Newborn mid-upper arm circumference identifies low-birth weight and vulnerable infants: A secondary analysis

BACKGROUND: Low birth weight (LBW) infants are at increased risk of morbidity and mortality. Identification of LBW may not occur in settings where access to reliable scales is limited. Mid-upper arm circumference (MUAC) may be an accessible, low-cost measure to identify LBW and vulnerable infants. OBJECTIVES: We explored the validity of newborn MUAC in identifying LBW and vulnerable newborns in rural Sierra Leone. METHODS: This study was a secondary analysis of infant data from a randomized controlled clinical trial of supplementary food and anti-infective therapies compared with standard care for undernourished pregnant women. Data for singleton liveborn infants with birth measurement and 6-mo survival data were included in this analysis. The primary outcome was validity of MUAC in identifying low-birth weight (LBW) neonates. Secondary outcomes included validity of MUAC and head circumference (HC) in identifying weight-for-length RESULTS: The study population included 1167 infants, 229 (19.6%) with LBW. Birth MUAC ( CONCLUSIONS: MUAC was used successfully to identify LBW infants and infants at risk of neonatal mortality in Sierra Leone. Further evidence is needed to support increased use of newborn MUAC measurement to identify LBW infants and infants at risk of neonatal mortality in community settings where scales are not available. Primary trial was registered at clinicaltrials.gov as NCT03079388. LAY SUMMARY: Mid-upper arm circumference (MUAC) can be used to identify infants with low birth weight and infants at risk for neonatal mortality, with an MUAC ≤9.0 cm indicating the highest risk

Assessing infant cognition in field settings using eye-tracking: A pilot cohort trial in Sierra Leone

OBJECTIVES: To investigate the feasibility of eye-tracking-based testing of the speed of visual orienting in malnourished young children at rural clinics in Sierra Leone. DESIGN: Prospective dual cohort study nested in a cluster-randomised trial. SETTING: 8 sites participating in a cluster-randomised trial of supplementary feeding for moderate acute malnutrition (MAM). PARTICIPANTS: For the MAM cohort, all infants aged 7-11 months at the eight sites were enrolled, 138 altogether. For controls, a convenience sample of all non-malnourished infants aged 7-11 months at the same sites were eligible, 60 altogether. A sample of 30 adults at the sites also underwent eye-tracking tests as a further control. INTERVENTIONS: Infants with MAM were provided with supplementary feeding. OUTCOME MEASURES: The primary outcomes were feasibility and reliability of eye-tracking-based testing of saccadic reaction time (SRT). Feasibility was assessed by the percent of successful tests in the infants. Reliability was measured with intraclass correlation coefficients (ICCs). Secondary outcomes were mean SRT based on nutritional state as well as and changes in mean SRT after supplementary feeding of MAM children. RESULTS: Infants exhibited consistent orienting to targets on a computer screen (\u3e95% of valid trials). Mean SRTs had moderate stability within visits (ICCs 0.60-0.69) and across the 4-week test-retest interval (0.53) in infants; the adult control group had greater SRT stability (within visit ICC=0.92). MAM infants had a trend toward higher adjusted SRT at baseline (difference=12.4 ms, 95% CI -2 to 26.9, p=0.09) and improvement in SRT 4 weeks thereafter (difference=-14 ms, 95% CI -26.2 to -1.7, p=0.025) compared with age-matched controls. CONCLUSIONS: The results demonstrate the feasibility of eye-tracking-based testing in a resource-poor field setting and suggest eye-tracking measures have utility in the detection of group level effects of supplementary feeding

Assessing infant cognition in field settings using eye-tracking: a pilot cohort trial in Sierra Leone

Objectives To investigate the feasibility of eye-tracking-based testing of the speed of visual orienting in malnourished young children at rural clinics in Sierra Leone. Design Prospective dual cohort study nested in a cluster-randomised trial. Setting 8 sites participating in a cluster-randomised trial of supplementary feeding for moderate acute malnutrition (MAM). Participants For the MAM cohort, all infants aged 7-11 months at the eight sites were enrolled, 138 altogether. For controls, a convenience sample of all non-malnourished infants aged 7-11 months at the same sites were eligible, 60 altogether. A sample of 30 adults at the sites also underwent eye-tracking tests as a further control. Interventions Infants with MAM were provided with supplementary feeding. Outcome measures The primary outcomes were feasibility and reliability of eye-tracking-based testing of saccadic reaction time (SRT). Feasibility was assessed by the percent of successful tests in the infants. Reliability was measured with intraclass correlation coefficients (ICCs). Secondary outcomes were mean SRT based on nutritional state as well as and changes in mean SRT after supplementary feeding of MAM children. Results Infants exhibited consistent orienting to targets on a computer screen (>95% of valid trials). Mean SRTs had moderate stability within visits (ICCs 0.60-0.69) and across the 4-week test-retest interval (0.53) in infants; the adult control group had greater SRT stability (within visit ICC=0.92). MAM infants had a trend toward higher adjusted SRT at baseline (difference=12.4 ms, 95% CI -2 to 26.9, p=0.09) and improvement in SRT 4 weeks thereafter (difference=-14 ms, 95% CI -26.2 to -1.7, p=0.025) compared with age-matched controls. Conclusions The results demonstrate the feasibility of eye-tracking-based testing in a resource-poor field setting and suggest eye-tracking measures have utility in the detection of group level effects of supplementary feeding.</p

espC Pathogenicity Island of Enteropathogenic Escherichia coli Encodes an Enterotoxin

At least five proteins are secreted extracellularly by enteropathogenic Escherichia coli (EPEC), a leading cause of infant diarrhea in developing countries. However only one, EspC, is known to be secreted independently of the type III secretion apparatus encoded by genes located within the 35.6-kb locus of enterocyte effacement pathogenicity island. EspC is a member of the autotransporter family of proteins, and the secreted portion of the molecule is 110 kDa. Here we determine that the espC gene is located within a second EPEC pathogenicity island at 60 min on the chromosome of E. coli. We also show that EspC is an enterotoxin, indicated by rises in short-circuit current and potential difference in rat jejunal tissue mounted in Ussing chambers. In addition, preincubation with antiserum against the homologous Pet enterotoxin of enteroaggregative E. coli eliminated EspC enterotoxin activity. Like the EAF plasmid, the espC pathogenicity island was found only in a subset of EPEC, suggesting that EspC may play a role as an accessory virulence factor in some but not all EPEC strains

Cleavage of a bacterial autotransporter by an evolutionarily convergent autocatalytic mechanism

Bacterial autotransporters are comprised of an N-terminal ‘passenger domain' and a C-terminal β barrel (‘β domain') that facilitates transport of the passenger domain across the outer membrane. Following translocation, the passenger domains of some autotransporters are cleaved by an unknown mechanism. Here we show that the passenger domain of the Escherichia coli O157:H7 autotransporter EspP is released in a novel autoproteolytic reaction. After purification, the uncleaved EspP precursor underwent proteolytic processing in vitro. An analysis of protein topology together with mutational studies strongly suggested that the reaction occurs inside the β barrel and revealed that two conserved residues, an aspartate within the β domain (Asp(1120)) and an asparagine (Asn(1023)) at the P1 position of the cleavage junction, are essential for passenger domain cleavage. Interestingly, these residues were also essential for the proteolytic processing of two distantly related autotransporters. The data strongly suggest that Asp(1120) and Asn(1023) form an unusual catalytic dyad that mediates self-cleavage through the cyclization of the asparagine. Remarkably, a very similar mechanism has been proposed for the maturation of eukaryotic viral capsids

Bacterial Infection in Chronic Obstructive Pulmonary Disease in 2000: a State-of-the-Art Review

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States. The precise role of bacterial infection in the course and pathogenesis of COPD has been a source of controversy for decades. Chronic bacterial colonization of the lower airways contributes to airway inflammation; more research is needed to test the hypothesis that this bacterial colonization accelerates the progressive decline in lung function seen in COPD (the vicious circle hypothesis). The course of COPD is characterized by intermittent exacerbations of the disease. Studies of samples obtained by bronchoscopy with the protected specimen brush, analysis of the human immune response with appropriate immunoassays, and antibiotic trials reveal that approximately half of exacerbations are caused by bacteria. Nontypeable Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae are the most common causes of exacerbations, while Chlamydia pneumoniae causes a small proportion. The role of Haemophilus parainfluenzae and gram-negative bacilli remains to be established. Recent progress in studies of the molecular mechanisms of pathogenesis of infection in the human respiratory tract and in vaccine development guided by such studies promises to lead to novel ways to treat and prevent bacterial infections in COPD