Whole body protein metabolism in children with cancer

Whole body protein synthesis and catabolism were measured using the [ring-2H5]phenylalanine and [1-13C]leucine primed constant infusion technique in 32 paediatric patients with cancer at different stages of treatment. Rates of synthesis (S) and catabolism (C) derived from the [ring-2H5]phenylalanine and [1-13C]leucine models were 4.7 (SD 1.3) (S) and 6.0 (1.5) (C) g/d/kg, and 5.5 (0.8) (S) and 6.8 (1.2) (C) g/d/kg, respectively. These results show that these two tracer techniques give similar results in this study population. Comparison of these values with results previously reported for groups of control children using the [ring-2H5]phenylalanine model (S = 3.69 and 3.93; C = 4.09 and 4.28 g/d/kg) and the [1-13C]leucine model (S = 4.32; C = 4.85 g/d/kg) show that rates of synthesis and catabolism were higher in cancer patients than in controls. Thus whole body protein turnover is increased in children under treatment for cancer. Other indices of metabolism such as plasma amino acids and intermediary metabolites were also measured and showed that, although subjects were in isotopic steady state, there were significant metabolic changes during the course of the primed constant infusions used to measure protein turnover.     

Creatinine related reference ranges for urinary homovanillic acid and vanillylmandelic acid at 6 months of age

The relationship between homovanillic acid (HVA), vanillylmandelic acid (VMA), and creatinine in the urine of 6 month old babies has been studied and reference ranges in the form of centiles constructed for HVA and VMA against creatinine. Over 10,000 urine samples were collected from babies in four health districts in the north of England. HVA and VMA concentration, either independently or when divided by creatinine concentration, were dependent upon the absolute concentration of creatinine in the sample. After adjustment for creatinine significant differences in the mean concentration of HVA were found between sexes. No such differences were found for VMA. HVA and VMA were also found to be age dependent. Centiles were constructed using a procedure which makes no distributional assumptions about the data. The net effect of utilising these centiles was to increase the predictive value of a positive screening test from 20% to 40% without any increase in the false negative rate.     

Computer graphics for digitally formatted images

The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use.     

Combination of immunofluorescence and immunoperoxidase techniques for serotyping mixtures of Mycoplasma species.

We describe a method for the simultaneous identification of up to three Mycoplasma species by the use of contrast-labeled fluorescent antibodies against two species and peroxidase-labeled antibody against a third species. The procedure enabled the rapid identification of colonies of three artificially mixed avian Mycoplasma species on agar blocks and also mixtures of species in cultures from naturally infected chickens. Furthermore, it was possible to quantitate the components of a mixture of Mycoplasma gallisepticum, M. synoviae, and M. gallinarum. This new procedure offers an improvement over existing methods in terms of both speed and analytical capability.     

Occurrence of validating clinical findings in the hospital record for appendectomy, cholecystectomy and intervertebral disc excision patients: comparisons among hospitals and among surgeons.

This study examines the variation among 36 Pennsylvania hospitals, and the individual surgeons practicing in them, in the proportion of appendectomy, cholecystectomy and intervertebral disc excision patients with clinical findings in the hospital record that validate the need for surgery. Using admissions from January 1990 through June 1991, we performed logistic regressions on the probability of validating clinical findings controlling for patient age, sex, admission severity of illness, and Medicaid and Health Maintenance Organization membership. Our results show that hospitals, and surgeons, vary significantly in their validation rates for cholecystectomy and disc surgery and, to a lesser extent, appendectomy. We also found that increased procedure-specific volume at both the hospital and surgeon levels is not related to the odds of validating clinical findings. We define a future research agenda to investigate the reasons for the observed differences among hospitals and among surgeons.