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Biomedical subjects

Z Zhu

Publications and source records attributed to Z Zhu.

At least 109 records · Page 6Linked to original sources
PubMed2001

[Antibacterial activities of seven commonly used antibiotics to 106 isolated strains of porphyromonas gingivalis in vitro].

OBJECTIVE: Porphyromonas gingivalis (Pg) is one of the main putative pathogens of periodontal disease, especially of adult periodontitis. This in vitro study was aimed at observing the inhibitory activities of 7 commonly used antimicrobical drugs on 106 stains of Pg which isolated from subgingival plaques of sites with adult periodontits. METHODS: Kirby-Bauer paper disk method was used in this study. RESULTS: Pg was highly susceptible to Clindamycin, Sulfamzthoxazole timethoprin, Tetracycline and Cefazolin, the susceptibility rates were 93.4%, 78.3%, 60.4% and 56.6% respectively. CONCLUSION: Majority of the strains of Pg was moderately susceptible to cefalexin and acetylspiramycin, while no strains of Pg was susceptible to Penicillin G. The concentrations of Pg solutions (10(5) CFU/ml, 10(6) CFU/ml and 10(8) CFU/ml) had not influence on the results. This data is helpful for clinically antibiotic selection of periodontal treatment.

Adult↗
PubMed2001

[Application of voice acoustic analysis in microlaryngoscopic surgery].

OBJECTIVE: To evaluate the relationship between the effect of microlaryngoscopic surgery of vocal polyp and the change of all-parameters. METHOD: Acoustic parameters of 80 patients with vocal polyp were measured by Dr. Speech Sciente for Windows, and analyzed preoperatively and postoperatively. RESULT: The jitter, shimmer and NNE were different significantly between preoperative and postoperative, the NNE and shimmer were more sensitive than jitter. CONCLUSION: The NNE and shimmer of acoustic parameter are objective parameter to evaluate the effect of the microlaryngoscopic surgery of vocal polyp.

Adolescent↗
PubMed2001

[Influence of anisodamine on guinea pig experimental nasal hypersensitivity].

OBJECTIVE: To observe the influence of anisodamine on guinea pig experimental nasal hypersensitivity. METHOD: Experimental animals were divided into normal control group, TDI group, reserpine group and anisodamine group. The scores of symptom of nose and the cytologic changes of nasal mucosa were parameters of observing. RESULT: The nasal symptom of reserpine group was significantly stronger than the TDI group, and the eosinophilia evidently increased (both P < 0.01). The nasal symptom of the anisodamine group reduced and the eosinophilia decreased. It is significantly difference between the TDI group and the reserpine group (both P < 0.01). CONCLUSION: Anisodamine may play a role in therapy of the experimental nasal hypersensitivity with hyperfunction of parasympathetic nerve.

Animals↗
PubMed2001

[Studies on the pharmacokinetics and relative bioavailability of salbutamol aerosol in healthy volunteers].

AIM: To study the pharmacokinetics and relative bioavailability of salbutamol aerosol in healthy volunteers. METHODS: An HPLC method for the determination of salbutamol in human plasma was improved. Ten healthy male subjects were enrolled. A randomized, two-way crossover, open design was adopted. After the subjects inhaled or orally administered salbutamol, fourteen blood samples were taken at predetermined time. The concentrations of salbutamol in plasma were determined by HPLC, and then assessed with PCNONLIN software to obtain the pharmacokinetic parameters and relative bioavailability of aerosol versus water solution. RESULTS: The standard curve was linear over the range 0.2-20 ng.mL-1. The intra- and interassay RSDs were 7.01% and 2.10% at 0.4 ng.mL-1, 2.18% and 5.25% at 4.0 ng.mL-1 and 4.61% and 4.85% at 15.0 ng.mL-1. The recoveries were between 90% and 110%. The pharmacokinetics of salbutamol aersol was described well with a two-compartment model, and the parameters for salbutamol inhaled and orally administered were assessed as follows: Tmax were (0.22 +/- 0.07) h and (1.8 +/- 0.6) h, Cmax were (3.4 +/- 1.1) ng.mL-1 and (3.9 +/- 1.4) ng.mL-1, T1/2 beta were (4.5 +/- 1.5) h and (4.6 +/- 1.1) h, respectively. The AUC0-20 min (inhal) was 7.94 times as high as the AUC0-20 min (p.o.). There were significant differences between Tmax, AUC, K12, K21, alpha and T1/2 alpha (P < 0.05). The relative bioavailability of salbutamol aerosol was 57.23% compared with its oral solution. CONCLUSION: The assay was sensitive, specific, accurate and precise. The absorption process of salbutamol aerosol in human was significantly different from that of the oral solution. It was demonstrated that AUC0-20 min reflected the lung availability of salbutamol inhaler.

Administration, Inhalation↗
PubMed2001

[Characterization of alumina adobe and sintered body of GI-infiltrated ceramic].

OBJECTIVE: This study was conducted to elucidate the mechanism of formation of porous structure by investigating the porosity of the alumina adobe and sintered body of GI-II Infiltrate Ceramic, and its role in strengthening and toughening this kind of ceramic composite. METHODS: The alumina powder size-mass distribution was obtained by BI-XDC powder size analysis device; the open pore parameters of alumina adobe and sintered body were analyzed using the mercury pressure method. Their fracture surfaces were observed under scanning electronic microscope. RESULTS: Fine powder had two main size groups of 0.09-0.1 micron and 0.2-0.5 micron, respectively, and coarse powder, with size between 1.5 to 4.5 microns, occupied the majority of powder mass. Alumina adobe's pores became larger after sintering. The median pore radii of adobe and sintered body were 0.2531 micron and 0.3081 micron, respectively; the average pore radii changed from 0.0956 micron to 0.1102 micron. Under scanning electronic microscope, fine alumina powders were fused partially together and their surfaces were blunted, but coarse powders did not show such phenomena. CONCLUSION: The alumina size distribution contributes to the formation of porous structure of alumina sintered body. This porous structure is not only the shape skeleton but also the mechanical skeleton of GI-II Infiltrated Ceramic. It plays an important role in raising the mechanical properties of this kind of ceramic composite.

Aluminum Oxide↗
PubMed2001

A preliminary study on comparison and fusion of metabolic images of PET with anatomic images of CT and MRI.

OBJECTIVE: To compare and match metabolic images of PET with anatomic images of CT and MRI. METHODS: The CT or MRI images of the patients were obtained through a photo scanner, andthen transferred to the remote workstation of PET scanner with a floppy disk. A fusion method was developed to match the 2-dimensional CT or MRI slices with the correlative slices of 3-dimensional volume PET images. RESULTS: Twenty-nine metabolically changed foci were accurately localized in 21 epilepsy patients' MRI images, while MRI alone had only 6 true positive findings. In 53 cancer or suspicious cancer patients, 53 positive lesions detected by PET were compared and matched with the corresponding lesions in CT or MRI images, in which 10 lesions were missed. On the other hand, 23 lesions detected from the patients' CT or MRI images were negative or with low uptake in the PET images, and they were finally proved as benign. CONCLUSIONS: Comparing and matching metabolic images with anatomic images helped obtain a full understanding about the lesion and its peripheral structures. The fusion method was simple, practical and useful for localizing metabolically changed lesions.

Carcinoma, Squamous Cell↗
PubMed2001

[Determination of micro-elements in six condiments by AAS].

In this paper, through atomic absorption detector, we determined the content of micro-elements, such as Sr, Ba, Fe, Al, Cu, Cr, Zn, Mo, Ni, Co, Mn, Cd, Mg, in six condiments. From the result, we found there is a differing content of micro-element in different condiments. At the same time, we also made a reclaiming experiment for these micro-elements in ginger, the rate of reclamation is about 90%-108%.

Barium↗
PubMed2001

[Contents analysis of zinc, manganese, copper and iron in 7 kinds of treatment gastritis Chinese traditional medicines].

The contents of Zn, Mn, Cu and Fe in 7 kinds of treatment gastritis Chinese traditional medicines are determined by FAAS. The results show that element Fe in medicines is very rich, but element Cu is lower. The relationship between trace elements and the factor that causes gastritis is discussed. It provides useful reference data for discussing the relations of trace elements and treatment of gastroenteritis.

Copper↗
PubMed2001

[Analysis of the contents of Zn, Cu, Fe, Mn and Ni in suxiaoweiningchongji].

The contents of Zn, Cu, Fe, Mn and Ni in five groups of Suxiaoweiningchongii were determined by AAS. The results showed that he Fe content is the highest and Cu is the lowest, and the reduced order of contents from highest to lowest is Fe to Zn to Mn to Ni to Cu. The relationship between the trace elements in Suxiaoweiningchongji and the curative effect was discussed.

Copper↗
PubMed2001

[Analysis of the content of ten kinds of metal elements in cerebrolysin by atomic absorption spectrophotometry].

The contents of Mg, K, Ca, Cr, Mn, Fe, Co, Ni, Cu and Zn in eight different brand cerbrolysins were determined by flame atomic absorption spectrophotometry. The statistical results as follows: the metal elements have significant difference between in seven kinds of Chinese products and in the cerebrolysin made by Austria. According to the results, we studied the inter relation of metal elements with medicine result, and analyzed the effect of trace elements in cerebrolysin. It provided useful data for medicine on clinical practice.

Amino Acids↗
PubMed2001

Engineered antibodies accelerating drug discovery and development.

This meeting, organized by the Strategic Research Institute, reviewed advances in both engineering technologies and clinical development of antibody products. A panel of speakers, mainly from the biotechnology and pharmaceutical industries, covered several important issues in the development of antibody therapeutics, including new display technologies, human antibody generation, high-level expression of antibodies in both mammalian cells and in transgenic plants, and the latest data from ongoing clinical trials of antibody products. In the case of human antibody generation, Abgenix Inc's XenoMax technology combines the powers of the transgenic XenoMouse and in vitro B cell culture and selection to enable the robust identification of antibodies with rare properties and very high affinity. MAbstract from Crucell NV provides a unique approach to the identification of human antibodies directed against tumor-specific glycosylation variants and activation epitopes of otherwise normal cellular molecules. Regarding antibody production, the use of transgenic plants is gaining more interest among biopharmaceutical industrials. Promising results were also reported on several antibody-based therapeutic, including antibody-drug conjugates and prodrugs.

Journal Article↗
PubMed2000

Phosphorylation and Cu+ coordination-dependent DNA binding of the transcription factor Mac1p in the regulation of copper transport.

Copper ions are essential at a proper level yet toxic when present in excess. To maintain a proper intracellular level, cells must be able to sense the changes in copper ion concentrations. The yeast transcription factor Mac1p plays a critical role in the transcriptional regulation of CTR1 and CTR3, both encoding high affinity copper ion transporters. Here we report that the Mac1p binding of the copper ion-responsive elements (CuREs) in the promoters of CTR1 and CTR3 is affected by copper ions. On one hand, the Mac1p DNA binding is Cu(+) coordination-dependent, and on the other hand, exogenous Cu(+) and isoelectronic Ag(+) ions disrupt the DNA binding of Mac1p. These results suggest that the Mac1p is able to sense two different levels of copper ions. These two levels are probably the physiological and toxic copper levels in yeast cells. Furthermore, we found that Mac1p undergoes posttranslational phosphorylation modification in yeast and that the phosphorylation is required for the Mac1p to become DNA-binding active. Nonphosphorylated Mac1p is unable to bind the CTR1 promoter DNA. The data support the model of intradomain interactions and indicate further that the phosphorylation probably prevents the inhibition of DNA-binding domain activity by the activation domain of Mac1p. Taken together, these findings demonstrate that Mac1p functions critically in maintaining a proper intracellular concentration of copper ions.

Base Sequence↗
PubMed2000

Identification and characterization of a 19q12 amplicon in esophageal adenocarcinomas reveals cyclin E as the best candidate gene for this amplicon.

Genomic DNA amplification in tumors is frequently associated with an increased gene copy number of oncogenes or other cancer-related genes. We have used a two-dimensional whole-genome scanning technique to identify gene amplification events in esophageal adenocarcinomas. A multicopy genomic fragment from a tumor two-dimensional gel was cloned, and genomic amplification encompassing this fragment was confirmed by Southern blot analysis. The corresponding DNA sequence was matched by BLAST to a BAC contig, which allowed the use of electronic-PCR to localize this amplicon to 19q12. Sequence tagged site-amplification mapping, an approach recently implemented in our laboratory (Lin, L. et al., Cancer Res., 60: 1341-1347,2000), was used to characterize the amplicon. Genomic DNA from 65 esophageal and 11 gastric cardia adenocarcinomas were investigated for 19q12 amplification using quantitative PCR at 11 sequence tagged site markers neighboring the cloned fragment. The amplicon was narrowed from >8 cM to a minimal critical region spanning <0.8 cM, between D19S919 and D19S882. This region includes the cyclin E gene. Fourteen expressed sequence tags (ESTs) covering the minimal region were then assayed for potential gene overexpression using quantitative reverse transcription-PCR. Seven of the selected ESTs were found to be both amplified and overexpressed. Among these seven ESTs, cyclin E showed the highest frequency of gene amplification and overexpression in the tumors examined, which allowed us to finalize the core-amplified region to <300 kb. These results indicate that cyclin E is the likely target gene selected by the amplification event at 19q12. The fact that cyclin E overexpression was found only in the amplified tumors examined indicates that gene amplification underlies the cyclin E gene overexpression. Our study represents the first extensive analysis of the 19q12 amplicon, and is the first to physically map the core-amplified domain to a region of <300 kb that includes cyclin E. Amplification of 19q12 was found neither in the 28 esophageal squamous cancers nor in the 39 lung adenocarcinomas examined but was observed in 13.8% of esophageal and 9.1% of gastric cardia adenocarcinomas.

Adenocarcinoma↗
PubMed2000

Generation of gene-modified T cells reactive against the angiogenic kinase insert domain-containing receptor (KDR) found on tumor vasculature.

The destruction of newly forming tumor vasculature is a promising approach to inhibit tumor growth. The goal of the present study was to investigate whether human lymphocytes gene modified to express a chimeric receptor specific for the angiogenic endothelial cell receptor, KDR, could react against KDR(+) cells. Gene-modified lymphocytes specifically lysed KDR(+) cells and secreted cytokines in response to KDR(+) target cells including human umbilical vein endothelial cells (HUVECs). Anti-KDR lymphocytes induced HUVECs to secrete the chemokine interleukin 8 and upregulate the adhesion molecules VCAM and E-selectin, which may be important in the recruitment of further immune effector cells to tumor. These KDR-specific lymphocytes may be useful in the adoptive immunotherapy of a broad range of cancers by inducing immune-mediated destruction of tumor neovasculature.

CD28 Antigens↗
PubMed2000

Interferon gamma induction of pulmonary emphysema in the adult murine lung.

Chronic inflammation containing CD8(+) lymphocytes, neutrophils, and macrophages, and pulmonary emphysema coexist in lungs from patients with chronic obstructive pulmonary disease. Although this inflammatory response is believed to cause the remodeling that is seen in these tissues, the mechanism(s) by which inflammation causes emphysema have not been defined. Here we demonstrate that interferon gamma (IFN-gamma), a prominent product of CD8(+) cells, causes emphysema with alveolar enlargement, enhanced lung volumes, enhanced pulmonary compliance, and macrophage- and neutrophil-rich inflammation when inducibly targeted, in a transgenic fashion, to the adult murine lung. Prominent protease and antiprotease alterations were also noted in these mice. They included the induction and activation of matrix metalloproteinase (MMP)-12 and cathepsins B, H, D, S, and L, the elaboration of MMP-9, and the selective inhibition of secretory leukocyte proteinase inhibitor. IFN-gamma causes emphysema and alterations in pulmonary protease/antiprotease balance when expressed in pulmonary tissues.

Animals↗
PubMed2000

In vitro effects of Se-allylselenocysteine and Se-propylselenocysteine on cell growth, DNA integrity, and apoptosis.

Two previously unevaluated selenium compounds, Se-allylselenocysteine (ASC) and Se-propylselenocysteine (PSC), have been shown recently to be active in the chemoprevention of experimentally induced mammary carcinogenesis. Other than their potential as chemopreventive agents, little is known about the pharmacological properties of these compounds. In this article, we report on the in vitro effects of ASC and PSC on cell growth inhibition, apoptosis, and the induction of DNA damage. The effects of ASC and PSC were examined in two mouse mammary epithelial cell lines derived from mammary hyperplasias. These cell lines, designated TM2H and TM12, have mutant or wild-type p53, respectively. It was observed that ASC but not PSC reduced, in a concentration- and time-dependent manner, the number of adherent cells in culture, and this suppressive effect was more prominent in TM12 than in TM2H cells. ASC was also found to induce alkaline-labile DNA damage and the oxidation of pyrimidines, and it also increased the rate of apoptosis. These changes were not seen by exposure to PSC or the sulfur analog of ASC. However, additional data obtained from the intact rat mammary gland suggest that the loss of DNA integrity induced by ASC might not be manifest in vivo at doses of ASC that inhibit carcinogenesis.

Animals↗