instruction:
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).
question:
Abstract: To determine the effect of hydration on the early osmotic and intravascular volume and endocrine responses to water immersion the hematocrit, hemoglobin, plasma renin activity (PRA), and plasma electrolyte, aldosterone (PA), and vasopressin (PVP) concentrations were measured during immersion following 24-h dehydration; these were compared with corresponding values following rapid rehydration. Six men and one woman (age 23-46 yr) underwent 45 min of standing immersion to the neck preceded by 45-min standing without immersion, first dehydrated, and then 105 min later after rehydration with water. Immersion caused an isotonic expansion of the plasma volume (P less than 0.001), which occurred independently of hydration status. Suppression of PRA (P less than 0.001) and PA (P less than 0.001) during both immersions also occurred independently of hydration status. Suppression of plasma vasopressin was observed during dehydrated immersion (P less than 0.001) but not during rehydrated immersion. It is concluded that plasma tonicity is not a factor influencing PVP suppression during water immersion. 
 Which is the apt title for the abstract? option1: Effect of hydration on plasma volume and endocrine responses to water immersion. option2: Leads from the MMWR. Smoking and health: a national status report.
answer:
Effect of hydration on plasma volume and endocrine responses to water immersion.


question:
Abstract: The chemotactic activity of human C5a des Arg is enhanced significantly by an anionic polypeptide (cochemotaxin) in normal human serum and plasma. We have found that the cochemotaxin attaches to the oligosaccharide chain of native C5a des Arg to form a complex with potent chemotactic activity for human polymorphonuclear leukocytes. Although capable of enhancing the chemotactic activity of native C5a des Arg, the cochemotaxin had no effect on the chemotactic activity of either deglycosylated C5a des Arg, native C5a, or N-formyl-methionyl-leucyl-phenylalanine. Of the known components of the oligosaccharide chain, only sialic acid prevented enhancement by the cochemotaxin of the chemotactic activity exhibited by native C5a des Arg. Sialic acid also prevented the formation of C5a des Arg-cochemotaxin complexes, detected by acid polyacrylamide gel electrophoresis, molecular sieve chromatography on polyacrylamide gels, and sucrose density gradient ultracentrifugation. 
 Which is the apt title for the abstract? option1: Attachment of human C5a des Arg to its cochemotaxin is required for maximum expression of chemotactic activity. option2: Appendectomy and the risk of tubal infertility.
answer:
Attachment of human C5a des Arg to its cochemotaxin is required for maximum expression of chemotactic activity.


question:
Abstract: Early mobilisation after arthroplasty of the knee sometimes results in wound breakdown. The two commonly used incisions, the anterior midline and the medial parapatellar incisions, were compared in order to determine which had the best potential for wound healing. Study of the cleavage lines around the knee demonstrated that the medial parapatellar incision lies parallel to the lines, whilst the anterior midline incision lies perpendicular to them. In addition, the medial parapatellar wound was found to be subjected to significantly less tension during flexion; after arthroplasty it can be expected to heal faster and to be less liable to disruption during early mobilisation. 
 Which is the apt title for the abstract? option1: Anterior midline or medial parapatellar incision for arthroplasty of the knee. A comparative study. option2: Urogenital tract carcinoma metastatic to the head and neck.
answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Anterior midline or medial parapatellar incision for arthroplasty of the knee. A comparative study.


