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      2. west china medical publishers
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        find Keyword "biology" 36 results
        • Infected endophthalmitis diagnosed by multiplex polymerase chain reaction

          Objective To evaluate the rapid diagnosis of bacterial and (or) fungal endophthalmitis by multiplex polymerase chain reaction (MPCR). Methods MPCR was performed to detect the DNA segment of bacteria and (or) fungi from standard strains and 41 samples of intraocular fluid or vitreous from 38 patients (3 with double eyes and 35 with single), and the results were compared with the cultured bacteria and fungi. Results Five hours after detected by MPCR, bacteria and (or) fungi in 34 out of 41 samples (82.9%) from patients were detected,in cluding bacteria in 26,fungi in 6,and both bacteria and fungi in 2. The positive rate of MPCR was obviously higher than the cultured ones(χ2=9.60, P<0.05). Conclusion With the advantages of rapidity, sensibility, and specificity, MPCR can make for the rapid and definitive diagnosis of bacterial and (or) fungal endophthalmitis. (Chin J Ocul Fundus Dis,2004,20:81-83)

          Release date:2016-09-02 05:58 Export PDF Favorites Scan
        • Microbiological characteristics of airway bacteria in adult patients with bronchiectasis and their correlation with the clinical features

          ObjectiveTo analyze the microbiological characteristics of airway bacteria in adult patients with bronchiectasis and to analyze their correlation with the clinical features. MethodsPatients diagnosed with bronchiectasis in the Department of Respiratory and Critical Care Medicine of West China Hospital of Sichuan University from October 2017 to April 2018 were classified into the bronchiectasis group, while the control group was those who were found to have pulmonary nodules (diameter less than 10 mm) requiring bronchoscopy by physical examination. All subjects in both groups had not used antibiotics or hormones within 4 weeks and had no other respiratory diseases. Bronchoalveolar lavage fluid (BALF) from the lesion site of the branchial expansion group was collected, and BALF from the basal segment of the contralateral inferior bronchial lobe of the pulmonary nodule was collected in the control group. Bacterial culture and 16S rRNA gene sequencing were performed in both groups. ResultsSeventeen cases and six controls were enrolled in this study and the BALF specimens were collected. Eight cases were in stable period and nine cases were in acute period. The case group was divided into the bacteria-positive group and negative group based on bacterial culture of BALF. Shannon index in the bacteria-positive group was significantly lower than the bacteria-negative group and the control group. And Shannon index showed a negative correlation with positive bacterial culture in BALF. When Shannon index ≤4.5 was used to predict positive bacterial culture, the sensitivity and specificity were 83.3% and 90.9% respectively. The average relative abundance of bacteria was higher and the average sample distribution uniformity was lower in patients with acute period, compared with those in patients with stable period. Shannon index was negatively correlated with the acute exacerbation in patients. When Shannon index <5.0 was used to predict acute exacerbation, the sensitivity and specificity were 77.8% and 100.0%, respectively. ConclusionsShannon index in 16S rRNA gene sequencing results has certain predictive value for acute exacerbation stage. 16S rRNA gene sequencing combined with bacterial culture results can help guide clinicians to provide more precise treatment plans.

          Release date:2023-09-22 05:51 Export PDF Favorites Scan
        • The Correlation Factors for The Formation of Cholesterol Calculus

          Objective To study the latest research progress of the formation mechanism of cholesterol stone disease and forming factors of cholesterol stone disease and to provide new theoretical level and develop a new development direction for guiding clinical application. Methods The related literatures at home and abroad were analyzed, compared and summarized, and the current relevant research dynamic of cholesterol stone disease was sketched. Results The formation of cholesterol gallstone is closely related to the abnormal levels of serum lipids metabolism, bacterial and viral infection, and the expression of genes related to cholesterol gallstone. Conclusions The formation of cholesterol calculus disease is a kind of interaction and intricate disease process involving of environmental factors, genetic factors, and biological factors. Although there has been a lot of blood lipid, protein correlation research with cholesterol stone, there are also many studies such as using gene transplantation and gene knockout, but gene technology of cholesterol stone disease diagnosis and treatment is expected to become the new hot research topic.

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        • Bioinformatics analysis of transcriptome sequencing of early hypoxia damage in photoreceptor 661W cell line

          ObjectiveTo analyze the early changes of gene expression levels and signaling pathways in 661W cell line under hypoxic conditions and to find potential functional target genes.MethodsThe cultured mouse 661W cells were divided into hypoxia treatment group and normoxia control group. Cells in the hypoxia treatment group were cultured in a three-gas incubator with volume fraction of 1% and 5% CO2 at 37 ℃. Cells in the normoxia control group were cultured in an incubator at 37 ℃ with volume fraction of 5% CO2. High-throughput sequencing technology was used to sequence the transcriptome of 661W cell treated with hypoxia and normoxia for 4 hours to screen for differentially expressed genes (DEG). Clustering heat map analysis, gene ontology (GO) functional enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and protein-protein interaction network (PPI) analysis were performed. The reverse transcription-polymerase chain reaction (RT-PCR) was used to verify the accuracy of the sequencing results.ResultsA total of 506 differentially expressed genes were screened, including 459 up-regulated genes and 47 down-regulated genes. GO functional enrichment analysis showed that the main biological processes of DEG were the cell's response to hypoxia, glycolysis, negative regulation of cell proliferation and apoptosis. hypoxia inducible factor (HIF)-1α pathway, glycolysis, Forkhead box O (FoxO) pathway, Insulin signaling pathway and Adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway were involved in the above process. PPI analysis results showed that hub genes related to hypoxia were Aldoa, Aldoc, Gpi1, Hk2, Hk1, Pfkl, Pfkp, Vhl, Fbxo10 and Fbxo27. The RT-PCR results showed that the relative expression levels of 15 DEG mRNA in the hypoxic treatment group were higher than that of the normoxic control group, and the difference was statistically significant (P<0.05). The mRNA expression levels of N-myc downstream-regulated gene-1 (Ndrg1), Mt1, and vascular endothelial growth factor A (VEGFA) were time-dependent on hypoxia.ConclusionsUnder hypoxia, DEG is mainly related to glucose metabolism, cell response to hypoxia, regulation of proliferation and apoptosis. HIF-1α pathway, glycolysis, FoxO pathway and AMPK pathway are involved in the early changes of 661W cells under hypoxia. Aldoa, Aldoc, Gpi1, Hk2, Hk1, Pfkl, Pfkp, Vhl, Fbxo10, Fbxo27 may play key roles in the response of 661W cells to hypoxia. Ndrg1, Mt1 and VEGFA could be potential functional target genes for the study of ischemia and hypoxia-related fundus diseases.

          Release date:2021-04-19 03:36 Export PDF Favorites Scan
        • Study on the characteristics of biology force line of proximal femur based on structural topology optimization

          Internal fixator is usually adopted in the treatment of bone fractures. In order to achieve anatomical reduction and effective fixation of fractures, the placement of internal fixators should comply with the biology force line of the bone and adapt to the specific anatomical morphological characteristics of the cortical bone. In order to investigate the distribution characteristics and formation regularity of biology force line and cortical thickness of human bone, three-dimensional model of proximal femur is established by using three-dimensional reconstruction technique in this paper. The normal physiological stress distribution of proximal femur is obtained by finite element analysis under three kinds of behavior conditions: one-legged stance, abduction and adduction. The structural topology optimization method is applied to simulate the cortex of the proximal femur under the combined action of three kinds of behavior conditions, and the anatomic morphological characteristics of the proximal femur are compared. The distribution trend of biology force line of proximal femur and the characteristics of cortex are analyzed. The results show that the biology force lines of bone structure and the morphological characteristics of cortex depend on the load of human activities. The distribution trend of biology force line is related to the direction of trabecular bone and the ridge trend and firmness of cortex when bone is loaded physiologically. The proposed analytical method provides a solution to determine the biology force line of bone and the distribution characteristics of cortex. The conclusions obtained may guide the reasonable placement of internal fixator components of fracture.

          Release date:2019-02-18 03:16 Export PDF Favorites Scan
        • Prediction and bioinformatic analysis of hsa-miRNA-451 target genes

          ObjectiveTo predict as well as bioinformatically analyze the target genes of has-miR-451. MethodsmiRBase, miRanda, TargetScan and PicTar were used to predict the target genes of hsa-miRNA-451. The functions of the target genes were demonstrated by Gene Ontology and pathway enrichment analysis. P < 0.05 was set as statistically significant. Results18 target spots of hsa-miRNA-451 were predicted by 3 databases or prediction software at least. The functions of the target genes were enriched in proliferation and development of epithelial cells and regulation of kinase activity (P < 0.05). Pathway analysis showed that transforming growth factor-beta signaling pathway, mitogen-activated protein kinase signaling pathway, epidermal growth factor signaling pathway, Wnt signaling pathway and mammalian target of rapamycin signaling pathway were significantly enriched (P < 0.05). Conclusionhsa-miRNA-451 might be involved in various signaling pathways related to proliferation and development of epithelial cells.

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        • Dynamic investigation on biological and molecular biological characteristics of SO-Rb50cloned cell strains

          Objective To compare the differences of chromosome aberration and Rb 1 gene mutation among 3 cloned cells of SO-Rb50 cell line of retinoblastoma. Methods 1.Three cell cloned strains named MC2, MC3, MC4 were isolated from SO-Rb50. 2. Gbanding and karyotype analysis were performed on the llth passage cells of the 3 cell strains.3.All exons and the promoter region of the Rb gene were detected by PCR-SSCP analysis in tumor cell DNA extracted from the 3 cell strains. Results 1.Both numerical and structural chromosomal aberrations could be observed in these 3 cell strains.Several kinds of structural chromosomal aberrations were observed.The chromosome aberrations in the same passage of different cell strains were different.Aberration of chromosome 13 was rare and the aberration feature was different in the 3 cell strains.Five marker chromosomes were identified.M1,t(1;1)qter-p35∷q24-ter could befound in all cell strains.Two of them M4 and M5,have not been reported in SO-Rb50 cell line previously.2.SSCP analysis of exon 24 showed that MC411 and MC3138 had abnormal band. Conclusions The characteristics of heterogeneity of the original tumor cell line SO-Rb50are still kept during a long-term culture in vitro and the cloned strains had dynamic changes during this period.Aberration of chromosome 13 is not the only cause of RB;aberration of chromosome 1,a commom event in some neoplasias as well as in SO-Rb50, plays a meaningful role in the immortalization of this cell line. (Chin J Ocul Fundus Dis, 1999, 15: 146-148)

          Release date:2016-09-02 06:07 Export PDF Favorites Scan
        • PLASTICITY AND APPLICATION OF MARROW-DERIVED STEM CELLS

          Objective To investigate plasticity of marrow-derived stem cells,possible mechanisms and application. Methods The recent literature concerned plasticity of marrow-derived stem cells was extensively reviewed. Results Although stem cells plasticity has not been proven, there is more and more evidenceto show that the stem cells may have the plasticity and at least four differentmechanisms are explained.Conclusion The extensive research will be required. If the plasticity is proven, adult stem cells can be used for more therapeutic purposes. For example, the use of stem cells from bone marrow may correct geneticor degenerative disorders of a second organ from which stem cells are more difficult to isolate.

          Release date:2016-09-01 09:29 Export PDF Favorites Scan
        • The research progress of intraductal papillary mucinous neoplasms

          Objective To summarize the research progress of intraductal papillary mucinous neoplasms (IPMNs). Method The domestic and international published literatures related to IPMNs in recent years were collected and reviewed. Results Based on the site of tumor involved, IPMNs were classified into main duct, branch duct, and mixed types. According to the histologic features, IPMNs were divided into intestinal, pancreatobiliary, gastric, and oncocytic types. The pathological and clinical presentations of IPMNs were vary, and multiple imaging approaches including endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasonography (EUS), CT, magnetic resonance cholangiopancreatography (MRCP) combined with MRI, could display morphologic and functional characteristics of IPMNs. In additon, the risk of malignancy in IPMNs could be evaluated and the functions of some genes (including KRAS, BRAF, GNAS, and so on) in the development process of IPMNs had been confirmed. Conclusion IPMNs is a kind of disease different from other tumors of the pancreas in clinicopathologic features, imaging performance, and molecular biology changes, and how to link the above three aspects needs to be further studied.

          Release date:2017-04-01 08:56 Export PDF Favorites Scan
        • Single-cell meta-analysis of T lymphocytes functional differences in various organs after SARS-CoV-2 infection

          ObjectiveTo explore the functional heterogeneity of T lymphocytes in various organs after SARS-CoV-2 infection. Methods Using the public database GEO data (GSE171668, GSE159812, GSE159556, GSE167747) and the analysis method of single-cell technology, the functional differences of T lymphocytes in various organs of patients after infection with SARS-CoV-2 were analyzed. Results Through single-cell data extraction of 16 livers, 19 hearts,2 spleens, 6 brains, 58 lungs, 21 kidneys and 5 pancreases from SARS-CoV-2 infected patients, invasion genes were relatively highly expressed in T lymphocytes of the lung and pancreas. The lung had a special ability to express the interferon signaling pathway, while the expression of other organs was relatively low; at the same time, the T lymphocytes of the lung also highly expressed fatty acid binding sites. Conclusion After SARS-CoV-2 infection, compared with other organs, the lung has a special interferon-activated signaling pathway and fatty acid binding site.

          Release date:2022-10-27 10:51 Export PDF Favorites Scan
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