Biomedical subjects

H Liu

Publications and source records attributed to H Liu.

At least 271 records · Page 15Linked to original sources

PubMed2001

[Changes in erythrocyte rheologic properties after mild burn injury].

The changes in erythrocyte deformability and osmotic fragility were studied with an animal model of mild burn injury. The results showed that after the burn injury there was a gradual decrease with time at first and then a recovery in erythrocyte deformability. Maximum deformation index [(DI)max], integration deformation index (IDI) and osmotic fragility of RBCs drawn just after burn were almost identical to those before burn injury. (DI)max and IDI significantly decreased at 1, 2 h but not at 4, 7 h when compared with those before burn injury, however, the RBCs were less deformable at 4, 7 h. Erythrocyte osmotic fragility significantly increased only at 4 h after burn injury when compared at the time points of 0, 1, 2, 4, 7 h after burn with that before burn injury. The results indicated that the lesion in (DI)max and IDI, and the increase in osmotic fragility might be only related to the body fluid factors in this animal model. The decrease in erythrocyte deformability and the increase in erythrocyte osmotic fragility did not synchronize, suggesting that the changes might come about not by the same mechanism.

Animals↗

PubMed2001

Preliminary assessment of turbo spectroscopic imaging for targeting in brain biopsy.

BACKGROUND AND PURPOSE: Brain biopsy remains an integral and necessary component in the diagnosis of brain lesions. We assessed the ability of turbo spectroscopic imaging (TSI) to provide a physiologically based target for tissue sampling. METHODS: TSI was performed in 26 anesthetized patients immediately before MR-guided brain biopsy. In 10 patients, single-voxel spectroscopy was performed on the TSI-indicated target and correlated with the TSI findings. Biopsy samples were taken from the imaging and spectroscopically defined target(s) under MR guidance, and pathologic findings were compared with preoperative spectra. RESULTS: TSI alone provided a definitive target based on a region of elevated choline in 17 of 21 patients in whom a neoplasm was confirmed. The remaining four neoplasms exhibited relatively low metabolic levels and were difficult to distinguish from the five cases of radiation necrosis seen in this study. TSI findings were in qualitative agreement with those obtained at single-voxel spectroscopy, although TSI spectra exhibited more contamination. Quantitative spectral analysis of TSI data is limited by low spectral resolution. CONCLUSION: TSI is helpful for determining an appropriate biopsy target in heterogeneous lesions. Coupling TSI targeting with conventional imaging and intraoperative confirmation of needle positioning resulted in a 100% diagnostic success rate and increased the clinician's confidence in the histologic findings.

Adolescent↗

PubMed2001

[Decomposition of aqueous sodium pentachlorophenolate (PCP-Na) by using TiO2 coating photocatalyst].

Titanium dioxide (TiO2) photocatalysts were coated on hollow glass beads by sodium silicate (Na2SiO3.9H2O) solution. The coated catalysts were characterized by BET, XRD. Their photoactivity were examined using photocatalytic degradation of sodium pentachlorophenolate(PCP-Na) and glucose solution. The impact of catalysts dosage, PCP-Na initial concentration, initial pH and oxygen concentration on reaction kinetics were also studied in detail. The experiments illustrated that the performance of C3-type catalysts was satisfactory. Conditions of the experiments were following: The initial concentration of PCP-Na and CODCr were 10 mg.L-1 and 400 mg.L-1, respectively, and illumination time was 2 hours and catalysts dosage was 2 g.L-1, the removal rates of CODCr and PCP-Na were above 65% and 92% respectively. Optimum dosage of C3-type catalysts was 2-2.5 g.L-1, DO was no less than 3 mg.L-1.

Catalysis↗

PubMed2001

[Quinoline removal in fluidized-bed bioreactor using immobilized cells].

Burkholderia pickettii, capable of using quinoline as sole source of carbon, nitrogen and energy, was immobilized by an innovative PVA-H3BO3-gauze method. A fluidized-bed bioreactor, in which immobilized cells were added, was constructed to degrade quinoline in wastewater. When the initial concentrations of quinoline were 100, 350 and 500 mg/L, the bioreactor can remove it completely within 2.5, 6 and 12 hours respectively. A series of zero-order reaction equations were proposed to describe quinoline biodegradation process in this bioreactor kinetically. In continuous flow experiments, the performance of the bioreactor was investigated at different HRT (dilution rate) for different quinoline concentrations in wastewater and the tolerance against shock loading was determined by increasing quinoline concentration from 100 to 300 to 500 mg/L at HRT 4 hours.

Bioreactors↗

PubMed2001

[Clinical application of the medial multiplex flap pedicled with the posterior tibial vessel].

OBJECTIVE: To investigate the clinical results of the medial multiplex flap pedicled with the posterior tibial vessel. METHODS: Twelve cases with soft tissue defects and bone defects of limbs were treated with the medial multiplex flap pedicled with the posterior tibial vessel from September 1992 to May 1999. Among them, bone and soft tissue defects following opened fracture in 7 cases, chronic ulcer following chronic osteomyelitis in 2 cases, melanoepithelioma in 2 cases, bone and soft tissue defects following osteoma resection in 1 case. The bone defect area was from 2.5 cm x 5.0 cm to 4.5 cm x 11.0 cm. Free graft was performed in 5 cases, bridged transposition in 3 cases and reversal transposition in 4 cases, among them, periosteal myocutaneous flap with autogenous or allogeneic bone grafting in 8 cases, myocutaneous flap in 4 cases. The area of the flaps from 6 cm x 8 cm to 12 cm x 25 cm. RESULTS: All flaps were healed by first intention, but in the distal fragments of bigger flaps were partially necrosed in 2 cases. In 10 cases bone healing were obtained after 16 weeks of operation according to the X-ray photos. All cases were followed up from 6 to 18 months. All cases achieved satisfactory result but 1 case died because of lung metastasis of osteoma. CONCLUSION: The multiplex graft pedicled with the posterior tibial vessel is an ideal graft for repairing the large soft tissue defects and bone defects, because it has such advantages as adequate blood supply, big vascular diameter, long pedicle and big dermatomic area.

Adolescent↗

PubMed2001

[Effects of yinchenhao decoction on normal animals and animal models of diabetes mellitus].

OBJECT: To study the effects of yinchenhao Decoction on the blood glucose level in a variety of animal models and its mechanism. METHODS: Normal mice, rats model of ailoxan (ALX)-induced diabetes mellitus (DM), mice model of ALX-DM and rats model of dexamethasone (DX)-induced insulin resistance (IR) were used. RESULTS: yinchenhao Decoction was able to inhibit the hyperglycemia by ALX-induced mice(P < 0.01), significantly reduce level of FBG in normal mice, ALX-DM mice and rats (P < 0.05-0.01), improve IGT and lower 2hBG (P < 0.01) after OGTT in DX-induced insulin-resistant rats. CONCLUSIONS: The results suggest that yinchenhao Decoction possesses similar hypoglycemic action to meftormin and gliclazied.

Animals↗

PubMed2001

[Identification of seeds of Cuscuta australis and C. chinensis by TLC and HPLC].

Identification of seeds of Cuscuta australis R. Br. and C. chinensis Lam. was carried out by TLC and HPLC. Polyamide membrane was used as stationary phase, MeOH-HOAc-H2O and CHCl3-MeOH-HOAc were used as mobile phase for TLC. For HPLC, Hypersil-ODS column was used; the mobile phase was MeOH-0.025 M H3PO4; the flow rate was 1.0 ml.min-1; detection wavelength was 360 nm; and column temperature was 40 degrees C. Both methods represented significant identification characteristics, and were simple, accurate and reproducible.

Chromatography, High Pressure Liquid↗

PubMed2001

[The technical method for noninvasive magnetic stimulation of nerve center and its clinical application].

The increasing use of non-invasive magnetic stimulation technique for nerve center function examination and functional neuromuscular rehabilitation is a new cynosure in biomedical engineering and neuro-electrophysiologic researches. This paper analyzes theoretically the magnetic stimulation of first demonstration extending the technique model to human body, and the magnetic principle of physics. The characteristics of magnetic stimulation can be highlighted by comparing it to conventional electrical stimulation. Also presented are the peripheral multichannel magnetic stimulation to mimic electrical stimulation and the clinical functions toward neuromuscular rehabilitation.

Central Nervous System↗

PubMed2001

[Removal of NH4(+)-N from polluted water resources by bioremediation of biofilm process with elastic packing & micropore aerator].

The effect of NH4(+)-N removal in the polluted raw water of water sources by the bioremediation action of the biocontact oxidation process with the elastic packing and micropore aerator was studied in this paper. The research results showed the bioremediation process can reach a removal ratio of 64%-95% for NH4(+)-N of water sources under the condition of ordinary temperature 20 degrees C-27 degrees C, CODMn 7-14 mg/L, NH4(+)-N 0.7-2.0 mg/L in the water sources and the running parameters HRT 1.4 h, gas and water ratio 0.5:1, and DO 7-9 mg/L for the bioremediation process and a removal ratio of 40%-63% for NH4(+)-N of water sources under the condition of low temperature 7 degrees C-12 degrees C, CODMn 6-11 mg/L, NH4(+)-N 1.2-8.0 mg/L in the water sources and the running parameters HRT 1.4 h, gas and water ratio 0.5:1, and DO 8-10 mg/L for the bioremediation process.

Biofilms↗

PubMed2001

[The growth hormone and insulin-like growth factors axis in liver failure patients].

OBJECTIVE: To measure circulating concentration of growth hormone (GH), insulin-like growth factors 1 (IGF-1), and it's binding protein 1 (IGFBP1) and binding protein 3 (IGFBP3) in patients with sever hepatitis, and to survey the clinical significance of GH-IGFS axis. METHODS: The study population consisted of 18 patients with liver failure caused by serious virous hepatitis, and of 20 normal volunteers. Serum concentration of GH, IGF-1, IGFBP1 and IGFBP3 was determined by ELISA. Liver biochemistric functions were measured by routine methods. RESULTS: Serum concentrations of IGF-1 and IGFBP3 were equally reduced (5.5microgram/ml +/- 6.2 microgram/ml vs 17.6 microgram/ml +/-7.0 microgram/ml, and 2.4 microgram/ml +/-1.3 microgram/ml vs 9.4 microgram/ml +/- 1.7microgram/ml, P<0.001, respectively); increased serum GH and IGFBP1 were observed (9.1ng/ml +/-12.4ng/ml vs 1.6ng/ml +/-2.4ng/ml, P<0.05; 67.9ng/ml+/-50.2ng/ml vs 45.8ng/ml+/-33.1ng/ml, P<0.01) in liver failure patients as compared with the controls. The positive relationship between IGF-1 and IGFBP3 (r=0.91, P<0.001) was observed. The closed relation between the serum IGF-1 and the prognosis of patients was also obtained. IGF-1<10 microgram/ml was in accord with 90% accurate rate of predicted death. CONCLUSIONS: The GH-IGFs axis is significantly abnormal in liver failure patients, suggesting the existence of GH resistance in these patients. Serum IGF-1 may act as a predictor for their prognosis.

Adult↗

PubMed2001

The sheepshead minnow as an in vivo model for endocrine disruption in marine teleosts: a partial life-cycle test with 17alpha-ethynylestradiol.

The sheepshead minnow (Cyprinodon variegatus Lacépède), an estuarine fish species, was exposed to 17alpha-ethynylestradiol (EE2) at nominal test concentrations of 0.2, 2, 20, 200, 400, 800, 1,600, and 3,200 ng/L. Fish were exposed for up to 59 d, from subadult stages to sexual maturity, under flow-through conditions. The exposure period was followed by an evaluation of reproductive success and survival of progeny. The reproductive success of exposed sheepshead minnows, as determined from data on egg production from two subsequent spawning trials, was reduced in fish exposed to 200 ng/L EE2 and, in one spawning trial, in the 20-ng/L treatment. Hatching success was reduced in the progeny of fish exposed to 200 ng/L EE2, but survival was good among fry that successfully hatched. Histological examination indicated generalized edema, damage to gill epithelia, hepatic toxicity, fibrosis of the testis, and evidence of sex reversal, including testes-ova and spermatagonia-like cells in ovaries. The maximum acceptable toxicant concentration (MATC) for gonadal development in males was within the normal range of EE2 concentrations in sewage treatment plant effluents. The exposure regimen and choice of test organism, combined with histological examination, allowed independent evaluation of ecologically significant acute, reproductive and estrogenic endpoints. Estrogen receptor-mediated effects occurred at concentrations where reproductive effects were measurable under standard reproduction assays. The sheepshead minnow appears to be a sensitive in vivo model for partial life-cycle testing of compounds that have the potential to disrupt the endocrine system as well as reproduction in estuarine and coastal marine fish species.

Animals↗

PubMed2001

Perfusion MR neuroimaging in patients undergoing balloon test occlusion of the internal carotid artery.

BACKGROUND AND PURPOSE: We sought to investigate whether the combination of conventional, diffusion-weighted, and perfusion-weighted MR imaging increases the diagnostic accuracy of balloon test occlusion of the internal carotid artery. We describe perfusion anomalies and patterns of enhancement seen in areas of altered brain perfusion during MR-monitored temporary balloon occlusion of the internal carotid artery. METHODS: Nine patients underwent balloon occlusion testing under standard angiographic conditions with continuous clinical and EEG monitoring. One patient who failed the test by clinical criteria underwent an external carotid to internal carotid bypass operation, followed by a repeat balloon test occlusion, thereby bringing the total number of procedures to 10. Patients were further imaged at 1.5 T with perfusion- and diffusion-weighted imaging as well as with conventional noncontrast and contrast-enhanced turbo fluid-attenuated inversion recovery (FLAIR) and T1-weighted sequences. RESULTS: Seven of 10 patients who tolerated unilateral carotid test occlusion without adverse clinical neurologic or EEG changes exhibited delayed first-pass transit of contrast material through the affected cerebral hemisphere, indicative of altered perfusion without significant concurrent cerebral blood flow or blood volume changes. Four of these patients and both symptomatic patients showed pial or subarachnoid contrast staining in areas of altered perfusion without abnormalities on diffusion-weighted images. CONCLUSION: Our findings indicate that MR perfusion-weighted imaging is safe and easily accomplished in a high-field-strength magnet and that contrast-enhanced turboFLAIR imaging may provide clinically useful MR imaging evidence of abnormal cerebral blood flow and subclinical ischemia.

Adult↗

PubMed2001

[Effects of pesticide imidacloprid and its metabolites on soil respiration].

Soil respiration was measured using NaOH absorbing technique. Imidacloprid were applied to soil samples at concentration of 0, 10, 40, 100 micrograms.g-1, its hydrolysis and photolysis products were applied at 40 micrograms.g-1. The more significant effect at higher concentration of imidacloprid was observed. The effect of its hydrolysis product was minor than imidacloprid, but the photolysis products of 10 min have stronger effect, the effect decreased greatly in 30 min. Soil respiration recovered after 13 days. It showed that imidacloprid and its metabolites have little effect on soil microorganism.

Carbon Dioxide↗

PubMed2001

[Cloning and expression of Aspergillus niger glucose oxidase gene in methylotrophic yeast].

The DNA fragment encoding A. niger glucose oxidase was amplified by PCR using A. niger genomic DNA as template, and was cloned into vector of pPIC9 for expression in Pichia pastoris. When transformed into methylotrophic yeast Pichia pastoris GS115, The constructed plasmid pPICGOD1 directed the synthesis and secretion of functionally active GOD. After induction in MM medium for 4 days, the GOD activity in the medium reached 30-40 u/mL. SDS-PAGE revealed that recombinant yeast GOD was expressed up to 60%-70% of the total soluble protein, and the secreted GOD could be purified to electrophoretic homogeneity with one purification step using Q Sepharose Fast Flow ion exchange chromatography. The recombinant yeast GOD had very high catalytic activity, showed about 1.6-fold increase of specific activity over the commercial A. niger GOD. Kinetic analysis clearly demonstrated that recombinant yeast GOD showed similar substrate affinity for glucose to A. niger GOD, but the turnover number of the GOD from yeast was determined to be much higher than that of A. niger GOD. In addition, the linear range of glucose electrode made with recombinant yeast GOD was efficiently widened due to the high catalytic activity of yeast GOD.

Aspergillus niger↗

PubMed2001

[The effect analysis of tuberculosis control project loaned by World Bank in Guangdong province].

OBJECTIVE: To evaluate the effect of tuberculosis control project loaned by World Bank in Guangdong province. METHODS: The registration and the treatment effect of pulmonary tuberculosis patients according to Guangdong tuberculosis report were analyzed. RESULTS: The above program had been conducted widespread since 1995. Over the past five years, 601,913 cases of suspicious tuberculosis patients have been received and diagnosed, in which 111,164 infectious patients (containing 91,612 newly-attacked infectious cases) were found. Just in 1999, the number of newly-attacked infectious patients was 1.2 times to that(19,858 newly-attacked infectious cases) of 1981-1990 prior to this program. And the average cure rate of infectious patients reached to 95.2%. The cure rate showed an uptrend amounting to 97.2% from 87.6%. CONCLUSION: Satisfactory effect have been achieved by the World-Bank loaned TB control project in Guangdong province.

China↗

PubMed2001

[Ecological fragility of wetlands in Sanjiang Plain].

This paper presented an index system and a method for evaluating the ecological fragility of wetlands. The indexes were chosen according to the properties and the development pattern of wetland ecosystem in Sanjiang Plain, the values of weighing the relative importance of the indexes were computed by the method of "APH"(The Analytic Hierarchy Process) and the fragility level was evaluated by the method of multi-indexes. A case study showed that the ecological fragility of wetlands in Sanjiang Plain was prominently high. The availability of this method and this index system was also discussed in the paper.

China↗

PubMed2001

[Assessment of ecosystem health--concept framework and indicator selection].

Based on the concept framework of ecosystem health, this paper discussed the suitable indicators to synthetically assess the ecosystem health in governed landscape. Healthy ecosystem means not only ecological health itself, but also the long-term maintenance of healthy human population and the beneficial promotion of social and economic development. Resilience, biodiversity and productivity are the characteristics of healthy ecosystem. The first step in the structure of indicators to assess ecosystem health should be the determination of precise indicator principles. According to the purpose of assessment and the principles of selecting indicator, the indicator system for assessing ecosystem health can be divided into three categories, namely, biophysical indicators, ecological indicators, and social and economic indicators.

Air↗

PubMed2001

Analysis of lenti- and trans-lentiviral vector genetic recombination.

Lentiviral vectors hold great promise for gene therapy, and clinical trials to examine their safety and efficacy for treating human disease are being planned. The principle concern for safety is that genetic recombination among components of the vector could lead to the emergence of replication competent retrovirus (RCR). Using a sensitive method for detecting genetic recombination, we found that the current design of lentiviral vectors permits the generation of envelope-deficient recombinant lentivirus, stable integration of the recombinant into chromosomes of transduced cells, and mobilization of the recombinant genomes to other cells when pseudotyped with an exogenous envelope. We split the lentiviral packaging construct (Gag/Gag-Pol) into two separate parts: one that expresses Gag and Gag-Pro, and another that expresses Pol (reverse transcriptase [RT] and integrase [IN]) as a fusion partner of Vpr (Vpr-RT-IN). This "trans-lentiviral" vector efficiently transduces non-dividing cells and achieves titres greater than 10(6) U/ml or 10(8) IU/ml after concentration by ultracentrifugation. The trans-lentiviral vector disarms the Gag-Pol structure and prevents the generation of recombinants containing functional RT and IN. Since RT and IN are absolutely required for any type of RCR and DNA mobilization, this new class of lentiviral vector, in combination with our sensitive in vitro assay for monitoring regeneration of the gag-pol structure, offers a unique advantage for predicting vector safety for clinical applications.

Base Sequence↗