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Late-life depression (LLD) is associated with poor social functioning. However, previous research uses bias-prone self-report scales to measure social functioning and a more objective measure is lacking. We tested a novel wearable device to measure speech that participants encounter as an indicator of social interaction.
Twenty nine participants with LLD and 29 age-matched controls wore a wrist-worn device continuously for seven days, which recorded their acoustic environment. Acoustic data were automatically analysed using deep learning models that had been developed and validated on an independent speech dataset. Total speech activity and the proportion of speech produced by the device wearer were both detected whilst maintaining participants' privacy. Participants underwent a neuropsychological test battery and clinical and self-report scales to measure severity of depression, general and social functioning.
Compared to controls, participants with LLD showed poorer self-reported social and general functioning. Total speech activity was much lower for participants with LLD than controls, with no overlap between groups. The proportion of speech produced by the participants was smaller for LLD than controls. In LLD, both speech measures correlated with attention and psychomotor speed performance but not with depression severity or self-reported social functioning.
Using this device, LLD was associated with lower levels of speech than controls and speech activity was related to psychomotor retardation. We have demonstrated that speech activity measured by wearable technology differentiated LLD from controls with high precision and, in this study, provided an objective measure of an aspect of real-world social functioning in LLD.
Neonatal infections are usually classified according to time and mode of onset in three categories: (1) prenatal, (2) perinatal (early onset), and (3) nursery-acquired (late onset). The division in time between early and late onset is usually 2 to 7 days of age (Table 94.1). Different investigators have divided early-onset from late-onset infections at different days of life but most early-onset infections are evident during the first day of life. Infections that begin within the first month of life are considered neonatal, but many intensive care units for neonates provide continuing care for infants several months of age with complex problems that are the result of prematurity and complications of neonatal disorders. Therefore, neonatal nursery-associated infections may occur in infants up to a year or more of age. Bacterial infections due to rapidly dividing high-grade pathogens that set in substantially before birth usually result in a stillbirth. Often it is difficult to distinguish infections acquired shortly prior to birth from those acquired as a result of contact with maternal vaginal, fecal, or skin flora during delivery.
Neonatal sepsis occurs in approximately 2 to 4 per 1000 live births in the United States. World-wide reports vary from <2 to 50 per 1000 live births. The rates of early-onset sepsis have fallen to <1.0/1000 in the United States and Western Europe. Risk factors noted in Table 94.1 have a very strong predictive influence on infection rates. Full-term infants born without incident have a very low incidence of infection, lower than any other population of hospitalized patients. Infants susceptible to early-onset postnatal infections are primarily those born prematurely. Those premature infants born to mothers with an infection or whose membranes rupture more than 18 hours before delivery may have an infection rate of 20% or more. In extremely premature infants extra vigilance is required for early recognition and treatment of infection. Premature infants are much more likely to develop sepsis as a consequence of the amnionitis caused by ascending infection than are full-term infants.
Hemoglobinopathies, including the thalassemia syndromes and sickle cell disease, are complex disorders with protean manifestations. Their pathophysiology is influenced by environmental and genetic factors in addition to the pleiotropic effects of the globin gene mutations themselves. The erythrocyte membrane plays a critical role in these disorders because of the effects of its structural and functional perturbations and alterations in ion and water homeostasis regulated by membrane proteins. The first portion of this chapter reviews the structural and functional characteristics of the erythrocyte membrane; this is followed by a review of the alterations in ion and water homeostasis observed in the erythrocytes of sickle cell disease and thalassemia.
MEMBRANE STRUCTURE AND FUNCTION
The erythrocyte membrane is a complex, multifunctional structure. Although providing a protective layer between hemoglobin and other intracellular components and the external environment, it provides the erythrocyte with the deformability and stability required to withstand its travels through the circulation. The erythrocyte is subjected to high sheer stress in the arterial system, dramatic changes in size in the microcirculation, and wide variations in tonicity, pH, and pO2 as it travels throughout the body. It facilitates the transport of cations, anions, urea, water and other small molecules in and out of the cell, but denies entry to larger molecules, particularly if charged. A unique anucleate cell, the erythrocyte has a limited capacity for self-repair.
The erythrocyte membrane is composed of a lipid bilayer linked to an underlying cortical membrane skeleton.
To compare and contrast the epidemiology of polymicrobial and monomicrobial bloodstream infections (BSIs) in newborn intensive care unit (NICU) patients.
Retrospective, matched case-control study.
The Yale-New Haven Hospital NICU from 1989 through 2006.
NICU patients with BSIs.
Each neonate with polymicrobial BSI (case patient) was matched to one neonate with monomicrobial BSI (control patient), by birth date, weight, and sex; and univariate and multivariate analyses were performed.
One hundred five cases of polymicrobial BSI were identified in 102 infants, representing 10% of all neonatal BSIs in our institution. Coagulase-negative staphylococci were the most common organisms recovered from culture. Infants with polymicrobial BSI had later onset of infection than infants with monomicrobial BSI (mean day of life, 37.5 vs 24.0; P< .001). Polymicrobial BSI occurred more frequently among infants with a severe underlying condition than in those without such a condition (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1-3.2) and among infants requiring an indwelling central venous catheter for a prolonged duration (mean, 16.9 days, compared with 9.8 days for infants with monomicrobial BSI; P = .001). Multivariate analysis revealed that later onset of infection (adjusted OR [aOR], 1.02; 95% CI, 1.00-1.04) and presence of a severe underlying condition (aOR, 1.91; 95% CI, 1.12-3.38) were independent risk factors for polymicrobial BSI. No differences in outcome or mortality were observed.
Changes in the microbiology and epidemiology of NICU-related polymicrobial BSI have occurred since the last North American review. In the present study, although differences were observed, most risk factors and outcomes were similar between monomicrobial BSI and polymicrobial BSI. Epidemiologic surveillance is critical to identify trends associated with neonatal polymicrobial BSI, particularly those that may impact preventative strategies, diagnostic measures, and therapeutic interventions.
Neonatal infections are usually classified according to time and mode of onset in 3 categories: (1) prenatal, (2) perinatal, (early onset), and (3) nursery-acquired (late onset). The division in time between early and late onset is usually 2 to 5 days of age (Table 92.1). Infections that begin within the first month of life are considered neonatal, but many intensive care units for neonates provide continuing care for infants several months of age with complex problems that are the result of prematurity and complications of neonatal disorders. Therefore, neonatal nursery-associated infections may occur in infants up to a year of age. Bacterial infections due to rapidly dividing high-grade pathogens that set in substantially before birth usually result in a stillbirth. Generally it is not possible to distinguish infections acquired shortly prior to birth from those acquired as a result of contact with maternal vaginal, fecal, or skin flora during delivery.
Neonatal sepsis occurs in approximately 2 to 4 per 1000 live births in the United States. Worldwide reports vary from 1 to 10/1000 live births. Risk factors noted in Table 92.1 have a very strong predictive influence on infection rates. Full-term infants born without incident have a very low incidence of infection, lower than any other population of hospitalized patients. Infants susceptible to early-onset postnatal infections are primarily those born prematurely. Those premature infants born to mothers with an infection or whose membranes rupture more than 18 hours before delivery may have an infection rate of 20% or more.
To determine the frequency of conjunctival colonization, identify the colonizing flora, and correlate culture results with physical findings in infants in a NICU
Level III NICU of a large university teaching hospital.
All infants admitted for longer than 24 hours during a 26-week period.
Weekly bacterial conjunctival cultures were performed for all infants. The conjunctival appearance at the time of culture was recorded. The frequency, identity, and correlation of culture results with physical findings were determined.
One thousand ninety-one cultures were performed for 319 infants: 133 (42%) had no positive cultures and 186 (58%) had at least one positive culture. Culture analysis revealed that 411 (38%) were positive and yielded 494 isolates comprising more than 18 bacterial species. Bacteria most commonly isolated included coagulase-negative Staphylococcus (CoNS) (75%), viridans group streptococci (8.7%), Staphylococcus aureus (3.8%), Enterococcus species (2.6%), and Serratia marcescens (2.4%). The frequency of non-CoNS isolates increased significantly during the first 6 weeks of patient hospital stay (6% [1 to 3 weeks] to 12% [4 to 6 weeks]; P = .01), with an increasing trend to 15 weeks (18%). Correlation of bacteriologic results with physical findings demonstrated that infants with non-CoNS isolates exhibited conjunctival edema, erythema, or exudates more frequently than did infants with CoNS alone (30% vs 13%; P = .0001).
Conjunctival colonization was common among infants in a NICU. Prolonged hospitalization predisposes to colonization with potentially pathogenic organisms. Physical findings were more likely in patients with non-CoNS conjunctival isolates.
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