Biomedical subjects

Ying Zhang

Publications and source records attributed to Ying Zhang.

At least 505 records · Page 28Linked to original sources

PubMed2002

[Nasopharyngeal tuberculosis: an analytical study and report on 12 cases].

OBJECTIVE: To understand the nasopharyngeal tuberculosis better. METHOD: 12 cases of nasopharyngeal tuberculosis collected from 1993 to 2000 were retrospectively analyzed and the clinical features were studied. RESULT: Only one case had known the previous history of pulmonary tuberculosis(8.33%). Cervical lymphadenopathy was the most common presenting symptom in our series (9 cases, 75%). 9 cases were diagnosed as nasopharyngeal malignant tumors by mistake at the beginning (75%), Anti tuberculous medical treatment was successful in all patients after follow-up from 6 months to 2 years. CONCLUSION: Nasopharyngeal tuberculosis may occur more frequently as part of an isolated upper respiratory tract infection than as secondary to pulmonary infection. It could get rise to cervical lymphadenopathy and should be taken into account when cervical lymphadenopathy is found. Nasopharyngeal malignant tumour is the most important disease in differential diagnosis for their similar clinical features. Antituberculous chemotherapy is usually effective.

Adult↗

PubMed2002

[Activation of phosphatidylinositol 3-kinase in human breast carcinoma].

BACKGROUND & OBJECTIVE: Phosphatidylinositol 3-kinase (PI3-K) has been implicated in the signaling pathways regulating cell growth by virtue of its activation in response to various mitogenic stimuli, but the role of PI3-K in human tumorigenesis has not yet to be defined. This study was designed to investigate the levels of both PI3-K protein and PI3-K mRNA and the activity of PI3-K in human breast tumors. METHODS: Western blot, immunoprecipitation, kinase activity assay, and RT-PCR were used to detect the expression and activity of PI3-K in 37 patients with breast cancers. RESULTS: Significantly increased expression of p85 subunit of PI3-K at levels of both protein and mRNA were found in 32 (86.49%) and 35(94.59%) out of the 37 breast tumors compared with adjacent normal tissue. Significantly higher level of the activity of PI3-kinase was observed in 25(67.57%) out of the 37 cases. CONCLUSIONS: PI3-K was highly activated in breast tumor tissue compared with adjacent normal tissue, suggesting that PI3-K was involved in the signal transduction of breast tumorigenesis. It may be a potential target for new strategies for the treatment of the patients with breast cancers.

Breast Neoplasms↗

PubMed2002

Study of gastrointestinal stromal tumors by light microscopy, electron microscopy and immunohistochemistry.

OBJECTIVE: To investigate the morphological features, immunohistochemical speciality of the gastrointestinal stromal tumors (GISTs), and its histogenesis as well. METHODS: The morphologic characteristics of GISTs were studied in 65 cases using light microscopy and 17 cases by electron microscopy. The expression of c-kit (CD117), CD34, vimentin, SMA, actin, desmin, S-100 and MBP were detected in all the cases with EnVision trade mark staining. RESULTS: Among 65 cases of GISTs, 46 were spindle cell type, 6 epithelioid cell type and 13 mixture type, equivalent to 85.5% (65 of 76) of all of the mesenchymal tumors of gastrointestinal tract admitted in the same period. The epithelioid cell type tumors composed of mainly the epithelioid cells, predominantly short spindle, oval or round in pattern, with an overall eosinophilic cytoplasm by hematoxylin-eosin stain. Focal cytoplasmic vacuolization was often seen. Sometimes signet-ring like cells and cells with a clear cytoplasm were seen in the epithelioid stromal tumor. The tumor cells arranged in interlacing fascicles forming whorls or sometimes cell clusters. Electronic microscopy showed the presence of interdigitating cell processes, in some areas, synapse-like structure and numerous desmosome-like junctions as well as a few gap junctions and small round neurosecretory granules. There were also abundant intermediate filaments and thin filaments of actin-type with longitudinal condensations (dense bodies). All of the 65 stromal tumors were strongly positive for vimentin (100%), 61 out of 65 tumors positive for CD117 (c-kit) (93.8%) and 51 out of 65 positive for CD34 (78.5%). Some cases also expressed SMA, actin, S-100 and MBP. CONCLUSIONS: GISTs were the most frequent mesenchymal tumor seen in the gastrointestinal tract. Under light microscope, the morphology of stromal tumors looks sometimes like a leiomyoma and Schwannoma. The application of immunohistochemical markers (particularly CD117 and CD34) and ultrastructural study are considered necessary for the differential diagnosis. GISTs may originate from the pluripotential precursor cells like the interstitial cells of Cajal.

Gastrointestinal Neoplasms↗

PubMed2002

[A study of the expression of CD(44) in pneumocytes in pulmonary sarcoidosis].

OBJECTIVE: To study the expression of CD(44) in pneumocytes in pulmonary sarcoidosis. METHODS: CD(44) and AE(1)/AE(3) were detected by immunostaining in lung tissues from 21 cases of pulmonary sarcoidosis, 5 cases of tuberculosis, 4 cases of idiopathic interstitial fibrosis, 3 cases of Wegener's granulomatosis and 8 normal controls. The numbers of CD(44) positive cells and AE(1)/AE(3) positive cells (total alveolar epithelial cells) per three high-power fields were counted, and the ratio of CD(44) cells to AE(1)/AE(3) cells (84 +/- 6) were calculated. RESULTS: The total number of alveolar epithelial cells (110 +/- 32) and the density of CD(44) cells were significantly higher in sarcoidosis than in the normal lungs. CD(44) (18 +/- 4) staining was localized in the pneumocyte membrane and the positive cells were mostly type II pneumocytes as confirmed by histology. CONCLUSION: Proliferation of pneumocytes and increased expression of CD(44) in pneumocyte membrane, especially in the type II pneumocytes, may play an important role in lung inflammation and repair in pulmonary sarcoidosis.

Adult↗

PubMed2002

Apoptosis of mortal human fibroblasts transformed by the bovine papillomavirus E5 oncoprotein.

Mortal human fibroblasts can be partially transformed by the bovine papillomavirus E5 oncoprotein through activation of the platelet-derived growth factor beta receptor. Here, we report that these cells undergo massive apoptosis 2 weeks after confluence. Although activation of caspase 3 was observed in the apoptotic cells, it was not required for apoptosis. The appearance of the mitochondrial proteins cytochrome c and apoptosis-inducing factor in cytosolic and nuclear compartments, respectively, provided a basis for mitochondrial dysfunction and a caspase-independent mechanism of apoptosis in these cells. Although an activating conformational change in Bax also was evident in the apoptotic cells, enforced overexpression of Bcl-2 was insufficient to prevent apoptosis. Finally, a small peptide present in the conditioned medium from dying transformed cells appeared responsible for inducing apoptosis through affecting a conformational change in Bax and eventual relocalization of apoptosis-inducing factor to the nucleus. Thus, an atypical apoptotic pathway is activated in mortal human fibroblasts in response to transformation induced by sustained receptor tyrosine kinase activation.

Apoptosis↗

PubMed2002

[Expression of CD56 in acute leukemia and its clinical significance].

In order to investigate the expression of CD56 on acute leukemia cells and its clinical significance, samples from 70 patients with acute leukemia were analyzed with multicolor flow cytometry to determine the CD56 and other leukocyte differentiation antigens. The results showed that 16 of 70 cases (22.86%) were identified to express CD56, of which 1/35 (2.86%) patient with acute lymphocytic leukemia (ALL) and 15/31 (48.39%) with acute myelocytic leukemia (AML) were CD56 positive. The positive rate of CD56 in AML was significantly higher than that in ALL (P < 0.01). The expression of CD56 varied in AML subtypes. The positive rate (11/15) of CD56 in AML-M(0), -M(1) and -M(2) was significantly higher than that in AML-M(3), -M(4) and -M(5) (4/16) (P = 0.013). 13 of 15 AML with CD56 expression were also positive for HLA-DR (41.94%), and a significant positive correlation was found between the expression of CD56 and HLA-DR (r = 0.439, P = 0.014). It was concluded that CD56 mainly expressed in AML cells. The analysis of CD56 expression on acute leukemia is of great value in the diagnosis, prognosis prediction and monitoring of minimal residual disease in AML patients.

Adolescent↗

PubMed2002

[Determination of furazolidone, carbenoxolone sodium and berberine hydrochloride in wei kang tablets by reversed-phase high performance liquid chromatography(RP-HPLC)].

An HPLC method with gradient elution was developed to separate and determine furazolidone, carbenoxolone sodium and berberine hydrochloride in Wei Kang Tablets on Nova-Pak C18 column (150 mm x 3.9 mm i.d., 4 microns), using acetonitrile-phosphate buffer solution (pH 7.0) as mobile phase and 3,5-dinitrobenzoic acid as the internal standard. Detection was performed with UV detector at 254 nm. The calibration curves were linear within the ranges of 141.2 mg/L -1,270.8 mg/L for furazolidone(r = 0.9997), 100.6 mg/L -905.4 mg/L for carbenoxolone sodium(r = 0.9995) and 99.2 mg/L -892.8 mg/L for berberine hydrochloride(r = 0.9991). The recoveries and RSDs were 99.5% and 1.38% for furazolidone, 100.3% and 1.73% for carbenoxolone sodium, 97.3% and 1.97% for berberine hydrochloride respectively. The results show that this method is simple, rapid, specific, accurate and reproducible.

Anti-Ulcer Agents↗

PubMed2002

[A study on morphology and distribution of mast cells in oral lichen planus].

OBJECTIVE: The aim of this study was to investigate the features of mast cell subtypes and relationship between mast cells and pathogenesis of oral lichen planus. METHODS: Mast cells in the tissue of oral lichen planus were stained with Alcian blue/safranine in order to demonstrate mature and immature mast cells, and the constituent ratio of these two subtypes was calculated. Afterwards, LUZEX-F image pattern analysis system was applied to demonstrate the size of these two subtypes and their morphological features. RESULTS: The constituent ratio of mature and immature types of mast cells in the tissue of oral lichen planus was significantly different from that in the normal tissue (P < 0.01), and such difference was also demonstrated among different types of this malady, including papule-, net- and erosion-type of oral lichen planus (P < 0.05). There was significant difference between the sizes of mature and immature mast cells (P < 0.01) and also the sizes, amount and distribution of the plasma granules within these two mast cells. CONCLUSION: It could be implied that mast cells might play a role in the pathogenesis of oral lichen planus.

Adult↗

PubMed2002

Percutaneous estrogen in prevention of early postmenopausal bone loss in Chinese women.

OBJECTIVE: To identify the optimal dosage of 17beta-estradiol gel + oral progestin for preventing bone loss in postmenopausal Chinese women. METHODS: A 3-year open label, randomized, prospective clinical trial was conducted. Sixty healthy women who had been postmenopausal for 1 to 5 years were recruited and divided into following 4 groups: group 1, percutaneous gel 17beta-estradiol (E(2)) 1.5 mg/d plus micronized progesterone (MP) 100 mg/d; group 2, percutaneous gel 17beta-estradiol (E(2)) 1.5 mg/d plus medroxyprogesterone acetate (MPA) 2 mg/d; group 3, percutaneous gel 17beta-estradiol (E(2)) 0.75 mg/d plus micronized progesterone (MP) 100 mg/d; and group 4, percutaneous gel 17beta-estradiol (E(2)) 0.75 mg/d plus medroxyprogesterone acetate (MPA) 2 mg/d. Estrogen and progestin were given continuously for 25 days per month. Bone mineral density (BMD) was measured using quantitative computed tomography (QCT) for trabecular bone of L2-5 and dual energy X-ray absorptiometry (DEXA) for L2-4 and hip 5 times during the trial at baseline and at the 6-, 12-, 18-, 24- and 36-month visits. RESULTS: Fifty-nine patients (98.3%, 59/60) stayed in the study for 1 year, 56 patients (93.3%, 56/60) for 2 years, and 51 (85%, 51/50) for 3 years. On average, menopausal symptoms were relieved by 80% after 6 months of treatment. By the 24th month, the mean increase in BMD ranged from 4.3% to 7.5% in trabecular bone; and by the 36th month, it ranged from 4.2% to 6.2% in L2-4 and 1.61% to 3.77% in the neck. There were significant difference after treatment (P < 0.05). Among the four groups, no significant difference (P > 0.05) was found in improvement of symptoms, levels of bone markers or BMD. CONCLUSION: A daily dose of estradiol gel, either 0.75 mg or 1.5 mg, is effective in preventing early postmenopausal bone loss and relieving menopausal symptoms. After 3-year treatment, spinal BMD could increase steadily, so does hip BMD, especially in the first 2 years.

Administration, Cutaneous↗

PubMed2002

[Study of ABO blood group secretor type alpha(1,2)-fucosyltransferase gene polymorphism in Chinese].

Secretor gene (FUT2)-encoded secretor type alpha(1,2)-fucosyltransferase (Se enzyme) that regulates expression and secretion of ABO(H) antigens in epithelial cell of glands and body fluids. It has the extensive polymorphism and race specificity. In the present study, we investigated the distribution of the fusion gene of the FUT2 locus in 191 Manchu individuals from Liaoning Province and 208 Mongolian individuals from Inner Mongolia, and analyzed the polymorphism of the FUT2 gene in 90 unrelated Han Chinese from Shandong Province and 90 Mongolian from Inner Mongolia, respectively. The fusion gene was not found in the two investigated ethnic groups. The frequencies of G849A nonsense mutation in Shandong Han Chinese and Mongolian of Inner Mongolia individuals were the same, 0.0055.

China↗

PubMed2002

[Determination of cirsilineol in Herba Artemisiae scopariae collected in autumn by HPLC].

OBJECTIVE: To establish a quantitative method for determination of cirsilineol in Herba Artemisiae Scopariae collected in Autumn. METHOD: Sample was extracted with methanol, and cleaned up with polyamide column. ODS column was used with methanol-acetonitrile-0.5% acetic acid solution (24:19:57) as mobile phase. Detection wavelength was 347 nm. RESULT: Cirsilineol in sample solution was well separated. Linearity of cirsilineol was good (r = 0.9998) in range of 0.1-0.8 microgram. The average recovery was 101.3%, RSD of repeatability was 3.04%. CONCLUSION: This method can be used for quality control of Herba Artemisiae Scopariae collected in autumn and its preparations.

Artemisia↗

PubMed2002

[Comparison study on total flavonoid content and anti-free redical activity of the leaves of bamboo, phyllostachys nigra, and Ginkgo bilabo].

OBJECTIVE: To investigate the differences of total flavonoid (TF) content and antifree radical activity between the-leaves of bamboo and Gingo biloba, as well as their seasonal changes. METHOD: Spectrophotometery and Chemiluminescence methods were adopted to determine TF and half inhibiting concentration (IC50) on active oxygen free radicals of the leaves of bamboo, phyllostachys nigra (Lodd. ex. Lindl.) Munro, and Ginkgo biloba. Two kinds of leaves were picked in the same plot at the same time monthly. RESULT: The TF of bamboo leaf varied in the range of 0.67%-1.71% (in dry basis of leaf, below as same) throughout a year, the minimum apparing in June and the maximum in July, then going down obviously, and remaining at a much high lever during November to next April. However, the TF of Ginkgo bilabo leaf varied in 1.48%-2.49% during whole growing period, early April to late November. It ascended with the growth of leaf, reaching the top during June and July, the going down slowly, and finally another peak appeared before defoliation. The average IC50 values on O2-. and .OH of bamboo leaf were at 11.0 micrograms.mL-1 and 5.3 mg.mL-1, and Ginkgo biloba at 19.0 micrograms.mL-1 and 3.6 mg.mL-1, respectively. CONCLUSION: The TF content and anti-free radical activity the bamboo leaf are comparable with the leaf of ginkgo biloba, which is a kind of potential resources for natural antioxidant and free radical scavenger.

Flavonoids↗

PubMed2002

[Qualitative and quantitative methods of chlorogenic acid in commercial Herba Artemisiae Scopariae].

OBJECTIVE: To develop the identification and assay for chlorogenic acid in commercial Herba Artemisiae Scopariae. METHOD: TLC method was used for identification with silica gel G plate and butyl acetate-formic acid-water (7:2.5:2.5) upper layer as a developing solvent. Chlorogenic acid in 85% methanolic extract was separated on the ODS column with methonal-3% acetic acid solution (15:85) as mobile phase. The detection wavelength was 327 nm. RESULT: The qualitative method is repeatable. Chlorogenic acid in extracts is well separated, relationship of injection amount and peak area is linear (r = 0.9998) within the range of 0.075-0.6 microgram. The average recovery is 100.9% and repeatability is 1.4%. Ten samples purchased from different areas in the country were identified and quantified with the methods. CONCLUSION: The methods and data could be used for quality control.

Artemisia↗

PubMed2002

[Studies on chemical constituents in buds of Artemisia scoparia].

OBJECTIVE: To investigate the chemical constituents in flower buds of Artemisia scoparia. METHOD: The constituents were separated and purified by means of various chromatographic techniques, and their structures were determined on the basis of physical and chemical properties and spectral data. RESULT: Four flavones were isolated and their structures were identified as cirsilineol (I), cirsimaritin(II), arcapillin(III) and cirsiliol(IV) respectively. CONCLUSION: Compounds I, III and IV were isolated from this plant for the first time.

Artemisia↗

PubMed2002

[Effects of extremely low frequency electromagnetic field and its combination with lead on the antioxidant system in mouse].

OBJECTIVE: To study the effects of extremely low frequency electromagnetic field(ELF EMF) and its combination with lead on the antioxidant system in mouse brain and liver tissues. METHOD: Mice were exposed to a 50 Hz sinusoidal 0.2 mT or 6.0 mT EMF for 2 weeks. At the same time, some groups were exposed to lead(50 mg/kg). After the exposure, the antioxidant system and cell membrane fluidity in brain and liver were measured. RESULTS: Malondiadehyde(MDA) content in brain and liver increased from the control levels of (1.33 +/- 0.12) and (3.95 +/- 0.21) nmol/mg pro to (1.35 +/- 0.09) and (6.15 +/- 0.28) nmol/mg pro respectively following 0.2 mT exposure, and to (3.98 +/- 0.10) and (6.50 +/- 0.79) nmol/mg pro respectively following 6.0 mT exposure. Total antioxidant capability(T-AOC) in brain and liver decreased from the control levels of (4.39 +/- 0.48) and (2.45 +/- 0.21) U/mg pro to (3.99 +/- 0.39) and (1.92 +/- 0.32) U/mg pro respectively following 0.2 mT, and to (3.12 +/- 0.37) and (1.57 +/- 0.14) U/mg pro respectively following 6.0 mT. GSH content decreased only in liver tissue from the control level of (194.60 +/- 20.93) mg/g pro to (189.24 +/- 5.61) mg/g pro(0.2 mT) and (153.04 +/- 1.18) mg/g pro(6.0 mT). Cellular membrane fluidity decreased from the control levels of (1.396 +/- 0.040) and (2.899 +/- 0.552) to (1.224 +/- 0.190) and (1.894 +/- 0.0761) (0.2 mT), (1.159 +/- 0.179) and (1.516 +/- 0.204)(6.0 mT) respectively. Compared with single EMF exposure(6.0 mT), EMF combined with lead exposure induced remarkable increase in MDA, GSH content and T-AOC and decrease in cell membrane fluidity both in the brain and liver, and increase in SOD activity only in liver. CONCLUSION: ELF EMF might alter the metabolism of free radicals, decrease anti-oxidant capability and enhance lipid peroxidation. The combination of EMF with lead showed synergic effects on lipid peroxidation.

Animals↗

PubMed2002

[Relationship between terminal sialyl and fucosyl residues of glycans on cell surface and cell biological behaviors].

The relationship between the structures of glycans on the surface of H7721 cells, a human hepatocarcinoma cell line, and the cell behaviors was studied by using neuraminidase and alpha-L-fucosidase to remove the terminal sialyl or fucosyl residues of surface glycans respectively. The cell adhesion to fibronectin (Fn), laminin (Ln) and human umbilical vein epithelial cell (HUVEC), as well as cell chemotactic migration and invasion were selected as the parameters of the cell behaviors. It was found that sialyl residue was not essential for the cell adhesion to Fn, but was important in the cell adhesion to Ln and chemotactic cell invasion, and very crucial in the cell adhesion to HUVEC and chemotactic migration. In contrast, fucosyl residue was probably participate in cell adhesion to Fn, Ln and HUVEC, but not important in chemotactic migration and invasion. The cell adhesion to HUVEC, chemotactic migration and invasion were inhibited by the monoclonal antibody of sialyl Lewis X (SLex), but not by the antibody of non-sialyl Lewis X (Lex). This result supports the finding that sialyl residue is more important than fucosyl residue in the contribution to the above-mentioned three cell processes.

Antibodies, Monoclonal↗

PubMed2002

[Studies of relationship between infection of HPV, synergistic factors and cervical carcinoma].

The carcinogenesis of the human cervical precancerous lesion,cervical carcinoma is known closely associated with human papillomavirus (HPV). The purpose of this article is to identify whether HSV and CMV play as co-factor role in the carcinogenesis. Eighty-one cases of various cervical lesions were analyzed by HPV6/11, HPV16/18 in situ hybridization. Meanwhile, HPV, HSV and CMV were determined in 103 cases of various cervical lesions. The results show that the distribution of positive hybridization signal was consistent with the distribution of Koilocytic cells in HE stain. Of these cervical specimens investigated, the positive rates of HPV16/18 and HPV6/11 using ISH were 51% and 64%, respectively,the infection rates of HPV16/18, HPV6/11, HSV and CMV using PCR were 21%,4% 23% and 0%, respectively. The co-operation effect of HPV and HSV occurred in the oncogenesis of human cervical carcinoma, and moreover, the cellular and molecular biological mechanisms were discussed.

English Abstract↗

PubMed1999

The PE-PGRS glycine-rich proteins of Mycobacterium tuberculosis: a new family of fibronectin-binding proteins?

A clone was isolated by screening of a cosmid library of Mycobacterium tuberculosis with an oligonucleotide designed from the N-terminal sequence of a previously reported proline-rich protein. Characterization of the 4481 bp insert showed the presence of polymorphic CG-repetitive sequences (PGRSs) with an ORF of 2.7 kb, encoding a 81.3 kDa protein (PE-PGRS81). Southern blot analysis and BLAST-p searches revealed several homologous sequences in the genome of M. tuberculosis. The deduced amino acid sequence was highly similar to a stretch of about 98 residues in the N-terminus present in several members of the PE-PGRS family available in the GenBank database, including 100% identity with the partial amino acid sequence of the potential protein encoded by orf3' as well as with the Rv0278c sequence. A neighbour-joining analysis of the 99 PE-PGRS sequences available in the database indicated that PE-PGRS81 is included in a group where its closest relatives are the sequences orf3', Rv0278c, Rv0279c, Rv1759c, Rv3652 and Rv0747. Probing with the complete coding regions of PE-PGRS81 and Rv1759c in Southern blot assays, on samples of genomic DNA from M. tuberculosis H37Rv, Mycobacterium bovis BCG and M. tuberculosis clinical isolates, showed a complex hybridization pattern for all strains. This shows the existence of intrastrain PGRS variability as reported for other PGRS members. In contrast, probing with the short conserved N-terminal region of Rv1759c reduced the hybridization to a single band. This marker allowed identification of M. tuberculosis clinical strains that lack Rv1759c. A recombinant C-terminal fragment of Rv1759c showed fibronectin-binding properties and was recognized by sera from patients infected with M. tuberculosis, suggesting that at least this member of the PE-PGRS is expressed in tuberculosis infection.

Adhesins, Bacterial↗