A dual-signal electrochemical immunosensor for the detection of HPV16 E6 oncoprotein based on PdBP dendritic ternary nanospheres and MBSi-Chi nanocomposites.

Cervical cancer is a common cancer in women. HPV16 E6 oncoprotein is a reliable biomarker for cervical cancer. Although there are other methods for detecting E6 oncoprotein, the electrochemical method has more advantages, such as low cost, convenience and speed. In this study, a novel dual-signal electrochemical immunosensor for quick and sensitive detection of E6 oncoprotein based on a high efficiency catalyst and signal label was developed. Herein, to achieve quick detection, palladium-boron-phosphorus dendritic ternary nanospheres (PdBP NSs) not only acted as a catalyst to catalyze H2O2, but also as a support material to capture antibodies. Moreover, to realize sensitive detection, nanocomposites of mesoporous silica nanoparticles loaded with methylene blue and coated with chitosan (MBSi-Chi) were synthesized as a signal label, which can produce electrochemical signal. Under optimal conditions, the label-free immunosensor exhibited a linear range of 100 fg mL-1 to 4 ng mL-1 with a detection limit of 72.8 fg mL-1 (S/N = 3), and the sandwich-type immunosensor presented a linear range of 50 fg mL-1 to 4 ng mL-1 with a detection limit of 34.1 fg mL-1 (S/N = 3). The as-prepared dual-signal immunosensor had desirable specificity, stability and repeatability, implying its potential applications in clinical laboratory.

Neuroglial activation in the auditory cortex and medial geniculate body of salicylate-induced tinnitus rats.

Neuroglial activation has been recognized as a pathological hallmark of a variety of neurological diseases, yet the role of neuroglia in tinnitus hasn't been well established so far. To explore the potential roles of two types of glia cells (astrocyte and microglia) in the development of tinnitus, we examined markers associated with them in the primary auditory (A1) cortex and medial geniculate body (MGB) of rats with salicylate-induced tinnitus. The results demonstrated that acute and chronic administrations of salicylate could cause reversible tinnitus-like behavior in rats. The expression level of GFAP markedly increased in the A1 cortex of rats following acute and chronic treatments of salicylate, accompanied by increased endpoint and process length of astrocyte. The expression level of GFAP and the morphology of astrocyte in the rat MGB remained almost constant following salicylate treatment. On the other hand, the expression level of Iba1 markedly increased in the rat A1 cortex and MGB following acute and chronic treatments of salicylate, together with increased endpoint and process length of microglia in the MGB. Additionally, interleukin 1ß (IL-1ß), a pro-inflammatory cytokine released by activated glia was significantly up-regulated in the A1 cortex and MGB of rats after salicylate treatments. These findings highlight astrocyte activation and microglia proliferation in the central auditory system of rats experiencing tinnitus, which potently implicate an indispensable glial regulation in tinnitus development.

Aberrant expression of Nav1.6 in the cochlear nucleus correlates with salicylate-induced tinnitus in rats.

Hyperactivity in cochlear nucleus (CN) is one of the major neural correlates for tinnitus induction, yet the molecular factors that participate in the neuronal hyperexcitability remain unclear. The present study showed that acute and chronic administrations of salicylate were both capable of inducing reversible tinnitus in rats. The number of GAD 65/67-immunoreactive neurons in the AVCN and DCN was decreased, while the number of VGLUT 1/2-immunoreactive neurons in the AVCN and DCN was increased when rats were experiencing tinnitus, providing evidence for excitatory-inhibitory imbalance in CN is correlated with tinnitus. Interestingly, the expression level of Nav1.6, an important subtype of voltage-gated sodium channels was significantly increased in the DCN and AVCN of rats experiencing tinnitus, the up-regulation of Nav1.6 was returned to normal level following the disappearance of tinnitus. Double-labeling experiments revealed that Nav1.6 expression was down-regulated in the GAD 65/67-positive neurons in the DCN and AVCN of rats experiencing tinnitus. Notably, the percentage of co-localization of Nav1.6 and NeuN-labeling fusiform neurons was markedly increased in the DCN during tinnitus. These findings uncover the tinnitus-associated alteration in Nav1.6, a potential key contributor that can lead to hyperexcitability in CN and contribute to salicylate-induced tinnitus.

Identifying the toxins in hornet (Vespa basalis) venom that induce rat pain responses.

The black-bellied hornet Vespa basalis is responsible for the large quantity of accidents and severe wasp envenomation in China. This study aims to identify the rat pain responses induced by experimental V. basalis sting and related-components in the venom. It was observed that unilateral intraplantar injection of crude V. basalis venom could induce several kinds of pain related behaviors in a dose-dependent manner including spontaneous pain, unilateral thermal and unilateral mechanical hypersensitivity at different time courses. Fourteen main fractions were separated from the crude venom of V. basalis using high performance liquid chromatography, among them, five components (1, 3, 4, 9 and 12) could absolutely mimic the crude venom-induced pain behaviors. According to the molecular mass and N-terminal sequence, the component 3 and 4 were identified as Mastoparan B and HP-1 respectively, the component 9 was speculated as a novel variant of HP-1/2. In addition, the other two sub-components (1-1 and 1-2) purified from component 1 cannot be determined. The results offered the key information about six active polypeptides from V. basalis contributing to pain responses, which might provide a basis for exploring mechanisms of wasp sting injury.

Distribution and Functional Characteristics of Voltage-Gated Sodium Channels in Immature Cochlear Hair Cells.

Voltage-gated sodium channels (VGSCs) are transiently expressed in cochlear hair cells before hearing onset and play an indispensable role in shaping spontaneous activity. In this study, we showed that Na+ currents shaped the spontaneous action potentials in developing mouse inner hair cells (IHCs) by decreasing the time required for the membrane potential to reach the action-potential threshold. In immature IHCs, we identified 9 known VGSC subtypes (Nav1.1α-1.9α), among which Nav1.7α was the most highly expressed subtype and the main contributor to Na+ currents in developing hair cells. Electrophysiological recordings of two cochlea-specific Nav1.7 variants (CbmNav1.7a and CbmNav1.7b) revealed a novel loss-of-function mutation (C934R) at the extracellular linker between segments 5 and 6 of domain II. In addition, post-transcriptional modification events, such as alternative splicing and RNA editing, amended the gating properties and kinetic features of CbmNav1.7a(C934). These results provide molecular and functional characteristics of VGSCs in mammalian IHCs and their contributions to spontaneous physiological activity during cochlear maturation.

Involvement of P2X7 receptors in satellite glial cells of dorsal root ganglia in the BmK I -induced pain model of rats.

The P2X7 receptor (P2X7R) plays an important role in inflammatory and neuropathic pain. Our recent study indicated that activation of P2X7R in microglial cells of spinal cord contributes to the inflammatory pain induced by BmK I, the major active compound from Buthus martensi Karsch (BmK). In the present study, we further investigated whether P2X7R in satellite glial cells (SGCs) of dorsal root ganglion (DRG) is involved in the BmK I-induced pain in rats. The results found that the expression of P2X7R in SGCs was increased in the ipsilateral side of L4-L5 DRGs after intraplantar injection of BmK I. Moreover, the expression of an inflammatory cytokine IL-1ß was increased in DRG after BmK I injection. Systemic administration of an inhibitor of P2X7R (A-438079) significantly inhibited both spontaneous and evoked nociceptive behaviors induced by BmK I. These results suggest that the P2X7R in SGCs of DRG might contribute to pain induced by toxins that sensitize peripheral sensory nerves.

Long-term exposure to moderate noise induces neural plasticity in the infant rat primary auditory cortex.

Previous studies have reported that rearing infant rat pups in continuous moderate-level noise delayed the formation of topographic representational order and the refinement of response selectivity in the primary auditory (A1) cortex. The present study further verified that exposure to long-term moderate-intensity white noise (70 dB sound pressure level) from postnatal day (P) 12 to P30 elevated the hearing thresholds of infant rats. Compared with age-matched control rats, noise exposure (NE) rats had elevated hearing thresholds ranging from low to high frequencies, accompanied by decreased amplitudes and increased latencies of the two initial auditory brainstem response waves. The power of raw local field potential oscillations and high-frequency ß oscillation in the A1 cortex of NE rats were larger, whereas the power of high-frequency γ oscillation was smaller than that of control rats. In addition, the expression levels of five glutamate receptor (GluR) subunits in the A1 cortex of NE rats were decreased with laminar specificity. These results suggest that the altered neural excitability and decreased GluR expression may underlie the delay of functional maturation in the A1 cortex, and may have implications for the treatment of hearing impairment induced by environmental noise.

Visual deprivation modifies glutamate receptor expression in visual and auditory centers.

Changes in the electrical activities of visual and auditory thalamic-cortical regions account for the cross-modal enhancement of auditory perception following visual deprivation, but the molecular regulatory factors mediating these changes remain elusive. In this study, we showed that the expression patterns of five glutamate receptor (GluR) subunits which involved in regulating the synaptic plasticity in mouse primary visual (V1) cortex and primary auditory (A1) cortex undergone elaborate modification with layer-specificity after visual deprivation using dark-exposure (DE). The expression levels of NR1 and NR2B were increased, and those of GluR1 and NR2B in the V1 cortex were decreased after DE. In the A1 cortex, the expression levels of NR1, NR2A and NR2B were increased, and the expression levels of GluR1 and GluR2 were decreased after DE. The altered expression levels of GluR subunits selectively happened in the different layers of V1 and A1 cortices. In addition, the expression level of GluR2 in lateral geniculate nucleus (LGN) was decreased. These results provide novel molecular clues for the plastic neural activity in visual and auditory centers in the absence of visual input, and hint the extensive refinement of intracortical circuits and thalamocortical feedback circuits underlying the multisensory cross-modal plasticity.

The complete mitochondrial genome of Parnassius cephalus (Lepidoptera: Papilionidae: Parnassinae).

The complete mitochondrial genome of Parnassius cephalus is 15,343 bp in length, containing 13 protein-coding genes (PCGs), 22 tRNA genes, 2 ribosomal RNA genes and a noncoding AT-rich region. All the 13 PCGs are initiated with the codon ATN, except for COI gene which starts with codon CGA. Eleven PCGs stop with the termination codon TAN, while the COI and COII genes end with single nucleotide T. All the tRNA genes have the typical secondary clover-leaf structures except tRNASer (AGN), which loses its DHU stem. The two rRNA genes (lrRNA and srRNA) are 1341 bp and 777 bp in length, with their AT contents being 83.75% and 85.33%, respectively. The AT-rich region is 487 bp in length, and contains some conservative structures similar to other butterfly mitogenomes, such as a 17 bp poly-T stretch preceded by the ATAGA motif, and a microsatellite-like (AT)10 element preceded by the ATTTA motif.

The complete mitochondrial genome of Parnassius imperator (Lepidoptera: Papilionidae: Parnassiinae).

The complete mitochondrial genome (mitogenome) of Parnassius imperator (Lepidoptera: Parnassiinae) is a circular molecule of 15,424 bp in length, containing 37 typical insect mitochondrial genes and one non-coding A + T-rich region. Its gene order and arrangement are identical to the common type found in most lepidopteran mitogenomes. All protein-coding genes (PCGs) start with a typical ATN initiation codon, except for the cox1, which is initiated by the CGA codon as observed in other lepidopteran species. Some PCGs use standard TAA, while others use TAG (nad1) or incomplete codon T (cox1 and cox2), as their termination codons. 15 intergenic spacers (175 bp in total) and 10 overlapping sequences (29 bp in total) are dispersed throughout the whole genome. The 491 bp long A+ T-rich region contains some conserved structures similar to those found in other lepidopteran mitogenomes, such as the motif ATAGA followed by an 18-bp poly-T stretch, a microsatellite-like (AT)6 element preceded by the ATTTA motif. In addition, a 36 bp sequence stretch potential to form stem-loop structures is also found in the A+ T-rich region.

The complete mitochondrial genome of Tirumala limniace (Lepidoptera: Nymphalidae: Danainae).

The complete mitochondrial nucleotide sequence of Tirumala limniace is 15,285 bp in size, containing typical metazoan 37 genes: 13 protein-coding genes (PCGs), 22tRNA genes, 2 ribosomal RNA genes and one noncoding AT-rich region. All the 13 PCGs initiated with ATN, except for COI gene which is started by CGA codon. Nine PCGs use the complete termination codon (TAA), whereas the COI, COII, ND4 and ND5 genes end with single T. A total of 132 bp intergenic spacers and a total of 37 bp overlapping sequences are interspersed throughout the whole genome. The two rRNA genes (rrnL and rrnS) are 1352 bp and 779 bp in size, with their AT contents of 84.6% and 85.5%, respectively. All tRNA genes display typical secondary cloverleaf structures except for trnS1 (AGN) which loses DHU arm. The 438 bp long AT-rich region contains several features common to the other lepidopterans, such as the ATAGA motif followed by a 18 bp poly-T stretch, a 9 bp poly-T stretch, a 10 bp poly-A stretch and some microsatellite-like (AT)n elements.

Experimental exploration of mouse kidney imaging with the SR PCI technology.

This paper explores mouse kidney imaging with diffraction enhanced imaging (DEI) and inline outline X-ray imaging (IOXI) technology, and evaluates latent value of kidney imaging with phase contrast imaging technology. In our experiment, spatial resolution and tissue contrast serve as element evaluation and comparison. Images obtained from our experiment exhibit clearly observable contrasts and high resolution, suggesting X-RAY and IOXO are suitable for capturing kidney images. Also, further comparison shows IOXO has a better performance than DEI in capturing microstructures.