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

Example Input: Abstract: Fifty ragweed-sensitive subjects were each administered a course of 12 injections of polyethylene glycol-modified ragweed extract. To investigate the effect of two treatment regimens, subjects were paired according to their skin sensitivity to ragweed extract and the severity of their rhinoconjunctivitis the previous year. One of each pair was randomly allocated to receive injections at weekly intervals, and the other subject was to receive injections daily until a local or systemic adverse reaction occurred and then to switch to a weekly schedule for the rest of the course. Blood was obtained immediately before each injection and at the end of the study to examine the rates of change of ragweed-specific IgE and IgG antibody levels and to evaluate whether these or other variables could be used to predict the occurrence of adverse reactions. Immediate reactions were minimal in both groups, but more late reactions occurred in subjects receiving the modified rush regimen; therefore, although the total number of injections received by the two groups was similar, the total dose of protein injected in the rush group was only half that achieved in the weekly group. Treatment induced increases in ragweed-specific IgE and IgG antibodies in both groups; the increase in IgE was similar in the two groups, but the increase in IgG was higher in the weekly group. There was a marked decrease in skin sensitivity to ragweed extract after treatment that was directly related to the IgG antibody response, and therefore, these changes were greater in the weekly group.(ABSTRACT TRUNCATED AT 250 WORDS)
Example Output: Polyethylene glycol-modified ragweed extract: comparison of two treatment regimens.

Example Input: Abstract: The split hydronephrotic kidney preparation was used to directly observe the effects of locally applied dopamine on the in vivo diameters of renal vessels. Dopamine (1 X 10(-6) to 3 X 10(-5) M) produced a concentration-dependent dilation of the arcuate and interlobular arteries and afferent arterioles. Efferent arterioles near the glomeruli also dilated to dopamine but the dilation was less than that of the preglomerular vessels. Higher dopamine concentrations (3 X 10(-4) and 1 X 10(-3) M) produced more variable effects, with a tendency for the arcuate and interlobular arteries and the afferent and efferent arterioles away from the glomeruli to decrease in diameter. After pretreatment with haloperidol, dopamine (1 X 10(-6) to 1 X 10(-4) M) did not dilate any pre- or postglomerular vascular segment, but the tendency for pre- and postglomerular constrictions with higher dopamine concentrations were not abolished. Pretreatment with phentolamine and propranolol enhanced the dilator response of the pre- and postglomerular vessels (except the afferent arterioles near glomeruli and efferent arterioles near welling points) to dopamine (3 X 10(-5) and 1 X 10(-4) M), and abolished the reductions in diameter produced by the high dopamine levels. These data indicate that the dilator effect of dopamine is mediated by interactions with specific dopaminergic receptors, while alpha and beta adrenergic receptors appear to mediate a constrictor influence observed with high dopamine concentrations. The overall effect of dopamine on the renal vessel diameters thus appears to depend on the balance of dilator and constrictor stimuli mediated by multiple receptors.
Example Output: Responses of in vivo renal microvessels to dopamine.

Example Input: Abstract: At the University of Texas Medical School at Houston we had a unique opportunity to examine performance through the medical curriculum and one year of postgraduate training of 50 students initially rejected for medical school. Each had been interviewed by the same Admissions Committee, which earlier had selected 150 students through the traditional process. In contrasting the initially accepted and initially rejected groups, academic and demographic variables accounted for only 28% of group difference. The 72% of group difference not accounted for by the variables examined was presumed to relate to Admissions Committee preference. In attrition and in both preclinical and clinical performance through medical school and one year of postgraduate training, there were no meaningful differences between the groups. The observations suggest that the traditional interview process probably does not enhance the ability to predict performance of medical school applicants.
Example Output:
Medical school performance of initially rejected students.