Journal of Tongji Medical University = Tong ji yi ke da xue xue bao最新文献

To investigate the role of nitric oxide (NO) in hyperoxic lung injury, the 3-day-old preterm rats were randomly assigned to four groups: group I (hyperoxia group), group II (hyperoxia + Nw-nitro-L-arginine methyl ester (L-NAME) group), group III (air group), and group IV (air + L-NAME) group. Group I and II were exposed to > or = 90% O2 for 3 or 7 days. Group II and IV received subcutaneous L-NAMEy on daily basis (20 mg/kg). After 3 day or 7 day exposure, the lung wet weight/dry weight ratio (W/D), total protein and malondialdehyde (MDA) in bronchoalveolar lavage fluid (BALF) and lung pathology were examined in all groups. NO content, expression of endothelial NOS (eNOS) and inducible NOS (iNOS) in lungs were measured in group I and III. Our results showed that after 3 day exposure, group I appeared acute lung injury characterized by the increase of MDA content (P < 0.01) and the presence of hyperaemia, red cell extravasation and inflammatory infiltration; after 7 day exposure, except MDA, total protein and W/D were also increased in comparison with group III (P < 0.01, 0.05), pathological changes were more severe than those after 3 day exposure. After 3 and 7 day exposure, total protein in group II was significantly increased as compared with group I (P < 0.01 for both). The pulmonary acute inflammatory changes were more obvious in group II than in group I. Occasionally, mild hemorrhage was detected in the lungs of group IV. BALF protein content in group IV was higher than that in group III after 7 day exposure (P < 0.01). After 3 and 7 day exposure, NO content in BALF were all significantly elevated in group I as compared with group III (P < 0.01 for all). In the lungs of group I, strong immunostaining for iNOS was observed in airway and alveolar epithelia, inflammatory cells, which were stronger than those in group III. Expression of iNOS in rats after 7 day hyperoxic exposure was stronger than that after 3 day exposure. Shortly after 7 day exposure, stronger immunostaining for eNOS in airway epithelia in group I than that in group III was seen. Our study suggested that treatment with L-NAME worsened acute hyperoxic lung injury in preterm rats and also had a deleterious effect on the rats exposed to air, indicating that endogenous nitric oxide may play a protective role in rats under both physiological and hyperoxic status. Hyperoxia can significantly upregulate the expression of iNOS and eNOS in inflammatory cells, epithelia in the lungs of preterm rats, promote NO generation, which suggests that endogenous NO may mediate the hyperoxic pulmonary damage. Over-stimulation of iNOS may contribute to the pathogenesis of hyperoxic lung injury. NO may have dual roles in pulmonary oxygen toxicity.

The roles of protein kinase C (PKC) signal pathway in the pathogenesis of obstructive jaundice were studied. PKC from cytosolic and membrane fractions of peripheral blood lymphocytes (PBL) in 51 patients with obstructive jaundice and 16 cases of normal controls was isolated and purified. The activities of PKC were determined by radioactive isotope gamma-32P-ATP-catalyzing assay. The results showed that the total PKC activities in PBL in the patients with obstructive jaundice were significantly increased as compared with those in the normal controls (P < 0.01). Moreover, the membrane PKC activities and their percentages of the total PKC activities were higher in obstructive jaundice group than in those in the normal controls (P < 0.05). The total PKC activities in PBL in the patients with obstructive jaundice were significantly positively correlated with the levels of soluble IL-2 receptor (sIL-2R) (r = 0.58, P < 0.01) and the degree of jaundice (T-BIL) (r = 0.67, P < 0.01) in serum. It was concluded that the activities of PKC signal pathway was related with the degree of T-BIL. PKC signal pathway might took part in the activation of T-lymphocytes in the patients with obstructive jaundice and play an important role in the immune regulation and the assessment of pathosis in the patients with obstructive jaundice.

The effect of transforming growth factor beta 1 (TGF-beta 1) gene transfection on the proliferation of bone marrow-derived mesenchymal stem cells (MSCs) and the mechanism was investigated to provide basis for accelerating articular cartilage repairing using molecular tissue engineering technology. TGF-beta 1 gene at different doses was transduced into the rat bone marrow-derived MSCs to examine the effects of TGF-beta 1 gene transfection on MSCs DNA synthesis, cell cycle kinetics and the expression of proliferating cell nuclear antigen (PCNA). The results showed that 3 microliters lipofectamine-mediated 1 microgram TGF-beta 1 gene transfection could effectively promote the proliferation of MSCs best; Under this condition (DNA/Lipofectamine = 1 microgram/3 microliters), flow cytometry and immunohistochemical analyses revealed a significant increase in the 3H incorporation, DNA content in S phase and the expression of PCNA. Transfection of gene encoding TGF-beta 1 could induce the cells at G0/G1 phase to S1 phase, modulate the replication of DNA through the enhancement of the PCNA expression, increase the content of DNA at S1 phase and promote the proliferation of MSCs. This new molecular tissue engineering approach could be of potential benefit to enhance the repair of damaged articular cartilage, especially those caused by degenerative joint diseases.

A novel in vitro cellular model producting recipient-donor histocompatibility in allograft was developed to select the donor validity. Fifteen couples of blood samples of donor and recipient in human BMT were examined using the model, and skin allograft in mice was performed to test the model. The results showed that the less the differences of histocompatibility evaluated by the model were, the later GVHR in human BMT occurred and the longer the survival time of skin allografts in mice. It was suggested that the model could be used to predict correctly histocompatibility between donor and recipient.

BCL-1 rearrangement (BCL-1/IgH gene rearrangement) in acute lymphocytic leukemia and its clinical significance was investigated. In 38 patients with acute lymphocytic leukemia (ALL), the genomic DNA of mononuclear cells isolated from peripheral blood and bone marrow was amplified by using hemi-nested polymerase chain reaction (PCR) technique and the expression of cyclin D1 protein of mononuclear cells was detected by using immunohistochemical method. Ten patients with acute granulocytic leukemia, 2 with chronic granulocytic leukemia and 10 with normal bone marrow served as control group. The results showed that BCL-1 rearrangement was detectable in 3 of 38 ALL patients (7.9%) and cyclin D1 protein positive expression was detected in 4 ALL patients (10.5%). Three ALL patients with BCL-1 rearrangement were all B-cell leukemia (B-ALL) and accompanied by cyclin D1 protein expression. No BCL-1/IgH rearrangement or cyclin D1 protein expression was detected in 12 patients with granulocytic leukemia and 10 cases of normal bone marrow. Leukocyte counts in peripheral blood of B-ALL patients with BCL-1 rearrangement and (or) cyclin D1 protein expression were significantly increased and the patients had bad reaction to chemotherapy. It was concluded that: 1) BCL-1/IgH gene rearrangement were detected in acute B lymphocytic leukemia; 2) B-ALL patients with BCL-1 rearrangement and (or) cyclin D1 protein expression had poor prognosis.

To explore the relationship of angiogenesis-related angiopoietin-2 gene and its receptor Tie2 with angiogenesis and the biology of hepatocellular carcinoma (HCC), angiopoietin-2 gene, Tie2 and CD34 protein expression in 22 resected HCC, 8 cirrhotic and 8 control liver specimens were investigated by in situ hybridization and immunohistochemistry respectively, and the level of angiopoietin-2 and Tie2 expression in HCC were compared in terms of tumor biological parameters. It was found that CD34 was not expressed in control liver, expressed scarcely in cirrhotic liver (17.8 +/- 13.5/HP), but intensively expressed in HCC (86.3 +/- 34.8/HP, P < 0.01). Tie2 receptor was not expressed in controls, expressed at low level in cirrhotic liver (11.3 +/- 8.7/HP), while strongly positive in the microvascular endothelia of HCC (52.4 +/- 16.7/HP, P < 0.01). The level of Tie2 receptor expression in HCC was closely related with tumor diameter, angiogenesis and portal invasion. Angiopoietin-2 gene was not expressed in control liver, expressed mildly in cirrhotic liver (11.2 +/- 9.7/HP), but extensively in tumor zone (36.4 +/- 17.5/HP), the level of angiopoietin-2 expression was closely related with angiogenesis, portal invasion and histological grading of HCC. It is concluded that angiogenesis is increased in HCC; angiopoietin-2/Tie2 expression in human hepatic carcinoma is closely related with angiogenesis, which are probably involved in the HCC angiogenesis regulation, promoting the development and metastasis of human hepatic cancer.

The effect of transforming growth factor-beta 2 (TGF-beta 2) on phagocytosis in bovine trabecular meshwork cells in vitro was investigated. After the cultured bovine trabecular meshwork cells were treated with 0 ng/ml, 0.32 ng/ml, 1 ng/ml, 3.2 ng/ml TGF-beta 2 for 24 h, latex beads were added into the incubation medium, and the numbers of the latex beads in 20 adjacent cells were counted under a microscope 24 h later, after treatment with Wright's stain. Our results showed that the average numbers of the latex beads in the trabecular meshwork cells treated with TGF-beta 2 of different concentrations were 53.1 +/- 1.7 beads/cell, 56.4 +/- 2.9 beads/cell and 77.9 +/- 6.5 beads/cell respectively, in comparison with 45.5 +/- 3.3 beads/cell of the control group. TGF-beta 2 significantly increased the number of the latex beads phagocytosed by cultured bovine trabecular meshwork cells in a dose-dependent manner. TGF-beta 2 could promote the phagocytosis of bovine trabecular meshwork cells in vitro. It may be involved in the cellularity decrease of the trabecular meshwork in the patients of primary open angle glaucoma through promoting the phagocytosis of trabecular meshwork cells.

Clinical characteristics of transmitted transfusion virus (TTV) infection and its pathogenicity in children were evaluated. Serum TTV DNA from 118 children (mean age: 7.8 +/- 2.8 years) was detected by nested PCR. The product of PCR was cloned and sequenced. The positive rate for serum TTV-DNA in 20 healthy children, 9 cases of acute hepatitis, 51 cases of chronic hepatitis, 24 cases of nephritis or nephrotic syndrome and 14 cases of hypoplastic anemia or acute leukemia was 20%, 11%, 29%, 42% and 21% respectively, but there was no significant difference in TTV-DNA frequency among them (P > 0.05). Of the 16 patients receiving immunosuppressive agent for a long time, 7 (44%) were positive for TTV-DNA, and of the 17 cases not receiving immunosuppressive agent, 5 (29%) were positive with the difference being not significant (P > 0.05). Essential characteristics were pathogen-carrier or asymptomatic infection in children with TTV infection. Long-term employment of immunosuppressive agent did not increase the incidence in TTV infection. There was still high prevalence in TTV infection in healthy children not receiving blood product, suggesting the possibility of non hematogenous transmitted transfusion in TTV transmission.

The isolated cardiac myocytes of rats were immediately infected by cosackievirus B3 (CVB3) to investigate the effects of such procedure on the cell cycle, apoptosis and intracellular ionized calcium (Ca2+ i) of cardiac myocytes. Newborn Balb/c murine cardiac myocytes were cultivated, then infected by CVB3. Intracellular Ca2+ i was measured by flow cytometer. The calcium in the medium for culturing cardiac myocytes was detected by using atom absorb spectrum test. It was found that CVB3 could markedly inhibit the differentiation and proliferation of the infected cardiac myocytes and induce the apoptosis. The intracellular Ca2+ i level in the infected group was significantly higher than in the control group (P < 0.01). The calcium concentration in the medium for culturing cardiac myocytes in the infected group was significantly lower than in the control group (P < 0.05). It was suggested that the apoptosis and intracellular calcium overload of the CVB3-affected cardiac myocytes are likely to play an important role in the pathogenesis of viral myocarditis.

In order to assess the impact of mRNA degradation on steady state levels of follicle-stimulating hormone receptor (FSHR) mRNA and on regulation of FSHR gene expression, the stability and half-life of FSHR mRNA were determined in transfected cells expressing recombinant FSHR. Time-dependent changes in FSHR mRNA content were determined by nuclease protection-solution hybridization assay (NPA) or by qualitative reverse transcription-competitive polymerase chain reaction (RT-PCR) in cultured hFSHR-YI cells, cell lines stably transfected with a human FSHR cDNA. FSHR mRNA content remained constant during 8 h control incubations of hFSHR-Y1 cells (NPA, 2.9 +/- 0.3 micrograms/mg RNA; RT-PCR, 2.7 +/- 0.3 micrograms/mg RNA). Actinomycin D (ActD, 5 micrograms/ml) inhibited mRNA synthesis, as assessed by incorporation of [3 H]uridine into total RNA, by 90% within 1 h in hFSHR-Y1 cells. No effect of ActD on cellular morphology or viability was observed. ActD caused a time-dependent decrease in FSHR mRNA content in hFSHR-Y1 cell lines with a lag time of 1 h. There were no significant differences in the rate of FSHR mRNA degradation between the two methods of mRNA quantification. The half-life of hFSHR mRNA was 3.6 +/- 0.2 h by NPA and 3.1 +/- 0.1 h by RT-PCR. The results indicated that degradation of mRNA was an important process in maintenance of steady state expression of the FSHR gene in cells stably expressing recombinant receptor.