Prognostic analysis of related factors of adverse reactions to immunotherapy in advanced gastric cancer and establishment of a nomogram model

BACKGROUND

Immunotherapy for advanced gastric cancer has attracted widespread attention in recent years. However, the adverse reactions of immunotherapy and its relationship with patient prognosis still need further study. In order to determine the association between adverse reaction factors and prognosis, the aim of this study was to conduct a systematic prognostic analysis. By comprehensively evaluating the clinical data of patients with advanced gastric cancer treated by immunotherapy, a nomogram model will be established to predict the survival status of patients more accurately.

AIM

To explore the characteristics and predictors of immune-related adverse reactions (irAEs) in advanced gastric cancer patients receiving immunotherapy with programmed death protein-1 (PD-1) inhibitors and to analyze the correlation between irAEs and patient prognosis.

METHODS

A total of 140 patients with advanced gastric cancer who were treated with PD-1 inhibitors in our hospital from June 2021 to October 2023 were selected. Patients were divided into the irAEs group and the non-irAEs group according to whether or not irAEs occurred. Clinical features, manifestations, and prognosis of irAEs in the two groups were collected and analyzed. A multivariate logistic regression model was used to analyze the related factors affecting the occurrence of irAEs, and the prediction model of irAEs was established. The receiver operating characteristic (ROC) curve was used to evaluate the ability of different indicators to predict irAEs. A Kaplan-Meier survival curve was used to analyze the correlation between irAEs and prognosis. The Cox proportional risk model was used to analyze the related factors affecting the prognosis of patients.

RESULTS

A total of 132 patients were followed up, of whom 63 (47.7%) developed irAEs. We looked at the two groups' clinical features and found that the two groups were statistically different in age ≥ 65 years, Ki-67 index, white blood cell count, neutrophil count, and regulatory T cell (Treg) count (all P < 0.05). Multivariate logistic regression analysis showed that Treg count was a protective factor affecting irAEs occurrence (P = 0.030). The ROC curve indicated that Treg + Ki-67 + age (≥ 65 years) combined could predict irAEs well (area under the curve = 0.753, 95% confidence interval: 0.623-0.848, P = 0.001). Results of the Kaplan-Meier survival curve showed that progression-free survival (PFS) was longer in the irAEs group than in the non-irAEs group (P = 0.001). Cox proportional hazard regression analysis suggested that the occurrence of irAEs was an independent factor for PFS (P = 0.006).

CONCLUSION

The number of Treg cells is a separate factor that affects irAEs in advanced gastric cancer patients receiving PD-1 inhibitor immunotherapy. irAEs can affect the patients' PFS and result in longer PFS. Treg + Ki-67 + age (≥ 65 years old) combined can better predict the occurrence of adverse reactions.

Mechanistic understanding of acclimation and energy metabolism of acetoclastic methanogens under different substrate to microorganism ratios

Mechanistic understanding of acetoclastic methanogenesis is pivotal for optimizing anaerobic digestion for efficient methane production. In this study, two different operational modes, continuous flow reactor (CFR) and sequencing batch reactor (SBR), accompanied with solids retention times (SRT) of 10 days (SBR10d and CFR10d) and 25 days (SBR25d and CFR25d) were implemented to elucidate their impacts on microbial communities and energy metabolism of methanogens in acetate-fed systems. Microbial community analysis revealed that the relative abundance of Methanosarcina (16.0%-46.0%) surpassed Methanothrix (3.7%-22.9%) in each reactor. SBRs had the potential to enrich both Methanothrix and Methanosarcina. Compared to SBRs, CFRs had lower total relative abundance of methanogens. Methanosarcina exhibited a superior enrichment in reactors with 10-day SRT, while Methanothrix preferred to be acclimated in reactors with 25-day SRT. The operational mode and SRT were also observed to affect the distribution of acetate-utilizing bacteria, including Pseudomonas, Desulfocurvus, Mesotoga, and Thauera. Regarding enzymes involved in energy metabolism, Ech and Vho/Vht demonstrated higher relative abundances at 10-day SRT compared to 25-day SRT, whereas Fpo and MtrA-H showed higher relative abundances in SBRs than those in CFRs. The relative abundance of genes encoding ATPase harbored by Methanothrix was higher than Methanosarcina at 25-day SRT. Additionally, the relative abundance of V/A-type ATPase (typically for methanogens) was observed higher in SBRs compared to CFRs, while the F-type ATPase (typically for bacteria) exhibited higher relative abundance in CFRs than that in SBRs.

Powdered activated carbon facilitated degradation of complex organic compounds and tetracycline in stressed anaerobic digestion systems

Tetracycline exerts an inhibitory effect on anaerobic digestion, inducing stressed microbial activities and even system failure. Continuous-flow reactors (CFRs) and sequencing batch reactors (SBRs) were employed along with the dosage of powdered activated carbon (PAC) to enhance tetracycline removal during anaerobic digestion of complex organic compounds. PAC increased the maximum methane production rate by 15.6% (CFRs) and 13.8% (SBRs), and tetracycline biodegradation by 24.4% (CFRs) and 19.2% (SBRs). CFRs showed higher tetracycline removal and methane production rates than SBRs. Geobacter was enriched in CFRs, where Methanothrix was enriched with the addition of PAC. Desulfomicrobium harbored abundant propionate degradation-related genes, significantly correlating with tetracycline removal. The genes encoding carbon dioxide reduction in Methanothrix along with the detection of Geobacter might indicate direct interspecies electron transfer for methanogenesis in CFRs and PAC-added reactors. The study offers new insights into anaerobic digestion under tetracycline-stressed conditions and strategies for optimizing tetracycline removal.

Operational mode and powdered activated carbon promoting syntrophic propionate oxidation during anaerobic digestion of complex organic substances

Operational mode and powdered activated carbon (PAC) are key factors facilitating microbial syntrophy and interspecies electron transfer during anaerobic digestion, consequently benefiting process stability and efficient methanogenesis. In this study, continuous-flow reactor (CFR) and sequencing batch reactor (SBR), with and without the addition of PAC, respectively, were operated to examine their effects on system performance and methanogenic activity. Based on the cycle-test result, the PAC-amended CFR (CFRPAC) recorded both the highest methane yield (690.1 mL/L) and the maximum CH4 production rate (28.8 mL/(L·h)), while SBRs exhibited slow methanogenic rates. However, activity assays indicated that SBRs were beneficial for organics removal in batch experiments fed with peptone. Taxonomic and functional analysis confirmed that CFRs were optimal for proliferating oligotrophs (e.g., Geobacter) and SBRs were more suitable for copiotrophs (e.g., Desulfobulbus). Metagenomic analysis revealed that CFRs had efficient acetate metabolic pathways from propionate and ethanol, whereas SBRs did not, resulting in the buildup of propionate. Furthermore, Methanobacterium and Methanothrix were acclimated to the different operational conditions, while acetoclastic Methanosarcina and hydrogenotrophic Methanolinea were acclimated in SBRs (5.1-13.4%) and CFRs (0.3-1.7%), respectively. This study confirmed the enhancement of microbial syntrophy by the addition of PAC as well as the acclimation of electroactive bacteria (e.g., Geobacter) with complex organic substances.

[Safety and efficacy of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis]

Objective: To investigate the efficacy and safety of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis. Methods: A retrospective analysis was carried out on 46 patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis who received endovascular treatment at the Strategic Support Force Medical Center from January 2015 to August 2022. Twenty-seven patients underwent balloon angioplasty alone and 19 patients underwent acute stent implantation. The baseline characteristics, modified thrombolysis in cerebral infarction (mTICI) score of the responsible vessels, modified Rankin scale (mRS) score 90 days after operation, incidence of symptomatic intracranial hemorrhage and mortality of the two groups were evaluated. Results: The proportion of effective recanalization of the offending vessels (mTICI≥2b) in the acute stenting group was slightly higher than that in the balloon angioplasty group (16/19 vs. 81.5%), but the difference was not statistically significant (P>0.05). Besides, there was no significant difference in the median of mRS between the acute stenting group [3.0(0, 4.0)] and the balloon angioplasty group [4.0(1.0, 5.0)] 90 days after operation (P>0.05). In terms of safety, the incidence of symptomatic intracranial hemorrhage and mortality were comparable between the two groups (P>0.05). Conclusions: The effect of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis is not inferior to that of balloon angioplasty, and it does not increase the risk of intracranial bleeding complications.

Deciphering anaerobic ethanol metabolic pathways shaped by operational modes

Efficient anaerobic digestion requires the syntrophic cooperation among diverse microorganisms with various metabolic pathways. In this study, two operational modes, i.e., the sequencing batch reactor (SBR) and the continuous-flow reactor (CFR), were adopted in ethanol-fed systems with or without the supplement of powdered activated carbon (PAC) to examine their effects on ethanol metabolic pathways. Notably, the operational mode of SBR and the presence of CO2 facilitated ethanol metabolism towards propionate production. This was further evidenced by the dominance of Desulfobulbus, and the increased relative abundances of enzymes (EC: 1.2.7.1 and 1.2.7.11) involved in CO2 metabolism in SBRs. Moreover, SBRs exhibited superior biomass-based rates of ethanol degradation and methanogenesis, surpassing those in CFRs by 53.1% and 22.3%, respectively. Remarkably, CFRs with the extended solids retention time enriched high relative abundances of Geobacter of 71.7% and 70.4% under conditions with and without the addition of PAC, respectively. Although both long-term and short-term PAC additions led to the increased sludge conductivity and a reduced methanogenic lag phase, only the long-term PAC addition resulted in enhanced rates of ethanol degradation and propionate production/degradation. The strategies by adjusting operational mode and PAC addition could be adopted for modulating the anaerobic ethanol metabolic pathway and enriching Geobacter.

New techniques to identify the tissue of origin for cancer of unknown primary in the era of precision medicine: progress and challenges

Despite a standardized diagnostic examination, cancer of unknown primary (CUP) is a rare metastatic malignancy with an unidentified tissue of origin (TOO). Patients diagnosed with CUP are typically treated with empiric chemotherapy, although their prognosis is worse than those with metastatic cancer of a known origin. TOO identification of CUP has been employed in precision medicine, and subsequent site-specific therapy is clinically helpful. For example, molecular profiling, including genomic profiling, gene expression profiling, epigenetics and proteins, has facilitated TOO identification. Moreover, machine learning has improved identification accuracy, and non-invasive methods, such as liquid biopsy and image omics, are gaining momentum. However, the heterogeneity in prediction accuracy, sample requirements and technical fundamentals among the various techniques is noteworthy. Accordingly, we systematically reviewed the development and limitations of novel TOO identification methods, compared their pros and cons and assessed their potential clinical usefulness. Our study may help patients shift from empirical to customized care and improve their prognoses.

New insights into syntrophic ethanol oxidation: Effects of operational modes and solids retention times

Anaerobic ethanol oxidation relies on syntrophic interactions among functional microorganisms to become thermodynamically feasible. Different operational modes (sequencing batch reactors, SBRs, and continuous flow reactors, CFRs) and solids retention times (SRT, 25 days and 10 days) were employed in four ethanol-fed reactors, named as SBR25d, SBR10d, CFR25d, and CFR10d, respectively. System performance, syntrophic relationships, microbial communities, and metabolic pathways were examined. During the long-term operation, 2002.7 ± 56.0 mg COD/L acetate was accumulated in CFR10d due to the washout of acetotrophic methanogens. Microorganisms with high half-saturation constants were enriched in reactors of 25-day SRT. Moreover, ethanol oxidizing bacteria and acetotrophic methanogens with high half-saturation constants could be acclimated in SBRs. In SBRs, Syner-01 and Methanothrix dominated, and the low SRT of 10 days increased the relative abundance of Geobacter to 38.0%. In CFRs, the low SRT of 10 days resulted in an increase of Desulfovibrio among syntrophic bacteria, and CFR10d could be employed in enriching hydrogenotrophic methanogens like Methanobrevibacter.

Metabolomics-transcriptomics joint analysis: unveiling the dysregulated cell death network and developing a diagnostic model for high-grade neuroblastoma

High-grade neuroblastoma (HG-NB) exhibits a significantly diminished survival rate in comparison to low-grade neuroblastoma (LG-NB), primarily attributed to the mechanism of HG-NB is unclear and the lacking effective therapeutic targets and diagnostic model. Therefore, the current investigation aims to study the dysregulated network between HG-NB and LG-NB based on transcriptomics and metabolomics joint analysis. Meanwhile, a risk diagnostic model to distinguish HG-NB and LG-NB was also developed. Metabolomics analysis was conducted using plasma samples obtained from 48 HG-NB patients and 36 LG-NB patients. A total of 39 metabolites exhibited alterations, with 20 showing an increase and 19 displaying a decrease in HG-NB. Additionally, transcriptomics analysis was performed on NB tissue samples collected from 31 HG-NB patients and 20 LG-NB patients. Results showed that a significant alteration was observed in a total of 1,199 mRNAs in HG-NB, among which 893 were upregulated while the remaining 306 were downregulated. In particular, the joint analysis of both omics data revealed three aberrant pathways, namely the cAMP signaling pathway, PI3K-Akt signaling pathway, and TNF signaling pathway, which were found to be associated with cell death. Notably, a diagnostic model for HG-NB risk classification was developed based on the genes MGST1, SERPINE1, and ERBB3 with an area under the receiver operating characteristic curve of 0.915. In the validation set, the sensitivity and specificity were determined to be 75.0% and 80.0%, respectively.

Efficient Registration for Human Surfaces via Isometric Regularization on Embedded Deformation

3D registration is a fundamental step to obtain the correspondences between surfaces. Traditional mesh alignment methods tackle this problem through non-rigid deformation, mostly accomplished by applying ICP-based (Iterative Closest Point) optimization. The embedded deformation method is proposed for the purpose of acceleration, which enables various real-time applications. However, it regularizes on an underlying simplified structure, which could be problematic for intricate cases when the simplified graph doesn't fully represent the surface attributes. Moreover, without elaborate parameter-tuning, deformation usually performs suboptimally, leading to slow convergence or a local minimum if all regions on the surface are assumed to share the same rigidity during the optimization. In this article, we propose a novel solution that decouples regularization from the underlying deformation model by explicitly managing the rigidity of vertex clusters. We further design an efficient two-step solution that alternates between isometric deformation and embedded deformation with cluster-based regularization. Our method can easily support region-adaptive regularization with cluster refinement and execute efficiently. Extensive experiments demonstrate the effectiveness of our approach for mesh alignment tasks even under large-scale deformation and imperfect data. Our method outperforms state-of-the-art methods both numerically and visually.

"Triple-low" radiation dose bronchial artery CT angiography before bronchial artery embolisation: a feasibility study

AIM

To explore the feasibility of a "triple-low" dose (low tube voltage, low tube current, and low contrast agent volume) bronchial artery computed tomography (CT) angiography (CTA) to replace routine dose bronchial artery CTA before bronchial artery embolisation (BAE).

MATERIALS AND METHODS

CTA was obtained from 60 patients with body mass index (BMI) < 30 kg/m2 using a 256 multi-section iCT system, and they were divided into two groups: (1) group A: 100 kVp, 100 mAs, 50 ml contrast medium (CM); (2) group B: 120 kVp, automatic tube current modulation (ACTM), 80 ml CM. CT attenuation of the thoracic aorta, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and subjective image quality scores and traceability scores assessed. The effective radiation dose was calculated.

RESULTS

The radiation dose was reduced by 79.7% in group A compared to group B (p<0.05). The CT attenuation of the thoracic aorta was increased by approximately 13% in group A compared to group B (p<0.05). Higher image noise, lower SNR, and CNR were obtained in group A compared to group B (all p<0.05). Both subjective image quality scores and traceability scores did not differ between groups A and B (both p>0.05).

CONCLUSION

It is feasible to use the "triple-low" dose CTA protocol for patients with a body mass index (BMI) < 30 kg/m2. The radiation dose was reduced by 79.7%, and the dose of contrast medium was reduced by 37.5% to ensure the diagnostic value.

Nitrate removal in iron sulfide-driven autotrophic denitrification biofilter: Biochemical and chemical transformation pathways and its underlying microbial mechanism

Iron sulfides-based autotrophic denitrification (IAD) is effective for treating nitrate-contaminated wastewater. However, the complex nitrate transformation pathways coupled with sulfur and iron cycles in IADs are still unclear. In this study, two columns (abiotic vs biotic) with iron sulfides (FeS) as the packing materials were constructed and operated continuously. In the abiotic column, FeS chemically reduced nitrate to ammonium under the ambient condition; this chemical reduction reaction pathway was spontaneous and has been overlooked in IAD reactors. In the biotic column (IAD biofilter), the complex nitrogen-transformation network was composed of chemical reduction, autotrophic denitrification, dissimilatory nitrate reduction to ammonium (DNRA) and sulfate reducing ammonium oxidation (Sulfammox). Metagenomic analysis and XPS characterization of the IAD biofilter further validated the roles of functional microbial communities (e.g., Acidovorax, Diaphorobacter, Desulfuromonas) in nitrate reduction process coupled with iron and sulfur cycles. This study gives an in-depth insight into the nitrogen transformations in IAD system and provides fundamental evidence about the underlying microbial mechanism for its further application in biological nitrogen removal.

Laparoscopic posterior pelvic exenteration is safe and feasible for locally advanced primary rectal cancer in female patients: a comparative study from China PelvEx collaborative

PURPOSE

Posterior pelvic exenteration (PPE) for locally advanced rectal cancer is a technical and challenging procedure. The safety and feasibility of laparoscopic PPE remain to be determined. This study aims to compare short-term and survival outcomes of laparoscopic PPE (LPPE) with open PPE (OPPE) in female patients.

METHOD

From January 2015 to December 2020, data from 105 female patients who underwent PPE at three institutions were retrospectively analyzed. The short-term and oncological outcomes between LPPE and OPPE were compared.

RESULTS

A total of 54 cases with LPPE and 51 cases with OPPE were enrolled. The operative time (240 vs. 295 min, p = 0.009), blood loss (100 vs. 300 ml, p < 0.001), surgical site infection (SSI) rate (20.4% vs. 58.8%, p = 0.003), urinary retention rate (3.7% vs. 17.6%, p = 0.020), and postoperative hospital stay (10 vs. 13 days, p = 0.009) were significantly lower in the LPPE group. The two groups showed no significant differences in the local recurrence rate (p = 0.296), 3-year overall survival (p = 0.129), or 3-year disease-free survival (p = 0.082). A higher CEA level (HR 1.02, p = 0.002), poor tumor differentiation (HR 3.05, p = 0.004), and (y)pT4b stage (HR 2.35, p = 0.035) were independent risk factors for disease-free survival.

CONCLUSION

LPPE is safe and feasible for locally advanced rectal cancers and shows lower operative time and blood loss, fewer SSI complications, and better preservation of bladder function without compromising oncological outcomes.

Joint analysis of the metabolomics and transcriptomics uncovers the dysregulated network and develops the diagnostic model of high-risk neuroblastoma

High-risk neuroblastoma (HR-NB) has a significantly lower survival rate compared to low- and intermediate-risk NB (LIR-NB) due to the lack of risk classification diagnostic models and effective therapeutic targets. The present study aims to characterize the differences between neuroblastomas with different risks through transcriptomic and metabolomic, and establish an early diagnostic model for risk classification of neuroblastoma.Plasma samples from 58 HR-NB and 38 LIR-NB patients were used for metabolomics analysis. Meanwhile, NB tissue samples from 32 HR-NB and 23 LIR-NB patients were used for transcriptomics analysis. In particular, integrative metabolomics and transcriptomic analysis was performed between HR-NB and LIR-NB. A total of 44 metabolites (P < 0.05 and fold change > 1.5) were altered, including 12 that increased and 32 that decreased in HR-NB. A total of 1,408 mRNAs (P < 0.05 and |log2(fold change)|> 1) showed significantly altered in HR-NB, of which 1,116 were upregulated and 292 were downregulated. Joint analysis of both omic data identified 4 aberrant pathways (P < 0.05 and impact ≥ 0.5) consisting of glycerolipid metabolism, retinol metabolism, arginine biosynthesis and linoleic acid metabolism. Importantly, a HR-NB risk classification diagnostic model was developed using plasma circulating-free S100A9, CDK2, and UNC5D, with an area under receiver operating characteristic curve of 0.837 where the sensitivity and specificity in the validation set were both 80.0%. This study presents a novel pioneering study demonstrating the metabolomics and transcriptomics profiles of HR-NB. The glycerolipid metabolism, retinol metabolism, arginine biosynthesis and linoleic acid metabolism were altered in HR-NB. The risk classification diagnostic model based on S100A9, CDK2, and UNC5D can be clinically used for HR-NB risk classification.

Point-of-care ultrasound for monitoring catheter tip location during umbilical vein catheterization in neonates: a prospective study

Background

Point-of-care ultrasound (POCUS) can guide umbilical vein catheter placement in real time and monitor catheter tip position, allowing avoidance of severe complications due to catheter malposition. This study aims to explore the effectiveness of POCUS in guiding venous catheter insertion and monitoring complications.

Methods

Sixty-eight neonates with ultrasound-guided venous catheter insertion at the Neonatal Department of Dongguan Children's Hospital between December 2020 and February 2022 were included. POCUS was applied to monitor catheter tip location daily until catheter removal. A displacement range exceeding the intersection of the inferior vena cava and right atrium by ±0.5 cm was considered misalignment.

Results

Sixty-four neonates had a displaced catheter tip (94.1%, 64/68), with a median displacement distance of 0.4 cm (minimum -0.2 cm, maximum 1.2 cm). Ten neonates had a misalignment (14.7%, 10/68) caused by displacement. Displacement usually occurs within 2-4 days after placement, with displacement rates of 94.1% (64/68), 90.6% (58/64), and 98.3% (59/60) on days 2, 3, and 4, respectively, and could still occur on day 9 post-placement. In addition, misalignment mainly occurs on the second day after placement. During the monitoring process, 58 neonates had catheter tip displacement ≥2 times, resulting in 252 displacement and 22 misalignment incidents. Among them, the catheter tip migrated outward from the inferior vena cava seven times, all of which were removed in time. Ultrasound was used for positioning 486 times, and x-ray was indirectly avoided 486 times.

Conclusion

The catheter tip is prone to displacement and misalignment after umbilical vein catheterization, which most commonly occurs on days 2-4. POCUS is recommended for daily monitoring of the tip location during umbilical vein catheterization until catheter removal.

An innovative immunotherapeutic strategy for rheumatoid arthritis: Selectively suppressing angiogenesis and osteoclast differentiation by fully human antibody targeting thymocyte antigen-1

Thymocyte antigen-1 (THY-1)is a potential target for rheumatoid arthritis (RA) treatment, and THY-1 positive fibroblast-like synoviocytes (FLS) are enriched in the synovium of RA patients and participate in angiogenesis to accelerate RA progression. In this study, we screened an antibody targeting THY-1 (THY-1 Ab) and explored its mechanism in alleviating RA progression. THY-1 Ab was screened from ScFv phage antibody library by phage display technology (PDT). THY-1 Ab-treated collagen induced arthritis (CIA) mice had lower degree of arthritis scores. We explore the mechanism of THY-1 Ab in alleviating RA progression. THY-1 Ab can remarkably inhibit the secretion of pro-inflammatory factors and promote the secretion of anti-inflammatory factors. Further experiments showed that THY1 Ab downregulated the expression of JUNB by the hsa_circ_0094342/miRNA-155-5P/SPI1 axis, inhibited RA angiogenesis and osteoclast differentiation, and relieved RA progression. These findings support that THY-1 Ab is a promising therapeutic antibody for RA treatment.

Plasma circulating cell-free MYCN gene: A noninvasive and prominent recurrence monitoring indicator of neuroblastoma

The postoperative recurrence of neuroblastoma (NB) patients is an essential reason for the high mortality of NB due to the lack of early, non-invasive, and dynamic strategies for monitoring NB recurrence. Therefore, whether the plasma circulating cell-free MYCN gene as an indicator for monitoring of NB recurrence was systematically evaluated. The MYCN copy number and NAGK (reference gene) copy number (M/N) ratio in plasma and corresponding tumor tissues of NB patients was detected using an economical, sensitive, and specific single-tube dual RT-PCR approach developed in this study. The plasma M/N ratio of the MYCN gene amplification (MNA) group (N = 25, median M/N ratio = 4.90) was significantly higher than that of the non-MNA group (N = 71, median M/N ratio = 1.22), p < .001. The M/N ratio in NB plasma (N = 60) was positively correlated with the M/N ratio in NB tumor tissue (N = 60), with a correlation coefficient of 0.9496. In particular, the results of dynamic monitoring of postoperative plasma M/N ratio of NB patients showed that an abnormal increase in M/N ratio could be detected 1-2 months before recurrence in NB patients. In summary, the single-tube double RT-PCR approach can be used to quantitatively detect MYCN copy number. The copy number of MYCN in the tissue and plasma of NB patients is consistent with each other. More importantly, the circulating cell-free MYCN gene of NB patients can be used as a monitoring indicator for early, non-invasive, and dynamic monitoring of NB recurrence.

Short- and long-term outcomes of laparoscopic versus open pelvic exenteration for locally advanced rectal cancer: a single-center propensity score matching analysis

BACKGROUND

Research on short-term outcomes and long-term oncological results of laparoscopic pelvic exenteration (LPE) for locally advanced rectal cancer (LARC) is still limited. The purpose of this study was to compare the outcomes of LPE and open pelvic exenteration (OPE).

METHODS

Between January 2010 and December 2019, consecutive LARC patients who underwent radical pelvic exenteration at Peking University First Hospital were enrolled. Groups were matched at a 1:1 ratio using propensity score matching. The primary endpoints were 3 year overall survival (OS) and disease-free survival (DFS). The secondary endpoints were postoperative short-term outcomes.

RESULTS

There were 144 patients (68 males and 76 females, median age 58.5 [range 27.0-86.0] years). After matching, patients were stratified into LPE (n = 48) and OPE (n = 48) groups (LPE: 24 males and 24 females, median age 57.0 [range 27.0-81.0] years; OPE: 26 males and 22 females, median age 58.0[range 36.0-80.0] years). There were no significant differences on baseline data between the two groups. Compared with the OPE group, the LPE group had a significantly lower estimated blood loss (200 vs 500 ml, p = 0.003), less overall postoperative complications (12/48 vs 25/48, p = 0.006), less surgical site infection (8/48 vs 20/48, p = 0.007), shorter length of stay (12 vs. 15 days, p = 0.005), but similar operative time (344 vs. 360 min, p = 0.493). The pathological R0 resection rate (98.0% vs. 93.7%, p = 0.610), 3 year local recurrence (18.4% vs. 23.5, p = 0.140), 3 year OS (74.6% vs. 65.5%, p = 0.290) and 3-year DFS (60.0% vs. 50.3%, p = 0.208) were similar between the two groups. Shorter distance from anal verge (HR = 0.92, p = 0.042), (y) pT4b (HR = 2.45, p = 0.023), (y)pN1-2 (HR = 2.42, p = 0.004) and positive CRM (HR = 6.23, p = 0.004) were independent prognostic risks for 3 year DFS.

CONCLUSIONS

LPE can be performed safely and has certain short-term advantages over OPE, most notably less blood loss and surgical site infection. However, LPE does not improve long-term oncological outcomes.

A systematic review of current status and challenges of vaccinating children against SARS-CoV-2

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has inflicted immense damage to countries, economies and societies worldwide. Authorized COVID-19 vaccines based on different platforms have been widely inoculated in adults, showing up to 100% immunogenicity with significant efficacy in preventing SARS-CoV-2 infections and the occurrence of severe COVID-19. It has also greatly slowed the evolution of SARS-CoV-2 variants, as shown in clinical trials and real-world evidence. However, the total dosage of COVID-19 vaccines for children is much smaller than that for adults due to limitations from parental concern of vaccine safety, presenting a potential obstacle in ending the COVID-19 pandemic. SARS-CoV-2 not only increases the risk of severe multisystem inflammatory syndrome (MIS-C) in children, but also negatively affects children's psychology and academics, indirectly hindering the maintenance and progress of normal social order. Therefore, this article examines the clinical manifestations of children infected with SARS-CoV-2, the status of vaccination against COVID-19 in children, vaccination-related adverse events, and the unique immune mechanisms of children. In particular, the necessity and challenges of vaccinating children against SARS-CoV-2 were highlighted from the perspectives of society and family. In summary, parental hesitancy is unnecessary as adverse events after COVID-19 vaccination have been proven to be infrequent, comprise of mild symptoms, and have a good prognosis.

Transcription factor MdLSD1 negatively regulates α-farnesene biosynthesis in apple-fruit skin tissue

α-Farnesene is a sesquiterpene present in plants. It was first discovered in apples. It plays an important role in the plant defence response and is considered a key factor in the occurrence of superficial scald. The gene encoding α-farnesene synthase, which is the last key enzyme in the biosynthetic pathway of α-farnesene in apple fruit, has become the primary target enzyme for controlling the genetic manipulation of α-farnesene biosynthesis. In this study, the yeast one-hybrid assay and the dual luciferase assay were used to ascertain the relationship between MdLSD1 and MdAFS. Real-time PCR was used to analyse the molecular mechanism underlying the regulation of MdAFS by MdLSD1. Our results revealed that transcription factor MdLSD1, which is closely related to programmed cell death in apple fruit tissues, binds to MdAFS. Transient transformation of apple skin with vectors overexpressing MdLSD1 showed that the gene negatively regulates MdAFS. Overall, we suggest that MdLSD1 negatively regulates MdAFS. Our results are of great significance for future research on the transcriptional regulation of the α-farnesene synthase gene and provide a new direction for exploring the specific mechanism of programmed cell death involved in superficial-scald incidence.

Distinguishing responses of acetoclastic and hydrogenotrophic methanogens to ammonia stress in mesophilic mixed cultures

A shift from the acetoclastic to the hydrogenotrophic pathway in methanogenesis under ammonia inhibition is a common observation in anaerobic digestion. However, there are still considerable knowledge gaps concerning the differential ammonia tolerance of acetoclastic and hydrogenotrophic methanogens (AMs and HMs), their responses to different ammonia species (NH₄⁺, NH₃), and their recoverability after ammonia inhibition. With the successful enrichment of mesophilic AMs and HMs cultures, this study aimed at addressing the above knowledge gaps through batch inhibition/recovery tests and kinetic modeling under varying total ammonia (TAN, 0.2-10 g N/L) and pH (7.0-8.5) conditions. The results showed that the tolerance level of HMs to free ammonia (FAN, IC₅₀=1345 mg N/L) and NH₄⁺ (IC₅₀=6050 mg N/L) was nearly 11 times and 3 times those of AMs (NH₃, IC₅₀=123 mg N/L; NH₄⁺, IC₅₀=2133 mg N/L), respectively. Consistent with general belief, the AMs were more impacted by FAN. However, the HMs were more adversely affected by NH₄⁺ when the pH was ≤8.0. A low TAN (1.0-4.0 g N/L) could cause irreversible inhibition of the AMs due to significant cell death, whereas the activity of HMs could be fully or even over recovered from severe ammonia stress (FAN≤ 0.9 g N/L or TAN≤10 g N/L; pH ≤8.0). The different tolerance responses of AMs and HMs might be associated with the cell morphology, multiple energy-converting systems, and Gibbs free energy from substrate-level phosphorylation.

Dual isothermal amplification all-in-one approach for rapid and highly sensitive quantification of plasma circulating MYCN gene of neuroblastoma

A dual isothermal amplification assay with dual fluorescence signal detection strategy, named dual isothermal amplification all-in-one approach, was developed for rapid, one-step, highly sensitive quantification of plasma circulating MYCN copy number of neuroblastoma (NB). The developed strategy consisted of rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) on a real-time PCR system using highly specific probe, molecular beacon (MB), as detection probe. The developed strategy possessing a broad linear dynamic range of 10 aM to 1 pM for both target gene (MYCN) and reference gene (NAGK). The ratio of the MYCN copy number to NAGK copy number (M/N ratio) was detected by the developed approach in cell lines, NB tumor tissues, hepatoblastoma tumor tissues and Wilms' tumor tissues, to which the M/N ratios were consistent with previous reports. In particular, the M/N ratio in NB clinical tissue specimens and NB plasma specimens detected with the developed approach were in keeping with the standard RT-PCR approach. More importantly, the M/N ratio in NB tissue samples and corresponding plasma samples of NB patients were consistent with each other with a correlation coefficient of 0.9690, indicating that plasma circulating MYCN is a promising indicator for the risk classification of NB.

Case Report: Langerhans Cell Sarcoma With Intracranial and Extracranial Communication on the Left Frontal Bone

Background

Langerhans cell sarcoma (LCS) is an extremely rare type of malignant tumor that originates from Langerhans cells (LC). It is characterized by the malignant proliferation and dissemination of LC and is extremely invasive, with rapid progression and a poor prognosis. Treatment includes resection of lesions, radiotherapy, chemotherapy, immunotherapy, and transplantation of hematopoietic stem cells. However, a unified and optimized treatment plan is lacking, and individualized treatment is accepted.

Case presentation

We report an 18-year-old man with intracranial and extracranial communicative LCS that occurred in only the left forehead without metastasis to other regions. Clinical and hematological data were normal. We undertook complete resection of diseased tissue, which was pathologically examined. Staining (hematoxylin and eosin) showed positivity for cluster of differentiation (CD)1a (++), S-100 protein (++), P53 (++), CD68 (+), cyclin D1 (+), cyclin A (+), cyclin B1 (+), IGF2BP3 (+), and Ki-67 (45%–50%). Recurrence or metastasis were not observed after long-term follow-up.

Conclusion

LCS is a rare malignant tumor, and one that occurs with intracranial and extracranial communication is even rarer. Active adoption of an individualized treatment plan is crucial.

POS1368 DIVERSITY OF HEMODYNAMIC TYPES IN CONNECTIVE TISSUE DISEASE ASSOCIATED PULMONARY HYPERTENSION: MORE THAN A SUBGROUP OF PULMONARY ARTERIAL HYPERTENSION

Background

Connective tissue disease (CTD) associated pulmonary hypertension (PH) is classified as a subgroup of WHO group 1 PH, also called pulmonary arterial hypertension (PAH). However, not all CTD-PH fit the hemodynamic definition of PAH. This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Objectives

This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Methods

We performed a retrospective cohort study. CTD-PH patients underwent right heart catheterization (RHC) were enrolled and divided into WHO group1 PH, WHO group 2 PH and high output PH (PVR<3WU and PAWP<15mmHg) according to hemodynamic features. Patients with obvious lung diseases, left heart disease and pulmonary embolism were excluded. Baseline characteristics, inflammatory markers, autoantibodies, cardiac function status, echocardiogram parameters, hemodynamics and survival rates were compared.

Results

207 CTD-PH patients were included, including 139 in WHO group 1 PH, 36 in WHO group 2 PH and 32 in high output PH. Incidence of anti-ribonucleoprotein antibody was lower in WHO Group 2 PH. High output PH is less severe, presenting lower NT-proBNP level, better WHO functional class, lower mPAP and PVR, higher cardiac output, and less cardiac remodeling. Among patients with elevated PAWP, combine pre& post-capillary PH had higher mPAP and larger right ventricle diameter. Association of mild to moderate interstitial lung disease didn’t show significant difference in disease characteristics. Short-term survival was significantly worse in WHO group 2 PH, yet 5-year survival rates didn’t differ between groups.

Conclusion

Pre-capillary PH is not the only hemodynamic type of CTD-PH. Different types of CTD-PH present different clinical phenotypes and outcome. Carefully phenotyping PH in CTD-PH patients is important.

Disclosure of Interests

None declared

Nutrient starvation intensifies chlorine disinfection-stressed biofilm formation

Bacterial surface attachment and subsequent biofilm expansion represent an essential adaptation to environmental signals and stresses, which are of great concern for many natural and engineered ecosystems. Yet the underlying mechanisms and driving forces of biofilm formation in a chlorinated and nutrient-restricted system remain sketchy. In this study, we coupled an experimental investigation and modeling simulation to understand how chlorination and nutrient limitation conspire to form biofilm using Pseudomonas aeruginosa as a model bacterium. Experimental results showed that moderate chlorination at 1.0 mg/L led to biofilm development amplified to 2.6 times of those without chlorine, while additional nutrient limitation (of 1/50-diluted or 0.4 g/L LB broth culture) achieved 4.6 times increment as compared to those of undiluted scenarios (of 20 g/L LB broth culture) with absence of chlorination after 24 h exposure. Meanwhile, intermediate chlorination stimulated instant flagellar motility and subsequently extracellular polymeric substances (EPS) secretion, particularly under limited nutrient condition (of 1/50-diluted or 0.4 g/L LB broth culture) that retarded chlorine consumption and provoked bacterial nutrient-limitation response. From our simulations, chlorine and resource levels along with associated spatio-temporal variations collectively drove bacterial cell movement and EPS excretion. Our results demonstrated that restraining nutrient intensified chlorination-excited cell movement and EPS production that reinforced biological and cell-surface interactions, thereby encouraging bacterial surface attachment and subsequent biofilm development. The findings provide the insights into the linkage of disinfectant and nutrient-regulated bacterial functional responses with consequent micro-habitats and biofilm dynamics.

[Safety and efficacy of intra-arterial tirofiban infusion in patients with acute cardiogenic cerebral embolism undergoing endovascular reperfusion therapy]

Objective: To evaluate the safety and efficacy of intra-arterial tirofiban infusion during endovascular reperfusion therapy in patients with acute cardiogenic cerebral embolism. Methods: Clinical data of 72 patients with acute cardiogenic cerebral embolism caused by large artery occlusion were retrospectively analyzed in Department of Neurology, Strategic Support Force Medical Center from August 2015 to August 2020.Among those, 52 patients were treated with intra-arterial tirofiban, the other 20 patients were treated with control medication. The baseline characteristics, modified thrombolysis in cerebral infarction (mTICI) score of responsible vessels, modified Rankin scale (mRS) score 90 days after operation, incidence of symptomatic intracranial hemorrhage and mortality were evaluated and compared in two groups. Results: The proportion of effective recanalization of the offending vessels (mTICI≥2b) in tirofiban group was higher than that in control group (92.3% vs. 75.0%), but the difference was not statistically significant (P=0.104). At 90 days after operation, the rate of patients with good prognosis (mRS≤2) in tirofiban group (61.5%) was significantly higher than that in control group (35.0%) (P<0.05). The incidence of symptomatic intracranial hemorrhage and mortality were comparable between the two groups (P>0.05). Conclusion: Intra-arterial tirofiban infusion in patients with acute cardiogenic cerebral embolism is effective and feasible, which improves the prognosis without increasing the risk of intracranial bleeding complications.

A systematic review of Vaccine Breakthrough Infections by SARS-CoV-2 Delta Variant

Vaccines are proving to be highly effective in controlling hospitalization and deaths associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, as shown by clinical trials and real-world evidence. However, a deadly second wave of coronavirus disease 2019 (COVID-19), infected by SARS-CoV-2 variants, especially the Delta (B.1.617.2) variant, with an increased number of post-vaccination breakthrough infections were reported in the world recently. Actually, Delta variant not only resulted in a severe surge of vaccine breakthrough infections which was accompanied with high viral load and transmissibility, but also challenged the development of effective vaccines. Therefore, the biological characteristics and epidemiological profile of Delta variant, the current status of Delta variant vaccine breakthrough infections and the mechanism of vaccine breakthrough infections were discussed in this article. In addition, the significant role of the Delta variant spike (S) protein in the mechanism of immune escape of SARS-CoV-2 was highlighted in this article. In particular, we further discussed key points on the future SARS-CoV-2 vaccine research and development, hoping to make a contribution to the early, accurate and rapid control of the COVID-19 epidemic.

Correlation of Four Single Nucleotide Polymorphisms of the RELN Gene With Schizophrenia

OBJECTIVE

This study aims to determine the association between single-nucleotide polymorphisms (SNPs) of the RELN gene and schizophrenia.

METHODS

134 patients aged 16 to 58 (mean, 38.0) years who were diagnosed with acute or chronic schizophrenia at the Zhongshan Third People's Hospital between January 2018 and April 2020 were recruited, as were 64 healthy controls aged 22 to 59 (mean, 45.6) years who matched with the age and sex of the patients. MassARRAY mass spectrometry genotyping technology was used to determine the genotypes of four SNPs of RELN (rs2073559, rs2229864, rs362691, and rs736707).

RESULTS

There were no significant between-group or between-sex differences in terms of genotype, allele frequency, or haplotype frequency of the SNPs (all p > 0.05). In the association analysis between genotypes and quantitative traits in the Positive and Negative Syndrome Scale, rs2229864 and rs736707 were associated with the scores for items P3 (hallucinatory behaviour) and G11 (attention disorder), and rs362691 was associated with G10 (disorientation). However, the associations did not remain significant after Bonferroni correction.

CONCLUSION

Multiple pathogenic polymorphisms of RELN might be associated with hallucinatory behaviour and attention disorder in Chinese patients with schizophrenia.

[Study on protective effect of dust mask for workers exposed to super absorbent polymer dust]

Objective: To analyze the protective effect of dust masks worn by super absorbent polymer (SAP) dust-exposed workers and the influence of each test exercise on the protective effect of mask. Methods: In March 2017, forty nine SAP dust-exposed workers in a large chemical enterprise were selected as subjects. The respirator fitness tester was used to test the protective effect of dust mask before and after training, and the influence of each test exercise on the protective effect of dust mask was analyzed. Results: After training, the qualified rate of dust mask protective effect of SAP dust-exposed workers was 95.92% (47/49) , which was significantly higher than that before training [63.31% (32/49) ], and the difference was statistically significant (χ²=14.69, P<0.01) . When the total protective effect was qualified, the fit factor (FF) decreased significantly when speaking aloud and bending down (Z=-2.59, -4.20, P<0.01) . The qualified rates of protective effect of each exercise were significantly different (χ²=42.70, P<0.01) , among which the qualified rates of deep breath was the highest (100.00%) , and the qualified rate of bending down was the lowest (70.21%) . Conclusion: Strengthening the training of workers to wear masks correctly is helpful to improve their respiratory protection efficiency. Under the condition that the total protective effect of dust masks is qualified, workers should try to avoid unnecessary actions, especially speaking aloud and bending down frequently.

[Clinical and molecular pathological features of uterine inflammatory myofibroblastic tumor]

Objective: To evaluate the clinical and molecular pathologic features of uterine inflammatory myofibroblastic tumor (UIMT). Methods: Six UIMT cases collected at Department of Pathology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University from 2019 to 2020. They were analyzed for their general characteristics and clinicopathologic features. ALK rearrangements were detected by fluorescence in situ hybridization. Results: The age of the six patients ranged from 14 to 65 years, the tumors ranged in size from 2.5 to 6.0 cm. The masses were intramural or submucosal in location. Most of them (4/6) were white with yellow foci, and two (2/6) were white with tan foci. Other features noted included a soft or firm appearance. The fasciitis-like pattern of UIMT had myxoid stroma around the spindle cells and inflammatory cells. The ganglion-like pattern showed either fascicular or storiform architecture with diffuse growth. Nuclear atypia was mild or moderate. Mitoses ranged from 2 to 4 per 10 high-power fields. Five tumors were ALK-positive with granular cytoplasmic staining by immunohistochemistry. ALK rearrangements were detected in five cases but was absent in one case. Conclusions: UIMT is an intermediate grade soft tissue tumor, a minority may present with extrauterine spread and/or recurrence. The tumors are composed of spindled cells. The main differentials include smooth muscle tumors and endometrial stromal tumors and their morphology may overlap with that of UIMT. Immunohistochemical positivity for ALK or FISH testing for ALK rearrangements can help in the diagnosis.

Transfemoral-venous transcatheter access to left ventricle through the created communication of inter-ventricular septum with the assistance of arterio-venous circuit

Background

During transcatheter aortic/mitral valve replacement (TA/MVR), current available routes are limited due to unfavorable entry-angle, vessel-anatomy or mini-thoracotomy. Through created communication of inter-ventricular septum (C-IVS), transfemoral venous transcatheter access to left ventricle becomes feasible with the assistance of arterio-venous circuit.

Purpose

The study was conducted to investigate the feasibility and safety of transfemoral-venous transcatheter access to left ventricle through the created C-IVS in a swine model.

Methods

Via femoral artery, transcatheter puncture of mid-IVS was performed with the custom-made nickel-titanium needle (0.038-inch, needle-tip bent 60 degrees automatically associated with increased hardness when temperature was above 30°C) and 6F-sheath in 20 healthy Chinese mini-swine. Then femoral arterio-venous circuit was established through created C-IVS with hydrophilic guidewire in all swine, and femoral veno-venous circuit was further created through C-IVS and atrial septum in 4 swine. After pre-dilation of C-IVS, a 20F-sheath was introduced into left ventricle transvenously over the guidewire. Furthermore, transfemoral-venous TAVR was attempted with this approach in one swine. C-IVS was evaluated postoperatively and was further confirmed pathologically 2 months later.

Results

All transcatheter puncture of IVS was performed successfully in left ventricle and the thickness of mid-IVS was 7.67±0.98 mm. During the puncture, ventricular fibrillation occurred in one swine (successfully defibrillation) and only isolated ventricular premature beats/non-sustained ventricular tachycardia were observed in other swine. In all swine, femoral arterio-venous/veno-venous circuit was established via C-IVS, and the 20F-sheath was introduced into left ventricle safely through femoral vein and C-IVS. With the aid of vessel circuit, the 20F-sheath was further advanced into aorta in 16 swine (the entry-angle was 145.3±12.2 degrees) and into left atrium in 4 swine. After the procedure, there was one swine with moderate tricuspid regurgitation and 5 swine with mild residual shunt (2.6±0.7 mm). In addition, epicardial coronary arteries were normal in all swine. Two months later, residual shunt was still detected in 3 swine and the communication was confirmed pathologically. In other swine, there was no defect of IVS and mild replacement-scar was identified along C-IVS. In the swine underwent transfemoral-venous TAVR, prosthetic valve was deployed successfully with good function.

Conclusions

With the aid of vessel circuit, transfemoral-venous transcatheter access to left ventricle is feasible and safe via C-IVS, and transfemoral-venous TAVR was achieved successfully using this novel approach with favorable entry-angle.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): National Natural Science Foundation of China

[The keypoints in treatment of the critical coronavirus disease 2019 patient(1)]

COVID-19 has been prevalent in Wuhan and spread rapidly to all of our country. Some cases can develop into ARDS, or even death. We will share the treatment experience of severe COVID-19 with the first-line treatment experience. The best respiratory support mode should be selected, but the timing of intubation and protection during intubation are two difficulties; patients with high level peep and poor effect in prone position can be given ECMO support. For COVID-19 patients with mechanical ventilation, reasonable sedation and analgesia strategies should be formulated; delirium should not be ignored. In addition, there is up regulation of inflammatory factors in patients with severe COVID-19, but the effect of renal replacement therapy needs to be further confirmed by clinical research.

Flagellar motility mediates early-stage biofilm formation in oligotrophic aquatic environment

Flagellar motility enables resource acquisition and noxious substance evasion, underpinning imperative ecological processes in aquatic environments. Yet the underlying mechanism that links flagellar motility with surface attachment and thereby biofilm formation, especially in conditions of limited resource availability, remains elusive. Here, we present experimental and modeling evidence to unveil bacterial motility and biofilm formation under nutrient-limited stresses with Pseudomonas aeruginosa (WT) and its nonflagellated isogenic mutant (ΔfliC) as model bacteria. Results revealed that boosted flagellar motility of WT strain promoted biofilm initialization to a peak value of 0.99 × 10⁷ cells/cm² at 1/50 dilution after 20 min incubation. We hypothesized that bacteria can invoke instant motility acceleration for survival confronting nutrient-limited stress, accompanied by optimized chemotactic foraging through sensing ambient chemical gradients. Accordingly, accelerated cell motility in oligotrophic environment created increased cell-cell and cell-surface interactions and thereof facilitated biofilm initialization. It was confirmed by the consistence of modeling predictions and experimental results of cell velocity and surface attachment. With the development of biofilm, promotion effect of flagellar motility responding to nutrient deprivation-stress faded out. Instead, loss of motility profiting increased growth rates and extracellular protein excretion, associated with an enhancement of biofilm development for the mutant in oligotrophic aquatic environment. For both strains, nutrient limitation evidently reduced planktonic cell propagation as expected. Our results offer new insights into the mechanical understanding of biofilm formation shaped by environmental stresses and associating biological responses.

[The keypoints in treatment of the critical coronavirus disease 2019 patient(2)]

The treatment of critically ill patients with coronavirus disease 2019(COVID-19) faces compelling challenges. In this issue, we'd like to share our first-line treatment experience in treating COVID-19. Hemodynamics need be closely monitored and different types of shock should be distinguished. Vasoconstrictor drugs should be used rationally and alerting of complications is of the same importance. The risk of venous thromboembolism (VTE) needs to be assessed, and effective prevention should be carried out for high-risk patients. It is necessary to consider the possibility of pulmonary thromboembolism (PTE) in patients with sudden onset of oxygenation deterioration, respiratory distress, reduced blood pressure. However, comprehensive analysis of disease state should be taken into the interpretation of abnormally elevated D-Dimer. Nutritional support is the basis of treatment. It's important to establish individual therapy regimens and to evaluate, monitor and adjust dynamically. Under the current epidemic situation, convalescent plasma can only be used empirically, indications need to be strictly screened, the blood transfusion process should be closely monitored and the curative effect should be dynamically evaluated.

Integrated sensing layer of bacterial cellulose and polyethyleneimine to achieve high sensitivity of ST-cut quartz surface acoustic wave formaldehyde gas sensor

Surface acoustic wave (SAW)-based formaldehyde gas sensor using bi-layer nanofilms of bacterial cellulose (BC) and polyethyleneimine (PEI) was developed on an ST-cut quartz substrate using sol-gel and spin coating processes. BC nanofilms significantly improve the sensitivity of PEI films to formaldehyde gas, and reduces response and recovery times. The BC films have superfine filamentary and fibrous network structures, which provide a large number of attachment sites for the PEI particles. Measurement results obtained using in situ diffuse reflectance Fourier transform infrared spectroscopy showed that the primary amino groups of PEI strongly adsorb formaldehyde molecules through nucleophilic reactions, thus resulting in a negative frequency shift of the SAW sensor due to the mass loading effect. In addition, experimental results showed that the frequency shifts of the SAW devices are determined by thickness of PEI film, concentration of formaldehyde and relative humidity. The PEI/BC sensor coated with three layers of PEI as the sensing layer showed the optimal sensing performance, which had a frequency shift of 35.6 kHz for 10 ppm formaldehyde gas, measured at room temperature and 30 % RH. The sensor also showed good selectivity and stability, with a low limit of detection down to 100 ppb.

Rapid and visual detection of 2019 novel coronavirus (SARS-CoV-2) by a reverse transcription loop-mediated isothermal amplification assay

OBJECTIVE

To evaluate a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and compare it with RT-PCR.

METHODS

We designed primers specific to the orf1ab and S genes of SARS-CoV-2. Total viral RNA was extracted using the QIAamp Viral RNA Mini Kit. We optimized the RT-LAMP assay, and evaluated it for its sensitivity and specificity of detection using real-time turbidity monitoring and visual observation.

RESULTS

The primer sets orf1ab-4 and S-123 amplified the genes in the shortest times, the mean (±SD) times were 18 ± 1.32 min and 20 ± 1.80 min, respectively, and 63°C was the optimum reaction temperature. The sensitivities were 2 × 10¹ copies and 2 × 10² copies per reaction with primer sets orf1ab-4 and S-123, respectively. This assay showed no cross-reactivity with 60 other respiratory pathogens. To describe the availability of this method in clinical diagnosis, we collected 130 specimens from patients with clinically suspected SARS-CoV-2 infection. Among them, 58 were confirmed to be positive and 72 were negative by RT-LAMP. The sensitivity was 100% (95% CI 92.3%-100%), specificity 100% (95% CI 93.7%-100%). This assay detected SARS-CoV-2 in a mean (±SD) time of 26.28 ± 4.48 min and the results can be identified with visual observation.

CONCLUSION

These results demonstrate that we developed a rapid, simple, specific and sensitive RT-LAMP assay for SARS-CoV-2 detection among clinical samples. It will be a powerful tool for SARS-CoV-2 identification, and for monitoring suspected patients, close contacts and high-risk groups.

[Pharmacotherapeutics for the new coronavirus pneumonia]

The new coronavirus pneumonia (NCP), also named as COVID-19 by WHO on Feb 11 2020, is now causing a severe public health emergency in China since. The number of diagnosed cases is more than 40,000 until the submission of this manuscript. Coronavirus has caused several epidemic situations world widely, but the present contagious disease caused by 2019 new coronavirus is unprecedentedly fulminating. The published cohorts of 2019 new coronavirus (n-Cov) are single-center studies, or retrospective studies. We here share the therapeutic experiences of NCP treatment with literature review. Combination of Ribavirin and interferon-α is recommended by the 5(th) edition National Health Commission's Regimen (Revised Edition) because of the effect on Middle East respiratory syndrome (MERS), and the effectiveness of Lopinavir/Ritonavir and Remdisivir needs to be confirmed by randomized controlled trial (RCT), given the situation of no specific antivirus drug on NCP is unavailable. Systemic glucocorticosteroid is recommended as a short term use (1~2 mg·kg(-1)·d(-1), 3~5 d) by the 5(th) edition National Health Commission's Regimen (Revised Edition) yet RCTs are expected to confirm the effectiveness. Inappropriate application of antibiotics should be avoided, especially the combination of broad-spectrum antibiotics, for the NCP is not often complicated with bacterial infection.

[Pharmacotherapeutics for the New Coronavirus Pneumonia]

The New Coronavirus Pneumonia (NCP, also named as COVID-19 by WHO on Feb 11 2020, is now causing a severe public health emergency in China since. The number of diagnosed cases is more than 40,000 until the submission of this manuscript. Coronavirus has caused several epidemic situations world widely, but the present contagious disease caused by 2019 new Coronavirus is unprecedentedly fulminating. The published cohorts of 2019 new Coronavirus (n-Cov) are single-center studies, or retrospective studies. We here share the therapeutic experiences of NCP treatment with literature review. Combination of Ribavirin and Interferon-α is recommended by the 5(th) edition National Health Commission's Regimen (Revised Edition) because of the effect on MERS (Middle East Respiratory Syndrome), and the effectiveness of Lopinavir/Ritonavir and Remdisivir needs to be confirmed by randomized controlled trial (RCT), given the situation of no specific antivirus drug on NCP is unavailable. Systemic glucocorticosteroid is recommended as a short term use (1~2 mg.kg(-1).d(-1), 3~5d ) by the 5(th) edition National Health Commission's Regimen (Revised Edition) yet RCTs are expected to confirm the effectiveness. Inappropriate application of antibiotics should be avoided, especially the combination of broad-spectrum antibiotics, for the NCP is not often complicated with bacterial infection.

Analysis of the Azimuth Ambiguity and Imaging Area Restriction for Circular SAR Based on the Back-Projection Algorithm

Circular synthetic aperture radar (CSAR) has a 360° observation capability on the central observation scenario. A typical way to process CSAR imaging is to cut data into small sub-apertures because most targets are only coherent at a very small observation angle. There are many sub-aperture imaging methods after development in recent years. The back-projection algorithm is widely used because it is simple and can be applied to an arbitrary trajectory. Because of the limitation of the Nyquist sampling frequency and influence of the antenna sidelobe, azimuth ambiguity is a phenomenon that may occur in the radar imaging process. The existing researches typically choose the back-projection (BP) imaging area according to the SAR platform flight path and the antenna beam width. The limitation of the CSAR imaging area and its azimuth ambiguity region are rarely analyzed theoretically. This paper focus on the sub-aperture imaging of CSAR, based on the BP algorithm, which derives the relationship of azimuth ambiguity with CSAR parameters such as the pause repeat frequency (PRF), slant range angle, velocity of radar platform, etc. This paper proposes an equation for the calculation of the azimuth ambiguity region and analyzes the limitations, which provides theoretical support for CSAR parameter design, imaging area selection, and azimuth ambiguity analysis.

Diagnostic accuracy of droplet digital PCR analysis of cerebrospinal fluid for tuberculous meningitis in adult patients

OBJECTIVES

Tuberculous meningitis (TBM) is difficult to diagnose. Digital PCR (dPCR) is a novel method which can quantify trace nucleic acids. This study sought to evaluate the diagnostic accuracy of dPCR analysis of cerebrospinal fluid (CSF) for TBM.

METHODS

We collected CSF specimens from hospitalized TBM and non-TBM patients. Total CSF DNA was purified and the concentrations of Mycobacterium tuberculosis insert sequence 6110 (IS6110) and gyrase subunit B (gyrB) were quantified using droplet dPCR. The receiver operating characteristic curves of dPCR were established and the diagnostic performances were obtained. We also compared the sensitivity of dPCR with routine diagnostic tests.

RESULTS

A total of 101 patients were recruited, 68 of whom suffered from TBM (26 definite, 34 probable and eight possible TBM) and 33 from non-TBM. The sensitivity of IS6110-dPCR assay for total TBM was higher than that of gyrB-dPCR assay (57.4% (44.8-69.3%) vs. 22.1% (12.9-33.8%)), and there was no significant difference for specificity between them (97.0% (84.2-99.9%) vs. 100% (89.4-100.0%)). The sensitivity of IS6110-dPCR in definite TBM was higher than that in probable and possible TBM (73.1% vs. 52.9% and 25.0%, respectively). IS6110-dPCR assay showed a higher sensitivity than smear microscopy (53.3% vs. 6.7%), mycobacterial culture (50.0% vs. 12.5%), IS6110-quantitative PCR (53.1% vs. 21.9%) and Xpert MTB/RIF (70.4% vs. 29.6%). Long anti-tuberculosis treatment time was found to be significantly associated with negative dPCR results.

CONCLUSION

CSF IS6110-dPCR assay is a rapid and sensitive molecular test, which has the potential to be used to enhance the diagnosis of TBM.