p21: One of the cell cycle-regulating protein and loss of its activity is associated with certain human cancers. p53: A gene, which encodes a protein that regulates cell growth and is able to cause potentially cancerous cells to destroy themselves. Packaging cells: Cells that contain all the genes necessary for retroviral protein synthesis. The viral vector contains only those sequences needed for transmission. The vector (the defective virus) containing the gene to be transferred is introduced in the packaging cells and cultured. This produces large quantities of vectors that could be administered to patients. Paget’s Nipple: Paget’s disease, mammary, an intraductal carcinoma of the breast extending to involve the nipple and areola, characterized clinically by eczema-like inflammatory skin changes and histologically by infiltration of the dermis by malignant cells (Paget’s cells). PAP Smear: Pap t., Papanicolaou test, a cytological test for the detection and diagnosis of various conditions particularly premalignant and malignant conditions of female genital tract (vagina, cervix, and endometrium). Cells are removed by scraping the surface layer and a smear is prepared on a glass slide which is then fixed and stained to visualize under the microscope for evidence of pathological changes in the cells. Paracrine: Denoting a type of hormone function in which hormone synthesized in and released from endocrine cells binds to its receptors in nearby cells and affects their functions. Denoting the secretion of a hormone by an organ other than an endocrine gland. Parenteral: Not through the alimentary canal (intestine) but rather by injection through some other route, as subcutaneous, intramuscular, intravenous. Pathologists: Persons dealing with the branch of medicine called pathology, the structural and functional manifestation of disease. Pathology: Study of characteristics of cells obtained from tissues of patients. PCR: Polymerase chain reaction, a sophisticated technique to amplify a small amount of DNA. PDGF: Platelet-derived growth factor. The major mitogen in serum for growth in culture of cells of connective tissue origin. It consists of 2 different but homologous polypeptides A and B (~30,000 D) linked by disulfide bonds. Believed to play a role in wound healing. It is carried in the alpha-granules of platelets and is released when platelets adhere to traumatized tissues. Connective tissue cells near the traumatized region respond by initiating the process of replication. Penetrance: In genetics, the frequency of expression of a genotype. Peptidase: Enzyme of the hydrolase class that catalyzes the hydrolysis of peptide bonds - the bond between amino acids in a protein. Peptide: Low molecular weight compounds containing two or more amino acids. Peptides form the constituent parts of proteins. Pericardial effusion: Escaped fluid into the fibrous sac that surrounds the heart. Pericarditis: Inflammation of the pericardium, the sac that surrounds the heart and roots of the great vessels. Peripheral neuropathy: A condition that describes a problem with the functioning of nerves that are outside the spinal cord. The symptoms may be minor such as numbness, weakness, or burning pain or could be severe. Perineal: Pertaining to the perineum. Perineum is the region between the thigh, bounded in the male by the scrotum and anus and in the female by the vulva and anus. Peritoneal cavity: The potential space between parietal (pertaining to the walls of the cavity) and visceral (pertaining to the interior organs) peritoneum, the serous membrane. Peritoneal membrane: The serous membrane lining the abdominopelvic walls and investing the viscera. Peritoneal: Pertaining to the peritoneum, the membrane lining the abdominopelvic walls and investing the viscera. Peritonitis: Inflammation of the peritoneum. Peroxidase: Enzyme that catalyzes the oxidation of organic substrates by hydrogen peroxide, which is reduced to water. These enzymes are heme proteins, found in plants and animals. Pfannenstiel incision: A curved abdominal incision, the convexity being directed downward, just above the symphysis (an articulation formed by intervening cartilage), passing through skin, superficial fascia, and aponeurosis (any one of the thicker and denser of the deep fasciae which cover, invest, and the terminations and attachments of, many muscles. They often differ from tendons only in being flat and thin), exposing the pyramidalis (crest of pubis) and rectus muscles, which are separated from each other in the midline, the peritoneum (the smooth serous membrane which lines the cavity of the abdomen) then being opened vertically. pg/ml: Picogram/milliliter. Picogram is 1/1000,000,000,000 of a gram P-glycoprotein: A membrane glycoprotein involved in the membrane transport system. It is found to take part in active removal of drugs from inside of a cell, thus causing multiple drug resistance in cancer patients. pH: The symbol relating the hydrogen ion concentration or activity of a solution to that of a given standard solution. Numerically the pH is approximately equal to the negative logarithm of hydrogen ion concentration expressed in molarity. PH 7 is neutral, above 7 is alkaline and below is acidic. Phage: Bacterial virus is known as phage. Phagocytes: Any cell that can ingest particulate matter. The term is usually refer to specific types of white blood cells that ingest microorganisms and other antigens coated with antibody. Phagocytosis: Activity of cells engulfing particles such as infectious agents. Pharmacodynamics: The study of the biochemical and physiological effects of drugs and the mechanisms of their actions, including the correlation of actions and effects of drugs with their chemical structure, also, such effects on the actions of a particular drug or drugs. Contrast with pharmacokinetics. Pharmacogenomics: The study of how variations in the human genome affects the response to medications. This will drugs to be tailor-made for individuals and adapted to each persons own genetic makeup. Pharmacokinetics: The action of drugs in the body over a period of time, including the process of absorption, distribution, and localization in tissue, biotransformation, and excretion. Phase I enzymes: Microsomal enzymes required for oxidation or reduction of chemicals. This process is called functionalization and helps in detoxification of compounds by the phase II enzymes. However, some of the phase I enzymes can convert some of the harmless chemicals to potent carcinogens. Phase II enzymes: Enzymes that takes part in the conjugation of two molecules for excretion. Unwanted chemicals are first oxidized or reduced in the cells usually with the help of specific enzymes (phase I enzymes) and are then conjugated with molecules like glutathione, glucuronic acid, and sulfate which make them more soluble for excretion. Phenotype: The total characteristics displayed by an organism under a particular set of environmental factors, regardless of the actual genotype of the organism. Results from interaction between the genotype and the environment. Philadelphia chromosome (Ph): An abnormality of chromosome 22 characterized by shortening of its long arms (the missing portion usually translocated to chromosome 9) and present in marrow cells of most patients with chronic myelocytic leukemia. Phlebitis: Inflammation of a vein. Phosphaturia: Excessive discharge of phosphate in the urine. Phosphodiesterase: An enzyme that cleaves phosphodiesters like DNA to give a phosphomonoester and a free hydroxyl group. Phospholipid: The major structural lipid of most cellular membranes (except the chloroplast, which has galactolipids). Contain phosphate, usually as a diester. Phosphorylase: Enzyme that catalyses the sequential removal of glycosyl residues from glycogen to yield one glucose-1- phosphate per reaction. Phosphorylation: The metabolic process of introducing a phosphate group into an organic molecule. Photodynamic therapy: Cancer treatment that uses the interaction between laser light and a substance that makes cells more sensitive to light. When light is applied to cells that have been treated with this substance, a chemical reaction occurs and destroys cancer cells. Photosynthesis: Synthesis in a cell that takes place in the presence of light. In plant and blue-green algae, carbohydrate is synthesized from carbon dioxide and water with the evolution of oxygen. Phytate: An anionic form of phytic acid occurring in the leaves of plants. Phytochemicals: Chemicals present in plant sources. Pituitary: This is an endocrine gland located in the base of the brain. It secretes hormone that influences the growth and activity of other endocrine glands. Plasma: The liquid part of the blood lymphatic fluid. Plasma is devoid of cells and, unlike serum, has not clotted. Blood plasma contains antibodies and other proteins. Plasma cells: Terminally differentiated cells of the B-lymphocyte lineage that produce antibodies. Plasma membrane: The external, limiting lipid bilayer membrane of cells. Plasmacytoma: A plasma cell tumor mass. Plasmid: An extrachromosomal circular double-stranded DNA molecule found in bacterial cells. Plasmid DNA contains gene essential for cell growth. These structures are self-replicating and can be transferred from one cell to another. Plasmin: An enzyme of the hydrolase class that catalyzes the hydrolysis of peptide bonds at the carbonyl end of lysine or arginine residues. The enzyme occurs in plasma as plasminogen, which is an inactive form and is activated by plasma or tissue activator such as urokinase. Plasminogen: The inactive precursor of plasmin, an enzyme that breaks down peptide bonds. Platelets: Small disc-shaped structure present in blood and chiefly known for its role in blood coagulation; platelets, which are formed in megakaryocyte and released from its cytoplasm in clusters, lack a nucleus and DNA but contain active enzymes and mitochondria. Pleiotropic: Indicates multiple effects. Pleiotropy: The ability of a single allele to have more than one distinguishable effect. The most familiar example is the allele responsible for color pattern in Siamese cats. Pleurodesis: The production of adhesions between the parietal and the visceral pleura. Pleuroperitoneal: Pertaining to both pleura (the membrane investing the lungs and lining the thoracic cavity) and the peritoneum (the membrane lining the abdominopelvic walls and investing the viscera). Polarizable: Can be converted into. charged species Polymorphism: The quality or character of occurring in several different forms. Polyp: Growth from mucous membrane (e.g., colorectal, nasal polyp), most often benign but can be cancerous. Polysomy: Situation in which all chromosomes are present and some are present in greater than the diploid number, for example, trisomy 21. Polyunsaturated Fatty Acid: Any straight-chain monocarboxylic acid with multiple double bonds, especially those naturally occurring in fats. Polyuria: The passage of large volume of urine in a given period, a characteristic of diabetes. Porphyrin: Any of a group of compounds containing the porphin structure, four pyrrole rings connected by methine (-CH=) bridges in a cyclic configuration, to which a variety of side chains are attached. Preeclampsia: A toximia of late pregnancy characterized by hypertension, edema, and protein urea; when convulsions and coma are associated, it is called eclampsia. Primordial Soup: The simplest and most undeveloped liquid environment present in the beginning of earth. Pro-cathepsin-D positivity: Cathepsin-D is one of a number of enzymes that breaks down peptide bond and hydrolyses protein. This enzyme is a marker of breast cancer. Procollagenase: The precursor enzyme of collagenase. Proctocolectomy: Surgical removal of the rectum and colon. Progenitor cell: A parent cell. Progesterone: Another sex hormone produced by ovaries, adrenal glands and placenta. Progestogen: A term applied to any substance possessing progestational activity. Progestin: The name originally given to the crude hormone of the corpora lutea. It has since been isolated in pure form and is now known as progesterone. The name progestin is used for certain synthetic or natural progestational agents. Progression: Stages after irreversible changes have taken place for cancerous growth. Prolactin: One of the hormones secreted by special cells of the anterior pituitary gland that stimulates and sustains lactation in postpartum mammals. Prolactinoma: A pituitary tumor, usually a microadenoma of the cells secreting prolactin. Promoter: A region of DNA to which RNA polymerase and transcription fcators bind before initiating the transcription of DNA into RNA Promotion: Stages following initiation of mutation on chromosome; can be caused or accelerated by other noncarcinogenic chemicals. Promotion could be reversible if DNA is not extensively damaged. Prophylactic surgery: Surgery to ward off disease. Prophylactic: Tending to ward of disease. Prospective studies: When data are collected from ongoing observation. Prostaglandin: Any of a group of components derived from unsaturated 20-carbon fatty acids via the cyclooxygenase pathway that are extremely potent mediators of a diverse group of physiologic processes. Prostate-specific membrane antigen (PSMA): is a multifunctional cell surface protein that is overexpressed in prostate cancer, including hormone-refractory and metastatic disease. This is an important biomarker for prostate cancer cells and is a potential target for multimodality therapies. Prostatectomy: Surgical removal of the prostate. Proteases: Enzymes that break down proteins. Proteasome: A large, multiprotein complex present in both the cytoplasm and the nucleus of eukaryotic cells that degrades cytosolic and nuclear proteins. Protein kinase C: Enzyme that catalyzes the transfer of high-energy phosphate group from ATP to an acceptor protein. This phosphorylation converts an inactive protein (enzyme) to the active form. Protein synthesis: Synthesis of protein from the gene via transcription of the gene into messenger RNA, and translation of messenger RNA into protein. Summarized in the diagram below. Proteolytic: Agent that causes breakdown of protein. Proto-oncogene: A normal gene that with mutation or other mechanisms becomes an oncogene. Provitamin A: Trivial name for carotenoids exhibiting qualitatively the biological activity of beta-carotene, i.e., vitamin A precursors (alpha-, beta-, and gamma-carotene and cryptoxanthin); contained in fish liver oils, spinach, carrots, egg yolk, milk products, and other green leaf or yellow vegetables and fruits. PSA: Prostate Specific Antigen: Specific antigenic protein found to be elevated both in benign and malignant prostate tumor. PSA level in blood is used as a marker for prostate disease. Pseudopodia: Temporary cytoplasmic extrusion by which an organism or cell moves about. Psoralen: Substances found in many different plants, especially psoralea corylifolia (legume). They are used for skin diseases, especially vitiligo (disorder characterized by regions of otherwise normal skin of nonpigmented white patches of varied sizes) and as sunscreens. They interact with nucleic acids and are also used as research tools. Psoralens have a coumarin molecule with a furan ring. Psychoneurosis: Freud’s term for neuroses such as hysteria, obsessions, and phobias originating in childhood experiences. Psychopharmacology: The study of the effect of drugs and medicines on psychological processes. Pulmonary embolism: The lodgment of a blood clot in the lumen of a pulmonary artery, causing a severe dysfunction in respiratory function.