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F Zhao

Publications and source records attributed to F Zhao.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Effects of pre-heating on the sensitivity of K562 cell to tumor necrosis factor-alpha].

In order to study the effects of pre-heating on the sensitivity of cells to tumor necrosis factor-alpha (TNF-alpha), the K562 cells were pre-heated at 40 degrees C for different times to induce heat shock protein 70 (HSP70). To observe the effects of TNF-alpha concentration on the sensitivity of pre-heated cells, cells were pre-heated for 60 min and treated with TNF-alpha (50, 100, 200 and 400 U/ml) for 16 hours, and the cells vitalities were detected by MTT. In order to observe the effect of pre-heating time on the sensitivity of cells to TNF-alpha, the pre-heated cells were treated with 100 U/ml TNF-alpha for 24 hours. The levels of HSP70 were tested by reversed transcription-PCR(RT-PCR). The results showed that HSP70 could be induced by pre-heating, and reached its top level after 120 mins, and the sensitivity of non-heated cells to TNF-alpha was lower than that of pre-heated cells. To 100 U/ml TNF-alpha, the sensitivity was lowest after the cells were pre-heated for 120 min. The results suggested that pre-heated could induce the expression of HSP70 and inhibit the sensitivity of cell to TNF-alpha, the mechanism may be involved with the overexpression of HSP70.

HSP70 Heat-Shock Proteins↗
PubMed2000

Dominant negative down-regulation of endotoxin-induced tumor necrosis factor alpha production by Lps(d)/Ran.

We recently showed that adenoviral transfer and expression of the Lps(d)/Ran gene isolated from endotoxin-resistant C3H/HeJ mice could protect endotoxin-sensitive mice from endotoxic shock. Elevation of proinflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha), is thought to be essential for the development of septic shock. To investigate the extent to which Lps(d)/Ran affects TNF-alpha production, we transduced primary macrophages from endotoxin-sensitive and -resistant mice with adenoviral vectors expressing the wild-type and the mutant Lps/Ran cDNAs and other control genes, and compared the amount of TNF-alpha produced by these various transduced macrophages. Successful transfer and expression of Lps(d)/Ran cDNA in endotoxin-sensitive C3H/HeOuJ macrophages reduced TNF-alpha production upon lipopolysaccharide (LPS) stimulation, as compared with macrophages transduced with vectors expressing the wild-type Lps(n)/Ran cDNA, the green fluorescent protein gene, or the lacZ gene. On the other hand, successful transfer and expression of the wild-type Lps(n)/Ran cDNA in primary macrophages from endotoxin-resistant C3H/HeJ mice failed to induce TNF-alpha production to any significant extent unless a very high LPS concentration was used. Given our previous demonstration that Lps(n)/Ran functions effectively in restoring LPS responsiveness in B cells from C3H/HeJ mice, we conclude that Lps/Ran is involved in a CD14-independent signal transduction pathway. This dominant negative down-regulation by Lps(d)/Ran on TNF-alpha production by macrophages and probably other innate immune responses may be key to the development of an effective gene therapy for endotoxic or septic shock.

Adenoviridae↗
PubMed2000

Heck reactions of iodobenzene and methyl acrylate with conventional supported palladium catalysts in the presence of organic and/or inorganic bases without ligands

The vinylation of iodobenzene with methyl acrylate has been studied with several supported palladium catalysts in N-methylpyrrolidone in the presence of triethylamine and/or sodium carbonate. The reaction can be performed in air without any solubilizing or activating ligands. It was found that significant amounts of palladium leach out into the solvent and these dissolved Pd species essentially catalyze the reaction. It is interesting, however, that almost all the palladium species in the solution can redeposit onto the surface of the supports after the reaction has been completed (at 100% conversion of iodobenzene). Thus, the catalysts were recyclable without loss of activity. The use of both inorganic and organic bases is very effective in the promotion of the palladium redeposition as well as in the enhancement of the reaction rate. For Heck reactions with bromobenzene and chlorobenzene it was found that the use of triethylamine and sodium carbonate increases the selectivity of the Heck coupling product (benzene is also produced for these two substrates), but the mixed bases do not affect the overall rate of reaction as much.

Journal Article↗
PubMed2000

Time course of trace of diffusion tensor [Trace(D)] and histology in brain edema.

We examined the correlation between changes in the trace of diffusion tensor [Trace(D)], regional water content and tissue ultrastructure relating to cellular (cytotoxic) and vasogenic brain edema. Cellular edema was induced by left middle cerebral artery occlusion in cats (Kuroiwa T et al., 1998). Vasogenic edema was induced in the white matter of cats by a cold lesion (Kuroiwa T et al., 1999). In cellular edema, the water content increase correlated linearly with the Trace(D) decrease in both the gray and white matter. However, both the slopes and intercepts of the correlation lines were significantly different. Hydropic astrocytic swelling was seen in both structures, and in the white matter, oligodendrocytic and myelinated axonal swelling were observed. In vasogenic edema, the increase in Trace(D) showed a significant linear correlation with the increase in tissue water content. Histologically, nerve fibers were dissociated and the extracellular space was markedly enlarged with protein-rich fluid. These result showed that the different slopes and intercepts of the water content--Trace(D) correlation lines for different subtype of brain edema, which reflect different ultrastructural localization of water, should be taken into account when evaluating brain edema using Trace(D) mapping.

Animals↗
PubMed2000

Expression of macrophage colony-stimulating factor receptor is increased in the AbetaPP(V717F) transgenic mouse model of Alzheimer's disease.

Inflammation is an important neuropathological change in Alzheimer's disease (AD). However, the pathophysiological factors that initiate and maintain the inflammatory response in AD are unknown. We examined AbetaPP(V717F) transgenic mice, which show numerous brain amyloid-beta (Abeta) deposits, for expression of the macrophage colony-stimulating factor (M-CSF) and its receptor (M-CSFR). M-CSF is increased in the brain in AD and dramatically augments the effects of Abeta on cultured microglia. AbetaPP(V717F) animals 12 months of age showed large numbers of microglia strongly labeled with an M-CSFR antibody near Abeta deposits. M-CSFR mRNA and protein levels were also increased in brain homogenates from AbetaPP(V717F) animals. Dystrophic neurites and astroglia showed no M-CSFR labeling in the transgenic animals. A M-CSF antibody decorated neuritic structures near hippocampal Abeta deposits in transgenic animals. M-CSF mRNA was also increased in AbetaPP(V717F) animals in comparison with wild-type controls. Simultaneous overexpression of M-CSFR and its ligand in AbetaPP(V717F) animals could result in augmentation of Abeta-induced activation of microglia. Because chronic activation of microglia is thought to result in neuronal injury, the M-CSF system may be a potential target for therapeutic intervention in AD.

Alzheimer Disease↗
PubMed2000

Simulation modeling of nuclear steam generator water level process--a case study

Simulation modeling of the nuclear steam generator (SG) water level process in Qinshan Nuclear Power Plant (QNPP) is described in this paper. A practical methodology was adopted so that the model is both simple and accurate for control engineering implementation. The structure of the model is in the form of a transfer function, which was determined based on first-principles analysis and expert experience. The parameters of the model were obtained by taking advantage of the recorded historical response curves under the existing closed-loop control system. The results of process dimensional data verification and experimental tests demonstrate that the simulation model depicts the main dynamic characteristics of the SG water level process and is in accordance with the field recorded response curves. The model has been successfully applied to the design and test of an advanced digital feedwater control system in QNPP.

Journal Article↗
PubMed2000

Mutations in TFAP2B cause Char syndrome, a familial form of patent ductus arteriosus.

Char syndrome is an autosomal dominant trait characterized by patent ductus arteriosus, facial dysmorphism and hand anomalies. Using a positional candidacy strategy, we mapped TFAP2B, encoding a transcription factor expressed in neural crest cells, to the Char syndrome critical region and identified missense mutations altering conserved residues in two affected families. Mutant TFAP2B proteins dimerized properly in vitro, but showed abnormal binding to TFAP2 target sequence. Dimerization of both mutants with normal TFAP2B adversely affected transactivation, demonstrating a dominant-negative mechanism. Our work shows that TFAP2B has a role in ductal, facial and limb development and suggests that Char syndrome results from derangement of neural-crest-cell derivatives.

3T3 Cells↗
PubMed2000

The role of a family history in King Kopetzky Syndrome (obscure auditory dysfunction).

King Kopetzky Syndrome (KKS) is a common condition in which individuals with normal audiograms complain of hearing difficulties, particularly in noisy places. Several studies have shown many patients with KKS to have a family history of hearing problems. In 82 consecutive patients with KKS and normal middle ear function, we compared the performance of those with and without a family history of hearing impairment on a number of sensitized tests. Those with a family history were more likely to have notches on Audioscan testing (p < 0.005) and these notches were broader than those found in patients with no family history (p < 0.05). There was also a tendency for those with a family history to be more likely to have notches on DPOAEs (p < 0.07), and the reproducibility of the TOAEs was poorer in those with a family history. Psychological testing showed males with a family history to have higher scores on free-floating anxiety (p < 0.01) and obsessionality (p < 0.05).

Adult↗
PubMed2000

Cerebral palsy and multiple births in China.

BACKGROUND: A population-based study on prevalence of cerebral palsy in multiple births has not been carried out in China. The purpose of this paper was to determine the prevalence of cerebral palsy in multiple births and to explore the influence of multiple pregnancy on cerebral palsy after controlling for birthweight. METHODS: A cross-sectional study of cerebral palsy was carried out among 388,192 children aged <7 years in seven cities of Jiangsu province in China. Information about birthweight and plurality was obtained from routine health care records. Pediatricians at city level diagnosed all cases. All the doctors involved had taken part in a training programme held by Beijing Medical University. Stratified analysis by birthweight and its standard normal deviate was employed to compare the prevalence of cerebral palsy in multiples and singletons. RESULTS: The prevalence of cerebral palsy for children aged <7 years in multiples was 9.7 per 1000 children (95% confidence interval [CI]: 6.5-14.0), which was 6.5 times that in singletons (95% CI: 4.4-9.3). The overall neonatal mortality rate was 60.9 per 1000 liveborn multiples, being highest (944.4 per 1000) in the 500-999 g birthweight groups. Most liveborn multiples weighing <1500 g at birth probably died from diseases related to very low birthweight prior to this study. The prevalence of cerebral palsy in multiple births was likely to be higher than that reported in developed countries for children weighing 1500-2499 g even though our data were from a cross-sectional study. When stratified by birthweight, the prevalence of cerebral palsy in multiples weighing <2500 g had tended to be lower than that of singletons in the same birthweight group. In contrast, in normal birthweight categories multiple births had a higher prevalence of cerebral palsy than singletons. When stratified by birthweight normal deviate, the prevalence of cerebral palsy in multiple births was uniformly higher than that in singletons in all birthweight strata and the prevalence of cerebral palsy among multiples appeared to be augmented as birthweight increased. CONCLUSION: The prevalence of cerebral palsy in multiples, 9.7 per 1000 children, is 6.5 times that in singletons. Survival of low birthweight infants is lower in China than in developed countries and survival quality of Chinese children weighing 1500-2499 g needs to be further improved. In terms of birthweight multiples and singletons may be heterogeneous. It might be difficult to directly use actual birthweight specific prevalence to compare the prevalence of cerebral palsy in multiples and singletons. Birthweight normal deviate specific prevalence of cerebral palsy suggests that multiple pregnancy is an independent risk factor for cerebral palsy in all birthweight groups. Multiples are in adverse circumstances very early in gestation and as the foetus matures the risk of cerebral palsy increases.

Birth Weight↗
PubMed2000

Characterization of a Mycobacterium smegmatis mutant that is simultaneously resistant to D-cycloserine and vancomycin.

A mutant of Mycobacterium smegmatis has been isolated that is simultaneously resistant to both D-cycloserine (D-CS) and vancomycin. Genetic complementation with a PBP4 homolog restores sensitivity to both drugs. Resistance to D-CS and vancomycin in this mutant is most likely due to a novel mechanism involving peptidoglycan assembly at the cell surface.

Amino Acid Sequence↗
PubMed2000

Fast algorithm for chirp transforms with zooming-in ability and its applications.

A general fast numerical algorithm for chirp transforms is developed by using two fast Fourier transforms and employing an analytical kernel. This new algorithm unifies the calculations of arbitrary real-order fractional Fourier transforms and Fresnel diffraction. Its computational complexity is better than a fast convolution method using Fourier transforms. Furthermore, one can freely choose the sampling resolutions in both x and u space and zoom in on any portion of the data of interest. Computational results are compared with analytical ones. The errors are essentially limited by the accuracy of the fast Fourier transforms and are higher than the order 10(-12) for most cases. As an example of its application to scalar diffraction, this algorithm can be used to calculate near-field patterns directly behind the aperture, 0 < or = z < d2/lambda. It compensates another algorithm for Fresnel diffraction that is limited to z > d2/lambdaN [J. Opt. Soc. Am. A 15, 2111 (1998)]. Experimental results from waveguide-output microcoupler diffraction are in good agreement with the calculations.

Algorithms↗
PubMed2000

Subcategories of patients with King-Kopetzky syndrome.

King-Kopetzky syndrome (Obscure Auditory Dysfunction, OAD) has been recognized as a clinically distinct condition in audiological and ENT clinics. It is characterized by normal hearing thresholds on pure tone audiometry (PTA) but complaints of difficulties in understanding speech in the presence of background noise. In a study on 110 consecutive patients with King-Kopezky syndrome referred to the Welsh Hearing Institute, subjects were subdivided into seven subcategories based on sensitized measures of auditory dysfunction and on psychological assessment. These were: (1) middle ear dysfunction; (2) mild cochlear pathology; (3) central/medial olivocochlear efferent system (MOCS) auditory dysfunction; (4) purely psychological problems; (5) multiple auditory pathologies; (6) combined auditory dysfunction and psychological problems and (7) unknown. Different subgroups may represent different pathogenic and aetiological factors. Thus, subcategorization provides further understanding of the basis of King-Kopetzky syndrome, and hence may guide the rehabilitative management of these patients.

Adolescent↗
PubMed2000

A data preprocessing framework for supporting probability-learning in dynamic decision modeling in medicine.

Data preprocessing is needed when real-life clinical databases are used as the data sources to learn the probabilities for dynamic decision models. Data preprocessing is challenging as it involves extensive manual effort and time in developing the data operation scripts. This paper presents a framework to facilitate automated and interactive generation of the problem-specific data preprocessing scripts. The framework has three major components: 1) A model parser that parses the decision model definition, 2) A graphical user interface that facilitates the interaction between the user and the system, and 3) A script generator that automatically generates the specific database scripts for the data preprocessing. We have implemented a prototype system of the framework and evaluated its effectiveness via a case study in the clinical domain. Preliminary results demonstrate the practical promise of the framework.

Artificial Intelligence↗
PubMed2000

[Effects of ultrasonography on evaluating the status of cervical lymphatic metastasis in patients with oral squamous cell carcinoma].

OBJECTIVE: To investigate effects of ultrasonography on evaluating the status of cervical lymphatic metastasis in patients with oral squamous cell carcinoma (OSCC). METHODS: Nineteen OSCC patients with the diagnosis confirmed by biopsy of primary focus were included in this study. All the patients were hospitalized in the department of stomatology, Beijing Medical University during June, 1995 and June, 1996, among them there were 13 men and 6 women. The ages were ranged from 31 to 71 years old, with the average of 54.4 years old. The primary focus of 13 cases were in tongue, 3 cases in cheek, 2 cases in gum, and 1 case in the conjunction of gum, mouth floor and tongue respectively. All the patients were examined by ultrasonography prior to operation, and operated with the procedures of excision of primary focus and radical neck dissection. The length, width, Vmax and Vmin and Resistance Index (RI = (Vmax-Vmin)/Vmax) of blood flow of cervical lymphatic nodes were measured with acuson 128 xp/10 color Doppler flow imaging scanner with a 7.5 MHz probe. The total of 34 cervical lymphatic nodes were examined by the scanner. L/W ratios in all nodes, RI and Vmax in 16 nodes were obtained respectively. All results were divided into two groups, metastases and non-metastases groups based on the pathological findings for further statistic analysis. Student t test was employed in the study. RESULTS: The average L/W ratios, the average Vmax and the average RI were 1.95 and 2.17, 0.24 and 0.14, and 0.80 and 0.56 in metastases and non-metastases groups respectively. There was a significant difference between RI in two groups, but no statistical differences were revealed in L/W ratios and Vmax, despite the great difference in the average Vmax in the two groups. When RI > or = 0.65 and Vmax > or = 0.20 m/s were regarded as the criterion for positive diagnosis, the accuracy rate, the sensibility and the specificity was 91.2%, 90%, and 91.7% respectively in making diagnosis of OSCC. CONCLUSION: The status of cervical lymphatic metastases in OSCC patients could be evaluated accurately by the color Doppler flow imaging scanner, which might be helpful in making accurately diagnosis of OSCC, selecting the appropriate operation procedure of neck dissection leading to increased survival ratio and improved quality of life for the patients.

Adult↗
PubMed2000

[Expression of the gene encoding human leukocyte differentiation antigen 5D4].

OBJECTIVE: To make sure that 5D4 cDNA is a full length cDNA and to prepare antigens to make monoclonal antibodies against different epitopes in 5D4 protein. METHODS: Recombinant expression vectors pGEX-5X-3-5D4 (full length) and pGEX-5X-3-5D4 (5'fragment) were constructed. 5D4 polypeptides were expressed in Escherichia coli DH5 alpha. 5D4 mRNA expression was detected in various tissues and cell lines with Northern blot assay and RT-PCR. RESULTS: Northern blot demonstrated five mRNA transcripts of 1.9, 2.4, 3.9, 4.5, and 10.0 kb in length existing and expressing of various extent in various tissues. The 1.9 kb mRNA transcript was observed only in the spleen and the small intestinal tissues. The expression of 5D4 mRNA was different in various cell lines. 5D4 polypeptides were expressed in Escherichia coli DH5 alpha. CONCLUSION: The 1,846 bp 5D4 cDNA is a full length cDNA. A full length 5D4 protein and a 5D4 polypeptide which is the NH2 side to the transmembrane region fused with GST with a molecular weight of 66,000 and 60,000 expressing in Escherichia coli DH5 alpha.

Antigens, CD↗
PubMed2000

[Effect of 6A8 alpha-mannosidase expression on the proliferative response of human B cell line 3D5].

OBJECTIVE: To study the effect of 6A8 alpha-mannosidase expression on the proliferative response of human B cell 3D5. METHODS: Recombination of adeno-associated virus vector(rAAV) mediated delivery of sense 6A8 DNA or antisense 6A8 DNA into 3D5 cells, and monoclonal antibody 6A8 alpha staining and Con A binding assay for determination of the change of 6A8 alpha-mannosidase expression, MTT assay for proliferation detection of 3D5 cells driven by Staphylococcus aureus crude cell suspension formalin-fixed (SAC), lower molecular weight B cell growth factor (LMW-BCGF), or rIL-6. RESULTS: The expression of 6A8 alpha-mannosidase was enhanced in sense 6A8-transduced cells and reduced in antisense 6A8-transduced cells. In comparison with the wild type and the mock-transduced cells, the proliferative response of the sense 6A8-transduced cells to SAC stimulation was enhanced (P < 0.05). However, transduction with antisense 6A8 did not affect the response. In addition, transduction with either sense or antisense 6A8 had no effect on proliferation of 3D5 cells induced by LMW-BCGF or IL-6. CONCLUSION: The proliferative response to SAC stimulation was enhanced in the 3D5 cells with enhanced expression of 6A8 alpha-mannosidase. Either enhancement or reduction of 6A8 alpha-mannosidase expression had no effect on proliferation induced by LMW-BCGF or IL-6.

B-Lymphocytes↗
PubMed2000

[Studies on the infrared and fluorescence spectra of europium-lanthanum-o-aminobenzoate-2,2'-dipyridyl complexes].

A series of mixed rare earth complexes of europium and lanthanum with o-aminobenzoate and 2,2-dipyridyl were synthesized by the reaction of EuCl3 and LaCl3 with o-aminobenzoate and 2,2' dipyridyl in solution. Their infrared and fluorescence spectra were investigated. The results showed that the chemical bonds have been formed between the two ligands with rare-earth ions. The fluorescence spectra excited by 343 nm UV-light indicated that the emission intensity for europium ions can be greatly enhanced if a part of europium ions in europium complexes were substituted by lanthanum ions. This paper discussed the luminance, mechanism of too.

2,2'-Dipyridyl↗