Shading-Dependent Greening Process of the Leaves in the Light-Sensitive Albino Tea Plant 'Huangjinya': Possible Involvement of the Light-Harvesting Complex II Subunit of Photosystem II in the Phenotypic Characteristic.

The light-sensitive albino tea plant can produce pale-yellow shoots with high levels of amino acids which are suitable to process high-quality tea. In order to understand the mechanism of the albino phenotype formation, the changes in the physio-chemical characteristics, chloroplast ultrastructure, chlorophyll-binding proteins, and the relevant gene expression were comprehensively investigated in the leaves of the light-sensitive albino cultivar 'Huangjinya' ('HJY') during short-term shading treatment. In the content of photosynthetic pigments, the ultrastructure of the chloroplast, and parameters of the photosynthesis in the leaves of 'HJY' could be gradually normalized along with the extension of the shading time, resulting in the leaf color transformed from pale yellow to green. BN-PAGE and SDS-PAGE revealed that function restoration of the photosynthetic apparatus was attributed to the proper formation of the pigment-protein complexes on the thylakoid membrane that benefited from the increased levels of the LHCII subunits in the shaded leaves of 'HJY', indicating the low level of LHCII subunits, especially the lack of the Lhcb1 might be responsible for the albino phenotype of the 'HJY' under natural light condition. The deficiency of the Lhcb1 was mainly subject to the strongly suppressed expression of the Lhcb1.x which might be modulated by the chloroplast retrograde signaling pathway GUN1 (GENOMES UNCOUPLED 1)-PTM (PHD type transcription factor with transmembrane domains)-ABI4 (ABSCISIC ACID INSENSITIVE 4).

Dihydrochalcones in Sweet Tea: Biosynthesis, Distribution and Neuroprotection Function.

Sweet tea is a popular herbal drink in southwest China, and it is usually made from the shoots and tender leaves of Lithocarpus litseifolius. The sweet taste is mainly attributed to its high concentration of dihydrochalcones. The distribution and biosynthesis of dihydrochaldones in sweet tea, as well as neuroprotective effects in vitro and in vivo tests, are reviewed in this paper. Dihydrochalones are mainly composed of phloretin and its glycosides, namely, trilobatin and phloridzin, and enriched in tender leaves with significant geographical specificity. Biosynthesis of the dihydrochalones follows part of the phenylpropanoid and a branch of flavonoid metabolic pathways and is regulated by expression of the genes, including phenylalanine ammonia-lyase, 4-coumarate: coenzyme A ligase, trans-cinnamic acid-4-hydroxylase and hydroxycinnamoyl-CoA double bond reductase. The dihydrochalones have been proven to exert a significant neuroprotective effect through their regulation against Aß deposition, tau protein hyperphosphorylation, oxidative stress, inflammation and apoptosis.

[Correlation of hepatitis B virus X antigen expression with liver cell apoptosis].

OBJECTIVE: To study the roles of hepatitis B virus (HBV) X antigen (HBxAg) in development of HBV-related liver diseases and carcinogenesis. METHODS: Liver tissues were collected from patients with HBV infection (HBV carriers, n = 14; chronic hepatitis B (CHB), n = 24), HBV-related liver cirrhosis (LC, n = 20), or hepatocellular carcinoma (HCC, n = 20). Immunohistochemistry was used to detect the expression of HBxAg and the host apoptosis-related genes Fas and Fas ligand (Fas-L). The correlations of HBxAg with HBV DNA level in serum, inflammation grade, and fibrosis stage were statistically analyzed. Liver inflammation grade and fibrosis stage were in accordance with Knodell standard. x2test and Fisher's exact test were adopted in count data, x2split method was adopted in pariwise comparisons between multiple samples, Rank-sum test was adopted in ranked data, Spearman rank correlation analysis was adopted in correlation analysis. RESULTS: The rates of HBxAg-positivity were similar between the patients with HBV infection (71.1%), LC (60.0%), and HCC (65.0%) (x2= 0.754, P = 0.686). The rates of Fas- and Fas-L-positivity in liver cells were also similar between the three groups (Fas: 28.9% vs. 20.0% vs. 5.0%, x2= 4.667, P = 0.101; Fas-L: 36.8% vs. 50.0% vs. 60.0%, x2= 2.988, P = 0.225). However, the positive rate of Fas in lymphocytes of liver tissue was significantly higher in the HCC patients than in the HBV-infected patients (90.0% vs. 68.4%, Z = -4.360, P = 0.00001). The expressions of HBxAg and Fas-L corresponded to regions of severe inflammation in tissues from LC patients and some HCC patients. Furthermore, the expression of HBxAg was positively correlated with Fas (r = 0.304, P = 0.02) and Fas-L (r = 0.368, P = 0.004) in the HBV-infected patients and LC patients, and the expression of Fas was positively correlated with that of Fas-L (r = 0.448, P = 0.0004). Patients with high and medium loads of HBV DNA showed significantly higher rates of HBxAg-positivity than those with low loads (88.9% and 69.2% vs. 26.7%, P less than 0.05). CONCLUSION: In the early stage of chronic HBV infection, HBxAg may induce liver cell apoptosis by up-regulating Fas expression, and in the later stage, HBxAg may induce immune escape by up-regulating Fas-L expression in liver cells. Together, HBxAg and high HBV DNA load may promote chronic HBV infection and progression to hepatocarcinogenesis.

Synthesis and antitumor activity of novel 2-(1-substituted-piperidin-4-ylamino)quinazolines as antitumor agents.

A variety of novel 2-(1-substituted-piperidine-4-ylamino)quinazoline derivatives were prepared and their antiproliferative activities on five cancer cell lines were evaluated by MTT assay. Quinazolines 4j-4l, 5a, 5b and 5d bearing a small hydrophobic alkyl group on piperidine ring exhibited potent antitumor activities with IC50 values at micromolar level. Compound 41 displayed significant in vivo antitumor activity with 72.9% inhibition on H22 tumor growth and 80% inhibition on Lewis lung cancer growth at a dose of 200 mg x kg(-1).

[The clinical application of videomediastinoscopy combined with the examination of CD(4)/CD(8) in the diagnosis of mediastinal tuberculosis and sarcoidosis].

OBJECTIVE: To evaluate the role of videomediastinoscopy combined with the examination of CD(4)/CD(8) in the diagnosis of tuberculosis and sarcoidosis of the mediastinum. METHODS: The clinical records of 90 patients who underwent videomediastinoscopy from February 2003 to September 2005 were retrospectively reviewed. The expression of CD(4)/CD(8) was studied using immunohistochemical method in the tissues from 57 cases with a diagnosis of tuberculosis or sarcoidosis and noncaseating granuloma without classical "sarcoid" pathology obtained by videomediastinoscopy. RESULTS: Sarcoidosis was diagnosed in 37 patients, tuberculosis in 14 patients, lymphoma in 15 patients, nodal metastasis in 18 patients, noncaseating granuloma without classical "sarcoid" in 6 patients. The diagnostic accuracy was 93.3% (84/90). The expression of CD(4) and CD(8) in sarcoidosis was (65 +/- 13)% and (9.4 +/- 2.6)%, respectively. While the expression of CD(4) and CD(8) in tuberculosis was (41 +/- 11)% and (11.8 +/- 3.4)%, respectively. The rate of CD(4)/CD(8) in sarcoidosis was higher than that in tuberculosis (7.3 +/- 1.8 and 3.6 +/- 1.1, respectively, t = 1.883, P = 0.000). The accuracy, specificity and sensitivity for diagnosis of sarcoidosis was 90.2%, 85.7% and 91.9%, respectively, if the cutoff value of CD(4)/CD(8) was 5. No complication or mortality was reported. CONCLUSION: Videomediastinoscopy is an effective procedure for the diagnosis of mediastinal diseases. The examination of CD(4)/CD(8) adds more information to the differentiation of tuberculosis from sarcoidosis.

[Expression and clinical significance of matrix metalloproteinase in gastric stromal tumor].

OBJECTIVE: To investigate the expression and clinical significance of matrix metalloproteinase (MMP) in gastric stromal tumor (GST). METHODS: MMP-2 and MMP-9 expression were determined by immunohistochemistry in tumor tissues in 44 patients with GST, and their relationship with clinicopathologic factors of the neoplasm was also investigated. RESULTS: MMP-2 and MMP-9 were expressed in the cytoplasm in 84.1% (37/44) and 81.8% (36/44) of tumors, respectively. The positive rates of MMP-2 and MMP-9 increased significantly in parallel to the increase in tumor malignancy (P < 0.05) and associated with pattern of tumor growth, tumor size, and centre necrosis (P < 0.05). In addition, there was a statistically significant positive correlation between the expression of the two markers in GST (r = 0.6523, P < 0.05). Furthermore, the 5-year postoperative survival rates of patients with positive expressions of MMP-2 and MMP-9 were significantly lower than those of patients with negative expressions of the two markers (P < 0.05). CONCLUSION: Over expression of MMP-2 and MMP-9 can be served as objective markers to judge the malignant degree and, to predict the prognosis of patients with GST.

A novel derivative of quinazoline, WYK431 induces G2/M phase arrest and apoptosis in human gastric cancer BGC823 cells through the PI3K/Akt pathway.

WYK431, a novel synthetic quinazoline derivative, showing potent inhibition of proliferation activity against a broad spectrum of human cancer cell lines. We investigated the anticancer effects of WYK431 on BGC823 cells both in vitro and in vivo. The results showed that WYK431 inhibited proliferation, arrested the cell cycle at the G(2)/M phase, which was related to CDK1 and CDC25C, and induced apoptosis associated with activation of caspase-3 and caspase-9 rather than caspase-8 in BGC823 cells. Treatment of BGC823 cells with WYK431 resulted in upregulation of Bax, release of cytochrome c from the mitochondria to the cytosol and disruption of mitochondrial membrane potential. Western blot analysis showed that WYK431 downregulated the levels of the PI3K/Akt signaling pathway. Moreover, WYK431 effectively suppressed tumor growth in xenograft models in BALB/c athymic nude mice without major side action. TUNEL analysis showed that WYK431 induced BGC823 cell apoptosis in vivo. Collectively, WYK431 is a novel small molecule agent which inhibits BGC823 cell proliferation inducing G(2)/M phase arrest and apoptosis via the mitochondrial apoptotic pathway. To assess its potential as a promising anticancer agent requires further investigation.

[The cloning, expression, purification and immunological identification of wild-type and mutant hepatitis B virus X gene in pGEX-6P-2 system].

To settle the foundation for the future research on the influence of wild and mutant (A1762T/ G1764A) HBV X gene on the progress of chronic HBV infection and hepatic tumorigenicity, wild and mutant (A1762T/G1764A) HBxAgs expression system was constructed. The wild and mutant (A1762T/ G1764A) HBV X genes were amplified with polymerase chain reaction (PCR) from HBV genome were inserted into pGEX-6P-2 and confirmed by sequencing respectively. Prokaryotic expression vectors pGEX-6P-2-hbvx(w) and pGEX-6P-2-hbvx(m) (A1762T/G1764A) were constructed and transformed to Trans1-blue; wild and mutant HBxAgs were expressed through IPTG induction respectively; after refolding of inclusion body, the wild and mutant HBxAgs were purified with GSTrap FF; and analysised by SDS-PAGE, Western blot and ELISA. SDS-PAGE analysis showed that the expression system was able to express target protein efficiently; the concentrations of purified wild HBxAg and mutant HBxAg were 4.88 mg/mL and 5.07 mg/mL respectively; Western blot analysis certified both the wild HBxAg and the mutant HBxAg could be recognized by the same monoclonal antibody against HBxAg; the two expressed fusion antigens coated in microtiter plate were able to react with the sera of HBV infected patients but not with the sera from healthy donors in ELISA. Results demonstrated that we successfully established a system for expression of hepatitis B x antigen and lay the foundation for further research on the role and molecular mechanisms of the mutant HBxAg in the progress of chronic HBV infection and hepatic tumorigenicity.

[Study on embryo development and somatic embryogenesis of jujube].

The results of embryological observation on embryo development in the thirteen cultivars of jujube indicated that they shared the same experience from proembryo to globular embryo, heart-shaped embryo, torpedo-shaped embryo and cotyledon stage embryo. Embryo began aborting from globular or heart-shaped embryo period in most of cultivars of jujube, but in few of them embryo could keep synchronous developing to cotyledon stage embryo. And the courses of embryo development were not synchronous.

[The effect of postoperative chemotherapy after esophagectomy on the survival rate to patients with original squamous cell carcinoma of esophagus].

OBJECTIVE: To study the prognostic factors affecting the survival rate after extended radical esophagectomy with three-field lymph node dissection for squamous cell carcinoma and the effect of postoperative chemotherapy. METHODS: Out of 126 patients with original squamous cell carcinoma of esophagus who accepted extended radical esophagectomy with three-field lymph node dissection from 1987 - 1992 in a hospital, 97 of them were included in this study. Data on the clinical/pathological characters and post surgery survival records of the subjects' were collected. Survival analysis methods included Kaplan-Meier, Log-rank test and Cox multivariable model and the effects of postoperative chemotherapy were analyzed for patients in early and late stages. RESULTS: There was no significant difference in clinical and pathological character between those patients only undergone surgery and patients accepting postoperative chemotherapy. The size of tumor, grade of differentiation of the tumor cells, infiltration deepness, with or without lymph node metastasis, expression of nm23 and EGFR and treatment after surgery etc. were correlated with the survival rate. For patients in early tumor stage, postoperative chemotherapy with cisplatin and 5-FU after surgery seemed to be a risk factor. For patients in late stage, postoperative chemotherapy with cisplatin and 5-FU after surgery did not seem to improve survival rate. CONCLUSION: It is imperative to study on the effect of adjuvant postoperative chemotherapy to patients, especially those at early stage with squamous cell carcinoma of esophagus. Doctors must be scrupulous when making decisions.