[Prognostic analysis of patients with myasthenia gravis after extended thymectomy].

Objective: To identify the long-term outcome of patients with myasthenia gravis (MG) after extended thymectomy, and to analyze the prognostic factors. Methods: The medical data and follow-up results in 72 patients with MG who underwent extended thymectomy in Department of Thoracic Surgery, Anhui Provincial Hospital Affiliated with Anhui Medical University from January 2006 to October 2015 were retrospectively reviewed and analyzed. There were 32 male and 40 female patients, aging from 10 to 70 years with a mean age of 39.5 years. The outcome-related factors including gender, age while being operated on, duration of preoperative period, whether taking steroid before operation, modified Osserman classification, pathology type of thymus were analyzed by χ(2) test and multivariate regression analysis. Results: All patients were followed up from 6 to 75 months (median 37 months). Among them, 21 patients (29.2%) achieved complete stable remission, 18 patients (25.0%) experienced pharmacological remission, 20 patients (27.8%) improved, 9 patients (12.5%) reminded stable and 4 patients (5.6%) deteriorated. Both univariate and multicariate analysis revealed that duration of preoperative period (OR=22.871, 95% CI: 2.813 to 185.917, P=0.003) and Osserman classification (OR=0.103, 95% CI: 0.014 to 0.774, P=0.027) showed significantly associated with the surgical curative effect. Conclusions: Extended thymectomy is an efective measure for MG. The duration of preoperative period and Osserman classification are prognostic factors for thymectomized MG. Those patients with generalized MG or whose duration of preperative period is less than 6 months are likely to have better prognosis.

[Prognostic significance of the number of dissected lymph nodes in Siewert type â ¡adenocarcinoma of the esophagogastric junction without lymphatic metastasis].

OBJECTIVE: To investigate the correlation between the number of dissected lymph nodes (LNs) and the prognosis of patients with node-negative Siewert type ⅡAEG. METHODS: 248 patients with Siewert type Ⅱ AEG treated in our hospital between January 1998 and December 2008 were retrospectively assessed. All cases underwent left transthoracic subtotal esophagogastrectomy with conventional two-field lymphadenectomy, and were histopathologically proved to be without lymph node involvement. The prognostic impact of the number of dissected LNs was analyzed. RESULTS: The overall median survival time and the 1-, 3-, and 5-year overall survival rates were 64 months, 80.4%, 60.8% and 51.0%, respectively. Cox regression showed that the number of dissected LNs and the depth of tumor invasion were independent prognostic factors. Patients with a high number of negative LNs had better overall survival than patients with a low number of negative LNs (P<0.05). The patients had better long-term survival outcomes with more than 10 LN dissected for cases with pT1 tumor (P<0.001), and so did those with more than 15 LN dissected for cases with pT2-3 tumor (P=0.003, 0.018, respectively). CONCLUSION: The number of negative lymph nodes and the depth of tumor invasion are independent prognostic factors for node-negative Siewert type Ⅱ AEG, and adequate lymph node dissection can improve the long-term survival.

Antitumour activity of 3-nitropropionic acid from Phomopsis sp. and optimization of fermentation conditions.

UNLABELLED: In this study, 3-nitropropionic acid (3-NPA) was separated and purified from endophytic fungi belonging to Phomopsis sp. and its cytotoxicity was determined by MTT assay. Treatment with 3-NPA for 24 h resulted in a dose-dependent apoptosis in MCF-7 cells. Through quantitative detection of the genes that are closely related to the Bcl-2 signalling pathway, there was an increased expression of p53 and Bax and a decreased expression of Bcl-2, which indicated apoptosis in these cells. Meanwhile, the overexpression of PARA (poly ADP-ribose polymerase) and apoptosis inducing factor (AIF) also suggested that 3-NPA induced cellular apoptosis through a caspase-3-independent pathway in caspase-3-deficient MCF-7 cells. The fermentation condition was also improved to produce more 3-NPA: glucose as a carbon source and yeast extract as a nitrogen source, fermentation for 8 days at 32°C and a solution environment of pH 5·0. Under these conditions, the yield of 3-NPA was increased to 529 mg l(-1) compared with 410 mg l(-1) under traditional fermentation conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: 3-Nitropropionic acid is a mitochondrial inhibitor and has some useful bioactivities such as antibacterial activity. In this paper we found that 3-NPA also has obvious cytotoxicity, so we studied its antitumour activity and tried to determine the antitumour molecular mechanism, opening a new perspective for potential antitumour prodrug development. As 3-NPA is often obtained from natural products with a low yield, in order to overcome the disadvantage of an endophytic fungi source of 3-NPA, we optimized the fermentation conditions for 3-NPA in Phomopsis sp. to obtain the maximum production of 3-NPA.

Role of surgery in the management and prognosis of limited-stage small cell carcinoma of the esophagus.

Small cell carcinoma of the esophagus (SCCE) is a rare, highly aggressive tumor characterized by early dissemination and a poor prognosis. Surgery, chemotherapy, and radiotherapy have been used alone or in combination for the treatment of this rare disease. The aim of this retrospective study was to analyze the role of surgery in the management of limited-stage SCCE at a high-volume center. We retrospectively evaluated 73 patients with limited-stage SCCE who received an esophagectomy at our center from January 1994 to December 2011. The clinical characteristics, median survival times (MSTs), overall survival (OS), and relevant prognostic factors were analyzed. The overall MST was 23.0 months, and the 1-, 2-, 3-, and 5-year OS rates were 61.6%, 47.9%, 22.7%, and 10.6%, respectively. The MST for patients without lymph node involvement (33.0 months) was greater than the MST for patients with lymph node involvement (17.0 months) (P = 0.014). Similarly, patients who underwent radical resection had a greater MST (25.0 months) than patients who underwent palliative resection (7.0 months) (P = 0.004). Patients who received chemotherapy had a greater MST (27.0 months) than patients who did not receive chemotherapy (13.0 months) (P = 0.021). Survival analysis confirmed that a radical operation, chemotherapy, and lymph node involvement were independent prognostic factors. This study suggests that radical resection combined with chemotherapy should be recommended for patients with limited-stage SCCE, especially patients with negative regional lymph nodes. A lack of lymph node metastasis was a good prognostic factor because patients without lymph node involvement had greater OS.

Controllability of vortex domain structure in ferroelectric nanodot: fruitful domain patterns and transformation paths.

Ferroelectric vortex domain structure which exists in low-dimensional ferroelectrics is being intensively researched for future applications in functional nanodevices. Here we demonstrate that adjusting surface charge screening in combination with temperature can provide an efficient way to gain control of vortex domain structure in ferroelectric nanodot. Systematical simulating experiments have been conducted to reveal the stability and evolution mechanisms of domain structure in ferroelectric nanodot under various conditions, including processes of cooling-down/heating-up under different surface charge screening conditions, and increasing/decreasing surface charge screening at different temperatures. Fruitful phase diagrams as functions of surface screening and temperature are presented, together with evolution paths of various domain patterns. Calculations discover up to 25 different kinds of domain patterns and 22 typical evolution paths of phase transitions. The fruitful controllability of vortex domain structure by surface charge screening in combination with temperature should shed light on prospective nanodevice applications of low-dimensional ferroelectric nanostructures.

Vortex domain structures of an epitaxial ferroelectric nanodot and its temperature-misfit strain phase diagram.

Phase field simulations were conducted to investigate the effect of misfit strain on the vortex domain structure (VDS) in a BaTiO3 nanodot. Taking into account the effect of inhomogeneous eletromechanical fields, ambient temperature and surface effects, our calculations demonstrate a strong effect of misfit strain on the orientation and magnitude of the polarization dipoles. As a consequence, fruitful equilibrium vortex domain patterns can be obtained by adjusting the epitaxial misfit strain between the substrate and the nanodot. While the nanodot exhibits a single transition from a paraelectric to a near-rhombohedral vortex state at zero misfit strain with the decrease of temperature, complicated transformations of vortex domain patterns are found under nonzero misfit strain. Typically, orthorhombic, tetragonal and several unreported vortex domain patterns (e.g., with zero toroidal moment) are found. Moreover, misfit strain-induced transformations into these domain patterns are also predicted for a ferroelectric nanodot with initial near-rhombohedral vortex state. Combining effects of the ambient temperature and misfit strain, a "temperature-misfit strain" phase-diagram depicting the fruitful vortex domain patterns of the nanodot was obtained. Our simulations indicate promising application of strain engineering in controlling the VDS in ferroelectric nanostructures.

Experimental study of bone marrow-derived mesenchymal stem cells combined with hepatocyte growth factor transplantation via noninfarct-relative artery in acute myocardial infarction.

We investigated the impact of bone marrow-derived mesenchymal stem cells (BM-MSCs) alone or in combination with hepatocyte growth factor (HGF) transplantation via noninfarct-relative artery in a swine myocardial infarction (MI) model. Donor BM-MSCs were derived in vitro from swine auto-bone marrow cultures labeled by bromodeoxyuridine (BrdU) incorporation. Host MI swine model was created by ligating the distal left anterior descending artery. After 4 weeks, age-matched male MI swines were used for the transplantation. Male MI swines were transfused via noninfarct-relative artery with vehicle (control, n=6) or BrdU-labeled BM-MSCs (5 x 10(6)) alone (MSCs, n=6) or BrdU-labeled BM-MSCs (5 x 10(6)) combined with HGF (4 x 10(9) PFU) (MSCs+HGF, n=6). To evaluate the collateral artery growth (Rentrop) and cardiac perfusion in these animals, gate cardiac perfusion imaging and coronary angiography were performed before and 4 weeks after transplantation, respectively. To assess the contribution of donor-originated cells in stimulation of cardiomyocyte regeneration and angiogenesis, immunohistochemistry for BrdU and alpha-smooth muscle actin (alpha-SMA) and quantitative image analysis were performed at 4 weeks after transplantation. The results are as follows: (1) BrdU-positive cells were detected in host myocardium in both MSCs and MSCs+HGF groups, but not in the vehicle group. Most BrdU-positive cells expressed myosin heavy chain beta. (2) alpha-SMA(-)positive arteriole densities in the infarcted border area and infarcted area were increased significantly in both transplantation groups compared with the vehicle group. (3) Gate cardiac perfusion imaging demonstrated that the cardiac perfusion was significantly improved in transplantation groups compared with the vehicle group. (4) Ejection fraction and alpha-SMA-positive arteriole densities were increased significantly in both transplantation groups compared with the vehicle group. However, there was no difference in ejection fraction and alpha-SMA-positive arteriole densities between the MSCs group and the MSCs+HGF group. Growth of collateral arteries was not detected by coronary angiography in all three groups. In conclusion, the current study indicates that BM-MSCs transplantation via noninfarct-relative artery stimulates cardiomyocyte regeneration and angiogenesis and improves cardiac function, but does not stimulate collateral artery growth. BM-MSCs transplantation combined with HGF therapy is not superior to BM-MSCs alone transplantation. BM-MSCs transplantation via noninfarct-relative artery may be an alternative for those patients who cannot be transplanted via infarct-relative artery in clinical practice.

[Changes in cyclin expression during proliferation and differentiation of CD34(+) cells derived from fetal liver induced by thrombopoietin].

In order to elucidate the intrinsic mechanism underlying proliferation and differentiation of megakaryocytes during ontogenesis, CD34(+) cells were isolated from human fetal liver (FL) with a high-gradient magnetic sorting system (MACS) and were incubated in liquid suspension with 50 and 100 ng/ml of thrombopoietin (TPO) and in MegaCult(Tm) -C semi-solid culture system with 0, 12.5, 25, 50, 100, and 200 ng/ml of TPO. The cell number, colony number of CFU-Mk, platelet-associated antigen phenotype, and DNA ploidy of CD41(+) cells were examined from d 0 to d 12 in culture. The expression patterns of cyclins B1, D1, and D3 were also analyzed by using immunoblot and flow cytometry. TPO stimulated proliferation of CD34(+) cells of FL from 1 x 10(5)/ml to 13.12 +/-4.06 10(5)/ml with 95% of CD41a(+) cells and 3% of CD34(+) cells after 12 d of culture. Most of the megakaryocytes (MKs) derived from FL were in 2 N ploidy class, and few in 4 N ploidy class, but no megakaryocytes ploidy class was higher than 4 N. The effect of TPO on the formation of CFU-Mk colonies from FL derived CD34(+) cells is shown in a dose-response curve. The expression of cyclin B1 increased progressively and the high level of cyclin B1 was maintained in FL CD34(+) cells induced by TPO during 12 d of culture. A high level of cyclin B1 appeared on FL derived MKs of G1 phase at d 12. The expression of cy-of cyclins D1 and D3 gradually increased in FL CD34(+) cells, which was induced by TPO during the initial 6-day incubation. Afterwards, the level of cyclins D1 and D3 decreased progressively, particularly in MKs which were in G2+M phases. These data suggest that (1) TPO induced proliferation and differentiation of FL derived CD34(+) cells through upregulation of cyclin B1 in G2+M phases and cyclins D1 and D3 in all phases of cell cycle, and (2) Continuing high level of cyclin B1 and decreases of cyclins D1 and cyclin D3 on MKs in G2+M phases may contribute to a retardation of MK endoreduplication.

CD34+ cells derived from fetal liver contained a high proportion of immature megakaryocytic progenitor cells.

Endoreplication and maturation of the megakaryocyte (MK) may be retarded or delayed during ontogenesis. In this study, CD34+ cells were isolated from both human fetal liver and adult bone marrow and incubated with thrombopoietin (TPO). The cell number, morphological characteristics, platelet-associated antigen phenotype, maturation stage and DNA ploidy of CD41+ cells were examined from day 0 to day 12 in culture. 1) TPO stimulated the proliferation of fetal liver (FL)-derived CD34+ cells with a mean 73.14-fold increase of CD41+ cells after 12 d in culture. Adult BM-derived CD34+ cells increased only slightly, with a mean 8.18-fold increase of CD41+ cells. 2) Although the membrane phenotype of both FL CD34+-derived MKs and BM CD34+ -derived MKs analyzed with CD41a, CD42a, CD61 and CD34 were similar, all FL CD34+-derived MKs were in maturation stage I and II and in low ploidy (<4N) class. By comparison, BM CD34+ MKs possessed 15% MKs in maturation stage III and IV and with 23% MKs in high ploidy class ( > 4N). 3) Most of cultured FL-derived CD34+ cells did not have a well developed demarcation system (DM) and numerous alpha-granules after 12 d incubation. von Willebrand factor (vWF) appeared earlier on the cultured BM-derived CD34+ cells than on FL-derived CD34+ cells. 4) The expression of both cyclin E and cyclin B1 progressively increased in FL CD34+ cells induced by TPO during 12 d in culture. 5) The expression of cyclin D1 gradually decreased in FL CD34+ cells induced by TPO over 12 d incubation. 6) Immunocytochemical analysis showed that cyclin D3 was detected only in cytoplasm of cultured FL-derived CD34+ cells, whereas in both cytoplasm and nuclei of cultured BM-derived CD34+ cells. These data suggest that FL-derived CD34+ cells contain a high proportion of immature megakaryocytic progenitor cells. It further suggests that TPO can push these progenitor cells into proliferation by upregulating the expression of cyclins B1 and E, and drive a high proportion of cells into megakaryocytic lineage.

Selective induction of apoptosis of NB4 cells from G2+M phase by sodium arsenite at lower doses.

Apoptosis of NB4 cells induced by sodium arsenite and arsenate was studied using flow cytometry and DNA gel electrophoresis in order to investigate their effects on cell cycle and determine the relationship between apoptosis and cell cycle. In this study, we found that: 1) at low doses, sodium arsenite selectively induced apoptosis of NB4 cells in G2+M phase of cell cycle after its being arrested in G2 phase. With increment of the cells blocked in G2 phase, dUTP-specifically labeling cells in G2+M phase increased without concomitant increment of dUTP-labeling cells in other two phases of cell cycle; 2) at high doses, extensive apoptosis was induced in NB4 cells from all phases of cell cycle without cell cycle preference and cell cycle blockade; 3) sodium arsenite-induced apoptosis of NB4 cells occurred in the presence of bcl-2 expression as the unapoptotic cells; 4) sodium arsenite with As3+ induced apoptosis of NB4 cells more strongly than sodium arsenate with As5+ did although both of them affected NB4 cells in the same pattern. These results not only suggested that both arsenite and arsenate induced apoptosis of NB4 cells through 2 different mechanisms--at low doses, arsenical might directly induce apoptosis through regulation of cell cycle checkpoint, while at high doses they might directly induce it, but also indicated that bcl-2 might not play an important role in arsenite or arsenate-induced apoptosis of NB4 cells, whereas chemical valence of As in a compound might be related to efficiency in arsenical induction of apoptosis.

[In vitro growth characteristics of rIL3 stimulated megakaryocytic progenitor cells (CFU-MK) of fetal liver].

In this study, plasma clot and methycellulose semi-solid and liquid culture technigues were employed to observe the in vitro growth characteristics of proliferation and differetiation of 4-5 months fetal liver and adult bone marrow CFU-MKs. Fetal liver MK colonies in plasma clot in the presence of rIL3 or Meg-CSA were larger (usually with > 50 cells/colony) than that of the adult (usually with < 50 cells/colony). The number (36.40 +/- 16.60/1 x 10(5) cells) of fetal liver Mk colonies in presence of 2 ng/ml rIL3 was larger than that (10.05 +/- 2.81/1 x 10(5) cells) of human adult bone marrow MK colonies (P < 0.01). In contrast, the major DNA ploidy classes of megakaryocytes derived from fetal liver CFU-MK were those of 2N and 4N cells and the major DNA ploidy classes of megakaryocytes derived from human adult bone marrow were those of 8N and 4N cells. The mean (5.45 +/- 0.86) of the ploidy of the former was lower than that (10.13 +/- 1.30) of the latter (P < 0.01). The same results were obtained with the presence of 10% Meg-CSA. These present results indicated that CFU-MK in fetal liver has a high ability of proliferation and low capacity of differentiation (polyploidization). Interestingly, the number of fetal liver MK colonies increased in the range of rIL3 concentration from 0.5 ng/ml to 2 ng/ml. At higher rIL3 concentration (2-8 ng/ml), the colony growth showed a steady decrease from the maximum value instead of an increase. However, in the same range of rIL3 concentration, the numbers of adult bone marrow MK colonies numbers and fetal liver CFU-GM colonies increased steadily and finally reached to a plateau. Furthermore, both fetal liver and adult bone marrow MK colonies showed dose-dependent response in the range of Meg-CSA concentration from 5% to 25%. In addition, there was no difference on DNA ploidy distributions of megakaryocytes derived from fetal liver CFU-MK between rIL3 and Meg-CSA as growth factors. Moreover, the DNA ploidy distribution of fetal liver derived megakaryocytes stimulited by rIL3 could not be changed by addition of rIL6 (100 u/ml). In summary, the above data suggest that CFU-MK in the fetal liver undergoes some intrinsic cellular modification in order to suit the need of ontogensis.

Developmental change of megakaryocyte maturation and DNA ploidy in human fetus.

Megakaryocytes in fetal livers obtained from 30 water-balloon aborted normal fetuses of 3 to 6 months' gestation, in the bone marrow from the same 30 fetuses, and another 9 fetuses of 7 to 8 months' gestation and in the normal bone marrow of adults were analyzed by immunocytochemical staining for size and maturation stage distribution and by flow cytometry for ploidy distribution simultaneously. In human fetuses, megakaryocytes showed a shift during ontogenesis from smaller towards larger size and from less mature towards a more mature stage with advancement of gestation. This was accompanied by a significant progressive shift to higher ploidy. However, the proportions (78.64%) of hypoploidy (< or = 8N) megakaryocytes in bone marrow of 7-8 months' gestation fetuses was still much higher than that (33.32%) in human adults (p < 0.05), with the proportion of hyperploidy (> or = 16N) megakaryocytes lower than that (67.86%) in human adults. This result indicated that megakaryocyte polyploidization may be retarded or inhibited during development.