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Biomedical subjects

M Fu

Publications and source records attributed to M Fu.

At least 127 records · Page 7Linked to original sources
PubMed1998

Regulation of macrophage eicosanoid generation is dependent on nuclear factor kappaB.

BACKGROUND: Prostaglandin E2 (PGE2) is a major contributor to the production and maintenance of immunosuppression after overwhelming injury, leading to increased infectious morbidity and mortality in trauma patients. Elucidation of the cellular pathways involved in PGE2 production could lead to potential therapeutic interventions. The purpose of this study was to determine the role of cyclooxygenase II (COX-2) in PGE2 production by Mphi and to investigate the cellular mechanism of COX-2 gene activation. METHODS: Mouse macrophages (Mphi), RAW 264.7, were exposed to Escherichia coli lipopolysaccharide (LPS) in the presence of cyclooxygenase inhibitors (ibuprofen or NS398). COX-1 and COX-2 mRNA expression and PGE2 production were measured by Northern blot assay and enzyme-linked immunosorbent assay, respectively. Nuclear factor kappaB (NFkappaB) activity was measured by electrophoretic mobility shift assay. To elucidate the role of NFkappaB in LPS-induced COX-2 gene activation, Mphi were exposed to LPS in the presence of an NFkappaB inhibitor, TPCK. RESULTS: LPS increased Mphi COX-2 mRNA expression but had no effect on COX-1 mRNA expression. Both ibuprofen and NS398 inhibited COX-2 mRNA as well as PGE2 production by LPS-stimulated Mphi. In addition, LPS-induced NFkappaB activity was attenuated by these agents. Inhibition of NFkappaB with TPCK reduced COX-2 but not COX-1 gene expression and decreased PGE2 production by LPS-stimulated Mphi. CONCLUSION: Our data indicate that COX-2 gene expression by LPS-stimulated Mphi is dependent on NFkappaB. Cyclooxygenase inhibitors reduced PGE2 production by inhibiting both COX-2 mRNA expression and preventing NFkappaB activation.

Animals↗
PubMed1998

Electromyographic investigation of masticatory muscles in unilateral cleft lip and palate patients with anterior crossbite.

OBJECTIVE: To evaluate the characteristics of masticatory muscle activity in operated unilateral cleft lip and palate (UCLP) patients with anterior crossbite compared with normal individuals. SUBJECTS: Sixteen male and 13 female Chinese patients with UCLP and anterior crossbite. Fifteen male and 13 female Chinese individuals without cleft abnormalities served as a control group. DESIGN: Electromyographic activity of the masseter muscles and anterior temporalis muscles was recorded bilaterally in different mandibular positions using bipolar surface electrodes. RESULTS: Compared to noncleft controls, patients with UCLP demonstrated (1) higher activation levels of masseter and temporalis muscles in the rest position, (2) lower potential function of masseter and temporalis, (3) inharmonious activity of the masticatory muscles during mandibular border movement, (4) a higher asymmetry index of the masseter and temporalis muscles, and (5) longer silent periods of the two muscles. CONCLUSIONS: The function of masticatory muscles is different in patients with UCLP with anterior crossbite. Muscle function should be considered when evaluating cleft patients for orthodontic treatment and orthognathic surgery.

Action Potentials↗
PubMed1998

Mycotic aneurysm leading to iliac arteriovenous fistula diagnosed by vascular duplex color scan.

Arteriovenous fistula between common iliac vessels is uncommon. Most of the reported cases are secondary to lumbar disc surgery. Mycotic aneurysm of iliac vessels caused by bacterial infection is even rarer. We describe the case of a 63 year old man with dyspnea, abdominal pain, bipedal edema, chills and fever. He had a right common iliac AVF as a result of a ruptured salmonella mycotic aneurysm, and the diagnosis was made by vascular duplex color scan.

Aneurysm, Infected↗
PubMed1998

[Insulin-like growth factor-I upregulates the growth stimulatory effect of epidermal growth factor on HCE16/3 cells].

OBJECTIVES: To examine the role of insulin-like growth factor-I (IGF-I) in growth and gene expression of human papillomavirus (HPV) type 16 DNA-immortalized human cervical epithelial cells (HCE16/3 cells). METHODS: The growth and gene expression of HCE16/3 cells treated with IGF-I and epidermal growth factor (EGF) were examined by flow cytometry, soft-agarose assay and RT-PCR analysis. RESULTS: Physiological concentration of IGF-I had little effect on proliferation of HCE16/3 cells in serum-free and growth factor-free medium but supraphysiological concentration of IGF-I stimulated moderate proliferation of HCE16/3 cells. EGF stimulated proliferation of HCE16/3 cells at physiological concentration. The stimulatory effect was stronger when combined with IGF-I than EGF alone. Furthermore, the combined use of EGF and IGF-I could induce colony formation of HCE16/3 cells in soft agarose. The expression of HPV 16 E7 gene in HCE16/3 cells was not altered by growth factors in RT-PCR analysis. CONCLUSION: IGF-I is a weak regulator of HCE16/3 cells but it enhances the growth stimulatory effect of EGF on HCE16/3 cells.

Cell Division↗
PubMed1998

[The study on the correlation between the effect of dental appliances on OSAS and the morphology of upper airway and craniofacial structures].

OBJECTIVE: The purpose of this present study was to evaluate the effectiveness of dental appliances on OSAS by combining the use of overnight polysomnography and cephalometry. METHODS: 22 OSAS adult patients wore the dental appliances designed by authors. The association between the improvement of respiratory variables and the cephalometric variables were investigated on the basis of linear correlation analysis. We also classified the subjects by AI of post-treatment to analyze the morphological disparity of upper airway and craniofacial structures among the groups. RESULTS: There was no significant correlation between the improvement of AI and the morphology of the upper airway and its surrounding soft structures, but there existed significant linear correlation between the improvement of AI and the morphology of the craniofacial skeletal structure. The improvement of the lowest SaO2 was only correlated significantly with the body length of the mandible and the anteroposterior position of the base of tongue. However, the improvement of the RDI wasn't associated significantly with any morphological variables. In addition, there were morphological differences among the different groups. CONCLUSION: The above findings suggested that the effectiveness of dental appliance on OSAS is mainly associated with craniofacial skeletal structures, but no correlation existed between the sagittal dimension of upper airway and the effectiveness.

Adult↗
PubMed1998

[The study of normal occlusion's perioral muscle pressure].

OBJECTIVE: To measure the perioral muscle pressure, to realize the relationship between the morphology of dent, occlusion, skeleton and muscle pressure, moreover we established the measuring system and the mini-pressure transducers. METHODS: Thirty volunteers of normal occlusions aging 18.4-20.2 years old were selected. Mini-pressure transducer were bonded on the surface of the tooth. We measured the muscle pressure at rest and during swalling. The collection, handing, statistics of muscle pressure were finished automatically by the computer system. RESULTS: Normal occlusion's muscle pressure is related with sex; there isn't large variation in the intra-individual, but there is great variation in the inter-individual; there isn't a force balance between the buccal and lingual sides of the dentition in normal occlusion subjects. CONCLUSION: No matter which kind of occlusion, it has its own stable character of perioral muscle pressure. The buccal and lingual sides force are not equal, the perioral muscle pressure is related with the type of occlusion.

Adolescent↗
PubMed1998

[Study on the adhesion of an endemic strain of Streptococcus mutans serotype C to acquired pellicle. II. Isolation and extraction of adhesins of an endemic strain of Streptococcus mutans serotype C].

Surface proteins of S. mutans WD9463 A(c) were separated by DEAE-Sephadex A25 Chromatography and Sepharose C1-6B Chromatography. The adhesins were distinguished by bacterial adhesin inhibition experiment and were identified by PAGE, SDS-PAGE, IEP-PAGE, immunol diffusion test, GTF activity test and annalization of the sorts of amino acid. The results showed P1, two proteins with molecular weight of 117 kD and 127 kD and two proteins with GTF activity could inhibit the adhesion effectively. On the other hand, another kind of GTF could improve the adhesion of the strain. These indicated that S. mutans may be many kinds of adhesins.

Adhesins, Bacterial↗
PubMed1998

Primary left atrial malignant mesenchymoma: a case report.

Primary malignant mesenchymoma involving the heart is extremely rare. It usually has a poor prognosis. We report a case of malignant mesenchymoma originating in the left atrium with protrusion into the right pulmonary veins. Clinically, this patient presented with congestive heart failure, hemoptysis and systemic arterial embolization. Transthoracic and transesophageal echocardiography revealed a huge mass originating in the posterior wall of the left atrium with extension into both upper and lower right pulmonary veins. An elevated pulmonary arterial wedge pressure, moderate pulmonary hypertension and stenosis of the lower abdominal aorta were found during cardiac catheterization. Magnetic resonance imaging with angiography disclosed a tumor mass over the abdominal aorta above the bifurcation with protrusion into the right common iliac artery. This patient underwent surgical resection of the cardiac tumor and postoperative adjuvant chemotherapy. The pathological finding of a tumor containing several cellular types of sarcoma confirmed the diagnosis of malignant mesenchymoma.

Adult↗
PubMed1997

Endotoxin-induced macrophage gene expression depends on platelet-activating factor.

BACKGROUND: The development of multiple organ failure in septic patients is due to a systemic inflammation orchestrated by macrophages (Mphi). Elucidation and control of the mechanism involved in Mphi activation in sepsis is crucial to improving survival. An early event of Mphi activation involves the hydrolysis of membrane phospholipid by phospholipase A2 (PLA2) and subsequent generation of platelet-activating factor (PAF). OBJECTIVE: We designed this study to test the hypothesis that Mphi gene expression depends on PAF. DESIGN: Rabbit alveolar Mphi were obtained by bronchoalveolar lavage and were stimulated with 10 ng/mL of Escherichia coli endotoxin lipopolysaccharide (LPS), PAF (1 micromol/L), LPS+/-CV3988 (10 micromol/L), a PAF receptor antagonist, or LPS+/-PLA2 inhibitors: AACOCF3 (50 micromol/L) or manoalide (10 micromol/L). After 4 hours of incubation, Mphi tumor necrosis factor (TNF) messenger RNA (mRNA) expression was assessed by Northern blot analyses. The TNF production in the Mphi supernatant was measured by L929 bioassays. RESULTS: The LPS-stimulated Mphi expressed increased levels of TNF mRNA and produced an enormous amount of TNF. CV3988, a PAF antagonist, inhibited LPS-induced TNF mRNA. Furthermore, inhibiting PAF production with AACOCF3, or manoalide, also inhibited LPS-induced Mphi TNF mRNA expression. The effect of PAF depends on changes in intracellular calcium concentration. Inhibitors of calcium flux attenuated the PAF effects on LPS-stimulated Mphi. CONCLUSIONS: Our data suggest that LPS-induced Mphi gene expression is mediated by PAF. It is likely that modulation of PAF production or activity may be beneficial in down-regulating the overactivity of Mphi in sepsis.

Animals↗
PubMed1997

Transradial coronary angiography and angioplasty in Chinese patients.

Radial artery punctures for diagnostic coronary angiography or coronary balloon angioplasty were performed in 211 patients with a success rate of 98% (207 patients). In the four failed transradial accesses, the procedure was accomplished via the transfemoral route. Major local vascular complications included one arteriovenous fistula, one pseudo-aneurysm, and one ischemic contracture of the right hand. Reduced radial pulses were noted in 25 (12%) patients at follow-up without ischemic manifestations. Transradial diagnostic coronary angiography was successfully completed in 184 (98%) of 187 patients. The technical success for balloon angioplasty was obtained in 73 (97%) of 75 patients. Clinical success was observed in 68 (91%) patients; balloon angioplasty resulted in one nonfatal myocardial infarction and four late deaths (3 cardiac and 1 stroke). We believe that transradial catheterization for diagnostic coronary angiography and balloon angioplasty in our relatively small built Chinese population is a safe and practical alternative approach.

Adult↗
PubMed1997

Macrophage TNF mRNA expression is modulated by protease inhibitors.

BACKGROUND: Nuclear factor kappa B (NF kappa B) is an important transcriptional activator protein and is a crucial component of the host's response to infection. The activation of NF kappa B is correlated with the phosphorylation of inhibitory kappa B (I kappa B) and its subsequent degradation. We hypothesized that protease inhibitors which prevented I kappa B degradation could inhibit the macrophage gene activation and reduce the production of inflammatory cytokines. METHODS: Rabbit alveolar macrophages (M phi) were obtained by bronchoalveolar lavage. M phi were exposed to Escherichia coli lipopolysaccharide (LPS) (10 ng/ml) in the presence of various concentrations of protease inhibitors, either N-tosyl-L-phenylalanine chloromethyl ketone (TPCK) or N-benzoyl-L-tyrosine ethyl ester (BTEE). Total RNA was extracted for Northern blot assay of tumor necrosis factor (TNF) mRNA expression using a rabbit genomic DNA probe. Total nuclear extracts were also obtained for the measurement of the NF kappa B activity with the electrophoretic mobility shift assay. The TNF production in the M phi supernatant was measured by L929 bio-assays. RESULTS: NF kappa B activity induced by LPS was inhibited by either BTEE or TPCK. Inhibition of NF kappa B activity by these agents also prevented TNF mRNA expression and TNF production induced by LPS. The cellular mechanism leading to NF kappa B activation was further studied. TNF mRNA expression and NF kappa B activation were inhibited by D609, a phospholipase C (PLC) inhibitor, as well as by protein kinase C (PKC) inhibitors. In addition, direct stimulation of PKC led to NF kappa B activation and TNF mRNA expression. CONCLUSIONS: These data suggest that TNF mRNA expression of LPS-stimulated M phi is mediated through NF kappa B, NF kappa B activation is intimately regulated by the PLC signaling pathway.

Animals↗
PubMed1997

The discovery and a study of the adventitia rectalis, a fibrous layer of the rectal wall.

In sacral anoplasty, it is frequently found that an outer layer of the rectal wall, which resembles the structure of the taenia bands of the colon, limits the elasticity of the rectum making it different from the small intestine, hence preventing the rectal stump from being advanced to reach the perineum. Results of autopsy studies on 40 human babies and 40 dogs showed that a special collagenous fibrous layer called adventitia rectalis was found to limit the free expansion of the rectal wall. This was responsible for keeping the rectum a straight tubular shape with a fixed volume. This tissue plays an important role in bowel movement by defining a threshold of intrarectal pressure in the bowel reflex of defecation and by transmitting the expulsive force from the abdomen above down to the anal opening. This discovery may explain why (1) in Hirschsprung's disease, the preservation of the rectal wall in Soave's or Rehbein's procedure or partial preservation in Duhamel's operation will preserve better bowel function; (2) in atresia ani, rectal tapering results in better bowel control than rectal pouch amputation; and (3) in sacral anoplasty, multiple releasing incisions of adventitia rectalis at different levels will lengthen the rectal stump to about double its original length to reach the perineal incision, and the divided fibers will soon regenerate.

Anal Canal↗
PubMed1997

Parathyroid Ca(2+)-conducting currents are modulated by muscarinic receptor agonists and antagonists.

Parathyroid cells express Ca(2+)-conducting cation currents, which are activated by raising the extracellular Ca2+ concentration ([Ca2+]o) and blocked by dihydropyridines. We found that acetylcholine (ACh) inhibited these currents in a reversible, dose-dependent manner (50% inhibitory concentration approximately equal to 10(-8) M). The inhibitory effects could be mimicked by the agonist (+)-muscarine. The effects of ACh were blunted by the antagonist atropine and reversed by removing ATP from the pipette solution (+)-Muscarine enhanced the adenosine 3',5'-cyclic monophosphate (cAMP) production by 30% but had no effect on inositol phosphate accumulation in parathyroid cells. Oligonucleotide primers, based on sequences of known muscarinic receptors (M1-M5), were used in reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify receptor cDNA from parathyroid poly (A)+ RNA. RT-PCR products displayed > 90% nucleotide sequence identity to human M2- and M4-receptor cDNAs. Expression of M2-receptor protein was further confirmed by immunoblotting and immunocytochemistry. Thus parathyroid cells express muscarinic receptors of M2 and possibly M4 subtypes. These receptors may couple to dihydropyridine-sensitive, cation-selective currents through the activation of adenylate cyclase and ATP-dependent pathways in these cells.

Acetylcholine↗
PubMed1997

[Finite element analysis of force produced by "T" loop retraction archwire].

This study introduced three presumed springs to imitate the three dimensional bolstering function of the bracket-tooth-periodontal tissue on the archwire with three dimensional finite element method (FEM), and, systematically analysed the force system produced by the "T" loop retraction archwire on the incisors. The following conclusions were drawn; (1) The activation of the "T" loop retraction archwire will produce extrusion and root lingual torque force as well as horizontal force on the incisors; (2) Adequate torqul on the incisor segment and gable bend mesial to the T-loop are necessary to control the position of the anterior teeth while they are being retracted; (3) retraction archwire should not be activated too much; (4) Lighter wire will produce milder and more durable forces.

Biomechanical Phenomena↗
PubMed1997

[The experimental study about the relations between Chinese herb-epimedium leptorrhizum stearn (CH-ELS) and endogenous cAMP in alveolar bone of orthodontic tooth in rats].

The aim of this study was, to explore the mechanism of CH-ELS promoting bone remodelling of orthodontic tooth in rats. 11 male sprague-Dawleg rats was divided into 3 groups. Group I (normal control group) Group II (applied force, no injection) Group III (applied force, injection). The experimental period was 3 days. The radioimmunoassay (RIA) method were used to investigate the effects of CH-ELS on the content of endogenous cAMP in alveolar bone of orthodontic tooth in rats. Results indicate that CH-ELS has no significant effects on endogenous cAMP in alveolar bone of orthodontic tooth, perhaps, cAMP were not involved to regulate the mechanism of CH-ELS promoting bone remodelling. To explore the mechanism of bone remodelling of orthodontic tooth is more significant in orthodontic clinic.

Alveolar Process↗