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Exhaled nitric oxide (eNO) may represent a useful noninvasive marker of airway inflammation, but data on the reference population values in schoolchildren are limited. No reference eNO study in Asian children has been published. Levels of eNO in a sample of 531 schoolchildren aged 11–18 years recruited from five schools (three international schools) in Hong Kong were measured online by a chemiluminescence analyser according to ERS/ATS standard. Each student also completed an International Study of Asthma and Allergic disease in Childhood questionnaire. Among the children without a physician's diagnosis of asthma or symptoms of wheeze, rhinitis and eczema, there were 258 Chinese and 33 Caucasians. In control Chinese children, the eNO level (median: interquantile range) was significantly higher ( P<0.001) in males (17.0 parts per billion (p.p.b.); 10.7–36.6) than in females (10.8 p.p.b.; 7.8–17.6). When compared with Caucasian control males (11.6 p.p.b.; 8.2–19.3) and females (9.1 p.p.b.; 7.5–11.9), the Chinese children had significantly higher eNO levels for both males ( P=0.011) and females ( P=0.037). For Chinese asthmatic males, the median eNO (interquartile range) was 39.8 p.p.b. (12.5–73.8), and for asthmatic females, 18.0 (9.6–56.3). After controlling for sex in Chinese controls, eNO did not have any significant correlation with height, weight and body mass index or body surface area. This study demonstrates a gender difference of eNO level in healthy Chinese schoolchildren. When compared with Caucasians, Chinese children have significantly higher eNO levels. [ABSTRACT FROM AUTHOR]

Type 2 helper T lymphocyte-specific chemokines including macrophage-derived chemokine (MDC), thymus and activation-regulated chemokine (TARC) and eotaxin are important mediators for allergic airway inflammation. We investigated whether these chemokines can be detected in exhaled breath condensate (EBC) and their relation to childhood asthma. Asthmatics recruited from paediatric clinics of a university teaching hospital were classified into intermittent asthma (IA) and persistent asthma (PA) according to Global Initiative for Asthma guidelines. EBC was collected by a disposable collection kit, whereas fractional exhaled nitric oxide (FENO) was measured by a chemiluminescence analyser. Concentrations of MDC, TARC and eotaxin in both EBC and plasma were measured using sandwich enzyme immunoassay. The intra-subject reproducibility of exhaled chemokine measurements was determined by co-efficients of variation (CV). Forty-eight patients with PA, 36 children with IA and 18 controls were recruited. MDC and eotaxin were present in EBC from nearly all subjects, whereas TARC could be measured in EBC from 33 (32%) subjects only. The median MDC concentration in EBC was higher in PA (117 pg/mL) as compared with IA (106 pg/mL) and controls (105 pg/mL; P=0.003 for both). The median plasma MDC concentration in PA (648 pg/mL) was also higher than that in IA (520 pg/mL; P=0.002) and controls (490 pg/mL; P=0.008). The median plasma TARC concentration was also increased in PA as compared with IA (72 pg/mL vs. 35 pg/mL; P=0.004). MDC concentrations in EBC were lower in patients with PA who received high-dose inhaled corticosteroid ( P=0.005). FENO was significantly higher in asthmatics than controls ( P<0.0001), but it was not associated with chemokines in EBC or plasma. The mean (range) CV for measuring MDC, TARC and eotaxin in EBC ( n=6) were 5.5 (2.0−7.2%), 8.8 (3.6−14.4%) and 5.2 (2.8−7.9%), respectively. Our results suggest that MDC in EBC and MDC and TARC in plasma are increased in children with PA as compared with IA or control. MDC concentrations in EBC are suppressed in patients on high-dose inhaled corticosteroid treatment. [ABSTRACT FROM AUTHOR]

We report elevated urinary excretion of 3-methylglutaconic (3MGC) and 3-methylglutaric acids (3MGR) in a patient with glycogen storage disease Ib. Combined excretion was 10-fold elevated in comparison to control during inadequate glucose maintenance, and still elevated following dietary improvement. 3MGC acid excretion correlated with plasma lactate and glucose. We speculate that imbalanced gluconeogenesis and de novo cholesterol synthesis result in secondarily increased 3MGC/3MGR production. [ABSTRACT FROM AUTHOR]

Objective: The factors accounting for the low 'ever breastfeeding' rate in Hong Kong remain unclear. The objective of this survey was to study the intention and planned duration of breastfeeding in Chinese women in Hong Kong, and to investigate the sociodemographic and atopic factors affecting the intention to breastfeed.Methods: All Chinese mothers who were Hong Kong residents and who delivered their babies in a University teaching hospital were given a self administered and anonymous Chinese questionnaire within 1 day postpartum. The questionnaire included items on sociodemographic data, the presence of allergic diseases in the families, and the intention and planned duration of breastfeeding for their newborn babies.Results: A total of 1374 eligible questionnaires were collected. About one-third of mothers were born outside Hong Kong and the majority (78%) of them were aged between 25 and 40 years. Logistic regression revealed that only socioeconomic factors, namely older maternal age (odds ratio (OR) 2.10, 95% confidence interval (CI) 1.14-3.89), parity (OR 3.08, 95% CI 1.02-9.27) and higher educational background (OR 2.87, 95% CI 1.92-4.27), significantly affected the intention to breastfeed. In addition, mothers born outside Hong Kong and those with first babies, had a longer intended duration of breastfeeding (P-values < 0.001 and 0.033, respectively). A family history of atopic disorders in parents or siblings did not influence the breastfeeding intention of these Chinese mothers.Conclusion: Several sociodemographic factors, rather than a history of atopic disorders, of Chinese mothers in Hong Kong affected their intention to breastfeed and the planned duration of breastfeeding. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of postnatal systemic dexamethasone on serum leptin, insulin and hormones of the hypothalamic-pituitary-adrenal (HPA) axis in preterm, very low birthweight (VLBW) infants. Nineteen VLBW infants who received a 3 wk dose tapering course of dexamethasone for treatment of bronchopulmonary dysplasia were prospectively enrolled. Blood for hormone assays was collected immediately before the start of the dexamethasone course (T[sub d-pre]), 3 wk after commencement of the drug (T[sub d-end]) and 2 wk after dexamethasone treatment had been stopped (T). In addition, 28 VLBW infants who participated in a d-post concurrent longitudinal leptin study within the same period but did not receive corticosteroid had their serum leptin and insulin concentrations serially monitored. Blood specimens for the latter group of infants were obtained at 2 (T[sub wk-2]), 5 (T[sub wk-5]) and 7 (T[sub wk-7]) wk of postnatal age. Serum leptin and insulin at T[sub d-end] were significantly increased, whereas plasma ACTH and serum cortisol were significantly suppressed compared with the pretreatment (T[sub d-pre]) levels in the corticosteroid group (p < 0.0001 for leptin and insulin; p < 0.05 and p < 0.001 for ACTH and cortisol, respectively). In contrast, serum leptin and insulin at weeks 5 (T[sub wk-5]) and 7 (T[sub wk-7]) did not differ significantly from their respective levels at week 2 (T[sub wk-2]) in the non-treatment group. Conclusion: The administration of systemic corticosteroid resulted in significant increases in serum leptin and insulin, but marked suppression of hormones of the HPA axis. The effect of dexamethasone on the "adipoinsular" and HPA axes was transient and reversible. The adipoinsular axis in preterm infants is likely to be functional and active at an early stage of human development, and leptin may regulate energy balance in VLBW infants in the early postnatal period. Corticosteroids may, through the adipoinsular axis or its associated pathways, mediate in the regulation of body weight in preterm neonates. [ABSTRACT FROM AUTHOR]

Summary objective Graves’ disease is associated with a polymorphism at position 49 in exon 1 of the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene in Caucasians and Japanese. A high incidence of childhood Graves’ disease has been documented in Hong Kong Chinese. The aims of this study were to investigate the CTLA-4 gene A–G polymorphism association in Chinese children with Graves’ disease. patients and design One hundred and twenty-three Chinese children with Graves’ disease (104 girls and 19 boys) and 158 racially matched healthy controls were recruited for the study. Genomic DNA was extracted from venous blood samples. The dimorphism at position 49 A–G was analysed by polymerase chain reaction, single-strand conformation polymorphism and restriction fragment-length polymorphism analysis. results The genotype distribution and allele frequencies of children with Graves’ disease differed significantly from those of the controls (P = 0·0023 and P = 0·022, respectively). The presence of at least one G allele (GG or AG) was associated with an increased risk of Graves’ disease (OR = 6·8, 95% CI = 2·0–36·1; P = 0·001). conclusions This study confirms that CTLA-4 49 A–G polymorphism is associated with Graves’ disease in Chinese children. The CTLA-4 49 G allele confers an increased risk of childhood Graves’ disease. [ABSTRACT FROM AUTHOR]

Background: Ex vivo expansion of cord blood (CB) hematopoietic stem and progenitor cells increases cell dose and may reduce the severity and duration of neutropenia and thrombocytopenia after transplantation. This study's purpose was to establish a clinically applicable culture system by investigating the use of cytokines, serum-free media, and autologous plasma for the expansion of CB cells and the engraftment of expanded product in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice.Study Design and Methods: Enriched CB CD34+ cells were cultured in four media (Iscove's modified Dulbecco's medium with FCS, Gibco; X-Vivo-10, BioWhittaker; QBSF-60, Quality Biological; and StemSpan SFEM, Stem Cell Technologies) with four cytokine combinations (thrombopoietin [TPO], SCF, Flt-3 ligand [FL] with and without G-CSF, and/or IL-6). The effect of autologous CB plasma was also investigated. The read-out measures were evaluated on Days 8 and 12. After expansion at the optimized condition, cultured cells were transplanted into sublethally irradiated NOD/SCID mice. The engraftment of human CD45+ cells and subsets in the bone marrow, spleen, and peripheral blood was determined.Results: QBSF-60 or StemSpan SFEM supported high yields of early progenitors (CD34+ cells, Conclusion: The data supported the strategy of expansion. The optimized condition may be applicable to clinical expansion for the abrogation or reduction of posttransplant cytopenia. [ABSTRACT FROM AUTHOR]

Unlabelled: Infants requiring parenteral nutrition (n = 244) were randomized to receive either 1 (group 1, n = 121) or 0.0182 micromol/kg/d (group 2, n = 123) of manganese supplementation. The whole-blood manganese and serum direct bilirubin concentrations of the infants were monitored, as was the development of cholestasis (peak serum direct bilirubin concentration >50 micromol/L). Subgroup analysis was carried out on the data of 78 infants in group 1 and 82 in group 2 who had received manganese supplementation and more than three-quarters of their total daily fluid as parenteral nutrition for >14 d. Of all the infants randomized, the high manganese group (group 1) showed a trend towards developing higher peak whole-blood manganese concentration [group 1 versus group 2: median (interquartile range): 606.0 (421.0; 1005.0) vs 566.0 (336.0: 858.0); p=0.061] and higher peak serum direct bilirubin concentration [37.0 (10.5; 122.5) vs 19.0 (8.0; 112.5); p=0.153], but the differences between the 2 groups did not reach statistical significance. The 2 groups did not differ in terms of the occurrence of cholestasis during parenteral nutrition (63/121 vs 57/123; p=0.444). Subgroup analysis of infants who had received more than three-quarters of their total daily fluid as parenteral nutrition showed, however, that the high manganese group developed significantly higher whole-blood manganese concentration [743.5 (498.0; 1211.0) vs 587.0 (438.0; 982.0); p=0.037] and serum direct bilirubin concentration [84.0 (28.0; 170.0) vs 25.5 (9.0; 117.0): p < 0.001]. Although there was no significant difference in the occurrence of cholestasis (58/78 vs 49/82; p = 0.073), more infants in the high manganese group developed a more severe degree of direct hyperbilirubinaemia, with peak serum direct bilirubin >100 micromol/L (32/78 vs 20/82; p = 0.038).Conclusion: We conclude that the pathogenesis of parenteral nutrition-related cholestasis is probably multifactorial, and that high manganese intake is a significant contributory factor. [ABSTRACT FROM AUTHOR]

BackgroundEpidemiological surveys have shown that the prevalence of asthma in the Asian population is relatively low. Within the Chinese population, schoolchildren from Hong Kong were found to have the highest rate of asthma. ObjectiveTo compare the prevalence of respiratory and atopic disorders, and to assess the role of atopy in the development of asthma, in Chinese schoolchildren from Hong Kong, Beijing and Guangzhou. MethodsCommunity-based random samples of schoolchildren aged 9–11 years from three Chinese cities (Hong Kong, Beijing and Guangzhou) were recruited for study using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase II protocol. Subjects were studied by parental questionnaires (n = 10902), skin-prick tests (n = 3479) and skin examination (n = 3479). ResultsThe prevalence rates of current wheeze, speech limiting wheeze, rhinoconjunctivitis and flexural dermatitis were significantly more common in Hong Kong than in Beijing or Guangzhou. The atopy rate was also higher in Hong Kong (41.2%) than in Beijing (23.9%) or Guangzhou (30.8%). Atopy was strongly correlated with current wheeze (OR 7.74; 95% CI = 5.70–10.51). Subgroup analyses of children from Hong Kong revealed that children born in mainland China who had subsequently migrated to Hong Kong had a significantly lower rate of allergic symptoms and atopy than those children born in Hong Kong. ConclusionUsing a standardized written questionnaire along with a skin prick test and skin examination, we confirmed that the prevalence of asthma, allergic diseases and atopy was highest in schoolchildren from Hong Kong. Atopic sensitization is an important factor associated with asthma in Chinese children. [ABSTRACT FROM AUTHOR]

BackgroundMany epidemiological studies have shown positive association between respiratory health and current levels of outdoor air pollution in Europe and America. ObjectiveThe aim of this study was to investigate the association between air pollution and the number of childhood admissions for asthma in Hong Kong. MethodsDaily counts of childhood admission for asthma to a large teaching Hospital were obtained from the computerized database for the period 1993–1994. A Poisson regression allowing for seasonal patterns and meteorological conditions was used to assess the associations between the number of Hospital admissions and the three pollutants: nitrogen dioxide, sulphur dioxide and inhalable particles (measured as PM10, particles < 10 µm in aerodynamic diameter). ResultsA total of 1217 children under 15 years of age were admitted for asthma during the study period. The calculated annual hospitalization rates were 283 and 178 per 100 000 for boys and girls, respectively. The mean PM10, NO2 and SO2 levels were 44.1 µg/m3, 43.3 µg/m3, and 12.2 µg/m3, respectively. Daily admission for asthma increased significantly with increasing ambient level of nitrogen dioxide (relative risk (RR) = 1.08 per 10 µg/m3 increase), sulphur dioxide (RR = 1.06) and inhalable particles (RR = 1.03). No association was found between hospital admission and humidity, temperature or atmospheric pressure. ConclusionThis is the first daily time series study of childhood admissions for asthma and air pollution in Hong Kong. The results support that current levels of air pollution contribute to the respiratory morbidity in asthmatic children in Hong Kong. [ABSTRACT FROM AUTHOR]

Background Atopic dermatitis (AD) is a distressing disease associated with pruritus and sleep disturbance. It is not known how well these symptoms correlate with the extent and intensity of eczematous involvement. We evaluated whether: (i) the level of sleep loss correlates with pruritus and (ii) the level of pruritus correlates with the extent or severity of AD in children according to the SCORing Atopic Dermatitis (SCORAD) index. Method Patients with AD younger than 18 years old were recruited from the pediatric dermatology clinic of a university teaching hospital, and AD severity was evaluated by the SCORAD index. Results One hundred and eighty-two Chinese children with AD (107 boys and 75 girls) [mean (SD) age of 9.6 (4.2) years] were recruited. Their mean (SD) overall SCORAD was 30.1 (19.2). Sleep loss was strongly correlated with pruritus ( r = 0.57, P < 0.001). However, the two subjective symptoms were only weakly correlated with the objective signs (extent and intensity) of AD. The correlations between pruritus and extent and intensity were 0.42 ( P < 0.001) and 0.38 ( P < 0.001), respectively, and the correlations between sleep loss and extent and intensity were 0.38 ( P < 0.001) and 0.34 ( P < 0.001), respectively. Conclusion We speculate that the lack of a better correlation was either because pruritus and sleep loss as reported by parents were imprecise, or that mechanisms other than disease extent or severity are responsible for the pathogenesis of these subjective symptoms. [ABSTRACT FROM AUTHOR]

Accurate clinical diagnosis of severe acute respiratory syndrome (SARS) based on the current World Health Organization definition is difficult and at times impossible at the early stage of the disease. Both false positive and false negative cases are commonly encountered and this could have far-reaching detrimental effects on the patients, their family and the clinicians alike. Contact history is particularly important in diagnosing SARS in children as their presenting features are often non-specific. The difficulty in making a correct diagnosis is further compounded by the lack of a sensitive rapid diagnostic test. Serology is not particularly helpful in the initial triaging of patients as it takes at least 3 weeks to become positive. Co-infection and other treatable conditions should not be missed and conventional antibiotics should remain as part of the first-line treatment regimen. We report five cases to illustrate the difficulties and dilemmas faced by clinicians in diagnosing SARS in children. [ABSTRACT FROM AUTHOR]

Five cases of moderately severe hypernatraemic dehydration were identified within a 5-month period between two regional hospitals in Hong Kong. Unlike previous reported cases, these exclusively breast-fed infants presented with the unusual triad of fever, absence of overt signs of dehydration and within the first week of life. Three of the cases also had high serum bilirubin concentrations at presentation. The fever subsided quickly and the serum bilirubin concentration fell rapidly within a few hours of rehydration. All infants made an uneventful recovery without permanent neurological sequelae. Fever, presumably secondary to dehydration, is an useful early warning sign. These cases emphasize the importance of early and regular measurement of bodyweight in exclusively breast-fed infants so that prompt identification of affected cases may prevent potentially detrimental complications. [ABSTRACT FROM AUTHOR]

Two cases of homozygous alpha-thalassaemia who received active treatment in accordance with parental wishes are reported. One infant survived and the other, although successfully weaned off mechanical respiratory support, unexpectedly developed portal vein thrombosis and died. Homozygous alpha-thalassaemia, a condition previously considered to be universally fatal, and an indication for therapeutic abortion, is now potentially curable with advances in diagnostic technology and treatment. However, active management of these cases raises serious ethical questions and has major financial implications on the health-care system. Invasive prenatal and intensive postnatal interventions should remain experimental and cannot be recommended as routine clinical practice until the questions of long-term neurodevelopmental outcome, and the morbidity and mortality associated with bone-marrow transplantation have been fully addressed. As a result of advances in information technology, more and more parents of affected foetuses are likely to request active treatment. [ABSTRACT FROM AUTHOR]

Non-traumatic massive subdural haematoma is a rare condition in newborn infants and is usually associated with hereditary coagulation disorders or congenital vascular malformation. Its occurrence in preterm very low birthweight infants secondary to systemic bacterial infection has not been reported. We describe two extremely preterm neonates who developed massive subdural haematoma as a result of gram-negative septicaemia and disseminated intravascular coagulation. Both infants suffered severe parenchymal cerebral injury and hydrocephalus. Clinicians should be aware of this unusual and catastrophic complication if a very low birthweight infant with severe sepsis and disseminated intravascular coagulation suddenly deteriorates despite successful treatment with antibiotics. Radiological imaging by cranial ultrasound or computed tomography scanning should be routinely considered in all such infants for the detection of intracranial bleeding. [ABSTRACT FROM AUTHOR]

Objective: To investigate the acute effects of red blood cell transfusion on haemodynamics in preterm babies.Setting: A neonatal unit in a University Hospital.Patients: Preterm babies whose postnatal age was less than four weeks and who required red blood cell transfusion.Measurement: Cardiac output and left ventricular systolic function was determined using Doppler echocardiography before, one hour and 24 h after red blood cell transfusion. Blood pressure and haematocrit were also recorded at the same time. Mixed-effects regression model was used to analyse the effect of blood transfusion on left ventricular function and cardiac output.Results: 57 preterm babies were recruited. Univariate analysis showed that cardiac index decreased significantly 24 h after transfusion (P<0.05). Systemic red cell transport increased by an average of 11.1% 24 h after transfusion (P<0.05). Multivariate analysis showed that the cardiac index was negatively associated with haematocrit and the index was higher in male babies.Conclusion: There was a significant drop in cardiac index and an increase in systemic red cell transport 24 h after transfusion in premature babies. [ABSTRACT FROM AUTHOR]

Describes the case of a five-year-old Chinese boy diagnosed with Wilson's disease. Results of the percutaneous liver biopsy; Determination of the liver copper content; Treatment advised for the patient.

A 15-year-old Chinese boy developed rhabdomyolysis with myoglobinuria and marked elevation of serum creatine phosphokinase following a prolonged and severe attack of asthma. He recovered after vigorous hydration and supportive treatment. Clinicians should be aware of this potentially fatal, albeit rare, complication of status asthmaticus. [ABSTRACT FROM AUTHOR]

Two rare cases of isolated central nervous system (CNS) candidiasis in preterm infants have been diagnosed in a tertiary neonatal centre over the past 6 years. Despite the life-threatening nature of the disease, biochemical infection markers were not useful for the early identification of localized fungal infection. Because the infection was likely to have been blood borne, we postulated that the initial fungal load was probably low and that the organisms were rapidly eliminated from the circulation after a few had been deposited in the CNS. Hence, the absence of fungaemia or systemic involvement precluded the activation of cytokines and cellular markers. Clinicians should be aware of the limitation of biochemical infection markers so that diagnosis and treatment of fungal infection will not be delayed. [ABSTRACT FROM AUTHOR]

We report a case of galactose-1-phosphate uridyl transferase (GALT) deficiency in a full-term Chinese neonate, who presented with atypical biochemical features of hyperammonaemia in addition to the classical presenting features of jaundice and lethargy after feeding. Red cell GALT activity was virtually absent in the patient while 50% of normal activity was found in parents and a sibling. Mutation screening excluded both Q188R and N314D as the causative mutation in GALT gene, which suggested a possible genetic segregation among ethnic groups. Data from a Taiwan screening program suggested that the incidence of the disease was approximately 1 in 400 000 in the Chinese population which was a sixth of that in Caucasian populations. [ABSTRACT FROM AUTHOR]

Megakaryocytopoiesis is regulated by thrombopoietin (TPO) and cytokines such as interleukin 3 (IL-3), IL-6 and IL-11. This study investigated the in vitro effects of IL-1beta on megakaryocytopoiesis and the expression of IL-1 type I and type II receptors (IL-1 RI and RII) on mega-karyocytic cell lines and primary cells. Our results demonstrated that IL-1beta alone or in combination with TPO induced megakaryocyte colony forming units (CFU-MK) from murine and human haematopoietic cells. Using reverse-transcription polymerase chain reaction (RT-PCR) and Southern hybridization techniques, the mRNA of IL-1beta, IL-1 RI, IL-1 RII and the transcription factor NF-E2 were detected in CD61+ CD41+ cells cultured from cord blood and four megakaryocytic cell lines, Meg-01, DAMI, CHRF-288-11 and M-07e. The expression of IL-1 RI and RII proteins was confirmed by flow cytometry and immunofluorescence staining. In Meg-01 cells, the expression of NF-E2 was increased at both mRNA and protein levels after treatment with IL-1beta for 4 h. This study demonstrated for the first time the presence of IL-1 receptors on megakaryocytic cells and the induction of NF-E2 by IL-1beta. The mitogenic effect of IL-1beta on this lineage could be mediated through IL-1 receptors and the activation of NF-E2.

Haemopoietic stem cells are present in fetal blood but their levels decline rapidly in the peripheral circulation of the infant after birth. We previously reported a case of stem cell transplant in a beta-thalassaemia boy using a combination of the cord blood (CB) and neonatal blood (NB) of his sister. This transplant resulted in a successful engraftment. To investigate the possibility of using NB to supplement CB for related transplants, we further characterized stem and progenitor cells and lymphocyte subsets in 20 NB samples, comparing the findings with those in 20 CB samples. Our data showed that NB contained substantial levels of CD34+ cells, CD34+CD38- cells, colony-forming units-granulocyte macrophage (CFU-GM), colony forming units-erythroid (CFU-E), burst forming units-erythroid (BFU-E) and long-term culture initiating cells (LTCIC). NB was similar to CB in the levels of T lymphocytes, but the amounts of B lymphocytes and natural killer cells were higher in CB (P = 0.033, P= 0.001, respectively). The kinetics of CD34+ cells in NB was investigated in serial blood samples obtained from 10 full-term infants at 2, 4, 6, 8, 24 and 48h after birth. CD34+ cells decreased rapidly after birth, declining to only 30% of the 2h level at 48h (P<0012). The rate of decline was greatest in the first 4 h of life. NB from four infants was expanded by culturing the blood samples in the presence of thrombopoietin (Tpo), interleukin 1beta (IL1beta), IL-3, IL-6, flt-3 ligand and stem cell factor (SCF) for 7 d. This resulted in the increase of CD34+ cells, CFU-GM and CFU-MK by 271+/-179, 556+/-385 and 113+/-75 fold respectively. Three of the five samples expanded for 7 d contained LTCIC. These findings suggest that NB might be a supplementary or alternative source of stem cells to CB for transplant. The ethics and practicality of this approach deserve further exploration.