Immunohistochemical analysis of receptor tyrosine kinase signal transduction activity in chordoma.

AIMS: Currently, there are no effective chemotherapeutic protocols for chordoma. Reports of receptor tyrosine kinase (RTK) expression in chordoma suggest that these tumours may respond to kinase inhibitor therapy. However, RTK signalling activity has not been extensively investigated in chordoma. METHODS: A tissue microarray containing 21 cases of chordoma was analysed for expression of a number of proteins involved in signal transduction from RTKs by immunohistochemistry. RESULTS: Platelet-derived growth factor receptor-beta, epidermal growth factor receptor (EGFR), KIT and HER2 were detected in 100%, 67%, 33% and 0% of cases, respectively. Platelet-derived growth factor receptor-beta staining was of moderate-to-strong intensity in 20 of 21 cases. In contrast, KIT immunoreactivity was weak and focal in each of the seven positive cases. Total EGFR staining was variable; weak staining for phosphorylated EGFR was detected in nine cases. Phosphorylated isoforms of p44/42 mitogen-activated protein kinase, Akt and STAT3, indicative of tyrosine kinase activity, were detected in 86%, 76% and 67% of cases, respectively. CONCLUSIONS: Chordomas commonly express RTKs and activated signal transduction molecules. Although there were no statistically significant correlations between the expression of any of the markers studied and disease-free survival or tumour location, the results nonetheless indicate that chordomas may respond to RTK inhibitors or modulators of other downstream signalling molecules.

Equations describing percentiles for birth weight, head circumference, and length of preterm infants.

OBJECTIVE: To describe growth of prematurely born infants and create a growth chart adequate to assess growth of infants with less than 29 completed weeks of gestation. STUDY DESIGN: Birth weight, head circumference and length measurements of 7,425 liveborn preterm infants from 1985 to 1997 were retrieved from a longitudinal database maintained by the neonatology division. The 3rd, 5th, 10th, 15th, 25th, 50th, 75th, 85th, 90th, 95th and 97th percentiles of each measurement were determined and used for mathematical modeling. RESULTS: Birth weight was described with an exponential function while head circumference and length were described with linear functions. A preterm growth chart for the 10th, 50th and 90th percentiles for birth weight, weight growth, head circumference and length was generated. CONCLUSION: The mathematical models of growth provide smooth representations of the percentiles across gestational ages.

The increased incidence on Mondays of work-related sprains and strains.

Insurance-industry researchers have shown an increase on Mondays of lost-time sprain and strains said to be work-related, but thought to be fraudulent claims for off-the-job weekend injuries. We examined this issue among civilian employees of the Department of the Navy, using data from claims for injuries occurring between 1989 and 1994. We found that the rate of Monday sprains and strains significantly exceeded the expected rate and that such claims were significantly more likely to be made by claimants who were craftsmen and mechanics, who reported an injury to the back or trunk, who were supervisors, or who did not have college degrees. We estimate that 22% of claims for Monday-occurring sprains and strains are possibly fraudulent and that their cost to the Department of the Navy during the 6 years studied was $38 million. For the entire federal government, cost for such claims during this period may have exceeded $250 million.