Toxicological Research on Nano and Microplastics in Environmental Pollution: Current Advances and Future Directions

This review explains the sources of nanoplastics (NPs) and microplastics (MPs), their release, fate, and associated health risks in the aquatic environment. In the 21st century, scientists are grappling with a major challenge posed by MPs and NPs. The global production of plastic has skyrocketed from 1.5 million tons in the 1950s to an astonishing 390.7 million tons in 2021. This pervasive presence of these materials in our environment has spurred scientific inquiry into their potentially harmful effects on living organisms. Studies have revealed that while MPs, with their larger surface area, are capable of absorbing contaminants and pathogens from the surroundings, NPs can easily be transferred through the food chain. As a result, living organisms may ingest them and accumulate them within their bodies. Due to their minuscule size, NPs are particularly difficult to isolate and quantify. Furthermore, exposure to both NPs and MPs has been linked to various adverse health effects in aquatic species, including neurological impairments, disruption of lipid and energy metabolism, and increased susceptibility to cytotoxicity, oxidative stress, inflammation, and reactive oxygen species (ROS) production. It is alarming to note that MPs have even been detected in commercial fish, highlighting the severity of this issue. There are also challenges associated with elucidating the toxicological effects of NPs and MPs, which are discussed in detail in this review. In conclusion, plastic pollution is a pressing issue that governments should tackle by ensuring proper implementation of rules and regulations at national and provincial levels to reduce its health risks.

Efficacy of fecal microbiota transplantation in patients with Parkinson's disease: clinical trial results from a randomized, placebo-controlled design

The occurrence and development of Parkinson's disease (PD) have been demonstrated to be related to gut dysbiosis, however, the impact of fecal microbiota transplantation (FMT) on microbiota engraftment in PD patients is uncertain. We performed a randomized, placebo-controlled trial at the Department of Neurology, Army Medical University Southwest Hospital in China (ChiCTR1900021405) from February 2019 to December 2019. Fifty-six participants with mild to moderate PD (Hoehn-Yahr stage 1-3) were randomly assigned to the FMT and placebo group, 27 patients in the FMT group and 27 in the placebo group completed the whole trial. During the follow-up, no severe adverse effect was observed, and patients with FMT treatment showed significant improvement in PD-related autonomic symptoms compared with the placebo group at the end of this trial (MDS-UPDRS total score, group×time effect, B = -6.56 [-12.98, -0.13], P < 0.05). Additionally, FMT improved gastrointestinal disorders and a marked increase in the complexity of the microecological system in patients. This study demonstrated that FMT through oral administration is clinically feasible and has the potential to improve the effectiveness of current medications in the clinical symptoms of PD patients.

One-pot synthesis of ultra-stable polyvinylpyrrolidone-modified MnO2 nanoparticles for efficient radiation protection

Radiobiological damage can be caused by radiation, and easy preparation of long-term stable radioprotectors is helpful for timely and efficient response to radiation emergencies. This study develops an ultra-stable radioprotector for rapid nuclear emergency with a simple preparing method. First of all, polyvinylpyrrolidone-modified MnO2 nanoparticles (PVP-MnO2 NPs) are obtained by one-pot synthesis with ultra-stability (remaining for at least three years) and multiple free radical scavenging activities. In the synthesis process, PVP acts as a reducing agent, a surfactant (soft template), and a steric stabilizer. PVP-MnO2 NPs can improve the survival rates of irradiated cells by effectively scavenging free radicals and protecting DNA from radiation damage. Besides, PVP-MnO2 NPs can also prevent peripheral blood cell and organ damage induced by radiation, and improve the survival rate of irradiated mice. Finally, PVP-MnO2 NPs are mainly metabolized by liver and kidney in mice, and basically excreted 72 h after administration. These results indicate that PVP-MnO2 NPs exhibit good biosafety and radioprotection activity, which is significant for the development of radioprotection agents.

Use of genome sequencing to hunt for cryptic second-hit variants: analysis of 31 cases recruited to the 100 000 Genomes Project

BACKGROUND

Current clinical testing methods used to uncover the genetic basis of rare disease have inherent limitations, which can lead to causative pathogenic variants being missed. Within the rare disease arm of the 100 000 Genomes Project (100kGP), families were recruited under the clinical indication 'single autosomal recessive mutation in rare disease'. These participants presented with strong clinical suspicion for a specific autosomal recessive disorder, but only one suspected pathogenic variant had been identified through standard-of-care testing. Whole genome sequencing (WGS) aimed to identify cryptic 'second-hit' variants.

METHODS

To investigate the 31 families with available data that remained unsolved following formal review within the 100kGP, SVRare was used to aggregate structural variants present in <1% of 100kGP participants. Small variants were assessed using population allele frequency data and SpliceAI. Literature searches and publicly available online tools were used for further annotation of pathogenicity.

RESULTS

Using these strategies, 8/31 cases were solved, increasing the overall diagnostic yield of this cohort from 10/41 (24.4%) to 18/41 (43.9%). Exemplar cases include a patient with cystic fibrosis harbouring a novel exonic LINE1 insertion in CFTR and a patient with generalised arterial calcification of infancy with complex interlinked duplications involving exons 2-6 of ENPP1. Although ambiguous by short-read WGS, the ENPP1 variant structure was resolved using optical genome mapping and RNA analysis.

CONCLUSION

Systematic examination of cryptic variants across a multi-disease cohort successfully identifies additional pathogenic variants. WGS data analysis in autosomal recessive rare disease should consider complex structural and small intronic variants as potentially pathogenic second hits.

Dynamic Effects of Thoracic Irradiation on Immune Status of Organs in and out of Radiation Field in Mice

PURPOSE/OBJECTIVE(S)

Thoracic irradiation involves large blood vessels and hematopoietic tissues which was easily inducing lymphopenia. Lymphocytes are important components of immune response and lymphopenia is associated with poorer survival. However, the dynamic recovery of lymphocyte subsets after thoracic irradiation were rarely reported in the literature. This study focused on dynamic changes of lymphocytes subsets of mice after receiving thoracic irradiation in and out of radiation field.

MATERIALS/METHODS

C57BL/6 male mice aged 6-8 weeks received 2Gy*5fx whole thoracic irradiation and were sacrificed on the 1 day, 7 days, 15 days, 25 days after irradiation. Peripheral blood was harvested for mature lymphocyte subsets (B cells, T cells, CD4+T cells, CD8+T cells, NK cells) detection by performing flow cytometry, while thymus, femur bone marrow and sternal bone marrow for hematopoietic stem cells (Long-term Hematopoietic Stem Cell [LT-HSC], Short-term Hematopoietic Stem Cell [ST-HSC]) and progenitor cells (Multipotent Progenitor [MPP], Common Lymphoid Progenitor [CLP]). Absolute counts method was used in flow cytometry and data analysis were performed by scientific 2-D graphing and statistics software.

RESULTS

We found that the lymphocyte subsets were significantly reduced in peripheral blood of irradiated mice (all p<0.05). The mature lymphocyte subsets returned to normal 2-3 weeks after irradiation. After radiation, thymus weight was significantly decreased (p<0.0001). With the recovery of thymus weight, the number of hematopoietic stem cells returned to the baseline. For the femur bone marrow (out of the radiation field), hematopoietic stem cells and progenitor cells showed a proliferation tendency. MPP significantly increased in the 1day after irradiation (p = 0.0347) and LT-HSC increased in the 8 days (p = 0.0011). However, although ST-HSC and CLP were slightly increased after irradiation, there were no statistically significance. The sternal bone marrow (in the radiation field) reached the lowest value 1day after irradiation (all p<0.0001). Although hematopoietic stem cells and progenitor cells recovered gradually, but still far away from the level of the control group (all p<0.05).

CONCLUSION

The recovery of lymphocytes in the peripheral blood might mainly come from the supplement of bone marrow out of the irradiation field, while bone marrow in the field suffered serious destruction which did slightly help for lymphocytes recovery.

Recovery Characteristics of Lymphocyte Subsets after Thoracic Radiotherapy: A Single Center Clinical Study

PURPOSE/OBJECTIVE(S)

Lymphocytes play a critical role in anti-tumor, and are highly sensitive to radiation. However, the dynamic changes of lymphocytes subsets after receiving thoracic radiotherapy have rarely been investigated. This study was to explore the recovery characteristics of each subset, and the role of thymosin α1 after thoracic radiotherapy.

MATERIALS/METHODS

A total of 252 patients receiving chest radiotherapy included in this study. Blood was harvested before, at the end of radiotherapy, 1 month, 4 months, 7 months, 10 months, 13 months, and 19 months after radiotherapy for lymphocyte subsets detection by performing flow cytometry. In addition, a total of 26 patients with thoracic malignancy were treated with thymosin α1 after radiotherapy for one month. The number of lymphocyte subsets at the end of 1 month after radiotherapy were compared with control group. Absolute counts method was used in flow cytometry.

RESULTS

At the end of radiotherapy, nearly all of the subsets decreased significantly (T cell: 65.4%, Tc cell: 64.8%, Th cell: 66.1%, B cell: 88.7%, NK cell: 68.8%), except Treg cell. Tc cells recovered rapidly to baseline level at 1 month. The number of NK cells increased by 1.95 times at 1 month, and recovered to baseline level at 7th month. The number of B cell at 1 month was still 19.2% compared baseline, and recovered slowly to baseline at 7th month. The number of Th cells were nearly no recovery, and were 44.1% compared with baseline even at 19th month. For patients with thymosin α1 injection, all of the lymphocyte subsets had no significant difference compared those without thymosin α1 injection. In addition, younger patients were with better recovery in Th cells (p = 0.011) and B cells (p < 0.001) than elder patients at 1 month.

CONCLUSION

B cell was the most radiosensitive lymphocyte, and Th cell was continuous exhaustion after thoracic radiation. Thymosin α1 had no effect on lymphocyte subpopulation recovery, and new drugs are urgently needed to explore in the future.

Randomized phase II adjuvant trial to compare two treatment durations of icotinib (2 years versus 1 year) for stage II-IIIA EGFR-positive lung adenocarcinoma patients (ICOMPARE study)

BACKGROUND

Despite the prolonged median disease-free survival (DFS) by adjuvant targeted therapy in non-small-cell lung cancer patients with epidermal growth factor receptor (EGFR) mutations, the relationship between the treatment duration and the survival benefits in patients remains unknown.

PATIENTS AND METHODS

In this multicenter, randomized, open-label, phase II trial, eligible patients aged 18-75 years with EGFR-mutant, stage II-IIIA lung adenocarcinoma and who had not received adjuvant chemotherapy after complete tumor resection were enrolled from eight centers in China. Patients were randomly assigned (1 : 1) to receive either 1-year or 2-year icotinib (125 mg thrice daily). The primary endpoint was DFS assessed by investigator. The secondary endpoints were overall survival (OS) and safety. This study was registered at ClinicalTrials.gov (NCT01929200).

RESULTS

Between September 2013 and October 2018, 109 patients were enrolled (1-year group, n = 55; 2-year group, n = 54). Median DFS was 48.9 months [95% confidence interval (CI) 33.1-70.1 months] in the 2-year group and 32.9 months (95% CI 26.6-44.8 months) in the 1-year group [hazard ratio (HR) 0.51; 95% CI 0.28-0.94; P = 0.0290]. Median OS for patients was 75.8 months [95% CI 64.4 months-not evaluable (NE)] in the 2-year group and NE (95% CI 66.3 months-NE) in the 1-year group (HR 0.34; 95% CI 0.13-0.95; P = 0.0317). Treatment-related adverse events (TRAEs) were observed in 41 of 55 (75%) patients in the 1-year group and in 36 of 54 (67%) patients in the 2-year group. Grade 3-4 TRAEs occurred in 4 of 55 (7%) patients in the 1-year group and in 3 of 54 (6%) patients in the 2-year group. No treatment-related deaths or interstitial lung disease was reported.

CONCLUSIONS

Two-year adjuvant icotinib was shown to significantly improve DFS and provide an OS benefit in EGFR-mutant, stage II-IIIA lung adenocarcinoma patients compared with 1-year treatment in this exploratory phase II study.

Beneficial effects of pioglitazone and α-lipoic acid in patients with polycystic ovaries syndrome

OBJECTIVE

Changes in hormone levels, improper lipid metabolism, and oxidative stress all significantly contribute to the pathogenic process of polycystic ovarian syndrome (PCOS). According to earlier research, pioglitazone and alpha-lipoic acid are crucial in the emergence of PCOS. The beneficial effects of pioglitazone and alpha-lipoic acid on PCOS were examined in the current study.

PATIENTS AND METHODS

The 120 patients with PCOS received three months of treatment in pioglitazone groups (n=40 case, 30 mg/time, 1 time/day), α-lipoic acid (n=40 case, 0.6 g/time, 1 time/day), and combination therapy (n=40 case, pioglitazone 30 mg/time, 1 time/day and α-lipoic acid, 0.6 g/time, 1 time/day). Before and after therapy, the following factors were evaluated: the hormonal profile, fasting serum insulin, body weight, body mass index (BMI), menstruation status, oxidative stress, and indications of lipid metabolism.

RESULTS

The combination of pioglitazone and α-lipoic acid has a significantly improving effect on BMI, body weight, oxidative stress levels, lipid metabolism, and menstrual status. A significant increase in body weight, BMI, and follicle-stimulating hormone (FSH) levels were found in mice after being treated with α-lipoic acid alone. However, the use pioglitazone alone improves body weight, BMI, the calculation of insulin resistance index (HOMA-IR), Area under the curve (AUC)-insulin, fasting glucose/insulin (G/I) ratio, total testosterone, and malondialdehyde (MDA) levels in post-treatment than pre-treatment.

CONCLUSIONS

These findings suggest that pioglitazone alone has a better effect than alpha-lipoic acid in improving oxidative stress levels, BMI, and menstrual cyclicity. Additionally, treatment with pioglitazone and alpha-lipoic acid did demonstrate a greater effect than monotherapy with each medication alone.

Lactobacillus plantarum-derived indole-3-lactic acid ameliorates colorectal tumorigenesis via epigenetic regulation of CD8+ T cell immunity

Previous studies have shown that Lactobacillus species play a role in ameliorating colorectal cancer (CRC) in a mouse model. However, the underlying mechanisms remain largely unknown. Here, we found that administration of a probiotic strain, Lactobacillus plantarumL168 and its metabolite, indole-3-lactic acid, ameliorated intestinal inflammation, tumor growth, and gut dysbiosis. Mechanistically, we indicated that indole-3-lactic acid accelerated IL12a production in dendritic cells by enhancing H3K27ac binding at the enhancer regions of IL12a that contributed to priming CD8⁺ T cell immunity against tumor growth. Furthermore, indole-3-lactic acid was found to transcriptionally inhibit Saa3 expression related to cholesterol metabolism of CD8⁺ T cells through changing chromatin accessibility and subsequent enhancing function of tumor-infiltrating CD8⁺ T cells. Together, our findings provide new insights into the epigenetic regulation of probiotics-mediated anti-tumor immunity and suggest the potential of L. plantarumL168 and indole-3-lactic acid to develop therapeutic strategies for patients with CRC.

The landscape in the gut microbiome of long-lived families reveals new insights on longevity and aging - relevant neural and immune function

Human longevity has a strong familial and genetic component. Dynamic characteristics of the gut microbiome during aging associated with longevity, neural, and immune function remained unknown. Here, we aim to reveal the synergistic changes in gut microbiome associated with decline in neural and immune system with aging and further obtain insights into the establishment of microbiome homeostasis that can benefit human longevity. Based on 16S rRNA and metagenomics sequencing data for 32 longevity families including three generations, centenarians, elderly, and young groups, we found centenarians showed increased diversity of gut microbiota, severely damaged connection among bacteria, depleted in microbial-associated essential amino acid function, and increased abundance of anti-inflammatory bacteria in comparison to young and elderly groups. Some potential probiotic species, such as Desulfovibrio piger, Gordonibacter pamelaeae, Odoribacter splanchnicus, and Ruminococcaceae bacterium D5 were enriched with aging, which might possibly support health maintenance. The level of Amyloid-β (Aβ) and brain-derived neurotrophic factor (BDNF) related to neural function showed increased and decreased with aging, respectively. The elevated level of inflammatory factors was observed in centenarians compared with young and elderly groups. The enriched Bacteroides fragilis in centenarians might promote longevity through up-regulating anti-inflammatory factor IL-10 expression to mediate the critical balance between health and disease. Impressively, the associated analysis for gut microbiota with the level of Aβ, BDNF, and inflammatory factors suggests Bifidobacterium pseudocatenulatum could be a particularly beneficial bacteria in the improvement of impaired neural and immune function. Our results provide a rationale for targeting the gut microbiome in future clinical applications of aging-related diseases and extending life span.Abbreviations: 16S rRNA: 16S ribosomal RNA; MAGs: Metagenome-assembled genomes; ASVs: Amplicon sequence variants; DNA: Deoxyribonucleic acid; FDR: False discovery rate: KEGG: Kyoto Encyclopedia of Genes and Genomes; PCoA: Principal coordinates analysis; PCR: Polymerase chain reaction; PICRUSt: Phylogenetic Investigation of Communities by Reconstruction of Unobserved States; Aβ: Amyloid-β (Aβ); BDNF: Brain-derived neurotrophic factor.

Evaluation of Knee Kinematics and Moments during Active Deep Flexion Activity after Oxford Mobile-Bearing Medial UKA-A Two-Year Follow-Up Study

Few studies have assessed knee range of motion (ROM) and moments of patients with mobile-bearing unicompartmental knee arthroplasty (MB UKA) during active deep flexion activities. We analyze knee kinematic and kinetic parameters during postoperative squatting-standing activity, aiming to evaluate the efficacy of MB UKA and postoperative rehabilitation progress. This was a clinical cohort study. We followed up with 37 patients diagnosed with medial knee osteoarthritis (OA) with primary UKA. After screening 31 patients were recruited to take gait tests. Squatting-standing activities were performed under the test of 10-camera motion analysis system and force plates preoperatively at different stages after UKA (12, 18, and 24 months). The average duration of follow-up was 24.4 months (from 22.8 to 26.7 months). Hip-knee-ankle angle improved significantly compared with pre-UKA as well as scores of American Knee Society Score, numeric rating scale, ORS, and Western Ontario and McMasters. University Osteoarthritis Index. About 83.6% (31/37) of follow-up patients completed squatting-standing activity independently. At 1-year follow-up, peak varus angle (20.6 ± 2.8 degrees), internal rotation angle (13.6 ± 1.8 degrees), extensor moment (1.44 ± 0.04N*m/kg), and internal rotator moment (0.02 ± 0.005N*m/kg) of UKA knees were inferior to contralateral knees. Peak adductor moment (0.76 ± 0.05N*m/kg) was superior to contralateral knees. At 2-year follow-up, peak flexion angle (125.0 ± 2.8 degrees) showed a growing trend meanwhile extensor (1.70 ± 0.03N*m/kg) and adductor (0.68 ± 0.06 N*m/kg) moment closely resembled those of the contralateral knee. MB UKA could alleviate the affected knee mainly in flexion-extension ROM and moment meanwhile did not affect the biomechanical indicators of healthy limbs. OA knees in the early postoperative period showed decreased extensor moment and increased adductor moment during active deep flexion activity. Better ROM and relatively more natural extensor and adductor moment of UKA knee with rehabilitation time increasing may predict ideal rehabilitation outcome in the medium or longer term.

The secret of H2 S to keep plants young and fresh and its products

Recently, accumulating evidence has shown that hydrogen sulphide (H₂ S), a newly determined gasotransmitter, plays important roles in senescence, which is an essential biological process for plant fitness and an important agricultural trait that is critical for the yield and quality of farm produce. Here, in this review, we summarize the roles of H₂ S in senescence, both before and after the harvesting of agricultural products, and the underlying mechanism is also discussed. During the plant growth process, the function of H₂ S in the leaf senescence process has been studied extensively, and H₂ S plays roles during the whole process, including the initiation, reorganization and terminal stages. While during the postharvest stage, H₂ S can prevents farm products from deterioration resulting from over-ripening, pathogen attack and incorrect storage. The underlying H₂ S-related mechanisms during different stages of the senescence process are summarized and compared. The most prominent interaction occurs between H₂ S and reactive oxygen species, and the molecular mechanism is explored. Additionally, the conserved action mode of H₂ S in different life processes and different species is also discussed. In the future, multi-omics analyses over time will be needed to investigate the detailed mechanisms of H₂ S, and a safety attribute analysis of H₂ S is also required before it can be used in agricultural production.

Gene variations in autism spectrum disorder are associated with alteration of gut microbiota, metabolites and cytokines

The genetic variations and dysbiosis of gut microbiota are associated with ASD. However, the role of the microbiota in the etiology of ASD in terms of host genetic susceptibility remains unclear. This study aims to systematically explore the interplay between host genetic variation and gut microbiota in ASD children. Whole-exon sequencing was applied to 26 ASD children and 26 matched controls to identify the single nucleotide variations (SNVs) in ASD. Our previous study revealed alteration in gut microbiota and disorder of metabolism activity in ASD for this cohort. Systematic bioinformatic analyses were further performed to identify associations between SNVs and gut microbiota, as well as their metabolites. The ASD SNVs were significantly enriched in genes associated with innate immune response, protein glycosylation process, and retrograde axonal transport. These SNVs were also correlated with the microbiome composition and a broad aspect of microbial functions, especially metabolism. Additionally, the abundance of metabolites involved in the metabolic network of neurotransmitters was inferred to be causally related to specific SNVs and microbes. Furthermore, our data suggested that the interaction of host genetics and gut microbes may play a crucial role in the immune and metabolism homeostasis of ASD. This study may provide valuable clues to investigate the interaction of host genetic variations and gut microbiota in the pathogenesis of ASD.

[Diagnosis and treatment of 21-hydroxylase deficiency with testicular adrenal rest tumors:a report of three cases and literature review]

Objective: To provide insight into the diagnosis for clinicians, the clinical characteristics, diagnosis and treatment history of 3 patients with 21-hydroxylase deficiency (21-OHD) and testicular adrenal rest tumors (TART) were analyzed. Methods: The clinical, laboratory and imaging data of 3 male patients with 21-OHD and TART, confirmed with CYP21 gene sequencing, from May 2010 to May 2021 in the First Medical Center of Chinese PLA General Hospital were analyzed retrospectively. The treatment strategy and clinical outcome were followed up. Results: All the 3 patients were first diagnosed with bilateral adrenal mass at the age of 27-42 years old. They were 145-162 cm tall. The levels of progesterone, 17-hydroxyprogesterone, and adrenocorticotropic hormone (ACTH) of the 3 patients were relatively high, and that of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) of the 3 patients were low. Testosterone level of 1 patient was significantly elevated, and that of the other 2 patients was below the lower limit of normal range. Testicular ultrasound showed heterogeneous hyperechoic masses in both testes. CT of the adrenal glands showed bilateral adrenal enlargement with mass. All 3 patients were treated with dexamethasone. After 4-96 months of follow-up, 17-hydroxyprogesterone level was kept above the median normal level. One of the patients got married and had a baby after treatment. The sizes of adrenal hyperplasia and testicular masses reduced to various degrees with the change of the testicular masses being proportional to that of adrenal hyperplasia. Conclusions: Patients with 21-OHD are prone to have TART, leading to the impaired testicular function. Early glucocorticold therapy is beneficial to the reduction of TART and restoration of testicular function.

Evaluating the performance of a clinical genome sequencing program for diagnosis of rare genetic disease, seen through the lens of craniosynostosis

PURPOSE

Genome sequencing (GS) for diagnosis of rare genetic disease is being introduced into the clinic, but the complexity of the data poses challenges for developing pipelines with high diagnostic sensitivity. We evaluated the performance of the Genomics England 100,000 Genomes Project (100kGP) panel-based pipelines, using craniosynostosis as a test disease.

METHODS

GS data from 114 probands with craniosynostosis and their relatives (314 samples), negative on routine genetic testing, were scrutinized by a specialized research team, and diagnoses compared with those made by 100kGP.

RESULTS

Sixteen likely pathogenic/pathogenic variants were identified by 100kGP. Eighteen additional likely pathogenic/pathogenic variants were identified by the research team, indicating that for craniosynostosis, 100kGP panels had a diagnostic sensitivity of only 47%. Measures that could have augmented diagnoses were improved calling of existing panel genes (+18% sensitivity), review of updated panels (+12%), comprehensive analysis of de novo small variants (+29%), and copy-number/structural variants (+9%). Recent NHS England recommendations that partially incorporate these measures should achieve 85% overall sensitivity (+38%).

CONCLUSION

GS identified likely pathogenic/pathogenic variants in 29.8% of previously undiagnosed patients with craniosynostosis. This demonstrates the value of research analysis and the importance of continually improving algorithms to maximize the potential of clinical GS.

Recent Progress in Polymeric AIE-Active Drug Delivery Systems: Design and Application

Aggregation-induced emission (AIE) provides a new opportunity to overcome the drawbacks of traditional aggregation-induced quenching of chromophores. The applications of AIE-active fluorophores have spread across various fields. In particular, the employment of AIEgens in drug delivery systems (DDSs) can achieve imaging-guided therapy and pharmacodynamic monitoring. As a result, polymeric AIE-active DDSs are attracting increasing attention due to their obvious advantages, including easy fabrication and tunable optical properties by molecular design. Additionally, the design of polymeric AIE-active DDSs is a promising method for cancer therapy, antibacterial treatment, and pharmacodynamic monitoring, which indeed helps improve the effectiveness of related disease treatments and confirms its potential social importance. Here, we summarize the current available polymeric AIE-active DDSs from design to applications. In the design section, we introduce synthetic strategies and structures of AIE-active polymers, as well as responsive strategies for specific drug delivery. In the application section, typical polymeric AIE-active DDSs used for cancer therapy, bacterial treatment, and drug delivery monitoring are summarized with selected examples to elaborate on their wide applications.

Immigration and Oral Health in Older Adults: An Integrative Approach

The aim of this study was to develop an integrative framework on aging, immigration, and oral health. The methodology was a critical review that used immigration as a social determinant framework through which to evaluate its impact on the oral health of older immigrants. We reviewed recent empirical evidence on factors related to oral health in older immigrants. In a systematic search across multiple databases, we identified 12 eligible studies in this review. Among the eligible studies, most were conducted among East Asian immigrants (8 articles), followed by non-Hispanic White/European origin (2 articles), Mexican origins (1 article), and Iran and other Middle East regions (1 article). The research revealed knowledge gaps in the evidence base, including the dynamic relationship between acculturation and oral health, the role of environmental factors on oral health for immigrants, psychosocial stressors and their relationship with oral health, and oral health literacy, norms, and attitude to dental care utilization and oral hygiene practices. The development of the integrative framework suggests the pathways/mechanisms through which immigration exerts influences on oral health in later life. This provides opportunities for researchers, practitioners, and policy makers to gain greater insights into the complex associations between immigration and oral health among older adults.

SARS-CoV-2 encoded microRNAs are involved in the process of virus infection and host immune response

The outbreak of COVID-19 caused by SARS-CoV-2 is spreading worldwide, with the pathogenesis mostly unclear. Both virus and host-derived microRNA (miRNA) play essential roles in the pathology of virus infection. This study aims to uncover the mechanism for SARS-CoV-2 pathogenicity from the perspective of miRNA. We scanned the SARS-CoV-2 genome for putative miRNA genes and miRNA targets and conducted in vivo experiments to validate the virus-encoded miRNAs and their regulatory role on the putative targets. One of such virus-encoded miRNAs, MR147-3p, was overexpressed that resulted in significantly decreased transcript levels of all of the predicted targets in human,i.e., EXOC7, RAD9A, and TFE3 in the virus-infected cells. The analysis showed that the immune response and cytoskeleton organization are two of the most notable biological processes regulated by the infection-modulated miRNAs. Additionally, the genomic mutation of SARS-CoV-2 contributed to the changed miRNA repository and targets, suggesting a possible role of miRNAs in the attenuated phenotype of SARS-CoV-2 during its evolution. This study provided a comprehensive view of the miRNA-involved regulatory system during SARS-CoV-2 infection, indicating possible antiviral therapeutics against SARS-CoV-2 through intervening miRNA regulation.

MoS2 nanosheets grown on hollow carbon spheres as a strong polysulfide anchor for high performance lithium sulfur batteries

Lithium sulfur batteries are expected to be one of the most promising energy storage systems due to their high energy density, low cost and environmental friendliness. However, the shuttle effect of lithium polysulfides severely hampers their practical application. The design of the sulfur cathode is one of the most important approaches to overcome the problem. In this work, MoS2 nanosheets have been successfully grown on the surface of hollow carbon spheres (HCS) to obtain MoS2@HCS nanocomposites with uniform morphology. The growth behavior of MoS2 nanosheets was also proved by adjusting the pore structure of HCS. With a sulfur loading of 74%, the MoS2@HCS/S cathode exhibits a high initial reversible capacity of 1419 mA h g-1 at a current density of 0.1 C and remains at 1010 mA h g-1 after 100 cycles. Even at 0.5 C, a capacity of 795 mA h g-1 can be retained after 600 cycles, corresponding to a capacity retention rate of 63.1%. By adjusting the concentration of the sulfur source, the relationship between different growth quantities of MoS2 and the cycling performance of the battery was also investigated. The excellent electrochemical performance of the MoS2@HCS/S cathode can be fully attributed to its physical and chemical double adsorption effect on lithium polysulfides, which has been confirmed through the visible adsorption and X-ray Photoelectron Spectroscopy (XPS) experiments. This work provides a simple design concept and method to synthesize a nanocomposite-based sulfur host for high performance lithium sulfur batteries.

[Clinical aspects of pregnancy-related lymphocytic hypophysitis]

Objective: To analyze clinical features, diagnosis, treatment and prognosis of pregnancy-related lymphocytic hypophysitis (LyH). Methods: The clinical data of 16 cases diagnosed as pregnancy-related LyH at Chinese PLA General Hospital between October 2010 and November 2019 were reviewed. Results: Sixteen patients were included (aged 20-40 years). All patients' symptoms occurred from the last 2 months of pregnancy to 12 months postpartum, with 6 cases in the third trimester and 10 cases during postpartum, and all the patients were diagnosed after delivery. Six patients had lymphocytic adenohypophysitis (LAH), 4 patients had lymphocytic infundibuloneurohypophysitis (LINH), 4 patients had lymphocytic panhypophysitis (LPH), and 2 had lymphocytic hypothalamitis. Eight patients presented with symptoms of intracranial space-occupying lesions, 14 patients had symptoms of anteriorpituitary hormone deficiencies, 9 patients had central diabetes insipidus (CDI), and 2 had hyperprolactinemia. Pituitary MRI showed that the pituitary presented with diffuse enlargement, pituitary stalk thickening, disappearing of high-intensity signals in posterior pituitary and space-occupying lesions in the infundibulum of hypothalamus. Nine patients were treated with immunosuppressive agent, 3 patients alleviated the space-occupying effects after surgery, and 4 patients recovered spontaneously. Fourteen patients were followed up with a period of 3-98 months. Four patients had a relapse, 2 patients had a complete remission, and 12 patients needed long-term hormone replacement therapy. Conclusions: Clinical manifestations of pregnancy-related LyH are diverse. LyH should be suspected in pregnant or postpartum women with a sellar mass to avoid missed diagnosis or misdiagnosis. Immunosuppressant therapy is effective. Overall, LyH patients have a favorable prognosis.

Therapeutic Effects Comparison and Revision Case Analysis of Unicompartmental Knee Arthroplasty and Open Wedge High Tibial Osteotomy in Treating Medial Knee Osteoarthritis in Patients Under 60 years: A 2-6-year Follow-up Study

Objective

To evaluate the therapeutic effects and revision cases of unicompartmental knee arthroplasty (UKA) and open wedge high tibial osteotomy (OWHTO) in treating medial knee osteoarthritis (MKOA) in patients under 60 years.

Methods

The present retrospective study included a total of 192 patients who were diagnosed with MKOA and treated by UKA or OWHTO in the Second Affiliated hospital of Xi'an Jiaotong University and Xi'an Honghui Hospital between December 2012 and December 2016. Among these patients, 83 were treated by UKA (17 men and 66 women, aged 53.7 ± 5.2 years) and 109 were treated by OWHTO (23 men and 86 women, aged 51.8 ± 6.9 years). Patients were followed up at 1, 3, 6, and 12 months for the first year postoperation, and every 6 months from the second year postoperation. Basic data, perioperative data, hospital for special surgery (HSS) score, visual analogue pain score (VAS), low‐impact recovery, and revision cases of the patients were evaluated.

Results

The average follow‐up periods of the UKA group and the OWHTO group were 39.3 ± 11.2 months and 40.2 ± 13.5 months, respectively. No significant difference was found in the basic data of the two groups (P ≥ 0.05). The operative time, incision length, and dominant blood loss of the UKA group was less than those of OWHTO group by 19.6%, 10.7%, and 35.1%, respectively, and the differences were significant (P < 0.05), while no significant difference was found in postoperative in‐bed time (P ≥ 0.05). The HSS scores of the UKA group at 1 and 3 months postoperation were higher than those of the OWHTO group by 5.1% and 3.9% (P < 0.05), while no differences were found from 6 months postoperation (P ≥ 0.05). The VAS score of the UKA group 1 month postoperation was lower than that of the OWHTO group by 12.2% (P < 0.05), while no differences were found from 3 months postoperation (P ≥ 0.05). One year after the operation, most patients in both groups could not achieve ideal recovery in low‐impact sports, and no significant differences were found (P < 0.05). The sport in which most patients could not achieve ideal recovery was mountain climbing. No revision cases occurred in the OWHTO group, while two revisions occurred in the UKA group.

Conclusion

Candidates for UKA should be chosen carefully and the current indications and contraindications raised by Goodfellow should be modified.

Melatonin activates autophagy via the NF-κB signaling pathway to prevent extracellular matrix degeneration in intervertebral disc

OBJECTIVE

This study investigated whether melatonin alleviates intervertebral disc degeneration (IVDD) by promoting autophagy through inhibiting the NF-κB signaling pathway.

METHODS

Magnetic resonance imaging (MRI), hematoxylin and eosin (H&E) staining and Safranin-O staining were used to measure disc degeneration in rat needle puncture IVDD models, and melatonin was injected intraperitoneally in the treated group to test its function. The expression of autophagy and extracellular matrix (ECM) degeneration related-markers were measured in the discs using immunohistochemistry. Transmission electron microscopy was used to evaluate the activation of autophagy in human nucleus pulposus (NP) tissues with different degenerated statuses. The expression of autophagy and disc degeneration related-markers were detected in NP cells by Western blot, RT-qPCR, and immunofluorescence analyses. NF-κB signaling pathway involvement was studied by lentivirus-mediated knockdown, Western blotting, and immunohistochemistry and immunofluorescence staining.

RESULTS

Melatonin prevented IVDD development in vivo and in vitro. Compared to non-degenerated disc tissues, degenerated human NP tissues showed a decrease in the autophagy-specific marker LC3B and the numbers of autophagosomes and autolysosomes, whereas the p62 level was increased; similar results were observed in rat IVDD models, indicating a negative correlation between autophagy and IVDD. Furthermore, both in vivo and in vitro studies found that melatonin application induced autophagy and reduced ECM disc degradation. Melatonin was also shown to regulate autophagy by inhibiting the NF-κB signaling pathway in vivo and vitro.

CONCLUSION

This study indicates that melatonin prevents IVDD by promoting autophagy, indicating its possible therapeutic potential for controlling the progression of IVDD.

Effects of MDM4 Gene Regulation by miR-34a on LOVO Cell Proliferation

This study aims to investigate the effects of regulation of murine double minute protein4 (MDM4) expression by microRNA (miR)-34a on the proliferation of colorectal cancer LOVO cells. Prediction results obtained using a gene microarray showed that MDM4 is a specific miR-34a target gene. The interaction between miR-34a and the 3'-untranslated region (UTR) of MDM4 was detected using a luciferase reporter system. The effect of miR-34a on MDM4 protein expression was detected by Western blotting, and the effect of miR-34a transfection on LOVO cell proliferation was detected using an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and flow cytometry. The luciferase activity in LOVO cells after addition of pmirGLO-UTR+miR-34a mimic was only 44% of that obtained with pmirGLO-UTR+miR-34a (p<0.01), and the luciferase activity in LOVO cells after addition of pmir-GLO-mutUTR+miR-34a was 94% of that observed after pmirGLO-UTR+miR-34a addition (p=0.57). These results indicated that miR-34a interacted with the 3'-UTR of MDM4. Results of Western blotting revealed that MDM4 protein expression level in LOVO cells after addition of miR-34a mimic was 29% that of non-treated LOVO cells (p<0.05), indicating that miR-34a negatively regulates MDM4 protein expression. The growth rate of LOVO cells with miR-34a overexpression was significantly reduced compared with that of non-treated LOVO cells (p<0.05), indicating that miR-34a overexpression inhibits LOVO cell proliferation. miR-34a negatively regulates MDM4 gene expression to inhibit LOVO cell proliferation.

[Differences of brain functional alterations between subtypes of Cushing's syndrome patients]

Objective: To compare the differences of brain functional damage of subtypes of patients with Cushing's syndrome (CS). Methods: A total of 11 adrenocorticotropic hormone (ACTH)-dependent CS patients and 29 ACTH-independent CS patients were recruited from Chinese PLA General Hospital between September 2015 and March 2017 with confirmed CS. The psychiatric scales and brain task functional magnetic resonance imaging (fMRI) were evaluated. Results: A total of 40 patients (34 females, 6 males) with a mean age of (39.20±12.10) years and a median education level of 12 (9, 16) years were enrolled. ACTH-dependent patients had significantly worse performance than the ACTH-independent patients in response to the depression evaluation (64.6±6.1 vs 56.2±12.8, P=0.008), positive emotion (17.8±4.2 vs 24.3±7.2, P=0.008) and CS life quality [31(29,33) vs 42(29,51), P=0.040]. In the reaction to positive target pictures, ACTH-dependent CS patients showed stronger activation in left superior temporal gyrus compared with patients in ACTH-independent group, while the activation degree of their bilateral dorsal anterior cingulate cortex, bilateralsuperior frontal gyrus and left middle frontal gyrus was much worse. In the reactions to negative target pictures, ACTH-dependent CS patients had weaker activation in bilateral cerebellum, left superior frontal gyrus, left middle frontal gyrus, left precuneus and right postcentral gyrus, compared with patients in the ACTH-independent CS group (P<0.01, AlphaSim corrected). The activation degree of some regions whose brain function was different between the two groups was correlated to the cortisol level, ACTH level, 24 h urinary free cortisol (UFC) level, depression evaluation and negative emotion assessment (all P<0.05). Conclusions: The severity of the depression and the life quality of patients in ACTH-dependent group are worse than ACTH-independent CS patients. The brain function of ACTH-dependent CS patients is much weaker.

Clinical and genetic heterogeneity in Melkersson-Rosenthal Syndrome

Melkersson Rosenthal syndromes (MRS) is a rare autosomal dominantly inherited neurocutaneous syndrome characterised by a triad of facial (seventh cranial) nerve palsy, recurrent orofacial swelling and fissuring of the tongue. A recent report implicated a heterozygous missense variant in SLC27A1 (FATP1) as the cause of this condition in members of an affected Chinese family. We undertook Sanger sequencing of this gene in 14 affected unrelated individuals affected by MRS. We did not detect any putative pathogenic variants. Our data indicates that there is both clinical and genetic heterogeneity in this condition and that the causative gene remains to be identified for the majority of cases.

Protective Effects of an Obesity-Associated Polymorphism (CDKAL1 rs9356744) on Prediabetes: The Cardiometabolic Risk in Chinese (CRC) Study

Background Obesity is strongly associated with insulin resistance and elevated plasma glucose levels. The rs9356744 polymorphism in the CDKAL1 gene is associated with body mass index (BMI) only in East Asians. Here, we examined the effect of the rs9356744 polymorphism on glucose-related traits and prediabetes in Chinese adults.

Methods A total of 2 357 participants were enrolled from the Cardiometabolic Risk in Chinese (CRC) Study, including 499 persons with prediabetes, 204 persons with type 2 diabetes, and 1 654 normoglycemic controls. The rs9356744 polymorphism in CDKAL1 was genotyped and analyzed in all participants.

Results Despite the positive relationship between obesity and glucose traits, the T allele of rs9356744, which is associated with a predisposition to obesity, was correlated with lower levels of 2-h oral glucose tolerance test (OGTT) plasma glucose (2hPG) (β=− 0.2104 and P=0.0233), glycated hemoglobin (HbA1c) (β=− 0.0551 and P=0.0298) and higher levels of homeostasis model of assessment β-cell function (HOMA-B) (β=5.282 and P=0.0424). After further adjustment for BMI, the levels of HOMA-B maintained a similar increased trend across rs9356744 genotype (β=3.277 and P=0.1958). In stratified analyses, the associations of rs9356744 with 2hPG and HbA1c were significant for individuals with a low BMI. Moreover, an antagonism action of BMI and rs9356744 on 2hPG (P for interaction=0.0055) was observed. In addition, we found a protective effect of rs9356744 on prediabetes.

Conclusions The CDKAL1 rs9356744 T allele associated with a predisposition to obesity showed a protective effect on HbA1c, 2hPG, and prediabetes. BMI was mediator of the association between the genetic variant and HbA1c, 2hPG, and prediabetes.

Right Atrial Ball Thrombus as a Complication of Subclavian Catheter Insertion for Hemodialysis Access

In two patients right atrial ball thrombi developed following prolonged subclavian cannulation for hemodialysis. One patient died, the other had the ball thrombus removed by open heart surgery. It appears that repeated friction of the catheter tip may have damaged the endothelium of the right atrial wall.

This hitherto unrecognised complication might be prevented by ensuring that subclavian hemodialysis catheters are never allowed to reach as far as the right atrium.

[Clinical features and prognosis of 18 cases of primary lymphocytic hypophysitis]

Objective: To analyze clinical features, prognosis and treatment of lymphocytic hypophysitis (LYH). Methods: The clinical data, treatments and outcomes of 18 cases diagnosed as LYH at Chinese PLA General Hospital between January 2001 and July 2017 was respectively reviewed. Results: Eighteen patients with histology-proven LYH (13 females and 5 males ) were identified. All lymphocytic adenohypophysitis (LAH) were females(n=6), two of whom were associated with pregnancy. Eleven patients (6 females and 5 males) had lymphocytic panhypophysitis (LPH) and one(female) had hypothalamitis. Pre-treatment evaluation revealed that 11 patients presented with symptoms of intracranial space-occupying lesions, 12 patients had symptoms of anterior pituitary hormone deficiencies, and 12 patients had central diabetes insipidus (CDI). All patients had space-occupying lesions on magnetic resonance imaging (MRI), which were symmetrically enlarged and homogenously enhanced with or without pituitary stalk thickening. Before or after surgery, 11 patients received immunosuppressant therapy or radiotherapy to alleviate space-occupying effect. After 4-204 months follow-up, 5 patients had a relapse and received immunosuppressants, radiotherapy or surgery to achieve remission. Full recovery (both symptomatic and radiographic) was seen in 6 patients, and 11 patients maintained stable replacement therapy. Conclusions: LYH presents with acute space-occupying effects such as headache, visual disturbances, hypopituitarism, CDI and mild hyperprolactinemia, especially with characteristic radiographic manifestations. Usually, surgery reliably establishes diagnosis, and immunosuppressant therapy is a necessity. On the whole, LYH has a good prognosis.

Transcatheter aortic valve replacement with balloon-expandable valve : Analysis of initial experience in China

Background

Transcatheter aortic valve replacement (TAVR) is widely applied for the treatment of severe aortic stenosis (AS) in developed countries; however, in China, it is still in the early stage of utilization. On the basis of previous studies, this work explored the feasibility of TAVR in patients with severe AS in China and analyzed the cause of death in four cases.

Methods

This retrospective study included 20 patients who had severe AS and underwent TAVR with a balloon-expandable system (Edwards SAPIEN XT) in our hospital from January 2011 to June 2016. The valve and heart functions of 16 survivors before and after the TAVR procedure were compared. TAVR endpoints, device success, and adverse events were assessed according to the definitions of the Valve Academic Research Consortium-2 (VARC-2).

Results

There were 13 male and seven female patients aged 65–81 years (average, 73.15) who underwent TAVR. The TAVR approach was transfemoral in 19 patients and transapical in one patient. Four patients died (two of coronary artery occlusion and two of aortic annulus rupture) during the TAVR procedure or shortly after; six patients had mild paravalvular leakage, and the rest of the patients showed a significant improvement in cardiac function. During the follow-up period (2–62 months), one patient died of lung cancer 13 months after the TAVR procedure.

Conclusion

TAVR with a balloon-expandable system is safe and effective and can be used for patients with severe AS in China. It requires careful patient selection and preoperative assessment so as to reduce the 30-day postoperative mortality rate.

[Clinical characteristics of 128 hospitalized patients with syndrome of inappropriate antidiuretics of different etiologies]

Objective: To summarize and analyze the clinical features and etiologies in hospitalized patients with syndrome of inappropriate antidiuretics (SIAD) during the past 25 years. Methods: All data of 128 patients with SIAD admitted to Chinese PLA General Hospital since January 1991 to January 2016 were collected. SIAD was diagnosed based on the 1957 criterion. Results: (1) The most frequent causes of increased inappropriate secretion of vasopressin were malignant tumors, lung diseases (e. g. pneumonia), and central nervous system diseases, in which malignant tumors accounted for 38.28% of the SIAD. (2) During the past 25 years, the proportion of malignant diseases declined from 4/7 to 35.29%, while, the proportion of pulmonary infection increased from 1/7 to 35.29% (P<0.05). (3) The patients with malignant tumors had the lowest serum sodium and serum osmolality among all SIAD patients. (4) CT scan had a high diagnostic value for chest and brain detection. (5) Among three SIAD subjects with unknown reasons at onset, two were diagnosed with small cell lung cancer and one with gastric cancer during follow-up. Conclusion: The etiology of SIAD is complex and it could be attributed to multifarious etiological factors. Malignant tumors account for the largest proportion of all patients, and pulmonary infection was ranked in second place. Cautions on tumors have to be taken when serum sodium of a SIAD patient is below 118.1 mmol/L.

A New Approach to Organization and Implementation of Military Medical Treatment in Response to Military Reform and Modern Warfare in the Chinese Army

BACKGROUND

Recent system reforms within the People's Liberation Army (PLA) have led to establishment of 5 theatre commands and a general joint logistics command. These reforms have presented new challenges to the organization and implementation of medical services. The medical service of the PLA must keep pace with these reforms by applying innovative theories to establish appropriate organizational guidelines and structures. The medical service must also adapt to the modern and future eras of information warfare.

METHODS

We review the existing structure and features of the military medical service of the PLA, highlighting issues related to ongoing reform within the PLA and the characteristics of modern and future information warfare. Reflection on current rules for medical evacuation and treatment of war-related injuries were made, and related organizational and structural innovations were proposed.

FINDINGS

Recent reforms and the characteristics of modern information warfare have rendered the current medical service and medical evacuation system of the PLA inefficient. The scale of the echelon configuration should be adjusted to establish a more focused, effective, and intelligent medical service. Resource allocation and general joint logistics should be optimized to establish a new well-rounded, three-dimensional medical evacuation system, and the "stabilize before healing" rule should be applied at all levels of the medical service. These changes should help to create a modern, effective, and responsive medical service within the PLA.

DISCUSSION

This article explores how the military medical service of the PLA could adapt to system reform in order to implement efficient treatment of war injuries, reduce mortality and morbidity rates, and maintain combat readiness in the modern era of information warfare.

Vertebral fracture in postmenopausal Chinese women: a population-based study

In a random sample of postmenopausal Chinese women, the prevalence of radiographic vertebral fractures increased from 13% between ages 50 and 59 to over 50% after age 80 years. A model with seven clinical risk factors predicted the probability of vertebral fractures as well with as without BMD and better than a model with only three risk factors. More than half an hour of outdoor activity per day might correlate with lower risk of vertebral fracture in this population.

INTRODUCTION

We aimed to describe the prevalence and develop a model for prediction of radiographic vertebral fractures in a large random sample of postmenopausal Chinese women.

METHODS

We enrolled 1760 women from an age-stratified random sample of postmenopausal women in Beijing, China. The presence of vertebral fracture was assessed by semi-quantitative grading of lateral thoracolumbar radiographs, risk factors by interview, bone mineral density (BMD) of the proximal femur and lumbar spine by dual x-ray absorptiometry (DXA), and markers of bone turnover from a fasting blood sample. Associations of these factors were analyzed in logistic models and discrimination by areas of receiver operating characteristics curves (AUC).

RESULTS

The prevalence of vertebral fracture, ranged from 13.4% ages 50 to 59 years old to 58.1% at age 80 years or older. Older age, a history of non-vertebral fracture, lower femoral neck BMD T-score, body mass index (BMI), height loss, housework, and less than half an hour of outdoor activity were significantly associated with increased probability of having a vertebral fracture. A model with those seven factors had a similar AUC with or without BMD and performed better than a simple model with three factors.

CONCLUSION

This study is from a true random sample of postmenopausal women in urban China with high response rate. The prevalence of vertebral fractures in postmenopausal women in Beijing increases from 13% under age 60 to over 50% by age 80 years. A model with seven clinical risk factors with or without BMD is better than simple models and may guide the use of spine x-rays to identify women with vertebral fractures. More than half an hour of outdoor activity might correlate with lower risk of vertebral fracture in this population.