Postnatal physiological changes in electrical activity of the diaphragm in extremely preterm infants.

OBJECTIVES: This study aimed to describe postnatal physiological changes in maximum values of peak electrical activity of the diaphragm (Edi) in extremely preterm infants during the preterm period. WORKING HYPOTHESIS: The amplitude and frequency of neural sigh are different at each postmenstrual age in extremely preterm infants. STUDY DESIGN: A retrospective, observational study. PATIENT-SUBJECT SELECTION: Edi values were evaluated in 14 extremely preterm infants with neurally-adjusted ventilatory assist. METHODOLOGY: Data of Edi peak and Edi minimum were collected from a ventilator. Edi-sigh was defined as the Edi peak value that was more than twice as large as the median Edi peak at each postmenstrual week in each patient. The frequency of Edi-sigh, and median values of Edi-sigh, Edi peak, and Edi minimum were evaluated at each postmenstrual week. The Jonckheere-Terpstra test was used to analyze the trend between postmenstrual weeks and Edi values. RESULTS: From 26 to 35 postmenstrual weeks, the number of Edi-sighs per hour significantly increased as postmenstrual weeks increased (P < .001). Furthermore, the median values of Edi-sigh significantly increased as postmenstrual weeks increased (16.9 µV at 26 weeks to 25.4 µV at 35 weeks, P < .001). There were no significant changes in the median values of Edi peak and Edi minimum at each week. CONCLUSIONS: The amplitude and frequency of neural sigh in extremely preterm infants increase with the number of postmenstrual weeks.

Effects of immersion disinfection of agar-alginate combined impressions on the surface properties of stone casts.

This study investigated the effects of disinfection of agar-alginate combined impressions on the surface properties of the resulting stone casts. Two brands of cartridge-form agar impression material and one alginate impression material were used. Agar-alginate combined impressions of smooth glass plates were prepared. The impressions were immersed in 0.55% ortho-phthalaldehyde solution or 0.5% sodium hypochlorite solution for 1, 3, 5 and 10 min. A stone cast made with an impression that had not been immersed was prepared as a control. The surface roughness (Ra) of the stone casts was measured, and the cast surfaces were observed by SEM. Immersion of agar-alginate combined impressions in 0.5% sodium hypochlorite solution for up to 10 min had no serious adverse effects on the surface properties of the stone casts. In contrast, even 1 min of immersion in 0.55% ortho-phthalaldehyde solution caused deterioration of the cast surface properties.

Dimensional changes in stone models simulating full crown preparations with adjacent teeth resulting from long-term immersion of medium-viscosity addition-type silicone rubber impressions in disinfectant solutions.

If impression materials could be immersed in disinfectant solutions for a longer period, then this form of disinfection would be easier to incorporate into dental preparation procedures. This study investigated the dimensional changes in stone models resulting from immersion of medium-viscosity hydrophilic addition-type silicone rubber impression material in disinfectant solutions for 30 min and 24 h. Impressions of a master die designed to simulate a full crown preparation with adjacent teeth were immersed in 2% glutaraldehyde and 0.55% ortho-phthalaldehyde solutions. The dimensional changes in the mesiodistal and buccolingual dimensions in the stone models were then measured using a three-dimensional coordinate system. It was found that the dimensional changes in the stone models caused by immersion of the impression materials were less than 15 µm. Immersion in 2% glutaraldehyde or 0.55% ortho-phthalaldehyde for 24 h was as clinically acceptable for medium-viscosity hydrophilic addition-type silicone rubber impressions as immersion for 30 min.

Bone mineral density and bone turnover among young women in Chiang Mai, Thailand.

The present study was carried out to investigate the influence of lifestyle on bone mineral density (BMD) and bone turnover among young women in Chiang Mai, Thailand. A total of 177 young women affiliated with Chiang Mai University hospital were enrolled. Firstly, questionnaires about their lifestyle and the Osteoporosis Knowledge Test (OKT) were examined. The measurement of BMD was assessed by Quantitative Ultrasound (QUS). Secondly, based on the measurement of BMD, the subjects were divided into 2 groups, a Low BMD group (L group: less than YAM-1.0SD) and a Normal BMD group (N group: more than YAM-1.0SD). L group (n=23) and N group (n=23) were examined using Osteocalcine (OC), type 1 collagen cross-linked N-telopeptide (NTx) and undercarboxylated osteocalcin (ucOC) as bone turnover markers, and serum Ca, 1,25-(OH)2Vitamin D, Vitamin K1 and Vitamin K2 (MK-4) as bone turnover related factors. Based on the results, the percentage of Low BMD group was 23.2%. Concerning lifestyle and BMD, the BMD of the low cheese intake group was 99.7± 17.0 and the BMD of the high cheese intake one was 110.0± 23.3 (p<0.05). The BMD of the fracture experience group was 82.5± 11.6 and the BMD of no-fracture group was 103.3± 19.6 (p<0.05). These were significant differences in ucOC and 1,25-(OH)2Vitamin D between L and N groups (p<0.05). It was suggested that BMI, food and fracture experience might affect BMD level and suppression of bone formation might have contributed to the low BMD group among young women in Chiang Mai, Thailand.

CSF-1 receptor-mediated differentiation of a new type of monocytic cell with B cell-stimulating activity: its selective dependence on IL-34.

With the use of a mouse FDC line, FL-Y, we have been analyzing roles for FDCs in controlling B cell fate in GCs. Beside these regulatory functions, we fortuitously found that FL-Y cells induced a new type of CD11b⁺ monocytic cells (F4/80⁺, Gr-1⁻, Ly6C⁻, I-A/E(-/lo), CD11c⁻, CD115⁺, CXCR4⁺, CCR2⁺, CX3CR1⁻) when cultured with a Lin⁻c-kit⁺ population from mouse spleen cells. The developed CD11b⁺ cells shared a similar gene-expression profile to mononuclear phagocytes and were designated as FDMCs. Here, we describe characteristic immunological functions and the induction mechanism of FDMCs. Proliferation of anti-CD40 antibody-stimulated B cells was markedly accelerated in the presence of FDMCs. In addition, the FDMC-activated B cells efficiently acquired GC B cell-associated markers (Fas and GL-7). We observed an increase of FDMC-like cells in mice after immunization. On the other hand, FL-Y cells were found to produce CSF-1 as well as IL-34, both of which are known to induce development of macrophages and monocytes by binding to the common receptor, CSF-1R, expressed on the progenitors. However, we show that FL-Y-derived IL-34, but not CSF-1, was selectively responsible for FDMC generation using neutralizing antibodies and RNAi. We also confirmed that FDMC generation was strictly dependent on CSF-1R. To our knowledge, a CSF-1R-mediated differentiation process that is intrinsically specific for IL-34 has not been reported. Our results provide new insights into understanding the diversity of IL-34 and CSF-1 signaling pathways through CSF-1R.