Objective To investigate the condition which can induce mouse ES cells to differentiate into epidermal-like stem cells for the clinical application of ES cells-derived epidermal-like stem cells and the research on the mechanism of committed differentiation of ES cells. Methods Coculture mouse ES cells with human amnion for 3-4 days, and the committed differentiation were detected by flow cytometry and immunohistochemistry. In experimental group 1, amnion was pasted covering the whole bottom of the wells, with the epithelial surface upward, and in group 2 covering the half bottom. No amnion was used in control. Results After 3-4 days of co-culture, epidermal-like stem cell clones were formed on the epithelial surface of amnion in group 1 and group 2, and expressed high levels of integrin-? 1, CK19 and CK15. The percentages of integrin-? 1, CK19 and CK15 positive cells counted in group 1 by flow cytometry were 89.2%, 86.8% and 71.2% respectively, versus the control group of 8.4%,9.6% and 11.8%, the differences were significant in all the three indices (Z tests P

Purpose:To study the apoptosis and proliferation in ovarian cancer and the relationship between gene and the histological grading as well as response to chemotherapy. Methods:In our study apoptosis in fifty fresh samples of epithelial ovarian carcinomas were evaluated by TDT (terminal deoxynucleotidyl transferase) assay. We used the techniques of immunohistochemistry to detect the proliferation and the protein expression of bcl-2,bax and p53 gene.Results:In 66% (30/50) samples of fresh epithelial ovarian carcinoma apoptosis was observed in different degrees. Our results showed that PCAN and p53 expression in poorly differentiated ovarian carcinoma is higher than that in well middle differentiated (P

Objective To study problems related to drug-induced liver lesion caused by antituberculotic therapy (DLL).Methods Totally, 172 cases of DLL occurred in 1 464 patients with pulmonary tuberculosis after antituberculotic therapy, hospitalized during January 1995 to December 2002, were reviewed and analyzed retrospectively.Results Patients aged 20 to 60 years with DLL by antituberculolis therapy accounted for 70.3% of the total. Symptoms of digestive tract and change in liver function usually occurred within 8 weeks of intensive treatment (73.8%), and discontinuation of autituberculotic drugs was not needed for the mild cases, but needed for the severe cases with liver protective therapy. In total, 157 of the 172 cases (91.3%) recovered completely and 13 case improved (7.6%), two cases deteriorated and discharged, and doses of autituberculotic drugs should be reduced or stopped in 41 cases (23.8%) affecting their treatment efficacy.Conclusions DLL was liable to occur in patients of pulmonary tuberculosis with antituberculotic therapy, especially in the elderly men with body weight less than 50 kilograms, those with previous liver damage or infected with hepatotropic virus, alcohol drinking, complicated with extrapulmonary tuberculosis, with combination of isoniazid rifampicin and pyrazinamide.

Objective To establish a detection method integrating DPRA ( direct peptide reactivity assay) with h?CLAT ( human cell line activation test) to screen the skin sensitization potency of chemicals and plant extracts. Methods 12 chemicals and 7 plant extracts were chosen as the test substances. Firstly, the test substances were incubated together with two different peptides ( cysteine and lysine) respectively for reaction for 24 h. The peptide consumptions were analyzed by HPLC. Simultaneously, THP?1 cells were cultured in vitro and then exposed to different concentrations of test sub?stances for 24 h to examine the cell viability, cell surface markers CD54 and CD86 were assessed by flow cytometry. The predicting results were compared further between DPRA and h?CLAT. Results 12 chemicals were distinguished correctly by DPRA classified as 2 non?sensitizers and 10 sensitizers. The results of DPRA were in accordance with h?CLAT. Predic?ting the sensitization potency of plant extracts by DPRA showed that 6 plant extracts were determined as suspected sensiti?zers except for green tea extract. But using the method of h?CLAT, 4 plant extracts were examined as suspected sensitizers except for green tea extract, herba portulacae extract and ginseng fruit extract. The coherence of DPRA and h?CLAT was 0?57. Conclusion This detection method integrating DPRA with h?CLAT can predict single compound accurately. As for complex compound, it can achieve preliminary prediction and need other integrating methods to make a further identifica?tion.

Objective To establish an in vitro skin sensitization test,human cell line activation test (h-CLAT),based on THP-1 cell line (a human acute monocytic leukemia cell line),and to assess the sensitizing potency of plant raw materials of chemical and cosmetic products by this in vitro skin sensitization test.Method THP-1 cells were cultured in vitro and exposed to 11 reference skin sensitization chemicals and 9 samples,by monitoring the cell viability,cell surface marker CD54 /CD86 and relative fluorescence intensity of cells surface after the cells was exposures to the substances,and to discover whether there is a positive reaction.At the same time,Buehler test was used to validate the results of samples tested by h-CLAT.Results 11 reference chemicals were distinguished correctly by h-CLAT.Among the 9 samples tested,7 samples were recognized as negative sensitizer and 2 plant extracted substances were identified as suspicious skin sensitizer.The qualitative classification of the 9 samples by h-CLAT test was consistent with the results obtained by animal test.Conclusions The h-CLAT-in vitro test can be used to replace some animal tests for the prediction of soluble skin sensitizing substances.

Objective To explore the use of integrated two methods in vitro in prediction of eye irritation caused by cosmetics.Method Chorioallantoic membrane vascular assay ( CAMVA), bovine corneal opacity and permeability (BCOP) and Draize rabbit eye irritation test were used to determine the predictive potential of eye irritation of 60 kinds of cosmetics.Results CAMVA method was able to distinguish 41 non-irritant samples and 18 irritant samples.BCOP method was able to predict 35 non-irritant samples , 21 mild-moderate irritant samples and 4 severe irritant samples . Combination of CAMVA and BCOP methods could obviously improve the identification ability of irritation , and the classification consistency with Draize rabbit eye irritation testing reached 98.3%.Conclusions The integrated test strategy combined BCOP with CAMVA can be used to appropriately predict ocular irritation of cosmetics , with a prediction range covering non-irritant to severe irritant samples .

Objective To investigate the expressions of thymidylate synthase (TS) and adenosine triphosphate (ATP)-binding cassette superfamily G member 2 (ABCG2) in advanced gastric cancer (GC) and to explore their correlation with clinical pathological features.Methods A total of 80surgical specimens of advanced gastric cancer patients were collected.The expressions of TS and ABCG2 in gastric cancer tissues and adjacent normal gastric tissues were detected by immunohistochemical method.The expression of P-glycoprotein in gastric cancer tissues was also examined.The correlations between TS,ABCG2 and clinical pathological features and P-glycoprotein were analyzed.Chi-square test was performed for two groups comparison and Kruskal-Wallis H test were used for multi-groups comparison.Results The positive rates of both TS and ABCG2 in gastric cancer tissues [85.0％ (68/80) and 90.0％ (72/80)] were higher than those of adjacent normal gastric tissues [62.5 ％ (50/80) and 78.7 ％ (63/80)],the differences were statistically significant (x2 =11.466 and 16.463,P=0.009 and 0.001).There were close correlation between the expression of TS,ABCG2 and tumor TNM stage,differentiation status,invasion depth (TS:x2 =30.686,61.470 and 40.545 ; ABCG2:x2=48.192,63.150 and 47.512; all P＜0.01).The later the tumor staged,the worse the cells differentiated and the deeper the tumor invaded,the higher level they expressed.Both TS and ABCG2expressions in gastric cancer tissues were correlated with the expression level of P glycoprotein (x2 =43.977and 29.509,both P＜0.01).Conclusion TS and ABCG2 may be potential indexes to predict the degree of malignancy,progression,drug resistance and prognosis in gastric cancer.

AIM: To demonstrate the susceptibility of cell apoptosis varies during the progress of cell malig- nant transformation from human being in vitro. METHODS: A SV40T - transfected human bronchial epithelial im- mortalized cell line (called M) was selected in this work, which has acquired some characteristics of malignant trans- formation at the later passage. The alterations of apoptosis and bcl- 2, P53 genes between early and later passage of M cells were investigated by means of TDT labeling in situ, chromosome FISH, RNA and protein testing, etc. RE- SULTS: Incidence of apoptosis induced by cis - platin was significantly lower in later than in early passages of M. Levels of bcl - 2 mRNA and protein in later passages were higher than early passages of M, and overxpression of bcl -2 was accumulated following the development of cellular malignancy. P53 protein level was as high in early as in later passages. CONCLUSION: Overexpression of bcl - 2 decreases the cellular sensitivity to apoptotic inductors plays an important role during progress of carcinogenesis in human bronchial epithelial cancers. The inactivation of P53 protein in the SV40 - T transfected M cell line may be one of reasons of bcl - 2 overexpression, but not associated with the accumulation of bcl - 2 expressed level during cell transformation.

To meet the need of cultivating high-quality medical talents for the 21 century,enlighten the thoughts and strengthen the practice and operation ability of medical students,we have probed and reformed our teaching methods in human parasitology for basic medicine students directing at the weak points in our traditional teaching.Moreover,we have conducted the survey among the students for three years on end so as to provide a consultation for improving our teaching methods and quality.

BACKGROUND: Many experiments indicate that the angiogenesis of tissue engineered bone graft plays a key role in the osteogenesis.OBJECTIVE: An experimental pattern was set up designed to prepare a kind of vascularized engineered-bone graft for repairing rhesus tibia defects and analyze the relation of angiogenesis and osteogenesis in vivo by rontgenographic and morphological approaches.DESIGN: Random controlled animal experiment.SETTING: Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University.MATERIALS: The composite graft was constructed by seeding the induced bone marrow stem cells (BMSCs) on to a beta-tricalcium phosphate(3-TCP) scaffold in vitro, a circular cylinder (20 mm × 8 mm diameter) with a slit (width 2 mm and length 3 mm ) open to both ends and slot. Porosity 60% and pore diameter 100-150 μm. Twenty-nine healthy rhesuses aged 4-5 years and weighted 3.5-5 kg were adopted without gender limitation.METHODS: The experiment was conducted in the Department of Orthopaedics and Traumatology, Nanfan Hospital, Southern Medical University from October 2003 to July 2005. ①Bone-periosteum defect of 20 mm was made in the middle part of right tibia of the 27 rhesuses, and randomly divided into 3 groups equally. ②The defect gaps in fascia-blood vessel group (A) were plugged with in vitro engineered composites constructed by bone marrow stem cells and 3-TCP scaffold, which were totally hugged by a sheet of pedicled deep fascia and additionally a corresponding portion of saphenous artery and veins. The gaps in fascia group (B) and control group(C), however, were inserted with fascia-coated tissue engineered bone and tissue engineered bone only, respectively. Furthermore, two rhesuses without filling materials on the defect were picked up as blanks fixed by steel pins. ③The angiogenesis and osteogenesis for each treatment was assessed by radioactive imaging, roentgenographic analyses, blocking density and vaso-area image analysis at time intervals of 4, 8 and 12 weeks postoperative.MAIN OUTCOME MEASURE: The score of radioactive imaging,roentgenographic, morphological and vaso-area image analyses RESULTS: Totally 29 rhesuses were involved in the result analysis.① General observation of samples: In group A, all the surfaces of the implanted material and the central part were wholly wrapped up or replaced by bonelike tissues which were hard and could not be broken. And 2/3 materials had been absorbed; In group B and C, partial materials of the medial surface and the front were not coated or replaced by bonelike tissues, which could be broken with force, and 1/3 material had been absorbed.②Histological observation of scaffolds: With time passing, the scaffold materials were absorbed to different degrees in group A, B and C, among which, group A was most significant; Under the microscope, the implanted materials at 12 weeks were completely coated with the bonelike tissues, while the blood vessels structures in the materials were mostly alveoli alike and multi-braches. In group B, most of the materials at 12 weeks were wrapped up by the new bone, and few blood vessels could be seen in the center of the materials. In group C, the implanted materials at 12 weeks were slightly absorbed. The new bone and the vascular structures were both increased a little, but still very few.③Analyses of vaso-area: The vaso-areas of both central and peripheral parts in group A were significantly bigger than those of group B and C (P ＜ 0.05). Furthermore, it tended to increase with the time.④X-rays observation: At 12 weeks, group A's images presented obviously decreased density which was lower than that of the normal bone in individual areas and the continual bony callus manifested. Whereas group B and C's images showed slightly decreased density and the continual bony callus appeared on the sections. ⑤The roentgenographic scores of bone defects: The results indicates that the scores of group A was better than those of group B and C at 4, 8 and 12 weeks, respectively (P ＜ 0.05).CONCLUSION: ①This study shows that a feasible and effective angiogenesis approach of tissue engineered bone can accelerate osteogenesis in vivo. ②The absorption level is positively related to local angiogenesis.