Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).

Ex Input:
Abstract: Hypocalcemic vitamin D (D)-depleted rats were supplemented with calcium or 1,25(OH)2D3, and the metabolism of D3 to 25(OH)D3 was studied. Infusion with 7 or 65 pmol 1,25(OH)2D3 X 24 h-1 led to normal or slight hypercalcemia associated with physiological and supraphysiological plasma concentrations of the hormone while calcium supplementation normalized plasma calcium despite 1,25(OH)2D3 concentrations as low as those observed in hypocalcemic controls. Constant administrations of [14C]D3 during the supplementation regimens uncovered a stimulation of the in vivo 25(OH)D3 production by calcium supplementation; this was further confirmed in vitro by an increase in the hepatic microsomal D3-25 hydroxylase. The group supplemented with pharmacological doses of the hormone displayed lower circulating concentrations of both D3 and 25(OH)D3 while the in vitro 25(OH)D3 production remained unaffected by 1,25(OH)2D3. Investigation of the kinetics of intravenous 25(OH)[3H]D3 revealed similar elimination constants in all groups. The data indicate that calcium supplementation of hypocalcemic D-depleted rats results in an increased transformation of D3 into 25(OH)D3 while supplementation with 1,25(OH)2D3 does not affect the in vitro D3-25 hydroxylase but seems to influence the in vivo handling of the vitamin by accelerating its metabolism.
Which is the apt title for the abstract? option1: Influence of calcium or 1,25-dihydroxyvitamin D3 supplementation on the hepatic microsomal and in vivo metabolism of vitamin D3 in vitamin D-depleted rats. option2: Differentiation of blast cells in acute nonlymphocytic leukemia [letter]

Ex Output:
Influence of calcium or 1,25-dihydroxyvitamin D3 supplementation on the hepatic microsomal and in vivo metabolism of vitamin D3 in vitamin D-depleted rats.

Ex Input:
Abstract: Random-dot stereograms were found to be capable of producing fusional vergence amplitudes in the absence of monocular contours. These vergence amplitudes are not an artefact of monocular contours provided by the target borders or test instrument and are comparable in range to vergence amplitudes measured clinically with second degree fusion targets in an amblyoscope. We conclude that diplopia of monocularly recognisable contours is not necessary for producing fusional vergence amplitudes.
Which is the apt title for the abstract? option1: Vergence amplitudes with random-dot stereograms. option2: Coronary vasodilation by nitrates is not mediated by the prostaglandin system: a quantitative cineangiographic study.

Ex Output:
Vergence amplitudes with random-dot stereograms.

Ex Input:
Abstract: Twenty-one patients with choanal atresia were treated from 1969 to 1985. Follow-up of 1 1/2 to 15 years postoperatively has been obtained in 17 patients. Thirteen patients had bilateral atresia and eight had unilateral atresia. All 13 patients with bilateral atresia were operated on within the first month of life. Eighteen patients were treated transnasally and two transpalatally. Ten of 15 patients treated by transnasal puncture and dilation followed by stenting of the choanae are patent after a single procedure. Five other patients, all of whom had other associated anomalies, required secondary dilations or transpalatal repair. Our results support the effectiveness of transnasal puncture and dilatation followed by stenting of the choanae as the initial surgical procedure of choice. It may be used safely in the neonate, and is often definitive.
Which is the apt title for the abstract? option1: Choanal atresia: clinical features, surgical approach, and long-term follow-up. option2: Transluminal dilatation of ureteropelvic junction strictures, ureteral strictures, and strictures at ureteroneocystostomy sites.

Ex Output:
Choanal atresia: clinical features, surgical approach, and long-term follow-up.