First Isolation and Identification of Aeromonas veronii in a Captive Giant Panda (Ailuropoda melanoleuca).

The objective of this study was to understand biological characteristics of one bacteria strain named as VPG which was isolated from multiple organs of a dead captive giant panda cub. Here, we use biochemical tests, 16S rRNA and gyrB genes for bacterial identification, the disk diffusion method for antibiotic resistance phenotype, smart chip real-time PCR for the antibiotic resistance genotype, multiplex PCR for determination of virulence genes, and the acute toxicity test in mice for testing the pathogenicity of isolates. The isolate was identified as A. veronii strain based on the biochemical properties and genetic analysis. We found that the strain carried 31 antibiotic resistance genes, revealed antimicrobial resistance phenotypically to several antibiotics including penicillin, ampicillin, oxacillin, amoxicillin, imipenem, and vancomycin, and carried virulence genes including aer, act, lip, exu, ser, luxs, and tapA. The main pathological changes in giant panda were congestion, necrotic lesions and a large number of bacteria in multiple organs. In addition, the LD50 in Kunming mice infected with strain VGP was 5.14 × 107 CFU/mL by intraperitoneal injection. Infection with strain VGP led to considerable histological lesions such as hemorrhage of internal organs, necrosis of lymphocytes and neurons in Kunming mice. Taken together, these results suggest that infection with strain VGP would be an important causes of death in this giant panda cub.

A snapshot of climate drivers and temporal variation of Ixodes ovatus abundance from a giant panda living in the wild.

Ticks and tick-borne diseases have negative impacts on the health of wild animals including endangered and vulnerable species. The giant panda (Ailuropoda melanoleuca), a vulnerable and iconic flagship species, is threatened by tick infestation as well. Not only can ticks cause anemia and immunosuppression in the giant panda, but also bacterial and viral diseases. However, previous studies regarding tick infestation on giant pandas were limited in scope as case reports from sick or dead animals. In this study, an investigation focusing on the tick infestation of a reintroduced giant panda at the Daxiangling Reintroduction Base in Sichuan, China was conducted. Ticks were routinely collected and identified from the ears of the giant panda from March to September in 2021. A linear model was used to test the correlation between tick abundance and climate factors. All ticks were identified as Ixodes ovatus. Tick abundance was significantly different among months. Results from the linear model showed temperature positively correlated to tick abundance, while air pressure had a negative correlation with tick abundance. To the best of our knowledge, this study is the first reported investigation of tick species and abundance on a healthy giant panda living in the natural environment, and provides important information for the conservation of giant pandas and other species sharing the same habitat.

Automated machine learning-based model for the prediction of delirium in patients after surgery for degenerative spinal disease.

OBJECTIVE: This study used machine learning algorithms to identify critical variables and predict postoperative delirium (POD) in patients with degenerative spinal disease. METHODS: We included 663 patients who underwent surgery for degenerative spinal disease and received general anesthesia. The LASSO method was used to screen essential features associated with POD. Clinical characteristics, preoperative laboratory parameters, and intraoperative variables were reviewed and were used to construct nine machine learning models including a training set and validation set (80% of participants), and were then evaluated in the rest of the study sample (20% of participants). The area under the receiver-operating characteristic curve (AUROC) and Brier scores were used to compare the prediction performances of different models. The eXtreme Gradient Boosting algorithms (XGBOOST) model was used to predict POD. The SHapley Additive exPlanations (SHAP) package was used to interpret the XGBOOST model. Data of 49 patients were prospectively collected for model validation. RESULTS: The XGBOOST model outperformed the other classifier models in the training set (area under the curve [AUC]: 92.8%, 95% confidence interval [CI]: 90.7%-95.0%), validation set (AUC: 87.0%, 95% CI: 80.7%-93.3%). This model also achieved the lowest Brier Score. Twelve vital variables, including age, serum albumin, the admission-to-surgery time interval, C-reactive protein level, hypertension, intraoperative blood loss, intraoperative minimum blood pressure, cardiovascular-cerebrovascular disease, smoking, alcohol consumption, pulmonary disease, and admission-intraoperative maximum blood pressure difference, were selected. The XGBOOST model performed well in the prospective cohort (accuracy: 85.71%). CONCLUSION: A machine learning model and a web predictor for delirium after surgery for the degenerative spinal disease were successfully developed to demonstrate the extent of POD risk during the perioperative period, which could guide appropriate preventive measures for high-risk patients.

Seroprevalence and risk factors of Toxoplasma gondii infection in captive giant panda (Ailuropoda melanoleuca).

Introduction: Toxoplasma gondii, a globally zoonotic protozoan parasite, infects most warm-blooded animals including the giant panda, and poses a serious threat to the giant panda conservation. However, the seroprevalence and the risk factors for toxoplasmosis in giant pandas are unknown. Here we aimed to determine the seroprevalence of T. gondii in the captive population of giant pandas and analyze the factors associated with the increased risk of infection. Methods: A total of 203 serum samples were collected from 157 (95 females and 62 males) captive giant pandas from 2007 to 2022, antibodies against T. gondii were screened using commercial ELISA and MAT kits. Results: The results showed 56 (35.67%) giant pandas were seropositive, age and transfer history between institutions were identifified as risk factors for T. gondii infection. It is suggested that age-related seroprevalence was the main factor, and housing multiple species in the same environment may increase the chance of cross-infection of T. gondii. Discussion: This study can provide research data for developing policies for the prevention and control of T. gondii and protecting the health of captive giant pandas and other wildlife.

Comparison of a commercial ELISA and indirect hemagglutination assay with the modified agglutination test for detection of Toxoplasma gondii antibodies in giant panda (Ailuropoda melanoleuca).

Toxoplasma gondii is a worldwide-distributed zoonotic protozoan parasite which causes toxoplasmosis and has a significant effect on public health. In the giant panda (Ailuropoda melanoleuca), toxoplasmosis can cause asymptomatic infections, reproductive disorder and even death, which poses a serious threat to the conservation of this rare protected species. Therefore, serological investigation of T. gondii is essential to understanding its risk to giant pandas, however, there are no specific testing kits for giant pandas. Previous research has used MAT as the reference method for screening T. gondii, to investigate this further, this study focused on the agreement comparing of MAT with ELISA and IHA tests for detecting T. gondii antibodies in 100 blood samples from 55 captive giant pandas in Chengdu, China. The results showed 87.0%, 87.0%, 84.0%, samples were sero-positive for T. gondii using ELISA (kits a, b, c), respectively, while MAT and IHA tests were 84.0% and 9.0% sero-positive, respectively. There was no significant difference between MAT and the three ELISA kits and these two methods had substantial agreement (0.61 < Ò› ≤ 0.80). Meanwhile, there was a significant difference (P < 0.001) between MAT and IHA, and these two methods had only a slight agreement (қ ≤ 0.20). The relative sensitivity of the ELISA (kits a, b, c) were 89.0%, 91.5% and 95.1%, and the specificity were 86.7%, 80.0% and 80.0%, respectively, which showed these three ELISA kits all had great accuracy. It is suggested that MAT is the recommended test method for primary screening T. gondii in giant pandas and then verified by ELISA.

Identification of extended-spectrum beta-lactamase (CTX-M)-producing Klebsiella pneumoniae belonging to ST37, ST290, and ST2640 in captive giant pandas.

BACKGROUND: Extended-spectrum ß-lactamases (ESBL)-producing strains of Klebsiella pneumoniae remain a worldwide, critical clinical concern. However, limited information was available concerning ESBL-producing Klebsiella pneumoniae in giant pandas. The objective of this study was to characterize ESBL-producing Klebsiella pneumoniae isolates from captive giant pandas. A total of 211 Klebsiella pneumoniae isolates were collected from 108 giant pandas housed at the Chengdu Research Base of Giant Panda Breeding (CRBGP), China. Samples were screened for the ESBL-producing phenotype via the double-disk synergy test. RESULT: A total of three (1.42%, n = 3/211) ESBL-producing Klebsiella pneumoniae strains were identified, and characterization of ESBL-producing Klebsiella pneumoniae isolates were studied by the detection of ESBL genes and mobile genetic elements (MGEs), evaluation of antimicrobial susceptibility and detection of associated resistance genes. Clonal analysis was performed by multi-locus sequencing type (MLST). Among the three ESBL-producing isolates, different ESBL-encoding genes, including blaCTX-M, and blaTEM, were detected. These three isolates were found to carry MGEs genes (i.e., IS903 and tnpU) and antimicrobial resistance genes (i.e., aac(6')-Ib, aac(6')-I, qnrA, and qnrB). Furthermore, it was found that the three isolates were not hypermucoviscosity, resistant to at least 13 antibiotics and belonged to different ST types (ST37, ST290, and ST2640). CONCLUSION: Effective surveillance and strict infection control strategies should be implemented to prevent outbreaks of ESBL-producing Klebsiella pneumoniae in giant pandas.

Mortality analysis of captive red panda cubs within Chengdu, China.

BACKGROUND: The red panda has been classified as an endangered species due to the decreased number in the world and disease is considered as a great threat to the health and survival of the cubs in captivity. RESULTS: This study analyzed 32 red panda cub mortalities (15 females and 17 males, age less than two months) through gross necropsy, microbiological examination, and histopathological observation at the Chengdu Research Base of Giant Panda Breeding, China, during 2014-2020. The results showed that screenings for canine distemper virus, canine parvovirus, rotavirus and parasite infection were all negative, however bacteria such as Klebsiella pneumoniae, Proteus mirabilis, Escherichia coli, Enterococcus faecalis, Pseudomonas were isolated from the tissue samples of some cubs. The major causes of death were respiratory (43.75%) and digestive system disease (28.13%), followed by cardiovascular disease (12.5%) and neonatal stillbirths (9.38%). Renal system diseases and trauma were also detected, at lower incidence (one case for each). The mortality rate within 15 days of birth was 68.75% and gradually decreased with age, there was no significant difference in gender. CONCLUSION: This study can provide a scientific basis for the analysis of the cause of death among red panda cubs in captivity, so as to improve the survival rate, help build the captive population and further the ex-situ conservation management of this endangered species. Additionally, our research may also provide insights into the in-situ conservation of wild red pandas by identifying emerging disease threats within the wild population and potential treatment for rescued individuals.

Viral metagenomics unveiled extensive communications of viruses within giant pandas and their associated organisms in the same ecosystem.

Cross-species transmission events were commonplace, with numerous cases of host-switching during the viral evolutionary history, but relatively little evidence for onward transmission in different species living in the same ecosystem. For understanding the communications of viruses in giant pandas (Ailuropoda melanoleuca) and their associated organisms, based on a large size of samples (N = 2305) collected between 2015 and 2020 from giant panda (N = 776) and other four giant panda-associated organisms in the same ecosystem, red pandas (N = 700), stray cats (N = 32), wild rats (N = 42), and mosquitoes (N = 755), viromics was used for the virus identification and subsequent virus traceability. The results showed that a feline panleukopenia virus (FPV) was found in giant pandas with clinical signs of vomiting and mild diarrhea. Meanwhile, the same FPV strain was also prevalent in the healthy red panda (Ailurus fulgens) population. From the viromes of the five different organisms, 250 virus genomes were determined. Our data revealed that besides FPV, other putative pathogenic viruses, such as red panda amdoparvoviruses (RPAVs) and Getah viruses (GETVs) were responsible for previous disease or death of some red pandas. We also demonstrated that a number of viruses were involved in potential interspecies jumping events between giant pandas and their associated species. Collectively, our results shed light on the genetic diversity and relationship of diverse viral pathogens in 'Giant pandas-Associated animals-Arthropods' and report some cases of possible viral host-switching among these host species living in the same ecosystem.

Albumin concentration is a candidate indicator for predicting the risk of calf venous thromboembolism in patients undergoing gynecologic surgery.

OBJECTIVE: To explore the ability of albumin concentration to predict calf venous thromboembolism (cVTE) in gynecologic diseases. METHODS: We analyzed data from 761 patients from the gynecology department. We screened the serum albumin concentration as an important indicator for predicting cVTE through logistic analysis. The data were divided into albumin below 35 and 35 g/L or more. Receiver operating characteristics analysis was used to compare the predictive ability of albumin, D-dimer, and a combination of these parameters as indicators for cVTE risk in different groups and subgroups. RESULTS: In gynecologic diseases, the albumin concentrations were lower in the surgery and malignancy group than in the chemotherapy and benign disease group. Albumin concentration had a predictive ability for cVTE risk. In ovarian cancer patients with albumin concentrations less than 35 g/L, albumin was better than D-dimer at predicting cVTE (area under the curve [AUC] 0.79, 95% confidence interval [CI] 0.70-0.87, P < 0.001 versus AUC 0.65, 95% CI 0.54-0.77, P = 0.016). CONCLUSION: The albumin concentration was a candidate indicator for predicting cVTE in surgical patients in the gynecology department, especially in ovarian cancer patients with albumin concentrations less than 35 g/L. A combination of the albumin and D-dimer parameters may improve the predictive ability for cVTE.

Contrasting Vaginal Bacterial Communities Between Estrus and Non-estrus of Giant Pandas (Ailuropoda melanoleuca).

Bacterial infection and imbalance of bacterial community in the genitourinary system of giant panda could affect the reproductive health. In severe cases, it can also lead to abortion. In this study, 13 of vaginal secretions in the estrue (E) group and seven of vaginal secretions in the non-estrue (NE) group were used to study the composition and diversity of vaginal bacterial communities between estrus and non-estrus by 16S rRNA gene sequencing analysis. The results showed that the vaginal microbiome in giant pandas shared the same top five abundant species between estrus and non-estrus at the phylum level. However, the vaginal microbiome changed significantly during estrus at the genus level. In top 10 genera, the abundance of Escherichia, Streptococcus, and Bacteroides in the E group was significantly higher than that in the NE group (p<0.05); Azomonas, Porphyromonas, Prevotella, Campylobacter, and Peptoniphilus in the NE group was significantly higher than that in the E group (p<0.05). The richness and diversity of vaginal microbiome in giant panda on estrus were significantly lower than those on non-estrus (p<0.05). It is noteworthy that the abundance of Streptococcus, Escherichia, and Bacteroides of vagina in giant pandas maintained low abundance in the daily. Whereas, they increased significantly during estrus period, which may play an important role in female giant pandas during estrus period. It was hypothesized that hormones may be responsible for the changes in the vaginal microbiome of giant pandas between estrus and no-estrus stages.

High Prevalence of Antimicrobial Resistance and Integron Gene Cassettes in Multi-Drug-Resistant Klebsiella pneumoniae Isolates From Captive Giant Pandas (Ailuropoda melanoleuca).

Multi-drug-resistant Klebsiella pneumoniae (MDR K. pneumonia) is increasingly being reported with corresponding increase in morbidity and mortality all over the world. However, limited information is available concerning MDR K. pneumonia in giant pandas. The objective of this study was to grasp the drug resistance profile of MDR K. pneumonia isolated from giant pandas. A total of 182 K. pneumoniae isolates were collected from fresh feces of 94 captive giant pandas of different ages and sex and separated by season. We performed a standard disk diffusion antimicrobial susceptibility test with the isolates and further evaluated the antibiotic resistance genes (ARGs) of multi-drug-resistant strains by high-throughput quantitative PCR. In addition, we then analyzed mobile genetic elements (MGEs), integron gene cassettes, and the multi-locus sequence typing of multi-drug-resistant strains by PCR. Antimicrobial susceptibility testing results demonstrated that a total of 30 (16.5%) K. pneumoniae isolates showed multiple drug resistances. The thirty MDR K. pneumonia isolates were mainly resistant to amoxicillin (100.0%), doxycycline (86.7%), chloramphenicol (60.0%), compound trimethoprim (60.0%) and trimethoprim (56.7%). Fifty different types of antibiotic resistance genes were found, which included a total of 671 antibiotic resistance genes, in the 30 multi-drug-resistant isolates. The top ten resistance genes were: vanTC-02, aacC, blaCTX-M-04, blaSHV-01, blaSHV-02, ampC-04, blaOXY, tetD, blaTEM and tetA-02. Thirteen mobile genetic elements were detected, of which IS26 (96.67%) and intI1 (96.67%) had the highest frequency. The thirty MDR K. pneumonia isolates were negative for the traA, traF, tnsA, IS1133, ISpa7, ISkpn6, intI2 and intI3 genes. Moreover, a further investigation of integrons revealed that two types of specific gene cassettes (dfrA12 + orfF + aadA2 and dfrA12 + orfF) were identified in class 1 integrons. Multi-locus sequence typing results showed that 22 STs in the thirty MDR K. pneumonia isolates were identified, the main type was ST37 (5/30). Our results illustrate that effective surveillance and strict biosecurity strategies should be taken to prevent the spread of multi-drug-resistant bacteria, and monitor the emergence of mobile genetic elements and integrons.

First detection and molecular identification of Babesia sp. from the giant panda, Ailuropoda melanoleuca, in China.

BACKGROUND: Parasitic infections are among the important causes of death of giant pandas (Ailuropoda melanoleuca) that hamper their survival in the wild. There are about 35 species of parasites which have been identified in giant pandas, but no information is currently available regarding the infection of Babesia in giant pandas. Babesia spp. are common intraerythrocytic parasite in wildlife, transmitted by ixodid ticks, which cause babesiosis. Clinical signs of babesiosis include fever, hemolysis, anemia, jaundice and death. METHODS: A species of Babesia was detected in the blood of a giant panda based on morphology and PCR amplification of the 18S rRNA gene. The phylogenetic relationship of Babesia sp. infecting giant panda was assessed by gene sequence alignment and phylogenetic analysis. RESULTS: Our analysis revealed that the Babesia isolate detected was most similar to an unidentified species of Babesia identified in black bears (Ursus thibetanus japonicus) from Japan (Babesia sp. Iwate, AB586027.1) with a 99.56% sequence similarity, followed by Babesia sp. EBB (AB566229.1, 99.50%) and Babesia sp. Akita (AB566229.1, 99.07%). CONCLUSIONS: To our knowledge, this is the first report of Babesia detected in the giant panda. The results indicate that this Babesia sp. may be a novel species, currently named Babesia sp. strain EBP01.

Isolation and characterization of Uropathogenic Escherichia coli (UPEC) from red panda (Ailurus fulgens).

BACKGROUND: Disease prevention and control is a significant part in the ex-situ conservation of the endangered red panda (Ailurus fulgens), being bacterial infection is one of the most important health threats to the captive population. To date, studies about the infection caused by Escherichia coli in the red panda are scarce. This study was conducted to determine the cause of death of a captive red panda through clinical symptoms, complete blood count, biochemical analysis, pathological diagnosis and bacterial whole genome sequencing. CASE PRESENTATION: The following report describes a case of a 1.5 year old captive red panda (Ailurus fulgens) that was found lethargic and anorectic. She was moved to the quarantine area for daily treatment with 50 mg of Cefpodoxime Proxetil. During the three-day treatment, she did not eat or defecate, and then died. Clinical hematology revealed the values of neutrophils, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and blood urea nitrogen (BUN) were significantly higher. Histological analysis demonstrated major pathological damage in the kidneys, liver and lungs, characterized by hyperemia, parenchymal cell degeneration and necrosis and inflammatory cell infiltration which were predominantly neutrophilic. A bacterial strain confirmed as Escherichia coli was isolated post mortem. Whole genome sequencing of the E. coli showed the complete genome size was 4.99 Mbp. PapA, PapC, OmpA, OmpU and other virulence factors which specific to Uropathogenic Escherichia coli (UPEC) were found in the isolate. Among the virulence factors, P pili, type I pili and related factors of the iron uptake system were associated with nephrotoxicity. CONCLUSION: The red panda died of bacterial infection caused by an uropathogenic strain of Escherichia coli. The pathogenic mechanisms of the strain are closely related to the expression of specific virulence genes.

Angular color shift of micro-LED displays.

Sidewall emission of a micro-scale light emitting diode (micro-LED) improves the light extraction efficiency, but it causes mismatched angular distributions between AlGaInP-based red micro-LED and InGaN-based blue/green counterparts due to material difference. As a result, color shift of RGB micro-LED displays may become visually noticeable. To address this issue, we first analyze the angular distributions of RGB micro-LEDs and obtain good agreement between simulation and experiment. Next, we propose a device structure with top black matrix and taper angle in micro-LEDs, which greatly suppresses the color shift while keeping a reasonably high light extraction efficiency.

Mutation analysis of 13 RM Y-STR loci in Han population from Beijing of China.

Two five-color fluorescence multiplex amplification systems of 13 Y chromosome short tandem repeat (Y-STR) loci (DYF387S1, DYF399S1, DYF403S1a/b, DYF404S1, DYS449, DYS518, DYS526a/b, DYS547, DYS570, DYS576, DYS612, DYS626, and DYS627) have been designed. A study was conducted measuring the mutation rates of the 13 Y-STRs in 501 father-son pairs of Han origin in Beijing, China. Among 7515 allele transmissions in 501 father-son pairs, 75 single-step and 2 two-step mutations were observed. Two father-son pairs had mutations at two different loci in 13 Y-STRs. The estimated mutation rates ranged from 2.00 × 10-3 (95% CI 1.00 × 10-4 to 1.11 × 10-2) for the DYF387S1, DYF403S1b, DYS526a, and DYS449 loci to 4.59 × 10-2 (95% CI 2.93 × 10-2 to 6.81 × 10-2) for the DYF399S1 locus. The average mutation rate is 1.02 × 10-2 (95% CI 8.10 × 10-3 to 1.28 × 10-2). Among these Y-STR markers, only DYF399S1, DYS627, DYF403S1a, DYS547, DYS612, and DYS626 had mutation rates higher than 1.00 × 10-2.

Diverse and abundant antibiotic resistance genes from mariculture sites of China's coastline.

With the rapid development of mariculture in China, large amounts of antibiotics are being discharged into the aquatic environment. Little information is available regarding antibiotics and corresponding antibiotic resistance genes (ARGs) associated with maricultural environments in China. Sediments from eleven typical mariculture areas along the whole coastline of China were collected, and the sediment in Meijijiao in southern China was used as a non-mariculture control. The results revealed that antibiotics and their corresponding ARGs were widely distributed in most maricultural sediments, and present at low concentrations in samples from Meijijiao. The sulfonamide-resistance genes were prevalent, and the sul1 and sul2 in Penglai were the highest detected by using quantitative PCR. Moreover, remarkable differences in ARGs among different sites were observed. Due to the limited availability of primers to detect ARGs, illumina high-throughput sequencing was also used for profiling ARGs, and the results showed that the abundance of bacA in all samples was the highest compared to other ARGs, followed by mexF and mexB. This is the first study to comprehensively investigate the antibiotic resistance profile in typical mariculture areas along the whole coast of China. This study provides insights into the impacts of mariculture on the profiles of bacterial and ARG compositions in China.

[Parecoxib suppresses the increase of neutrophil-to-lymphocyte ratio after the modified radical mastectomy].

OBJECTIVE: To observe the effect of parecoxib on neutrophil-to-lymphocyte ratio (NLR)after the modified radical mastectomy, and to explore its potential mechanisms for inhibition of perioperative inflammation.
 Methods: A total of 40 breast cancer patients undergone the modified radical mastectomy were randomly divided into a parecoxib group (n=20) and a control group (n=20). The parecoxib group received intravenous parecoxib (40 mg, 5 mL) during general anesthesia induction, post-operative day 1 and day 2; the control group received intravenous normal saline (5 mL) at the corresponding time points. Their peripheral bloods were collected for routine test in the morning of the surgery day (T1), and Day 1 (T2), Day 3 (T3) and Day 7 (T4) after the surgery, and NLR was calculated.
 Results: Compared with T1, NLR in the control group at T2 and T3 was significantly increased (P<0.05), but not at T4 (P>0.05); NLR in the parecoxib group was sharply increased at T2 (P<0.01), and returned to preoperative levels at T3 and T4 (P>0.05). NLR in the parecoxib group was significantly lower than that in the control group at T2 (P<0.05), but there were no significant difference between the two groups at other time points (P>0.05).
 Conclusion: Parecoxib can restrain the inflammatory responses and improve immune function of the breast cancer patients by suppressing the elevation of NLR after the modified radical mastectomy, which is expected to improve the prognosis of the breast cancer patients.

The ventricular late potentials in children with vasodepressor response of vasovagal syncope.

OBJECTIVES: To discuss ventricular late potentials (VLPs) in children with vasodepressor response of vasovagal syncope (VVS-V). METHODS: 184 children diagnosed as VVS-V by head-up tilt test (HUTT) were enrolled as VVS-V group, 105 age and gender matched healthy individuals without syncope were used as control group, then signal-averaged electrocardiogram was measured. RESULTS: HR was decreased [(83.98±12.27) vs (87.28±13.75)bpm, P<0.05] in VVS-V group compared with control group. The prevalence of positive VLPs was not significantly different between the two groups. However the absolute values of TQRS [(84.89±12.05) vs (81.21±8.23)ms, P<0.01], RMS40 [(28.73±7.23) vs (26.89±7.36)µV, P<0.05] and LAS40 [(62.43±19.17) vs (56.79±1.83)ms, P<0.05] were significantly prolonged in VVS-V group compared with control group, and more patients in VVS-V group had abnormal prolonged LAS40 (94.57% vs 83.80%, P<0.01). CONCLUSIONS: The prevalence of positive VLPs was not significantly different, TQRS, RMS40, LAS40 were longer in children with VVS-V in comparison with healthy individuals, and the abnormal LAS40 occurred in a higher proportion of VVS-V group.

Dexmedetomidine Inhibits Maturation and Function of Human Cord Blood-Derived Dendritic Cells by Interfering with Synthesis and Secretion of IL-12 and IL-23.

AIMS: To investigate the effects and underlying mechanism of dexmedetomidine on the cultured human dendritic cells (DCs). METHODS: Human DCs and cytotoxic T lymphocytes (CTLs) were obtained from human cord blood mononuclear cells by density gradient centrifugation. Cultured DCs were divided into three groups: dexmedetomidine group, dexmedetomidine plus yohimbine (dexmedetomidine inhibitor) group and control group. DCs in the three groups were treated with dexmedetomidine, dexmedetomidine plus yohimbine and culture medium, respectively. After washing, the DCs were co-incubated with cultured CTLs. The maturation degree of DCs was evaluated by detecting (1) the ratios of HLA-DR-, CD86-, and CD80-positive cells (flow cytometry), and (2) expression of IL-12 and IL-23 (PCR and Elisa). The function of DCs was evaluated by detecting the proliferation (MTS assay) and cytotoxicity activity (the Elisa of IFN-γ) of CTLs. In addition, in order to explore the mechanisms of dexmedetomidine modulating DCs, α2-adrenergic receptor and its downstream signals in DCs were also detected. RESULTS: The ratios of HLA-DR-, CD86-, and CD80-positive cells to total cells were similar among the three groups (P>0.05). Compared to the control group, the protein levels of IL-12 and IL-23 in the culture medium and the mRNA levels of IL-12 p35, IL-12 p40 and IL-23 p19 in the DCs all decreased in dexmedetomidine group (P<0.05). In addition, the proliferation of CTLs and the secretion of IFN-γ also decreased in the dexmedetomidine group, compared with the control group (P<0.05). Moreover, these changes induced by dexmedetomidine in the dexmedetomidine group were reversed by α2-adrenergic receptor inhibitor yohimbine in the dexmedetomidine plus yohimbine group. It was also found the decrease of mRNA levels of IL-12 p35, IL-12 p40 and IL-23 p19 in the dexmedetomidine group could be reversed by ERK1/2 or AKT inhibitors. CONCLUSION: Dexmedetomidine could negatively modulate human immunity by inhibiting the maturation of DCs and then decreasing the proliferation and cytotoxicity activity of CTLs. The α2-adrenergic receptors and its downstream molecules ERK1/2 and AKT are closely involved in the modulation of dexmedetomidine on DCs.

Propranolol Attenuates Surgical Stress-Induced Elevation of the Regulatory T Cell Response in Patients Undergoing Radical Mastectomy.

Surgical stress and inflammatory response induce the release of catecholamines and PGs, which may be key factors in facilitating cancer recurrence through immunosuppression. Animal studies have suggested the efficacy of perioperative blockades of catecholamines and PGs in reducing immunosuppression. In this study, to our knowledge, we present the first report of the effects of perioperative propranolol and/or parecoxib on peripheral regulatory T cells (Tregs) in breast cancer patients. Patients were randomly assigned to control, propranolol, parecoxib, and propranolol plus parecoxib groups. We demonstrated that levels of circulating epinephrine, norepinephrine, and PGE2increased in response to surgery. Meanwhile, peripheral FOXP3 mRNA level and Treg frequencies were elevated on postoperative day 7. Propranolol administration, rather than parecoxib, attenuated such elevation of Tregs, indicating the critical roles for catecholamines in surgery-induced promotion of Tregs. Besides, propranolol plus parecoxib treatment demonstrated no additive or synergistic effects. Furthermore, a study of Treg activity on CD4(+)T cell responses to specific tumor Ags was performed in the control and propranolol groups. Propranolol abrogated the increased Treg activity and accompanying suppression of CD4(+)T cell responses after surgery. Finally, we conducted ex vivo experiments on the effects of varying concentrations of epinephrine and/or propranolol on Treg proliferation over PBMCs from breast cancer patients, to provide further direct evidence strengthening our clinical observations. Epinephrine markedly promoted Treg proliferation, whereas propranolol prevented such enhancement effect. In conclusion, our study highlights beneficial roles for propranolol in inhibiting Treg responses in vivo and in vitro, and demonstrates that propranolol could alleviate surgical stress-induced elevation of Tregs in breast cancer patients.