Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.
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Question: Abstract: After overnight food and fluid restriction, nine healthy males were examined before, during, and after lower body positive pressure (LBPP) of 11 +/- 1 mmHg (mean +/- SE) for 30 min and before, during, and after graded lower body negative pressure (LBNP) of -10 +/- 1, -20 +/- 2, and -30 +/- 2 mmHg for 20 min each. LBPP and LBNP were performed with the subject in the supine position in a plastic box encasing the subject from the xiphoid process and down, thus including the splanchnic area. Central venous pressure (CVP) during supine rest was 7.5 +/- 0.5 mmHg, increasing to 13.4 +/- 0.8 mmHg (P less than 0.001) during LBPP and decreasing significantly at each step of LBNP to 2.0 +/- 0.5 mmHg (P less than 0.001) at 15 min of -30 +/- 2 mmHg LBNP. Plasma arginine vasopressin (AVP) did not change significantly in face of this large variation in CVP of 11.4 mmHg. Mean arterial pressure increased significantly during LBPP from 100 +/- 2 to 117 +/- 3 Torr (P less than 0.001) and only at one point during LBNP of -30 +/- 2 mmHg from 102 +/- 1 to 115 +/- 5 mmHg (P less than 0.05). Heart rate did not change during LBPP but increased slightly from 51 +/- 3 to 55 +/- 3 beats/min (P less than 0.05) only at 7 min of LBNP of -30 +/- 2 mmHg. Plasma osmolality, sodium, and potassium did not change during the experiment. Hemoglobin concentration increased during LBPP and LBNP, whereas hematocrit only increased during LBNP.(ABSTRACT TRUNCATED AT 250 WORDS)

Answer: Influence of central venous pressure change on plasma vasopressin in humans.

Question: Abstract: Between 1971 and 1980, the senior one of us (C.S.R.) performed 101 primary total hip replacements in eighty-five consecutive patients who were less than fifty-five years old. All of the patients had degenerative joint disease. Survivorship analysis was used to calculate a predicted cumulative rate of success for this series of total hip replacements over ten years of follow-up. This method of analysis of the data was chosen because it provides a prediction of the expected durability of a total hip arthroplasty in any individual patient. The need for revision because of loosening or infection or else radiographic evidence of migration of a component was the criterion for failure. Two revisions were performed for aseptic loosening of the acetabular component. One infection necessitated revision, and radiographic evidence of loss of fixation was seen in one additional acetabular component and one femoral stem. Life-table calculations predicted that the survivorship of all of the total hip replacements in this series would be 87.6 per cent at ten years of follow-up. Based on the results of the application of this method of analysis to the current series, we concluded that a primary cemented total hip replacement, when performed for coxarthrosis, can be expected to function durably in an active middle-aged patient.

Answer: Survivorship analysis of total hip replacements. Results in a series of active patients who were less than fifty-five years old.

Question: Abstract: Papillomas of the respiratory and genital tracts are caused by the same papillomavirus genotypes, and mothers of children with respiratory papillomatosis often have a history of genital warts. Only one of 109 cases reviewed gave a history of birth by cesarean section, whereas ten cesarean deliveries would have been the expected number for this group on the basis of national rates. The single case was delivered by elective cesarean section before the rupture of the membranes, and the child developed respiratory papillomatosis in the first year of life. These findings suggest that in juvenile-onset disease, the transmission of infection from mother to child occurs most often during passage through an infected birth canal, but that intrauterine infection of the fetus is also possible. Papillomavirus infection of the female genital tract is common, but respiratory papillomatosis is rare. On the basis of crude estimates of annual number of children born to infected mothers and of new cases of juvenile-onset disease, the risk of developing disease for a child born to an infected mother was calculated to be one in several hundred exposures.

Answer:
Rarity of cesarean delivery in cases of juvenile-onset respiratory papillomatosis.