Rare Diseases: A large group of diseases which are characterized by a low prevalence in the population. They frequently are associated with problems in diagnosis and treatment.Orphan Drug Production: Production of drugs or biologicals which are unlikely to be manufactured by private industry unless special incentives are provided by others.Lymphangioleiomyomatosis: A disease characterized by the progressive invasion of SMOOTH MUSCLE CELLS into the LYMPHATIC VESSELS, and the BLOOD VESSELS. The majority of the cases occur in the LUNGS of women of child-bearing age, eventually blocking the flow of air, blood, and lymph. The common symptom is shortness of breath (DYSPNEA).Lithiasis: A condition characterized by the formation of CALCULI and concretions in the hollow organs or ducts of the body. They occur most often in the gallbladder, kidney, and lower urinary tract.Patient Advocacy: Promotion and protection of the rights of patients, frequently through a legal process.Legislation, Drug: Laws concerned with manufacturing, dispensing, and marketing of drugs.Actinomycosis: Infections with bacteria of the genus ACTINOMYCES.Pulmonary Alveolar Proteinosis: A PULMONARY ALVEOLI-filling disease, characterized by dense phospholipoproteinaceous deposits in the alveoli, cough, and DYSPNEA. This disease is often related to, congenital or acquired, impaired processing of PULMONARY SURFACTANTS by alveolar macrophages, a process dependent on GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Drug Approval: Process that is gone through in order for a drug to receive approval by a government regulatory agency. This includes any required pre-clinical or clinical testing, review, submission, and evaluation of the applications and test results, and post-marketing surveillance of the drug.Neuroaxonal Dystrophies: A nonspecific term referring both to the pathologic finding of swelling of distal portions of axons in the brain and to disorders which feature this finding. Neuroaxonal dystrophy is seen in various genetic diseases, vitamin deficiencies, and aging. Infantile neuroaxonal dystrophy is an autosomal recessive disease characterized by arrested psychomotor development at 6 months to 2 years of age, ataxia, brain stem dysfunction, and quadriparesis. Juvenile and adult forms also occur. Pathologic findings include brain atrophy and widespread accumulation of axonal spheroids throughout the neuroaxis, peripheral nerves, and dental pulp. (From Davis & Robertson, Textbook of Neuropathology, 2nd ed, p927)Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.National Institutes of Health (U.S.): An operating division of the US Department of Health and Human Services. It is concerned with the overall planning, promoting, and administering of programs pertaining to health and medical research. Until 1995, it was an agency of the United States PUBLIC HEALTH SERVICE.Histiocytosis, Langerhans-Cell: A group of disorders resulting from the abnormal proliferation of and tissue infiltration by LANGERHANS CELLS which can be detected by their characteristic Birbeck granules (X bodies), or by monoclonal antibody staining for their surface CD1 ANTIGENS. Langerhans-cell granulomatosis can involve a single organ, or can be a systemic disorder.Birt-Hogg-Dube Syndrome: Autosomal dominant neoplastic syndrome characterised by genodermatosis, lung cysts, spontaneous and recurrent PNEUMOTHORAX; and RENAL CANCER. It is associated with mutations in the folliculin protein gene (FLCN protein).Health Level Seven: An American National Standards Institute-accredited organization working on specifications to support development and advancement of clinical and administrative standards for healthcare.Patient Rights: Fundamental claims of patients, as expressed in statutes, declarations, or generally accepted moral principles. (Bioethics Thesaurus) The term is used for discussions of patient rights as a group of many rights, as in a hospital's posting of a list of patient rights.Biological Ontologies: Structured vocabularies describing concepts from the fields of biology and relationships between concepts.Retroperitoneal Fibrosis: A slowly progressive condition of unknown etiology, characterized by deposition of fibrous tissue in the retroperitoneal space compressing the ureters, great vessels, bile duct, and other structures. When associated with abdominal aortic aneurysm, it may be called chronic periaortitis or inflammatory perianeurysmal fibrosis.Histiocytoma: A neoplasm containing HISTIOCYTES. Important forms include BENIGN FIBROUS HISTIOCYTOMA; and MALIGNANT FIBROUS HISTIOCYTOMA.European Union: The collective designation of three organizations with common membership: the European Economic Community (Common Market), the European Coal and Steel Community, and the European Atomic Energy Community (Euratom). It was known as the European Community until 1994. It is primarily an economic union with the principal objectives of free movement of goods, capital, and labor. Professional services, social, medical and paramedical, are subsumed under labor. The constituent countries are Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden, and the United Kingdom. (The World Almanac and Book of Facts 1997, p842)Drug Industry: That segment of commercial enterprise devoted to the design, development, and manufacture of chemical products for use in the diagnosis and treatment of disease, disability, or other dysfunction, or to improve function.United States Food and Drug Administration: An agency of the PUBLIC HEALTH SERVICE concerned with the overall planning, promoting, and administering of programs pertaining to maintaining standards of quality of foods, drugs, therapeutic devices, etc.Urea Cycle Disorders, Inborn: Rare congenital metabolism disorders of the urea cycle. The disorders are due to mutations that result in complete (neonatal onset) or partial (childhood or adult onset) inactivity of an enzyme, involved in the urea cycle. Neonatal onset results in clinical features that include irritability, vomiting, lethargy, seizures, NEONATAL HYPOTONIA; RESPIRATORY ALKALOSIS; HYPERAMMONEMIA; coma, and death. Survivors of the neonatal onset and childhood/adult onset disorders share common risks for ENCEPHALOPATHIES, METABOLIC, INBORN; and RESPIRATORY ALKALOSIS due to HYPERAMMONEMIA.Erdheim-Chester Disease: A rare form of non-Langerhans-cell histiocytosis (HISTIOCYTOSIS, NON-LANGERHANS-CELL) with onset in middle age. The systemic disease is characterized by infiltration of lipid-laden macrophages, multinucleated giant cells, an inflammatory infiltrate of lymphocytes and histiocytes in the bone marrow, and a generalized sclerosis of the long bones.Eosinophilic Granuloma: The most benign and common form of Langerhans-cell histiocytosis which involves localized nodular lesions predominantly of the bones but also of the gastric mucosa, small intestine, lungs, or skin, with infiltration by EOSINOPHILS.Angioedemas, Hereditary: Inherited disorders that are characterized by subcutaneous and submucosal EDEMA in the upper RESPIRATORY TRACT and GASTROINTESTINAL TRACT.Iron Metabolism Disorders: Disorders in the processing of iron in the body: its absorption, transport, storage, and utilization. (From Mosby's Medical, Nursing, & Allied Health Dictionary, 4th ed)Medical Laboratory Personnel: Health care professionals, technicians, and assistants staffing LABORATORIES in research or health care facilities.Epidermolysis Bullosa: Group of genetically determined disorders characterized by the blistering of skin and mucosae. There are four major forms: acquired, simple, junctional, and dystrophic. Each of the latter three has several varieties.Breast Neoplasms, Male: Any neoplasms of the male breast. These occur infrequently in males in developed countries, the incidence being about 1% of that in females.Academies and Institutes: Organizations representing specialized fields which are accepted as authoritative; may be non-governmental, university or an independent research organization, e.g., National Academy of Sciences, Brookings Institution, etc.Tropheryma: A genus of gram-positive bacteria in the family Cellulomonadaceae.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Biomedical Research: Research that involves the application of the natural sciences, especially biology and physiology, to medicine.Syndrome: A characteristic symptom complex.