Protein turnover in patients before and after elective orthopaedic operations

Whole body protein turnover was measured in 11 patients before and after elective orthopaedic operations by giving 15N-glycine orally every 4 hours for 32 hours. The patients were maintained throughout on a constant protein intake. In two control subjects a comparison was made between intermittent dosage and continuous infusion of 15N-glycine for the estimation of total turnover. With intermittent dosage the 15N abundance in urinary urea reached a constant level after about 24 hours. Rates of total protein synthesis and breakdown were calculated from the 15N abundance at the plateau level. After surgery there was a moderate increase in urinary N output. The apparent N balance (intake - urinary N) was -0.25 ñ 1.31 g/d (mean ñ s.d.) before operation and =7.51 ñ 4.5g/d/ after operation. The rate of protein synthesis fell from 3.83 ñ 0.73g kg-1d-1 before operation to 2.94 ñ 0.83 g kg-1d-1 after operation. This difference is statistically significant (0.05 > p > 0.01). There was no significant change in the rate of protein breakdown. The possibility remains that a block in protein synthesis, probably mainly in muscle, may be partly responsible for the so-called 'catabolic' loss of nitrogen after injury, but this has not been proved. (AU)

Chondrolysis following slipped capital femoral epiphysis in Jamaica

We reviewed the cases of all patients with slipped capital femoral epiphysis at the University Hospital of the West Indies. Forty-seven hips in thirty-six Black patients were evaluated, and in 40 per cent of those hip chondrolysis developed. The appearance of roentgenographic changes of chondrolysis was predictable. There was a high percentage occuring within one year of diagnosis of slipped epihysis and within six months of closure of the proximal femoral growth plate. The persistent absence of motion in all planes following slipping of the capital femoral epiphysis was a constant finding in patients with chondolysis. This loss of motion can be diagnostic of impending chondrolysis and is usually present before the appearance of the roentgenographic changes. The microscopic changes suggest that the primary lesion is not necrosis of cartilage but a replacement of articular cartilage by pannus formation (Summary)