Search

Biological systems precisely and selectively control ion binding through various chemical reactions, molecular recognition, and transport by virtue of effective molecular interactions with biological membranes and proteins. Because ion binding is inhibited in highly polar media, recognition systems for anions in aqueous media, which are relevant to biological and environmental systems, are still limited. In this study, we explored the anion binding of Langmuir monolayers formed by amphiphilic naphthalenediimide (NDI) derivatives with a series of substituents at air/water interfaces via anion-π interactions. Density functional theory (DFT) simulations revealed that the binding of anions originating from anion-π interactions is related to the electron density of the anions. At the air/water interfaces, amphiphilic NDI derivatives formed Langmuir monolayers, and the addition of anions caused expansion of the Langmuir monolayers. The anions with larger hydration energies related to electron density showed larger binding constants ( K a ) for 1:1 stoichiometry with the NDI derivatives. The loosely packed monolayer formed by the amphiphilic NDI derivatives with bromine groups showed a better anion response. In contrast, the binding of NO 3 - was significantly enhanced in the highly packed monolayer. These results indicate that the packing of NDI derivatives with rigid aromatic rings influenced the binding of the anions. These results provide insight into ion binding using the air/water interface as a promising recognition site for mimicking biological membranes. In future, sensing devices can be developed using Langmuir-Blodgett films on electrodes. Furthermore, the capture of anions on electron-deficient aromatic compounds can lead to doping or composition technologies for n-type semiconductors.

Meiotic cells generate physiological programmed DNA double-strand breaks (DSBs) to initiate meiotic recombination. Interhomolog repair of the programmed DSBs by meiotic recombination is vital to ensure accurate chromosome segregation at meiosis I to produce normal gametes. In budding yeast, the DNA damage checkpoint kinase Rad53 is activated by DSBs which accidentally occur as DNA lesions in mitosis and meiosis; however, meiotic programmed DSBs which occur at approximately 160 loci per genome fail to activate the kinase. Thus, Rad53 activation appears to be silenced in response to meiotic programmed DSBs. In this study, to address the biological significance of Rad53's insensitivity to meiotic DSBs, we examined the effects of Rad53 overexpression on meiotic processes. The overexpression led to partial activation of Rad53, uncovering that the negative impacts of Rad53 kinase activation on meiotic progression, and formation and interhomolog repair of meiotic programmed DSBs., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We conducted a hospital based investigation of the actual conditions of medical care at schools. There were the seventy-four children in need of some type of medical care. These children had severe handicaps both mentally and physically. The suction of oral secretions and tube feeding are the two main problems in medical care in school. Most of them were given this medical care by their mothers. From the point of view of children's independence and mother's respite in caring, medical care in school could be provided by the school teachers. The Ministry of Education has made progress in the study of medical care practice. Our team attempted to develop a strategy for the practice of medical care in our prefecture.

We report on a 7-month-old boy with interstitial deletion of 6q21-q23 and split-hand defect. He died at 7 months. This is the fifth patient with distal limb anomaly associated with a rearrangement of 6q21 region, and supports previous suggestions that there may be candidate gene(s) for distal limb development in the 6q21 region.

Chlamydia pneumoniae has been established as an important etiologic agent of acute respiratory tract infection in humans, especially in adults. However, there is little information available on C. pneumoniae infection in the pediatric age group. The microimmunofluorescence test and Chlamydia pneumoniae-specific polymerase chain reaction (PCR) method were applied to reveal the role of C. pneumoniae as an etiologic agent of acute lower respiratory tract infection in children in Japan. Among 136 patients aged between 2 months and 15 years with acute lower respiratory tract infection, five patients with pneumonia were found to have recent C. pneumoniae infection by the microimmunofluorescence test. C. pneumoniae-specific PCR products were detected from specimens of four patients among these five. Neither C. trachomatis nor C. psittaci infection was found in this population. These results suggest that C. pneumoniae is an important causative agent of acute childhood pneumonia and may be the most prevalent pathogen among the genus Chlamydia that causes acute lower respiratory disease in this age group in Japan.

Cytochemical and immunological studies of increased eosinophils were performed in three children with marked eosinophilia. These children were diagnosed as having non-Hodgkin's lymphoma, transient eosinophilia, and hyper-eosinophilic syndrome. All showed marked eosinophilia, with eosinophil counts of more than 5,000/mm3 in the peripheral blood and with eosinophils in all maturational stages in the bone marrow. In contrast to normal eosinophils, the increased eosinophils in three patients on cytochemical analysis showed moderately to strongly positive reactions for staining with alpha-naphthyl-butyrate esterase. Also, the mature eosinophils in the patient with lymphoma showed a strongly positive reaction for periodic acid-Schiff staining. The positive reaction for alpha-naphthyl-butyrate esterase and periodic acid-Schiff stain indicates the presence of eosinophilic proliferative disorders in these cases. Surface marker analysis of peripheral eosinophils demonstrated that an increased proportion of eosinophils expressed My7, a marker of granulocytes, in two patients with transient eosinophilia or hyper-eosinophilic syndrome, but not in a patient with lymphoma. In addition, 30-40% of eosinophils expressed Ia antigen, a differentiation marker of eosinophils, in two patients with lymphoma or hypereosinophilic syndrome. Thus, eosinophils in transient eosinophilia showed mature features, and those in hypereosinophilic syndrome showed immature features immunologically. Whereas, eosinophils in lymphoma may have a dysmaturity on the expression of Ia and My7. Cytochemical and immunological analyses of increased eosinophils may play an important role in clarifying the etiology of eosinophilia, especially its association with malignancy or other proliferative disorders.