Pericardial effusion complicating a percutaneous central venous line in a neonate

A premature infant developed pericardial effusion four days after the insertion of a 25-gauge silastic percutaneous central venous catheter. The effusion contained parenteral nutrition fluid and resolved rapidly after withdrawal of the catheter. Pericardial effusion is a potential complication of percutaneous, as well as surgically placed, central venous catheters.     

The STR system in the human phenylalanine hydroxylase gene: true fragment length obtained with fluorescent labelled PCR primers

We present a simple, fast, non-radioactive method for the analysis of the polymorphic short tandem repeat (STR) system in the human phenylalanine hydroxylase gene. Previously, sizing of the STR marker involved radiolabelling of PCR amplified fragments and resolution on denaturing polyacrylamide gels using M13 sequencing ladder as a standard. However, this method consistently gave sizes 2 bp longer than the known sequence. The fluorescent method presented here employs internal lane standards and enables accurate sizing of the fragments. To avoid confusion, we suggest that the true fragment lengths are used as reference values in the future. The analysis of STR alleles is valuable for population genetic studies and for targeted mutation screening in phenylketonuria (PKU). It can replace RFLP-based haplotype analysis for carrier detection, and we report its use for prenatal diagnosis in a Northern Irish family with PKU. The analysis of 250 Northern Irish chromosomes, including 128 PKU alleles, showed no significant difference between normal and PKU alleles, with fragment lengths of 238 and 242 bp most common in both groups.     

Molecular analysis of PKU in Ireland

Classical phenylketonuria (PKU: McKusick No. 261600) is caused by mutations occurring at the phenylalanine hydroxylase (PAH) locus on chromosome 12 and has a prevalence in Ireland of 1 in 4500. We examined 304 independent alleles from 350 patients for the presence of six mutations and have characterized VNTR alleles within the minisatellite region 3' to the PAH gene in patients carrying the most prevalent mutation. R408W was the most common mutation found, with a relative frequency of 42%. All other mutations had relative frequencies of <10%. VNTR analysis showed that the R408W mutation is associated with the VNTR-8 allele in the Irish population, indicating that R408W is associated with RFLP haplotype 1. This differs from that reported from eastern Europe where R408W is associated with RFLP haplotype 2/VNTR-3; an observation which has led several groups to propose a Balto-Slavic origin for this mutation. These results support the hypothesis of a second, independent founding event for the R408W mutation on an RFLP haplotype 1 VNTR-8 chromsome background in the Irish/Celtic population.     

Fructosamine and glycated haemoglobin in the assessment of long term glycaemic control in diabetes

Fructosamine and glycated haemoglobin were measured simultaneously in 147 children with diabetes. If glycated haemoglobin is considered as the 'gold standard' for long term glycaemic control, then fructosamine is a poor indicator of actual glycated haemoglobin values, with wide 95% confidence (fiducial) limits. This shows that it is impossible to accurately predict glycated haemoglobin concentrations and therefore, by implication, longer term glycaemic control, from measurements of fructosamine. As the major studies on the prevention of microvascular complications in diabetes have used glycated haemoglobin levels to assess glycaemic control, it is suggested that this measurement should be used in all children with diabetes in preference to the measurement of fructosamine.     

Is an ultrasound assessment of gestational age at the first antenatal visit of value? A randomised clinical trial

OBJECTIVES: To assess the efficacy of an ultrasound scan at the first antenatal visit. DESIGN: Randomised clinical trial. SETTING: Women's and Children's tertiary level hospital, Adelaide, Australia. POPULATION: Six hundred and forty-eight women attending for their first antenatal visit at less than 17 weeks of gestation who had no previous ultrasound scan in the pregnancy, who were expected to give birth at the hospital, and for whom there was no indication for an ultrasound at their first visit. METHODS: Eligible consenting women were enrolled by telephone randomisation into either the ultrasound at first visit group, who had an ultrasound at the time of their first antenatal visit, or the control group in whom no ultrasound assessment was done at their first antenatal visit. Both groups of women completed a questionnaire at the end of the first visit on their feelings towards the pregnancy and anxiety levels. Data were collected on details of any ultrasound assessments, including the 18 to 20 weeks morphology scan, and pregnancy outcome. All primary analyses were on an intention-to-treat basis. MAIN OUTCOME MEASURES: The number of women who needed adjustment in dates of 10 days or more on the basis of their 18 to 20 weeks ultrasound morphology scan, who were booked for their morphology scan at sub-optimal gestations, who had a repeat of their maternal serum screening test, or who felt worried about their pregnancy at the end of the first antenatal visit. RESULTS: Fewer women (9%) in the ultrasound at first visit group needed adjustment of their expected date of delivery as a result of the 18 to 20 week ultrasound, compared with 18% of women in the control group (RR 0.52, 95% CI 0.34-0.79; P = 0.002). The number of women who had the 18 to 20 week ultrasound assessment timed suboptimally was similar to that in the control group (16% vs. 21%), as was the number of women who had a repeat blood sample taken for maternal serum screening (6% vs. 6%). Fewer women in the ultrasound at first visit group reported feeling worried about their pregnancy (RR 0.80, 95% CI 0.65-0.99; P = 0.04) or not feeling relaxed about their pregnancy (RR 0.73, 95% CI 0.56-0.96; P = 0.02), compared with women in the control group. CONCLUSIONS: A routine ultrasound assessment for dating offered to women at the first antenatal visit provides more precise estimates of gestational age and reduces the need to adjust the estimate of the date of delivery in mid-gestation. Women who had an ultrasound at the first visit reported more positive feelings about their pregnancy, compared with women in the control group at that time.     

A combined ultrasonic linear array scanner and pulsed Doppler velocimeter for the estimation of blood flow in the foetus and adult abdomen--I: Technical aspects

A method is proposed for estimating the volume blood flow of deep lying vessels in the foetus and in adult portal vein and renal vessels. The equipment combines a 3.5 MHz linear array scanner with a 2 or 4 MHz pulsed Doppler. The pulsed Doppler tranducer is connected to the linear array by two movable arms. A real time spectrum analyser is used to process the Doppler signals. A water bath was used to perform an in vitro calibration of the complete system and to adjust the registration of the Doppler sample volume with the echo picture. Several possible inaccuracies in vessel diameter measurement are discussed and the mean of several caliper measurements described by Eik-Ness (1982) is used. Time Motion is thought to be the better method but is more complicated in practice.     

Prevalence of deep venous thrombosis in the lower extremities of children in the intensive care unit

Purpose. To determine the prevalence of lower extremity deep venous thrombosis (LE-DVT) in children who spent at least 72 h in the pediatric intensive care unit (ICU). Materials and methods. Children up to the age of 17 years who spent at least 72 h in the ICU underwent lower extremity venous ultrasound at the end of their stay. Prevalence range for the sample size was calculated with a confidence interval of 95%. Results. Among 76 children who spent 3–141 days in the ICU, the prevalence of acute (and silent) DVT was 4 % (confidence interval 0–9 %). All three affected children had femoral venous catheters in that leg during their ICU stay (17 unaffected children also had catheters). Conclusion. Children in an ICU setting are at significantly lower risk for thrombosis than adults in the same setting.     

Metronidazole (Flagyl): characterization as a cytotoxic drug specific for hypoxic tumour cells.

The cytocidal properties of metronidazole against hypoxic mammalian cells are described. This chemotherapeutic action has been shown to be dependent on drug concentration and duration of exposure. The x-ray TCD50 for a murine anaplastic carcinoma was reduced from 6081 rad to 4643 rad when animals were given metronidazole orally for 36 h before radiation treatment. The effect is attributed to the direct killing of hypoxic tumour cells by a mechanism analogous to that proposed for the action of the drug on anaerobic micro-organisms. It is concluded that further work with metronidazole as a cytotoxin specific for hypoxic cells is warranted, particularly in view of the reported lack of toxicity associated with the preliminary clinical use of the drug as a radiosensitizer in man.