Encapsulation and characterization of soy protein-based ω-3 medium- and long- chain triacylglycerols microencapsulated with diverse homogenization techniques for improving oxidation stability

Recently, MLCTs have attracted considerable attention as a potential alternative to traditional oils due to their suppressive effect on fat accumulation and insulin sensitivity. In this study, the microcapsules of MLCTs with superior performance were fabricated through different homogenization processes to overcome the limitations of ω-3 medium- and long- chain triacylglycerols (MLCTs), including poor stability and prone oxidation. Additionally, the impact of various homogenization techniques, namely, high-pressure, ultrasound, and cavitation jet, on the particle structure, encapsulation efficiency, and oxidation stability of microcapsules (MLCTs) was investigated. The MLCTs microcapsules fabricated through high-pressure homogenization had a smaller particle size of 295.12 nm, lower PDI of 0.24, and a higher zeta-potential absolute value of 32.65, which significantly improved their dispersion and encapsulation efficiency, reaching 94.56 % after the spray-drying process. Furthermore, the low moisture content and superior storage stability of MLCTs microcapsules have the potential to serve as carriers of liposoluble actives.

[Imaging risk factors for postoperative cerebral infarction in adults with ischemic Moyamoya disease]

Objective: To investigate the imaging factors associated with postoperative cerebral infarction in adult patients aged 18 and above with ischemic Moyamoya disease. Methods: The clinical data of adult patients who underwent surgeries for ischemic Moyamoya disease in the Department of Neurosurgery at Peking University International Hospital from October 2015 to October 2020 were retrospectively analyzed. Of the 239 patients, 120 were male and 119 were female, with ages ranging from 18 to 63 (41.7±10.3) years. A total of 239 patients(290 cases) underwent direct and indirect combined revascularization (CR).Gender, age, surgical side, preoperative transient ischemic attack (TIA), presence of old cerebral infarction, and imaging features were compared between the patients with (48 cases) and without (242 cases) cerebral infarction within 1 week after surgery. Multivariate logistic binary regression model was used to analyze the imaging risk factors of postoperative cerebral infarction. Results: Cerebral infarction occurred in 48 cases(16.5%) among the 290 CR group within 1 week after surgery. The proportion of patients with TIA, old cerebral infarction, ICA stenosis, A1 segment stenosis, M1 segment stenosis, abnormal posterior cerebral artery (PCA), and unstable compensation before CR in the cerebral infarction group was higher than that in the non-cerebral infarction group (P<0.05).Preoperative TIA (OR=4.514, 95%CI: 1.920-10.611), old cerebral infarction (OR=2.856,95%CI:1.176-6.936), A1 stenosis (OR=7.027,95%CI:1.877-26.308), M1 stenosis (OR=6.968,95%CI:2.162-22.459), abnormal PCA (OR=4.114,95%CI:1.330-12.728)and unstable compensation (OR=4.488,95%CI:1.194-16.865) were risk factors for cerebral infarction after CR surgery (all P<0.05). Conclusion: Among the imaging factors, TIA, old cerebral infarction, A1 stenosis, M1 stenosis, abnormal PCA and unstable compensation were risk factors for cerebral infarction in adult patients with ischemic Moyamoya disease treated by combined revascularization.

[Haploidentical donor peripheral blood stem cell transplantation using third-party cord blood compared with matched unrelated donor transplantation for patients with hematologic malignancies]

Objectives: To assess the efficacy of cord blood-assisted haploid peripheral blood stem cell transplantation (haplo-cord-PBSCT) versus unrelated donor peripheral blood stem cell transplantation (UD-PBSCT) in the treatment of malignant hematological diseases. Methods: A retrospective analysis was performed on one hundred and four patients with malignant hematological diseases who underwent haplo-cord-PBSCT and fifty-two patients who underwent UD-PBSCT at Xiangya Hospital of Central South University between January 2016 and December 2021. Results: ①The median implantation time for neutrophils in the haplo-cord-PBSCT and UD-PBSCT groups was 13 (9-22) days and 13 (10-24) days, respectively (P=0.834), whereas the median implantation time for platelets was 15 (7-103) days and 14 (8-38) days, respectively (P=0.816). The cumulative implantation rate of neutrophils at 30 days after transplantation in the haplo-cord-PBSCT group and the UD-PBSCT group was 100% (P=0.314), and the cumulative platelet implantation rate at 100 days after transplantation was 95.2% (95% CI 88.3% - 98.1% ) and 100% (P=0.927), respectively. 30 days after transplantation, both groups of patients achieved complete donor chimerism, and no umbilical cord blood stem cells were implanted. ②The cumulative incidence rates of grade Ⅱ-Ⅳ acute GVHD within 100 days after transplantation in the haplo-cord-PBSCT group and the UD-PBSCT group were 29.1% (95% CI 20.1% -38.1% ) and 28.8% (95% CI 17.2% -41.6% (P=0.965), respectively. The cumulative incidence rates of grade Ⅲ/Ⅳ acute GVHD were 7.8% (95% CI 3.6% -14.0% ) and 9.6% (95% CI 3.5% -19.5% ) (P=0.725). The cumulative incidence rates of 2-year chronic GVHD in the haplo-cord-PBSCT group and the UD-PBSCT group were 45.3% (95% CI 36.1% -56.1% ) and 35.1% (95% CI 21.6% -44.1% ), respectively (P=0.237). The cumulative incidence rates of severe chronic GVHD at 2 years after transplantation were 13.6% (95% CI 7.6% -21.3% ) and 12.9% (95% CI 5.1% -24.3% ), respectively (P=0.840). ③The 2-year CIR after transplantation in the haplo-cord-PBSCT group and UD-PBSCT group were 12.8% (95% CI 7.0% -20.5% ) and 10.0% (95% CI 3.6% -20.2% ), respectively (P=0.341), and the NRM were 14.7% (95% CI 8.4% -22.6% ) and 16.2% (95% CI 7.4% -28.0% ), respectively (P=0.681). ④The 2-year OS rates in the haplo-cord-PBSCT and UD-PBSCT groups after transplantation were 82.2% (95% CI 74.8% -90.3% ) and 75.5% (95% CI 64.2% -88.7% ), respectively (P=0.276). The 2-year DFS rates were 69.9% (95% CI 61.2% -79.8% ) and 73.8% (95% CI 62.4% -87.3% ), respectively (P=0.551). The 2-year rates of GVHD-free/recurrence-free survival (GRFS) were 55.3% (95% CI 44.8% -64.8% ) and 64.7% (95% CI 52.8% -79.3% ), respectively (P=0.284) . Conclusion: The findings of this study indicate that haplo-cord-PBSCT and UD-PBSCT have comparable efficacy and safety in the treatment of malignant hematological diseases and can be used as an alternative treatment options.

Circulating Metabolites and Dental Traits: A Mendelian Randomization Study

It is of great importance to uncover causal biomarkers to gain insight into the pathogenesis of oral diseases and identify novel treatment targets for prevention and treatment thereof. This study aimed to systematically evaluate the causal effects of hundreds of metabolites on 10 dental traits using a 2-sample Mendelian randomization (MR) approach. Genetic variants from genome-wide association studies of 309 known metabolites were used as instrumental variables. We selected 10 dental traits, including clinical measures of dental diseases, from the Gene-Lifestyle Interactions in Dental Endpoints Consortium and self-reported oral health data from the UK Biobank. The causal relationships between metabolites and dental traits were inferred using the inverse variance-weighted approach and further controlled for horizontal pleiotropy using 5 additional MR methods. After correcting for multiple tests, 5 metabolites were identified as causal biomarkers. Genetically predicted increased levels of mannose were associated with lower risk of bleeding gums (odds ratio [OR] = 0.72; 95% confidence interval [CI], 0.61-0.85; P = 9.9 × 10-5). MR also indicated 4 metabolites on the causal pathway to dentures, with fructose (OR = 0.50; 95% CI, 0.36-0.70; P = 5.2 × 10-5) and 1-palmitoleoyl-glycerophosphocholine (OR = 0.67; 95% CI, 0.56-0.81; P = 4.8 × 10-5) as potential protective factors and glycine (OR = 1.22; 95% CI, 1.11-1.35; P = 5.6×10-5) and 1,5-anhydroglucitol (OR = 1.32; 95% CI, 1.14-1.52; P = 1.5 × 10-4) as risk factors. The causal associations were robust in various sensitivity analyses. We further observed some shared metabolites among different dental traits, implying similar biological mechanisms underlying the pathogenic processes. Finally, the pathway analysis revealed several significant metabolic pathways that may be involved in the development of dental disorders. Our study provides novel insights into the combination of metabolomics and genomics to reveal the pathogenesis of and therapeutic strategies for dental disorders. It highlighted 5 metabolites and several pathways as causal candidates, warranting further investigation.

Adaptation and validation of a TB stigma scale for adolescents in Lima, Peru

BACKGROUND: TB-related stigma contributes to poor clinical outcomes and reduced wellbeing for affected individuals. Adolescents may be particularly susceptible to TB-related stigma due to their heightened sensitivity to peer acceptance, yet few studies have evaluated TB-related stigma in this group. Without a validated scale, it remains challenging to measure TB-related stigma in adolescents.METHODS: We adapted and validated the Van Rie TB Stigma Scale (VTSS) for adolescents on treatment for rifampicin-susceptible TB in Lima, Peru. The modified stigma scale was administered within a larger survey, which measured other psychosocial factors, including depression, adverse childhood experiences (ACEs), and social support. Data analysis included factor analysis, internal consistency, and convergent validity.RESULTS: From October 2020 to September 2021, 249 adolescents (individuals aged 10-19 years) completed the survey. Preliminary confirmatory factor analysis led to removal of two items. The final 10-item scale demonstrated good internal consistency (Cronbach's α = 0.82) and adequate model fit (χ²/df = 2.0; root mean square error of approximation: 0.06; comparative fit index: 0.94; Tucker-Lewis Index: 0.92: standardized root mean square residual: 0.05). Stigma was positively correlated with ACEs (γ = 0.13), depression (γ = 0.39), and suicidal ideation (γ = 0.27), and negatively correlated with social support (γ = -0.19).CONCLUSION: This adolescent TB stigma scale may serve as a practical tool to measure TB-related stigma and evaluate the impact of stigma-reduction interventions in adolescents.

Outcomes of WHO-conforming, longer, all-oral multidrug-resistant TB regimens and analysis implications

BACKGROUND: Evidence of the effectiveness of the WHO-recommended design of longer individualized regimens for multidrug- or rifampicin-resistant TB (MDR/RR-TB) is limited.OBJECTIVES: To report end-of-treatment outcomes for MDR/RR-TB patients from a 2015-2018 multi-country cohort that received a regimen consistent with current 2022 WHO updated recommendations and describe the complexities of comparing regimens.METHODS: We analyzed a subset of participants from the endTB Observational Study who initiated a longer MDR/RR-TB regimen that was consistent with subsequent 2022 WHO guidance on regimen design for longer treatments. We excluded individuals who received an injectable agent or who received fewer than four likely effective drugs.RESULTS: Of the 759 participants analyzed, 607 (80.0%, 95% CI 77.0-82.7) experienced successful end-of-treatment outcomes. The frequency of success was high across groups, whether stratified on number of Group A drugs or fluoroquinolone resistance, and ranged from 72.1% to 90.0%. Regimens were highly variable regarding composition and the duration of individual drugs.CONCLUSIONS: Longer, all-oral, individualized regimens that were consistent with 2022 WHO guidance on regimen design had high frequencies of treatment success. Heterogeneous regimen compositions and drug durations precluded meaningful comparisons. Future research should examine which combinations of drugs maximize safety/tolerability and effectiveness.

Concordance of three approaches for operationalizing outcome definitions for multidrug-resistant TB

BACKGROUND: The WHO provides standardized outcome definitions for rifampicin-resistant (RR) and multidrug-resistant (MDR) TB. However, operationalizing these definitions can be challenging in some clinical settings, and incorrect classification may generate bias in reporting and research. Outcomes calculated by algorithms can increase standardization and be adapted to suit the research question. We evaluated concordance between clinician-assigned treatment outcomes and outcomes calculated based on one of two standardized algorithms, one which identified failure at its earliest possible recurrence (i.e., failure-dominant algorithm), and one which calculated the outcome based on culture results at the end of treatment, regardless of early occurrence of failure (i.e., success-dominant algorithm).METHODS: Among 2,525 patients enrolled in the multi-country endTB observational study, we calculated the frequencies of concordance using cross-tabulations of clinician-assigned and algorithm-assigned outcomes. We summarized the common discrepancies.RESULTS: Treatment success calculated by algorithms had high concordance with treatment success assigned by clinicians (95.8 and 97.7% for failure-dominant and success-dominant algorithms, respectively). The frequency and pattern of the most common discrepancies varied by country.CONCLUSION: High concordance was found between clinician-assigned and algorithm-assigned outcomes. Heterogeneity in discrepancies across settings suggests that using algorithms to calculate outcomes may minimize bias.

The impact of local colleges' interference in middle school students' family psychological intervention on the psychological health status of students learning at home - a case study of northern Guangdong

OBJECTIVE

Using college psychological resources, this paper attempts to intervene in the family psychology of middle school students learning at home during the epidemic in northern Guangdong. Focusing on the impact of family system on the psychological health status of middle school students learning at home, it provides reference for targeted family psychological intervention and treatment of students.

SUBJECTS AND METHODS

The "Psychological Health Survey Questions for Middle School Students Learning at Home during the Epidemic" was compiled to conduct a class-based random sampling survey of primary and secondary schools in northern Guangdong. Family psychological intervention is provided for key groups.

RESULTS

(1) The middle school students' psychological health level was above average on the whole, but with great individual differences. (2) Families have a significant impact on students' psychological health, among which parents' occupation, family integrity, family economy, family atmosphere, and the number of children in the family all exert a significant impact on middle school students' psychological health. (3) Stepwise regression analysis reveals that the six factors of gender, grade, ethnicity and place of residence, family economy and atmosphere in the family environment system are included in the regression equation, explaining 11.6% of middle school students' psychological health. (4) Family psychological intervention significantly improves middle school students' psychological health.

CONCLUSIONS

Local colleges' interference in middle school students' family psychological intervention can effectively improve psychological health of middle school students learning at home. Society, families and schools should value family psychological construction, and effectively unite social forces to jointly promote students' psychological health.

The Safety and Efficacy of Flow Diversion versus Conventional Endovascular Treatment for Intracranial Aneurysms: A Meta-analysis of Real-world Cohort Studies from the Past 10 Years

BACKGROUND

Although the flow diverter has advantages in the treatment of intracranial aneurysms, pooled studies that directly compare it with conventional endovascular treatments are rare.

PURPOSE

Our aim was to compare the safety and efficacy of flow-diverter and conventional endovascular treatments in intracranial aneurysms.

DATA SOURCES

We performed a comprehensive search of the literature using PubMed, EMBASE, and the Cochrane Database.

STUDY SELECTION

We included only studies that directly compared the angiographic and clinical outcomes of flow-diverter and conventional endovascular treatments.

DATA ANALYSIS

Random effects or fixed effects meta-analysis was used to pool the cumulative rate of short- and long-term angiographic and clinical outcomes.

DATA SYNTHESIS

Eighteen studies with 1001 patients with flow diverters and 1133 patients with conventional endovascular treatments were included; 1015 and 1201 aneurysm procedures were performed, respectively. The flow-diverter group had aneurysms of a larger size (standard mean difference, 0.22; 95% CI, 0.03-0.41; P = .026). There was a higher risk of complications in the flow-diverter group compared with the conventional endovascular group (OR, 1.4; 95% CI, 1.01-1.96; P = .045) during procedures. The follow-up angiographic results of flow-diverter treatment indicated a higher rate of complete occlusion (OR, 2.55; 95% CI, 1.70-3.83; P < .001) and lower rates of recurrence (OR, 0.24; 95% CI, 0.12-0.46; P < .001) and retreatment (OR, 0.31; 95% CI, 0.21-0.47; P < .001).

LIMITATIONS

Limitations include a retrospective, observational design in some studies, high heterogeneity, and selection bias.

CONCLUSIONS

Compared with the conventional endovascular treatments, the placement of a flow diverter may lead to more procedure-related complications, but there is no difference in safety, and it is more effective in the long term.

[Effects of typical PKC subtypes on the proliferation of mouse pulmonary artery smooth muscle cells and the expression of ERK1/2 and Akt induced by hypoxia]

Objective: To study the effects of specific isoforms of classic protein kinase C (cPKCs) on hypoxia-induced proliferation and the expression of ERK1/2 and Akt using drug intervention or virus transfection in vitro. Methods: Dynal MPC-1 magnetic particle concentrator was used to separate iron-containing pulmonary arterioles fragments, and the pulmonary artery smooth muscle cells (PASMCs) were primary cultured and identified. The cells were intervened by PKC agonist (PMA), PKCα inhibitor (safingol), PKCβⅠ inhibitor (Go6976) and PKCβⅡ inhibitor (LY333531) respectively, and the changes in protein expressions of cPKCs, and the phosphorylation levels of ERK1/2 and Akt were observed by immunoblotting under the condition of normal oxygen or hypoxia. The lentiviral vectors of PKCα and PKCβ were used to specifically knock-down the activity of target genes by virus transfection techniques, and Western blotting was used to observe the protein expressions of cPKCs, and the phosphorylation levels of ERK1/2 and Akt in hypoxia-induced PASMCs in mice. Results: With Brdu method, the proliferation of PASMCs induced by hypoxia was significantly inhibited by safingol, Go6976 and LY333531 by inhibiting cPKCα, βⅠ and βⅡ respectively. Compared with the hypoxic control group, the rates of Brdu positive cells were (7.35±0.26)% vs (11.28±0.43)%, (3.76±0.25)% vs (7.98±0.28)% and (4.12±0.46)% vs (7.78±0.53)%. We also observed that PMA could significantly promote the proliferation of PASMCs under normoxic condition. Compared with the normoxia control group, the Brdu-positive cell rates were (9.65±0.47)% vs (6.34±0.52)%, (9.34±0.38)% vs (5.42±0.21)% and (7.78±0.53)% vs (4.12±0.46)%. In addition, after transfection with PKCα or PKCβ lentiviral vector, the proliferation of PASMCs was significantly lower in hypoxia transfection group than in the control group. The rates of Brdu positive cells were (3.58±0.54)% vs (5.97±0.63)%, respectively. Using Western blotting, we also observed that after being inhibited by safingol, Go6976 and LY333531 respectively, the phosphorylation levels of ERK1/2 and Akt in PASMCs induced by hypoxia was significantly lower than the control group. After using safingol, the phosphorylation levels of ERK1/2 and Akt were (0.56±0.07) vs (1.08±0.13) and (0.49±0.04) vs (0.97±0.08). After using Go6976, the phosphorylation levels of ERK1/2 and Akt were (0.41±0.09) vs (0.79±0.10) and (0.48±0.09) vs (0.82±0.16), after using LY333531, the phosphorylation levels of ERK1/2 and Akt were (0.42±0.03) vs (0.87±0.06) and (0.34±0.07) vs (0.78±0.05). While PMA could promote the phosphorylation levels of ERK1/2 and Akt under normoxic condition, 1.25±0.12 vs 0.41±0.07 and 0.98±0.06 vs 0.37±0.08, respectively. Using transfection technique to specifically knock down the expression of cPKCα and β, we found that under hypoxic conditions, transfection of PASMCs could significantly lower the phosphorylation levels of ERK1/2, its phosphorylation level was 0.29±0.06 vs 0.76±0.05, with no evident change in the phosphorylation levels of Akt. Conclusions: Hypoxia may lead to phosphorylation of ERK1/2 by promoting the protein expression of cPKCα, cPKCβⅠ and cPKCβⅡ respectively, which eventually induces abnormal proliferation of PASMCs from the distal pulmonary arteries, participating in the development of hypoxic pulmonary hypertension (HPH) of the mice. Regulation of the expression of cPKCα, cPKCβⅠ and cPKCβⅡ may help to attenuate the formation of pulmonary vascular remodeling. Target therapy based on cPKCs is expected to be a new direction for HPH therapy in the future.

A Cross-Sectional Study of Association between Plasma Selenium Levels and the Prevalence of Osteoarthritis: Data from the Xiangya Osteoarthritis Study

OBJECTIVES

Selenium plays an indispensable role in antioxidant and antiinflammation processes. Oxidative stress and inflammation have been hypothesized to be involved in the pathogenesis of cartilage degeneration. We sought to examine the association between plasma selenium levels and the prevalence of radiographic osteoarthritis (ROA).

DESIGN

A population-based cross-sectional study.

SETTING AND PARTICIPANTS

Individuals aged ≥ 50 years were retrieved from the Xiangya Osteoarthritis (XO) Study, a community-based study conducted among the residents of the rural areas of China.

METHODS

Plasma selenium concentration was measured by inductively coupled plasma-dynamic reaction cell-mass spectrometry. ROA was defined as Kellgren/Lawrence score ≥ 2 in at least one knee, hip or hand joint. The association between plasma selenium levels and ROA was evaluated by applying logistic and spline regression.

RESULTS

A total of 1,032 subjects (women: 52.5%; mean age: 63.1 years; ROA prevalence: 45.4%) were included. Compared with the highest tertile, the odds ratios (ORs) for ROA were 1.24 (95% confidence interval [CI]: 0.91 to 1.68) and 1.77 (95% CI: 1.31 to 2.40) in the middle and lowest tertile of plasma selenium, respectively (P for trend<0.05). The results were not changed materially with adjustment of potential confounders. In addition, subjects who had lower plasma selenium levels exhibited a higher prevalence of ROA in a dose-response relationship manner (P=0.005).

CONCLUSION

This study suggests that subjects with lower levels of plasma selenium exhibited a higher prevalence of ROA in a dose-response relationship manner. However, additional studies are still needed to verify the potential causal relationship.

Association between bariatric surgery with long-term analgesic prescription and all-cause mortality among patients with osteoarthritis: a general population-based cohort study

OBJECTIVES

There is still a large unmet need for novel osteoarthritis (OA) treatments that could provide clinically important effects on long-term pain relief (≥12 months). We examined the relation of bariatric surgery along with weight loss to analgesic prescription and all-cause mortality among individuals with OA.

METHODS

We conducted a cohort study among individuals with OA using The Health Improvement Network. We compared the rate of no analgesic prescription ≥12 consecutive months and the risk of all-cause mortality using inverse probability weighting Cox-proportional hazard models and the difference in number of analgesic prescriptions (non-steroidal anti-inflammatory drugs, opioids, and paracetamol) in the 50^th, 75^th and 90^th percentiles using quantile regression model between bariatric and non-bariatric cohorts.

RESULTS

Included were 588,494 individuals (694 had bariatric surgery). Compared with non-bariatric group, the rate of no analgesic prescription ≥12 consecutive months was higher (HR = 1.23, 95% CI: 1.08-1.38) in bariatric surgery group, and the number of analgesic prescriptions was lower in the 75^th (44 vs 58) and 90^th (74 vs 106) percentiles during a mean follow-up of 4.3 years. All-cause mortality in bariatric surgery group was lower than comparison group (HR = 0.46, 95% CI: 0.41-0.51).

CONCLUSION

This study presents the first evidence that bariatric surgery was associated with decreased long-term analgesic prescription and decreased all-cause mortality among individuals with OA. However, our findings may be overestimated owing to intractable confounding by indication for bariatric surgery; thus, future studies (e.g., clinical trials) are warranted.

Comparative efficacy and safety of acetaminophen, topical and oral non-steroidal anti-inflammatory drugs for knee osteoarthritis: evidence from a network meta-analysis of randomized controlled trials and real-world data

OBJECTIVE

Current global guidelines regarding the first-line analgesics (acetaminophen, topical or oral non-steroidal anti-inflammatory drugs [NSAIDs]) for knee osteoarthritis remain controversial and their comparative risk-benefit profiles have yet to be adequately assessed.

DESIGN

Pubmed, Embase, Cochrane Library, and Web of Science were searched from database inception to March 2021 for randomized controlled trials (RCTs) comparing acetaminophen, topical NSAIDs and oral NSAIDs directly or indirectly in knee osteoarthritis. Bayesian network meta-analyses were conducted. A propensity-score matched cohort study was also conducted among patients with knee osteoarthritis in The Health Improvement Network database.

RESULTS

122 RCTs (47,113 participants) were networked. Topical NSAIDs were superior to acetaminophen (standardized mean difference [SMD] = -0.29, 95% credible interval [CrI]: -0.52 to -0.06) and not statistically different from oral NSAIDs (SMD = 0.03, 95% CrI: -0.16 to 0.22) for function. It had lower risk of gastrointestinal adverse effects (AEs) than acetaminophen (risk ratio [RR] = 0.52, 95%CrI: 0.35 to 0.76) and oral NSAIDs (RR = 0.46, 95%CrI: 0.34 to 0.61) in RCTs. In real-world data, topical NSAIDs showed lower risks of all-cause mortality (hazard ratio [HR] = 0.59, 95% confidence interval [CI]: 0.52 to 0.68), cardiovascular diseases (HR = 0.73, 95%CI: 0.63 to 0.85) and gastrointestinal bleeding (HR = 0.53, 95%CI: 0.41 to 0.69) than acetaminophen during the one-year follow-up (n = 22,158 participants/group). A better safety profile was also observed for topical than oral NSAIDs (n = 14,218 participants/group).

CONCLUSIONS

Topical NSAIDs are more effective than acetaminophen but not oral NSAIDs for function improvement in people with knee osteoarthritis. Topical NSAIDs are safer than acetaminophen or oral NSAIDs in trials and real-world data.

[The clinical effects of oral contraceptive pretreatment on the outcome of gonadotropin releasing hormone antagonist protocol in non-polycystic ovary syndrome patients]

Objective: To evaluate the clinical effect of oral contraceptive (OC) pretreatment on the outcome of gonadotropin releasing hormone antagonist (GnRH-a) protocol in patients with non-polycystic ovary syndrome. Methods: From January 2017 to May 2019, a total of 436 patients undergoing in vitro fertilization and embryo transfer/Intracytoplasmic sperm injection (IVF-ET/ICSI) treatment in Peking University First Hospital reproductive center clinic were included in this retrospective cohort study. A total of 144 patients (147 cycles) used OC pretreatment prior to GnRH-a protocol and 292 patients (306 cycles) used GnRH-a protocol without OC pretreatment. The drug usage as well as pregnant outcomes between groups were examined. The primary outcome was the cumulative clinical pregnancy rate of oocyte retrieval cycle and the secondary outcome included the number of oocytes, MⅡ oocytes, embryos and clinical pregnancy rate of fresh embryo transfer cycle. Results: The median ages (and Q₁, Q₃) of OC pretreatment group and non-OC group were 33 (30,36) and 34 (30,38) years old, respectively. The number of MⅡ oocytes was higher in OC pretreatment group (7/9) than in non-OC group (6/8) (P=0.002). The significant difference were not found in the cumulative clinical pregnancy rate of each oocyte retrieval cycle (61.7% vs 54.6%), the clinical pregnancy rate of fresh embryo transfer cycle (34.4% vs 35.6%), and the number of oocytes (9 vs 8) and embryos (6 vs 6) between groups. Conclusion: Our findings suggest that compared to non-OC pretreatment group, pretreatment with OC is associated with more MⅡ oocytes, and with an increasing trend of the cumulative clinical pregnancy rate in non-polycystic ovary syndrome patients undergoing fresh IVF-ET/ICSI.

Does smoking cessation increase risk of knee replacement? a general population-based cohort study

OBJECTIVE

Smoking represents a major issue for global public health. Owing to methodologic challenges, findings of an association between smoking and risk of knee osteoarthritis (OA) are inconsistent. We sought to assess the relation of onset of smoking cessation to the risk of OA sequelae, i.e., knee replacement, and to perform sub-cohort analysis according to weight change after smoking cessation.

DESIGN

Using The Health Improvement Network, we conducted a cohort study to examine the association between smoking cessation and risk of knee replacement among patients with knee OA. Participants who stopped smoking were further grouped into three sub-cohorts: weight gain (body mass index [BMI] increased>1.14 kg/m²), no substantial weight change (absolute value of BMI change<1.14 kg/m²), and weight loss (BMI loss>1.14 kg/m²) after smoking cessation.

RESULTS

We identified 108 cases of knee replacement among 1,054 recent quitters (26.7/1,000 person-years) and 1,108 cases among 15,765 current smokers (17.4/1,000 person-years). The rate difference of knee replacement in recent quitter cohort vs current smoker cohort was 10.4 (95% confidence interval [CI]:5.3-15.6)/1,000 person-years and the adjusted hazard ratio (HR) was 1.30 (95%CI:1.05-1.59). Compared with current smokers, risk of knee replacement was higher among quitters with weight gain (HR = 1.42,95%CI:1.01-1.98), but not among those with no substantial weight change (HR = 1.29,95%CI:0.90-1.83) or those with weight loss (HR = 1.11,95%CI:0.71-1.75).

CONCLUSIONS

Our large population-based cohort study provides the first evidence that smoking cessation was associated with a higher risk of knee replacement among individuals with knee OA, and such an association was due to weight gain after smoking cessation.

Novel variants and uncommon cases among southern Chinese children with X-linked hypophosphatemia

PURPOSE

X-linked hypophosphatemia (XLH) is the most common inherited renal phosphate wasting disorder and is often misdiagnosed as vitamin D deficiency. This study aims to provide clinical and mutational characteristics of 65 XLH pediatric patients in southern China.

METHODS

In this work, a combination of DNA sequencing and qPCR analysis was used to study the PHEX gene in 80 pediatric patients diagnosed with hypophosphatemia. The clinical and laboratory data of confirmed 65 XLH patients were assessed and analyzed retrospectively.

RESULTS

In 65 XLH patients from 61 families, 51 different variants in the PHEX gene were identified, including 23 previously reported variants and 28 novel variants. In this cohort of XLH patients, the c.1601C>T(p.Pro534Leu) variant appears more frequently. Fourteen uncommon XLH cases were described, including four boys with de novo mosaic variants, eight patients with large deletions and a pair of monozygotic twins. The clinical manifestations in this cohort are very similar to those previously reported.

CONCLUSION

This study extends the mutational spectrum of the PHEX gene, which will contribute to accurate diagnosis. This study also suggests a supplementary qPCR or MLPA assay may be performed along with classical sequencing to confirm the gross insertion/deletion.

SAT0453 DELAYED DENOSUMAB INJECTIONS AND FRACTURES RISK AMONG SUBJECTS WITH OSTEOPOROSIS: A POPULATION-BASED COHORT STUDY

Background:

Denosumab is effective for osteoporosis, but discontinuation leads to rapid reversal of its therapeutic effect[1].

Objectives:

To estimate the risk for fracture among users of denosumab who delayed subsequent dosages compared with users who received dosages on time.

Methods:

Population-based cohort study. We included patients aged over 45 years who initiated denosumab for osteoporosis from UK THIN database, 2010 to 2019. Observational data were used to “emulate a hypothetical trial”[2, 3] with three dosing intervals: subsequent denosumab injection 24-28 weeks after prior dose (“on time”), delay by 4-16 weeks (“short delay”), and delay by over 16 weeks (“long delay”). The primary outcome was a composite of all fracture types. Secondary outcomes included major osteoporotic fracture, vertebral fracture, and hip fracture.

Results:

The rate of composite fracture per 1000 person-years was 58.9 for on-time, 61.7 for short delay, and 85.4 for long delay of subsequent denosumab injections. Compared to on-time injections, short delay had a hazard ratio (HR) for composite fracture 1.03 (95% CI 0.63-1.69) and long delay HR 1.44 (95% CI 0.96-2.17; p for trend 0.093). For major osteoporotic fractures, short delay had an HR 0.94 (95% CI 0.57-1.55) and long delay an HR of 1.69 (95% CI 1.01-2.83; p for trend 0.056). For vertebral fractures, short delay had an HR 1.48 (95% CI 0.58-3.79) and long delay 3.91 (95% CI 1.62-9.45; p for trend 0.005).

Conclusion:

While delayed subsequent denosumab dosages over 16 weeks was associated with an increased risk of vertebral and major osteoporotic fracture compared to no delay, composite fracture risk was not increased with longer delays.

References:

[1]Cummings SR, Ferrari S, Eastell R, et al. Vertebral Fractures After Discontinuation of Denosumab: A Post Hoc Analysis of the Randomized Placebo-Controlled FREEDOM Trial and Its Extension. J Bone Miner Res, 2017.

[2]Hernán MA. How to estimate the effect of treatment duration on survival outcomes using observational data. BMJ 2018.

[3]Hernán MA, Robins JM. Using Big Data to Emulate a Target Trial When a Randomized Trial Is Not Available. Am J Epidemiol 2016.

Table.

Rates and Adjusted Hazard Ratios of Fracture

On-timeShort delayLong delayP for linear trendComposite FractureRate (per 1000 person-years)5961.785.4-Unadjusted HR (95 %)Ref1.05 (0.62, 1.76)1.45 (0.95, 2.21)0.097Adjusted HR (95% CI)†Ref1.03 (0.63, 1.69)1.44 (0.96, 2.17)0.093Major Osteoporotic FractureRate (per 1000 person-years)34.831.958-Unadjusted HR (95 %)Ref0.92 (0.55, 1.53)1.67 (0.98, 2.84)0.074Adjusted HR (95% CI)†Ref0.94 (0.57, 1.55)1.69 (1.01, 2.83)0.056Vertebral FractureRate (per 1000 person-years)4.97.319.4-Unadjusted HR (95 %)Ref1.47 (0.58, 3.71)3.93 (1.59, 9.72)0.006Adjusted HR (95% CI)†Ref1.48 (0.58, 3.79)3.91 (1.62, 9.45)0.005Hip FractureRate (per 1000 person-years)10.29.618.3-Unadjusted HR (95 %)Ref0.94 (0.43, 2.04)1.78 (0.80, 3.97)0.18Adjusted HR (95% CI)†Ref0.97 (0.44, 2.12)1.75 (0.81, 3.79)0.173

†Adjusted model: adjusted by age, sex, baseline CCI index, major osteoporotic fracture, oral BP duration (years), 10-year risk of major osteoporotic fracture, prior denosumab doses.

Acknowledgments:

We acknowledge Dr. Dani Prieto-Alhambra for kindly providing Read codes.

Disclosure of Interests:

Houchen Lyu: None declared, Kazuki Yoshida: None declared, Sizheng Steven Zhao: None declared, Xabier García-Albéniz: None declared, Jie Wei: None declared, Chao Zeng: None declared, Sara Tedeschi: None declared, Benjamin Leder Grant/research support from: Research funding from Amgen, Guanghua Lei: None declared, Peifu Tang: None declared, Daniel Solomon Grant/research support from: Funding from Abbvie and Amgen unrelated to this work

[Application of combined angiography in diagnosis and treatment of carotid artery stenosis]

Objective: To evaluate the safety and clinical value of combined cardiac and cerebral angiography in the diagnosis and treatment of patients with carotid artery stenosis. Methods: Clinical data of patients from May 2016 to June 2019 were collected. The patient underwent combined angiography under local anesthesia. Clinical characteristics, prognosisand complications were retrospectively analyzed. Results: A total of 45 patients with carotid artery stenosis received combined angiography, among which 12 patients had no obvious carotid artery stenosis. There were 22 cases with unilateral carotid artery stenosis, including 12 cases with mild stenosis and 10 cases with moderate to severe stenosis. There were 11 cases of bilateral stenosis, including 3 cases with mild stenosis and 8 cases with moderate to severe stenosis. 12 patients had no obvious stenosis incoronary arteries, 11 patients had single-vessel disease, 7 patients had 2-vessel disease, and 15 patients had 3-vessel disease. In the whole group of patients, surgical indications are available of 18 patients with carotid artery stenosis, 4 of the mreceived combined therapy. 2 of them under went Carotid Endarterectomy (CEA)+Percutaneous Transluminal Coronary Intervention (PCI), 2 under went Carotid Artery Stenting (CAS)+PCI. CAS+coronary artery angiography was performed in 3 cases. CEA+coronary angiography was performed in 5 cases. 5 patients received conservative treatment after combined angiography. In one case, the condition of coronary artery was so complicated that PCI was performed firstly. No cardiac or cerebrovascular complications such as myocardial infarction or cerebral infarction occurred during perioperative period. Conclusion: Combined cardio-cerebrovascular angiography is a good method to evaluate the cardiovascular and cerebrovascular in the diagnosis and treatment of patients with carotid artery stenosis, which can provide a clear diagnosis for treatment with a low complications frequency.

[Simultaneous treatments in patients with severe carotid artery stenosis and coronary artery disease]

Objective: To implement simultaneous treatments in patients with severe carotid artery stenosis and coronary artery disease (CAD), we sought to investigate its efficacy of reducing perioperative major adverse cardiac and cerebrovascular event (MACCE). Methods: Brain-and-Heart treatment team in Peking University International Hospital performed hybrid Digital Substraction Angiography (DSA) of carotid artery and coronary artery for 37 patients meeting the group criterion from September 2017 to February 2019.Twelve patients were diagnosed and received simultaneous treatments of severe carotid artery stenosis and coronary artery disease after hybrid DSA. We conducted the retrospective study and made analysis of these patients. Results: The diagnosis rate by simultaneous treatmentsin patients with carotid artery stenosis and coronary artery disease is 59.5% (22/37), the rate of severe carotid artery stenosis or multi-vessel CAD is 77.3% (17/22).The rate of severe carotid artery stenosis with CAD is 54.5% (12/22), therate of simultaneous treatmentsis 83.3%(10/12). Nine patients post-operative symptoms release, one patient with ischemic stroke after CABG, and two patients of medical therapy with stable symptoms. Conclusion: Simultaneous treatments in patients with severe carotid artery stenosis and coronary artery disease not only reveal the positive correlation between carotid stenosis and CAD, but also accurately evaluate severity degree or rapidly formulate scheme and reduce MACCE.

Thiazide diuretics and risk of knee replacement surgery among patients with knee osteoarthritis: a general population-based cohort study

OBJECTIVE

Thiazide diuretic use is associated with higher bone mineral density (BMD) and possibly lower serum magnesium levels than loop diuretic use, and both high BMD and low serum magnesium have been linked to high prevalent knee osteoarthritis. This study aimed to compare the risk of a clinically relevant endpoint, knee replacement (KR) surgery, among initiators of thiazide and loop diuretics.

DESIGN

Among patients aged ≥50 years with a diagnosis of knee osteoarthritis in The Health Improvement Network (THIN) in United Kingdom, we conducted a propensity score-matched cohort study to examine the relation of thiazide diuretic initiation vs loop diuretic initiation to the risk of KR over 5 years.

RESULTS

Among thiazide and loop diuretic initiators (n = 3,488 for each group; mean age: 73 years; female ratio: 59%), 359 (28.6/1,000 person-years) and 283 (24.1/1,000 person-years) KRs occurred during the follow-up period, respectively. The hazard ratio (HR) of KR for thiazide diuretic initiation vs loop diuretic initiation was 1.26 (95% confidence interval [CI]: 1.08-1.47). The adherence-adjusted HR of KR for continuous use of thiazide diuretics was 1.44 (95% CI: 1.21-1.72).

CONCLUSIONS

In this population-based cohort of patients with knee osteoarthritis, thiazide diuretic use was associated with a higher risk of KR than loop diuretic use. This association may potentially be due to thiazide diuretics' effect on BMD and serum magnesium.

Intra-articular corticosteroids and the risk of knee osteoarthritis progression: results from the Osteoarthritis Initiative

OBJECTIVE

A recent randomized clinical trial reported that repeated intra-articular corticosteroids (IACs) were associated with a greater cartilage loss. This study aimed to examine the relation of IACs to knee radiographic osteoarthritis (ROA) progression in a real-world setting.

DESIGN

A cohort that initiated IACs and a comparison cohort without IACs from participants with mild to moderate knee ROA in the Osteoarthritis Initiative (OAI) were assembled (from 0-month to 48-month). Two measures of knee ROA progression were assessed during the follow-up period: (1) an increase in Kellgren and Lawrence (KL) grade by ≥1 grade or having a knee replacement (i.e., KL grade worsening); and (2) a decrease in joint space width (JSW) by ≥0.7 mm or having a knee replacement (i.e., JSW worsening). The associations of IACs initiation using a propensity-score matched cohort study and continuous IACs using marginal structural models with the risk of knee ROA progression were examined.

RESULTS

Among 684 propensity-score matched participants at baseline (148 IACs initiators, 536 comparators), 65 knees (21.7/100 person-years) in the IACs initiation cohort and 90 knees (7.1/100 person-years) in the comparison cohort experienced KL worsening. The hazard ratios (HRs) of KL worsening from IACs initiation and continuous IACs were 3.02 (95% confidence interval [CI], 2.19-4.16) and 4.67 (95% CI, 2.92-7.47), respectively. The corresponding HRs of JSW worsening were 2.93 (95% CI, 2.13-4.02) and 3.26 (95% CI, 1.78-5.96), respectively. All HRs for continuous use of IACs were further away from the null.

CONCLUSIONS

IACs, especially continuous IACs, may be associated with an increased risk of knee ROA progression.

[Vascular endothelial growth factor is up-regulated by leukemia inhibitory factor and interleukin-6 in human endometriotic stromal cells]

Objective: To compare the expression of leukemia inhibitory factor (LIF), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in tissue and fluid samples from patients with endometriosis, and investigate whether LIF and IL-6 regulate VEGF in human endometriotic stromal cells (ESC). Methods: The levels of VEGF, LIF, IL-6 in serum, peritoneal fluid of patients with and without endometriosis were measured by ELISA. The mRNA of these three factors in the ectopic and eutopic endometrial tissue and stromal cells were measured by real-time PCR. ESC derived from ovarian endometriomas were cultured using the method of primary cell culture with LIF and IL-6, and the level of VEGF mRNA and protein were measured by the method of real-time PCR and ELISA respectively. Results: VEGF and IL-6 concentration were 1.2 and 1.3 times higher in the serum of patients with endometriosis than in the control group [(94±19) versus (78±17) ng/L; (45±14) versus (35±9) ng/L; all P<0.05]. VEGF and IL-6 concentration were 1.2 and 1.4 times higher in the peritoneal fluid of patients with endometriosis than in the control group [(110±25) versus (91±21) ng/L; (69±20) versus (49±15) ng/L; all P<0.05]. VEGF and IL-6 concentrations in peritoneal fluid of patients with endometriosis were 1.2 and 1.5 times higher than in serum (all P<0.01). VEGF, LIF and IL-6 mRNA expression were 2.2, 8.6, 44.7 times higher in ESC compared with the matching eutopic endometrial stromal cells (all P<0.01). LIF and IL-6 mRNA were 2.0 and 64.8 times higher in ectopic endometrial tissue than the matching eutopic endometrial tissue (all P<0.05).ESC cultured with LIF, IL-6 and LIF+IL-6 induce VEGF protein secretion [(106±18), (124±30), (140±27) ng/L] by 1.3, 1.5 and 1.7 times (all P<0.05). Conclusion: Overexpression of LIF and IL-6 may synergistically contribute to upregulation of VEGF in ESC and promote development of endometriosis.

Risk factor heterogeneity for medial and lateral compartment knee osteoarthritis: analysis of two prospective cohorts

OBJECTIVE

To evaluate the etiologic heterogeneity between medial and lateral tibiofemoral radiographic osteoarthritis (ROA).

METHODS

Knees without medial or lateral tibiofemoral ROA at baseline were followed for 60-month in Multicenter Osteoarthritis Study (MOST) and for 48-month in Osteoarthritis Initiative (OAI). We examined the relation of previously reported risk factors to incident medial and lateral tibiofemoral ROA separately and determined the etiology heterogeneity with a ratio of rate ratios (RRs) (i.e., the RR for medial tibiofemoral ROA divided by the RR for lateral tibiofemoral ROA) using a duplication method for Cox proportional hazard regression.

RESULTS

Of 2,016 participants in MOST, 436 and 162 knees developed medial or lateral tibiofemoral ROA, respectively. Obesity and varus malalignment were 95% and 466% more strongly associated with incident medial tibiofemoral ROA than with lateral tibiofemoral ROA, respectively (ratios of RRs, 1.95 [95% confidence interval (CI):1.05-3.62] and 5.66 [95% CI:3.20-10.0]). In contrast, the associations of female sex and valgus malalignment with incident medial tibiofemoral ROA were weaker or in an opposite direction compared with lateral tibiofemoral Osteoarthritis (OA) (ratios of RRs, 0.40 [95% CI:0.26-0.63] and 0.20 [95% CI:0.12-0.34], respectively). Older age tended to show a weaker association with incident medial tibiofemoral ROA than with incident lateral tibiofemoral ROA. No heterogeneity was observed for the relation of race, knee injury, or contralateral knee ROA. These findings were closely replicated in OAI.

CONCLUSION

Risk factor profiles for medial and lateral tibiofemoral ROA are different. These results can provide a framework for the development of targeted prevention and potential treatment strategies for specific knee OA subtypes.

Mechanical stress contributes to osteoarthritis development through the activation of transforming growth factor beta 1 (TGF-β1)

Objectives

The role of mechanical stress and transforming growth factor beta 1 (TGF-β1) is important in the initiation and progression of osteoarthritis (OA). However, the underlying molecular mechanisms are not clearly known.

Methods

In this study, TGF-β1 from osteoclasts and knee joints were analyzed using a co-cultured cell model and an OA rat model, respectively. Five patients with a femoral neck fracture (four female and one male, mean 73.4 years (68 to 79)) were recruited between January 2015 and December 2015. Results showed that TGF-β1 was significantly upregulated in osteoclasts by cyclic loading in a time- and dose-dependent mode. The osteoclasts were subjected to cyclic loading before being co-cultured with chondrocytes for 24 hours.

Results

A significant decrease in the survival rate of co-cultured chondrocytes was found. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) assay demonstrated that mechanical stress-induced apoptosis occurred significantly in co-cultured chondrocytes but administration of the TGF-β1 receptor inhibitor, SB-505124, can significantly reverse these effects. Abdominal administration of SB-505124 can attenuate markedly articular cartilage degradation in OA rats.

Conclusion

Mechanical stress-induced overexpression of TGF-β1 from osteoclasts is responsible for chondrocyte apoptosis and cartilage degeneration in OA. Administration of a TGF-β1 inhibitor can inhibit articular cartilage degradation.

Cite this article: R-K. Zhang, G-W. Li, C. Zeng, C-X. Lin, L-S. Huang, G-X. Huang, C. Zhao, S-Y. Feng, H. Fang. Mechanical stress contributes to osteoarthritis development through the activation of transforming growth factor beta 1 (TGF-β1). Bone Joint Res 2018;7:587–594. DOI: 10.1302/2046-3758.711.BJR-2018-0057.R1.

Potential benefit of (-)-epigallocatechin-3-gallate for macrovascular complications in diabetes

Vascular problems are the most common complications in diabetes. Substantial evidence from epidemiological and pathophysiological studies show that hyperglycemia is a major risk factor for macrovascular complications in patients with diabetes. (-)-Epigallocatechin-3-gallate (EGCG), the major catechin derived from green tea, is known to exert a variety of cardiovascular beneficial effects. The protective effects of EGCG in diabetes are also evident. However, whether EGCG is beneficial against macrovascular complications that occur in diabetes remains unknown. Our previous studies demonstrated that treatment of EGCG inhibits high glucose-induced vascular smooth muscle cell proliferation and suppresses high glucose-mediated vascular inflammation in human umbilical vein endothelial cells. Therefore, we hypothesize that EGCG might be an effective potential candidate to reduce the macrovascular complications in diabetes.

mTORC1 activation downregulates FGFR3 and PTH/PTHrP receptor in articular chondrocytes to initiate osteoarthritis

OBJECTIVE

Articular chondrocyte activation, involving aberrant proliferation and prehypertrophic differentiation, is essential for osteoarthritis (OA) initiation and progression. Disruption of mechanistic target of rapamycin complex 1 (mTORC1) promotes chondrocyte autophagy and survival, and decreases the severity of experimental OA. However, the role of cartilage mTORC1 activation in OA initiation is unknown. In this study, we elucidated the specific role of mTORC1 activation in OA initiation, and identify the underlying mechanisms.

METHOD

Expression of mTORC1 in articular cartilage of OA patients and OA mice was assessed by immunostaining. Cartilage-specific tuberous sclerosis complex 1 (Tsc1, mTORC1 upstream inhibitor) knockout (TSC1CKO) and inducible Tsc1 KO (TSC1CKO^ER) mice were generated. The functional effects of mTORC1 in OA initiation and development on its downstream targets were examined by immunostaining, western blotting and qPCR.

RESULTS

Articular chondrocyte mTORC1 was activated in early-stage OA and in aged mice. TSC1CKO mice exhibited spontaneous OA, and TSC1CKO^ER mice (from 2 months) exhibited accelerated age-related and DMM-induced OA phenotypes, with aberrant chondrocyte proliferation and hypertrophic differentiation. This was associated with hyperactivation of mTORC1 and dramatic downregulation of FGFR3 and PPR, two receptors critical for preventing chondrocyte proliferation and differentiation. Rapamycin treatment reversed these phenotypes in KO mice. Furthermore, in vitro rescue experiments demonstrated that p73 and ERK1/2 may mediate the negative regulation of FGFR3 and PPR by mTORC1.

CONCLUSION

mTORC1 activation stimulates articular chondrocyte proliferation and differentiation to initiate OA, in part by downregulating FGFR3 and PPR.

Catching a virus in a molecular net

A metal-organic molecular net composed of tannic acid (TA) and iron(iii) was constructed around the brome mosaic virus (BMV) particle to determine whether the added net could act as a transport barrier for water, and if the net could stabilize the virus in physically or chemically challenging environments. This new virus engineering strategy is expected to provide benefits both in the study and technological applications of viruses. For instance, a virus wrapped in a thin molecular layer could be extracted from solution either in air or vacuum, and its structure, composition and even internal dynamics could be interrogated by methods not compatible with a liquid environment. Atomic force microscopy (AFM) studies of Fe(iii)-TA coated BMV in liquid and in air supported a marked resistance to dehydration when compared to wtBMV. Native charge detection mass spectrometry (CDMS), was employed to estimate the number of molecules in the molecular net which wrapped the virus. The CDMS data suggested that less than one molecular monolayer wrapped the virus. Additionally, it was found, that this very thin molecular coat was sufficient to render the coated viruses resistant to storage conditions that typically lead to virus disassembly over time. A temporary coat imparting increased resistance to disassembly could be useful in adding time delay control or alleviate required storage conditions of engineered viruses for therapeutic purposes.