Effects of cryopreservation on gram-positive bacteria contaminants in umbilical cord blood.

OBJECTIVE: To evaluate the effects of cryopreservation in post-thaw umbilical cord blood units for the survivability of Gram-positive bacteria strains. BACKGROUND: Microbial screening is required for all cord blood units (CBUs). Four gram-positive contaminants were documented to survive cryopreservation poorly and isolation of other contaminants were reported. METHODS: Forty-eight contaminated CBUs detected with either Staphylococcus epidermidis, Corynebacterium species, Peptostreptococcus or Streptococcus species before cryopreservation were used in this study. CBUs were processed, DMSO-infused and microbial screened before cryopreservation. Post-thaw microbial screening was achieved using 1 and 10 ml inoculants in BACTEC culture bottles. Positive bottles were subjected for microbial identification and results were compared with those from pre-freeze. RESULTS: A higher rate of microbial contamination was found using the 10 ml inoculant. Screening of 11 CBUs did not detect any contaminants while 30 CBUs screened detected more than one unknown contaminants and majority of contaminants were identified to be gram-negative species. CONCLUSION: A higher inoculation volume used at post-thaw for microbial screening improves contamination detection but leads to the loss of precious cord blood. Some contaminants did not survive cryopreservation or were not identified due to their low microbial levels. Contrasting contaminants found at post-thaw suggest the improvements made in detection and identification of contaminants over the years.

Influence of Electronic Modulation of Phenanthroline-Derived Ligands on Separation of Lanthanides and Actinides.

The solvent extraction, complexing ability, and basicity of tetradentate N-donor 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline (CyMe4-BT- Phen) and its derivatives functionalized by Br, hydroxyphenyl, nitryl were discussed and compared. It was demonstrated that four BTPhen ligands are able to selectively extract Am(lll) over Eu(lll). It was notable that the distribution ratio of 5-nitryl-CyMe4-BTPhen for Eu(lll) was suppressed under 0.02, which was much lower compared to DEu(lll) = 1 by CyMe4-BTPhen. The analysis of the effect of the substituent on the affinity to lanthanides was conducted by UV/vis and fluorescence spectroscopic titration. The stability constants of various ligands with Eu(lll) were obtained by fitting titration curve. Additionally, the basicity of various ligands was determined to be 3.1 ± 0.1, 2.3 ± 0.2, 0.9 ± 0.2, 0.5 ± 0.1 by NMR in the media of CD3OD with the addition of DClO4. The basicity of ligands follows the order of L1 > L2 > L3 > L4, indicating the tendency of protonation decreases with the electron-withdrawing ability increase.

[Effects of density on growth and gene transcription characteristics of Rehmannia glutinosa].

The present study analyzed the effects of planting density on the development, quality, and gene transcription characte-ristics of Rehmannia glutinosa using 85-5 and J9 as materials with three planting densities of 5 000, 25 000, and 50 000 plants/Mu(1 Mu≈667 m~2). The agronomic characteristics of leaves and tuberous roots, the content of catalpol and acteoside, and the changes of gene expression were determined. The results showed that the leaf size, the diameter of tuberous root, leaf biomass, tuberous root number, and tuberous root biomass per plant at low density were significantly higher than those of medium and high densities. The content of catalpol and acteoside in leaves was higher at high density. The content of catalpol in tuberous roots was higher at low density, and the change trend was similar to that in leaves, while the content of acteoside in tuberous roots was higher at high density. Transcriptome analysis found that about 1/2 of the expansin genes could change regularly in response to density treatment, which was rela-ted to the development of tuberous roots. The change trend of the gene expression of multiple catalytic enzymes involved in the biosynthesis of catalpol and acteoside was consistent with that of their content, which was presumedly involved in the accumulation and regulation of density-responsive medicinal components. Based on the analysis of the development, medicinal components, and gene expression characteristics of R. glutinosa at different densities, this study is expected to provide an important basis for regulating the quality and yield of medicinal materials of R. glutinosa by managing the planting density.

Palladium-Catalyzed Asymmetric Hydrosulfonylation of 1,3-Dienes with Sulfonyl Hydrazides.

A highly enantio- and regioselective hydrosulfonylation of 1,3-dienes with sulfonyl hydrazides has been realized by using a palladium catalyst containing a monodentate chiral spiro phosphoramidite ligand. The reaction provided an efficient approach to synthetically useful chiral allylic sulfones. Mechanistic studies suggest that the reaction proceeds through the formation of an allyl hydrazine intermediate and subsequent rearrangement to the chiral allylic sulfone product. The transformation of the allyl hydrazine intermediate to the product is the enantioselectivity-determining step.

Feasibility and Short-Term Stability of Portal Vein Infusion Port Placement by Transjugular Access.

Six pigs underwent implantation of a portal vein infusion port by transjugular access. The technical success rate was 100% (n = 6), with no surgical complications or deaths. At 1 month after implantation, the catheter tip had moved from the splenic vein to the main portal vein, while the catheter protruded into the right ventricle through the right atrium in all cases. Hence, the infusion port system has not been used in clinical practice due to its obvious displacement after implantation. However, this study provides a new idea for future exploration of portal vein infusion pathways.

[Aerobic exercise reduces the expression of pyroptosis-related proteins and inflammatory factors in hippocampus of mice with insulin resistance].

The aim of the present study was to observe the expression of pyroptosis- and inflammation-related proteins in the hippocampus of mice with insulin resistance (IR) after aerobic exercise, and to explore the possible mechanism of exercise to improve IR. C57BL/6J male mice of 6 weeks old were randomly fed with normal diet (n = 12) and high-fat diet (HFD) (n = 26) for 12 weeks respectively. Glucose tolerance test (GTT) and insulin tolerance test (ITT) were performed to determine whether IR occurred in HFD mice. Then the mice were randomly divided into control group (n = 12), IR group (n = 10) and IR + aerobic exercise group (AE, n = 10). Mice in AE group performed a 12-week progressive speed treadmill training after being adapted to the treadmill for one week. After the intervention, the expression of pyroptosis- and inflammation-related proteins in hippocampus was detected by Western blot. The results showed that compared with control group, NFκB, Nod-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), pyroptosis-related proteins like pro-Caspase-1, gasdermin D (GSDMD), GSDMD-N, and inflammatory factors IL-1ß, IL-18 were significantly increased. The inflammasome-related protein NIMA-related kinase 7 (NEK7) and pyroptosis-related protein Caspase-1 showed an increasing trend, but there was no significant difference. Compared with the IR group, progressive speed treadmill training significantly reduced the expression of NFκB, NLRP3, NEK7, ASC, pro-Caspase-1, GSDMD, GSDMD-N, IL-1ß, and IL-18 in the hippocampus of mice with IR. These results suggested 12-week progressive speed treadmill training can significantly reduce the expression of pyroptosis-related proteins and inflammatory factors in the hippocampus of mice with IR, and inhibit pyroptosis.

Pumping a Ring-Sliding Molecular Motion by a Light-Powered Molecular Motor.

Designing artificial molecular machines to execute complex mechanical tasks, like coupling rotation and translation to accomplish transmission of motion, continues to provide important challenges. Herein, we demonstrated a novel molecular machine comprising a second-generation light-driven molecular motor and a bistable [1]rotaxane unit. The molecular motor can rotate successfully even in an interlocked [1]rotaxane system through a photoinduced cis-to -trans isomerization and a thermal helix inversion, resulting in concomitant transitional motion of the [1]rotaxane. The transmission process was elucidated via 1H NMR, 1H-1H COSY, HMQC, HMBC, and 2D ROESY NMR spectroscopies, UV-visible absorption spectrum, and density functional theory calculations. This is the first demonstration of a molecular motor to rotate against the appreciably noncovalent interactions between dibenzo-24-crown-8 and N-methyltriazolium moieties comprising the rotaxane unit, showing operational capabilities of molecular motors to perform more complex tasks.

Nickel(0)-Catalyzed Hydroalkylation of 1,3-Dienes with Simple Ketones.

We developed a highly regioselective addition of 1,3-dienes with simple ketones by nickel-hydride catalyst bearing DTBM-SegPhos ligand. A wide range of aromatic and aliphatic ketones directly coupled with 1,3-dienes, providing synthetically useful γ,δ-unsaturated ketones in high yield and regioselectivity. The asymmetric version of the reaction was also realized in high enantioselectivity by using novel chiral ligand DTBM-HO-BIPHEP. The utility of this hydroalkylation was demonstrated by facile product modification and enantioselective synthesis of ( R)-flobufen.

Prospective evaluation of the diagnostic accuracy of hepatic copper content, as determined using the entire core of a liver biopsy sample.

UNLABELLED: Hepatic copper determination is an important test for the diagnosis of Wilson's disease (WD). However, the method has not been standardized, the diagnostic accuracy has not been evaluated prospectively, and the optimal cut-off value remains controversial. Accordingly, we aimed to prospectively evaluate the diagnostic accuracy of hepatic copper content, as determined using the entire core of a liver biopsy sample. Patients for whom a liver biopsy was indicated were consecutively enrolled. Hepatic copper content was determined with atomic absorption spectroscopy. All assays were performed using careful quality control by a single technician. WD diagnosis was based on WD score or its combination with clinical follow-up results. A total of 3,350 consecutive patients underwent liver biopsy. Six hundred ninety-one patients, including 178 with WD, underwent two passes of liver biopsy with hepatic copper determination. Mean hepatic content in WD patients was 770.6 ± 393.2 µg/g dry weight (wt). Sensitivity, specificity, and positive and negative predictive values of hepatic copper content for WD diagnosis in the absence of primary biliary cirrhosis (PBC) or primary sclerosing cholangitis at the cut-off value of 250 µg/g dry wt. were 94.4%, 96.8%, 91.8%, and 97.8%, respectively. The most useful cut-off value was 209 µg/g dry wt, with a sensitivity and specificity of 99.4% and 96.1%, respectively. A total of 23.3% of patients without WD and PBC had hepatic copper content >75 µg/g dry wt. CONCLUSION: A liver biopsy sample of more than 1 mg dry wt may reliably reflect hepatic copper content and should be used for hepatic copper determination. Hepatic copper determination is a very valid procedure for the diagnosis of WD, and the most useful cut-off value is 209 µg/g dry wt.

The Nature of the Noncovalent Interactions between Benzene and C60 Fullerene.

Noncovalent interactions between aromatic compounds and fullerenes have received considerable attention in various fields of science and technology. Employing benzene (C6H6) and C60 fullerene as model molecules, we theoretically explored in the present study the nature of this kind of noncovalent interaction. Our results clearly show that the π···π stacking configurations of the complex C6H6···C60 are more strongly bound than in the C-H···π analogues, and the C-H···π interactions in the C-H···π configurations of C6H6···C60 are not of the hydrogen bonds. According to symmetry adapted perturbation theory analyses, all of the configurations of C6H6···C60 are dominated by dispersion forces. The percentage of the dispersion components in the overall attractive interactions for the π···π stacking configurations is smaller than the percentage of the dispersion components in the overall attractive interactions for the C-H···π configurations, whereas the percentage of the electrostatic terms in the overall attractive interactions for the π···π stacking configurations is larger than the percentage of the electrostatic terms in the overall attractive interactions for the C-H···π configurations. This is distinctly different from the case of the benzene dimer.

Enhanced hypoxia-inducible factor (HIF)-1α stability induced by 5-hydroxymethyl-2-furfural (5-HMF) contributes to protection against hypoxia.

We first reported the role of 5-hydroxymethyl-2-furfural (5-HMF) against hypoxia. Here, we studied the mechanism by using oxygen-dependent degradation domain (ODD)-Luc mice, which are a useful model to probe the stabilization of hypoxia-inducible factor 1α (HIF-1α). Compared with three other compounds that have been reported to have a role in stabilizing HIF-1α, 5-HMF caused stronger bioluminescence, which is indicative of HIF-1α stability in the brain and kidney of ODD-Luc mice. We further demonstrated that the HIF-1α protein accumulated in response to 5-HMF in the brains and kidneys of these mice, as well as in PC12 cells. Additionally, 5-HMF promoted the nuclear translocation of HIF-1α and the transcriptional activity of HIF-1, which was evaluated by detecting vascular endothelial growth factor (VEGF ) mRNA expression. These results suggest that 5-HMF stabilized HIF-1α and increased its activity. Considering the role of proline hydroxylases (PHDs) in negatively regulating HIF-1α stability, we explored whether 5-HMF interacts with the substrates and cofactors of PHDs, such as 2-oxoglutarate (2-OG), Fe(2+) and vitamin C (VC), which affects the activity of PHDs. The result revealed that 5-HMF did not interact with Fe(2+) or 2-OG but interacted with VC. This interaction was confirmed by subsequent experiments, in which 5-HMF entered into cells and reduced the VC content. The enhanced stability of HIF-1α by 5-HMF was reversed by VC supplementation, and the improved survival of mice caused by 5-HMF under hypoxia was abrogated by VC supplementation. Thus, we demonstrated for the first time that 5-HMF increases HIF-1α stability by reducing the VC content, which mediates the protection against hypoxia.

Polycyclic Polyprenylated Acylphloroglucinol Congeners Possessing Diverse Structures from Hypericum henryi.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of hybrid natural products sharing the mevalonate/methylerythritol phosphate and polyketide biosynthetic pathways and showing considerable structural and bioactive diversity. In a systematic phytochemical investigation of Hypericum henryi, 40 PPAP-type derivatives, including the new compounds hyphenrones G-Q, were obtained. These compounds represent 12 different structural types, including four unusual skeletons exemplified by 5, 8, 10, and 17. The 12 different core structures found are explicable in terms of their biosynthetic origin. The structure of a known PPAP, perforatumone, was revised to hyphenrone A (5) by NMR spectroscopic and biomimetic synthesis methods. Several compounds exhibited inhibitory activities against acetylcholinesterase and human tumor cell lines. This study deals with the structural diversity, function, and biogenesis of natural PPAPs.

Hupehenols A-E, selective 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) inhibitors from Viburnum hupehense.

Five selective 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) competitive inhibitors, hupehenols A-E (1-5), were isolated from Viburnum hupehense. The structure elucidation indicated that compounds 1-5 are new 20,21,22,23,24,25,26,27-octanordammarane triterpenoids. Their structures were established on the basis of NMR spectroscopic and mass spectrometric analysis. Hupehenols A-E (1-5) showed inhibition against human 11ß-HSD1, with hupehenols B (2) and E (5) having IC50 values of 15.3 and 34.0 nM, respectively. Moreover, hupehenols C (3) and D (4) are highly selective inhibitors of human 11ß-HSD1 when compared to murine 11ß-HSD1.

Association of the TLR4 signaling pathway in the retina of streptozotocin-induced diabetic rats.

BACKGROUND: Diabetic retinopathy is severe damage to the retina caused by complications of diabetes, and is the prevailing cause of blindness. Accumulating evidence from both animal models and humans suggests that the inflammatory process plays a key role in the development of diabetic retinopathy and is facilitated by innate immune response. The aim of this study was to examine whether the TLR4 signaling pathway was involved in the streptozotocin-induced diabetic rat retina. METHODS: Diabetes was induced by a single intraperitoneal injection of streptozotocin, and rat diabetic retinopathy was examined at 4 weeks of diabetes duration. Then the accumulated leukocytes were counted in vivo by acridine orange leukocyte fluorography, and the retinal vascular permeability was measured by the Evans blue assay. The expressions of TLR4 and its downstream signaling molecules were measured by RT-PCR or Western blot respectively. To evaluate the effect of blocking TLR4 on diabetic retinopathy, TAK-242, a selective TLR4 antagonist, was administered by intraperitoneal injection. RESULTS: Our results showed that the retina of diabetic rats demonstrated accumulated leukocytes and retinal vascular permeability. The mRNA and protein expressions of TLR4 were upregulated in streptozotocin-treated diabetic rat retina. Furthermore, the protein levels of TLR4 downstream signaling molecules were significantly increased in streptozotocin-treated animals. In addition, the protein levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and interferon (IFN)-ß, three downstream proinflammatory cytokines of TLR4 signal transduction pathway, were also markedly increased in diabetic rats. Administration of TAK-242 attenuated leukocytes accumulated and retinal vascular permeability, and decreased TLR4 downstream signaling molecules and proinflammatory cytokines in streptozotocin-induced animals. CONCLUSIONS: Together, these data have demonstrated that TLR4 has a critical role in streptozotocin-induced diabetic retinopathy at the level of inflammatory cytokine induction, in both the MyD88-dependent and MyD88-independent pathways. TLR4 may become a new potential pharmacological target for treating diabetic retinopathy.

Surgical Myectomy and Myotomy for Refractory Blepharospasm in Meige Syndrome Patients: A Case Report.

Meige syndrome is a rare neurological disease characterized by segmental dystonia, specifically blepharospasm and oromandibular dystonia. These symptoms are often accompanied by complex movements of the eyelids, lower facial muscles, mandible, and neck muscles. Bilateral blepharospasm is the most common feature of this disease. In this case report, we present the successful treatment of refractory blepharospasm in a 72-year-old woman with Meige syndrome via 2 incisions resulting from myectomy and in situ surgery.

The Incidences and Related CT Features of Vascular Lake Phenomenon on Angiography Before Chemoembolization.

PURPOSE: To elucidate incidence rates of vascular lake phenomenon (VLP) in hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), hepatic metastasis (HMT) on transarterial angiography before chemoembolization, and to identity CT features predictive for it. MATERIALS AND METHODS: A comprehensive evaluation involved 665 subjects for incidence analysis, comprising 527 of HCC, 33 of ICC and 105 of HMT. VLP was characterized as intratumoral contrast material pool persisting late into venous phase. Incidences were cataloged on both super-selective and common hepatic artery angiography. For CT features analysis, a subset of 182 cases were analyzed. Enhancement ratio served as an index for comparative analysis of nodule enhancement degrees. RESULTS: In HCC, incidence of VLP ascertained via super-selective angiography was 13.5%, whereas it as 7.8% on common hepatic artery angiography. Remarkably, no incidences of VLP were recorded in either ICC or HMT cases. On pre-interventional CT, the prevalence of pseudocapsule was statistically greater in VLP group than Non-VLP group (66.6% vs. 37.6%, P = 0.015). The Houndsfield units (HU) of tumors in plain scan (P = 0.007), arterial phase (P = 0.001), venous phase (P = 0.041), arterial phase enhancement ratio (P < 0.001) were statistically higher in VLP group compared to Non-VLP group. Arterial phase enhancement ratio (P = 0.025), presence of pseudocapsule (P = 0.001), HU of tumor in plain scan (P = 0.035) serve as independent risk factors for VLP manifestation. CONCLUSION: VLP is a distinct angiography phenomenon uniquely associated with HCC. High arterial phase enhancement ratio, presence of pseudocapsule, high HU of tumor in plain scan are independent risk factors for VLP.

[Study on triterpenoid saponins in the rhizome of Anemone hofengensis].

OBJECTIVE: To study the triterpenoid saponins in the rhizome of Anemone hofengensis. METHODS: The constituents were separated with various chromatographic techniques and their structures were elucidated by physicochemical properties and spectral data. RESULTS: Five compounds were isolated and identified as 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabino-pyranosyl-oleanolic acid (1), 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 2)-alpha-L-rhamnopyranosyl-oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1 --> 4) -beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (2), 3-O-alpha-L-rhamnopyranosyl-(1 --> 2) [beta-D-glucopyranosyl-(1 --> 4)]-alpha-L-rhamnopyranosyl-oleanolic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-gluco-pyranoside (3), 3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-xylopyranosyl-oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (4), oleanolic acid-28-O-alpha-L-rhamnopyra-nosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (5). CONCLUSION: Compound 1 - 5 are isolated from this plant for the first time.

[Meteorological Characteristics, Influence Analysis and Prediction of PM2.5 Concentration in Taiyuan City].

Based on the pollutant concentration data of Taiyuan City from 2016 to 2020 and the surface meteorological data of the national benchmark meteorological observation station in the same period, the variation characteristics of PM2.5 concentration in Taiyuan City and the effects of meteorological conditions such as humidity, precipitation, wind, and mixing layer thickness on PM2.5 concentration were analyzed. At the same time, the causes of pollutant concentration changes were discussed, and the PM2.5 concentration prediction model based on the LSTM neural network was established. The results showed that the number of days of heavy pollution in Taiyuan City from 2016 to 2020 was the highest in winter, of which the maximum number of days in 2017 was 28 days. The PM2.5 concentration was generally high in autumn and winter and low in spring and summer. The PM2.5 concentration on weekends was higher than that on weekdays. The daily variation in PM2.5 concentration roughly presented a bimodal distribution, which appeared around 09:00 and 23:00 to 01:00 the following day. Except for relative humidity and winter temperature, other air pressure, wind speed, and PM concentration showed negative correlations in the four seasons. The pollution sources affecting the increase in PM2.5 concentration in Taiyuan City were mainly located in the NE-ENE-E direction, and the pollution in the northwest was not relatively apparent. In flood season, when the precipitation reached the level of moderate rain (rainfall ≥ 10 mm), it had an obvious effect on the reduction of PM2.5 concentration. The increase in atmospheric mixing layer height was very beneficial to the diffusion and dilution of PM2.5 in the vertical direction. The strong northwest air flow in winter, low relative humidity, high pressure control on the ground, and high height of the mixing layer belonged to the cluster most conducive to the reduction in PM2.5 concentration. Using the LSTM model for modeling, the R2 of PM2.5 concentration prediction was as high as 0.95, which was significantly better than that of the traditional tree model and linear regression model (R2<0.60). The residual of the prediction results was close to the normal distribution, of which the absolute error of 84.2% prediction results was less than 20 µg·m-3, and the MAE, MAPE, and RMSE of the model were 38.17, 17.19%, and 20.6, respectively.

Analysis of the risk factors in patients with unexplained recurrent spontaneous abortion.

PROBLEM: We aimed to explore the risk factors in patients with unexplained recurrent spontaneous abortion (URSA) and to provide a basis for clinically targeted therapy. METHOD OF STUDY: This case-control study comprised 202 patients with URSA treated at our hospital and 115 women in early pregnancy with a normal birth history during the same period. After procuring the data we conducted a multivariate logistic regression analysis of risk factors related to URSA. RESULTS: Logistic regression analysis showed (i) that the number of spontaneous abortions (SAs; odds ratio [OR] = 492.123), the levels of autoantibodies (OR = 19.322) and tumor necrosis factor alpha (TNF-α; OR = 9.615), and the CT and TT genotypes of methylenetetrahydrofolate reductase (MTHFR) C677T (OR = 6.217 and 15.009, respectively) were risk factors for URSA and (ii) that 25-hydroxyvitamin D (25-(OH)D; OR = 0.919) was a protective factor. The most important risk factor was a history of one or more SAs, with the risk of pregnancy loss increasing 491.123-fold. Every unit increase in serum 25-(OH)D reduced the risk of SA by 8.1%. CONCLUSIONS: The risk factors for URSA included the number of SAs, the levels of autoantibodies and TNF-α, and the MTHFR C677T T allele; 25-(OH)D was a protective factor. We recommend that women diagnosed with URSA receive intervention as soon as possible so as to actively reduce the incidence of recurrent SA.

Feasibility and efficacy of endoscopic purse-string suture-assisted closure for mucosal defects induced by endoscopic manipulations.

BACKGROUND: Large or transmural defects induced by gastrointestinal endoscopic manipulations are difficult to close, although complete closure is recommended for better recovery. Endoscopic purse-string assisted suturing (EPSS) has been used in clinical practice and has proven to be an effective and safe technique for the closure of large mucosal defects. However, details regarding the efficacy of endoscopic pre-purse-string suture (P-EPSS) are unknown, especially that it offers several advantages over conventional EPSS (C-EPSS). AIM: To elucidate the outcomes of EPSS-assisted closure in different clinical situations, and evaluate the efficacy of P-EPSS. METHODS: This retrospective observational study included a total of 180 patients who underwent closure assisted by P-EPSS (n = 63) or C-EPSS (n = 117) between July 2014 and June 2020. The P-EPSS and C-EPSS groups were compared and the intergroup differences in aspects such as the lesion size, location, and mor-phology, incidence of complete closure, intraoperative perforation, and delayed adverse events were evaluated. Data on the features and clinical course of cases with adverse events were collected for further analysis. RESULTS: Patients with lesion size larger than 3 cm, lesions located at the fundus of stomach, or submucosal tumors originating from the deep mucosa were more likely to undergo P-EPSS-assisted closure. The P-EPSS group showed a sign-ificantly higher proportion of intraoperative perforation (56% vs 17%) and a much shorter procedure time (9.06 ± 6.14 min vs 14.84 ± 7.25 min). Among adverse events, the incidence of delayed perforation (5% vs 4%; P = 0.82) and delayed bleeding (3% vs 4%; P = 0.96) did not differ significantly between the groups. Multivariate analysis revealed that lesions with incomplete closure [odds ratio (OR) = 21.33; 95% confidence interval (CI): 5.45-83.45; P < 0.01] or size greater than 3 cm (OR = 3.14; 95%CI: 1.08-9.18; P = 0.039) showed a statistical tendency to result in an increase in delayed adverse events. CONCLUSION: The present study revealed that EPSS could achieve secure complete closure of mucosal defect. P-EPSS could shorten the procedure and yield complete closure of mucosal defects. Rather than closure-type selection, incomplete closure or lesion size larger than 3 cm were associated with worse outcomes.