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Fan Wu

Publications and source records attributed to Fan Wu.

32 records · Page 2Linked to original sources
PubMed2005

Oscillations in a simple microvascular network.

We have identified the simplest topology that will permit spontaneous oscillations in a model of microvascular blood flow that includes the plasma skimming effect and the Fahraeus-Lindqvist effect and assumes that the flow can be described by a first-order wave equation in blood hematocrit. Our analysis is based on transforming the governing partial differential equations into delay differential equations and analyzing the associated linear stability problem. In doing so we have discovered three dimensionless parameters, which can be used to predict the occurrence of nonlinear oscillations. Two of these parameters are related to the response of the hydraulic resistances in the branches to perturbations. The other parameter is related to the amount of time necessary for the blood to pass through each of the branches. The simple topology used in this study is much simpler than networks found in vivo. However, we believe our analysis will form the basis for understanding more complex networks.

Animals↗
PubMed2005

Molecular characterization of hand flora and environmental isolates in a community setting.

We analyzed 69 bacterial isolates, comprising seven species of gram-negative bacterial rods and three species of coagulase-negative staphylococci, recovered from both the hands of caretakers and their environment in households sampled in upper Manhattan. Repetitive sequence-based PCR and dendrogram analysis were used to determine strain similarity. Greater than 25% of individual species of Acinetobacter, Enterobacter, and coagulase-negative staphylococci recovered from the hands and immediate environment within each household shared the same genotype. This study is the first to demonstrate the frequency of bacteria shared within community households. These strains may serve as potential reservoirs for either community- or hospital-acquired infections.

Coagulase↗
PubMed2005

[The impact of gender factor on the candidate gene study of essential hypertension].

OBJECTIVE: To study the impact of gender factor on the candidate gene study of essential hypertension (EH). METHODS: The polymerase chain reaction (PCR) was performed to analyze the ACE gene I/D polymorphism of hypertensive patients (50 men and 50 women) and normal controls (50 men and 50 women). The investigation was further focused on possible influence of sex proportion on the conclusion of this kind of research. RESULTS: The frequency of DD genotype in male hypertensive patients is significantly higher than that in male normal controls (chi(2) = 6.98, P = 0.004). The frequency of D allele in male EH group is significantly higher than that of male normal controls (chi(2) = 6.87, P = 0.009), while no significant difference was observed for II and ID genotype between male EH group and control group (P > 0.05). For female EH group and normal controls, there were no significant differences in frequency of genotype and allele (P > 0.05), the distribution ratio of DD genotype in male EH group is significantly different from that of female EH group (chi(2) = 4.06, P = 0.044). Furthermore, males with DD genotype in EH group had higher SBP and PP than that of males with II and ID genotype (P < 0.05). However, there was no significant difference in DBP in all three genotypes (P > 0.05). At the same time, there was no difference in SBP, DBP and PP (P > 0.05) between II and ID genotype in male EH group. In female hypertensive patients, there was no significant difference in SBP, DBP and PP between all three genotypes (P > 0.05). CONCLUSIONS: The relationship between DD genotype in male and EH (especially SBP and PP) is closer than any other genotype-EH relationships in both male and female. The gender factor, as a probable confounding factor, can affect many candidate gene studies of essential hypertension including ACE gene I/D polymorphism, and thus biases the conclusion.

Aged↗
PubMed2004

Benzhydryl as an efficient selective nitrogen protecting group for uracils.

Regioselective N-substitution of the less active nitrogen within uracil analogues has been achieved following preliminary N-protection at the more active N-position with a benzhydryl protecting group. This protecting group is stable to concentrated HCl (aqueous) at reflux temperature, TFA at room temperature, and Pd-C-catalyzed normal pressure hydrogenation at room temperature; the benzhydryl group can be removed quantitatively and selectively with a 10% triflic acid solution in TFA at 0 degree C.

Journal Article↗
PubMed2004

Concise synthesis of novel practical sulfamide-amine alcohols for the enantioselective addition of diethylzinc to aldehydes.

Novel sulfamide-amine alcohol ligands were designed using a grafting strategy and synthesized from readily available starting materials via a simple, efficient method. The key features of these ligands for the asymmetric addition of diethylzinc to aldehydes included stability, enhanced effectiveness without using Ti(O(i)Pr)(4), suitability for a variety of aldehydes, the ability to operate at room temperature, and selectability to afford either absolute configuration products with enantiomeric excess up to >99%.

Journal Article↗
PubMed2004

Structures and reactivity of Zr(IV) chlorobenzene complexes.

The synthesis, structures, and unusual reactivity of (C5R5)2ZrR'(ClPh)+ chlorobenzene complexes are described. The reaction of (C5R5)2ZrR'2 with [Ph3C][B(C6F5)4] in C6D5Cl affords [(C5R5)2ZrR'(ClC6D5)][B(C6F5)4] chlorobenzene complexes (1-d5, R' = CH2Ph and (C5R5)2 = (C5H5)2; 2a-d-d5, R' = Me and (C5R5)2 = rac-(1,2-ethylene(bis)indenyl) (2a), (C5H5)2 (2b), (C5H4Me)2 (2c), (C5Me5)2 (2d, C5Me5 = Cp*)). Complexes 1 and 2b,c are thermally robust but are converted to [{(C5R5)2Zr(mu-Cl)}2][B(C6F5)4]2 (4b,c) by a photochemical process in ClPh solution. In contrast, 2d undergoes facile thermal ortho-C-H activation to yield [Cp*2Zr(eta2-C,Cl-2-Cl-C6H4)][B(C6F5)4] (5), which slowly rearranges to [(eta4,eta1-C5Me5C6H4)Cp*ZrCl][B(C6F5)4] (6) via beta-Cl elimination and benzyne insertion into a Zr-CCp* bond. The higher thermal reactivity of 2d versus that of 1 and 2b,c is attributed to steric crowding associated with the Cp* ligands of 2d, which forces a ClPh ortho-hydrogen close to the Zr-Me group.

Journal Article↗
PubMed2004

Role of VLDL receptor in the process of foam cell formation.

The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, beta-VLDL or low density lipoprotein (LDL), respectively for 24 h and 48 h, foam cells formation was identified by oil red O staining and cellular contents of triglyceride (TG) and total cholesterol (TC) were determined. The mRNA levels of LDLR, LDLR related protein (ILRP) and VLDLR were detected by semi-quantitative RT-PCR. The results demonstrated that VLDL, beta-VLDL and LDL could increase the contents of TG and TC in macrophages. Cells treated with VLDL or beta-VLDL showed markedly increased expression of VLDLR and decreased expression of LDLR, whereas LRP was up-regulated slightly. For identifying the effect of VLDL receptor on cellular lipid accumulation, ldl-A7-VR cells, which expresses VLDLR and trace amount of LRP without functional LDLR, was used to incubate with lipoproteins for further examination. The results elucidated that the uptake of triglyceride-rich lipoprotein mediated by VLDLR plays an important role in accumulation of lipid and the formation of foam cells.

Animals↗
PubMed2004

Preparation and characterization of polyclonal antibodies against VLDL receptor.

The polyclonal antibodies against VLDL receptor were prepared and identified. Rabbits were immunized with polypeptide fragment of VLDL receptor as antigen. The collected blood serum of the immunized rabbits was analyzed and identified by using ELISA and Western Blot. The results showed that the rabbit against mouse and human VLDL receptor antibodies were obtained with high titer and could recognize the natural VLDL receptors through Western blot. The prepared polyclonal antibodies against VLDL receptor provide a new tool to study the protein of VLDL receptor.

Animals↗
PubMed2004

Beta-VLDL induced VLDL-R's up-regulation via PKC-ERK1/2 signal pathway.

To explore the intracellular signal pathways for beta-VLDL induced very low density lipoprotein receptor (VLDL-R) transcription up-regulation and their effects on lipid accumulation in macrophages, Western Blot was used to examine phosphorylated ERK1/2 protein and regulated effects by different singal kinase inhibitants. It was found that beta-VLDL induced an increase in ERK1/2 activity in a protein kinase C (PKC)-dependent manner in murine RAW264.7 macrophages. By using different protein kinases inhibitors or activators, it was observed that the effect of beta-VLDL induced VLDL receptor transcription, which was monitored by RT-PCR analysis of VLDL receptor mRNA, was not affected by the inhibitor of p38 kinase and cAMP analog, but extremely abolished by pretreating cells with PD98059, an inhibitor of ERK and GF 109203X, an inhibitor of PKC. These results demonstrated that the PKC-ERK1/2 cascade is the essential signaling pathway by which beta-VLDL activated VLDL-R mRNA expression. Inhibition of the ERK1/2 signaling cascade resulted in suppression of the cellular lipid accumulation induced by beta-VLDL in macrophages.

Cells, Cultured↗
PubMed2004

[Relationship between fibrinogen B beta gene FGB -455G/A polymorphism and atherosclerotic cerebral infarction].

OBJECTIVE: To explore the distribution of fibrinogen (FGB) B beta polymorphism in Chinese Han population and the association of the polymorphisms with the occurrence of atherosclerotic cerebral infarction (ACI). METHODS: The B beta gene FGB -455G/A polymorphism was identified by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) in 132 patients with ACI and 148 healthy controls matching on age and sex. Turbidimetric assays were performed to measure the plasma fibrinogen levels of all cases. RESULTS: The plasma fibrinogen level in ACI group (3.42+/-0.52 g/L), was significantly higher than that in the controls (2.96+/-0.42g/L), P<0.001. The A allele was associated with the elevated plasma fibrinogen levels in both patients and controls. Among the A allele carriers, smokers had significantly higher plasma fibrinogen levels than did the non-smokers (P<0.05). The distribution of B beta gene FGB -455G/A polymorphism was in accordance with the Hardy-Weinberg equilibrium (P>0.05). The A allelic frequency in ACI group (0.258) was significantly higher than that in the control group (0.152) (P<0.05). Logistic regression analysis showed that the cases carrying A allele (GA+AA genotype) had 1.653 times the risk of ACI. CONCLUSION: The study demonstrates that A allele of the B beta gene FGB -455G/A polymorphism may be a susceptible predictor of the occurrence of ACI, particularly in smokers.

Aged↗
PubMed2004

[Cloning and characterization of two MADS box genes from peach (Prunus persica)].

With the aim of finding genes involved in the floral transition of Prunus species (Prunus sp.), the EST (expressed sequence tags) sequences were extracted from the public databases. Eight MADS box genes' cDNAs were obtained. Two of them, PpMADS4 and PpMADS6 (The accession numbers in GenBank are AY705972 and AY705973), were cloned from peach (Prunus persica). The full length cDNA of PpMADS4 is 850 bp long. It contains an open reading frame of 732 bp, coding for a polypeptide of 243 amino acids. The full length cDNA of PpMADS6 is 1,190 bp long. It contains an open reading frame of 768 bp coding for a polypeptide of 256 amino acids. PpMADS4 closely resembles the Arabidopsis AGAMOUS gene. It is an AGAMOUS-like C class MADS box gene, and it expresses in petal, carpel, fruit and nutlet as demonstrated by RT-PCR analysis. PpMADS6 is likely to be the peach orthologue of the Petunia PFG genes and it is an A class MADS box gene. It has been shown with RT-PCR that it expresses in leaf, sepal, petal, carpel and fruit. It may be involved in the transition from the juvenile to the adult stage.

Amino Acid Sequence↗
PubMed2003

Induction of very low density lipoprotein receptor (VLDLR) transcription by VLDL is mediated by the extracellular signal-regulated kinase signaling pathway.

To elucidate the intracellular signaling pathways for VLDL-induced VLDLR transcription, Western blot analysis was used to examine phosphorylated ERK1/2 protein. It was found that that VLDL induced an increase in ERK1/2 activity in a protein kinase C (PKC)-dependent manner in murine RAW264.7 macrophages. By using different protein kinases inhibitors or activators it was observed that the effect of VLDL-induced VLDL receptor transcription, which is monitored by RTPCR analysis of VLDL receptor mRNA, was not affected by the inhibitor of p38 kinase and cAMP analog, but completely abolished by pretreatment of the cells with PD 98059, an inhibitor of MEK and GF 109203X, an inhibitor of PKC. These results demonstrated that the PKC/ERK1/2 cascade is the essential signaling pathway by which VLDL activates VLDL receptor mRNA expression.

Animals↗
PubMed2002

Decision support system for the analysis of hospital operation indicators.

The inauguration of national health insurance (NHI) in many countries and their worsening financial condition has increased the sensitivity to operational cost and efficiency in hospitals. For several years, hospitals have been monitoring their operations by analyzing the financial and operational reports that are provided. Because of the rapidly changing character of the medical industry, statistical data shown on paper are no longer sufficient for decision makers. This paper describes a decision support system (DSS) for hospital administrators to assist in analyzing their operations efficiently and precisely. In hospitals, operational data of outpatients and inpatients are now stored on computers, resulting in much easier and faster data acquisition for administrators. The proposed system makes suggestions to hospital administrators and is able to self-learn to improve its future usefulness. With the dual capabilities of integrating evaluations and data collecting, the system can assist administrators in discovering and resolving problems quickly. The system provides multidimensional and multilevel analyses, by using data warehousing techniques, and generates appropriate advice to users by employing decision-making methodology. The self-learning function of the system makes it work like an expert, continually modifying its content (knowledge) and generating advice that is promptly updated to accord with changes in the medical industry.

Age Distribution↗