[Role of exosomal miRNA in tumor progression and its possible mechanism].

Exosome is a kind of biological nano-vesicle with a diameter of about 30-100 nm and is synthesized, secreted, and released in almost all types of body cells. Recent studies have found that exosomes contain a variety of functional proteins, including mRNA and microRNAs (miRNAs) and so on, which play an important role in the process of material transfer and information exchange in cells. In addition, the related-exosomal microRNAs secreted by tumor cells play an important role in regulating theoccurrence, development, invasion and metastasis of tumors and other biological processes.. Therefore, the study of tumor-related exosomal microRNAs will help us to explore the mechanism of tumor progression from the perspective of tumor gene regulation and new tumor markers, which will contribute to the early diagnosis, treatment, disease monitoring and prognosis evaluation.

Inhibition of steroidogenesis and induction of apoptosis in rat luteal cells by cell-permeable ceramide in vitro.

The present study was undertaken to investigate the effects of ceramide on progesterone production and apoptosis in rat luteal cells in vitro. Luteal cells were prepared from the ovaries of pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) primed female Wistar rats and incubated with cell permeable C2-ceramide. The effects of ceramide on progesterone production and apoptosis in luteal cells were assessed by radio immunoassay (RIA) and flow cytometry analysis. In addition, changes in nitric oxide synthase (NOS) activity and nitric oxide (NO) production by luteal cells treated with C2-ceramide were also evaluated. Ceramide was found to reduce hCG-stimulated progesterone production in a dose-dependent manner, whereas it had little effect on basal progesterone content. Spontaneous apoptosis in luteal cells was observed after a 12-hour incubation in vitro and 5 mumol/L of ceramide significantly increased the apoptotic rate (P < 0.05). Enhanced apoptotic peak was seen in the histogram by flow cytometry. Moreover, 50 mumol/L of C2-ceramide significantly increased NOS activity (P < 0.01) and NO production (P < 0.001). It is suggested that ceramide may serve as an important signaling molecule mediating certain ovarian processes, such as luteal regression.

Direct interaction of two homeoproteins, homothorax and extradenticle, is essential for EXD nuclear localization and function.

The Drosophila Homothorax (HTH) and Extradenticle (EXD) are two homeoproteins required in a number of developmental processes. EXD can function as a cofactor to Hox proteins. Its nuclear localization is dependent on HTH. In this study we present evidence of in vivo physical interaction between HTH and EXD, mediated primarily through an evolutionarily conserved MH domain in HTH. This interaction is essential for the mutual stabilization of both proteins, for EXD nuclear localization, and for the cooperative DNA binding of the EXD-HTH heterodimer. Some in vivo functions require both EXD and HTH in the nucleus, suggesting that the EXD-HTH complex may function as a transcriptional regulator.

A common mechanism for antenna-to-Leg transformation in Drosophila: suppression of homothorax transcription by four HOM-C genes.

The Drosophila HOM-C genes encode transcription factors containing the DNA-binding homeodomain. Mutations in the HOM-C genes can cause specific homeotic transformation, suggesting that the HOM-C genes determine segmental identities by acting on different target genes. However, misexpression of several HOM-C genes in the antenna disc causes similar antenna-to-leg transformations. Here we show that the Scr, Antp, Ubx, and abd-A HOM-C genes all exert their effects through a common mechanism: suppressing the transcription of the homothorax (hth) homeobox gene and thereby preventing the nuclear localization of the Extradenticle homeodomain protein. We also show that ectopic hth expression can cause duplication of the proximodistal axis of the antenna, suggesting that it is involved in proximodistal development of the antenna.

[Effect of liuwei dihuang granules, pills and decoction on contents of cAMP, E2, T, Zn and Cu in plasma of renal yin deficient patients].

Experiments showed that in patients of renal yin deficiency who took orally Liuwei Dihuang granules for 4 weeks, the contents of cAMP, E2, Zn and Cu were found mankedly lower, but the contents of T mankedly higher than before using the drugs. This indicates that the granules are equally effective as pills and decoction.

Technetium pyrophosphate labelling following catheter shock: potential for a new intraoperative mapping technique.

Technetium pyrophosphate uptake at the site of catheter shock was studied in four patients and seven experimental dogs. Technetium pyrophosphate scintigraphy was performed following five catheter ablation attempts in humans at different cardiac sites, and following 24 J catheter shocks delivered in the right and left ventricles of seven dogs. In the patients, gamma camera imaging with tomographic reconstruction showed intense focal uptake at the sites of shock. The scans were positive from 1.5 to 5.5 h following ablation and stayed positive for up to five days. In the animals, the low energy shocks produced circumscribed areas of coagulation and contraction band necrosis. The binding of technetium pyrophosphate at these sites was confirmed by in vivo gamma camera imaging, epicardial counting with a 1.2 cm scintillation probe and ex vivo imaging. Ratios of focal binding to normal myocardial uptake of technetium pyrophosphate were calculated from the digital gamma camera images. In all cases, technetium pyrophosphate was bound to myocardial sites where transcatheter energies were delivered in both humans and dogs. Intraoperative localization of the origin of tachycardia in man may be facilitated by combining preoperative endocardial catheter mapping, catheter shock, radionuclide labelling of the site of shock and a search for the focus of radionuclide concentration during subsequent surgery.

Incessant ventricular tachycardia complicating acute myocardial infarction: treatment by map-guided infarctectomy.

A 58-year-old man developed incessant ventricular tachycardia on the fourth and fifth days following acute anterior myocardial infarction. The tachycardia was resistant to antiarrhythmic drugs, cardioversion and pacing. Preoperative and intraoperative mapping suggested a subendocardial origin, and successful infarctectomy was performed on the fifth day of the infarction.

On-line epicardial mapping of intraoperative ventricular arrhythmias: initial clinical experience.

An on-line automatic mapping system was developed for beat by beat display of epicardial activation during ventricular tachycardia induced at the time of cardiac surgery. A sock array of 110 button electrodes was used to record and display local activation on a video monitor at 8.3 ms intervals. On instant replay in slow motion, epicardial pacing sites were accurately localized to the nearest electrode. Local unipolar electrograms were also recorded, first from the sock array, then from an array of 16 transmural needle electrodes. The epicardial display was verified by retrospective manually derived maps using the recorded epicardial electrograms. In four patients with coronary artery disease and recurrent inducible ventricular tachycardia, earliest epicardial activation was located on slow motion replay within 1 minute. Subendocardial sites of early activation were located within 10 minutes by replay of electrograms from the needle array before ventriculotomy. Transmural and endocardial resection of these sites prevented inducibility of the tachycardia on postoperative electrophysiologic study in three of the four patients. There has been no clinical recurrence of ventricular tachycardia after 3 to 14 months of follow-up despite cessation of antiarrhythmic therapy in three of the patients. This technique has unique advantages over existing mapping methods. It provides beat by beat display of activation sequences so that clinical tachycardias that are short in duration or pleomorphic in configuration now become amenable to mapping. In addition, it markedly shortens total time on cardiopulmonary bypass.