Biomedical subjects

H Zhang

Publications and source records attributed to H Zhang.

At least 433 records · Page 24Linked to original sources

PubMed2001

[Bioslurry remediation of soil contaminated with polycyclic aromatic hydrocarbons].

Through the operation of the pilot-scale slurry reactor, the operational parameters of bioslurry remediation for soil contaminated with polycyclic aromatic hydrocarbons(PAHs), including temperature, ratio of water to soil, aeration flux, were determined. As the operational condition was that the ratio of water to soil was 2:1, the temperature was 20 degrees C-25 degrees C and aeration flux was 60 L/h, a good result of the remediation could be achieved. With the fungi isolated from contaminated soil as pure culture to degrade PAHs, after 34 days incubation, 90% of pyrene and 33.3% of benz[a]anthracene were degraded by Fusarium, 81.5% of pyrene and 49.2% of benz[a]anthracene were degraded by Mucor, 52% of pyrene and of 46% of benz[a]anthracene were degraded by Penicillium.

Biodegradation, Environmental↗

PubMed2001

[Pretreatment of benzoic acid wastewater].

The benzoic acid wastewater produced from toluene by liquid-phase oxidation is one of the difficult wastewater to treat because of multi-component, high CODcr value (20,000-100,000 mg/L) and nonbiodegradability. A pretreatment way of this wastewater by extraction based on chemical complexation was carried out, and tributyl phosphate (TBP), trialkylamine (7301) and trialkyphosphine oxide (TRPO) were used as complexing agent with n-octanol, kerosene as cosolvent and diluent respectively. Results showed that benzoic acid was recovery successfully and the CODcr value of wastewater was reduced to 1/6 of the initial value through multi-stages cross-flow extraction. Back-extraction was quite easy and the solvent could be reused.

Benzoic Acid↗

PubMed2001

[Sulfa-drug wastewater treatment with anaerobic/aerobic process].

Sulfa drug wastewater was treated with anaerobic/aerobic process. The removal ratios of TOC reached about 50% in anaerobic phase and about 70% in aerobic phase respectively, while volume loading rate of TOC was about 1.2 kg/(m3.d) in anaerobic phase and about 0.6 kg/(m3.d) in aerobic phase. Removal of TOC in anaerobic phase was attributed to the reduction of sulfate.

Aerobiosis↗

PubMed2001

[Studies on fatty liver, blood glucose and related factors in simple obese children].

OBJECTIVE: To study the prevalence of fatty liver, blood glucose and related factors in simple obese children. METHODS: Their liver was scanned with B-type ultrasound and fasting blood glucose (with a microassay glucometer), as well as other related morphological and functional indices, were measured in 62 children aged 8 to 11 years, including 32 obese ones and 30 control ones. RESULTS: Prevalence of fatty liver in obese and control groups was 93.8% and 10%, respectively, with very statistically significant difference (P < 0.01). Blood glucose level in obese and control groups was 5.42 mmol/L and 5.54 mmol/L, respectively, with statistically significant difference (P < 0.05). Proportion of children with normal cardiac function was 62.5% and 93.3%, respectively, in obese and control groups, with significant difference (P < 0.05). The prevalence of fatty liver correlated positively with skin-fold thickness, waist to hip ratio (WHR) and body mass index (BMI), with coefficients of correlation of 0.8786, 0.6256 and 0.8454, respectively (P < 0.01). Blood glucose correlated with skin-fold thickness and BMI positively, with coefficients of correlation of 0.3403 and 0.3155, respectively (P < 0.05). Regression analysis showed that skin-fold thickness and WHR were major risk factor for fatty liver and skin-fold thickness was major risk factor for high blood glucose. CONCLUSIONS: Simple obesity could cause damage to the liver, glucose metabolism and cardiac function in children, forming the potential risk factors for cardiovascular diseases, diabetes and disturbance of lipid metabolism in adults.

Blood Glucose↗

PubMed2001

[Antisense oligodeoxynucleotide of telomerase gene enhances cisplatin-induced apoptosis in acute myeloid leukemia and chronic myeloid leukemia cells].

OBJECTIVE: To explore the effect of human telomerase reverse transcriptase(hTERT) gene antisense oligodeoxynucleotide (ASODN) on cisplatin-induced apoptosis in cultured primary acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) cells. METHODS: Cell surviving fraction was determined using the trypan blue dye exclusion assay. Apoptosis was detected by DNA gel electrophoresis and flow cytomertric cell cycle analysis. RESULTS: Treatment with cisplatin after 24 hours of exposure of the cells to ASODN significantly reduced the number of viable AML and CML cells. However, there was no difference on AML and CML cells survival between those treated with sense oligodeoxynucleotide (SODN)/cisplatin combination and cisplatin alone. Agarose gel electrophoresis of genomic DNA from the blasts of AML and CML treated with ASODN and cisplatin combination for 72 hours showed typical DNA "ladder", but DNA from AML or CML cells treated with SODN plus cisplatin or cisplatin alone did not. The percentage of apoptotic AML and CML cells treated with cisplatin for 48 or 72 hours after 24 hours of exposure to ASODN (42.68%, 35.72%) was significantly different with that of apoptotic cells treated with SODN plus cisplatin (29.02%, 23.84%) or cisplatin alone (27.53%, 21.02%). CONCLUSION: hTERT ASODN could enhance the cisplatin-induced apoptosis of AML and CML cells.

Acute Disease↗

PubMed2001

Expression and function of c-kit receptor in bone marrow mononuclear cells of patients with myelodysplastic syndromes.

OBJECTIVE: To determine the expression and function of the c-kit receptor in bone marrow mononuclear cells (BMMNC) of patients with myelodysplastic syndromes (MDS). METHODS: Direct immunofluorescence assay and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to detect c-kit protein and c-kit mRNA expressions in the BMMNC of 29 MDS patients and 10 normal controls. Cell culture was used to detect the function of the c-kit receptor. RESULTS: c-kit protein expression in the MDS group was significantly higher than that in the control group (8.58% +/- 5.28% vs 3.04% +/- 1.49%, P < 0.05). c-kit protein expression in the refractory anemia (RA) group was significantly lower than that in the RA with an excess of blasts (RAEB)/RAEB in transformation (RAEB-t) group (5.12% +/- 2.13% vs 10.01% +/- 5.07%, P < 0.05). The rate of c-kit protein expression was 32.43% in acute myeloblastic leukemia (AML) cases transformed from MDS (t-AML). c-kit mRNA expression in the MDS group was correlated with c-kit protein expression. Interleukin-3 (IL-3) and erythropoietin (Epo), with or without stem cell factor (SCF), upregulated c-kit protein and its mRNA expression. In the presence of IL-3 and Epo, SCF showed significant stimulating effects on the formation of CFU-GM and BFU-E in semi-solid cultures of normal BMMNC, but had no effects on those of the MDS patients. CONCLUSION: The protein and mRNA expression of the c-kit receptor in the BMMNC of MDS patients were higher than those of normal controls, and the function of this receptor in MDS BMMNC was abnormal.

Bone Marrow Cells↗

PubMed2001

[Significance of lung perfusion scanning with technetium labeled macroaggregated albumin and pulmonary function assay for diagnosis of early hepatopulmonary syndrome].

OBJECTIVE: To evaluate the values of pulmonary function assay and dynamic pulmonary perfusion imaging with technetium labeled macroaggregated albumin ((99m)TcMAA) in the early diagnosis of hepatopulmonary syndrome (HPS). METHODS: The pulmonary function assay and (99m)TcMAA scans were performed in 28 patients with HPS, 30 cirrhotic patients (CP) without HPS, and 21 healthy controls (HC). RESULTS: In the patients with HPS, PaO(2), SaO(2) and diffusion capacity for carbon monoxide of lungs (DLco) was significantly lower than that in CP (P<0.01) and HC (P<0.01), and alveolar-arterial gradient [P((A-a))O(2)] was significantly increased (P<0.001). Results from (99m)TcMAA scans showed that the radionuclides were distributed over the spleen, kidney, liver and brain, and the ratios of arterivenous shunt were significantly higher than that in CP (P<0.001) and NC (P<0.001). In cirrhotic patients, DLco significantly decreased (P<0.05), P((A-a))O(2) and shunt ratios increased (P<0.01 and 0.001). CONCLUSIONS: Pulmonary function assay and dynamic pulmonary perfusion imaging with (99m)TcMAA are sensitive methods for diagnosis of the early HPS.

Hepatopulmonary Syndrome↗

PubMed2001

[Bispecific McAb mediated multiple tumor cytotoxicity in gastric cancer].

OBJECTIVE: McAb against CD3 and McAb against TNP were combined into bispecific McAb by chemical methods. With this bispecific McAb, human peripheral blood lymphocytes (PBLS) were introduced to in vitro and in vivo cytotoxic test of any tumor cells by different TNP-McAb against gastric cancer. METHODS: The activity of bispecific McAb prepared by chemical method, was detected by enzyme-linked immunosorbent assay (ELISA). The bispecific McAb was identified by bridge ELISA. Ouchterlony test and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Cytotoxic test of tumor cells in vitro and tumor growth inhibition test in vivo were performed for the bispecific McAb function. RESULTS: Anti-CD3 and Anti-TNP McAbs were successfully combined into bispecific McAb which could conjugate any TNP-McAb against gastric cancer and induce PBLS to cytotoxic test of gastric cancer cells in vitro and in vivo. CONCLUSION: The bispecific McAb may very will be useful in the immuno-biotherapy of tumors.

Animals↗

PubMed2001

[The emulation of aortic valve vibration during early diastole].

A finite element aortic valve model is described. The geometry and material property of the model are more exact than before. The finite element dynamic analysis was used to, emulate the closed valve motion during the early diastole. The results of emulating demonstrate that the closed valve vibrates during early diastole. They also reveal that the increase in stiffness of valve, the augmentation thickness of valve, the decrease in the rate of change of the pressure, and the reduction of the initial pressure may affect the vibration and cause the diminution of the aortic component of the second heart sound.

Aortic Valve↗

PubMed2001

Point mutations of muscle mitochondrial DNA from patients with mitochondrial encephalomyopathies.

OBJECTIVE: To study the relation between point mutations at nt3243 and nt8344 of muscle mitochondrial DNA from patients with mitochondrial encephalomyopathies and phenotypes. METHODS: DNA was extracted from muscle specimens from 5 patients with mitochondrial encephalomyopathies and and amplified by PCR method, using corresponding oligonucleotide primers. DNA fragments were digested with restriction enzymes Bgl I and Apa I, then the digested DNA fragments were analyzed with an electrophoresis method. RESULTS: The point mutation at nt3243 of mtDNA was found in 2 patients, one with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) and another with myoclonic epilepsy with ragged red fibers (MERRF). The point mutation at nt8344 was found in 2 patients with MERRF, including the one with point mutation at nt3243. CONCLUSION: The point mutation of DNA at nt3243 correlated with MELAS and nt8344 correlated with MERRF. In addition, the detection of point mutations at both nt3243 and nt8344 in a patient with MERRF shows the association of mutation with diversity in clinical manifestations of mitochondrial encephalomyopathies.

Adolescent↗

PubMed2001

[A pilot study on the value of duplex polymerase chain reaction method in early diagnosis of Legionella pneumonia].

OBJECTIVE: To investigate the value of duplex polymerase chain reaction (DPCR) in early diagnosis of Legionella pneumonia by detecting Legionella DNA in sputum and bronchoalveolar lavage fluid(BALF). METHODS: During the process of DPCR, two different sets of oligonucleotide primers were simultaneously used to amplify 386bp 16SrRNA gene fragment and 206bp mip gene fragment. These two primers were designed according to the sequences of 16SrRNA gene and mip gene of Legionella. The sputum and BALF of patients from two groups, including a Legionella pneumonia group (n = 15) and an ordinary pneumonia group (n = 31) were collected at early course of the disease. All of the samples were detected with DPCR for Legionella DNA. Simulated samples were also detected to investigate the sensitivity of the method for testing clinical samples. RESULTS: All the samples collected from the Legionella pneumonia patients, including 25 of sputum,and 8 of BALF showed positive DPCR. The results of DPCR, which could distinguish Legionella pneumophila from non-pneumophila Legionella spp. to some degree, were in good accordance with those of the specific serum antibodies. All of the samples from the ordinary pneumonia group including 40 of sputum and 16 of BALF demonstrated negative DPCR. Different samples of the same patient showed the same DPCR results. The lowest detection level of simulated sputum sample was the same as that of simulated BALF sample, being 1 x 10(3) cfu/ml. CONCLUSIONS: This preliminary study showed that DPCR had satisfactory sensitivity, specificity and stability for detecting Legionella DNA in sputum and BALF. The method is of value in early diagnosis of Legionella pneumonia. Its wide use for clinical work requires further investigation.

Adult↗

PubMed2001

[A prospective study of histological changes after AraAMP treatment in patients with chronic hepatitis B infection].

OBJECTIVE: To investigate the histological changes in liver biopsy tissue induced by AraAMP therapy for 50 days in patients with chronic hepatitis B infection. METHODS: Eleven patients were enrolled into this prospective study. All the patients had liver biopsy performed within 1 week before starting AraAMP therapy. A second liver biopsy was taken for comparison six months after the end of therapy. Blinded biopsies were scored according to Knodell's histology activity index (HAI), and examined for HBeAg and alpha-smooth muscle actin with immunohistochemistry as well as HBV DNA by using in situ hybridization. RESULTS: Histological improvement of >or=2 points decrease in the necroinflammatory HAI scores was seen in 8 of the 11 (72.7%) of patients after treatment. In these patients histological assessment revealed a significant improvement in intralobular inflammation and fibrosis as compared with pretreatment values(P < 0.05). There was significant difference of HAI changes in 6 cases graded as G3 based on the degree of periportal interface hepatitis and spotty parenchymal injury, but not in 5 cases graded as G2. HBeAg disappeared from liver tissue in 4 of the 9 cases and a significant reduction of activated liver stellate cells was demonstrated in the second biopsy(P = 0.018). Of the nine cases with HBV DNA positive at the first biopsy with in situ hybridization examination, 4 were negative at the second biopsy. CONCLUSION: Significant improvement in intralobular inflammation and fibrosis can be observed in liver tissue from patients with chronic hepatitis B infection treated with AraAMP.

Adolescent↗

PubMed2001

[Study on active constituents of traditional Chinese medicine reversing multidrug resistance of tumor cells in vitro].

OBJECTIVE: To screen drugs reversing multidrug resistance of tumor cells from active constituents of traditional Chinese medicine and to study the reversal action. METHODS: The kill effects of the drugs on tumor cell lines in vitro were determined with MTT method. The Jin's formula was used to analyse the effect of drug combination. RESULTS: 5 micrograms/ml rhynchophylline, 2 micrograms/ml jatrorrhizine and 1.25 micrograms/ml indirulin could reverse multidrug resistance for vincristine on KBv200 cell line by 16.8, 5.1 and 4 fold respectively. 1.56-12.5 micrograms/ml curcumine combining with vincristine could sensitize antitumor effect both on KB and KBv200 cell lines. CONCLUSION: All rhynchophylline, jatrorrhizine and indirulin could reverse multidrug resistance for vincristine on KBv200 cell line. Curcumine combinating vincristine could sensitize antitumor effect both on kB and kBv200 cell lines.

Antineoplastic Agents, Phytogenic↗

PubMed2001

[The study of intrapleural urokinase in the prevention of pleural thickening and loculated effusions by tuberculous pleurisy].

OBJECTIVE: To investigate the effects of intrapleural urokinase in the prevention of pleural thickening and loculated pleural effusions by tuberculous pleural effusion. METHOD: Eighty-one patients with tuberculous pleural effusion were randomized into 2 groups, intrapleural urokinase group (group I) and conventional group (group C). The patients in group I were injected with urokinase 100 000 IU intrapleurally after each thoracocentesis on twice a week basis, other therapies were similar to group C. RESULTS: The mean volume of fluid drained in group I was (3 981 +/- 573) ml, while it was (3 045 +/- 498) ml in group C (P < 0.01). The mean thickness of pleura in group I was (1.10 +/- 0.20) mm, but it was (1.40 +/- 0.30) mm in group C (P < 0.01), the incidence of pleural adhesion and location in group I was 10%, while it was 36% in group C (P < 0.01). The mean number of injection was (4.6 +/- 1.4) (ranged 3 approximately 8). The resolution time of pleural effusion was prolonged slightly, but there was no significant difference between two groups. CONCLUSION: Intrapleural urokinase can evidently increase the volume of pleural effusion drained and prevent pleural thickening and adhesion.

Adolescent↗

PubMed2001

[The role of neutrophils and interleukin-8 in pathogenesis of asthma].

OBJECTIVE: To investigate the role of neutrophils and interleukin-8 (IL-8) in pathogenesis of asthma. METHODS: Pulmonary function and bronchial provocation test were performed to identify and evaluate asthma. Superoxide anion O(2)(-.) generation of peripheral blood neutrophils, IL-8 and malondialhyde (MDA) levels in plasma and induced sputum were measured. RESULTS: The O(2)(-.) generation [(20.9 +/- 5.1) nmol] of peripheral blood neutrophils from moderate-severe asthmatics were significantly higher than that [(15.2 +/- 4.2) nmol] from mild asthmatics (P < 0.01), in which that was still significantly higher than that [(11.3 +/- 2.4) nmol] from normal subjects (P < 0.05). The O(2)(-.) generation of peripheral blood neutrophils had significantly negative correlation with PD(20)FEV(1) (r = -0.693, P < 0.05). The levels of IL-8 [(585 +/- 75) ng/L, (791 +/- 103) ng/L] and MDA levels [(6.3 +/- 1.6) mmol/L, (21.8 +/- 6.3) mmol/L] in plasma and induced sputum from unstable asthmatics were higher than those [(227 +/- 54) ng/L, (322 +/- 95) ng/L and (5.4 +/- 1.0) mmol/L, (15.1 +/- 5.6) mmol/L] from stable asthmatics (P < 0.01), more over, in the latter group, they were still significantly higher than those (188 +/- 46) ng/L, (224 +/- 51) ng/L and [(4.1 +/- 0.4) mmol/L, (9.5 +/- 4.2) mmol/L] from normal subjects (P < 0.05). The levels of MDA in the induced sputum from stable asthmatics showed a negative correlation with PD(20)FEV(1) (r = -0.708, P < 0.01). The levels of IL-8 in the induced sputum showed a positive correlation with percentage of neutrophils in the induced sputum (r = 0.838, P < 0.01). CONCLUSIONS: IL-8 and oxygen free radicals generated by neutrophils might participate in development of airway inflammation and airway hyperresponsiveness in asthma.

Adult↗

PubMed2001

[The relationship between eosinophils, activated T lymphocyte, leukotreine and the exercise-induced asthma].

OBJECTIVE: To explore the relationship between eosinophils, T lymphocyte, leukotreine (LT) and exercise-induced asthma (EIA). METHODS: In 32 asthmatic patients (13 with EIA and 19 asthmatic without EIA) and 8 normal persons, serum eosinophil cationic protein (ECP) and actived T lymphocyte (CD(25)(+)%) in peripheral blood were measured at the time before and 10, 60 minutes after exercise testing. The maximum minute ventilation (V(E)) were also measured. Another 22 non-smoking asthmatic patients with EIA and 10 normal subjects were enrolled for measuring urinary leukotriene E(4) levels before and 2 hours after exercise. EIA patients received zafirlukast 20 mg twice a day for three days. Standardized exercise challenge were performed after 72 hours of medication. RESULTS: There was a linear relationship between ECP, CD(25)(+)% and the forced expiratory volume in one second (FEV(1)) in asthmatic group (r = -0.79 and -0.61 all P < 0.01). Expressions of IL-4 mRNA, IL-5 mRNA CD(25)(+)% and serum ECP levels showed no significant difference at all testing points between two asthmatic groups, meanwhile, V(E) also showed no difference among three groups. Urinary LTE(4) levels in EIA group increased significantly two hours after exercise. Zafirlukast significantly reduced AUC(0 approximately 60 min) and the percentage of maximum fall in FEV(1) and accelerated the falling FEV(1) to return to pre-exercise baseline. CONCLUSIONS: Hyperventilation during exercise may not be the cause leading to EIA, neither did the activation of T lymphocytes, IL-4 and IL-5 gene expression nor ECP. Leukotriene may play an important role in the pathogenesis of EIA.

Adult↗

PubMed2001

Role of I(K) and I(f) in the pacemaker mechanisms of sino-atrial node myocytes.

The role of I(K) (delayed rectifier current) and I(f) (hyperpolarization-activated current) in dominant and subsidiary pacemaker ranges was studied in single myocytes isolated from the guinea pig sino-atrial node by means of a perforated patch-clamp technique. In the dominant pacemaker range (approx. -55 to -40 mV), I(K) tails are present whereas I(f) is not activated. In the subsidiary pacemaker range (approx. -80 to -70 mV), I(f) is large whereas I(K) is minimal and reversing. The threshold for I(f) activation is more negative at short time intervals. Larger or longer depolarizations to -40 mV and +20 mV deactivate I(f) more and are followed by faster reactivation of I(f). Steps of 200-300 ms duration to +20 mV completely deactivate I(f). The slope conductance decreases during depolarizations at -40 and +20 mV and quickly re-increases after the steps. The I(f) deactivation range is between -70 and +10 mV, with a V(1/2) of -35 mV. Depolarizations from -80 to +20 mV at a rate of 120/min limit the subsequent I(f) reactivation owing to the short diastole. We conclude that I(K) plays a predominant role in the dominant pacemaker range and I(f) does so in the subsidiary pacemaker range. Either pacemaker mechanism is used by sino-atrial node cells depending on the diastolic potential range. A previous depolarization markedly increases the amplitude and rate of I(f) reactivation.

Action Potentials↗

PubMed2001

[The change of tear secretion and tear film stability in castrated male rabbits].

OBJECTIVE: To evaluate the effect of androgen on tear secretion and tear film stability by observing the changes of ocular surface and tear film in the castrated male rabbit. METHODS: Sixteen male rabbits were selected and randomly divided into the normal control group (8 rabbits) and the castrated group (8 rabbits). Schirmer's tests, tear film break-up time (BUT) and rose bangle (rb) staining were performed on the eyes of two groups at 1, 2, 3, 4 weeks, 2 and 3 months. The Chiron Diagnostics ACS: 180 Automato Chemilluminescence Systems was used to determine the two groups' testosterone level in serum at pre-castrate and post-castrate. Results were analyzed statistically. Lacrimal gland, Harder's gland, conjunctiva, cornea and limbus were removed for observation histopathologically after three months. RESULTS: Both Schirmer's test and break-up time scores were significantly lower in the castrated group compared with the control group. The difference became more and more prominent in the course of observation. Rose bangle staining was positive in the castrated group. Testosterone level in serum was significantly lower in the post-castrate than that in the pre-cartrate. Histopathological observation showed that lacrimal glandular epithelial cells were atrophic and flat, the lumen of gland was enlarged and vesicular mucous in acinus cells disappeared. PAS positive material and conjunctival globlet cells were significantly decreased in the castrated group. Compared with the control group there were no significant morphologic changes in the corneal epithelium and limbal stem cells. CONCLUSIONS: The low level of testosterone in castrated rabbit may contribute to the atrophy and applanation of lacrimal glandular epithelium, disappearance of vesicular mucous in acinar cells and the significant decrease of the number of conjunctival globlet cells. All these can lead to decrease of both the quantity and quality of tear secretion and thus cause the instability of tear film.

Androgens↗