Hemodynamic effects on oxygen consumption and bile flow in isolated skate liver

A technique is described for perfusion of livers from the little skate, Raja erinacea, in the isolated state at 15 degrees C utilizing a recirculating, well-oxygenated elasmobranch Ringer solution. Bile flow and oxygen consumption were optimal and remained relatively constant over a 4- to 5-h perfusion at portal vein pressures of 2.5-5.0 cm Ringer. At these pressures, bile flow rates were comparable to values previously observed in the free-swimming skate. In contrast to mammalian species, bile secretion in the elasmobranch is particularly sensitive to small changes in perfusion pressure. Hepatic clearance of sulfobromophthalein and [14C]sodium taurocholate demonstrated initial fractional disappearance rates that were also similar to values obtained in vivo. Only small amounts of sulfobromophthalein appeared in bile by 5 h, whereas 78.5 +/- 6.5% of [14C]sodium taurocholate was recovered in bile at this time. These experiments establish portal vein perfusion pressures for study of skate livers in the isolated state in which oxygen consumption is maximal and organic anion clearance from perfusate to bile exceeds values obtained in vivo.     

Microbiological profiles of the Viking spacecraft

Planetary quarantine requirements associated with the launch of two Viking spacecraft necessitated microbiological assessment during assembly and testing at Cape Canaveral and the Kennedy Space Center. Samples were collected from selected surface of the Viking Lander Capsules (VLC), Orbiters, (VO), and Shrouds at predetermined intervals during assembly and testing. Approximately 7,000 samples were assayed. Levels of bacterial spores per square meter on the VLC-1 and VLC-2 were 1.6 x 10(2) and 9.7 x 10(1), respectively, prior to dry-heat sterilization. The ranges of aerobic mesophilic microorganisms detected on the VO-1 and VO-2 at various sampling events were 4.2 x 10(2) to 4.3 x 10(3) and 2.3 x 10(2) to 8.9 x 10(3)/m2, respectively. Approximately 1,300 colonies were picked from culture plates, identified, lypholipized, and stored for future reference. About 75% of all isolates were microorganisms considered indigenous to humans; the remaining isolates were associated with soil and dust in the environment. The percentage of microorganisms of human origin was consistent with results obtained with previous automated spacecraft but slightly lower than those observed for manned (Apollo) spacecraft.     

Perioperative myocardial ischaemia in patients undergoing transurethral surgery: a pilot study comparing general with spinal anaesthesia

We have studied the incidence and duration of perioperative myocardial ischaemia using ambulatory ECG monitoring in 100 patients undergoing transurethral surgery, who were allocated randomly to receive either general or spinal anaesthesia. The overall incidence of myocardial ischaemia increased from 18% to 26% between the preoperative and postoperative periods. Patients with ischaemic heart disease had a significantly greater incidence of myocardial ischaemia after operation than patients without known ischaemic heart disease (P < 0.05). There was an increase in both the incidence and duration of myocardial ischaemia after operation with both anaesthetic techniques, but no significant difference between the two.     

Arthroscopy of a dislocated hip replacement: a case report

A 55-year-old woman had a dislocation of a total hip arthroplasty that could not be reduced by closed manipulation because of an obstructing cement fragment. The use of percutaneous arthroscopic instrumentation allowed reduction by successful manipulation of the fragment out of the joint.     

Fungal degradation of anaerobically digested sewage sludge

It can be shown that both the mean plasma levels observed and the mean analgesic scores (effectiveness) are related to the dose of an orally effective analgesic agent, although wide individual variations exist. Based on the pharmacokinetic characteristics of propoxyphene, it can be predicted and confirmed that equilibrium (or steady state) plasma levels will be achieved after about six doses when administered on a q. 6h. schedule. Similar predictions indicate that an initial loading dose of 2 to 2 1/2 times the maintenance dose will produce more promptly plasma levels within or close to the equilibrium levels.     

Hemodialysis of acute arsenic intoxication with transient renal failure

A striking reduction in serum arsenic level was achieved after four hours of hemodialysis in a patient with acute arsenic intoxication and transient renal failure. Quantitative dialysance of arsenic and a comparison of daily urinary excretion of arsenic with amount removed by dialysis suggested that hemodialysis is indicated in the treatment of acute arsenic intoxication if there is concomitant renal failure. In the presence of normal renal function, supportive measures, including dimercaprol (BAL in Oil) therapy, constitute the best available treatment.     

Duration discrimination by rats

A psychophysical procedure was used to determine the difference limen for the duration of a signal that ranged from .5 to 8.0 sec. The accuracy of three rats in keeping track of the duration was assumed to be limited by three factors: (a) inattention to the signal on some trials, (b) variability in starting to time the duration when the signal begins (and/or in stopping to time the duration when the signal ends), and (c) factors related to signal duration itself. A generalized Weber model provided a better approximation to the growth in the difference limen as a function of signal than a generalized Counter model.