Biomedical subjects

Li Zhou

Publications and source records attributed to Li Zhou.

At least 127 records · Page 7Linked to original sources

PubMed2003

[Studies on sexual dysfunction in male patients with chronic renal insufficiency].

OBJECTIVES: To investigate the prevalence, main manifestation and related factors of sexual dysfunction in male patients with chronic renal insufficiency (CRI). METHODS: A cross-section study was conducted by six hospitals in Sichuan Province. The prevalence and severity of sexual dysfunction were assessed by SCASF microsoft among patients with chronic renal disease. Logistic regression was used to examine and test the association between sexual dysfunction and other medical conditions. RESULTS: The prevalence of sexual dysfunction was wider in patients with CRI than in those without. The main manifestations in male patients were decreased libido, erectile dysfunction and premature ejaculation. Stratified analysis in uremia showed that the prevalence and severity of sexual dysfunction were similar between patients on haemodialysis(HD) and those on peritoneal dialysis(PD). The patients receiving no replacement treatment suffered more decreased libido and performance anxiety than dialyzed patients (HD and PD) and transplantation patients(Tx). The patients receiving no replacement treatment and dialysis suffered more erectile dysfunction than Tx men. A multivariable analysis demonstrated that the duration, creatinine clearance(Ccr), parathyroid hormone (PTH), albumin(Alb) were not associated with sexual dysfunction. The use of beta-blocker, anemia and depression were risky factors for decreased libido, and increasing age was a risky factor for erectile dysfunction. The use of angiotensin-converting-enzyme inhibitor(ACEI)/angiotention receptor antagonist (ARB) and recombinant human erythropoietin(r-HuEpo) were protective factors for erectile dysfunction. CONCLUSIONS: The main manifestations of sexual dysfunction in male patients with CRI are decreased libido, erectile dysfunction and premature ejaculation. The replacement therapy, especially transplantation, can decrease the prevalence or severity of sexual dysfunction. The genesis of sexual dysfunction is multifactorial, including age, physiological factors, psychological factors and medical conditions.

Adult↗

PubMed2003

[Effects of deltamethrin on cell survival rate and intracellular free Ca2+ concentration in primary cultured astrocytes of rat].

OBJECTIVE: To study the effects of deltamethrin (DM) on cell survival rate and intracellular Ca(2+) ([Ca(2+)]i) concentration in primary cultured astrocytes of rat. METHODS: The cell survival rate was measured by Typan Blue assay; the intracellular [Ca(2+)]i concentration was determined by the fluorescent Ca(2+) indicator Fura-2/AM. RESULTS: The survival rate of astrocytes was decreased to 91.9% after astrocytes were incubated with 1 x 10(-5) mol/L DM for 72 h (P < 0.05). The cell survival rates were 89.0%, 84.8%, 81.2% and 79.2% respectively when astrocytes were administered with 1 x 10(-4) mol/L DM for 4, 12, 24 and 72 h, which were remarkably lower than control groups (P < 0.01). Comparing with controls and before DM treatment, sharp increases in [Ca(2+)]i concentration [(451.4 +/- 42.3), (536.9 +/- 47.5) and (870.9 +/- 100.5) nmol/L respectively] were observed when astrocytes were incubated with 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5) mol/L DM for 5 minutes (P < 0.01). After astrocytes were treated with 1 x 10(-8), 1 x 10(-7), 1 x 10(-6), 1 x 10(-5) mol/L DM for 15 minutes, the [Ca(2+)]i concentrations were decreased to (124.3 +/- 6.0), (131.3 +/- 19.1), (118.9 +/- 1.4), (136.6 +/- 3.8) nmol/L respectively, which were significantly different from those of controls and before treatment. And this situation was almost keeping stable to 30 min. CONCLUSION: The cell survival rate was decreased and the [Ca(2+)]i concentration was temporarily increased when astrocytes were treated with DM.

Animals↗

PubMed2003

[Effect of xanthnotoxol on contraction of rabbit thoracic aortic strips].

OBJECTIVE: To study the effect of xanthnotoxol (XT) on contractility of rabbit thoracic aorta strips and its relationship with Ca2+. METHODS: Routine experimental methods for isolated thoracic aorta strips were adopted. RESULTS: XT and verapamil (Ver) can make the dose-response curve of rabbit thoracic aorta strips induced by NE, KCl, CaCl2 shifed right (the pD'2 of KCl and CaCl2 value was 3.58 +/- 0.07 and 4.12 +/- 0.12) and depressed the maximal responses. Like verapamil (Ver), it is accomplished by calcium antagonism. XT could selectively block the voltage dependence calcium channel (VDC), and have no effect on the receptor operated calcium channel (ROC). CONCLUSION: It suggested XT had selectly blocking effect on voltage dependence calcium channel.

Animals↗

PubMed2002

Reproduction of scalp acupuncture therapy on strokes in the model rats, spontaneous hypertensive rats-stroke prone (SHR-SP).

Scalp acupuncture (SA) therapy on strokes has been empirically established and widely used in clinics in China. SA is particularly effective at ameliorating paralyses and speech disturbances, and the recovery rate is twice that for those treated with medication alone. To investigate the effects of SA on a scientific basis, we have developed a new experimental system that provides reliable controls and excludes psychological effects by using a genetic strain of rats, spontaneous hypertensive rats-stroke prone. Here we report that SA indeed has rapid and powerful effects to remove limb paralyses caused either by cerebral infarct or by cerebral haemorrhage. This model is well suited to study the mechanism of the effects of SA in parallel with clinical studies, and to describe the whole recovery process after the stroke onset.

Acupuncture Therapy↗

PubMed2002

Association of prothrombin and protein S with plasma triglyceride-rich lipoproteins in humans after test meals rich in milk fat or soybean oil.

INTRODUCTION: Prothrombin can associate with rat chylomicrons in vitro. This enhances a platelet factor Xa mediated prothrombin activation when the chylomicron-prothrombin complex is exposed to platelets. Vitamin K-dependent pro- and anti-coagulation proteins are associated with TG-rich lipoproteins obtained from human plasma. In the present study, we examined the effects of saturated and unsaturated fat meals on the association of prothrombin and protein S with TG-rich lipoproteins in vivo. MATERIALS AND METHODS: Human EDTA plasma was separated from normal subjects after overnight fasting and 2.5 h after ingestion of either a saturated fat meal (butter and cream) or an unsaturated fat meal (soybean oil) containing 54-80 g fat (60.2 E%). The prothrombin and protein S in delipidated lipoproteins were determined by SDS-PAGE combined with Western blotting. RESULTS: Both prothrombin and protein S associated with TG-rich lipoproteins in fasting and in postprandial samples. The levels of prothrombin and protein S in postprandial TG-rich lipoproteins, especially after ingestion of a saturated fat meal, were higher than those in fasting TG-rich lipoproteins. CONCLUSIONS: The levels of both prothrombin and protein S in TG-rich lipoproteins in plasma increased after a single fat meal. This association is more pronounced after saturated fat meals and one may hypothesize that it can be linked to atherogenic properties of TG-rich lipoproteins.

Adult↗

PubMed2002

Studies on the transition behavior of physical adsorption from the sub- to the supercritical region: experiments on silica gel.

Adsorption equilibria of nitrogen and methane on a mesoporous silica gel were measured over a temperature range from the sub- to the supercritical region. Determination of the compressibility factor shows a significant effect on the experimentally measured isotherms under conditions rho(g)/rho(c)>0.3. The transition of adsorption mechanisms in passing over the critical temperature was proven by the transformation of isotherms from type II to type I. The characteristic feature of subcritical adsorption was still observed at a temperature 8 K higher than the critical and the critical depletion phenomenon was clearly shown on such an isotherm. The limit quantities defined in different ways for the supercritical adsorption are in reasonable agreement, indicating the existence of an upper limit state of the supercritical adsorbate.

Journal Article↗

PubMed2002

Murine peripherin gene sequences direct Cre recombinase expression to peripheral neurons in transgenic mice.

Spatially and temporally regulated somatic mutations can be achieved by using the Cre/loxP recombination system of bacteriophage P1. To develop a cell type-specific system of gene targeting in the peripheral nervous system, we generated the transgenic mouse lines expressing Cre recombinase under the control of the mouse peripherin gene promoter. The activity of the Cre recombinase during embryonic development was examined by mating the peripherin-Cre transgenic mice to the knock-in Cre-mediated recombination reporter strain, R26R. Analysis of F1 embryos from this cross showed specific excision of loxP-flanked sequences in the dorsal root ganglia, trigeminal ganglia, and olfactory epithelium, in a pattern very similar to the expression of the endogenous mouse peripherin gene, and the previously reported peripherin-lacZ transgenic mice. Thus, the peripherin-Cre mouse described here will provide a valuable tool for Cre-loxP-mediated conditional expression in the peripheral nervous system.

Animals↗

PubMed2002

The M603 idiotype is lost in the response to phosphocholine in terminal deoxynucleotidyl transferase-deficient mice.

The majority of anti-phosphocholine (PC) antibodies induced by the PC epitope in Proteus morganii (PM) express the M603 idiotype (id), which is characterized by an invariant Asp to Asn substitution at the V(H):D(H) junction. To elucidate the molecular basis by which M603-like B cells acquire the mutations resulting in this invariant substitution, we analyzed the immune response to PC-PM in terminal deoxynucleotidyl transferase (TdT) gene knockout (KO) mice. In the absence of TdT, T15-id antibodies comprised 80-100% of the primary response to PC-PM. Less than 10% of the response in wild-type mice is T15-id(+). In TdT KO mice, the secondary response to PC-KLH was higher than in wild-type mice and was dominated by the germ-line T15-id. About 10% of this response, in both TdT KO and wild-type mice, comprised M167-id(+) antibodies. Additionally, none of the functionally rearranged V1/DFL16.1/J(H)1 cDNA isolated from PC-PM-immunized TdT KO mice showed the Asp/Asn substitution characteristic of PC-binding, PC-PM-induced M603-like antibodies. These data indicate that production of M603-id antibody is TdT dependent, while generation of M167-id antibody is TdT independent, and that in the absence of competition from M603-like B cells, T15-id B cells can respond to PC-PM.

Amino Acid Substitution↗

PubMed2002

Endoenzymes associated with haemocyte types in the scallop (Chlamys farreri).

Haemocyte types of the scallop (Chlamys farreri) were identified by Giemsa stain and flow cytometry (FCM). Additionally, the activities of peroxidase (POD), phenoloxidase (PO) and alkaline phosphatase (ALP) in haemocytes were analysed by immunocytochemical and biochemical methods. The results indicate that there were two types of haemocytes in the scallop, hyalinocytes and granulocytes, and that POD, PO and ALP were more abundant and more active in granulocytes than in hyalinocytes.

Alkaline Phosphatase↗

PubMed2002

The combination of soluble IL-18Ralpha and IL-18Rbeta chains inhibits IL-18-induced IFN-gamma.

Although the beta chain of interleukin-18 receptor (IL-18Rbeta) is required for signaling, the soluble (extracellular) form does not bind IL-18, and its role in inhibiting IL-18 is unclear. In the present study, both the soluble human IL-18 ligand binding alpha chain (sIL-18Ralpha) and the sIL-18Rbeta chain were investigated for inhibition of IL-18-induced interferon-gamma (IFN-gamma) production in human peripheral blood mononuclear cells (PBMC), whole blood, and KG-1 macrophage and natural killer (NK) cell lines. Neutralization of IL-18 by soluble receptors was compared with that of the IL-18 binding protein (IL-18BP). An equimolar concentration IL-18BP inhibited 90% of IL-18 activity, whereas a 4-fold molar excess of sIL-18Ralpha had no effect. A dimeric construct of sIL-18Ralpha linked to the Fc domain of IgG1 (sIL-18Ralpha:Fc) increased IL-18 activity 2.5-fold. In PBMC stimulated with lypopolysaccharide (LPS) or in whole blood stimulated with Staphylococcus epidermidis, 3 nM IL-18BP reduced IFN-gamma by 80%, whereas IL-18Ralpha:Fc had no effect. A construct of the sIL-18Rbeta linked to Fc (sIL-18Rbeta:Fc) did not affect IL-18-induced IFN-gamma even at 80-fold molar excess of IL-18. However, the combination of both soluble receptors reduced IFN-gamma by 80%. In KG-1 cells, a 50% reduction in IL-18 activity was observed using an 80-fold molar excess of sIL-18Ralpha:Fc but only in the presence of sIL-18Rbeta:Fc. Similarly, a 50% reduction was observed using sIL-18Rbeta:Fc in the presence of a molar excess of sIL-18Ralpha:Fc. Similar inhibition was observed in NK cells. These studies reveal that the combination of the ligand-binding and the nonligand-binding extracellular domains of IL-18R is needed to inhibit IL-18, whereas IL-18BP neutralizes at equimolar concentration.

Adult↗

PubMed2002

Quantitative role of plasma free fatty acids in the supply of arachidonic acid to extrahepatic tissues in rats.

Local desaturation-elongation of linoleic acid, uptake of 2-arachidonyl-lysophosphatidylcholine, and uptake plasma unesterified arachidonic acid (AA) are assumed to be the most important sources of AA for extrahepatic tissues. In this study, we investigated the clearance rate as well as the retention rate of plasma unesterified (14)C-AA in different tissues in fed rats. The initial half-life of (14)C-AA in rat plasma was 3.8 s, and the average pool size of rat plasma unesterified AA was 76 nmol. We calculated that 604 nmol of unesterified AA was cleared from the rat plasma per minute. The retention rate of AA per gram of tissue in the heart (13 nmol/min per g), lungs (12 nmol/min per g), kidney (8 nmol/min per g) and bone marrow (6 nmol/min per g) was higher than that in other tissues but was lower than that in liver (23 nmol/min per g). The total uptake was highest in skeletal muscle (249 +/- 27 nmol/min), in liver (226 +/- 15 nmol/min) and in bone marrow (39 +/- 3 nmol/min). More than 80% of retained (14)C-AA was found in phospholipids in most tissues. The conclusion is that despite the low concentration plasma unesterified, AA is a major source of phospholipid AA in several extrahepatic tissues in rats, due to its rapid turnover and selective acylation into phospholipids.

Animals↗

PubMed2002

A unique short-chain dehydrogenase/reductase in Arabidopsis glucose signaling and abscisic acid biosynthesis and functions.

Glc has hormone-like functions and controls many vital processes through mostly unknown mechanisms in plants. We report here on the molecular cloning of GLUCOSE INSENSITIVE1 (GIN1) and ABSCISIC ACID DEFICIENT2 (ABA2) which encodes a unique Arabidopsis short-chain dehydrogenase/reductase (SDR1) that functions as a molecular link between nutrient signaling and plant hormone biosynthesis. SDR1 is related to SDR superfamily members involved in retinoid and steroid hormone biosynthesis in mammals and sex determination in maize. Glc antagonizes ethylene signaling by activating ABA2/GIN1 and other abscisic acid (ABA) biosynthesis and signaling genes, which requires Glc and ABA synergistically. Analyses of aba2/gin1 null mutants define dual functions of endogenous ABA in inhibiting the postgermination developmental switch modulated by distinct Glc and osmotic signals and in promoting organ and body size and fertility in the absence of severe stress. SDR1 is sufficient for the multistep conversion of plastid- and carotenoid-derived xanthoxin to abscisic aldehyde in the cytosol. The surprisingly restricted spatial and temporal expression of SDR1 suggests the dynamic mobilization of ABA precursors and/or ABA.

Abscisic Acid↗

PubMed2002

Studying suicide with psychological autopsy: social and cultural feasibilities of the methodology in China.

As China opens its door to the world, suicide research is making rapid progress using methods and instruments developed in the West. This is a feasibility study of the psychological autopsy methodology applied in China, with its emphasis on the social and cultural environments. With samples of 66 completed suicides and 66 community normal living controls, the authors found that it is feasible to interview at least two informants for each suicide case and each control, between 2 and 6 months after the suicide. With the Chinese-cultivated contacting method of recruiting cases, the refusal rate is nearly zero. The Western-developed methodology per se proved to be valid in the Chinese culture. Ethical considerations in the context of Chinese culture are as important as in the West. Psychological autopsy technique is shown to be an equally applicable method for the study of completed suicides in Chinese culture as it is in the West. Future epidemiological research on Chinese suicide should use the psychological autopsy method to collect data from larger samples in order to increase our understanding of the risk factors for Chinese suicides.

Adult↗

PubMed2002

[The construction of the hammerhead ribozyme genes targeting against apple scar skid viroid and its activity detection in vitro].

The genes of short armed hammerhead ribozyme targeting against two sites on positive strand (194-196) and negative strand (89-91) of ASSVd were designed, synthesized and cloned according to the action manner of hammerhead ribozyme. The full lengths of the genes are 42 bp (RzASSVd(+)) and 40 bp (RzASSVd(-)). After transcription in vitro, the ASSVd positive and negative RNA labeled with 32P were mixed with the ribozyme transcript and incubated 3-4 h at 50 degrees C or 37 degrees C. The results were assayed on 8% PAGE (containing 8 mol/L urea) and autoradiogrammed. As predicted, the transcript of the active RzASSVd(-) could cleave the ASSVd negative strand RNA with a high activity but had no cleavage effect on the ASSVd positive strand. The transcript of the RzASSVd(+) gene could cleave the ASSVd positive strand but its cleavage activity was very low. As the same, it cannot cleave the negative strand either. On the base of the result, we construct dimmer ribozyme gene pGEMRzASSVd(+/-) containing both RzASSVd(+) and RzASSVd(-).

Cloning, Molecular↗

PubMed2002

[Construction of a proteomic map database].

The first proteomic map database of China will be published by Bioinformation Center and Research Center of Proteomics, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences.The database consists of physical layer, link layer and interfacial layer. As Java technique was introduced to construct the database system, the database does not depend on special working platform. With the search instruments users can easily look through the proteomic map and get concrete information of proteins they are interested in.

China↗

PubMed2002

[Design and preparation of the multimeric self-cleavable hammerhead ribozyme targeting apple scar skid viroid and its activity detection in vitro].

A self-cleaving hammerhead ribozyme gene containing a 14nt target sequence of ASSVd at the 3' end of hammerhead ribozyme was synthesized, amplified and cloned at the Xho I-Hind III site of pGEM7Zf(+). The ends produced by Xho I or Sal I can link together, thus the recognition sites of both enzymes vanish and can't be cut by either one. We used this property to get the recombinant plasmid bearing 2, 4, 6, 8, 10 and 12 copies of self-cleavable ribozyme respectively after successively sub-cloning five times. Linearized recombinat plasmid model catalyzed by T7 RNA polymerase was transcribed in vitro. The multimeric ribozyme molecules efficiently self-cleaved via cis-acting to release many ribozyme molecules It indicates that the concentration of ribozyme transcripts has been enhanced during transcription. Trans-cleavage reaction was carried out by incubating monomeric and multimeric ribozymes with same mol concentration and 32P labeled target ASSVd. Both ribozymes and target transcripts were mixed in 1:1 ratio. Autoradiograms showed the transcripts of multimeric ribozyme were substantially more effective against the ASSVd target RNA than the monomeric ribozymes. We confer that the multimeric self-clevable ribozyme is likely to provide more valuable application in vivo.

Malus↗

PubMed2002

[McNamara cephalmetric analysis of the 67 chengdu adolescents with normal occlusions].

OBJECTIVE: The purpose of this study was to obtain the normal value of McNamura analysis for Chengdu adolescents with normal occlusion of early permanent dentition. METHODS: McNamara analysis was conducted on the basis of the lateral cephalograms of 67 Chengdu adolescents with normal occlusions, and the obtained data was compared with that of Shanghai adolescents and McNamara. RESULTS: There was no difference in the normal value of McNamara analysis between male and female Chengdu adolescents. The Comparative results between Chengdu and Shanghai adolescents indicated significantly larger values of Shanghai adolescents in effective middle facial lengths, mandibular lengths and lower anterior facial heights. The vertical distances from the upper incisor to point A and, from the lower incisor to A-Po line of Chengdu adolescents were larger than those of white adolescents. CONCLUSION: There is significantly difference in values of normal occlusions of McNamara analysis among different regions and different races.

Asian People↗

PubMed2002

Serial therapies oriented by surgery for large primary liver carcinoma.

OBJECTIVE: To discuss the methods and effects of serial therapies oriented by surgery in the treatment of primary large liver cancers. METHODS: From January 1993 to June 1999, 191 patients with large liver carcinoma were treated surgically. The size of tumors varied from 5.2 to 19.7 cm (mean 9.4 cm). Several types of liver resections were made in 121 patients and as a supplement, cryosurgery was carried out for the remaining 70 patients. Importable drug delivery system was instituted intraoperatively. Transcatheter arterial chemo-embolization (THP 30-60 mg, E-ADM 20-40 mg, CDDP 40-80 mg, MMC 10-20 mg, iodin oil 5-30 ml), percutaneous ethanol injection, bioimmunotherapy and traditional Chinese medicine were used pre- and post-operatively. CT angiography and CT during arterial portography were used to find satellite nodules. Early stage recurrences were predicted by AFPmRNA in peripheral blood. Child-Pugh's classification plus branch chain amino acid/aromatic amino acid ratio (BCAA/AAA) was adopted in evaluating pre-operative liver functions. RESULTS: Marked results were observed after serial treatments oriented by surgery. The 1-, 3- and 5-year survival rates in resection group were 75.8%, 45.6% and 30.4%, respectively. The 1- and 3-year survival rates in cryosurgery group were 63.2% and 37.0%. The operative mortality was 1.57%. Recurrence rates were 69.2% in AFPmRNA positive group and 33.3% in AFPmRNA negative group (P<0.05). The BCAA/AAA ratio was lower than 1.5 in two patients who died of hepatic failure after resection. CONCLUSIONS: Serial treatments with surgery as the chief modality gives satisfactory results in patients with large primary liver carcinoma. This regimen should be regarded as a main strategy to deal with large liver carcinoma. AFPmRNA in the peripheral blood, signifying a recurrence, may become a new clinical parameter. The BCAA/AAA ratio plus Child-Pugh's classification is able to evaluate more accurately liver function reserve before surgery.

Adolescent↗