Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Example Input: Abstract: We report the causes of obstructive jaundice in 56 black South African patients. Chronic pancreatitis and malignant biliary obstruction occurred with equal frequency. These two conditions may be difficult to differentiate clinically and radiologically, and only operative pancreatic biopsy may be diagnostic. Choledocholithiasis caused jaundice in only 7.1% of the patients, reflecting the relatively low prevalence of gallstones in this population.
Example Output: Obstructive jaundice in the South African black population.

Example Input: Abstract: Pain thresholds to a pinch stimulus were measured at eight sites on the dorsum of both feet from 17 diabetic patients. Sixteen feet had neuropathic ulcers and seven had Charcot arthropathy. Vibration perception thresholds, radial nerve action potentials, muscle action potentials of flexor digitorum brevis, autonomic cardiovascular reflexes and reflex sweat output were also measured. Pinch pain threshold was abnormal in 15 diabetic feet, 11 having one or more insensitive sites. There was a greater variability in threshold between sites tested in diabetic than control subjects.
Example Output: A study of pain threshold in diabetics with neuropathic foot lesions.

Example Input: Abstract: Previous studies of the effect of tricyclic antidepressants on left ventricular function in depressed patients with moderate to severe ventricular impairment have focused primarily on imipramine hydrochloride. In a prior study, we found that although imipramine had no effect on ejection fraction as measured by first-pass radionuclide angiography, the treatment could not be tolerated by 50% of the patients because of intolerable drug-induced orthostatic hypotension. Nortriptyline hydrochloride is an effective antidepressant that, in depressed patients without heart disease, causes significantly less orthostatic hypotension than imipramine. To see if this advantage could be safely extended to patients with congestive failure, we measured the effect of nortriptyline on ejection fraction and blood pressure in 21 depressed patients with left ventricular impairment. Ejection fraction was unchanged by nortriptyline treatment, and orthostatic hypotension developed in only one (5%) of 21 patients. Nortriptyline emerges as a relatively safe treatment for depression in patients with left ventricular impairment.
Example Output:
Nortriptyline in depressed patients with left ventricular impairment.