Biomedical subjects

W Zhang

Publications and source records attributed to W Zhang.

At least 343 records · Page 19Linked to original sources

PubMed2001

[The value of color Doppler imaging ultrasound in diagnosis of orbital diseases].

OBJECTIVE: To study the useful value of color Doppler imaging (CDI) ultrasound in the diagnosis and differential diagnosis of orbital diseases. METHODS: By using the technique of CDI ultrasound, 288 cases with orbital diseases were examined to show color Doppler flow imaging and pulsed wave Doppler (PWD) spectrum. RESULTS: Among 288 cases of the orbital diseases, 38 cases of malignant tumors and 23 cases inflammatory pseudotumors showed the signals of blood flow. From CDI ultrasound examination, there were 18 in 23 cases with benign mixed tumors of the lacrimal gland showing artery blood flow and 22 in 28 cases with neurilemoma showing signals of blood flow. No blood flow was obtained in 62 among 74 cases with cavernous hemangioma, in 16 cases of dermoid cysts or epidermoid cysts and 1 case of lipoma. From CDI, rich blood flow was seen in 4 and scarce in 3 cases with meningioma, and in 6 cases of optic nerve gliomas, there were 5 cases without any blood flow signals. Other 2 cases with benign hemangioendothelioma, 2 hemangiopericytoma and 1 neurofibroma showed rich or scarce blood flow signals. Among 29 cases of venous hemangiomas, 16 cases showed venous flow. Three cases with arteriovenous aneurysms showed artery blood flow in the CDI. Fifteen cases with varicosis exhibited a dynamic blood flow changes in the CDI. Six cases with infantile hemangioma, the decreased blood supply was shown in the CDI after treatment. In the thirteen cases with carotid artery cavernous sinus fistula, including 8 cases of internal carotid artery cavernous sinus fistula (CCF) and 5 dural cavernous sinus fistula (DCF), dilated superior ophthalmic vein (SOV) with arterialized blood flow was seen. In the mean time, PWD showed that the SOV of CCF had a higher velocity and a higher flow volume than that of DCF, while its resistance index was lower than that of the DCF. In 1 case with thrombophlebitis, its SOV showed dilated superior ophthalmic vein without blood flow. CONCLUSIONS: CDI can provide the information of color blood flow in orbital diseases, especially the tumors with rich vascular tissue and orbital vascular diseases. It is important in the diagnosis and differential diagnosis of the orbital diseases in combination with B-mode ultrasound, CT or MRI.

Adolescent↗

PubMed2001

[A case-control study on the risk factors of esophageal cancer in Jieyang City of Guangdong in China].

OBJECTIVE: To study the risk factors of esophageal cancer in Jieyang city of Guangdong province. METHODS: Two hundred and fourteen cases with pathological diagnosis of esophageal cancer were recruited at Jieyang Municipal People's Hospital in 1999. Two hundred and fourteen controls were selected from healthy residents matched with sex, age and residential places (town) of the cases. All cases and controls had resided in Jieyang city for over 20 years and were studied through a uniformed questionnaire. Non-conditional logistic regression was used for multivariate analysis. RESULTS: The important risk factors were over-hot tea drinking habit (OR:1.39-3.74), fast eating (OR:1.54-4.10), animal oil (OR:3.57-42.03) and meat consumption (OR:1.36-5.05) while the protective factors were tap water (OR:0.13-0.51) drinking habil for over 20 years. Histories of smoking and family esophageal cancer were not significantly correlated with esophageal cancer. CONCLUSION: The risk factors revealed in this study were commonly exposed to the residents of Jieyang city. Most of the factors were in agreement to the results from other similar studies, but the factors of animal oil and meat were unique in this study, which called for further studies.

Case-Control Studies↗

PubMed2001

[Single topotecan or in combination with other chemotherapeutic agents for 18 recurrent advanced ovarian cancer patients].

OBJECTIVE: This study was designed to evaluate the efficacy and toxicity of topotecan hydrochloride, used singly or combined with other drugs in patients with recurrent advanced ovarian cancer. METHODS: Eighteen ovarian cancer patients who had received cytoreductive operation 1 to 3 times and 8 to 18 courses of chemotherapy but still failed in DDP-based(86.3%) and Taxol-based(32.7%) as well as combined DDP and Taxol-based(30.7%) chemotherapy, were divided into 3 groups: 1. Topotecan 1.2 mg/m2 q.d.i.v. for 5 consecutive days every 3 weeks for a total of 6 patients and 14 courses. 2. Topotecan 0.7 mg/m2 q.d.i.v. for 5 consecutive days and cis-platin 20 mg/m2 q.d.i.v. for 3 consecutive days over 4 weeks and 3. Topotecan 0.7 mg/m2 q.d.i.v. for 4 consecutive days and taxol 100 mg/m2 q.d.i.v. for one day as well as cis-platin 20 mg/m2 q.d.i.v. for 3 consecutive days totalling 12 patients and 27 courses. All together 18 courses, median 2.7 courses, were given. RESULTS: All 18 patients were evaluable. PR was achieved in 3 patients with a response rate of 16.7%. The main adverse effects were hematological toxicity, lasting for 3-27 days. Ten (55.6%) patients developed leucocytopenia Grade III-IV which occurred in 16(33.3%) courses. Six(33.3%) patients developed thrombocytopenia Grade III-IV which occurred in 8(16.7%) courses. Six(33.3%) patients developed RBC reduction Grade III which occurred in 8(16.7%) courses. Peripheral nerve inflammation was most serious in the non-hematologic toxicity. CONCLUSION: Topotecan is effective in recurrent advanced ovarian cancer patients who have failed in DDP or/and taxol-based regimes. Topotecan combined with cisplatin and taxol would be effective even if single topotecan has failed. Careful evaluation before treatment is indicated.

Adult↗

PubMed2001

[Efficacy of topical cyclosporine A on keratoplasty rejection in rats].

OBJECTIVE: To evaluate the efficacy of topical cyclosporine A (CsA) on a penetrating keratoplasty rejection model in rats. METHODS: Lou rats received orthotopic corneal allografts from inbred F344 donors. The rats were treated with one drop of topical solution four times daily for 30 days. Sixty rats were divided into one control (the matrix of CsA solution) and five treatment groups (0.5%, 1.0%, 2.0% CsA, glucocorticoid, glucocorticoid and 1.0% CsA). Rejection index (RI) and mean survival time (MST) were calculated, and histopathological and immunohistopathological examination were performed for each group. RESULTS: The graft MST was postponed by topical CsA treatment. There was significant difference between each treatment group and the control group (t greater-than-or-equal 2.28, P < 0.0l), especially 2% CsA, steroid and combined 1% CsA and steroid groups, the combined group being the most effective. The RI was lower in all the groups with topical CsA than that in the control group (P < 0.01). The effect of 2% CsA was the same as that of the steroid, while 1% CsA combined steroid was the most effective. The histopathological findings confirmed that the topical application of CsA reduced the inflammatory cells infiltrating the graft stroma and the neovascularization. Immunohistopathological analysis demonstrated that there were fewer CD(+)(11a) T cells and macrophages in the infiltration and intercellular adhesion molecule (ICAM)-1 positive cells in keratocytes and endothelium of grafts in the treatment groups than in the control group. CONCLUSIONS: Topical CsA can inhibit the keratoplasty rejection episodes in the rat and afford better results when combined with topical steroid.

Animals↗

PubMed2001

[Preparation of genetically engineered retinal pigment epithelial cells capable of secreting nerve growth factor].

OBJECTIVE: To develop genetically engineered retinal pigment epithelial (RPE) cells which are able to express bioactive nerve growth factor (NGF) steadily and efficiently and to combine gene therapy with retinal transplantation techniques to treat retinal degeneration. METHODS: Replication-deficient retrovirus-plasmid recombinant pLXSN-NGF was constructed via subclone and clone, and then packaged into pT67 cells to obtain virion containing a secretable form of NGF gene. We evaluated titer of the retroviral recombinant with NIH 3T3 cells and then transduced NGF gene into cultured RPE cells by the retroviral recombinant. We also analyzed the expression of NGF gene in transduced and untransduced RPE cells via reverse transcription (RT)-PCR and Western blot. The bioactivity of expressed NGF were evaluated by stimulating PC 12 cells with conditioned medium from transduced and untransduced RPE cells. RESULTS: The titer of replication-deficient retroviral recombinant reached 1.2 x 10(7) cfu/ml. NGF protein and mRNA were detected in the conditioned medium from transduced RPE cells, but not from the normal RPE cells. Marked neurite process outgrowth from PC 12 cells was observed after being stimulated with the conditioned medium from transduced RPE cells. CONCLUSIONS: RPE cells are able to be transduced by replication-deficient retrovirus with high efficiency, and secret bioactive NGF at a high level, which might be an ideal candidate for engineered cells.

3T3 Cells↗

PubMed2001

[An experimental study on subconjunctival interleukin-1 receptor antagonist for promotion of corneal transplant survival].

OBJECTIVE: To determine whether the subconjunctival application of interleukin-1 receptor antagonist (IL-1ra) can prolong the corneal graft survival in the rat model of orthotopic penetrating keratoplasty. METHODS: For all experiments, F344 corneas were transplanted into LOU (major histocompatibility-disparate) eyes. Experimental groups received subconjunctival injection of 50, 100 and 200 microg IL-1ra respectively, and the control group received the same volume of 0.9% normal saline instead for consecutive 2 weeks. All transplants were evaluated for 4 weeks after surgery for signs of rejection. RESULTS: The mean survival time (MST) of the grafts of the experimental groups was increased significantly (t = 0.00, P < 0.01) in comparison with the control group. The MST of the IL-1ra 200 microg group was increased significantly than that of the IL-1ra 50 microg group (t = 0.00, P < 0.01). Furthermore, the IL-1ra-treated grafts had significantly less corneal inflammation, infiltration, lower levels of opacity, edema, neovascularization and rejection index compared with the control group. CONCLUSIONS: Subconjunctival treatment of IL-1ra has a significantly positive effect on promoting corneal allograft survival. And its effect is dosage-dependent.

Animals↗

PubMed2001

[Phacoemulsification of the subluxated lens with cataract].

OBJECTIVE: To study the efficiency of phacoemulsification in the treatment of subluxated lens with cataract. METHOD: Phacoemulsification combined with intraocular lens implantation was performed on 19 eyes of 18 patients. RESULT: The visual acuity in 18 eyes was improved to different degrees. The visual acuity in one eye was not improved due to the preoperative macular contusion. CONCLUSION: Phacoemulsification for treatment of subluxated lens with cataract may decrease many complications occurring in the past procedure.

Adult↗

PubMed2001

[The relationship of clinicopathology and immunophenotypes in non-Hodgkin's lymphomas of the spleen].

OBJECTIVE: To investigate the relationship between clinicopathologic features and immunophenotypes in non-Hodgkin's lymphoma (NHL) of the spleen. METHODS: Clinicopathologic analysis and follow up; immunohistologic staining by SP method and EBER in situ hybridization. RESULTS: (1) Splenomegaly was found in all 19 cases of spleen NHL, 10 of the 19 (52.6%) cases had masses or a mass in their enlarged spleen; (2) 14 of the 19 (73.7%) cases were of B-cell type (including 5 cases of follicular type and 9 cases of diffuse type), in which 8 cases were centroblastic, 3 of centroblast/centrocyte and 4 cases of small lymphocyte types; all 10 cases of primary splenic lymphomas (PSL) were B-cell type; (3) 5 of the 19 cases (26.3%) had peripheral T-cell origin, including 4 cases of large cell type and 1 case of small cell type; of the 3 TIA-1 positive cases, 2 were also positive for EBER 1/2 (one CD 8+ and another CD56+), the remaining case was CD8-, CD56-, EBER1/2-; all 5 cases were secondary NHL of the spleen; (4) Follow up data were obtained for 14/19 cases (73.7%). 8 of 9 surviving cases were primary NHL. The range of survival period varied from 8 to 10 years. All 5 deceased cases had secondary NHL and their survival period was 2 to 6 months. CONCLUSIONS: Some relationship exists between the clinicopathology and origin of the tumor cells in splenic NHL, the prognosis of primary NHL is better than that of the secondary NHL and the diagnosis of primary NHL should be made with discretion.

Adolescent↗

PubMed2001

[A clinicopathologic study on 9 cases of epithelioid hemangioendothelioma].

OBJECTIVE: To study the clinicopathological features of epithelioid (histiocytoid) hemangioendothelioma (EHE). METHODS: 9 cases of EHE were examined by light microscopy and immunohistochemistry, 1 case with ultrastructural observation. RESULTS: The patients' age ranged from 16 to 47 years (mean 32 years). The lesions occurred in both sexes and presented at a variety of sites including head and facial area (4 cases), upper limbs (3 cases) and lower limbs (2 cases). The morphological characters were: (1) "epithelioid" or "histiocytoid" tumor cells; (2) rounded or polygonal tumor cells arranged in nests, cords and irregular patterns; (3) the tumor cells were embedded in myxoid or hyaline matrix; (4) primitive lumen formation within a single tumor cell (intracytoplasmic lumens); (5) lack of pleomorphism, mitotic activity and necrosis; (6) presence of spindle cell hemangioendothelioma in some cases; (7) osteoclast like giant cells scattered throughout the entire lesion were observed in one case. Immunohistochemistry studies on 7 cases found that tumor cells were positive for vimentin (7/7), factor VIII-RAg (5/7), CD31 (5/7), CD34 (5/7), cytokeratin (2/7), CD68 and alpha-AT (1/7). Ultrastructural study of 1 case demonstrated Weibel-Palade bodies and an abundance of intermediate filaments in the cytoplasm. The follow-up of 6 cases found that 3 cases developed local recurrences but none of them metastasized. CONCLUSIONS: EHE is a distinctive low-grade sarcoma whose etiology remains unknown. Recognizing its morphological characters is important to avoid confusion with other similar lesions.

Adolescent↗

PubMed2001

[Study on expression of caspase-3 and bcl-2 proteins and their relations with cell apoptosis and proliferation in non-Hodgkin's lymphoma].

OBJECTIVE: To explore the possible roles of caspase-3 and bcl-2 proteins in the development and progression of non-Hodgkin's lymphoma (NHL) and their relationship. METHODS: TdT-mediated dUTP nick end labeling (TUNEL) and immunohistochemistry were used to study cell apoptosis and expression of proliferating cell nuclear antigen (PCNA), caspase-3 and bcl-2 in 119 NHL cases. RESULTS: The caspase-3 and bcl-2 positive rates were 86.6% (103/119) and 53.8% (64/119) respectively. Contrasting expression of these two proteins were found in reactive and malignant lymphoid tissues: In reactive lymphoid follicles, caspases-3 exhibited strong immunoactivity in cells located in germinal centers but not in mantle zone lymphocytes, whereas bcl-2 exhibited strong immunoactivity in mantle zone lymphocytes but not in cells located in germinal centers, and in neoplastic follicles, caspase-3 was negatively or weakly expressed, whereas bcl-2 was often positively expressed. In B cell lymphomas, the high grade group had a higher caspase-3 immunointensity and a lower bcl-2 immunointensity than the low grade group (P < 0.01). Apoptotic index correlated positively with expression of caspase-3 (r = 0.512, P < 0.01) and inversely with expression of bcl-2 (r = -0.436, P < 0.01). In addition, apoptotic index and proliferative index were positively related (r = 0.710, P < 0.01). CONCLUSIONS: caspase-3 may participate in the regulation mechanism of lymphoma cell apoptosis. The contrasting expression of caspase-3 and bcl-2 is often seen in reactive and malignant lymphoid tissues, and it may indicate a close relationship between these two proteins in the regulation of lymphocyte proliferation kinetics.

Adolescent↗

PubMed2001

[Study on the correlation between the expression of protein p53 at stage III nasopharyngeal carcinoma and its biological behavior, prognosis, p53 gene mutation and the expression of LMP-1].

OBJECTIVE: To investigate p53 protein expression at stage III nasopharyngeal differentiated non-keratinizing squamous carcinoma (DNKSC) and their correlation with biological behavior and prognosis;the relationship between p53 protein expression and p53 gene mutation and LMP-1 protein expression at 58 cases of stage III DNKSC. METHODS: Immunohistochemistry (Envision) was applied to detect p53 protein and LMP-1 protein expression. Non-isotopic PCR-SSCP was used to detect p53 gene mutation. RESULTS: The p53 protein expression showed general positive rates of 65.5% (38/58) in the patients with nasopharyngeal DNKSC, being significantly higher in the group surviving less than 5 years 82.1% (32/39) than in the group surviving longer than 5 years 31.6% (6/19) (P < 0.05). Besides, it was closely correlated with the local invasion to the cranial base, there was a significant difference between invasion 74.4% (29/39) and non-invasion 47.4% (9/19) (P < 0.05). The expression of LMP-1 protein rated 72.4% (42/58), exhibiting a positive correlation with the expression of p53 protein (r = 0.504). The p53 gene mutation was found in none of the cases (0/15). CONCLUSIONS: In stage III nasopharyngeal DNKSC, the expression of p53 protein is not related to p53 gene mutation, whereas it relates to the expression of LMP-1 protein. Declined expression of p53 protein is closely related to the time of survival, and the p53 protein expression is higher in the invasive carcinoma.

Carcinoma, Squamous Cell↗

PubMed2001

[Establishment of detective systems for GL-7ACA acylase expression].

Glutaryl-7-amino cephalosporanic acid (GL-7ACA) acylase catalyzes the conversion of GL-7ACA to 7-amino cephalosporanic acid (7-ACA). The product 7-ACA is a starting compound for semi-synthetic cephalosporin antibiotics in industry. In order to detect the expression and specific activity of protein-engineered GL-7ACA acylase accurately, two useful detective systems for its expression has been established, in which reporter genes xylE and lacZ were fused to the downstream the GL-7ACA acylase gene acy respectively and the activity of catechol dioxygenase or beta-galactosidase could indicate the amount of acy expression.

Catechol 2,3-Dioxygenase↗

PubMed2001

[Restaging laparotomy of presumed early ovarian cancer].

OBJECTIVE: To assess the value and complications of restaging laparotomy in women with presumed early ovarian cancer who have undergone inadequate initial staging procedures. METHODS: Between 1986 and 1996, 42 patients underwent restaging laparotomy in Cancer Hospital, Peking Union Medical College after receiving inadequate initial surgical procedure for presumed early ovarian cancer. Presumed stages from initial surgery include stage I a in 28 cases; I b in 1 case; I c in 12 cases; II a in 1 case. Histological distributions were as follows: epithelial cancer in 26 cases; malignant germ cell tumor in 9 cases; granulose cell tumor in 7 cases. RESULTS: Twelve patients (28.6%) had disease upstaged and eight (19.0%) had stage III disease confirmed by restaging laparotomy. Positive findings at restaging laparotomy were mainly in omentum (16.7%) and pericolic gutters (33.3%). Peritoneal cytology was positive in 25.0 percent of patients. Three and five year survival rates for 30 patients with negative findings were 96.7% and 86.7%, respectively. Complications of restaging laparotomy included hemorrhage blood loss (50-1,100 ml, average 280 ml) and lymphocyst (7.1%). CONCLUSIONS: Patients with presumed early ovarian cancer who had undergone inadequate staging procedures should undergo restaging laparotomy. Patients with negative findings have an excellent prognosis. Complications of restaging laparotomy were minor.

Adult↗

PubMed2001

[Analysis of the nucleotide sequence for C and NS5 regions and the genotype of HCV isolate in Shandong Province].

OBJECTIVE: To study the genotype of HCV epidemic strains in Shandong Province. METHODS: HCV fragments of C(432 bp) and NS5(319 bp) regions were amplified by RT nested PCR. The fragments were cloned to T vector and sequenced by dideoxynucleotide chain termination reaction. RESULTS: Three of all 4 strains in C region were 1b genotype, and 1 was 2a. All of 10 strains of NS5 region were 1b genotype. No other genotype was found in this region. The homology of nucleotide sequence was over 90% compared with that of more than 50 strains in Gen Bank. CONCLUSIONS: The major genotype of HCV epidemic strains in Shandong Province is 1b. The 2a genotype is also found in this area.

Genotype↗

PubMed2001

[Measurement of distortion product otoacoustic emissions in guinea pig].

OBJECTIVE: To establish a stable detecting method of distortion product otoacoustic emissions (DPOAEs). METHOD: After cutting off tragus, seven healthy pigmented guinea pigs (thirteen ears) were selected to measure the DPOAEs at the frequency of 2f1-f2 (cubic DPOAEs). The I/O function and latency at f2 = 2, 4, 6 kHz were analyzed. RESULT: The incidence of DPOAEs at all frequencies was 100%. The maximal amplitude of input-output function was (27.24 +/- 4.15) dB SPL, (27.98 +/- 4.05) dB SPL and (41.45 +/- 1.20) dB SPL respectively; latency was (2.06 +/- 0.21) ms, (1.52 +/- 0.16) ms and (1.37 +/- 0.08) ms at the corresponding frequencies. CONCLUSION: After the improvement of detection, it is satisfactory to measuring DPOAE in animals because of the high incidence, high amplitude and good repetition.

Animals↗

PubMed2001

[The detection of phenol degrading strain in environment with specific primer of phenol hydroxylase gene].

A 684 bp oligonucleotide fragment was produced by PCR amplification from phenol-degrading strain Acinetobacter calcoaceticus PHEA-2 with the specific primers of gene encoding phenol hydroxylase. The nucleotide sequence of this fragment and its deduced amino acid sequence share 84% and 98% homology with the phenol hydroxylase gene and its deduced amino acid sequences of phenol-degrading strain Acinetobacter calcoaceticus NCIB8250. Sets of different aromatic compounds degrading strains were used to test this specific prime. The 684 bp-fragments were amplified only from phenol-degrading strains by PCR. When using this pair of primers to detect the bacterial isolates from wastewater discharged from coking plant, all the tested strains, which possess 684 bp characteristic fragment, showed the ability to degrade phenol in this study.

Acinetobacter calcoaceticus↗

PubMed2001

[Study on the Apriona germari(Hope) larvae's intestinal bacterial flora].

Intestinal flora of 47 Apriona germari(Hope) larvae, collected from fields, had been isolated and identified. The results showed that the predominant bacteria were Staphylococcus. Its viable count was 7.63 +/- 0.21, and the detection rate was 100%. Meanwhile, a strain of cellulose-utilizing bacterium was isolated from the fore-midgut fluid of A. germari larvae with the cellulose-congo red agar medium. The bacterium was tentatively identified as Cellulomonas. The detection rate of the cellulolytic bacterium was 23.40%, and the count was 3.84 +/- 0.54 approximately. Its contribution to the borer's cellulose digestion needs further investigations.

Animals↗

PubMed2001

[Advances on the biological effect indices for fine particles (PM2.5) in air].

Fine particles are complex mixture of air pollutants containing not only a great deal of organic compounds but also varied kind of metals, such as B(a)p, Pb, Cd, Cr etc. Most of those compounds are toxic. Some of them are the cause of lung inflammation and asthma, some are genotoxic with a potential of carcinogenesis. Because the fine particles can be inhaled into lung and deposit in lung tissue, which have adverse effects on human health. Epidemiological studies indicated that increased mortality and morbidity, especially for cardiovascular and lung diseases, was associated with the amount of ambient fine particles. Although some scientists thought fine particles damaging the body through oxidant stress, inflammation and genetic materials and so on, the mechanism for them is not known well. Therefore, it is necessary to explore the biological effects of fine particle on human health in the future.

Air Pollutants↗