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Biomedical subjects

Li Wang

Publications and source records attributed to Li Wang.

At least 433 records · Page 24Linked to original sources

Hypertonic perfusion reduced myocardial injury during subsequent ischemia and reperfusion in normal and hypertensive rats.

AIM: To determine the effects of hypertonic solution on myocardial ischemia and reperfusion injury in normal and stroke-prone hypertensive rat hearts in vitro. METHODS: Hearts were perfused in an isolated-perfused Langendorff apparatus and perfused with normal or hypertonic solution (360 mOsm/L, by addition of NaCl to the normal perfusate of 300 mOsm/L) before subjected to 30 min ischemia followed by 40 min isotonic reperfusion. Heart function, myocardial creatine kinase leakage, norepinephrine release, and ventricular calcium content were determined. RESULTS: Normal rat hearts with hypertonic perfusion showed higher recovery rate of spontaneous beating than control hearts after ischemia. Hypertensive rat hearts perfused with hypertonic solution also had better recovery in diastolic function and less creatine kinase leakage than hypertensive controls. Concomitantly, myocardial release of norepinephrine was also reduced from hypertensive hearts perfused with hypertonic solution. There was no significant difference in myocardial calcium content between normal and hypertonic perfused hypertensive hearts. CONCLUSION: Hypertonic perfusion may precondition the hearts and protect them from ischemia and reperfusion injury in both normal and hypertensive rats. The modulation of hypertonic perfusion on myocardial norepinephrine release and its role in cardioprotection needs further investigation.

Animals↗

[Study on preparation procedure of Suppositoria Radix Bupleuri for kids].

OBJECTIVE: To optimize the preparation procedure of Suppositoria Radix Bupleuri for Kids. METHODS: The extraction process and preparation procedure were studied by orthogonal experimental design. RESULTS: The extraction process was selected and suppositoria was prepared by hard fat. CONCLUSION: This preparation procedure is suitable.

Bupleurum↗

[Role of activation of renin angiotensin system in cyclosporine A nephropathy].

OBJECTIVE: To investigate the role of renin angiotensin system (RAS) activation in cyclosporine A nephropathy. METHODS: Rats were fed with low salt diet. After seven days, they were randomly divided into four groups: vehicle (n=7), CsA treated (n=7), CsA+verapamil (n=7), CsA+enalapril (n=7). All rats except vehicle received a daily subcutaneous injection of CsA (15 mg/kg) for four weeks. Plasma and renal tissue angiotensin II (Ang II) levels were measured by radioimmunoassay. The expression of angiotensin II type 1 receptor (AT1R) was examined by Northern blot. RESULTS: Plasma and renal tissue angiotensin II levels were significantly elevated in CsA treated rats when compared to that in vehicle rats ((190+/-36)ng/L vs. (492+/-92)ng/L, (29.8+/-6.0)ng/g vs. (8.7+/-1.7) ng/g, P<0.001). Enalapril reduced angiotensin II levels significantly (both P<0.05). The expression of AT1R mRNA was down-regulated by CsA, this down-regulation was reversed by enalapril. CsA treated animals showed marked tubulointerstitial fibrosis, enalapril lessened the tubulointerstitial fibrosis significantly (P<0.05). Verapamil did not improve tubulointerstitial fibrosis significantly (P>0.05). CONCLUSION: RAS activation plays an important part in CsA nephropathy. Blockade of RAS may retard the progression of tubulointerstitial fibrosis caused by CsA.

Angiotensin II↗

[Study on the disabilities in aged 0-7 years children in Shenzhen, China].

OBJECTIVE: To explore the prevalence of vision, mental, audibility, language, psychiatry, extremity, and influence factors in the 0 - 7 year olds. METHODS: A total number of 77,727 0 - 7 year old children living in Shenzhen city were tested with tree phase screening under the Chinese standard of evaluation in disabilities. RESULTS: The prevalence of all disabilities was 5.59 per thousand (adjusted rate was 8.49 per thousand with a false negative of 3.1 per thousand ). The prevalence of mental disease was the highest (1.88 per thousand, with adjusted rate 3.43 per thousand ), the prevalence of language disability was 1.88 per thousand (including retarded language development, with adjusted rate 3.43 per thousand ). The prevalence rates of psychiatry, extremity and audibility disability were 1.59 per thousand, 1.56 per thousand, 1.11 per thousand respectively with of vision the lowest (0.37 per thousand ). The prevalence of all disabilities, audibility, language and mental was on the increase with age. The difference was statistically significant. Among all different age groups regarding psychiatric disease, the highest fell in the 2 - 4 year olds. The prevalence of extremity was not statistically different among age groups. The suspected agents of disease which occurred before or during pregnancy took up 45.7%. CONCLUSION: The prevalence of six kinds disabilities in Shenzhen was about 10 per thousand lower than that of the samples of the nation in 1989, but two times higher than that of similar studies in Japan. The prevalence rates of language and psychiatric disease were higher than that of the nation in 1989. The causation should be further studied.

Age Factors↗

[Inhibitory effects of salviae miltiorrhizae and beta-aescinom natrium on the postburn acute lung injury in rats].

OBJECTIVE: To explore the inhibitory effect and its mechanism of salviae miltiorrhizae and beta-aescinom natrium on the postburn acute lung injury in rats. METHODS: Forty-five rats were randomly divided into sham control (C, n = 9), sodium chloride group (S, n = 9), salviae miltiorrhizae group (M, n = 9), beta-aescinom natrium group (A, n = 9), and combination group (MA, n = 9). The rats in M, A and MA groups were subjected to 30% TBSA III degree scald on the back, and all the rats were sacrificed at 24 PBH. The blood and pulmonary tissue samples were harvested from the rats at 24 PBH for the determination of leukocyte adhesiveness/aggregation (LAA) in peripheral blood, myeloperoxidase (MPO), malondialdehyde (MDA) and superoxide dismutase (SOD) contents, and the ratio of wet to dry weights (W/D) of lung tissue. RESULTS: Compared with those in S group, the LAA in blood and the pulmonary tissue contents of MPO, MDA and W/D rate in M and A groups, and especially in MA group, were decreased significantly, but the SOD content in pulmonary tissue increased obviously in M and A groups, especially in MA group. Furthermore, blood LAA was positively correlated with pulmonary tissue MDA content. CONCLUSION: Postburn intra-pulmonary agglutination and aggregation of PMNs and pulmonary injury by oxygen free radicals (OFRs) and their products could be inhibited by either Salviae Miltiorrhizae or beta-aescinom natrium. In addition, these agents could also increase the tissue content of antioxidant capacity and decrease pulmonary microvascular permeability and lung water content. The results indicated that all the agents used might be effective in prevention and treatment of postburn pulmonary injury, especially when used together.

Acute Lung Injury↗

[Displaying polyhistidine peptide on the cell surface of Bacillus thuringiensis by S-layer protein].

Cell surface layer (S-layer) is the outmost structure of bacterium cell and covers the intact cell. S-layer protein of Bacillus thuringiensis strain CTC (CTC protein) was used as carrier protein to display polyhistidine (polyHis) peptides on the cell surface. Series fusion protein genes were constructed by inserting DNA fragments encoding (6His)1, (6His)2, (6His)3, (6His)9 and (6His)15 polyHis peptides into CTC protein gene at the site of downstream of slh domain. With the help of recombinant plasmid pBMB-CSA, which contains operon csaAB needed for S-layer protein anchoring on cell surface, fusion protein genes were expressed in crystal negative B. thuringiensis strain 4Q7. SDS-PAGE profiles demonstrated that all the fusion proteins except CTC-(6His)15 were expressed. Ni-NTA-agarose beads binding test showed that all recombinant strains could attach to agarose beads except 4Q7 (pBMB-CSA, pBMB-SH15). Cd2+ adsorption test indicated that the adsorption ability of all recombinant strains except 4Q7 (pBMB-CSA, pBMB-SH15) were higher than that of host strains. The Cd2+ adsorption quantity of the recombinant strain with strongest adsorption ability was twice higher than that of host strain.

Adsorption↗

[Susac syndrome: a report of two cases].

OBJECTIVE: To investigate the clinic characters and diagnosis of Susac syndrome. METHODS: Two cases were systematically studied by the authors. RESULTS: All the two cases were young women. The clinical manifestations include acute and subacute multifocal and diffuse encephalopathic symptoms, hearing loss, and visual loss. Diagnosis is facilitated by demonstration of retinal arteriolar occlusions without uveitis or keratoconjunctivitis, mid-to-low frequency unilateral or bilateral sensorineural hearing loss, and numerous small foci of increased signal in the white and gray matter on T2-weighted brain magnetic resonance imaging. CONCLUSIONS: This rare syndrome often can be identified at an early stage with a careful history and physical examination. MRI, SPECT, retinal fluorescein angiography and audiometry will contribute to diagnosis.

Adult↗

[Parameters of energy flow in wheat-corn intercropping agroecosystem].

The parameters of energy flow of primary producers (agricultural crop and weed), consumers (pests and their natural enemies) and decomposer (soil microbe, protozoan and saprozoite) in wheat-corn intercropping agroecosystem in Tibet of China were studied by field investigation and laboratory measurement. The results showed that the wheat-corn intercropping agroecosystem had high primary productivity and energy translation efficiency, and the degression rate of energy flow through food chain was also high. At each nutritive layer of this agroecosystem, relatively less energy was required to product unit energy, and degree of energy utilization of superior nutritive layer from lower nutritive layer was increased gradually.

Animals↗

[Expression of nuclear factor-kappa B mRNA, inducible nitric oxide synthase and interleukin-6 in nasal polyp and its role].

OBJECTIVE: To evaluate the expression and significance of nuclear factor-kappa B (NF-kappa B) mRNA, inducible nitric oxide synthase(iNOS) and interleukin-6 (IL-6) in the pathophysiology of nasal polyp(NP). METHODS: The specimens from 59 nasal polyps (NP) and 20 inferior turbinates (IT) were studied by in situ hybridization for NF-kappa B mRNA, and by immunohistochemistry for iNOS and IL-6. Tissue sections were observed under optical microscope. RESULTS: NF-kappa B mRNA, iNOS and IL-6 overexpressions were localized mainly to the nasal polyp epithelium, the various inflammatory cells, in submucosal endothelial cells around the vessel and in submucosal glands. The positive frequency of activation of NF-kappa B mRNA was higher in NP (54.24%) than in IT (P < 0.01), whereas the positive frequency of iNOS and IL-6 overexpression were higher in NP (62.71% and 64.41%) than in IT (P < 0.01). Eosinophils and neutrophils in NP were higher than in IT (P < 0.01). CONCLUSION: These results suggest that NF-kappa B, iNOS and IL-6 are strongly correlated with the formation of NP. NF-kappa B, iNOS and IL-6 may act as anti-apoptotic molecules in eosinophils and neutrophils that may be responsible for the recruitment of inflammatory cells, particularly eosinophils, through the initiation of the transcriptional pathway of the related cytokines. NF-kappa B might play a key role in the pathogenesis of NP process and therefore is a potential target for medical treatment and new therapeutic intervention.

Adolescent↗

[Phanerogenetic retrocochlear low frequency hearing loss].

OBJECTIVE: To study the pathogenisis of retrocochlear low frequency hearing loss. METHODS: Clinical and audiologic findings [auditory brainstem response (ABR), evoked otoacoustic emission (EOAE), et al] of 29 cases with retrocochlear low frequency hearing loss were studied. RESULTS: The head injury, acoustic neuroma, peripheral neurophathy, hereditary hear loss, multiple sclerosis and brainstem disease can cause retrocochlear low frequency hearing loss. The typical clinical manifestations of retrocochlear low frequency hearing loss were normal EOAE which cannot be suppressed by contralateral white noise, but with abnormal ABR as well as with no acoustic reflex and -SP/AP > 0.44. CONCLUSIONS: The results suggest that phanerogenetic retrocochlear low frequency hearing loss should be a syndrome rather than a disease called "auditory neuropathy". The main lesions of the disease are brainstem, cochlear nuclei and auditory nerve.

Adolescent↗

[The expression and application of human Fas ligand in E.coli].

AIM: To express recombinant human FasL molecule in E.coli. METHODS: RT-PCR was applied to amplify FasL cDNA from the total RNA extracted from activated human peripheral blood lymphocytes. The DNA fragment was cloned into PCR2.1 vector. After sequencing, the FasL gene was inserted into pQE-31 vector and expressed in E.coli M15. The FasL protein was purified through Ni-ATA affinity chromatography column and identified by SDS-PAGE and Western blot. The mice were immunized with the FasL protein and the specific anti-serum was harvested 6 weeks after immunization. The serum level of FasL from with different kinds of diseases patients were detected using the anti-FasL antibodies from the immunized mice. RESULTS: The expressed protein could be recognized by anti-human FasL antibody in Western-blot analysis with M(r)40 000. This protein could induce Jurket cells apoptosis. anti-FasL serum prepared from mouse could detect the serum FasL as sensitive as commercial ELISA kits. CONCLUSION: The human FasL protein is obtained. It lays the foundation for the further detecting the concentration of FasL and sFasL of patients.

Animals↗

[Cloning of human testicular carcinoma antigen MAGE-E1 gene and its expression in E.coli].

AIM: To clone and express the testicular carcinoma antigen MAGE-E1 gene in E.coli. METHODS: The cDNA encoding human MAGE-E1 gene was amplified by RT-PCR from human glioma cell line BT-325, then the MAGE-E1 gene was inserted into plasmid pGEM-T easy. After sequencing, the MAGE-E1 was cloned into the prokaryotic expression vector pGEX-4T-2 to construct the recombinant expression vector pGEX-4T-2-MAGE-E1 which was used to transform E.coli. RESULTS: The expressed product reached the highest level at 5 h after IPTG induction. SDS-PAGE and scanning analysis of gel density indicated that the expressed protein was about M(r) 41 000 and account for 35% of the total bacterial protein. CONCLUSION: The high efficient expression of the MAGE-E1 gene fragment lays the foundation for further preparing antibody against MAGE-E1 protein and the tumor vaccine for glioma immunotherapy.

Cloning, Molecular↗

[Role of uncoupling proteins in the pathogenesis of obesity and type II diabetes].

Uncoupling proteins (UCPs) are mitochondria carrier proteins,which are able to dissipate the proton gradient of the inner mitochondria membrane. The uncoupling procedure reduces the amount of ATP generated through an oxidation of fuels. Therefore, UCPs are suggested as candidate genes for human obesity or type II diabetes mellitus. Experimental evidences,that genetically engineered mice over expressing different UCP homologues were resistant to diet-induced obesity and 45 bp insertion polymorphism in the UCP2 3' untranslated region and C-55T in UCP3 promoter region were associated with obesity related phenotype, supported the hypothesis. The roles of UCP genes in polygenic obesity and type II diabetes are evaluated and discussed in this paper.

English Abstract↗

[Associated genes for dementia of the Alzheimer type].

Dementia of the Alzheimer type (AD) is the leading cause of dementias for the elders. It is a progressively neurodegenerative disorder characterized by global cognitive decline. While most of the rare early-onset AD can be explained by mutations in APP gene and presenilin genes,the genetic etiology of the more common late-onset AD is only partly explained by the APOE-epsilon4 genotype. But the APOE-epsilon4 allele is neither necessary nor sufficient to cause disease and it can only account for less than one-half of the genetic variance of AD. Thus, more genes involved in AD are our special attention.

English Abstract↗

Genomic analysis of protein kinases, protein phosphatases and two-component regulatory systems of the cyanobacterium Anabaena sp. strain PCC 7120.

Anabaena sp. PCC 7120 is a cyanobacterium capable of performing several important biological functions: photosynthesis, nitrogen fixation, cell differentiation, cell-cell communication, etc. These activities require an extensive signaling capability in order to respond to the changing environment. Based on the genomic data, we have retrieved several gene families encoding signaling components. It is estimated that 211 genes encode two-component signaling elements, and 66 genes encode Ser/Thr kinases and phosphatases. These genes together represent 4.2% of the coding capacity of the whole genome, making Anabaena PCC 7120 a leading member among prokaryotes in terms of its signaling potential. It is known that two-component systems are composed of a few basic modules that can arrange into different structures best adapted for each signaling system. Many proteins in Anabaena PCC 7120 have incorporated both modules of two-component systems and catalytic domains of either Ser/Thr kinases or phosphatases. A family of 13 genes encode proteins with both a Ser/Thr kinase domain and a His kinase domain, and another four genes were also found whose products have both a response regulator domain and a Ser/Thr phosphatase domain. Of all the signaling proteins in Anabaena PCC 7120, about one third (35%) are conserved in the genome of the unicellular cyanobacterium strain Synechocystis sp. PCC 6803. Interestingly, one subfamily of His kinases and two subfamilies of response regulators are found in Anabaena PCC 7120 but are absent in Synechocystis PCC 6803. This study constitutes a basis for analyses of signal transduction in Anabaena PCC 7120 using functional genomic approaches.

Anabaena↗

H11 kinase is a novel mediator of myocardial hypertrophy in vivo.

By subtractive hybridization, we found a significant increase in H11 kinase transcript in large mammalian models of both ischemia/reperfusion (stunning) and chronic pressure overload with hypertrophy. Because this gene has not been characterized in the heart, the goal of the present study was to determine the function of H11 kinase in cardiac tissue, both in vitro and in vivo. In isolated neonatal rat cardiac myocytes, adenoviral-mediated overexpression of H11 kinase resulted in a 37% increase in protein/DNA ratio, reflecting hypertrophy. A cardiac-specific transgene driven by the alphaMHC-promoter was generated, which resulted in an average 7-fold increase in H11 kinase protein expression. Transgenic hearts were characterized by a 30% increase of the heart weight/body weight ratio, by the reexpression of a fetal gene program, and by concentric hypertrophy with preserved contractile function at echocardiography. This phenotype was accompanied by a dose-dependent activation of Akt/PKB and p70(S6) kinase, whereas the MAP kinase pathway was unaffected. Thus, H11 kinase represents a novel mediator of cardiac cell growth and hypertrophy.

Animals↗

Near-IR tunable laser with an integrated LiTaO3 electro-optic deflector.

We report the successful demonstration of a near-IR tunable laser (1525.4-1558.2 nm) that uses an integrated LiTaO3 deflector in combination with a reflection grating as an electronically tunable filter. The electro-optic deflector is a unique integrated optical device and consists of a horn-shaped array of electro-optic prisms in series. The almost 33 nm of tuning covers a wavelength region of high interest to the communications industry (1527-1550 nm).

Journal Article↗