Optimization of the Prodrug Moiety of Remdesivir to Improve Lung Exposure/Selectivity and Enhance Anti-SARS-CoV-2 Activity

COVID-19 patients with severe symptoms still lack antiviral treatment options. Although remdesivir is the only FDA-approved drug for those patients, its efficacy is limited by premature hydrolysis to nucleoside (NUC), low accumulation in the disease-targeted tissue (lungs), and low antiviral potency. In this study, we synthesized a new series of remdesivir analogues by modifying the ProTide moiety. In comparison with remdesivir, the lead compound MMT5-14 showed 2- to 7-fold higher antiviral activity in four variants of SARS-CoV-2. By reducing premature hydrolysis in hamsters, MMT5-14 increased the prodrug concentration by 200- to 300-fold in the plasma and lungs but also enhanced lung accumulation of the active metabolite triphosphate nucleosides (NTP) by 5-fold. Compared to remdesivir, MMT5-14 also increased the intracellular uptake and activation in lung epithelial cells by 4- to 25-fold. These data suggest that MMT5-14 could be a potential antiviral drug to treat COVID-19 patients with severe symptoms.

[Correlation of muscle strength with cognitive function and medial temporal lobe atrophy in patients with mild to moderate Alzheimer's disease]

Objective: To analyze the correlation of muscle strength with cognitive function and medial temporal lobe atrophy (MTA) in patients with mild to moderate Alzheimer's disease (AD). Methods: General information, sarcopenia-related indicators, neuropsychological tests and MTA score were collected in 80 confirmed AD patients (41 mild and 39 moderate patients) and 43 normal controls (NC) from the Memory Disorders Clinic of Department Of Neurology in the Second Affiliated Hospital of Soochow University between January and December 2021. Appendicular skeletal muscle mass index (ASMI), grip strength and 5-times sit-to-stand time and 6-m gait speed were used for assessing muscle mass, muscle strength and physical function, respectively. Cognitive function was assessed by Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment scale (MoCA), Memory and Executive Screening Scale (MES), Digit Symbol Substitution Test (DSST), Digital Span Test (DST) and Verbal Fluency Task (VFT), respectively. DST included Forward Digit Span Test (FDST) and Backward Digit Span Test (BDST). All the subjects underwent 3.0T coronal three-dimensional gradient echo sequence MRI. MTA scale was performed to evaluate the degree of medial temporal lobe atrophy. The differences in the sarcopenia-related indicators, cognitive score and MTA score were analyzed among the three groups, and the partial correlation analysis was performed between the inter-groups. Results: Eighty AD patients (24 males and 56 females) were included, aged (72±7) years old, with 41 mild and 39 moderate patients. Meanwhile, 43 NC included 19 males and 24 females, with a mean age of (70±6) years old. The disease duration in moderate AD patients was longer than that of mild AD patients [34.0 (25.0, 43.5) months vs 24.0 (11.0, 34.0) months, P<0.001]. The differences of sarcopenia-related indicators and MTA score among the three groups were statistically significant (all P<0.001), including 5-times sit-to-stand time [(13.6±1.8) s vs (11.5±1.7) s vs (10.3±1.9) s, P<0.001] and MTA score [2.0 (2.0, 3.0) vs 1.0 (1.0, 2.0) vs 0 (0, 0), P<0.001]. In neuropsychological tests, compared to the NC group, MMSE, MoCA, MES and VFT scores in mild and moderate AD groups were lower (all P<0.001); meanwhile, compared to the mild AD group, the moderate group had lower MMSE, MoCA, MES, DSST and VFT scores (all P<0.001). In sarcopenia-related indicators, muscle strength in particular was correlated with widespread cognitive functioning domains and MTA score in AD patients. Grip strength was positively correlated with MMSE, MoCA , MES, FDST (r=0.387, 0.418, 0.522 and 0.484, respectively, all P<0.001), DSST (r=0.327, P=0.006) and VFT score (r=0.354, P=0.003), and negatively correlated with MTA score (r=-0.631, P<0.001). 5-times sit-to-stand time was negatively correlated with MMSE, MoCA, MES, DSST, FDST, VFT score (r=-0.583, -0.587, -0.814, -0.591, -0.552 and -0.485, respectively, all P<0.001), and BDST (r=-0.355, P=0.003) strongly positively correlated with MTA score (r=0.836, P<0.001). ASMI was positively correlated with MMSE, MoCA, MES, DSST, FDST score (r=0.257, 0.238, 0.428, 0.282 and 0.364, respectively, all P<0.05), and negatively correlated with MTA score (r=-0.377, P=0.001). 6-m gait speed was positively correlated with MMSE, MoCA, MES, DSST, FDST score (r=0.419, 0.486, 0.699, 0.559 and 0.500, respectively, all P<0.001), BDST and VFT score (r=0.384、0.377, respectively, both P=0.001), and strongly negatively correlated with MTA score (r=-0.803, P<0.001). Conclusions: Patients with mild to moderate AD have widespread cognitive impairment. Muscle mass, muscle strength and physical function are all significantly impaired. Compared to muscle mass and physical function, decreased muscle strength is significantly associated with widespread cognitive decline and increased degree of medial temporal lobe atrophy.

P11.75.B Survival benefit of radiotherapy and surgery in patients with lung cancer brain metastases with poor prognosis factors

Background

Radiotherapy and surgery are the standard treatments for lung cancer brain metastases (BMs). However, limitted studies focused on the treatments for patients with lung cancer BMs with poor prognosis factors. The purpose of this study was to investigate the effects of radiotherapy and surgery in patients with lung cancer BMs with poor prognosis factors, providing reference for clinical strategies.

Material and Methods

We analyzed retrospectively 714 patients with lung cancer BMs. A 1:1 propensity score matching (PSM) was performed to balance potential confounders. Analyses of overall survival (OS) and risk factors for OS were assessed by log-rank test and Cox proportional hazard model.

Results

Age ≥65 years, Karnofsky Performance Scale (KPS) score ≤70, anaplastic large-cell lymphoma kinase (ALK)/epidermal growth factor receptor (EGFR) wild type, extracranial metastases, non-surgery and non-radiotherapy led to poor prognosis. Patients were stratified according to these factors. Radiotherapy and surgery showed no survival benefit in patients with aged ≥65 years or pretreatment KPS score ≤70 before and after PSM. Before PSM, whole brain radiotherapy (WBRT) improved the OS and predicted good prognosis in patients with ALK/EGFR wild type or extracranial metastases. WBRT also predicted good prognosis in patients with non-surgery. Stereotactic radiosurgery (SRS) improved the OS and predicted good prognosis in patients with ALK/EGFR wild type or non-surgery. WBRT plus SRS improved the OS and predicted good prognosis in patients with extracranial metastases or non-surgery. WBRT plus SRS also predicted good prognosis in patients with ALK/EGFR wild type. Surgery improved the OS and predicted good prognosis in patients with non-radiotherapy. After PSM, SRS improved the OS and predicted good prognosis in patients with non-surgery. WBRT plus SRS improved the OS and predicted good prognosis in patients with non-surgery or extracranial metastases. WBRT plus SRS also predicted good prognosis in patients with ALK/EGFR wild type. Surgery improved the OS of patients with non-radiotherapy. We defined that the treatment would provide significant survival benefit if it both prolonged the OS and predicted good prognosis. Meanwhile, the results after PSM were more convincing than the results before PSM.

Conclusion

Radiotherapy has significant survival benefit in patients with lung cancer BMs with poor prognosis factors, including patients with ALK/EGFR wild type or extracranial metastases or non-surgery. Surgery only has significant survival benefit in patients with non-radiotherapy.

[Diethylhexyl phthalate induces anxiety-like behavior and learning and memory impairment in mice probably by damaging blood-brain barrier]

OBJECTIVE

To investigate the effects of diethylhexyl phthalate (DEHP) exposure on anxiety-like behaviors and learning and memory ability in mice and explore the underlying mechanism.

METHODS

Forty male ICR mice were randomized equally into control group (0 mg/kg) and 10, 50 and 100 mg/kg DEHP exposure groups, in which the mice were exposed to DEHP at the indicated doses by gavage for 4 weeks. After the treatments, the mice were assessed for behavioral changes using open filed test, elevated plus-maze and Morris water maze test. Brain tissues were collected from the mice for determination of malondialdehyde (MDA) content, pathologies and expressions of ZO-1 and occludin in the hippocampus.

RESULTS

Compared with the control group, the mice with DEHP exposure for 4 weeks exhibited no significant body weight change (P>0.05) but presented with obvious behavioral changes, manifested by reduced movement distance (P < 0.05) and time spent in the center of the open field (P < 0.05), reduced movement distance (P < 0.05) and time spent in the open arm of the elevated maze (P < 0.05), significantly increased latency of searching for the platform (P < 0.05), and decreased frequency of crossing the platform (P < 0.05). HE staining showed obvious vertebral cell death in the hippocampal CA1 to CA3 regions of the mice with DEHP exposure. The exposed mice showed significantly increased MDA content and decreased expressions of ZO-1 and occludin at both the mRNA and protein levels in the hippocampus (P < 0.05 or 0.01). Multivariate linear regression analysis suggested a close correlation between anxiety-like behaviors and learning and memory abilities in DEHP-exposed mice.

CONCLUSION

DEHP exposure may cause damages of the blood-brain barrier and the pyramidal cells in the hippocampus of mice, thereby inducing anxiety-like behaviors and learning and memory impairment.

Defining a nitrogen efficiency index in Holstein cows and assessing its potential effect on the breeding program of bulls

The purposes of this study were (1) to explore the relationship between 3 milk mid-infrared predicted features including nitrogen intake (NINT), milk true protein N (MTPN), and milk urea-N yield (MUNY); (2) to integrate these 3 features into an N efficiency index (NEI) and analyses approximate genetic correlations between the NEI and 37 traits (indices) of interest; and (3) to assess the potential effect of including the NEI into breeding programs of bulls. The edited data were 1,043,171 test-day records on 342,847 cows in 1,931 herds and 143,595 test-day records on 53,660 cows in 766 herds used for estimating breeding values (EBV) and variance components, respectively. The used records were within 5 to 50 d in milk. The records were grouped into primiparous and multiparous. The genetic parameters for the included mid-infrared features and EBV of the animals included in the pedigree were estimated using a multiple-trait repeatability animal model. Then, the EBV of the NINT, MTPN, MUNY were integrated into the NEI using a selection index assuming weights based on the N partitioning. The approximate genetic correlations between the NEI and 37 traits of interest were estimated using the EBV of the selected bulls. The bulls born from 2011 to 2014 with NEI were selected and the NEI distribution of these bulls having EBV for the 8 selected traits (indices) was checked. The heritability and repeatability estimates for NINT, MTPN, and MUNY ranged from 0.09 to 0.13, and 0.37 to 0.65, respectively. The genetic and phenotypic correlations between NINT, MTPN, and MUNY ranged from -0.31 to 0.87, and -0.02 to 0.42, respectively. The NEI ranged from -13.13 to 12.55 kg/d. In total, 736 bulls with reliability ≥0.50 for all included traits (NEI and 37 traits) and at least 10 daughters distributed in at least 10 herds were selected to investigate genetic aspects of the NEI. The NEI had positive genetic correlations with production yield traits (0.08-0.46), and negative genetic correlations with the investigated functional traits and indices (-0.71 to -0.07), except for the production economic index and functional type economic index. The daughters of bulls with higher NEI had lower NINT and MUNY, and higher MTPN. Furthermore, 26% of the bulls (n = 50) with NEI born between 2011 to 2014 had higher NEI and global economic index than the average in the selected bulls. Finally, the developed NEI has the advantage of large-scale prediction and therefore has the potential for routine application in dairy cattle breeding in the future.

ASSOCIATION BETWEEN THE CTLA-4 EXON 1+49A/G POLYMORPHISM AND THE RELAPSE OF GRAVE'S DISEASE AFTER ATD WITHDRAWAL: A META-ANALYSIS

Background

The cytotoxic T lymphocyte-associated molecules-4 (CTLA-4) is related to the relapse of Graves' disease (GD) after anti-thyroid drugs (ATDs) withdrawal. We performed a meta-analysis to generate large-scale evidence on whether the CTLA-4 exon 1+49A/G polymorphism can predict the relapse of GD after ATDs withdrawal.

Methods and Results

The PubMed, EMBASE,the Cochrane Library and reference lists of relevant studies were searched to identify eligible studies from inception to Jan, 2021. Ten eligible studies consisting of 1450 GD patients with a total of 848 relapsed patients were included in the meta-analysis.In Caucasians patients, the CTLA-4 exon 1+49A/G polymorphism significantly elevated the relapse risk of GD in additive (OR = 2.07, 95% CI: 1.18-3.62, P=0.011), dominant (OR = 2.52, 95% CI: 1.17-5.41, P=0.02), homozygote model(OR = 3.264, 95% CI: 1.25-8.52, P=0.016), except recessive (OR = 2.18, 95% CI = 0.98-4.86, P = 0.062) and heterozygote model (OR = 2.141, 95% CI = 0.958-4.786, P = 0.064). In Asian subgroup, none of these genotypes show any associations with the relapse of GD after ATDs withdrawal.

Conclusion

This meta-analysis suggests that the CTLA-4 exon1 +49A/G polymorphism is associated with the relapse risk of GD after ATDs withdrawal in Caucasians, not Asians. Compared with the AA genotype, Caucasian patients with GG genotype have 3.264 times risk of relapse. A more aggressive treatment such as radioactive iodine or thyroidectomy, or longer periods treatment of ATDs should be recommended in Caucasian patients with the GG genotype.

Albumin nanoparticle containing a PI3Kγ inhibitor and paclitaxel in combination with α-PD1 induces tumor remission of breast cancer in mice

Immunomodulators that remodel the tumor immunosuppressive microenvironment have been combined with anti-programmed death 1 (α-PD1) or anti-programmed death ligand 1 (α-PDL1) immunotherapy but have shown limited success in clinical trials. However, therapeutic strategies to modulate the immunosuppressive microenvironment of lymph nodes have been largely overlooked. Here, we designed an albumin nanoparticle, Nano-PI, containing the immunomodulators PI3Kγ inhibitor (IPI-549) and paclitaxel (PTX). We treated two breast cancer mouse models with Nano-PI in combination with α-PD1, which remodeled the tumor microenvironment in both lymph nodes and tumors. This combination achieved long-term tumor remission in mouse models and eliminated lung metastases. PTX combined with IPI-549 enabled the formation of a stable nanoparticle and enhanced the repolarization of M2 to M1 macrophages. Nano-PI not only enhanced the delivery of both immunomodulators to lymph nodes and tumors but also improved the drug accumulation in the macrophages of these two tissues. Immune cell profiling revealed that the combination of Nano-PI with α-PD1 remodeled the immune microenvironment by polarizing M2 to M1 macrophages, increasing CD4⁺ and CD8⁺ T cells, B cells, and dendritic cells, decreasing regulatory T cells, and preventing T cell exhaustion. Our data suggest that Nano-PI in combination with α-PD1 modulates the immune microenvironment in both lymph nodes and tumors to achieve long-term remission in mice with metastatic breast cancer, and represents a promising candidate for future clinical trials.

Association between Sedentary Time and 6-Year All-Cause Mortality in Adults: The Rural Chinese Cohort Study

OBJECTIVES

This study aims to prospectively explore the association between sedentary time and the risk of all-cause mortality in adults based on a cohort from rural areas of China.

METHODS

The study population included 20,194 adults at baseline (2007-2008) who participated in the Rural Chinese Cohort Study. Cox's proportional hazard regression model was used to analyze the hazard ratios (HRs) and 95% confidence intervals (CIs) of sedentary time and all-cause mortality, and a restricted cubic spline was used to model the dose-response relation. We also carried out a series of sensitivity analyses to verify the robustness of our main results.

RESULTS

The median follow-up duration was 6 years, with a total of 17,265 participants (response rate 85.5%) followed up, and 1,106 deaths observed. Data for 17,048 participants were analyzed, with the mean age of participants being 52.00. Compared with sedentary time <4 h/day group, the risk of all-cause mortality was significantly increased in the 8-11 h/day (HR=1.27, 95%CI:1.03-1.56) and ≥11 h/day groups (HR=1.48, 95%CI:1.20-1.84). With increases in sedentary time, the risk of all-cause mortality increased gradually (Ptrend <0.001). For each 1 h/day increase in sedentary time, the risk of all-cause mortality increased by 3% (HR=1.03, 95%CI: 1.01-1.05). Sensitivity analyses showed our main results were consistent.

CONCLUSIONS

Prolonged sedentary time increases the risk of all-cause mortality in the adult rural Chinese population. Reducing sedentary time may have important implications for reducing mortality risk.

Structure‒tissue exposure/selectivity relationship (STR) correlates with clinical efficacy/safety

Drug optimization, which improves drug potency/specificity by structure‒activity relationship (SAR) and drug-like properties, is rigorously performed to select drug candidates for clinical trials. However, the current drug optimization may overlook the structure‒tissue exposure/selectivity-relationship (STR) in disease-targeted tissues vs. normal tissues, which may mislead the drug candidate selection and impact the balance of clinical efficacy/toxicity. In this study, we investigated the STR in correlation with observed clinical efficacy/toxicity using seven selective estrogen receptor modulators (SERMs) that have similar structures, same molecular target, and similar/different pharmacokinetics. The results showed that drug's plasma exposure was not correlated with drug's exposures in the target tissues (tumor, fat pad, bone, uterus), while tissue exposure/selectivity of SERMs was correlated with clinical efficacy/safety. Slight structure modifications of four SERMs did not change drug's plasma exposure but altered drug's tissue exposure/selectivity. Seven SERMs with high protein binding showed higher accumulation in tumors compared to surrounding normal tissues, which is likely due to tumor EPR effect of protein-bound drugs. These suggest that STR alters drug's tissue exposure/selectivity in disease-targeted tissues vs. normal tissues impacting clinical efficacy/toxicity. Drug optimization needs to balance the SAR and STR in selecting drug candidate for clinical trial to improve success of clinical drug development.

[Third ventricle width measured by transcranial ultrasound and its diagnostic value in patients with Alzheimer's disease]

Objective: To explore the diagnostic value of third ventricle width (TVW) measured by transcranial ultrasound (TCS) in the clinical diagnosis of Alzheimer's disease (AD) by analyzing and comparing the image characteristics of TVW in AD patients and healthy controls, and its correlation with cranial magnetic resonance medial temporal lobe atrophy (MTA) visual score and neuropsychological characteristics. Methods: TCS examination, MTA score and neuropsychological tests were performed in 39 confirmed AD and 41 normal controls from the Second Affiliated Hospital of Soochow University between January and July 2021. The correlation of TVW with MTA score and neuropsychological characteristics was analyzed and compared between the two groups. Results: A total of thirty-nine AD patients were enrolled, with 28 males and 11 females, aged (73±9) years, including 18 mild, 20 moderate, and 1 severe AD patient. Meanwhile, 41 healthy controls were also included, with 24 males and 17 females, aged (69±6) years old. TVW in AD patients was significantly wider than that in normal controls [0.76(0.66, 0.87) cm vs 0.50(0.44, 0.56) cm, P<0.001]. In neuropsychological tests, compared with normal controls, AD patients showed impaired performances in several cognitive functions, and there were statistically significant differences in delayed memory [0(0, 0) vs 4.0(4.0, 5.0), P<0.001], naming [2.0(1.0, 3.0) vs 3.0(2.0, 3.0), P<0.001], executive function [2.0(2.0, 3.0) vs 3.0(2.5, 3.0), P<0.001], language [0.0(0.0, 2.0) vs 3.0(2.0, 3.0), P<0.001] and other aspects between AD patients and normal controls (all P<0.05). TVW was negatively correlated with immediate memory (r=-0.339, P=0.035), delayed recall (r=-0.523, P<0.001), attention and computing power (r=-0.409, P=0.045), visual space and executive function (r=-0.333, P=0.039), but positively correlated with the atrophy of the medial temporal lobe (r= 0.552, P<0.001). Conclusions: TCS can be used to measure TVW in AD patients. When combined with MTA score and neuropsychological tests, it can provide a reliable objective basis for the clinical diagnosis of AD.

Clinical features and risk factors of pulmonary tuberculosis complicated with pulmonary aspergillosis

OBJECTIVE

This study was carried out to explore the clinical features and risk factors of pulmonary tuberculosis complicated with pulmonary aspergillosis.

PATIENTS AND METHODS

Through a retrospective analysis of 3,000 patients with pulmonary tuberculosis history or active pulmonary tuberculosis complicated with pulmonary aspergillosis in the inpatient department of pulmonary tuberculosis in Shandong Provincial Public Health Clinical Center from January 2017 to January 2021, 70 cases of pulmonary aspergillosis were selected and diagnosed. In addition, 70 patients with pulmonary tuberculosis without other fungal infections in the same period were randomly selected as the control group. The risk factors of pulmonary tuberculosis complicated with pulmonary aspergillosis were analyzed by multi-factor logistic analysis, and the clinical characteristics of pulmonary tuberculosis complicated with pulmonary aspergillosis were analyzed by collecting the basic information of patients, drug use of pulmonary tuberculosis, imaging characteristics, past medical history, and test indicators.

RESULTS

Univariate analysis showed that the single risk factors of pulmonary tuberculosis complicated with pulmonary aspergillosis were: the types of pulmonary tuberculosis (initial diagnosis or previous reexamination), hormone application time, antibiotic application time (rifampicin), hemoptysis/sputum blood, C-reactive protein, and pulmonary cavity were significantly correlated with pulmonary tuberculosis complicated with pulmonary aspergillosis (p-value <0.05). The proportion of patients with pulmonary tuberculosis complicated with pulmonary aspergillosis was higher than that of patients with simple pulmonary tuberculosis in the follow-up of pulmonary tuberculosis, the time of antibiotics application ≥ 1 month, the time of hormone application ≥ 1 week and C-reactive protein. The incidence of hemoptysis/blood in sputum in the clinical symptoms of pulmonary aspergillosis group (24/70) was higher than that of simple pulmonary tuberculosis group (20/70), and the difference was statistically significant (p-value < 0.05). Multivariate logistic regression analysis showed that there were significant differences between the two groups in the two indexes of "hormone application time ≥ 1 week" and "antibiotic application time ≥ 1 month" (p-value < 0.05).

CONCLUSIONS

Hemoptysis/blood in sputum can be considered as the main clinical feature of pulmonary tuberculosis complicated with pulmonary aspergillosis. The main risk factors for pulmonary tuberculosis complicated with pulmonary aspergillosis were the application time of antibiotics ≥ 1 month and the application time of hormones ≥ 1 week.

Degradation of oxalic acid produced by Botrytis elliptica infection in two ploidy levels of Lilium rosthornii Diels

Oxalic acid (OA) is a crucial pathogenic factor for Sclerotinia spp. fungi, which is closely related to Botrytis spp. fungi. Whether OA is a pathogenic factor for the causal agent of grey mould in lily, Botrytis elliptica, and the response of lily to OA are poorly understood. To address these questions, lesion tissues and deposition of calcium oxalate (CaOX) and callose were observed in diploid and tetraploid leaves of L. rosthornii after inoculation with B. elliptica. Oxalate oxidase (OXO) activity and the transcript levels of some genes related to OA degradation (LrGLP1, LrGLP2 and LrWRKY4), reactive oxygen species (ROS) production/scavenging systems (LrRBOHD, LrGST, LrPOD and LrAPX1) and pathogen-related protein (PR) synthesis (LrCHI, LrBGL and LrPR10) were compared. After diploid and tetraploid leaves inoculation, lesion tissue and callose and CaOX were separately observed around in guard cells and stomata rather than the epidermis in the infected area. OXO activity was triggered at 2 h post-inoculation (hpi) in both ploidy leaves, and it was higher in the latter from 12-48 hpi. Expression of LrGLP1, LrGLP2, LrRBOHD, LrGST, LrPOD, LrCHI, LrBGL and LrPR10 was higher in tetraploids than in diploids from 24(12)-36(48) hpi. In conclusion, for B. elliptica, OA mainly chelates Ca²⁺ from the stomata cell wall. The strong capability to degrade OA and higher expression levels of some genes related to ROS accumulation/scavenging and PR synthesis may partially explain the relatively higher grey mould resistance of tetraploid L. rosthornii.

Are late hernia mesh complications linked to Staphylococci biofilms?

Purpose

The purpose of this study was to investigate the link between bacterial biofilms and negative outcomes of hernia repair surgery. As biofilms are known to play a role in mesh-related infections, we investigated the presence of biofilms on hernia meshes, which had to be explanted due to mesh failure without showing signs of bacterial infection.

Methods

In this retrospective observational study, 20 paraffin-embedded tissue sections from explanted groin hernia meshes were analysed. Meshes have been removed due to chronic pain, hernia recurrence or mesh shrinkage. The presence and bacterial composition of biofilms were determined. First, specimens were stained with fluorescence in situ hybridisation (FISH) probes, specific for Staphylococcus aureus and coagulase-negative staphylococci, and visualised by confocal laser scanning microscopy. Second, DNA was extracted from tissue and identified by S. aureus and S. epidermidis specific PCR.

Results

Confocal microscopy showed evidence of bacterial biofilms on meshes in 15/20 (75.0%) samples, of which 3 were positive for S. aureus, 3 for coagulase-negative staphylococci and 9 for both species. PCR analysis identified biofilms in 17/20 (85.0%) samples, of which 4 were positive for S. aureus, 4 for S. epidermidis and 9 for both species. Combined results from FISH/microscopy and PCR identified staphylococci biofilms in 19/20 (95.0%) mesh samples. Only 1 (5.0%) mesh sample was negative for bacterial biofilm by both techniques.

Conclusion

Results suggest that staphylococci biofilms may be associated with hernia repair failure. A silent, undetected biofilm infection could contribute to mesh complications, chronic pain and exacerbation of disease.

Machine learning predicts all-cause mortality in patients with severe aortic regurgitation

Funding Acknowledgements

Type of funding sources: None.

Background

Aortic regurgitation (AR) is a common valvular lesion associated with left ventricular (LV) enlargement and dysfunction and increased risk of death with onset of symptoms, significant LV enlargement, or systolic dysfunction. The current guidelines are based on symptoms, LV size and LV function to evaluate the candidacy for surgery in patients with severe AR.

Purpose

 We propose a machine-learning (ML) based algorithm to identify patients at risk for death from AR independent of aortic valve replacement (AVR) surgery (patients were censored at AVR event unless the operation occurred within 100 days of the first visit, in which case baseline AVR is included as a predictor).

Methods

The model was trained with 5-fold cross-validation on a dataset of 1035 patients. Model performance is reported on an independent dataset of 207 patients. Optimal predictive performance was observed with a Conditional Random Survival Forest model. A subset of 19 / 41 variables were selected for inclusion in the final model. Variable selection was performed with 10-fold cross validation using Random Survival Forest model; variables that were on an average selected by less than 6/10 splits were excluded.

Results

The mean age of patients was 60 ± 17 years and 198 (18%) were females. The variables included in the models were age, end-diastolic volume, end systolic dimension, body surface area, ejection fraction, NYHA class, body mass index, diastolic blood pressure, bicuspid valve, regurgitant volume, filling pressure, mid ascending aorta diameter, mitral tissue early relaxation velocity, pulmonary artery systolic pressure, and comorbidities, and the relative variable importances averaged across five splits of cross validation in each repeat were evaluated (Figure). The predictive AUC for predicting survival of the best-performing model was 0.84 at 1 year, 0.86 at 2 years, and 0.87 overall, respectively.

Conclusion

Using commonly observed echo parameters and patient characteristics we successfully trained a ML model to predict survival in patients with severe AR. This technique could identify high-risk patients who would benefit from early intervention, thereby improving patient outcomes. Abstract Figure.

Why 90% of clinical drug development fails and how to improve it?

Ninety percent of clinical drug development fails despite implementation of many successful strategies, which raised the question whether certain aspects in target validation and drug optimization are overlooked? Current drug optimization overly emphasizes potency/specificity using structure‒activity-relationship (SAR) but overlooks tissue exposure/selectivity in disease/normal tissues using structure‒tissue exposure/selectivity–relationship (STR), which may mislead the drug candidate selection and impact the balance of clinical dose/efficacy/toxicity. We propose structure‒tissue exposure/selectivity–activity relationship (STAR) to improve drug optimization, which classifies drug candidates based on drug's potency/selectivity, tissue exposure/selectivity, and required dose for balancing clinical efficacy/toxicity. Class I drugs have high specificity/potency and high tissue exposure/selectivity, which needs low dose to achieve superior clinical efficacy/safety with high success rate. Class II drugs have high specificity/potency and low tissue exposure/selectivity, which requires high dose to achieve clinical efficacy with high toxicity and needs to be cautiously evaluated. Class III drugs have relatively low (adequate) specificity/potency but high tissue exposure/selectivity, which requires low dose to achieve clinical efficacy with manageable toxicity but are often overlooked. Class IV drugs have low specificity/potency and low tissue exposure/selectivity, which achieves inadequate efficacy/safety, and should be terminated early. STAR may improve drug optimization and clinical studies for the success of clinical drug development.

Tau Pathologies Mediate the Associations of Vascular Risk Burden with Cognitive Impairments in Non-demented Elders: The CABLE Study

BACKGROUND

Studies suggested that vascular dysfunction might increase the risk of developing Alzheimer's disease (AD), but the underlying mechanisms still remain obscure.

OBJECTIVE

To evaluate the associations of vascular risk burden with AD core pathologies and investigate the effects of AD core pathologies on relationships between vascular risk burden and cognitive impairments.

DESIGN

The Chinese Alzheimer's Biomarker and LifestyLE (CABLE) study was principally focusing on aging, as well as the risk factors and biomarkers of AD initiated in 2017.

SETTING

The CABLE study was a large cohort study established in Qingdao, China.

PARTICIPANTS

A total of 618 non-demented elders were obtained from CABLE study.

MEASUREMENTS

The general vascular risk burden was assessed by the Framingham General Cardiovascular Risk Score (FGCRS). Multivariate linear regression analyses were performed to evaluate the associations of FGCRS with cerebrospinal fluid (CSF) AD biomarkers and cognition. Casual mediation analyses were performed to investigate the mediating effects of AD biomarkers on cognition.

RESULTS

Increased FGCRS was related to higher levels of CSF total tau (t-tau, p < 0.001), phosphorylated tau (p-tau, p < 0.001) as well as the ratio of t-tau and amyloid-β 42 (t-tau/Aβ42, p = 0.010), and lower Chinese-Modified Mini-Mental State Examination (CM-MMSE, p = 0.010) score. Stratified analysis indicated that age modified the associations, with FGCRS being significantly associated with tau pathology (p < 0.001 for t-tau and p-tau) in middle-aged group (<65 years old), instead of older group. The influences of FGCRS on cognitive impairments were partially mediated by tau pathologies (a maximum proportion of 20.9%).

CONCLUSIONS

Tau pathology might be a pivotal mediator for effects of vascular risk on cognitive decline. Early and comprehensive intervention for vascular risk factors might be a potential approach to delaying or preventing cognitive impairment and AD.

Biological soil crusts alleviate the stress of arsenic on rice germination and the underlying immobilization mechanisms

The high concentration of arsenic (As) in paddy soil has seriously threatened the growth of rice and human food safety. Biological soil crusts (BSC), which are ubiquitous in paddy fields, have been shown a high ability to capture trace metal elements. In the present study, we investigated the effectiveness and mechanism of BSC for immobilizing As, and tested their potential to alleviate the stress of As on rice germination. It is found that BSC can remove 77.8% of arsenic in solution with 3.5 mg L^-1 initial As concentration. The As content in BSC reached 514.5 mg kg^-1 after 216 h exposure, and the entrapped As was mainly distributed in BSC as a non-EDTA-exchangeable fraction, which might be intracellularly accumulated. Proteobacteria and Bacteroidetes were the dominant phyla in BSC after being exposed to As, playing a significant role in tolerating As and As biogeochemical cycling. The presence of BSC notably promoted the germination rate (18.3%) and dry biomass (103.4%) of rice seeds under 3.5 mg L^-1 As stress while reducing the As content in plant roots (8.2-34.3%) and shoots (8.7-47.6%). These findings demonstrate that BSC have a great entrapping effect on As and highlight the importance of BSC in alleviating the stress on rice germination by As, providing a potential nature-based and low-cost strategy to decontaminate paddy fields polluted with As.

Development of a Predictive Model for Screening Patients with Psoriasis at Increased Risk of Psoriatic Arthritis

Introduction

This study aimed to develop a predictive model based on ultrasound variables which can be used to screen patients with psoriasis who are prone to progress to psoriatic arthritis (PsA) in clinical practice.

Methods

This is a cross-sectional study conducted in a single center from October 2018 to November 2020. All subjects (non-PsA group, PsA group, and control group) underwent an ultrasound examination and their ultrasound abnormalities were recorded. On the basis of statistical analysis and clinical experts’ advice, several variables were selected for modelling. We used logistic regression to establish the prediction model. To assess the discrimination and accuracy of this model, internal validation and external validation were performed.

Results

A total of 852 patients with psoriasis but without PsA, 261 patients with PsA, and 86 healthy volunteers were included. Ultimately, the predictive model consisted of six variables, namely hand joint power Doppler (PD) signals (grade 0: OR 2.94, 95% CI 1.94–4.47; grade ≥ 1: OR 109.30, 95% CI 14.35–832.27; P < 0.001), wrist joint synovial thickening (grade 1: OR 1.29, 95% CI 0.69–2.43; grade 2: OR 4.30, 95% CI 1.92–9.65; grade 3: OR 11.05, 95% CI 1.01–120.64; P = 0.001), knee joint PD signals (grade 0: OR 1.01, 95% CI 0.56–1.80; grade ≥ 1: OR 14.77, 95% CI 3.99–54.69; P < 0.001), toe joint PD signals (grade 0: OR 1.18, 95% CI 0.78–1.79; grade ≥ 1: OR 5.74, 95% CI 2.84–11.63; P < 0.001), quadriceps tendon and patellar tendon enthesitis (OR 1.95, 95% CI 1.36–2.78, P < 0.001), Achilles tendon and plantar aponeurosis enthesitis (OR 1.63, 95% CI 1.14–2.32, P = 0.007). C-index for the predictive model was 0.80 (95% CI 0.76–0.83). After bootstrapping validation (1000 times), it was confirmed to be 0.79. The external validation showed the accuracy of the predictive model is 0.87 (95% CI 0.69–0.95).

Conclusion

This study succeeded in developing a predictive model with a high degree of accuracy to predict the risk of PsA in patients with psoriasis.

Psoriatic arthritis often occurs in the population of patients with psoriasis. It brings a huge burden and pain to patients. At present, the diagnosis for psoriatic arthritis is very challenging. Numerous research studies have begun to focus on identifying patients with psoriasis at increased risk of psoriatic arthritis. Among a lot of modalities, ultrasound has been considered as a sensitive and convenient tool for screening early psoriatic arthritis. Our study successfully established a predictive model based on ultrasound variables to screen patients with psoriasis at high risk of transiting to psoriatic arthritis. After internal and external validation, it showed great accuracy and generalizability. We recommend that clinicians perform ultrasound screening of patients with psoriasis in clinical routine and get their risk value of transiting to psoriatic arthritis by using this model. For those patients with a high risk of progression to psoriatic arthritis, clinicians should refer them to a rheumatology department as soon as possible so that they could have access to early and effective management which might bring them good clinical and imaging outcomes.

Drug-coated balloon angioplasty for failing haemodialysis access: meta-analysis of randomized clinical trials

BACKGROUND

Arteriovenous fistulas, a major treatment for end-stage kidney disease, frequently require endovascular reinterventions to maintain haemodialysis function. Drug-coated angioplasty balloons (DCBs) were developed with the intention of reducing reintervention rates. The aim of this study was to perform a systematic review and meta-analysis of DCBs in the treatment of failing haemodialysis access.

METHODS

Electronic databases were searched systematically to identify all relevant RCTs and any follow-up studies from RCTs. Pooled estimates of dichotomous outcomes were calculated using the odds ratio (OR) and 95 per cent confidence interval. Effect data are presented as summary hazard ratio and 95 per cent confidence interval.

RESULTS

Some 19 studies from 18 RCTs and comprising 1898 patients were included in the meta-analysis. Compared with plain balloon angioplasty (PBA), DCB use was associated with higher target-lesion primary patency (HR 0.60, 95 per cent c.i. 0.45 to 0.79), access-circuit primary patency (HR 0.67, 0.56 to 0.80), and less target-lesion revascularization (TLR) within 6 months (OR 0.33, 0.23 to 0.47). No difference was observed between DCB and PBA in 12-month TLR (OR 0.62, 0.28 to 1.37). Mortality after DCB use was similar to that associated with PBA use at 6 months (OR 1.20, 0.65 to 2.21) and 12 months (OR 0.99, 0.66 to 1.49), and was higher at 24 months (23.1 versus 16.6 per cent), although the difference was not statistically significant (OR 1.53, 0.92 to 2.53).

CONCLUSION

Drug-coated balloon angioplasty of haemodialysis fistulas is associated with higher patency rates and lower rates of reintervention in the short to mid term. Although mortality rates appeared to be higher with drug-coated angioplasty at 24 months, this did not reach statistical significance.

Malignant acanthosis nigricans and diseases with extensive oral papillary hyperplasia

Oral papillary lesions represent a variety of developmental and neoplastic conditions. Early diagnoses of different papillary lesions are challenging for oral medicine specialists. Malignant acanthosis nigricans (MAN) is a rare cutaneous disorder and a potential marker of underlying hidden tumours. It is characterized by papillary lesions that always involve the oral mucosa. In oral medicine specialities, MAN is not well understood. When the early signs of MAN are extensive oral lesions and slight cutaneous pigmentation without obvious florid cutaneous papillomatosis, the diagnosis can be incorrect or delayed. Oral medicine specialists should ask affected patients to provide details of their medical history and conduct a timely systemic examination.