Autotransplantation of the kidney in primates: a model of renal damage to study the ischemia-reperfusion injury.
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Animals↗
Biomedical subjects
S Zheng
Publications and source records attributed to S Zheng.
Fibrinogen degradation products in patients with the Quebec platelet disorder.
The Quebec platelet disorder is a serious bleeding disorder associated with proteolysis of alpha-granular proteins, including fibrinogen. We evaluated fibrinogen degradation product (FDP) assays as screening tests for this disorder. Patients with the Quebec platelet disorder (13/13) had elevated serum FDPs (P < 0.01) due to secreted degraded platelet fibrinogen, but normal plasma FDPs and D-dimers. Unrelated controls with bleeding disorders (32/34) had undetectable FDPs, and controls with FDPs due to disseminated intravascular coagulation (DIC) and other illnesses (11/11) had elevated FDPs in all assays (P < 0.01). Immunoblot analyses indicated plasma fibrinogen was normal in the Quebec patients and platelet FDPs were found in their platelet lysates, releasates and serum samples. Their platelet FDPs were not altered by treatment with fibrinolytic inhibitors and were different from the FDPs in DIC and in plasmin-digested fibrinogen. Tests for serum FDPs may provide a simple rapid way to screen for the Quebec platelet disorder.
Antifibrinolytic Agents↗
Promoter analysis and expression of a phospholipase D gene from castor bean.
The expression of a castor bean (Ricinus communis L.) phospholipase D (PLD; EC 3.1.4.4) gene has been studied by examining its promoter activity in transgenic tobacco (Nicotiana tabacum) carrying a PLD promoter-glucuronidase transgene and by monitoring the levels of PLD mRNA in castor bean. Sequence and the 5' truncation analyses revealed that the 5' flanking region from nucleotide -1200 to -730 is required for the regulation and basal function of the PLD promoter. The PLD promoter in vegetative tissues is highly active in the rapidly growing regions such as the shoot apex and the secondary meristem producing axillary buds and vascular tissues of young leaves and stems. The PLD promoter activity in floral tissues was high in stigma, ovary, and pollen grains, but low in petals, sepals, the epidermis of anthers, styles, and filaments. The PLD promoter activity was enhanced by abscisic acid. Northern-blot analysis of PLD in castor bean showed that the PLD mRNA levels were high in young and metabolically more active tissues such as expanding leaves, hypocotyl hooks, developing seeds, and young seedlings, and they decreased in mature tissues such as fully expanded leaves and developed seeds. These patterns of expression suggest a role of PLD in rapid cell growth, proliferation, and reproduction.
Base Sequence↗
Antisense suppression of phospholipase D alpha retards abscisic acid- and ethylene-promoted senescence of postharvest Arabidopsis leaves.
Membrane disruption has been proposed to be a key event in plant senescence, and phospholipase D (PLD; EC 3.1.4.4) has been thought to play an important role in membrane deterioration. We recently cloned and biochemically characterized three different PLDs from Arabidopsis. In this study, we investigated the role of the most prevalent phospholipid-hydrolyzing enzyme, PLD alpha, in membrane degradation and senescence in Arabidopsis. The expression of PLD alpha was suppressed by introducing a PLD alpha antisense cDNA fragment into Arabidopsis. When incubated with abscisic acid and ethylene, leaves detached from the PLD alpha-deficient transgenic plants showed a slower rate of senescence than did those from wild-type and transgenic control plants. The retardation of senescence was demonstrated by delayed leaf yellowing, lower ion leakage, greater photosynthetic activity, and higher content of chlorophyll and phospholipids in the PLD alpha antisense leaves than in those of the wild type. Treatment of detached leaves with abscisic acid and ethylene stimulated PLD alpha expression, as indicated by increases in PLD alpha mRNA, protein, and activity. In the absence of abscisic acid and ethylene, however, detached leaves from the PLD alpha-deficient and wild-type plants showed a similar rate of senescence. In addition, the suppression of PLD alpha did not alter natural plant growth and development. These data suggest that PLD alpha is an important mediator in phytohormone-promoted senescence in detached leaves but is not a direct promoter of natural senescence. The physiological relevance of these findings is discussed.
Abscisic Acid↗
[The effect of NO-like relaxing factor on vascular reactivity in tourniquet shock rat].
This work was done on rat tourniquet shock (ToS) model. It was found that reactivity of isolated perfused aortic ring to noradrenaline decreased, while cGMP content of the aortic tissue increased. These changes could be potentiated by perfusion with L-arginine (NO-precursor). On the other side, when the aortic ring was perfused with L-NNA (NO-synthesis inhibitor) or methylene blue (soluble cGMPase inhibitor), the changes could be attenuated. The effect of these drugs are independent of the presence of vascular endothelium. The results suggest that non-endothelium-derived NO-like relaxing factor may be one of the factors causing low vascular reactivity of the ToS animals.
Animals↗
[Cloning of genes associated with taxol-induced apoptosis of human breast cancer cells].
The method of mRNA differential display was employed to isolate expressing genes involved in taxol-induced apoptosis of human breast cancer cells (BCap 37). Results demonstrated that the expressive alteration of twelve clones isolated was associated with taxol-induced apoptosis identified by Northern blot. cDNA sequence of clone C3P3 was highly homologous (99%) to human S-adenosylmethionine (S-AdoMet) synthetase. Increased transcriptional level of clone C3P3 induced by taxol was parallel to enhanced enzyme activity of S-AdoMet synthetase. These results suggested that the expression of these clones isolated by the mRNA differential display be possibly involved in the regulation of taxol-induced apoptosis. Their function in details need further study.
Antineoplastic Agents, Phytogenic↗
[Efficient expression of human C1-inhibitor in CHO cells by using a dicistronic expression vector].
The full-length cDNA fragment encoding human C1-INH was obtained by gene recombination techniques and a stable expression plasmid was constructed by inserting the human C1-INH cDNA into an efficient dicistronic expression vector pED. This plasmid was transfected into DHFR-deficient Chinese Hamster Ovary cells (CHO-dhfr-) by Lipofectin method, and the positive CHO-dhfr+ cell clones which stably express C1-INH was generated. Expression of C1-INH mRNA was detected by Northern blot. Expression of C1-INH protein was confirmed by immunoprecipitation and Western blot analysis. The level of expressed C1-INH was estimated at 0.4 microgram/ml by specific ELISA techniques. The biological activity of recombinant C1-INH was assayed by using the inhibition of C1 estrolytic activity.
Animals↗
[Use of appendix to restore a ureter: report of 2 cases].
In two cases the appendix was utilised as a substitute for part of the left ureter. Case one used the appendix as a conduit from the upper left ureter to the right one to treat the megaureter, and the other one used the appendix as a connection to join the two transected openings of the left ureter to treat the obstruction caused by the chronic ureteritis of the left ureter. Long-term observation after the operation showed satisfactory functions of kidneys. We suggested that the appendix is an autologus tissue whose active peristalsis, little mucous absorption along with its easy performance make this method highly valuable and practical.
Adolescent↗
[Mechanism of taxol-induced apoptosis in human breast cancer cells].
OBJECTIVE: To investigate the mechanism by which taxol induces apoptosis in human breast cancer cells. METHODS: Cell morphology, agarose gel electrophoresis, flow cytometry, video time-lapse monitor and Western blot were performed for taxol-induced apoptosis in human breast cancer cells (Bcap 37). RESULTS: BCap 37 cells treated with taxol (100 nm) underwent the arrests of cell mitosis at metaphase of mitosis and induction of apoptosis. Apoptotic cells demonstrated cell shringkage, condensation and fragmentation of chromosomes. Nuclear DNA of apoptotic cells displayed ladder bands characteristic of internucleosomal DNA fragmentation. The expression of bcl-2, inhibitor of apoptosis, was decreased with modification, while that of bax, inducer of apoptosis, increased only at early stage of the apoptotic pathway and decreased later. CONCLUSION: In human breast cancer cells the induction of apoptosis by taxol was closely associated with mitotic arrest of cell cycle, and altered expression of bcl-2 and bax gene, possibly playing an important role in regulating taxol-induced apoptosis.
Antineoplastic Agents, Phytogenic↗
[Changes in the levels of artemisia pollen specific antibodies during rush immunotherapy for pollinosis].
Artemisa pollen-specific immumoglobulins (IgG4, IgG and IgE) were evaluated by means of ELISA during rush immunotherapy in 49 patients with pollinosis. The results showed that six weeks after the beginning of immunotherapy, the levels of specific IgG4(P < 0.05) and IgG (P < 0.001) antibodies were significantly higher than those of patients prior to receiving rush immunotherapy. These results suggest that rush immunotherapy may result in a rapid increase in IgG antibody levels, and high specific IgG level may implicate a clinical improvement in allergic patients due to the rush immunotherapy.
Allergens↗
[Computer image analysis of 20 tiny medicinal seeds].
Twenty tiny medicinal seeds were determined by computer image analysis. The diameter, perimeter, area, volume and irregular parameter of the seeds are presented.
Image Processing, Computer-Assisted↗
[The study on chemical composition and crystalline structure of hypoplastic primary dental enamel].
The present study, firstly, analyzed chemical composition of hypoplastic primary teeth by electron probe analyzer and compared the hypoplastic part with the normal part in the same tooth; secondly, by X-ray diffraction analyzer, studied the hypoplastic dental enamel and the normal dental enamel, and compared the crystalline structure between different dental enamel and with that of the hydroxyapatite. The aim was to find out any change of crystalline structure. Two exfoliated hypoplastic deciduous anterior teeth were used for the electron probe study. The normal part of each tooth served as control. Determinations of weight percentage (wt%) were made for P, Al, Mg, Ca, Mn, Fe, Zn, Sr, Na, K and F. Four exfoliated hypoplastic deciduous anterior teeth and eight exfoliated normal deciduous anterior teeth were used for the X-ray diffraction study. We found by X-ray diffraction that the length of the alpha-axis of enamel crystallite and the distance of lattice plane (corresponding 300) were increased in defective enamel and could be associated with the increased content of magnesium detected by electron probe. Thus, the present study demonstrated that there were both quantity and quality changes in the enamel hypoplasia lesion, which may increase the susceptibility of the defective teeth to caries.
Calcium↗
[The stress reaction induced by intensive noise exposure in rats].
To study the effects of sustained intensive noise on rats, fifty SD male rats were randomly divided into: control group and 1 d, 3 d, 7 d and 14 d noise exposure groups (120 dBSPL, broadband noise, 2 h daily). The results showed that after noise exposure, the ACTH level and the corticosterone level in serum increased, but the content of DA in diencephalon decreased, the weight of adrenal gland increased, while that of thymus and spleen decreased. Change of weight of adrenal gland and thymus became maximum after 7d-exposure. The ACTH level in serum and the content of DA in diencephalon decreased and the later reached the lowest value and the weight of adrenal gland and thymus returned to normal level after 14 d exposure. It indicated that the acute response began to decrease after 7d-exposure, and the response turned into a chronic inhibitory state after 14d-exposure.
Adrenal Glands↗
[Study on effects of combined hearing protector on communication quality and noise protection].
To study the communication quality and the protection effects of single protector and the combined ones, sound attenuation experiments and the communication experiments were conducted in 14 male subjects. The results showed that the sound attenuation of combined protectors were 13 dB or 6dB more than that of single earplug or earmuff respectively, and combined protectors could avoid sound attenuation caused by the harmonics on some frequency bands in single one. After combined usage, the single protector reduced the distortion which came from the overload of hearing organs and maintained the communication quality. The combined protector is an effective hearing protection device in high noise environment in aerospace field.
Communication↗
[The prospective study of the influence of cytomegalovirus (CMV) infection of pregnant women to fetus].
Screening of CMV infection in 450 pregnant women in Shenyang was carried on by ELISA and PCR methods, and CMV infection was detected in 100 of their infants prospectively. The results were 97.11% of pregnant women with past infection, 0.89% with primary infection, 11.11% with recurrent infection, only 2% were susceptible. From 450 pregnant women, there were 3 infants with congenital defects and 3 abortions in active infective group, who were positive for IgM antibody, CMV DNA were positive in heparin peripheral blood, cervical secretion, placenta or amnionic fluid. The fetal infection rate and congenital defect rate in infective group were higher than that in inactive control group. Within 100 maternal-infant pair group, congenitally infected infants were 1.43 times higher in infective group than that in control group (RR = 1.43). Two infants with mental retardations (MDI<70) were born in infective group, but none in control group. In our study, primary infection of early pregnancy was most harmful to fetus, the intrauterine transmission rate was 33.3%. Among nine infected infants born from the infective group, two infants were with CID, and seven were symptomless. CMV screening is important for pregnant women in view of eugenic. When active CMV infection is found in early pregnancy, termination of pregnancy is better considered while CMV detection of amniotic fluid is also positive.
Adult↗
Initial study on naturally occurring products from traditional Chinese herbs and vegetables for chemoprevention.
A number of naturally occurring products from vegetables and herbs exert chemopreventive properties against carcinogenesis. In this paper, two such compounds, isolated from garlic and from a traditional Chinese medicinal herb, are described for review. Elemene, isolated from the Chinese medicinal herb Rhizoma zedoariae, was shown to exhibit antitumor activity in human and murine tumor cells in vitro and in vivo. This novel antineoplastic agent has substantial clinical activity against various tumors. The in vitro effect of elemene on the growth of leukemia cells was evaluated by MTT assay. The IC50 values of elemene for promyelocytic leukemia HL-60 cells and erythroleukemia K562 cells were 27.5 micrograms/mL and 81 micrograms/mL, respectively, while IC50 for peripheral blood leukocytes (PBL) was 254.3 micrograms/mL. The inhibitory effect of elemene on proliferation of HL-60 cells was associated with cell cycle arrest from S to G2M phase transition and with induction of apoptosis. The apoptosis of tumor cells was confirmed by DNA ladder formation on gel electrophoresis and characteristic ultrastructural alterations. The results also demonstrated that inhibitory effects of allicin, a natural organosulfide from garlic, on proliferation of tumor cells were associated with the cell cycle blockage of S/G2M boundary phase and induction of apoptosis. These findings suggest that induction of apoptosis may contribute to the mechanisms of antitumor activity of elemene and allicin, which merit investigation as potential chemoprevention agents in humans.
Anticarcinogenic Agents↗
Screening and identification of down-regulated genes in colorectal carcinoma by subtractive hybridization: a method to identify putative tumor suppressor genes.
OBJECTIVE: To search for new putative tumor suppressor genes in colorectal carcinoma. METHODS: Subtractive hybridization technologies were applied to screen and select genes, the expression of which was down-regulated in colorectal carcinoma. mRNAs uniquely expressed in normal cells but not in colorectal carcinoma were recovered as cDNA (sub-cDNA) after two rounds of subtractive hybridization with mRNA prepared from colorectal carcinoma. The sub-cDNAs were then used as probes to screen a normal human colon cDNA library constructed in lambda-Zap II phage. The DNAs of positive clones were in vivo excised, and partial DNA sequences were analyzed and compared with DNA sequence database Genbank. RESULTS: A total of 46 different clones with an average of about 1 kilobases in transcript size was recovered. Among these 46 down-regulated genes in colorectal carcinoma were genes encoding immunoglobulin (n = 32), 40-kDa keratin intermediate filamentous protein or IFP (n = 1), major histocompatibility complex-related protein (n = 1), unrelated structural proteins (n = 10) and gene products yet to be identified (n = 2). RNA dotblot hybridizations confirmed that all 46 clones contained genes that were down-regulated and have not been reported before in colorectal carcinoma. CONCLUSION: The results of this study suggested that the 46 clones were down-regulated in colorectal carcinoma, they should be further studied as new putative tumor suppressor genes and could be used as new tumor markers of colorectal carcinoma.
Colorectal Neoplasms↗
Recent study on colorectal cancer in China: early detection and novel related gene.
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Adult↗