Search

Since the authors are not responding to the editor’s requests to fulfill the editorial requirement, therefore, the article has been withdrawn. Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php Bentham Science Disclaimer: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

Purpose. Ultraviolet radiation (UVR) is one of the exogenous stimuli increasing melanogenesis. UV light, especially UVB, is also a potent inducer of epidermal cytokine release. This study is aimed at determining the underlying mechanisms by which UVB-induced cytokines in keratinocytes regulate melanin production in vitro. Methods. Expression levels of mRNA for interleukin- (IL-) 1, IL-1β, IL-6, IL-10, IL-17, and tumor necrosis factor-alpha (TNF-α) were measured using RT-qPCR at various time points after UVB irradiation in C57BL/6 mice and HaCaT cells. NaOH lysis and L-dihydroxyphenylalanine (L-DOPA) oxidation method were used to measure melanin content and tyrosinase (TYR) activity, respectively, in melanoma B16 cells. RT-qPCR and Western blot were used to assess mRNA and protein levels of microphthalmia-associated transcription factor (MITF), TYR, tyrosine-related protein-1 (TRP-1), and tyrosine-related protein-2 (TRP-2) in B16 cells. Finally, expression levels of cyclooxygenase-2 (COX-2) mRNA and stem cell factor (SCF) in HaCaT cells were measured following knockdown of IL-1β using siRNA (siIL-1β). Results. UVB irradiation increased IL-1β mRNA expression levels in both C57BL/6 mice and HaCaT cells. The melanin content, TYR activity, and expression levels of TYR and TRP-1 were all raised when B16 cells were treated with 4 pg/l of IL-1. Moreover, IL-1β also upregulated the expression levels of SCF and COX-2 in nonirradiated HaCaT cells. Conversely, knockdown of IL-1β attenuated UVB irradiation-induced upregulation of SCF and COX-2 expression in keratinocytes. Conclusions. UVB-induced melanogenesis is mediated in part by IL-1β, leading to upregulation of the TYR/TRP1 expression in melanoma B16 cells. IL-1β can also stimulate the expression of COX-2 and SCF in HaCaT cells, which in turn increase melanin synthesis in melanocytes. These results suggest that anti-inflammatory approaches could possibly mitigate UVB-induced hyperpigmentation.

Lignin-based carbon materials have excellent properties, which are greatly enhanced by the doping of different elements, such as non-metallic elements (O, N, S, P, etc.) and metallic elements (Cu, Co, Ni, Fe, Mn, etc.).

Background Oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA) represents an important issue, as its oxacillin susceptibility has contributed to misidentification by conventional susceptibility tests and consequently potential therapeutic failure, but limited data on the current status of OS-MRSA infection in Chinese hospitals are available. Methods This multicenter study performed a battery of susceptibility tests and diagnostic tests for 956 S. aureus isolates from 10 hospitals, including automated susceptibility testing on VITEK 2, broth microdilution, disk diffusion, and detection of PBB2a, mecA gene and mecC gene. For all identified OS-MRSA, multi-locus sequence typing (MLST), together with spa typing, SCCmec typing and PVL detecting, was carried out. Results OS-MRSA, most of which were from pediatric inpatients, represented 1.8% (17/956) of total isolates. Of these 17 OS-MRSA, 10 were ST59, followed by ST965 (3/17), and 11 carried SCCmec type IV, while 5 carried SCCmec type V, but only one was Panton–Valentine leucocidin (PVL)-positive, also, 16 had one or two point mutations within mecA promoter. OS-MRSA had inducible oxacillin resistance and significantly lower MDR (Multi-Drug Resistant) rate. We observed that the VITEK 2 system exhibited some deficiency in OS-MRSA detection, whereas cefoxitin disk diffusion was shown to be a reliable and cost-saving alternative and should be supplemented in detecting S. aureus with borderline oxacillin susceptible MICs. Conclusion This study has characterized phenotypically and molecularly OS-MRSA in China, and provided insights into more effective management of OS-MRSA.

Cutaneous squamous cell carcinoma (cSCC) is the second most frequent of the keratinocyte-derived malignancies with actinic keratosis (AK) as a precancerous lesion. To comprehensively delineate the underlying mechanisms for the whole progression from normal skin to AK to invasive cSCC, we performed single-cell RNA-seq (scRNA-seq) to acquire the transcriptomes of 138,982 cells from 13 samples of six patients including AK, squamous cell carcinoma in situ (SCCIS), cSCC and their matched normal tissues, covering comprehensive clinical courses of cSCC. We identified diverse cell types, including important subtypes with different gene expression profiles and functions in major keratinocytes. In SCCIS, we discovered the malignant subtypes of basal cells with differential proliferative and migration potential. Differentially expressed genes (DEGs) analysis screened out multiple key driver genes including transcription factors (TFs) along AK to cSCC progression. Immunohistochemistry (IHC) / immunofluorescence (IF) experiments and single-cell ATAC sequencing (scATAC-seq) data verified the expression changes of these genes. The functional experiments confirmed the important roles of these genes in regulating cell proliferation, apoptosis, migration and invasion in cSCC tumor. Furthermore, we comprehensively described the tumor microenvironment (TME) landscape and potential keratinocyte-TME crosstalk in cSCC providing theoretical basis for immunotherapy. Together, our findings provide a valuable resource for deciphering the progression from AK to cSCC and identifying potential targets for anticancer treatment of cSCC.

We performed a bioinformatics analysis with validation by multiple databases, aiming to evaluate the diagnostic and prognostic value of Kelch-like ECH-associated protein 1 (Keap1) mRNA for lung cancer, and to explore possible mechanisms. Diagnostic performance of Keap1 mRNA was determined by receiver operating characteristic (ROC) curve analysis. Prognostic implication of Keap1 mRNA was estimated by Kaplan-Meier survival analysis. Co-expressed genes with both Keap1 and Nfe2L2 were identified by LinkedOmics. Mechanisms of Keap1-Nfe2L2-co-expressed genes underlying the pathogenesis of lung cancer were explored by function enrichment and pathway analysis. The ROC curve analysis determined a good diagnostic performance of Keap1 mRNA for lung squamous cell carcinoma (LUSC), with an area under the ROC curve (AUC) of 0.833, sensitivity of 72.7%, and specificity of 90.6% (P

Background/purpose As the incidence of fungal infections in China increases, the demand for rapid and accurate diagnosis of mycoses is growing. Yet, information on current diagnostic capacity is scarce. Methods An online survey was conducted in February 2018 to collect information on mycology testing from tertiary care hospitals across China. Responses from 348 hospitals were analyzed, and a scoring system was designed and employed to assess the overall diagnostic capacity. Results Most of the surveyed hospitals did not have separate laboratory space, manpower, or equipment dedicated for fungal testing. Conventional staining methods were widely available (>70%), whereas GMS and fluorescent staining were less common. Fungal identification services were offered mostly with chromogenic medium, morphological characterization or automated identification systems, other than more advanced methods such as MALDI-TOF MS and DNA sequencing. Fungal serology testing was available in 81.1%, with G test being the most often used. Though 91.8% of the respondents had the ability to perform antifungal susceptibility testing for yeasts, less than 13% conducted such testing for molds. The percentage of laboratories participating in External Quality Assessment programs and research was 57.5% and 32.5%, respectively. The average score for the 348 surveyed hospitals was 37.2 (out of a maximum of 89 points), with only 15 hospitals scoring >60, suggesting a general lack of high-quality mycology laboratories. Conclusions The overall clinical testing capacity for fungal infection in China is insufficient. More investment and training efforts are warranted to establish centers of excellence and promote access to high-quality diagnostic services.

With the rapid development of the global economy, the depletion of fossil fuels and the intensification of environmental pollution, there is an increasingly urgent need for new and green electrochemical energy storage technologies in society. In this thesis, ligninsulfonate/polyaniline nanocomposites were synthesized by

Carbon aerogels (CAs) are excellent carrier materials with a large surface area and high porosity. In addition to the above-mentioned wonderful characteristics, aerogel with lignin as a precursor is also a material with high bioactivity and degradability. Lignin carbon aerogels (LCAs) have a wide range of applications, and can be used in supercapacitors, adsorbents and catalysts

BACKGROUND: To investigate the relationship between sagittal alignment and coronal deformity in patients with adolescent idiopathic scoliosis (AIS) through analysis of the spinal imaging data. METHODS: Four hundred and fifty-four AIS patients who underwent anteroposterior and lateral radiography of the while spine were enrolled, and the spinal parameters of Cobb angle, cervical lordosis, C1-C2 angle, T1 slope, thoracic kyphosis, lumbar lordosis, sacral slope, pelvic tilt (PT), pelvic incidence (PI), cervical sagittal vertical axis (SVA), and spinal SVA were analyzed. RESULTS: The patients were divided into two groups according to the size of the Cobb angle: group A (Cobb angle ≤45°, n=414) and group B (Cobb angle >45°, n=40). In group A, the Cobb angle was in a medium negative correlation with the cervical lordosis angle (r=−0.637, P

Surgery for patients with adolescent idiopathic scoliosis (AIS) may change spinal sagittal alignment, and postoperative adding-on may affect spinal sagittal balance after reconstruction. This study was to investigate the effect of surgery on spinal sagittal alignment and the relationship between postoperative adding-on and spinal sagittal balance in patients with AIS.The hypothesis of this study was that the effect of surgery on AIS was associated with recovery of the spinal sagittal plane and that presence of postoperative adding-on might affect the spinal sagittal balance. Materials and methods This retrospective study enrolled 22 patients who received surgical treatment. Clinical, imaging and follow-up data were analyzed.After surgery, T1 slope (T1S) and thoracic kyphosis (TK) were significantly (P0.05) lower in patients with postoperative adding-on (16.73°±6.12° for T1S and 28.95°±11.3° for TK) than those without adding-on (24.82°±8.59° for T1S and 40.29°±12.08° for TK). At the last follow-up, cervical lordosis (CL), T1S, and TK were significantly (P0.05) lower in patients with adding-on (3.05°±11.41° for CL, 22.12°±3.68° for T1S, and 37.89°±8.97° for TK) than those without adding-on (15.94°±°13.6 for CL, 28.86°±4.26° for T1S, and 47.64°±7.1° for TK). The Cobb angle was significantly (19.65°±8.69° vs. 50.66°±11.46°; P0.001) decreased after compared with that before surgery. At the final follow-up, the Cobb angle (26.48°±9.61° vs. 19.65°±8.69°, P0.001), T1S (24.87°±5.11° vs. 20.04°±8.13°), and TK (41.88°±9.45° vs 33.53°±12.71°) all significantly (P0.01) increased compared with those immediately after surgery. The Cobb angle significantly (26.48°±9.61° vs. 50.66°±11.46°, P0.001) decreased while CL, T1S, and TK all significantly (8.32°±13.67° vs 2.47°±14.42° for CL, T1S 24.87°±5.11° vs. 21.28°±5.88° for T1S, and 41.88°±9.45° vs. 33.13°±10.97° for TK, P0.05) increased at the final follow-up compared with those before surgery.Surgery affects spinal sagittal alignment, and postoperative adding-on may affect spinal sagittal balance after reconstruction. Surgery as the ultimate approach for AIS has good effects but may result in some side effects.III, retrospective cohort study.

This article investigates the dynamic non-local stress analysis of two collinear semi-permeable mode-I cracks in a piezoelectric medium under the harmonic waves by using the generalized Almansi theorem and the Schmidt method. Based on the Fourier transform technique, this problem is formulated into coupled dual integral equations. The dynamic stress and the dynamic electric displacement fields at the crack tips are obtained by solving the derived dual integral equations. Numerical examples are provided to show the effects of the crack length, the distance between the two collinear cracks, the lattice parameter, the electric permittivity of the air inside the crack, and the characteristics of the harmonic wave on the dynamic stress field and the dynamic electric displacement field near the crack tips. The dynamic stress and electric displacement decrease with increasing the distance between two collinear cracks and lattice parameter in a piezoelectric medium. Meanwhile, the dynamic field will impede or enhance crack propagation in piezoelectric medium depending on the circular frequency of the incident wave. Different from the classical solutions, the present solutions exhibit no stress and electric displacement singularities at the crack tips. This work is expected to be helpful for theoretical modeling of piezoelectric medium at nanoscale.

This paper deals with the stabilization problem for discrete-time linear system with unsymmetric saturation. To handle the structural properties of the unsymmetric saturation nonlinearity, the description of the transformation carries from the symmetric case to the unsymmetric case is employed. By using the parametric Lyapunov equation-based low gain feedback design approach, linear matrix inequality formulations for the state feedback and output feedback control design are given. The effectiveness of the proposed method is confirmed by numerical examples.

Background: Anhydrous ethanol, for its part, has been successfully used to treat renal cyst, hepatocellular carcinoma and ovarian chocolate cyst et al. However, in spite of the high frequency of tuberculous purulent pleural effusion, we found that only a few very early studies that attempted to assess the use of intrapleural anhydrous ethanol in tuberculous effusions with signs of empyema. We report a patient who was injected anhydrous ethanol into pleural cavity to treat chronic tuberculous empyema. Case presentation: A 23-year old male was admitted in the hospital because of chronic tuberculous empyema. Ultra-sonography guided thoracentesis and thoracic close drainages were done, but had no effect. However, the patient refused Video-assisted Thoracoscopic Surgery (VATS) and traditional thoracotomy. Therefore, we injected anhydrous ethanol into the pleural cavity after getting the patient's consent. Pyothorax was quickly controlled and the patient finally recovered fully. Conclusion: Surgical operation is the main treatment of chronic tuberculous empyema, which has a high cost and large injury, and many patients do not accept this treatment. In this study, intrapleural injection of anhydrous ethanol could achieve the purpose of eliminating the pus cavity, which is particularly suitable for patients who cannot tolerate surgery or are unwilling to undergo surgical treatment. Keywords: Tuberculous, Chronic empyema, Anhydrous ethanol

Background: Intramedullary well-differentiated osteosarcoma (IMWDOS) is rare and may easily be misdiagnosed. Objective: This study aimed at investigating the clinical, imaging, and pathological features of IMWDOS for correct diagnosis. Materials and Methods: Seventeen patients with IMWDOS were enrolled, and their clinical, imaging, and pathological data were analyzed. Results: Total 13 males and 4 females aged 19-55 years (mean 36. 1) were selected. The lesion was located at long bones in 16 patients and the second region of the acetabulum in one patient. Except for three patients with limited areas of lesions, all the other patients had a wide distribution of tumor, and the lesion in long bones involved the metaphysis area with possible extension towards the diaphysis. In imaging, the lesion usually had an unclear boundary with the destruction of bone cortex, uneven thickness of the bone cortex, thick and coarse trabecula in the lesion, but few periosteal reactions and soft tissue masses. The lesion was histologically composed of spindle cells with slight atypia. Follow-up was performed 2-101 months (mean 31.9m) in 14 cases, 10 years in one case, and 26 years in the remaining two. At follow-up, 12 patients (12/17 or 70.6%) who had a complete resection, including amputation (n=2), wide excision (n=8), and endoprosthetic replacement (n=2), showed no recurrence or metastasis. Among five patients who underwent curettage, three (3/17 or 17.6%) had recurrent lesions, leading to death in two of them, and the third one died during post-operation chemotherapy. Conclusion: Intramedullary well-differentiated osteosarcoma tends to occur at the metaphysis of long bones, especially at the distal femur. Histological, clinical, and imaging findings lack specific characteristics and should be examined collectively to reach a correct diagnosis. The prognosis of patients with complete lesion resection is good, while incomplete lesion curettage or resection will lead to recurrence and transformation into a highly malignant tumor.

The authors have requested that this preprint be removed from Research Square.

The authors have requested that this preprint be removed from Research Square.

The authors have requested that this preprint be removed from Research Square.

Tigecycline is an alternative antibiotic for managing carbapenem-resistant Gram-negative bacterial infections. However, disk diffusion and automated testing often show false-intermediate or false-resistant results in tigecycline susceptibility, misleading clinical antimicrobial therapy. Broth microdilution (BMD) is the reference method for testing tigecycline susceptibility, but it is labor intensive and time consuming to perform in clinical laboratories. Therefore, a simple and accurate method is urgently needed. We evaluated the performance of VITEK 2, E-test, Kirby-Bauer disk diffusion (KB), and modified KB disk diffusion (mKB) versus BMD in testing tigecycline susceptibility of 372 strains of carbapenem-resistant Klebsiella pneumoniae (CRKP) and 346 strains of carbapenem-resistant Acinetobacter baumannii (CRAB). BMD confirmed that 96.8% of CRKP and 91% of CRAB strains were susceptible to tigecycline. E-test, VITEK 2, KB, and mKB yielded categorical agreement of 96.7/59.3%, 69.9/54.3%, 78.5/87.3%, and 96.5%/91% for CRKP/CRAB, respectively. No very major error was found for either CRKP or CRAB by any method. No major error was found for CRKP or CRAB by the mKB method. The mKB method enhanced by R-buffer is simple, accurate, and inexpensive for clinical laboratories to test the susceptibility of CRKP and CRAB isolates to tigecycline.

The aim of the present study was to investigate the synergistic effect of LY294002 (a PI3K inhibitor) and ABT199 (a BCL2 inhibitor) on the cell cycle in acute myeloid leukemia (AML). The optimal concentration and duration of combined LY294002 and ABT199 were determined in human erythroleukemia (K562), promyelocytic leukemia (HL60) and myeloid leukemia (KG1a) cell lines. The mRNA and protein expression levels of cell cycle‑related molecules, including S‑phase kinase‑associated protein 2 (Skp2), p27, BCL2, Bax, cleaved caspase 3 (caspase‑3) and caspase 9 (caspase‑9) were detected via reverse transcription‑quantitative PCR and western blot analysis, respectively. At the molecular level, LY294002 and ABT199 combination treatment significantly downregulated Skp2, Bcl2, procaspase‑3 and procaspase‑9 expression levels, but markedly upregulated p27, Bax, cleaved caspase‑3 and caspase‑9 expression levels in K562, HL‑60 and KG1a cells. The results of the present study demonstrated that LY294002 and ABT199 combination treatment may serve as a novel therapeutic strategy for AML.

This study was to analyze ankle fractures for determining the epidemiology, types, distribution, possible mechanisms and diagnosis precision. Between January 2013 and December 2017, all Chinese patients older than 16 years of age with ankle fractures excluding old ankle fractures and pathological fractures in a tertiary care hospital were analyzed by using the Danis-Weber and Lauge-Hansen classification systems. Among 3952 patients with ankle fractures, 1225 fractures (31%) were Danis-Weber type A, 1640 (42%) were type B, 751 (19%) were type C, and 336 (9%) were perpendicular compression fracture. There were 1949 fractures on the left side and 2003 on the right with no significant difference (P > 0.05). Male patients between 16 and 50 years of age and women over 50 years had a higher incidence of ankle fractures accounting for 38.4% (1517/3952) and 22.2% (800/3952), respectively. Posterior malleolar fractures, fibular fractures above the inferior tibiofibular joint and Tillaux fractures were easily missed in the diagnosis, with 38 fractures (0.96%) being missed in the diagnosis. In conclusion, young and middle-aged men and older women have a higher incidence of ankle fractures, and use of the Lauge-Hansen and Danis-Weber classification systems can better help assessing the varied and complex ankle fractures, predicting the injuries, increasing diagnostic precision and decreasing misdiagnosis rate.

To investigate the characteristics of imaging changes with time of facial fractures, patients with facial fractures who had computed tomographic scan were enrolled including 500 patients who were divided into six groups based on the time of scanning: super early (2 months). The data were compared and analyzed. Forty two patients with frontal bone fractures had high-energy impact as the reason of fractures. The fracture line was clear and sharp within one week but blunt and sclerotic due to bone absorption at 2–3 weeks, and might exist for a long time. All patients had soft tissue swelling and paranasal sinus effusion at 1–2 weeks after injury. Air might gather in the adjacent soft tissues and/or intracranially within 3 days of injury if the fracture involved the frontal or other sinuses. Twelve of the 42 patients (28.6%) had intracranial hematoma, and five (11.9%) had epidural effusion. Subarachnoid hemorrhage was mostly absorbed within one week while epidural hematoma was completely absorbed over 3 weeks. Significant changes (P

To investigate the proliferation inhibition and pro-apoptosis effect of LY294002 (PI3K/AKT inhibtor) combined with daunorubicin (DNR) on the chronic myeloid leurenia cell line K562 and its possible mechanisms.The effect of LY294002 and DNR on the proliferation of K562 cells in different treating time and concentration were measured by MTT assay. The cell cycle was determined by flow cytometry, the mRNA and protein expression of SKP2 , P27, BCL-2 and BAX were determined by RT-PCR and Western blot.LY294002 and DNR were able to inhibit the growth of K562 cells and promote apoptosis in time- and concentration-dependent manner (P＜0.05), both the cell proliferation-inhibiting rate and apoptosis rate in combination therapy group were higher than that in DNR-monotherapy group (P＜0.05). After K562 cells treated by LY294002 combined DNR for 36 h, the cells were statistically significantly reduced in GLY294002 has the sensibilizative effect on DNR chemotherapy, which may be relative with blocking the cell cycle and inducing cell apoptosis.LY294002增强K562细胞对柔红霉素敏感性的研究.探讨PI3K/Akt抑制剂LY294002联合蒽环类化疗药物柔红霉素（DNR）对慢性髓系白血病细胞株K562细胞增殖的抑制作用、促凋亡作用及其相关机制.应用MTT法检测LY294002和DNR在不用浓度、不同作用时间点对K562细胞增殖的影响，流式细胞术分析细胞周期的变化，应用RT-PCR和Western blot法检测LY294002和DNR对K562细胞SKP2、P27、BCL-2和BAX2基因和蛋白表达的影响.LY294002联合DNR能够抑制K562细胞的生长并促进细胞凋亡，且具有浓度及时间依赖性（P＜0.05）；2药联合后细胞增殖抑制率及细胞凋亡率明显增加（P＜0.05）。2药联合作用于K562细胞36 h，随着浓度的增加其GLY294002对DNR的化疗作用有增敏效果，其作用机制可能与阻滞细胞周期及诱导细胞凋亡有关.

Bacterial diseases are common opportunistic infections among HIV/AIDS patients. Skin and mucosa are the primary and predilection sites of infection. The incidence of bacterial infection significantly increased in HIV/AIDS patients, and sepsis is a common cause of death. In this chapter, the authors present many cases of bacterial infection in HIV/AIDS patients, including folliculitis, furuncle, carbuncle, erysipelas, acne, abscess, impetigo, cellulitis, mycobacteriosis, nontuberculous mycobacterium infection, and nocardiosis.

To investigate the value of modified calcaneal axial radiograph—the horizontal calcaneal axial radiograph in diagnosing calcaneal fractures, patients who had acute calcaneal fractures or internal fixation were enrolled, and three groups were established, including the acute fracture group (n = 20), the internal fixation group (n = 20), and the healthy control group (n = 20). All the subjects had regular and modified calcaneal axial radiograph for comparison. In analysis of the results, all volunteers could have ankle dorsiflexion at different degrees. When the ankle was at 30º dorsiflexion for regular axial radiograph, the subtalar joint and the sustentaculum tali could not be clearly displayed. The calcaneus was elongated if the tube tilted in a larger angle but shortened if the tube titled in a smaller angle. When the ankle was at neutral (0º dorsiflexion) location with the tube tilting 45° cephalad or when the ankle was at 20° plantarflexion with the tube tilting 35° cephalad, the subtalar joint, sustentaculum tali, calcaneal body and internal and external calcaneal processes could all be clearly demonstrated. No significant difference (P = 0.79) existed in displaying the bony anatomical structures in regular compared with modified calcaneal axial radiography. For patients with acute calcaneal factures or with internal fixation, the modified calcaneal axial radiography could display more significantly clearly (P = 0.001) bony anatomical structures than the regular one. In conclusion, the modified calcaneal axial radiograph can be performed easily and can clearly show the bony structure of the calcaneus and surrounding bones without adding pain to the patients with calcaneal fractures.

To explore the effect of bone morphogenetic protein 4(BMP4) on the cell cycle and apoptosis of hemaropoictic stem and progenitor cells (HSPC) in conditions of 5-fluorouracil (5-FU)-inducing bone marrow suppression and stress hemogenesis, and its possible mechanism.The C57BL transgenic mice with BMP4 overexpression were established and were enrolled in transgenic group (BMP4 group), at the same time the wild type mice matching in age, sex and body weight were selected and were enrolled in control group (WT group). The bone marrow suppression was induced by injection with 5-FU in dose of 150 mg/kg, then the nucleated cells were isolated from bone marrow. After the HSPCs were markered with C-kit/sca-1 fluorescent antibodies, the changes of cell cycle and apoptosis of HSPC were detected by Aunexin V/PI and Ki67/DAPI double staining; the cell cycle-essociated hemotopoietic regulatory factors were detected by RT-qPCR.Under physiologic status, there were no significant differences in cell cycle and apoptotic rate of HSPC between WT group and BMP-4 group. After the bone marrow was suppressed, the ratio of HSPC at G0 phase in BMP4 group significantly decreased(P＜0.05); the apoptosis rate of HSPC significantly increased(P＜0.05); the mRNA expression levels of hypoxia-inducing factor Hif-1α and chemotactic factor CXCL12 in stroma of BMP4 group were down-regulated significanfly(P＜0.05).Under non-physiologic conditions such as stress hemogenesis or bone marrow suppression, the up-regulation of BMP4 can promote HSPC into cell cycle and apoptosis of HSPC, moreover, the BMP4 may play a regulatory role for cell cycle of HSPC through direct or indirect down-regulation of Hif-1α and CXCL-12 expressions.化疗抑制下骨髓BMP4对造血干/祖细胞周期、凋亡的调控及其机制.探讨5-氟尿嘧啶（5-FU）诱导的骨髓抑制或应激造血条件下骨形态发生蛋白4（bone morphogenetic protein 4，BMP4）对造血干/祖细胞（HSPC）的周期、凋亡调控的作用及其相关机制.设计构建BMP4过表达的C57BL/6转基因小鼠（transgenec group），选取周龄、性别、体重相匹配的野生型（WT）雌鼠为对照组，各实验重复3次。5-FU以150 mg/kg的剂量诱导骨髓抑制模型，提取骨髓有核细胞。通过c-kit/Sca-1荧光抗体双标HSPC，分别用Annexin V/PI和Ki-67/DAPI双染法观察其凋亡和细胞周期的变化。RT-g-PCR检测周期相关的造血调控因子，探讨BMP4调控HSPC细胞周期的分子机制.生理状态下，野生型组和转基因组HSPC细胞周期和凋亡率无明显差异。骨髓抑制后，BMP4过表达小鼠骨髓中HSPC的G0期比例明显降低（P＜0.01），凋亡率明显上升（P＜0.05）。BMP4过表达小鼠骨髓基质中维持HSPC静息的低氧诱导因子Hif-1α和趋化因子CXCL12水平明显下调（P＜0.01）.在造血应激或骨髓抑制等非生理条件下，BMP4蛋白上调能促进HSPC进入细胞周期，促进其凋亡，且可能通过直接或间接下调Hif-1α和CXCL12表达来发挥对HSPC的周期调控功能.