Biomedical subjects

M Fu

Publications and source records attributed to M Fu.

At least 91 records · Page 5Linked to original sources

PubMed1999

Arsenic trioxide induces apoptosis of HPV16 DNA-immortalized human cervical epithelial cells and selectively inhibits viral gene expression.

Arsenic trioxide (As2O3), a major ingredient of arsenic compounds in traditional Chinese medicine, exhibits anti-acute promyelocytic leukemic activity. Considering that over 80% of human malignant tumors derive from epithelial cells, we studied the effect of As2O3 on HPV 16 DNA-immortalized human cervical epithelial cells (HCE16/3 cells) in vitro. As2O3 reduced HCE16/3 cell survival, induced apoptosis at a low concentration and selectively inhibited expression of viral early genes. This effect was evidenced by a reduction of cell viability in the MTT assay, G1 arrest and significant apoptosis upon flow-cytometric analysis, presence of apoptotic bodies, formation of DNA ladders upon gel electrophoresis and inhibition of viral early gene expression by RT-PCR and Western blot. There was a good correlation between cell apoptosis and viral early gene inhibition after As2O3 treatment, suggesting that induction of apoptosis of HCE16/3 cells by As2O3 treatment might be associated with down-regulation of viral oncogene expression. In conclusion, our findings indicate that As2O3 induces apoptosis of HCE16/3 cells, which may provide a new approach for treating HPV-associated tumors.

Antineoplastic Agents↗

PubMed1999

Receptor recruitment: a mechanism for interactions between G protein-coupled receptors.

There is a great deal of evidence for synergistic interactions between G protein-coupled signal transduction pathways in various tissues. As two specific examples, the potent effects of the biogenic amines norepinephrine and dopamine on sodium transporters and natriuresis can be modulated by neuropeptide Y and atrial natriuretic peptide, respectively. Here, we report, using a renal epithelial cell line, that both types of modulation involve recruitment of receptors from the interior of the cell to the plasma membrane. The results indicate that recruitment of G protein-coupled receptors may be a ubiquitous mechanism for receptor sensitization and may play a role in the modulation of signal transduction comparable to that of the well established phenomenon of receptor endocytosis and desensitization.

Adrenergic alpha-Agonists↗

PubMed1999

Short- and long-term outcomes after percutaneous transluminal coronary angioplasty in chronic hemodialysis patients.

The aim of this study was to obtain data on the outcomes of chronic hemodialysis patients who underwent percutaneous transluminal coronary angioplasty (PTCA). A retrospective chart analysis identified 31 such patients between August 1992 and October 1996. The mean follow-up period was 12.4 +/- 11.7 months. Angiographic success was achieved in 39 of 41 (95.1%) stenoses attempted. There were three in-hospital deaths. Clinical success was achieved in 28 of 31 patients (90%). Two of the 28 survivors were lost to follow-up. Recurrent angina developed within 6 months in 14 of 26 patients (53.8%). Eleven and 17 of the 26 patients (42.3% and 65.4%) died within 6 and 14 months, respectively, after the PTCA procedure. Ten of the 17 deaths (58.8%) were due to cardiovascular events. Our study suggests that PTCA is technically feasible with high angiographic success rate in chronic hemodialysis patients. In-hospital mortality rate and rate of recurrent angina are high. Long-term prognosis is poor.

Aged↗

PubMed1999

Fish oil decreases macrophage tumor necrosis factor gene transcription by altering the NF kappa B activity.

BACKGROUND: Fish oil-supplemented diets have anti-inflammatory and immunomodulating effects, though the exact mechanism(s) are unknown. This study investigated the effects of eicosapentanenoic acid (EPA), a major component of fish oil, on transcriptional regulation of tumor necrosis factor (TNF) gene in lipopolysaccharide (LPS)-stimulated macrophages (MO). METHODS: RAW 264.7 cells, a mouse MO cell line, were grown in EPA-rich media for 24-48 h. MO were washed and exposed to Escherichia coli LPS (1 microg/ml) for 2 h. TNF mRNA expression was measured by Northern blot assays. Total nuclear extracts were harvested for the measurement of NF kappa B with electrophoretic mobility shift assays. Supershift assays were performed with anti-P50 or anti-P65 antibodies to show components of NF kappa B dimers. TNF production was determined by L929 bioassays. RESULTS: LPS stimulated RAW cell TNF mRNA expression and NF kappa B activity. In contrast, RAW cells grown in EPA-rich media had less TNF mRNA expression and an altered composition of the NF kappa B subunits (P65/P50 dimers) in the presence of LPS. TNF production by LPS-stimulated MO was reduced by EPA. CONCLUSIONS: The inhibitory effect of EPA on LPS-stimulated MO TNF gene transcription and protein elaboration is, in part, mediated through altering NF kappa B activation by reducing the P65/P50 dimers.

Animals↗

PubMed1999

Fish oil augments macrophage cyclooxygenase II (COX-2) gene expression induced by endotoxin.

BACKGROUND: Fish oil-supplemented diets have anti-inflammatory and immunomodulating effects. Although fish oil is readily incorporated into the cell membrane and influences the production of eicosanoids, the exact mechanism is not clear. This study was designed to investigate the effects of eicosapentaenoic acid (EPA), a major component of fish oil, on macrophage (Mphi) cyclooxygenase (COX) gene expression induced by LPS. METHODS: RAW 264.7 cells, a mouse Mphi cell line, were grown in EPA-rich media for 24 h. Mphi were washed and exposed to Escherichia coli LPS (10 microg/ml). Membrane lipid profile was determined by gas chromatographic analysis. COX-1 and COX-2 mRNA expressions were determined by Northern blot assays with mouse-specific cDNA probes. PGE(2) production of Mphi was measured by ELISA. Mphi production of COX-2 protein was determined by Western blot assays with an anti-COX-2 antibody. RESULTS: Incubation in EPA-rich media increased membrane EPA and decreased arachidonic acid (AA) composition. COX-2 mRNA expression was induced by EPA and further augmented by LPS stimulation. EPA also augmented Mphi production of COX-2 protein. In comparison, COX-1 mRNA expression was not affected by either LPS stimulation or EPA incubation. EPA reduced PGE(2) production by LPS-stimulated Mphi. To further support that COX-2 mRNA was regulated by COX product, exogenous PGE(2) was added to Mphi prior to LPS stimulation. PGE(2) reduced COX-2 mRNA of LPS-stimulated Mphi. CONCLUSION: EPA displaces AA and reduces PGE(2) production by LPS-stimulated Mphi. Fish oil inhibition of Mphi PGE(2) production induces COX-2 mRNA expression through a COX-2 product-mediated feedback mechanism.

Animals↗

PubMed1999

Involvement of calcineurin in angiotensin II-induced cardiomyocyte hypertrophy and cardiac fibroblast hyperplasia of rats.

A rapidly emerging body of literature implicates a pivotal role for the Ca2+-calmodulin-dependent phosphatase, calcineurin, as a cellular target for a variety of Ca2+-dependent signaling pathways culminating in cardiac hypertrophy. The aim of the present study was to test whether calcineurin is involved in the signal transduction of angiotensin II (AngII)-induced cardiac myocyte hypertrophy and fibroblast hyperplasia. Firstly, we observed that calcineurin activity was significantly increased in AngII-stimulated cardiac myocytes as well as fibroblasts, but was markedly inhibited by Losartan (50 micromol/l), H7 (50 micromol/l), and Fura-2/AM (5 micromol/l). It is indicated that AngII-induced activation of calcineurin is through an ATI receptor, may be dependent on the sustained increases of [Ca2+]i, and be regulated by protein kinase C. In a second experiment, we found that cyclosporin (0.1-10micromol/l), a specific inhibitor of calcineurin, decreased the protein synthesis rate in AngII-stimulated cardiomyocytes and the DNA synthesis rate in AngII-treated fibroblasts in a dose-dependent manner. In the latter experiment, calcineurin inhibition reduced the mRNA level of the atrial natriuretic factor gene. These results indicate that calcineurin is involved in the signal transduction of AngII-induced cardiomyocyte hypertrophy and fibroblast hyperplasia.

Angiotensin II↗

PubMed1999

Isolation and characterization of the product of inactivation of gamma-aminobutyric acid aminotransferase by gabaculine.

Gabaculine (5-amino-1,3-cyclohexadienylcarboxylic acid, 1), a naturally occurring neurotoxin isolated from Streptomyces toyocaenis, has been shown to be a mechanism-based inactivator of gamma-aminobutyric acid aminotransferase (GABA-AT) (Rando, R. R. Biochemistry 1977, 16, 4604). Inactivation results from reaction of gabaculine with the pyridoxal 5'-phosphate (PLP) cofactor. Two HPLC systems for isolating this inactivator-PLP adduct are described as well as a detailed characterization of the adduct, including the ultraviolet-visible spectrum, electrospray mass spectra, and NMR spectrum. The same spectral characterization of the chemically synthesized gabaculine-PLP adduct is also reported.

4-Aminobutyrate Transaminase↗

PubMed1999

System analysis of the flow/pressure response of rotodynamic blood pumps.

Design of a rotodynamic blood pumping system to have a suitable, controllable output is a key configuration issue. This study evaluates the benefits of selecting the impeller running specific speed, motor speed-torque line, and pump operating logic to jointly combine into a suitable characteristic. In this study, a "constant" flow for a given choice of control parameter value was the selected objective. The operating condition selected for analysis was chosen to be typical of an implanted, chronic support pump. Open-loop operation, fixed torque, fixed power, and fixed power/rpm2 ratio were combined with choices of impeller diameter and speed and motor speed-torque line. It was found that setting the running specific speed at a higher value than that associated with the best efficiency point resulted in a much more controllable pump. Overall efficiency was only slightly penalized for the model impeller chosen. Power/rpm2 control followed by torque control were most effective. With these control modes, motor characteristics were not critical.

Algorithms↗

PubMed1999

Intracardiac echocardiography via the transvenous approach with use of 8F 10-MHz ultrasound catheters.

OBJECTIVE: To study the safety and feasibility of intracardiac imaging using a novel 8F 10-MHz non-over-the-wire ultrasound catheter system. SUBJECTS AND METHOD: Intracardiac imaging using a transfemoral venous approach was performed in 33 adults, 14 men and 19 women, aged 25 to 66 years (mean, 46 years). Six were normal subjects, 12 had congenital heart diseases (5 atrial septal defects, 3 ventricular septal defects, 1 tetralogy of Fallot, 2 patent ductus arteriosus, and 1 Ebstein anomaly), 14 had valvular heart diseases (12 mitral stenoses and 2 calcific aortic stenoses), and 1 had acute pulmonary embolism. RESULTS: Ultrasound images were obtained, without any complications, from the right side of the heart in all subjects. The atria and ventricles could be recognized by anatomic relationships to the cardiac chambers and the valves by their characteristic motion during each cardiac cycle. The vessels were verified by their connections to the cardiac chamber and by contrast echocardiography if indicated. CONCLUSION: Intracardiac imaging using the 8F 10-MHz non-over-the-wire ultrasound catheter system via a transfemoral venous approach is feasible and safe. Intracardiac echocardiography is potentially useful for assessing a variety of cardiac anomalies and in guiding and monitoring certain intervention procedures.

Adult↗

PubMed1999

Coronary dissection and myocardial infarction following blunt chest trauma.

Myocardial infarction (MI) following blunt chest trauma is rarely diagnosed because the ensuing cardiac pain is commonly attributed to contused myocardium or the traumatic injuries in the local chest wall. There are only scattered reports on the coronary pathology associated with MI secondary to blunt chest trauma. Because differentiation of the pathology is difficult but important, we report here three cases of acute anterior MI secondary to coronary dissection following blunt chest trauma. Coronary dissection was demonstrated by coronary angiography. Two of the patients had intimal tears at the proximal left anterior descending artery (LAD) with normal flow, and the other patient had nearly total occlusion of the LAD associated with filling defects probably caused by an intracoronary thrombus. All three patients received conservative treatment without major complications and remained free from angina or heart failure throughout a 5-year follow-up period. In order to exclude associated MI in cases of blunt chest trauma, electrocardiography is necessary, and coronary angiography may be indicated to demonstrate coronary arterial pathology. Dissection of the coronary artery with subsequent thrombus formation is one of the possible pathophysiologic mechanisms of MI following blunt chest trauma.

Adult↗

PubMed1999

Macrophage TNF mRNA expression induced by LPS is regulated by sphingomyelin metabolites.

Metabolism of macrophage (MO) membrane phospholipids produces key mediators of inflammation and major second messengers that modulate inflammatory responses during sepsis. Sphingomyelin is a major class of phospholipid that releases ceramide and sphingosine. This study was designed to investigate the involvement of sphingomyelin metabolites in MO activation by lipopolysaccharide (LPS). Rabbit alveolar MO were obtained by bronchoalveolar lavage and exposed to C6-ceramide, a cell-permeable analogue of natural ceramide, or sphingosine in the presence of Escherichia coli LPS (100 ng/mL). Tumor necrosis factor (TNF) mRNA expression was measured by Northern blot assays. Total nuclear extract was harvested for the measurement of nuclear factor KB (NFkappaB) with electrophoretic mobility shift assays. MO TNF production was measured by L929 bioassays. C-6 ceramide did not have any effects on MO TNF production or TNF mRNA expression with or without LPS stimulation. Inhibition of ceramide metabolism with 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), or N-oleoyl-ethanolamine (NOE) also did not induce TNF mRNA or TNF production. In comparison, sphingosine inhibited TNF mRNA expression as well as TNF production of LPS-stimulated MO. LPS-induced MO NFkappaB activity was also reduced by sphingosine. Our data indicate that ceramide alone has no effect on macrophage activity, but its metabolite sphingosine down-regulates MO activation induced by LPS stimulation. Therefore, the sphingomyelin pathway is involved in the regulation of MO activation.

Animals↗

PubMed1999

Primary stenting of the left main coronary artery in acute myocardial infarction complicated by cardiogenic shock: case report.

Although acute left main coronary artery (LMCA) occlusion is a rare angiographic finding, it carries a very high mortality rate and most of the patients with this clinical condition die from sudden death or cardiogenic shock due to malignant arrhythmia or pump failure. The high mortality rate and tendency to lead rapidly to death are chiefly related to extensive myocardial injury. We report a case of cardiogenic shock resulting from acute myocardial infarction. Emergency cardiac catheterization was performed and coronary angiography showed a totally occluded LMCA. Prompt revascularization by means of primary LMCA stenting was successful and the patient was discharged 2 weeks later with only mild congestive heart failure. We suggest that the rapid performance of angiographic studies in this patient with cardiogenic shock was the turning point in saving her life. We also suggest primary LMCA stenting as an effective procedure for saving lives because it may reverse cardiogenic shock and prevent a probable fatal outcome.

Aged↗

PubMed1999

[Effect of human plasma HDL on the HDL receptors of plasma membranes of cholesterol-fed rabbit].

Atherosclerosis(As) rabbit model was developed by high-cholesterol feeding for 12 weeks. The rabbits were injected intravenously with human plasma HDL preparation per week, and then the effects of HDL on the lipids contents of serum, liver and bile nd the activity of HDL receptors on liver plasma membranes of cholesterol-fed rabbit were investigated. The results showed that HDL preparation had no effect on decreasing the lipids contents of serum, but it could low down the lipid depositions in liver, and promote the excretion of lipids from bile. The value of Bmax of HDL receptor showed decreasing trendy and the value of Kd showed increasing trendy in cholesterol-fed rabbits. In HDL-treated rabbits, the value of Bmax increased significantly as compared with that of normal group(P < 0.05), but the value of Kd showed no difference. The results suggested that human plasma HDL could enhance the activity of HDL receptors on the liver plasma membranes of cholesterol-fed rabbit.

Animals↗

PubMed1999

Lack of human papillomavirus types 16 and 18 DNA in esophageal squamous carcinoma cell lines.

OBJECTIVE: To assess the role of human papillomavirus (HPV) in the carcinogenesis of the esophageal carcinomas in a high-incidence geographical area in Northern China. METHODS: The presence of HPV types 16 and 18 DNA in the three esophageal carcinoma cell lines was examined by type-specific polymerase chain reaction (PCR). RESULTS: No HPV type 16 and 18 DNA was found in any of the three esophageal carcinoma cell lines. CONCLUSION: The results suggest that the role of HPV in human esophageal carcinogenesis in a high-incidence geographical area remains to be elucidated.

Adult↗

PubMed1999

[A study on the conjugation of Streptococcus mutans adhesins and its salivary receptors].

OBJECTIVE: To investigate the conjugation specificity of Streptococcus mutans' adhesins and their salivary receptors. METHODS: Include purified salivary receptor or adhesin competitive bacteria adhesion inhibition test and enzyme linked immuno-receptor assay (ELIRA) on S. mutans WD9463A. RESULTS: Salivary amylases can both enhance and competitively inhibit the adhesion of the strain to HA, while IgA degraded fragments and MW = 13,000 protein only promote its adhesion. P1 and a 117,000 surface protein of WD9463A both inhibit adhesion of the strain to IgA degraded fragments and salivary amylases. An 127,000 protein of WD9463A and a kind of GTFase inhibit its adhesion to IgA degraded fragments and salivary amylases respectively. No conjugation was found between IgA degraded fragments and the adhesins, while reaction between amylases and the adhesins had basically accordance with adhesion inhibition test. CONCLUSION: The adhesion of S. mutans is a result of reaction between multireceptors and multiadhesins.

Adhesins, Bacterial↗

PubMed1999

[Magnetic resonance imaging in dental appliance treatment of obstructive sleep apnea syndrome].

OBJECTIVE: To investigate the upper airway changes after wearing dental appliance in obstructive sleep apnea syndrome(OSAS). METHODS: The research included 11 aged OSAS patients and 11 matched controls. Through dental appliance therapy the OSAS was proved by polysomnography to have ideal treatment results (AHI had decreased from 44.6 +/- 22.5 per hour to 7.53 +/- 6.44 per hour). Magnetic resonance imaging (MRI) had been performed before and after wearing dental appliance. The MRI images of upper airway after wearing dental appliance were compared with those of without wearing, and even with those of the controls. RESULTS: After wearing dental appliance the size of upper airway increased greatly, from 12.27 ml +/- 4.13 ml to 13.93 ml +/- 4.58 ml(P < 0.01), While the size of oropharynx was increased from 5.55 ml +/- 2.10 ml to 6.88 ml +/- 2.26 ml (P < 0.001). There was still remained significant difference at nasopharynx, soft palate and tongue compared with the matched controls. CONCLUSION: Dental appliance worked with the effect of enlarging upper airway. The abnormal airway morphology can not be changed completely by dental appliance treatment. MRI technique, especially the 3-D reconstruction model of upper airway, is an effective and special method in OSAS research.

Adult↗

PubMed1999

[Pre- and post surgical orthodontic treatment of mandibular prognathism].

OBJECTIVE: To analyze the patients we treated in clinic through combined orthodontic-orthognathic surgery, and get some guidance for the future clinical work. METHODS: All 40 skeletal Class III malocclusion patients we analyzed were from joint clinic of our hospital. They aged from 17 to 38. RESULTS: The duration for presurgical orthodontic treatment was 9 months on average (2-25 months), and for postsurgical orthodontic treatment about 7.6 months on average (2-15 months). The duration for whole active treatment was 16 months on average (4-41 months). The objectives of presurgical orthodontic are: Alignment of dental arches, decompensation of anterior and posterior teeth, leveling of arches, and coordination of the width of the upper and lower arches. After presurgical orthodontic treatment, most of the patients could be treated by one piece surgery, which could simplify the surgical procedure and reduce the relapse rate of surgery. During the surgery, we modified the intermaxilary fixation wires. We used rigid rectangular stainless steel wires with Edgewise appliances as the fixation wires instead of conventional canine and molar bands with multiloop wires. The aims of the postsurgical orthodontic treatment are: closing residual spacing, extrusion of posterior teeth for correction of local openbite in premolars region, paralleling of the teeth, and adjustment of occlusion. CONCLUSION: Pre- and post-ssurgical orthodontic treatment is essential to the surgical treatment for mandibular prognathism.

Adolescent↗

PubMed1999

[19 cases of Paget's disease].

OBJECTIVE: The clinical signs of Paget's disease are similar to those of chronic eczema. The two are often confused, especially extramammary Paget's disease. Only biopsy can help to differentiate them correctly. METHODS: 19 patients with Paget's disease were reviewed with regard to clinical analysis and treatment from 1987 to 1997. RESULTS: Six patients had breast Paget's disease and 13 had extramammary one. The latter involved scrotum and penis in 11 patients, the groin in 1, and perianal and anal in 1. Follow up showed that 3 patients had recurrences in extramammary patients who had had positive surgical margin biopsy. One patient died of other disease. CONCLUSIONS: Surgery is the first choice of treatment for Paget's disease either of breast or of extramammary regions. Negative margins must be achieved to prevent local recurrence.

Adult↗