Food allergy in nursery children of Kawasaki city, Japan.

BACKGROUND: Food allergies are often life threatening. In order to establish appropriate food allergy measures in nursery children, it is important to analyze local epidemiological data on the food allergy prevalence in nursery children. However, no such data are currently available for the city of Kawasaki, Japan. OBJECTIVE: The present study retrospectively evaluated food allergy prevalence among nursery children in Kawasaki city. METHODS: Data from children with food allergies requiring food avoidance in the nurseries of Kawasaki city between 2007 and 2016 were evaluated. RESULTS: From 2007 to 2016, the prevalence of food allergies among nursery children in Kawasaki city increased from 2.7% to 5.3%. The increase of food allergy prevalence was higher in 2-5 year-old children than in 0-1 year-old children (2.0% to 4.7% vs. 5.3% to 7.0%, respectively). The top five most common food allergies were hen's egg (73.0%), cow's milk (29.3%), nuts (9.7%), soy (8.9%), and wheat (6.5%). Hen's egg was consistently identified as a causative food of food allergy in more than 70% (73.0-89.1%) of food avoidance cases over the 10 year period. The increase of egg allergy prevalence was higher in 2-5 year-old children than in 0-1 year-old children (1.7% to 3.2% vs. 5.2% to 6.0%, respectively). CONCLUSIONS: Food allergies, to hen's egg in particular, have increased considerably among nursery children in the city of Kawasaki, Japan, and that increase was higher among older children.

Microfluidic System Enabling Multistep Tuning of Extraction Time Periods for Kinetic Analysis of Droplet-Based Liquid-Liquid Extraction.

When analyzing the kinetics of liquid-liquid extraction (LLE), the change in the concentration of extracted target molecules over time should be monitored for a known interfacial area. Herein, we developed a microfluidic system for precisely analyzing the kinetics of LLE using droplets of a constant size even in the presence of additives. Extraction is initiated by exchanging the carrier fluid for the droplets with a target solution and then terminated by phase separation, based on the principle of hydrodynamic filtration. By using one out of several pairs of outlet/buffer inlet at a given time, the extraction time period is tuned stepwise without changing the flow rate condition. We successfully demonstrated droplet-based LLE by controlling the extraction period from ∼0.03 to ∼1.2 s and evaluated the extraction kinetics of rhodamine B from the continuous aqueous phase to droplets of 1-octanol with a diameter of ∼40 µm. In addition, the effect of additives on extraction efficiency was evaluated. The system presented in this study would be useful for determining rate constants for interfacial mass transfer in general LLE kinetic studies as well as for developing new extraction chemistries and optimizing microfluidic chemical/biochemical analysis systems that involve an LLE process.

Phosphate bound to calcareous sediments hampers skeletal development of juvenile coral.

To test the hypothesis that terrestrial runoff affects the functions of calcareous sediments in coral reefs and hampers the development of corals, we analysed calcareous sediments with different levels of bound phosphate, collected from reef areas of Okinawajima, Japan. We confirmed that phosphate bound to calcareous sediments was readily released into ambient seawater, resulting in much higher concentrations of phosphorous in seawater from heavily polluted areas (4.3-19.0 µM as compared with less than 0.096 µM in natural ambient seawater). Additionally, we examined the effect of phosphate released from calcareous sediments on the development of Acropora digitifera coral juveniles. We found that high phosphate concentrations in seawater clearly inhibit the skeletal formation of coral juveniles. Our results demonstrate that calcareous sediments in reef areas play a crucial role in mediating the impact of terrestrial runoff on corals by storing and releasing phosphate in seawater.

[Local reactions after diphtheria-tetanus-acellular pertussis vaccines in mice; changes in histopathology at the injection site].

Diphtheria-tetanus-acellular pertussis vaccine (DTaP) developed in Japan is now widely used worldwide. DTaP is safer than the diphtheria-tetanus-whole-cell pertussis vaccine (DTwP) and has fewer severe side effects, but local reactions such as redness, swelling, and induration are still reported. The pathophysiological mechanism of these reactions is controversial. To clarify the cause of local reactions, we conducted studies using the mouse model. After administering either one or two abdominal subcutaneous DTaP inoculations, we observed changes in histopathology at the injection site at 24h, 48h, and 7 days. The control group, inoculated with physiologic saline, showed no significant changes either pathologically or with the naked eye. All mice after DTaP vaccination showed indurations at the injection site. Pathologically, we watched leukocyte invasion into or around the site, especially neutrophils and eosinophils. After the first vaccination, the extent of the invasion was strong 24h and 7 days later. At 24h following the second vaccination, a dramatic leukocyte invasion seen persisted at 7days. At 7 days after the first vaccination, peripheral fibrosis had begun, and when a second vaccination was administered, it began even earlier at the second site. These histopathological changes show that local reactions are caused by both inflammatory and allergic responses. Because this mouse study resulted in the same pattern of reactions observed in humans, this method will be useful for studies focusing on local reactions.

Delivery of plasmid DNA expressing small interference RNA for TGF-beta type II receptor by cationized gelatin to prevent interstitial renal fibrosis.

Renal interstitial fibrosis is the common pathway of chronic renal disease, while it causes end-stage renal failure. Transforming growth factor-beta (TGF-beta) is well recognized to be one of the primary mediators to induce accumulation of extracellular matrix (ECM) in the fibrotic area. Therefore, it is expected that local suppression of TGF-beta receptor (TGF-betaR) is one of the crucial strategies for anti-fibrotic therapy. The objective of this study is to investigate feasibility of small interference RNA (siRNA) for TGF-betaR in the selective degradation of TGF-betaR mRNAs, resulting in fibrotic inhibition. A plasmid DNA of TGF-betaR siRNA expression vector with or without complexation of a cationized gelatin was injected to the left kidney of mice via the ureter. Unilateral ureteral obstruction (UUO) was performed for the injected mice to evaluate the anti-fibrotic effect. The injection of plasmid DNA-cationized gelatin complex significantly decreased the level of TGF-betaR and alpha-smooth muscle actin (alpha-SMA) over-expression, the collagen content of mice kidney, and the fibrotic area of renal cortex, in contrast to free plasmid DNA injection. It is concluded that retrograde injection of TGF-betaR siRNA expression vector plasmid DNA complexed with the cationized gelatin is available to suppress progression of renal interstitial fibrosis.

Enhanced anti-fibrotic activity of plasmid DNA expressing small interference RNA for TGF-beta type II receptor for a mouse model of obstructive nephropathy by cationized gelatin prepared from different amine compounds.

The objective of this study is to increase the transfection efficiency of a plasmid DNA expressing small interference RNA (siRNA) for transforming growth factor-beta receptor (TGF-betaR) by various cationized gelatins of non-viral carrier and evaluate the anti-fibrotic effect with a mouse model of unilateral ureteral obstruction (UUO). Ethylenediamine, putrescine, spermidine or spermine was chemically introduced to the carboxyl groups of gelatin for the cationization. The plasmid DNA of TGF-betaR siRNA expression vector with or without complexation of each cationized gelatin was injected to the left kidney of mice via the ureter to prevent the progression of renal fibrosis of UUO mice. Irrespective of the type of cationized gelatin, the injection of plasmid DNA-cationized gelatin complex significantly decreased the renal level of TGF-betaR over-expression and the collagen content of mice kidney, in marked contrast to free plasmid DNA injection. It is concluded that retrograde injection of TGF-betaR siRNA expression vector plasmid DNA complexed with the cationized gelatin is available to suppress the progression of renal interstitial fibrosis.

Targeting of plasmid DNA to renal interstitial fibroblasts by cationized gelatin.

Renal interstitial fibrosis is the common pathway of chronic renal disease, while it causes end-stage renal failure. A lot of cytokines and biologically active substances are well recognized to be the candidates of primary mediators to induce accumulation of extracelluar matrix (ECM) in the interstitial fibrotic area. Interstitial fibroblasts are played a crucial role in the accumulation of excess ECM during renal interstitial fibrogenesis. Therefore, the targeting of therapeutic drugs and genes to interstitial renal fibroblasts is effective in suppressing the progress of interstitial renal failure. However, despite various approaches and techniques, few successful results have been reported on the in vivo targeting for interstitial fibroblasts. The objective of this study is to deliver an enhanced green fluorescent protein (EGFP) plasmid DNA, as a model plasmid DNA, into renal interstitial space by a cationized gelatin. After the plasmid DNA with or without complexation of the cationized gelatin was injected to the left kidney of mice via the ureter, unilateral ureteral obstruction (UUO) was performed for the mice injected to induce the renal interstitial fibrosis. When the EGFP plasmid DNA complexed with the cationized gelatin was injected, EGFP expression was observed in the fibroblasts in the interstitial area of renal cortex. It is concluded that the retrograde injection of EGFP plasmid DNA complexed with the cationized gelatin is available to target the interstitial renal fibroblasts which are currently considered as the cell source responsible for excessive ECM synthesis.

CpG inhibits IgE class switch recombination through suppression of NF kappa B activity, but not through Id2 or Bcl6.

The CpG motif in DNA plays a critical role in immunity via modulating the Th1/Th2 balance. In B cells, CpG-containing oligodeoxynucleotides (CpG ODNs) inhibit IL-4-mediated class switch recombination (CSR) to IgG1 and IgE through inhibition of the germline transcription (GLT) of these isotypes. However, the molecular mechanism of this inhibitory effect remains elusive. We showed here that Id2 and Bcl6, both of which inhibit IgE GLT and CSR, are not involved in this inhibitory pathway. We demonstrated that there is reduced activity of NF kappa B binding to the IgE promoter and a reduction of Irf4 protein in CpG ODN-treated B cells. These data indicate the critical role of NF kappa B and Irf4 in the regulation of IgE CSR through actions downstream of CpG signaling.

Measles outbreak in a suburb of Tokyo, Japan, in 1998-1999.

A 1998-1999 outbreak of measles in Kawasaki City was studied to provide an up-to-date epidemiological understanding of the disease in Japan. 21 of the 69 total patients (30.4%) seen at the hospital were under 1 y of age. None of the 69 patients had received measles vaccine. 43 out of 50 nasopharyngeal swabs subjected to polymerase chain reaction assay (86%) were positive for the hemagglutinin (H) gene. The measles strain isolated from patients was classified as a D3 genotype. Such outbreaks are important epidemiologically, and these findings shed light on vaccination and immunity patterns in this urban population.