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: Yersinia enterocolitica was cultured from feces of 122 symptomatic adults in a single facility using selective culture media; all isolates were confirmed in an independent reference laboratory. Of 128 isolates, multiple serotypes were defined and all were biochemically typical for Yersinia enterocolitica. Other agents were seen in 20 patients; of these, seven were Yersinia fredriksenii and six were Clostridium difficile. Diarrhea (80%) and abdominal pain (64%) were common, whereas other features such as fever (9%) and bloody stools (8%) were unusual. Use of antibiotics (24%) or opiates (28%) in the month before culture was common. The terminal ileum was seen radiographically in 20 patients, but only two barium studies showed abnormalities. Fiberoptic endoscopy and biopsy studies, done in greater than 50% of the cases, showed minimal or no changes in most patients. However, 3 patients had pseudomembranous colitis with concomitant Clostridium difficile cytotoxin and 7 had diffuse severe colitis. New culture techniques, and possibly geographic differences, have contributed to the high isolation rates of this organism. Yersinia enterocolitica occurs sporadically, involves a variety of serotypes, and is associated with a broader clinical spectrum than was formerly appreciated.
Which is the apt title for the abstract? option1: Gastrointestinal features of culture-positive Yersinia enterocolitica infection. option2: The laboratory's role in environmental health emergency investigations.

Ex Output:
Gastrointestinal features of culture-positive Yersinia enterocolitica infection.

Ex Input:
Abstract: Patients with essential hypernatremia maintain urinary concentrating ability despite plasma hyperosmolality and low plasma vasopressin concentrations. We investigated renal sensitivity to ultralow dose vasopressin infusions in two patients with a syndrome of hypodipsia, hypernatremia with selective osmoreceptor dysfunction, early puberty, and aggressive behavior. The patients were water loaded until a hypotonic diuresis was established. Vasopressin was infused in stepwise increments from 0.4-12 fmol/kg X min. Both patients had increased renal sensitivity to vasopressin, achieving negative free water clearance at infusion rates of 0.4 and 4 fmol/kg X min (normal greater than or equal to 6). Treatment for 3 months with 1-desamino-8-D-arginine vasopressin (DDAVP) led to an improvement in behavior and the reporting, for the first time, of a sensation of thirst. After DDAVP therapy both patients had a reduction of their renal sensitivity to infused vasopressin. We conclude that untreated patients with essential hypernatremia have increased renal sensitivity to vasopressin which is reduced by DDAVP administration.
Which is the apt title for the abstract? option1: Increased renal sensitivity to vasopressin in two patients with essential hypernatremia. option2: AAEE minimonograph #25: Single-fiber electromyography in myasthenia gravis.

Ex Output:
Increased renal sensitivity to vasopressin in two patients with essential hypernatremia.

Ex Input:
Abstract: It has been postulated that increased energy expenditure results in shortened survival. To test this "rate-of-living theory" we examined the effect of raising energy expenditure by means of cold exposure on the longevity of rats. Male 6-mo-old SPF Long-Evans rats were gradually accustomed to immersion in cool water (23 degrees C). After 3 mo they were standing in the cool water for 4 h/day, 5 days/wk. They were maintained on this program until age 32 mo. The cold exposure resulted in a 44% increase in food intake (P less than 0.001). Despite their greater food intake, the cold-exposed rats' body weights were significantly lower than those of control animals from age 11 to 32 mo. The average age at death of the cold-exposed rats was 968 +/- 141 days compared with 923 +/- 159 days for the controls. The cold exposure appeared to protect against neoplasia, particularly sarcomas; only 24% of the necropsied cold-exposed rats had malignancies compared with 57% for the controls. The results of this study provide no support for the concept that increased energy expenditure decreases longevity.
Which is the apt title for the abstract? option1: Longevity of cold-exposed rats: a reevaluation of the "rate-of-living theory". option2: Factors determining renal response to water immersion in non-excretor cirrhotic patients.

Ex Output:
Longevity of cold-exposed rats: a reevaluation of the "rate-of-living theory".