Inter-fraction Dynamics during Adaptive Hypofractionated Radiotherapy for Brain Metastases with a MR LINAC

PURPOSE/OBJECTIVE(S)

This study examined the displacement and deformation in brain metastases (BMs) during adaptive hypofractionated radiotherapy (HFRT) on a magnetic resonance imaging linear accelerator (MR LINAC). In addition, the contouring variability between enhanced T1 (T1+c) and T2/FLAIR (T2f) sequence to define gross tumor volume (GTV) was compared.

MATERIALS/METHODS

Patients with 1-3 BMs and treated with MR LINAC were enrolled. T1+c sequence was acquired at initial planning, while T2/T2f was acquired during each fraction. GTV at initial planning (GTVi) and fraction 1-n (GTV1-n) were contoured in all images. Dice similarity coefficient (DSC) was used to quantify the contouring variability between different sequences at initial planning. The three-dimensional coordinate values of geometric centers of GTVi and GTV1-n were recorded and the distance was calculated. Statistical analysis was performed using two-sided paired t-test.

RESULTS

Between December 2019 and October 2022, 19 patients with 22 BMs were analyzed. The median age was 64 y (37-84 y) and the major primary tumor was lung cancer (89.5%). The median dose was 52 Gy in 13 fractions (30 Gy/5f- 60 Gy/20 f). The median GTVi on T1c, T2f and T2 sequences were 6.70cc (0.41-84.85 cc), 6.70 cc (0.35-84.14 cc, p = 0.924) and 6.16 cc (0.32-79.44 cc, p = 0.117), respectively. The mean DSC was 0.95 (0.76-1.00) and 0.86 (0.64-0.97) when comparing GTVi on T1c/T2f and T1c/T2, respectively. All of the lesions achieved volume reduction during HFRT and the mean reduction rate was 28.8% (4.8%-71.0%) at the end of HFRT. 54.5% of the BMs were reduced by more than 20%. The median treatment course and BED to get 20% reduction was 2/3 (40%-93%) and 40.8 Gy (24.5-67.5 Gy), respectively. The median shift of center of GTV1-n was 0.8 mm (0-2.5mm). The center of 7 lesions (31.8%) deviated more than 1mm from GTVi.

CONCLUSION

GTV contouring variability was seen between T1c, T2f and T2 sequences. The coincidence of T1+c and T2f was better than T1+c and T2 in BMs. Since reductions in volume and changes of lesion center was observed during HFRT, the use of MR-guided radiation therapy (RT) and treatment adaptation is needed. The optimal timing for treatment plan modification might be when the course of treatment reaches 2/3 for most large BMs. Further research to find out patients who may benefit form MR-guided adaptive RT is ongoing.

Resource allocation of rural institutional elderly care in China's new era: spatial-temporal differences and adaptation development

OBJECTIVES

In the new era of China, to ensure that rural residents can get the corresponding institutional elderly services equally, it is necessary to investigate the current situation of resource allocation of rural institutional elderly care and make corresponding adaptation suggestions.

STUDY DESIGN

This research discusses the characteristics and evolution pattern of rural aging, the resource allocation of rural elderly care institutions, and the adaptation degree of rural institutional elderly care resource and aging.

METHODS

The research methodology consists of the following stages: entropy-based Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), kernel density estimation, coupling coordination, spatial autocorrelation, and Theil index decomposition.

RESULTS

The degree of aging in rural areas of China is rising, and the whole population has entered a moderate aging society, showing the spatial characteristics of 'high in the east and low in the west'. The resource allocation of rural institutional elderly care in China is at a low level, and the absolute differences among provinces tend to reduce over time, and the overall resource allocation level tends to decline. The provinces that were in the mismatched adaptation relationship in the early stage have improved; however, the number of provinces with mismatched adaptability has continued to increase. The local spatial autocorrelation of resource adaptation verifies that the middle and lower reaches of the Yangtze River as the core form a hot spot, and during the observation period, the spatial agglomeration effect of the core is strengthened. The Theil index decomposition of resource adaptation indicates that the within-group differences between the eastern and western regions is significantly higher than that between the northeastern and central regions.

CONCLUSIONS

First, special attention should be paid to preventing the resource allocation of rural institutional elderly care in the eastern and western regions from falling again. Second, to avoid more and more low-adapted provinces falling into the 'mismatch dilemma' with the deepening of the aging degree. Third, strengthen cooperation among regions and promote the coordinated development of resource allocation of institutional elderly care in various regions. Fourth, the priority of institutional elderly care balanced development should be given to the eastern region and western region, thus weakening the overall difference.

Chemoradiotherapy Combined with Nab-Paclitaxel plus Cisplatin in Patients with Locally Advanced Borderline Resectable or Unresectable Esophageal Squamous Cell Carcinoma: A Phase I/II Study

PURPOSE/OBJECTIVE(S)

To evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) plus cisplatin as the regimen of conversional chemoradiotherapy (cCRT) in locally advanced borderline resectable or unresectable esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Patients with locally advanced ESCC (cT3-4, Nany, M0-1, M1 was limited to lymph node metastasis in the supraclavicular area) were enrolled. All the patients received the cCRT of nab-PTX plus cisplatin. After the cCRT, those resectable patients received esophagectomy; those unresectable patients continued to receive the definitive chemoradiotherapy (dCRT). The locoregional control (LRC), overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), pathological complete response (pCR), R0 resection rate and adverse events (AEs) were calculated.

RESULTS

A total of 45 patients with ESCC treated from October 2019 to May 2021 were finally included. The median follow-up time was 30.3 months. The LRC, OS, EFS, DMFS at 1and 2 years were 81.5%, 86.6%, 64.3%, 73.2% and 72.4%, 68.8%, 44.8%, 52.7% respectively. 21 patients (46.7%) received conversional chemoradiotherapy plus surgery (cCRT+S). The pCR rate and R0 resection rate were 47.6% and 84.0%. The LRC rate at 1 and 2 years were 95.0%, 87.1% in cCRT+S patients and 69.3%, 58.7% in dCRT patients respectively (HR, 5.14; 95% CI, 1.10-23.94; P = 0.021). The OS rate at 1 and 2 years were 95.2% and 84.2% in resectable patients compared to 78.8% and 54.4% in unresectable patients (HR, 3.41; 95% CI, 1.10-10.61; P = 0.024). The toxicities during chemoradiotherapy were tolerated, the most common grade 3-4 toxicities were radiation esophagitis (15.6%).

CONCLUSION

Nab-PTX plus cisplatin were effective and safe as the regimen of conversional chemoradiotherapy of ESCC. The patients receiving conversional chemoradiotherapy plus surgery (cCRT+S) were prone to have a better survival.

Clinical Outcomes with Thoracic Radiotherapy for Extensive-Stage Small-Cell Lung Cancer in the Era of Immunotherapy: A Retrospective Analysis

PURPOSE/OBJECTIVE(S)

Chemo-immunotherapy has shown significant benefits for extensive-stage small-cell lung cancer (ES-SCLC), which prolonged overall survival (OS) of nearly 2-4.5 months compared with platinum-based chemotherapy alone. However, thoracic radiotherapy (TRT), was not allowed to be used in previous trials. This retrospective study aimed to evaluate the safety and efficiency of TRT for ES-SCLC patients in the era of Immunotherapy.

MATERIALS/METHODS

We retrospectively reviewed ES-SCLC patients treated with chemo-immunotherapy between 2017 and 2021 in our center. Patients who accepted consolidative or salvage TRT were included. The overall survival, progression-free survival (PFS), local progression-free survival (LPFS), and distant progression free-survival (DPFS) were calculated using the Kaplan-Meier method. Toxicity was recorded based on CTCAE 5.0 scale.

RESULTS

We finally enrolled 30 patients in our study. The median follow-up time was 26.0 months (95% confidence interval, 18.2-33.8 months). 26(86.7%) patients have undergone first-line chemotherapy and immunotherapy, while 4(13.3%) have undergone immunotherapy as a second-line agent. 23(76.6%) patients achieved CR/PR/SD to initial systematic therapy. All patients were treated with TRT with a median dose of 51 Gy (24-60.2 Gy). The median interval between TRT and immunotherapy was 35 days. Median OS was 26 months (95% confidence interval, 17.8-34.2 months) and median PFS was 8 months (95% confidence interval, 5.3-10.7 months). 2-year OS, PFS, and DPFS were 51.4%, 21.4%, and 27.4%, respectively. 18 months LPFS was 59.6%. There was no ≥ G3 radiation-related adverse event except 2(6.7%) G3 esophagitis. G1-2 pneumonitis was reported in 8(26.7%) patients.

CONCLUSION

TRT is well-tolerated and effective for selected ES-SCLC patients in the modern era of immunotherapy. Prospective trials are still needed to further evaluate the combination of TRT and immunotherapy for patients with ES-SCLC.

Multiview Deep Graph Infomax to Achieve Unsupervised Graph Embedding

Unsupervised graph embedding aims to extract highly discriminative node representations that facilitate the subsequent analysis. Converging evidence shows that a multiview graph provides a more comprehensive relationship between nodes than a single-view graph to capture the intrinsic topology. However, little attention has been paid to excavating discriminative representations of each node from multiview heterogeneous networks in an unsupervised manner. To that end, we propose a novel unsupervised multiview graph embedding method, called multiview deep graph infomax (MVDGI). The backbone of our proposed model sought to maximize the mutual information between the view-dependent node representations and the fused unified representation via contrastive learning. Specifically, the MVDGI first uses an encoder to extract view-dependent node representations from each single-view graph. Next, an aggregator is applied to fuse the view-dependent node representations into the view-independent node representations. Finally, a discriminator is adopted to extract highly discriminative representations via contrastive learning. Extensive experiments demonstrate that the MVDGI achieves better performance than the benchmark methods on five real-world datasets, indicating that the obtained node representations by our proposed approach are more discriminative than by its competitors for classification and clustering tasks.

The KRAS-Variant and Cetuximab in HPV-Positive Oropharyngeal Cancer in NRG/RTOG 1016

PURPOSE/OBJECTIVE(S)

NRG/RTOG 1016 was a non-inferiority phase III trial comparing radiation with cisplatin versus cetuximab monotherapy for patients with HPV-positive oropharyngeal squamous cell carcinoma (SCC). The trial did not meet the non-inferiority criteria for overall survival (OS) and had significantly worse progression-free survival (PFS) and locoregional failure (LRF) in patients treated with cetuximab. Based on prior evidence that HNSCC patients with a germ-line mutation in KRAS (the KRAS-variant) had a positive response to radiation with cisplatin plus cetuximab without increased toxicity, samples from RTOG 1016 were used to test the protocol-specified hypothesis that KRAS-variant patients will have better outcomes when receiving IMRT + cetuximab monotherapy compared to IMRT + cisplatin.

MATERIALS/METHODS

The KRAS-variant was tested in 562 samples at MiraDx, a CLIA-certified laboratory. OS, PFS, LRF, and distant metastases (DM) were as defined per the RTOG 1016 protocol, and hazard ratios (HRs) were estimated by (cause-specific) Cox models. Negative binomial regression was used to model the number of treatment-related acute and late (≤ and > 180 days from end of treatment, respectively) grade 3-5 adverse events. To assess the predictive role of the KRAS-variant, all models included KRAS, assigned treatment, and their interaction, with the interaction tested at two-sided 0.05. HRs and toxicity ratios are expressed as IMRT + cetuximab / IMRT + cisplatin.

RESULTS

The prevalence of the KRAS-variant was 16% with similar patient and tumor characteristics and well-balanced treatment arms for variant and non-variant patients. Median follow-up was 8.6 years. There was no significant interaction between KRAS and treatment for OS (p = 0.99), PFS (p = 0.56), LRF (p = 0.09), or DM (p = 0.19) (Table 1). In KRAS-variant patients the mean acute and late toxicity ratios were 0.53 (95% CI 0.36, 0.80) and 1.62 (95% CI 0.57, 4.62). In non-variant patients, the mean acute and late toxicity ratios were 0.80 (95% CI 0.67, 0.95) and 0.55 (95% CI 0.35, 0.87), respectively. The interaction of KRAS and treatment was not significant for acute (p = 0.07) or late toxicity (p = 0.07).

CONCLUSION

While this study does not directly refute prior evidence that KRAS-variant patients benefit from radiation + cisplatin and cetuximab, this study does not support the hypothesis that the KRAS-variant is a predictive biomarker of improved outcome in HPV+ oropharyngeal SCC patients treated with IMRT + cetuximab alone, and suggests that for KRAS-variant patients, potential benefits in LRF and acute toxicity with cetuximab may be offset by worse DM and worse late toxicity.

Retrospective study of preservation and transection of the round ligament of uterus during laparoscopic transabdominal preperitoneal inguinal hernia repair in adult women

PURPOSE

The processing of the round ligament of uterus in laparoscopic transabdominal preperitoneal (TAPP) repair of inguinal hernia in women has contended. This study aimed to explore whether there is any difference in the surgical outcome and postoperative complications between the two processing modalities, preservation, and transection of the round ligament of uterus, in adult female inguinal hernia patients undergoing TAPP.

METHODS

Retrospective analysis of 84 female patients (117 sides) who underwent TAPP in XXX Hospital from July 2013 to August 2022. Patient characteristics and technical details of the surgical procedure were collected and divided into two groups according to whether the round ligament of uterus was severed intraoperatively or not. There were 52 cases (77 sides) in the group with preservation of the round ligament of uterus and 32 cases (40 sides) in the group with transection of the round ligament of uterus, comparing the general condition, surgical condition, and the occurrence of postoperative related complications between the 2 groups.

RESULTS

The operative time for unilateral primary inguinal hernia was (129.2 ± 35.1) and (89.5 ± 42.6) minutes in the preservation and transection groups, respectively. There were no statistical differences between the two groups in terms of age, length of hospital stay, ASA, BMI, history of lower abdominal surgery, type and side of hernia, intraoperative bleeding, and time to surgery for primary bilateral hernia (P > 0.05). In addition, there was likewise no statistical difference in the occurrence of postoperative Clavien-Dindo classification, VAS, seroma, mesh infection, labia majora edema, chronic pain or abnormal sensation in the inguinal region, and hernia recurrence in the two groups as well (P > 0.05).

CONCLUSION

There is no evidence that the transection of the round ligament of the uterus during TAPP has an impact on postoperative complications in patients. However, given the important role of the uterine round ligament in the surgical management of patients with uterine prolapse and the high incidence of uterine prolapse in older women, hernia surgeons should also be aware of the need to protect the round ligament of uterus in older women.

[Development and application of a rapid scheme for detection of respiratory virus nucleic acid]

This study aimed to develop a portable, accurate and easy-to-operate scheme for rapid detection of respiratory virus nucleic acid. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the effect of extraction-free respiratory virus treatment reagent (RTU) on viral nucleic acid treatment and the effect of ultra-fast fluorescence quantitative PCR instrument (FQ-8A) on nucleic acid amplification, respectively. RTU and FQ-8A were combined to develop a rapid detection scheme for respiratory virus nucleic acid, and the positive detection rate was judged by Ct value using a fluorescence quantitative PCR instrument, and the accuracy of the scheme in clinical samples detection was investigated. The results showed that RTU had comparable sensitivity to the automatic nucleic acid extraction instrument, its extraction efficiency was comparable to the other 3 extraction methods when extracting samples of different virus types, but the extraction time of RTU was less than 5 min. FQ-8A had good consistency in detection respiratory syncytial virus (RSV) and adenovirus (ADV) compared with the control instrument ABI-7500, with kappa coefficients of 0.938 (P < 0.001) and 0.887 (P < 0.001), respectively, but the amplification time was only about 0.5 h. The RTU and FQ-8A combined rapid detection scheme had a highly consistent detection rate with the conventional detection scheme, with a sensitivity of 91.70% and specificity of 100%, and a kappa coefficient was 0.944 (P < 0.001). In conclusion, by combining RTU with FQ-8A, a rapid respiratory virus nucleic acid detection scheme was developed, the whole process could be completed in 35 min. The scheme is accurate and easy-to-operate, and can provide important support for the rapid diagnosis and treatment of respiratory virus.

[Genetic analysis of a family with hereditary hemorrhagic telangiectasia caused by endoglin gene mutation]

Objective: To explore the genetic characteristics of a family with hereditary hemorrhagic telangiectasia (HHT) caused by endoglin (ENG) gene mutations. Methods: A total of 17 individuals from a 3-generation HHT family attending the First Affiliated Hospital of Dali University were selected as the research subjects. Clinical data and familial disease status of the HHT family proband were collected. Whole exome sequencing technology was used to screen for suspected pathogenic genes in the proband, and Sanger sequencing was used for family validation. Results: The proband and her mother had recurrent epistaxis and skin mucosal telangiectasia, and enhanced CT scans of the chest of the proband and her mother, daughter, and cousin indicated the presence of varying degrees of pulmonary arteriovenous malformations. The results of the full exon sequencing results showed that the proband carried the ENG gene c.579_599del non-shift deletion mutation, and Sanger sequencing showed that the mother, daughter, and cousin carried the same mutation. Conclusion: ENG gene c.579_ 599del mutation may be the genetic basis of HHT in this family.

Hypoxic erythrocytes mediate cardioprotection through activation of soluble guanylate cyclase and release of cyclic GMP

Red blood cells (RBCs) mediate cardioprotection via nitric oxide-like bioactivity, but the signaling and the identity of any mediator released by the RBCs remains unknown. We investigated whether RBCs exposed to hypoxia release a cardioprotective mediator and explored the nature of this mediator. Perfusion of isolated hearts subjected to ischemia-reperfusion with extracellular supernatant from mouse RBCs exposed to hypoxia resulted in improved postischemic cardiac function and reduced infarct size. Hypoxia increased extracellular export of cyclic guanosine monophosphate (cGMP) from mouse RBCs, and exogenous cGMP mimicked the cardioprotection induced by the supernatant. The protection induced by hypoxic RBCs was dependent on RBC-soluble guanylate cyclase and cGMP transport and was sensitive to phosphodiesterase 5 and activated cardiomyocyte protein kinase G. Oral administration of nitrate to mice to increase nitric oxide bioactivity further enhanced the cardioprotective effect of hypoxic RBCs. In a placebo-controlled clinical trial, a clear cardioprotective, soluble guanylate cyclase-dependent effect was induced by RBCs collected from patients randomized to 5 weeks nitrate-rich diet. It is concluded that RBCs generate and export cGMP as a response to hypoxia, mediating cardioprotection via a paracrine effect. This effect can be further augmented by a simple dietary intervention, suggesting preventive and therapeutic opportunities in ischemic heart disease.

ViWrap: A modular pipeline to identify, bin, classify, and predict viral-host relationships for viruses from metagenomes

Viruses are increasingly being recognized as important components of human and environmental microbiomes. However, viruses in microbiomes remain difficult to study because of the difficulty in culturing them and the lack of sufficient model systems. As a result, computational methods for identifying and analyzing uncultivated viral genomes from metagenomes have attracted significant attention. Such bioinformatics approaches facilitate the screening of viruses from enormous sequencing datasets originating from various environments. Though many tools and databases have been developed for advancing the study of viruses from metagenomes, there is a lack of integrated tools enabling a comprehensive workflow and analyses platform encompassing all the diverse segments of virus studies. Here, we developed ViWrap, a modular pipeline written in Python. ViWrap combines the power of multiple tools into a single platform to enable various steps of virus analysis, including identification, annotation, genome binning, species- and genus-level clustering, assignment of taxonomy, prediction of hosts, characterization of genome quality, comprehensive summaries, and intuitive visualization of results. Overall, ViWrap enables a standardized and reproducible pipeline for both extensive and stringent characterization of viruses from metagenomes, viromes, and microbial genomes. Our approach has flexibility in using various options for diverse applications and scenarios, and its modular structure can be easily amended with additional functions as necessary. ViWrap is designed to be easily and widely used to study viruses in human and environmental systems. ViWrap is publicly available via GitHub (https://github.com/AnantharamanLab/ViWrap). A detailed description of the software, its usage, and interpretation of results can be found on the website.

Bevacizumab biosimilar candidate TAB008 compared to Avastin® in patients with locally advanced, metastatic EGFR wild-type non-squamous non-small cell lung cancer: a randomized, double-blind, multicenter study

BACKGROUND

Bevacizumab (Avastin®) is a monoclonal antibody targeting the vascular endothelial growth factor (VEGF). Used alone or in combination with chemotherapy and/or immunotherapy, Avastin® has shown promising efficacy in many cancers. This study compared the efficacy and safety of TAB008 with Avastin® sourced from the EU (bevacizumab-EU), in patients with non-squamous non-small cell lung cancer (nsNSCLC).

METHOD

In this randomized, double-blind, multicenter, phase III similarity study, treatment naïve for metastatic lung cancer., EGFR wild-type, locally advanced, metastatic, or recurrent non-squamous, non-small cell, lung cancer (nsNSCLC) patients were enrolled and randomized (1:1) into TAB008 or Avastin® groups. Patients received TAB008 or Avastin® 15 mg/kg intravenously plus paclitaxel/carboplatin for 4-6 cycles followed by TAB008 or Avastin® 7.5 mg/kg until disease progression, unacceptable toxicity or death. The primary endpoint compared the objective response rate (ORR) within 6 cycles as read by an independent radiological review committee (IRRC). Secondary endpoints compared disease control rate (DCR) Within 6 cycles, duration of response (DoR), progression-free survival (PFS), a year overall survival rate (OSR), overall survival (OS), safety, immunogenicity, and steady-state pharmacokinetics.

RESULTS

A total of 549 nsNSCLC patients were enrolled (277 in TAB008 group and 272 in Avastin® group). In the full analysis set, ORRs were 55.957% for TAB008 and 55.720% for Avastin®, and the ORR ratio was 1 (90% CI 0.89-1.14), well within the predefined equivalence margin of 0.75-1.33. No significant differences were found in DCR within 6 cycles (95.703% vs 95.367%, p = 0.8536), DoR (8.17 vs 7.3 months, p = 0.3526), PFS (9.10 vs. 7.97 months, p = 0.9457), 1 year overall survival rate (66.2% vs 68%, p = 0.6793), or OS (20.4 vs 17.6 months, p = 0.6549). Serious adverse events (SAEs) occurred in 37.55% (104/277) of patients in the TAB008 group and 34.32% (93/271) in the Avastin® group. Anti-drug antibodies were reported in 3 of 277 (1.08%) TAB008 patients, and 5 of 271 (1.85%) Avastin® patients, neutralizing antibody (Nab) was positive in 1 patient on Avastin®, which became negative upon follow-up. The steady-state trough concentrations (Cssmin) were 106.13 μg/mL in TAB008 group and 96.03 μg/mL in Avastin® groups, with the treatment group ratio of LS geometric means fully contained within the bioequivalence limits of 80.00-125.00% (90% CI was 101.74-120.05%).

CONCLUSIONS

TAB008 is similar to Avastin® in terms of efficacy, safety, and pharmacokinetic parameters, with comparable immunogenicity.

TRIAL REGISTRATION

ClinicalTrials.gov number; NCT05427305.

Stimulation of Erythrocyte Soluble Guanylyl Cyclase Induces cGMP Export and Cardioprotection in Type 2 Diabetes

Reduced nitric oxide (NO) bioactivity in red blood cells (RBCs) is critical for augmented myocardial ischemia-reperfusion injury in type 2 diabetes. This study identified the nature of "NO bioactivity" by stimulating the intracellular NO receptor soluble guanylyl cyclase (sGC) in RBCs. sGC stimulation in RBCs from patients with type 2 diabetes increased export of cyclic guanosine monophosphate from RBCs and activated cardiac protein kinase G, thereby attenuating ischemia-reperfusion injury. These results provide novel insight into RBC signaling by identifying cyclic guanosine monophosphate from RBC as a mediator of protection against cardiac ischemia-reperfusion injury induced by sGC stimulation in RBCs.

[Pulmonary vein stenosis with pulmonary infarction secondary to primary mediastinal seminoma: a case report]

Pulmonary vein stenosis is a rare condition that is often underdiagnosed and misdiagnosed. The clinical and radiologic manifestations are unspecific such as cough, hemoptysis and pulmonary lesions and are therefore difficult to distinguished with pneumonia and tuberculosis. The present study is a successful case report of pulmonary vein stenosis and pulmonary infraction secondary to mediastinal seminoma. This case suggested that pulmonary vein stenosis should be considered when a mediastinal mass is accompanied by pulmonary opacites that cannot be explained by common causes such as infection.

Identification of conserved linear epitopes in the SARS-CoV-2 receptor-binding region using monoclonal antibodies

The ongoing coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused millions of cases of infections, leading to a global health emergency. The SARS-CoV-2 spike (S) protein plays the most important role in viral infection, and S1 subunit and its receptor-binding domain (RBD) are widely considered the most attractive vaccine targets. The RBD is highly immunogenic and its linear epitopes are important for vaccine development and therapy, but linear epitopes on the RBD have rarely been reported. In this study, 151 mouse monoclonal antibodies (mAbs) against the SARS-CoV-2 S1 protein were characterized and used to identify epitopes. Fifty-one mAbs reacted with eukaryotic SARS-CoV-2 RBD. Sixty-nine mAbs reacted with the S proteins of Omicron variants B.1.1.529 and BA.5, indicating their potential as rapid diagnostic materials. Three novel linear epitopes of RBD, R6 (³⁹¹CFTNVYADSFVIRGD⁴⁰⁵), R12 (⁴⁶³PFERDISTEIYQAGS⁴⁷⁷), and R16 (⁵¹⁰VVVLSFELLHAPAT⁵²³), were identified; these were highly conserved in SARS-CoV-2 variants of concern and could be detected in the convalescent serum of COVID-19 patients. From pseudovirus neutralization assays, some mAbs including one detecting R12 were found to possess neutralizing activity. Together, from the reaction of mAbs with eukaryotic RBD (N501Y), RBD (E484K), and S1 (D614G), we found that a single amino acid mutation in the SARS-CoV-2 S protein may cause a structural alteration, exerting substantial impact on mAb recognition. Our results could, therefore, help us better understand the function of the SARS-CoV-2 S protein and develop diagnostic tools for COVID-19.

[Activation of GABAergic neurons in the zona incerta accelerates anesthesia induction with sevoflurane and propofol without affecting anesthesia maintenance or awakening in mice]

OBJECTIVE

To explore the regulatory effects of GABAergic neurons in the zona incerta (ZI) on sevoflurane and propofol anesthesia.

METHODS

Forty-eight male C57BL/6J mice divided into 8 groups (n=6) were used in this study. In the study of sevoflurane anesthesia, chemogenetic experiment was performed in 2 groups of mice with injection of either adeno-associated virus carrying hM3Dq (hM3Dq group) or a virus carrying only mCherry (mCherry group). The optogenetic experiment was performed in another two groups of mice injected with an adeno-associated virus carrying ChR2 (ChR2 group) or GFP only (GFP group). The same experiments were also performed in mice for studying propofol anesthesia. Chemogenetics or optogenetics were used to induce the activation of GABAergic neurons in the ZI, and their regulatory effects on anesthesia induction and arousal with sevoflurane and propofol were observed; EEG monitoring was used to observe the changes in sevoflurane anesthesia maintenance after activation of the GABAergic neurons.

RESULTS

In sevoflurane anesthesia, the induction time of anesthesia was significantly shorter in hM3Dq group than in mCherry group (P < 0.05), and also shorter in ChR2 group than in GFP group (P < 0.01), but no significant difference was found in the awakening time between the two groups in either chemogenetic or optogenetic tests. Similar results were observed in chemogenetic and optogenetic experiments with propofol (P < 0.05 or 0.01). Photogenetic activation of the GABAergic neurons in the ZI did not cause significant changes in EEG spectrum during sevoflurane anesthesia maintenance.

CONCLUSION

Activation of the GABAergic neurons in the ZI promotes anesthesia induction of sevoflurane and propofol but does not affect anesthesia maintenance or awakening.

[A region-level contrastive learning-based deep model for glomerular ultrastructure segmentation on electron microscope images]

OBJECTIVE

We propose a novel region- level self-supervised contrastive learning method USRegCon (ultrastructural region contrast) based on the semantic similarity of ultrastructures to improve the performance of the model for glomerular ultrastructure segmentation on electron microscope images.

METHODS

USRegCon used a large amount of unlabeled data for pre- training of the model in 3 steps: (1) The model encoded and decoded the ultrastructural information in the image and adaptively divided the image into multiple regions based on the semantic similarity of the ultrastructures; (2) Based on the divided regions, the first-order grayscale region representations and deep semantic region representations of each region were extracted by region pooling operation; (3) For the first-order grayscale region representations, a grayscale loss function was proposed to minimize the grayscale difference within regions and maximize the difference between regions. For deep semantic region representations, a semantic loss function was introduced to maximize the similarity of positive region pairs and the difference of negative region pairs in the representation space. These two loss functions were jointly used for pre-training of the model.

RESULTS

In the segmentation task for 3 ultrastructures of the glomerular filtration barrier based on the private dataset GlomEM, USRegCon achieved promising segmentation results for basement membrane, endothelial cells, and podocytes, with Dice coefficients of (85.69 ± 0.13)%, (74.59 ± 0.13)%, and (78.57 ± 0.16)%, respectively, demonstrating a good performance of the model superior to many existing image-level, pixel-level, and region-level self-supervised contrastive learning methods and close to the fully- supervised pre-training method based on the large- scale labeled dataset ImageNet.

CONCLUSION

USRegCon facilitates the model to learn beneficial region representations from large amounts of unlabeled data to overcome the scarcity of labeled data and improves the deep model performance for glomerular ultrastructure recognition and boundary segmentation.

Upscaling dispersivity for conservative solute transport in naturally fractured media

Physical heterogeneities are prevalent features of fracture systems and significantly impact transport processes in aquifers across different spatiotemporal scales. Upscaling solute transport parameter is an effective way of quantifying parameter variability in heterogeneous aquifers including fractured media. This paper develops conceptual models for upscaling conservative transport parameters in fracture media. The focus is on upscaling dispersivity. Lagrangian-based transport model (LBTM) for dispersivity upscaling are derived for the solute transport in two-dimensional fractures surrounded by an impermeable matrix. The LBTM is validated against the random walk particle tracking (RWPT) model, which enables highly efficient and accurate predictions of conservative solute transport. The results show that the derived scale-dependent analytical expressions are in excellent agreement with RWPT model results. In addition, LBTM results are also compared to experimental results from the observed breakthrough curve of a conservative solute transport through a single natural fracture within a granite core. Comparing results from the LBTM and transport experiment shows that LBTM based estimated dispersivity is 10.55% higher than the measured value. Errors introduced by the experiments, the conceptual assumptions in deriving models, and the heterogeneities of fracture apertures not fully sampled by measuring instruments are main factor for such discrepancy. The sensitivity analysis indicates that the longitudinal and transverse dispersivities are positively related to the integral scale and the variance of the log-fracture aperture. The longitudinal dispersivity is strongly contolled by the variance of the log-fracture aperture. The LBTM may be useful for directly predicting solute transports, requiring only the acquisition of fractured geostatistical data. This work provides a better understanding of transport processes in fractured media which ultimately control water quality across scales.

Sulfur cycling connects microbiomes and biogeochemistry in deep-sea hydrothermal plumes

In globally distributed deep-sea hydrothermal vent plumes, microbiomes are shaped by the redox energy landscapes created by reduced hydrothermal vent fluids mixing with oxidized seawater. Plumes can disperse over thousands of kilometers and their characteristics are determined by geochemical sources from vents, e.g., hydrothermal inputs, nutrients, and trace metals. However, the impacts of plume biogeochemistry on the oceans are poorly constrained due to a lack of integrated understanding of microbiomes, population genetics, and geochemistry. Here, we use microbial genomes to understand links between biogeography, evolution, and metabolic connectivity, and elucidate their impacts on biogeochemical cycling in the deep sea. Using data from 36 diverse plume samples from seven ocean basins, we show that sulfur metabolism defines the core microbiome of plumes and drives metabolic connectivity in the microbial community. Sulfur-dominated geochemistry influences energy landscapes and promotes microbial growth, while other energy sources influence local energy landscapes. We further demonstrated the consistency of links among geochemistry, function, and taxonomy. Amongst all microbial metabolisms, sulfur transformations had the highest MW-score, a measure of metabolic connectivity in microbial communities. Additionally, plume microbial populations have low diversity, short migration history, and gene-specific sweep patterns after migrating from background seawater. Selected functions include nutrient uptake, aerobic oxidation, sulfur oxidation for higher energy yields, and stress responses for adaptation. Our findings provide the ecological and evolutionary bases of change in sulfur-driven microbial communities and their population genetics in adaptation to changing geochemical gradients in the oceans.

Metagenome-based metabolic modelling predicts unique microbial interactions in deep-sea hydrothermal plume microbiomes

Deep-sea hydrothermal vents are abundant on the ocean floor and play important roles in ocean biogeochemistry. In vent ecosystems such as hydrothermal plumes, microorganisms rely on reduced chemicals and gases in hydrothermal fluids to fuel primary production and form diverse and complex microbial communities. However, microbial interactions that drive these complex microbiomes remain poorly understood. Here, we use microbiomes from the Guaymas Basin hydrothermal system in the Pacific Ocean to shed more light on the key species in these communities and their interactions. We built metabolic models from metagenomically assembled genomes (MAGs) and infer possible metabolic exchanges and horizontal gene transfer (HGT) events within the community. We highlight possible archaea-archaea and archaea-bacteria interactions and their contributions to the robustness of the community. Cellobiose, D-Mannose 1-phosphate, O2, CO2, and H2S were among the most exchanged metabolites. These interactions enhanced the metabolic capabilities of the community by exchange of metabolites that cannot be produced by any other community member. Archaea from the DPANN group stood out as key microbes, benefiting significantly as acceptors in the community. Overall, our study provides key insights into the microbial interactions that drive community structure and organisation in complex hydrothermal plume microbiomes.

[Analysis of the pathogenesis and risk factors of gallstone]

Objective: To explore the pathogenesis and risk factors of gallstone formation. Methods: The findings of hepatobiliary ultrasound and related data were collected from healthy subjects who underwent a physical examination at Xuanwu Hospital of Capital Medical University from January 2012 to December 2021. A total of 98 344 healthy subjects were included in the study,including 48 241 males and 50 103 females,with a ratio of 1∶1.03,aged (42.0±15.6)years(range:14 to 97 years). The gender,age,body mass index,waist circumference,systolic pressure,diastolic pressure,ALT,AST,total bilirubin,fasting blood glucose,triglyceride,total cholesterol,low-density lipoprotein,high-density lipoprotein were collected.Healthy subjects were required to sit for at least 10 minutes before blood pressure was measured.Rresults of fasting venous blood were collected after 8 to 12 hours on an empty stomach.According to the presence of gallstones by ultrasound results, healthy subjects were divided into study group and control group. Data were analyzed by rank-sum tests and χ² test, and risk factors for gallstone formation were explored by Logistic regression analysis. Results: The incidence of gallstones in this group was 5.42%(5 333/98 344). Among them,the incidence of gallstones in people aged 60 years and above was significantly higher than that in people under 60 years old(15.31%(2 348/15 334) vs. 3.60%(2 985/83 010), χ²=3 473.46,P<0.05).The healthy subjects were divided by age for every 10 years,and the results showed that the incidence of gallstones increased with age. The incidence of gallstones in females was 5.68%(2 844/50 103),greater than 5.16%(2 489/48 241) in males(χ²=11.81,P<0.05). Among them,1 478 cases underwent gallbladder surgical resection due to gallstones,and the operation rate was 27.71%. The operation rate reached the peak between 60 and <70 years old,and decreased after 70 years old. The results of the multivariate analysis showed that,female(OR=1.38, P<0.01),age(OR=1.58, P<0.01),body mass index≥24 kg/m²(OR=1.31, P<0.01),waist circumference≥85 cm(OR=1.24, P<0.01),fasting blood glucose>6.1 mmol/L(OR=1.18,P<0.01),total cholesterol≥5.18 mmol/L(OR=0.87, P=0.019),low-density lipoprotein≥3.37 mmol/L(OR=1.15,P=0.001) were the risk factors for gallstone formation;high-density lipoprotein≥1.55 mmol/L(OR=0.87, P<0.01) was a protective factor for gallstone formation. Conclusions: The incidence of gallstones increases with age in male and female. Gender,age,body mass index,waist circumferenc,fasting blood glucose,total cholesterol,LDL,and HDL are related factors with gallstone formation.

The long noncoding RNA THBS1-AS1 promotes cardiac fibroblast activation in cardiac fibrosis by regulating TGFBR1

Cardiac fibrosis is associated with an adverse prognosis in cardiovascular disease that results in a decreased cardiac compliance and, ultimately, heart failure. Recent studies have identified the role of long noncoding RNA (lncRNA) in cardiac fibrosis. However, the functions of many lncRNAs in cardiac fibrosis remain to be characterized. Through a whole-transcriptome sequencing and bioinformatics analysis on a mouse model of pressure overload-induced cardiac fibrosis, we screened a key lncRNA termed thrombospondin 1 antisense 1 (THBS1-AS1), which was positively associated with cardiac fibrosis. In vitro functional studies demonstrated that the silencing of THBS1-AS1 ameliorated TGF-β1 effects on cardiac fibroblast (CF) activation, and the overexpression of THBS1-AS1 displayed the opposite effect. A mechanistic study revealed that THBS1-AS1 could sponge miR-221/222 to regulate the expression of TGFBR1. Moreover, under TGF-β1 stimulation, the forced expression of miR-221/222 or the knockdown TGFBR1 significantly reversed the THBS1-AS1 overexpression induced by further CF activation. In vivo, specific knockdown of THBS1-AS1 in activated CFs significantly alleviated transverse aorta constriction-induced (TAC-induced) cardiac fibrosis in mice. Finally, we demonstrated that the human THBS1-AS1 can also affect the activation of CFs by regulating TGFBR1. In conclusion, this study reveals that lncRNA THBS1-AS1 is a potentially novel regulator of cardiac fibrosis and may serve as a target for the treatment of cardiac fibrosis.

Erythrocyte-Derived microRNAs: Emerging Players in Cardiovascular and Metabolic Disease

Recent studies have demonstrated a novel function of red blood cells (RBCs) beyond their classical role as gas transporters, that is, RBCs undergo functional alterations in cardiovascular and metabolic disease, and RBC dysfunction is associated with hypertension and the development of cardiovascular injury in type 2 diabetes, heart failure, preeclampsia, familial hypercholesterolemia/dyslipidemia, and COVID-19. The underlying mechanisms include decreased nitric oxide bioavailability, increased arginase activity, and reactive oxygen species formation. Of interest, RBCs contain diverse and abundant micro (mi)RNAs. microRNA expression pattern in RBCs reflects the expression in the whole blood, serum, and plasma. microRNA levels in RBCs have been found to be altered in various cardiovascular and metabolic diseases, which contributes to the development of cardiovascular complications. Evidence has shown that RBC-derived miRNAs interact with the cardiovascular system via extracellular vesicles and argonaute RISC catalytic component 2 as carriers. Alteration of RBC-to-vascular communication via miRNAs may serve as potential disease mechanism for vascular complications. The present review summarizes RBCs and their released miRNAs as potential mediators of cardiovascular injury. We further focus on the possible mechanisms by which RBC-derived miRNAs regulate cardiovascular function. A better understanding of the function of RBC-derived miRNAs will increase insights into the disease mechanism and potential targets for the treatment of cardiovascular complications.

The Effect of Sodium Bentonite in the Thermo-Catalytic Reduction of Viscosity of Heavy Oils

To study the synergistic catalysis of an ex situ catalyst and in situ clay in the aquathermolysis of heavy oil, in this paper, a series of bentonite-supported catechol-metal complexes were prepared, and the catalytic viscosity reduction performance in the aquathermolysis of heavy oil was investigated. Under the optimized conditions, the viscosity can be reduced by 73%, and the pour point can be lowered by 15.0 °C at most, showing the synergistic catalysis of the ex situ catalyst and in situ clay in this aquathermolytic reaction. Thermogravimetry, physical adsorption-desorption, and scanning electron microscopy were conducted to characterize the thermal stability and microstructure of the ex situ catalyst. The components of the heavy oil before and after the reaction were fully characterized. Six model compounds were used to simulate the aquathermolysis reaction process. In order to study the mechanism of viscosity reduction after the catalytic aquathermolysis reaction, the compounds were analyzed by GC-MS. It is believed that these results will be beneficial in the future for related research in this field.