Biomedical subjects

X Fu

Publications and source records attributed to X Fu.

At least 37 records · Page 2Linked to original sources

PubMed2001

Isomerization of a uniquely designed amplicon during herpes simplex virus-mediated replication.

Herpes simplex virus (HSV) type 1 DNA isomerization was studied using a uniquely designed amplicon that mimics the viral genomic structure. The results revealed that amplicon concatemers frequently contain adjacent amplicon units with their segments in opposed orientations. These unusual concatemers were generated through homologous recombination, which does not require HSV DNA as the source of homology.

Animals↗

PubMed2001

Extrahepatic expression of apolipoprotein A-II in mouse tissues: possible contribution to mouse senile amyloidosis.

Apolipoprotein A-II (apoA-II), an apolipoprotein in serum high-density lipoprotein, is a precursor of mouse senile amyloid fibrils. The liver has been considered to be the primary site of synthesis. However, we performed nonradioactive in situ hybridization analysis in tissue sections from young and old amyloidogenic (R1.P1-Apoa2C) and amyloid-resistant (SAMR1) mice and revealed that other tissues in addition to the liver synthesize apoA-II. We found a strong hybridization signal in the basal cells of the squamous epithelium and the chief cells of the fundic gland in the stomach, the crypt cells and a small portion of the absorptive epithelial cells in the small intestine, the basal cells of the tongue mucosa, and the basal cells of the epidermis and hair follicles in the skin in both mouse strains. Expression of apoA-II mRNA in those tissues was also examined by RT-PCR analysis. Immunolocalization of apoA-II protein also indicated the cellular localization of apoA-II. ApoA-II transcription was not observed in the heart. Amyloid deposition was observed around the cells expressing apoA-II mRNA in the old R1.P1-Apoa2C mice. These results demonstrate that the apoA-II mRNA is transcribed and translated in various extrahepatic tissues and suggest a possible contribution of apoA-II synthesized in these tissues to amyloid deposition.

Aging↗

PubMed2001

Loss of nm23 expression predicts distal metastases and poorer survival for breast cancer.

The nm23 gene, originally identified by differential hybridization of metastatic murine melanoma cell lines has been associated with decreased metastatic potential. In this study, we evaluated the utility of nm23 expression levels as a predictive and a prognostic biomarker for distal metastases and poor survival in a Chinese cohort of 168 breast cancer patients. Our study indicates that high nm23 expression is associated with older age (older than 35 years) and smaller tumor size. There is no statistically significant association between nm23 expression and pathologic type or axillary metastasis. High nm23 expression is associated with the absence of distal metastases. Nearly 80% of women with high nm23 expression are alive after 10 years compared to 25% with low expression; at five years the cumulative survival proportions are 86% and 46%, respectively. The Cox model for survival indicates that controlling for tumor size and presence of axillary metastases at diagnosis, the hazard for women with low nm23 expression is nearly 4 times that of women with high nm23 expression. Low nm23 expression is predictive of distal metastases and appears to be a risk factor that is independent of the presence or absence of positive axillary nodes at diagnosis.

Adult↗

PubMed2001

[Photocatalytic degradation of bromomethane on sol-gel-derived SO4(2-)/TiO2].

SO4(2-)/TiO2 photocatalysts were prepared by sol-gel method and characterized by X-ray diffraction (XRD), FTIR spectroscopy and N2 sorption analysis applying BET method. Photocatalytic decomposition of CH3Br in air stream was studied over SO4(2-)/TiO2 photocatalysts under the different reaction conditions. The results showed that the addition of SO4(2-) to TiO2 greatly enhanced its structural and photocatalytic properties. The optimum concentration of SO4(2-) on TiO2 was 9% wt and the best calcination temperature was 450 degrees C. Moreover, the sulfated TiO2(SO4(2-)/TiO2) exhibited excellent stability of activity under the moist reaction condition. When the reaction temperature was below 85 degrees C, the reactivity of bromomethane was enhanced with increasing reaction temperatures, and the apparent Arrehenius activation energy was 19.6 kJ.mol-1. In the reaction temperature range of 85 degrees C-105 degrees C, the apparent Arrehenius activation energy was zero.

Catalysis↗

PubMed2001

Bringing a family practice model of health to the People's Republic of China.

The health care system in the People's Republic of China (PRC) is undergoing a major transition that has made the government revise its approach to how medicine is taught and practiced. Family medicine, which provides a generalist approach to medical care, is at the forefront of this transition. This article reviews the recent history of medical education in the PRC, including the establishment of the discipline of family medicine in the mid 1980s, and factors promoting development of family medicine. These include the movement away from government-subsidized health care in hospital settings, the aging population, increased urbanization, increasing incidence of infectious diseases, and rising health care costs. We conclude from observations made in the PRC and from a review of secondary sources that family medicine in China is in its infancy. The value of understanding the role that family medicine plays within China's changing health care system is that we gain a broader perspective of the variety and growing international importance of family practice as a profession.

Delivery of Health Care↗

PubMed2001

[mRNA and protein expression of three growth-related factors and their possible signal transduction pathways in wound healing].

OBJECTIVE: To observe the time course and tissue distribution of c-fos, c-myc and basic fibroblast growth factor(bFGF) genes and their proteins in burned skin, and explore the possible network regulation mechanisms of c-fos, c-myc and bFGF in wound healing and the role of the protein kinase C pathway involved in signal transduction among these growth-related factors. METHODS: The study was carried out on 188 Wistar rats. Animal model with 30% partial thickness scald injury was made and all rats were randomly divided into several groups: normal control (n = 8), injured control (n = 36), anti-c-fos (n = 36), bFGF (n = 36), 1-5-Isoquinolinyl-sulfony-2methylpiperazine (H7), and 2, 3-Butanedione monoxime (BDM) (n = 36). In situ hybridization, reverse transcription polymerase chain reaction (RT-PCR) and streptavidin peroxidase (SP) immunohistochemistry methods were used to detect the gene and protein expression of c-fos, c-myc and bFGF in the wounded tissues. RESULTS: (1) The first appeared induction of growth-related gene was c-fos, the second bFGF, and the last c-myc. They were peaked at 3 h, 1 d and 3 d postburn with values of 14.5 +/- 1.3, t = 13.306; 0.15 +/- 0.04, t = 3.460 and 0.11 +/- 0.05, t = 2.292, respectively (P < 0.05). (2) Treatment with c-fos antibody decreased the expression of these three growth-related factors when compared with that in the controls. There were a 80% decrease in c-myc and a 85% decrease in bFGF. (3) Treatment with H7 inhibited the gene and protein expression of c-fos and bFGF. The peak times of c-myc gene and protein were delayed to 6 hours post injury. Treatment with BDM induced an earlier expression of c-myc mRNA at 6 hours, and increased the gene and protein expressions of c-fos and bFGF. The total amount of their values was increased to 0.23 +/- 0.07, t = 2.942 and 0.69 +/- 0.07, t = 5.134 (P < 0.01). CONCLUSIONS: Thermal injury can induce a series of growth-related gene expression showing a phasic control and regional distribution. c-fos plays an important role in wound healing process. Protein kinase C pathway may repair wound.

Animals↗

PubMed2001

Expression of oncoproteins c-fos and c-jun in hypertrophic scars and chronic dermal ulcers and their regulation of basic fibroblast growth factor.

OBJECTIVE: To explore the characteristics of oncoprotein expression of c-fos and c-jun in hypertrophic scars and chronic dermal ulcers and their regulation of basic fibroblast growth factor (bFGF). METHODS: Tissues of hypertrophic scars (n = 8), chronic dermal ulcers (n = 8) and normal skin (n = 5) were taken from 21 patients with burns and chronic dermal ulcers in operation. The ABC immunohistochemical method was used to characterize the gene product expression of c-fos, c-jun and bFGF in the above tissues. RESULTS: In normal skin, both c-fos and c-jun protein expression and bFGF protein expression were observed. The signals of both oncoproteins were localized mainly in subcutaneous fibroblasts, but, positive expression of the bFGF protein was mainly in keratinocytes. In hypertrophic scars, positive expression of both oncoproteins could be found mainly in fibroblasts, but bFGF was mainly in fibroblasts and endothelial cells. In chronic dermal ulcers, endothelial cells, some of inflammatory cells and fibroblasts were positive for both of oncoproteins, but the expression of bFGF was only seen in fibroblasts and endothelial cells. CONCLUSIONS: The results indicate that the interaction between both oncoproteins and bFGF exists, and the regulating action between protooncogenes and bFGF is a major course in wound healing. The different expressions of c-fos and c-jun gene products play an important role in regulate bFGF action, thus affecting wound healing.

Chronic Disease↗

PubMed2001

Expression characteristics of c-fos, c-myc and bFGF in early burn tissue.

OBJECTIVE: To investigate the sequence and characteristics of expression of proto-oncogenes, c-fos, c-myc and endogenous basic fibroblast growth factor (bFGF), in burn tissue from rats. METHODS: A partial thickness burn of 30% TBSA was created on the backs of Wistar rats. Immunohistochemistry was used to detect the expression of these proteins in normal and burned skin at 3 hours, 6 hours, 1 day, 3 days, 7 days and 14 days postburn. RESULTS: Expression of c-fos, c-myc and bFGF was induced by the burn, but these three proteins showed different expression levels in sequence and distribution. Expression of c-fos increased and peaked at 3 hours postburn. Stain positive granules were distributed mainly in the cytoplasm of basal cells and the nuclei of fibroblasts. The expression of bFGF protein increased at 6 hours and peaked at 1 day postburn; it was distributed in the cytoplasm of fibroblasts. c-myc protein peaked at 3 days postburn and was also distributed in the cytoplasm of fibroblasts. CONCLUSIONS: Thermal injury can induce c-fos, c-myc and bFGF expression and show phasic control and regional distribution. The phasic expression of these three proteins indicates that there maybe a regulatory relationship between proto-oncogenes and growth factors in early burn. This may play an important role in late tissue repair.

Animals↗

PubMed2001

[Expression of nm23 in breast cancer: correlation with distant metastasis and prognosis].

OBJECTIVE: To investigate the relationship between expression of nm23 gene and distant metastasis and prognosis in breast cancer. METHODS: To detect nm23 protein expression in 101 patients with breast cancer by means of immunohistochemistry and nm23 mRNA expression in 68 patients with breast cancer by RT-PCR. RESULTS: Expression of nm23 gene was inversely correlated with distant metastasis and lymph node metastasis. Among 9 patients with negative node but with distant metastasis, 7 had low expression of nm23. In 29 patients with positive nodes but without distant metastasis, 24 had high expression of nm23, while 6 of 6 patients with positive nodes and distant metastasis expressed high levels of nm23 mRNA. CONCLUSION: Expression of nm23 gene, tumor size and status of axillary lymph node are independent prognostic indicators to breast cancer prognosis.

Adult↗

PubMed2001

[Clinical and pathologic analysis of Sjögren's syndrome with renal impairment: a report of 84 cases].

OBJECTIVE: To further study the renal damage of Sjögren's syndrome (SS) and its clinical and pathologic characteristics with biopsy and recent technology. METHODS: 84 patients of SS with renal impairment from 1993 to 1999 were analyzed by routine, immunoassay, tubular function and biopsy examination. RESULTS: 55 of the 84 cases presented with renal tubular acidosis (RTA), 5 with diabetes insipidus and 3 with hypokalemic paralysis. Glomerulopathy occurred in 22 cases (nephrotic syndrome 12, glomerulonephritis 10) and mild renal failure (RF) was found in 14. 69.1% of the patients had hypergamma-globulinemia. 64.3% and 44.1% of the patients showed positive anti SS-A and anti SS-B. In 37 renal biopsy specimens 21 showed chronic interstitial nephritis (CIN) with extensive lymphoplasmic cell infiltration and tubular atrophy. 10 of the 37 specimens revealed lupus nephritis (LN, type III and IV) and 5 mesangial proliferative glomerulonephritis (MsPGN). With immunofluorescence tests, no positive findings were seen in most of the specimens, but deposition of IgA, IgM or C(3) was seen in some patients. IgG deposits in the interstitial lymphoplasmic cells were found in 1 patient. 25 patients were treated with prednisone combined with cytoxan (CTX). In 14 patients with renal failure, serum creatinine level returned to normal after treatment. CONCLUSION: Renal impairment may be the presenting or predominant feature in SS. The major clinical manifestations are RTA and GN. Treatment with prednisone may decrease the infiltration of lymphoplasmic cells in the interstitium, improve the renal function and correct RTA.

Adolescent↗

PubMed2001

[Accelerated hyperfractionation radiation therapy combined with chemotherapy for non-small cell lung cancer complicated with superior vena cava syndrome].

OBJECTIVE: This retrospective study was done to evaluate the patient's tolerance and effect of accelerated hyperfractionation radiation therapy in the treatment of superior vena cava syndrome (SVCS) caused by non-small cell lung cancer (NSCLC). METHODS: Thirty-four NSCLC patients complicated with SVCS were treated between January 1992 and September 1996. Their ages ranged from 36-78 years (median 57). There were 30 (88.2%) male and 4(11.8%) female patients. Dyspnea (67.6%) and facial swelling (52.9%) were the two most common symptoms. Engorgement of neck veins (38.2%) and dilated chest wall veins (28.5%) were the most common physical findings. According to their pathological diagnosis, there were 17(50%) squamous cell carcinomas, 14(41.2%) adenocarcinomas, 2(5.9%) mixed squamous and adenocarcinomas and 1(2.96%) poorly differentiated carcinomas. By thoracic CT scans, a mass was most commonly found in the right upper lobe and the upper mediastinum. For these patients, chemotherapy IEP or IAP (IFO 2.0 g d1-4, DDP 40 mg d1-3, Vp-16 0.1 g d1-3 or ADM 50 mg d1) was given first. Twenty-four to 72 hours after chemotherapy, accelerated hyperfractionation radiation therapy was started to deliver to the primary tumor and the metastatic mediastinal lymph nodes, a tumor dose of 30 Gy/20 fx/2 wk followed by a boost to 36-40.8 Gy/30-34 fx/3-3.5 wk. Diuretics, steroids and dehydrating agents were concomittantly prescribed during the radiation therapy. RESULTS: Relief of SVCS to various degrees was noted in all patients. CR, PR and MR rates were 20.6% (7/34), 50% (17/34) and 29.4% (10/34), respectively. The median survival was 12 months (4-26 months). The 1-2 year actuarial survival rates were 58.1% and 18.2% Except radio-esophagitis in different degrees, no other severe complications were observed. CONCLUSION: The fraction and total dose of radiotherapy are tolerable in this accelerated hyperfractionation trial. Radiation therapy combined with chemotherapy gives similar results as non-surgery for stage III NSCLC. No significant difference in the survival rates of the various histological types is observed.

Adenocarcinoma↗

PubMed2001

[Clinical study of P-gp, and bcl-2 protein expression in non-Hodgkin's lymphomas patients].

OBJECTIVE: To investigate the relationship between the expression of P-gp, P26-bcl-2 and the prognosis in intermediate and high grade non-Hodgkin's lymphomas (NHL). METHODS: Sixty cases of intermediate and high grade NHL were retrospectively reviewed using immunohistochemical method. All patients were received CHOP chemotherapy over 4 courses. RESULTS: P-gp was identified in 15 and P26-bcl-2 in 25 cases. The 3-year survival rates for patients with P26-bcl-2 (+) and P26-bcl-2 (-) were 37.64% and 76.80%, respectively (P < 0.005), and for patients with both positive P-gp and P26-bcl-2 and both negative were 15.38% and 48.48%, respectively (P = 0.038). CONCLUSIONS: There is direct relationship between the P-gp, P26-bcl-2 protein expression and the prognosis in intermediate and high grade non-Hodgkin's lymphoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

[Spectrum studies on titania photocatalysts].

The nano-sized TiO2 photocatalysts were prepared by sol-gel method and characterized by FTIR spectroscopy, FT-Raman spectroscopy and diffuse reflectance spectroscopy(DRS). Photocatalytic degradation of oleic acid over the TiO2 catalysts was investigated. The result showed that calcination temperature has strong effect on crystal structure, energy band structure, optical adsorption and photocatalytic activity of the TiO2 catalysts. It was found that the TiO2 photocatalyst calcined at 400 degrees C has the best apparent optical adsorption, the biggest band edge position and the highest photoactivity. The effect of calcination temperature on photocatalytic activity of TiO2 catalysts has been ascribed to the changes in structure and optical property of catalyst such as crystal size, content of rutile, residual NO3-, and band-edge position of light adsorption.

Adsorption↗

PubMed2000

Temporalis exteroceptive suppression in generalized anxiety disorder and major depression.

The duration abnormality of the exteroceptive suppressions, or silent periods, of peripheral or jaw-closing muscle activities induced by transcranial magnetic or trigeminal electrical stimuli in patients suffering from anxiety or depression is ill-defined. We therefore studied the exteroceptive suppression periods of the temporalis muscle electromyography elicited by trigeminal territory electrical stimuli, Zuckerman-Kuhlman's Personality Questionnaire, and Plutchik-van Praag's Depression Inventory (PVP) in 12 patients suffering from generalized anxiety disorder (GAD) and 16 from major depression (MD) as well as in 17 healthy volunteers. Durations of the second suppression period (ES2) sociability scores were decreased in GAD patients, while PVP and neuroticism-anxiety scores were elevated in both GAD and MD patients. There was a positive correlation between ES2 duration and sociability score in the GAD group. This study indicates that anxiety can modify the temporalis ES2 duration through cortical descending inhibitory controls.

Adolescent↗

PubMed2000

Gas chromatography-mass spectrometry with tert.-butyldimethylsilyl derivation: use of the simplified sample preparations and the automated data system to screen for organic acidemias.

A simplified, sensitive screening method for organic acidemias by gas chromatography-mass spectrometry using urease/direct preparations and tert.-butyldimethylsilylation (TBDMS) instead of trimethylsilylation (TMS) is described. We compiled GC-MS data on TBDMS derivatives, including methylene unit values, and quantifying and confirming ions, for use in the automated data system we developed. Quantification using [M-57]+ ions by mass chromatography was more sensitive, and the coefficient variation was smaller, compared with TMS derivatives. We confirmed the usefulness of this system, analyzing urine specimens from 53 patients with 15 different disorders.

Acids↗

PubMed2000

Folding pathway mediated by an intramolecular chaperone. The inhibitory and chaperone functions of the subtilisin propeptide are not obligatorily linked.

The subtilisin propeptide functions as an intramolecular chaperone (IMC) that facilitates correct folding of the catalytic domain while acting like a competitive inhibitor of proteolytic activity. Upon completion of folding, subtilisin initiates IMC degradation to complete precursor maturation. Existing data suggest that the chaperone and inhibitory functions of the subtilisin IMC domain are interdependent during folding. Based on x-ray structure of the IMC-subtilisin complex, we introduce a point mutation (E112A) to disrupt three hydrogen bonds that stabilize the interface between the protease and its IMC domain. This mutation within subtilisin does not alter the folding kinetics but dramatically slows down autoprocessing of the IMC domain. Inhibition of E112A-subtilisin activity by the IMC added in trans is 35-fold weaker than wild-type subtilisin. Although the IMC domain displays substantial loss of inhibitory function, its ability to chaperone E112A-subtilisin folding remains intact. Our results show that (i) the chaperone activity of the IMC domain is not obligatorily linked with its ability to bind with and inhibit active subtilisin; (ii) degradation and not autoprocessing of the IMC domain is the rate-limiting step in precursor maturation; and (iii) the Glu(112) residue within the IMC-subtilisin interface is not crucial for initiating folding but is important in maintaining the IMC structure capable of binding subtilisin.

Catalysis↗

PubMed2000

Alternative silencing effects involve distinct types of non-spreading cytosine methylation at a three-gene, single-copy transgenic locus in rice.

We investigated transgene silencing in a line of rice plants that carries a single-copy 6.6-kb transgenic locus comprising three heterologous transgenes: bar, hpt and gusA. We identified at least three distinct types of silencing effects associated with different methylation patterns, including a novel form of transcriptional silencing involving methylation of cytosine residues only at non-conventional acceptor sites in the coding region. Silencing arose de novo in individual R1, R2 and R3 plants despite the stability of the transgenic locus, although the basic structure of the locus, transgene dosage and position effects remained constant within the line. We found that different silencing effects could occur concurrently in adjacent heterologous transgenes in the same plant, with no evidence for spreading of silenced states or methylation patterns from one transgene to another.

Base Sequence↗

PubMed2000

Presence and localization of connexins 43 and 26 in cell cultures derived from myometrial tissues from nonpregnant and pregnant women and from leiomyomas.

OBJECTIVE: Our objective was to study the appearance and distribution of connexins 43 and 26 in various human myometrial cell cultures. STUDY DESIGN: Scrape loading, Western blotting, and immunohistochemical techniques were applied to cultured cells derived from myometrial tissues obtained from nonpregnant and pregnant women (upper and lower uterine segments) and from leiomyomas (tumor and analogous myometrial tissues). RESULTS: Scrape loading revealed the presence of metabolic coupling in all tissues. Indirect immunohistochemical studies showed membrane localization of connexin 43 in all myometrial cultures. Western blots and indirect immunohistochemical studies showed the presence and localization of the connexin 26 protein and associated gap junctions in tissues from myomas and from nonpregnant and pregnant women except for those derived from the upper segment of the pregnant uterus. CONCLUSION: These results show that human myometrial cultures express various gap junction proteins and that there are regional differences in expression of connexins in tissues from pregnant women.

Blotting, Western↗