: 142 In 1982, Quinton together with Dr Sakharam Mahurkar, a nephrologist at County Cook Hospital in Chicago, developed dual-lumen catheter which became the standard for haemodialysis and apheresis.Sheridan was dubbed the "Catheter King" by Forbes magazine in 1988. He also invented the modern "disposable" plastic endotracheal tube now used routinely in surgery. Materials
Urinary catheters
A range of polymers are used for the construction of catheters, including silicone rubber, nylon, polyurethane, polyethylene terephthalate (PET), latex, and thermoplastic elastomers. Silicone is one of the most common implantable choice because it is inert and unreactive to body fluids and a range of medical fluids with which it might come into contact. On the other hand, the polymer is weak mechanically, and a number of serious fractures have occurred in catheters. For example, silicone is used in Foley catheters where fractures have been reported, often requiring surgery to remove the tip left in the bladder. There are many different types of catheters for bladder problems. A typical modern intermittent catheter is made from polyurethane and comes in different lengths and sizes for men, women and children.Some catheters are packed in a sterile saline solution.
The majority of MRKH syndrome cases are characterized as sporadic, but familial cases have provided evidence that, at least for some patients, MRKH is an inherited disorder. The underlying causes of MRKH syndrome is still being investigated, but several causative genes have been studied for their possible association with the syndrome. Most of these studies have served to rule-out genes as causative factors in MRKH, but thus far, only WNT4 has been associated with MRKH with hyperandrogenism.Reports of MRKH syndrome can be traced back to Hippocrates (460 B.C.–377 B.C.). The medical eponym honors August Franz Josef Karl Mayer (1787–1865), Carl Freiherr von Rokitansky (1804–1878), Hermann Küster (1879–1964) and Georges Andre Hauser (1921–2009). Signs and symptoms
A female with this condition is hormonally normal; that is, the woman will enter puberty with development of secondary sexual characteristics including thelarche and pubarche (pubic hair). The womans karyotype will be 46,XX. At least one ovary is intact, if not both, and ovulation usually occurs. Typically, the vagina is shortened and intercourse may, in some cases, be difficult and painful. Medical examination supported by gynecologic ultrasonography demonstrates a complete or partial absence of the cervix, uterus, and vagina.If there is no uterus, a woman with MRKH cannot carry a pregnancy without intervention. It is possible for the woman to have genetic offspring by in vitro fertilization (IVF) and surrogacy.