Biomedical subjects

Zhen Zhang

Publications and source records attributed to Zhen Zhang.

115 records · Page 7Linked to original sources

PubMed2002

[GATA-3 in the development of anterior chamber associated immune deviation].

OBJECTIVE: To determine the role of GATA-3 (a transcript factor that has influences on Th2 cell differentiation) in the development of anterior chamber associated immune deviation (ACAID). METHOD: Immunohistochemistry and Western blot were used to determine the localization and relative protein levels of GATA-3 respectively at different time points after anterior chamber injection of 50 microgram interphotoreceptor retinoid binding protein (IRBP). RESULT: GATA-3 was detected weakly in normal spleen and increased significantly at 5, 7, 14 and 21 days after anterior chamber inoculation. It was detected mainly in CD(4)(+) T cells in spleen. CONCLUSION: The expression of GATA-3 increases earlier than development of ACAID. It suggests that GATA-3 play an important role in Th2 commitment during ACAID development.

Animals↗

PubMed2002

Proteomics and bioinformatics approaches for identification of serum biomarkers to detect breast cancer.

BACKGROUND: Surface-enhanced laser desorption/ionization (SELDI) is an affinity-based mass spectrometric method in which proteins of interest are selectively adsorbed to a chemically modified surface on a biochip, whereas impurities are removed by washing with buffer. This technology allows sensitive and high-throughput protein profiling of complex biological specimens. METHODS: We screened for potential tumor biomarkers in 169 serum samples, including samples from a cancer group of 103 breast cancer patients at different clinical stages [stage 0 (n = 4), stage I (n = 38), stage II (n = 37), and stage III (n = 24)], from a control group of 41 healthy women, and from 25 patients with benign breast diseases. Diluted serum samples were applied to immobilized metal affinity capture Ciphergen ProteinChip Arrays previously activated with Ni2+. Proteins bound to the chelated metal were analyzed on a ProteinChip Reader Model PBS II. Complex protein profiles of different diagnostic groups were compared and analyzed using the ProPeak software package. RESULTS: A panel of three biomarkers was selected based on their collective contribution to the optimal separation between stage 0-I breast cancer patients and noncancer controls. The same separation was observed using independent test data from stage II-III breast cancer patients. Bootstrap cross-validation demonstrated that a sensitivity of 93% for all cancer patients and a specificity of 91% for all controls were achieved by a composite index derived by multivariate logistic regression using the three selected biomarkers. CONCLUSIONS: Proteomics approaches such as SELDI mass spectrometry, in conjunction with bioinformatics tools, could greatly facilitate the discovery of new and better biomarkers. The high sensitivity and specificity achieved by the combined use of the selected biomarkers show great potential for the early detection of breast cancer.

Adult↗

PubMed2002

[Echocardiographical features during the rejection free period after heart transplantation: report of one case].

OBJECTIVE: To study the echocardiographic features during the period free of acute allograft rejection after heart transplantation by monitoring one patient within one year after heart transplantation. METHODS: The dimension of atrial and ventricular, interventricular septal and ventricular wall thickness, blood flow pattern through the mitral and tricuspid valves, left ventricular muscle weight (LVMW) and LVMW index during different periods were measured by echocardiography, and all these data were compared with those of the donor before operation. RESULTS: The patient recovered well without any signs of acute rejection. Echocardiography revealed that the dimension of right atrial, left and right ventriculars decreased significantly while left atrial showed significant increase, with obvious increase in the interventricular septal and ventricular wall thickness. LVMW and LVMW index were also significantly increased. The peaks E-and A.wave velocifies of the mitral and tricuspid E peak flow velocity decreased significantly, while the A peak flow velocity of the tricuspid did not undergo any significant changes. Mitral back flow occurred 4 months after the operation and tricuspid back flow persisted after operation. CONCLUSIONS: The changes of morphology, structure and function of the transplanted heart during periods without rejection are to some extent specific to this special phase, when some of these changes are similar to those during early acute rejection, and correct diagnosis relies on endo-myocardial biopsy.

Adult↗

PubMed2002

Affects of different access routes on autologous satellite cell implantation stimulating myocardial regeneration.

OBJECTIVE: To study the effect of different access routes on autologous satellite cell implantation to stimulate myocardial regeneration. METHODS: Satellite cells were procured from skeletal muscle (gluteus max) of adult mongrel canine, cultured, proliferated and labeled with 4', 6-diamidino-2-phenylindone (DAPI) in vitro. The cells were autologously implanted into the site of acute myocardial infarction by local injection or perfusion through the ligated distal left anterior descending coronary artery. Specimens were harvested 2, 4 and 8 weeks later for histological study. RESULTS: The labeling efficiency of satellite cells with DAPI was close to 100%. Fluorescent cells were found at the infarcted zone, papillary muscle and local injection site. Some of these cells had progressively differentiated into striated muscle fibers connected to intercalated discs. The infant cells appeared different from the mature myocardium under an electron microscope. Satellite cells implanted by perfusion through the coronary artery were arranged in order of consistency with host myocardial fibers. The satellite cells, implanted by local injection, were found growing in a disordered way. CONCLUSION: Satellite cells, implanted by coronary artery perfusion, can progressively differentiate into striated muscle fibers, arranging in order and disseminating over the infarcted zone. This approach seems more favorable for the recovery of myocardial contractile function than that of local injection.

Animals↗

PubMed2002

[Osteogenesis of HA/TCP biphasic ceramics implanted into muscle: a long-term study].

New bone formation in long-term intramuscle implant of Ca-P biomaterial was investigated in this experiment. After implanting into dog dorsal muscle for 15 months, a thin fibrous membrane that wrapped HA/TCP implant was still observed obviously. Three types of tissues, i.e. mesenchymal tissue, bone and bone marrow, regularly distributed in different pores of implant. Nearly all the pores of implants were occupied by bone. Bone in the pores located in the central region of implant was matured lamellar bone characterized by obvious lacuna and rich bone marrow. However, bone in the peripheral pores was immature woven bone without bone marrow formation. Furthermore, mesenchymal tissues only exist in the peripheral pores and usually were connected with immature woven bone. It was demonstrated that porous HA/TCP has bone inductivity and it could induce new bone formation at non-osseous site. Well-regulated distribution of mesenchymal tissue, bone and bone marrow in the pores suggest bone morphogenesis in the implant must obey a specific space-time program.

Animals↗

PubMedDate not supplied

The early detection research network surface-enhanced laser desorption and ionization prostate cancer detection study: A study in biomarker validation in genitourinary oncology.

Prostate-specific antigen (PSA) screening has led to a dramatic increase in prostate cancer detection with a concurrent stage migration. Although the test has revolutionized prostate cancer detection by identifying disease that is potentially curable in the majority of men, only 25% of men receiving test results of PSA > 4 ng/ml will have prostate cancer and many men receiving a normal PSA will have disease, including high-grade disease. There is a need for improved biomarkers for detecting prostate cancer. One such method of cancer detection is surface-enhanced laser desorption and ionization (SELDI). The Early Detection Research Network (EDRN) validation study for SELDI for prostate cancer is described. In a three-stage study, the portability and reproducibility of the technique will be determined; the predictive algorithm will be refined in a multi-institutional case-control population; followed by ultimate validation in the context of a prospective trial with complete disease ascertainment. The unique aspect of the EDRN SELDI validation study is the novel use of two groups of cancer cases: those cases with higher-risk disease (Gleason > or = 7) and those cases with lower-risk disease (Gleason < or = 6). This study will allow the first evaluation of a predictive algorithm that includes prognosis in disease screening. The EDRN SELDI prostate cancer biomarker validation study is a rigorous evaluation of a new detection method for prostate cancer. The methodologies used for this evaluation will prove useful for guiding future biomarker studies in this challenging disease.

Biomarkers, Tumor↗

PubMedDate not supplied

Serum protein expression profiling for cancer detection: validation of a SELDI-based approach for prostate cancer.

Multiple studies have reported that analysis of serum and other bodily fluids using surface enhanced laser desorption/ionization time of flight mass spectroscopy (SELDI-TOF-MS) can identify a "fingerprint" or "signature" of spectral peaks that can separate patients with a specific disease from normal control patients. Ultimately, classification by SELDI-TOF-MS relies on spectral differences in position and amplitude of resolved peaks. Since the reproducibility of quantitation, resolution and mass accuracy of the SELDI-TOF-MS, or any high throughput mass spectrometric technique, has never been determined this method has come under some skepticism as to its clinical usefulness. This manuscript describes a detailed design of a three-phase study to validate the clinical usefulness of SELDI-TOF-MS in the identification of patients with prostatic adenocarcinoma (PCA). At the end of this validation study, the usefulness of the general SELDI-TOF-MS approach to identifying patients with PCA will be demonstrated and how it compares with PCA diagnosis by measuring prostate specific antigen.

Adenocarcinoma↗