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Biomedical subjects

Z Tian

Publications and source records attributed to Z Tian.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Functional improvement of remnant stomach after proximal subtotal gastrectomy for cardiac cancer].

OBJECTIVE: To evaluate the function of the remnant stomach after proximal subtotal gastrectomy for cardiac cancer and to improve the life quality of post-surgical patients. METHODS: 17 patients with cardiac cancer underwent proximal subtotal gastrectomy combined with disconnection of pyloric sphincter (PSG + DPS) by finger pressing. Intraoperative pyloric manometric studies were performed in the 17 patients before and after DPS. Five subjects who underwent laparotomy for non-esophagogastric reasons was taken as controls. Total bile acids (TBA) in gastric juice was tested in the 17 patients at 5th postoperative day, and radionuclide gastric emptying was also studied from the 18th to 20st postoperative day. RESULTS: Both pyloric resting pressure and pyloric contracting pressure were significantly decreased after DPS (P > 0.01). In comparison with normal subjects, PCP was increased before DPS (P > 0.01) and decreased after the procedure (P < 0.05). However, PRP did not show significant differences before (P > 0.05) and after (P > 0.05) DPS. There were no significant differences regarding TBA content in gastric juice in PSG + DPS group, PSG group, and normal subjects (P > 0.05). The time required for the stomach to empty half of its radioactive contents (T1/2) was longer in the patients having PSG only than those undergoing PSG + DPS (P < 0.01) and normal controls (P < 0.05). However, there were no significant differences regarding T1/2 between the patients with PSG + DPS and normal controls (P > 0.05). CONCLUSIONS: The emptying of remnant stomach after subtotal gastrectomy for cardiac cancer is delayed because of the increase of emptying-resistance and decrease of peristalsis. PSG combined with DPS not only improves gastric emptying, but also prevents duodenogastric reflux. Consequently, postoperative life quality of the patients with cardiac cancer can be effectively improved.

Aged↗
PubMed1999

[Left ventricular function evaluation after mitral valve replacement with preservation the subvalvular apparatus].

The objective of this study was to evaluate the left ventricular function after mitral valve replacement (MVR) with preservation of all chordae. Fourteen patients with a diagnosis of mitral regurgitation were studied. These patients, 4 males and 10 females, age from 24 to 59 years, who underwent mitral valve replacement, in which all chordae tendineae were preserved. The mean follow-up interval was 6 months. Preoperation and postoperation multigated equilibrium radionuclide angiography was performed by Elscint Helix Apex SPECT. Each patient was injected with 740MBq 99mTc-HSA, rest ejection fraction (global EF) of LV (%), regional ejection fraction (EF) of LV (%), PER/S and PFR/S were measured. Regional EF was calculated by the method of dividing the left ventricle into five segments by radial axis. The results showed that the postoperative EF of the whole left ventricle of the chordae-preserved patients was significantly greater than their preoperative EF (40.0% +/- 17.8%, to 51.6% +/- 18.2%, P < 0.02), and also the regional EF at the lateral wall of the chordae-preserved MVR was significantly greater than the preoperative regional EF (an increase from 51.0% +/- 18.1% to 69.7% +/- 21.2%, P < 0.01). MVR with preservation of all chordae, the patient's left ventricular function remarkably improved.

Adult↗
PubMed1999

[Immunohistochemical study of basement membrane proteins expression in adenoid cystic carcinoma of salivary glands].

OBJECTIVE: To investigate the expression of the basement membrane proteins in adenoid cystic carcinoma (ACC) of the salivary glands and discuss the relationship between the expression of the proteins and the differentiation as well the prognosis of ACC. METHODS: 101 patients which were confirmed pathologically were collected and made a follow-up, and 30 cases of them were selected to detect the basement membrane proteins (type IV collagen, fibronectin, laminin and heparan sulfate proteoglycan) by the means of immunohistochemistry. RESULTS: The cribriform pattern of ACC had a more favorable prognosis than the solid pattern which had a lower rates of metastasis of/and recurrence. The positive locations and the degrees of the four proteins varied with the histological patterns of ACC. The cribriform pattern had the strongest positive expression and the solid pattern the weakest. In addition, the staining of fibronectin were weaker in all three patterns of ACC. CONCLUSION: The degree of the positive expression of the four proteins has a negative relation to the differentiation of the tumor cells. The lower degree of differentiation the tumor cells are, the weaker positive signals they express. Of the four substances in the basement membrane, laminin is the main material which adhere the parenchymal cell to the collagen in basement membrane of the tumor. Basement membrane proteins could be regarded as one of the basis to evaluate the prognosis of ACC.

Basement Membrane↗
PubMed1999

[Study of bacterial adhesion to prosthetic valve materials in vitro].

This article reports a study of the bacterial adhesion to prosthetic valve materials in vitro. The method for assessing the degree of bacterial adhesion to prosthetic valve materials was established primarily. The capacities of staphylococcus aureus(SA), staphylococcus epidermidis(SE), Escherichia Coli(EC) and Pseudomonas aeruginosa(PA) for adhesion to Dacron, Pyrolytic carbon and polytetrofluoroethylene (PTFE) were quantitatively determined by the plate counting and Gamma-ray counting of 125I radiolabeled bacteria in vitro. The results showed that the capacities of four types of bacteria for adhesion to Dacron, Pyrolytic carbon and PTFE coincided with the bacterial-growth curve. The capacities of four bacteria for adhering to Dacron were stronger. The adhesion of SE to Pyrolytic carbon was the strongest. The adhesion of PA Kept up a high level. The capacities of EC and PA for adhering to PTFE were the strongest. The results indicate that the capacities of different types of bacteria for adhesion to the same prosthetic valve material are different, and the capacities of one type of bacteria for adhesion to different materials are also different.

Bacterial Adhesion↗
PubMed1999

[The expression of E-cadherin-catenin complex in human salivary adenoid cystic carcinoma]

OBJECTIVE: The aim of this study was to investigate the expression of the E-cadherin-catenin(E-cad-cat) complex in human salivary adenoid cystic carcinoma(ACC) and determine the effects of E-cad-cat expression on tumor differentiation,metastasis and invasion as well as their clinical significance. METHODS:The expression of adhesion molecules,which included E-cadherin,alpha-catenin and beta-catenin,in 10 cases of normal salivary glands,50 cases of human salivary ACC was investigated by immunohistochemistry.RESULT:Co-expression of E-cadherin,alpha-catenin and beta-catenin was detected in 29(58%) of the 50 ACC specimens.Positive staining of E-cad-cat complex was detected in 7(39%) of the 18 ACC primary sites which had aggressive phenotype of nerve and vasculature.CONCLUSION:Strong positive signals of E-cad-cat complex were showed in normal salivary glands,and the down regulation expression was observed in ACC cases,The expression of E-cad-cat complex was associated with a more aggressive phenotype on nerve and vasculature.No association with various histopathologic subtypes was found;Down-regulation of E-cad-cat complex may be associated with canceration of normal salivary glands.

Journal Article↗
PubMed1999

[Expression of p53 protein and PCNA in premalignant lesions of oral mucosa and its clinical significance]

OBJECTIVE:The study was to investigate the expression features of p53 protein and PCNA antigens in premalignant lesions of oral mucosa and further to discuss its clinical significance.METHODS: 50 samples were retrieved from the biopsy of the patients with suspicious premalignancy.Followed by the diagnosis pathologically,the sections were labeled with p53 and PCNA antigens by immunohistochemistry. RESULTS: In premalignant lesions,the progression staining with p53 and PCNA antigens were positively corresponding to the epithelial dysplasia from the basal layer to the keratinous layer. CONCLUSION: The p53 and PCNA antigens expressed synchronously in premalignant lesions of oral mucosa and exhibited direct correlation with the degree of epithelial dysplasia;The positive signals with p53 and PCNA antigens in the premalignant lesions may be the earlier incidence in carcinogenesis, which may initiated at the earlier stage of epithelial dysplasia.This phenomenon is deserving of clinicians' attention for discovering the premalignant lesions earlier;The detection of p53 and PCNA antigens would be helpful to find out the lesion which has the tendency turning to dysplasia.

Journal Article↗
PubMed1999

[Transmission grating spectrograph for soft X-ray spectrum measurements with a pre-optics].

A novel diffraction spectroscopic instrument consisting of a large area transmission grating and a grazing-incidence pre-optics comprising of a toroidal mirror, a slit and a cylindrical mirror has been implemented. A nearly perfect stigmatism and a medium spectral resolution are due to the separation of the focusing and dispersing function. The experimental results show that it is possible to construct large area transmission grating spectrograph with high collecting efficiency and good spatial resolution.

English Abstract↗
PubMed1998

CT-guided stereotactic biopsy of deep brain lesions: report of 310 cases.

OBJECTIVE: To evaluate the accuracy of CT-guided stereotactic biopsy in making correct pathological diagnosis and choosing corresponding management of brain tumors. METHODS: From 1991 to 1995, CT-guided stereotactic biopsy was performed in 310 patients with intracerebral lesions which were deep-seated or located in certain main functional areas. The patients were 198 men and 112 women. Their ages ranged from 4.5 to 70 years (average: 39.3 years). The lesions were located in the deep cerebrum (74 patients), the sellar area (62), the basal ganglion (51), the posterior part of the third ventricle (38), other intraventricleular area (21), the cerebellum (17) and the brain stem (9), and intracranial multiple lesions were found in 38 patients. RESULTS: Brain tumors were diagnosed pathologically in 266 patients (85.8%); inflammatory process in 25 (8.1%), other lesions in 8 (2.6%) and uncertain cases were 11 (3.6%). The overall positive rate of biopsy was 96.4% and the positive rate for brain tumor was 85.8%. Intracranial hematomas after biopsy were found in 5 patients (1.6%). There were no deaths induced by the biopsy or other serious complications. CONCLUSIONS: The results suggest that CT-guided stereotactic biopsy is a reliable method for histopathological diagnosis of brain tumors and it is also of great help in selecting appropriate management.

Adolescent↗
PubMed1998

[Effect of ischemia/reperfusion in cardiac surgery with cardiopulmonary bypass on nitric oxide levels of peripheral blood in patients].

To examine the effect of ischemia/reperfusion in cardiac surgery with cardiopulmonary bypass (CPB) on nitric oxide (NO) levels of peripheral blood, venous levels of NO2- and NO3- were measured at multiple time-points before, during, and after CPB by means of high-pressure liquid chromatograph to reflect NO concentration indirectly in 20 patients. The results showed there was a linear regression between the decreased trend of NO release at the period of peri-CPB is related to the endothelial cell activation caused by ischemia/reperfusion at the same time. Therefore it is necessary to explore the regulation and action of NO release during systemic inflammatory response procedure in CPB.

Adult↗
PubMed1998

[The predominant expression of Th2 type cytokines in human tumor cells].

OBJECTIVE: To observe the expression of Th1 versus Th2 type cytokines in human tumor cells. METHODS: The gene expression of Th1/Th2 cytokines in human tumor cells was detected by RT-PCR and RNA dot hybridization using IL-2 and IFN gamma as Th1 type cytokine genes, IL-4, IL-10 and IL-13 as Th2 type cytokine genes. RESULTS: There were predominant expressions of Th2 type cytokines in 20 different human tumor cell lines including 11 solid tumor and 9 hematogenous tumor cells. CONCLUSION: Predominant expression of Th2 type cytokines by tumor cells may be related to the evasion of tumor cells from immune surveillance.

Breast Neoplasms↗
PubMed1998

[Multiple subpial transection in surgical treatment of intractable epilepsy].

OBJECTIVE: To increase the effect of epilepsy surgery, we use multiple subpial transection (MST) clinically on the basis of experimental study. METHOD: We analyzed the seizure type and course of 116 intractable epilepsy patients treated with MST and surgical technique were modified. RESULT: 100 patients were followed up for 1 to 5 years. Complete control of seizure was obtained in 62 patients (62%), significant reduction (over 75%) in 20 (20%), reduction (over 50%) in 12 (12%), and no change in 6 (6%). The total effective rate was 94%, and the significant effective rate was 82%. No functional defect was found in any patients. CONCLUSION: MST is a effective in surgical treatment of intractable epilepsy and can replace conventional methods. Combined bilateral frontal lobe MST and anterior callosotomy is a good way to treat intractable generalized epilepsy.

Adolescent↗
PubMed1997

Antitumor effects of nonconjugated murine Lym-2 and human-mouse chimeric CLL-1 monoclonal antibodies against various human lymphoma cell lines in vitro and in vivo.

Lym-2 is a murine monoclonal antibody (MoAb) directed towards a human class II molecule variant reactive with both normal and neoplastic human B lymphocytes. Previous studies have shown that signals transmitted by class II molecules that stimulate normal lymphocytes can be inhibitory for B-cell lymphoma growth by signaling activation-induced cell death. Therefore, we sought to evaluate the effects of nonconjugated murine Lym-2 and a human-mouse chimeric Lym-2 (chCLL-1; with murine variable regions and human constant regions) MoAb on the growth of various human lymphomas by using both in vitro and in vivo assays. Cell lines derived from Burkitt's lymphomas, diffuse large cell B-cell lymphomas, anaplastic large-cell lymphomas, and Epstein-Barr virus-induced B-cell lymphomas were incubated with Lym-2 or chCLL-1 in vitro, and effects on proliferation were determined by [3H]-thymidine incorporation. The effects of Lym-2 in vitro were also compared with those of Lym-1, which is a similar MoAb that has been evaluated clinically. After immobilization, which enhances crosslinking of the MoAbs, both Lym-2 and chCLL-1 were capable of directly inhibiting the growth of various lymphoma lines in vitro. These human lymphomas were then transferred into mice with severe combined immunodeficiency to evaluate the efficacy of these MoAbs in vivo. Treatment with either murine Lym-2 or the chimeric chCLL-1 were significantly effective in improving the survival of tumor-bearing mice. These results indicate that stimulation by nonconjugated chCLL-1 may offer a biological approach to the treatment of various human lymphomas.

Animals↗
PubMed1997

[Colony-stimulating activities of serum from patients with severe aplastic anemia].

OBJECTIVE: To investigate the correlation between colony-stimulating activities of serum from patients with severe aplastic anemia (SAA) and their responses to immunosuppressive therapy (IST). METHODS: In vitro effects of sera from SAA patients before and after IST and from normal subjects on human marrow colony growth were examined in a semisolid methylcellulose culture system for burst promoting activity (BPA) and granulocyte/macrophage colony-stimulating activity (GM-CSA). Serum erythropoietin (Epo) level was also measured by ELISA method before and after IST in SAA patients. RESULTS: Serum BPAs in SAA patients at diagnosis were significantly higher than that in normal controls (P<0.001), but serum GM-CSAs in 13 of 22 SAA patients were normal,and in 9 of 22 extremely low as compared with normal values. After IST, serum BPA and GM-CSA in SAA patients had no changes. Serum Epo levels in SAA patients at diagnosis were significantly higher than that in normal controls (P<0.001). After IST,serum Epo levels declined in responded patients, while further increased in nonresponded. CONCLUSION: Serum GM-CSA of SAA patients was a predictive factor for responsiveness to IST, and a normal value was associated with a good response.

Anemia, Aplastic↗
PubMed1997

[HLA-DR-positive T lymphocytes in the bone marrow and peripheral blood of patients with severe aplastic anemia and their in vitro inhibitory effecton BFU-E and CFU-GM].

OBJECTIVE: [corrected] To elucidate the role of immunodysfunction in the pathogenesis of severe aplastic anemia (SAA). METHODS: HLA-DR+ T cells were detected in bone marrow (BM) and peripheral blood (PB) of 20 SAA patients and controls (9 for BM and 11 for PB). PHA-LYCM conditioned medium was prepared, and its in vitro effect on normal bone marrow BFU-E and CFU-GM was studied. RESULTS: The percentages of HLA-DR+ T lymphocytes in BM and PB of newly diagnosed SAA patients were significantly higher than that of controls (P<0.001), and that of recovered SAA (rSAA) patients after ALG therapy (P<0.05). Compared with controls, the PBA-LYCMs from newly diagnosed SAA patients showed significant inhibitory effect on normal BFU-E and CFU-GM (P<0.001). CONCLUSION: The activated T lymphocyte may play an important role in the pathogenesis of SAA.

Adolescent↗
PubMed1997

[Colony formation of bone marrow hematopoietic progenitor cells in patients with severe aplastic anemia and its relation to the results of immunosuppressive therapy].

OBJECTIVE: To explore the defect of hematopoietic stem cell and analyze the relationship between the colony formation capacity of bone marrow hematopoietic progenitor cells and the results of immunosuppressive therapy (IST) in severe aplastic anemia (SAA) patients. METHODS: Methylcellulose semisolid culture was used. RESULTS: Thirty patients with SAA at diagnosis were studied. In 90% of the patients, the CFU-E and CFU-GM yields were strikingly decreased and in 56.7% of the patients there was no colony formation at all. Nevertheless, there was still 10% of the patients having normal CFU-E, BFU-E or/ and CFU-GM yields. After IST, 59.1% of the patients showed colony formation improvement. The difference between the results obtained pre- and post-IST(for CFU-E and BFU-E, P < 0.01, for CFU-GM, P < 0.05) was significant. In the majority of the patients, the colony formation capacities were still under the normal post-IST. Moreover, 22.7% of the patients remained no colony formation post-IST. The IST response rates between the patients with or without colony formation had no statistically difference (80% versus 50%, P < 0.05). The increment of colony formation appeared later than the therapeutic effect did, but frequently concurred with the appearance of magkaryocytes in the bone marrow smear. CONCLUSION: In the majority of SAA patients, the hematopoietic stem cells or progenitors were defective perhaps caused by immune damage; IST can improve the hematopoiesis in vitro and in vivo of SAA patients.

Adolescent↗
PubMed1997

[SERS and electrochemistry studies on the structure of thiourea adsorption layer on silver electrode].

The structure of thiourea adsorption layer on silver electrode was studied by SERS and electrochemistry. It was found that the thiourea can be adsorbed on the electrode surface and can inhibit the reaction of hydrogen separation. And a change in structure of the thiourea adsorption layer on electrode surface took place at the voltage of about -0.6V. The further SERS experiment showed that the thiourea adsorption layer has a loose structure at about -0.9V and a compact structure at about -0.3V - -0.5V. The transition region is at about -0.6V - -0.8V.

English Abstract↗
PubMed1997

Chemical modification and structure-activity relationships of pyripyropenes. 3. Synthetic conversion of pyridine-pyrone moiety.

Structure-activity relationships of the pyridine-pyrone moiety in pyripyropene A (1), a potent acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor of fungal origin, were studied. Several kinds of aromatic or hetero ring substituents for the pyridine moiety were synthesized using unique degradation reaction, following by gamma-acylation. All the six synthesized analogs decreased the inhibitory activity with 20 to 200 times larger IC50 values than that of 1. Furthermore, the pyridine-pyrone substituent also dramatically decrease the inhibitory activity. Thus, the pyridine-pyrone moiety is important for eliciting potent ACAT inhibition.

Enzyme Inhibitors↗