A randomised trial of a T2-composite-biomarker strategy adjusting corticosteroidtreatment in severe asthma, a post- hoc analysis by sex

BACKGROUND

Approximately 5-10% of patients with asthma have severe disease with a consistent preponderance in females. Current asthma guidelines recommend stepwise treatment to achieve symptom control with no differential treatment considerations for either sex.

OBJECTIVES

To examine whether patient sex affects outcomes when using a composite T2-biomarker score to adjust corticosteroid treatment in patients with severe asthma compared to standard care.

METHODS

Post-hoc analysis stratifying patient outcomes by sex of a 48-week, multicentre, randomised controlled clinical trial comparing a biomarker-defined treatment algorithm with standard care. The primary outcome was the proportion of patients with a reduction in corticosteroid treatment (inhaled (ICS) and oral (OCS) corticosteroids). Secondary outcomes included exacerbation rates, hospital admissions and lung function.

RESULTS

Of 301 patients randomised; 194 (64.5%) were females and 107 (35.5%) were males. The biomarker algorithm led to a greater proportion of females being on a lower corticosteroid dose vs standard care which was not seen in males (effects estimate females: 3.57, 95% CI: 1.14, 11.18 vs. males 0.54, 95% CI: 0.16, 1.80). In T2-biomarker low females, reducing corticosteroid dose was not associated with increased exacerbations. Females scored higher in all ACQ-7 domains, but with no difference when adjusted for BMI/ anxiety and/or depression. Dissociation between symptoms and T2-biomarkers were noted in both sexes, with a higher proportion of females being symptom high/T2-biomarker low (22.8% vs. 15.6%; p=0.0002), whereas males were symptom low/T2-biomarker high (11.4% vs. 22.3%; p<0.0001).

CONCLUSION

This exploratory post-hoc analysis identified females achieved a greater benefit from biomarker-directed corticosteroid optimisation versus symptom-directed treatment.

An approach for evaluating early and long term mother-to-child transmission of HIV (MTCT) in low and middle income countries: a South African experience

BACKGROUND

Eliminating mother-to-child transmission of HIV is a global public health target. Robust, feasible methodologies to measure population level impact of programmes to prevent mother-to-child transmission of HIV (PMTCT) are needed in high HIV prevalence settings. We present a summary of the protocol of the South African PMTCT Evaluation (SAPMTCTE) with its revision over three repeated rounds of the survey, 2010-2014.

METHODS

Three cross sectional surveys (2010, 2011-2012 and 2012-2013) were conducted in 580 primary health care immunisation service points randomly selected after stratified multistage probability proportional to size sampling. All infants aged 4-8 weeks receiving their six-week immunisation at a sampled facility on the day of the visit were eligible to participate. Trained research nurses conducted interviews and took infant dried blood spot (iDBS) samples for HIV enzyme immunoassay (EIA) and total nucleic acid polymerase chain reaction (PCR) testing. Interviews were conducted using mobile phones and iDBS were sent to the National Health Laboratory for testing. All findings were adjusted for study design, non-response, and weighted for number of South African live-birth in each study round. In 2012 a national closed cohort of these 4 to 8-week old infants testing EIA positive (HIV Exposed Infants) from the 2012-2013 cross-sectional survey was established to estimate longer-term PMTCT impact to 18 months. Follow-up analyses were to estimate weighted cumulative MTCT until 18 months, postnatal MTCT from 6 weeks until 18 months and a combined outcome of MTCT-or-death, using a competing risks model, with death as a competing risk. HIV-free survival was defined as a child surviving and HIV-negative up to 18 months or last visit seen. A weighted cumulative incidence analysis was conducted, adjusting for survey design effects.

DISCUSSION

In the absence of robust high-quality routine medical recording systems, in the context of a generalised HIV epidemic, national surveys can be used to monitor PMTCT effectiveness; however, monitoring long-term outcomes nationally is difficult due to poor retention in care.

"I would love if there was a young woman to encourage us, to ease our anxiety which we would have if we were alone": Adapting the Mothers2Mothers Mentor Mother Model for adolescent mothers living with HIV in Malawi

Background

Pregnant and post-partum adolescent girls and young women (AGYW) living with HIV in sub-Saharan Africa experience inferior outcomes along the prevention of mother-to-child transmission of HIV (PMTCT) cascade compared to their adult counterparts. Yet, despite this inequality in outcomes, scarce data from the region describe AGYW perspectives to inform adolescent-sensitive PMTCT programming. In this paper, we report findings from formative implementation research examining barriers to, and facilitators of, PMTCT care for HIV-infected AGYW in Malawi, and explore strategies for adapting the mothers2mothers (m2m) Mentor Mother Model to better meet AGYW service delivery-related needs and preferences.

Methods

Qualitative researchers conducted 16 focus group discussions (FGDs) in 4 Malawi districts with HIV-infected adolescent mothers ages 15–19 years categorized into two groups: 1) those who had experience with m2m programming (8 FGDs, n = 38); and 2) those who did not (8 FGDs, n = 34). FGD data were analyzed using thematic analysis to assess major and minor themes and to compare findings between groups.

Results

Median participant age was 17 years (interquartile range: 2 years). Poverty, stigma, food insecurity, lack of transport, and absence of psychosocial support were crosscutting barriers to PMTCT engagement. While most participants highlighted resilience and self-efficacy as motivating factors to remain in care to protect their own health and that of their children, they also indicated a desire for tailored, age-appropriate services. FGD participants indicated preference for support services delivered by adolescent HIV-infected mentor mothers who have successfully navigated the PMTCT cascade themselves.

Conclusions

HIV-infected adolescent mothers expressed a preference for peer-led, non-judgmental PMTCT support services that bridge communities and facilities to pragmatically address barriers of stigma, poverty, health system complexity, and food insecurity. Future research should evaluate implementation and health outcomes for adolescent mentor mother services featuring these and other client-centered attributes, such as provision of livelihood assistance and peer-led psychosocial support.

Oral medicine acceptance in infants and toddlers: measurement properties of the caregiver-administered Children's acceptance tool (CareCAT)

BACKGROUND

Developing age-appropriate medications remains a challenge in particular for the population of infants and toddlers, as they are not able to reliably self-report if they would accept and consequently take an oral medicine. Therefore, it is common to use caregivers as proxies when assessing medicine acceptance. The outcome measures used in this research field differ and most importantly lack validation, implying a persisting gap in knowledge and controversy in the field. The newly developed Caregiver-administered Children's Acceptance Tool (CareCAT) is based on a 5-point nominal scale, with descriptors of medication acceptance behavior. This cross-sectional study assessed the measurement properties of the tool with regards to the user's understanding and its intra- and inter-rater reliability.

METHODS

Participating caregivers were enrolled at a primary healthcare facility where their children (median age 6 months) had been prescribed oral antibiotics. Caregivers, trained observers and the tool developer observed and scored on the CareCAT tool what behavior children exhibited when receiving the medicine (n = 104). The video-records of this process served as replicate observations (n = 69). After using the tool caregivers were asked to explain their observations and the tool descriptors in their own words. The tool's reliability was assessed by percentage agreement and Cohen's unweighted kappa coefficients of agreement for nominal scales.

RESULTS

The study found that caregivers using CareCAT had a satisfactory understanding of the tool's descriptors. Using its dichotomized scores the tool reliably was strong for acceptance behavior (agreement inter-rater 84-88%, kappa 0.66-0.76; intra-rater 87-89%, kappa 0.68-0.72) and completeness of medicine ingestion (agreement inter-rater 82-86%, kappa 0.59-0.67; intra-rater 85-93%, kappa 0.50-0.70).

CONCLUSIONS

The CareCAT is a low-cost, easy-to-use and reliable instrument, which is relevant to assess acceptance behavior and completeness of medicine ingestion, both of which are of significant importance for developing age-appropriate medications in infants and toddlers.

Association of ORMDL3 with rhinovirus-induced endoplasmic reticulum stress and type I Interferon responses in human leucocytes

BACKGROUND

Children with risk alleles at the 17q21 genetic locus who wheeze during rhinovirus illnesses have a greatly increased likelihood of developing childhood asthma. In mice, overexpression of the 17q21 gene ORMDL3 leads to airway remodelling and hyperresponsiveness. However, the mechanisms by which ORMDL3 predisposes to asthma are unclear. Previous studies have suggested that ORMDL3 induces endoplasmic reticulum (ER) stress and production of the type I interferon (IFN)-regulated chemokine CXCL10.

OBJECTIVE

The purpose of this study was to determine the relationship between ORMDL3 and rhinovirus-induced ER stress and type I IFN in human leucocytes.

METHODS

ER stress was monitored by measuring HSPA5, CHOP and spliced XBP1 gene expression, and type I IFN by measuring IFNB1 (IFN-β) and CXCL10 expression in human cell lines and primary leucocytes following treatment with rhinovirus. Requirements for cell contact and specific cell type in ORMDL3 induction were examined by transwell assay and depletion experiments, respectively. Finally, the effects of 17q21 genotype on the expression of ORMDL3, IFNB1 and ER stress genes were assessed.

RESULTS

THP-1 monocytes overexpressing ORMDL3 responded to rhinovirus with increased IFNB1 and HSPA5. Rhinovirus-induced ORMDL3 expression in primary leucocytes required cell-cell contact, and induction was suppressed by plasmacytoid dendritic cell depletion. The degree of rhinovirus-induced ORMDL3, HSPA5 and IFNB1 expression varied by leucocyte type and 17q21 genotype, with the highest expression of these genes in the asthma-associated genotype.

CONCLUSIONS AND CLINICAL RELEVANCE

Multiple lines of evidence support an association between higher ORMDL3 and increased rhinovirus-induced HSPA5 and type I IFN gene expression. These associations with ORMDL3 are cell type specific, with the most significant 17q21 genotype effects on ORMDL3 expression and HSPA5 induction evident in B cells. Together, these findings have implications for how the interaction of increased ORMDL3 and rhinovirus may predispose to asthma.

In Utero ART Exposure and Birth and Early Growth Outcomes Among HIV-Exposed Uninfected Infants Attending Immunization Services: Results From National PMTCT Surveillance, South Africa

BACKGROUND

Despite the recognized benefit of antiretroviral therapy (ART) for preventing and treating HIV, some studies have reported adverse birth outcomes with in utero ART exposure. We evaluated the effect of infant in utero HIV and ART exposure on preterm delivery (PTD), low birth weight (LBW), small for gestational age (SGA), and underweight for age (UFA) at 6 weeks.

METHODS

We surveyed 6179 HIV-unexposed-uninfected (HUU) and 2599 HIV-exposed-uninfected (HEU) infants. HEU infants were stratified into 3 groups: ART, Zidovudine alone, and no antiretrovirals (None). The ART group was further stratified to explore pre- or postconception exposure. Multivariable logistic regression evaluated effects of HIV and ARV exposure on the outcomes.

RESULTS

We found higher odds of PTD, LBW, SGA, and UFA in HEU than HUU infants. HEU in the None group (adjusted odds ratio [AOR], 1.9; 95% confidence interval [CI], 1.2-3.0) or those whose mothers initiated ART preconception (AOR, 1.7; 95% CI, 1.1-2.5) had almost twice the odds of PTD than infants whose mothers started ART postconception, but no increased odds for other outcomes.

CONCLUSIONS

There was an association between preconception ART and PTD. As ART access increases, pregnancy registers or similar surveillance should be in place to monitor outcomes to inform future policy.

Structural Level Differences in the Mother-to-Child HIV Transmission Rate in South Africa: A Multilevel Assessment of Individual-, Health Facility-, and Provincial-Level Predictors of Infant HIV Transmission

OBJECTIVES

In 2010, South Africa reported an early mother-to-child transmission (MTCT) rate of 3.5% at 4-8 weeks postpartum. Provincial early MTCT rates ranged from 1.4% [95% confidence interval (CI): 0.1 to 3.4] to 5.9% (95% CI: 3.8 to 8.0). We sought to determine reasons for these geographic differences in MTCT rates.

METHODS

This study used multilevel modeling using 2010 South African prevention of mother-to-child transmission (PMTCT) evaluation (SAPMTCTE) data from 530 facilities. Interview data and blood samples of infants were collected from 3085 mother-infant pairs at 4-8 weeks postpartum. Facility-level data on human resources, referral systems, linkages to care, and record keeping were collected through facility staff interviews. Provincial level data were gathered from publicly available data (eg, health professionals per 10,000 population) or aggregated at province-level from the SAPMTCTE (PMTCT maternal-infant antiretroviral (ARV) coverage). Variance partition coefficients and odds ratios (for provincial facility- and individual-level factors influencing MTCT) from multilevel modeling are reported.

RESULTS

The provincial- (5.0%) and facility-level (1.4%) variance partition coefficients showed no substantive geographic variation in early MTCT. In multivariable analysis accounting for the multilevel nature of the data, the following were associated with early MTCT: individual-level-low maternal-infant ARV uptake [adjusted odds ratio (AOR) = 2.5, 95% CI: 1.7 to 3.5], mixed breastfeeding (AOR = 1.9, 95% CI: 1.3 to 2.9) and maternal age <20 years (AOR 1.8, 95% CI: 1.1 to 3.0); facility-level-insufficient (≤2) health care-personnel for HIV-testing services (AOR = 1.8, 95% CI: 1.1 to 3.0); provincial-level PMTCT ARV (maternal-infant) coverage lower than 80% (AOR = 1.4, 95% CI: 1.1 to 1.9), and number of health professionals per 10,000 population (AOR = 0.99, 95% CI: 0.98 to 0.99).

CONCLUSIONS

There was no substantial province-/facility-level MTCT difference. This could be due to good overall performance in reducing early MTCT. Disparities in human resource allocation (including allocation of insufficient health care personnel for testing and care at facility level) and PMTCT coverage influenced overall PMTCT programme performance. These are long-standing systemic problems that impact quality of care.

Toward elimination of mother-to-child transmission of HIV in South Africa: how best to monitor early infant infections within the Prevention of Mother-to-Child Transmission Program

BACKGROUND

South Africa has utilized three independent data sources to measure the impact of its program for the prevention of mother-to-child transmission (PMTCT) of HIV. These include the South African National Health Laboratory Service (NHLS), the District Health Information System (DHIS), and South African PMTCT Evaluation (SAPMTCTE) surveys. We compare the results of each, outlining advantages and limitations, and make recommendations for monitoring transmission rates as South Africa works toward achieving elimination of mother-to-child transmission (eMTCT).

METHODS

HIV polymerase chain reaction (PCR) test data, collected between 1 January 2010 to 31 December 2014, from the NHLS, DHIS and SAPMTCTE surveys were used to compare early mother-to-child transmission (MTCT) rates in South Africa. Data from the NHLS and DHIS were also used to compare early infant diagnosis (EID) coverage.

RESULTS

The age-adjusted NHLS early MTCT rates of 4.1% in 2010, 2.6% in 2011 and 2.3% in 2012 consistently fall within the 95% confidence interval as measured by three SAPMTCTE surveys in corresponding time periods. Although DHIS data over-estimated MTCT rates in 2010, the MTCT rate declines thereafter to converge with age-adjusted NHLS MTCT rates by 2012. National EID coverage from NHLS data increases from around 52% in 2010 to 87% in 2014. DHIS data over-estimates EID coverage, but this can be corrected by employing an alternative estimate of the HIV-exposed infant population.

CONCLUSION

NHLS and DHIS, two routine data sources, provide very similar early MTCT rate estimates that fall within the SAPMTCTE survey confidence intervals for 2012. This analysis validates the usefulness of routine data sources to track eMTCT in South Africa.

Population-level effectiveness of PMTCT Option A on early mother-to-child (MTCT) transmission of HIV in South Africa: implications for eliminating MTCT

Background

Eliminating mother–to–child transmission of HIV (EMTCT), defined as ≤50 infant HIV infections per 100 000 live births, is a global priority. Since 2011 policies to prevent mother–to–child transmission of HIV (PMTCT) shifted from maternal antiretroviral (ARV) treatment or prophylaxis contingent on CD4 cell count to lifelong maternal ARV treatment (cART). We sought to measure progress with early (4–8 weeks postpartum) MTCT prevention and elimination, 2011–2013, at national and sub–national levels in South Africa, a high antenatal HIV prevalence setting ( ≈ 29%), where early MTCT was 3.5% in 2010.

Methods

Two surveys were conducted (August 2011–March 2012 and October 2012–May 2013), in 580 health facilities, randomly selected after two–stage probability proportional to size sampling of facilities (the primary sampling unit), to provide valid national and sub–national–(provincial)–level estimates. Data collectors interviewed caregivers of eligible infants, reviewed patient–held charts, and collected infant dried blood spots (iDBS). Confirmed positive HIV enzyme immunoassay (EIA) and positive total HIV nucleic acid polymerase chain reaction (PCR) indicated infant HIV exposure or infection, respectively. Weighted survey analysis was conducted for each survey and for the pooled data.

Findings

National data from 10 106 and 9120 participants were analyzed (2011–12 and 2012–13 surveys respectively). Infant HIV exposure was 32.2% (95% confidence interval (CI) 30.7–33.6%), in 2011–12 and 33.1% (95% CI 31.8–34.4%), provincial range of 22.1–43.6% in 2012–13. MTCT was 2.7% (95% CI 2.1%–3.2%) in 2011–12 and 2.6% (95% CI 2.0–3.2%), provincial range of 1.9–5.4% in 2012–13. HIV–infected ARV–exposed mothers had significantly lower unadjusted early MTCT (2.0% [2011–12: 1.6–2.5%; 2012–13:1.5–2.6%]) compared to HIV–infected ARV–naive mothers [10.2% in 2011–12 (6.5–13.8%); 9.2% in 2012–13 (5.6–12.7%)]. Pooled analyses demonstrated significantly lower early MTCT among exclusive breastfeeding (EBF) mothers receiving >10 weeks ARV prophylaxis or cART compared with EBF and no ARVs: (2.2% [95% CI 1.25–3.09%] vs 12.2% [95% CI 4.7–19.6%], respectively); among HIV–infected ARV–exposed mothers, 24.9% (95% CI 23.5–26.3%) initiated cART during or before the first trimester, and their early MTCT was 1.2% (95% CI 0.6–1.7%). Extrapolating these data, assuming 32% EIA positivity and 2.6% or 1.2% MTCT, 832 and 384 infants per 100 000 live births were HIV infected, respectively.

Conclusions

Although we demonstrate sustained national–level PMTCT impact in a high HIV prevalence setting, results are far–removed from EMTCT targets. Reducing maternal HIV prevalence and treating all maternal HIV infection early are critical for further progress.

Genetic associations with viral respiratory illnesses and asthma control in children

BACKGROUND

Viral respiratory infections can cause acute wheezing illnesses in children and exacerbations of asthma.

OBJECTIVE

We sought to identify variation in genes with known antiviral and pro-inflammatory functions to identify specific associations with more severe viral respiratory illnesses and the risk of virus-induced exacerbations during the peak fall season.

METHODS

The associations between genetic variation at 326 SNPs in 63 candidate genes and 10 phenotypes related to viral respiratory infection and asthma control were examined in 226 children enrolled in the RhinoGen study. Replication of asthma control phenotypes was performed in 2128 children in the Copenhagen Prospective Study on Asthma in Childhood (COPSAC). Significant associations in RhinoGen were further validated using virus-induced wheezing illness and asthma phenotypes in an independent sample of 122 children enrolled in the Childhood Origins of Asthma (COAST) birth cohort study.

RESULTS

A significant excess of P values smaller than 0.05 was observed in the analysis of the 10 RhinoGen phenotypes. Polymorphisms in 12 genes were significantly associated with variation in the four phenotypes showing a significant enrichment of small P values. Six of those genes (STAT4, JAK2, MX1, VDR, DDX58, and EIF2AK2) also showed significant associations with asthma exacerbations in the COPSAC study or with asthma or virus-induced wheezing phenotypes in the COAST study.

CONCLUSIONS

We identified genetic factors contributing to individual differences in childhood viral respiratory illnesses and virus-induced exacerbations of asthma. Defining mechanisms of these associations may provide insight into the pathogenesis of viral respiratory infections and virus-induced exacerbations of asthma.

Effects of early feeding on growth velocity and overweight/obesity in a cohort of HIV unexposed South African infants and children

BACKGROUND

South Africa has the highest prevalence of overweight/obesity in Sub-Saharan Africa. Assessing the effect of modifiable factors such as early infant feeding on growth velocity and overweight/obesity is therefore important. This paper aimed to assess the effect of infant feeding in the transitional period (12 weeks) on 12-24 week growth velocity amongst HIV unexposed children using WHO growth velocity standards and on the age and sex adjusted body mass index (BMI) Z-score distribution at 2 years.

METHODS

Data were from 3 sites in South Africa participating in the PROMISE-EBF trial. We calculated growth velocity Z-scores using the WHO growth standards and assessed feeding practices using 24-hour and 7-day recall data. We used quantile regression to study the associations between 12 week infant feeding and 12-24 week weight velocity (WVZ) with BMI-for-age Z-score at 2 years. We included the internal sample quantiles (70th and 90th centiles) that approximated the reference cut-offs of +2 (corresponding to overweight) and +3 (corresponding to obesity) of the 2 year BMI-for-age Z-scores.

RESULTS

At the 2-year visit, 641 children were analysed (median age 22 months, IQR: 17-26 months). Thirty percent were overweight while 8.7% were obese. Children not breastfed at 12 weeks had higher 12-24 week mean WVZ and were more overweight and obese at 2 years. In the quantile regression, children not breastfed at 12 weeks had a 0.37 (95% CI 0.07, 0.66) increment in BMI-for-age Z-score at the 50th sample quantile compared to breast-fed children. This difference in BMI-for-age Z-score increased to 0.46 (95% CI 0.18, 0.74) at the 70th quantile and 0.68 (95% CI 0.41, 0.94) at the 90th quantile . The 12-24 week WVZ had a uniform independent effect across the same quantiles.

CONCLUSIONS

This study demonstrates that the first 6 months of life is a critical period in the development of childhood overweight and obesity. Interventions targeted at modifiable factors such as early infant feeding practices may reduce the risks of rapid weight gain and subsequent childhood overweight/obesity.

Late outcomes in adults with coarctation of the aorta

AIMS

Previous cohort studies of patients with coarctation of the aorta (CoA) demonstrate reduced long-term survival. Improved surgical outcomes in children and evolution of adult congenital heart disease (ACHD) services have resulted in improved survival in patients with other CHDs. We hypothesise that for young adult patients with CoA long-term outcomes have improved in the contemporary era.

METHODS

151 patients (58% men) with simple CoA followed up at a tertiary ACHD service in Sydney, Australia, from 1993 to 2013 were included. We documented mortality and major morbidity such as the need for re-intervention for re-coarctation or aneurysms.

RESULTS

140 patients (mean age 35±15 years) underwent CoA repair at median age of 5 (IQR 0-10) years. Initial surgical strategy included end-to-end repair in 43, subclavian flap aortoplasty in 28 and patch aortoplasty in 31 patients (and was not documented in 28 cases). 6 patients had endovascular repair, 4 had interposition tube grafts and 11 were unrepaired. There were a total of seven deaths at a median age of 60 years. Actuarial survival was 98% at 40, 98% at 50 and 89% at 60 years of age. Re-coarctation occurred in 34% and descending aortic aneurysms were noted in 18%. Patients with end-to-end repair had lower rates of significant re-coarctation or descending aortic aneurysms (p=0.026 and <0.001, respectively). 66% had bicuspid aortic valve and 44% were hypertensive.

CONCLUSIONS

Patients with CoA who reach adolescence demonstrate very good long-term survival up to age 60 years. Long-term morbidity is common, however, related largely to aortic complications and late hypertension.

First population-level effectiveness evaluation of a national programme to prevent HIV transmission from mother to child, South Africa

Background

There is a paucity of data on the national population-level effectiveness of preventing mother-to-child transmission (PMTCT) programmes in high-HIV-prevalence, resource-limited settings. We assessed national PMTCT impact in South Africa (SA), 2010.

Methods

A facility-based survey was conducted using a stratified multistage, cluster sampling design. A nationally representative sample of 10 178 infants aged 4–8 weeks was recruited from 565 clinics. Data collection included caregiver interviews, record reviews and infant dried blood spots to identify HIV-exposed infants (HEI) and HIV-infected infants. During analysis, self-reported antiretroviral (ARV) use was categorised: 1a: triple ARV treatment; 1b: azidothymidine >10 weeks; 2a: azidothymidine ≤10 weeks; 2b: incomplete ARV prophylaxis; 3a: no antenatal ARV and 3b: missing ARV information. Findings were adjusted for non-response, survey design and weighted for live-birth distributions.

Results

Nationally, 32% of live infants were HEI; early mother-to-child transmission (MTCT) was 3.5% (95% CI 2.9% to 4.1%). In total 29.4% HEI were born to mothers on triple ARV treatment (category 1a) 55.6% on prophylaxis (1b, 2a, 2b), 9.5% received no antenatal ARV (3a) and 5.5% had missing ARV information (3b). Controlling for other factors groups, 1b and 2a had similar MTCT to 1a (Ref; adjusted OR (AOR) for 1b, 0.98, 0.52 to 1.83; and 2a, 1.31, 0.69 to 2.48). MTCT was higher in group 2b (AOR 3.68, 1.69 to 7.97). Within group 3a, early MTCT was highest among breastfeeding mothers 11.50% (4.67% to 18.33%) for exclusive breast feeding, 11.90% (7.45% to 16.35%) for mixed breast feeding, and 3.45% (0.53% to 6.35%) for no breast feeding). Antiretroviral therapy or >10 weeks prophylaxis negated this difference (MTCT 3.94%, 1.98% to 5.90%; 2.07%, 0.55% to 3.60% and 2.11%, 1.28% to 2.95%, respectively).

Conclusions

SA, a high-HIV-prevalence middle income country achieved <5% MTCT by 4–8 weeks post partum. The long-term impact on PMTCT on HIV-free survival needs urgent assessment.

Human platelet antigen (HPA)-1a peptides do not reliably suppress anti-HPA-1a responses using a humanized severe combined immunodeficiency (SCID) mouse model

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) occurs most frequently when human platelet antigen (HPA)-1a-positive fetal platelets are destroyed by maternal HPA-1a immunoglobulin (Ig)G antibodies. Pregnancies at risk are treated by administration of high-dose intravenous Ig (IVIG) to women, but this is expensive and often not well tolerated. Peptide immunotherapy may be effective for ameliorating some allergic and autoimmune diseases. The HPA-1a/1b polymorphism is Leu/Pro33 on β3 integrin (CD61), and the anti-HPA-1a response is restricted to HPA-1b1b and HLA-DRB3*0101-positive pregnant women with an HPA-1a-positive fetus. We investigated whether or not HPA-1a antigen-specific peptides that formed the T cell epitope could reduce IgG anti-HPA-1a responses, using a mouse model we had developed previously. Peripheral blood mononuclear cells (PBMC) in blood donations from HPA-1a-immunized women were injected intraperitoneally (i.p.) into severe combined immunodeficient (SCID) mice with peptides and HPA-1a-positive platelets. Human anti-HPA-1a in murine plasma was quantitated at intervals up to 15 weeks. HPA-1a-specific T cells in PBMC were identified by proliferation assays. Using PBMC of three donors who had little T cell reactivity to HPA-1a peptides in vitro, stimulation of anti-HPA-1a responses by these peptides occurred in vivo. However, with a second donation from one of these women which, uniquely, had high HPA-1a-specific T cell proliferation in vitro, marked suppression of the anti-HPA-1a response by HPA-1a peptides occurred in vivo. HPA-1a peptide immunotherapy in this model depended upon reactivation of HPA-1a T cell responses in the donor. For FNAIT, we suggest that administration of antigen-specific peptides to pregnant women might cause either enhancement or reduction of pathogenic antibodies.

HIV infection, viral load, low birth weight, and nevirapine are independent influences on growth velocity in HIV-exposed South African infants

Data from a prospective multisite cohort study were used to examine the effect of HIV exposure, untreated HIV infection, and single-dose nevirapine on infant growth velocity. The 2009 WHO growth velocity standards constitute a new tool for this type of investigation and are in need of functional validation. In period 1 (3-24 wk), 65 HIV-infected, 502 HIV-exposed uninfected (HEU), and 216 HIV-unexposed infants were included. In period 2 (25-36 wk), 31 infants moved from the HEU group to the HIV-infected group. We compared weight velocity Z-scores (WVZ) and length velocity Z-scores (LVZ) by HIV group and assessed their independent influences. In period 1, mean WVZ (95% CI) was significantly (P < 0.001) lower in infected [-0.87 (-1.77, 0.04)] than HEU [0.81 (0.67, 0.94)] and unexposed [0.55 (0.33, 0.78)] infants. LVZ showed similar associations. In both periods, sick infants and those exposed to higher maternal viral loads had lower WVZ. Higher mean LVZ was associated with low birth weight. Infants that had received nevirapine had higher LVZ. In conclusion, HIV infection and not exposure was associated with low WVZ and LVZ in period 1. Eliminating infant HIV infection is a critical component in averting HIV-related poor growth patterns in infants in the first 6 mo of life.

Specific patterns of allergic sensitization in early childhood and asthma & rhinitis risk

BACKGROUND

Specific patterns of allergic sensitization as well as quantification of the in vitro IgE response in early life may provide relevant clinical insight into future rhinitis and asthma risk.

OBJECTIVE

To define relationships among established sensitization to particular aeroallergens, quantitative analyses of allergen-specific IgE levels, pet exposure and sensitization, and asthma and rhinitis risk.

METHODS

Children at high-risk for the development of asthma and allergic diseases were enrolled at birth into the Childhood Origins of ASThma (COAST) study. Allergen-specific IgE was assessed at ages 1, 3, 6, and 9 years by fluoroenzyme immunoassay (Unicap(®) 100; Pharmacia Diagnostics). Current asthma and rhinitis were diagnosed at age 6 and 8 years.

RESULTS

Sensitization to dog was strongly associated with increased asthma risk (P < 0.0001). Sensitization to perennial compared with seasonal allergens was more strongly associated with asthma risk, while sensitization to seasonal allergens was more closely associated with rhinitis risk. Increased levels of specific IgE to perennial allergens were associated with an increased asthma risk (P = 0.05), while any detectable level of IgE to seasonal allergens was associated with increased rhinitis risk (P = 0.0009). While dog and cat sensitization were both independently associated with increased asthma and rhinitis risk, dog exposure at birth was associated with a reduced risk of asthma, regardless of dog sensitization status during the first 6 years of life (P = 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

Analysing specific patterns of an individual's allergic sensitization profile reveals additional relevant associations with asthma and rhinitis risk as opposed to the information gained from characterizing an individual as 'atopic' by the presence of any demonstrable sensitization alone. Furthermore, protective mechanisms of dog exposure with regards to asthma risk appear to be unrelated to the prevention of sensitization.

International consensus on (ICON) pediatric asthma

Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.

Infant feeding practices at routine PMTCT sites, South Africa: results of a prospective observational study amongst HIV exposed and unexposed infants - birth to 9 months

BACKGROUND

We sought to investigate infant feeding practices amongst HIV-positive and -negative mothers (0-9 months postpartum) and describe the association between infant feeding practices and HIV-free survival.

METHODS

Infant feeding data from a prospective observational cohort study conducted at three (of 18) purposively-selected routine South African PMTCT sites, 2002-2003, were analysed. Infant feeding data (previous 4 days) were gathered during home visits at 3, 5, 7, 9, 12, 16, 20, 24, 28, 32 and 36 weeks postpartum. Four feeding groups were of interest, namely exclusive breastfeeding, mixed breastfeeding, exclusive formula feeding and mixed formula feeding. Cox proportional hazards models were fitted to investigate associations between feeding practices (0-12 weeks) and infant HIV-free survival.

RESULTS

Six hundred and sixty five HIV-positive and 218 HIV-negative women were recruited antenatally and followed-up until 36 weeks postpartum. Amongst mothers who breastfed between 3 weeks and 6 months postpartum, significantly more HIV-positive mothers practiced exclusive breastfeeding compared with HIV-negative: at 3 weeks 130 (42%) versus 33 (17%) (p < 0.01); this dropped to 17 (11%) versus 1 (0.7%) by four months postpartum. Amongst mothers practicing mixed breastfeeding between 3 weeks and 6 months postpartum, significantly more HIV-negative mothers used commercially available breast milk substitutes (p < 0.02) and use of these peaked between 9 and 12 weeks. The probability of postnatal HIV or death was lowest amongst infants living in the best resourced site who avoided breastfeeding, and highest amongst infants living in the rural site who stopped breastfeeding early (mean and standard deviations: 10.7% ± 3% versus 46% ± 11%).

CONCLUSIONS

Although feeding practices were poor amongst HIV-positive and -negative mothers, HIV-positive mothers undertake safer infant feeding practices, possibly due to counseling provided through the routine PMTCT programme. The data on differences in infant outcome by feeding practice and site validate the WHO 2009 recommendations that site differences should guide feeding practices amongst HIV-positive mothers. Strong interventions are needed to promote exclusive breastfeeding (to 6 months) with continued breastfeeding thereafter amongst HIV-negative motherswho are still the majority of mothers even in high HIV prevalence setting like South Africa.

An evolutionary fast-track to biocalcification

The ability to construct mineralized shells, spicules, spines and skeletons is thought to be a key factor that fuelled the expansion of multicellular animal life during the early Cambrian. The genes and molecular mechanisms that control the process of biomineralization in disparate phyla are gradually being revealed, and it is broadly recognized that an insoluble matrix of proteins, carbohydrates and other organic molecules are required for the initiation, regulation and inhibition of crystal growth. Here, we show that Astrosclera willeyana, a living representative of the now largely extinct stromatoporid sponges (a polyphyletic grade of poriferan bauplan), has apparently bypassed the requirement to evolve many of these mineral-regulating matrix proteins by using the degraded remains of bacteria to seed CaCO(3) crystal growth. Because stromatoporid sponges formed extensive reefs during the Paelozoic and Mesozoic eras (fulfilling the role that stony corals play in modern coral reefs), and fossil evidence suggests that the same process of bacterial skeleton formation occurred in these stromatoporid ancestors, we infer that some ancient reef ecosystems might have been founded on this microbial-metazoan relationship.

An update on HIV and infant feeding issues in developed and developing countries

The field of mother to child transmission of human-immunodeficiency virus is rapidly evolving. In the United States, prevention focuses on implementation of universal human-immunodeficiency virus testing to assure compliance with recommended treatment regimens and infant-feeding strategies. In most cases, this is the avoidance of all breastfeeding. In developing countries, avoidance of breastfeeding places infants at higher risk of morbidity and mortality. Current World Health Organization recommendations require individualized counseling to determine the best feeding method for each woman.

Transfers among women intending a birth center delivery in the San Diego birth center study

Using data from the San Diego Birth Center Study that enrolled underserved women between 1994 and 1996, we examined demographic, sociobehavioral, and medical predictors of hospital transfer in a group of women who intended to deliver at a freestanding birth center. Of the 1808 women, 34.6% transferred to the hospital antenatally and 19.6% transferred during labor, while 45.7% delivered at the birth center. Compared with multiparous women who had never had a cesarean and never had a previous hospital delivery, nulliparous women were 2.0 times more likely (95% confidence interval [CI], 1.4-2.7), multiparous women with a previous cesarean were 2.6 times more likely (95% CI, 1.7-3.8), and women without a previous cesarean but who had a previous hospital delivery were 2.1 times more likely (95% CI, 1.5-3.0) to transfer after adjusting for other predictors of transfer. Nulliparity, cesarean history and having a previous hospital delivery were among the strongest predictors of a hospital transfer even after adjusting for demographic, sociobehavioral, and other medical conditions. Understanding predictors of transfer may assist practitioners, patients, and policy makers in considering the appropriateness of individuals for birth center delivery or to target further education to reduce nonmedical transfers.

Knowledge, attitudes and practices related to healthy childbearing in the West Coast/Winelands

INTRODUCTION

Many of the known risk factors associated with low birth weight (LBW) infants, such as socio-economic status, ethnicity, genetic makeup, and obstetric history, are not within a woman's immediate control. However, there are many things that a woman can do to improve her chances of having a normal healthy child. Lifestyle behaviours, such as cigarette smoking, nutrition and the use of alcohol, play an important role in determining the growth of the foetus. There is a high rate of low birth weight infants born to women living and working on the farms in the Western Cape. Very little is known about the knowledge, attitudes and practices of the women living and working on the farms that may be influencing their pregnancy outcomes. The aim of this qualitative exploratory study was to establish the knowledge, attitudes and practices of reproductive age women related to lifestyle factors such as alcohol use, smoking and nutrition, and the perceptions of these factors by health care workers, in Stellenbosch and Vredendal areas (small towns in the Western Cape).

METHODS

Four methods of data collection were employed: focus groups and individual interviews with women on farms, and focus groups and semi-structured interviews with health workers. All focus groups and interviews were recorded, transcribed, and then coded to form themes. Findings were then triangulated across data collection methods.

RESULTS

Participants described high levels of use of alcohol and cigarettes by women living on the farms in general, and in pregnancy, despite reasonable levels of awareness of the dangers to the foetus. Regarding nutrition, women have a fairly good sense of eating in a balanced way during pregnancy, but affording this on very low wages is difficult. Many ideas regarding how to increase healthy lifestyles were offered, ranging from environmental improvements, such as access to recreational facilities and handwork classes, to more contact with health services, and improvement in conditions of employment.

CONCLUSION

This study highlights the lifestyle factors related to LBW infants on farms, and proposes that these should be addressed collectively by all the relevant sectors in the community. Although some of these processes have been initiated, there are gaps in the health services, which should be addressed immediately to provide women with opportunities to ensure acceptable pregnancy outcomes.

Early postpartum breastfeeding and acculturation among Hispanic women

BACKGROUND

Exclusive breastfeeding in the hospital is predictive of postpartum breastfeeding patterns. Although breastfeeding rates are similar for Hispanic and white women in the United States, evidence shows that more acculturated Hispanic mothers have lower rates of breastfeeding than those less acculturated. To date, no studies have examined whether this pattern exists in the immediate postpartum period.

METHODS

We used medical record data from 1,635 participants in the San Diego Birth Center Study, a cohort study of low-income, low-risk pregnant women. We applied a proxy measure of acculturation to categorize participants into a low acculturation (Hispanic, Spanish speaking [n = 951]); high acculturation (Hispanic, English speaking [n = 408]); or white, English speaking (n = 276) group. Logistic regression was used to examine the relationship between acculturation and exclusive breastfeeding at the time of hospital discharge while controlling for potential confounders.

RESULTS

Exclusive breastfeeding rates were significantly different across acculturation groups (p < 0.01). After adjusting for available confounding variables, women in the low acculturation group were more likely to breastfeed exclusively at discharge than those in the high acculturation group (OR = 1.36, 95% CI = 1.01-1.84). Women in the white, English-speaking group also had greater odds of exclusive breastfeeding when compared with those in the high acculturation group (OR = 1.49, 95% CI = 1.02-2.19).

CONCLUSIONS

This cross-sectional study provides evidence of a correlation between acculturation and immediate postpartum breastfeeding, where higher acculturation is associated with lower odds of exclusive breastfeeding. Additional research is needed to understand how the process of acculturation may affect short- and long-term breastfeeding behavior.

Effect of smoking and alcohol use during pregnancy on the occurrence of low birthweight in a farming region in South Africa

The aim of this case-control study was to determine the risk factors for low birthweight in a farming region in South Africa, with particular attention to maternal alcohol use and smoking, both independently and in combination. Data collection was via structured postpartum interviews and review of antenatal and delivery records. The study setting was a regional referral hospital in a farming region. The study subjects were 200 infants with birthweight < 2500 g (cases) and 200 unmatched control infants of normal weight born during the same period as the cases. The outcome measure was low birthweight, i.e. infant birthweight <2500 g. Results showed the contribution of term low birthweight (as a measure of intrauterine growth retardation) to the total low-birthweight incidence was almost 50%, indicating a substantial intrauterine growth retardation component in this population. Sociodemographic factors were not as predictive of low birthweight in this predominantly low income population. Smoking (adjusted OR 2.67, [95% CI 1.69, 4.20]) was the strongest life style-related predictor of low birthweight. The alcohol low-birthweight relationship was not significant when adjusted for smoking status (crude OR 2.15, [95% CI 1.37, 3.39]; adjusted OR 1.32, [95% CI 0.80, 2.20]). However, there appeared to be an interaction with combined use of these two substances during pregnancy that increased the risk of low birthweight (adjusted OR increased to 4.24, [95% CI 1.01, 17.76]. It is clear that life style factors such as smoking and drinking are contributing to the occurrence of low birthweight in the target region. A comprehensive health promotion programme needs to be implemented as an integral part of antenatal and family planning services, to reduce smoking and drinking by women in this community.

Operational effectiveness and 36 week HIV-free survival in the South African programme to prevent mother-to-child transmission of HIV-1

OBJECTIVE

Previous studies on the operational effectiveness of programmes to reduce transmission of HIV from mother-to-child (PMTCT) in Africa have generally been hospital-based pilot studies with short follow-up periods.

METHOD

Prospective cohort study to evaluate the routine operational effectiveness of the South African National PMTCT Programme, primarily measured by HIV-free survival at 36 weeks post-delivery. Three of eighteen pilot sites participating in the programme were selected as they reflected differences in circumstances, such as HIV prevalence, socioeconomic status and rural-urban location. A total of 665 HIV-positive mothers and their infants were followed.

RESULTS

HIV-free survival at 36 weeks varied significantly across sites with 84% in Paarl, 74% in Umlazi and 65% in Rietvlei (P = 0.0003). Maternal viral load was the single most important factor associated with HIV transmission or death [hazard ratio (HR), 1.54; 95% confidence interval (CI), 1.21-1.95]. Adjusting for health system variables (fewer than four antenatal visits and no antenatal syphilis test) explained the difference between Rietvlei and Paarl (crude HR, 2.27; 95% CI, 1.36-3.77; adjusted HR, 1.81; 95% CI, 0.93-3.50). Exposure to breastmilk feeding explained the difference between Umlazi and Paarl (crude HR, 1.74; 95% CI, 1.06-2.84; adjusted HR, 1.41; 95% CI, 0.81-2.48).

CONCLUSION

Ever breastfeeding and underlying inequities in healthcare quality within South Africa are predictors of PMTCT programme performance and will need to be addressed to optimize PMTCT effectiveness.

Reactivity of T cells from women with antibodies to the human platelet antigen (HPA)-1a to peptides encompassing the HPA-1 polymorphism

The human platelet antigen-1a (HPA-1a) is the most common alloantigenic target in fetal and neonatal alloimmune thrombocytopenia (NAIT). Treatment currently depends on the outcome in previous pregnancies. HPA-1 specific T cell responses were determined in 14 HPA-1a alloimmunized women during or after pregnancies affected by NAIT. Peripheral blood mononuclear cells were incubated with peptides encompassing the Leu33Pro polymorphism (residues 20-39 and 24-45 in both Leu33 (HPA-1a) and Pro33 (HPA-1b) forms) or control recall antigens in the presence of autologous sera and T cell proliferation was measured by (3)H-thymidine incorporation. Control antenatal and postpartum sera suppressed T cell proliferation and use of such sera was avoided. Most patients (86%) responded to the HPA-1a peptides with 64% also having weaker T cell proliferation to the HPA-1b peptides; 14% had no activity towards any peptide despite responding to control antigens. Administration of IVIG during pregnancy appeared to reduce T cell reactivity to HPA-1 peptides. Postnatal anti-HPA-1a T cell responses from women who had a severe history of NAIT (an intracranial haemorrhage in a previous fetus) were greater than those from women with a mild history. This assay may have the potential to predict disease severity if performed prior to or early in pregnancy.

Correlation between blood and milk serum leptin in goats and growth of their offspring

Boer and Boer crossbred meat-type does were used in two experiments to determine whether goat milk serum contains leptin and to investigate possible correlations of milk and serum leptin in does and subsequent growth of their offspring. Blood and milk samples were collected within 2 h of kidding (d 0) from 20 (Exp. 1; spring) or 22 does (Exp. 2; the following fall). Blood milk samples were then collected again on d 0.5, 1, 3, 5, 7, 14, 21, 28, 35, 42, 49, and 56 (Exp. 1) or d 0.5, 1, 2, 3, 4, 5, 6, 7, 14, and 21 (Exp. 2). Body weights of kids were recorded on d 0, and BW of kids and does were recorded weekly beginning on d 7 (kids) or 21 (does), with BCS also recorded for does beginning on d 28 for Exp. 1 and on d 0.5, 1, 2, 3, 4, 5, 6, 7, 14, and 21 for Exp. 2. Leptin was detected in colostral milk and was influenced by days postpartum, decreasing (P < 0.001) over time with an average of 4.4 +/- 0.3 ng/mL (Exp. 1) and 18.1 +/- 1.0 ng/mL (Exp. 2) on d 0 compared with 1.0 +/- 0.3 ng/mL on d 56 (Exp. 1) and 2.9 +/- 0.2 ng/mL on d 21 (Exp. 2). Day postpartum and milk serum leptin were negatively correlated (P < 0.001) for Exp. 1 (r = -0.27) and Exp. 2 (r = -0.46). For Exp. 1 only, blood serum leptin tended (P = 0.09) to be influenced by day, with a weak positive correlation (r = 0.15; P < 0.02). Weak positive correlations (P < 0.01) were found between blood serum leptin and doe BCS (r = 0.42 in Exp. 1, and r = 0.13 in Exp. 2) and doe BW (r = 0.44 in Exp. 1, and r = 0.26 in Exp. 2), with the absence of a stronger relationship likely due in part to the short time period measured and the lack of significant changes in BCS and BW during that time. In conclusion, leptin was present in milk and blood serum of does, and blood serum leptin was weakly correlated with doe BW and BCS, but it was not related to kid BW. Therefore, further studies are needed to clarify the relationships involving milk and serum leptin in goats.

Flow cytometric characterisation of cells of differing densities isolated from human term placentae and enrichment of villous trophoblast cells

Cells were isolated from human term placentae by trypsinisation of fragments of chorionic villi and fractionation of cells on a Percoll density gradient into six layers. A panel of 10 monoclonal antibodies to antigens on or in trophoblast cells (placental alkaline phosphatase (PLAP), cytokeratin-7, beta-human chorionic gonadotrophin (beta-hCG), human leucocyte antigen-G (HLA-G)), leucocytes (CD45), monocytes, macrophages, dendritic cells, B cells (HLA class II), mesenchyme cells (vimentin), fibroblasts (fibroblast antigen) and nucleated cells excluding villous trophoblast (HLA class I, CD9) was used to characterise the cells by flow cytometry. For staining intracellular antigens (cytokeratin, vimentin, beta-hCG) the cells were first fixed and permeabilised. The upper two layers from the gradient (density 1.013-1.039 g/ml) contained predominantly PLAP-positive cells or fragments, probably derived from the syncytiotrophoblast. Cytokeratin-positive cells accumulated mainly in the layer of density 1.039-1.052 g/ml and comprised the majority of the cell types identified in this fraction. Few or no cells reactive with antibodies to beta-hCG or HLA-G were identified in any layer. Non-trophoblast cells were heavier, being present mainly at densities 1.052-1.079 g/ml (CD45, HLA class I, vimentin) and 1.066-1.092 g/ml (fibroblast). Fewer than 10% of cells in any layer were HLA class II- or CD9-positive. Further purification of trophoblast cells was by negative immunomagnetic separation with removal of CD45-positive cells and HLA class II-positive cells to less than 1%. On culture of the cells from each layer, those of density 1.039-1.066 g/ml exhibited characteristics of cytotrophoblast cells; they secreted high levels of human chorionic gonadotrophin and formed adherent multinucleate cells. This procedure enabled the selection and enrichment of cytotrophoblast cells and/or syncytiotrophoblast fragments that are suitable for cellular and molecular studies.

Direct measurements of Ab and Ac using vertex and kaon charge tags at the SLAC detector

Exploiting the manipulation of the SLAC Linear Collider electron-beam polarization, we present precise direct measurements of the parity-violation parameters A(c) and A(b) in the Z-boson-c-quark and Z-boson-b-quark coupling. Quark-antiquark discrimination is accomplished via a unique algorithm that takes advantage of the precise SLAC Large Detector charge coupled device vertex detector, employing the net charge of displaced vertices as well as the charge of kaons that emanate from those vertices. From the 1996-1998 sample of 400 000 Z decays, produced with an average beam polarization of 73.4%, we find A(c)=0.673+/-0.029(stat)+/-0.023(syst) and A(b)=0.919+/-0.018(stat)+/-0.017(syst).

Association of Acculturation with Cesarean Section among Latinas

OBJECTIVES

Examine the association of acculturation and cesarean section after adjusting for clinical and non-clinical factors that could influence clinical discretion in performing the surgery.

METHODS

A sample of 2102 low-risk, low-income primarily Mexican Latinas in San Diego County was divided into two groups: primiparas and multiparas. For each parity group, logistic regression was used to assess the association of acculturation and cesarean section.

RESULTS

Among multiparous Latinas, the risk of cesarean section for highly acculturated women exceeded the risk for the less-acculturated women, but the result was reverse for primiparous women. The adjusted relative odds of cesarean section were twice as high [OR 2.1, 95%CI 1.1-4.1] for multiparous US-born Latinas relative to multiparous Spanish-speaking women born in Mexico. While for primiparous women this same comparison showed US-born Latinas to be approximately half as likely to have a cesarean delivery [OR 0.4, 95%CI 0.2-0.7].

CONCLUSIONS

In order to reduce the chances of unnecessary cesarean sections among Latinas, the role of acculturation in women who have and have not already given birth needs to be investigated further.

Reduction of human anti-tetanus toxoid antibody in hu-PBL-SCID mice by immunodominant peptides of tetanus toxoid

Immunotherapy of murine autoimmune and allergic diseases by administration of peptides corresponding to the dominant T cell epitope is a reality. However, problems remain in applying this therapy to reduce antibody responses in humans. To overcome these difficulties, a preclinical system was developed to test the effect of immunodominant peptides from a common antigen, tetanus toxoid (TT), on the long-term human anti-TT response. Individuals whose T cells proliferated against dominant TT peptides were identified. Peripheral blood leucocytes (PBL) from these donors were injected intraperitoneally (i.p.) into mice with severe combined immunodeficiency (SCID) that had been depleted of murine natural killer (NK) cells (hu-PBL-SCID mice). Peptides or PBS were injected i.p. before a further injection of PBL and immunization with TT. The concentration of human IgG and anti-TT in murine plasma was followed for 10 weeks. The total IgG was similar in both groups. By contrast, there was a statistically significant reduction in IgG anti-TT from eight weeks onwards. It is considered that the hu-PBL-SCID model system may provide a means by which the efficacy of peptide immunotherapy for reduction of pathological antibodies in humans can be examined.

Analysis of thyroid hormone responsive gene expression in osteoblastic cells

Thyroid hormones regulate gene expression to influence the development and metabolism of many tissues including bone. The identification of genes that are regulated by thyroid hormones during skeletal development requires sensitive and quantitative techniques that are not limited by small amounts of available tissue and RNA. We have compared the efficiencies of differential display and poly A PCR subtraction hybridisation methods for the detection of thyroid hormone responsive genes expressed in osteoblastic cells. The utility of each technique was evaluated with respect to its sensitivity, specificity, cost and ability to identify novel genes. Subtraction hybridisation was rapid and more efficient in all categories. Poly A PCR facilitates quantitative and representative global amplification of cDNAs from low concentrations of RNA extracted from small tissue samples. The method, in combination with microarray analyses, may prove useful as an additional, complementary strategy to subtraction hybridisation for the analysis of differential gene expression in tissues where sample size is limiting.

Outcomes, safety, and resource utilization in a collaborative care birth center program compared with traditional physician-based perinatal care

OBJECTIVE

We compared outcomes, safety, and resource utilization in a collaborative management birth center model of perinatal care versus traditional physician-based care.

METHODS

We studied 2957 low-risk, low-income women: 1808 receiving collaborative care and 1149 receiving traditional care.

RESULTS

Major antepartum (adjusted risk difference [RD] = -0.5%; 95% confidence interval [CI] = -2.5, 1.5), intrapartum (adjusted RD = 0.8%; 95% CI = -2.4, 4.0), and neonatal (adjusted RD = -1.8%; 95% CI = -3.8, 0.1) complications were similar, as were neonatal intensive care unit admissions (adjusted RD = -1.3%; 95% CI = -3.8, 1.1). Collaborative care had a greater number of normal spontaneous vaginal deliveries (adjusted RD = 14.9%; 95% CI = 11.5, 18.3) and less use of epidural anesthesia (adjusted RD = -35.7%; 95% CI = -39.5, -31.8).

CONCLUSIONS

For low-risk women, both scenarios result in safe outcomes for mothers and babies. However, fewer operative deliveries and medical resources were used in collaborative care.

Improved direct measurement of the parity-violation parameter Ab using a mass tag and momentum-weighted track charge

We present an improved direct measurement of the parity-violation parameter A(b) in the Z boson-b-quark coupling using a self-calibrating track-charge technique applied to a sample enriched in Z-->bb events via the topological reconstruction of the B hadron mass. Manipulation of the Stanford Linear Collider electron-beam polarization permits the measurement of A(b) to be made independently of other Z-pole coupling parameters. From the 1996-1998 sample of 400,000 hadronic Z decays, produced with an average beam polarization of 73.4%, we find A(b)=0.906+/-0.022(stat)+/-0.023(syst).

Impact of collaborative management and early admission in labor on method of delivery

OBJECTIVE

This study compared the effects of early admission in labor and perinatal care provider on delivery method. Higher spontaneous vaginal delivery rates for certified nurse midwives as compared with physicians have been reported in observational studies and randomized clinical trials. Certified nurse midwives, with their more expectant approach to labor management, would be expected to admit women later in labor than obstetricians.

METHODS

Prospective cohort study of 2,196 low-risk pregnancies, with singleton, vertex infants admitted in spontaneous labor. Independent and joint effects of perinatal care provider and cervical dilation at admission on delivery method were evaluated. Confounding was addressed using restriction and multiple regression.

RESULTS

Fewer (23.4%) women in collaborative care were admitted in early labor (< 4 cm cervical dilation) than women managed by obstetricians (95% CI = -27.6 to -19.2). Obstetrician care had 9% to 30% fewer spontaneous vaginal deliveries. Women admitted early in labor also had 6% to 34% fewer spontaneous vaginal deliveries. Evaluation of joint effects suggested that interaction between obstetrician provider and earlier admission increased the risk of operative delivery.

CONCLUSION

Later admission in labor (at 4 cm or greater cervical dilation) and management of perinatal care by certified nurse midwives in collaboration with obstetricians increased the rate of spontaneous vaginal delivery in low-risk women.

HIV and infant feeding: issues in developed and developing countries

Women in developed countries who are human immunodeficiency virus (HIV)-positive generally feed their infants formula to avoid virus transmission via breastfeeding. However, for most of the world's women who are HIV positive, the choice of infant feeding method is not so clear. Poor socioeconomic and living conditions place infants on breast milk substitutes at higher risk of non-HIV infectious diseases as compared with breastfed infants. Mothers in these settings who are HIV positive must weigh the risks and benefits of breastfeeding to choose the best infant feeding option.

Study of CP-violating asymmetries in B0-->pi(+)pi(-) decays

We present a measurement of CP-violating asymmetries in B0-->pi(+)pi(-) decays based on a 41.8 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We fully reconstruct one neutral B meson as a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters S(pipi)=-1.21(+0.38)(-0.27)(stat)+0.16-0.13(syst) and A(pipi)=+0.94(+0.25)(-0.31)(stat)+/-0.09(syst).

Observation of chi(c2) production in B meson decay

We report the first observation of chi(c2) production in B meson decays. We find an inclusive B-->chi(c2)X branching fraction of (1.80(+0.23)(-0.28)+/-0.26) x 10(-3). The data set, collected with the Belle detector at the KEKB e(+)e(-) collider, consists of 31.9 x 10(6) BB events. We also present branching fractions and momentum spectra for both chi(c1) and chi(c2) production.

Improved direct measurement of A(b) and A(c) at the Z(0) pole using a lepton tag

The parity violation parameters A(b) and A(c) of the Zb(b) and Zc(c) couplings have been measured directly, using the polar angle dependence of the polarized cross sections at the Z(0) pole. Bottom and charmed hadrons were tagged via their semileptonic decays. Both the electron and muon analyses take advantage of new multivariate techniques to increase the analyzing power. Based on the 1993-1998 SLD sample of 550,000 Z(0) decays produced with highly polarized electron beams, we measure A(b) = 0.919+/-0.030(stat)+/-0.024(syst), and A(c) = 0.583+/-0.055(stat)+/-0.055(syst).

Observation of the color-suppressed decay B( 0)-->D(0)pi(0)

We report the first observation of color-suppressed B( 0)-->D(0)pi(0), D(*0)pi(0), D0eta, and D0omega decays, and evidence for B( 0)-->D(*0)eta and D(*0)omega. The branching fractions are B(B( 0)-->D0pi(0)) = (3.1 +/- 0.4 +/- 0.5)x10(-4), B(B( 0) -->D(*0)pi(0)) = (2.7(+0.8+0.5)(-0.7-0.6))x10(-4), B(B( 0) --> D0eta) = (1.4(+0.5)(-0.4) +/- 0.3)x10(-4), B(B( 0) --> D0omega) = (1.8 +/- 0.5(+0.4)(-0.3))x10(-4), and we set 90% confidence level upper limits of B(B( 0) --> D(*0)eta)<4.6 x 10(-4) and B(B( 0)-->D(*0)omega)<7.9 x 10(-4). The analysis is based on a data sample of 21.3 fb(-1) collected at the Upsilon(4S) resonance by the Belle detector at the KEKB e(+)e(-) collider.

Observation of B+ --> chi(c0)K+

Using a sample of 31.3x10(6) BB pairs collected with the Belle detector at the Upsilon(4S) resonance, we make the first observation of the charged B meson decay to chi(c0) and a charged kaon. The measured branching fraction is B(B+-->chi(c0)K+) = (6.0(+2.1)(-1.8)+/-1.1)x10(-4), where the first error is statistical, and the second is systematic.