ObjectiveTo explore the mechanism of action of Paeoniae Radix Rubra and Aconiti Lateralis Radix Praeparata （CSFZ） in the treatment of acute-on-chronic liver failure （ACLF） through network pharmacology， molecular docking， and animal experiments. MethodsNetwork pharmacology was used to identify potential targets and related signaling pathways for the treatment of ACLF with CSFZ. Molecular docking was used to examine the binding activity of the core components with corresponding key targets. An ACLF rat model was established by subcutaneous and tail vein injections of bovine serum albumin combined with lipopolysaccharide （LPS） + D-galactosamine （D-GalN） intraperitoneal injection. A normal control group （NC）， a model group， a CSFZ group （CSFZ， 5.85 g·kg^-1）， and a hepatocyte growth-promoting granule group （HGFG， 4.05 g·kg^-1） were set up in this study. Pathological changes in rat liver tissue were observed using hematoxylin and eosin （HE） and Masson staining. Enzyme-linked immunosorbent assay （ELISA） was used to detect the expression levels of interleukin-6 （IL-6）， B-cell lymphoma-2 （Bcl-2）， Caspase-3， and albumin （ALB）. Real-time quantitative polymerase chain reaction （Real-time PCR） and Western blot were used to measure the mRNA and protein expression levels of phosphoinositide 3-kinase （PI3K）， protein kinase B （Akt）， phosphorylated PI3K （p-PI3K）， and phosphorylated Akt （p-Akt）. ResultsNetwork pharmacology screening identified 49 active ingredients of CSFZ， 103 action targets， and 3 317 targets related to ACLF. Among these， 74 targets overlapped with CSFZ drug targets. Key nodes in the protein-protein interaction （PPI） network included Akt1， tumor necrosis factor （TNF）， IL-6， Bcl-2， and Caspase-3. Gene Ontology （GO） functional analysis and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment analysis identified multiple signaling pathways， with the PI3K/Akt signaling pathway being the most frequent. Molecular docking showed that the core components of the drug exhibited good binding activity with the corresponding key targets. Animal experiments confirmed that CSFZ significantly improved liver tissue pathological damage in ACLF rats， reduced the release of inflammatory factors and liver cell apoptosis， and upregulated the expression levels of the PI3K/Akt signaling pathway. ConclusionThrough network pharmacology， molecular docking， and in vivo experiments， this study confirms the effect of CSFZ in reducing liver cell inflammatory damage and inhibiting liver cell apoptosis. The specific mechanism may be related to its involvement in regulating the PI3K/Akt signaling pathway.

[Objective] To analyze the prevalence of human T-lymphocyte leukemia virus (HTLV) among blood donors in Guangzhou from 2016 to 2021, and provide a basis for blood collection and supply management in this region. [Methods] A total of 2 116 951 voluntary blood donors were screened for anti-HTLV by enzyme-linked immunosorbent assay (ELISA) from March 2016 to December 2021 in Guangzhou, and the reactive cases were further confirmed by Western blotting (WB). Qualitative data were analyzed by χ2 with spss19 software. The trend of the total positive rate of HTLV confirmation test by WB from 2016 to 2021 was analyzed with the Joinpoint software, and the annual percent change (APC) was used to determine whether the trend changes were statistically significant. [Results] From March 2016 to December 2021, the total positive rate for anti-HTLV by ELISA among voluntary blood donors in Guangzhou was 0.019 7% (416/ 2116 951), and the WB confirmed positive rate was 0.001 1% (23/2 116 951). The total positive rate of HTLV among individual voluntary blood donors in the six main districts (0.002 12%, 19/895 301) was higher than that among group voluntary blood donors (0.000 32%, 3/951 947) (P<0.05). There was no significant difference in the total positive rate of HTLV confirmation between the six main districts (0.001 19%) and the three non-main districts (0.000 37%) (P>0.05). The trend of the total positive rate of HTLV infection in the six main districts and the Guangzhou area(including the six main districts and three non-main districts) showed no significant increase or decrease. [Conclusion] The prevalence of HTLV among blood donors in Guangzhou remains at a low level.

ObjectiveTo study the regulatory effects of Yinchenhao Tang combined with Yinchen Zhufu Tang on the expression of regulatory T （Treg）/helper T 17 （Th17） cells cultured in vitro from the patients with hepatitis B virus-related acute-on-chronic liver failure （HBV-ACLF）. MethodsFresh peripheral blood was collected from the patients with HBV-ACLF for the separation of peripheral blood mononuclear cells （PBMCs）. Immunomagnetic beads were used to isolate primary Treg and naive CD4⁺ T cells. After in vitro expansion， naive CD4⁺ T cells were induced to differentiate into Th17 cells. Rats were treated with the clearing method （Yinchenhao Tang）， warming method （Yinchen Zhufu Tang）， and combination of clearing method with warming method （Yinchenhao Tang combined with Yinchen Zhufu Tang， also known as Wenyang Jiedu Huayu Prescription）， respectively， and then the medicated plasma samples were collected. Meanwhile， blank plasma was collected from the rats treated with normal saline. Cells were classified into blank， clearing method （5.04 g·kg^-1）， warming method （6.21 g·kg^-1）， and combination of clearing method with warming method （17.1 g·kg^-1） groups and treated with corresponding plasma. The frequency of Treg/Th17 cells was detected by flow cytometry. The level of transforming growth factor-β （TGF-β） was measured by the enzyme-linked immunosorbent assay. The cytometric bead array （CBA） was employed to measure the levels of interleukin-10 （IL-10）， interleukin-17A （IL-17A）， tumor necrosis factor-α （TNF-α）， and interleukin-23 （IL-23）. The mRNA and protein levels of Forkhead box P3 （FoxP3） and retinoic acid-related orphan receptor-gamma t （ROR-γt） were determined by Real-time PCR and Western blot， respectively. ResultsCompared with the blank group， the combination of clearing method with warming method group showed decreased frequency of Treg and Th17 cells， lowered levels of Treg cytokines （TGF-β and IL-10） and Th17 cytokines （TNF-α， IL-17A， and IL-23）， and down-regulated mRNA and protein levels of FoxP3 and ROR-γt （P<0.01）. Compared with the clearing method group， the combination of clearing method with warming method group showed decreased Treg cell frequency and down-regulated mRNA and protein levels of FoxP3. Meanwhile， the combination group showed decreased Th17 cell frequency， lowered levels of TGF-β， IL-10， TNF-α， IL-17A， and IL-23， and down-regulated mRNA and protein levels of ROR-γt （P<0.05， P<0.01）. Compared with the warming method group， the combination of clearing method with warming method group showed decreased frequency of Treg cells and down-regulated mRNA and protein levels of FoxP3. Meanwhile， the combination group showed decreased Th17 cell frequency， declined levels of TGF-β， IL-10， TNF-α， IL-17A， and IL-23， and down-regulated mRNA and protein levels of ROR-γt （P<0.05）. ConclusionThe combination of clearing method with warming method can down-regulate the expression of specific cytokines of Treg and Th17 cells， inhibit the over activation of Treg and Th17 cells， and reduce the secretion of cytokines such as TGF-β， IL-10， TNF-α， IL-17A， and IL-23， thereby alleviating inflammation and improving the prognosis of the patients with liver failure.

ObjectiveTo investigate the differential expression of intestinal flora in patients with different traditional Chinese medicine （TCM） syndrome types （Yang Huang syndrome， Yin-Yang Huang syndrome， and Yin Huang syndrome） of hepatitis B virus-related acute-on-chronic liver failure （HBV-ACLF） and clarify the biological basis of jaundice and Yin Huang syndrome in liver failure. MethodsA total of 20 cases of HBV-ACLF patients were included in the Yang Huang group， 20 cases in the Yin-Yang Huang group， 16 cases in the Yin Huang group， and 20 healthy adult volunteers. 16S rRNA gene sequencing was used to detect the diversity， species distribution， and differences of the subjects' intestinal flora， and bioinformatics analysis was conducted. ResultsCompared with those in the healthy control group， the species richness and diversity of intestinal flora in the HBV-ACLF Yang Huang group， Yin-Yang Huang group， and Yin Huang group were significantly reduced， and there were significant differences in the composition of intestinal flora compared with healthy volunteers. However， there were no significant differences in the species richness， diversity， and composition of intestinal flora among the three groups. LEfSe analysis showed that compared with the healthy control group， the HBV-ACLF Yang Huang group showed significant enrichment of Staphylococcus aureus（P<0.01）. Yin-Yang Huang group showed significant enrichment of s_Ileibacterium valens（P<0.05，P<0.01）， and the Yin Huang group showed significant enrichment of Enterococcus faecium and Streptococcus sali varius（P<0.05）. These strains may be biomarkers between the three groups of patients and the healthy control group. Compared with that in the Yin-Yang Huang group， Tyzzerella_nexilis was significantly enriched in the Yang-Huang group， and Streptococcus lactiae was significantly enriched in the Yin-Yang Huang group. Compared with that in the Yang-Huang group and the Yin-Yang Huang group， Enterococcus faecalis was significantly enriched in the Yin Huang group. The above strains may be biomarkers among the three groups of patients， and Enterococcus faecium may be a biomarker for the transition from the Yang Huang group to the Yin Huang group. ConclusionsThere are significant differences in the intestinal flora between patients with HBV-ACLF Yang Huang syndrome， Yin-Yang Huang syndrome， and Yin Huang syndrome. Enterococcus faecium is significantly enriched in the Yin Huang syndrome group， suggesting that dysbiosis of the intestinal flora may be the biological basis for jaundice and Yin Huang syndrome in liver failure.

ObjectiveTo study the expression differences of regulatory T cells （Treg） and T helper 17 cells （Th17） in the peripheral blood of patients with hepatitis B virus-related acute-on-chronic liver failure （HBV-ACLF） in five types of traditional Chinese medicine （TCM） syndrome. MethodsA total of 144 patients with HBV-ACLF were included and divided into five types of TCM syndrome， including 34 cases of heat-toxin amassment syndrome， 44 cases of dampness-heat amassment syndrome， 27 cases of Qi-deficiency and stasis jaundice syndrome， 21 cases of spleen-kidney Yang deficiency syndrome， and 18 cases of liver-kidney Yin deficiency syndrome. Meanwhile， 30 healthy volunteers were included as controls. The frequency of Treg and Th17 cells in the peripheral blood of subjects in each group was detected by flow cytometry， and the Treg/Th17 ratio was calculated. Cytometric bead array （CBA） was used to detect the levels of cytokines interleukin （IL）-10， transforming growth factor-β （TGF-β）， tumor necrosis factor-α （TNF-α）， IL-17A， and IL-23. Real-time fluorescence quantitative PCR （Real-time PCR） detected the mRNA expression of forkhead box P3 （FoxP3） and retinoic acid-related orphan receptor gamma t （ROR-γt）. Results（1） Compared with that in the healthy control group， the frequency of Treg and Th17 cells in patients with various TCM syndrome types of HBV-ACLF increased （P<0.05）. Compared with that in the heat-toxin amassment syndrome group， the frequency of Treg and Th17 cells decreased in the dampness-heat amassment syndrome group （P<0.05）， while the frequency of Treg and Th17 cells increased in the Qi-deficiency and stasis jaundice syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with that in the dampness-heat amassment syndrome group， the frequency of Treg and Th17 cells increased in the dampness-heat amassment syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with that in the Qi-deficiency and stasis jaundice syndrome group， the frequency of Treg and Th17 cells increased in the spleen-kidney Yang deficiency syndrome group （P<0.05）， while the frequency of Treg and Th17 cells decreased in the liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with the spleen-kidney Yang deficiency syndrome group， the frequency of Treg and Th17 cells decreased in the liver-kidney Yin deficiency syndrome group （P<0.05）. （2） Compared with that in the healthy control group， the Treg/Th17 cell ratio in patients with various TCM syndromes of HBV-ACLF decreased （P<0.05）. Compared with that in the heat-toxin amassment syndrome group， the Treg/Th17 cell ratio increased in the dampness-heat amassment syndrome group （P<0.05）， while it decreased in the Qi-deficiency and stasis jaundice syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with that in the dampness-heat amassment syndrome group， the Treg/Th17 cell ratio decreased in the Qi-deficiency and stasis jaundice syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with that in the Qi-deficiency and stasis jaundice syndrome group， the Treg/Th17 cell ratio increased in the spleen-kidney Yang deficiency syndrome group and liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with the spleen-kidney Yang deficiency syndrome group， the Treg/Th17 cell ratio in the liver-kidney Yin deficiency syndrome group increased （P<0.05）. （3） Compared with those in the healthy control group， the levels of Treg-related cytokines IL-10 and TGF-β， as well as Th17-related cytokines TNF-α， IL-17A， and IL-23， were elevated in patients with various TCM syndrome types of HBV-ACLF （P<0.05）. There was no significant difference in TNF-α levels among different TCM syndrome types. Compared with those in the heat-toxin amassment syndrome group， the levels of IL-10， TNF-β， IL-17A， and IL-23 in the dampness-heat amassment syndrome group， Qi-deficiency and stasis jaundice syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome groups increased （P<0.05）. Compared with those in the dampness-heat amassment syndrome group， the levels of IL-10， TGF-β， IL-17A， and IL-23 increased in the Qi-deficiency and stasis jaundice syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with those in the Qi-deficiency and stasis jaundice syndrome group， the levels of IL-10， TGF-β， IL-17A， and IL-23 in the spleen-kidney Yang deficiency syndrome group increased （P<0.05）， while those in the liver-kidney Yin deficiency syndrome group decreased （P<0.05）. Compared with those in the spleen-kidney Yang deficiency syndrome， the levels of IL-10， TGF-β， IL-17A， and IL-23 in the liver-kidney Yin deficiency syndrome group decreased （P<0.05）. （4） Compared with that in the healthy control group， the mRNA of Treg/Th17 cell specific transcription factors FoxP3 and ROR-γt were elevated in patients with various TCM syndrome types of HBV-ACLF （P<0.05）. Compared with that in the heat-toxin amassment syndrome group， the mRNA of FoxP3 and ROR-γt increased in the Qi-deficiency and stasis jaundice syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with that in the dampness-heat amassment syndrome group， the mRNA of FoxP3 and ROR-γt increased in the Qi-deficiency and stasis jaundice syndrome group， spleen-kidney Yang deficiency syndrome group， and liver-kidney Yin deficiency syndrome （P<0.05）. Compared with that in the Qi-deficiency and stasis jaundice syndrome group， the mRNA of FoxP3 and ROR-γt in the spleen-kidney Yang deficiency syndrome group increased （P<0.05）， and it decreased in the liver-kidney Yin deficiency syndrome group （P<0.05）. Compared with that in the spleen-kidney Yang deficiency syndrome group， the mRNA of FoxP3 and ROR-γt decreased in the liver-kidney Yin deficiency syndrome group （P<0.05）. ConclusionThe frequency and ratio of Treg/Th17 cells， as well as the expression of related cytokines and specific receptors in peripheral blood of patients with HBV-ACLF in five types of TCM syndromes are different， which has certain reference value for TCM syndrome differentiation and treatment of patients with HBV-ACLF.

Objective To clarify the expression and distribution of brain⁃derived neurotrophic factor (BDNF) in the cerebrum of plateau yaks and cattle, and to explore the relationship between BDNF function and the adaptability of altitude hypoxia. Methods Five yaks and five cattles were selected.The content and distribution of BDNF in frontal lobe, temporal lobe, parietal lobe, occipital lobe, cerebrum white matter and hippocampus of yak and cattle were analyzed by Real⁃time PCR, Western blotting and Immunohistochemistry. Results Real⁃time PCR result showed that BDNF mRNA expression in the cerebrum of yaks and cattles was highest in temporal cortex, followed by hippocampus, parietal cortex, occipital cortex and frontal cortex, and lowest in white matter. Western blotting results showed that the content of BDNF protein in the cerebrum of yaks was the highest in temporal cortex,followed by hippocampus. The content of BDNF protein in other tissues was parietal cortex, frontal cortex and cerebrum white matter, and the content of BDNF protein was the lowest in occipital cortex. The content of BDNF protein intlecerebrum of cattles was the highest in the temporal cortex, followed by the hippocampus. The content of BDNF protein in other tissues was parietal cortex, occipital cortex and frontal cortex in descending order, and the protein content in cerebrum white matter was the lowest. Immunohistochemical results showed that the positive expression of BDNF protein in the cerebrum of yaks and cattles was basically similar, mainly distributed in the granulosa cells and glial cells in the frontal cortex, temporal cortex, parietal cortex and occipital cortex, glial cells in cerebrum white matter, pyramidal cell layer and polyform cell layer in the hippocampus. There was the small amount of distribution in Martinotti cells and the molecular layer of hippocampus in the cerebral cortex. Conclusion BDNF mRNA and protein are distributed and expressed in different brain regions of yaks and cattles, but the expression level different, which is speculated to be closely related to the specific functions of different cerebrum regions. The expression level of the cerebrum of yak is higher than that of cattle except occipital cortex, suggesting that it is related to the altitude hypoxic environment. BDNF may play an important role in enhancing hypoxic tolerance and protecting internal environmental homeostasis in the process of animal adaptation to hypoxic environment.

ObjectiveTo observe the effect of water extract of Mori Folium （MLE） on oxidative stress in adipose tissue of type 2 diabetes mellitus （T2DM） mice and explore its mechanism. MethodTwenty-four male db/db mice were randomly divided into model group， metformin group， low-dose MLE （MLE-L） group， and high-dose MLE （MLE-H） group according to their body weight and blood glucose， with six mice in each group， and other six C57BLKS/JGpt wild littermate mice were selected as normal group. The mice in the metformin group were given 200 mg·kg^-1 metformin suspension， and the mice in the MLE-L and MLE-H groups were respectively given 2 g·kg^-1 and 4 g·kg^-1 MLE， while the mice in the normal group and model group were given the same dose of deionized water by daily gavage for eight weeks. Body weight， subcutaneous fat index， fasting blood glucose （FBG）， and oral glucose tolerance level （OGTT） of the mice were detected， and serum superoxide dismutase （SOD）， glutathione peroxidase （GSH-Px）， and malondialdehyde （MDA） were measured. The expression levels of silent information regulator 1 （SIRT1） and NADPH oxidase type 4 （NOX4） protein in subcutaneous adipose tissue of the mice were detected by Western blot. ResultThe FBG level， OGTT， and subcutaneous fat index of T2DM mice were significantly decreased （P<0.05， P<0.01） after administration of MLE compared with the blank group. The contents of serum SOD and GSH were significantly increased， while the level of oxidative stress damage marker MDA was significantly decreased （P<0.05， P<0.01）. The expression of SIRT1 protein in adipose tissue was significantly increased， while the expression of NOX4 protein was significantly decreased （P<0.05， P<0.01）. ConclusionMLE can ameliorate T2DM by alleviating oxidative stress in adipose tissue of T2DM mice and reducing blood glucose.

ObjectiveTo investigate the protective effects of Mori Folium extract （MLE） on the kidney of db/db diabetic mice and its mechanism. MethodTwenty-four male C57BLKS/JGpt-Leprdb/Leprdb （db/db） mice were randomly divided into model group， metformin group， low-dose group of MLE （MLE-L）， and high-dose group of MLE （MLE-H） according to their fasting blood glucose （FBG）， with six mice in each group， and other six C57BLKS/JGpt wild littermate （m/m） mice were selected as normal group. The mice in the drug administration groups were given corresponding drugs by gavage， and the mice in the normal group and model group were given the same dose of deionized water by gavage once a day for continuous eight weeks. Body weight， bilateral kidney weight， and FBG were measured， and an oral glucose tolerance test （OGTT） was performed. The pathological changes in the kidney tissue of mice were observed by hematoxylin-eosin （HE） and periodic acid-silver （PAS） staining， and serum creatinine （SCr） and blood urea nitrogen （BUN） levels were detected. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of tumor necrosis factor-alpha （TNF-α） and interleukin-6 （IL-6） in serum and urinary microalbumin （U-mAlb） of mice. The expression levels of toll-like receptor 4 （TLR4）， myeloid differentiation factor 88 （MyD88）， and nuclear factor-kappa B p65 （NF-κB p65） protein in kidney tissue of mice were tested by Western blot. ResultCompared with the normal group， the body weight， absolute renal weight， FBG， and the area under the curve （AUC） of OGTT of mice in the model group were significantly increased （P<0.01）， and the levels of SCr， BUN， and U-mAlb， as well as TNF-α and IL-6 in serum were significantly increased （P<0.01）. The glomerular basement membrane in the kidney tissue of mice was thicker， with obvious inflammatory cell infiltration. The protein expression levels of TLR4， MyD88， and NF-κB p65 in the kidney tissue of mice were increased significantly （P<0.01）. Compared with the model group， there was no statistical difference in the body weight of mice in each drug administration group. The absolute renal weight of mice in the MLE-H and metformin groups was significantly reduced （P<0.05， P<0.01）. The FBG levels of mice in the metformin， MLE-L， and MLE-H groups started to decrease after treatment for four to eight weeks （P<0.05， P<0.01）. The AUC of mice in the MLE-H and metformin groups was significantly decreased （P<0.01）. The levels of SCr， BUN， and U-mAlb of mice in the MLE-H and metformin groups were significantly decreased （P<0.01）， and those of SCr and U-mAlb of mice in the MLE-L group were significantly decreased （P<0.01）. The levels of TNF-α and IL-6 in the serum of mice in the MLE-H and metformin groups were significantly decreased （P<0.01）. The renal tissue pathology of mice in each drug administration group was improved to varying degrees， and the protein expression levels of TLR4， MyD88， and NF-κB p65 in the MLE-H group were decreased significantly （P<0.05， P<0.01）. ConclusionMLE can improve the renal structure and function of db/db diabetic mice， and its mechanism may be related to the inhibition of the TLR4/MyD88/NF-κB signaling pathway.

Mori Folium， the dried leaves of Morus alba， is widely used in clinical practice for dispersing wind and heat， clearing the lung and moistening dryness， soothing the liver and improving vision， and cooling blood and stopping bleeding. It has been used to regulate blood glucose since ancient times， and modern studies have shown that the active components of Mori Folium for lowering blood glucose mainly include flavonoids， alkaloids， polysaccharides， and phenols. These components are mainly extracted by solvents such as water and alcohols with the assistance of ultrasound and microwave. In addition， new extraction methods are emerging， such as CO₂ supercritical fluid extraction， enzymatic hydrolysis， and cloud point extraction. Mori Folium lowers blood glucose via multiple components， pathways， and targets. Specifically， it can improve glucose and lipid metabolism， protect pancreatic β cells， and alleviate insulin resistance to reduce the damage caused by hyperglycemia and restore normal physiological functions. Although a large number of studies have been carried out on diabetes， the causes and radical treatment methods remain to be explored， and diabetes is still a major disease that endangers human health and needs to be solved urgently. The articles about extraction process and mechanism of active components in Mori Folium for lowering blood glucose were retrieved from the China National Knowledge Infrastructure （CNKI）， Web of Science， and PubMed. We analyzed the applicable extraction methods for the blood glucose-lowering components such as flavonoids， polysaccharides， and alkaloids in Mori Folium， and compared the conventional and emerging methods. Furthermore， we summarized our research achievements in the extraction of active components from Mori Folium and the blood glucose-lowering effect and mechanisms. This review aims to provide theoretical support for the optimization of the extraction process， the research on the blood glucose-lowering components and mechanism， and the development of new drugs and clinical application of Mori Folium.

Objective:To study the clinical application and complications of umbilical arterial catheterization (UAC) in premature infants.Methods:From January 2021 to December 2022, premature infants with UAC successfully inserted in NICU of our hospital were enrolled. According to birth weight (BW), the infants were assigned into three groups: <1 000 g, 1 000~1 499 g and ≥1 500 g. The perinatal data, UAC usage, UAC-related complications and risk factors of UAC-related complications were retrospectively analyzed.Results:A total of 39 premature infants received UAC, with gestational age 29.3(27.3, 30.4) weeks and BW 1 100 (900, 1 310) g. The insertion length (IL) of UAC was calculated using the average value of two formulas: a, IL (cm) =4×BW (kg) +7; and b, IL(cm) =3×BW (kg)+9. The accuracy of tube end position was determined using chest/abdomen radiography. 30(76.9%) cases had accurate position, 6(15.4%) had higher position and 3(7.7%) had lower position. The proportion of appropriately positioned tube end in <1 000 g, 1 000~1 499 g and ≥1 500 g groups were 80.0%, 76.5% and 71.4%, respectively, without statistically significant differences ( P>0.05) .No significant differences existed among the three groups in UAC duration and UAC routinely removal rate ( P>0.05). 9 cases (23.1%) of UAC were removed for specific reasons, including 4 cases of arterial spasm, 2 cases of withdrawal of treatment, 1 case of tube end displacement, 1 case of abdominal distension and 1 case of death. 21 cases received 1 U/ml heparin (0.9%NaCl solution) 0.5~1 ml/h arterial infusion. 23.8% (5/21) had hypernatremia and the level of sodium became normal after reducing the concentration of NaCl solution. Arterial vasospasm occurred in 4 patients with skin color changes of one side of the lower extremities. After UAC removal, the skin color returned to normal. Conclusions:UAC is helpful and safe for preterm infants, however, its complications should be alerted to.