[Epidemiological characteristics of mpox epidemic in Guangzhou].

Objective: To understand the epidemiological characteristics of mpox epidemic in Guangzhou and provide scientific evidence for the prevention and control of the disease. Methods: Based on the mpox surveillance system in Guangzhou, suspected mpox cases with fever and rash were reported by local hospitals at all levels to centers for disease control and prevention in Guangzhou for sampling, investigation and diagnosis. Descriptive epidemiological analysis was conducted on the clinical characteristics and treatment of the mpox cases and positive detection rate reported in Guangzhou as of 24:00 on June 23. Whole genome sequencing of the virus isolates was performed using Illumina Miniseq high-throughput sequencing platform. Results: The first mpox case in Guangzhou was reported on June 10 in 2023. As of 24:00 on June 23, a total of 25 confirmed mpox cases were reported. All the mpox cases were men with a M(Q1,Q3) of 32 (26, 36) years, the majority of the cases were MSM (96.0%). The main clinical features were rash (100.0%, 25/25), lymphadenectasis (100.0%, 25/25) and fever (52.0%, 13/25). Rash usually occurred near the genitals (88.0%, 22/25). The close contacts, mainly family members (40.4%, 23/57), showed no similar symptoms, such as fever or rash. The positive rate of mpox virus in household environment samples was 30.5%. The analyses on 3 complete gene sequences of mpox virus indicated that the strains belonged to West African type Ⅱb clade, B.1.3 lineage. Conclusions: Hidden transmission of mpox virus had occurred in MSM in Guangzhou. However, the size of affected population is relatively limited, and the possibility of wide spread of the virus is low.

High-throughput miRNA sequencing and identification of a novel ICE1-targeting miRNA in response to low temperature stress in Eucalyptus camaldulensis.

MicroRNAs (miRNAs) play a crucial role in the growth, development, morphogenesis, signal transduction, and stress response in plants. The ICE (Inducer of CBF expression)-CBF (C-repeat binding factor)-COR (Cold-regulated gene) regulatory cascade is an important signalling pathway in plant response to low temperature stress, and it remains unknown whether this pathway is regulated by miRNAs. In this study, high-throughput sequencing was employed for predicting and identifying the miRNAs that were likely to target the ICE-CBF-COR pathway in Eucalyptus camaldulensis. A novel ICE1-targeting miRNA, eca-novel-miR-259-5p (nov-miR259), was further analysed. A total of 392 conserved miRNAs and 97 novel miRNAs were predicted, including 80 differentially expressed miRNAs. Of these, 30 miRNAs were predicted to be associated with the ICE-CBF-COR pathway. The full-length of mature nov-miR259 was 22 bp and its precursor gene was 60 bp in length, with a typical hairpin structure. The RNA ligase-mediated 5' amplification of cDNA ends (5'-RLM-RACE) and Agrobacterium-mediated tobacco transient expression assays demonstrated that nov-miR259 could cleave EcaICE1 in vivo. Moreover, qRT-PCR and Pearson's correlation analysis further revealed that the expression levels of nov-miR259 were almost significantly negatively correlated with those of its target gene, EcaICE1, and the other genes in the ICE-CBF-COR pathway. We first identified the nov-miR259 as a novel ICE1-targeting miRNA, and the nov-miR259-ICE1 module may be involved in regulating the cold stress response in E. camaldulensis.

Infantile intracardiac thrombus in severe encephalo-myocarditis.

Myocarditis is an uncommon disease in childhood and has a wide range of clinical presentations, from subtle to devastating and thus requires a high index of suspicion. Intracardiac thrombus formation following myocarditis is rare and thus its management remains challenging and not well defined. We report a child whom presented with a viral prodrome, rapidly deteriorated into multi organ failure and developed fulminant viral myocarditis with encephalitis that was complicated with an intracardiac thrombus formation. We describe the challenges faced, the successful medical treatment offered and propose factors that can help guide appropriate treatment.

Alendronate use in older patients with reduced renal function: challenges and opportunities in clinical practice.

In this retrospective cohort study, alendronate use among older osteoporosis patients (age>65 years) with reduced renal function (creatinine clearance<35ml/min) was not associated with significant deterioration in renal function from baseline nor increased incidence of osteoporotic fractures or acute kidney injury, compared with patients conservatively managed with only calcium/vitamin D supplementation. INTRODUCTION: Oral bisphosphonates are not recommended in patients with creatinine clearance (CrCl) <35ml/min, although this is not supported by post hoc analyses of pivotal oral bisphosphonate studies. As both osteoporosis and renal insufficiency are more prevalent with advancing age, it is important to determine the safety and efficacy of oral bisphosphonates among these patients. METHODS: Patients with CrCl <35ml/min on alendronate (group A, n=98), with CrCl <35ml/min conservatively managed (group B, n=96), and with CrCl ≥35ml/min on alendronate (group C, n=96) were followed up to 22 months. Primary outcomes were mean change in CrCl from baseline in group A compared with groups B and C, respectively. Secondary outcomes were the incidence of osteoporotic fractures and adverse events between groups. RESULTS: There was no significant change in CrCl from baseline when comparing group A (-1.53±6.83ml/min) with group B (0.59±5.17ml/min) (p=0.075), and group A with group C (-3.71±7.54ml/min) (p=0.163). There was no significant increase in incidences of osteoporotic fractures in group A compared with group B (adjusted relative risk (aRR) 2.02, 95% confidence interval (CI) 0.64-6.37) and group A compared with group C (aRR 1.15, 95% CI 0.46-2.89). There was no significant difference in incidences of acute kidney injury (AKI) in group A compared with group B (aRR 0.48, 95% CI 0.20-1.12). Although statistically non-significant, there was an increase in AKI incidence in group A compared with group C (RR 7.84, 95% CI 0.98-62.66). CONCLUSION: Among patients with CrCl <35ml/min, alendronate therapy was not associated with significant deterioration in renal function from baseline. Although not powered for secondary outcomes, there were no statistically significant differences in osteoporotic fracture or AKI incidence between the groups.

Frequency Up-Conversion Photon-Type Terahertz Imager.

Terahertz imaging has many important potential applications. Due to the failure of Si readout integrated circuits (ROICs) and the thermal mismatch between the photo-detector arrays and the ROICs at temperatures below 40 K, there are big technical challenges to construct terahertz photo-type focal plane arrays. In this work, we report pixel-less photo-type terahertz imagers based on the frequency up-conversion technique. The devices are composed of terahertz quantum-well photo-detectors (QWPs) and near-infrared (NIR) light emitting diodes (LEDs) which are grown in sequence on the same substrates using molecular beam epitaxy. In such an integrated QWP-LED device, photocurrent in the QWP drives the LED to emit NIR light. By optimizing the structural parameters of the QWP-LED, the QWP part and the LED part both work well. The maximum values of the internal and external energy up-conversion efficiencies are around 20% and 0.5%. A laser spot of a homemade terahertz quantum cascade laser is imaged by the QWP-LED together with a commercial Si camera. The pixel-less imaging results show that the image blurring induced by the transverse spreading of photocurrent is negligible. The demonstrated pixel-less imaging opens a new way to realize high performance terahertz imaging devices.

Dual mechanisms of angiotensin-induced activation of mouse sympathetic neurones.

Ang II directly activates neurones in sympathetic ganglia. Our goal was to define the electrophysiological basis of this activation. Neurones from mouse aortic-renal and coeliac ganglia were identified as either 'tonic' or 'phasic'. With injections of depolarizing currents, action potentials (APs) were abundant and sustained in tonic neurones (TNs) and scarce or absent in phasic neurones (PNs). Resting membrane potentials were equivalent in TNs (-48 +/- 2 mV, n = 18) and PNs (-48 +/- 1 mV, n = 23) while membrane resistance was significantly higher in TNs. Ang II depolarized and increased membrane resistance equally in both TNs (n = 8) and PNs (n = 8) but it induced APs only in TNs, and enhanced current-evoked APs much more markedly in TNs (P < 0.05). The AT1 receptor antagonist losartan (2 microm, n = 6) abolished all responses to Ang II, whereas the AT2 receptor blocker PD123,319 had no effect. The transient K+ current (IA), which was more than twice as large in TNs as in PNs, was significantly inhibited by Ang II in TNs only whereas the delayed sustained K+ current (IK), which was comparable in both TNs and PNs, was not inhibited. M currents were more prominent in PNs and were inhibited by Ang II. The IA channel blocker 4-aminopyridine triggered AP generation in TNs and prevented the Ang II-induced APs but not the depolarization. Blockade of M currents by oxotremorine M or linopirdine prevented the depolarizing action of Ang II. The protein kinase C (PKC) inhibitor H7 (10 microm, n = 9) also prevented the Ang II-induced inhibition of IA and the generation APs but not the depolarization nor the inhibition of M currents. Conversely, the PKC agonist phorbol 12-myristate 13-acetate mimicked the Ang II effects by triggering APs. The results indicate that Ang II may increase AP generation in sympathetic neurones by inducing a PKC-dependent inhibition of IA currents, and a PKC-independent depolarization through inhibition of M currents. The differential expression of various K+ channels and their sensitivity to phosphorylation by PKC may determine the degree of activation of sympathetic neurones and hence may influence the severity of the hypertensive response.

Effects of a chronic compression of the dorsal root ganglion on voltage-gated Na+ and K+ currents in cutaneous afferent neurons.

A chronic compression of the dorsal root ganglion (CCD) produces ipsilateral cutaneous hyperalgesia that is associated with an increased excitability of neuronal somata in the compressed ganglion, as evidenced by spontaneous activity and a lower rheobase. We searched for differences in the properties of voltage-gated Na+ and K+ currents between somata of CCD- and control (unoperated) rats. CCD was produced in adult rats by inserting two rods through the intervertebral foramina, one compressing the L4, and the other, the ipsilateral, L5 dorsal root ganglion (DRG). After 5-9 days, DRG somata were dissociated and placed in culture for 16-26 h. Cutaneous neurons of medium size (35-45 microm), Fluorogold-labeled from the hindpaw, were selected for whole cell patch-clamp recording of action potentials and ion currents. In comparison with control neurons, CCD neurons had steady-state activation curves for TTX-sensitive (TTX-S) Na+ currents that were shifted in the hyperpolarizing direction, and CCD neurons had enhanced TTX-resistant (TTX-R) current. CCD neurons also had smaller, fast-inactivating K+ currents (Ka) at voltages from -30 to 50 mV. The reduction in Ka, the hyperpolarizing shift in TTX-S Na+ current activation, and the enhanced TTX-R Na+ current may all contribute to the enhanced neuronal excitability and thus to the pain and hyperalgesia associated with CCD.

Rhizobium yanglingense sp. nov., isolated from arid and semi-arid regions in China.

A novel rhizobial group, cluster 9, defined in previous research [Tan, Z. Y., Wang, E. T., Peng, G. X., Zhu, M. E., Martinez-Romero, E. & Chen, W. X. (1999). Int J Syst Bacteriol 49, 1457-1469], was further characterized by determination of DNA base composition, whole-cell protein SDS-PAGE analysis, DNA-DNA hybridization, 16S rRNA gene sequencing and host specificity. These isolates were collected from the wild legumes Amphicarpaea trisperma, Coronilla varia and Gueldenstaedtia multiflora growing in arid and semi-arid regions in northwestern China. Isolates within cluster 9 grouped into a single cluster above a similarity level of 90.6% in a cluster analysis based on protein SDS-PAGE, and they were differentiated from defined rhizobial species. Comparative analysis of 16S rRNA gene sequences showed that isolate CCBAU 71623T, representing cluster 9, was most related to Rhizobium gallicum and Rhizobium mongolense. The DNA-DNA homologies were lower than 42.4% among cluster 9 and defined species, including R. gallicum and R. mongolense. These data indicated that cluster 9 was a unique genomic species. Isolates within this cluster could share their host plants. They could not nodulate Galega orientalis and Leucaena leucocephala and formed ineffective nodules on Phaseolus vulgaris. This group could also be differentiated from defined species by phenotypic characteristics. It is therefore proposed as a new species, Rhizobium yanglingense, with isolate CCBAU 71623 as the type strain.

The inhibitory effects of BmK IT2, a scorpion neurotoxin on rat nociceptive flexion reflex and a possible mechanism for modulating voltage-gated Na(+) channels.

Buthus martensi Karsch IT2 (BmK IT2), a scorpion neurotoxin, was found to display a biphasic inhibitory effect on the C component of the rat nociceptive flexion reflex by subcutaneous injection in vivo, and also on the total Na(+) currents of rat dorsal root ganglion neurons using whole-cell patch clamping. BmK IT2 blocked the tetrodotoxin-resistant (TTX-R) component of the Na(+) currents with a degree of selectivity. The partial block of the TTX-R Na(+) currents, brought about by 0.01 microg/microl BmK IT2, reversed less rapidly and completely than the partial block of the tetrodotoxin-sensitive (TTX-S) current brought about by the same concentration of BmK IT2. These results suggest that the inhibition of the rat nociceptive flexion reflex by BmK IT2 may be attributed to modulation of the different voltage-gated Na(+) channels.

Buthus martensi Karsch agonist of skeletal-muscle RyR-1, a scorpion active polypeptide: antinociceptive effect on rat peripheral nervous system and spinal cord, and inhibition of voltage-gated Na(+) currents in dorsal root ganglion neurons.

The antinociceptive effect and potential antinociceptive mechanism of Buthus martensi Karsch agonist of skeletal-muscle RyR-1 (BmK AS-1), a scorpion venom derived neurotoxic polypeptide, have been investigated in rats. The results show that: (a) the withdrawal latency to rat plantar radiant heat was increased significantly by 100 and 150% after intrathecal injection of 0.6 and 1.2 microg doses; (b) C components of rat nociceptive flexion reflex were reduced to 72, 50 and 29% after intraplantar injection of 5, 10 and 20 microg doses; (c) both central (spinal cord) and peripheral antinociceptive effects of BmK AS-1 could not be reversed by naloxone; (d) tetrodotoxin-resistant (TTX-R) Na(+) current was depressed to 83.87+/-1.64, 64.73+/-5.43 and 15.85+/-17.63%, and tetrodotoxin-sensitive (TTX-S) Na(+) current was depressed to about 81.27+/-2.5, 49.08+/-8.09 and 9.03+/-12.34% with 0.2, 1.0 and 10 microg/ml BmK AS-1 measured using patch clamp recording in rat small dorsal root ganglion (DRG) neurons, respectively. The results indicate that BmK AS-1 may be a new component with potent antinociceptive activity mediated by modulating TTX-S and TTX-R Na(+) channels.

Antihyperalgesia effect of BmK IT2, a depressant insect-selective scorpion toxin in rat by peripheral administration.

The study was undertaken to assess the antihyperalgesia effect of BmK IT2, a sodium channel-specific ligand purified from the venom of Chinese scorpion Buthus martensi Karsch in rat by peripheral injection. The peripheral inflammation of rat was induced by carrageenan resulted in hyperalgesia to heat stimulus. The heat hyperalgesia was measured by paw withdrawal latency (PWL). PWL was increased to 272 +/- 18%, 217 +/- 19% and 186 +/- 16% of the control by application of 10 microl BmK IT2 at the concentration of 0.1, 0. 01 and 0.001 mg/ml in inflammatory rats, respectively. In contrast, PWL was enhanced to about 177 +/- 16%, 141 +/- 15% and 133 +/- 15% of the control at the same applied concentrations of BmK IT2 in normal rats. The results thus suggest that BmK IT2 can produce peripheral antihyperalgesia and antinociception, which might be attributed a pathway of modulating the sodium channels on nociceptor.

The binding of BmK IT2, a depressant insect-selective scorpion toxin on mammal and insect sodium channels.

Binding assay of (125)I-BmK IT2, a depressant insect-selective scorpion toxin showed two non-interacting binding sites on insect neuronal membranes: a high affinity (K(d(1))=0.65+/-0.20 nM) and low capacity (B(max(1))=0.46+/-0.13 pmol/mg protein) binding site, as well as a low-affinity (K(d(2))=78.7+/-16.4 nM) and high capacity (B(max(2))=33.1+/-8.5 pmol/mg protein) binding site. BmK IT2 could associate with and dissociate from its binding sites on insect neuronal membranes in quick manner (k(1)=5.4 x 10(5) S(-1) M(-1) and k(2)=3.2 x 10(4) S(-1) M(-1); k(-1)=7.4 x 10(-4) S(-1) and k(-2)=5.3 x 10(-3) S(-1)). The binding of (125)I-BmK IT2 to insect synaptosomes could be significantly inhibited by native BmK IT2, BmK AS and BmK AS-1 in a dose-dependent manner, and partially by BmK I, but not modified by depolarization of membrane potential and veratridine, In addition, specific binding of (125)I-BmK IT2 seem to be undetectable on rat brain synaptosomes even at high concentration. Whole cell patch-clamping recording found that BmK IT2 could partially inhibit total sodium currents of rat DRG neurons, the inhibitory effects were reversible. The results suggest that the receptor binding site of BmK IT2 on insect sodium channels might be similar to that on sodium channels of mammal peripheral nervous system, but different from that of mammal central nervous system.

Sinorhizobium meliloti associated with Medicago sativa and Melilotus spp. in arid saline soils in Xinjiang, China.

Of 42 rhizobial isolates from Medicago sativa and Melilotus spp. growing in arid saline fields in Xinjiang, China, 40 were identified as Sinorhizobium meliloti by a polyphasic approach. However, diverse groups were obtained from these isolates in numerical taxonomy and SDS-PAGE of proteins. They could grow at pH 10.5 and were tolerant to 2.5-4.0% (w/v) NaCl.

Purification, cDNA cloning and function assessment of BmK abT, a unique component from the Old World scorpion species.

A new neurotoxic component named BmK abT was purified from the venom of Chinese scorpion Buthus martensi Karsch. The molecular weight of BmK abT was determined to be 7212 Da on a mass spectrum. The minimum lethal dose of BmK abT was tested to be about 1.5 microg per mouse by intracerebroventricular injection, and the dose induced significant paralysis effect on cockroach was about 5 microg by i.p. injection. The partial amino acid sequence indicated that it was a distinctive polypeptide in the scorpion neurotoxin family. Thereafter, the whole amino acid sequence of mature BmK abT was deduced from cDNA sequence by 5'- and 3'-rapid amplification of cDNA ends. Finally, it was defined to be composed of 63 residues with amidation at the C-terminal residue. By sequence comparison, BmK abT was found to be most similar to Ts VII, a beta-toxin from the New World scorpion. The patch-clamp recording on DRG neurons, unexpectedly, showed this toxin could prolong the action potential and increase the amplitude of the peak Na+ currents, which are the typical characters of alpha-toxin. These results suggested that BmK abT was a new toxic component found in the Old World scorpion species structurally similar to beta-toxins, but functionally similar to alpha-toxins.

Characterization of bacteria isolated from wild legumes in the north-western regions of China.

Nodule isolates from 11 species of wild legumes in north-western China were characterized by numerical taxonomy, PCR-based 16S rRNA gene RFLP and sequence analyses, DNA-DNA hybridization, restriction patterns of nodDAB and nifH genes, and symbiotic properties. Based on the results of numerical taxonomy, most of the 35 new isolates were grouped into five clusters (clusters 7, 9, 12, 14 and 15). Clusters 7 and 12 were identified as Mesorhizobium amorphae and Agrobacterium tumefaciens, respectively, based on their high DNA homologies with the reference strains for these species, their 16S rRNA gene analysis and their phenotypic features. Results of 16S rDNA PCR-RFLP analysis showed that cluster 9 belonged to Rhizobium. Clusters 14 and 15 were identified as Mesorhizobium based on their moderately slow-growing, acid-producing characters and the high similarity of their 16S rDNA PCR-RFLP patterns to those of Mesorhizobium species. These two clusters were genomic species distinct from all described species based on analysis of DNA relatedness within this genus. The isolates in cluster 12 (Agrobacterium tumefaciens) failed to nodulate their original host and other selected hosts and they did not hybridize to nif or nod gene probes. The possibility of opportunistic nodulation of these isolates is discussed. Identical restriction patterns were obtained in the nif or nod gene hybridization studies from the three isolates within cluster 15, which were isolated from the same host species. The isolates from different host plants in each of clusters 9 and 14 produced different nodDAB RFLP patterns, but similar nifH RFLP patterns appeared (one band for each isolate). Different patterns were observed among different clusters from both the nod and nif gene hybridization studies. Crossnodulation was recorded among the isolates and the host plants in the same cluster and promiscuous properties were found among some of the hosts tested.

[Voltage-gated Na+ channel in nociceptive afferents of DRG neurons].

This communication briefly summarizes the molecular characteristics, expression, electrophysiological and pharmacological properties of voltage-gated sodium channels in dorsal root ganglion (DRG) neurons, and the effects of voltage-gated sodium channels on regulation of nociceptive afferents.

Rhizobium hainanense sp. nov., isolated from tropical legumes.

A fast-growing rhizobial group isolated from leguminous plants in Hainan Province, a tropical region of China, is proposed as a new Rhizobium species on the basis of 16S rRNA gene sequencing. DNA-DNA hybridization, and phenotypic characterization. This new species belongs to the phylogenetic branch which includes Rhizobium leguminosarum. We propose the name Rhizobium hainanense sp. nov. for this species. The strain CCBAU 57015 (166) is the type strain; it has been deposited in the culture collection of Beijing Agricultural University, People's Republic of China.

Phylogenetic and genetic relationships of Mesorhizobium tianshanense and related rhizobia.

The genetic and phylogenetic relationships for strains of Mesorhizobium tianshanense and its relatives were compared by an analysis of the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole-cell proteins, DNA-DNA hybridization, and full 16S rRNA gene sequencing. The strains of M. tianshanense formed a cluster which was distinct from those of other rhizobium species in the clustering analysis of SDS-PAGE. DNA-DNA relatedness between A-1BS (type strain of M. tianshanense) and the type or reference strains for Mesorhizobium loti, M. huakuii, M. ciceri, M. mediterraneum, and cluster U, an unnamed rhizobial group, ranged from 4.4 to 43.8%. The phylogenetic analysis based on the 16S rRNA gene sequences showed that M. tianshanense was closely related to the Mesorhizobium phylogenetic branch and could be distinguished from the other four species in this branch. These results further confirmed that these bacteria constitute a distinct rhizobial species.

The dependence of stomatal closure on protein synthesis.

Seven different inhibitors of the synthesis of protein and RNA, all of which are found to delay the senescence of detached oat leaves in darkness, also cause the opening of the stomata in the dark. The concentration ranges for activity on the two processes agree closely. Four other compounds of similar effects on RNA and protein synthesis, but which are inactive on senescence, correspondingly fail to open the stomata. This not only strengthens the relationship between stomatal closure and senescence, but-more important-provides strong evidence that continued protein synthesis is necessary to keep foliar stomata closed.