Magnetic Graphene Oxide Nanocomposites Boosts Craniomaxillofacial Bone Regeneration by Modulating circAars/miR-128-3p/SMAD5 Signaling Axis.

Background: The ability of nanomaterials to induce osteogenic differentiation is limited, which seriously imped the repair of craniomaxillofacial bone defect. Magnetic graphene oxide (MGO) nanocomposites with the excellent physicochemical properties have great potential in bone tissue engineering. In this study, we aim to explore the craniomaxillofacial bone defect repairment effect of MGO nanocomposites and its underlying mechanism. Methods: The biocompatibility of MGO nanocomposites was verified by CCK8, live/dead staining and cytoskeleton staining. The function of MGO nanocomposites induced osteogenic differentiation of BMSCs was investigated by ALP activity detection, mineralized nodules staining, detection of osteogenic genes and proteins, and immune-histochemical staining. BMSCs with or without MGO osteogenic differentiation induction were collected and subjected to high-throughput circular ribonucleic acids (circRNAs) sequencing, and then crucial circRNA circAars was screened and identified. Bioinformatics analysis, Dual-luciferase reporter assay, RNA binding protein immunoprecipitation (RIP), fluorescence in situ hybridization (FISH) and osteogenic-related examinations were used to further explore the ability of circAars to participate in MGO nanocomposites regulation of osteogenic differentiation of BMSCs and its potential mechanism. Furthermore, critical-sized calvarial defects were constructed and were performed to verify the osteogenic differentiation induction effects and its potential mechanism induced by MGO nanocomposites. Results: We verify the good biocompatibility and osteogenic differentiation improvement effects of BMSCs mediated by MGO nanocomposites. Furthermore, a new circRNA-circAars, we find and identify, is obviously upregulated in BMSCs mediated by MGO nanocomposites. Silencing circAars could significantly decrease the osteogenic ability of MGO nanocomposites. The underlying mechanism involved circAars sponging miR-128-3p to regulate the expression of SMAD5, which played an important role in the repair craniomaxillofacial bone defects mediated by MGO nanocomposites. Conclusion: We found that MGO nanocomposites regulated osteogenic differentiation of BMSCs via the circAars/miR-128-3p/SMAD5 pathway, which provided a feasible and effective strategy for the treatment of craniomaxillofacial bone defects.

Rediscovery and systematics of the enigmatic genus Helicostoa reveals a new species of sessile freshwater snail with remarkable sexual dimorphism.

Helicostoa sinensis E. Lamy, 1926 is a unique freshwater gastropod species with a sessile habit. This enigmatic species was first found cemented on river limestones from China about 120 years ago and described together with the genus. It was never collected again and has been considered monotypic. Here, we report the rediscovery of Helicostoa from several rivers in China, and describe a second species of this genus based on a comprehensive study. In addition to the unique sessile habit of both species, the new Helicostoa species presents one of the most remarkable cases of sexual dimorphism within molluscs. Only the adult female is sessile and the original aperture of the female is sealed by shell matter or rock, while an opening on the body whorl takes the function of the original aperture. The male is vagile, with a normal aperture. Our results confirm the recently suggested placement of Helicostoa within the family Bithyniidae. The sessility of Helicostoa species is considered as an adaption to the limestone habitat in large rivers. The extreme sexual dimorphism and secondary aperture of females are considered as adaptations to overcome the obstacles for mating and feeding that come with a sessile life style.

High-risk groups of neonatal lupus erythematosus in term infants: a birth cohort study.

This study aims to analyze the clinical characteristics and risk factors of high-risk groups of neonatal lupus erythematosus (NLE) in term infants. High-risk groups of NLE infants whose mothers were positive for anti-SSA, anti-SSB or anti-U1RNP antibodies during pregnancy were enrolled. They were born between February 2013 and February 2020, with a gestational age not less than 37 weeks. We analyzed their clinical data from birth to 24 months after birth. A total of 105 patients in the NLE high-risk group were included. Among them, 30 patients were diagnosed with NLE (NLE group), and 75 patients were not (non-NLE group). The affected systems of the NLE group included the dermal (13.3%), hepatic (76.0%), and hematological systems (43.3%). Hepatic involvement, anemia and thrombocytopenia did not emerge until 60 days, 41 days and 22 days after birth, respectively, in some cases. Systemic involvement could be cured within 3 to 12 months after birth. The clearance time of specific autoantibodies was 12 months after birth. There was no significant difference in the clinical characteristics of babies and their mothers between the two groups, neither in the positive rate nor in the clearance time of specific autoantibodies. CONCLUSION: After standardized prenatal health care, there is still a high risk of dermal, hepatic, or hematological system involvement for high-risk groups of NLE. There are no specific indicators for the prediction of whether babies will develop NLE. All of these patients need to be followed up closely within one year after birth. WHAT IS KNOWN: • Neonatal lupus erythematosus (NLEs) can affect the cardiac, dermal, hepatic, and hematological systems of infants. WHAT IS NEW: • After standardized prenatal health care employing good multidepartment cooperation in our center, no neonates had cardiac block in this study. However, dermal, hepatic, and hematological system involvement of NLE can still gradually appear (as long as 60 days after birth in some cases) during follow-up, and some of these conditions are serious and require timely and active intervention. No single factor has been found to predict whether offspring at high-risk of NLE whose mothers are positive for anti-SSA, SSB and/or RNP will develop NLE.

Regulation of m6A modification on ferroptosis and its potential significance in radiosensitization.

Radiotherapy is often used to treat various types of cancers, but radioresistance greatly limits the clinical efficiency. Recent studies have shown that radiotherapy can lead to ferroptotic cancer cell deaths. Ferroptosis is a new type of programmed cell death caused by excessive lipid peroxidation. The induction of ferroptosis provides a potential therapeutic strategy for radioresistance. As the most common post-transcriptional modification of mRNA, m6A methylation is widely involved in the regulation of various physiopathological processes by regulating RNA function. Dynamic m6A modification controlled by m6A regulatory factors also affects the susceptibility of cells to ferroptosis, thereby determining the radiosensitivity of tumor cells to radiotherapy. In this review, we summarize the mechanism and significance of radiotherapy induced ferroptosis, analyze the regulatory characteristics of m6A modification on ferroptosis, and discuss the possibility of radiosensitization by enhancing m6A-mediated ferroptosis. Clarifying the regulation of m6A modification on ferroptosis and its significance in the response of tumor cells to radiotherapy will help us identify novel targets to improve the efficacy of radiotherapy and reduce or overcome radioresistance.

GPX8 deficiency-induced oxidative stress reprogrammed m6A epitranscriptome of oral cancer cells.

Glutathione peroxidase 8 (GPX8) is a key regulator of redox homoeostasis. Whether its antioxidant activity participates in the regulation of m6A modification is a crucial issue, which has important application value in cancer treatment. In this study, MeRIP-seq was used to explore the characteristics of transcriptome-wide m6A modification in GPX8-deficient oral cancer cells. Oxidative stress caused by the lack of GPX8 resulted in 1,279 hyper- and 2,287 hypo-methylated m6A peaks and 2,036 differentially expressed genes in GPX8-KO cells. Twenty-eight differentially expressed genes were related to the cell response to oxidative stress, and half of them changed their m6A modification. In GPX8-KO cells, m6A regulators IGF2BP2 and IGF2BP3 were upregulated, while FTO, RBM15, VIRMA, ZC3H13, and YTHDC2 were downregulated. After H2O2 treatment, the expression changes of RBM15, IGF2BP2, and IGF2BP3 were further enhanced. These data indicated that GPX8-mediated redox homoeostasis regulated m6A modification, thereby affecting the expression and function of downstream genes. This study highlights the possible significance of GPX8 and the corresponding m6A regulatory or regulated genes as novel targets for antioxidant intervention in cancer therapy.

Lack of GPX8 caused oxidative stress of oral cancer cells.Oxidative stress induced by GPX8 deficiency reprogrammed m⁶A epitranscriptome.GPX8 deletion­caused oxidative stress regulated expression of m⁶A regulatory genes.m⁶A modification of antioxidant genes is the adaptive response of cells to oxidative stress.

The effect of antinuclear antibody titre and its variation on outcomes in children with primary immune thrombocytopenia.

Antinuclear antibody (ANA) can be positive in children with primary immune thrombocytopenia (ITP), but the effect of ANA titre and its variation on outcomes of children with primary ITP remains unclear. Here, we conducted a single-centre retrospective cohort study of children with primary ITP at the Peking Union Medical College Hospital in China. A total of 324 children with primary ITP included in this study were followed for a median time of 25 months. In this cohort, 39.2% had an ANA titre of 1:160 or higher. Results from a generalized estimating equation model revealed that patients with higher ANA titres had lower platelet counts at onset but a higher recovery rate of subsequent platelet counts. Results from Cox regression models adjusted for potential confounders revealed that patients with ANA titres of 1:160 or more were more likely to develop to autoimmune disease (AID) than those without, and the risk of AID development increased with the rise of ANA titres (p value for trend less than 0.001). These data highlight the predictive value of ANA titre for platelet counts and the risk of AID development in children with primary ITP.

Graphdiyne Oxide-Mediated Photodynamic Therapy Boosts Enhancive T-Cell Immune Responses by Increasing Cellular Stiffness.

Purpose: Nanomaterial-based photodynamic therapy (PDT) has been commonly used for the treatment of cancerous tumors. Despite significant achievements made in this field, the intrinsic impact of nanomaterials-based PDT on the mechanical properties of oral squamous cell carcinoma (OSCC) cells is not entirely understood. Here, we used atomic force microscopy (AFM) to measure the stiffness of OSCC cells subjected to PDT in co-culture systems to evaluate the T cell-mediated cancer cell-killing effects. Methods: In this study, AFM was used to assess the stiffness of PDT-subjected cells. The phototoxicity of graphdiyne oxide (GDYO) was assessed using confocal laser scanning microscopy (CLSM), measurements of membrane cholesterol levels, and assessments of the F-actin cytoskeleton. A co-culture system was used to evaluate the effects of CD8+ T cells (cytotoxic T lymphocytes), demonstrating how PDT modulates the mechanical properties of cancer cells and activates T cell responses. The antitumor immunotherapeutic effect of GDYO was further evaluated in a murine xenograft model. Results: GDYO increased the mechanical stiffness of tumor cells and augmented T-cell cytotoxicity and inflammatory cytokine secretion (IFN-γ and TNF-α) under laser in vitro. Furthermore, GDYO-based PDT exerted inhibitory effects on OSCC models and elicited antitumor immune responses via specific cytotoxic T cells. Conclusion: These results highlight that GDYO is a promising candidate for OSCC therapy, shifting the mechanical forces of OSCC cells and breaking through the barriers of the immunosuppressive tumor microenvironment. Our study provides a novel perspective on nanomaterial-based antitumor therapies.

Size-optimized nuclear-targeting phototherapy enhances the type I interferon response for "cold" tumor immunotherapy.

There is growing interest in the effect of innate immune silencing in "cold" tumors, which always fail in the immune checkpoint blockade monotherapy using PD-L1 monoclonal antibodies (aPD-L1). Combination of aPD-L1 with photodynamic therapy, i.e., photoimmunotherapy, is a promising strategy to improve the mono immunotherapy. Nuclear-targeting nanoparticles could elicit a type I interferon (IFN)-mediated innate immune response and reverse the immunosuppressive microenvironment for long-term immunotherapy of "cold" tumors. Photosensitizers such as zinc phthalocyanine (ZnPc) have limited ability to target the nucleus and activate innate sensing pathways to minimize tumor recurrence. Additionally, the relationship between nanoparticle size and nuclear entry capacity remains unclear. Herein, graphene quantum dots (GQDs) were employed as aPD-L1 and ZnPc carriers. Three particle sizes (200 nm, 32 nm and 5 nm) of aPD-L1/ZnPc/GQD-PEG (PZGE) were synthesized and tested. The 5 nm nanoparticles achieved the best nuclear enrichment capacity contributing to their ultrasmall size. Notably, 5 nm PZGE-based photodynamic therapy enabled an amplification of the type I IFN-mediated innate immune response and could convert "immune-cold" tumors into "immune-hot" ones. Utilizing their size advantage to target the nucleus, 5 nm nanoparticles induced DNA damage and activated the type I IFN-mediated innate immune response, subsequently promoting cytotoxic T-lymphocyte infiltration and reversing negative PD-L1 expression. Furthermore, the nanoplatform we designed is promising for the effective suppression of distant oral squamous cell carcinoma. Thus, for the first time, this study presents a size design strategy for nuclear-targeted photo-controlled immune adjuvants and the nuclear-targeted phototherapy-mediated immunomodulatory functions of type I IFN innate immune signalling for "immune-cold" tumors. STATEMENT OF SIGNIFICANCE: The potential of commonly used photosensitizers to activate innate sensing pathways for producing type I IFNs is limited due to the lack of nuclear targeting. Facilitating the nuclear-targeting of photosensitizers to enhance innate immune response and execute long-term tumor killing effect would be a promising strategy for "cold" tumor photoimmunotherapy. Herein, we report an optimal size of PZGE nanoparticles that enable the nuclear-targeting of ZnPc, which reinforces the type I IFN-mediated innate immune response, synergistically reversing "cold tumors" to "hot tumors" for effective primary and distant tumor photoimmunotherapy. This work highlights the marked efficacy of ultrasmall nuclear-located nanocarriers and offers new insight into "immune-cold tumors" via prominent innate immune activation mediated by nuclear-targeting photoimmunotherapy.

Early indicators of neonatal-onset hereditary thrombotic thrombocytopenia purpura.

Background: Neonatal-onset hereditary thrombotic thrombocytopenia purpura (hTTP) is often misdiagnosed due to its rarity. It begins with jaundice, similar to infants with ABO incompatibility. Objective: To explore early indicators of neonatal-onset hTTP. Methods: This study was a retrospective case series of newborns with hTTP and ABO incompatibility. We compared the clinical characteristics and laboratory test results in these two groups. Results: This study included four hTTP patients and 20 ABO-incompatible newborns. All patients manifested disease during the neonatal period. There were equal numbers of males and females in each group. hTTP newborns showed earlier (median difference, 57.0 h; 95% confidence interval [CI], 24.0-65.0) and more severe hyperbilirubinemia (mean difference, 8.0 mg/dl; 95% CI, 3.8-12.1) than ABO-incompatible newborns. In hTTP newborns, anemia was more common within 7 days after birth than in ABO-incompatible newborns (odds ratio, 25.4; 95% CI, 1.2-551.6), and platelet counts were lower than in ABO-incompatible newborns (17 ± 12 × 109/L vs. 291 ± 76 × 109/L). The levels of serum creatinine (median difference, 51.8 µmol/L; 95% CI, 16.0-109.4) and blood urea nitrogen (median difference, 5.7 mmol/L; 95% CI, 2.8-38.7) were higher in hTTP newborns than in ABO-incompatible newborns. There were no significant differences in white blood cell counts, C-reactive protein, alanine aminotransferase, or albumin levels. Conclusions: Severe jaundice soon after birth, early anemia, and severe thrombocytopenia were more common in newborns with hTTP than ABO incompatibility. These are distinguishing early features of hTTP.

Can fractal dimensions objectivize gastropod shell morphometrics? A case study from Lake Lugu (SW China).

Morphometrics are fundamental for the analysis of size and shape in fossils, particularly because soft parts or DNA are rarely preserved and hard parts such as shells are commonly the only source of information. Geometric morphometrics, that is, landmark analysis, is well established for the description of shape but it exhibits a couple of shortcomings resulting from subjective choices during landmarking (number and position of landmarks) and from difficulties in resolving shape at the level of micro-sculpture.With the aid of high-resolution 3D scanning technology and analyses of fractal dimensions, we test whether such shortcomings of linear and landmark morphometrics can be overcome. As a model group, we selected a clade of modern viviparid gastropods from Lake Lugu, with shells that show a high degree of sculptural variation. Linear and landmark analyses were applied to the same shells in order to establish the fractal dimensions. The genetic diversity of the gastropod clade was assessed.The genetic results suggest that the gastropod clade represents a single species. The results of all morphometric methods applied are in line with the genetic results, which is that no specific morphotype could be delimited. Apart from this overall agreement, landmark and fractal dimension analyses do not correspond to each other but represent data sets with different information. Generally, the fractal dimension values quantify the roughness of the shell surface, the resolution of the 3D scans determining the level. In our approach, we captured the micro-sculpture but not the first-order sculptural elements, which explains that fractal dimension and landmark data are not in phase.We can show that analyzing fractal dimensions of gastropod shells opens a window to more detailed information that can be considered in evolutionary and ecological contexts. We propose that using low-resolution 3D scans may successfully substitute landmark analyses because it overcomes the subjective landmarking. Analyses of 3D scans with higher resolution than used in this study will provide surface roughness information at the mineralogical level. We suggest that fractal dimension analyses of a combination of differently resolved 3D models will significantly improve the quality of shell morphometrics.

Selective immunoglobulin A deficiency (SIgAD) primarily leads to recurrent infections and autoimmune diseases: A retrospective study of Chinese patients in the past 40 years.

Selective immunoglobulin A deficiency (SIgAD) is considered to be the most common human primary immune-deficiency disease in the world. However, the incidence in China is obviously lower than Caucasian races. The definition of SIgAD has changed over time with the progress of people's understanding. The scientific community did not reach a consensus on the definition until 1999. As a result, many previously reported cases need to be excluded under the current definition. SIgAD can lead to several spectra of diseases including infections and autoimmune diseases. We retrospectively summarized the SIgAD patients in Peking Union Medical College Hospital (PUMCH), and summarized the Chinese SIgAD reported in China and abroad in past 40 years. Fourty three SIgAD patients were confirmed in the study, in which 9 were healthy without clinical symptoms. Of the 34 patients with clinical symptoms, recurrent infections were found in 29 (85.3%) patients; 13 (38.2%) patients were with autoimmune diseases; 6 (17.6%)cases had allergic symptoms; 3 patients (8.8%) were with tumors, only one case (2.9%) had a family history. Compared with other countries, sIgAD patients in China showed similar symptoms, but the rate of recurrent infections and autoimmune diseases were higher than some other countries; most of the allergic symptoms are drug allergy, different with the allergic sequelae reported in other countries, such as asthma, rhinitis, food allergy and atopic dermatitis; and it is rare to have family history in Chinese patients. We also figured out that more female SIgAD patients tend to have more autoimmune diseases than men (P = 0.039).

Individualized Human Milk Fortification to Improve the Growth of Hospitalized Preterm Infants.

BACKGROUND: Human milk (HM) is the first choice for preterm infants, but exclusive HM feeding is inadequate for the growth of very preterm infants. The hypothesis of this trial is that infants fed according to an individualized fortification regimen will have higher protein intake and improved weight gain velocity (WGV). METHODS: A prospective, randomized, controlled study was conducted. Infants <34 weeks of gestational age were enrolled when enteral feeding volume reached 60 mL/kg/d and were randomly allocated to the individualized fortification (IF) group or the standard fortification group. The IF group was fed using a regimen that featured modifying HM fortifier and supplemental protein powder based on the protein concentration in HM, current body weight of infants, and blood urea nitrogen (fortification level was set as L-1, L0, L1, L2, L3; the amount of HM fortifier and protein powder were determined accordingly). RESULTS: Between September 2012 and August 2016, 51 preterm infants completed the study. In the IF group, 62.5% (15/24) of preterm infants were fed with HM fortified to level 1, 29.2% (7/24) to level 2, and 12.5% (3/24) to level 3. The WGV of the third week in the IF group was greater than the standard group (20.8 ± 7.9 vs 14.9 ± 4.5 g/kg/d, P = 0.022). CONCLUSION: About two-thirds of preterm infants needed to adjust the HM fortification to a higher level. The WGV of infants in the IF group was better than that of the standard group in the third week of this study.

Breast milk concentration of hydroxychloroquine in Chinese lactating women with connective tissue diseases.

PURPOSE: Considering the very limited while varying information about the excretion of hydroxychloroquine (HCQ) into human milk, we sought to determine the breast milk concentrations of HCQ in Chinese lactating patients with connective tissue diseases to assess the safety of HCQ in infants of this population. METHODS: Breastfeeding women who had been on HCQ for at least 1 year were recruited. Milk samples were collected at five time points over 12 h. Breast milk HCQ levels were measured by a validated high-performance liquid chromatography (HPLC) assay. According to the general daily milk consumption of 0.15 L/kg for an infant, the dose of HCQ received by the infants via breastfeeding was calculated. RESULTS: Thirty-three patients completed the study who received HCQ treatment with the following regimens: 0.1 g bid (n = 3), 0.2 g qd (n = 8), 0.2 g bid (n = 21), and 0.2 g qod (n = 1). The mean breast milk HCQ levels (µg/mL) over the 12-h sampling period for each dosage regimen group were 0.4, 0.7, 1.4, and 0.4, respectively. The dose of HCQ (mg) received by the infants via breastfeeding would be 0.4, 0.4, 0.9, and 0.2, which were 0.26%, 0.26%, 0.29%, and 0.26% of the daily maternal doses, respectively. The infant's weight-adjusted relative dose (mg/kg) was 0.1, 0.1, 0.2, and 0.1, respectively, equivalent to 1.9%, 3.0%, 3.0%, and 3.2% of the maternal dose per kilogram body weight, respectively. CONCLUSION: Our study found that HCQ has very low concentrations in breast milk. It is probably safe for the patients to give breastfeeding during HCQ therapy period.

[SLC2A2 gene analysis in three Chinese children with Fanconi-Bickel syndrome].

Fanconi-Bickel syndrome (FBS, OMIM 227810), a rare autosomal recessive disorder of carbohydrate metabolism, is caused by SLC2A2 (GLUT2) mutations. The study reported 3 cases of FBS who were confirmly diagnosed by SLC2A2 gene analysis. The three patients showed typical features like glycogen storage disease and proximal renal tubular nephropathy. Homozygous splice-site mutation IVS8+5G>C (c.1068+5 G>C) was found in patient A and homozygous nonsense mutation c.1194T>A (p.Tyr398X) in patient B. Patient C harboured a missense mutation c.380C>A (p.Ala127Asp) and a de novo insertion c.970dupT (p.324TyrfsX392) which was not inherited from her parents. Four mutations were identified in the 3 Chinese FBS patients. Except IVS8+5G>C mutation, the other 3 mutations were novel in Chinese population. To the best of our knowledge, patient C may be the first FBS case worldwide with de novo mutation.

[Effect of aggressive nutritional support on preterm infants during hospitalization].

OBJECTIVE: To explore the effect of aggressive nutritional support in early life on growth of preterm infants during hospitalization. METHOD: Two retrospective cohorts of preterm infants were compared; 81 infants of group A (born between January 1, 2005 and June 30, 2006) and 79 infants of group B (June 1, 2009 and November 30, 2010) with gestational age above 28 weeks and birth weight between 1000 g and 2000 g, transfered to NICU of PUMCH within 12 hours after birth, hospitalized for > or = 2 weeks, who were free of major congenital anomalies and survived to discharge were recruited. The comparison of enteral and parenteral nutrition, growth rate, biochemical indices during hospitalization between these both groups were made. RESULT: Compared to group A, group B was given greater volume of amino acid infusion on the 3(rd) and 7(th) day of life [2.00 (2.00, 2.50) g/kg vs 1.50 (1.50, 2.00) g/kg, 3.00 (2.00, 3.00) g/kg vs 2.00 (1.80, 2.60) g/kg, all P < 0.001], and Consumed more milk and total energy intake on the 3rd day of life [9.41(2.66, 18.74) ml/kg vs 14.47 (4.23, 30.77) ml/kg, P < 0.05, (64.87 ± 16.04) kcal/kg vs (55.62 ± 17.68) kcal/kg, P = 0.001]. Total energy intakes after a week of life were similar between the two groups. More infants received human milk fortifier in group B (62.8% vs 14.3%, P = 0.001). After stratification according to weight, both very low birth weight infants and infants with birth weight between 1500 g and 2000 g in group B grew more rapidly (P < 0.001). The percentage of growth retardation was increased after hospitalization in group A (65.4% vs 40.7%, P < 0.05), there were no statistically significant differences in group B. The mean Z scores at birth were comparable. The mean Z scores by discharge were higher in group B (-1.24 vs -1.54, P < 0.05). Serum albumin, prealbumin and urea values were similar in both groups at birth, but higher in group B after two weeks of life (P < 0.001). Before discharge, Serum albumin, prealbumin, and urea values in group B was higher (P < 0.001). CONCLUSION: Improvements in nutritional practices in early life of preterm infants effectively enhanced the growth and improved the nutritional status of preterm infants during hospitalization.

[Clinical analysis of nosocomial infection in neonatal intensive care units].

OBJECTIVE: Nosocomial infections (NIs) have become a matter of major concern in neonatal intensive care units (NICU). The objectives of this study were to investigate the incidence of nosocomial infections of newborn infants in NICU and to explore the risk factors and strategies of infection control. METHODS: The study enrolled 638 hospitalized newborn infants from Apr 2003 to Dec 2004. The clinical data, such as the clinical manifestation, the condition of colonized bacteria, were collected and analyzed by using SPSS software. RESULT: There were 88 times of nosocomial infections in 74 newborn infants. The overall incidence of nosocomial infections was 11.6%. The mean duration from admission to first episode of NI was 7.98 +/- 4.58 days. The incidence density was 14.9 per 1000 NICU patient-days. Catheter-correlated hematogenous infection rate was 18 per 1000 umbilical or central line-days; the ventilator-associated nosocomial pneumonia rate was 63.3 per 1000 ventilator days. The smaller the gestational age and the lower the birth weight, the higher the incidences of nosocomial infection. The duration of hospitalization was longer in these infected infants than those non-infected infants. Univariate analysis indicated that gestational age < or = 32 W, the parenteral nutrition, birth weight < or = 1500 g and mechanical ventilation, apnea, small for gestational age infant, central venous catheter (P < 0.05) were risk factors for NIs. Multivariate analysis identified 3 independent risk factions: the parenteral nutrition ([OR] = 7.185 [95% CI, 3.399 - 15.188]), birth weight < or = 1500 g ([OR] = 3.310 [95% CI, 1.100 - 9.963]) and mechanical ventilation ([OR] = 2.527 [95% CI, 1.092 - 5.850]). The most common infection was pneumonia (45.4%). The mortality rate of nosocomial infections was 4.1%. Bacterial surveillance was examined by nasopharyngeal and rectal swab culture immediately on hospital admission and then once a week. The incidence rate of NIs was 24.8% in patients whose nasopharyngeal and rectal swab culture indicated bacterial colonization, and 1.9% in patients without bacterial colonization (chi(2) = 79.7, P < 0.001). CONCLUSION: It is important to identify the high risk factors for nosocomial infections in newborn infants in NICU. Reducing the duration of the parenteral nutrition and the virulence manipulation as far as possible and getting the message of individual bacterial colonization in NICU may be conducive to decrease of the incidence of nosocomial infections and provide reference for rational clinical drug administration.