Biomedical subjects

Qi Zhou

Publications and source records attributed to Qi Zhou.

At least 37 records · Page 2Linked to original sources

PubMed2006

Vasopressin or epinephrine for out-of-hospital cardiac arrest.

STUDY OBJECTIVE: The use of vasopressin in patients with cardiac arrest presenting with specific rhythms is controversial. We performed an evidence-based emergency medicine review of evidence comparing vasopressin to epinephrine in structured cardiac arrest protocols. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library, and other databases for randomized trials or systematic reviews comparing vasopressin to epinephrine for adults with cardiac arrest and measuring survival to hospital discharge and neurologic function in survivors. We used standard criteria to appraise the quality of published trials and systematic reviews. We used the random effects model in supplementary analyses to summarize results and to test for significant differences across subgroups of patients presenting with different arrest rhythms. RESULTS: We found 3 high-quality well-reported randomized trials and 1 rigorous meta-analysis. The evidence does not confirm a consistent benefit of vasopressin over epinephrine in increasing survival or improving neurologic outcome in survivors. Subgroup analysis reveals a large difference in effect of vasopressin over epinephrine in cardiac arrest patients with asystole, compared to other arrest rhythms, coming from within-trial comparisons. The difference is not consistent across otherwise similar trials, is not statistically significant, may reflect the application of multiple unplanned subgroup analyses, and is not supported by a plausible biological hypothesis. CONCLUSION: Evidence from randomized trials does not establish a benefit of vasopressin over epinephrine in increasing survival to discharge or improving neurologic outcomes in adult patients with nontraumatic cardiac arrest.

Brain Damage, Chronic↗

PubMed2006

Friction between cellulose surfaces and effect of xyloglucan adsorption.

The forces and friction between cellulose spheres have been measured in the absence and presence of xyloglucan using an atomic force microscope. The forces between cellulose are monotonically repulsive with negligible adhesion after contact is achieved. The friction coefficient is observed to be unusually high in comparison with other nanotribological systems. We have confirmed that xyloglucan adsorbs strongly to cellulose, which results in a much stronger adhesion, which is dependent on the time the surfaces are in contact. Xyloglucan also increases the repulsion on approach of the cellulose surfaces, and the friction is markedly reduced. The apparently incompatible observations of decreased friction in combination with increased adhesion fulfills many of the necessary criteria for a papermaking additive.

Adsorption↗

PubMed2006

Grafting of cellulose fibers with poly(epsilon-caprolactone) and poly(L-lactic acid) via ring-opening polymerization.

In this study, ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) and L-lactide (L-LA) has been performed from cellulose fibers. The hydroxyl groups on cellulose act as initiators in the polymerization, and the polymers are covalently bonded to the cellulose fiber. As an attempt to introduce more available hydroxyl groups on the surface, and thereby obtain higher grafting efficiency in the ROP of epsilon-CL and L-LA, unmodified paper was modified with xyloglucan-bis(methylol)-2-methylpropanamide (XG-bis-MPA) and 2,2-bis(methylol)propionic acid (bis-MPA), respectively. The grafted substrates were characterized via Fourier transform infrared spectroscopy (FTIR), contact angle measurement, atomic force microscopy, and enzymatic degradation. The results showed a successful grafting of poly(epsilon-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) from the cellulose fiber surfaces. Furthermore, the results showed an improved grafting efficiency after activation of the cellulose surface with bis-MPA, and showed that the amount of grafted polymer could be controlled by the ratio of added free initiator to monomer.

Cellulose↗

PubMed2006

Defective RhoA/Rho-kinase signaling contributes to vascular hypocontractility and vasodilation in cirrhotic rats.

BACKGROUND & AIMS: Portal hypertension is associated with arterial hypotension and vascular hypocontractility, which persists despite elevated plasma levels of vasoconstrictors. We investigated the role of the RhoA/Rho-kinase pathway in vascular smooth muscle hypocontractility of rats with secondary biliary cirrhosis. METHODS: Aortic expressions of RhoA and Rho-kinase were analyzed in sham-operated and BDL rats by reverse-transcription polymerase chain reaction (RT-PCR) and immunoblots. Activation of aortic RhoA was examined by pull down of guanosine triphosphate (GTP)-RhoA and membrane translocation of RhoA. Rho-kinase activity was assessed as phosphorylation of its substrate, moesin. Contractility of isolated aortic rings was determined myographically. The hemodynamic effect of the Rho-kinase inhibitor (R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) was determined in vivo by measuring changes in mean arterial pressure and systemic vascular resistance (SVR) (microspheres). RESULTS: Contraction of aortic rings from BDL rats was impaired in response to the alpha(1)-adrenergic receptor agonist methoxamine but not to high molar KCl. Aortic expression of RhoA was unchanged in cirrhotic rats, whereas Rho-kinase was down-regulated posttranscriptionally. Methoxamine-induced activation of RhoA as well as basal and methoxamine-induced phosphorylation of moesin were strongly reduced in aortas from cirrhotic rats. Aortic rings from cirrhotic rats precontracted with methoxamine showed an increased sensitivity to relaxation with Y-27632. The drop in SVR induced by Y-27632 was larger in cirrhotic rats than in sham-operated rats. CONCLUSIONS: An impaired vascular activation of RhoA and a down-regulation of Rho-kinase might contribute to vasodilation and vascular hypocontractility in BDL-induced cirrhosis.

Amides↗

PubMed2006

Chemically modified short interfering hybrids (siHYBRIDS): nanoimmunoliposome delivery in vitro and in vivo for RNAi of HER-2.

A blunt-ended 19-mer short interfering hybrid (siHybrid) (H) comprised of sense-DNA/antisense-RNA targeting HER-2 mRNA was encapsulated in a liposomal nanoplex with anti-transferrin receptor single-chain antibody fragment (TfRscFv) as the targeting moiety for clinically relevant tumor-specific delivery. In vitro delivery to a human pancreatic cell line (PANC-1) was shown to exhibit sequence-specific inhibition of 48-h cell growth with an IC50 value of 37 nM. The inhibitory potency of this siHybrid was increased (IC50 value of 7.8 nM) using a homologous chemically modified siHybrid (mH) in which the 19-mer sense strand had the following pattern of 2 '-deoxyinosine (dI) and 2 '-O-methylribonucleotide (2 '-OMe) residues: 5'-d(TITIT)-2'OMe(GCGGUGGUU)-d(GICIT). These modifications were intended to favor antisense strand-mediated RNAi while mitigating possible sense strand-mediated off-target effects and RNase H-mediated cleavage of the antisense RNA strand. The presently reported immunoliposomal delivery system was successfully used in vivo to inhibit HER-2 expression, and thus induce apoptosis in human breast carcinoma tumors (MDA-MB-435) in mice upon repeated i.v. treatment at a dose of 3 mg/kg of H or mH. The in vivo potency of modified siHybrid mH appeared to be qualitatively greater than that of H, as was the case in vitro.

Animals↗

PubMed2006

Tumor-targeting nanoimmunoliposome complex for short interfering RNA delivery.

The potential of short interfering RNA (siRNA) to be developed for therapeutic use against cancer depends on the availability of an efficient tumor-specific delivery vehicle. We have previously shown that a nanoscale nonviral liposome-based complex that includes an anti-transferrin receptor single-chain antibody fragment as the targeting moiety can, when systemically administered, specifically and efficiently target primary and metastatic tumors and deliver molecules useful in gene medicine, including plasmid DNA and antisense oligonucleotides. Here we explore the ability of this complex to deliver a fluorescein-labeled siRNA to tumor cells in vivo and examine the intracellular localization in vitro by confocal microscopy. We show that the immunoliposome--siRNA complex maintains its nanoscale size and, using three separate tumor models, can efficiently and specifically deliver siRNA to both primary and metastatic disease after systemic delivery, thus increasing the possibility for translating the potent effects of siRNA observed in vitro into clinically useful therapeutics.

Animals↗

PubMed2006

Fiber for the treatment of hemorrhoids complications: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the impact of laxatives on a wide range of symptoms in patients with symptomatic hemorrhoids. METHODS: We searched using the following sources: MEDLINE, EMBASE, CINAHL and CENTRAL, BIOSIS, AMED, Papers First and Proceedings; study authors, industry, and experts in the field. We included all published and unpublished parallel group randomized controlled trials comparing any type of laxative to placebo or no therapy in patients with symptomatic hemorrhoids. Two reviewers independently screened studies for inclusion, retrieved all potentially relevant studies, and extracted data on study population, intervention, prespecified outcomes, and methodology. RESULTS: Seven trials randomized 378 patients to fiber or a nonfiber control. Studies were of moderate quality for most outcomes. Meta-analyses using random effects models suggested that fiber has an apparent beneficial effect. The risk of not improving/persisting symptoms decreased by 47% in the fiber group (RR = 0.53, 95% CI 0.38-0.73) and the risk of bleeding by 50% (RR = 0.50, 95% CI 0.28-0.89). Studies with multiple follow-ups, usually at 6 wk and at 3 months, showed consistent results over time. Results are also compatible with large treatment effects in prolapse, pain, and itching, but even in the pooled analyses confidence intervals were wide and compatible with no effect (RR = 0.79, 95% CI 0.37-1.67; RR = 0.33, 95% CI 0.07-1.65; and RR = 0.71, 95% CI 0.24-2.10, respectively). One study suggested a decrease in recurrence. Results showed a nonsignificant trend toward increases in mild adverse events in the fiber group (RR = 6.0, 95% CI 0.57-64.8). CONCLUSIONS: Trials of fiber show a consistent beneficial effect for symptoms and bleeding in the treatment of symptomatic hemorrhoids.

Constipation↗

PubMed2006

Developmental abnormalities of NT mouse embryos appear early after implantation.

In mammals, cloning by nuclear transfer (NT) into an enucleated oocyte is a very inefficient process, even if it can generate healthy adults. We show that blastocysts derived from embryonic stem (ES) donor cells develop at a high rate, correctly express the pluripotential marker gene Oct4 in ICM cells and display normal growth in vitro. Moreover, the majority of them implant in the uterus of recipient females. We combine embryological studies, gene expression analysis during gastrulation and generation of chimaeric embryos to identify the developmental origin (stage and tissue affected) of NT embryo mortality. The majority died before mid-gestation from defects arising early, either at peri-implantation stages or during the gastrulation period. The first type of defect is a non-cell autonomous defect of the epiblast cells and is rescued by complementation of NT blastocysts with normal ES or ICM cells. The second type of defect affects growth regulation and the shape of the embryo but does not directly impair the initial establishment of the patterning of the embryo. Only chimaeras formed by the aggregation of NT and tetraploid embryos reveal no growth abnormalities at gastrulation. These studies indicate that the trophoblast cell lineage is the primary source of these defects. These embryological studies provide a solid basis for understanding reprogramming errors in NT embryos. In addition, they unveil new aspects of growth regulation while increasing our knowledge on the role of crosstalk between the extra-embryonic and the embryonic regions of the conceptus in the control of growth and morphogenesis.

Animals↗

PubMed2006

Comparability of five analytical systems for the determination of triiodothyronine, thyroxine and thyroid-stimulating hormone.

BACKGROUND: The purpose of an external quality assessment (EQA) is to evaluate the analytical capability of clinical laboratories, identify differences among the laboratories and improve analytical quality. Our EQA results show that the rates of unsatisfactory performance for thyroid hormone tests were the highest in all of our EQA programs. Therefore, the main purpose of this study was to investigate unsatisfactory results by comparing the analytical values of five routinely used analytical systems. METHODS: The Kruskal-Wallis and two-sample Kolmogorov-Smirnov tests were used to identify analytical differences among and between analytical systems, respectively. RESULTS: The rates of significantly different results compared to the total number of analytical results were 81.1%, 64.5%, 93.3%, 50.0% and 56.7% for free triiodothyronine, total triiodothyronine, free thyroxine, total thyroxine and thyroid-stimulating hormone, respectively. CONCLUSIONS: Relatively large analytical differences between analytical systems were observed, especially when the analytical systems were used to measure free thyroid hormones.

Blood Chemical Analysis↗

PubMed2006

[Preparation and characterization of anti-morphine vaccine antibody].

AIM: To prepare anti-morphine vaccine antibody with high titer and good specificity and to identify its properties. METHODS: Chemically synthesized 6-succinylmorphine (M-6-S) was cross-linked to BSA in pH 9.0 carbonate buffer. After being purified by gel filtration and (NH4)2SO4 salting out, the immunogen was used to immunize BALB/c mice and SD rats. The titer and specificity of antisera were identified by ELISA and neutralization inhibition test, respectively. The effect of the immunization was examined by the radiant heat tail-flick (TF) reflex test. RESULTS: The titers of antiserum from immunized BALB/c mice and SD rats were up to 1:200,000 and over 1:20,000, respectively. Neutralization inhibition test proved that the anti-morphine vaccine antibody had the cross-reactions to following drugs with analogous structure as morphine: 6-monoacetylmorphine, heroin and codeine. The TF reflex test showed: (1) TF reflexes were notable inhibited after intraperitoneal injection of 2 mg/kg morphine, and (2) percentage of the maximum possible effect (% MPE) reduced 74.7%, (3) the TF latency recovered to the baseline level much more rapidly compared with the control rats. CONCLUSION: The M-6-S-BSA vaccine has been prepared successfully. The BALB/c mice and SD rats immunized with the vaccine can produce anti-morphine antibody with high titer and satisfactory specificity, which may significantly reduce rats' antinociception against morphine.

Animals↗

PubMed2006

[Relationships between loading rates and nitrogen removal effectiveness in subsurface constructed wetlands].

About forty kinds of nitrogen loading removal rate were studied in field in 15 months, inflow and outflow loading rules of reeds/Zizania caduciflora/mixing and no-plant bed were discussed in different inflow loading. The four kinds SFS inflow loading changed from 400 mg x (m2 x d)(-1) to 8 000 mg x (m2d)(-1), while outflow loading is less than 7,000 mg (m2 d)(-1). Results show that outflow loading increase with the increase of inflow loading, linear relation is obvious. Total nitrogen removal rate has the same trend at low inflow loading. But in high inflow loading TN removal rate has much variation. The system had better run between 2,000 mg x (m2 x d)(-1) and 4,000 mg x (m2 x d)( -1) inflow loading. Average removal rate in between 1062 mg x (m2 x d)(-1) and 2 007 mg x (m2 x d)(-1). Plant SFS removal rate is better than no-plant SFS. TN removal rate of reed and zizania caduciflora bed is 63 % and 27 % higher than no-plant bed. Plant harvesting is unimportant and contributes less than 5% of TN removal loading, plant can improve system microenviroment and hydrology condition which could increase TN removal rate. The results provided deep insight to SFS nitrogen removal and reference to SFS design.

Biodegradation, Environmental↗

PubMed2006

[Capability of Cu2+ adsorption on cell surface of Pseudomonas putida 5-x].

Analysis of Cu2+ adsorption on cell surface of a Gram-negative bacterium P. putida 5-x was carried out. Isolated cell envelopes possess fivefold more Cu2+ adsorption capacity than that of the fresh intact cells. Experimental results also indicate that the content of the peptidoglycan layer, the outer membrane and inner membrane in the cell envelope is in order of inner membrane > outer membrane > PEG layer, while their Cu2+ adsorption capacity is in order of PEG layer > outer membrane > inner membrane. The total contribution of the separated PEG layer material to Cu2+ adsorption is no more than 15% part, and the cell outer membrane and inner membrane contribute about 30%-35% and 25%-30% part, respectively, to Cu2+ adsorption by the cell envelope. The relatively high phospholipid content in the outer wall might result in its higher adsorption capacity to Cu2+, and leads to a higher adsorption capacity of the cell envelope of P. putida 5-x.

Adsorption↗

PubMed2006

[Impact of pH on the generation of COD, phosphorous and ammonia-nitrogen during the anaerobic fermentation of excess activated sludge].

There are mainly two kinds of sludge in the municipal wastewater treatment plant, i. e. , primary and secondary sludge. This study investigated the effect of pH, ranging from 4.0-11.0, on hydrolysis in terms of soluble chemical oxygen demand (SCOD) production in the anaerobic solubilization of excess activated sludge at 20-22 degrees C. It was found that when the value of pH was 8.0-10.0, the production quantity of SCOD were higher than pH = 5.0-7.0. Especially when the pH was 10.0 or 11.0, the value of SCOD was almost 10 times of pH = 6.0 during the whole fermentation of 20 days. And volatile fatty acids (VFA) production on the 8th day under alkaline condition was higher than that under acidic condition.

Ammonia↗

PubMed2006

[Experimental study on the mechanism of oilfield wastewater treatment by using hydrolysis-acidification with aerobic biological processes].

Hydrolysis-acidification + aerobic biological processes were conducted experimentally to treat oilfield wastewater pretreated with physical and chemical treatment in Xinjiang oilfield. The results showed that when the COD concentration in influent was 190-220 mg x L(-1), that in effluent reduced to 65-75 mg x L(-1) under HRT of 10h in both hydrolysis-acidification process and aerobic biological process, reaching the strictest requirement of Effluent Standards for Wastewater from Petroleum Development Industry (GB3550-83). Using GC/MS technology, the relative content of various organic pollutants was analyzed to discover the transfer and degradation law in the oilfield wastewater in biological treatment process. The system of DNA extraction technique, PCR and DGGE reacting systems were practical to analyze the microbial community in the hydrolysis-acidification and aerobic biological processes. The predominant sequences of several 16S rDNA DGGE fragments were determined and confirmed in comparison in GeneBank (NCBI).

Bacteria, Aerobic↗

PubMed2006

[Research on polyhydroxyalkanoate form a key aspect to enhanced biological phosphorus transformation].

To investigate the influence of PHB and PHV formed on phosphorus (P) release, uptake and removal during enhanced biological phosphorus removal (EBPR), anaerobic/aerobic batch experiments were conducted with biomass acclimated with propionic to acetic acid carbon molar ratios of 0.5 and 2 on two sequencing batch reactors (SBR1 and SBR2). Statistically significant correlations between polyhydroxyalkanoate (PHA) quantity and form and P release/uptake and removal were observed (R2 >0.90). The regression coefficients showed that for biomass cultured with customizing wastewater P release and uptake were both a function of PHB but not of PHV, but higher P removal was largely because of PHV as the predominant type rather than PHV. For biomass cultured with different ratios of propionic to acetic acid, the SBR2 biomass synthesized and utilized more PHB and less PHV and showed higher net P removal (average increase of 16.69%) than SBR1. Thus acetate/propionate content of influent had a major influenceon PHA type and quantity and determine phosphorus (P) release, uptake and removal. Accordingly, PHB and PHV transformations should be taken into account as key aspect for optimizing EBPR.

Bacteria, Aerobic↗

PubMed2006

[Expression and clinical significance of coagulate and fibrolysis factors in tissue and plasma from hepatocellular carcinoma patients].

BACKGROUND & OBJECTIVE: Considerable evidences showed that changes of coagulation and proteolysis factors are closely related to the genesis and growth of malignancy. This study was to detect the expression of tissue factor (TF), urokinase-type plasminogen activator (uPA), and urokinase-type plasminogen activator receptor (uPAR) in cancer tissues and plasma of patients with hepatocellular carcinoma (HCC), and analyze their prognostic significance. METHODS: Blood samples were obtained from 50 HCC patients and 30 patients with non-tumor disease. Plasma levels of TF, uPA, and uPAR were detected by ELISA. Cancer tissue and adjacent tissue samples were obtained randomly from 27 patients in HCC group; normal liver tissue samples were also collected from 27 patients in benign disease group. The mRNA levels of TF, uPA, and uPAR in all tissue samples were detected by reverse transcription-polymerase chain reaction (RT-PCR). Their correlations to clinicopathologic features of HCC were analyzed. RESULTS: Plasma levels of TF, uPA, and uPAR were significantly higher in HCC group than in control group [(409.4+/-13.0) pg/ml vs. (318.8+/-69.1) pg/ml, (1.63+/-0.52) ng/ml vs. (1.20+/-0.40) ng/ml, (1.36+/-1.00) ng/ml vs. (0.68+/-0.28) ng/ml, P<0.05]. Poor differentiation, larger size, and cirrhosis of HCC increased plasma TF level (P<0.05); cirrhosis also increased plasma uPA level (P<0.05); lymphatic metastasis, extrahepatic metastasis, and portal venous tumor thrombus (PVTT) increased plasma levels of TF, uPA, and uPAR (P<0.05). The positive rates of TF, uPA, and uPAR in HCC tissues were 62.96%, 70.37%, 77.78%, respectively; the mRNA levels of TF, uPA, and uPAR were 0.57+/-0.27, 0.96+/-0.46, 0.78+/-0.32, respectively. The positive rates and mRNA levels of TF, uPA, and uPAR were all significantly higher in HCC tissues than in adjacent tissues and normal liver tissues (P<0.05). Intrahepatic metastasis and PVTT increased the positive rate and mRNA levels of TF, uPA, and uPAR in HCC (P<0.05). Pearson test showed that TF expression was positively correlated to uPA, and uPAR expression (r=0.373, P<0.01; r=0.534, P<0.01); uPA expression was positively correlated to uPAR expression (r= 0.365, P<0.01). COX regression analyses showed that TF, uPA, and uPAR were independent prognostic factors of HCC (Chi(2)=6.05, P=0.014; Chi(2)=4.29, P=0.038; Chi(2)=4.40, P=0.036). CONCLUSION: TF, uPA, uPAR might have synergetic effect in invasion and metastasis of HCC, and they might relate to prognosis.

Adult↗

PubMed2006

[Biodegradability and degradation mechanism of 3-fluorophenol by the activated sludge].

An acclimated activated sludge was examined for its ability to degrade 3-fluorophenol in aerobic batch cultures. The result indicated that the organism degrades up to 100 mg/L 3-fluorophenol completely with approximately 100% fluoride anion release within 16 h. 3-Fluorophenol can serve as the sole carbon source and energy source for the organism. The acclimated activated sludge can degrade 3-fluorophenol effectively. The degradation mechanism study reveal that the initial step in the aerobic biodegradation of 3-fluorophenol is its transformation to fluorocatechol. Following transformation of the fluorophenol to fluorocatechol, ring cleavage by catechol 1, 2-dioxygenase proceedes via an ortho-cleavage pathway, then defluorination occurres.

Acclimatization↗

PubMed2005

[Role of bcl-2 transcriptional regulation induced by calmodulin I pressure overload rat hypertrophic hearts].

This study was designed to evaluate the role of bcl-2 transcriptional regulation induced by calmodulin I (CaM I) in pressure overload rat hypertrophic hearts. The model of hypertensive Sprague-Dawley rat was established by abdominal aortic constriction. The hearts were collected four weeks after abdominal aortic constriction. Velocity and isopyknic gradient centrifugation was employed to fractionate rat myocardial nuclei. Western blot analysis revealed a marked increase in phosphorylated cAMP response-element binding protein (pCREB) of cardiac hypertrophy group compared with that in control group (P<0.05), while the protein level of cAMP response-element binding protein (CREB) was constant (P>0.05). Immunohistochemistry results showed a significant increase of CaM I protein in cardiac hypertrophy group relative to the control group (P<0.05). Nuclear run off transcription assay displayed a significant increase in bcl-2 mRNA treated with trifluoperazne compared with non-drug treatment (P<0.05). The results obtained suggest that the transcription of bcl-2 is possibly regulated by CaM I hypertrophic rat hearts, and CREB phosphorylation seems to be a minor factor in bcl-2 transcriptional regulation.

Animals↗