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Cisplatin is in a class of drugs known as platinum-containing compounds used to treat various types of cancers including metastatic testicular and ovarian tumors. The molecule was first discovered in 1845, but did not receive FDA approval until 1978. Today it is known as the "penicillin of cancer drugs," because it is so effective for many different cancers. There are three key players involved in Cisplatin's mechanism: (1) Cisplatin, (2) DNA (3) and an HMG Protein. Most Cisplatin enters the body through active transport, but some molecules are passively defused through the cell membrane. Once in the nucleus, Cisplatin can form an adduct with two consecutive guanine bases within a strand of DNA. The molecule loses its chlorine atoms in exchange for the nitrogen atoms of the target guanines. Cisplatin can bond more tightly with nitrogen because nitrogen balances the platinum charge more effectively than chlorine. It is this adduct-induced DNA bend that allows binding of proteins which contain the high mobility group, HMG domain. Once the protein is bound to the DNA, it inserts a wedge-like phenyl group of phenylalanine 37 into the widened minor groove created by the bend. The tightly bound HMG protein causes destacking of the nucleotide bases, resulting in the DNA helix becoming kinked. In this way, Cisplatin can be thought of as a monkey wrench in the DNA repair system. With the HMG protein bound to the DNA, the modified strand is not repaired properly and so the cell dies. The success of Cisplatin depends on its ratio of efficacy between cancerous and healthy cells.
Rafael Nadal missed seven months last year with a knee injury. That knee will face its toughest test when he plays in the French Open, his first Grand Slam event since his return.
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Analysis of Rafael Nadal's Knee Injury (Computer Animation)
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Colonoscopy is a test that allows your doctor to look at the inner lining of your large intestine (rectum and colon). He or she uses a thin, flexible tube called a colonoscope to look at the colon. A colonoscopy helps find ulcers, colon polyps, tumors, and areas of inflammation or bleeding.
Knee replacement, also called arthroplasty, is a surgical procedure to resurface a knee damaged by arthritis. Metal and plastic parts are used to cap the ends of the bones that form the knee joint, along with the kneecap. This surgery may be considered for someone who has severe arthritis or a severe knee injury.
Embryonic cardiovascular system. ... The human arterial and venous systems develop from different embryonic areas. Aortic Arches. The aortic arches—or pharyngeal arch arteries—are a series of six, paired, embryological vascular structures that give rise to several major arteries .
Waardenburg syndrome is a group of genetic conditions that can cause hearing loss and changes in coloring (pigmentation) of the hair, skin, and eyes. Although most people with Waardenburg syndrome have normal hearing, moderate to profound hearing loss can occur in one or both ears. The hearing loss is present from birth (congenital). People with this condition often have very pale blue eyes or different colored eyes, such as one blue eye and one brown eye. Sometimes one eye has segments of two different colors. Distinctive hair coloring (such as a patch of white hair or hair that prematurely turns gray) is another common sign of the condition. The features of Waardenburg syndrome vary among affected individuals, even among people in the same family.
Pompe disease is a rare multisystem genetic disorder that is characterized by absence or deficiency of the lysosomal enzyme alpha-glucosidase (GAA). This enzyme is required to breakdown (metabolize) the complex carbohydrate glycogen and convert it into the simple sugar glucose.
Cushing's disease is a serious condition of an excess of the steroid hormone cortisol in the blood level caused by a pituitary tumor secreting adrenocorticotropic hormone (ACTH). ACTH is a hormone produced by the normal pituitary gland. ACTH stimulates the adrenal glands (located on top of the kidneys) to produce cortisol, commonly referred to as the stress hormone.
Experts do not know the exact cause of Zollinger-Ellison syndrome. About 25 to 30 percent of gastrinomas are caused by an inherited genetic disorder called multiple endocrine neoplasia type 1 (MEN1). MEN1 causes hormone-releasing tumors in the endocrine glands and the duodenum.