Neonatal weight loss in breast and formula fed infants

OBJECTIVE: To define the range of neonatal weight loss in a population relative to feeding method. DESIGN: Prospective observational cohort study. SETTING: Maternity service providing geographically defined, community based newborn follow up. PARTICIPANTS: 971 consecutive term newborns of birth weight > or = 2500 g during the first 2-3 weeks of life; 34 excluded (inadequate data). 937 included: 45% breast fed, 42% formula fed, 13% breast and formula fed. OUTCOME MEASURES: Maximum weight loss and timing, age on regaining birth weight. RESULTS: Median weight loss: formula fed 3.5%, breast fed 6.6%. Upper centiles for maximum weight loss differ considerably (95th centiles: breast fed = 11.8%, formula fed = 8.4%; 97.5th centiles: breast fed = 12.8%, formula fed = 9.5%). Median time of maximum weight loss: 2.7 days for breast fed and formula fed. Recovery of birth weight: breast fed median 8.3 days, 95th centile 18.7 days, 97.5th centile 21.0 days; formula fed median 6.5 days, 95th centile 14.5 days, 97.5th centile 16.7 days. The time taken to regain birth weight correlates with both the degree and timing of initial weight loss for all groups. CONCLUSIONS: Early neonatal weight loss is defined allowing identification of infants who merit closer assessment and support.     

Condyloma in pregnancy is strongly predictive of juvenile-onset recurrent respiratory papillomatosis

OBJECTIVE: To assess the risk of juvenile-onset recurrent respiratory papillomatosis conferred by a maternal history of genital warts in pregnancy, and to identify additional cofactors such as the method of delivery (cesarean versus vaginal) and procedures or complications during pregnancy. METHODS: A retrospective cohort design was used to evaluate maternal and infant characteristics associated with respiratory papillomatosis among Danish births between 1974 and 1993. Using data from Danish registries, we identified 3033 births with a maternal history of genital warts during pregnancy. Fifty-seven respiratory papillomatosis cases were identified by review of medical records from ear, nose, and throat departments. RESULTS: Seven of every 1000 births with a maternal history of genital warts resulted in disease in the offspring, corresponding to a 231.4 (95% confidence interval 135.3, 395.9) times higher risk of disease relative to births without a maternal history of genital warts. In women with genital warts, delivery times of more than 10 hours were associated with a two-fold greater risk of disease. Cesarean delivery was not found to be protective against respiratory papillomatosis, and no other procedures or complications during pregnancy were observed to increase the risk of respiratory papillomatosis. CONCLUSION: A maternal history of genital warts in pregnancy is the strongest risk factor for respiratory papillomatosis in the child. Future studies should examine the efficacy of genital wart treatment for the prevention of disease.     

Extracting material parameters from x-ray attenuation: a CT feasibility study using kilovoltage synchrotron x-rays incident upon low atomic number absorbers

The work reported here is a feasibility study of the extraction of material parameters from measurements of the linear x-ray attenuation coefficient of low atomic number absorbers. Computed tomography (CT) scans of small samples containing several liquids and solids were carried out with synchrotron radiation at the Australian National Beamline Facility (BL 20B) in Japan. Average values of the x-ray linear attenuation coefficient were extracted for each material for x-ray energies ranging from 11 keV to 20.5 keV. The electron density was estimated by applying results derived from a parametrization of the x-ray linear attenuation coefficient first developed by Jackson and Hawkes and extended for this work. Average estimates for the electron density of triethanolamine and acetic acid were made to within +5.3% of the actual value. Other materials examined included furfuraldehyde, perspex and teflon, for which average estimates of the electron density were less than 10% in excess of the calculated value.     

The International Endogene Study: a collection of families for genetic research in endometriosis

OBJECTIVE: The aim of the International Endogene Study is to discover genes that influence susceptibility to endometriosis. DESIGN: The study brings together two research groups based in Australia and the United Kingdom that independently have been collecting families for linkage analysis and candidate gene studies. Both groups used similar methods to recruit families, obtain clinical notes, assign disease status based on the operative records and available histology, and collect common clinical data including age at onset of symptoms, age at diagnosis, and symptoms experienced. SETTING: Recruitment has been mainly from Australia, the United Kingdom, and the United States. PATIENT(S): All affected participants have surgically confirmed disease. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Clinical and epidemiological data.RESULT(S): To date, >1,100 families with affected sisters have been recruited, and >1,200 triads (affected women and both parents), for case-control studies.CONCLUSION(S): We have created the largest resource yet assembled of clinical data and DNA for linkage and association studies in endometriosis. The increase in power to detect susceptibility genes vindicates the decision to merge the two studies and demonstrates the value of large-scale international collaboration.     

A heterozygote phenotype is present in the jvs +/- mutant mouse livers

The juvenile visceral steatosis (jvs) mouse, having a mutation in the carnitine transporter gene Octn2, is a model of primary systemic carnitine deficiency in humans (SCD, OMIM 212140). Like humans with SCD, homozygous jvs -/- mice have hepatic and cardiac steatoses, reduced plasma and tissue carnitines, and increased urinary carnitine clearance. Because symptomatic heterozygotes have been reported for some fatty acid oxidation disorders, including SCD, we compared the jvs heterozygotes to normal control mice. We measured the free and esterified carnitine, total cholesterol, and triglycerides in adult liver samples, myocardium, and skeletal muscle. Our results indicate significant differences between the livers of nonfasting adult normal (n = 8) vs jvs heterozygotes (n = 8) (means +/- SEM, p < 0.01) for the following parameters: free carnitine, 2.28 +/- 0.36 nmol/mg protein vs 0.41 +/- 0.13; total carnitine, 3.48 +/- 0.36 vs 1.27 +/- 0.25; triglycerides, 0.14 +/- 0.04 vs 0.39 +/- 0.02; and total cholesterol, 0.21 +/- 0.02 vs 0.39 +/- 0.04, but not for esterified carnitine, 1.18 +/- 0.17 vs 0.90 +/- 0.17 (p > 0.05). There is also a negative correlation between hepatic free carnitine and triglycerides from jvs heterozygotes (p < 0.05). Similar results were obtained with myocardium and skeletal muscle. We conclude that free and total carnitine levels are significantly lower in the heterozygote mouse liver and heart while triglyceride and total cholesterol levels are significantly higher. We speculate that in situations of lipolytic stress, some SCD heterozygotes might develop clinical symptoms of carnitine deficiency.     

Reproducibility of the blood lactate threshold, 4 mmol·l<Superscript>–1</Superscript> marker,heart rate and ratings of perceived exertion during incremental treadmill exercise in humans

The aim of this study was to investigate the reproducibility of blood lactate measurements, heart rate (HR) and ratings of perceived exertion (RPE) during treadmill exercise at speeds corresponding to the lactate threshold (v _Th,la-) and a fixed blood lactate concentration of 4 mmol·l^–1(v _la-_,4). Possible differences in reproducibility related to fitness levels were also investigated. A group of 20 men [mean (SD)] [age 20.5 (1.4) years] and 16 women [age 21.2 (0.9) years] took part in the study. The subjects performed two identical incremental exercise tests consisting of at least six 4 min stages. Blood lactate concentrations, HR and RPE were recorded at the end of each stage. Limits of agreement (LoA), correlation coefficients and 95% confidence intervals for the mean difference between tests were employed to investigate the level of agreement and reproducibility of blood lactate concentration, HR and RPE. For the group as a whole, the sample correlation coefficient for speed at v _Th,la- was r=0.88, and was r=0.92 for the speed at v _la-_,4. At v _Th,la -, the correlation coefficients for the moderately fit and unfit were r=0.94 and r=0.36, respectively, and at v _la-_,4 r=0.93 and r=0.68, respectively. The LoA for the moderately fit group indicated that a change of 1.62 km·h^–1 in v _Th,la- would be necessary to be considered a change in training status. For HR and RPE, relationships between the tests were generally poor. The LoA suggested that changes in scores must be unacceptably large. These findings cast doubt on the sensitivity of testing for change of blood lactate concentration, HR and RPE in this population. Electronic Publication