Predictors of Time to Recovery in Infants with Probable Serious Bacterial Infection

Introduction

Serious bacterial infections continue to be an important cause of death and illness among infants in developing countries. Time to recovery could be considered a surrogate marker of severity of the infection. We therefore aimed to identify clinical and laboratory predictors of time to recovery in infants with probable serious bacterial infection (PSBI).

Methods

We used the dataset of 700 infants (7-120 days) enrolled in a randomised controlled trial in India in which 10mg of oral zinc or placebo was given to infants with PSBI. PSBI was defined as signs/symptoms of possible serious bacterial infection along with baseline C-reactive protein(CRP) level >12mg/L. Time to recovery was defined as time from enrolment to the end of a 2-day period with no symptoms/signs of PSBI and daily weight gain of at least 10g over 2 succesive days on exclusive oral feeding. Cox proportional hazard regression was used to measure the associations between relevant variables and time to recovery.

Results

Infants who were formula fed prior to illness episode had 33% longer time to recovery (HR-0.67, 95%CI-0.52, 0.87) than those who were not. Being underweight (HR-0.84, 95%CI-0.70, 0.99), lethargic (HR-0.77, 95%CI-0.62, 0.96) and irritable (HR-0.81, 95%CI-0.66, 0.99) were independent predictors of time to recovery. Baseline CRP was significantly associated with time to recovery (P<0.001), higher CRP was associated with longer time to recovery and this association was nearly linear.

Conclusion

Simple clinical and laboratory parameters such as formula feeding prior to the illness, being underweight, lethargic, irritable and having elevated CRP levels could be used for early identification of infants with PSBI at risk for protracted illness and could guide prompt referral to higher centers in resource limited settings. This also provides prognostic information to clinicians and family as longer recovery time has economic and social implications on the family in our setting.

Trial Registration

ClinicalTrials.gov NCT00347386     

Early Interactions Between Mothers and Their Medically Fragile Infants

The purpose of this study was to examine the interactions of 56 medically fragile infants and their mothers and to determine the influence of infant age, neurological status, maternal education, ethnicity, and observation location on these interactions. The interactions were observed for about 1 hr every 2 months while in the hospital, 1 month after hospital discharge, and at 6 months corrected age. The age of the infants had the greatest effect on the interaction. As infants grew older, mothers spent less time feeding, involved, holding, in body contact, looking, rocking, gesturing, and touching. However, mothers talked more, and played more with older infants. Older medically fragile infants were alert more, vocalized more, and slept less. Only one variable was directly affected by neurological status: Mothers moved neurologically normal infants more often. The neurologically normal and compromised groups were also more similar at older ages than younger ages in the percentage of time the mother was involved and the infant vocalized. Mothers with more years of education fed their infants more and looked at them more often, and minority mothers talked to their infants less and moved them more.     

Teaching Biologists the Philosophy of Their Time

Acta Biotheoretica -     

He-Ne激光照射对金鱼受精卵及其幼鱼的生物学效应

用ＨｅＮｅ６２３．８ｎｍ激光照射金鱼精卵,并对其受精率、孵化率和孵化时间进行测量。结果表明,适宜剂量的激光照射对金鱼受精卵发育生长有显著的促进作用。跟踪观察发现,经激光照射而孵化出的金鱼有较大的变异效应。     

早产儿语言发展的影响因素及其干预对策

早产儿的语言发展受到多种因素的影响,可能导致他们在词汇、语法、语音等方面出现发展滞后或障碍。本文首先简述了影响早产儿语言发展的生物学和环境因素的研究进展,其中生物学因素包括早产程度、体重和性别、新生儿发病率和疾病严重程度等,环境因素则包括新生儿重症监护室的环境、家庭中的语言环境和社会因素等。在明确这些影响因素的基础上,本文强调了早期评估和早期干预是优化早产儿语言发育效果的关键步骤,并分析了具体的干预对策,例如生理和神经干预、优化新生儿重症监护室（NICU）环境、增强家庭语言互动、多学科合作和社会支持等。此综述旨在探讨影响早产儿语言发展的各种因素,并总结出有效的早期干预措施,为其提供更为全面的语言发展支持。     

Determinants of the Relationship between Cytokine Production in Pregnant Women and Their Infants

Exposure to environmental factors during fetal life and infancy is thought to play an important role in the early development of innate and adaptive immunity. The immunological relationship between mother and infant and the effect that environmental exposures have during pregnancy and early childhood have not been studied extensively. Here the production of cytokines was measured in 146 pairs of mothers and their 2- month-old infants. The effect of place of residence, socio-economic variables, parasitic infections as well as maternal and child characteristics on measured cytokine production was determined. Mothers producing high levels of IL-10, IFN-γ and IL-5 were more likely to have infants who also produced high levels of these cytokines either spontaneously (OR 2.6(95%CI 1.2–5.4), OR 2.9(CI 1.3–6.6), OR 11.2(CI 4.6–27.2), respectively) or in response to PHA (IL-10: OR 3.0(CI 1.4–6.6), IFN-γ: OR 2.0(CI 1.0–4.2), respectively) even after adjustment for potential confounding variables. This was not the case for TNF-α. In response to LPS, place of residence was a strong determinant of infant IL-10 (OR 0.2(CI 0.1–0.9)) and TNF-α (OR 0.3(CI 0.1–0.9)) production. Maternal protozoan infections was independently associated with reduced infant IL10 in response to PHA and to LPS as well as reduced TNF-α and IFN-γ in response to PHA. These results indicate strong relationship between maternal and infant''s cellular immune responses even after taking into account many environmental influences that could affect infant''s response directly or indirectly through uterine microenvironment. However, place of residence and intestinal infections may still directly affect the immune responses of the infant. Taken together, the study provides evidence for imprinted cytokine responses of an infant which may have implications for their reaction to incoming antigens, warranting further investigation into the role that genetics or epigenetics play in shaping the cytokine response by an infant to self or external antigens.     

Move Over,Bacteria! Viruses Make Their Mark as Mutualistic Microbial Symbionts

Viruses are being redefined as more than just pathogens. They are also critical symbiotic partners in the health of their hosts. In some cases, viruses have fused with their hosts in symbiogenetic relationships. Mutualistic interactions are found in plant, insect, and mammalian viruses, as well as with eukaryotic and prokaryotic microbes, and some interactions involve multiple players of the holobiont. With increased virus discovery, more mutualistic interactions are being described and more will undoubtedly be discovered.     

Joint Attention without Gaze Following: Human Infants and Their Parents Coordinate Visual Attention to Objects through Eye-Hand Coordination

The coordination of visual attention among social partners is central to many components of human behavior and human development. Previous research has focused on one pathway to the coordination of looking behavior by social partners, gaze following. The extant evidence shows that even very young infants follow the direction of another''s gaze but they do so only in highly constrained spatial contexts because gaze direction is not a spatially precise cue as to the visual target and not easily used in spatially complex social interactions. Our findings, derived from the moment-to-moment tracking of eye gaze of one-year-olds and their parents as they actively played with toys, provide evidence for an alternative pathway, through the coordination of hands and eyes in goal-directed action. In goal-directed actions, the hands and eyes of the actor are tightly coordinated both temporally and spatially, and thus, in contexts including manual engagement with objects, hand movements and eye movements provide redundant information about where the eyes are looking. Our findings show that one-year-olds rarely look to the parent''s face and eyes in these contexts but rather infants and parents coordinate looking behavior without gaze following by attending to objects held by the self or the social partner. This pathway, through eye-hand coupling, leads to coordinated joint switches in visual attention and to an overall high rate of looking at the same object at the same time, and may be the dominant pathway through which physically active toddlers align their looking behavior with a social partner.     

Time Course Study of Blood Pressure in Term and Preterm Infants Immediately after Birth

Objective

To describe temporal changes in systolic, diastolic, and mean blood pressure (SBP, DBP, and MBP, respectively) in term and preterm infants immediately after birth.

Methods

Prospective observational two-center study. In term infants SBP, DBP, and MBP were assessed non-invasively every minute for the first 15 minutes, and in preterm infants every minute for the first 15 minutes, as well as at 20, 25, 30, 45, and 60 minutes after birth. Regression analyses were performed by gender and respiratory support in all neonates; and by mode of delivery, cord clamping time, and development of ultrasound-detected brain injury in preterm neonates.

Results

Term infants (n = 54) had a mean (SD) birth weight of 3298 (442) g and gestational age of 38 (1) weeks, and preterm infants (n = 94) weighed 1340 (672) g and were 30 (3) weeks gestation. Term infants’ SBP, DBP and MBP within the first 15 minutes after birth were independent of gender or respiratory support. Linear mixed regression analysis showed that preterm infants, who were female, born vaginally, had delayed cord clamping and did not require positive pressure ventilation nor develop periventricular injury or ventriculomegaly, had significantly higher SBP, DBP, and MBP at some measurement points within the first hour after birth.

Conclusions

We present novel reference ranges of BP immediately after birth in a cohort of term and preterm neonates. They may aid in optimization of cardiovascular support during early transition at all gestations.