The association between sleep spindles and IQ in healthy school-age children

Recent studies have suggested that sleep is associated with IQ measures in children, but the underlying mechanism remains unknown. An association between sleep spindles and IQ has been found in adults, but only two previous studies have explored this topic in children. The goal of this study was to examine whether sleep spindle frequency, amplitude, duration and/or density were associated with performance on the perceptual reasoning, verbal comprehension, working memory, and processing speed subscales of the Wechsler Intelligence Scale for Children-IV (WISC-IV). We recruited 29 typically developing children 7–11 years of age. We used portable polysomnography to document sleep architecture in the natural home environment and evaluated IQ. We found that lower sleep spindle frequency was associated with better performance on the perceptual reasoning and working memory WISC-IV scales, but that sleep spindle amplitude, duration and density were not associated with performance on the IQ test.     

Electrochemical functionalization of gold and silicon surfaces by a maleimide group as a biosensor for immunological application

In the present study we investigated the preparation of biofunctionalized surfaces using the direct electrochemical grafting of maleimidophenyl molecules with subsequent covalent immobilization of specific peptide to detect target antibody, thereby extending the application of the biosensing systems towards immunodiagnostics. Para-maleimidophenyl (p-MP) functional groups were electrochemically grafted on gold and silicon surfaces from solutions of the corresponding diazonium salt. A specially synthesized peptide modified with cysteine (Cys-peptide) was then immobilized on the p-MP grafted substrates by cross-linking between the maleimide groups and the sulfhydryl group of the cysteine residues. Accordingly, the Cys-peptide worked as an antigen that was able to bind specifically the target antibody (anti-GST antibody), while it was non-sensitive to a negative contrast antibody (i.e. anti-Flag β). The immobilization of both specific and non-specific antibodies on the Cys-peptide-modified surfaces was monitored by infrared spectroscopic ellipsometry, a quartz crystal microbalance integrated in flow injection analysis system and potentiometric response. The results obtained clearly demonstrated that the direct modification of a surface with maleimidophenyl provides a very simple and reliable way of preparing biofunctionalized surfaces suitable for the construction of immunological biosensors.     

Isolation and Characterization of Streptococcus mutans Phage as a Possible Treatment Agent for Caries

Streptococcus mutans is a key bacterium in dental caries, one of the most prevalent chronic infectious diseases. Conventional treatment fails to specifically target the pathogenic bacteria, while tending to eradicate commensal bacteria. Thus, caries remains one of the most common and challenging diseases. Phage therapy, which involves the use of bacterial viruses as anti-bacterial agents, has been gaining interest worldwide. Nevertheless, to date, only a few phages have been isolated against S. mutans. In this study, we describe the isolation and characterization of a new S. mutans phage, termed SMHBZ8, from hundreds of human saliva samples that were collected, filtered, and screened. The SMHBZ8 genome was sequenced and analyzed, visualized by TEM, and its antibacterial properties were evaluated in various states. In addition, we tested the lytic efficacy of SMHBZ8 against S. mutans in a human cariogenic dentin model. The isolation and characterization of SMHBZ8 may be the first step towards developing a potential phage therapy for dental caries.     

Diverse Profiles of Ricin-Cell Interactions in the Lung Following Intranasal Exposure to Ricin

Ricin, a plant-derived exotoxin, inhibits protein synthesis by ribosomal inactivation. Due to its wide availability and ease of preparation, ricin is considered a biothreat, foremost by respiratory exposure. We examined the in vivo interactions between ricin and cells of the lungs in mice intranasally exposed to the toxin and revealed multi-phasic cell-type-dependent binding profiles. While macrophages (MΦs) and dendritic cells (DCs) displayed biphasic binding to ricin, monophasic binding patterns were observed for other cell types; epithelial cells displayed early binding, while B cells and endothelial cells bound toxin late after intoxication. Neutrophils, which were massively recruited to the intoxicated lung, were refractive to toxin binding. Although epithelial cells bound ricin as early as MΦs and DCs, their rates of elimination differed considerably; a reduction in epithelial cell counts occurred late after intoxication and was restricted to alveolar type II cells only. The differential binding and cell-elimination patterns observed may stem from dissimilar accessibility of the toxin to different cells in the lung and may also reflect unequal interactions of the toxin with different cell-surface receptors. The multifaceted interactions observed in this study between ricin and the various cells of the target organ should be considered in the future development of efficient post-exposure countermeasures against ricin intoxication.     

Outcomes of ultrasound and physical-exam based cerclage: assessment of risk factors and the role of adjunctive progesterone in preventing preterm birth—a retrospective cohort study

To assess outcomes of ultrasound and physical examination-based cerclage performed at mid to late second trimester and to assess the potential added value of progesterone treatment combined with cerclage for preventing preterm birth. A retrospective cohort study of women who underwent cerclage in a university-affiliated tertiary medical center (2012–2018). Inclusion criteria included only ultrasound-based cerclage and physical examination-based cerclage. Women who underwent history-based cerclage or multiple gestations were excluded. Study groups were stratified by previous PTB < 37 weeks and other risk factors for PTB. Primary outcome was the incidence of preterm birth < 35 weeks of gestation. Secondary outcomes included the potential added value of progesterone treatment and neonatal outcome. Sixty-nine women underwent cervical cerclage placement between 16–23 weeks of gestation. All women had short cervix (cervical length of < 25 mm) at presentation. Indications for cerclage placement included: 29% previous PTB, 32% prior cervical interventions (history of at least one D&C, hysteroscopy or cold-knife conization in the past), 22% had cervical dilatation > 1 cm at presentation, 12% due to failure of progesterone treatment defined as continued cervical shortening after 14 days of progesterone treatment, and 5% had other indications. Overall, 42 women (61%) gave birth at term. 27 women (39%) delivered prior to 37 weeks of gestation, of them, 20 women (29%) gave birth prior to 35 weeks. Overall median gestational age at delivery was 35 + 5 ± 4.7 weeks. Cervical dilatation at presentation of > 1 cm was associated with an increased risk for PTB < 35 weeks (OR 3.57, CI 1.43–30.81, p = 0.036). Previous PTB, prior cervical interventions and extent of cervical shortening at presentation did not increase the risk of PTB. Progesterone treatment in addition to cerclage did not result in a decreased risk for PTB < 35 weeks of gestation (OR 2.83, CI 0.58–13.89, p = 0.199). Late second trimester cerclage is a practical measure for preventing PTB in cases of asymptomatic cervical shortening. Our study did not find adjunctive benefit for progesterone treatment with physical or ultrasound-based cerclage in reducing the rate PTB.