Biomedical subjects

Z Peng

Publications and source records attributed to Z Peng.

At least 37 records · Page 2Linked to original sources

PubMed2001

The cellular level of PR500, a protein complex related to the 19S regulatory particle of the proteasome, is regulated in response to stresses in plants.

In Arabidopsis seedlings and cauliflower florets, Rpn6 (a proteasome non-ATPase regulatory subunit) was found in two distinct protein complexes of approximately 800 and 500 kDa, respectively. The large complex likely represents the proteasome 19S regulator particle (RP) because it displays the expected subunit composition and all characteristics. The small complex, designated PR500, shares at least three subunits with the "lid" subcomplex of 19S RP and is loosely associated with an hsp70 protein. In Arabidopsis COP9 signalosome mutants, PR500 was specifically absent or reduced to an extent that correlates with the severity of the mutations. Furthermore, PR500 was also diminished in response to potential protein-misfolding stresses caused by the heat shock and canavanine treatment. Immunofluorescence studies suggest that PR500 has a distinct localization pattern and is enriched in specific nuclear foci. We propose that PR500 may be evolved in higher plants to cope with the frequently encountered environmental stresses.

Arabidopsis↗

PubMed2001

CpG oligodeoxynucleotide vaccination suppresses IgE induction but may fail to down-regulate ongoing IgE responses in mice.

Antigen-specific IgE plays an important role in the pathogenesis of allergic disorders. Immunostimulatory CpG motifs (CpG) in bacterial DNA or synthesized oligodeoxynucleotides (ODN) are gaining recognition as potential immunomodulators for switching on protectiveT(h)1-mediated immunity and preventing or potentially inhibiting T(h)2-dependent allergic responses. To date, allergic models used in CpG ODN studies have been established by immunization of mice with allergen in the presence of adjuvant. This, in addition to failure to assess specific IgE production in most of the studies, has limited understanding of the role of CpG ODN vaccination in allergic responses. Here, we examine the effects of synthesized CpG ODN on both developing and ongoing IgE responses in mice sensitized using a recombinant mosquito salivary antigen (rAed a 2) without adjuvant. Pretreatment of mice with CpG ODN mixed with rAed a 2 successfully inhibited subsequent induction of serum rAed a 2-specific IgE (but not IgG1) and antigen-induced IL-4 and IL-5 production in spleen cells. This was associated with an increase of serum IgG2a and IL-12, and increased IFN-gamma and IL-12 production by spleen cells. In this model, however, co-administration of CpG ODN with rAed a 2 to presensitized mice failed to down-regulate ongoing IgE responses despite significant up-regulation of serum IL-12 and specific IgG2a. Strikingly, a transient skin delayed-type hypersensitivity reaction occurred in CpG ODN-treated mice. These observations provide a new insight into the potential therapeutic application of CpG ODN to allergic disorders.

Adjuvants, Immunologic↗

PubMed2001

Expression, purification, characterization and clinical relevance of rAed a 1--a 68-kDa recombinant mosquito Aedes aegypti salivary allergen.

Accurate diagnosis of mosquito allergy has been precluded by the difficulty of obtaining salivary allergens. In this study, we expressed, purified, characterized and investigated the clinical relevance of a recombinant Aedes aegypti salivary allergen, rAed a 1. Two cDNA segments were ligated together to form the full-length Aed a 1 gene. rAed a 1 was expressed using a baculovirus/insect cell system, and purified using a combination of anion-exchange and gel-filtration chromatography. The purified rAed a 1 bound to human IgE, as detected by ELISA, ELISA inhibition tests and immunoblot analyses. Epicutaneous tests with rAed a 1 and a commercial whole-body AE: aegypti extract, and AE: aegypti bite tests were performed in 48 subjects. Nine of 31 (29%) of the subjects with positive immediate bite tests also had a positive rAed a 1 immediate skin reaction and 32% had an positive immediate test to the commercial extract. Six of 33 (18%) of the subjects with positive delayed bite tests also had a positive rAed a 1 delayed skin reaction and 6% had a positive delayed test to the commercial extract. Furthermore, rAed a 1-induced flare sizes significantly correlated with mosquito bite-induced flare sizes. None of the subjects with negative bite tests had a positive skin test to rAed a 1 or to commercial extract. We conclude that the rAed a 1 has identical antigenicity and biological activity to native Aed a 1, can be used in the in vitro and in vivo diagnosis of mosquito allergy, and is more sensitive than mosquito whole-body extract for detecting delayed skin reactions.

Aedes↗

PubMed2001

Molecular characterization of subunit 6 of the COP9 signalosome and its role in multifaceted developmental processes in Arabidopsis.

The COP9 signalosome is a highly conserved protein complex initially identified as a repressor of photomorphogenesis. Here, we report that subunit 6 of the Arabidopsis COP9 signalosome is encoded by a family of two genes (CSN6A and CSN6B) located on chromosomes V and IV, respectively. The CSN6A and CSN6B proteins share 87% amino acid identity and contain a MPR1p and PAD1p N-terminal (MPN) domain at the N-terminal region. The CSN6 proteins share homology with CSN5 and belong to the Mov34 superfamily of proteins. CSN6 proteins present only in the complex form and coimmunoprecipitate with other known subunits of the COP9 signalosome. Partial loss-of-function strains of the COP9 signalosome created by antisense and cosuppression with CSN6A exhibit diverse developmental defects, including homeotic organ transformation, symmetric body organization, and organ boundary definition. Protein blot analysis revealed that the defective plants accumulate significant amounts of ubiquitinated proteins, supporting the conclusion that the COP9 signalosome regulates multifaceted developmental processes through its involvement in ubiquitin/proteasome-mediated protein degradation.

Amino Acid Sequence↗

PubMed2001

A role of Arabidopsis COP9 signalosome in multifaceted developmental processes revealed by the characterization of its subunit 3.

The COP9 signalosome is a highly conserved eight-subunit protein complex initially defined as a repressor of photomorphogenic development in Arabidopsis. It has recently been suggested that the COP9 signalosome directly interacts and regulates SCF type E3 ligases, implying a key role in ubiquitin-proteasome mediated protein degradation. We report that Arabidopsis FUS11 gene encodes the subunit 3 of the COP9 signalosome (CSN3). The fus11 mutant is defective in the COP9 signalosome and accumulates significant amount of multi-ubiquitinated proteins. The same mutant is specifically impaired in the 26S proteasome-mediated degradation of HY5 but not PHYA, indicating a selective involvement in protein degradation. Reduction-of-function transgenic lines of CSN3 produced through gene co-suppression also accumulate multi-ubiquitinated proteins and exhibit diverse developmental defects. This result substantiates a hypothesis that the COP9 signalosome is involved in multifaceted developmental processes through regulating proteasome-mediated protein degradation.

Amino Acid Sequence↗

PubMed2001

[Evaluation on comprehensive benefits of different regulation models of agroforestry ecosystem in snail river beach].

The economic, ecological, social and comprehensive benefits of different regulation models of agroforestry ecosystem in Nangeng river beach were evaluated by AHP. The results showed that agroforestry ecosystem was significantly superior to reed(Phragmites communis) system. Different regulation models of agroforestry ecosystem had different benefits. The sheet-thinning model had the highest economic, social, and comprehensive benefits, and it was the optimal regulation model. For all thinning models, the key approach to further raise benefits was to choose some intercrop variations, which had a high economic value, especially a high ratio of output to input. For no-thinning model, keeping on intercropping was the effective measure to raise the social and comprehensive benefits.

Ecosystem↗

PubMed2001

[A method of desulfurization with calcium sulfite and it's mechanism].

Directing to the scaling problem lying in wet desulfurization with lime slurry, a method of desulfurization with calcium sulfite was proposed. Reaction mechanism and the effects of different conditions on desulfurization efficiency were studied. The optimum conditions were obtained, i.e. air velocity of 2.75 m/s in empty tower, L/G = 3.0 L/m3, solid content 6.7%, air temperature 31 degrees C, concentration inlet of SO2 1500 x 10(-6) and inlet suspension pH of 8.0. Under the conditions, the desulfurization efficiency was about 87%. The presented method theoretically and practically solved the scaling problems, which is a novel indirect lime-method with Ca-contained material as desulfurization agent.

Calcium↗

PubMed2001

[Analysis on the genotype of measles virus epidemic strains in Dongguan city, Guangdong province in 2000].

OBJECTIVE: To analyze the genotype of the measles virus epidemic strains in Dongguan according to the patients suffered measles in 2000. METHODS: The saliva of 55 patients with acute measles symptoms were collected and detected with RT-PCR. The PCR products of the 5 samples were sequenced and analyzed with the software DNASTAR. RESULTS: The positive detection rate was 87.3%, whereas the positive rate of anti MV-IgM in serum was only 70.9%. 68.8% of the saliva samples of patients with anti MV-IgM negative results showing MV RNA positive. The 293 bp fragment of N gene and 194 bp fragment of M gene were amplified from the vaccine virus and the specimens. The sequences of the epidemic strains were identical in both M gene and N gene. CONCLUSION: These results suggested that the outbreak came from a single MV strain. The epidemic strain was obviously different from the standard strains discovered in other countries of the world (the deviation were 1.4%-11.7%) that might belong to H genotype.

China↗

PubMed2001

Hepatic artery angiography and embolization for hemobilia after hepatobiliary surgery.

OBJECTIVE: To evaluate the effectiveness of hepatic angiography and embolization in the diagnosis and treatment of hemobilia after hepatobiliary surgery. METHODS: Nine patients had upper gastrointestinal bleeding 7 days to 3 months after surgery. They underwent emergency hepatic artery angiography and were treated by embolization using Gelfoam particles only (8 patients) and Gelfoam particles plus microcoils (1 patient). RESULTS: Hepatic artery angiography revealed hepatic artery pseudoaneurysms in 3 patients, diffuse hemorrhage of the hepatic artery branches in 3, right hepatic artery-bile duct fistulas in 2, and hepatic artery-small intestine fistula in 1. Hemobilia was controlled with embolization in 7 patients, of whom 1 had recurrent bleeding 1 day after treatment. During the follow-up, 3 patients died of multiple organ dysfunction syndrome. Two patients whose hemorrhage could not be controlled due to technical reasons died several days later. CONCLUSION: When hemobilia after hepatobiliary surgery is suspected, patients should receive hepatic angiography as a first diagnostic procedure and be treated with minimally invasive procedure of selective embolization of the involved artery as soon as possible.

Adolescent↗

PubMed2001

[Therapeutic effects of adenovirus-bcl-xs gene to the ascites tumor of nude mice model of human ovarian carcinoma].

OBJECTIVE: To investigate the effects of adenovirus-bcl-xs gene on the ascites tumor growth inhibition and survival rate of nude mice with human ovarian carcinoma transplanted intraperitoneally. METHODS: Making an adenovirus-bcl-xs gene vector infected in JH293T cell and reproduced in it. After having detected the inhibitory potential of adenovirus-bcl-xs gene on NUTU-19 cell we use it to transfer intraperitoneally to ascites tumor model of human ovarian carcinoma transplanted in nude mice. Detected the ascites formation, the survival time and survival rate of nude mice with the human ascites tumour. The weight and toxic-adverse systemically effects of nude mice was observed and morphology of adenovirus was observed by electromicroscope and the gene expression was detected by immunocell chemistry. RESULTS: The adenovirus-bcl-xs gene could reproduce in JH293T cell and had inhibitory potential on NUTU-19 cell, the survival time of nude mice was longer and the survival rate was higher, and the time of ascites formation was retarted. There was no obvious alternation in the weight and systemic toxic-adverse effects observed. CONCLUSIONS: The data suggests that the transfer of adenovirus-bcl-xs gene to the ascites tumour of nude mice with human ovarian carcinoma could improve the survival rate of nude mice and retard the time of ascites formation. It may be a useful method of gene therapy in the treatment of ovarian carcinoma.

Adenoviridae↗

PubMed2001

[A study of bone development and metabolism in childhood].

OBJECTIVE: To explore the regularity of bone development and metabolism in childhood. METHODS: A survey was made to collect and analyze the data on bone biochemistry, the density of lumbar vertebrae and the X-ray examination of calcaneus in 224 healthy children aged 3-15 years in the urban area of Chengdu. RESULTS: Comparative analysis of serum and urine calcium and phosphate concentrations showed no significant difference between the age groups. The serum alkaline phosphatase (ALP) and bone alkaline phosphatase (BALP) were found to increase with age and reach their peak values in children aged 7-12 years, and their values were significantly higher than that of adults (P < 0.05). The density of lumbar vertebrae and the trabecular bone of calcanesus also developed with age. CONCLUSION: The measurements of the bone biochemistry, bone density and the trabecular bone of calcaneus which reflect the bone development and metabolism have their special regularity in childhood. The criteria in use for adulthood is not fit for the evaluation in childhood. The data obtained can be used in clinical diagnosis and treatment of the bone metabolic diseases of children.

Adolescent↗

PubMed2001

[Expression of cell cycle associated proteins cyclin D1 and P16 in endometrial carcinoma and the correlation between their expression status].

OBJECTIVE: To study the expression of cell cycle associated proteins Cyclin D1, P16 in endometrial carcinoma and their correlation to clinical parameters, and to assess the correlation between their expression status. METHODS: Immunohistochemical method was used to detect Cyclin D1 and P16 expressions in 64 cases of endometrial carcinoma. RESULT: The positive rate of Cyclin D1 was 54.68%. The Cyclin D1 expression was significantly associated with FIGO stage (P < 0.05). The positive rate of P16 was 53.13% and its expression was related to age, histological grade and FIGO stage (P < 0.05). There was an inverse correlation between Cyclin D1 and P16, r = -0.4007 (P < 0.01). CONCLUSION: Cyclin D1 and P16 had cooperative effect and may play an important role in the development and progression of endometrial carcinoma.

Adenocarcinoma↗

PubMed2001

[A study of prognostic factors of stage IV epithelial ovarian cancer].

OBJECTIVE: To determine the effects of treatments for stage IV epidermal ovarian cancer and detect the prognostic factors. METHODS: 31 cases primarily treated in our hospital from 1990 to 1998 were analyzed retrospectively. RESULTS: Univariate analysis showed that the number of courses of chemotherapy, the size of residual disease, the histologic cell type, and the metastatic site were the significant prognostic factors(P < 0.05). Cox proportional hazard model confirmed that two factors (the size of residual lesion < or = 2 cm and the cycles of chemotherapy > or = 8 decreased the death odds ratio by 0.28 and 0.72 respectively. Three factors (lack of operation, presence of supraclavicular lymph node involvement and liver involvement) increased the death odds ratio by 14.25 times, 11.44 times and 1.85 times respectively (P < 0.05). CONCLUSION: Surgical debulking, aggressive and appropriate chemotherapy are important measures to improve survival rate for patients with stage IV epithelial ovarian cancer.

Adult↗

PubMed2001

[Investigation on the value of applying interventional radiologic treatment in the management of advanced gynecological malignancies].

OBJECTIVE: To investigate the value of applying interventional radiologic treatment (IRT) in the management of advanced gynecological malignancy. METHODS: Twenty-four historically confirmed advanced gynecological malignancy patients from September 1997 to June 1998 were included. After receiving internal iliac arterial infusion chemotherapy with Seldinger, the patients' tumor tissues were pathologically studied at different times. The tumor size was measured by ultrasonography two weeks after IRT. RESULTS: Before internal iliac arterial infusion chemotherapy, internal iliac arteriography showed that uterus artery was thickened and tortuous, the new vessels appeared and the tumors were stained. In some cases, the image of blood vessel-lake and arteriovenous shunt were seen in tumor tissues. Twenty-four hours after internal iliac arterial infusion chemotherapy, focal necrosis was observed in tumor cells, seventy-two hours after, the necrosis became more thorough. In regard to the tumor size, two patients were CR, nineteen patients were PR, and two patients were NC. Only one patient failed to respond to IRT. Chemotherapy side effects were slight. Patients' WBC returned normal within two weeks after chemotherapy. No complication happened. CONCLUSION: 1. Internal iliac arteriography has practical significance in assessing the tumor size and evaluating the therapeutic effects; 2. the internal iliac arterial infusion chemotherapy can reduce the tumor size, which prepares the patient in a better condition for operation. The most appropriate time for operation is two weeks after internal iliac arterial infusion chemotherapy. Even for the patient who is not suitable for operation, the reduction of the tumor size still can enhance the therapeutic effects of radiotherapy. 3. IRT is easy to perform, effective and with few slight side effects and complication. It is an effective way to save the patient's life.

Adult↗

PubMed2000

Interferon-gamma-responsive neuronal sites in the normal rat brain: receptor protein distribution and cell activation revealed by Fos induction.

Constitutive expression of the interferon-gamma receptor protein (IFN-gammaR), and the distribution of cells in which Fos, a marker of cell activation, is induced by intracerebroventricular administration of IFN-gamma, were studied in the rat brain by immunohistochemistry. IFN-gammaR immunopositivity was found in neuronal elements, which exhibited a selective distribution being concentrated in the piriform and entorhinal cortex, midline thalamus and medial hypothalamic structures, brainstem nociceptive relays (including the periaqueductal gray, the parabrachial nuclei and the caudal part of the spinal trigeminal nuclei), and circumventricular organs such as the median eminence and area postrema. IFN-gamma-induced Fos expression mostly corresponded to neuronal sites of receptor distribution. Because of its topographical distribution, it is suggested that activation of the IFN-gammaR in neurons may play a role to limit spread of infections in the brain and, in concert with other proinflammatory cytokines, to modulate adaptive responses to an antigen challenge mediated by the central nervous system.

Animals↗

PubMed2000

Hierarchical unfolding of the alpha-lactalbumin molten globule: presence of a compact intermediate without a unique tertiary fold.

The difference between the framework model and the hydrophobic collapse model of protein folding largely rests on whether a secondary-structure framework can exist independently of native tertiary interactions. Here, we used circular dichroism and disulfide exchange experiments to examine the unfolding mechanism of alpha-LA(alpha), a two- disulfide variant of human alpha-lactalbumin (alpha-LA) that adopts a molten globule conformation under near physiological conditions. Our results show that as the concentration of denaturant increases, the alpha-LA molten globule first loses its ability to form a specific, native-like tertiary fold. Subsequently, at a higher denaturant concentration, the protein loses its secondary structure and adopts an extended conformation. A compact, non-native disulfide bond isomer, which does not form significantly under both native and strongly denaturing conditions, was found to be moderately populated in approximately 2 M guanidine hydrochloride (GuHCl). Qualitatively the same result was also obtained in urea. These results suggest that formation of secondary structure is a necessary, but not sufficient condition for formation of the native-like tertiary fold and support a hierarchical model of protein folding.

Amino Acid Substitution↗

PubMed2000

Cloning and overexpression of a tyrosinase gene mel from Pseudomonas maltophila.

The tyrosinase gene (mel), which is responsible for melanin formation, was isolated by shotgun cloning of SalI fragments of Pseudomonas maltophila DNA. A 0.7-kb SalI fragment in the recombinant plasmid pWSY8 imparted the ability to synthesize melanin to an Escherichia coli host HB101. The nucleotide sequence of this DNA fragment revealed an open reading frame of 504 bp, encoding a protein of 169 amino acids. The fragment containing the mel gene was then cloned into an expression plasmid pPAS1 under the control of a promoter isolated from the host, P. maltophilia AT18. This strain increased the melanin production by 70.6% compared with the strain HB101/pWSY8, in which the cloned mel gene was under the control of the lac promoter from the vector pUC18.

Amino Acid Sequence↗

PubMed2000

Analysis of diversity and genetic relationships between four Chinese indigenous pig breeds and one Australian commercial pig breed.

The genetic diversities and relationships of four Chinese indigenous pig breeds and one Australian commercial pig breed have been evaluated using 27 microsatellites recommended by the International Society of Animal Genetics (ISAG) and the Food and Agriculture Organization (FAO). The allele frequencies, effective numbers of alleles and the polymorphic information content have been calculated. Nei's standard genetic distances have been used to construct a UPGMA dendrogram, which has been evaluated by the Bootstrap test. The utility of microsatellites for evaluating genetic diversity of pigs is discussed.

Alleles↗