Interactions among microorganisms open up a new world for anti-infectious therapy

The human microbiome, containing bacteria, fungi, and viruses, is a community that coexists peacefully with humans most of the time, but with the potential to cause disease under certain conditions. When the environment changes or certain stimuli are received, microbes may interact with each other, causing or increasing the severity of disease in a host. With the appropriate methods, we can make these microbiota work for us, creating new applications for human health. This review discusses the wide range of interactions between microorganisms that result in an increase in susceptibility to, severity of, and mortality of diseases, and also briefly introduces how microorganisms interact with each other directly or indirectly. The study of microbial interactions and their mechanisms has revealed a new world of treatments for infectious disease. The regulation of the balance between intestinal flora, the correct application of probiotics, and the development of effective drugs by symbiosis all demonstrate the great contributions of the microbiota to human health and its powerful potential value. Consequently, the study of interactions between microorganisms plays an essential role in identifying the causes of diseases and the development of treatments.

Characterisation of highly virulent and colistin-resistant ST367-KL1 Klebsiella quasipneumoniae subsp. similipneumoniae Strain

OBJECTIVES

To elucidate the characteristics of a colistin-resistant and hypervirulent Klebsiella quasipneumoniae subsp. similipneumoniae strain (KP8) using whole genome sequencing and various phenotypic assays.

METHODS

Antimicrobial susceptibility testing was performed using broth microdilution. Whole genome sequencing and comparative genomics were utilised to elucidate genomic characteristics. Phenotypic assays to evaluate virulence factors included measurements of mucosal viscosity, biofilm production, siderophore production, infection of A549 cells, serum-killing assays, and Galleria mellonella infection models.

RESULTS

Whole-genome sequencing revealed that the strain (KP8) belongs to sequence type 367 (ST367) and capsular type 1 (KL1), and it harbours several virulence genes, including regulator of mucoid phenotype (rmpA/A2), salmochelin (iroBCDN) and aerobactin (iucABCDiutA). Antibiotic susceptibility tests showed that KP8 was resistant to colistin. Genome analysis showed that the colistin resistance of KP8 might be related to amino acid insertions in pmrB (L215_D217, insL) and pagP (M1_S3, insV). Importantly, KP8 demonstrated comparable mucosal viscosity, biofilm production capacity, siderophore production levels to hvKP. Serum-killing experiments, A549 cell infection models, and G. mellonella infection models further indicated that KP8 displayed high virulence, akin to the hypervirulent strain NUTH-K2044. Notably, global genome analysis of the K. quasipneumoniae subsp. similipneumoniae strains highlighted that the ST367 lineage has a higher tendency to carry virulence-associated genes compared to other sequence types. The prevalence of virulence-associated factors concentrated within Chinese ST367 isolates reinforces this observation.

CONCLUSION

These findings further enhance our understanding of the resistance and pathogenicity of ST367 K. quasipneumoniae subsp. similipneumoniae strain and also providing a broader perspective on the global epidemiological landscape.

[The interpretation of the updated American Urological Association guideline of interstitial cystitis/bladder pain syndrome in 2022]

In 2022, American Urological Association updated the guideline for the diagnosis and treatment of interstitial cystitis/bladder pain syndrome (IC/BPS). A significant change has been made in treatment recommendations. The updated guideline no longer divided treatments into first-line through sixth-line tiers. Instead, treatment is categorized into behavioral/non-pharmacologic, oral medicines, bladder instillations, procedures, and major surgery. This change emphasizes the heterogeneity of IC/BPS patients and the importance of individualized treatment, overturns traditional unreasonable ideas about hierarchical and progressive treatment, and encourages patients and physicians to make treatment decisions together. At the same time, the panel emphasized the importance of early implementation of cystoscopy in patients suspected of Hunner lesions and warned against the possibility of pentosan polysulfate causing a unique retinal pigmentary maculopathy. Urinary reconstruction surgery was considered to only be used as a last resort for the treatment of IC/BPS, and there is uncertainty about the overall balance between benefits and risks/burdens. The updated guideline provides a new understanding and decision-making basis for the diagnosis and treatment of IC/BPS. However, it should be noted that the clinical characteristics of Chinese patients should be considered in practice and the application of the guideline should be localized.

Vegetation-fire feedbacks increase subtropical wildfire risk in scrubland and reduce it in forests

Climate dictates wildfire activity around the world. But East and Southeast Asia are an apparent exception as fire-activity variation there is unrelated to climatic variables. In subtropical China, fire activity decreased by 80% between 2003 and 2020 amid increased fire risks globally. Here, we assessed the fire regime, vegetation structure, fuel flammability and their interactions across subtropical Hubei, China. We show that tree basal area (TBA) and fuel flammability explained 60% of fire-frequency variance. Fire frequency and fuel flammability, in turn, explained 90% of TBA variance. These results reveal a novel system of scrubland-forest stabilized by vegetation-fire feedbacks. Frequent fires promote the persistence of derelict scrubland through positive vegetation-fire feedbacks; in forest, vegetation-fire feedbacks are negative and suppress fire. Thus, we attribute the decrease in wildfire activity to reforestation programs that concurrently increase forest coverage and foster negative vegetation-fire feedbacks that suppress wildfire.

[Comparison of efficacy and safety between domestic immune checkpoint inhibitors and pembrolizumab in the treatment of driver gene-negative advanced non-small cell lung cancer]

Objective: To compare the efficacy and safety of domestic immune checkpoint inhibitors and pembrolizumab in the treatment of driver gene-negative advanced non-small cell lung cancer. Methods: A retrospective analysis was conducted on the data of 1 241 patients with driver gene-negative, unresectable stage ⅢB to Ⅳ non-small cell lung cancer who were treated at the Hunan Cancer Hospital from January 1, 2017 to October 1, 2022. All patients received monotherapy or combination therapy with domestic immune checkpoint inhibitors or pembrolizumab. Among the 1 241 patients, there were 1 066 males and 175 females, with an age range of 14 to 84 years and a median age of 62 years. Among them, 67 patients received monotherapy with domestic immune checkpoint inhibitors, 695 patients received combination therapy with domestic immune checkpoint inhibitors, 102 patients received monotherapy with pembrolizumab, and 377 patients received combination therapy with pembrolizumab. The efficacy and safety of domestic immune checkpoint inhibitors and pembrolizumab monotherapy or combination therapy were compared. Results: In the immune checkpoint inhibitor monotherapy group, the objective response rate (ORR) using domestic immune checkpoint inhibitors and pembrolizumab was 43.3%(29/67) and 44.1%(45/102), respectively, and the disease control rate (DCR) was 79.1%(53/67) and 84.3%(86/102), respectively, with no statistically significant differences (both P>0.05). In the immune combination therapy group, the ORR using domestic immune checkpoint inhibitors and pembrolizumab was 60.9%(423/695) and 62.9%(237/377), respectively, and the DCR was 92.9%(646/695) and 91.0%(343/377), respectively, with no statistically significant differences (both P>0.05). In the immune checkpoint inhibitor monotherapy group, the median progression-free survival (PFS) using domestic immune checkpoint inhibitors and pembrolizumab was 9.0 (95%CI: 3.0-15.0) months and 7.4 (95%CI: 4.8-9.8) months, respectively, with no statistically significant differences (P=0.660). The median overall survival (OS) was 27.0 (95%CI: 25.0-29.0) months and 22.0 (95%CI: 17.1-26.9) months, respectively, with no statistically significant differences (P=0.673). In the immune combination therapy group, the median PFS using domestic immune checkpoint inhibitors and pembrolizumab was 9.0 (95%CI: 8.2-9.8) months and 10.5 (95%CI: 9.0-12.0) months, respectively, with no statistically significant differences (P=0.186). The median OS was 24.0 (95%CI: 19.1-28.9) months and 26.0 (95%CI: 21.3-30.7) months, respectively, with no statistically significant differences (P=0.359). The incidence of grade 1-2 reactive capillary proliferation of the skin in the domestic immune checkpoint inhibitor group and pembrolizumab group was 14.0% (107/762) and 0, respectively. The incidence of grade≥3 reactive capillary proliferation of the skin was 1.0% (7/762) and 0, respectively, with statistically significant differences (both P<0.05). No statistically significant differences were observed in other adverse reactions (all P>0.05). Conclusions: The efficacy of domestically produced immune checkpoint inhibitors is comparable to that of pembrolizumab in the treatment of driver gene-negative advanced non-small cell lung cancer. There is little difference in safety, except for the specific difference in domestically produced immune checkpoint inhibitor, which has a unique risk of reactive cutaneous capillary endothelial proliferation.

Assessment of cefiderocol disk diffusion versus broth microdilution results when tested against Acinetobacter baumannii complex clinical isolates

IMPORTANCE

Carbapenem-resistant Acinetobacter baumannii is a major global health concern due to its high prevalence and limited treatment options. Cefiderocol is the only novel Food and Drug Administration (FDA)-approved β-lactam agent for the salvage treatment of carbapenem-resistant A. baumannii infection. Currently, a commercial automated susceptibility testing panel of cefiderocol is unavailable. Both the preparation of iron-depleted cation-adjusted Mueller-Hinton broth and the performance of broth microdilution are cumbersome in routine microbiology laboratories. A disk diffusion method is convenient for cefiderocol antimicrobial susceptibility testing, but limited data are available specifically for A. baumannii clinical isolates. Moreover, the Clinical and Laboratory Standards Institute published revisions to the A. baumannii cefiderocol disk diffusion breakpoints in 2022. Hence, we evaluated the performance of cefiderocol disk diffusion compared with the reference BMD against A. baumannii clinical isolates, especially those with cefiderocol zone diameters ≤ 14 mm.

[Preliminary analysis of seasonal pollen allergens of allergic rhinitis in a hospital of Nanchang City]

The study was aimed to analyze the seasonal pollen allergen spectrum of patients with allergic rhinitis (AR) in Nanchang city, and to provide evidence for improving the clinical diagnosis, treatment, prevention and epidemiology of seasonal AR. A retrospective analysis was conducted on the results of skin prick test (SPT) among 1 752 patients with AR in outpatient at Department of Otolaryngology, the First Affiliated Hospital of Nanchang University from September 2020 to August 2021 (a total of 1 069 males and 683 females, age ranged from 2 to 84 years old). SPSS 22.0 software was used to analyze the positive rates of main allergens and their differences in gender, age, and month of visit. Differences among groups were compared by student t test, Wilcox rank sum test, or χ2 test. The results showed that among 1 752 SPT-positive patients, the number of simple seasonal AR and the number of perennial combined seasonal AR were 102 (5.82%) and 281 (16.04%), respectively. There was no significant difference between male and female patients in positive seasonal pollen allergens (χ2=2.181, P>0.05), but the positive rate of indoor seasonal pollen allergens in males was higher than that in females (χ2=7.901, P<0.05). The seasonal pollen allergens ranking top 5 of the positive rates were willow (6.62%, 116/1 752), humulus scandens (5.71%, 100/1 752), rape (5.54%, 97/1 752), grey pigweed (4.62%, 81/1 752) and birch (3.60%, 63/1 752). The positive rates of indoor and seasonal pollen allergens increased first and then decreased in different age groups, and the highest positive rates of seasonal pollen allergens were in the age group of 31-40 years old, with statistical significance compared with other groups (χ2=61.269, P<0.05). The seasonal allergen positive rate showed two peaks in time: March to May and September to November. The positive rate of pollen in spring was 60.27% (132/219), which was significantly higher than that in autumn (39.73%,87/219) (χ2=9.247, P<0.05). The positive rate of pollen combination in spring and autumn was 68.29% (112/164), which was significantly higher than that in spring and autumn alone (18.9%,31/164) and (12.8%, 21/164) (χ2=14.731, P<0.05). In summary, pollen allergy in Nanchang City cannot be ignored, accounting for more than 20% of the total number of AR. The incidence of seasonal AR in Nanchang City showed two peaks (March to May and September to November). The common allergens for seasonal AR in Nanchang City were willow, humulus scandens, rape, grey chenopods and birch.

Developmental programming: Impact of preconceptional and gestational exposure to a real-life environmental chemical mixture on maternal steroid, cytokine and oxidative stress milieus in sheep

BACKGROUND

Gestational exposure to environmental chemicals (ECs) is associated with adverse, sex-specific offspring health effects of global concern. As the maternal steroid, cytokine and oxidative stress milieus can have critical effects on pregnancy outcomes and the programming of diseases in offspring, it is important to study the impact of real-life EC exposure, i.e., chronic low levels of mixtures of ECs on these milieus. Sheep exposed to biosolids, derived from human waste, is an impactful model representing the ECs humans are exposed to in real-life. Offspring of sheep grazed on biosolids-treated pasture are characterized by reproductive and metabolic disruptions.

OBJECTIVE

To determine if biosolids exposure disrupts the maternal steroid, cytokine and oxidative stress milieus, in a fetal sex-specific manner.

METHODS

Ewes were maintained before mating and through gestation on pastures fertilized with biosolids (BTP), or inorganic fertilizer (Control). From maternal plasma collected mid-gestation, 19 steroids, 14 cytokines, 6 oxidative stress markers were quantified. Unpaired t-test and ANOVA were used to test for differences between control and BTP groups (n = 15/group) and between groups based on fetal sex, respectively. Correlation between the different markers was assessed by Spearman correlation.

RESULTS

Concentrations of the mineralocorticoids - deoxycorticosterone, corticosterone, the glucocorticoids - deoxycortisol, cortisol, cortisone, the sex steroids - androstenedione, dehydroepiandrosterone, 16-OH-progesterone and reactive oxygen metabolites were higher in the BTP ewes compared to Controls, while the proinflammatory cytokines IL-1β and IL-17A and anti-inflammatory IL-36RA were decreased in the BTP group. BTP ewes with a female fetus had lower levels of IP-10.

DISCUSSION

These findings suggest that pre-conceptional and gestational exposure to ECs in biosolids increases steroids, reactive oxygen metabolites and disrupts cytokines in maternal circulation, likely contributors to the aberrant phenotypic outcomes seen in offspring of BTP sheep - a translationally relevant precocial model.

Stereotactic Body Radiotherapy (SBRT) for Breast Cancer Spinal Metastases is Associated with Low Rates of Long-Term Local Failure (LF) and Vertebral Compression Fracture (VCF) Independent of Molecular Status

PURPOSE/OBJECTIVE(S)

There is limited outcome data specific to breast cancer spinal metastases following spine SBRT. This study aims to report outcomes specific to breast cancer spinal metastases receiving spine SBRT and determine the implication of biomarker status.

MATERIALS/METHODS

We have been maintaining a prospective database since the inception of the spine SBRT program. A retrospective review identified 168 breast cancer patients with 409 spinal segments treated with spine SBRT between January 2008 and January 2023. Molecular subtypes were grouped based on luminal A, luminal B, basal, and HER2 enriched. Patients were followed with q3-monthly full-spine MRI and a clinical assessment. The primary endpoint was MRI-based local failure (LF), and secondary endpoints were overall survival (OS) and vertebral compression fracture (VCF).

RESULTS

The median follow-up was 33 months (range, 3.3-123 months). Amongst the 168 patients, the majority were ECOG 0 or 1 (95%), neurologically intact (94%), polymetastatic (74%), and either luminal A (71%) or luminal B (8%). A total of 17% of patients were HER2+ve versus 83% HER2-ve. Of 409 treated segments the majority (76%) had no prior radiation or surgery (de novo), were SINS stable (60%), had either no or low-grade epidural disease (86%) and treated with 24-28 Gy in 2 fractions (73%). The LF and OS rates at 1, 3, and 5 years were 5%, 11%, and 14%, respectively, and 91%, 65%, and 45%, respectively, independent of molecular subtype on univariate analyses. The cumulative risk of VCF at 2 and 5 years was 7% and 10%, respectively.

CONCLUSION

We observe, in the largest breast cancer spine cohort to date, excellent long-term local control rates independent of molecular sub-group, and acceptable VCF rates.

Anaemia prevalence and risk factors among children aged 6 to 23 months in rural China

INTRODUCTION

Anaemia is a global public health problem among children. However, few studies have examined anaemia prevalence and risk factors among Chinese children of different ages, particularly in poor rural areas. This study investigated these two aspects among children aged 6 to 23 months in poor rural areas of China.

METHODS

This cross-sectional study included 1132 children aged 6 to 23 months in three prefectures of the Qinba Mountains area. A finger prick blood test for haemoglobin and anaemia was conducted, along with household surveys of socio-demographic characteristics, illness characteristics, and feeding practices. Multiple linear and logistic regression analyses were used to determine predictors of anaemia.

RESULTS

Overall, 42.6% of children in the study displayed anaemia. Children aged 6 to 11 months had the highest anaemia prevalence (53.6%). Anaemia risk factors differed among age-groups and throughout the overall sample. Bivariate and multivariable regression results showed that continued breastfeeding, any history of formula feeding, and consumption of iron-rich or iron-fortified foods were prominent risk factors for anaemia. However, continued breastfeeding and any history of formula feeding had the greatest impact across age-groups (both P<0.05).

CONCLUSION

Anaemia remains a severe public health problem among children aged 6 to 23 months in rural China. Healthy feeding practices, nutritional health knowledge, and nutrition improvement projects are needed to reduce the burden of anaemia among children in rural areas of China.

Outcomes Specific to Spinal Metastases with Paraspinal Disease Extension Following Spine Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

Spinal metastases with paraspinal disease (PD) extension are known to have worse outcomes following stereotactic body radiotherapy (SBRT). Characteristics of the PD itself have not been investigated to determine the impact on outcomes such as local control, which is the purpose of this study.

MATERIALS/METHODS

We retrospectively reviewed those patients who had SBRT for spinal metastases with PD disease, identified from a prospectively maintained database. Spinal metastases previously irradiated or surgical resected were excluded. The extent of PD was classified as involving the rib, neuroforamina, and muscle invasion. The gross tumor volume of PD (GTV_PD) and the clinical target volume of PD (CTV_PD) were segregated from the bony compartments based on the treatment plan contours. The outcomes of interest included the cumulative risk of local failure (LF), re-irradiation rates (ReRT), and overall survival (OS). LF and ReRT were estimated for each treated sites using the competing risk model (death as the competing risk), while OS was evaluated per patient using the Kaplan Meier method.

RESULTS

A total of 86 patients with 96 spinal metastases sites with PD were included. Of the 96 treated sites, 65% (62/96), 29% (28/96) and 6% (6/96) of PD spanned 1, 2, and 3 vertebral levels respectively. The median follow-up was 12.4months (range: 0.6-100months). The 6- and 12-month OS for the cohort was 81% and 51%, respectively. 33/86 (38%) patients had radioresistant cancer (gastrointestinal, renal cell carcinoma, thyroid, sarcoma, or melanoma). Involvement of rib, neuroforamina and muscle invasion were observed in 39% (37/96), 65% (62/96) and 21% (20/96) of the treated sites, respectively. Epidural disease was present in 57% (55/96) of treated sites. The median GTV_PD volume was 7cc (range: 0.3-114cc), and the median CTV_PD volume was 24cc (range: 0.4-248cc). The prescribed doses were 24 Gy/2 fractions (fx) (80%), 28 Gy/2 fx (10%) and 30 Gy/4 fx (10%). There were 84 treated sites with at least one post-treatment MRI available for LF assessment. The crude LF risk was 32% (27/84), and the 6- and 12-month cumulative LF rates were 12% and 28%, respectively. There was a trend towards an increased risk of LF when PD involved the rib (35% vs 24% at 1 year respectively, P = 0.07) and muscle (67% vs 20% at 1 year respectively; P = 0.06), but no difference in LF for neuroforamina involvement (26% vs 34% at 1 year respectively, P = 0.5). There were no differences in LF based on cancer radioresistance (P = 0.6), GTV_PD volume (P = 0.3) or CTV_PD volume (P = 0.4). Of the 96 treated sites, 14% (14/96) were re-irradiated (9 with repeat SBRT and 5 with conventional EBRT) at a median of 15 months (range: 4.7-59 months) post initial SBRT. The cumulative incidence of ReRT at 6- and 12-months were 1.2% and 7.3%, respectively.

CONCLUSION

PD involving adjacent rib and muscle may be associated with worse LF following SBRT. Further expansion of the cohort and dosimetric analyses are ongoing.

Stereotactic Body Radiotherapy for Posterior Element Only Spinal Metastases: Outcomes and Validation of Recommended Clinical Target Volume Delineation Practice

PURPOSE/OBJECTIVE(S)

Spine stereotactic body radiotherapy (SBRT) results in improved local control and pain response compared to conventional external beam radiotherapy. Consensus stipulates MRI-based delineation of the clinical target volume (CTV) is critical and is based on spine segment sector involvement. The applicability of these contouring guidelines to metastases confined to the posterior elements is unknown. The purpose of this study was to determine the patterns of failure, as well as the safety of treating posterior element metastases when the vertebral body was intentionally excluded from the CTV.

MATERIALS/METHODS

A retrospective review of a prospectively maintained database of 605 patients and 1412 spine segments treated with spine SBRT was performed. Only treated segments involving the posterior elements alone were included for the analyses. The primary outcome was local failure, as per SPINO recommendations, and secondary outcomes included patterns of failure, toxicities. Clinical and tumor factors were reported with descriptive statistics. The cumulative risk of local failure was estimated using the Fine-Gray method, accounting for death before local failure as a competing risk.

RESULTS

A total of 24/605 patients and 31/1412 segments within the database were treated to the posterior elements only. Local failure occurred in 11/31 segments. The cumulative rate of local recurrence was 9.7% at 12 months and 30.8% at 24 months. Amongst local failures, the most common histologies were renal cell carcinoma (36.4%) and non-small cell lung cancer (36.4%). At baseline, 4/11 (36.4%) segments with local failure (36.4%) had epidural disease and 8/11 (72.7%) had paraspinal disease. Most local failures were treated in the de novo setting (8/11, 72.7%). 6/11 (54.5%) failed exclusively within treated CTV sectors and 5/11 (45.5%) with both treated and adjacent untreated sectors. Of these five, four had disease progression within the untreated vertebral body. No failures occurred exclusively within the untreated vertebral body. One patient (4.2%) experienced a grade 4 skin toxicity and one patient (4.2%) developed an iatrogenic Grade 1 vertebral compression fracture.

CONCLUSION

Posterior element alone metastases are rare. Our analyses support SBRT consensus contouring guidelines such that the vertebral body can be excluded from CTV in spinal metastases confined to the posterior elements.

A photo-controlled, all-solid, and frequency-tunable ultra-wideband pulse generator

With the continuous exploration of the bioelectric effect, nanosecond and picosecond pulsed electric fields used in cancer therapy and drug introduction have attracted great attention. In this paper, an ultrashort pulsed electric field generator is proposed, which connects two photoconductive semiconductor switches in parallel to generate unipolar and bipolar pulses. We described the experimental scheme of the generator and the simulation of the radio frequency combiner. A 532 nm laser with pulse widths of 1 ns and 500 ps is used to trigger the photoconductive semiconductor switches. The experimental results show that the scheme can achieve adjustments of 357 and 720 MHz for the center frequency and the 3 dB bandwidth, respectively. The results confirm that this proposed scheme can be used for unipolar/bipolar frequency-adjustable ultra-wideband pulse generation.

Staged Stereotactic Radiosurgery as a Novel Adaptive Approach to Salvage Previously Irradiated Brain Metastases

PURPOSE/OBJECTIVE(S)

We report outcomes specific to a novel 3 fraction (frx) staged stereotactic radiosurgery (St-SRS) regimen designed to salvage metastases previously irradiated and considered to be at high risk of radiation necrosis (RN).

MATERIALS/METHODS

A total of 24 patients with 55 metastases treated with our 3 frx St-SRS approach were reviewed. Prior to each frx, patients were re-simulated and planned with a new MRI to allow for treatment adaption. The primary endpoint was the cumulative incidence of local failure (LF) and secondary endpoints included tumor dynamics and RN rates.

RESULTS

The median follow up was 9.0 months (range: 2.7-40.1 months) and median age was 59-years (range: 32-84). Primary cancers were of breast (44%), lung (33%), melanoma (22%), and gastro-intestinal (1%) origin. Individual metastases treated with St-SRS had initially failed surgery and post-op cavity hypofractionated SRS (HSRS) for 2/55 (4%), SRS alone for 19/55 (34%), whole brain radiation (WBRT) alone for 6/55 (11%), HSRS for 2/55 (4%), and prior SRS and WBRT exposure for 28/55 (51%). 46/55 (84%) were prescribed 8 Gy, 8 Gy, 4 Gy; 8/55 (14%) had 6 Gy, 6 Gy, 4 Gy and 1/55 (2%) had 8 Gy, 8 Gy, 6 Gy. The median number of weeks between frx was 2.6 (range: 1.0-6.8). The median of the mean and maximum target doses were 9.7 Gy (range: 5.4-11.7 Gy) and 12.4 Gy (range, 7.5-16.0 Gy) respectively. The median prescription isodose line was 62% (range: 50-85%). The mean lesion volume and diameter was 3.8cc (range: 0.05-24.8cc) and 1.6cm (range: 0.2-4.4cm), respectively. The mean percent target volume coverage, Paddick Conformality Index and Gradient Index were 100% (range: 97-100%), 0.7 (range: 0.1-0.9), and 3.2 (range: 2.5-6.7), respectively. The mean volume change between staged frxs was -4.2% (range: -69.3 to +63.1%), and based on the first and last St-SRS MRI was -10.8% (range: -86.6% to +68.7%). The crude LF rate was 27%. The median time to LF was 3.4 months (range: 1.2-7.4 months). Amongst those with a LF, 7/15 (46%) were melanoma, 6/15 (40%) HER2 positive breast cancer, 1/15 (7%) gastrointestinal and 1/15 (7%) non-small cell lung carcinoma. 8/15 (53%) had prior WBRT and SRS exposure, 1/16 (7%) surgery and cavity HSRS, 5/15 (33%) SRS alone and 1/15 (7%) WBRT alone. Only asymptomatic RN events were observed in 4/55 (7%).

CONCLUSION

St-SRS is a promising approach to salvage previously irradiated brain metastases, including prior SRS, with a favorable rate of RN. Tumor volume dynamics between stages can be significant warranting adaptive replanning.

The Incidence and Prognosis Value of Perineural Invasion in Rectal Carcinoma: From Meta-Analyses and Real-World Clinical Pathological Features

AIMS

Perineural invasion (PNI) is a special type of metastasis of several cancers and has been reported as being a factor for poor prognosis in colorectal carcinoma. However, investigations of PNI in only rectal cancer and a comprehensive analysis combining meta-analyses with real-world case studies remain lacking.

MATERIALS AND METHODS

First, articles from 2000 to 2020 concerning the relationship between PNI and rectal cancer prognoses and clinical features were meta-analysed. Subsequently, we carried out a retrospective analysis of 312 rectal cancer cases that underwent radical surgery in the real world. The incidence of PNI and the relationship between PNI and prognosis, as well as clinicopathological factors, were investigated.

RESULTS

The incidence of PNI was 23.09% and 33.01% in the meta-analysis and clinical cases, respectively. PNI occurred as early as stage I (2.94%). Moreover, neoadjuvant therapy significantly reduced the PNI-positive rate (20.34% versus 26.54%). Both meta-analysis and real-world clinical case studies suggested that PNI-positive patients had poorer prognoses than PNI-negative patients. We established an effective risk model consisting of T stage, differentiation and lymphovascular invasion to predict PNI in rectal cancer.

CONCLUSION

PNI is a poor prognostic factor for rectal cancer and could occur even in stage I. Additionally, neoadjuvant therapy could sufficiently reduce the PNI-positive rate. T stage, lymphovascular invasion and differentiation grade were independent risk factors for PNI and the risk model that included these factors could predict the probability of PNI.

Risk factors for bloodstream infection in paediatric haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Haematopoietic stem cell transplantation (HSCT), a standard treatment for paediatric haematological diseases, is highly associated with bloodstream infection (BSI), which may increase mortality.

AIM

To explore the risk factors for BSI in paediatric HSCT recipients.

METHODS

Three English databases and four Chinese databases were searched from inception to March 17th, 2022. Eligible studies included randomized controlled trials, cohort studies, and case-control studies that enrolled HSCT recipients aged ≤18 years and reported BSI risk factors. Two reviewers independently screened studies, extracted data, and assessed the risk of bias. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), certainty of body of evidence was assessed.

FINDINGS

Fourteen studies involving 4602 persons were included. The incidences of BSI and associated mortality in paediatric HSCT recipients were approximately 10-50% and 5-15%, respectively. Meta-analysis of all studies revealed that previous BSI before HSCT (relative effect (RE): 2.28; 95% confidence interval (CI) 1.19-4.34, moderate certainty) and receiving an umbilical cord blood transplant (RE: 1.55; 95% CI: 1.22-1.97, moderate certainty) were probably associated with an increased risk of BSI. Meta-analysis of studies with low risk of bias reassured that previous BSI before HSCT probably increased the risk of BSI (RE: 2.28; 95% CI: 1.19-4.34, moderate certainty), and revealed that steroid use (RE: 2.72; 95% CI: 1.31-5.64, moderate certainty) was likely a risk factor whereas autologous HSCT was probably a protective factor of BSI (RE: 0.65; 95% CI: 0.45-0.94, moderate certainty).

CONCLUSION

These findings could inform the management of paediatric HSCT recipients, helping identify who may benefit from prophylactic antibiotics.

[Results analysis of mNGS applied to infectious diseases]

The application of metagenomic second-generation sequencing (mNGS) is shifting from research to clinical laboratories due to rapid technological advances and significant cost reductions. Although many studies and case reports have confirmed that the success of mNGS in improving the prevention, diagnosis, treatment and tracking of infectious diseases, there are still some obstacles that must be overcome. The results of mNGS show all the possible pathogens in the sample, however, in the face of thousands of microbes that can infect humans, it remains challenging to accurately identify the key pathogens. So far, there is no unified interpretation standard for mNGS in clinical practice. This article reviews the interpretation of mNGS results for pathogen infection in different systems, the clinical interpretation and application regulations of mNGS results, and the challenges of mNGS interpretation in pathogen diagnosis.

A novel Doppler backscattering (DBS) system to simultaneously measure radio frequency plasma fluctuations and low frequency turbulence

A novel quadrature Doppler Backscattering (DBS) system has been developed and optimized for the E-band (60-90 GHz) frequency range using either O-mode or X-mode polarization in DIII-D plasmas. In general, DBS measures the amplitude of density fluctuations and their velocity in the lab frame. The system can simultaneously monitor both low-frequency turbulence (f < 10 MHz) and radiofrequency plasma density fluctuations over a selectable frequency range (20-500 MHz). Detection of high-frequency fluctuations has been demonstrated for low harmonics of the ion cyclotron frequency (e.g., 2fci ∼ 23 MHz) and externally driven high-frequency helicon waves (f = 476 MHz) using an adjustable frequency down conversion system. Importantly, this extends the application of DBS to a high-frequency spectral domain while maintaining important turbulence and flow measurement capabilities. This unique system has low phase noise, good temporal resolution (sub-millisecond), and excellent wavenumber coverage (kθ ∼ 1-20 cm-1 and kr ≲ 30 cm-1). As a demonstration, localized internal DIII-D plasma measurements are presented from turbulence (f ≤ 5 MHz), Alfvenic waves (f ∼ 6.5 MHz), ion cyclotron waves (f ≥ 20 MHz), as well as fluctuations around 476 MHz driven by an external high-power 476 MHz helicon wave antenna. In the future, helicon measurements will be used to validate GENRAY and AORSA modeling tools for prediction of helicon wave propagation, absorption, and current drive location for the newly installed helicon current drive system on DIII-D.

Targeting the post-synaptic proteome has therapeutic potential for psychosis in Alzheimer Disease

Individuals with Alzheimer Disease who develop psychotic symptoms (AD + P) experience more rapid cognitive decline and have reduced indices of synaptic integrity relative to those without psychosis (AD-P). We sought to determine whether the postsynaptic density (PSD) proteome is altered in AD + P relative to AD-P, analyzing PSDs from dorsolateral prefrontal cortex of AD + P, AD-P, and a reference group of cognitively normal elderly subjects. The PSD proteome of AD + P showed a global shift towards lower levels of all proteins relative to AD-P, enriched for kinases, proteins regulating Rho GTPases, and other regulators of the actin cytoskeleton. We computationally identified potential novel therapies predicted to reverse the PSD protein signature of AD + P. Five days of administration of one of these drugs, the C-C Motif Chemokine Receptor 5 inhibitor, maraviroc, led to a net reversal of the PSD protein signature in adult mice, nominating it as a novel potential treatment for AD + P.

Comparative effectiveness and safety of antibiotic prophylaxis during induction chemotherapy in children with acute leukaemia: a systematic review and meta-analysis

BACKGROUND

Bacterial infections are common during induction therapy in children and adolescents with acute leukaemia and may cause infection-related mortality.

AIM

To determine the efficacy and safety of prophylactic antibiotics in paediatric patients with acute leukaemia receiving induction chemotherapy.

METHODS

From three English databases and four Chinese databases, we searched for randomized controlled trials (RCTs) and cohort studies that compared prophylactic antibiotics to placebo, no prophylaxis, or that compared one antibiotic versus another in paediatric patients with acute leukaemia undergoing induction chemotherapy. Two reviewers independently screened the studies, extracted data, and assessed the risk of bias using Cochrane Risk of Bias 2 tool and Newcastle-Ottawa Scale, and the certainty of evidence using Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

FINDINGS

Two RCTs and ten cohort studies were finally included. For children with acute lymphoblastic leukaemia, antibiotic prophylaxis, including levofloxacin, sulfamethoxazole-trimethoprim, or other antibiotics, probably reduced bacteraemia (risk ratio (RR): 0.44; 95% confidence interval (CI): 0.33-0.60; moderate certainty) without significantly increasing Clostridioides difficile infection (CDI) or invasive fungal infection. Levofloxacin reduced the CDI rate (RR: 0.08; 95% CI: 0.01-0.62; high certainty). Ciprofloxacin prophylaxis probably reduced infection-related mortality (RR: 0.12; 95% CI: 0.01-0.97; moderate certainty). In children with acute myeloid leukaemia, ciprofloxacin plus vancomycin may reduce febrile neutropenia (RR: 0.79; 95% CI: 0.66-0.94; low certainty). Individual studies indicated that prophylaxis increased antibiotic exposure but reduced non-preventive antibiotic exposure.

CONCLUSION

In children with acute leukaemia undergoing induction therapy, antibiotic prophylaxis may improve the bacterial infection and mortality.

Vulnerable newborn types: analysis of subnational, population-based birth cohorts for 541 285 live births in 23 countries, 2000-2021

OBJECTIVE

To examine prevalence of novel newborn types among 541 285 live births in 23 countries from 2000 to 2021.

DESIGN

Descriptive multi-country secondary data analysis.

SETTING

Subnational, population-based birth cohort studies (n = 45) in 23 low- and middle-income countries (LMICs) spanning 2000-2021.

POPULATION

Liveborn infants.

METHODS

Subnational, population-based studies with high-quality birth outcome data from LMICs were invited to join the Vulnerable Newborn Measurement Collaboration. We defined distinct newborn types using gestational age (preterm [PT], term [T]), birthweight for gestational age using INTERGROWTH-21st standards (small for gestational age [SGA], appropriate for gestational age [AGA] or large for gestational age [LGA]), and birthweight (low birthweight, LBW [<2500 g], nonLBW) as ten types (using all three outcomes), six types (by excluding the birthweight categorisation), and four types (by collapsing the AGA and LGA categories). We defined small types as those with at least one classification of LBW, PT or SGA. We presented study characteristics, participant characteristics, data missingness, and prevalence of newborn types by region and study.

RESULTS

Among 541 285 live births, 476 939 (88.1%) had non-missing and plausible values for gestational age, birthweight and sex required to construct the newborn types. The median prevalences of ten types across studies were T+AGA+nonLBW (58.0%), T+LGA+nonLBW (3.3%), T+AGA+LBW (0.5%), T+SGA+nonLBW (14.2%), T+SGA+LBW (7.1%), PT+LGA+nonLBW (1.6%), PT+LGA+LBW (0.2%), PT+AGA+nonLBW (3.7%), PT+AGA+LBW (3.6%) and PT+SGA+LBW (1.0%). The median prevalence of small types (six types, 37.6%) varied across studies and within regions and was higher in Southern Asia (52.4%) than in Sub-Saharan Africa (34.9%).

CONCLUSIONS

Further investigation is needed to describe the mortality risks associated with newborn types and understand the implications of this framework for local targeting of interventions to prevent adverse pregnancy outcomes in LMICs.

Lactiplantibacillus plantarum attenuates Coxsackievirus B3-induced pancreatitis through the BAX/BCL2/CASP3 signaling pathway

Lactiplantibacillus plantarum is a lactic acid bacterium widely used in food production. Coxsackievirus B3 (CVB3) is an important human pathogen associated with acute pancreatitis development, and no antiviral therapeutics or vaccines are approved to treat or prevent its infection. However, whether L. plantarum could inhibit CVB3 infection remains unclear. Here, L. plantarum FLPL05 showed antiviral activity against CVB3 infection in vivo and in vitro. Pretreatment with L. plantarum FLPL05 reduced serum amylase levels, CVB3 viral load in the pancreas, serum pro-inflammatory cytokine levels, and macrophage infiltration in CVB3-infected mice. In mice, L. plantarum FLPL05 inhibited CVB3-induced pancreas apoptosis via the B cell leukemia/lymphoma 2 (BCL2)/BCL2-associated X protein (BAX)/caspase-3 (CASP3) signaling pathway. Furthermore, L. plantarum FLPL05 reduced CVB3 replication, protected cells from the cytopathic effect of CVB3 infection, and inhibited cell apoptosis. Moreover, L. plantarum FLPL05's exopolysaccharide (EPS) had activity against CVB3 in vitro, reducing the CVB3 titer and improving cell activity. Therefore, L. plantarum FLPL05 pretreatment improved CVB3-induced pancreatitis by partially reversing pancreatitis, which might be associated with EPS. Consequently, L. plantarum FLPL05 could be a potential probiotic with antiviral activity against CVB3.

A novel whole "Joint-in-Motion" device reveals a permissive effect of high glucose levels and mechanical stress on joint destruction

OBJECTIVE

Osteoarthritis (OA) has recently been suggested to be associated with diabetes. However, this association often disappears when accounting for body mass index (BMI), suggesting that mechanical stress may be a confounding factor. We investigated the combined influence of glucose level and loading stress on OA progression using a novel whole joint-in-motion (JM) culture system.

DESIGN

Whole mouse knee joints were placed in an enclosed chamber with culture media and actuated to recapitulate leg movement, with a dynamic stress regimen of 0.5 Hz, 8 h/day for 7 days. These joints were treated with varying levels of glucose and controlled for osmolarity and diffusion. Joint movement and joint space were examined by X-ray fluoroscopy and microCT. Cartilage matrix levels were quantified by blinded Mankin scoring and immunohistochemistry.

RESULTS

Culturing in the JM device facilitated proper leg extension and flexion movements, and adequate mass transport for analyzing the effect of glucose on cartilage. Treatment with higher levels of glucose either via media supplementation or intra-articular injection caused a significant decrease in levels of glycosaminoglycan (GAG) and an increase in aggrecan neoepitope in articular cartilage, but only under dynamic stress. Additionally, collagen II level was slightly reduced by high glucose levels.

CONCLUSIONS

High levels of glucose and dynamic stress have permissive effects on articular cartilage GAG loss and aggrecan degradation, implicating that mechanical stress confounds the association of diabetes with OA. The JM device supports novel investigation of mechanical stress on the integrity of an intact living mouse joint to provide insights into OA pathogenesis.

[Human bone marrow mesenchymal stem cell exosome-derived miR-335-5p promotes osteogenic differentiation of human periodontal ligament stem cells to alleviate periodontitis by downregulating DKK1]

OBJECTIVE

To observe the effect of miR-335-5p derived from human bone marrow mesenchymal stem cell (hBMMSCs) exosomes on osteogenic differentiation of human periodontal ligament stem cell (PDLSCs) model of periodontitis and explore its mechanism.

METHODS

The exosomes extracted from hBMMSCs were identified by transmission electron microscopy, Western blotting and PKH67 labeling. The human PDLSC model of TNF-α-induced periodontitis were co-cultured with the extracted exosomes, and qRT-PCR was performed to detect the changes in the expressions of miR-335-5p and the mRNA levels of pro-inflammatory cytokines (IL-1β, IL-6, and IL-8) and the osteogenic marker genes (RunX2, OCN and BMP-2). Alizarin red staining and ALP staining were used to detect the formation of calcium nodules in the treated cells, and the expression level of DKK1 protein was detected with Western blotting. Dual luciferase reporter gene assay was used to verify the targeting relationship between miR-335-5p and DKK1.

RESULTS

High expressions of CD9 and CD81 were detected in the extracted hBMMSC exosomes (P < 0.05). In TNF-α-induced hPDLSCs, treatment with the extracted exosomes significantly reduced the mRNA expressions of IL-1β, IL-6 and IL-8, enhanced the mRNA expressions of RunX2, OCN, and BMP-2, and promoted the formation of calcium nodules. MiR-335-5p was highly expressed in hBMMSC-derived exosomes, and overexpression of miR-335-5p significantly downregulated DKK1 protein expression, inhibited the mRNA expressions of IL-1β, IL-6 and IL-8, and promoted the mRNA expressions of osteogenic markers and the formation of calcium nodules in hPDLSCs.

CONCLUSION

HBMMSC exosome-derived miR-335-5p promotes osteogenic differentiation of hPDLSCs and inhibits the development of periodontitis by downregulating DKK1.

A213 UNDERSTANDING PATIENT AND PHYSICIAN ATTITUDES AND EXPECTATIONS REGARDING IDENTIFYING AND MANAGING ANXIETY AND DEPRESSION IN IBD

Background

Patients living with Inflammatory Bowel Disease (IBD) commonly experience a number of mental health-related challenges, specifically anxiety and mood disorders (AMDs). Although there has been an awareness of the relationship between IBD and AMD within the GI research and clinical space; detection, treatment, and management amongst care providers is limited. Therefore, we are seeking to explore the overall experiences of patients living with Inflammatory Bowel Disease to identify and evaluate their experiences in interactions with GI clinicians around mental health in diverse care settings in order to determine how to best support mental health care amongst IBD patients.

Purpose

We aimed to explore perspectives, experiences and barriers to engaging with mental health-related challenges amongst IBD patients when interacting with gastroenterologists over the course of their health journey.

Method

We conducted 5 semi-structured online focus groups co-facilitated by patient researchers in early 2020 through Zoom which spanned for a total of 2.5 hours each. Participants were recruited through social media channels, GI clinics, the IMAGINE-SPOR unit, and Crohn’s and Colitis Canada. A semi-structured interview guide was developed for patient researchers to follow during the focus groups which provided guided questions that would allow patient participants to explore and reflect on: their experiences living with IBD, their expectations around mental health support, their perception of the engagement of GIs in mental health discussions, and their expectations for mental health support and services moving forward. Audio recordings from the semi-structured focus groups were then transcribed and thematic analysis was used to identify emerging themes and patient expectations.

Result(s)

We identified the following key themes: 1) experiences with IBD: difficulties related to reintegrating into social settings, feelings of loneliness; 2) expectations around mental health support: the need to develop their own resiliency strategies due to the lack of structural resources regarding mental health and IBD in the clinical space; 3) GI engagement: HCPs were dismissive of mental health symptoms, often gaslighting patients when mentioning mental health concerns during clinical encounters; and 4) expectations: a need to standardize mental health care across IBD care practice with a focus on potentially integrating healthcare providers of diverse care settings to help address the need for mental health support in such a vast patient population.

Conclusion(s)

Our study suggests that effective detection, management and awareness, along with the integration of feedback from patient lived experiences can help inform the development of mental health support and services which cater to the needs of people living with IBD. Results from this study will be interpreted in line with insight gathered from upcoming interviews of gastroenterologists and HCPs.

Please acknowledge all funding agencies by checking the applicable boxes below

CIHR, Other

Please indicate your source of funding;

IMAGINE SPOR INCUBATOR Grant

Disclosure of Interest

None Declared

Contribution of flagellar cap gene in virulence and pathogenicity of Aeromonas veronii

Aeromonas veronii is an important zoonotic and aquatic pathogen that causes a number of illnesses in both humans and animals. It is related to gastroenteritis, skin and soft tissue infections and bacteremia in humans, as well as causing significant economic losses in aquaculture owing to fish sepsis. Here, we constructed the flagellar cap gene (fliD) mutant strain of A. veronii by suicide plasmid-mediated homologous recombination system and analysed its characteristics. It was found that the deletion of fliD had no effect on growth and biochemical properties and could be inherited stably. However, the motility of A. veronii ΔfliD was significantly reduced, the flagellum was defective and the biofilm formation was attenuated compared with that of A. veronii wild-type strain. In vivo experiments revealed that the colonization capacity of ΔfliD was significantly lower than that of the wild-type strain in the period of first 24 h, and the median lethal dose (LD₅₀ ) was 56 times higher than that of the wild-type strain. The Cyprinus carpio infected with the wild-type strain indicated faster death speed and more severe clinical signs compared to ΔfliD strain. These results suggest that fliD is closely related to the virulence of A. veronii and plays an important role in pathogenicity, providing the foundation for pathogenic mechanism studies of A. veronii.

QCR7 affects the virulence of Candida albicans and the uptake of multiple carbon sources present in different host niches

Background

Candida albicans is a commensal yeast that may cause life-threatening infections. Studies have shown that the cytochrome b-c1 complex subunit 7 gene (QCR7) of C. albicans encodes a protein that forms a component of the mitochondrial electron transport chain complex III, making it an important target for studying the virulence of this yeast. However, to the best of our knowledge, the functions of QCR7 have not yet been characterized.

Methods

A QCR7 knockout strain was constructed using SN152, and BALb/c mice were used as model animals to determine the role of QCR7 in the virulence of C. albicans. Subsequently, the effects of QCR7 on mitochondrial functions and use of carbon sources were investigated. Next, its mutant biofilm formation and hyphal growth maintenance were compared with those of the wild type. Furthermore, the transcriptome of the qcr7Δ/Δ mutant was compared with that of the WT strain to explore pathogenic mechanisms.

Results

Defective QCR7 reduced recruitment of inflammatory cells and attenuated the virulence of C. albicans infection in vivo. Furthermore, the mutant influenced the use of multiple alternative carbon sources that exist in several host niches (GlcNAc, lactic acid, and amino acid, etc.). Moreover, it led to mitochondrial dysfunction. Furthermore, the QCR7 knockout strain showed defects in biofilm formation or the maintenance of filamentous growth. The overexpression of cell-surface-associated genes (HWP1, YWP1, XOG1, and SAP6) can restore defective virulence phenotypes and the carbon-source utilization of qcr7Δ/Δ.

Conclusion

This study provides new insights into the mitochondria-based metabolism of C. albicans, accounting for its virulence and the use of variable carbon sources that promote C. albicans to colonize host niches.

Radiomics signature based on CECT for non-invasive prediction of response to anti-PD-1 therapy in patients with hepatocellular carcinoma

PURPOSE

This study aimed to develop a radiomics signature (RS) based on contrast-enhanced computed tomography (CECT) and evaluate its potential predictive value in hepatocellular carcinoma (HCC) patients receiving anti-PD-1 therapy.

METHOD

CECT scans of 76 HCC patients who received anti-PD-1 therapy were obtained in this study (training group = 53 and validation group = 23). The least absolute shrinkage and selection operator (LASSO) regression was applied to select radiomics features of primary and metastatic lesions and establish a RS to predict lesion-level response. Then, a nomogram combined the mean RS (MRS) and clinical variables with patient-level response as the end point.

RESULTS

In the lesion-level analysis, the area under the curves (AUCs) of RS in the training and validation groups were 0.751 (95% CI, 0.668-0.835) and 0.734 (95% CI, 0.604-0.864), respectively. In the patient-level analysis, the AUCs of the nomogram in the training and validation groups were 0.897 (95% CI, 0.798-0.996) and 0.889 (95% CI, 0.748-1.000), respectively. The nomogram stratified patients into low- and high-risk groups, which showed a significant difference in progression-free survival (PFS) (p<0.05).

CONCLUSIONS

The RS is a noninvasive biomarker for predicting anti-PD-1 therapy response in patients with HCC. The nomogram may be of clinical use for identifying high-risk patients and formulating individualised treatments.

Coxsackievirus Group B3 Has Oncolytic Activity against Colon Cancer through Gasdermin E-Mediated Pyroptosis

Colon cancer is the second leading cause of cancer-related death, and there are few effective therapies for colon cancer. This study explored the use of coxsackievirus group B3 (CVB3) as an oncolytic virus for the treatment of colon cancer. In this study, we verified that CVB3 induces death of colon cancer cell lines by directly observing cell morphology and Western blot results, and observed the oncolytic effects of CVB3 by constructing an immunodeficient nude mice model. Our data show that CVB3 induces pyroptosis in colon cancer cell lines. Mechanistically, we demonstrated that CVB3 causes cleavage of gasdermin E (GSDME), but not gasdermin D (GSDMD), by activating caspase-3. This leads to production of GSDME N-termini and the development of pores in the plasma membrane, inducing pyroptosis of colon cancer cell lines. We also demonstrate that CVB3-induced pyroptosis is promoted by reactive oxygen species (ROS). Finally, in vivo studies using immunodeficient nude mice revealed that intratumoral injection of CVB3 led to significant tumor regression. Our findings indicate that CVB3 has oncolytic activity in colon cancer cell lines via GSDME-mediated pyroptosis.

A Complete Genome of Nocardia terpenica NC_YFY_NT001 and Pan-Genomic Analysis Based on Different Sources of Nocardia spp. Isolates Reveal Possibly Host-Related Virulence Factors

OBJECTIVE

We aimed to identify the possible virulence genes associated with Nocardia NC_YFY_NT001 isolated by ourselves and other Nocardia spp.

METHODS

The genome of Nocardia terpenica NC_YFY_NT001 was completed by using PacBio and Illumina platforms. A pan-genomic analysis was applied to selected complete Nocardia genomes.

RESULTS

Nocardia terpenica NC_YFY_NT001 can cause healthy mice death by tail intravenous injection. The genome of NT001 has one circular chromosome 8,850,000 bp and one circular plasmid 70,000 bp with ~68% GC content. The chromosome and plasmid encode 7914 and 80 proteins, respectively. Furthermore, a pan-genomic analysis showed a total of 45,825 gene clusters, then 304 core, 21,045 shell and 24,476 cloud gene clusters were classified using specific parameters. In addition, we found that catalases were more abundant in human isolates. Furthermore, we also found no significant differences in the MCE proteins between different strains from different sources. The pan-genomic analysis also showed that 67 genes could only be found in humoral isolates. ReX3 and DUF853 domain protein were found in all eight human isolates. The composition of unique genes in humoral isolate genomes indicated that the transcriptional regulators may be important when Nocardia invades the host, which allows them to survive in the new ecological system.

CONCLUSION

In this study, we confirmed that NT001 could cause infected animal death, and identified many possible virulence factors for our future studies. This study also provides new insight for our further study on Nocardia virulence mechanisms.

Extracellular vesicles, a novel model linking bacteria to ferroptosis in the future?

Ferroptosis is a recently discovered modulated cell death mechanism caused by the accumulation of iron-dependent lipid peroxides to toxic levels and plays an important role in tumor immunology and neurology. Recent studies have shown that ferroptosis may play a crucial role in bacterial infection pathogenesis, which may be useful in anti-infection therapies. However, how bacteria enter cells to induce ferroptosis after invading the host immune system remains largely unknown. In addition, the current studies only focus on the relationship between a single bacterial species or genus and host cell ferroptosis, and there is no systematic summary of its regulatory mechanism. Therefore, our review firstly sums up the role of ferroptosis in bacterial infection and its regulatory mechanism, and innovatively speculates on the function and potential mechanism of extracellular vesicles (EVs) in bacterial-induced ferroptosis, in order to provide possible novel directions and ideas for future anti-infection research. KEY POINTS: • Ferroptosis presents a novel mechanism for bacterial host interaction • EVs provide the potential mechanism for bacterial-induced ferroptosis • The relationship of EVs with ferroptosis provides possible directions for future treatment of bacterial infection.

A dual action small molecule enhances azoles and overcomes resistance through co-targeting Pdr5 and Vma1

Fungal infection threatens human health worldwide due to the limited arsenal of antifungals and the rapid emergence of resistance. Epidermal growth factor receptor (EGFR) is demonstrated to mediate epithelial cell endocytosis of the leading human fungal pathogen, Candida albicans. However, whether EGFR inhibitors act on fungal cells remains unknown. Here, we discovered that the specific EGFR inhibitor osimertinib mesylate (OSI) potentiates azole efficacy against diverse fungal pathogens and overcomes azole resistance. Mechanistic investigation revealed a conserved activity of OSI by promoting intracellular fluconazole accumulation via inhibiting Pdr5 and disrupting V-ATPase function via targeting Vma1 at serine 274, eventually leading to inactivation of the global regulator TOR. Evaluation of the in vivo efficacy and toxicity of OSI demonstrated its potential clinical application in impeding fluconazole resistance. Thus, the identification of OSI as a dual action antifungal with co-targeting activity proposes a potentially effective therapeutic strategy to treat life-threatening fungal infection and overcome antifungal resistance.

Glycosylphosphatidylinositol Mannosyltransferase Ⅰ Protects Chinese Giant Salamander, Andrias davidianus, against Iridovirus

Glycosylphosphatidylinositol mannosyltransferase I (GPI-MT-I) is an essential glycosyltransferase of glycosylphosphatidylinositol-anchor proteins (GPI-APs) that transfers the first of the four mannoses in GPI-AP precursors, which have multiple functions, including immune response and signal transduction. In this study, the GPI-MT-I gene that regulates GPI-AP biosynthesis in Andrias davidianus (AdGPI-MT-I) was characterized for the first time. The open reading frame (ORF) of AdGPI-MT-I is 1293 bp and encodes a protein of 430 amino acids that contains a conserved PMT2 superfamily domain. AdGPI-MT-I mRNA was widely expressed in the tissues of the Chinese giant salamander. The mRNA expression level of AdGPI-MT-I in the spleen, kidney, and muscle cell line (GSM cells) was significantly upregulated post Chinese giant salamander iridovirus (GSIV) infection. The mRNA expression of the virus major capsid protein (MCP) in AdGPI-MT-I-overexpressed cells was significantly reduced. Moreover, a lower level of virus MCP synthesis and gene copying in AdGPI-MT-I-overexpressed cells was confirmed by western blot and ddPCR. These results collectively suggest that GSIV replication in GSM cells was significantly reduced by the overexpression of the AdGPI-MT-I protein, which may contribute to a better understanding of the antiviral mechanism against iridovirus infection.

Rapid Nucleic Acid Extraction for Aquatic Animal DNA Virus Determination Using Chelex 100 Resin via Conventional PCR and Digital Droplet PCR Detection

Simple Summary

Convenient, fast, and high-quality nucleic acid extraction methods are urgently needed in molecular diagnostic testing for viral pathogens in aquaculture. We developed a viral DNA extraction method from diseased tissues and cells using the Chelex 100 resin solution workflow. The only extraction reagents required are the Chelex 100 resin and phosphate-buffered saline. The whole extraction process only takes about 15 min from the tissue homogenate to obtain the DNA. The concentration of extracted DNA is at least 100 ng/µL. This methodology has clear benefits in terms of cost and time saving compared to the commercial kit extraction for aquatic animal DNA virus determination by PCR in the laboratory. In addition, the simplified method using Chelex 100 resin with a pH value of 10–11 presented excellent results in PCR application and could be a standard for the DNA extraction for DNA virus testing in the future.

Abstract

Molecular diagnostic testing for viral pathogens is crucial in aquaculture. The efficient and convenient preparation of pathogenic microbial nucleic acids is the basis of molecular diagnosis. Here, we developed a simplified deoxyribonucleic acid (DNA) extraction method from aquatic animal DNA viruses using the Chelex 100 resin. The nucleic acid was extracted from infected tissues and cell culture for the detection of three common aquatic viral pathogens (CEV, CyHV-2, and GSIV). We compared the extraction effects of a current commercial kit extraction method and the Chelex 100 resin extraction method according to nucleic acid concentration, conventional polymerase chain reaction (PCR), and digital droplet PCR (ddPCR). The results indicated that both extraction procedures could obtain high-quality nucleotide samples. Extracting DNA using the Chelex 100 resin led to better detective efficiency for ddPCR molecular diagnostic testing. The whole process took less than 20 min, and only Chelex 100 resin solution was added to the tissues or cells without multiple tubes being transferred several times. The extracted DNA concentration and the detection sensitivity were high. These results indicated that the Chelex 100 resin solution has the advantages of speed, efficiency, and economy compared to the commercial kit. In addition, the higher pH value (10–11) of the Chelex 100 resin solution markedly improved the detection sensitivity compared to a lower pH value (9–10). In conclusion, the comparison of the Chelex 100 Resin and commercial viral DNA extraction kits revealed the good performance of the Chelex 100 resin solution at pH 10–11 in DNA extraction for PCR amplification from aquatic animal viral samples of tissues and cells in molecular diagnostic testing. It is both rapid and cost-effective.

Molecular Epidemiology and Antifungal Resistance of Cryptococcus neoformans From Human Immunodeficiency Virus-Negative and Human Immunodeficiency Virus-Positive Patients in Eastern China

Cryptococcosis is an opportunistic and potentially lethal infection caused by Cryptococcus neoformans and Cryptococcus gattii complex, which affects both immunocompromised and immunocompetent people, and it has become a major public health concern worldwide. In this study, we characterized the molecular epidemiology and antifungal susceptibility of 133 C. neoformans isolates from East China Invasive Fungal Infection Group (ECIFIG), 2017–2020. Isolates were identified to species level by matrix-assisted laser desorption ionization-time of flight mass spectrometry and confirmed by IGS1 sequencing. Whole-genome sequencing (WGS) was conducted on three multidrug-resistant isolates. Among the 133 strains, 61 (45.86%) were isolated from HIV-positive patients and 72 (54.16%) were isolated from HIV-negative patients. In total, C. neoformans var. grubii accounted for 97.74% (130/133), while C. neoformans var. neoformans was rare (2.06%, 3/133). The strains were further classified into nine sequence types (STs) dominated by ST5 (90.23%, 120/133) with low genetic diversity. No association was observed between STs and HIV status. All strains were wild type to voriconazole, while high antifungal minimal inhibitory concentrations (MICs) above the epidemiological cutoff values (ECVs) were observed in C. neoformans strains, and more than half of isolates were non-wild-type to amphotericin B (89.15%, 109/133). Eight isolates were resistant to fluconazole, and eight isolates were non-wild type to 5-fluorocytosine. Furthermore, WGS has verified the novel mutations of FUR1 in 5-fluorocytosine-resistant strains. In one isolate, aneuploidy of chromosome 1 with G484S mutation of ERG11 was observed, inducing high-level resistance (MIC: 32 μg/ml) to fluconazole. In general, our data showed that there was no significant difference between HIV-positive and HIV-negative patients on STs, and we elucidate the resistant mechanisms of C. neoformans from different perspectives. It is important for clinical therapy and drug usage in the future.

[Therapeutic mechanism of emodin for treatment of rheumatoid arthritis: a network pharmacology-based analysis]

OBJECTIVE

To investigate the therapeutic mechanism of emodin in the treatment of rheumatoid arthritis (RA) using a network pharmacology-based method and validate this mechanism in a fibroblast-like synovial cell line.

METHODS

The PubChem, Targetnet, SwissTargetPrediction, Genecards, OMIM, and DisGeNET databases were searched to obtain emodin targets and RA-related genes. A protein-protein interaction (PPI) network was constructed, and GO and KEGG pathway enrichment analyses were carried out to analyze the intersection genes. AutoDock4.2.6 software was used to simulate molecular docking between emodin and its candidate targets. In a cultured fibroblast-like synovial cell line (MH7A), the effects of different concentrations of emodin on proliferation of tumor necrosis factor-α (TNF-α)-induced cells were investigated using CCK-8 assay, cell scratch experiment and flow cytometry; the changes in the expressions of nuclear factor-κB (NF-κB) pathway proteins were detected using Western blotting, and the mRNA expressions of the hub genes were examined with RT-qPCR.

RESULTS

We identified 32 intersection genes of emodin and RA, and the key targets including CAPS3, ESR1, and MAPK14 involved mainly the NF-κB signaling pathway. Cell scratch experiment and flow cytometry demonstrated a strong inhibitory effect of emodin on MH7A cell proliferation. Treatment with TNF-α significantly increased the cellular expressions of the NF-κB pathway proteins, which were obviously lowered by treatment with 80 μmol/L emodin. The results of RT-qPCR showed that TNF-α treatment obviously up-regulated the expressions of the hub genes COX2 and P38MAPK, and emodin treatment significantly down-regulated the expressions of MAPK and PTGS2 and up-regulated the expression of CASP3.

CONCLUSION

The therapeutic effect of emodin on RA is mediated mainly through regulation of cell proliferation, apoptosis, and the NF-κB pathway.

Vibrio metschnikovii, a Potential Pathogen in Freshwater-Cultured Hybrid Sturgeon

Simple Summary

In an era of shrinking stocks and intensive fisheries production, pathogenic microorganisms are a serious threat to fish health. This study confirms that Vibrio metschnikovii—a pathogen mainly found in aquatic environments—was the pathogenic bacterium causing disease in hybrid sturgeon. The authors reveal the hazard of V. metschnikovii to hybrid sturgeon and the potential risks to the sturgeon farming industry.

Abstract

In July 2021, a disease with a high mortality rate broke out in freshwater cultured hybrid sturgeon in Zhengzhou, Henan Province. A dominant strain, H-701, was isolated from diseased fish; physiological changes in diseased fish were investigated and molecular identification, biochemical characterization, and pathogenicity and drug sensitivity tests of H-701 were performed. The 16S rRNA gene sequence of H-701 was 99.86% homologous with that of Vibrio metschnikovii in GenBank. The 50% lethal dose of H-701 was 3.72 ± 0.929 × 10⁴ CFU/g fish weight. The proportion of monocytes, neutrophils, and eosinophils in the blood of diseased sturgeon increased significantly, whereas the proportion of lymphocytes decreased. In diseased fish, the serum levels of total protein, albumin, globulin, and alkaline phosphatase decreased significantly, and those of aspartate aminotransferase, alanine aminotransferase, and complement C3 increased significantly. There were obvious pathological changes in several tissues of the diseased fish. H-701 was sensitive to antibiotics such as florfenicol, enrofloxacin, and doxycycline. This study not only demonstrated that V. metschnikovii was the cause of death of a large number of hybrid sturgeon but also revealed its potential risk in hybrid sturgeon aquaculture. The results provide a basis for the diagnosis and prevention of this disease.

Characterization, expression pattern and antiviral activities of oligoadenylate synthetase in Chinese Giant Salamander, Andrias davidianus

The enzyme 2'-5'-oligoadenylate synthetase (OAS) is an antiviral protein induced by interferons (IFNs), which plays an important role in IFN-mediated antiviral signaling pathway. In this study, the OAS of Chinese Giant Salamander, Andrias davidianus (AdOAS) was identified for the first time, and the expression profiles in vivo and the antiviral activities in vitro were investigated. The open reading frame (ORF) of AdOAS gene is 1185 bp in length, encoding a putative protein of 394 amino acids, in which a Nucleotidyltransferase (NTase) domain (40-143 aa) and a conserved OAS1 C superfamily domain (165-341 aa) are included. qRT-PCR analysis revealed a broad expression of AdOAS in vivo, with the highest expression level in intestine and heart. After infection with Chinese giant salamander iridovirus (GSIV), the mRNA level of AdOAS in liver increased significantly at 24 h and 48 h post infection and reached the peak at 72 h compared with the control group. The AdOAS mRNA level in kidney increased slightly at 6 h and 12 h post infection, declined to the initial level at 24 h and peaked at 48 h post infection, while in spleen it was slightly up-regulated at 6 h, inhibited at 12 h, 24 h and 48 h, and then significantly increased to the peak at 72 h post infection. In vitro, AdOAS mRNA level in Chinese giant salamander muscle (GSM) cells was not noticeably up-regulated until 24 h and then peaked at 48 h post GSIV infection. In antiviral activity test, the mRNA transcription and protein level of virus major capsid protein (MCP) in AdOAS over-expressed cells was significantly reduced compared with that in control cells by qRT-PCR and western blot analysis. In addition, ddPCR results showed that lower MCP gene copy was found in AdOAS over-expressed cells compared with the control group. These results collectively suggest that AdOAS plays a crucial role against GSIV infection in Chinese giant salamander, and provide a solid base for the further studies on the mechanism of immune defense and the control of the disease in this animal.

The quantitative proteomic analysis of rare minnow, Gobiocypris rarus, infected with virulent and attenuated isolates of grass carp reovirus genotype Ⅱ

Grass carp reovirus genotype Ⅱ (GCRV II) causes severe hemorrhagic disease in grass carp and affects the aquaculture industry in China. GCRV Ⅱ isolates have been collected from different epidemic areas in China, and these isolates can lead to different degrees of hemorrhagic symptoms in grass carp. Rare minnow (Gobiocypris rarus) is widely used as a model fish to study the mechanism of hemorrhagic disease because of its high sensitivity to GCRV. In this study, the protein levels in the spleen of rare minnow after infection with GCRV virulent isolate JZ809 and attenuated isolate XT422 were investigated using isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics. 109 and 50 differentially expressed proteins (DEPs) in the virulent and attenuated infection groups were obtained, respectively, among which 40 DEPs were identified in both groups. Combining protein expression profiling with gene ontology (GO) annotation, the responses of rare minnow to the two genotypes GCRV Ⅱ in terms of upregulated proteins were similar, focusing on ATP synthesis, in which ATP can serve as a "danger" signal to activate an immunoreaction in eukaryotes. Meanwhile, the virulent genotype JZ809 induced more immunoproteins and increased the levels of ubiquitin-proteasome system members to adapt to virus infection. However, together with a persistent and excessive inflammatory response and declining carbon metabolism, rare minnow presented more severe hemorrhagic disease and mortality after infection with virulent JZ809 than with attenuated XT422. The results provide a valuable information that will increase our understanding of the pathogenesis of viruses with different levels of virulence and the mechanism of interaction between the virus and host. Furthermore, the 6 proteins that were only significantly upregulated in the XT422 infection group all belonged to cluster 2, and 28 of 30 proteins that were only upregulated in JZ809 infection group were clustered into cluster 1. For the downregulated proteins, all DEPs in the XT422 infection group were clustered into cluster 4, and 25 of 39 proteins that were only significantly downregulated in the JZ809 infection group belonged to cluster 3. The results indicated that the DEPs in the attenuated XT422 infection group might be sensitive and their abundance changed more quickly when fish experienced virus infection.

[Correlation between professional quality of life and social support of Chinese nurses: a meta-analysis]

Objective: To systematically evaluate the correlation between professional quality of life and social support of Chinese nurses based on Pearson and Spearman correlation coefficients. Methods: In databases including PubMed, Cochrane Library, CINAHL, Medline, CBM, CNKI、Wanfang, and other databases were searched by computer for the literatures on correlation between Chinese nurses' professional quality of life and social support from January 2005 to July 2020. The Chinese and English search terms are "nurse" "professional quality of life" "empathy satisfaction" "empathy fatigue" "professional quality of life" "ProQOL" "comparison satisfaction" "comparison fatigue" "social support" "competent social support" "SSRS" "PSSS", etc. Literatures were screened according to the inclusion and exclusion criteria. After evaluating quality and extracting data, meta-analysis was conducted using RevMan 5.3 software. Results: A total of 12 studies were included. The meta analysis showed that nurses' compassion satisfaction, burnout, secondary traumatic stress were related to social support, summary r were 0.35, -0.26 and -0.23 respectively. The correlation between compassion satisfaction and social support were increased with sample, the south was higher than the north, and comprehensive departments were higher than other departments (P<0.05) . The correlation between burnout and social support were increased with time and sample, and the south was higher than the north, oncology was higher than others, non-random sampling was higher than random sampling, using ProQOL and Perceived Social Support Scale (PSSS) was higher than Professional Quality of Life Scale (ProQOL) and Social Support Racting Scale (SSRS) (P<0.05) . The correlation coefficient between secondary traumatic stress and social support in oncology was higher than others, random sampling was higher than non-random sampling, using ProQOL and PSSS was higher than ProQOL and SSRS (P<0.05) . Conclusion: There is a positive and weak correlation between compassion satisfaction and social support, and a negative and weak correlation between burnout and secondary traumatic stress and social support. There are differences in different time, research design, region and department.

Susceptibility of a cell line derived from the kidney of Chinese rice-field eel, Monopterus albus to the infection of rhabdovirus, CrERV

Chinese rice-field eels rhabdovirus (CrERV), belonging to the genus Perhabdovirus in the family Rhabdoviridae, is the causative agent of the haemorrhagic disease of Chinese rice-field eels, Monopterus albus. The present study aims to establish a cell line derived from the kidney of Chinese rice-field eel (CrEK) for the further study of the pathogenic virus. CrEK cells were epithelioid-like and grew well in M199 medium supplemented with 10% foetal bovine serum at 28°C, and the cell line has been subcultured for more than 80 times. Karyotyping analysis of CrEK cells at 25th passage indicated a modal chromosome number of 24. Significant cytopathic effect (CPE) was observed in CrEK cells after infection with CrERV, and the virus titre reached 10^{7.8 ± 0.45} TCID₅₀ /mL. The transmission electron microscopy revealed that there were a large number of virus particles in the cytoplasm of cells. The virus infection in cells was also assayed by using indirect immunofluorescence assay (IFA), fluorescence in situ hybridization (FISH), reverse transcription PCR (RT-PCR) and quantitative real-time reverse transcription-PCR (qRT-PCR). In experimental infection, CrERV cultured by cells could cause over 90% mortality in fish. CrEK represents the first kidney cell line originated from Chinese rice-field eels and be a potential material for investigating the mechanism of virus infection in this fish and the control methods for the disease.

[The effectiveness of psychological intervention on nursing staff' compassion fatigue: a meta-analysis]

Objective: To systematically evaluate the impact of psychological intervention on nursing staff' compassion fatigue. Methods: From March to May 2020, PubMed, Cochrane Library, EMbase, Web of Science, CNKI, VIP, Wanfang and other databases were electronically searched to collect randomized controlled trials (RCTs) on the influence of psychological intervention on nursing staff' compassion fatigue with the main search terms including compassion fatigue, nurs*, psychological intervention, mental intervention, RCT and so on from inception to March 31, 2020. Screened literature, extracted data and assessed the risk of bias of included studies. The Stata 16.0 software was used to calculate the pooled effectiveness of psychological intervention on nursing staff' compassion fatigue. Results: All 13 RCTs were enrolled, including 940 nursing staff. Meta-analysis results demonstrated that the psychological intervention group was superior to the control group in the improvement of the compassion fatigue score (SMD=-0.96, 95%CI: -1.17-0.74, P=0.001) , compassion satisfaction score (SMD=0.61, 95%CI: 0.45-0.77, P=0.002) , burnout score (SMD=-0.46, 95%CI: -0.62-0.29, P=0.006) , secondary trauma score (SMD=-0.40, 95%CI: -0.68-0.12, P=0.020) , and the difference was statistically significant. Subgroup analysis found that the psychological intervention group was more effective than the control group in improving compassion satisfaction score, reducing burnout score and secondary trauma score, and the differences were statistically significant (P<0.05) in different intervention time (<8 weeks and ≥8 weeks) and intervention methods. Conclusion: The psychological intervention can improve the level of compassion satisfaction, and reduce the compassion fatigue among nursing staff, and have a certain preventive effect on compassion fatigue.