Contribution of TRESK two-pore domain potassium channel to bone cancer-induced spontaneous pain and evoked cutaneous pain in rats.

Cancer-associated pain is debilitating. However, the mechanism underlying cancer-induced spontaneous pain and evoked pain remains unclear. Here, using behavioral tests with immunofluorescent staining, overexpression, and knockdown of TRESK methods, we found an extensive distribution of TRESK potassium channel on both CGRP+ and IB4+ nerve fibers in the hindpaw skin, on CGRP+ nerve fibers in the tibial periosteum which lacks IB4+ fibers innervation, and on CGRP+ and IB4+ dorsal root ganglion (DRG) neurons in rats. Moreover, we found a decreased expression of TRESK in the corresponding nerve fibers within the hindpaw skin, the tibial periosteum and the DRG neurons in bone cancer rats. Overexpression of TRESK in DRG neurons attenuated both cancer-induced spontaneous pain (partly reflect skeletal pain) and evoked pain (reflect cutaneous pain) in tumor-bearing rats, in which the relief of evoked pain is time delayed than spontaneous pain. In contrast, knockdown of TRESK in DRG neurons produced both spontaneous pain and evoked pain in naïve rats. These results suggested that the differential distribution and decreased expression of TRESK in the periosteum and skin, which is attributed to the lack of IB4+ fibers innervation within the periosteum of the tibia, probably contribute to the behavioral divergence of cancer-induced spontaneous pain and evoked pain in bone cancer rats. Thus, the assessment of spontaneous pain and evoked pain should be accomplished simultaneously when evaluating the effect of some novel analgesics in animal models. Also, this study provides solid evidence for the role of peripheral TRESK in both cancer-induced spontaneous pain and evoked cutaneous pain.

Smart metasurface with self-adaptively reprogrammable functions.

Intelligence at either the material or metamaterial level is a goal that researchers have been pursuing. From passive to active, metasurfaces have been developed to be programmable to dynamically and arbitrarily manipulate electromagnetic (EM) wavefields. However, the programmable metasurfaces require manual control to switch among different functionalities. Here, we put forth a smart metasurface that has self-adaptively reprogrammable functionalities without human participation. The smart metasurface is capable of sensing ambient environments by integrating an additional sensor(s) and can adaptively adjust its EM operational functionality through an unmanned sensing feedback system. As an illustrative example, we experimentally develop a motion-sensitive smart metasurface integrated with a three-axis gyroscope, which can adjust self-adaptively the EM radiation beams via different rotations of the metasurface. We develop an online feedback algorithm as the control software to make the smart metasurface achieve single-beam and multibeam steering and other dynamic reactions adaptively. The proposed metasurface is extendable to other physical sensors to detect the humidity, temperature, illuminating light, and so on. Our strategy will open up a new avenue for future unmanned devices that are consistent with the ambient environment.

Outbreak of macrolide-resistant mycoplasma pneumoniae in a primary school in Beijing, China in 2018.

BACKGROUND: On 7th June, 2018, a primary school in Beijing, China notified Shunyi CDC of an outbreak of acute respiratory disease characterized by fever and cough among students and resulting in nine hospitalization cases during the preceding 2 weeks. We started an investigation to identify the etiologic agent, find additional cases, develop and implement control measures. METHODS: We defined probable cases as students, teachers and other staffs in the school developed fever (T ≥ 37.5 °C) with cough or sore throat; or a diagnosis of pneumonia during May 1-June 31, 2018. Confirmed cases were probable cases with Mycoplasma pneumoniae detected in oropharyngeal (OP) swabs by quantitative real-time polymerase chain reaction (qPCR). We searched case by reviewing school absenteeism records and interviewing students, teachers and staff in this school. Oropharyngeal swabs were collected from symptomatic students. Two qPCR) assay, a duplex qPCR assay, and sequencing were performed to determine the pathogen, genotype and macrolide resistance at the gene level, respectively. RESULTS: From May 1st to June 31st, 2018, we identified 55 cases (36 probable and 19 confirmed), of whom 25 (45%) were hospitalized for complications. All cases were students, none of the teachers and other staffs in the school were with similar symptoms. The attack rate (AR) was 3.9% (55/1398) for all students. The cases were mainly male (58%), with an age range of 7-8 years (median: 7 years). 72% (18/25) of inpatients had radiograph findings consistent with pneumonia, and some cases were hospitalized for up to 4 weeks. Pathogen detection results indicated that Mycoplasma pneumonia (M. pneumoniae) P1 type 1 was the causative agent in this outbreak, and the strain harbored one point mutation of A to G at position 2063. CONCLUSIONS: The infections by macrolide-resistant M. pneumoniae are not always mild and pneumonia was common and M. pneumoniae could causes serious complications which require long-term hospitalization. In the future infectious disease prevention and control practice, M. pneumoniae should be paid more attention. It is necessary to establish and improve the pathogen and drug resistance surveillance system in order to prevent and control such mutated strains of M. pneumoniae from causing future outbreaks or epidemics in China.

Contribution of microglial reaction to increased nociceptive responses in high-fat-diet (HFD)-induced obesity in male mice.

The progressive increase in the prevalence of obesity in the population can result in increased healthcare costs and demands. Recent studies have revealed a positive correlation between pain and obesity, although the underlying mechanisms still remain unknown. Here, we aimed to clarify the role of microglia in altered pain behaviors induced by high-fat diet (HFD) in male mice. We found that C57BL/6CR mice on HFD exhibited enhanced spinal microglial reaction (increased cell number and up-regulated expression of p-p38 and CD16/32), increased tumor necrosis factor-α (TNF-α) mRNA and brain-derived neurotrophic factor (BDNF) protein expression as well as a polarization of spinal microglial toward a pro-inflammatory phenotype. Moreover, we found that using PLX3397 (a selective colony-stimulating factor-1 receptor (CSF1R) kinase inhibitor) to eliminate microglia in HFD-induced obesity mice, inflammation in the spinal cord was rescued, as was abnormal pain hypersensitivity. Intrathecal injection of Mac-1-saporin (a saporin-conjugated anti-mac1 antibody) resulted in a decreased number of microglia and attenuated both mechanical allodynia and thermal hyperalgesia in HFD-fed mice. These results indicate that the pro-inflammatory functions of spinal microglia have a special relevance to abnormal pain hypersensitivity in HFD-induced obesity mice. In conclusion, our data suggest that HFD induces a classical reaction of microglia, characterized by an enhanced phosphorylation of p-38 and increased CD16/32 expression, which may in part contribute to increased nociceptive responses in HFD-induced obesity mice.

Decreased abundance of TRESK two-pore domain potassium channels in sensory neurons underlies the pain associated with bone metastasis.

Cancer-associated pain is debilitating. Understanding the mechanisms that cause it can inform drug development that may improve quality of life in patients. Here, we found that the reduced abundance of potassium channels called TRESK in dorsal root ganglion (DRG) neurons sensitized nociceptive sensory neurons and cancer-associated pain. Overexpressing TRESK in DRG neurons suppressed tumor-induced neuronal hyperexcitability and pain hypersensitivity in bone metastasis model rats, whereas knocking down TRESK increased neuronal hyperexcitability and pain hypersensitivity in normal rats. Mechanistically, tumor-associated production of vascular endothelial growth factor (VEGF) activated the receptor VEGFR2 on DRGs, which increased the abundance of the calcineurin inhibitor DSCR1, which, in turn, decreased calcineurin-mediated activation of the transcription factor NFAT, thereby reducing the transcription of the gene encoding TRESK. Intrathecal application of exogenous calcineurin to tumor-bearing rats rescued TRESK abundance and abrogated both DRG hyperexcitability and pain hypersensitivity, whereas either inhibition or knockdown of calcineurin in normal rats reduced TRESK abundance and increased DRG excitability and pain sensitivity. These findings identify a potentially targetable mechanism that may cause bone metastasis-associated pain in cancer patients.

Activation of CRF/CRFR1 signaling in the basolateral nucleus of the amygdala contributes to chronic forced swim-induced depressive-like behaviors in rats.

The basolateral nucleus of the amygdala (BLA) plays a key role in processing stressful events and affective disorders. Previously we have documented that exposure of chronic forced swim (FS) to rats produces a depressive-like behavior and that sensitization of BLA neurons is involved in this process. In the present study, we demonstrated that chronic FS stress (CFSS) could activate corticotropin-releasing factor (CRF)/CRF receptor type 1 (CRFR1) signaling in the BLA, and blockade of CRF/CRFR1 signaling by intra-BLA injection of NBI27914 (NBI), a selective CRFR1 antagonist, could prevent the CFSS-induced depressive-like behaviors in rats, indicating that activation of CRF/CRFR1 signaling in the BLA is required for CFSS-induced depression. Furthermore, we discovered that exposure of chronic FS to rats could reinforce long-term potentiation (LTP) at the external capsule (EC)-BLA synapse and increase BLA neuronal excitability, and that all these alterations were inhibited by CRFR1 antagonist NBI. Moreover, we found that application of exogenous CRF also may facilitate LTP at the EC-BLA synapse and sensitize BLA neuronal excitability in normal rats via the activation of CRFR1. We conclude that activation of CRF/CRFR1 signaling in the BLA contributes to chronic FS-induced depressive-like behaviors in rats through potentiating synaptic efficiency at the EC-BLA pathway and sensitizing BLA neuronal excitability.

BDNF Contributes to Spinal Long-Term Potentiation and Mechanical Hypersensitivity Via Fyn-Mediated Phosphorylation of NMDA Receptor GluN2B Subunit at Tyrosine 1472 in Rats Following Spinal Nerve Ligation.

Previously we have demonstrated that brain-derived neurotrophic factor (BDNF) contributes to spinal long-term potentiation (LTP) and pain hypersensitivity through activation of GluN2B-containing N-methyl-D-aspartate (GluN2B-NMDA) receptors in rats following spinal nerve ligation (SNL). However, the molecular mechanisms by which BDNF impacts upon GluN2B-NMDA receptors and spinal LTP still remain unclear. In this study, we first documented that Fyn kinase-mediated phosphorylation of GluN2B subunit at tyrosine 1472 (pGluN2BY1472) was involved in BDNF-induced spinal LTP and pain hypersensitivity in intact rats. Second, we revealed a co-localization of Fyn and GluN2B-NMDA receptor in cultured dorsal horn neurons, implying that Fyn is a possible intermediate kinase linking BDNF/TrkB signaling with GluN2B-NMDA receptors in the spinal dorsal horn. Furthermore, we discovered that both SNL surgery and intrathecal active Fyn could induce an increased expression of dorsal horn pGluN2BY1472, as well as pain hypersensitivity in response to von Frey filaments stimuli; and more importantly, all these actions were effectively abrogated by pre-treatment with either PP2 or ifenprodil to respectively inhibit Fyn kinase and GluN2B-NMDA receptors activity. Moreover, we found that intrathecal administration of BDNF scavenger TrkB-Fc prior to SNL surgery, could prevent the nerve injury-induced increase of both pFynY420 and pGluN2BY1472 expression, and also inhibit the mechanical allodynia in neuropathic rats. Collectively, these results suggest that Fyn kinase-mediated pGluN2BY1472 is critical for BDNF-induced spinal LTP and pain hypersensitivity in SNL rats. Therefore, the BDNF-Fyn-GluN2B signaling cascade in the spinal dorsal horn may constitute a key mechanism underlying central sensitization and neuropathic pain development after peripheral nerve injury.

Characterization of the new GII.17 norovirus variant that emerged recently as the predominant strain in China.

Human noroviruses are the most important viral pathogens causing epidemic acute gastroenteritis, in which the GII.4 viruses have been predominant worldwide for the past decades. During 2014-2015 winter season, a new GII.17 variant emerged as the predominant virus in China surpassing the GII.4 virus in causing significantly increased acute gastroenteritis outbreaks. Genome sequences of the new GII.17 variant was determined and compared with other GII.17 noroviruses, revealing residue substitutions at specific locations, including the histo-blood group antigen-binding site and the putative antigenic epitopes. Further study of GII.17 outbreaks focusing on host susceptibility showed that the new GII.17 variant infected secretor individuals of A, B, O and Lewis types. Accordingly, the P particles of the new GII.17 variant bound secretor saliva samples of A, B, O and Lewis types with significantly higher binding signals than those of the P particles of the previous GII.17 variants. In addition, human sera collected from the outbreaks exhibited stronger blockade against the binding of the new GII.17 P particles to saliva samples than those against the binding between the P particles of previous GII.17 variants and saliva samples. Taken together, our data strongly suggested that the new GII.17 variant gained new histo-blood group antigen-binding ability and antigenic features, which may contribute to its predominance in causing human norovirus epidemics.

Differential motor and sensory functional recovery in male but not female adult rats is associated with remyelination rather than axon regeneration after sciatic nerve crush.

Peripheral nerve functional recovery after injuries relies on both axon regeneration and remyelination. Both axon regeneration and remyelination require intimate interactions between regenerating neurons and their accompanying Schwann cells. Previous studies have shown that motor and sensory neurons are intrinsically different in their regeneration potentials. Moreover, denervated Schwann cells accompanying myelinated motor and sensory axons have distinct gene expression profiles for regeneration-associated growth factors. However, it is unknown whether differential motor and sensory functional recovery exists. If so, the particular one among axon regeneration and remyelination responsible for this difference remains unclear. Here, we aimed to establish an adult rat sciatic nerve crush model with the nonserrated microneedle holders and measured rat motor and sensory functions during regeneration. Furthermore, axon regeneration and remyelination was evaluated by morphometric analysis of electron microscopic images on the basis of nerve fiber classification. Our results showed that Aα fiber-mediated motor function was successfully recovered in both male and female rats. Aδ fiber-mediated sensory function was partially restored in male rats, but completely recovered in female littermates. For both male and female rats, the numbers of regenerated motor and sensory axons were quite comparable. However, remyelination was diverse among myelinated motor and sensory nerve fibers. In detail, Aß and Aδ fibers incompletely remyelinated in male, but not female rats, whereas Aα fibers fully remyelinated in both sexes. Our result indicated that differential motor and sensory functional recovery in male but not female adult rats is associated with remyelination rather than axon regeneration after sciatic nerve crush.

Proteome analysis of Streptococcus suis serotype 2.

Outbreaks in humans, caused by Streptococcus suis serotype 2 (SS2), were reported in 1998 and 2005 in China. However, the mechanism of SS2-associated infection remains unclear. For the first time, a 2-D gel approach combined with MS was used to establish a comprehensive 2-D reference map for aiding our understanding of the pathogenicity of SS2. The identification of 694 out of 834 processed spots revealed 373 proteins. Most of the identified proteins were located in the cytoplasm and were involved in energy metabolism, protein synthesis, and cellular processes. Proteins that were abundant in the 2-DE gels could be linked mainly to housekeeping functions in carbohydrate metabolism, protein quality control and translation. 2-DE of secretory proteins was performed using IPG strips of pH 4-7. Among the 102 protein spots processed, 87 spots representing 77 proteins were successfully identified. Some virulence-associated proteins of SS2 were found, including arginine deiminase, ornithine carbamoyl-transferase, carbamate kinase, muramidase-released protein precursor, extracellular factor, and suilysin. Enolase and endopeptidase have been proposed as putative virulence-associated factors in this study. The 2-D reference map might provide a powerful tool for analyzing the virulence factor and the regulatory network involved in the pathogenicity of this microorganism.

[Isolation and identification of Streptococcus suis serotype 2 from sick-pig samples of Sichuan province].

Streptococcus suis serotype 2 (SS2) is a major pathogen frequently associated with infections in pigs. There are presently 35 serotypes of S.suis (serotype 1 to 34 and serotype 1/2) recognized on the basis of capsular antigens. Few people were reported to infect with SS2 in the past years. However, an accidental case happened in Sichuan province of China in 2005. Some people got ill and died, and all of them were closely contacted with sick pigs. Based on clinical features and epidemiologic data, this case could be caused by SS2 infection. Liver, spleen, kidney, lung and serum samples were collected and used for pathogen isolation and identification in laboratory, three strain bacteria were isolated. The three strains of SS2 showed typical morphology of SS2 on blood agar and under microscope with Gram stain. They were also agglutinated with standard serum of SS2. Biochemical characteristics of the three bacteria were tested using API 20 strep and analyzed by API software (version 3.3), results showed they were SS2. Four pairs of primer were designed, which were exactly matched the extracellular factor gene, muraminidase released protein gene, capsular polysaccharides gene and 16S rRNA gene respectively. These primers were used on polymerase chain reaction (PCR), and the PCR products were 626bp, 885bp, 487bp and 297bp on agarose gel, respectively. Drug sensitivity test were also done and results showed that they were sensitive to cefazolin, clindamycin, erythromycin, levofloxacin, nitrofurantoin, penicillin-G, and vancomycin and resistive to tetracycline. Balb/c mice infected with the isolated SS2 strain showed swelling in stomach and intestine, cyanochroia at mouth and suggillation under skin, which were similar to the clinical features of patients. Streptococcus suis serotype 2 were also found on lung sheeting sample under microscope with Gram stain. Rabbits infected with the isolated SS2 showed the similar clinical features with mice.

Epidemiological analysis of group A streptococci recovered from patients in China.

Since the mid-1980s, there has been a resurgence of severe forms of invasive group A streptococcal (GAS) disease in many countries and regions. However, there has not been any systemic epidemiologic analysis of GAS disease reported in mainland China. To analyse the molecular epidemiology of GAS disease, 86 strains from patients in different regions of mainland China were collected. The collection sites included blood, pus, wounds, the epipharynx and other sites. A total of 21 different emm types were identified in the isolates. In both invasive and non-invasive isolates, M1 (29.1%) and M12 (23.3%) were the most prevalent types, a different distribution to M type distributions reported in other countries. Furthermore, minor emm gene sequence alterations were noted for six types. Several important GAS virulence factors were detected by PCR using specific primers. The speB and slo genes were detected in all isolates and were species specific. Four superantigen genes, speA, speC, smeZ and ssa, were found in 52% (45/86), 51% (44/86), 82% (71/86) and 23% (27/86) of isolates, respectively. M1 isolates harboured more speA (84%) and fewer speC genes (44%), while M12 isolates had fewer speA (35%) and more speC genes (100%). There was also an association between some virulence genes and isolation sites, perhaps due to the correlation between the emm type distribution and virulence gene occurrence. For two important virulence genes related to necrotizing fasciitis, the sil gene was only carried by 11 of 86 isolates, and no sil gene contained the start codon ATA. The sla gene rarely occurred in GAS isolates, only four of 86 GAS strains being positive, including two isolates obtained from blood. In antimicrobial susceptibility tests, the overall rate of drug resistance in GAS isolates was higher than reported rates in other countries, and the resistance rates to erythromycin, tetracycline and clindamycin were 91.8, 93.4 and 80%, respectively. This epidemiological study may help to understand the pathogenesis of GAS disease and aid in vaccine development.