Glossary of Terms

Glossary_IconAkt (also called protein kinase B, or PKB)
An enzyme that plays a key role in cell proliferation and survival. One of Akt’s major functions is to block programmed cell death (apoptosis).

AML (angiomyolipomas)
A non-malignant kidney (and rarely extra-renal) tumor composed of three distinct tissue/cell types: blood vessel, fat and smooth muscle cells. Often found in patients suffering of TSC syndrome or LAM.

AMPK (AMP-activated protein kinase)
An enzyme that is activated during times of metabolic stress, to turn off energy-consuming processes and turn on energy-producing processes.

Chylothorax
Also known as chyle leak is a type of pleural effusion caused by lymphatic fluid (chyle) accumulating in the pleural cavity.

Chylous pleural effusion
Escape of lymphatic fluid into the pleural cavity.

Cyanosis
A physical sign causing bluish discoloration of the skin and mucous membranes. Cyanosis is caused by a lack of oxygen in the blood. Cyanosis is associated with cold temperatures, heart failure, lung diseases, and smothering.

Dyspnea
Breathing disorder where the individual feels “Shortness of breath”.

Hamartin
A protein made by the TSC1 gene. Hamartin and tuberin, a protein produced by the TSC2 gene, function together in cells to regulate cell growth and prevent the overgrowth of cells into tumors.

Hemoptysis
Hemoptysis is the coughing up of blood or bloody sputum from the lungs or airway. It may be either self-limiting or recurrent.

LAM cells
A cell type that have been observed to form part of the lesions found in the lung of LAM patients. The origin of them, however, is not known. They often show features of mixed phenotype between smooth muscle cells and melanocytes.

Lymphangioleiomyomas
Large cystic tumors primarily found in the abdomen, retro-peritoneum and pelvis.

Lymphangioleiomyomatosis (LAM)
A rare, fatal lung disease that affects women in their childbearing years. In LAM, abnormal smooth muscle-like cells proliferate in the lungs, pulmonary airway, parenchyma, lymphatics, and blood vessels, ultimately leading to respiratory failure.

Lymphatic system
A complex network of specialized vessels that circulates the lymphatic fluid. It plays a key role in the immune system.

mTOR
A key regulatory protein complex, found in two forms (mTOR1 and mTOR2), that integrates inputs from system controlling cell energy and metabolism, cell growth and survival. It is the activated state of this complex that is thought to play a key role associated with the pathology of LAM.

NIH Roadmap for Medical Research
A set of initiatives developed by the U.S. National Institutes of Health aimed at accelerating medical research. The Roadmap identifies the most compelling opportunities in three arenas: new pathways to discovery, research teams of the future, and reengineering the clinical research enterprise.

Pneumothorax
Accumulation of air in the space between the lungs and the chest wall caused by “holes” in the lung tissue.

Proof of concept trials
Clinical trials, performed with a small number of patients, which are aimed at validating understanding of a disease mechanism while giving initial data about the efficacy and safety of an investigational treatment chosen to address that mechanism.

Rapamycin (sirolimus)
An immunosuppressive drug commonly given to transplant patients to avoid organ rejection. Rapamycin binds to and inhibits a key regulatory protein called the target of rapamycin (TOR).

Rheb (Ras homolog enriched in brain)
A protein that appears to activate nutrient signaling input to mTOR, in combination with the tuberin-hamartin complex.

Sporadic or isolated LAM 
LAM disease found not associated with known germ line defect of the TSC gene family. Thought to be caused by somatic mutations of mostly TSC2 gene, however , others genes might also be defective.

Systems biology
The study of the dynamic networks of interacting biological elements. (R Aebersold. Institute for Molecular Systems Biology, Zürich, Switzerland).

Translational research
An approach to research in which basic science discoveries are translated into clinical applications and clinical observations in turn generate research projects for basic sciences.

TSC1, TSC2
Genes that, when mutated, produce the tuberous sclerosis complex. TSC1 and TSC2 produce the proteins hamartin and tuberin, respectively.

Tuberin
A protein made by the TSC2 gene. Tuberin and hamartin, a protein produced by the TSC1 gene, function together in cells to regulate cell growth and prevent the overgrowth of cells into tumors.

Tuberous sclerosis complex (TSC)
A complex genetic (inherited) condition characterized by seizures and tumor growth in the brain, kidneys, heart, eyes, lungs and skin. Developmental delay, mental retardation and autism may also be associated with the disease. The disease affects some people severely, while others are mildly affected. Nearly 1 million people worldwide are known to have Tuberous Sclerosis. There are many undiagnosed cases due to the obscurity of the disease and the mild form symptoms may take in some people. Approximately 39 percent of women with TSC also have LAM.