A Multisource Process Evaluation of a Community-Based Healthy Lifestyle Programme for Child and Adolescent Obesity.

Whanau Pakari is a healthy lifestyle assessment and intervention programme for children and adolescents with obesity in Taranaki (Aotearoa/New Zealand), which, in this region, replaced the nationally funded Green Prescription Active Families (GRxAF) programme. We compared national referral rates from the GRxAF programme (age 5-15 years) and the B4 School Check (B4SC, a national preschool health and development assessment) with referral rates in Taranaki from Whanau Pakari. We retrospectively analysed 5 years of clinical data (2010-2015), comparing referral rates before, during, and after the Whanau Pakari clinical trial, which was embedded within the programme. We also surveyed programme referrers and stakeholders about their experiences of Whanau Pakari, analysing their responses using a multiple-methods framework. After the Whanau Pakari trial commenced, Taranaki GRxAF referral rates increased markedly (2.3 pretrial to 7.2 per 1000 person-years), while NZ rates were largely unchanged (1.8-1.9 per 1000 person-years) (p < 0.0001 for differences during the trial). Post-trial, Taranaki GRxAF referral rates remained higher irrespective of ethnicity, being 1.8 to 3.2 times the national rates (p < 0.001). Taranaki B4SC referrals for obesity were nearly complete at 99% in the last trial year and 100% post-trial, compared with national rates threefold lower (31% and 32%, respectively; p < 0.0001), with Taranaki referral rates for extreme obesity sustained at 80% and exceeding national rates for both periods (58% and 62%, respectively; p < 0.01). Notably, a referral was 50% more likely for referrers who attended a Whanau Pakari training half-day (RR = 1.51; p = 0.009). Stakeholders credited the success of Whanau Pakari to its multidisciplinary team, family-centred approach, and home-based assessments. However, they highlighted challenges such as navigating multidisciplinary collaboration, engaging with families with complex needs, and shifting conventional healthcare practices. Given its favourable referral trends and stakeholder endorsement, Whanau Pakari appears to be a viable contemporary model for an accessible and culturally appropriate intervention on a national and potentially international scale.

Infants Eligible for Neonatal Hypoglycemia Screening: A Systematic Review.

Importance: Neonatal hypoglycemia is common, occurring in up to 50% of infants at risk for hypoglycemia (infant of diabetic mother [IDM], small for gestational age [SGA], large for gestational age [LGA], and preterm) and is associated with long-term neurodevelopmental impairment. Guidelines recommend screening infants at risk of hypoglycemia. The proportion of infants who require screening for neonatal hypoglycemia is unknown. Objective: To determine the proportion of infants eligible for neonatal hypoglycemia screening using criteria from the highest-scoring critically appraised clinical guideline. Design, Setting, and Participants: This systematic review of the literature was conducted to identify clinical practice guidelines for neonatal hypoglycemia and took place at a tertiary maternity hospital in Auckland, New Zealand. Eligible guidelines were critically appraised using the Appraisal of Guidelines for Research and Evaluation II tool. Using screening criteria extracted from the highest-scoring guideline, the proportion of infants eligible for neonatal hypoglycemia screening was determined in a retrospective observational cohort study of infants born January 1, 2004, to December 31, 2018. Data were analyzed by logistic regression. Infant participants were included if gestational age was 35 weeks or more, birth weight was 2000 g or more, and they were not admitted to a neonatal intensive care unit less than 1 hour after birth. The data were analyzed from November 2022 through February 2023. A total of 101 372 infants met the inclusion criteria. Exposure: Risk factors for neonatal hypoglycemia. Main Outcome: Proportion of infants eligible for neonatal hypoglycemia screening. Results: The study team screened 2366 abstracts and 18 guidelines met inclusion criteria for appraisal. There was variability in the assessed quality of guidelines and a lack of consensus between screening criteria. The highest-scoring guideline defined screening criteria as: IDM, preterm (less than 37 weeks' gestation), SGA (less than 10th percentile), birth weight of less than 2500 g or more than 4500 g, LGA (more than 90th percentile), or gestational age more than 42 weeks. A total of 101 372 infants met criteria for inclusion in the cohort study; median (IQR) gestational age was 39 (38-40) weeks and 51% were male. The overall proportion of infants eligible for screening was 26.3%. There was an increase in the proportion of eligible infants from 25.6% to 28.5% over 15 years, which was not statistically significant after adjustment for maternal age, body mass index, ethnicity, and multiple pregnancy (odds ratio, 0.99; 95% CI, 0.93-1.03; change in proportion per year). Conclusion: A systematic review found that practice guidelines providing recommendations for clinical care of neonatal hypoglycemia were of variable quality with is a lack of consensus regarding definitions for infants at risk for hypoglycemia. In the cohort study, one-quarter of infants were eligible for hypoglycemia screening. Further research is required to identify which infants may benefit from neonatal hypoglycemia screening.

Determinants of exclusive breastfeeding for wahine Maori.

AIM: Breastfeeding is a fundamental aspect of tikanga Maori (Maori cultural traditions/practices) requiring protection and promotion. This study identifies determinants of exclusive breastfeeding in wahine Maori. METHODS: Wahine Maori enrolled in the Growing Up in New Zealand child cohort study participated (n=1060). Exclusive breastfeeding duration was self-reported. Hierarchical regression analyses were framed by a model of Maori health and wellbeing. RESULTS: Most wahine Maori initiated breastfeeding (96%), with 12% exclusively breastfeeding for six or more months. Wahine Maori had increased odds of exclusively breastfeeding for six or more months if they: thought it best to breastfeed for >6 months (adjusted odds ratio (aOR)=1.94, 95% confidence interval (CI)=1.05-3.78); thought returning to work would not (aOR=2.17, 95% CI=1.17-4.24) or may (aOR=4.25, 95% CI=1.86-9.85) limit breastfeeding; were experienced mothers (aOR=2.55, 95% CI=1.35-5.06); or were undecided about vaccination (aOR=3.16, 95% CI=1.55-6.39). Exclusive breastfeeding for six or more months was less likely if mothers experienced depression during pregnancy (aOR=0.47, 95% CI=0.20-0.99) or viewed cultural traditions/practices as "fairly important" (aOR=0.53, 95% CI=0.27-0.99), compared to "very important". CONCLUSION: Determinants of exclusive breastfeeding in wahine Maori are knowledge of breastfeeding recommendations, return to work, motherhood experience, connection to Te Ao Maori (Maori worldview) and tikanga Maori, antenatal depression and vaccine indecision. Interventions delivered within a Kaupapa Maori framework will best address breastfeeding inequities in Aotearoa New Zealand.

Randomised controlled trial of nebulised gentamicin in children with bronchiectasis.

AIM: Following trials of inhaled antibiotics in adults, this study investigates the efficacy of nebulised gentamicin to improve respiratory function in children with bronchiectasis. METHODS: This is a randomised, double-blind, placebo-controlled, crossover trial of 12-week nebulised placebo/gentamicin, 6-week washout, 12-week gentamicin/placebo. Participants were children (5-15 years) with bronchiectasis, chronic infection (any pathogen), and able to perform spirometry from a hospital bronchiectasis clinic. Primary outcomes were change in forced expiratory volume in 1 s (FEV1 ) and hospitalisation days. Secondary outcomes included sputum bacterial density, sputum inflammatory markers, additional antibiotics and symptom severity. Analyses were on an intention-to-treat basis. RESULTS: Fifteen children (mean 11.7-years-old) completed the study. There was no significant change in mean FEV1 (56%/55%, P = 0.38) or annual rate of hospital admissions (1.1/0, P = 0.12) between gentamicin and placebo, respectively. However, Haemophilus influenzae sputum growth (27% vs. 80%, P = 0.002) and bacterial density (2.4 log10 cfu/mL lower P < 0.001) improved with gentamicin. Sputum inflammatory markers interleukin-1ß (P < 0.001), interleukin-8 (P < 0.001) and tumour necrosis factor-α (P = 0.003) were lower with gentamicin. Poor recruitment limited study power and treatment adherence was challenging for this cohort. CONCLUSIONS: In this crossover study of nebulised gentamicin in children with bronchiectasis, there was a reduction in sputum bacterial density and inflammation. However, there were no major improvements in clinical outcomes and adherence was a challenge.

The relationship between diet and sleep in 2-y-old children: Results from Growing Up in New Zealand.

OBJECTIVES: This study aimed to examine the relationship between dietary practices and sleep in young children. METHODS: In this study, 2-y-old children (n = 6327) and their mothers were enrolled at birth and during pregnancy, respectively. The study obtained maternal demographic, health, and lifestyle data during late pregnancy. Parents reported the 2-y-old child's dietary practices on a food frequency questionnaire, as well as sleep duration and night-waking frequency. Measures of dietary intake quantified servings per day for each food group (grouped as low/moderate/high intake). Sleep measures were as inadequate sleep when <11 h sleep in a 24-h period and increased night waking when waking ≥2 times per night. Multivariable logistic regression analyses examined associations between toddler diet and sleep, which were described using adjusted odds ratios (ORs) and 95% confidence intervals. RESULTS: In this study, 2-y-old children (n = 6288) slept for a mean of 12.3 hours (standard deviation: ±1.5 hours) over a 24-h period, with 734 children (12%) getting <11 h of sleep in 24 h. Increased night waking occurred in 1063 children (17%). Compared with low intake, high soft drink/snack/fast food intake was associated with inadequate sleep (OR: 1.37) and increased night waking (OR: 1.34). High milk/cheese/yoghurt intake (OR: 1.55) was associated with increased odds of night waking, but moderate (OR: 0.81) or high (OR: 0.78) vegetable intake was associated with decreased odds of night waking. Exposure to screens (OR: 1.28) and heavy maternal cigarette smoking (OR: 2.20) were also associated with inadequate sleep and increased night waking, respectively. CONCLUSIONS: At age 2 y, higher consumption of soft drinks/snacks/fast foods is associated with shorter, more disrupted sleep. Conversely, higher vegetable consumption is associated with less disrupted sleep. Dietary modifications may improve toddlers' sleep.

Vaccination information fathers receive during pregnancy and determinants of infant vaccination timeliness.

The information fathers receive about infant vaccination may influence their decision to vaccinate. We describe fathers' sources of vaccination information and paternal determinants of timely infant vaccinations. Participants were from a child cohort study in New Zealand. The child cohort was established by enrolling pregnant women and their partners. During pregnancy, fathers (n = 4017) of the cohort children born 2009-2010 described information sources that encouraged or discouraged infant vaccination. The National Immunization Register provided infant vaccination data. Independent associations of the vaccination information received by fathers with the timeliness of their infant's vaccination were determined using multivariable logistic regression. Associations were described using adjusted odds ratios and 95% confidence intervals. One-third of fathers (1430/4017 [36%]) recalled receiving vaccination information, 64% of which encouraged vaccination. Most infants (2900/4017 [72%]) received all their vaccinations on time, however only 58% of Maori infants were vaccinated on time. Paternal determinants of vaccination timeliness were the father receiving discouraging or conflicting information about vaccination, father's ethnicity, father's vaccination hesitancy, and whether the mother received vaccination information. To improve vaccination uptake and timeliness, a vaccination conversation with mothers, fathers and whanau could be included in routine antenatal care, informing and supporting decision-making, and addressing concerns. Vaccination education should address present and historic distrust of the health system. Framing vaccination within a Maori model of health and including fathers and whanau in decision-making will address vaccination inequities in New Zealand.

Surveillance of pediatric parapneumonic effusion/empyema in New Zealand.

AIM: The incidence of childhood empyema has been increasing in some developed countries despite the introduction of pneumococcal vaccination. This study aimed to document the incidence, bacterial pathogens, and morbidity/mortality of parapneumonic effusion/empyema in New Zealand. METHODS: A prospective study of 102 children <15 years of age requiring hospitalization with parapneumonic effusion/empyema between May 1, 2014 and May 31, 2016 notified via the New Zealand Paediatric Surveillance Unit. Parapneumonic effusion/empyema was defined as pneumonia and pleural effusion persisting ≥7 days, and/or any pneumonia, and pleural effusion necessitating drainage. Notifying pediatricians completed standardized questionnaires. RESULTS: Annual pediatric parapneumonic effusion/empyema incidence was 5.6/100,000 (95% confidence interval [CI]: 4.7-6.9). Most children (80%) required surgical intervention and 31% required intensive care. A causative organism was identified in 71/102 (70%) cases. Although Staphylococcus aureus (25%) and Streptococcus pneumoniae (25%) infection rates were equal, prolonged hospitalization and intensive care admission were more common in children with S. aureus PPE/E. Maori and Pasifika children were over-represented at 2.2 and 3.5 times, their representation in the New Zealand pediatric population. Pneumococcal vaccination was incomplete, with only 61% fully immunized and 30% unimmunized. Haemophilus influenzae type b vaccine uptake was near complete at 89/94 (95%), with influenza immunization only 3/78 (4%). CONCLUSIONS: New Zealand has a high incidence of pediatric complicated parapneumonic effusion/empyema with significant morbidity. S. aureus was a significant cause of severe empyema in New Zealand, particularly for Maori and Pasifika children. Improvements in vaccine coverage are needed along with strategies to reduce S. aureus disease morbidity.

Adherence to neonatal hypoglycaemia guidelines: A retrospective cohort study.

AIM: To determine if the routine use of automatically calculated birthweight centiles prior to discharge from the delivery unit is associated with improved adherence to the neonatal hypoglycaemia guideline. METHODS: We conducted retrospective audits of adherence to the neonatal hypoglycaemia guideline in a tertiary maternity hospital in Auckland, New Zealand in a randomly selected cohort of newborn infants at risk of neonatal hypoglycaemia before (2011) and after (2015) the introduction of routine use of calculated birthweight centiles for all infants. The primary outcome was adherence to the guideline, defined as (i) blood glucose concentration screening in the first 48 h after birth; (ii) the initial measurement taken 1-2 h after birth; and (iii) at least three consecutive blood glucose concentrations ≥2.6 mmol/L, over 12 h, prior to cessation of screening. RESULTS: The audits examined the records of 400 infants (200 each in 2011 and 2015) to determine guideline adherence. Adherence improved from 2011 to 2015 (59/200 (30%) vs. 95/200 (48%), P < 0.001), with the largest improvement in large-for-gestational age infants (7/50 (14%) vs. 25/50 (50%), P = <0.001). Screened infants whose care was adherent to the guideline had a higher incidence of hypoglycaemia detection (adherent, 64/154 (42%) vs. non-adherent, 34/246 (14%), P < 0.001). CONCLUSIONS: The routine use of calculated birthweight centiles was associated with improved adherence to the neonatal hypoglycaemia guideline and increased detection of neonatal hypoglycaemia in at-risk infants. Thus, identifying practices that improve guideline adherence may improve the detection of hypoglycaemia in asymptomatic at-risk infants.

Hospital readmissions with acute infectious diseases in New Zealand children < 2 years of age.

BACKGROUND: Infectious diseases are the leading cause of hospital admissions in young children. Hospitalisation with an infectious disease is a recurrent event for some children. Our objective was to describe risk factors for infectious disease readmission following hospital admission with an infectious disease in the first two years of life. METHODS: We performed a national cohort study of New Zealand children, born 2005-2009, with an infectious disease admission before age 24 months. Children readmitted with an infectious disease within 12 months of the first infectious disease admission were identified. Every infectious disease admission was categorised as a respiratory, enteric, skin and soft tissue, urinary or other infection. Independent associations of demographic and child health factors with infectious disease readmission were determined using multiple variable logistic regression. RESULTS: From 2005 to 2011, there were 69,902 infectious disease admissions for 46,657 children less than two years old. Of these 46,657 children, 10,205 (22%) had at least one infectious disease readmission within 12 months of their first admission. The first infectious disease admission was respiratory (54%), enteric (15%), skin or soft tissue (7%), urinary (4%) or other (20%). Risk of infectious disease readmission was increased if the first infectious disease admission was respiratory (OR = 1.87, 95% CI 1.78-1.95) but not if it was in any other infectious disease category. Risk factors for respiratory infectious disease readmission were male gender, Pacific or Maori ethnicity, greater household deprivation, presence of a complex chronic condition, or a first respiratory infectious disease admission during autumn or of ≥3 days duration. Fewer factors (younger age, male gender, presence of a complex chronic condition) were associated with enteric infection readmission. The presence of a complex chronic condition was the only factor associated with urinary tract infection readmission and none of the factors were associated with skin or soft tissue infection readmission. CONCLUSIONS: In children less than two years old, infectious disease readmission risk is increased if the first infectious disease admission is a respiratory infectious disease but not if it is another infectious disease category. Risk factors for respiratory infectious disease readmission are different from those for other infectious disease readmissions.

Vaccine Education During Pregnancy and Timeliness of Infant Immunization.

OBJECTIVES: Pregnant women routinely receive information in support of or opposing infant immunization. We aimed to describe immunization information sources of future mothers' and determine if receiving immunization information is associated with infant immunization timeliness. METHODS: We analyzed data from a child cohort born 2009-2010 in New Zealand. Pregnant women (N = 6822) at a median gestation of 39 weeks described sources of information encouraging or discouraging infant immunization. Immunizations received by cohort infants were determined through linkage with the National Immunization Register (n = 6682 of 6853 [98%]). Independent associations of immunization information received with immunization timeliness were described by using adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Immunization information sources were described by 6182 of 6822 (91%) women. Of these, 2416 (39%) received information encouraging immunization, 846 (14%) received discouraging information, and 565 (9%) received both encouraging and discouraging information. Compared with infants of women who received no immunization information (71% immunized on-time), infants of women who received discouraging information only (57% immunized on time, OR = 0.49, 95% CI 0.38-0.64) or encouraging and discouraging information (61% immunized on time, OR = 0.51, 95% CI 0.42-0.63) were at decreased odds of receiving all immunizations on time. Receipt of encouraging information only was not associated with infant immunization timeliness (73% immunized on time, OR = 1.00, 95% CI 0.87-1.15). CONCLUSIONS: Receipt, during pregnancy, of information against immunization was associated with delayed infant immunization regardless of receipt of information supporting immunization. In contrast, receipt of encouraging information is not associated with infant immunization timeliness.

Increasing Incidence of Life-threatening Pertussis: A Retrospective Cohort Study in New Zealand.

BACKGROUND: Pertussis immunization programs aim to prevent severe infant disease. We investigated temporal trends in infant pertussis deaths and pediatric intensive care unit (PICU) admissions and associations of changes in disease detection and vaccines used with death and PICU admission rates. METHODS: Using national data from New Zealand (NZ), we described infant pertussis deaths and PICU admissions from 1991 to 2013, over which time national immunization coverage at 2 years of age increased from <80% to 92%. In NZ, pertussis became a notifiable disease with polymerase chain reaction (PCR) diagnosis available in 1997 and acellular replaced whole-cell vaccine in 2000. We used Poisson regression to model temporal trends and compared rates in time intervals using rate ratios (RRs) with 95% confidence intervals (CIs). RESULTS: There were 10 pertussis deaths and 159 infant PICU admissions with pertussis from 1991 to 2013. The annual number of infant pertussis PICU admissions increased from 1991 to 2013 (P = 0.02) but the number of pertussis deaths did not (P = 0.09). The risk of PICU admission during infancy with pertussis was increased in the notification/PCR versus the non-notification/PCR era (RR: 1.12; 95% CI: 1.02-1.19) and when acellular replaced whole-cell vaccine (RR: 1.19; 95% CI: 1.06-1.31). Median Pediatric Index of Mortality scores during 2001-2013 were lower than during 1991-1999 (P < 0.001). CONCLUSIONS: Infant PICU pertussis admission rates have increased in NZ despite improvements in immunization coverage. Higher rates have occurred since pertussis notification/PCR became available and since acellular replaced whole-cell vaccine. The severity of disease in infants admitted to PICU with pertussis has decreased in recent years.

Antenatal immunisation intentions of expectant parents: Relationship to immunisation timeliness during infancy.

BACKGROUND: Most women decide about infant immunisation during pregnancy. However, we have limited knowledge of the immunisation intentions of their partners. We aimed to describe what pregnant women and their partners intended for their future child's immunisations, and to identify associations between parental intentions and the subsequent timeliness of infant immunisation. METHODS: We recruited a cohort of pregnant New Zealand (NZ) women expecting to deliver between April 2009 and March 2010. The cohort included 11% of births in NZ during the recruitment period and was generalisable to the national birth cohort. We completed antenatal interviews independently with mothers and partners. We determined immunisation receipt from the National Immunisation Register and defined timely immunisation as receiving all vaccines (scheduled at 6-weeks, 3- and 5-months) within 30 days of their due date. We described independent associations of immunisation intentions with timeliness using adjusted odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Of 6172 women, 5014 (81%) intended full immunisation, 245 (4%) partial immunisation, 140 (2%) no immunisation and 773 (13%) were undecided. Of 4152 partners, 2942 (71%) intended full immunisation, 208 (5%) partial immunisation, 83 (2%) no immunisation and 921 (22%) were undecided. Agreement between mothers and partners was moderate (Kappa=0.42). Timely immunisation occurred in 70% of infants. Independent of their partner's intentions, infants of pregnant women who decided upon full immunisation were more likely to be immunised on time (OR=7.65, 95% CI: 4.87-12.18). Independent of the future mother's intentions, infants of partners who had decided upon full immunisations were more likely to be immunised on time (OR=3.33, 95% CI: 2.29-4.84). CONCLUSIONS: During pregnancy, most future parents intend to fully immunise their child; however, more partners than mothers remain undecided about immunisation. Both future mothers' and future fathers' intentions are independently associated with the timeliness of their infant's immunisations.

The impact of primary care on emergency department presentation and hospital admission with pneumonia: a case-control study of preschool-aged children.

BACKGROUND: In children, community-acquired pneumonia is a frequent cause of emergency department (ED) presentation and hospital admission. Quality primary care may prevent some of these hospital visits. AIMS: The aim of this study was to identify primary care factors associated with ED presentation and hospital admission of preschool-aged children with community-acquired pneumonia. METHODS: A case-control study was conducted by enrolling three groups: children presenting to the ED with pneumonia and admitted (n = 326), or discharged home (n = 179), and well-neighbourhood controls (n = 351). Interviews with parents and primary care staff were conducted and health record review was performed. The association of primary care factors with ED presentation and hospital admission, controlling for available confounding factors, was determined using logistic regression. RESULTS: Children were more likely to present to the ED with pneumonia if they did not have a usual general practitioner (GP) (odds ratio (OR) = 2.50, 95% confidence interval (CI) = 1.67-3.70), their GP worked ⩽ 20 h/week (OR = 1.86, 95% CI = 1.10-3.13) or their GP practice lacked an immunisation recall system (OR = 5.44, 95% CI = 2.26-13.09). Lower parent ratings for continuity (OR=1.63, 95% CI = 1.01-2.62), communication (OR = 2.01, 95% CI = 1.29-3.14) and overall satisfaction (OR = 2.16, 95% CI = 1.34-3.47) increased the likelihood of ED presentation. Children were more likely to be admitted when antibiotics were prescribed in primary care (OR = 2.50, 95% CI = 1.43-4.55). Hospital admission was less likely if children did not have a usual GP (OR = 0.22, 95% CI = 0.11-0.40) or self-referred to the ED (OR = 0.48, 95% CI = 0.26-0.89). CONCLUSIONS: Accessible and continuous primary care is associated with a decreased likelihood of preschool-aged children with pneumonia presenting to the ED and an increased likelihood of hospital admission, implying more appropriate referral. Lower parental satisfaction is associated with an increased likelihood of ED presentation.

Maternal and perinatal predictors of newborn iron status.

AIM: To describe iron status at birth in a population sample of children. METHOD: Cord blood samples were obtained at birth from 131 infants enrolled in the cohort study Growing Up in New Zealand. Cord blood serum ferritin (SF) and haemoglobin (Hb) concentrations were measured and associations of SF and Hb with maternal and birth characteristics were determined. RESULTS: Demographics were comparable to the larger cohort, except for having a higher pre-pregnancy body mass index (26.9 vs. 25.4 kg/m2, P=0.005), lower frequency of cigarette smoking during pregnancy (2% vs. 11%, P=0.0004), and smaller proportion with birth-weight <2500 g (0% vs. 5%, P=0.03). Median (interquartile range) SF was 135 (88-180) mcg/L and mean (plus or minus SD) Hb was 160 plus or minus 17 g/L. Eight newborns (7%) had cord SF levels indicative of iron deficiency (SF <35 mcg/L), two newborns were anaemic (Hb <130 g/L) and none had iron deficiency anaemia. Median SF was lower in newborns whose mothers consumed greater than or equal to 3 servings of milk/day during the pregnancy (131 vs. 151 mcg/L, P=0.04). No other associations with SF or Hb were observed. CONCLUSION: Iron deficiency is present in 7% of newborns in New Zealand. Newborns whose mothers consumed more milk during pregnancy had a lower median SF concentration.

Therapeutic reactivation of mutant p53 protein by quinazoline derivatives.

PURPOSE: The human tumour suppressor protein p53 is mutated in nearly half of human tumours and most mutant proteins have single amino acid changes. Several drugs including the quinazoline derivative 1 (CP-31398) have been reported to restore p53 activity in mutant cells. The side chain of 1 contains a styryl linkage that compromises its stability and we wished to explore the activity of analogues containing more stable side chains. METHODS: Reactivation of p53 function was measured by flow cytometry as the ability to potentiate radiation-induced G(1)-phase cell cycle arrest and by western blotting to determine expression of p21(WAF1). DNA binding was measured by competition with ethidium and preliminary pharmacological and xenograft studies were carried out. RESULTS: Screening of analogues for potentiation of radiation-induced G(1)-phase cell cycle arrest using NZOV11, an ovarian tumour cell line containing a p53(R248Q) mutation, demonstrated that the (2-benzofuranyl)-quinazoline derivative 5 was among the most active of the analogues. Compound 5 showed similar effects in several other p53 mutant human tumour cell lines but not in a p53 null cell line. 5 also potentiated p21(WAF1) expression induced by radiation. DNA binding affinity was measured and found to correlate with p53 reactivation activity. Plasma concentrations of 5 in mice were sufficient to suggest in vivo activity and a small induced tumour growth delay (7 days) of NZM4 melanoma xenografts was observed. CONCLUSION: Compound 5 restores p53-like function to a human tumour cells lines expressing a variety of mutant p53 proteins, thus providing a basis for the design of further new drugs.

The ubiquitin-proteasome system is inhibited by p53 protein expression in human ovarian cancer cells.

The ubiquitin-proteasome system (UPS) and autophagy provide major cellular pathways for protein degradation. Since the p53 pathway controls autophagy, we investigated whether p53 regulates UPS in ovarian tumour cell lines. A reporter cell line (SKOV3-EGFPu) was established to measure UPS function against a constant genetic background. Transient expression of either wild type or mutant p53 in SKOV3-EGFPu cells reduced UPS activity as compared to vector control. These results, together with those from endogenous p53 expression in seven ovarian cancer cell lines, suggest that expression of both wild-type and mutant p53 protein impairs UPS function. Thus, p53 expression may regulate protein homeostasis by down-regulating UPS function in response to cellular stress.

The mouse polyubiquitin gene UbC is essential for fetal liver development, cell-cycle progression and stress tolerance.

UbC is one of two stress-inducible polyubiquitin genes in mammals and is thought to supplement the constitutive UbA genes in maintaining cellular ubiquitin (Ub) levels during episodes of cellular stress. We have generated mice harboring a targeted disruption of the UbC gene. UbC(-/-) embryos die between embryonic days 12.5 and 14.5 in utero, most likely owing to a severe defect in liver cell proliferation. Mouse embryonic fibroblasts from UbC(-/-) embryos exhibit reduced growth rates, premature senescence, increased apoptosis and delayed cell-cycle progression, with slightly, but significantly, decreased steady-state Ub levels. UbC(-/-) fibroblasts are hypersensitive to proteasome inhibitors and heat shock, and unable to adequately increase Ub levels in response to these cellular stresses. Most, but not all of the UbC(-/-) phenotypes can be rescued by providing additional Ub from a poly hemagglutinin-tagged Ub minigene expressed from the Hprt locus. We propose that UbC is regulated by a process that senses Ub pool dynamics. These data establish that UbC constitutes an essential source of Ub during cell proliferation and stress that cannot be compensated by other Ub genes.