Gastrointestinal manifestations of postnatal cytomegalovirus infection in infants admitted to a neonatal intensive care unit over a five year period

Sixteen cases of postnatal cytomegalovirus (CMV) infection were identified in a neonatal intensive care unit population over a five year period. Eleven of these infants had gastrointestinal signs at the time of presentation. These ranged from minor and transient (abdominal distension and enteral feed intolerance) to severe and life threatening (protein losing enteropathy, diarrhoea, and hypernatraemic dehydration). An initial diagnosis of necrotising enterocolitis was common, but no infant showed intestinal or hepatic portal pneumatosis. The gestational age of the infants was 24-38 weeks. All had received fresh maternal breast milk. It is suggested that CMV enteritis is added to the spectrum of clinical manifestations of postnatal CMV infection. Signs suggestive of necrotising enterocolitis with atypical features should prompt investigations for CMV infection.

Changing epidemiology of neonatal septic arthritis

PURPOSE

To study the changing epidemiological pattern of micro-organisms as an aetiology of septic arthritis, and to correlate the pattern with the outcome of neonatal septic arthritis, in terms of joint function and morphology.

METHODS

15 consecutive cases of neonatal septic arthritis of hip admitted between 1999 and 2002 were studied. Diagnosis of septic arthritis was made on the basis of Morrey's criteria. All patients were treated by arthrotomy after aspiration of purulent fluid from the joint. Patients were followed up for a mean period of 2.4 years. Clinical and radiological examinations were performed at follow-up.

RESULTS

The mean age of the 15 patients was 20.35 days. 13 (87%) patients had primary septic arthritis, while only 2 (13%) had associated osteomyelitis. Culture reports revealed that the spectrum consisted of 33% gram-negative organisms, 7% fungal, and only 20% gram-positive organisms-Staphylococcus aureus in 3 patients, Klebsiella in 2 patients, one each of Proteus, Candida, Escherichia coli, and Enterobactor. Six patients were pus-cell positive with negative culture. No organism was found in 6 (40%) cases. Investigations showed leukocytosis, raised C-reactive protein and erythrocyte sedimentation rate in all 15 patients. 12 patients had normal clinical and radiological parameters at follow-up. Three patients had delayed surgical drainage of more than 72 hours due to late presentation, and showed various radiological sequelae with terminal restriction of joint movements.

CONCLUSION

There are more cases of primary septic arthritis than secondary septic arthritis. Clinicians should be alert of the aetiology shift to gram-negative organisms, in addition to fungal and gram-positive ones. Arthrotomy to drain pus from the joint should not be delayed. Better long-term results can be achieved by early surgical drainage and immediate antibiotic coverage.

Management of fluid balance in the very immature neonate

Preterm birth requires rapid adaptation from a liquid to a gaseous, low humidity environment. There are several ways in which this can be facilitated. The management of sodium and water balance is considered here.

Haemopoietic growth factors for neonates: assessing risks and benefits

This review summarises the rationale, clinical trial evidence for benefit and potential toxicities of Erythropoietin, Thrombopoietin, Granulocyte Colony Stimulating Factor and Granulocyte-Macrophage Colony Stimulating Factor. Erythropoietin has failed to have a clinical impact on red cell transfusion requirement in very low birth weight infants; it is uncertain whether Thrombopoietin will find a significant clinical role in neonatal thrombocytopenia and there is, as yet, insufficient evidence for the routine use of Granulocyte- or Granulocyte-Macrophage Colony Stimulating Factor to prevent or treat bacterial infection. A number of theoretical risks of haemopoietic growth factor use in neonates have been suggested, but no toxicities have been observed during their clinical use. Exploring the potential for benefit in selected groups of infants should be encouraged.

Fast and reproducible method for the direct quantitation of adipose tissue in newborn infants

The role of body fat content and distribution in infants is becoming an area of increasing interest, especially as perception of its function appears to be rapidly evolving. Although a number of methods are available to estimate body fat content in adults, many are of limited use in infants, especially in the context of regional distribution and internal depots. In this study we developed and implemented a whole-body magnetic resonance imaging (MRI)-based protocol that allows fast and reproducible measurements of adipose tissue content in newborn infants, with an intra-observer variability of <2.4% and an inter-observed variability of <7%. The percentage total body fat for this cohort of infants ranged from 13.3-22.6% (mean and standard deviation: 16.6 +/- 2.9%), which agrees closely with published data. Subcutaneous fat accounted for just over 89% of the total body fat, whereas internal fat corresponded to almost 11%, most of which was nonabdominal fat. There were no gender differences in total or regional body fat content. These results show that whole-body MRI can be readily applied to the study of adipose tissue content and distribution in newborn infants. Furthermore, its noninvasive nature makes it an ideal method for longitudinal and interventional studies in newborn infants.

The effects of repeated antenatal glucocorticoid therapy on the developing brain

Antenatal glucocorticoid (GC) therapy improves infant outcome following preterm birth. As approximately 50% of women given a first course of antenatal GCs remain undelivered 7-14 d later, many clinicians administer further courses. GCs are known to be neurotoxic and there is concern that exposure during early development may have adverse effects on the immature brain. The aim of this investigation was to compare magnetic resonance (MR) indices of brain maturation in infants exposed to repeated antenatal GC therapy and born at or close to term, with non-GC exposed control infants. MR images were obtained during quiet sleep without sedation. T1 weighted volume images were obtained in the sagittal plane and T1, T2 weighted spin echo and inversion recovery images in the transverse plane. Brain volume and surface area were calculated from segmented image slices, and a measure of the complexity of cortical folding, the whole cortex convolution index (WCCI), from computerized analysis of a vector coded contour following algorithm. Analysis of covariance was used to compare the two groups after allowing for the effect of postmenstrual age. There were 10 infants in the GC group (range of antenatal GC exposure, 3-11 courses) and 6 controls. Each GC course comprised two 12-mg IM doses of betamethasone 24 h apart. GC exposed infants had a significantly lower WCCI (p = 0.001) and smaller surface area (p = 0.02), after allowing for postmenstrual age. There was no significant difference in brain volume (p = 0.5). Repeated antenatal GC exposure results in measurable differences in brain maturation when compared with gestational age matched non-GC exposed controls. The clinical relevance of these observations is not known.

Evidence for antibiotic induced Clostridium perfringens diarrhoea

Clostridium difficile is a well documented cause of antibiotic associated diarrhoea in hospitalised patients, but may account for only approximately 20% of all cases. This leader reviews the current knowledge and understanding of the pathogenesis, epidemiology, and diagnosis of non-food borne Clostridium perfringens diarrhoea. Although enterotoxigenic C perfringens has been implicated in some C difficile negative cases of antibiotic associated diarrhoea, C perfringens enterotoxin detection methods are not part of the routine laboratory investigation of such cases. Testing for C perfringens enterotoxin in faecal samples from patients with antibiotic associated diarrhoea and sporadic diarrhoea on a routine basis would have considerable resource implications. Therefore, criteria for initiating investigations and optimum laboratory tests need to be established. In addition, establishing the true burden of C perfringens antibiotic associated diarrhoea is important before optimum control and treatment measures can be defined.

The current practices, training and concerns of a group of hospital-based speech therapists working in the area of dysphagia

The aim of the study was to investigate the current practices, training, and concerns of a group of hospital-based speech therapists regarding the area of dysphagia practice. Questionnaires were posted to 75 speech therapists working in the major hospitals around Gauteng, Kwa-Zulu Natal and the Cape Province and responses were obtained from 50 therapists within the stipulated time. Closed-ended questions were analysed quantitatively using descriptive statistics, while open-ended items were subjected to content analysis of themes articulated by respondents. Results indicated that the overwhelming majority of the respondents were involved in assessing and treating dysphagia patients. Specific problems faced by respondents included limited staff to share their workloads, large caseloads, restricted access to supervision/mentor systems and poor knowledge by other health personnel of their role in dysphagia. Almost half of the respondents also reported that they were involved in student training which included the area of dysphagia. Investigation of respondents' undergraduate and postgraduate training in dysphagia suggested that there were gaps in the theoretical content of these courses as well as a limited focus on practical training. Another finding was that respondents showed an awareness of the specific roles of the speech therapist in dysphagia intervention as well as the roles of the professionals constituting a multidisciplinary dysphagia team. Most of the respondents reported that they had access to dysphagia team members as well as to diet modification services. However, many of the respondents showed decreased knowledge of and awareness regarding accessibility of diagnostic procedures and suctioning methods used in dysphagia. The majority of the respondents rated their knowledge about specific theoretical areas as well as their counselling abilities to be better than their actual skills and confidence in assessing and treating dysphagia patients. Implications of the study included the need for clinicians, universities and professional organizations to work together to improve the existing situation.

Randomised controlled trial of postnatal sodium supplementation in infants of 25-30 weeks gestational age: effects on cardiopulmonary adaptation

BACKGROUND

It has previously been shown that, in preterm babies, routine sodium supplementation from 24 hours after birth is associated with increased risk of oxygen dependency and persistent expansion of the extracellular compartment.

OBJECTIVE

To explore whether this is mediated by a delayed fall in pulmonary artery pressure (PAP). Postnatal changes in PAP, estimated as the ratio of time to peak velocity to right ventricular ejection time, corrected for heart rate (TPV:RVET(c)), were compared in preterm infants who received routine sodium supplements that were either early or delayed.

METHODS

Infants were randomised, stratified according to sex and gestation, to receive a sodium intake of 4 mmol/kg/day starting either from 24 hours after birth or when a weight loss of 6% of birth weight was achieved. Echocardiographic assessment was made on the day of delivery (day 0), and on days 1, 2, 7, and 14. Babies with congenital heart disease were excluded.

RESULTS

There was no difference between the two groups in TPV:RVET(c) measured sequentially after birth. On within group testing, when compared with values at birth, the ratio was higher by day 3 in the early supplemented group, suggesting a more rapid fall in PAP compared with the late supplemented group, in whom a significant fall did not occur until day 14.

CONCLUSIONS

The timing of sodium supplementation after preterm birth does not appear to affect the rate of fall in PAP as measured by the TPV:RVET(c) ratio. The previous observation linking routine sodium supplementation from 24 hours after birth with increased risk of continuing oxygen requirement therefore does not appear to be mediated by a delayed fall in PAP. Instead, the increased risk of continuing oxygen requirement is likely to be a direct consequence of persistent expansion of the extracellular compartment and increased pulmonary interstitial fluid, resulting from a sodium intake that exceeded sodium excretory capacity. This adds further weight to the view that clinical management, in this case the timing of routine sodium supplementation, should be individually tailored and delayed until the onset of postnatal extracellular volume contraction, marked clinically by weight loss.

Pharmacokinetics of a transdermal testosterone system in men with end stage renal disease receiving maintenance hemodialysis and healthy hypogonadal men

Androgen deficiency is common in men with end stage renal disease (ESRD) on maintenance hemodialysis. Pharmacokinetics of transdermal testosterone in men receiving maintenance hemodialysis have not been studied. Our objective was to compare the pharmacokinetics of a transdermal testosterone system in healthy hypogonadal men and in men with ESRD on maintenance hemodialysis. We recruited 10 healthy hypogonadal men and 8 medically stable men on maintenance hemodialysis, 18--70 yr old, who had serum testosterone less than 300 ng/dL. After baseline sampling during a 24-h control period, two testosterone patches were applied daily for 28 days, to achieve a nominal delivery of 10-mg testosterone daily. In addition to single, pooled samples on days 7, 14, and 21, blood was drawn at 0, 2, 4, 6, 8, and 24 h on day 28 in healthy hypogonadal men and on an interdialytic day (day 21 or 28) as well as a dialysis day (day 21 or 28) in men on hemodialysis. On the dialysis day (day 21 or 28), serum free and total testosterone levels were measured hourly for 4 h before hemodialysis and for 4 h during hemodialysis. The dialysate was sampled for testosterone measurement. Baseline mean + SD total (92 +/- 82 vs. 222 +/- 50 ng/dL) and free (11 +/- 9 vs. 27 +/- 6 pg/mL) testosterone concentrations were lower in healthy hypogonadal men than in men with ESRD. After application of two testosterone patches, serum total and free testosterone concentrations rose into the midnormal range in both groups of men. Time-average, steady state (total testosterone, 506 +/- 88 vs. 516 +/- 86 ng/dL; free testosterone, 55 +/- 9 vs. 67 +/- 11 pg/mL), minimum, and maximum total and free testosterone concentrations were not significantly different between the two groups of men during treatment. Increments in total and free testosterone concentrations above baseline, baseline-subtracted areas under the total and free testosterone curves, and half-life of testosterone elimination (t(1/2), 2.1 +/- 0.1 vs. 2.1 +/- 0.2 h, P = not significant) were not significantly different between the two groups. In men receiving hemodialysis, time-average, steady state, and maximal total and free testosterone concentrations and baseline-subtracted areas under the total and free testosterone curves were higher on dialysis day than on an interdialytic day. On the day of hemodialysis, time-average total and free testosterone concentrations were not significantly different during the 4 h before or during hemodialysis. The amount of testosterone removed in the dialysate (8.4 +/- 1.6 microg during 4 h of hemodialysis) was small compared with the daily testosterone production rates in healthy young men. Serum dihydrotestosterone and estradiol concentrations increased into the normal male range and were not significantly different between the two groups. Percent suppression of LH was greater in men with ESRD than in healthy hypogonadal men. A regimen of two Testoderm TTS testosterone patches (Alza Corp., Mountain View, CA) daily can maintain serum concentrations of total and free testosterone and its metabolites dihydrotestosterone and estradiol in the midnormal range in healthy hypogonadal men and men on hemodialysis. The amount of testosterone cleared by hemodialysis is small, and hemodialysis does not significantly affect serum total and free testosterone concentrations in men treated with the testosterone patch.

Transcutaneous bilirubin measurement: a multicenter evaluation of a new device

OBJECTIVES

The early discharge of neonates from hospitals makes transcutaneous measurement of total bilirubin concentration a useful tool to monitor neonatal jaundice. The objectives of this study were to determine whether 1) transcutaneous bilirubin (TcB) measurement, as performed using BiliCheck (BC), correlates with total serum bilirubin (TSB) levels, measured with standard laboratory methods and with high-pressure liquid chromatography (HPLC-B); 2) infant race, gestational age, postnatal age, or body weight interferes with the measurement of TcB levels in newborn infants; 3) the variability of the TcB measurement is comparable to the variability of TSB measurements; and 4) TcB measurements obtained from the forehead (BCF) and sternum (BCS) generate comparable results.

STUDY DESIGN

Newborn infants who were <28 days and >30 weeks' gestational age and who underwent tests for TSB as part of their normal care in 6 different European hospitals were studied. A total of 210 infants were enrolled in the study, 35 at each site. Near simultaneous (within +/- 30 minutes) blood collection for TSB and BCF and BCS measurements were performed. TSB levels were determined by the serum bilirubin method in use at each site, and all HPLC-B determinations were made at the same, independent laboratory.

RESULTS

The study group consisted of 140 white, 31 Asian, 14 Hispanic, 9 African, and another 16 newborns of different races. The correlation coefficient (r) between BCF and HPLC-B was 0.890 (95% confidence interval = 0.858-0.915). BCF and BCS generated similar results (r value = 0.890 for BCF and 0.881 for BCS), even if BCS slightly overestimated (mean error = -0.04 mg/dL) and BCF slightly underestimated (mean error = 0.96 mg/dL) in comparison with HPLC-B. Analysis of covariance demonstrated that BC accuracy was independent of race, birth weight, gestational age, and postnatal age of the newborn. Receiver operating characteristic curves were evaluated for BCF and TSB, each compared with HPLC-B. With the use of a cutoff point for HPLC-B of 13 mg/dL (222 micromol/L) and a cutoff of 11 mg/dL on the BCF and TSB, similar sensitivity/specificity (93%/73% for BCF, 95%/76% for TSB) were observed. The use of a cutoff point for HPLC-B of 17 mg/dL (290 micromol/L) and 14 mg/dL (240 micromol/L) for BCF and TSB also produced similar sensitivity/specificity (90%/87% for the BC and 87%/83% for TSB).

CONCLUSIONS

Because the correlation coefficient for HPLC-B and BCF is very similar to that found for HPLC-B and laboratory TSB, BC could be used not only as a screening device but also as a reliable substitute of TSB determination. At higher levels of TSB, in which phototherapy and/or exchange transfusion might be considered, BC performed slightly better than the laboratory. The accuracy and precision of the TcB measurement in this study was observed to be comparable to the standard of care laboratory test.

Infant massage improves mother-infant interaction for mothers with postnatal depression

BACKGROUND

Postnatal depression can have long term adverse consequences for the mother-infant relationship and the infant's development. Improving a mother's depression per se has been found to have little impact on mother-infant interaction. The aims of this study were to determine whether attending regular massage classes could reduce maternal depression and also improve the quality of mother-infant interaction.

METHOD

Thirty-four primiparous depressed mothers, median 9 weeks postpartum, identified as being depressed following completion of the Edinburgh Postnatal Depression Scale (EPDS) at 4 weeks postpartum, were randomly allocated either to an infant massage class and a support group (massage group) or to a support group (control group). Each group attended for five weekly sessions. Changes in maternal depression and mother-infant interaction were assessed at the beginning and the end of the study by comparing EPDS scores and ratings of videotaped mother-infant interaction.

RESULTS

The EPDS scores fell in both groups. Significant improvement of mother-infant interaction was seen only in the massage group.

LIMITATION

The sample size was small and had relatively high dropout. It was not possible to distinguish which aspects of the infant massage class contributed to the benefit.

CONCLUSION

This study suggests that learning the practice of infant massage by mothers is an effective treatment for facilitating mother-infant interaction in mothers with postnatal depression.

Postnatal weight loss and contraction of the extracellular compartment is triggered by atrial natriuretic peptide

Following birth there is a contraction in the extracellular compartment, marked clinically by natriuresis, diuresis and weight loss. It is uncertain how these postnatal phenomena, which suggest an interrelationship with cardiopulmonary adaptation, are brought about. The aim of this study was to evaluate the temporal relationship between alterations in circulating atrial natriuretic peptide (ANP), respiratory status, sodium excretion and extracellular fluid volume (ECFV) in preterm babies, in the first days after birth. Eighteen male infants below 34 weeks gestational age were studied longitudinally, measuring urine output, sodium balance, arterial-alveolar oxygen ratio and circulating ANP. Daily changes in ECFV were assessed by endogenous chloride balance, following baseline measurement of bromide space. There was a clear period of improvement in respiratory function in 15 babies and in these there was a highly significant elevation in circulating ANP, either immediately prior to, or during, the period of improvement. In three infants there was no definable period of respiratory improvement. In four babies, two of whom had very mild respiratory distress, there was an immediate decline in ECFV after birth, in contrast to the remaining 14 infants, in whom there was an initial increase. This study demonstrates that there is a temporal relationship between improvement in respiratory function and an acute elevation in circulating ANP. Babies with respiratory distress syndrome are at risk of initial expansion of the extracellular compartment after birth. This is likely to increase morbidity. These observations are of relevance with regard to the clinical management of newborns with respiratory distress syndrome.

7H-benzo[c]fluorene: a major DNA adduct-forming component of coal tar

Coal tar is a complex mixture that exhibits high carcinogenic potency in lungs of animals when administered in the diet. Studies have noted that lung tumor induction does not correlate with the benzo[a]pyrene content of coal tar, suggesting that other hydrocarbons may be involved in the observed tumorigenicity. Our previous studies have demonstrated that a major 'unknown' chemical-DNA adduct is formed in the lung of mice exposed to coal tar. We have used an in vitro rat microsomal activation system to generate the 'unknown' adduct with neat coal tar and fractions of coal tar obtained by chemical fractionation and HPLC. Chemical-DNA adduct formation was evaluated by (32)P-postlabeling using both multi-dimensional TLC and HPLC. GC-MS analysis of the coal tar fractions obtained from HPLC, which produced the 'unknown' adduct in vitro, demonstrated that the adducting hydrocarbon had a mass of 216. A careful evaluation of candidate hydrocarbons led to the conclusion that a benzofluorene derivative may be responsible for forming the 'unknown' chemical-DNA adduct. Comparative in vitro and in vivo studies on the adducting properties of all three isomers of benzofluorene indicated that 7H-benzo[c]fluorene is responsible for producing the 'unknown' adduct observed in the lung of mice ingesting coal tar. Animal feeding studies also demonstrated that 7H-benzo[c]fluorene formed considerably more lung DNA adducts than 11H-benzo[a]fluorene and 11H-benzo[b]fluorene. These data indicate that the four-ring polycyclic aromatic hydrocarbon 7H-benzo[c]fluorene, a hydrocarbon not previously shown to form DNA adducts in lung, is in fact a potent lung DNA adductor and is a candidate PAH for causing lung tumors in animals treated with coal tar.

Body water content of extremely preterm infants at birth

BACKGROUND

Preterm birth is often associated with impaired growth. Small for gestational age status confers additional risk.

AIM

To determine the body water content of appropriately grown (AGA) and small for gestational age (SGA) preterm infants in order to provide a baseline for longitudinal studies of growth after preterm birth.

METHODS

All infants born at the Hammersmith and Queen Charlotte's Hospitals between 25 and 30 weeks gestational age were eligible for entry into the study. Informed parental consent was obtained as soon after delivery as possible, after which the extracellular fluid content was determined by bromide dilution and total body water by H(2)(18)O dilution.

RESULTS

Forty two preterm infants were studied. SGA infants had a significantly higher body water content than AGA infants (906 (833-954) and 844 (637-958) ml/kg respectively; median (range); p = 0.019). There were no differences in extracellular and intracellular fluid volumes, nor in the ratio of extracellular to intracellular fluid. Estimates of relative adiposity suggest a body fat content of about 7% in AGA infants, assuming negligible fat content in SGA infants and lean body tissue hydration to be equivalent in the two groups.

CONCLUSIONS

Novel values for the body water composition of the SGA preterm infant at 25-30 weeks gestation are presented. The data do not support the view that SGA infants have extracellular dehydration, nor is their regulation of body water impaired.

Randomised controlled trial of postnatal sodium supplementation on oxygen dependency and body weight in 25-30 week gestational age infants

AIM

To compare the effects of early against delayed sodium supplementation on oxygen dependency and body weight, in preterm infants of 25-30 weeks of gestational age.

METHODS

Infants were stratified by gender and gestation and randomly assigned to receive a sodium intake of 4 mmol/kg/day starting on either the second day after birth or when weight loss of 6% of birthweight was achieved. Daily sodium intake, serum sodium concentration, total fluid intake, energy intake, clinical risk index for babies (CRIB) score and duration of ventilatory support and additional oxygen therapy were recorded. Infants were weighed daily. Weights at 36 weeks and six months of postmenstrual age were also recorded.

RESULTS

Twenty four infants received early, and 22 delayed, sodium supplementation. There were no significant differences in total fluid and energy intake between the two groups. There was a significant difference in oxygen requirement at the end of the first week, with 9% of the early group in air in contrast to 35% of the delayed group (difference 26%, 95% confidence interval 2, 50). At 28 days after birth the proportions were 18% of the early group and 40% of the delayed group (difference 22%, 95% CI -5, 49). Proportional hazards modelling showed early sodium supplementation and lower birthweight to be significantly associated with increased risk of continuing oxygen requirement. The delayed sodium group had a greater maximum weight loss (delayed 16.1%; early 11.4%, p=0.02), but there were no significant differences in time to maximum weight loss, time to regain birthweight, and weight at 36 weeks and 6 months of postmenstrual age.

CONCLUSION

In infants below 30 weeks of gestation, delaying sodium supplementation until at least 6% of birthweight is lost has a beneficial effect on the risk of continuing oxygen requirement and does not compromise growth.

Randomised controlled trial of postnatal sodium supplementation on body composition in 25 to 30 week gestational age infants

AIMS

To compare the effects of early and delayed sodium supplementation on body composition and body water compartments during the first two weeks of postnatal life.

METHODS

Preterm infants of 25-30 weeks' gestation were stratified and randomly assigned according to gender and gestational age, to receive a sodium intake of 4 mmol/kg/day beginning either on the second day after birth or when weight loss of 6% of birthweight had been achieved. Daily sodium intake, total fluid intake, energy intake, urine volume, and urinary sodium excretion were recorded. Total body water was measured by H(2)(18)O dilution on days 1, 7, and 14, and extracellular fluid volume by sodium bromide dilution on days 1 and 14.

RESULTS

Twenty four infants received early, and 22 delayed, sodium supplementation. There were no significant differences between the groups in body water compartments on day 1. In the delayed group, but not the early group, there was a significant loss of total body water during the first week (delayed -44 ml/kg, p=0. 048; early 6 ml/kg, p=0.970). By day 14 the delayed, but not the early group, also had a significant reduction in extracellular fluid volume (delayed -53 ml/kg, p=0.01; early -37 ml/kg, p=0.2). These changes resulted in a significant alteration in body composition at the end of the first week (total body weight: delayed 791 ml/kg; early 849 ml/kg, p=0.013). By day 14 there were once again no significant differences in body composition between the two groups.

CONCLUSIONS

Body composition after preterm birth is influenced by the timing of introduction of routine sodium supplements. Early sodium supplementation can delay the physiological loss of body water that is part of normal postnatal adaptation. This is likely to be of particular relevance to babies with respiratory distress syndrome. A tailored approach to clinical management, delaying the introduction of routine sodium supplements until there has been postnatal loss of body water, is recommended.

Engineering Chinese hamster ovary cells to maximize sialic acid content of recombinant glycoproteins

We have engineered two Chinese hamster ovary cell lines secreting different recombinant glycoproteins to express high levels of human beta1,4-galactosyltransferase (GT, E.C. 2.4.1.38) and/or alpha2, 3-sialyltransferase (ST, E.C. 2.4.99.6). N-linked oligosaccharide structures synthesized by cells overexpressing the glycosyltransferases showed greater homogeneity compared with control cell lines. When GT was overexpressed, oligosaccharides terminating with GlcNAc were significantly reduced compared with controls, whereas overexpression of ST resulted in sialylation of >/=90% of available branches. As expected, GT overexpression resulted in reduction of oligosaccharides terminating with GlcNAc, whereas overexpression of ST resulted in sialylation of >/=90% of available branches. The more highly sialylated glycoproteins had a significantly longer mean residence time in a rabbit model of pharmacokinetics. These experiments demonstrate the feasibility of genetically engineering cell lines to produce therapeutics with desired glycosylation patterns.

A randomized, controlled trial of prophylactic granulocyte-macrophage colony-stimulating factor in human newborns less than 32 weeks gestation

OBJECTIVE

Preterm neonates undergoing intensive care have high morbidity from sepsis. These infants also frequently develop neutropenia, and when this is associated with sepsis, mortality is high. This study investigates the potential for granulocyte-macrophage colony-stimulating factor (GM-CSF) to effect a clinically relevant increase in neutrophil number when used prophylactically in high-risk preterm neonates, and assesses its safety in this population.

DESIGN

In an open, randomized, controlled study, 75 neonates (25 small for gestational age) <32 weeks gestation were randomized to receive GM-CSF (10 microg/kg/d) by subcutaneous injection for 5 days from <72 hours after birth, or to a control group. The primary outcome measure was the neutrophil count during 14 days from study entry. The infants were monitored for potential toxicity. Clinical outcomes, sepsis, and mortality, were recorded, but this initial study was not designed to address clinical benefit.

RESULTS

Prophylactic GM-CSF therapy completely abolished neutropenia in treated infants, when both well and septic, throughout the period of study. Neutropenia (</=1.7 x 10(9)/L) developed in 16 of 39 control infants. Five control infants experienced an acute decrease in neutrophil count coincident with the onset of sepsis. There was no evidence of hematologic, respiratory, or gastrointestinal toxicity in treated infants. Treated infants had a trend to fewer symptomatic, blood culture positive septic episodes than controls during 2 weeks from study entry (11/36 vs 18/39).

CONCLUSION

Five-day prophylactic GM-CSF completely abolishes postnatal neutropenia and sepsis-induced neutropenia in preterm neonates at high risk of sepsis, and so removes an important risk factor for sepsis and sepsis-related mortality.GM-CSF, preterm neonates, neutropenia, sepsis.

In utero nephropathy, Denys-Drash syndrome and Potter phenotype

We report an unusual case of Denys-Drash syndrome presenting in a newborn infant with end-stage renal failure of antenatal origin and Potter phenotype. DNA analysis showed a novel missense change in arginine 394 of zinc finger 3 of the WT1 gene. This mutation may lead to an earlier and more severe presentation of Denys-Drash syndrome. It may be of interest to look for this mutation in other Potter phenotype cases.

Assessment of total body water using bioelectrical impedance analysis in neonates receiving intensive care

AIMS

To determine the most suitable anthropometric and impedance measures and current frequency for the application of bioelectrical impedance to neonates receiving intensive care; and to derive predictive models for the estimation of total body water.

METHODS

Twenty eight babies (median gestational age 30.5 weeks, range 24-38; median birthweight 1.388 kg, range 0.690-3.510) were each studied once during the first week after birth. Total body water was first measured by the method of dilution of isotopic water (H218O). Bioelectrical measurements were made using the tetrapolar surface electrode method from four main distal limb positions (right hand-right foot; right hand-left foot; left hand-left foot; left hand-right foot), the left upper arm-left thigh position and the left scapula-right buttock position, and using six frequencies ((500, 250, 100, 50, 10 and 5 kHz). Regression models, to predict total body water, which were both independent and dependent of body weight on the day of study, were derived.

RESULTS

Resistance readings at 50 kHz obtained from the distal limb positions performed best. There was no difference between the distal limb positions. There was no difference in the goodness of fit of the models when using each of three indices of conductor length, foot, spine and sternum. The model total body water (litres) (TBW) = 0.016 + 0.674 body-weight(kg)-0.038 wt2 + 3.84 foot length (cm)2/resistance (50 kHz in OHMS) performed best, accounting for 99.5% of the variation in TBW, with a 95% prediction interval of 165 ml. The model TBW = 0.144 + 15.518 foot length (cm)2/resistance (50 kHz in ohms) accounted for 96.4% of the variation and had a 95% prediction interval of 420 ml.

CONCLUSIONS

Bioelectrical impedance analysis is a simple, non-invasive method of estimating total body water in neonates receiving intensive care. It can be applied to both the assessment of changes in body water and body composition.

Influence of respiratory distress syndrome on body composition after preterm birth

AIM

To observe changes in body composition during the first week after birth, in preterm neonates with and without respiratory distress syndrome (RDS), so as to be able to provide optimal fluid and energy intake.

METHODS

Twenty four babies with RDS and 19 healthy preterm babies, with gestational ages ranging from 26-36 weeks, were studied daily for the first week after birth. Total body water (TBW) was measured using bioelectrical impedance analysis. The babies were weighed daily and a record made of fluid and energy intake. Body solids were calculated as the difference between body weight and TBW.

RESULTS

There was a highly significant reduction in body weight by the end of the week, with the RDS babies losing more than the healthy babies (RDS 7.6%; non-RDS 3.7%). There was no significant difference in the amount of TBW at birth in the babies with and without RDS (RDS 85.1%; non-RDS 85.5%) and both groups lost the same amount of body water (RDS 10.9%; non-RDS 9.9%) by the end of the first week. The amount of total body water lost was unrelated to the volume of fluid administered. There was a loss of body solids during the first day in the RDS group, but, overall, there was a highly significant increase in both groups between birth and day 7, which was greater in the healthy babies (RDS 13.0%; non-RDS 42.7%).

CONCLUSIONS

Loss of body water after birth occurs to the same extent in healthy preterm neonates and in babies with RDS and is unrelated to the volume of fluid administered. Given adequate nutritional support, an increase in body solids can accompany early postnatal weight loss and begins almost immediately after birth, in both healthy preterm babies and babies with RDS.

A soluble tissue factor mutant is a selective anticoagulant and antithrombotic agent

One approach to developing safer and more efficacious agents for the treatment of thrombotic disease involves the design and testing of inhibitors that block specific steps in the coagulation cascade. We describe here the development of a mutant of human tissue factor (TF) as a specific antagonist of the extrinsic pathway of blood coagulation and the testing of this mutant in a rabbit model of arterial thrombosis. Alanine substitutions of Lys residues 165 and 166 in human TF have been shown previously to diminish the cofactor function of TF in support of factor X (FX) activation catalyzed by factor VIIa (FVIIa). The K165A:K166A mutations have been incorporated into soluble TF (sTF; residues 1-219) to generate the molecule "hTFAA." hTFAA binds FVIIa with kinetics and affinity equivalent to wild-type sTF, but the hTFAA x FVIIa complex shows a 34-fold reduction in catalytic efficiency for FX activation relative to the activity measured for sTF x FVIIa. hTFAA inhibits the activation of FX catalyzed by the complex formed between FVIIa and relipidated TF(1-243). hTFAA prolongs prothrombin time (PT) determined with human plasma and relipidated TF(1-243) or membrane bound TF, and has no effect on activated partial thromboplastin time, but is 70-fold less potent as an inhibitor of PT with rabbit plasma. The rabbit homologue of this mutant ("rTFAA") was produced and shown to have greater potency with rabbit plasma. Both hTFAA and rTFAA display an antithrombotic effect in a rabbit model of arterial thrombosis with rTFAA giving full efficacy at a lower dose than hTFAA. Compared to heparin doses of equal antithrombotic potential, hTFAA and rTFAA cause less bleeding as judged by measurements of the cuticle bleeding time. These results indicate that TF x FVIIa is a good target for the development of new anticoagulant drugs for the treatment of thrombotic disease.

Continuous negative extrathoracic pressure in neonatal respiratory failure

OBJECTIVE

In uncontrolled clinical trials, negative extrathoracic pressure has been shown to be an effective respiratory support. We aimed to assess its role in the context of current neonatal intensive care.

DESIGN

A randomized controlled trial, with sequential analysis of matched pairs of infants. Matching was undertaken by stratified randomization from 15 groups divided according to gestational age, oxygen requirement, and whether patients were intubated at 4 hours of age.

SETTING

Two neonatal intensive care units.

PATIENTS

Two hundred forty-four patients (birth weight 1.53 +/- 0.69 kg (mean +/- SD); gestational age 30.4 +/- 3.5 weeks) with respiratory failure.

INTERVENTIONS

Patients were randomized at 4 hours of age to receive either standard neonatal intensive care, or standard care plus continuous negative extrathoracic pressure (CNEP, -4 to -6 cmH2O) applied within a purpose-designed neonatal incubator. OUTCOME SCORES: Clinical scores were calculated for each infant at 56 days of age, or death if earlier. Scores included measures for mortality, respiratory outcome, the presence of cerebral ultrasound abnormalities, patent arterial duct, necrotizing enterocolitis, and retinopathy. The treatment given for the higher score for each pair was recorded and the cumulative net number of pairs favoring CNEP plotted in the sequential analysis to provide an ethical early termination strategy. Individual components of the outcome score and other secondary measurements were analyzed on completion of the trial.

RESULTS

The sequential analysis reached a decision boundary after 122 out of a possible maximum of 124 pairs were completed. The overall outcome score showed an overall significant benefit for CNEP. Secondary analysis showed that the use of CNEP was associated with an increase in mortality, cranial ultrasound abnormalities, and pneumothoraces, which were not statistically significant. However, 5% fewer patients were intubated (95% confidence interval [CI], 0-10), and the total duration of oxygen therapy among surviving infants at 56 days was lower (20.5 days, compared with 38.9 in controls; difference 18.4 days, 95% CI 3.8 to 33.0). Among all infants, the mean total duration of oxygen therapy was 18.3 days among CNEP-treated infants compared with 33.6 days among the controls (difference -15.3 days, 95% CI -0.2 to -30.4). This reduction in mean levels is entirely attributable to substantially fewer patients requiring prolonged oxygen therapy, the median duration of treatment being very similar in the two groups. As a result, commensurately fewer surviving infants showed chronic lung disease of prematurity.

CONCLUSIONS

The use of continuous negative pressure improves the respiratory outcome for neonates with respiratory failure.

Reasons for admission, causes of death and costs of admission to a tertiary referral neonatal unit in India

The aim of this study was to determine the reasons for admission, charges made, and causes of death in a tertiary referral neonatal unit in India. Records of the Christian Medical College Hospital, Vellore, Tamil Nadu, India, were reviewed for the period 1 January-31 December 1992. The principal cause of death was ascertained with reference to predetermined diagnostic criteria. There were 5592 livebirths, 138 stillbirths and 1809 admissions to the nurseries (1603 inborn, 206 outborn). Suspected sepsis accounted for 24 per cent of admissions, 14 per cent required preterm care, 13 per cent phototherapy and 8 per cent were full term low birth weight babies admitted for observation. There were 87 early neonatal deaths, 4 per cent (49) of inborn admissions and 18 per cent (38) of outborn admissions. A further 11 babies were discharged to receive terminal care at home and nine were discharged, critically ill, against medical advice. Causes of death were respiratory problems of prematurity (49 per cent), lethal congenital malformations (22 per cent), complications of asphyxia (20 per cent) and sepsis (5 per cent). The median duration of nursery care was 2 days (range 1-21) and the median charge made Rs 714 (range 122-5036). Although the pattern of admissions and deaths still reflects the substantial problems of suspected sepsis, asphyxia, and congenital malformations, problems of immaturity may be on the increase. We caution against hospital-based statistics that fail to take account of babies who are discharged alive in the knowledge that death is imminent. Considered strategies for the provision or selective provision, of neonatal care in India, are called for.

Evaluation of a new cytotoxicity assay for Clostridium perfringens type D epsilon toxin

A new cytotoxicity assay for determining the activity of epsilon toxin produced by Clostridium perfringens type D has been developed. Viability of cultured cells was determined by the ability of only live cells to convert 5-(3-carboxymethoxyphenyl)-2-(4,5-dimethylthiazolyl)-3-(4- sulfophenyl)tetrazolium to the coloured product formazan in the presence of phenazine methosulfate. Of the 12 cell lines tested, only the MDCK cell line was susceptible to epsilon toxin. Specificity was confirmed by the ability of only specific monoclonal antibodies to inhibit cytotoxicity. Good correlation was obtained with the mouse lethality assay (r = 0.991) and over a wide range of viability (15-75%) as determined by ethidium bromide/acridine orange staining (r = 0.995).