The effects of social context on the hormonal and behavioral responsiveness of human fathers

We tested first-time fathers with their 22-month old toddlers to determine whether social context variables such as pre-test absence from the child and presence of the mother affected physiological measures associated with paternal responsiveness. Heart rate and blood pressure readings as well as blood samples to determine prolactin, testosterone and cortisol levels were taken before and after the 30-min father–toddler interactions. Fathers were tested on a day when they were away from their child for several hours before testing (‘without-child’ day) and on another day where they remained with their child throughout the day (‘with-child’ day). Most measures decreased over the 30-min test period but relative decreases were context-dependent. Men maintained higher prolactin levels when they were away from their children longer before testing on the ‘without-child’ day. Cortisol levels decreased during both tests and they decreased more on the ‘with-child’ day for men who had spent more time alone with their toddler before the test. Heart-rate and diastolic (but not systolic) blood pressure decreased more on the ‘with-child’ day than on the ‘without-child’ day. Fathers' testosterone levels decreased when their partners were less involved in the interactions. Compared to men with high responsiveness ratings on both days, men whose responsiveness increased after being away from their child on the ‘without-child’ day maintained higher systolic blood pressure and had a greater decrease in testosterone levels. We conclude that context may be more important in determining fathers' physiological responses to child contact than has previously been appreciated, particularly for some individuals.     

Parental age and the risk of childhood acute myeloid leukemia: results from the Childhood Leukemia International Consortium

BackgroundParental age has been associated with several childhood cancers, albeit the evidence is still inconsistent.AimTo examine the associations of parental age at birth with acute myeloid leukemia (AML) among children aged 0–14 years using individual-level data from the Childhood Leukemia International Consortium (CLIC) and non-CLIC studies.Material/methodsWe analyzed data of 3182 incident AML cases and 8377 controls from 17 studies [seven registry-based case-control (RCC) studies and ten questionnaire-based case-control (QCC) studies]. AML risk in association with parental age was calculated using multiple logistic regression, meta-analyses, and pooled-effect estimates. Models were stratified by age at diagnosis (infants <1 year-old vs. children 1–14 years-old) and by study design, using five-year parental age increments and controlling for sex, ethnicity, birthweight, prematurity, multiple gestation, birth order, maternal smoking and education, age at diagnosis (cases aged 1–14 years), and recruitment time period.ResultsAdjusted odds ratios (ORs) and 95% confidence intervals (CIs) derived from RCC, but not from the QCC, studies showed a higher AML risk for infants of mothers ≥40-year-old (OR = 6.87; 95% CI: 2.12–22.25). There were no associations observed between any other maternal or paternal age group and AML risk for children older than one year.ConclusionsAn increased risk of infant AML with advanced maternal age was found using data from RCC, but not from QCC studies; no parental age-AML associations were observed for older children.     

布拉酵母菌与酪酸梭菌治疗婴幼儿轮状病毒性肠炎的疗效及安全性比较

目的比较布拉酵母菌与酪酸梭菌治疗小儿轮状病毒性肠炎（Rotavirus viral enteritis,RVE）的疗效及安全性。方法将68例RVE患儿随机分为观察组和对照组。两组均予常规治疗（抗病毒、补液、纠正水电解质及酸碱平衡紊乱）。对照组予以酪酸梭菌,〈1岁0.25 g/次,〉1岁0.50 g/次,bid口服;观察组用布拉酵母菌,〈1岁0.125 g/次,〉1岁0.25 g/次,bid口服。5 d为一个疗程,观察两组患儿治疗后临床疗效、症状与体征消失时间及不良反应。结果观察组临床总有效率为94.29%,明显高于对照组的69.70%（χ^2=7.06,P〈0.01）。观察组症状与体征消失时间明显短于对照组（P〈0.01）。治疗过程中对照组便秘3例,腹痛1例。观察组未见明显不良反应。结论布拉酵母菌治疗小儿RVE具有较好的临床疗效及安全性。     

Antimicrobial resistance in Gram-negative bacilli isolated from infant formulas

A total of 90 samples of infant formula (IF) were collected from the lactary of a teaching hospital, during a 4-month period from July to August 1999. The sanitary conditions of the formulas were analyzed, and a physiological characterization of Gram-negative bacillus isolates and antimicrobial susceptibility testing were performed. Colony counts were considered to be unacceptable for the majority of the IF samples and the contamination rates were related to inadequate handling. Coliforms (35 degrees C and 45 degrees C growth) were detected in most of the IF tested. Klebsiella pneumoniae, Citrobacter freundii, Cedacea davisae, Klebsiella planticola and Enterobacter cloacae were the isolates most commonly identified. Antimicrobial susceptibility testing showed significant resistance rates, particularly to amoxicillin/clavulanic acid, cefoxitin, cephalotin or ampicillin. One extended-spectrum beta-lactamase-producing K. pneumoniae strain was also recovered.     

Patterns of infant handling and relatedness in Barbary macaques (<Emphasis Type="Italic">Macaca sylvanus</Emphasis>) on Gibraltar

Among papionin primates, the Barbary macaque (Macaca sylvanus) shows the most extensive interactions between infants and group members other than the mother. Two different types of interactions occur: (1) long-lasting dyadic interactions between a handler and an infant, and (2) brief triadic interactions between two handlers involving an infant. Previous investigations showed that infant handling by males is best explained as use of infants to manage relationships with other males. In contrast, no adaptive explanation for infant handling by females emerged. Here, we compared the infant-handling pattern between subadult/adult males and subadult/adult females in a free-ranging group of 46 Barbary macaques on Gibraltar to test whether the relationship management hypothesis also applies to female handlers. We further investigated the infant-handling pattern of juveniles and used microsatellite markers to estimate relatedness between infant handlers and the infant’s mother. We found that males, females and juveniles all participated extensively in triadic interactions using infants of above-average related females. In contrast, only males and juveniles were highly involved in dyadic interactions with infants of related females, while females rarely handled infants other than their own. The pattern of infant handling was entirely compatible with the predictions of the relationship management hypothesis for males and mostly so for females. Moreover, our genetic analysis revealed that males and females differ in their partner choice: while females preferred to interact with related females, males had no significant preference to interact with related males. We further discuss the observed above-average relatedness values between infant handlers and the infant’s mother in the light of kin-selection theory.     

Effect of organic acids on inhibition of Escherichia coli O157:H7 colonization in gnotobiotic mice associated with infant intestinal microbiota

Previously, we produced two groups of gnotobiotic mice, GB-3 and GB-4, which showed different responses to Escherichia coli O157:H7 challenge. E. coli O157:H7 was eliminated from GB-3, whereas GB-4 became carriers. In this study, we analysed the mechanisms of E. coli O157:H7 elimination using GB-3 and GB-4. When GB-3 and GB-4 mice were challenged with E. coli O157:H7, the E. coli O157:H7 population was reduced in the caecum of GB-3 when compared to that in the GB-4 caecum, although the numbers of E. coli O157:H7 in the small intestine were not significantly different between these two groups of gnotobiotic mice. The lag time of E. coli O157:H7 growth in a 50% GB-3 caecal suspension increased when compared to that in a GB-4 caecal suspension. Acetate and lactate were detected in the GB-3 caecal contents, and acetate and propionate in those from GB-4. Although E. coli O157:H7 growth was not suppressed when it was cultured in anaerobic broth supplemented with these organic acids, the motility of E. coli O157:H7 was suppressed when it was cultured on semi-solid agar supplemented with the combination of acetate and lactate. These results indicate that the organic acid profile in the caecum is an important factor related to the elimination of E. coli O157:H7 from the intestine.     

Competition for proline between indigenous Escherichia coli and E. coli O157:H7 in gnotobiotic mice associated with infant intestinal microbiota and its contribution to the colonization resistance against E. coli O157:H7

Previously, we produced two groups of gnotobiotic mice, GB-3 and GB-4, which showed different responses to Escherichia coli O157:H7 challenge. E. coli O157:H7 was eliminated from GB-3, whereas GB-4 mice became carriers. It has been reported that the lag time of E. coli O157:H7 growth in 50% GB-3 caecal suspension was extended when compared to GB-4 caecal suspension. In this study, competition for nutrients between intestinal microbiota of GB-3 and GB-4 mice and E. coli O157:H7 was examined. Amino acid concentrations in the caecal contents of GB-3 and GB-4 differed, especially the concentration of proline. The supplementation of proline into GB-3 caecal suspension decreased the lag time of E. coli O157:H7 growth in vitro. When E. coli O157:H7 was cultured with each of the strains used to produce GB-3 mice in vitro, 2 strains of E. coli (proline consumers) out of 5 enterobacteriaceae strains strongly suppressed E. coli O157:H7 growth and the suppression was attenuated by the addition of proline into the medium. These results indicate that competition for proline with indigenous E. coli affected the growth of E. coli O157:H7 in vivo and may contribute to E. coli O157:H7 elimination from the intestine.     

Effects of therapeutic hypothermia on the gut microbiota and metabolome of infants suffering hypoxic-ischemic encephalopathy at birth

Neonatal hypoxic ischemic encephalopathy (HIE) in the perinatal period can lead to significant neurological deficits in later life. Total body cooling (TBC) is a neuroprotective strategy used in the treatment of HIE and has been shown to reduce seizures and improve neurodevelopmental outcomes in treated infants. Little is known, however, about the effects of HIE/TBC on the developing gut microbiota composition and subsequent metabolic profile. Ten term infants with HIE who received TBC at 33.5 °C for 72 h were recruited. A control group consisted of nine healthy full term infants. Faecal samples were collected from both groups at 2 years of age and stored at −20 °C. 16S rRNA amplicon Illumina sequencing was carried out to determine gut microbiota composition and 1H NMR analysis was performed to determine the metabolic profile of faecal water. The gut microbiota composition of the HIE/TBC infants were found to have significantly lower proportions of Bacteroides compared to the non-cooled healthy control group. Alpha diversity measures detected significantly lower diversity in microbial richness in the HIE/TBC infant group compared to the control infants (Shannon index, <0.05). High inter-individual variation was found in gut microbiota composition and metabolic profile of both groups. Initial principal coordinate analysis and hierarchal clustering of compounds on MetaboAnalyst 3.0 indicated no clear separation in the metabolic profile of these two infant groups. These results suggest that there is no significant impact on the gut microbial development of HIE/TBC infants compared to healthy infants at 2 years of life. To our knowledge this is the first study to report the gut microbiota composition and metabolic profile of infants who have experienced HIE/TBC at birth.     

Analyzing infant mortality with geoadditive categorical regression models: a case study for Nigeria

In this paper, we analyze infant mortality in Nigeria based on the data set from the 1999 Nigeria Demographic and Health Survey (NDHS). We investigate spatial patterns at a highly disaggregated level of Nigerian states and consider non-linear effects of mother's age at birth. Time to the occurrence of a child's death can intuitively be considered to be categorical in nature and the determinants of a child's death may differ in different age groups. Thus, it may be desirable to investigate separately the death of a child in the first month and in the remaining 11 months of the first year of life. To avoid selection bias, the data set used for this case study is based on information on children who were born 12 months preceding the survey. Inference is Bayesian and is based on Markov chain Monte Carlo (MCMC) techniques. We find that spatial variation and the determinants of death indeed differ considerably for the two age groups considered.