Plague,caused by Yersinia pestis,is a zoonotic disease that infects both humans and animals.Y.pestis not only encodes various virulence factors that can disrupt host immune signaling but also can modify its lipopolysaccharide(LPS)struc-ture,thereby evading host immune surveillance and potently suppressing the host's immune response,in an important molecu-lar mechanism underlying its high pathogenicity.The LPS of Y.pestis lacks an O antigen,and its lipid A structure possesses a unique temperature transition regulatory mechanism.At different temperatures,Y.pestis forms lipid A with different numbers of acyl side chains,which plays a pivotal role in the evasion of host innate immune recognition and clearance.Here,we present a comprehensive review of research progress in the biosynthetic regulation,structural variation,and immune escape mechanism of Y.pestis LPS,to provide a reference for the study of the molecular mechanisms of pathogens using LPS structural modifica-tions to elude host innate immune defenses.

Objective: To describe the epidemiological characteristics and clinical manifestations of the 2019 coronavirus disease (COVID-19) in pediatric patients, and to provide data support and decision-making basis for the prevention and control of COVID-19. Methods: Cases of children aged 0-17 years reported by provincial health commissions in Anhui, Shandong, Zhejiang and Henan provinces were collected to analyze their spatial, temporal, and demographic distribution. Results: By 24:00 on February 6, 2020, a total of 107 pediatric patients had been reported in the four provinces, accounting for 3.8% (107/2 808) of the total cases reported in the four provinces during the same period. Anhui, Shandong, Zhejiang and Henan provinces had 25, 25, 28 and 29 cases, respectively. Cases ranged in age from 5 days after birth to 17 years, with a median age of 8 years. Boys accounted for 58.9%. Totally 38 cases had a history of sojourn in Wuhan or Hubei, 63 cases had a history of exposure to confirmed cases, and 6 cases with unknown exposure history. A group of 52 family clustering were found in 107 cases. All cases presented mild symptoms, no serious and no death. Conclusion Children were also susceptible to the COVID-19. Before February 2, the index pediatric cases were mainly the first generation cases, and after February 3, these pediatric cases were mainly the secondary-generation cases and those who had close contact with confirmed cases. The monitoring of children with secondgeneration cases and close contact with COVID-19 cases were valued.

We used the epidemic data of COVID-19 published on the official website of the municipal health commission in Anhui province. We mapped the spatiotemporal changes of confirmed cases, fitted the epidemic situation by the population growth curve at different stages and took statistical description and analysis of the epidemic situation in Anhui province. It was found that the cumulative incidence of COVID-19 was 156/100 000 by February 18, 2020 and the trend of COVID-19 epidemic declined after February 7, changing from J curve to S curve. The actual number of new cases began to decrease from February 2 to February 4 due to the time of case report and actual onset delayed by 3 to 5 days.

The general secretory (Sec) pathway represents a common mechanism by which bacteria secrete proteins, including virulence factors, into the extracytoplasmic milieu. However, there is little information about this system, as well as its associated secretory proteins, in relation to the fire blight pathogen Erwinia amylovora. In this study, data mining revealed that E. amylovora harbors all of the essential components of the Sec system. Based on this information, we identified putative Sec-dependent secretory proteases in E. amylovora on a genome-wide scale. Using the programs SignalP, LipoP, and Phobius, a total of 15 putative proteases were predicted to contain the N-terminal signal peptides (SPs) that might link them to the Sec-dependent pathway. The activities of the predicted SPs were further validated using an Escherichia coli-based alkaline phosphatase (PhoA) gene fusion system that confirmed their extracytoplasmic property. Transcriptional analyses showed that the expression of 11 of the 15 extracytoplasmic protease genes increased significantly when E. amylovora was used to inoculate immature pears, suggesting their potential roles in plant infection. The results of this study support the suggestion that E. amylovora might employ the Sec system to secrete a suite of proteases to enable successful infection of plants, and shed new light on the interaction of E. amylovora with host plants.
Erwinia amylovora/metabolism* ; Escherichia coli/genetics* ; Peptide Hydrolases/genetics* ; Plant Diseases/microbiology* ; Pyrus/microbiology*

BACKGROUNDIt has not been solved what kind of needle sensation might influence outcomes of acupuncture treatment. Effects of personality factors on the therapeutic effect of acupuncture have not been investigated. This study aimed to find the effects of the traits of personality on the objective outcome when different acupuncture techniques were used in treating patients with Bell's palsy.

METHODSWe performed a secondary analysis of a prospective multicenter randomized controlled trial of acupuncture for Bell's palsy. Patients were randomly assigned to the de qi and control groups, respectively. The primary outcome was facial nerve function at month 6. The intensity of each needle sensation was rated by a visual analog scale. Psychosocial factors were assessed by the pretreatment mediator questionnaire; 16 Personality Factor Questionnaire (16PF) was used for assessing personality factors and digit cancellation test for assessing attention.

RESULTSAfter 6 months, patients in the de qi group had better facial function (adjusted odds ratio [OR]: 4.16, 95% confidence interval [CI]: 2.23-7.78). Path analysis showed that intensity of needle sensation of fullness had direct effect on House-Brackmann (HB) score at month 6. In de qi group, the low HB score on day 1 (OR: 0.13, 95% CI: 0.03-0.45) and the low Social Boldness score (OR: 0.63, 95% CI: 0.41-0.97) in 16PF were associated with better facial function. In control group, low HB score on day 1 (OR: 0.25, 95% CI: 0.13-0.50), low Vigilance score (OR: 0.66, 95% CI: 0.50-0.88), and high Tension score (OR: 1.41, 95% CI: 1.12-1.77) in 16PF were related to better facial function.

CONCLUSIONSThe needle sensation of fullness could predict better facial function and personality traits might influence outcomes of acupuncture treatment. Both of them should be considered seriously in acupuncture treatment and research.

Acupuncture Therapy ; Adolescent ; Adult ; Aged ; Bell Palsy ; psychology ; therapy ; Facial Nerve ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Needles ; Odds Ratio ; Personality Tests ; Recovery of Function ; Surveys and Questionnaires ; Treatment Outcome ; Young Adult

OBJECTIVETo investigate the functional relations between the putative proteins YpCD1.08, YpCD1.09, YpCD1.16 encoded in pCD1 plasmid of Yersinia pestis and its type III secretion system (T3SS).

METHODSMutants of YpCD1.08, YpCD1.09, YpCD1.16 were constructed using λ-Red recombinant system. The growth curves of the mutant strains cultivated in TMH medium with or without calcium at 26 °C and 37 °C were determined to analyze the low calcium response phenotype. The transcription levels of ΔYpCD1.08, ΔYpCD1.09, ΔYpCD1.16 in Yersinia pestis and the dependence to temperature were determined using real time RT-PCR after cultivation at 26 °C and 37 °C and extraction of RNA. A β-lactamases reporter system was adopted to study the influence of these genes on the translocation of effector YopE of T3SS.

RESULTSWhen grown in TMH medium without calcium at 26 °C and 37 °C, the growth curve of the YpCD1.08, YpCD1.09, YpCD1.16 mutants were similar to that of the wild-type strain, indicating that the low calcium response of all the mutants were normal. The ratios of YpCD1.08, YpCD1.09, YpCD1.16 gene transcriptional level at 37 °C and 26 °C were 2.3 ± 0.3, 2.3 ± 0.5 and 3.2 ± 0.7, respectively, indicating that these genes were transcribed in Yersinia pestis and their transcription regulations showed a temperature-dependence that was consistent with the well established temperature-dependent expression of Yersinia T3SS genes. The β-lactamases reporter assays demonstrated that ΔYpCD1.08 could translocate much higher level of YopE into HeLa cells, since that the light intensity ratio of 477/520 nm at 140 min was 2.5, whereas it was 1.8 for the wild-type strain, and the values in ΔYpCD1.09 and ΔYpCD1.16 were similar to the wild-type strain.

CONCLUSIONYpCD1.08, YpCD1.09, YpCD1.16 gene are likely to be the new members of T3SS, and the putative protein YpCD1.08 could play some roles in YopE secretion and translocation.

Bacterial Outer Membrane Proteins ; secretion ; Bacterial Secretion Systems ; genetics ; Genes, Bacterial ; Plasmids ; Protein Interaction Mapping ; Yersinia pestis ; genetics ; metabolism ; pathogenicity

OBJECTIVEGas chromatography (GC) was used to investigate the cellular fatty acid (CFA) composition of 141 Acinetobacter baumannii and 32 A. calcoaceticus isolates from different locations in China and to find chemical markers to differentiate these two closely related bacteria.

METHODSWhole cell fatty acid methyl esters (FAMEs) were obtained by saponification, methylation, and extraction for GC analysis, followed by a standardized Microbial Identification System (MIS) analysis.

RESULTSAll A. baumannii and A. calcoaceticus strains contained some major fatty acids, namely, 18:1 ω9c, 16:0, Sum In Feature 3, 12:0, 17:1ω8c, 3-OH-12:0, 17:0, Sum In Feature 2, 2-OH-12:0, and 18:0 compounds. Although most of the total CFAs are similar between A. baumannii and A. calcoaceticus strains, the ratios of two pairs of CFAs, i.e., Sum In Feature 3/18:1 ω9c versus 16:0/18:1 ω9c and Sum In Feature 3/18:1 ω9c versus unknown 12.484/18:1 ω9c fatty acids, could differentiate these two closely related bacteria. A. baumannii could be easily classified into two subgroups by plotting some ratios such as Sum In Feature 3/16:0 versus 17:0 and Sum In Feature 3/2-OH-12:0 versus 17:0 fatty acids.

CONCLUSIONThe ratios of some CFAs could be used as chemical markers to distinguish A. baumannii from A. calcoaceticus.

Acinetobacter baumannii ; classification ; cytology ; metabolism ; Acinetobacter calcoaceticus ; classification ; cytology ; metabolism ; Biomarkers ; metabolism ; Fatty Acids ; metabolism ; Species Specificity

OBJECTIVETo investigate antagonistic effect of microwave on hematopoietic damage of mice induced by gamma-ray irradiation.

METHODSMale healthy Kunning mice were treated with low dose microwave radiation before exposure to (60)Co gamma-ray irradiation of 8.0 Gy. The 30-day survival rate and average survival time of the mice after the treatment were examined. Peripheral blood parameters and the organ indexes of thymus and spleen were also observed in the irradiated mice. After exposure to 5.0 Gy gamma irradiation, indexes of hematopoietic foci formation of bone marrow cells (CFU-GM) and the proliferation activity of BMNCs were examined. The serum concentration of hemopoietic factors (GM-CSF and IL-3) were detected by ELISA kits.

RESULTSPre-exposure with 120 microW/cm(2) 900 MHz microwave increased the 30-day survival rate (P < 0.05) and the number of white blood cells of gamma-ray treated mice. The increases of the organ indexes of thymus and spleen, proliferation activity of BMNCs and CFU-GM hematopoietic foci numbers, as well as the higher serum concentration of GM-CSF and IL-3 were observed in the microwave pre-exposure group.

CONCLUSIONLow dose microwave radiation may exert potential antagonistic effects on hematopoietic injuries induced by ionizing radiation. The underlying mechanisms might be related with stimulation of hematopoietic growth factors expression, promotion of HSCs/HPCs proliferation, suppression on the reduction of HSCs/HPCs caused by (60)Co gamma-ray, and enhanced construction of the hematopoietic system.

Animals ; Bone Marrow ; pathology ; radiation effects ; Bone Marrow Cells ; pathology ; radiation effects ; Cell Differentiation ; radiation effects ; Cell Proliferation ; radiation effects ; Gamma Rays ; adverse effects ; Granulocyte-Macrophage Colony-Stimulating Factor ; blood ; Interleukin-3 ; blood ; Male ; Mice ; Microwaves ; Radiation Injuries, Experimental ; blood ; pathology ; prevention & control

OBJECTIVETo investigate radiation protection and possible mechanisms of low intensity microwave on gamma-ray exposed mice.

METHODS96 healthy Kunming mice were randomly divided into the following four groups: normal control, microwave (120 microW/cm(2), 900 MHz), gamma-ray irradiation (5 Gy), combined exposure of microwave and gamma-ray (120 microW/cm(2) + 5 Gy). The microwave group and combined group were exposed to 120 microW/cm(2) microwave firstly, 1 h/d, for 14 days. Then the ionization and combined group were exposed to 5 Gy (60)Co gamma-ray irradiation on the 15th day. Animals were sacrificed on the third, 6th, 9th and 12th day after irradiation. The sternum and spleen paraffin section were produced, and the histological changes were observed. Apoptosis rate of mice splenic cells in each group was examined by flow cytometry, and serum concentration of antioxidant and lipid peroxide was detected at the same time.

RESULTSBone marrow was obviously injured either by radiation or microwave exposure, characterized by undergoing four-phase lesions, namely apoptosis-necrosis, void, regeneration and recovery phase. Compared with the gamma-ray group, the pathological changes in combined group were slighter and the recovery was quicker. The pathological injuries of spleen were similar to that of bone marrow. Injuries in the combined group were slighter than gamma-ray group. It showed that apoptosis rate of splenic cells in combined group was significantly lower on the 6th and 9th day after gamma-ray radiation (23.02% +/- 15.18%, 25.37% +/- 11.62% respectively) from FCM results. Assays of oxidative damages suggested that serum superoxide dismutase (SOD) level in combined group increased while lipid peroxide level decreased significantly (P < 0.05).

CONCLUSIONLow intensity microwave may exert protection effects on injuries induced by ionizing radiation. The underlying mechanisms might be related with suppression on the hematopoietic cells apoptosis induced by gamma-ray radiation, inhibition of oxidative damages, and thus enhanced reconstruction of the hematopoietic system.

Animals ; Apoptosis ; radiation effects ; Dose-Response Relationship, Radiation ; Gamma Rays ; adverse effects ; Male ; Mice ; Microwaves ; Radiation Protection

OBJECTIVETo investigate the associations between periodontal diseases, presence of Porphyromonas gingivalis (P. gingivalis), serum levels of pro-inflammatory mediators and preterm low birth weight (PLBW).

METHODS60 women (30 PLBW and 30 healthy women), were recruited after postpartum within 3 days in this case-control study. Periodontal measurements including plaque index (PI), bleeding index (BI), probing pocket depth (PD) and clinical attachment loss (CAL) were assessed. The subgingival plaque was collected before periodontal examination and analysed by polymerase chain reaction (PCR) for the presence of the 16S rRNA gene specific to P. gingivalis, while the venous and umbilical cord blood specimens collected were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTSThe PLBW cases had a poorer oral conditions and the presence of P. gingivalis was found in a higher proportion in the PLBW than the healthy pregnant (56.7% vs. 30.0%, P < 0.05). Both of the presence of periodontitis and P. gingivalis have been found to be associated weakly with a shorter gestational age and a lower birth weight (P < 0.05). The levels of IL-1beta, IL-6 and prostaglandin-E2 (PGE2) in both of the blood samples showed higer levels between the PLBW and normal groups (P < 0.01). The IL-1beta and PGE2 levels in maternal serum were higher with a severe periodontal disease in the PLBW group (P < 0.01).

CONCLUSIONThere may be a possible link between periodontal diseases and PLBW.

Adult ; Case-Control Studies ; Dental Plaque ; Dental Plaque Index ; Female ; Humans ; Infant, Low Birth Weight ; Infant, Newborn ; Interleukin-6 ; Periodontal Diseases ; Periodontitis ; Porphyromonas gingivalis ; Pregnancy ; Premature Birth ; RNA, Ribosomal, 16S