In eukaryotes, the endonucleolytic activity of the calf RTH-1 class 5'- to 3'-exo/endonuclease can function without RNase H1 to remove initiator RNA from Okazaki fragments. Cleavage requires that the RNA be displaced to form an unannealed single-stranded 5'-tail or flap structure. On substrates with RNA-initiated primers, DNA oligomers that competed with the RNA for template binding simulated strand displacement synthesis from an upstream Okazaki fragment. This allowed cutting of displaced RNA segments by RTH-1 nuclease. Requirements for the reaction also were examined on substrates in which the tail was unannealed because it was intentionally mispaired. On both types of substrate, the nuclease slides over the RNA region from the 5'-end and cleaves at the beginning of the annealed region, irrespective of whether ribo- or deoxyribonucleotides are at the cleavage site. Presence of a triphosphate or a 7-methyl 3'G5'ppp5' G cap structure at the 5'-end of the RNA does not affect cleavage. The previously reported stimulation of the nuclease by an upstream primer was not always observed, suggesting that not every site in the downstream Okazaki fragment is equally susceptible to cleavage during displacement synthesis in vivo. The biological role of the endonuclease activity of RTH-1 nuclease in Okazaki fragment processing is discussed.

A total of 100 patients who underwent elective lobar donor hepatectomy from 2000 to 2002 at the University of Rochester Medical Center were reviewed. Assessed clinical data were estimated blood loss, intraoperative central venous pressure (CVP), blood product and fluid administration, perioperative arterial blood gas tension and acid-base state, metabolic status, perioperative serum levels of aspartate aminotransferase, alanine aminotransferase, prothrombin time, albumin, and lactate, procedure duration, and perioperative complications. All patients survived surgery, and the average duration of surgery (from skin incision to skin closure) was 615 Ϯ 99.6 minutes. Mean blood loss was 549 Ϯ 391 mL (range, 80-2,500 mL), and only 4 patients required homologous blood transfusion. The intraoperative blood loss did not correlate with CVP values. A total of 72 patients received isotonic sodium bicarbonate solution, and their metabolic variables were superior to those of normal saline group patients (arterial pH, 7.35 Ϯ 0.03 vs. 7.29 Ϯ 0.07; base excess, -4.3 Ϯ 2.4 vs. 7.3 Ϯ 3.4; and serum bicarbonate level, 20.6 Ϯ 2.2 vs. 18.6 Ϯ 2.9). However, the better control of metabolic acidosis was not associated with serum lactate levels or other outcome measures. Maintaining the CVP Ͻ 5 mmHg was not associated with blood loss. Clinically significant anesthetic complications were severe metabolic acidosis, pneumothorax and respiratory insufficiency immediately following extubation in the operating room. In conclusion, placement of a thoracic epidural catheter delivering a local anesthetic in addition to intravenous (IV) patient-controlled analgesia with opiates provided safe and effective pain control in most patients. Further prospective studies should shed a light on the optimal care of patients undergoing liver donor hepatic resection. Liver Transpl 13: 537-542, 2007.

At the mild to moderate level of sedation studied, midazolam and propofol sedation resulted in the same propensity for UAO. In this homogeneous group of healthy subjects, there was a considerable range of negative pressures required to cause UAO. The specific factors responsible for the maintenance of the upper airway during sedation remain to be elucidated.

Differences between the two propofol formulations were slight and not clinically significant. Similar gender differences in plasma concentrations and awaking times were found for both formulations.

There are cases in which it is desirable to find an optimum linear least-squares fit to data with significant uncertainties in both the x and y variables.