Pre- and perinatal risk factors for childhood leukaemia and other malignancies: a Scottish case control study.

A case control study of Scottish children aimed to identify risk factors for leukaemia and other cancers operating in the prenatal environment, during delivery and neonatally. Cases (0-14 years) were age-and sex- matched to two population-based controls and details abstracted from the mother's hospital obstetric notes. Analyses of 144 leukaemias (124 acute lymphoblastic leukaemias (ALL)), 45 lymphomas, 75 central nervous system (CNS) tumours and 126 'other solid tumours' were conducted using conditional logistic regression. The presence of a neonatal infection significantly reduced the risk of ALL (odds ratio (OR) 0.49, 95% confidence interval (CI) 0.26-0.95), particularly in 0- to 4-year-olds. Positive swab tests confirmed 47% of ALL cases with any infection and 46% of controls. This is consistent with the hypothesis that early exposure to infections may reduce the risk of childhood ALL. Asphyxia at birth significantly increased the risk of leukaemia, which was accounted for by ALL. For the 'other solid tumours' higher levels of maternal education were inversely associated with risk (OR 0.59, 95% CI 0.37-0.94) but positively associated with antibiotics (OR 2.16 95% CI 1.10-4.25) and respiratory tract infections (OR 14.1, 95% CI 1.76-113.7) in pregnancy. No obvious plausible patterns of risk were detected either within or across disease subgroups.

A simplified vertical reduction mammaplasty: shortening the learning curve.

Although the vertical reduction mammaplasty is effective in reducing scarring, the technique has not achieved widespread acceptance in North America. There are several reasons for this. Some believe that the vertical reduction mammaplasty is only applicable to smaller breast reductions and that the learning curve is difficult. This article describes modifications to the standard Lejour vertical reduction mammaplasty that simplify the technique and make it more reliable and easier to perform. These modifications include using a medial (or lateral) dermoglandular pedicle, not undermining the skin, using liposuction only rarely to reduce breast volume, and not using pectoralis fascia sutures; the modified technique has been used in a series of 400 vertical breast reductions. In this series, scarring was reduced and the technique was easily learned and applied. It is useful for both small and large breast reductions, with a series average of 525 g removed per breast (range, 100 to 1425 g). By using these modifications, scarring in reduction mammaplasty was effectively reduced while the nipple and areola were safely transposed on a medial or lateral dermoglandular pedicle. Incorporating these technical modifications in a vertical reduction mammaplasty is recommended as a method of improving results and limiting complications.

Case-control study of childhood leukaemia and cancer in Scotland: findings for neonatal intramuscular vitamin K.

OBJECTIVE: To test the hypothesis of an association between neonatal intramuscular vitamin K and childhood leukaemia and other cancers. DESIGN: Population based case-control study with data abstracted from hospital records. SETTING: Scotland. SUBJECTS: Children aged 0-14 years resident in Scotland from 1991-4 and diagnosed with leukaemia (150), lymphomas (46), central nervous system tumours (79), a range of other solid tumours (142), and a subset of acute lymphoblastic leukaemia (129). Controls were 777 children matched for age and sex, providing 417 matched sets (360 triplets and 57 pairs) for analysis. MAIN OUTCOME MEASURE: Odds ratios for the risk of childhood leukaemia and cancer and intramuscular vitamin K versus a combined group of oral doses, none, and no record. Results are given for information recorded in medical notes and data supplemented by hospital policy. RESULTS: Odds ratios based on medical record abstractions showed no significant positive association for leukaemias (odds ratio 1.30; 95% confidence interval 0.83 to 2.03), acute lymphoblastic leukaemia (1.21; 0.74 to 1.97), lymphomas (1.06; 0.46 to 2.42), central nervous system tumours (0.74; 0.40 to 1.34), and other solid tumours (0.59; 0.37 to 0.96). There was no association with acute lymphoblastic leukaemia in children aged 1 to 6 years. Imputation of exposure from hospital policy gave similar results. Adjustment for deprivation and type of delivery moved risk estimates closer to unity for all major diagnostic groups. CONCLUSIONS: The observation of an increased risk of childhood leukaemia and cancer associated with intramuscular vitamin K is not confirmed by this independent population based study.

The chief scientist reports ... The Scottish case control study of childhood leukaemia and cancer: methodology and environmental measures of exposure.

This major case control study of childhood leukaemia and other cancers aims to identify risk factors and test prior aetiological hypotheses related to exposure to ionising radiation, chemicals, electromagnetic fields and patterns of infections in early life. This paper describes the comprehensive study methodology and demonstrates the efficacy of collecting traditional epidemiological data in conjunction with direct measures of exposure. The data collection phase is incomplete but the preliminary descriptive results indicate that an optimal sample of children will be included in the analyses. This complete and representative data set will provide a unique opportunity for investigating the causes of malignant disease in Scottish children, with the additional weight of exposure measures to complement the body of interview and medically abstracted information.

Phase behavior of synthetic phosphatidylglycerols and binary mixtures with phosphatidylcholines in the presence and absence of calcium ions.

Using differential thermal analysis, scanning calorimetry and light scattering, transition temperatures and enthalpy data for the gel to liquid crystalline phase transitions of five synthetic phosphatidylglycerol sodium salts (PG-Na+) were measured. The values obtained were almost identical with literature values for the corresponding phosphatidylcholines (PC). However, transition temperatures for the fully protonated forms of the saturated phosphatidylglycerols (PG-H+) were approximately 20 degrees C higher. For binary mixtures of PG-Na+ and PC in which the acyl chains of the two species were identical, the width of the thermal transition for the phase change was not appreciably greater than that observed with either of the two components alone. In contrast, mixing of PG-Na+ and PC with different chain lengths increases the transition width. In the presence of Ca2+, narrow transitions were also observed with mixtures of PG and PC when the chain length of the PG-Ca2+ was equal to or two carbons shorter than the PC but the transition width was clearly increased when the chain length of the PG-Ca2+ was two carbons longer than the PC. Mixing lipids with greater differences in chain length or mixing saturated lipids with unsaturated lipids in the presence of Ca2+ produced two minima in the thermograms, clearly indicative of phase separation. In sum, these results provide evidence for a high degree of miscibility of the phosphoglycerol and phosphocholine head groups, either in the presence or absence of Ca2+, such that the characteristic phase behavior of each mixture is determined primarily by differences in the hydrocarbon chain structure.