The long-term biomechanical and viscoelastic performance of repairing anterior cruciate ligament after hemitransection injury in a goat model.

To test the healing of the partially torn anterior cruciate ligament, we transected the posterolateral bundle in 11 adult female goats and tested the ligaments at 12, 24, and 52 weeks and 3 years after surgery. As early as 12 weeks after surgery translucent fibrous tissue covered the wound. The differences in anteroposterior laxity between right and left knees measured at 45 degrees and 90 degrees of flexion were not significantly different at each period.

Biomechanics of patellar tendon autograft for reconstruction of the anterior cruciate ligament in the goat: three-year study.

This study examined the biomechanics of anterior cruciate ligament-patellar tendon autografts for as long as 3 years after surgery. Twenty-seven adult female goats were tested; four served as controls and the others received an autograft to the right knee with each left knee serving as an additional control. The animals with grafts were tested at 0 week (n = 4), 6 weeks (n = 4), 12 weeks (n = 4), 24 weeks (n = 3), 1 year (n = 5), and 3 years (n = 3) after surgery.

Eradication of Brucella ovis from the Falkland Islands 1977-1993.

A campaign to eradicate Brucella ovis from sheep in the Falkland Islands, using a combination of serological tests and culling, was initiated in 1977 and continued until 1993 when, after a total of 65,266 tests had been carried out, the organism had been eradicated from the national flock. The paper discusses the relative values of the serological tests and suggests guidelines for maintaining the flock free of the infection.

Further evaluation of the use of buparvaquone in the infection and treatment method of immunizing cattle against Theileria parva derived from African buffalo (Syncerus caffer).

Three experiments were undertaken to determine the efficacy of different doses of buparvaquone in the infection and treatment immunization of cattle against Theileria parva derived from African buffalo (Syncerus caffer). Two of these experiments also compared buparvaquone with standard doses of long- and short-acting formulations of oxytetracycline. In addition, different dilutions of stabilates were used in the experiments.

Immunisation of cattle against theileriosis in Nakuru District of Kenya by infection and treatment and the introduction of unconventional tick control.

One hundred and one cross European-Boran cattle (50 cows and 51 calves), on a farm in Nakuru District, Kenya, were immunised against theileriosis using Theileria parva lawrencei and Theileria parva parva stocks from another district of Kenya. The stabilates used were T.p.

Computer-controlled muscle paralysis with atracurium in the sheep.

Paralysis was maintained in sheep by computer-controlled infusion of atracurium, using the integrated electromyogram as a measure of neuromuscular transmission. A number of experiments were conducted to ascertain the average infusion rate required to achieve a given level of paralysis for one hour. Each experiment yielded a point on a plot of paralysis versus infusion rate.

Local cerebral blood flow following transient cerebral ischemia. II. Effect of arterial PCO2 on reperfusion following global ischemia.

Following 5 minutes of global ischemia, local cerebral blood flow (LCBF) was shown to have an initial reactive hyperemia that was followed, within the first hour, by persistent hypoperfusion (Part I). Intracranial pressure (ICP) was never elevated during the period of poor reperfusion. These experiments attempted to reverse the state of subnormal LCBF by inducing hypercarbia or hyocarbia or maintaining normocarbia.

Local cerebral blood flow following transient cerebral ischemia. I. Onset of impaired reperfusion within the first hour following global ischemia.

Using the hydrogen clearance technique, local cerebral blood flow (LCBF) in 22 dogs was estimated at 6 parietal sites prior to and following 5 min of total global ischemia. Ischemia was immediately followed by an initial reactive hyperemia during which the electrocorticogram (ECoG) usually began to recover, and within the first 30 min, most of the LCBF's decreased to subnormal values. This onset of hypoperfusion was accompanied by a concomitant decrease in ECoG activity.

Reversal of non-depolarizing block by neostigmine.

Paralysis was maintained in the sheep for 30 or 90 minutes by computer-controlled injection of gallamine, pancuronium, alcuronium or d-tubocurarine, using the integrated electromyogram as a measure of neuromuscular transmission. Neostigmine was given and the recovery time measured. In all trials the recovery rise time was no longer than two minutes, but varied between one and two minutes.

Dosage patterns of non-depolarizing neuromuscular blockers in the sheep.

Eighty per cent paralysis was induced and maintained for 90 minute in the sheep by computer-controlled injection of gallamine, pancuronium, alcuronium or d-tubocurarine, using the integrated electromyogram as a measure of neuromuscular transmission. The dosage pattern consisted of a loading phase before any IEMG depression was detected, an onset phase during which a moderate amount of drug was required to achieve increasing paralysis, and a maintenance phase during which a substantially constant and relatively low infusion rate was required. The steady state rates of infusion in microgram/kg/min during "maintenance" was found to be 6.

D-tubocurarine requirement during hypothermia.

The effect of hypothermia on the action of d-tubocurarine (d-TC) was studied under carefully controlled experimental conditions. It was found that with computer controlled infusion, 60% less d-TC was required to sustain 75% muscle paralysis in cats, during steady-state, in vivo, when the temperature was changed from 37 degrees C to 30 degrees C. The corresponding relaxant consumption rates were 0.

Derivation of reliable electromyograms and their relation to tension in mammalian skeletal muscles during synchronous stimulation.

There exists a good correlation between the measured electrical activities and isometric twitch tension in the cat soleus muscle during synchronous stimulation. For an unbiased sampling of electrical activities by averaging a number of electromyograms over the muscle concerned, a relation of the form E = 0.98T + 5.

Local cerebral blood flow and the electrocorticogram during sodium nitroprusside hypotension.

Changes in local cerebral blood flow during sodium nitroprusside hypotension were measured using the hydrogen electrode technique. At mean arterial pressures from 90% to 50% of control values, local cerebral blood flow showed a significant decrease by 20%. When blood pressure was reduced below 50%, the local cerebral blood flow increased significantly and approached control levels.

Intra-ocular pressure during retrobulbar injection.

It was found that the use of retrobulbar injections can cause quite large transient rises in intra-ocular pressure which can be significantly reduced by using local anaesthetic in the injected saline, and by injecting in small steps, typically 0.2 to 0.3 mls/kg body weight at 1 minute intervals for a total of not more than ten steps.

Computer controlled studies in surface cooling hypothermia: the effect of carbon dioxide on brain temperature.

A computer controlled ventilation system was employed to maintain a constant end-expired CO2 percentage (FECO2) during a series of studies on young dogs aimed at measuring brain temperature differences during surface cooling hypothermia. The conclusion is that an FECO2 of six per cent or more is desirable if brain temperature differences are to be minimized. Additional experiments showed that ethyl alcohol and sodium nitroprusside infusions during cooling did not decrease brain temperature differences.

Computer controlled muscle relaxation: a comparison of four muscle relaxants in the sheep.

Computer control of anaesthesia has been extended to include muscle relaxant drugs. Injection of d-tubocurarine, gallamine, alcuronium or pancuronium was controlled by computer to reduce the integrated electromyogram to a preset level (40 per cent of control) for one hour. A programmed level of muscle paralysis is therefore possible for use in physiological and pharmacological experiments, and in clinical practice where precise control of the degree of paralysis together with minimal dosage is advantageous.