[Safety and efficacy of donor-derived chimeric antigen receptor T-cell therapy in patients with relapsed B-cell acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation]

Objective: To investigated the safety and efficacy of donor-derived CD19+ or sequential CD19+ CD22+ chimeric antigen receptor T-cell (CAR-T) therapy in patients with B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: The data of 22 patients with B-ALL who relapsed after allo-HSCT and who underwent donor-derived CAR-T therapy at the Zhujiang Hospital of Southern Medical University and the 920th Hospital of Joint Logistics Support Force of the People's Liberation Army of China from September 2015 to December 2022 were retrospectively analyzed. The primary endpoint was overall survival (OS), and the secondary endpoints were event-free survival (EFS), complete remission (CR) rate, and Grade 3-4 adverse events. Results: A total of 81.82% (n=18) of the 22 patients achieved minimal residual disease-negative CR after CAR-T infusion. The median follow-up time was 1037 (95% CI 546-1509) days, and the median OS and EFS were 287 (95% CI 132-441) days and 212 (95% CI 120-303) days, respectively. The 6-month OS and EFS rates were 67.90% (95% CI 48.30%-84.50%) and 58.70% (95% CI 37.92%-79.48%), respectively, and the 1-year OS and EFS rates were 41.10% (95% CI 19.15%-63.05%) and 34.30% (95% CI 13.92%-54.68%), respectively. Grade 1-2 cytokine release syndrome occurred in 36.36% (n=8) of the patients, and grade 3-4 occurred in 13.64% of the patients (n=3). Grade 2 and 4 graft-versus-host disease occurred in two patients. Conclusion: Donor-derived CAR-T therapy is safe and effective in patients with relapsed B-ALL after allo-HSCT.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Wave optics of imaging with contact ball lenses

Recent progress in microspherical superlens nanoscopy raises a fundamental question about the transition from super-resolution properties of mesoscale microspheres, which can provide a subwavelength resolution [Formula: see text], to macroscale ball lenses, for which the imaging quality degrades because of aberrations. To address this question, this work develops a theory describing the imaging by contact ball lenses with diameters [Formula: see text] covering this transition range and for a broad range of refractive indices [Formula: see text]. Starting from geometrical optics we subsequently proceed to an exact numerical solution of the Maxwell equations explaining virtual and real image formation as well as magnification M and resolution near the critical index [Formula: see text] which is of interest for applications demanding the highest M such as cellphone microscopy. The wave effects manifest themselves in a strong dependence of the image plane position and magnification on [Formula: see text], for which a simple analytical formula is derived. It is demonstrated that a subwavelength resolution is achievable at [Formula: see text]. The theory explains the results of experimental contact-ball imaging. The understanding of the physical mechanisms of image formation revealed in this study creates a basis for developing applications of contact ball lenses in cellphone-based microscopy.

[Related factors of negative conversion time of nucleic acid in children with COVID-19]

Objective: To explore the related factors of negative conversion time (NCT) of nucleic acid in children with COVID-19. Methods: A retrospective cohort study was conducted. A total of 225 children who were diagnosed with COVID-19 and admitted to Changxing Branch of Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from April 3^rd to May 31^st 2022 were enrolled in the study. The infection age, gender, viral load, basic disease, clinical symptoms and information of accompanying caregivers were retrospectively analyzed. According to age, the children were divided into<3 years of age group and 3-<18 years of age group. According to the viral nucleic acid test results, the children were divided into positive accompanying caregiver group and negative accompanying caregiver group. Comparisons between groups were performed using Mann-Whitney U test or Chi-square test. Multivariate Logistic regression analysis was used to analyze the related factors of NCT of nucleic acid in children with COVID-19. Results: Among the 225 patients (120 boys and 105 girls) of age 2.8 (1.3, 6.2) years, 119 children <3 years and 106 children 3-<18 years of age, 19 cases were diagnosed with moderate COVID-19, and the other 206 cases were diagnosed with mild COVID-19. There were 141 patients in the positive accompanying caregiver group and 84 patients in the negative accompanying caregiver group.Patients 3-<18 years of age had a shorter NCT (5 (3, 7) vs.7 (4, 9) d, Z=-4.17, P<0.001) compared with patients <3 years of age. Patients in the negative accompanying caregiver group had a shorter NCT (5 (3, 7) vs.6 (4, 9) d,Z=-2.89,P=0.004) compared with patients in the positive accompanying caregiver group. Multivariate Logistic regression analysis showed that anorexia was associated with NCT of nucleic acid (OR=3.74,95%CI 1.69-8.31, P=0.001). Conclusion: Accompanying caregiver with positive nucleic acid test may prolong NCT of nucleic acid, and decreased appetite may be associated with prolonged NCT of nucleic acid in children with COVID-19.

[Etiological diagnostic value of metagenomic next-generation sequencing in peritoneal dialysis-related peritonitis]

Objective: To explore the etiological diagnostic value of metagenomic next-generation sequencing (mNGS) in peritoneal dialysis (PD)-related peritonitis. Methods: The study was a retrospective cohort study. The clinical data of patients with PD-related peritonitis who were treated and underwent microbial cultivation and mNGS test at the same time from June 2020 to July 2021 in the Affiliated Drum Tower Hospital, Medical School of Nanjing University were analyzed. The positive rate, detection time and consistency between mNGS test and traditional microbial culture were compared. Results: A total of 18 patients with age of (50.4±15.4) years old and median dialysis time of 34.0 (12.4, 62.0) months were enrolled in the study, including 11 males and 7 females. Pathogenic microorganisms were isolated in 17 patients by mNGS test, with a positive rate of 17/18, which was higher than 13/18 of microbial culture, but the difference was not statistically significant (P=0.219). Both mNGS test and microbial culture isolated positive pathogenic bacteria in 12 patients, and mNGS test isolated the same types of pathogenic bacteria as microbial cultivation did in 11 patients. In five patients with negative microbial culture, mNGS test also isolated pathogenic microorganisms, including 3 cases of Staphylococcus epidermidis, 1 case of Mycobacterium tuberculosis and 1 case of Ureaplasma urealyticum. In 1 patient, microbial culture isolated pathogenic bacteria (Escherichia coli) whereas mNGS test did not. The detection time of mNGS was 25.0 (24.0, 27.0) h, which was significantly shorter than 89.0 (72.8, 122.0) h of microbial culture (Z=3.726, P<0.001). Conclusions: mNGS test can improve the detection rate of pathogenic microorganisms in PD-related peritonitis and greatly shorten the detection time, and has good consistency with microbial culture. mNGS may provide a new approach for pathogen identification of PD-related peritonitis, especially refractory peritonitis.

[Changes of brain network characteristics in patients with depression before and after precise repetitive transcranial magnetic stimulation]

Objective: To investigate the changes of brain network characteristics in patients with depression before and after precise repetitive transcranial magnetic stimulation (rTMS) treatment. Methods: Patients with depression in the Second Affiliated Hospital of Xinxiang Medical University and healthy volunteers in the community of Xinxiang city from February 2018 to March 2019 were simultaneously recruited. The left dorsolateral prefrontal cortex was precisely selected as the stimulation target through the latest Human Brainnetome Atlas, and the near infrared navigation was used to achieve accurate brain stimulation treatment in combination with the structural magnetic resonance data. Moreover, functional connectivity was analyzed before and after rTMS treatment in significantly altered brain areas of patients with depression. Results: Nineteen patients (11 males and 8 females) with depression were included, aged (34±11) years. Meanwhile, 22 healthy controls (9 males and 13 females), aged (30±9) years, were also enrolled. Functional connectivity of insular cortex was decreased in depression patients when the insula was analyzed as the target area (P<0.05). The functional connection from insula to middle frontal lobe and superior parietal lobe in patients with depression decreased before rTMS treatment (P<0.05), but increased after rTMS treatment (P<0.05). The functional connection between dIg_L of the insula and the right middle prefrontal lobe was correlated with Beck Anxiety Index (BAI) before rTMS treatment and Beck Depression Index (BDI) after rTMS treatment (r=0.737, P=0.003; r=0.696, P=0.005). Conclusions: Abnormal functional connectivity of insula may be the brain imaging mechanism of rTMS treatment. Precise brain region selection based on Human Brainnetome Atlas provides a new technical method for clinical rTMS precision treatment.

Interleukin 17 Receptor C, but not Polo-like Kinase 4, Plays a Critical Role in the Development of Skin Papilloma and Psoriasis in Mouse Models

Introduction/Objective

Hyperproliferation of epidermis is a histopathological hallmark of skin cancers and psoriasis. As a master regulator of centriole replication, overexpression of Polo-like kinase 4 (PLK4) has been identified in skin cancers. The aberrant proliferation of epidermal keratinocytes provoked by interleukin 17 (IL17) leads to psoriasis. Thus, targeting centriole replication and IL17 signaling simultaneously has been speculated as a potential therapeutic strategy. We hypothesized that inhibition of centriole duplication enhances the blockade of epidermal proliferation through Il17rc knockout.

Methods/Case Report

To test our hypothesis, 37 mice were used to imbed a two-stage model of skin carcinogenesis using wild-type (WT), IL17 receptor A (T779A) knock-in (Il17ra(T779A)-KI), and IL17 receptor C knock-out (Il17rc-KO) C57BL/6J mouse strains. Furthermore, an imiquimod-induced psoriasis model was established using 69 mice with the same strains.

Results (if a Case Study enter NA)

In our two-stage skin carcinogenesis model, Il17ra(T779A)-KI mice showed significantly decreased tumor incidence, tumor multiplicity, and tumor volume compared to the WT mice. Il-17rc-KO mice didn’t develop any skin papilloma. The skin papilloma formed never progressed into squamous carcinoma. However, centrinone, a selective inhibitor of PLK4, didn’t affect skin papilloma formation or epidermal thickening. In our psoriasis model, the epidermis thickness of Il-17rc-KO mice was dramatically decreased compared to WT and Il17ra(T779A)-KI mice. There was no significant difference between WT and Il17ra(T779A)-KI mice in terms of skin lesion and thickening of the epidermis. Centrinone didn’t stall the thickening of the epidermis in the psoriasis model. IHC staining showed significantly increased Ki67+ basal keratinocytes in the untreated skin of Il17ra(T779A)-KI male mice compared to WT mice. In imiquimod-treated skin, the percentage of Ki67+ basal keratinocytes significantly decreased in the order from WT, Il17ra(T779A)-KI to Il17rc-KO mice.

Conclusion

Our data suggest that the proliferation of keratinocytes is not stalled by centrinone but is inhibited by Il17rc-KO. Il17ra(T779A)-KI significantly inhibits skin papilloma formation, but slightly decreases epidermal thickening in the psoriasis model. However, Il17ra(T779A)-KI increases keratinocyte proliferation based on Ki67 staining in the untreated normal skin.

IFITM3 restricts virus-induced inflammatory cytokine production by limiting Nogo-B mediated TLR responses

Interferon-induced transmembrane protein 3 (IFITM3) is a restriction factor that limits viral pathogenesis and exerts poorly understood immunoregulatory functions. Here, using human and mouse models, we demonstrate that IFITM3 promotes MyD88-dependent, TLR-mediated IL-6 production following exposure to cytomegalovirus (CMV). IFITM3 also restricts IL-6 production in response to influenza and SARS-CoV-2. In dendritic cells, IFITM3 binds to the reticulon 4 isoform Nogo-B and promotes its proteasomal degradation. We reveal that Nogo-B mediates TLR-dependent pro-inflammatory cytokine production and promotes viral pathogenesis in vivo, and in the case of TLR2 responses, this process involves alteration of TLR2 cellular localization. Nogo-B deletion abrogates inflammatory cytokine responses and associated disease in virus-infected IFITM3-deficient mice. Thus, we uncover Nogo-B as a driver of viral pathogenesis and highlight an immunoregulatory pathway in which IFITM3 fine-tunes the responsiveness of myeloid cells to viral stimulation.

AnatomySketch: An Extensible Open-Source Software Platform for Medical Image Analysis Algorithm Development

The development of medical image analysis algorithm is a complex process including the multiple sub-steps of model training, data visualization, human-computer interaction and graphical user interface (GUI) construction. To accelerate the development process, algorithm developers need a software tool to assist with all the sub-steps so that they can focus on the core function implementation. Especially, for the development of deep learning (DL) algorithms, a software tool supporting training data annotation and GUI construction is highly desired. In this work, we constructed AnatomySketch, an extensible open-source software platform with a friendly GUI and a flexible plugin interface for integrating user-developed algorithm modules. Through the plugin interface, algorithm developers can quickly create a GUI-based software prototype for clinical validation. AnatomySketch supports image annotation using the stylus and multi-touch screen. It also provides efficient tools to facilitate the collaboration between human experts and artificial intelligent (AI) algorithms. We demonstrate four exemplar applications including customized MRI image diagnosis, interactive lung lobe segmentation, human-AI collaborated spine disc segmentation and Annotation-by-iterative-Deep-Learning (AID) for DL model training. Using AnatomySketch, the gap between laboratory prototyping and clinical testing is bridged and the development of MIA algorithms is accelerated. The software is opened at https://github.com/DlutMedimgGroup/AnatomySketch-Software .

[Application of two RT-PCR methods for detection of norovirus in market-sold oysters and norovirus genetic characteristic analysis, a survey conducted in Beijing]

Objective: To evaluate the application of real-time RT-PCR and semi-nested RT-PCR in the detection of norovirus in oysters and analyzing the genetic characteristics of the isolates. Methods: Real-time fluorescent RT-PCR and semi-nested RT-PCR were used to detect norovirus GⅠ/GⅡ in fresh oysters collected from the markets in Beijing from November 2014 to October 2015. The detection rate of the parallel test was also analyzed. In addition, the reliability of semi-nested RT-PCR was evaluated by agreement rate and consistency test (Kappa value). The positive products of norovirus GⅠ/GⅡ capsid protein region gene by semi-nested RT-PCR were sequenced. Software BioEdit 7.0.9.0 was used for sequence alignment, and software Mega 6.0 was used to construct the evolutionary tree. Results: In 72 samples, the detection rate of norovirus was 31.94% (23/72) by real-time RT-PCR, 38.89% (28/72) by semi-nested RT-PCR and 48.61% (35/72) by parallel test. The coincidence rate of the two methods was 73.61%, a moderate degree (Kappa value =0.43). A total of 13 norovirus strains were successfully sequenced, and 11 strains (7 GⅡ.17 strains, 2 GⅡ. 4 Sydney_ 2012 strains, 1 GⅡ. 1 strain and 1 GⅡ. 21 strain) were obtained from norovirus positive samples by two RT-PCR methods, two strains (1 GⅡ. 17 strain and 1 GⅡ. 3 strain) were obtained from real-time RT-PCR negative samples which were positive for norovirus by semi-nested RT-PCR. The similarity between these strains and reference strains from diarrhea patients, environmental sewage, and shellfish products were 84.4% - 100.0%. Conclusions: The parallel test of norovirus in oysters by two RT-PCR methods can improve the detection rate and detect more genotypes. Norovirus strains in oysters were highly homologous with reference strains from diarrheal patients, environmental sewage, and shellfish products. Therefore, surveillance, prevention and control for norovirus should be carried out in people who have frequent contacts with oysters and related environments.

EPIGENETIC FACTORS OF SERUM URIC ACID LEVEL AND RELATED GENE POLYMORPHISMS IN SHENYANG, CHINA

BACKGROUND

The purpose of this study was to explore the influencing factors of serum uric acid (SUA) level and related gene polymorphisms in the healthy population.

METHODS

A total of 346 healthy individuals screened from different areas in Shenyang City and 195 patients with high SUA levels were included.

RESULTS

The levels of TC (total cholesterol), HDL-C (high-density lipoprotein cholesterol), LDL-C (low-density lipoprotein cholesterol), TG (triglycerides), GLU (blood glucose) ALT (alanine aminotransferase), TBA (total bile acid), TBIL (total bilirubin), CR (creatinine) and CYSC (Cystatin C) were statistically different between the healthy and hyperuricemia population (P<0.05). However, there was no statistical difference in the UA level between the two groups (P>0.05). After adjusting for UA, TC, HDL-C, LDL-C, GLU, TBIL and CYSC, the additive and recessive models of rs2231142 were statistically significant in females (P<0.05). For males, haplotypes of A-C-A-A-G-G, A-C-G-C-G-G and A-T-G-A-A-G had significant difference between the healthy and hyperuricemia population (P<0.05). For females, the haplotypes of A-C-G-C-G-G and A-T-A-C-A-T had significant differences (P<0.05).

CONCLUSION

The distributions of SLC2A9 (solute carrier family 2 and facilitated glucose transporter member 9), ABCG2 (ATP-binding cassette G2), GCKR (glucokinase regulatory protein), KCNQ1, IGFIR (Insulin-like growth factor-I receptor) and VEGFR (Vascular Endothelial Growth Factor Receptor) were balanced in the population in Shenyang City. The haplotypes of A-C-A-A-G-G, A-C-G-C-G-G and A-T-G-A-A-G were the influencing factors of high SUA in the population in Shenyang City.

Research Progress on Pathological Fibrosis of Sinoatrial Node

Abstract

Human heart rhythm is mainly regulated and controlled by the sinoatrial node. Fibrosis plays an important regulating role in adjusting the structural and functional integrity of the sinoatrial node pacemaker complex. In physiological state, the fibrosis degree of sinoatrial node is negatively correlated with heart rate, positively correlated with age and heart size, and can maintain a relatively stable heart rate. Pathological fibrosis of sinoatrial node can induce various types of arrhythmias which can result in sudden death. Determination of the mechanisms related to sinoatrial node pathological fibrosis could provide a target for clinical treatment of sinoatrial node fibrosis and diagnosis basis for forensic pathologists. This paper reviews the main mechanism of sinoatrial node pathological fibrosis, including abnormal activation of cardiac fibroblast cells in sinoatrial node, hyperplasia of epicardial adipose tissue, calcium clock disorder, artery stenosis, etc., introduces the test methods, diagnostic criteria as well as its role in sudden cardiac death and discusses the potential application, to provide reference for relevant research and application.

The scale-up of antiretroviral therapy coverage was strongly associated with the declining tuberculosis morbidity in Africa during 2000-2018

OBJECTIVES

Antiretroviral therapy (ART) reduces the risk of tuberculosis (TB). We aimed to examine the association between ART coverage scale-up on the changes in TB incidence in Africa from 2000 to 2018.

STUDY DESIGN

The design of the study is a retrospective ecological study.

METHODS

Data for 54 countries were obtained from several institutional-based sources, including the World Health Organization, the Joint United Nations Programme on HIV/AIDS, and the World Bank. A fixed-effects regression method of longitudinal data analysis was used to estimate the association between ART coverage and changes in TB incidence rate during 2000-2018. Statistical analyses were conducted using STATA 15.0/IC.

RESULTS

The TB incidence declined significantly, by an average of 2.3% per year during 2000-2018. The highest significant declines occurred in eastern and southern Africa. In adjusted analysis, each 1% increase in ART coverage was associated with a 3.97 per 100,000 decline of TB incidence. However, the marginal effects of ART on overall population TB incidence was dependent on the prevalence of human immunodeficiency virus infection.

CONCLUSIONS

Investment in the widespread scale-up of ART may contribute to the control of the TB epidemic in Africa. However, interventions are also needed to augment the effect of ART on population TB incidence.

Enhancement of tendon-bone healing after rotator cuff injuries using combined therapy with mesenchymal stem cells and platelet rich plasma

OBJECTIVE

The injuries of rotator cuff will cause the shoulder dysfunctions. Due to limited self-regeneration abilities of the tendon-bone part, rotator cuff injuries remain a clinical challenge. Previous studies have proposed many strategies for treating this disease. In this work, we aimed to combine different strategies to achieve better beneficial effects on tendon-bone repair.

MATERIALS AND METHODS

We isolated mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) and tested the effects of PRP on the gene expression, cell death resistance, and osteogenic differentiation of MSCs. Then, we utilized multiple strategies to treat rotator cuff injuries. We evaluated the expression of genes that related to tissue repair, bone formation, and tendon regeneration. We also tested the biomechanical property of repair tissues.

RESULTS

We found that the in-vitro co-culture with PRP endowed MSCs with enhanced production of growth factors, better osteogenic differentiation ability, and stronger ability to resist cell death. Next, we applied MSCs, PRP, and MSCs-PRP combined therapies in rat rotator cuff injury model to compare their therapeutic effects in vivo. Through biomechanical testing, we found that the combined therapy was most efficient to promote tissue regeneration and enhance the biomechanical property of the newly generated bone.

CONCLUSIONS

The combined treatment induced strongest signals related to angiogenesis, bone formation, and tendon generation in-situ. We demonstrated that the combination of MSCs and PRP synergistically promotes tendon-bone healing and holds great promise for the treatment of rotator cuff injuries.

Sustained BMP-2 release and platelet rich fibrin synergistically promote tendon-bone healing after anterior cruciate ligament reconstruction in rat

OBJECTIVE

Anterior cruciate ligament (ACL) injuries which cause knee disabilities remain a clinical challenge due to the compromised tendon-bone repair. Multiple strategies have been proposed to treat the tendon-bone injuries, and the combination of these therapies hold great potential to achieve synergistic effects.

MATERIALS AND METHODS

We built PLGA-BMP-2 (bone morphogenetic protein 2) system and confirmed the sustained release of BMP-2 both in vitro and in vivo. We then applied different therapies to treat rat ACL reconstruction. We collected the tissue sample and analyzed the BMP-2 concentration both in serum and in injured sites. We tested the mRNA expression of genes that were related to inflammation, tissue repair and bone formation in damaged tissues. We also analyzed the protein levels of some genes associated with tendon formation and check the function of newly generated bone through biomechanical test.

RESULTS

We found that, compared to monotherapies, simultaneous utilization of sustained BMP-2 release and platelet-rich fibrin (PRF) after anterior cruciate ligament reconstruction showed better therapeutic effects on tendon-bone healing in rat. This combined therapy efficiently enhanced the levels of growth factors that favor the angiogenesis and relieved the inflammatory responses in the injured sites. Of note, the combined therapy efficiently promoted the signals associated with bone formation and tendon regeneration.

CONCLUSIONS

We demonstrated that the combined therapy with BMP-2 and PRF achieves synergistic effects on tendon-bone healing and holds great potential for the treatment of ACL reconstruction.

Analysis of Characteristics and Relevant Factors of 1 340 Cases of Intentional Injury Cases in Southwest China

Abstract

Objective To investigate the characteristics and patterns of factors such as victims' information, injury tools and time of occurrence of intentional injury cases in southwest China. Methods One thousand three hundred and forty intentional injury cases from several places in southwest China from 2014 to 2016 assessed as minor injury level Ⅱ and above had been randomly selected. Data on victims' information, motives, injury tools, sites of occurrence, time of occurrence, injured parts and degrees of injury were classified and gathered, and then association analyses of motives and types of injury tools as well as degrees of injury and injury tools were made. Results Most of the victims were young adults between 20-50 years （65.2%）, male （82.3%）, rural household registration （62.8%）; the motives were mainly dispute （45.8%）. Injury tools were mostly blunt （54.6%） or sharp （36.0%）. Specifically, injuries were mostly made bare-handed （36.9%） and by cutting tools （33.2%）; the cases mainly occurred in public areas （59.0%）. Cases occurred more frequently in January （11.3%）, February （13.1%）, March （11.6%） and from 22：00 to 01：00 every night. Injuries mainly involved the craniofacial region. The wounds were mainly assessed as minor injury level Ⅱ （61.6%）. There was statistical significance in the difference of types of injury tools among cases with different motives （P<0.05）. There was statistical significance in the difference of the distribution of injury tools among cases with different degrees of injury （P<0.05）. Conclusion The occurrence of intentional injury cases in southwest China has potential patterns and relevant influencing factors. Prevention and analysis of such cases need to be comprehensively considered from the aspects such as victims' information, injury tools and time of occurrence.

Evolution and persistence of resistance-associated substitutions of hepatitis C virus after direct-acting antiviral treatment failures

Daclatasvir plus asunaprevir (DCV+ASV) treatment is an all-oral direct-acting antiviral (DAA) therapy for the genotype 1b HCV-infected patients. In this study, we investigated how resistance-associated substitutions (RASs) evolved after treatment failures and assessed the effect of those substitutions on viral fitness. Sequencing of NS5A and NS3 revealed typical RASs after treatment failures. Interestingly, the RASs of NS3 reverted to the wild-type amino acid within 1 year after treatment failures. However, the RASs of NS5A were stable and did not change. The effect of NS5A and NS3 RASs on viral RNA replication was assessed after mutagenic substitution in the genotype 1b HCV RNA. Among single substitutions, the effect of D168V was more substantial than the others and the effect of the triple mutant combination (D168V+L31V+Y93H) was the most severe. The RAS at NS5A Y93 affected both viral RNA replication and virus production. Finally, the effect of trans-complementation of NS5A was demonstrated in our co-transfection experiments and these results suggest that such a trans-complementation effect of NS5A may help maintain the NS5A RASs for a long time even after cessation of the DAA treatment. In conclusion, the results from this investigation would help understand the emergence and persistence of RASs.

Growth arrest specific 1 (Gas1) and glial cell line-derived neurotrophic factor receptor α1 (Gfrα1), two mouse oocyte glycosylphosphatidylinositol-anchored proteins, are involved in fertilisation

Recently, Juno, the oocyte receptor for Izumo1, a male immunoglobulin, was discovered. Juno is an essential glycosylphosphatidylinositol (GIP)-anchored protein. This result did not exclude the participation of other GIP-anchored proteins in this process. After bibliographic and database searches we selected five GIP-anchored proteins (Cpm, Ephrin-A4, Gas1, Gfra1 and Rgmb) as potential oocyte candidates participating in fertilisation. Western blot and immunofluorescence analyses showed that only three were present on the mouse ovulated oocyte membrane and, of these, only two were clearly involved in the fertilisation process, namely growth arrest specific 1 (Gas1) and glial cell line-derived neurotrophic factor receptor α1 (Gfrα1). This was demonstrated by evaluating oocyte fertilisability after treatment of oocytes with antibodies against the selected proteins, with their respective short interference RNA or both. Gfrα1 and Gas1 seem to be neither redundant nor synergistic. In conclusion, oocyte Gas1 and Gfrα1 are both clearly involved in fertilisation.

Interface effect on the cohesive energy of nanostructured materials and substrate-supported nanofilms

The cohesive energy is a key quantity to determine the mechanical, physical, chemical, and electronic properties of materials.

Atf3 deficiency promotes genome instability and spontaneous tumorigenesis in mice

Mice lacking genes involving in the DNA damage response (DDR) are often tumor prone owing to genome instability caused by oncogenic challenges. Previous studies demonstrate that activating transcription factor 3 (ATF3), a common stress sensor, can activate the tumor suppressor p53 and regulate expression of p53 target genes upon DNA damage. However, whether ATF3 contributes to the maintenance of genome stability and tumor suppression remains unknown. Here we report that Atf3-deficient (Atf3^-/-) mice developed spontaneous tumors, and died significantly earlier than wild-type (Atf3^+/+) mice. Consistent with these results, Atf3^-/- mouse embryonic fibroblasts (MEFs) had more aberrant chromosomes and micronuclei, and were genetically unstable. Whereas we demonstrated that ATF3 activated p53 and promoted its pro-apoptotic activity in mouse thymi and small intestines, the chromosomal instability caused by Atf3 deficiency was largely dependent on the regulation of p53 by ATF3. Interestingly, loss of Atf3 also promoted spontaneous tumorigenesis in Trp53^+/- mice, but did not affect tumor formation in Trp53^-/- mice. Our results thus provide the first genetic evidence linking ATF3 to the suppression of the early development of cancer, and underscore the importance of ATF3 in the maintenance of genome integrity.

Association between Toll-like receptor 4 Asp299Gly polymorphism and coronary heart disease susceptibility

Published data on the association between Toll-like receptor 4 (TLR4) Asp299Gly polymorphism and coronary heart disease (CHD) susceptibility are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. English-language studies were identified by searching PubMed and Embase databases (up to November 2016). All epidemiological studies were regarding Caucasians because no TLR4 Asp/Gly and Gly/Gly genotypes have been detected in Asians. A total of 20 case-control studies involving 14,416 cases and 10,764 controls were included in the meta-analysis. Overall, no significant associations were found between TLR4 Asp299Gly polymorphism and CHD susceptibility in the dominant model (OR=0.89; 95%CI=0.74 to 1.06; P=0.20) pooled in the meta-analysis. In the subgroup analysis by CHD, non-significant associations were found in cases compared to controls. When stratified by control source, no significantly decreased risk was found in the additive model or dominant model. The present meta-analysis suggests that the TLR4 Asp299Gly polymorphism was not associated with decreased CHD risk in Caucasians.

Tissue-specific effects of estrogen on glycerol channel aquaporin 7 expression in an ovariectomized mouse model of menopause

OBJECTIVE

Elevated fat mass and redistribution of body fat are commonly observed in postmenopausal women. Aquaporin 7 (AQP7), a unique glycerol permeable integral membrane protein, has been associated with the onset of obesity. We hypothesized that estrogen supplementation could counteract this fat accumulation and redistribution through tissue-specific modulation of AQP7.

METHODS

We measured fat depot weight, adipocyte size, and the expression of AQP7 and glycerol kinase (GK) in visceral and subcutaneous fat tissues of ovariectomized mice supplemented with or without 17β-estradiol.

RESULTS

Removal of the ovaries resulted in a significant decrease in AQP7 expression and an increase in GK expression in visceral adipocyte tissue; expression of AQP7 and GK in subcutaneous adipose tissue remained unaltered. Supplementation with estrogen significantly restored the visceral, but not subcutaneous, fat depot mass and adipocyte size to those of sham-operated mice. A marked increase in the expression of AQP7 and a reduction of GK were observed selectively in the visceral fat depots in estrogen-treated mice.

CONCLUSIONS

Our results suggest that estrogen has tissue-specific effects on AQP7 expression, and modulation of AQP7 by estrogen alters the balance of adipocyte metabolism between adipose tissue depots.

Dysfunction of the WT1-MEG3 signaling promotes AML leukemogenesis via p53-dependent and -independent pathways

Long non-coding RNAs (lncRNAs) play a pivotal role in tumorigenesis, exemplified by the recent finding that lncRNA maternally expressed gene 3 (MEG3) inhibits tumor growth in a p53-dependent manner. Acute myeloid leukemia (AML) is the most common malignant myeloid disorder in adults, and TP53 mutations or loss are frequently detected in patients with therapy-related AML or AML with complex karyotype. Here, we reveal that MEG3 is significantly downregulated in AML and suppresses leukemogenesis not only in a p53-dependent, but also a p53-independent manner. In addition, MEG3 is proven to be transcriptionally activated by Wilms’ tumor 1 (WT1), dysregulation of which by epigenetic silencing or mutations is causally involved in AML. Therefore MEG3 is identified as a novel target of the WT1 molecule. Ten–eleven translocation-2 (TET2) mutations frequently occur in AML and significantly promote leukemogenesis of this disorder. In our study, TET2, acting as a cofactor of WT1, increases MEG3 expression. Taken together, our work demonstrates that TET2 dysregulated WT1-MEG3 axis significantly promotes AML leukemogenesis, paving a new avenue for diagnosis and treatment of AML patients.

[Expression of LIM and SH3 protein 1 in renal clear cell carcinoma and its effects on invasion and migration of renal clear cell carcinoma 786-O cells]

Objective: To investigate the expression of LIM and SH3 protein 1 (LASP1) in renal cell carcinoma and its significance in the invasion and migration of renal clear cell carcinoma 786-O cell line. Methods: The expression level of LASP1 in 41 cases of renal cell carcinoma tissues and normal renal tissues was analyzed by immunohistochemistry. The relationship between the expression level of LASP1 and clinical characteristics was further analyzed. Expression of LASP1 in 10 cases of tumor tissues with or without lymph node metastasis was analyzed by Western blot. Furthermore, small interfering RNA (siRNA) targeting LASP1 was constructed and transfected into 786-O cells to downregulate LASP1 expression. The interference effect of LASP1 siRNA on LASP1 protein and the expression of related proteins in epithelial mesenchymal transition (EMT) pathway were detected by Western blot. The effects of LASP1 knockdown on cell proliferation, migration and invasion and gene expression were then assessed using CCK8 assay, transwell cell migration system and western blot analysis, respectively. Results: The positive rate of LASP1 expression in renal clear cell carcinoma tissues was 90.2% (37/41), which was significantly higher than that in the adjacent tissues (29.3%, P=0.002). The expression of LASP1 in renal cell carcinoma was positively correlated with lymph node metastasis and TNM stage of renal cell carcinoma (P<0.05). The results of Western blot showed that LASP1 (0.696±0.053) was highly expressed in renal cell carcinoma (1.459±0.628), especially in cases with lymph node metastasis (2.692±0.186, P<0.05). The LASP1 siRNA remarkably down-regulated the expression of LASP1 protein in 786-O cells. The abilities of proliferation, invasion and migration of 786-O cells were decreased significantly in the LASP1 siRNA groups.The relative expression of E-cadherin protein in the siRNA group (0.848±0.020) was significantly higher than those in the siRNA-NC group (0.671±0.018) and control group (0.691±0.037, P<0.05). The relative expression of N-cadherin protein in the siRNA group (0.449±0.047) was significantly lower than those in the siRNA-NC group (0.613±0.018) and control group (0.633±0.045, P<0.05). The relative expression of vimentin protein in the siRNA group (0.477±0.029) was significantly lower than those in the siRNA-NC group (0.598±0.069) and control group (0.633±0.045, P<0.05 for both). Conclusions: LASP1 is highly expressed in renal clear cell carcinoma, which is closely related to the development of the cancer. The effects of LASP1 on the invasion and migration of 786-O cells and lymph node metastasis may be related to the EMT.

[Value of prostate volume, PSAD and F/T in the detection of prostate cancer in males with PSA 4-10 μg/L]

OBJECTIVE

To evaluate the association of prostate volume, PSAD and F/T with prostate cancer detection rate in males with a total PSA of 4-10 μg/L.

METHODS

Clinical data of 196 patients who underwent prostate biopsy from November 2006 to September 2010 and with a PSA of 4-10 μg/L were retrospectively analyzed. The association of detection rate of prostate cancer with prostate volume, prostate specific antigen density PSAD) and free PSA/total PSA ratio (F/T) was analyzed by Spearman coefficient, receiver operating characteristic curve and logistic regression analysis.

RESULTS

The prostate volume, PSAD and F/T had a significant association with detection rate of prostate cancer (P<0.05 for all). The odd ratio was 0.96, 1.91 and 0.02, respectively. The area under curve (AUR) was 0.31, 0.66 and 0.63, respectively. The cancer detection rate was decreased along with the increase of prostate volume. When PSAD 0.15 ng·ml(-1)·ml(-1) was used as the cut-off value, the sensitivity, specificity, positive prediction rate and negative prediction rate was 72.3%, 51.1%, 42.3% and 21.2%, respectively. When the patients were divided by prostate volume into <19.9, 20-39.9, 40-59.9, 60-79.9 and >80 ml subgroups, the cancer detection rate of each subgroup was 50.0%, 45.6%, 30.8%, 15.4% and 5.6%, respectively.

CONCLUSION

In patients with a total PSA of 4-10 μg/L, the prostate cancer detection rate has a significant association with prostate volume, PSAD and F/T.

Expressions of NDRG1, VEGF and Ki-67 in Condyloma Acuminatum

The objective of this study was to explore the expressions and significance of NDRG1 (N-myc downregulated gene family 1), VEGF (vascular endothelial growth factor) and Ki-67 in lesions of Condyloma Acuminatum (CA). Immunohistochemistry was adopted to measure the expressions of NDRG1, VEGF and Ki-67 in 48 cases of CA and 18 normal skin controls. The positive rates of NDRG1, VEGF and Ki-67 were 63. 83.33% (40/48), 93.75% (45/48) and 85.42% (41/48) in the CA tissues, and 27.78% (5/18), 94.44%(17/18) and 61.11% (11/18) in the controls, respectively. The intensities of the expressions of NDRG1, VEGF and Ki-67 in CA tissues were significantly higher than those in the controls. There were significant differences both in the positive rates and the expression intensities of NDRG1, VEGF and Ki-67 between the two groups (P less than0.05). The Spearman’s Rank-Order Correlation analysis indicated that the expressions of NDRG1 protein and VEGF protein were positively correlated by the Spearman’s Rank-Order Correlation analysis (r = 0.346, P=0.016). For the CA tissues with high expressions of NDRG1 and VEGF, NDRG1 and VEGF influenced both the occurrence and development of CA.

Gastric Metastasis of Hepatocellular Carcinoma With Gastrointestinal Bleeding After Liver Transplant: A Case Report

Gastrointestinal (GI) metastasis of hepatocellular carcinoma is very rare. This is the first report of post-transplantation gastric metastasis. A 43-year-old man with a history of hepatitis B-related hepatocellular carcinoma (HCC) in the right anterior segment of the liver received an orthotopic liver transplant. Three months after the transplantation, pulmonary metastasis was found by chest computed tomography, and he received 1 course of gamma knife treatment. He complained of melena with anemia 17 months post liver transplantation. Abdominal CT scan showed new occupying lesions in the liver and a mass in the stomach and around the spleen with embolus in the splenic vein. Endoscopy revealed a large irregular cauliflower-like mass in fundus with ulceration and bleeding on the surface. He received symptomatic treatment, but died of cancer-related bleeding 4 months later. GI bleeding may due to gastric metastasis after liver transplantation.

Association of Beclin-1 and microRNA-30a expression with the severity and treatment response of colorectal cancer

We investigated the associations between Beclin-1 and microRNA-30a (miR-30a) expression and the severity and treatment response in colorectal cancer (CRC). Our sample size consisted of 139 CRC patients who were treated with surgery alone. Immunohistochemistry was used to investigate the expression and prognostic significance of Beclin-1 in CRC, while the weak expression of Beclin-1 in normal tissue was used as the basis for assessing tumors (control group). Real-time reverse transcription-polymerase chain reaction quantified miR-30a levels. The expression levels of Beclin-1 and miR-30a were associated with clinical variables and prognoses. Beclin-1 was expressed more highly in CRC tissues than in controls. This expression was related to gender (P = 0.023), histological grade (P = 0.006), M stage (P = 0.004), tumor node metastasis stage (P = 0.020), vascular invasion, and nodal involvement. Patients with higher Beclin-1 expression levels had higher survival rates (P = 0.08) than patients with lower Beclin-1 expression levels. Beclin-1 was a prognostic indicator (P < 0.05) in a multivariate analysis. Beclin-1 was overexpressed in CRC tissues and was correlated with lower levels of miR-30a (P < 0.05, r = -0. 4189). In conclusion, Beclin-1 was a good prognostic indicator in CRC and was correlated with survival rate. Beclin-1 is important in the growth and metastasis of CRC. Apoptosis in CRC might be due to the increased autophagy induced by decreased levels of miR-30a.

HLA-DR3 antigen in the resistance to idiopathic dilated cardiomyopathy

Idiopathic dilated cardiomyopathy (IDC) has been hypothesized as a multifactorial disorder initiated by an environment trigger in individuals with predisposing human leukocyte antigen (HLA) alleles. Published data on the association between HLA-DR3 antigen and IDC risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Studies were identified by searching the PUBMED and Embase database (starting from June 2015). A total of 19 case-control studies including 1378 cases and 10383 controls provided data on the association between HLA-DR3 antigen and genetic susceptibility to IDC. Overall, significantly decreased frequency of HLA-DR3 allele (OR=0.72; 95%CI=0.58-0.90; P=0.004) was found in patients with IDC compared with controls. When stratified by myocardial biopsy or non-biopsy cases, statistically decreased risk was found for IDC in myocardial biopsy cases (OR=0.69; 95%CI=0.57-0.84; P=0.0003). In the subgroup analysis by ethnicity, borderline statistically significantly decreased risk was found among Europeans from 12 case-control studies (OR=0.76; 95%CI=0.58-1.00; P=0.05). In conclusion, our results suggest that individuals with HLA-DR3 antigen may have a protective effect against IDC.

Contact force-guided catheter ablation for the treatment of atrial fibrillation: a meta-analysis of randomized, controlled trials

Contact force (CF) sensing technology allows real-time monitoring during catheter ablation for atrial fibrillation (AF). However, the effect of CF sensing technology on procedural parameters and clinical outcomes still needs clarification. Because of the inconsistent results thus far in this area, we performed a meta-analysis to determine whether CF sensing technology can improve procedural parameters and clinical outcomes for the treatment of AF. Studies examining the benefits of CF sensing technology were identified in English-language articles by searching the MEDLINE, Web of Science, and Cochrane Library databases (inception to May 2015). Ten randomized, controlled trials involving 1834 patients (1263 males, 571 females) were included in the meta-analysis (681 in the CF group, 1153 in the control group). Overall, the ablation time was significantly decreased by 7.34 min (95%CI=-12.21 to -2.46; P=0.003, Z test) in the CF group compared with the control group. CF sensing technology was associated with significantly improved freedom from AF after 12 months (OR=1.55, 95%CI=1.20 to 1.99; P=0.0007) and complications were significantly lower in the CF group than in the control group (OR=0.50, 95%CI=0.29 to 0.87; P=0.01). However, fluoroscopy time analysis showed no significantly decreased trend associated with CF-guided catheter ablation (weighted mean difference: -2.59; 95%CI=-9.06 to 3.88; P=0.43). The present meta-analysis shows improvement in ablation time and freedom from AF after 12 months in AF patients treated with CF-guided catheter ablation. However, CF-guided catheter ablation does not decrease fluoroscopy time.

Differential expression of microRNAs may regulate pollen development in Brassica oleracea

MicroRNAs (miRNAs) are a class of non-coding endogenous negative regulators that regulate gene expression at both the transcriptional and post-transcriptional levels. However, little is known about the expression characteristics of miRNAs during pollen development in Brassica oleracea. In this study, five known and three novel miRNAs were identified and their expression patterns were compared in the flower buds of B. oleracea using stem-loop reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR. The results revealed that the eight miRNAs were constantly expressed during pollen development but exhibited different expression patterns during the five developmental stages of the flower buds between the cytoplasmic male sterile (CMS) line and its fertile maintainer. The highest miRNA expression levels occurred at the uninucleate microspore stage in the fertile line Bo01-12B and at the bicellular pollen stage in the CMS line Bo01-12A. Potential target genes for the miRNAs were predicted and analyzed, and suggested that miRNAs are involved in the regulation of target genes related to pollen development. The results of this study further our understanding of the regulatory role of miRNAs in pollen development.