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Q Wu

Publications and source records attributed to Q Wu.

At least 361 records · Page 20Linked to original sources
PubMed1995

Non-invasive identification of gastric contractions from surface electrogastrogram using back-propagation neural networks.

Gastric contractions play an important role in the digestive process of the stomach. The established method for the measurement of gastric contractions is invasive and involves the insertion through the nose of a manometric probe into the stomach. A non-invasive method is introduced in this paper for the identification of gastric contractions using the surface electrogastrogram. The electrogastrogram (EGG) was measured by placing surface electrodes on the abdominal skin over the stomach in ten subjects. Gastric contractions were simultaneously monitored using an intraluminal manometric probe. The back-propagation neural network was applied to identify gastric contractions from the EGG. The input of the neural network was composed of spectral data points of the EGG which was computed using the exponential distribution method. Experiments were conducted to optimize network structures and parameters. Using the EGG data in five subjects as the training set and the EGG data in another five subjects as the testing set, an overall accuracy of 92% was achieved in the identification of gastric contractions with an optimized three-layer back-propagation neural network (number of nodes for input:hidden:output layers being 64:10:2).

Adult↗
PubMed1995

Quantitative multivariate analysis of myoepithelioma and myoepithelial carcinoma.

The nuclear DNA content and morphologic data of 30 surgical samples (eight normal parotid gland, 12 myoepithelioma, and 10 myoepithelial carcinoma) were analyzed by the IBAS II analysis system. The results suggest that there are relationships between tumor ploidy distribution and prognosis, and that correct pathologic diagnosis can be obtained by the IBAS image system.

Adolescent↗
PubMed1995

Effect of Chloramphenicol on Denitrification in Flexibacter canadensis and "Pseudomonas denitrificans".

It was recently reported that chloramphenicol inhibits existing denitrification enzyme activity in sediments and carbon-starved cultures of "Pseudomonas denitrificans." Therefore, we studied the effect of chloramphenicol on denitrification by Flexibacter canadensis and "P. denitrificans." Production of N(inf2)O from nitrate by F. canadensis cells decreased as the concentration of chloramphenicol was increased, and 10.0 mM chloramphenicol completely inhibited N(inf2)O production. "P. denitrificans" was less sensitive to chloramphenicol, and production of N(inf2)O from nitrate was inhibited by only about 50% even in the presence of 10.0 mM chloramphenicol. These results suggested that inhibition of denitrification enzyme activity depended on the concentration of chloramphenicol. Increasing the concentration of chloramphenicol decreased the rate of production of nitrite from nitrate by F. canadensis cells, and the concentration of chloramphenicol which resulted in 50% inhibition of production of nitrite from nitrate was 2.5 mM. In contrast, the rates of production of nitrite from nitrate by intact cells and cell extracts of "P. denitrificans" were inhibited by only 58 and 54%, respectively, at a chloramphenicol concentration of 10.0 mM. Chloramphenicol caused accumulation of NO from nitrite but not from nitrate and inhibited NO consumption in F. canadensis; however, it had neither effect in "P. denitrificans." Chloramphenicol did not affect N(inf2)O consumption by these organisms. We concluded that chloramphenicol inhibits denitrification at the level of nitrate reduction and, in F. canadensis, also at the level of NO reduction.

Journal Article↗
PubMed1995

Subinhibitory concentrations of antibiotics affect cell surface properties of Streptococcus sobrinus.

Several antibiotics, at subinhibitory concentrations, caused an increase in the ability of Streptococcus sobrinus to bind alpha-1,6-glucans, whereas other antibiotics decreased glucan binding. In every case, glucan binding was inversely proportional to cell surface hydrophobicity. High levels of glucan-binding activity resulted in low levels of hydrophobicity, whereas low levels of glucan binding caused high levels of cellular hydrophobicity. The results show that low concentrations of antibiotics may modulate lectin and hydrophobin adhesins in streptococci.

Alkanes↗
PubMed1995

[Light microscope and energy dispersive X-ray analysis of amalgam pigmentation].

24 cases of amalgam pigmentation were analyzed by light microscope. 16 cases were amalgam debris, 8 cases were amalgam fragments and debris mixed. The amalgam distributed mainly along basement membrane of the epithelium, wall of blood vessels, nerve fibers, reticular fibers and endomysiums. In case where amalgam entered the bone, bone cells disappeared, lacuna emptied and microfracture of bony trabecullae occurred. In 8 cases pathologic calcification were found and in 18 cases there were inflammatory responses. 2 cases were analyzed by energy dispersive X-ray. It was found that in the different sites of tissues there were different content of Ag, Hg, Sn and Ca.

Adolescent↗
PubMed1995

[The ultrastructure study of white sponge nevus in oral mucosa].

Biopsies from 7 patients with white sponge nevus were examined histologically. Two of them had family history. Light microscopic observation reveals that the epithelium was thickened; the spinous cell layers had enlarged and oedematous cells and ballon-like degeneration; the keratohyalin granules were increased in upper spinous cells; the superficial layers of epithelium exhibited parakeratosis and thickening. 3 specimens were examined by electron microscopy. The basal and parabasal cells were cylindrical. The cytoplasmic tonofilaments were aggregated into boundles. It was characteristics of keratinized epithelium. In middle and superficial stratum spinosum the tonofilaments were homogeneously distributed in the cell plasma and the electron-dense granulars were located near the cell boundary and attached to desmosomes by tonofilaments, unlike normal non-keratinized oral mucosa. Many Odland bodies with a lamellar structure and irregular in both size and shape were seen. It is concluded that this leasion have a dyskeratinized process. The characteristic features of keratinized oral mucosa in non-keratinized mucosa is appeared. The thickening of superficial layer is due to shedding disturbance relating to dysfunction of Odland bodies.

Biopsy↗
PubMed1995

[Histogenesis of pleomorphic adenoma of the salivary gland].

Six parotid pleomorphic adenomas were studied histochemically by electron microscopy after staining with ruthenium red. It was found that the myxoid region was filled with ruthenium red granules. Similar positive ruthenium red-stained intracellular granules were observed within the Golgi-derived vacuoles of the neoplastic myoepithelial cells in the myxoid region. Some cells located at the periphery of the double-layer ductal structure had the features of myoepithelial cell, they also showed similar positive ruthenium red-stained granules in the intracellular vacuoles and intercellular space. No ruthenium red-stained granules was obtained in neoplastic ductal epithelium and the mucus in ductal cavities were negative for ruthenium red stain. The observations indicate that the neoplastic myoepithelial cells in the myxoid region probably derive from the periphery of the double-layer ductal structure, they secrete the proteoglycans forming the myxoid region and play an important role in the histogenesis of pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed1995

Structural and ultrastructural studies of the synovial membrane in temporomandibular joint disturbance syndrome.

To gain further knowledge on temporomandibular joint disturbance syndrome (TMJDS), the synovial membranes of 7 patients and 3 cadavers were examined with light microscope and transmission electron microscope. The results showed that the synoviocytes degenerated or disappeared in TMJDS. The cytoplasm contained numerous fibrils, while the organelles diminished in number. The surface of the synovial membrane was covered with a fibrinoid material. The surface of the synovial membrane was covered with a fibrinoid material. The authors consider that these pathological changes reduce or eliminate the normal functions of the synovial membrane, which may lead to damage to the articular cartilage. The articular adhesion found sometimes in TMJDS may be related to the changes in the synovial membrane.

Adult↗
PubMed1995

[Abnormal expression and clinical significance of mutation p53 gene on human bladder cancer].

In order to study the relationships between the mutant p53 gene and human bladder cancer, the authors used in situ hybridization to detect 30 of bladder cancer and 4 of normal bladder samples. The results showed that p53 gene positive rate of mRNA was 23.3% in cancer patient, and all negative in normal-bladder. The positive rate was significantly different in pathological grading and clinical stages of carcinoma (P < 0.05). It suggests that the mutant p53 gene participats in transformation of carcinoma and may be used as a tumor marker for determinating invasiveness and prognosis of bladder carcinoma.

Carcinoma, Transitional Cell↗
PubMed1995

Lipopolysaccharide induces exposure of fibrinogen receptors on human platelets.

The effect of lipopolysaccharide (LPS) on the exposure of platelet fibrinogen receptors was investigated. The results showed that: 1) LPS increased the binding of fibrinogen-gold complexes to platelets and the labels were primarily limited to shape-changed platelets; 2) LPS caused a dose-dependent rise in intracellular Ca2+ concentration in platelets; 3) LPS induced the activation of platelet protein kinase C (PKC) and the phosphorylation of glycoprotein llla (GPllla) which was inhibited by H-7. All these results suggest that stimulation of platelets with LPS causes a conformational change in glycoprotein llb/llla (GPllb/llla) through platelet shape change and/or phosphorylation of GPllla via PKC, which serves to expose the fibrinogen binding sites of GPllb/llla on human platelets.

Biological Transport, Active↗
PubMed1995

[Expression of proliferating cell nuclear antigen (PCNA) in squamous cell carcinoma of the oral cavity].

Proliferating cell nuclear antigen (PCNA) was identified by immunohistochemistry in 52 cases. PCNA-positive cells had been detected in the basal cells of normal epithelium known to contain proliferating cells. PCNA scores of normal epithelium was 1 as "low", and carcinomas were 3 or 4 as "high". The PCNA scores of high-grade carcinoma was significantly higher than the low-grade carcinoma. The study shows that expression of PCNA correlated with carcinoma grade.

Carcinoma, Squamous Cell↗
PubMed1995

[Some new concepts of cardiac myxoma].

The surgical treatment of cardiac myxoma in 211 consecutive cases (single tumor in 204 cases, multiple in 7, and recurrent in 3) from Dec. 1975 through Dec. 1993 was reviewed. Totally 228 myxomas were found and 215 operations performed. Data from this series and literature show that there were some complicated cases so that cardiac myxoma can not be simply regarded as a benign tumor only, but may be classified into two kinds: simple (or sporadic) cardiac myxoma and complicated cardiac myxoma. The latter includes myxoma complex, familial myxoma, and myxoma from multicenters. The clinical features, main points of diagnosis and surgery are concisely summarized.

Adolescent↗
PubMed1995

[Antibacterial components of rat uterus].

The acid-soluble extract of rat uterus cavity wall was obtained by washing out the normal Sprague-Dawley rat uterus cavity with 1% acetic acid in the presence of protease inhibitors. When tested for antibacterial activity by sensitive agarose diffusion assay, the extract effectively killed E. coli ML-35P. The bactericidal activity of the acid-soluble extract was further analyzed by gel overlay technique. The result showed that three protein bands, which were designated rat uterus protein 1 (rat UP-1), rat uterus protein 2 (rat UP-2), and rat uterus protein 3 (rat UP-3), were potently antibacterial against E. coli ML-35P. The rat UP-1, rat UP-2, and rat UP-3 accounted for 4.5%, 5.7%, and 6.6% of the total proteins of the rat uterus acid-soluble extract respectively. The lysoplate assay for the determination of lysozyme activity showed that extract had some lysozyme activity, but the activity was very low. AU-PAGE analysis of the extract did not show the presence of lysozyme on the gel. This study suggested that the uterus wall might secrete some currently-unknown antibiotic polypeptides which play an important role in the uterus defense against bacterial infections.

Animals↗
PubMed1995

Cells and circuits contributing to functional properties in area V1 of macaque monkey cerebral cortex: bases for neuroanatomically realistic models.

Anatomical and physiological data obtained from investigations of area V1 of the macaque monkey visual cerebral cortex have been used in 3 models outlining possible circuitry underlying functional properties of the region. The 3 models use, respectively, a fully implemented computer neural network, a mathematical formulation of interactions in a descriptive model of anatomical circuitry and a purely descriptive account of circuitry that could underlie particular functions. The 1st 2 models involve as part of their design an interpolation principle where afferents of opposite physiological property establish spatially offset but adjacent terminal fields and the postsynaptic neurons' dendrites have a continuum of different degrees of overlap into the 2 afferent pools and therefore different synaptic weights from the 2 afferents; this creates a functional and spatial gradient of response properties in the postsynaptic neurons between the properties of the different sets of afferents. The 3rd model examines lateral excitatory and inhibitory interactions in such gradients. Model 1 addresses the transformation of distinct thalamic axon properties to a gradient of response properties in postsynaptic spiny stellate neurons in layer 4C of V1. Model 2 proposes circuitry producing orientation specificity in V1 that begins by generating specificity of responses to orthogonal orientations; this is achieved by means of orthogonally oriented lateral axon projections made by the layer 4C spiny stellate neurons; this is followed by generation of a full cycle of orientation specificities by means of pyramidal neuron dendritic overlap across spatially separated fields of spiny stellate neuron axons responding preferentially to orthogonal orientations. Model 3 describes a circuitry to explain inhibitory and facilitatory interactions observed to occur in single unit responses when the classical receptive field is stimulated concurrently with the surround region. All the proposed models make predictions that can be tested by further anatomical and physiological experiments in the real visual cortex.

Animals↗
PubMed1995

Protoplast culture and plant regeneration from the suspension cells of Gynostemma pentaphyllum (Thumb) Mak.

From the suspension cultures of Gynostemma pentaphyllum (Thumb) Mak. protoplasts were isolated and cultured in a different medium with liquid and nurse culture method. Cell division was observed within 4 days and microcalli were formed within 4 weeks. On an MS solid medium with 1 mg/L of KT and 0.5 mg/L of IAA, protoplast-derived calli differentiated into embryos. Stems and leaves were formed on the MS medium with 1 mg/L of 6-BA and 0.5 mg/L of IAA. Finally, complete plantlets were obtained on a hormone-free MS solid medium.

Cells, Cultured↗
PubMed1995

[Molecular cloning of cellulase gene from the bacillus].

The CMCase gene from the Bacillus sp. strain E2 was cloned into E. coli DH5 alpha F' using plasmid pBR322 as a vector. Recombinant plasmid pBG3 was isolated from transformants producing CMCase, and the cloned CMCase gene was found to be in a 4.0kb HindIII fragment. The CMCase gene was subcloned in a functional state on a 2.4kb DNA fragment. The optimum pH and temperature for activity of CMCase encoded by pBG3 were pH 6.5 and 55 degrees C respectively. The CMCase could not hydrolyze any natural cellulose examined. Eighty-three percent of the CMCase was detected in the inner cellular fraction, 9% and 8% were in the periplasmic space and medium respectively. Result of Southern hybridization indicates that the cloned DNA fragment was derived from Bacillus sp. strain E2 chromosomal DNA.

Bacillus↗