[Human umbilical cord mesenchymal stem cells with adenovirus-mediated interleukin 12 gene transduction inhibits the growth of ovarian carcinoma cells both in vitro and in vivo].

OBJECTIVE: To study the inhibitory effect of human umbilical cord mesenchymal stem cells (UC-MSCs) infected by a adenoviral vector containing interleukin 12 (IL-12) gene on the proliferation of ovarian carcinoma SKOV3 in vitro and the growth of tumor explants in nude mice. METHODS: Cultured human UC-MSCs were infected with the recombinant adenovirus vector harboring IL-12 gene to establish the IL-12-expressing cell line AdIL-12-MSCs. Western blotting and RT-PCR were used to detect IL-12 expressions in AdIL-12-MSCs at the protein and mRNA levels, respectively. ELISA were used to detect IL-12 content in the supernatant of AdIL-12-MSCs, whose effect on the proliferation and apoptosis of ovarian carcinoma SKOV3 cells was evaluated with MTT assay and flow cytometry, respectively. In a nude mouse model bearing subcutaneous SKOV3 tumor explants, AdIL-12-MSCs were infused via the tail vein and the inhibitory effect on the tumor growth was observed. RESULTS: The exogenous IL-12 gene was successfully transduced into UC-MSCs by the recombinant adenovirus vector, resulting in efficient IL-12 expression in the cell at both the protein and mRNA levels. The supernatant of AdIL-12-MSCs significantly inhibited the proliferation of SKOV3 cells and induced cellular apoptosis in vitro as compared with UC-MSC supernatant. In the tumor-bearing nude mouse model, the transplantation of AdIL-12-MSCs significantly inhibited the growth of SKOV3 tumor explants (P<0.05). CONCLUSION: Human UC-MSCs with IL-12 gene transduction, which express IL-12 at protein and mRNA levels, can inhibit the proliferation and induce apoptosis of ovarian carcinoma SKOV3 cells in vitro, and suppress the growth of ovarian cancer explants in nude mice.

Primary gastric signet ring cell carcinoma presenting as cardiac tamponade.

Primary gastric signet ring cell carcinoma presenting as cardiac tamponade is difficult to diagnosis early. Patients are generally asymptomatic until the disease is advanced. General practitioners usually focus on the initial symptoms related to pericarditis and pericardial effusion. We report a case of signet-ring cell carcinoma of the stomach presenting as cardiac tamponade with pericarditis and pericardial effusion but without any gastrointestinal symptoms. A 49-year old woman was admitted because of progressive dyspnea and cough. Chest X-ray revealed an increased cardiothoracic ratio and a small amount of bilateral pleural effusion. Two dimensional ultrasonographic echocardiography pericardial effusions with atrial and right ventricular early diastolic collapse were found, establishing the diagnosis of cardiac tamponade. Pericardiocentesis was performed and 420 mL of bloody fluid was taken. The patient died of respiratory failure and cardiac arrest on October 28, 2009. Post-mortem examination revealed diffuse gastric mucosa erosion and edema with stomach mucosa incrassation in the greater curvature. The primary lesion was histopathologically diagnosed as signet-ring cell carcinoma of the stomach.

Electrocatalytic oxidation of phytohormone salicylic acid at copper nanoparticles-modified gold electrode and its detection in oilseed rape infected with fungal pathogen Sclerotinia sclerotiorum.

Salicylic acid (SA) is a biological substance that acts as a phytohormone and plays an important role in signal transduction in plants. It is important to accurately and sensitively detect SA levels. A gold electrode modified with copper nanoparticles was used to assay the electrocatalytic oxidation of salicylic acid. It was found that the electrochemical behavior of salicylic acid was greatly improved at copper nanoparticles, indicating that anodic oxidation could be catalyzed at copper nanoparticles. And the pH had remarkable effect on the electrochemical process, a very well-defined oxidation peak appeared at pH 13.3 (0.2M NaOH). The kinetics parameters of this process were calculated and the heterogeneous electron transfer rate constant (k) was determined to be 1.34x10(-3)cms(-1), and (1-alpha)n(alpha) was 1.22. The gold electrode modified with copper nanoparticles could detect SA at a higher sensitivity than common electrodes. The electrode was used to detect the SA levels in oilseed rape infected with the fungal pathogen Sclerotinia sclerotiorum. The results showed that the SA concentration reached a maximum during the 10th-25th hours after infection. This result was very similar to that determined by HPLC, indicating that the gold electrodes modified with copper nanoparticles could be used as salicylic acid sensors.

A robust sampling approach for identification and quantification of methyl jasmonate in leaf tissue of oilseed rape for analysis of early signaling in Sclerotinia sclerotiorum resistance.

INTRODUCTION: Methyl jasmonate (MJA), which is a natrual hormonal regulator, is thought to be essential for the regulation of systemic defence responses. The information about MJA levels in plant tissues is helpful for the study of the disease resistance mechanism and genetically engineered cultivars with increased resistance. Therefore, the quantification of MJA levels in plant tissues by means of a sensitive and reliable method is of interest. OBJECTIVE: Development of a film extraction method coupled with GC for determination of methyl jasmonate in leaf tissue of oilseed rape for analysis of early signalling in sclerotinia sclerotiorum resistance. METHODOLOGY: A robust polydimethylsiloxane film was prepared and used for extraction of MJA in leaf tissues. By using in-solution extraction mode, optimum extraction efficiency was achieved with methanol-water (1 : 5, v/v) as extraction medium at 40 degrees C for 60 min. RESULTS: Under the optimal conditions, a detection limit of 0.2 ng/mL was achieved. Excellent reproducibility was found over a linear range of 1-1000 ng/mL. MJA in leaves infected by sclerotinia sclerotiorum was determined, with the results showing that basal levels of MJA (15 ng/g) were present in noninfested controls, but increased to 313 ng/g 10 h after fungal attack. CONCLUSION: The film extraction method is a simple, rapid and inexpensive sampling technique for determination of endogenous MJA in plant tissues that can be applied to most plants.

[Cloning and functional analysis of the stable plasmid pBMB175 in Bacillus thuringiensis subsp. tenebrionis strains YBT-1765].

A 15.2 kb plasmid pBMB175 from Bacillus thuringiensis subsp. tenebrionis strains YBT-1765 was cloned and the restriction map was constructed. The mini-replicating region of pBMB175 was located in a 1151 bp fragment by functional analysis. The sequence of a 4152 bp fragment which contained the mini-replicating region was analyzed and results showed that the fragment had three potential open reading frames (ORF1, ORF2 and ORF3). Sequence comparison and homology search revealed that ORF1 (767AA) has 20% approximately 30% similarity to UvrD-helicase, RecD and RecB family proteins; no homology was found between ORF2 (149AA) and other known proteins; ORF3 shared 34% identification to a potential protein (ORF7) in pGI3. Deletion and sequence analysis presumed that the protein encoded by ORF2 maybe a new replication protein. Above all, pBMB175 likely belongs to a new plasmid family with a new replicon. The recombinant plasmid harboring the mini-replicating region is very stable, even after growth for more than 40 generations without selection, so it might be used as a cloning and expression vector.