Biomedical subjects
Publications and source records attributed to Xin Li.
Two new gamma-pyranone derivatives and a new triterpene, together with eight known compounds, were isolated from the aerial parts of Erigeron annuus. Their structures were elucidated by spectroscopic methods. Besides, the anti-tumor activities of the gamma-pyranone derivatives to human hepatoma (SMMC-7721), human embryo liver (L-02) and human leukemia (HL-60) cells were evaluated.
Under constant light, increases in V(t) (total respiration rate), V(alt) (capacity of alternative pathway), and V(alt)/V(t) ration values (Figs.1-3) in fully etiolated rice seedlings leaves were founded. Northern hybridization with special probes for rice AOX1a, AOX1b and AOX1c revealed that the AOX1c mRNA was mainly present under constant light (Fig.4). SHAM (salicylhydroxamic acid) decreased the relative oxygen evolution rate and chlorophyll content during the rapid greening of the etiolated rice seedlings (Figs.6, 7). We found that illumination caused bigger increase in V(alt) in fully etiolated rice seedlings than in any partially etiolated rice seedlings (Fig.8A), while the soluble sugar contents did not show any significant differences (Fig.8B). This revealed the connection between greening process and cyanide-resistant respiration in rice seedlings. We infer that one of the possible functions of the cyanide-resistant respiration is to maintain a high rate of respiratory electron transport for the essential biosynthesis processes at the early stage of chloroplast development. Cyanide-resistant respiration may provide a regulatory mechanism for the balance between the requirements of the energy and substances.
OBJECTIVE: To observe the preventive and therapeutic effect of tanshinone (TA) on artery restenosis in the rat carotid injury model and explor the mechanism. METHOD: Male SD rats were randomly divided into model control group, and low dose, moderate dose and high dose TA groups. Each group had 10 rats. The rats in the high, moderate and low dose groups were respectively fed with TA 120, 40,13.3 mg x kg(-1) x d(-1) by gast rogavage; the rats in the model control group were fed with the same volume solvent. Two days later, the rat's right carotid artery was injuried by balloon dilatation to induce intimal thickening for establishing the restenosis model. After 2 weeks of treatment, the artery was harvested and stained by hematoxylin-elsin (HE) and immunohistochemistry of PCNA, NF-kappaB and iNOS. The morphological changes were checked under microscope. The area of the intimal and medial layer of the vessels, and their ratios were analyzed with image analysis software. The expression level of PCNA, NF-kappaB and iNOS were used as the positive index. RESULT: The intimal area and intima-to-media ratio of the injuried artery increased obviously, suggesting the model was successful. Compared with the model group, TA significantly decreased the intimal area and intima-to-media ratio (P < 0.05), and also decreased the positive index of PCNA and the positive ratio of NF-kappaB and iNOS (P < 0.05). CONCLUSION: TA can effectively inhibit intimal thickening and inflammation. This result suggestes that TA may play a positive role in the prevention of restenosis after PTCA.
OBJECTIVE: To explore the impact of Foxp3 expression and CD(4)(+)CD(25)(+) regulatory T cells on pathogenesis of childhood asthma. METHODS: Totally 15 patients with acute asthma exacerbation, 15 children with asthma remission and 10 children who were hospitalized for skeleton deformity without atopic disorders or history of allergic diseases or respiratory infections within a month as controls were recruited in this study from Sep. 2004 to Mar. 2005. The percentage of CD(4)(+)CD(25)(+) T cells were detected by 2-color flow cytometry. The levels of interleukin (IL)-4, IL-10, interferon (IFN)-gamma, transforming growth factor (TGF)-beta in plasma and supernatant were assayed by ELISA. Both the asthmatic children and the control children were selected to induce sputum by hypertonic saline. Sputum was processed for detecting the expression of Foxp3-mRNA. The expression of Foxp3-mRNA in both sputum and PBMC was detected by semi-quantitative RT-PCR with beta-actin as internal control. RESULTS: The percentage of CD(4)(+)CD(25)(+) regulatory T cells in exacerbation and remission asthmatic children was significantly lower than that of the control children both prestimulation [(10.1 +/- 2.1)% vs. (15.5 +/- 2.7)%, (11.7 +/- 2.5)% vs. (15.5 +/- 2.7)%, P < 0.05] and poststimulation with PHA [(12.4 +/- 2.3)% vs. (26.9 +/- 3.8)%, (17.3 +/- 3.2)% vs. (26.9 +/- 3.8)%, P < 0.05]. The percentage of CD(4)(+)CD(25)(+) regulatory T cells was significantly higher after PHA stimulation in normal children [(15.5 +/- 2.7)% vs. (26.9 +/- 3.8)%, P < 0.01]. The expression of Foxp3-mRNA (Foxp3/beta-actin) in asthmatic children was significantly lower than that in the control children in both PBMC and induced sputum. The expression of Foxp3-mRNA in PBMC was significantly higher after PHA stimulation in the control children (0.77 +/- 0.22 vs. 1.07 +/- 0.21, P < 0.05). However, there was no significant difference in Foxp3-mRNA expression in asthmatic children pre and post PHA stimulation. A significant positive correlation between the Foxp3-mRNA expression and the percentage of CD(4)(+)CD(25)(+) regulatory T cells was detected. The levels of IFN-gamma and TGF-beta were significantly lower in asthmatic children than those in the control children, and the levels of IFN-gamma and TGF-beta correlated positively with Foxp3-mRNA expression and the percentage of CD(4)(+)CD(25)(+) regulatory T cells. The level of IL-4 both in plasma and supernatant was higher in asthmatic children. The levels of IL-10 was higher only in exacerbation than in control children, the levels of IL-4 and IL-10 had no correlation with Foxp3-mRNA expression and the percentage of CD(4)(+)CD(25)(+) regulatory T cells. CONCLUSION: Insufficient secretion of TGF-beta, decreased Foxp3 expression, insufficient number of CD(4)(+)CD(25)(+) regulatory T cells and the defective ability of converting CD(4)(+)CD(25)(-) T cells to CD(4)(+)CD(25)(+) regulatory T cells might play an important role in pathogenesis of asthma.
This study was aimed to investigate various factors influencing long-term survival in patients with acute promyelocytic leukemia. A single institutional retrospective study with long-term follow-up was performed to better define the prognostic factors and a rationale for the use of ATRA, chemotherapy, and As(2)O(3) in the treatment of newly diagnosed APL patients. Newly diagnosed patients with APL entering complete remission (CR) were followed up for 6 to 185 months (n = 170) from January 1990 to December 2004. Univariate and multivariate analysis of 8 potential factors influencing survival and prognosis were carried out with Log-Rank and Cox regression method, including sex, age, initial WBC count, the level of lactic hydrogenase (LDH), first induction regimen, time from induction therapy to CR, post-remission therapy, negative or positive rate of PML-RAR alpha and follow-up of reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the estimated 5-year overall survival (OS) and relapse-free survival (RFS) were 80.9% +/- 4.0% and 71.0% +/- 4.0% respectively. The 23 patients relapsed at the median time of 15 months (6 - 70) after CR. Univariate analysis revealed that initial WBC count, first induction regimen, time from induction therapy to CR, type of post-remission therapy and persistent negative RT-PCR in remission were important prognostic factors for long-term survival. Multivariate study demonstrated that only type of post-remission therapy was associated with RFS and OS. It is concluded that the post-remission treatment combining ATRA, As(2)O(3) and chemotherapy would significantly improve the long-term survival of APL patients entering CR(1).
OBJECTIVE: To investigate the effect of baicalin (Bai) on lung injury, the level of TNF-alpha in cultured liquid of pulmonary interstitial macrophage and the expression of heme oxygenase-1 (HO-1) in lung injury associated with paraquat poisoning. METHODS: Rats were randomizedly divided into four groups: control group, PQ group, Bai group (Bai, 300 mg.kg(-1).d(-1)) and simple Bai group (Bai, 300 mg. kg(-1).d(-1)) (n = 10 in each group). The 2% PQ was injected (25 mg/kg) in PQ group. Bai was injected in the rats (300 mg.kg(-1).d(-1) x 3 d) through caudal vein after paraquat poisoning in Bai group. In simple Bai group, Bai was injected in the healthy rats (300 mg.kg(-1).d(-1) x 3 d). The samples were obtained three days after intraperitoneal administration of 2% paraquat (25 mg/kg). The injury of lung was estimated with HE dyeing and electron microscope. Pulmonary interstitial macrophage (PIM) were obtained, and then cultured for 24 hours. The content of TNF-alpha was evaluated. The expression of HO-1 mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). The expression of HO-1 protein was evaluated by Western blot analysis. RESULTS: The lung tissue was normal in control group and simple Bai group. The degree of lung injury in PQ group was higher than that in control group by HE dyeing and electron microscope observation. The level of TNF-alpha expression in cultured PIM in Bai group [(484.2 +/- 39.5) microg/L] was lower than that in PQ group [(790.2 +/- 35.0) microg/L], but higher than that in the control group [(121.6 +/- 19.2) microg/L] (P < 0.05). The expression of HO-1 mRNA and protein [(59.8 +/- 5.40) and (122.0 +/- 31.98)] in Bai group were higher than those in PQ group [(45.9 +/- 5.82) and (77.92 +/- 10.23)] (P < 0.05). CONCLUSION: The lung injury associated with paraquat poisoning was alleviated by baicalin, which was possibly related to the decrease of level of TNF-alpha in cultured PIM and the increase of the expression of HO-1 mRNA and protein.
OBJECTIVE: To evaluate the effect and safety of transrectal 137Cs gamma-ray therapy for benign prostatic hyperplasia. METHODS: Thirty cases of BPH were treated by transrectal 137Cs gamma-rays. RESULTS: After 6 months there was significant improvement in the maximum urine flow, IPSS and QOL (P < 0.05). But no significant changes were observed in the prostate volume and residual urine (P > 0.05). CONCLUSION: Transrectal 137Cs gamma-ray therapy is safe and effective in the treatment of BPH.
In this paper, a comparative study was made on the growth, morphology, biomass allocation, and photosynthesis of two invasive plant species Ageratina adenophora and Chromolaena odorata under five soil phosphorus levels, aimed to know how the test plant species acclimate to the changes of soil phosphorus level, evaluate which plant traits were associated with the invasiveness of the two species, and know whether the increased level of soil phosphorus could facilitate their invasion. The results showed that the two species had considerable phenotypic plasticity and ? phosphorus acclimation ability. At low phosphorus levels, their root mass ratio increased, which could enhance the nutrient capture ability, while at high phosphorus levels, their specific leaf area, maximum net photosynthetic rate, light saturation point, and chlorophyll and carotenoid contents per unit area were high, and the assimilative capacity and area increased, which could facilitate their carbon gain. A. adenophora had higher phosphorus acclimation ability than C. odorata. With the increase of phosphorous level, the relative growth rate, total biomass, branch number, leaf area index, and maximum net photosynthetic rate of the two species increased significantly, and most of the parameters were not decreased significantly under over-optimal phosphorus level. The two species could grow better under high phosphorus levels which were usually excessive and/or harmful for most native species, and enhanced soil phosphorus level might promote their invasion. At high phosphorus levels, the two invasive plant species might shade out native species through increasing their plant height, branch number, and leaf area index. The two species could maintain relatively high growth rate under high phosphorus levels in dry season when native plant species almost stopped growing. The ability that the invasive plant species could temporally use natural resources which native plant species could not use was also associated with their invasiveness.
EDTA was used as extractant to leach Pb, Zn, Cu and Cd from tailing soils in soil columns. The redistributions of Pb, Zn, Cu and Cd were determined using the sequential extraction procedure of the optimized European Community Bureau of Reference (BCR) before and after extraction. The results indicated that EDTA was an effective extracting agent because of its strong chelating ability for different heavy metals. Percentage extractabilities of metal followed the sequence of Cd>Zn>Cu>Pb. The four fractions of metal could be extracted by EDTA and the proportions of Pb, Zn, Cu and Cd in the four fractions varied largely after EDTA extraction. The extraction efficiency of EDTA on the acid-extractable fraction was significant in shallow soil column, while in deeper soil column, a descent of the extraction efficiency on reduced, oxidizable and residual fractions was obtained. And heavy metals chelated by EDTA were more easily desorption by soil particles with the depth of the soil columns increased.
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OBJECTIVE: To investigate the probability of improving radical surgery to resect uterus thoroughly and to decrease various complications after the surgery. METHODS: We compared the clinical effect of reformed radical hysterectomy for 79 patients with the effect of tradition radical hysterectomy for 60 patients. Reformed surgery had the following features: We firstly resected the uterus and then dissected the pelvic lymph node. Urinary bladder gap and rectum gap were opened. After exposing the route of ureter, we excised the uterus artery at the point between the ureter and the uterus artery. Cardinal ligament and uterosacral ligament were cut off by electric knives. The pelvic lymph node was dissected with a titanium pinch. RESULTS: The average operation time and the time of keeping uterine pipe were shortened. Bleeding during the operation was reduced. No complication was observed. All patients were followed up for 11 to 20 months and no patient died. One patient recurred. CONCLUSION: Reformed surgery can resect the uterus, dissect the pelvic lymph node thoroughly, and reduce various complications. The reformed surgery can not only ensure the curative effect, but also benefit patient's recovery and life quality.
OBJECTIVE: To study the effect on anti-respiratory syncytial virus of an active compound GD4 from Glycyrrhiza in vitro. METHODS: GD4 was extracted from Glycyrrhiza by hot water extraction, dichloromethane extraction and column chromatography. The CPE inhibition assay was used to test the antiviral activity of GD4 on RSV in Hela cells. RESULTS: GD4 was effective antiviral agent for RSV in a concentration-dependent manner and its median toxic concentration (TC50) and median effeicacious concentration (EC50) and treatment index (TI) was 0.23 mg/ml, 28.73 microg/ml and 8.0. 120 microg/ml GD4 exhibited inhibitory effect when added into cell culture for every 2h within 12h post-infection. GD4 didn't contain glycyrrhizic acid. CONCLUSION: The active compound of Glycyrrhiza (GD4) was an evident inhibitory effect on RSV.
OBJECTIVE: To induce hematopoietic progenitor/stem cells of umbilical cord blood to differentiate into mature megakaryocytes and platelets in vitro and to investigate the mechanism of production of platelets. METHODS: The CD34+ cells were sorted from umbilical cord blood by magnetic activated cell sorting (MACS) and then cultured in vitro with optimized medium to be differentiated into mature megakaryocytes and platelets. The cultured cells and the platelet-like particles were isolated from the culture and were checked by the fluorescence-activated cell sorter (FACS), immunohistochemistry assays, light microscope,electron microscope and platelet aggregation tests. RESULTS: The cultured megakaryocytes were detected with proplatelets and both the cultured cells and the platelet-sized particles were found to have the same structure with the normal megakaryocytes and platelets by light and electron microscope. The immunohistochemistry assays revealed the cultured cells expressed GP II b III a with a positivity of 95% which was a special antigen for platelets and megakaryocytes. Culture-derived platelet-sized particles aggregated in response to thrombin as the plasma derived-platelets did. The cultured platelets had the same positivity of CD41 as the platelets from platelet rich plasma. CONCLUSION: The hematopoietic progenitor/stem cells can be induced to differentiate into purified and mature megakaryocytes and platelets. It provides a practical way to study the mechanism of platelets production.
OBJECTIVE: To evaluate the effects of sodium arsenite on the activity, the mRNA and the protein expression of CAT in human keratinocyte cell line (HaCaT). METHODS: The activity of catalase (CAT) was detected by ultraviolet direct velocity assay. RT-PCR was used to detect the mRNA expression of CAT and Western blotting was conducted to detect the protein expression of CAT. RESULTS: If the cells were treated with higher than 5.0 micromol/L sodium arsenite, the activity, mRNA and protein expression of CAT were decreased significantly and in a dosage dependent fashion (P < 0.05). CONCLUSION: CAT is inhibited by sodium arsenite in the transcription, translation and activity levels.
OBJECTIVE: To Summarize and compare the effects of the different post-remission treatment on long-term survival in acute promyelocytic leukemia (APL) patients. METHODS: The long-term survival and relapse of 111 APL patients with different post-remission treatment were retrospectively analyzed. The patients were divided into four groups. Group 1: All-trans-retinoic acid (ATRA) + As(2)O(3) + chemotherapy; Group 2: ATRA + chemotherapy; Group 3: As(2)O(3) + chemotherapy; Group 4: chemotherapy alone. The median follow-up time was 32 (6 - 185) months. RESULTS: A total of 85 patients survived without diseases, 18 patients died and 8 patients dropped out. In the four groups, the patients survived without disease were (36/40, 23/30, 21/26, 5/15), respectively. The cases of patients survived over 3 years were (16/40, 12/30, 11/26, 1/15), respectively. The patients died were (3/40, 5/30, 5/26, 5/15), respectively. The estimated 5-year overall survival (OS) and relapse-free survival (RFS) were (78.3 +/- 4.9)%, (76.9 +/- 5.1)%, respectively. There were 21 patients relapsed. CONCLUSION: The APL patients receiving combined post-remission therapy had better OS and RFS those receiving chemotherapy alone. Sequential therapy combining ATRA, As(2)O(3) and chemotherapy is the best post-remission therapy for long-term survival of APL patients.
Chronic arsenicosis is a newly-emerged public-health issue in China and many other Asian countries. Over 200 million people are estimated to be at the risk of high arsenic exposure from drinking-water in the Asian region. To protect people from the hazards of chronic arsenic poisoning, the Chinese Government has been providing low-arsenic drinking-water to some seriously-affected rural areas, such as Inner Mongolia autonomous province. Results of follow-up studies showed that both the average values of arsenic, including inorganic arsenic (iAs), monomethylated arsenic, dimethylated arsenic and trimethylated arsenic, and 8-hydroxydeoxyguanine in urine, decreased significantly after drinking low-arsenic water for one year, and arsenic-specific skin lesions also improved to some extent. However, a five-year follow-up study showed no more significant improvement of skin lesions, while the potential risk of arsenic-induced cancers after cutting off high-arsenic exposure was still uncertain and indefinite. The susceptibility of children compared to adults to chronic arsenic exposure and the need to re-evaluate the appropriate standard of arsenic in drinking-water were also discussed in this paper.
OBJECTIVE: To investigate the clinical presentation, hormonal profile and metabolic abnormalities in subgroups of women with PCOS and explore a reasonable classification for PCOS. METHODS: A cross-sectional study of 192 women with PCOS (14 - 38 years of age) was performed. The patients were divided into 3 groups of A, B and C according to the revised 2003 consensus on diagnostic criteria and also divided into 2 groups according to body mass index (BMI): group A (n = 110), long term anovulation, clinical and biochemical evidence of high androgen level, ovary enlargement with its size larger than 10 ml or number of small follicles of 2 - 9 mm >or= 12 under ultrasound with exclusion of other diseases caused by high androgen; group B (n = 46), long term anovulation, clinical and biochemical evidence of high androgen level; group C (n = 36), long term anovulation, ovary enlargement with its size larger than 10 ml or number of small follicles of 2 - 9 mm >or= 12 under ultrasound with exclusion of other disease caused by high androgen; obesity PCOS group (OB-PCOS, n = 70), BMI >or= 25 (kg/m(2)); no obesity PCOS group (NOB-PCOS, n = 122), BMI < 25 (kg/m(2)). One hundred and four women with bilateral tubal block factor caused infertility served as control group. Anthropometric measurements, Ferriman Gallwey hirsutism scoring, presence of acne and acanthosis nigricans were noted. Hormonal profile was assessed by measuring follicle-stimulating hormone (FSH), luteinizing hormone (LH), free testosterone (FT), prolactin (PRL), sex hormone binding globulin (SHBG). The metabolic profile was investigated by measurements of oral glucose tolerance test (OGTT), serum lipid levels, including total cholesterol (Chol), triglycerides (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL). Hyperinsulinemia was estimated by measurement of fasting insulin (FINS) and insulin area under the curve (IAUC). The extent of insulin resistance (IR) and hyperandrogenism was estimated by homeostasis model assessment (HOMA) and free androgen index (FAI) respectively. RESULTS: (1) Clinical phenotypes: the presence of obesity was 36.4% (70/192), among which 80.0% (56/70) were central obesity. Higher rates of acanthosis nigricans were observed in OB-PCOS group (35.7%, 25/70) compared with NOB-PCOS group (7.4%, 9/122; P < 0.01). Waist to hip ratio (WHR) was lower in group C than those in groups A and B (P < 0.05). (2) Endocrinology: FAI level was higher in OB-PCOS group than in NOB-PCOS group (P < 0.01), whereas LH/FSH ratio was lower in OB-PCOS group compared with NOB-PCOS group (P < 0.01). FAI level was higher in groups A and B than in group C (P < 0.01). SHBG, LH/FSH ratio did not differ between groups A, B, and C. (3) Metabolism: the prevalence of IR was 43.2% (83/192). A higher prevalence was observed in group OB-PCOS (82.8%, 58/70) compared with group NOB-PCOS (20.5%, 25/122; P < 0.01). FINS, HOMA-IR, glucose area under the curve (GAUC), IAUC and TG were higher in group OB-PCOS than in group NOB-PCOS (P < 0.01), whereas HOMA-IR, lipid profile did not differ between groups A, B, and C. CONCLUSION: The classification according to the revised 2003 consensus on diagnosis reflects the basic characteristics of PCOS; while the classification based on obesity shows the severity of hyperandrogenism and degree of IR, and thus has substantial significance for evaluation of metabolic complications.
The study was purposed to explore the role of mesenchymal stem cells (MSCs) in the pathogenesis of bone disease particularly observed in multiple myeloma (MM), the biological features of marrow derived MSCs from patients with MM have been investigated. Marrow aspirates were harvested from 11 newly diagnosed patients with MM and 5 normal adults and MSCs were isolated and culture-expanded by the cell properties of adherence to plastic flasks, The phenotype was analyzed by flow cytometric technique. The proliferation of MSCs was observed by MTT assay and their differentiation capacities into osteoblasts and adipoblasts were assessed with lineage-specific histochemical staining. The concentrations of IL-6 and SCF in the culture supernatant were detected by enzyme-linked immunosorbent assay (ELISA). MSC culture supernatants were collected and MTT assay was performed to evaluate their support on the proliferation of an MM cell line SKO007 cells. The results showed that bone marrow-derived MSCs from MM patients were homogeneously positive for CD29, CD73, CD166 and HLA-ABC and negative for hematopoietic cell marker CD45 and endothelial cell marker CD31, the phenotype of which was similar to that of marrow counterparts from normal adults. MTT assay indicated that MSCs from MM patients or normal adults proliferated at similar rates. MSCs from MM patients occupied in vitro osteogenic and adipogenic capacity as those from normal adults. The levels of IL-6 and SCF in culture supernatant were greatly up-regulated in MM patients by ELISA assay. Furthermore, MSC culture supernatants from MM bone marrow displayed enhanced activity to promote the proliferation of SKO007 cells. It is concluded that marrow-derived MSCs from bone marrow of MM patients are normal in their proliferation and differentiation capacities, and myeloma bone disease may not be ascribed to the differentiation of MSCs while the elevated secretion of IL-6 and SCF may provide necessary cues for the survival of malignant myeloma cells.