Fine structural changes in the gastro-intestinal tract of the hypoxic puppy: a study of natural history

The present study demonstrates that a 2 hr period of sustained hypoxia results in a focally destructive process, a process which resolves by 5 days. That the changes described in earlier work are not overwhelming to the animal suggest that an early, focal, and reversible stage of the development of acute enterocolitis in the puppy can be described with the aid of electron microsocpy.     

The Effects of Learning on Optimal Lot Size Determination—Single Product Case

In this article the effects of learning on production lot sizing models are analyzed for the single product case. A general equation is developed for the average production time per unit, for producing the the annual demand in batches with some percentage of learning not retained between lots. Two models are developed, the first restricted to equal lot sizes and the second restricted to equal production intervals. A sample problem is solved to demonstrate the applications of learning to lot size determination.     

Polycentric total knee arthroplasty. A two-year follow-up study

Polycentric total knee arthroplasty provided significant relief of pain in 86 per cent of 500 knees. The independence and activity levels of the patients increased dramatically. The frequency of major complications as reflected by reoperation was 10 per cent in this series. There was a 2.8 per cent deep infection rate. One-third of the infected knees were salvaged and two-thirds required arthrodesis. Loosening of a component was noted in 2.4 per cent. After operation the average range of motion was from 6 to 101 degrees of flexion, for a range of 95 degrees; this was a 5-degree increase over average preoperative motion. Ninety-six per cent of the patients expressed satisfaction with the surgical result.     

Editorial. Phencyclidine: an emerging drug problem

A technique was developed for catheterization of the portal vein in rhesus monkeys (Macaca mulatta). Silicone rubber catheters (0.040 ID by 0.085 inch OD, or 0.030 ID by 0.065 inch OD) were surgically placed into the portal vein via the umbilical, inferior mesenteric, right colic, or ileocolic veins. The right colic and ileocolic veins proved to be the preferred route for catheterization. Both single end-hole and multiple end-hole catheters with 2 side holes were used. Catheter function was dependent upon proper placement within the portal vein and on maintaining patency. Single-hole catheters were successfully maintained by periodic flushing (2-3 times daily) with heparinized saline solution (1.5-4.0 units/ml), and multiple-hole catheters were best maintained by a continuous flow (1-2 ml/hour) of heparinized saline solution (1.5 units/ml). No adverse clinical effects due to the portal catheter were observed in any of the monkeys catheterized. The technique allowed placing the monkey in a restraint chair, thus enabling one to utilize the monkey in a conscious state.