alone lining the seminiferous tubules. A substantial subset of men with this uncommon syndrome have microdeletions in the Yq11 region of the Y chromosome, an area known as the AZF (azoospermia factor) region. In particular, sertoli cell only syndrome (SCO) correlates with AZFa microdeletions. It is possible to recognize two types of SCO: SCO type 1 shows total absence of spermatogonia because of an altered migration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoplasia
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potentially m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DiGeorge Syndrome
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent infections, developmental delay, learning problems and cleft palate. Associated conditions include kidney problems, schizophrenia, hearing loss and autoimmune disorders such as rheumatoid arthritis or Graves' disease. DiGeorge syndrome is typically due to the deletion of 30 to 40 genes in the middle of chromosome 22 at a location known as ''22q11.2''. About 90% of cases occur due to a new mutation during early development, while 10% are inherited from a person's parents. It is autosomal dominant, meaning that only one affected chromosome is needed for the condition to occur. Diagnosis is suspected based on the symptoms and confirmed by genetic testing. Although there is no cure, treatment can improve symptoms. This often includes a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoplasia
Hypoplasia (from Ancient Greek ὑπo- ''hypo-'' 'under' + πλάσις ''plasis'' 'formation'; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ. Dictionary of Cell and Molecular Biology (11 March 2008) Although the term is not always used precisely, it properly refers to an inadequate or below-normal number of cells.Hypoplasia Stedman's Medical Dictionary. lww.com Hypoplasia is similar to |
Aplasia Cutis Congenita
Aplasia cutis congenita is a rare disorder characterized by congenital absence of skin. Ilona J. Frieden classified ACC in 1986 into 9 groups on the basis of location of the lesions and associated congenital anomalies.Moss C, Shahidulla H. Naevi and other developmental defects. In: Burns T, Breathnach S, Cox N, Griffiths C, editors. Rook's Textbook of Dermatology. 8th ed. United Kingdom (UK): Wiley-Blackwell Publication; 2010. p. 18, 18.98-18. 106. The scalp is the most commonly involved area with lesser involvement of trunk and extremities. Frieden classified ACC with fetus papyraceus as type 5. This type presents as truncal ACC with symmetrical absence of skin in stellate or butterfly pattern with or without involvement of proximal limbs.Meena N, Saxena AK, Sinha S, Dixit N. Aplasia cutis congenita with fetus papyraceus. Indian J Paediatr Dermatol 2015;16:48-9. It is the most common congenital cicatricial alopecia, and is a congenital focal absence of epidermis with or without ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymus
The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule. The thymus is made up of immature T cells called thymocytes, as well as lining cells called epithelial cells which help the thymocytes develop. T cells that successfully develop react appropriately with MHC immune receptors of the body (called ''positive selection'') and not against proteins of the body (called ''negative selection''). The thymus is largest and most active during the neonatal and pre-adolescent periods. By the early teens, the thymus begins to decrease in size and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birth Defect
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth defects are divided into two main types: structural disorders in which problems are seen with the shape of a body part and functional disorders in which problems exist with how a body part works. Functional disorders include metabolic and degenerative disorders. Some birth defects include both structural and functional disorders. Birth defects may result from genetic or chromosomal disorders, exposure to certain medications or chemicals, or certain infections during pregnancy. Risk factors include folate deficiency, drinking alcohol or smoking during pregnancy, poorly controlled diabetes, and a mother over the age of 35 years old. Many are believed to involve multiple factors. Birth defects may be visi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomy
Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated, both over immediate and long-term timescales. Anatomy and physiology, which study the structure and function (biology), function of organisms and their parts respectively, make a natural pair of related disciplines, and are often studied together. Human anatomy is one of the essential basic research, basic sciences that are applied in medicine. The discipline of anatomy is divided into macroscopic scale, macroscopic and microscopic scale, microscopic. Gross anatomy, Macroscopic anatomy, or gross anatomy, is the examination of an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
