Biomedical subjects

B Zhang

Publications and source records attributed to B Zhang.

At least 163 records · Page 9Linked to original sources

PubMed2001

[Study on an enhancing agent for removing arsenic from drinking water].

Drinking water contaminated by arsenic for an extended period of time could be detrimental to the health of people. Some preliminary symptoms could be alleviated by drinking water non-contaminated. It is important to develop an arsenic removal agent with a specific property of most efficient, cost-effective and easy for operation. The results showed that the capacity of the agent developed in this study was 10 times higher for arsenic removal than other agent available. The lowest arsenic content of the treated water was 0.05 mg/L. The special function of this agent was arsenic removing without changing other components and the concentrations of other elements in the treated water. The operation and management was simple without adjusting pH of the influent and effluent water. The agent was 5 times cheaper in cost than alumina or activated carbon, because it was a reusable oxidation-catalyst. Therefore, the agent could be widely applied in drinking water plants or used as a purifier at home in the high arsenic areas.

Arsenic↗

PubMed2001

[Study of pharyngo-cutaneous fistula after total laryngectomy].

OBJECTIVE: To explore the factors which lead to pharyngo-cutaneous fistula after total laryngectomy. METHOD: A retrospective study of 125 patients who underwent total laryngectomy during a 16-year period was carried out. RESULT: The rate of post-laryngectomy pharyngo-cutaneous fistula is 16.0% (20/125), it appears reduced tendency. With single-factor analysis, the factors effect on the rate of post-laryngectomy pharyngo-cutaneous fistula include clinical tumor stage, tumor types, pre-operative radiotherapy dose, intraoperative blood transfusion, operative duration. With all variable logistic model analysis, the factors effect on the rate of pharyngo-cutaneous fistula are clinical tumor stage and pre-operative radiotherapy dose, but pre-operative radiotherapy is very possible to be a risk factor (P = 0.0566). With logistic model stepwise regression analysis, the factors effect on the rate of pharyngo-cutaneous fistula are clinical tumor stage and operative duration. CONCLUSION: Pharyngo-cutaneous fistula appears easily in patients with T3, T4 tumor, and have pre-operative radiotherapy, especially have large dose preradiotherapy. For these high risk patients, the duration of operation should be as short as possible to reduce the rate of post-laryngectomy pharyngo-cutaneous fistula.

Adult↗

PubMed2001

[Augmenter of liver regeneration: a novel cytokine].

Augmenter of liver regeneration (ALR) is a novel cytokine which specifically stimulates hepatic cell proliferation and is able to rescue acute liver failure caused by carbon tetrachloride. This article reviews the discovery, tissue distribution, functions and prospect of ALR and its relationship with hepatic stimulatory substance (HSS).

Animals↗

PubMed2001

[Cloning and expression of D-arabitol dehydrogenase gene from Acetobacter suboxydans in Escherichia coli].

The partial genomic library of Acetobacter suboxydans was constructed using Yeast-E. coli shuttle plasmid YEp352 as vector. Two positive transformants, designated as DH5 alpha(pAD91) and DH5 alpha(pAD98), were obtained by screening the growth of transformants on the agar plate in which D-arabitol was used as the sole carbon source. The results of Southern blot and restriction endonuclease analysis showed that the two recombinants are identical. The insert is about 2.3 kb. Arabitol dehydrogenase activity assay indicated that the transformants could produce D-xylulose-forming D-arabitol dehydrogenase. Hence, the gene encoding D-arabitol dehydrogenase exists in the cloned DNA fragment.

Acetobacter↗

PubMed2001

[Introduction of the chromogenic gene to the plant growth-promoting rhizobacteria of cucumber].

Using a bicomponent transposition system with the E. coli lacZY gene cloned between Tn7 termini, a sensitive, selectable marker based on expression of the E. coli lac operon genes encoding beta-galactosidase and lactose permease was transformed into the rifampicin resistant mutant of plant growth-promoting rhizobacteria of cucumber, Pseudomonas aeruginosa CN116 and Pseudomonas corrugata CN31, respectively. Transformants were conferred the ability to utilize lactose as a sole carbon source and the ability to cleave the chromogenis substrate X-Gal to show a specific blue color. Southern blotting analysis showed that lacZY gene was inserted into the genome DNA of target strains. Compared with the wild type strains, the cultural characters, morphological features, growth promoting and disease control effects of transformants were almost unchanged, except the new marked phenotype. This marker system enabled the detection of lac+ transformants at sensitivity of 10 CFU/g soil, which makes the further studies on PGPR more easily.

Cucumis sativus↗

PubMed2001

[Expression of alpha-acetolactate decarboxylase gene from Bacillus subtilis in Brewer's yeast].

Yeast YIp-type expression recombinant plasmid(pCMA2-1) was constructed. The expression of alpha-acetolactate decarboxylase gene from Bacillus subtilis was controled by CUP1 promoter and its own terminator. The recombinant plasmid pCMA2-1 was introduced into the brewer's yeast PJ3-5. Transformants were selected using copper resistance as selected marker. The results of activity assay showed that PJ3-5 didn't produce alpha-acetolactate decarboxylase(ALDC), where as the activity of alpha-ALDC in transformants were induced by copper sulfate. The laboratory scale fermentation test confirmed that the total diacetyl concentration was reduced effectively by alpha-ALDC in transformant.

Bacillus subtilis↗

PubMed2001

[A pilot study on arsenic removal facilities for central supply of drinking water].

In order to promote the application and industrialization of an arsenic removal agent developed in this project, and to improve the technology, it is necessary to have a median sized facility to test the effects, capacity and regeneration of the agent. A facility with the capacity of 1 m3/h for arsenic removal was installed in a bottled water plant, which has been operated since April 1999. The results showed that the arsenic content of effluent water has met the requirement of the national standard for drinking water. The effect of arsenic removal was by 2 mg/g. The annual cost per person was only 1.46 Yuan RMB. The operation and maintenance of the facility was simple and no need to adjust the pH of influents and effluents. The chemical regenerative agent was safe, low cost and effective. Therefore, the facility can be used in rural areas and the water plants while the arsenic in source water was higher than 0.05 mg/L.

Arsenic↗

PubMed2001

[Expression significance of P21WAF1/CIP1 protein in eye-lid primary malignant tumor].

PURPOSE: To study the expression of P21waf1/cip1 protein in eye-lip primary malignant tumor (E-LPMT). METHODS: Immunohistochemical streptavidin biotin peroxidase complex(SP) method was used to stain section of E-LPMT. RESULTS: In 61 cases of E-LPMT, positive expression of P21waf1/cip1 protein was found locating in the nuclei. In Cell carcinoma, Squamous and Adenocarcinomas, the positive rate of P21waf1/cip1 protein expression were 36.0%, 27.8% and 22.2% respectively. The positive rate of P21waf1/cip1 protein expression in well-differentiated Cell carcinomas or Adenocarcinomas was higher than in poor-differentiated ones (P < 0.01). CONCLUSION: P21waf1/cip1 protein expresses in various type of E-IPMT and its positive expression in Cell carainomas and Adenocarcinomas are related to their different degrees.

Adenocarcinoma↗

PubMed2001

[Preliminary experimental study on therapeutic mechanism of kangzhen zhijing capsule in treating Parkinson's disease].

OBJECTIVE: To explore the therapeutic mechanism of Kangzhen Zhijing Capsule (KZZJC) on rats with Parkinson's disease (PD). METHODS: PD rat model was established by microinjection of 6-hydroxydopamine solution into left substantia nigra zona compacta (SNZC). Model rats were randomly divided into 3 groups and treated with KZZJC, levodopa and normal saline respectively for 30 days. The rotational behavior of rats before and after treatment was observed. Then rats were sacrificed and relevant indexes of left SNZC and striatum were examined. RESULTS: In rats treated with KZZJC, the rotational behavior was improved (P < 0.05), the levels of dopamine (DA) content and DA/homovanillic acid (HVA) ratio in striatum, and glutathione peroxidase, superoxide dismutase and glutathione in SNZC increased, but malondialdehyde in SNZC decreased, as compared with those in rats treated with normal saline, the difference was significant (P < 0.01 or P < 0.05). Rotational behavior in rats treated by levodopa was improved significantly (P < 0.01). CONCLUSION: KZZJC could partially improve the rotational behavior in PD model rats, increase DA content and DA/HVA ratio in striatum. The mechanism might be the reducing of free radical damage and DA catabolism.

Animals↗

PubMed2001

[Transforming growth factor-beta can induce differentiation of hypertrophic chondrocytes into osteoblast-like cells in epiphyseal plate].

OBJECTIVE: To investigate the effect of transforming growth factor-beta (TGF-beta) on the differentiation of hypertrophic chondrocytes in epiphyseal plate in order to understand its role in the mechanism of bone and cartilage formation. METHODS: We observed the effect of TGF-beta in varied time and dosage on the differentiation of hypertrophic chondrocytes in embryonic chick femora which were cultured in serum-free medium, using histochemical staining to detect the expression of alkaline phosphatase (ALP) and immunohistochemical staining to detect the expression of type I collagen and fibronectin. RESULTS: TGF-beta enabled the chondrocytes to express type I collagen and fibronectin, and it enhanced the expression of ALP in hypertrophic zone. Time-effect and dosage-effect relationships were observed. CONCLUSION: TGF-beta can induce the differentiation of hypertrophic chondrocytes into osteoblast-like cells in epiphyseal plate of embryonic chick femora. The inducing effect might be closely related to time and dosage of TGF-beta.

Animals↗

PubMed2001

[Relations of electrolytes to the by-product CHCl3 produced in electrochemical disinfection].

OBJECTIVE: To investigate the relation of electrolytes(NaCl, Na2SO4) to the by-product CHCl3 produced in the electrochemical disinfection process. METHODS: Taking filtering water, we used the graphite and Ti (matrix)-Ti as electrodes, adjusted the current sample for analysis in different time, and determined the production of CHCl3 under different conditions. RESULTS: Na2SO4 had no effect on the production of CHCl3 in the electrolysis(P > 0.05). but NaCl had the effect and the higher the concentration of Cl- was, the more the production of CHCl3 increased. The production of CHCl3 increased with the length of electrolysis time, and it exceeded the national standard after 10 minutes' electrolysis using Ti (matrix)-Ti as electrodes. When graphite was used as electrodes, the production of CHCl3 was much less. CONCLUSION: Na2SO4 has no effect on the production of CHCl3. Our suggestion is that graphite should be used as the electrodes for electrochemical disinfection of drinking water.

Chloroform↗

PubMed2001

[Rapid construction of directional cDNA library from human nasopharynx].

OBJECTIVE: To construct a directional cDNA library from human adult nasopharynx by SMART (switching mechanism at 5' end of RNA transcript) technique. METHODS: The total RNA was separated from human adult nasopharynx epithelial tissue and the first-strand cDNA was synthesized through reverse transcription by a modified oligo(dT) primer(contained sfi IB site) while the SMART oligonucleotide(contained sfi IA site) was utilized as a template so that the first-strand cDNA could be extended over the 5' end of mRNA. The double-strand cDNA was amplified by LD-PCR(long-distance PCR) with the above two primers and then digested by sfi I (IA & IB) restriction enzyme. After cDNA size fractionation through CHROMA SPIN column, the double-strand cDNA was ligated into the sfi I-digested lambda TripIEx2 vector and then the recombinant DNA was packaged in vitro. RESULTS: The unamplified human adult nasopharynx cDNA library consists of 1.5 x 10(6) independent clones in which the percentage of recombinant clones is about 100%. The titer of the amplified cDNA library is 3.8 x 10(9) pfu/ml and the average exogenous inserts of the recombinants is 1.5 kb. CONCLUSION: These results shows that the human adult nasopharynx cDNA library has an excellent quality and lays solid foundation for screening and cloning new tumor suppressor genes of nasopharyngeal carcinoma(NPC) and tissue-specific genes of human nasopharynx.

Adult↗

PubMed2001

[Titanium miniplate fixation in head and neck cancer surgery].

OBJECTIVE: To evaluate the rigid fixation with miniplates in head and neck cancer surgery. METHOD: A consecutive series of 40 patients with head and neck tumor underwent rigid fixation with the Martin titanium miniplates system in a 6 years period. The miniplates were used to fix bone graft reconstruction following mandible resection (n = 14), mandibulotomies for oral and oropharyngeal surgical access (n = 12), maxilla swinging for nasopharyngeal access (n = 11) and other purposes (n = 3). Twenty-three of all cases(57.5%) received perioperative radiotherapy with average doses of 60Gy at the osteotomy site. RESULTS: Eleven of the 40 patient (22%) developed plate related complication which included 5 infections, 3 mandibular osteonecroses, 1 plate exposure, 1 screw loose and 1 nonunion. Complications were more likely to occur in patients with perioperative radiation than patients without (39.1% versus 11.8%, P = 0.079). Except one case, All the uncomplicated dentulous patients demonstrated stable and good occlusion. Oral feeding usually started on the 3-4th day after surgery. There was no need for intermaxillary fixation. CONCLUSION: The miniplate provided stable mandibular or maxillary fixation and accurate repositioning, eliminated the need for intermaxillary fixation. The malleability and versatility of miniplate make it unique in bone graft shaping for mandibular reconstruction. Complication seems to be related to perioperative radiotherapy. Median or paramedian mandibular osteotomy, which is non-radiated region in most radiotherapy cases, is advocated.

Adolescent↗

PubMed2001

[Relationship among lymphatic metastasis, pericancerous lymphocytic reaction and dendritic cell infiltration in laryngeal carcinoma cells].

OBJECTIVE: To study the role and the clinical significance of dendritic cell infiltration against tumor cells in patients with laryngeal squamous cell carcinoma. METHODS: Immunohistochemical method using S-100 protein antibody was employed to detect dendritic cells (DC) on paraffin-embedded tissue sections from 23 patients with laryngeal squamous cell carcinomas. The relationships among the density of dendritic cell infiltration in laryngeal carcinomas and cervical lymphatic metastasis, pericancerous lymphocytic reaction and other clinicopathologic parameters were observed. RESULTS: The numbers of dendritic cells infiltrating among laryngeal carcinoma cells in patients with no cervical lymph metastasis was significantly larger than those with cervical lymphatic metastasis (t = 4.889, P < 0.01). Significant increase DC infiltration among laryngeal carcinoma cells was found in the group with intensively positive reaction of pericancerous lymphocyte than in the medium and weakly positive groups. The number of infiltrating dendritic cells in patients who had survived more than 5 years was significantly larger than those survived less than 5 years (t = 4.423, P < 0.01). The numbers of the infiltrating dendritic cells in patients with well-differentiated squamous cell carcinoma and poorly differentiated squamous cells carcinoma were 2.2 +/- 1.07 and 14.6 +/- 7.14 respectively, which were significantly different (q = 4.532, P < 0.05). CONCLUSION: The study showed that DC infiltration among laryngeal squamous carcinoma cells played an important role in the host immune reaction against tumor. It indicated that when the density of infiltrating DC is higher, the patients had less chance of cervical lymph metastasis and may have a longer survival time. There was a coordinative effect between DC infiltration in tumor cells and pericancerous lymphocyte reaction. Thus, the DC infiltration among laryngeal squamous cells could be used as an index of prognosis.

Aged↗

PubMed2001

[Determination of cobalt in solidified resin promoter by successive extraction and FAAS].

A new method had been investigated for the analysis of micro-amount of cobalt in solidified resin promoter. Methyl isobutyl ketone (MIBK) was used in 1 mol.L-1 NH4SCN medium followed by 4 mol.L-1 nitric acid back extraction step, then analysis by flame atomic absorption spectrometry. The results indicated that the method was accurate and the interference with concomitant in solidified resin promoter was negligible. The method had a recovery of 96.2%-104.6%.

Carboxylic Acids↗

PubMed2001

[IL-1alpha, IL-1beta and TNF-alpha mRNA expression in experimental periapical lesions in the rat].

OBJECTIVE: IL-1alpha, IL-1beta and TNF-alpha mRNA expression were analyzed in rat experimental periapical lesions to understand the relationship between the aforementioned cytokines and periapical lesion. METHODS: The molar tooth pulps of 16 SD rats were surgically exposed and left open to permit infection from the oral environment. Total cell RNA was isolated from periapical tissue obtained on days 3, 7, 14 and 28 after exposure. mRNA for IL-1alpha, IL-1beta and TNF-alpha was amplified by reverse transcription polymerase chain reaction(RT-PCR), and levels were estimated by comparison to the parallel amplification of the housekeeping gene beta-actin. RESULTS: IL-1alpha,IL-1beta and TNF-alpha mRNA were all expressed beginning on day 7, peaked on day 14, and declined somewhat on day 28, but IL-1beta mRNA was expressed at much lower levels with the same kinetics (P<0.01). CONCLUSION: IL-1alphaand TNF-alpha may be primarily cytokines in rat periapical lesion model.

English Abstract↗

PubMed2000

Oligomerization of Rac1 gtpase mediated by the carboxyl-terminal polybasic domain.

The Rho family GTPase Rac1 mediates a variety of signal transduction processes leading to activation of NADPH oxidase, actin cytoskeleton reorganization, transcription activation, and stimulation of DNA synthesis. In this study, Rac1 was found to form a reversible monomer and oligomer in both the GDP- and GTP-bound states in vitro and in cells. Mutational analysis and peptide competition experiments showed that the unique C-terminal domain of Rac1 consisting of six consecutive basic residues (amino acids 183-188) is required for the homophilic interaction. Oligomerization of Rac1-GTP led to a self-stimulatory GTPase-activating protein (GAP) activity, resulting in a significantly enhanced intrinsic GTP hydrolysis rate of Rac1-GTP. Deletion or mutation of the polybasic residues drastically decreased its intrinsic GTPase activity and resulted in a loss of the self-stimulatory GAP activity. In the oligomeric state, Rac1 became insensitive to the RhoGAP stimulation, albeit maintaining the responsiveness to the guanine nucleotide exchange factor. The ability of the Rac1 C-terminal mutants to activate the effector p21(cdc42/rac)-activated kinase-1 correlated with their oligomerization states, suggesting that oligomer formation potentiates effector activation. Furthermore, the oligomer-to-monomer transition of Rac1-GDP could be driven effectively by interaction with the Rho guanine nucleotide dissociation inhibitor. Building on previous characterizations of Rac1 interaction with regulatory proteins and effectors, these results suggest that Rac1 may employ yet another means of regulation by cycling between the monomeric and oligomeric states to effectively generate a transient and augmented signal.

Amino Acid Sequence↗

PubMed2000

Early pregnancy factor suppresses experimental autoimmune encephalomyelitis induced in Lewis rats with myelin basic protein and in SJL/J mice with myelin proteolipid protein peptide 139-151.

Early pregnancy factor (EPF) is a secreted protein with immunosuppressive and growth factor properties. During pregnancy, it appears in maternal serum within 6-24 h of fertilization, is present for at least the first two-thirds of pregnancy in all species studied and is essential for embryonic survival. It is a homologue of chaperonin 10, a heat shock protein, but, unlike other members of this family, EPF has an extracellular role. As it has the ability to modulate CD4+ T cell-dependent immune responses, its role in treatment of experimental autoimmune encephalomyelitis (EAE) was investigated. EAE is a CD4+ T cell-mediated disease, the best available animal model of multiple sclerosis (MS). Two models of EAE were investigated, acute EAE induced in Lewis rats by inoculation with myelin basic protein (MBP-EAE) and chronic relapsing EAE induced in SJL/J mice by inoculation with myelin proteolipid protein peptide (residues 139-151) (PLP-EAE). EPF, delivered intraperitoneally or orally to rats or intraperitoneally to mice, suppressed clinical signs of disease. Mice with PLP-EAE were also treated with interferon-beta, with and without EPF. Both EPF and IFN-beta suppressed clinical signs of EAE and, when administered together, gave greater suppression than when given separately. These findings suggest that EPF may be a potential candidate for use in treatment of MS and may be of use in combined therapy with IFN-beta.

Adjuvants, Immunologic↗