Biomedical subjects

Fei Cao

Publications and source records attributed to Fei Cao.

12 recordsLinked to original sources

PubMed2006

Chlamydia pneumoniae--induced macrophage foam cell formation is mediated by Toll-like receptor 2.

Chlamydia pneumoniae induces macrophage foam cell formation, a hallmark of early atherosclerosis, in the presence of low-density lipoprotein (LDL). This study examined the role that Toll-like receptor 2 (TLR2) and TLR4 may play in pathogen-induced foam cell formation. Murine macrophage RAW 264.7 cells either infected with C. pneumoniae or treated with the TLR4 ligand E. coli lipopolysaccharide (LPS) or the TLR2 ligand Pam(3)-Cys-Ala-Gly-OH (Pam) became Oil Red O-stained foam cells and showed increased cholesteryl ester (CE) content when cocultured with LDL. In macrophages from TLR2(-/-) mice, foam cells were induced by Escherichia coli LPS but not by C. pneumoniae or Pam. Conversely, C. pneumoniae or Pam, but not E. coli LPS, induced foam cells in the TLR4-deficient GG2EE macrophage cell line, suggesting that C. pneumoniae elicits foam cell formation predominantly via TLR2. Enhancing cholesterol efflux using the liver X receptor (LXR) agonist GW3965 significantly decreased the CE content of cells exposed to each of the three TLR ligands (C. pneumoniae, Pam, and E. coli LPS). Overall, our results suggest that activation of the LXR signaling pathway may affect potentially atherogenic processes modulated by the TLR ligands.

Animals↗

PubMed2006

[Symptomatic vasospasm after subarachnoid hemorrhage: study of 186 cases].

OBJECTIVE: To identify the risk factors associated with symptomatic vasospasm after aneurysmal subarachnoid hemorrhage (SAH). METHODS: The clinical data of 186 cases with SAH verified by radiology and lumbar puncture were reviewed retrospectively. RESULTS: Fifty-five of the 186 patients (29.6%) developed symptomatic vasospasm. The incidence of symptomatic vasospasm was significantly higher in the patients of Fisher grade III than in those of Fisher grade I and Fisher grade II, in the patients in poor clinical status at admission the in those in better clinical status, and in the patients with repeated reoccurrence of SAH then in those without reoccurrence (all P < 0.01). Sex, age, treatment modality, and use of antifibrinolytic drugs (AFD) did not influence the development of symptomatic vasospasm (all P > 0.05). Multivariate analysis showed that Fisher grade III [odds ratio (OR) 2.549, 95% confidence interval (CI) 1.406 - 4.517], poor clinical status at admission (OR 2.342, 95% CI 1.320 - 4.159) and repeated reoccurrence of SAH (OR 2.492, 95% CI 1.394 approximately 4.448) were associated with the increased risk of symptomatic vasospasm. CONCLUSION: Fisher grade III, poor clinical status at admission and repeated reoccurrence of SAH are significant independent risk factors of symptomatic vasospasm. The presence of symptomatic vasospasm can be independently predicted by the amount of subarachnoid hemorrhage, clinical status at admission, and times of SAH.

Adult↗

PubMed2006

Establishment of a mechanical injury model of rat hippocampal neurons in vitro.

OBJECTIVE: To establish a simple, reproducible, and practical mechanical injury model of hippocampal neurons of Sprague-Dawley rats in vitro. METHODS: Hippocampal neurons isolated from 1-2-day old rats were cultured in vitro. Mild, moderate and severe mechanical injuries were delivered to the neurons by syringe needle tearing, respectively. The control neurons were treated identically with the exception of trauma. Cell damage was assessed by measuring the Propidium Iodide (PI) uptaking at different time points (0.5, 1, 6, 12 and 24 hours) after injury. The concentration of neuron specific enolase was also measured at some time points. RESULTS: Pathological examination showed that degeneration, degradation and necrosis occurred in the injured cultured neurons. Compared with the control group, the ratio of PI-positive cells in the injured groups increased significantly after 30 minutes of injury (P<0.05). More severe the damage was, more PI-positive neurons were detected. Compared with the control group, the concentration of neuron specific enolase in the injured culture increased significantly after 1 hour of injury (P<0.05). CONCLUSIONS: The established model of hippocampal neuron injury in vitro can be repeated easily and can simulate the damage mechanism of traumatic brain injury, which can be used in the future research of traumatic brain injury.

Analysis of Variance↗

PubMed2005

Relationship between host survival and the type of immune response in different organs during disseminated candidiasis.

To examine the relationship between host survival and the type of immune response in different organs during disseminated candidiasis, the murine model of disseminated candidiasis was established by injection with Candida albicans via tail vein. The survival time was observed for up to 60 days. And the expression levels of cytokines in the spleen and kidney, including IFN-gamma and IL-4, were determined with RT-PCR. Our results showed that in the spleen, both non-fatal and fatal inoculum caused a type II immune response with steady expression levels of IFN-gamma and the obviously increased levels of IL-4. While in the kidney, non-fatal inoculum induced a type I immune response with the obviously increased levels of IFN-gamma and the steady expression levels of IL-4. However, fatal inoculum induced a type II immune response with a constant expression of IFN-gamma and the evidently increased levels of IL-4. It is concluded that in disseminated candidiasis, host survival is associated with the type of immune responses in the kidney, but not in the spleen.

Animals↗

PubMed2005

Susceptibility to vaginal candidiasis under different conditions in mice.

In order to study the susceptibility of murine vaginal mucosa to Candida albicans under different conditions, vaginal lavage fluid and vaginal tissue of mice were observed and compared between murine models with normal immune system (estrogen-treated mice) and immunosuppressed murine model, and between primary infection model of vaginal candidiasis and secondary infection one. The average level of colony forming unit (CFU) from the immuosuppressed group was higher than that from estrogen-treated group at each time point and the peak time was delayed. The differences between the two groups were statistically significant (P < 0.05) from the fourth day after inoculation. A significant difference existed in the average level of CFU between the control group and the estrogen-treated group (P < 0.05), and between the control group and the immuosuppressed group (P < 0.01). It was concluded that the vaginal mucosa from the immunosuppressed mice is more susceptible to Candida albicans and no difference is found in susceptibility between mice with primary infection and secondary infection.

Animals↗

PubMed2004

Computer-assisted bone age assessment: graphical user interface for image processing and comparison.

The current study is part of a project resulting in a computer-assisted analysis of a hand radiograph yielding an assessment of skeletal maturity. The image analysis is based on features selected from six regions of interest. At various stages of skeletal development different image processing problems have to be addressed. At the early stage, feature extraction is based on Lee filtering followed by the random Gibbs fields and mathematical morphology. Once the fusion starts, wavelet decomposition methods are implemented. The user interface displays the closest neighbors to each image under consideration. Results show the sensitivity of different regions to both stages of development and certain feature sensitivity within each region. At the early stage of development, the distal features are more reliable indicators, whereas at the stage of epiphyseal fusion, a larger dynamic range of middle features makes them more sensitive. In the current study, a graphical user interface has been designed and implemented for testing the image processing routines and comparing the results of quantitative image analysis with the visual interpretation of extracted regions of interest. The user interface may also serve as a teaching tool. At the later stage of the project it will be used as a classification tool.

Adolescent↗

PubMed2003

Point mutation in the parkin gene on patients with Parkinson's disease.

To investigate the distribution of possible novel mutations from parkin gene in variant subset of patients with Parkinson's disease (PD) in China and explore whether parkin gene plays an important role in the pathogenesis of PD, 70 patients were divided into early-onset group and late-onset group; 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes by using standard procedures. Mutations of parkin gene (exon 1-12) in all the subjects were screened by PCR-single strand conformation polymorphism (SSCP), and further sequencing was performed in the samples with abnormal SSCP results, in order to confirm the mutation and its location. A new missense mutation Gly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 patients were found. All the DNA variants were sourced from the samples of the patients with early-onset PD. It was concluded that Parkin point mutation also partially contributes to the development of early-onset Parkinson's disease in Chinese.

Aged↗

PubMed2003

Experimental study on inhibition of neuronal toxical effect of levodopa by ginkgo biloba extract on Parkinson disease in rats.

In order to observe neuronal toxical effect of Levodopa and investigate if using Levodopa together with Ginkgo Bilobar Extract (EGb) would be an workable method to treat Parkinson disease, rat models of Parkinson disease (PD) were made by injecting 6-OHDA stereotaxically to right side of the mesencephic ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Rotational behavioral observation, TUNEL, immunocytochemistry, Nissl's body staining were performed to measure the difference between group treated by Levodopa (50 mg/kg every day for 3 days, 5 days, 7 days, L-dopa group) and group treated by Levodopa combined with EGb (100 mg/kg every day, E-D group). The results showed that in the L-dopa group, the numbers of apoptosis of substantial nigra, rings of rotational behavior were more than those in the E-D group (P < 0.05). The numbers of Nissl's cells in L-dopa group were fewer than in E-D group (P < 0.05). The results suggested that Levodopa had neur toxic effect and EGb may decrease the toxicity of levodopa. The combined use of EGb with Levodopa may be a workable method to treat PD and may be better than using Levodopa alone.

Animals↗

PubMed2003

Blocking oligo--a novel approach for improving chip-based DNA hybridization efficiency.

For most of the commonly used DNA chips, the probes are usually single-stranded oligonucleotides and the targets are double-stranded DNAs (dsDNAs). Only one strand of the DNA serves as the target while the other competes with the probes immobilized on the chip for the target and therefore is regarded as the interfering strand. In this report, a novel technique was developed for improving the hybridization efficiency on DNA chips by using blocking oligos, which is complimentary to the target interfering strand to reduce the influence of the interfering strand. The hybridization efficiency of dsDNA was much lower than that of single-stranded DNA (ssDNA) when synthesized DNA targets were tested on the DNA chip. Blocking oligos can improve the hybridization efficiency of dsDNA to about 2/3 that of ssDNA. Blocking oligos have also been applied to PCR products of different lengths for hybridization. The hybridization efficiency with blocking oligos is about three times higher than that without blocking oligos. We have tested PCR products of 1054 and 435 bp using our blocking procedure, and the results are consistent.

DNA↗

PubMed2003

Integration of computer assisted bone age assessment with clinical PACS.

Computer assisted bone age assessment (BAA) integrated with a clinical PACS is described. The image analysis is performed on a DICOM compliant workstation able to accept images from a PACS server or directly from an image modality (digital radiography or film scanner). Images can be processed in two modes. If the image is acquired from a normally developed subject, it can be added to the digital hand atlas. An image may also be subjected only to a diagnostic analysis for the BAA without archiving the features in the database. The image analysis is performed in three steps. A location of six region of interest is followed by their segmentation and feature extraction. The features analysis results in retrieving the closest image match from the standard database. Based on currently analyzed image data in the hand atlas, the standard deviation of the assessment bone age does not exceed 1 yr of age.

Age Determination by Skeleton↗

PubMed2003

[A novel point mutation in parkin gene was identified in an early-onset case of Parkinson's disease].

OBJECTIVE: To investigate the distribution of possible novel mutation of parkin gene in variant subset patients with Parkinson's disease (PD) in China and to explore the role of parkin gene in the pathogenesis of PD. METHODS: Seventy patients were divided into early onset and late-onset groups, and 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes with standard procedures. Mutations of parkin gene (exons 1-12) in all subjects mentioned above were screened by PCR-SSCP. And in the samples with abnormal SSCP result, further sequencing was performed to confirm the mutation and its location. RESULTS: A new missense mutation (Gly284Arg) on exon 7 was found in a sample, while 4 samples from all subjects exhibited abnormal mobility shift on SSCP electrophoresis. All mentioned DNA variants were sourced from the samples of the patients with early-onset PD. CONCLUSION: Point mutation in parkin gene also contributes partly to the development of early-onset Parkinson's disease in Chinese population.

Adult↗

PubMedDate not supplied

Informatics in radiology (infoRAD): A complete continuous-availability PACS archive server.

The operational reliability of the picture archiving and communication system (PACS) server in a filmless hospital environment is always a major concern because server failure could cripple the entire PACS operation. A simple, low-cost, continuous-availability (CA) PACS archive server was designed and developed. The server makes use of a triple modular redundancy (TMR) system with a simple majority voting logic that automatically identifies a faulty module and removes it from service. The remaining two modules continue normal operation with no adverse effects on data flow or system performance. In addition, the server is integrated with two external mass storage devices for short- and long-term storage. Evaluation and testing of the server were conducted with laboratory experiments in which hardware failures were simulated to observe recovery time and the resumption of normal data flow. The server provides maximum uptime (99.999%) for end users while ensuring the transactional integrity of all clinical PACS data. Hardware failure has only minimal impact on performance, with no interruption of clinical data flow or loss of data. As hospital PACS become more widespread, the need for CA PACS solutions will increase. A TMR CA PACS archive server can reliably help achieve CA in this setting.

Computer Communication Networks↗