Expression analysis of microRNAs in murine cochlear explants

MicroRNAs (miRNAs) play functional roles in sound transduction in cochlea. This study focuses on the validity of cochlear culture as an in vitro experimental tool, in view of miRNA expression. E15 cochleae were dissected and maintained in vitro for 48 h before extraction of miRNAs. MiRNA expression was comprehensively screened in explanted cochleae using a miRNA array that covers 380 miRNAs. A strong correlation was observed between expression levels of miRNAs in in vitro and in in vivo cochleae. Levels of 43 miRNAs were altered in vitro and these changes were reproducible over three trials. These findings indicate that in vitro miRNA profiling is a viable method for analysis of gene expression and action of chemical compounds on cochleae

Orbital Emphysema Causing Syncope

Orbital emphysema is an abnormal condition in which air is present within the orbit. We report a rare case of a 19-year-old man who suffered syncopic attacks caused by sniffles following orbital emphysema as a result of trauma. Treating rhinitis is important in patients with orbital emphysema, and patients with cardiac disorders in addition to those with this condition must be warned about the risks of sniffles, sneezing, or nose blowing

Trans-synaptic interaction of GluRdelta2 and Neurexin through Cbln1 mediates synapse formation in the cerebellum

SummaryElucidation of molecular mechanisms that regulate synapse formation is required for the understanding of neural wiring, higher brain functions, and mental disorders. Despite the wealth of in vitro information, fundamental questions about how glutamatergic synapses are formed in the mammalian brain remain unanswered. Glutamate receptor (GluR) δ2 is essential for cerebellar synapse formation in vivo. Here, we show that the N-terminal domain (NTD) of GluRδ2 interacts with presynaptic neurexins (NRXNs) through cerebellin 1 precursor protein (Cbln1). The synaptogenic activity of GluRδ2 is abolished in cerebellar primary cultures from Cbln1 knockout mice and is restored by recombinant Cbln1. Knockdown of NRXNs in cerebellar granule cells also hinders the synaptogenic activity of GluRδ2. Both the NTD of GluRδ2 and the extracellular domain of NRXN1β suppressed the synaptogenic activity of Cbln1 in cerebellar primary cultures and in vivo. These results suggest that GluRδ2 mediates cerebellar synapse formation by interacting with presynaptic NRXNs through Cbln1

In situ drag coefficient measurements for rooftop trees

To evaluate the drag coefficients for roof-top tree crowns, previously-developed field test methods for monitoring wind speed, wind direction, and stem deflection were improved using solar cells as a source of power. A field test was conducted for a Norway spruce and a shirakanba located on a rooftop. The drag coefficients showed large variations during low wind speeds, which were caused by the flexural vibration of the tree trunk due to the fluctuating wind speed. To compensate for this effect, the upper percentage of drag coefficients obtained for the 0.5 m/s wind speed classes were used for the exponential regression for drag coefficient as a function of wind speed. As a result, a conservative evaluation of drag coefficients for a greater range of wind speeds could be established instead of using all data. The drag coefficients at 30 m/s wind speed were estimated to be 0.594 for the Norway spruce, and 0.154 for the shirakanba using the upper 50% of the data. The exponential function convergence was more gradual for the spruce than for the shirakanba, which may be affected by a difference in the streamlining behavior

The Progression of Xylem Vessel Cell Differentiation is Dependent on the Activity Level of VND7 in Arabidopsis thaliana

Xylem vessels are important for water conduction in vascular plants. The VASCULAR-RELATED NAC-DOMAIN (VND) family proteins, master regulators of xylem vessel cell differentiation in Arabidopsis thaliana, can upregulate a set of genes required for xylem vessel cell differentiation, including those involved in secondary cell wall (SCW) formation and programmed cell death (PCD); however, it is not fully understood how VND activity levels influence these processes. Here, we examined the Arabidopsis VND7-VP16-GR line, in which VND7 activity is post-translationally activated by treatments with different concentrations of dexamethasone (DEX), a synthetic glucocorticoid. Our observations showed that 1 nM DEX induced weak SCW deposition, but not PCD, whereas 10 or 100 nM DEX induced both SCW deposition and PCD. The decreased chlorophyll contents and SCW deposition were apparent after 24 h of 100 nM DEX treatment, but became evident only after 48 h of 10 nM DEX treatment. Moreover, the lower DEX concentrations delayed the upregulation of VND7 downstream genes, and decreased their induction levels. They collectively suggest that the regulation of VND activity is important not only to initiate xylem vessel cell differentiation, but also regulate the quality of the xylem vessels through VND-activity-dependent upregulation of the PCD- and SCW-related genes