Hepatoprotective effect of a curcumin/absinthium compound in experimental severe liver injury

OBJECTIVE: A preliminary in vitro study with hepatocyte culture showed that concentrations as low as 10 µg/mL of PN‐M001 are able to significantly mitigate CCl4 hepatocyte damage (P < 0.05) comparable to 100 µg/mL silymarin, and 100 µg/mL proved to be more protective than either silymarin 100 µg/mL or glycyrrhizin 10 µg/mL (P < 0.05). METHODS: Wistar rats were allocated into three groups: (A) 0.1 mL/100 g body weight (BW) mixture of CCl₄ in olive oil (1 : 1 v/v) subcutaneous injection twice daily for 4 weeks; (B) as A, plus oral administration of 50 mg/kg of K‐17.22 dissolved in 5% glucose; (C) as B but with PN‐M001 given 1 week after the first injection of CCl₄. Rats were killed at the end of the study and blood and liver samples were obtained. RESULTS: When compared with a control, group A showed a significant decrease of glutathione (GSH;>45%, P < 0.001) and oxidized GSH (GSSG; P < 0.01) liver content, a lower liver wet weight (P < 0.01) together with an increase of both transaminases (>15‐fold, P < 0.001) whereas groups B and C both showed only a mild increase in transaminases (<4‐fold, P < 0.05). Group A showed a significant decrease of Y‐protein fraction and of GST activity, as tested by both substrates (P < 0.01 vs control). However, both these parameters were reverted to normal by PN‐M001 (P < 0.05 vs A). CONCLUSIONS: These preliminary data suggest that PN‐M001 exerts a highly protective and prolonged effect (either preventive or therapeutic) on GSH depletion in CCl₄‐induced liver injury, which suggests its potential use in the clinical setting.     

Controlled comparison of percutaneous and microsurgical sperm retrieval in men with obstructive azoospermia

A controlled comparison of the efficacy and reliability of sperm retrieval by testicular fine needle aspiration (TFNA), percutaneous testicular needle biopsy (PercBiopsy) and microsurgical epididymal sperm aspiration (MESA) was performed in nine patients with obstructive azoospermia. During a planned MESA procedure, sperm retrieval was attempted on the same testis with TFNA and PercBiopsy. Spermatozoa were obtained from all patients using MESA and PercBiopsy. Spermatozoa were retrieved using TFNA from 6/9 (67%) men. The mean number of epididymal spermatozoa retrieved with MESA (15 x 106) was significantly higher (P = 0.003) than that retrieved percutaneously from the testis. The mean number of spermatozoa obtained by PercBiopsy was 0.116 x 10(6) while TFNA recovered 0.014 x 106 spermatozoa (P = 0.025). MESA is the optimal choice to retrieve the greatest number of spermatozoa with highest motility for assisted reproduction and subsequent cryopreservation. However, percutaneous testicular retrieval does not require microsurgical expertise and is less invasive. Our results suggest that the optimal percutaneous procedure for sperm retrieval from the testis involves percutaneous testicular needle biopsy with an automatic biopsy gun.      

Basaloid squamous cell carcinoma of the esophagus: an immunohistochemical study of 8 cases

Objective To explore the biological features of basaloid squamous cell carcinoma (BSC) of the esophagus.Methods Cytokeratins (CK4, CK18 and CK19), epithelial membrane antigen (EMA), carcino e mbryo antigen (CEA), α-smooth muscle antigen (α-SMA), S-100, laminin (LN), collagen Ⅳ (Col-Ⅳ), neural-specific enolase (NSE), proliferating cell nuclea r antigen (PCNA) and p53 antibodies were used to detect the corresponding antigen expression in 8 cases of BSC with ABC immunohistochemical methods.Results Two kinds of BSC cell components have different responses to the above antibodies. For basaloid cells (BCs), 7 cases were positive for CK19, and were negative for the other 4 epithelial antibodies CK4, CK18, CEA and EMA. BCs of 4 cases were positive to the muscular antibodies α-SMA and S-100, and the hyaline degeneration in the tumor nests was positive for LN and Col-Ⅳ. BCs h ad a high index of PCNA, with an average level of 54%. For squamous cells (SC s), 7 cases were positive for the epithelial antigen CK4, CEA and EMA, but were negative for CK19, α-SMA and S-100. The index of PCNA of SC was low, with a n average level of 25%.Conclusion BSC of the esophagus is a high-malignancy tumor which is of multi-oriented di fferentiation. BCs represent basal cells which have the tendency of myoepitheli al differentiation and have strong proliferation ability, whereas SCs represent typical squamous cell differentiation.     

Dehydroepiandrosterone and related steroids alter 3T3-L1 preadipocyte proliferation and differentiation.

The purpose of the present study was to determine if the anti-adipogenic effects of dehydroepiandrosterone (DHEA) are mediated solely by DHEA or by one or more of its downstream metabolites. In Experiment 1, preconfluent proliferating cultures of 3T3-L1 preadipocytes were incubated for either 24 or 72 h with 0, 1, 5 or 25 microM DHEA, DHEA sulfate (DHEAS), testosterone, estrone and 17beta-estradiol. Pregnenolone, a precursor of DHEA(S), was also tested at these concentrations. After 24 h of incubation, DHEAS, 17beta-estradiol and estrone at the 1 microM level stimulated preadipocyte proliferation. In contrast, DHEA and 17beta-estradiol at the 25 microM level attenuated proliferation to a greater extent than all other steroids. After 72 h of incubation, DHEA and 17beta-estradiol at the 25 microM level attenuated proliferation to a greater extent than all other steroids. In Experiment 2, post-confluent cultures of differentiating 3T3-L1 preadipocytes were incubated for 6 days with 0, 5, 30, or 60 microM levels of these steroids. Preadipocyte differentiation, as assessed by lipid content and glycerol-3-phosphate dehydrogenase activity, decreased markedly when treated with 30 and 60 microM DHEA, 17beta-estradiol, estrone and pregnenolone. In contrast, DHEAS had no impact on preadipocyte proliferation or differentiation. These results suggest that the anti-adipogenic actions of DHEA in adipose tissue may be mediated, in part, by one or more of its distal metabolites, including 17beta-estradiol.     

Accurate and independent measurement of volume and hemoglobin concentration of individual red cells by laser light scattering

Cell volume (MCV) and hemoglobin concentration (MCHC) are the red cell indices used to characterize the blood of patients with anemia. Since the introduction of flow cytometric methods for the measurement of these indices, it has generally been assumed that the values derived by these instruments are accurate. However, it has recently been shown that a number of cellular factors, including alterations in cellular deformability, can lead to inaccurate measurement of cell volume by these automated instruments. Because cell hemoglobin concentration and hematocrit are computed from the measured values of cell volume, accuracy of these indices is also compromised by inaccurate determination of cell volume. A recently developed experimental flow cytometric method based on laser light scattering, which can independently measure volume and hemoglobin concentration, has been used in the present study to measure MCV and MCHC of density- fractionated normal and sickle red cells, hydrated and dehydrated normal red cells, and various pathologic cells. We found that the new method accurately measures both volume and hemoglobin concentrations over a wide range of MCV (30 to 120 fL) and MCHC (27 to 45 g/dL) values. This is in contrast to currently available methods in which hemoglobin concentration values are accurately measured over a more limited range (27 to 35 g/dL). In addition, as the experimental method independently measures volume and hemoglobin concentration of individual red cells, it allowed us to generate histograms of volume and hemoglobin concentration distribution and derive coefficient of variation for volume distribution and standard deviation of hemoglobin concentration distribution. We have been able to document that volume and hemoglobin concentration distributions can vary independently of each other in pathologic red cell samples.     

Inhibitory effect of black tea on the growth of established skin tumors in mice: effects on tumor size, apoptosis, mitosis and bromodeoxyuridine incorporation into DNA

Female CD-1 mice were initiated with a single topical application of 7,12-dimethylbenz[a]anthracene and promoted with 12-O- tetradecanoylphorbol-13-acetate. Mice with established papillomas were then treated with black tea or decaffeinated black tea (approximately 4 mg tea solids/ml) as the sole source of drinking fluid for 11-15 weeks. In four separate experiments, oral administration of black tea inhibited the growth of papillomas (increase in tumor volume/mouse) by an average of 35%, 37%, 41% and 48%, respectively. Studies with decaffeinated black tea gave inconsistent results. In one experiment, administration of decaffeinated black tea inhibited papilloma growth (increase in tumor volume/mouse) by 27%, but in two additional experiments papilloma growth was stimulated by 14% and 193%, respectively. In a separate experiment, skin tumors were generated by treating SKH-1 female mice with ultraviolet B light (UVB; 30 mJ/cm2) twice weekly for 22 weeks, after which UVB administration was stopped. Tumors were allowed to develop during the following 13 weeks, and tumor- bearing mice were then treated with black tea (6 mg/ml tea solids) as the drinking fluid for 11 weeks. In this experiment, tumor growth (increase in tumor volume/mouse) was inhibited by 70%. Histological examination revealed that tea-treated mice had a 58% decrease in the number of nonmalignant tumors (primarily keratoacanthomas)/mouse and a 54% decrease in the number of squamous cell carcinomas/mouse. In addition, administration of black tea decreased the volume per tumor by 60% for nonmalignant tumors and by 84% for carcinomas. Mechanistic studies with tumors from these mice revealed that administration of black tea decreased the bromodeoxyuridine labeling index in squamous cell papillomas, keratoacanthomas and squamous cell carcinomas by 56%, 45% and 35%, respectively, and the apoptosis index was increased by 44%, 100% and 95%, respectively. Administration of black tea decreased the mitotic index in keratoacanthomas and squamous cell carcinomas by 42% and 16%, respectively. The results indicate that oral administration of black tea to tumor-bearing mice inhibited proliferation and enhanced apoptosis in nonmalignant and malignant skin tumors.      

Effect of green tea on p53 mutation distribution in ultraviolet B radiation-induced mouse skin tumors

In the present study, administration of green tea to SKH-1 mice, via the drinking fluid, was found to significantly reduce the incidence and volume of ultraviolet B (UVB) radiation-induced skin tumors. Thirty-six skin tumors induced by UVB and 32 skin tumors induced by UVB, in mice treated with green tea in their drinking water, were collected and examined for the presence of mutations in the p53 gene. Polymerase chain reaction products from p53 exons 5-8 were screened by single- strand conformation polymorphism and direct sequence analyses. Eight of 36 UVB-induced tumors contained nine p53 mutations, with four in exon 5 and five in exon 8. In contrast, nine of 32 UVB-induced tumors in mice treated with green tea contained 11 p53 mutations, with two in exon 5, five in exon 6 and four in exon 8. All of the p53 mutations occurred at dipyrimidine sequences. These results were further corroborated by p53 immunohistochemistry. The most frequent mutations were C-->T or T-->C transitions, which are consistent with the genetic alterations caused by UVB exposure. Interestingly, mutations found in exon 6 of the p53 gene occurred only in tumors from the UVB/green tea group. Thus, the tumors observed in UVB/green-tea-treated mice have a different exon distribution of p53 mutations than tumors obtained from mice treated with UVB alone.      

Survivin基因在人胎儿血中的表达

目的:观察Survivin基因在人胎儿血中的表达及其意义。方法:实验于2003-10/2004-03在广西医科大学第一附属医院血液科完成。①实验材料:50份胎儿血、40份足月脐带血分别取自广西民族医院及南宁第二人民医院妇产科和本院妇产科,产妇均知情同意,并经医院伦理委员会批准。35份成人外周血为无血液系统疾患的健康献血者。②实验方法:无菌操作条件下取EDTA抗凝骨髓液4mL,常规分离单个核细胞,洗涤后制备合适密度备用。采用RT-PCR技术对50份孕龄为18～32周人胎儿血、40份足月脐带血和35份成人外周血Survivin基因m RNA表达水平进行检测。结果:①Survivin基因在人胎儿血、脐带血及成人外周血表达阳性率的比较:人胎儿血Survivin基因mRNA表达阳性率高于脐血组,差异有显著性意义(68.0%,47.5%,P<0.05)。②Survivin基因在人胎儿血及脐带血中表达水平的比较:人胎儿血Survivin基因mRNA表达水平高于脐带血,差异有显著性意义(0.575±0.276,0.444±0.626,P<0.05)。③Survivin基因表达水平与孕龄的关系:Survivin基因mRNA表达水平随着孕龄增加有下降趋势,对Survivin基因mRNA表达水平与孕龄的相关性进行直线相关分析,结果显示两者之间存在负相关(r=-0.373,P=0.030)。结论:①Survivin基因在人胎儿血及脐带血中均有表达,Survivin基因在人胎儿血中表达水平高于脐带血,在成人外周血中检测不到Survivin基因表达。②随着孕龄增加,人胎儿血中Survivin基因表达水平随之下降。③Survivin基因可能在人胎儿发育过程中起一定作用,具体机制还需进一步研究探讨。     

趋化因子受体阻断剂与艾滋病防治

化学趋化因子受体作为协同受体,主要包括CCR5与CXCR4,为人免疫缺陷病毒(HIV-1)进入细胞所必需. HIV协同受体的发现为治疗艾滋病开辟了新的途径. 利用趋化因子拮抗剂与天然配体封闭趋化因子受体可阻止HIV的感染;以靶细胞表面的趋化因子受体为靶点治疗HIV感染的新方法已成为国内外研究的热点,现对这一方面研究进展作一综述.