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Biomedical subjects

T Zhang

Publications and source records attributed to T Zhang.

At least 109 records · Page 6Linked to original sources
PubMed2001

[The role of CA125 in the differential diagnosis of primary ovarian carcinoma and metastatic ovarian carcinoma originated from the gastrointestinal tract].

OBJECTIVE: To assess the role of CA125 monoclonal antibody in the differential diagnosis of primary ovarian carcinoma and metastatic ovarian carcinoma originated from the gastrointestinal tract. METHODS: Immunohistochemical study using CA125 monoclonal antibody was performed on 33 primary ovarian cancer and 50 metastatic ovarian cancer of gastrointestinal origin. RESULTS: The positivity of CA125 was 84.5% in 33 cases of primary ovarian carcinoma, while in 50 metastatic ovarian carcinoma cases, only 4.0% was CA125 positive. The positivity of CA125 was significantly higher in primary ovarian carcinoma than metastatic ovarian carcinoma (P < 0.001). CONCLUSION: CA125 monoclonal antibody is useful in the differential diagnosis of ovarian carcinoma.

CA-125 Antigen↗
PubMed2001

[Primary cutaneous CD30-positive anaplastic large cell lymphoma].

OBJECTIVE: To analyse the clinical manifestations, pathological and immunohistochemical features of 9 cases of primary cutaneous CD30-positive anaplastic large cell lymphoma (ALCL) in order to improve the criteria for its early and differential diagnosis. METHODS: Histopathological method was used to study the morphological characteristics. Immunohistochemical stainings (SP or ABC method) for leukocyte common antigen (LCA), CD20, CD30, CD45RO, CD68, epithelium membrane antigen (EMA), cytokeratin (CK) and HMB45 were applied to the routine paraffin sections of all the 9 cases. RESULTS: The 9 cases of primary cutaneous CD30-positive ALCL consisting of 6 males and 3 females, aged 31 to 84 years (mean 58.2 years). All patients presented with subcutaneous masses or papular eruptions on lower trunk and extremities. Histopathologically, the lesions were composed of numerous large round, oval or pleomorphic cells with abundant cytoplasm, amphophilic or basophilic, and large nucleus with distinct nucleolus. Mitosis was often observed. Multinucleated giant cells and Reed-Sternberg cells may be seen. The neoplastic cells displayed positive antigen markers for CD30 in 9 cases, 6 positive for CD45RO and 3 cases negative for both CD45RO and CD20. Two patients died of metastasis, 2 patients experienced recurrence and 5 patients still well during follow-up. CONCLUSIONS: Primary cutaneous CD30-positive ALCL is a morphologically distinctive neoplasm with a comparatively favorable prognosis. This tumor can be differentiated from other malignant tumors on the basis of histopathologic features and positive CD30 which is of significance.

Adult↗
PubMed2001

[Apoptosis of bone marrow cells aplastic anemia patients treated with cyclosporin A].

OBJECTIVE: To evaluate the effects of cyclosporin A (CsA) on the apoptosis of bone marrow cells of aplastic anemia (AA) patients. METHODS: The apoptosis of and Fas antigen expression on the bone marrow mononuclear cells (MNC) in 25 AA patients and 10 normal controls were assayed by TUNEL and FACS, respectively. RESULT: The percentage of CD(34)(+) cells was decreased significantly in AA patients than in normal controls (P < 0.05), and so did the percentage of CD(34)(+)Fas(+) cells (P < 0.05). The percentage of apoptotic cells in AA patients was higher than that of controls (P < 0.01). After the patients were treated with CsA for 2 months, the percentage of apoptotic cells was decreased (P < 0.01). The percentage of CD(34)(+)Fas(+) cells was positively correlated with that of apoptotic cells in AA patients. CONCLUSION: Fas is involved in the apoptosis of CD(34)(+) cells of AA patients. CsA could reduce the percentage of apoptosis of bone marrow cells in AA patients.

Adolescent↗
PubMed2001

[Pathological and virological studies of the liver tissues from the patients with sporadic hepatitis E].

OBJECTIVE: To study the pathological feature, viral distribution and replication in the liver tissue of sporadic hepatitis E(HE), and to explore the mechanism of the liver injury induced by hepatitis E virus(HEV). METHODS: The total bioptic liver tissues (n=54) were obtained from the patients with sporadic hepatitis E, including the clinical acute stage (n=20), the convalescent stage (n=16), and the chronic hepatitis B (CHB) overlapped with HEV infection recently (n=18). The pathological changes in the liver tissues were observed under the light and the electron microscope. HEV RNA was detected by in situ hybridization, and Kupffer cells were marked with immunohistochemistry. RESULTS: The HE liver tissues showed the pathological features in the clinical acute stage, presenting frequently with feathery degeneration of hepatocytes (100%), cholangiolar cholestasis (75.0%), and double nuclei and multinuclei hepatocytes (65.0%). The apoptotic body of hepatocyte was larger and irregular, and the proliferation of Kupffer cells was prominent. HEV RNA was distributed in hepatocyte cytoplasm near the nuclei. The positive rate of HEV RNA in acute stage was evidently higher than that in convalescent stage (100% vs 12.5%,P < 0.001), and the HEV RNA positive hepatocytes and the viral copies in acute stage were also more than in convalescent stage, in which the liver tissues were becoming normal. The liver tissue changes of the CBH overlapped with HEV infection were more severe compared with the single CHB. CONCLUSIONS: Sporadic HE had histopathological characteristics. HEV infection and replication in hepatocytes occurred mainly during clinical acute stage and regressed in convalescent stage, which suggested sporadic acute HE may have a good result. The immune-mediated liver injury by lymphocytes might be a main pathogenesis of HE,but the liver injury induced directly by HEV might not be excluded.

Adolescent↗
PubMed2001

[Study on applicability of hepatitis C virus serotyping].

BACKGROUND: To explore the applicability of HCV serotyping. METHODS: Enzyme immunoassay (EIA) was used to detect the serotypes of 148 patients with viral hepatitis C. RESULTS: 56.08%(83/148) patients were serotyped,of whom 50.06%(42/83) were identified to be serotype 1,43.37%(36/83) serotype 2, and 6.03%(5/83)mixed serotype 1 and 2. The sera from 70 HCV RNA-positive patients out of the 83 ones who were successfully serotyped were detected for genotyping. The results were completely consistent between serotyping and genotyping. CONCLUSIONS: Serotyping of HCV has its clinical applicable value.

Genotype↗
PubMed2001

[Study on specificity of IgM antibody response in patients with coxsackie virus B infection].

OBJECTIVE: To study the specificity of IgM antibody response in patients with Coxsackie virus B infection. METHODS: A Coxsackie virus B specific immunoblot assay was established for detection of CVB IgM antibody response in patients with recent CVB infection. RESULTS: Of 28 patients' serum samples, positive by ELISA captured CVB IgM test, analysis results of specific IgM response defined by immunoblot assay revealed VP1 protein specific which was crossly reactive among CVB group. CONCLUSION: This finding suggested that VP1 protein in Coxsackie virus B group potentially functioned as a predominant antigen inducing detectable IgM antibody following CVB infection.

Antibodies, Viral↗
PubMed2001

[The impact of lateral rhinotomy on nasal airway].

OBJECTIVE: In order to ascertain the lateral operation and medial maxillectomy affect on nasal airway. METHOD: Report 16 cases of nasal cavity or nasal sinus neoplasm who were therapied by lateral rhinotomy and medial maxillectomy. They were observed by acoustic rhinometer (AR) and CT examination in 1-2.5 years after the surgery. RESULT: The feeling of nasal obstruct were disappeared in 3 months after the surgery. The nasal airway resistance(NAR) of the ill nasal cavity was markedly decreased after the surgery, and the total NAR were decreasing unmarkably. The mucous proliferation was notable only in the first year after surgery, and especially on remains of the inferior turbinate or extra wall of nasal cavity. CONCLUSION: Lateral rhinotomy operation and medial maxillectomy have less impact on nasal airway and the functions.

Adult↗
PubMed2001

[A clinical analysis of cholesterol granuloma following chronic suppurative otitis media].

OBJECTIVE: To investigate the pathophysiological mechanism, clinical menifestation and radiographic diagnosis of cholesterol granuloma following chronic suppurative otitis media. METHOD: Six cases of CG following chronic suppurative otitis media, confirmed by surgery and pathology, were reviewed and analyzed. RESULT: CG frequently accompanied with other middle ear diseases, and was shown as a high signal intensity on both T1-and T2-weighted images in magnetic resonance imaging(MRI). CONCLUSION: It was postulated that the obstruction of pneumatized temporal bone air cell, caused by other middle ear diseases such as cholesteatoma and tympanosclerosis, might be the pathophysiological mechanism of CG. The evaluations of computed tomography (CT) and clinical manifestation were limited to distinguish CG from cholesteatoma or other neoplasm, while the MRI can be of great value to characteristic diagnosis.

Adolescent↗
PubMed2001

[3D-QSAR of antiinflammatory activities of 5,6-diaryl-2,3-dihydro-1-pyrrolizinone derivatives].

AIM: To study the SARs of 5,6-diaryl-2,3-dihydrol-1-pyrrolizinone derivatives to provide information for the design of new structural compounds. METHODS AND RESULTS: Three dimensional quantitative structure-activity relationship (3D-QSAR) model was constructed by Apex-3D. CONCLUSION: The antiinflammatory activities of 5, 6-diaryl-pyrrolizinones were related to the global hydrophobicity and volume, the properties of the group at 1-position of pyrrolizinone ring and the two secondary sites; improved the pi-electronic density of the group at 1-position of pyrrolizinone ring and lowered the global hydrophobicity and the volume of p-substituent of the phenyl ring at 6-position of pyrrolizinone contributed to the antiinflammatory activities of the title compounds.

Animals↗
PubMed2001

[Studied on docking of 5,6-diaryl-2,3-dihydro-1-pyrrolizinone derivatives with cyclooxygenase].

AIM: To theoretically explore the mechanism of action of 5,6-diaryl-2, 3-dihydro-1-pyrrolizinone derivatives. METHODS: The interactions of the compound ZZ-122 with cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) were modeled by docking method. RESULTS: According to the binding pattern, intermolecular energy and capacity to form H-bond, it was easy for ZZ-122 to bind to COX-2 and not easy to COX-1. CONCLUSION: Compound ZZ-122 may be a selective COX-2 inhibitor, which has to be confirmed by experiment.

Cyclooxygenase 1↗
PubMed2000

Separation of tanshinones from Salvia miltiorrhiza Bunge by high-speed counter-current chromatography using stepwise elution.

High-speed counter-current chromatography (HSCCC) was successfully used for isolation and purification of tanshinones from the roots of Salvia miltiorrhiza Bunge by stepwise elution. A set of three solvent systems and other experimental conditions were determined by analytical HSCCC. Using the optimized conditions, the preparative HSCCC separation was performed on 50 mg of crude light petroleum extract yielding pure tanshinones of tanshinone HA (7 mg), tanshinone I (3 mg) and cryptotanshinone (4 mg) all at purities of over 95% in a single run.

Abietanes↗
PubMed2000

A role for the homeobox protein Distal-less 3 in the activation of the glycoprotein hormone alpha subunit gene in choriocarcinoma cells.

Synthesis and secretion of chorionic gonadotropin in trophoblast cells of the placenta is required for establishment of early pregnancy in primates. Chorionic gonadotropin is a heterodimeric glycoprotein hormone consisting of alpha and beta subunits. Regulation of the alpha subunit gene within the placenta requires an array of cis elements within the 5'-flanking region of the promoter. Within this array of elements, the junctional regulatory element (JRE) putatively binds a placental-specific transcription factor. The aim of our studies was to determine the identity and role of the transcriptional regulator that binds to the JRE in choriocarcinoma cells (JEG3 cells). Mutations within the JRE resulted in reduction in basal expression of an alpha subunit reporter gene, suggesting that the JRE binding factor was necessary for full basal activity. Using electrophoretic mobility shift assays, we determined that the JRE was capable of serving as a homeobox factor-binding site. The homeobox factor, Distal-less 3 (Dlx 3) was found to be expressed in JEG3 cells and in the trophoblast layer of human chorionic villus but not in a gonadotrope cell line that also expresses the alpha subunit gene. Electrophoretic mobility shift assays revealed that recombinant Dlx 3 could bind specifically to the JRE and endogenous Dlx 3 was present in JRE/JEG3 nuclear protein complexes. Overexpression of Dlx 3 resulted in activation of an alpha subunit reporter gene. A JRE mutation resulted in attenuated activation of the alpha subunit reporter via an adjacent cis element, suggesting that JRE/Dlx 3 interactions may facilitate regulation of the alpha subunit gene at sites immediately upstream of the JRE. Our studies support the conclusion that Dlx 3 is a placental-specific transcriptional regulator that binds to the JRE and contributes to expression of the alpha subunit gene in cells of trophoblast origin.

Base Sequence↗
PubMed2000

Pepstatin A-sensitive aspartic proteases in lysosome are involved in degradation of the invariant chain and antigen-processing in antigen presenting cells of mice infected with Leishmania major.

We previously reported that CA074, a specific inhibitor of cathepsin B, significantly deviated immune responses from the disease-promoting Th2 type to the protective Th1 type in BALB/c mice infected with Leishmania major. Herein, we found that pepstatin A-sensitive aspartic proteases (PSAP) in lysosomes seem to play a different role from that of cathepsin B in antigen-processing and Ii-degradation. That is, cathepsin B appears to digest 16-, 28-, and 31-kDa peptides of soluble leishmania antigen (SLA), whereas PSAP seems to process mainly 28-kDa peptides. Furthermore, the latter protease contributed to the degradation of Ii but cathepsin B did not. Following treatment with pepstatin A, both Th1 and Th2 responses were profoundly suppressed in resistant DBA/2 mice (H-2(d)) and in susceptible BALB/c mice (H-2(d)), and both strains of mice became markedly susceptible compared with the untreated groups, probably owing to failure in degradation of Ii and partly to failure in digestion of 28-kDa peptide.

Animals↗
PubMed2000

Separation of gallic acid from Cornus officinalis Sieb. et Zucc by high-speed counter-current chromatography.

Gallic acid was separated from a n-butanol extract of the fruit of Cornus officinalis Sieb. et Zucc by high-speed countercurrent chromatography in two steps using two solvent systems composed of ethyl-acetate-ethanol n-butanol-water (5:1.8:6, v/v/v) and ethyl acetate-ethanol-water (5:0.5:6, v/v/v) successively. From 1 g of n-butanol extract the method produced 60 mg of gallic acid at a purity of 97%.

Chromatography, High Pressure Liquid↗
PubMed2000

Preparative isolation and purification of notopterol and isoimperatorin from Notopterygium forbessi Boiss (Chinese traditional medicinal herb) by high-speed counter-current chromatography.

Preparative high-speed counter-current chromatography was successfully used for isolation and purification of coumarins from Chinese traditional medicinal herb Notopterygium forbessi Boiss (Qianghuo in Chinese) using stepwise elution with a pair of two-phase solvent systems composed of light petroleum-ethyl acetate-methanol-water at volume ratios of 5:5:4.8:5 and 5:5:5:4. Four major components including notopterol and isoimperatorin were isolated, each at over 98% purity.

Chromatography, Liquid↗
PubMed2000

On-line investigation of the generation of nonaqueous intermediate radical cations by electrochemistry/mass spectrometry

Anodic oxidation of triphenylamine (TPA) in acetonitrile was investigated by electrochemistry (EC) combined online with mass spectrometry (MS) through a particle beam (PB) interface, EC/PB/MS. Electrooxidation of TPA generates a TPA*+ radical cation (m/z 245) which dimerizes to tetraphenylbenzidine (TPB, MW 488). TPB is readily oxidized to TPB*+ (m/z 488) and TPB2+ (m/z 244) at the oxidation potential of TPA. In EC/PB/MS, direct monitoring of the oxidation of TPB to TPB*+ radical cation as a function of the electrode potential was achieved via selective ion monitoring of the ion peak at m/z 488. By using the relative intensity ratio of ions at m/z 244 (TPB2+) to 245 (TPA*+), the formation of TPB2+ as a function of the electrode potential was also monitored. EC/PB/MS showed a maximum rate of formation of TPB*+ at +1.2 Vvs Pd, while TPB2+ is generated at a maximum rate at +1.6 V vs Pd. The effect of spectral interference from the electron impact ionization of TPA, on EC/PB/MS results, is also discussed. Finally, a significant signal enhancement is observed in the presence of tetrabutylammonium perchlorate (TBAP) and is reported for the first time. Compatibility of coupling of EC with MS via PB interface for EC/MS studies in nonaqueous solvents is demonstrated. The observation of significant signal enhancement in the presence of TBAP may facilitate other applications of LC/MS.

Journal Article↗
PubMed2000

Mammalian homologues of yeast sec31p. An ubiquitously expressed form is localized to endoplasmic reticulum (ER) exit sites and is essential for ER-Golgi transport.

The yeast coat protein II (COPII) is responsible for vesicle budding from the endoplasmic reticulum (ER). Mammalian functional homologues for all yeast COPII components, except for Sec31p, have been reported. We have cloned a mammalian cDNA whose product (Sec31A) is about 26% identical to Saccharomyces cerevisiae Sec31p. Data base searches also revealed another partial sequence encoding a polypeptide (Sec31B) that is 40% identical to Sec31A. Northern analysis revealed that Sec31A transcripts are ubiquitously and abundantly expressed, while Sec31B transcripts are particularly enriched in the testis and thymus, but present in very low levels in other tissues. Sec31A is localized to vesicular structures that scatter throughout the cell but are concentrated at the perinuclear region. The structures marked by Sec31A contain Sec13, a component of COPII that is well characterized to mark the ER exit sites. Immunoelectron microscopy revealed that Sec31A colocalizes with Sec13 in structures with extensive vesicular-tubular profiles. Antibodies raised against a C-terminal portion of Sec31A co-precipitate Sec13 and inhibit ER-Golgi transport of temperature-arrested vesicular stomatitis G protein in a semi-intact cell assay. Cytosol immunodepleted of Sec31A failed to support vesicular stomatitis G protein transport, which can be rescued by a high molecular weight fraction of the cytosol containing both Sec31A and Sec13. We conclude that Sec31A represents a functional mammalian homologue of yeast Sec31p.

Amino Acid Sequence↗