Synthesis and bacterial mutagenicity of the cyclopenta oxides of the four cyclopenta-fused of isomers of benzanthracene

Many polycyclic aromatic hydrocarbons containing peripherallyfused cyclopenta rings are believed to be activated primarilyby epoxidation of the cyclopenta ring. The cyclopenta epoxidesof a series of four cyclopenta benzanthracene derivatives, benz[e]aceanthrylene-5,6-oxide,benz[j]ace-anthrylene-1,2-oxide, benz(l)anthrylene-1,2-oxideand benz[k]acephenaceanthrylene-4,5-oxide were synthesized fromtheir parent hydrocarbons by formation of the bromohydrin followedby dehydrobromination, and characterized by u.v. – vis,and ¹H n.m.r. spectroscopy and mass spectrometry. The mutagenicityof these compounds was investigated in the Ames plate incorporationassay with Salmonella typhimurium strain TA98. All the oxideswere active without exogenous metabolic activation (170–320His⁺ revertants per nanomole) and also toxic above 0.5 µg/plate.Addition of S9 protein did not increase, and generally decreased,the mutagenicity of the oxides, while toxicity was largely unchanged.These results are consistent with the postulated role of cyclopentaoxides as major contributors to the mutagenicity of the parentcompounds in the Ames assay.     

Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

Hemodialysis and the elderly patient: potential advantages as to quality of life, urea generation, serum creatinine, and less interdialytic weight gain

A total of 204 patients treated by maintenance hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) were studied to ascertain how advancing age influences adaptation to uremia therapy. No difference in Karnofsky score was noted among patients over 70 years of age and two groups of patients, 16 to 59, and 60 to 69 years of age, respectively. In a subset of 33 hemodialysis patients studied midweek, it was noted that increasing age is associated with a lower serum creatinine concentration, lower interdialytic weight gain, and a lower urea generation rate. These three findings contribute to a relative ease in treating older uremia patients with hemodialysis or CAPD, as they tend to be stable and compliant relative to younger patients.     

Laparoscopic Cholecystectomy: Results of an Early Experience

Ninety consecutive patients over a 6-month period with acute (31 patients) or chronic (59 patients) cholecystitis underwent a laparoscopic cholecystectomy on an ambulatory (49 patients), one-night (33 patients), or two-night (5 patients) basis. Three patients required open procedures for 1) perforated duodenal ulcer at 48 h, postoperatively, 2) a cholecystoduodenal fistula, and 3) Mirizzis syndrome with erosion of the common duct. The procedure is safe, efficacious, and should be offered to patients with acute and chronic biliary disease.     

Impact of Shorter-acting Neuromuscular Blocking Agents on Fast-track Recovery of the Cardiac Surgical Patient

Background: Residual paralysis associated with the use of long-acting muscle relaxants can delay recovery from anesthesia and surgery. The authors tested the hypothesis that use of shorter-acting neuromuscular blocking agents is associated with reductions in tracheal extubation times and intensive care unit (ICU) length of stay in patients undergoing cardiac surgery with cardiopulmonary bypass.

Methods: One hundred ten patients scheduled for elective coronary artery bypass grafting or single valve surgery were randomized prospectively to receive either pancuronium or rocuronium intraoperatively. Anesthetic management and muscle relaxant maintenance dosing were standardized. In the ICU, the time required to wean ventilatory support, the duration of tracheal intubation, and length of stay were recorded. Subjects were asked to quantify generalized muscle weakness as they awakened in the ICU and again after tracheal extubation.

Results: Complete data were collected on 51 patients in the pancuronium group and 52 patients in the rocuronium group. No differences were found between the groups in anesthetic, surgical, or ICU management. Significant increases in the duration of weaning of ventilatory support were observed in patients who received pancuronium (median, 180 min; range, 50-780 min) compared with the rocuronium group (median, 110 min; range, 45-250 min). Tracheal extubation was significantly delayed in the pancuronium group (median, 500 min; range, 240-1,305 min) compared with the rocuronium group (median, 350 min; range, 210-1,140 min). Subjects in the pancuronium group experienced more mild to severe weakness in the ICU. However, the choice of muscle relaxant did not influence ICU length of stay.