Free Practice Question
RC · Reading Comprehension
655-705
Short Passage - Science
Reading Passage
It has long been assumed that strictures of the bile duct are the result of poor dietary habits and alcohol abuse, especially if such degradation has occurred over a period of ten or more years. Recent studies have shown, however, that bile duct strictures are most often an unfortunate consequence of certain types of surgery, as the body reacts to invasive procedures. These strictures occur when the liver produces an excess of bile, which then becomes stuck in the ducts and crystallizes. It is believed that the use of general anesthetics halts the ducts’ natural motion of undulation, allowing the excess bile to build up. It has further been hypothesized that, strangely, the type of surgery performed has a causal effect on where the stricture occurs within the duct system.
These new ideas could have a profound impact on the diagnosis of strictures, especially since the medications generally given to surgical patients mask the obvious warning signs of bile duct strictures. In the past, those suffering from such strictures would exhibit telltale symptoms - an oozing of pus from the pores of the chest and a dark discoloration of the urine and saliva. But the prevalent use of multivitamins and antibiotics keeps these symptoms hidden in patients, giving doctors no external indications of a problem in the bile duct system. Doctors have had to resort to other methods of detection, primarily biopsy through either traditional means or endoscopy. However, even microendoscopy is enough of an invasive technique that the procedure itself could provoke the same reaction that may cause bile duct strictures. Newer, noninvasive technologies such as MRI (magnetic resonance imaging) or ultrasound could, thus, prove to be beneficial. Still, even these techniques are not useful unless the approximate location of the stricture is known. Without some empirical evidence of where the blockage is occurring or some theory that could successfully pinpoint its locale, an ultrasound scan could be a quixotic endeavor.
These new ideas could have a profound impact on the diagnosis of strictures, especially since the medications generally given to surgical patients mask the obvious warning signs of bile duct strictures. In the past, those suffering from such strictures would exhibit telltale symptoms - an oozing of pus from the pores of the chest and a dark discoloration of the urine and saliva. But the prevalent use of multivitamins and antibiotics keeps these symptoms hidden in patients, giving doctors no external indications of a problem in the bile duct system. Doctors have had to resort to other methods of detection, primarily biopsy through either traditional means or endoscopy. However, even microendoscopy is enough of an invasive technique that the procedure itself could provoke the same reaction that may cause bile duct strictures. Newer, noninvasive technologies such as MRI (magnetic resonance imaging) or ultrasound could, thus, prove to be beneficial. Still, even these techniques are not useful unless the approximate location of the stricture is known. Without some empirical evidence of where the blockage is occurring or some theory that could successfully pinpoint its locale, an ultrasound scan could be a quixotic endeavor.
The author’s primary purpose in this passage is to
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Difficulty
655-705
Type
RC
Category