Supportive role of the Na+ transporter CmHKT1;1 from Cucumis melo in transgenic Arabidopsis salt tolerance through improved K+/Na+ balance.

KEY MESSAGE: CmHKT1;1 selectively exports Na+ from plant cells. Upon NaCl stress, its expression increased in a salt-tolerant melon cultivar. Overexpression of CmHKT1;1 increased transgenic Arabidopsis salt tolerance through improved K+/Na+ balance. High-affinity K+ transporters (HKTs) are thought to be involved in reducing Na+ in plant shoots under salt stress and modulating salt tolerance, but their function in a moderately salt-tolerant species of melon (Cucumis melo L.) remains unclear. In this study, a Na+ transporter gene, CmHKT1;1 (GenBank accession number: MK986658), was isolated from melons based on genome data. The transcript of CmHKT1;1 was relatively more abundant in roots than in stems or leaves from melon seedlings. The tobacco transient expression system showed that CmHKT1;1 was plasma-membrane localized. Upon salt stress, CmHKT1;1 expression was more strongly upregulated in a salt-tolerant melon cultivar, 'Bingxuecui' (BXC) compared with a salt-sensitive cultivar, 'Yulu' (YL). Electrophysiological evidence demonstrated that CmHKT1;1 only transported Na+, rather than K+, when expressed in Xenopus laevis oocytes. Overexpression of CmHKT1;1 increased salt sensitivity in Saccharomyces cerevisiae and salt tolerance in Arabidopsis thaliana. Under NaCl treatments, transgenic Arabidopsis plants accumulated significantly lower concentrations of Na+ in shoots than wild type plants and showed a better K+/Na+ balance, leading to better Fv/Fm, root length, biomass, and enhanced plant growth. The CmHKT1;1 gene may serve as a useful candidate for improving crop salt tolerance.

Clinical and genetic characteristics of Chinese pediatric patients with chronic granulomatous disease.

BACKGROUND: Chronic granulomatous disease (CGD) is a rare disease in China, and very little large-scale studies have been conducted to date. We aimed to investigate the clinical and genetic features of CGD in Chinese pediatric patients. METHODS: Pediatric patients with CGD from Beijing Children's Hospital, Capital Medical University, China, were enrolled from January 2006 to December 2016. RESULTS: A total of 159 pediatric patients with CGD were enrolled. The median age of clinical onset was 1.4 months, and 73% (116/159) had clinical onset symptoms before the 1 year of age. The most common site of invasion was the lungs. The lymph nodes, liver, and skin were more frequently invaded in X-linked (XL) CGD patients than in autosomal recessive (AR) CGD patients (P < 0.05). Approximately 64% (92/144) of the pediatric patients suffered from abnormal response to BCG vaccination. The most frequent pathogens were Aspergillus and Mycobacterium tuberculosis. Gene analysis indicated that 132 cases (89%, 132/147) harbored CYBB pathogenic variants, 7 (5%, 7/147) carried CYBA pathogenic variants, 4 (3%, 4/147) had NCF1 pathogenic variants, and 4 (3%, 4/147) had NCF2 pathogenic variants. The overall mortality rate in this study was 43%, particularly the patients were males, with CYBB mutant and did not receive HSCT treatment. CONCLUSIONS: Chronic granulomatous disease is a rare disease affecting Chinese children; however, it is often diagnosed at a later age, and thus, the mortality rate is relatively high. The prevalence and the severity of disease in XL-CGD are higher than AR-CGD.

The epidemiology of paediatric Mycoplasma pneumoniae pneumonia in North China: 2006 to 2016.

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2-3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2-3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.

Clinical characteristics of disseminated cryptococcosis in previously healthy children in China.

BACKGROUND: Disseminated cryptococcosis is a rare and fatal disease, and limited data exist regarding it in children. This study aimed to investigate the clinical characteristics of disseminated cryptococcosis in previously healthy children in China. METHODS: Hospitalized patients with disseminated cryptococcosis were enrolled during January 1996 to December 2015 in Beijing Children's Hospital, Capital Medical University, China. Data on clinical manifestations, laboratory tests, treatment, and prognosis were evaluated. RESULTS: A total of 52 pediatric patients with no underlying disease were enrolled, including 38 boys and 14 girls. Only 10 cases had a history of exposure to pigeon droppings. Fever, cough, and hepatomegaly were 3 main manifestations of disseminated cryptococcosis. However, headache was more common in patients with central nervous system (CNS) invasion than in patients with non-CNS invasion (P < 0.05). Lung (96.2%, 50/52) was the most commonly invaded organ, but only 9.6% (5/52) of patients had respiratory signs. The most common findings on chest imaging were hilar or mediastinal lymphadenopathy (46.8%, 22/47), and nodules (44.7%, 21/47), including small nodules in a scattered distribution (57.1%, 12/21) or miliary distribution (42.9%, 9/25), especially localized in subpleural area. Subsequent invasion occurred in the CNS, abdomen lymph nodes, liver, spleen, peripheral lymph nodes, and skin. In all patients, 42.3% (22/52) and 51.9% (27/52) had elevated eosinophils or IgE, respectively. The positive rate of serum cryptococcal antigen was higher, especially in patients with CNS invasion (approximately 83.3%), than with other primary methods used for pathogen detection, including cerebrospinal fluid (CSF) cryptococcal antigen, cultures of blood, bone marrow, or CSF, and CSF ink staining. The overall mortality rate of pediatric patients in our study was 11.5% (6/52). Some cases had long-term sequela, including hydrocephalus, cirrhosis, or blindness. CONCLUSIONS: Disseminated cryptococcosis can occur in previously healthy or immunocompetent children in China. Lung and CNS were most commonly invaded by this disease. Furthermore, most cases usually showed no obvious or specific symptoms or signs, and therefore pediatricians should pay more careful attention to identify this disease.

[Updated molecular genetic mechanisms of globozoospermia].

Globozoospermia is a rare and serious teratozoospermia, which is one of the important causes contributing to human male infertility. The assisted reproductive technique remains the only means for such patients to produce offspring. However, the pathogenesis of globozoospermia is not yet clear. In recent years, related studies have shown that some genes are connected with the onset of globozoospermia. This paper outlines the progress in the studies of pathogenicity genes, aiming to contribute to the molecular diagnosis and mechanism investigation of the disease.

[Forensic analysis of 24 dismembered homicide cases in Shanghai].

OBJECTIVE: To explore the characteristics of the dismembered homicide cases in Shanghai and to provide the valuable guidance for forensic pathological practices. METHODS: Twenty-four cases of dismembered homicides were selected from 2005 to 2012 in Institute of Forensic Science, Shanghai Public Security Bureau. The general information of the victims and suspects, cause of death, criminal motive, postmortem body parts, tools and information of discarding body parts were retrospectively analyzed. RESULTS: Among the 24 dismembered homicide cases, victims were female in 16 cases, and suspects were male in 23 cases and were acquaintances in 22 cases. The main causes of death were mechanical asphyxia and traumatic brain injury. Most of the criminal motives were emotional disputes. The number of postmortem body parts was commonly from 20 to 30. The tools were mainly sharp instruments, including kitchen knives used in 20 cases. The postmortem body parts were discarded to different transregional areas, mainly using vehicles. CONCLUSION: The dismembered homicide cases in Shanghai show the following characteristics: the number of postmortem body parts is in large quantity; the methods of dismembered corpse are complex and different; the job characteristics of suspects are difficult to determine; the distance from homicide scene is far and the vehicles are commonly used.

Diagnosis, treatment, and prevention of monkeypox in children: an experts' consensus statement.

Monkeypox is a zoonotic disease. Since the first human monkeypox case was detected in 1970, it has been prevalent in some countries in central and western Africa. Since May 2022, monkeypox cases have been reported in more than 96 non-endemic countries and regions worldwide. As of September 14, 2022, there have been more than 58,200 human monkeypox cases, and there is community transmission. The cessation of smallpox vaccination in 1980, which had some cross-protection with monkeypox, resulted in a general lack of immunity to monkeypox, which caused global concern and vigilance. As of September 14, 2022, there are four monkeypox cases in China, including three in Taiwan province and one in Hong Kong city. Previous foreign studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications. In order to improve pediatricians' understanding of monkeypox and achieve early detection, early diagnosis, early treatment,  and early disposal, we have organized national authoritative experts in pediatric infection, respiratory, dermatology, critical care medicine, infectious diseases, and public health and others to formulate this expert consensus, on the basis of the latest "Clinical management and infection prevention and control for monkeypox" released by The World Health Organization, the "guidelines for diagnosis and treatment of monkeypox (version 2022)" issued by National Health Commission of the People's Republic of China and other relevant documents. During the development of this consensus, multidisciplinary experts have repeatedly demonstrated the etiology, epidemiology, transmission, clinical manifestations, laboratory examinations, diagnosis, differential diagnosis, treatment, discharge criteria, prevention, disposal process, and key points of prevention and control of suspected and confirmed cases.

[Distribution and Ecological Risk Assessment of Antibiotics in the Songhua River Basin of the Harbin Section and Ashe River].

Solid phase extraction (SPE) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) were used to detect and analyze the distribution of 10 antibiotics including sulfonamides, fluoroquinolones, and macrolides in the Harbin section of Songhua River basin and Ashe River, a tributary of Songhua River. The correlation between the antibiotic concentration and water quality indexes was analyzed and the ecological risks were evaluated. The results showed that only six antibiotics were detected in the entry section of Harbin city on the Songhua River and the concentration was relatively low. However, nine antibiotics were detected in the exit section and only sulfamethazine (SM1) was not detected. The concentrations of macrolide antibiotics increased most significantly, followed by those of sulfonamides and fluoroquinolones. The inflow of three tributaries in Harbin city was the direct cause of the increase in antibiotic concentration in the Songhua River. Only sulfapyridine (SMPD) was not detected in the upper section of Ashe River. Ten antibiotics were detected in the section where the Ashe River enters the Songhua River. The other nine antibiotics were the highest except norfloxacin (NOR). Wastewater discharged from four sewage treatment plants along Ashe River is an important factor affecting the concentration of antibiotics in the Ashe River. Correlation analysis shows that three kinds of antibiotics in the Songhua River have certain positive correlations with ammonia nitrogen, total phosphorus, and total organic carbon. There is a significant positive correlation between the three kinds of antibiotics and ammonia nitrogen and total phosphorus in the Ashe River system, indicating that the water quality indexes of the Harbin section of Songhua River and Ashe River are closely related to their antibiotic concentrations. The results of ecological risk assessment showed that macrolide antibiotics in the Harbin section of Songhua and Ashe Rivers had certain ecological risks.

A highly active heparinase I from Bacteroides cellulosilyticus: Cloning, high level expression, and molecular characterization.

As one of the most extensively studied glycosaminoglycan lyases, heparinase I has been used in producing low or ultra-low molecular weight heparin. Its' important applications are to neutralize the heparin in human blood and analyze heparin structure in the clinic. However, the low productivity and activity of the enzyme have greatly hindered its applications. In this study, a novel Hep-I from Bacteroides cellulosilyticus (BcHep-I) was successfully cloned and heterologously expressed in E. coli BL21 (DE3) as a soluble protein. The molecular mass and isoelectric point (pI) of the enzyme are 44.42 kDa and 9.02, respectively. And the characterization of BcHep-I after purified with Ni-NTA affinity chromatography suggested that it is a mesophilic enzyme. BcHep-I can be activated by 1 mM Ca2+, Mg2+, and Mn2+, while severely inhibited by Zn2+, Co2+, and EDTA. The specific activity of the enzyme was 738.3 U·mg-1 which is the highest activity ever reported. The Km and Vmax were calculated as 0.17 mg·mL-1 and 740.58 U·mg-1, respectively. Besides, the half-life of 300 min at 30°C showed BcHep-I has practical applications. Homology modeling and substrate docking revealed that Gln15, Lys74, Arg76, Lys104, Arg149, Gln208, Tyr336, Tyr342, and Lys338 were mainly involved in the substrate binding of Hep-I, and 11 hydrogen bonds were formed between heparin and the enzyme. These results indicated that BcHep-I with high activity has great potential applications in the industrial production of heparin, especially in the clinic to neutralize heparin.

Updated diagnosis, treatment and prevention of COVID-19 in children: experts' consensus statement (condensed version of the second edition).

In the early February, 2020, we called up an experts' committee with more than 30 Chinese experts from 11 national medical academic organizations to formulate the first edition of consensus statement on diagnosis, treatment and prevention of coronavirus disease 2019 (COVID-19) in children, which has been published in this journal. With accumulated experiences in the diagnosis and treatment of COVID-19 in children, we have updated the consensus statement and released the second edition recently. The current version in English is a condensed version of the second edition of consensus statement on diagnosis, treatment and prevention of COVID-19 in children. In the current version, diagnosis and treatement criteria have been optimized, and early identification of severe and critical cases is highlighted. The early warning indicators for severe pediatric cases have been summarized which is utmost important for clinical practice. This version of experts consensus will be valuable for better prevention, diagnosis and treatment of COVID-19 in children worldwide.

Artemisinin enhances the anti-tumor immune response in 4T1 breast cancer cells in vitro and in vivo.

BACKGROUND: Breast cancer is a prominent cause of death among women worldwide. Recent studies have demonstrated that artemisinin (ART) displays anti-tumor activity. Using a mouse breast cancer model, we investigated the effects of ART in vitro and in vivo to determine how it influences the anti-tumor immune response. METHODS: We measured the proliferation and apoptosis of 4T1 cells in vitro after ART treatment by MTT assay and FACS. To examine the effects of ART in vivo, tumor volumes and survival rates were measured in 4T1 tumor-bearing mice. FACS was used to determine the frequencies of Tregs, MDSCs, CD4+ IFN-γ+ T cells, and CTLs in the tumors and spleens of the mice. mRNA levels of the transcription factors T-bet and FOXP3 and cytokines IFN-γ, TNF-α, TGF-ß, and IL-10 were also determined by real-time RT-PCR. ELISA was used to measure TGF-ß protein levels in the cell culture supernatants. RESULTS: ART supplementation significantly increased 4T1 cell apoptosis and decreased TGF-ß levels in vitro. ART also impeded tumor growth in 4T1 TB mice and extended their survival. MDSC and Treg frequencies significantly decreased in the 4T1 TB mice after ART treatment while CD4+ IFN-γ+ T cells and CTLs significantly increased. ART significantly increased T-bet, IFN-γ, and TNF-α mRNA levels within the tumor and significantly decreased TGF-ß mRNA levels. CONCLUSION: ART supplementation hindered 4T1 tumor growth in vivo by promoting T cell activation and quelling immunosuppression from Tregs and MDSCs in the tumor.

[Comparative proteomic analysis of human large cell lung cancer cell line with high and low metastasis potentials].

OBJECTIVE: A comparative proteomic analysis on two human large cell lung cancer strains with high metastasis potential (L9981) and low metastasis potential (NL9980) were conducted. METHODS: The total proteins of the two cell lines were separated by immobilized pH gradient (IPG )-based two-dimensional gel electrophoresis. The differential expression proteins of the two cell lines were analyzed using image analysis software. Thirteen differential expressed proteins were further identified using in-gel digestion with trypsin, of which peptide extracts were prepared for MALDI-TOF MS/MS analysis by Daltonics AutoFlex TOF-TOF LIFT Mass Spectrometer (Bruker). Protein identifications were searched in the NCBInr protein database using the Mascot search engine. RESULTS: Protein image analysis indicated that 8 protein spots were observed only in L9981, not in NL9980; 8 protein spots were observed only in NL9980, not in L9981; 19 protein spots were detected in both L9981 and NL9980, of which 9 showed significantly higher volumes in L9981 than in NL9980 and 10 showed significantly higher volumes in NL9980 than in L9981. MS and biological informatics study found that the expressions of heat shock 70 kD protein 9B precursor, MTHSP75 and glutathione synthetas incerased in L9981 cells. However, a variant of P47 protein, immunoglobulin heavy chain variable region, enolasel, heat shock protein and eukaryotic translation initiation fact 3 were down-regulated in L9981 cells. Pyruvate kinase (PK) was only expressed in L9981 cells while WD-40 repeat protein was only expressed in NL9980 cells. CONCLUSIONS: The metastatic lung cancer cell lines display different protein profiles compared to the non metastatic lung cancer cell lines. The identified proteins are likely to be associated with tumor metastasis, 4hich could serve as a basis for searching potential prognosis markers of lung cancer and elucidating the mechanisms of the metastasis of lung cancer.

Comprehensive bioinformatics analysis identifies several potential diagnostic markers and potential roles of cyclin family members in lung adenocarcinoma.

PURPOSE: The aim of this study was to identify critical genes in lung cancer progression. METHODS: We downloaded and reanalyzed gene expression profiles from different public data-sets using comprehensive bioinformatics analysis. Differentially expressed genes (DEGs) were identified in lung adenocarcinoma tissues compared with adjacent nonmalignant lung tissues. The overlapping DEGs identified from different datasets were used for functional and pathway enrichment analyses and protein-protein interaction (PPI) analysis. Moreover, transcription factors (TFs) and miRNAs that regulated the overlapping DEGs were predicted, followed by a TF-miRNA-target network construction. Furthermore, survival analysis of genes was performed. Several genes were further validated by quantitative real-time PCR (qRT-PCR). RESULTS: A total of 647 overlapping upregulated genes and 979 overlapping downregulated genes were identified. The overlapping upregulated genes and downregulated genes were involved in different functions, such as cell cycle, p53 signaling pathway, immune response, and cell adhesion molecules (CAMs). Several genes belonging to the cyclin family, including CCNB1, CCNB2, and CCNA2, were hubs of the PPI network and TF-miRNA-target network. Additionally, genes, including NPAS2, GNG7, CHIA, and SLC2A1, were predicted to be prognosis-related DEGs. Gene expression profiles determined by bioinformatics analysis and qRT-PCR were highly comparable. CONCLUSION: CCNB1, CCNB2, CCNA2, NPAS2, GNG7, CHIA, and SLC2A1 are promising targets for the clinical diagnosis and therapy of lung adenocarcinoma.

Genome-wide analysis of auxin transport genes identifies the hormone responsive patterns associated with leafy head formation in Chinese cabbage.

Auxin resistant 1/like aux1 (AUX/LAX), pin-formed (PIN) and ATP binding cassette subfamily B (ABCB/MDR/PGP) are three families of auxin transport genes. The development-related functions of the influx and efflux carriers have been well studied and characterized in model plants. However, there is scant information regarding the functions of auxin genes in Chinese cabbage and the responses of exogenous polar auxin transport inhibitors (PATIs). We conducted a whole-genome annotation and a bioinformatics analysis of BrAUX/LAX, BrPIN, and BrPGP genes in Chinese cabbage. By analyzing the expression patterns at several developmental stages in the formation of heading leaves, we found that most auxin-associate genes were expressed throughout the entire process of leafy head formation, suggesting that these genes played important roles in the development of heads. UPLC was used to detect the distinct and uneven distribution of auxin in various segments of the leafy head and in response to PATI treatment, indicated that the formation of the leafy head depends on polar auxin transport and the uneven distribution of auxin in leaves. This study provides new insight into auxin polar transporters and the possible roles of the BrLAX, BrPIN and BrPGP genes in leafy head formation in Chinese cabbage.

Transcriptomic and proteomic analyses provide new insights into the regulation mechanism of low-temperature-induced leafy head formation in Chinese cabbage.

UNLABELLED: In Chinese cabbage, leafy head-related traits are directly related to the cabbage yield and marketability, which are often primarily concerned target for breeders. Although intensive studies has been on head formation in Chinese cabbage in the past decade, very scanty information is available on mechanism involved in the head formation under the influence of low temperature at transcriptome and proteome perspective. In this study, quantitative expression profiling based on RNA-Seq transcriptome and iTRAQ proteome were combined to investigate this trait for a global picture of the molecular dynamics. Total of 2931 transcripts and 365 proteins were identified with significantly changed level in abundance from heading and non-heading Chinese cabbage. Related analyses including function annotations, hierarchical categories, as well as the correlation from transcript-to-proteins were performed. The results indicated that the leafy head formation of Chinese cabbage has involved a complex regulatory pattern. The correlated genes that were mapped to the pathway of plant hormone signal transduction suggested that the head formation might be an integrated result of various plant hormones. Our combined analysis will provide a comprehensive approach to understanding the regulation mechanism of leafy head formation in Chinese cabbage. BIOLOGICAL SIGNIFICANCE: This study revealed the direct relation of leafy-heading traits with the yield of the plant. A comprehensive investigation was done by integrating quantitative expression profiling analysis of transcriptome and proteomic to provide crucial information for further research on the molecular mechanism involved in head formation in Chinese cabbage. The correlation of transcript-to-protein in abundance may afford some necessary information of involvement of post-transcriptional factors influencing leafy head formation in Chinese cabbage.

[Characteristic of nuclear antigen 1 gene and latent membrane protein 1 gene of Epstein-Barr virus in primary EBV infection in children in Beijing area in 2005-2010].

OBJECTIVE: To analyze the characteristic of nuclear antigen 1 gene and latent membrane protein 1 gene of Epstein-Barr virus in primary EBV infection in children in Beijing area in 2005-2012. METHODS: Polymerase chain reaction (PCR) was used to amplify the EBNA-3C, EBNA1 and LMP1 genes. The amplified products were sequenced directly and the sequences were analyzed by BioEdit 7. 0. 9 and MEGA 4. 0. 2. RESULTS: Type A EBV was detected in 98% samples. Nucleotide sequence analysis of the carboxy-terminal region of EBNA1 showed that Vvvl was deteted in 98% samples. DNA sequence analysis of LMP1 C-terminus indicated that China 1 was 90% in this study. There were no significant differences in the frequency of Vvv1 and China 1 between the IM and HLH samples (P = 1.00). Linkage analysis of EBV types, EBNA1 and LMP1 variants indicated that 90% of EBV type A was associated with EBNA1-Vvv1 variant and LMP1-China 1 variant in 40 cases. Full length of LMP1 gene was successfully amplified in 35 cases. Four Chinese groups (CG1-4) were identified. The percentage of CG1-CG4 were 85%, 6%, 6% and 3%, respectively. CONCLUSION: EBV type A is predominant in primary EBV infection in children in Beijing Area. EBNA1-Vvv1 and LMP1-China 1 variants were predominant genotypes in this area. There is a high linkage between EBNA1-Vvv1 variant and LMP1-China 1 variant. Four Chinese groups (CG1-4) were identified according to the full length of LMP1 gene and CG1 was the most prevalent.

[Cardioprotective effects of limb ischemic postconditioning by different strength and time in rabbits].

OBJECTIVE: In this study, we try to find the better protocol of limb ischemia postconditioning by observing different protective effects of limb ischemic postconditioning (different strength and time windows in rabbits). METHODS: 42 healthy New Zealand rabbits were randomly divided into 7 groups (n = 6): Sham; Control (CON); Skeletal muscle postconditioning (SP); 6 min-delayed skeletal muscle postconditioning (6M-DSP); 1 min-delayed skeletal muscle postconditioning (1M-DSP); Strengthen skeletal muscle postconditioning (SSP); Weakened skeletal muscle postconditioning (WSP). Acute ischemia/reperfusion (I/R) model was induced by 45 minutes occlusion on left circumflex coronary artery (LCX) and 2 hours reperfusion in all anesthetized open-chest rabbits except the Sham. Limb ischemia was induced by external iliac arteries occlusion and reperfusion through artery clamps. The extent of myocardial infarction was assessed by triphenyltetrazolium (TTC) staining. Blood serum creatine kinase (CK) activity and lactate dehydrogenase (LDH) activity were measured at baseline,the end of ischemia, after 1 hour and 2 hours of reperfusion respectively. RESULTS: Compared with the CON, the weight ratio and area ratio of myocardial infarction size were significantly decreased by 49.97% and 43.78% in SP, by 42.32% and 42.68% in 1M-DSP, by 48.36% and 48.86% in SSP (P < 0.05). But there was no significant difference between SP and 1M-DSP and SSP (P > 0.05). Otherwise, compared with the CON, myocardial infarct size was not significantly reduced in 6M-DSP or WSP (P > 0.05). The change of CK was similar to the trend of myocardial infarct size. CONCLUSION: The limb ischemia strength of 5 mini/1 minR x 1 cycle could significantly reduce the myocardial ischemia/ reperfusion injury in rabbits, if it was achieved before myocardial reperfusion.