Robotic pyelolithotomy for treating large renal stone disease: a systematic review and single-arm meta-analysis.

Robotic pyelolithotomy continues to gain attention as an alternative to percutaneous nephrolithotomy (PCNL) for managing complex renal stones. We performed a single-arm meta-analysis and systematically searched the English-language literature published in PubMed, Web of Science, Scopus, and Google Scholar databases up to June 2024. The risk of non-randomized bias was assessed using ROBINS-I, and the quality of the literature was assessed using MINORS (Methodological Index for Non-Randomized Studies). Merger parameters were calculated using Stata16/SE under a random-effects model. Five non-comparative single-arm studies were included in the meta-analysis. Results showed that the operative time for robotic pyelolithotomy was 168.10 min (95% CI 133.63, 202.56). The hospital stay was 2.63 days (95% CI 0.96, 4.29), and blood loss was 44.13 ml (95% CI 19.76, 68.51). The stone clearance rate was 87% (95% CI 79-93%). The incidence of minor postoperative complications (Clavien grade I-II) was 23.7% (95% CI 13.4-35.8%), and the incidence of major complications (Clavien grade ≥ III) was 7% (95% CI 0.3-20.7%).The safety and efficacy of robotic pyelolithotomy in treating complex renal stones are acceptable, but future large prospective cohort studies are needed to validate the treatment.

Prognostic Value and Therapeutic Significance of CCL Chemokines in Gastric Cancer.

BACKGROUND: Gastric cancer is one of the most common malignant tumours of the gastrointestinal tract, which has a significant negative impact on human health. AIMS: CCL chemokines play important roles in a variety of tumor microenvironments; nevertheless, gastric cancer has surprisingly limited associations with CCL chemokines. METHODS: In our study, we comprehensively utilized bioinformatics analysis tools and databases such as cBioPortal, UALCAN, GEPIA, GeneMANIA, STRING, and TRRUST to clarify the clinical significance and biology function of CCL chemokines in gastric cancer. RESULTS: The mRNA expression levels of CCL1/3/4/5/7/8/14/15/18/20/21/22/26 were up-regulated, while the mRNA expression levels of CCL2/11/13/16/17/19/23/24/25/28 were down-regulated. The chemokine significantly associated with the pathological stage of gastric cancer is CCL2/11/19/21. In gastric cancer, the expression level of CCL chemokines was not associated with disease-free survival, but low expression of CCL14 was significantly associated with longer overall survival. Therein, associated with the regulation of CCL chemokines are only 10 transcription factors (RELA, NFKB1, STAT6, IRF3, REL, SPI1, STAT1, STAT3, JUN and SP1). The major biological process and functional enrichment of CCL chemokines are to induce cell-directed migration. CONCLUSION: These results may indicate that CCL chemokines may be immunotherapeutic targets and promising prognostic biomarkers for gastric cancer.

Dihydromyricetin ameliorates experimental ulcerative colitis by inhibiting neutrophil extracellular traps formation via the HIF-1α/VEGFA signaling pathway.

Dihydromyricetin (DHM), which has various biological functions, possesses therapeutic potential for ulcerative colitis (UC). Neutrophil extracellular traps (NETs) and their components play a crucial role in several pathological processes in UC. However, whether DHM alleviates UC by regulating NETs remains unclear. Mice with dextran sulfate sodium (DSS)-induced acute colitis were treated with DHM at different concentrations, and the severity of colitis was evaluated by assessing body weight, colon length, histological scores, cytokine production, and epithelial barrier integrity. To quantify and visualize NETs, the expression of cell free-DNA (cf-DNA) in serum and Cit-H3 in colonic tissue was analyzed via western blotting and immunofluorescence analysis. HL-60 cells and mouse bone marrow-derived neutrophils (BMDNs) were used to evaluate the effects of DHM on NETs in vitro. NETs were treated with DHM at varying concentrations or DNase I and used to repair the intestinal epithelial barrier in a Caco-2/HIEC-6 cell monolayer model. Furthermore, the genes targeted by DHM through neutrophils for alleviating UC were identified by screening online databases, and the results of network pharmacological analysis were verified via western blotting and quantitative real-time polymerase chain reaction. DHM alleviated DSS-induced colitis in mice by reversing weight loss, increased DAI score, colon length shortening, enhanced spleen index, colonic pathological damage, cytokine production, and epithelial barrier loss in a dose-dependent manner. In addition, it inhibited the formation of NETs both in vivo and in vitro. Based on the results of network pharmacological analysis, DHM may target HIF-1α and VEGFA through neutrophils to alleviate UC. Treatment with PMA increased the expression of HIF-1α and VEGFA in D-HL-60 cells and BMDNs, whereas treatment with DHM or DNase I reversed this effect. Treatment with DMOG, an inhibitor of HIF prolyl hydroxylase (HIF-PH), counteracted the suppressive effects of DHM on NETs formation in D-HL-60 cells and BMDNs. Accordingly, it partially counteracted the protective effects of DHM on the intestinal epithelial barrier in Caco-2 and HIEC-6 cells. These results indicated that DHM alleviated DSS-induced UC by regulating NETs formation via the HIF-1α/VEGFA signaling pathway, suggesting that DHM is a promising therapeutic candidate for UC.

UBE2L3 expression in human gastric cancer and its clinical significance.

PURPOSE: Gastric cancer (GC) is prevalent as one of the most common malignant tumors globally, with a particularly high incidence in China. The role of UBE2L3 in the initiation and progression of various cancers has been well documented, but its specific significance in GC is not yet fully elucidated. The objective of this study is to examine the expression and importance of UBE2L3 in human gastric cancer tissues. METHODS: Immunohistochemical staining and survival analysis were conducted on 125 cases of GC. Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to assess the expression of UBE2L3 in GC cell lines. Cell lines with UBE2L3 knockdown and overexpression were cultured through lentivirus transfection and subsequently assessed using Western blot analysis. The involvement of UBE2L3 in the proliferation, invasion, and apoptosis of GC cells was confirmed through in vitro experiments, and its capacity to facilitate tumor growth was also validated in in vivo studies. RESULTS: The up-regulation of UBE2L3 expression was observed in GC, and its high expression was found to be significantly associated with the degree of differentiation (χ2 = 6.153, P = 0.0131), TNM stage (χ2 = 6.216, P = 0.0447), and poor overall survival. In vitro, UBE2L3 has been shown to enhance functions in GC cell lines, such as promoting proliferation and invasion, and inhibiting apoptosis. In vivo experiments have validated the role of UBE2L3 in promoting tumor growth. CONCLUSIONS: The findings of our study demonstrate the significant involvement of UBE2L3 in the pathogenesis and advancement of gastric cancer, suggesting its potential as a therapeutic target.

Hematological and biochemical parameters of giant pandas (Ailuropoda melanoleuca) in captive and semi-natural environments.

Physiological indexes like blood parameters have been widely used to monitor the health of free-roaming animals. Attempts to reintroduce one of China's most endangered species, the giant panda (Ailuropoda melanoleuca), have been hampered by a lack of data on its ecology and physiology. We examined three giant pandas' hematological and blood chemistry parameters in a soft release program and 30 captive giant pandas as controls and determined the reference intervals (RIs) for those blood parameters in the captive animals. Elevation, captivity status and the interaction of those factors were statistically significant for hematologic measures. Release pandas had significantly higher hemoglobin and hematocrit values after they moved to high elevation locations. We also found significant difference in the enzyme parameters between high and low elevation pandas such as higher aspartate aminotransferase, alanine aminotransferase, creatinine kinase, amylase and lower lactate dehydrogenase and alkaline phosphatase. Release pandas also had higher nutrition parameter values such as higher albumin, globulin and creatinine. The RI for blood parameters in our study provides a baseline to monitor the health of captive animals and forms the basis for assessing the health of free-roaming giant pandas in future reintroduction efforts.

Exploration of mRNA nanoparticles based on DOTAP through optimization of the helper lipids.

Lipid nanoparticles (LNPs) are one of the most efficient carriers for RNA packaging and delivery, and vaccines based on mRNA-LNPs have received substantial attention since the outbreak of the COVID-19 pandemic. LNPs based on 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) have been widely used in preclinical and clinical settings. A novel non-viral gene delivery system called LNP3 was previously developed, which was composed of DOTAP, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and cholesterol. One of the helper lipids in this carrier was DOPE, which belongs to phospholipids. Given that substituting DOPE with non-phospholipids as helper lipids can increase the delivery efficiency of some LNPs, this study aimed to examine whether non-phospholipids can be formulated with DOTAP as helper lipids. It was found that monoglycerides with C14:0, C16:0, C18:0, C18:1, and C18:2 mediated mRNA transfection, and the transfection efficiency varied between C18:0, C18:1, and C18:2. Furthermore, substituting of the glycerol with other moieties such as the cholesterol or the ethanolamine similarly mediated mRNA transfection. The introduction of cholesterol can further improve the transfection capacity of some DOTAP-based LNPs. One of the best-performing formulations, LNP3-MO, was used to mediate luciferase-mRNA expression in vivo, and the luminescence signal was found to be mainly enriched in the lung and spleen. In addition, the level of SARS-CoV-2 spike antibody in the serum increased after three doses of LNP3-MO mediated SARS-CoV-2 spike mRNA. Altogether, this study demonstrates that non-phospholipids are promising helper lipids that can be formulated with DOTAP to facilitate efficient delivery of mRNAs in vitro and in vivo with organ-specific targeting.

A dual-modal ROS generator based on multifunctional PDA-MnO2@Ce6 nanozymes for synergistic chemo-photodynamic antibacterial therapy.

The rapid emergence of drug-resistant bacteria has attracted great attention to exploring advanced antibacterial methods. However, single-modal antibacterial therapy cannot easily eliminate drug-resistant bacteria completely due to its low efficacy. Therefore, it is essential to achieve multi-modal antibacterial therapy effectively. Herein, a dual-modal ROS generator was designed based on photosensitive PDA-MnO2@Ce6/liposome (PMCL) nanozymes for synergistic chemo-photodynamic therapy. PMCL nanozymes adhere to bacteria through liposome-membrane fusion. Meanwhile, PMCL catalyzes endogenous hydrogen peroxide (H2O2) to generate hydroxyl radicals (˙OH) and singlet oxygen (1O2) under laser irradiation. Furthermore, the photothermal effect can accelerate the generation of ROS. Based on dual-enzyme activities (mimicking peroxidase and catalase) and photodynamic properties, PMCL achieves powerful antibacterial efficacy and mature bacterial biofilm eradication. With the synergistic chemo-photodynamic effects, bacterial populations decrease by >99.76% against Gram-positive S. aureus and Gram-negative E. coli. Notably, the synergistic antibacterial properties of PMCL nanozymes are further explored using a mouse wound model of S. aureus infection. This work fabricated an efficient dual-modal ROS generator to kill bacteria, further providing a new strategy for treating wound infection.

Constructed the ceRNA network and predicted a FEZF1-AS1/miR-92b-3p/ZIC5 axis in colon cancer.

The purpose of this study was to identify the role of FEZF1-AS1 in colon cancer and predicted the underlying mechanism. We extracted sequencing data of colon cancer patients from The Cancer Genome Atlas database, identified the differential expression of long noncoding RNA, microRNA, and messenger RNA, constructed a competitive endogenous RNA network, and then analyzed prognosis. Then, we used the enrichment analysis databases for functional analysis. Finally, we studied the FEZF1-AS1/miR-92b-3p/ZIC5 axis. We detected the expression of FEZF1-AS1, miR-92b-3p, and ZIC5 via quantitative reverse transcription-PCR, transfected colon cancer cell RKO with lentivirus and conducted FEZF1-AS1 knockdown, and performed cancer-related functional assays. It indicated that many RNA in the competitive endogenous RNA network, such as ZIC5, were predicted to be related to overall survival of colon cancer patients, and enrichment analysis showed cancer-related signaling pathways, such as PI3K/AKT signaling pathway. The expression of FEZF1-AS1 and ZIC5 was significantly higher and that of miR-92b-3p was lower in the colon cancer than in the normal colon tissues. FEZF1-AS1 promoted the migration, proliferation, as well as invasion of RKO. According to the prediction, FEZF1-AS1 and ZIC5 might competitively bind to miR-92b-3p, leading to the weakening of the inhibitory impact of miR-92b-3p on ZIC5 and increasing expression of ZIC5, thus further activating the PI3K/AKT signaling pathway, which led to the occurrence and development of colon cancer. The study suggested that FEZF1-AS1 might be an effective diagnosis biomarker for colon cancer.

The Potential Role of Small Nucleolar RNAs in Cancers - An Evidence Map.

Purpose: Cancer seriously endangers human health in every country of the world. New evidence shows that small nucleolar RNAs play important roles in tumorigenesis. Herein, we created this evidence map to systematically assess the impact of dysregulated snoRNAs on cancers. Methods: We searched four databases to February 2022 using the keywords, "carcinoma", "neoplasms", "tumor", "cancer", "snoRNA", and "small nucleolar rna". The research data were independently screened by two reviewers. Bubble plot, mind map, heatmap were used to depict the relationship between snoRNAs and cancers. Results: In total, 102 studies met the inclusion criteria and were analyzed in this evidence map. In this study, we found that dysregulated snoRNAs were statistically associated with the clinicopathological characteristics of cancer patients, and affected tumor cell phenotypes. Abnormally expressed snoRNAs were associated with poor survival in cancer patients. Current research confirmed that snoRNAs have good diagnostic efficiency for cancers. snoRNAs could modulate biological processes and signaling pathways of different cancer cells by altering rRNA, regulating mRNA, and recruiting protein factors. Conclusion: Taken all together, ectopic snoRNAs may serve as new biomarkers for clinical assessment, diagnostic, prognostic prediction of cancer patients, and provide a potential therapeutic strategy for cancer treatment. This article provided a visual analysis of existing evidence on snoRNAs and cancers, which can offer useful information for different researchers interested in snoRNAs.

AGT May Serve as a Prognostic Biomarker and Correlated with Immune Infiltration in Gastric Cancer.

Purpose: Angiotensinogen (AGT), as a component of the renin-angiotensin system (RAS), is associated with multiple risk factors for gastric cancer (GC). However, the relationship between AGT and tumor-infiltrating lymphocytes in GC remains elusive. Methods: AGT expression was analyzed based on the Cancer Genome Atlas (TCGA) dataset. Kaplan-Meier curve was employed to assess the role of AGT expression in gastric patients' prognosis. The association between AGT expression and tumor immune infiltration was further evaluated via exploring Tumour Immune Estimation Resource (TIMER) and The Gene Expression Profiling Interactive Analysis (GEPIA). We also used multiple public databases to analyse the aberrant methylation of AGT, construct protein-protein interaction (PPI) and gene ontology (GO) analyses. Results: AGT was overexpressed in GC tissues compared with normal gastric tissues (P<0.05). High AGT expression related with poorer overall survival of patients with GC, especially in advanced GC patients. Immune infiltration analysis revealed that AGT was associated with several immune cells (including B cells, CD4+ T cells, macrophages), and AGT expression was also associated with the markers of NK cells, TAMs, Tregs, and so on (all P<0.05). Methylation analysis indicated that hypomethylation may lead to abnormal upregulation of the AGT. GO analysis showed that AGT and its related genes were enriched in systemic arterial blood pressure by hormone, regulation of blood volume by renin-angiotensin, NIK/NF-kappaB signaling, ficolin-1-rich granule and so on. Conclusion: AGT could act as a promising biomarker for prognosis and immune infiltration in GC.

Efficacy of a newly developed bioabsorbable pancreatic clip for distal pancreatectomy in swine.

PURPOSE: At present, ≥ 20% of patients experience clinically relevant postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP). METHODS: We developed a new bioabsorbable pancreatic clip (BioPaC) made of polycaprolactone that does not crush the pancreatic parenchyma during occlusion of the pancreatic stump. We confirmed the efficacy of this BioPac in a porcine DP model and compared it to a linear stapling device (Reinforce®). RESULTS: Pigs were killed at 1 month after DP. In the BioPaC group, all swine (n = 3) survived well without POPF. In the Reinforce® group (n = 2), one pig died early at postoperative day 7 with Grade C POPF (amylase 43 700 U/l), and the other survived until 1 month at scarification with biochemical leakage of POPF (amylase 3 725 U/l). Pathologically, the main pancreatic duct and pancreatic parenchyma were well closed by BioPaC. CONCLUSION: The newly developed BioPaC is effective in a porcine DP model.

Field metabolic rates of giant pandas reveal energetic adaptations.

Knowledge of energy expenditure informs conservation managers for long term plans for endangered species health and habitat suitability. We measured field metabolic rate (FMR) of free-roaming giant pandas in large enclosures in a nature reserve using the doubly labeled water method. Giant pandas in zoo like enclosures had a similar FMR (14,182 kJ/day) to giant pandas in larger field enclosures (13,280 kJ/day). In winter, giant pandas raised their metabolic rates when living at - 2.4 °C (36,108 kJ/day) indicating that they were below their thermal neutral zone. The lower critical temperature for thermoregulation was about 8.0 °C and the upper critical temperature was about 28 °C. Giant panda FMRs were somewhat lower than active metabolic rates of sloth bears, lower than FMRs of grizzly bears and polar bears and 69 and 81% of predicted values based on a regression of FMR versus body mass of mammals. That is probably due to their lower levels of activity since other bears actively forage for food over a larger home range and pandas often sit in a patch of bamboo and eat bamboo for hours at a time. The low metabolic rates of giant pandas in summer, their inability to acquire fat stores to hibernate in winter, and their ability to raise their metabolic rate to thermoregulate in winter are energetic adaptations related to eating a diet composed almost exclusively of bamboo. Differences in FMR of giant pandas between our study and previous studies (one similar and one lower) appear to be due to differences in activity of the giant pandas in those studies.

Gate-tunable plasmons in mixed-dimensional van der Waals heterostructures.

Surface plasmons, collective electromagnetic excitations coupled to conduction electron oscillations, enable the manipulation of light-matter interactions at the nanoscale. Plasmon dispersion of metallic structures depends sensitively on their dimensionality and has been intensively studied for fundamental physics as well as applied technologies. Here, we report possible evidence for gate-tunable hybrid plasmons from the dimensionally mixed coupling between one-dimensional (1D) carbon nanotubes and two-dimensional (2D) graphene. In contrast to the carrier density-independent 1D Luttinger liquid plasmons in bare metallic carbon nanotubes, plasmon wavelengths in the 1D-2D heterostructure are modulated by 75% via electrostatic gating while retaining the high figures of merit of 1D plasmons. We propose a theoretical model to describe the electromagnetic interaction between plasmons in nanotubes and graphene, suggesting plasmon hybridization as a possible origin for the observed large plasmon modulation. The mixed-dimensional plasmonic heterostructures may enable diverse designs of tunable plasmonic nanodevices.

Flexible Multiplexed In2O3 Nanoribbon Aptamer-Field-Effect Transistors for Biosensing.

Flexible sensors are essential for advancing implantable and wearable bioelectronics toward monitoring chemical signals within and on the body. Developing biosensors for monitoring multiple neurotransmitters in real time represents a key in vivo application that will increase understanding of information encoded in brain neurochemical fluxes. Here, arrays of devices having multiple In2O3 nanoribbon field-effect transistors (FETs) were fabricated on 1.4-µm-thick polyethylene terephthalate (PET) substrates using shadow mask patterning techniques. Thin PET-FET devices withstood crumpling and bending such that stable transistor performance with high mobility was maintained over >100 bending cycles. Real-time detection of the small-molecule neurotransmitters serotonin and dopamine was achieved by immobilizing recently identified high-affinity nucleic-acid aptamers on individual In2O3 nanoribbon devices. Limits of detection were 10 fM for serotonin and dopamine with detection ranges spanning eight orders of magnitude. Simultaneous sensing of temperature, pH, serotonin, and dopamine enabled integration of physiological and neurochemical data from individual bioelectronic devices.

Tunneling Spectroscopy in Carbon Nanotube-Hexagonal Boron Nitride-Carbon Nanotube Heterojunctions.

Electron tunneling spectroscopy is a powerful technique to probe the unique physical properties of one-dimensional (1D) single-walled carbon nanotubes (SWNTs), such as the van Hove singularities in the density of states or the power-law tunneling probability of a Luttinger liquid. However, little is known about the tunneling behavior between two 1D SWNTs over a large energy spectrum. Here, we investigate the electron tunneling behavior between two crossed SWNTs across a wide spectral window up to 2 eV in the unique carbon nanotube-hexagonal boron nitride-carbon nanotube heterojunctions. We observe many sharp resonances in the differential tunneling conductance at different bias voltages applied between the SWNTs. These resonances can be attributed to elastic tunneling into the van Hove singularities of different 1D subbands in both SWNTs, and they allow us to determine the quasi-particle bandgaps and higher-lying 1D subbands in SWNTs on the insulating substrate.

Nonlinear Luttinger liquid plasmons in semiconducting single-walled carbon nanotubes.

Interacting electrons confined in one dimension are generally described by the Luttinger liquid formalism, where the low-energy electronic dispersion is assumed to be linear and the resulting plasmonic excitations are non-interacting. Instead, a Luttinger liquid in one-dimensional materials with nonlinear electronic bands is expected to show strong plasmon-plasmon interactions, but an experimental demonstration of this behaviour has been lacking. Here, we combine infrared nano-imaging and electronic transport to investigate the behaviour of plasmonic excitations in semiconducting single-walled carbon nanotubes with carrier density controlled by electrostatic gating. We show that both the propagation velocity and the dynamic damping of plasmons can be tuned continuously, which is well captured by the nonlinear Luttinger liquid theory. These results contrast with the gate-independent plasmons observed in metallic nanotubes, as expected for a linear Luttinger liquid. Our findings provide an experimental demonstration of one-dimensional electron dynamics beyond the conventional linear Luttinger liquid paradigm and are important for understanding excited-state properties in one dimension.

Metallic Carbon Nanotube Nanocavities as Ultracompact and Low-loss Fabry-Perot Plasmonic Resonators.

Plasmonic resonators enable deep subwavelength manipulation of light matter interactions and have been intensively studied both in fundamental physics as well as for potential technological applications. While various metallic nanostructures have been proposed as plasmonic resonators, their performances are rather limited at mid- and far-infrared wavelengths. Recently, highly confined and low-loss Luttinger liquid plasmons in metallic single-walled carbon nanotubes (SWNTs) have been observed at infrared wavelengths. Here, we tailor metallic SWNTs into ultraclean nanocavities by advanced scanning probe lithography and investigate plasmon modes in these individual nanocavities by infrared nanoimaging. The dependence of mode evolutions on cavity length and excitation wavelength can be captured by a Fabry-Perot resonator model of a plasmon nanowaveguide terminated by highly reflective ends. Plasmonic resonators based on SWNT nanocavities approach the ultimate plasmon confinement limit and open the door to the strong light-matter coupling regime, which may enable various nanophotonic applications.

Application of computed tomography, positron emission tomography-computed tomography, magnetic resonance imaging, endobronchial ultrasound, and mediastinoscopy in the diagnosis of mediastinal lymph node staging of non-small-cell lung cancer: A protocol for a systematic review.

BACKGROUND: Ruling out distant metastases, non-small cell lung cancer (NSCLC)treatment depends on the results of mediastinal node staging (N staging). Several diagnostic methods play central roles in mediastinal N staging. This study is intended to evaluate the existing diagnostic methods and report quality, and to search for the best method for staging mediastinal lymph nodes. METHODS: We searched PubMed, Embase, and the Cochrane Library to identify relevant studies, including randomized controlled trials and retrospective studies. These studies report the application of computed tomography, positron emission tomography-computed tomography, magnetic resonance imaging, endobronchial ultrasound, and mediastinoscopy in the diagnosis of mediastinal lymph node staging of NSCLC. The quality of the literature was assessed using the Quality Assessment of Diagnostic Accuracy Study 2. The true positive, false positive, true negative, and false negative of each study was extracted. The corresponding sensitivity, specificity, and other indicators were calculated and the Summary Receiver Operating curve was established. Then, head-to-head and indirect comparison meta-analyses will be conducted. RESULTS: The results of this study will be published in a peer-reviewed journal. CONCLUSION: This study will provide basis for mediastinal lymph node staging of non-small cell lung cancer. PROSPERO REGISTRATION NUMBER: CRD42019145667.

Serum Surfactant Protein D is a Potential Biomarker for Chronic Obstructive Pulmonary Disease: a Systematic Review and Meta-analysis.

BACKGROUND: A number of studies have been conducted to investigate the association between serum surfactant protein D (SP-D) concentration and chronic obstructive pulmonary disease (COPD) risk. However, the results are inconsistent. This systematic review and meta-analysis aim to investigate whether serum SP-D concentration is a potential biomarker for COPD diagnosis. METHODS: We searched Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), and Wanfang Database from inception through July 18, 2018. The standardized mean difference (SMD) with 95% confidence interval (CI) was used to investigate the effect sizes. RESULTS: Seventeen eligible studies from a total of 4,639 subjects were finally included in this systematic review and meta-analysis. The results indicated that serum SP-D levels in COPD patients were significantly higher than those in controls (SMD = 1.01, 95% CI = 0.62 - 1.41, p < 0.001). We also found that serum SP-D concentration in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients was significantly higher than that in stable COPD patients (SMD = 1.50, 95% CI = 0.92 - 2.08, p < 0.001), and serum SP-D concentration was higher in smokers than in nonsmokers in healthy population (SMD = 1.50, 95% CI = 0.35 - 2.64, p = 0.025). CONCLUSIONS: The current systematic review and meta-analysis indicates that serum SP-D levels may be a promising biomarker for COPD. In particular, increased serum SP-D levels appear to be associated with acute exacerbation of COPD and smoking in healthy population.