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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.
Symptoms of serotonin syndrome include a classic triad of mental status changes (eg, anxiety, delirium, confusion, restlessness), autonomic dysregulation (eg, diaphoresis, tachycardia, hypertension, hyperthermia, diarrhea, mydriasis), and neuromuscular hyperactivity (eg, hyperreflexia, tremor, rigidity, myoclonus, ocular clonus). Serotonin syndrome is clinically diagnosed and laboratory tests are used to rule out other etiologies. It usually occurs due to inadvertent interactions between drugs, therapeutic use of multiple serotonergic agents, or serotonergic medication overdose. Treatment involves discontinuation of serotonergic drugs, supportive measures, and sedation with benzodiazepines. In severe cases, a serotonin antagonist (cyproheptadine) may be used.
"How to Perform a Transthoracic Echocardiographic Study Volume 1: Transducer Position and Anatomy" is an instructional video, offered by ASE, and can be used for professional lectures and offers an interactive section for flexible presentations. The video includes an overview of relevant cardiac anatomy, a step by step presentation of all Transducer Positions, and the sequential transducer movements to acquire standard echo images needed to complete a Transthoracic Echocardiographic Study.
giant systolic pulsations, known as C-V waves, were noticeable during jugular venous examination of a 33-year-old woman who had tricuspid-valve endocarditis. In video 2, transthoracic echocardiography revealed severe tricuspid regurgitation.
Esophageal manometry is a test used to measure the function of the lower esophageal sphincter (the valve that prevents reflux of gastric acid into the esophagus) and the muscles of the esophagus (see diagram). This test will tell your doctor if your esophagus is able to move food to your stomach normally.
Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly progressive dysphagia, usually to both liquids and solids, and regurgitation of undigested food. Evaluation typically includes manometry, barium swallow, and endoscopy. Treatments include dilation, chemical denervation, surgical myotomy, and peroral endoscopic myotomy.
lesions at the anterior skull base invading the paranasal area and the paracavernous area can be reached without brain retraction by the shown subfrontal approach. it enables to control the paranasal sinus, optic nerve, periorbital tissue, carotid artery and pituary gland. reconstruction is not easy... but cosmetically appealing. CSF leaks are rare with the use of fascia lata and tissucol ( fibrin glue). osseous reconstruction is done by microsrews and calciumpyrophosphate ( norian, synthes).
Chiari malformation (kee-AH-ree mal-for-MAY-shun) is a condition in which brain tissue extends into your spinal canal. It occurs when part of your skull is abnormally small or misshapen, pressing on your brain and forcing it downward.
Delayed puberty is defined as the absence of any signs suggestive of puberty by 14 years of age. In this case, the patient's pubertal delay appears to be constitutional because of his positive family history, absence of syndromic features or systemic illness, and bone age of 12 years. Puberty correlates more closely with bone age than chronological age. On follow-up, the patient will most likely demonstrate a similar onset of puberty as his father.