Effect of a lytic bacteriophage on rabbits experimentally infected with pathogenic Escherichia coli

Pathogenic <em>Escherichia coli</em> (<em>E. coli</em>) is severely threatening the rabbit industry in China, and the concern over antibiotic-resistant bacteria has given rise to an urgent need for antibiotic alternatives. In this study, a member (ZRP1) of the <em>Myoviridae</em> family was isolated from rabbit faeces using a strain of rabbit atypical enteropathogenic <em>E. coli</em> (ZR1) as host. The one-step growth curve indicated that the latent period was around 25 to 30 min and the burst size was 144±31 plaque-forming unit/cell. The rate of phage-resistant mutation was 7×10^–5±4×10^–5. When the bacteriophage input at the multiplicity of infection (MOI) was 0.1, 1 or 10, the growth of host <em>E. coli</em> in broth was inhibited for 5 h. A single intravenous injection of ZRP1 at MOI 0.1, 1 or 10 significantly prolonged the survival time of rabbits which simultaneously received a lethal dose of ZR1.

Chemical investigations of volatile kairomones produced by Hyphantria cunea (Drury), a host of the parasitoid Chouioia cunea Yang

In tritrophic 'plants-herbivores-natural enemies' systems, there are relatively few reports concerning the role(s) of kairomones in pupal parasitism. Chouioia cunea Yang (Hymenoptera: Eulophidae), an endoparasitic chalcid wasp, parasitizes pupae of the fall webworm (Hyphantria cunea Drury). The role of host-related kairomones was investigated using electroantennogram (EAG) and behavioral techniques. Chemicals from some host stages (pupae) and host by-products (frass), induced arrestment behavior of female parasitoids, while chemicals from prepupae, were inactive. Gas chromatography-mass spectrometry analysis of volatiles collected from pupae, frass and prepupae using solid-phase microextration revealed seven compounds with carbon chain lengths ranging from C4 to C20. All of the chemicals elicited significant EAG responses in C. cunea. Y-tube olfactometer bioassays demonstrated a significant positive response of mated female C. cunea to 1-dodecene. These data provide a better understanding of the host location mechanisms of pupal parasitoid.

In vitro production of Sudanese camel (Camelus dromedarius) embryos from epididymal spermatozoa and follicular oocytes of slaughtered animals

Application of assisted reproductive technology in camelidea, such as artificial insemination (AI) and embryo transfer, has been slow in comparison to that for other livestock species. In Egypt, there are few attempts to establish in vitro maturation (IVM) and fertilization (IVF) techniques in dromedary camel. The present study was carried out to produce Sudanese camel embryos using in vitro matured oocytes and epididymal spermatozoa. Dromedary camel ovaries were collected from abattoirs and then, the oocytes were aspirated from all the visible follicles on the ovarian surface (~2-8 mm in a diameter). Meanwhile, Fetal Dromedary Camel Serum (FDCS) was obtained from camel fetuses after slaughtering. Thereafter, only Cumulus Oocyte Complexes (COCs) were matured in vitro in the Tissue Culture Medium (TCM-199) complemented with 10% FDCS. Spermatozoa required for in vitro fertilization were collected from testes (epididymal cauda) of the slaughtered camel bulls. The results clearly showed that the maturation rate of oocytes at metaphase II was about 59.5% while the fertilization rate was around 70.4%. Intriguingly, the embryo rates determined were 13.1%, in 2-cell; 0.0%, in 4-cell; 34.7%, in 8-16% cell; 39.1%, in morula and 13.1% in a blastocyst stage. This study represented a successful in vitro production of Sudanese dromedary camel embryos from epididymal sperm cells and in vitro matured oocytes recovered from slaughtered camels.

Increased expression of nerve growth factor correlates with visceral hypersensitivity and impaired gut barrier function in diarrhoea-predominant irritable bowel syndrome: a preliminary explorative study

BACKGROUND

Neural-immune-endocrine network mechanism has attracted increased attention in diarrhoea-predominant irritable bowel syndrome (IBS-D). Pre-clinical evidence indicates that nerve growth factor (NGF) mediates visceral hypersensitivity and gut barrier dysfunction, via interactions with mast cells and sensory nerve fibres.

AIM

To explore the role of nerve growth factor, as well as mast cell-nerve growth factor-nerve interaction in IBS-D pathophysiology.

METHODS

In this cross-sectional study, IBS-D patients and healthy controls first underwent clinical and psychological assessments. Visceral sensitivity to rectal distension was tested. As gut barrier function markers, serum diamine oxidase and d-lactate were detected. Rectosigmoid biopsies were taken for the analyses of nerve growth factor expression, mast cell count and activation, and sensory nerve fibres expressing transient receptor potential vanilloid 1 and calcitonin gene-related peptide. Correlations between these parameters were examined in patients.

RESULTS

Thirty-eight IBS-D patients (28 males, 10 females; average age 30.2 years) and 20 healthy controls (12 males, 8 females; average age 26.8 years) participated in the study. The patients presented increased psychological symptoms, visceral hypersensitivity and impaired gut barrier function. NGF gene expression, mast cell count and sensory nerve fibres were significantly increased in the patients (P < 0.05). In correlation analysis, NGF expression was positively correlated with the disease severity, anxiety and serum diamine oxidase; visceral sensitivity thresholds were negatively associated with NGF expression (Bonferroni corrected P < 0.0029).

CONCLUSIONS

Elevated mucosal NGF may interact with mast cells and sensory nerve fibres, contributing to visceral hypersensitivity and impaired gut barrier function in IBS-D.

Increased expression of LncRNA BANCR and its prognostic significance in human epithelial ovarian cancer

PURPOSE

Long non-coding RNAs (lncRNAs) have been proved to play important roles in the tumorigenesis and development of human epithelial ovarian cancer (EOC). The aim of the present study was to investigate the expression and clinical value of BRAF-activated non-coding RINA (BANCR) in EOC patients.

MATERIALS AND METHODS

BANCR expression was detected in 84 EOC and 36 normal ovarian epithelial tissue samples. Association between BANCR levels and clinicopathological factors and patient prognosis was also analyzed.

RESULTS

BANCR expression was increased in EOC compared with normal ovarian epithelial tissues. Moreover, high expression of BANCR was closely correlated with advanced FIGO stage, higher serum, CAI125 expression level, and lymph node metastasis. Multivariate regression analysis identified BANCR overexpression as an independent unfavorable prognostic factor in EOC patients.

CONCLUSIONS

These findings suggested that BANCR may act as a tumor promoter in EOC and would be a novel diagnostic and prognostic marker for this disease.

A new phytase continuously hydrolyzes phytate and improves amino acid digestibility and mineral balance in growing pigs fed phosphorous-deficient diet

Ten ileal T-cannulated pigs (19.26 ± 1.06 kg) were used to evaluate the effects of a novel phytase on apparent ileal digestibility (AID) of AA and apparent total tract digestibility (ATTD) and hindgut disappearance of DM, GE, CP, crude fiber, NDF, and ADF as well as minerals balance. Pigs were fed in a duplicated 5 × 4 incomplete Latin square design (5 diets with 4 periods). Each period consisted of a 5-d adjustment period followed by a 3-d total collection of feces and urine and then a 2-d collection of ileal digesta. The 5 diets included a P-deficient basal diet (0.43% Ca and 0.38% total P) that was supplemented with 0 (negative control [NC]), 500, 1,000, or 20,000 phytase units (FTU)/kg phytase and a positive control (PC) diet that was P adequate (0.64% Ca and 0.52% total P). The addition of phytase to the NC diet improved ( < 0.05) AID of phytate from 11.1 to 62.8, 70.6, and 90.5% at the inclusion rates of 500, 1,000, and 20,000 FTU/kg, respectively. In general, phytase supplementation at a dose of 20,000 FTU/kg further increased ( < 0.05) AID of Ca, total P, and phytate and reduced ( < 0.05) the ileal phytate concentration compared with diets with 500 or 1,000 FTU/kg phytase. Pigs fed the diet with 20,000 FTU/kg phytase but not diets with 500 and 1,000 FTU/kg phytase showed improved ( < 0.05) ATTD of CP and AID of DM, GE, CP, Leu, Lys, Thr, Val, Asp, and Ser compared with pigs fed the PC or NC diet. However, hindgut disappearance of crude fiber and NDF ( < 0.05) were reduced in pigs fed the diet with 20,000 FTU/kg phytase compared with pigs fed the PC or NC diet. Pigs fed diets with 500 or 1,000 FTU/kg phytase had greater ATTD and retention of Ca and P than pigs fed the NC diet but less compared with pigs fed the diet with 20,000 FTU/kg phytase. Supplementation of 20,000 FTU/kg phytase to the NC diet improved ( < 0.05) digestibility of Na, Mn, and Zn as well as retention (%) of Zn. Increasing phytase supplementation doses from 0 to 1,000 FTU/kg linearly improved ( < 0.05) retention of Mg; meanwhile, digestibility of Mg and Mn and AID of Thr showed a linear increase trend ( = 0.084). In conclusion, supplementation of the novel phytase at doses up to 20,000 FTU/kg hydrolyzed most of the phytate (90%) and consequently further improved mineral and protein utilization.

The antisense expression of

Although phosphoenolpyruvate carboxylases (PEPCs) are reported to be involved in fatty acid accumulation, nitrogen assimilation, and salt and drought stresses, knowledge regarding PEPC gene functions is still limited, particularly in peanuts (Arachis hypogaea L.). In this study, the antisense expression of the peanut PEPC isoform 1 (AhPEPC1) gene increased the lipid content by 5.7%–10.3%. This indicated that AhPEPC1 might be related to plant lipid accumulation. The transgenic plants underwent more root elongation than the wild-type under salinity stress. Additionally, the specific down regulation of the AhPEPC1 gene improved the salt tolerance in peanuts. This is the first report on the role of PEPC in lipid accumulation and salt tolerance in peanuts.

Trends in state/territorial obesity prevalence by race/ethnicity among U.S. low-income, preschool-aged children

BACKGROUND

Understanding state/territorial trends in obesity by race/ethnicity helps focus resources on populations at risk.

OBJECTIVE

This study aimed to examine trends in obesity prevalence among low-income, preschool-aged children from 2008 through 2011 in U.S. states and territories by race/ethnicity.

METHODS

We used measured weight and height records of 11.1 million children aged 2-4 years who participated in federally funded health and nutrition programmes in 40 states, the District of Columbia and two U.S. territories. We used logistic regression to examine obesity prevalence trends, controlling for age and sex.

RESULTS

From 2008 through 2011, the aggregated obesity prevalence declined among all racial/ethnic groups (decreased by 0.4-0.9%) except American Indians/Alaska Natives (AI/ANs); the largest decrease was among Asians/Pacific Islanders (A/PIs). Declines were significant among non-Hispanic whites in 14 states, non-Hispanic blacks in seven states/territories, Hispanics in 13 states, A/PIs in five states and AI/ANs in one state. Increases were significant among non-Hispanic whites in four states, non-Hispanic blacks in three states, Hispanics in two states and A/PIs in one state. The majority of the states/territories had no change in obesity prevalence.

CONCLUSIONS

Our findings indicate slight reductions in obesity prevalence and variations in obesity trends, but disparities exist for some states and racial/ethnic groups.

[Efficacy of GLIDE chemotherapy for patients with newly diagnosed advanced-stage or relapsed/refractory extranodal natural killer cell lymphoma]

目的

研究GLIDE（吉西他滨、门冬酰胺酶、异环磷酰胺、地塞米松、依托泊苷）方案治疗初发进展期及复发难治性结外鼻型NK/T细胞淋巴瘤（ENKL）患者的有效性及安全性。

方法

纳入2010年3月至2016年3月收治的初发进展期及复发难治性ENKL患者42例，给予GLIDE方案化疗，中位疗程数为3(2~6）个，评估化疗结束后缓解率及早期（2个疗程后）缓解率，采用Kaplan-Meier方法统计无进展生存（PFS）及总生存（OS），同时采用Cox回归方法进行多因素分析，寻找影响患者PFS及OS的独立预后因素。

结果

31例（73.8%）患者达到完全缓解（CR），其中22例（52.4%）为早期CR，31例CR患者中14例接受序贯自体造血干细胞移植（ASCT）。1年PFS与OS率分别为65.6％和82.7%，4年PFS与OS率分别为48.2％和63.1%，中位OS时间未达到，中位PFS时间为30.5个月。多因素分析提示美国东部肿瘤协作组体能状态评分（ECOG评分）0~1分以及CR后序贯ASCT为减少复发、延长患者生存的有利因素。

结论

GLIDE方案能够有效治疗初发进展期及复发难治性ENKL, ECOG评分0~1分及CR后序贯ASCT治疗是患者获得较长PFS和OS时间的独立预后因素。

[A multi-center clinical observation on safety and efficacy of a plasma derived coagulator factor Ⅷ for treatment of patients with hemophilia A]

OBJECTIVE

To evaluate the efficacy and safety of homemade plasma derived coagulation factor Ⅷ in patients with hemophilia A.

METHODS

Patients with congenital hemophilia A who met the inclusive and exclusive criteria were enrolled in the study after informed consent. The doses of factor Ⅷ were calculated according to the weight, disease severity etc. FⅧ activity and infusion efficacy value at 10 min and 60 min after infusion were recorded, as well as adverse events and validity rating according to the improvement of clinical syndromes. Viral infections including HBV, HCV, HIV and FⅧ inhibitor were determined after 3 and 6 months.

RESULTS

A total of 65 patients were enrolled in this study, all of whom were evaluable for drug safety. Treatment efficacy was evaluated in 60 patients and 57 cases completed the trial finally. In this 57 cases, most (52/57) subjects were of middle and severe hemophilia A mainly characterized by joint bleeding. Overall response rate of acute bleeding events was classified as "excellent" (70.00%) or "better" (30.00%). The non-responder was 0. FⅧ activity and infusion efficiency value of first administration after 10 min and 60 min improved significantly [10 min: (123.66±47.54)%; 60 min: (108.05±43.24)%]. The incidence of adverse events was 1.54%. Neither allergic reaction nor reactivation of HBV, HCV, HIV was detected after treatment of 3 and 6 months. No FⅧ inhibitor negative patients converted to positive during follow-up.

CONCLUSION

This homemade plasma derived coagulation factor Ⅷ is safe and effective for the treatment of acute bleeding in patients with hemophilia A.

Inhibition of miR-141 reverses cisplatin resistance in non-small cell lung cancer cells via upregulation of programmed cell death protein 4

OBJECTIVE

MicroRNAs are a class of essential regulators in cancer, and previous studies have shown that miR-141 is a tumor suppressor in non-small cell lung cancer (NSCLC). However, it is still unknown whether it regulates chemosensitivity. We aimed to investigate the role of miR-141 in cisplatin resistance in NSCLC cells.

MATERIALS AND METHODS

MiR-141 expression in A549 and A549/DDP cell lines have been quantified by real-time PCR. Protein level of PDCD4 and caspase-3 have been determined by Western blot analysis. Drug sensitivity and apoptosis have been determined by MTT assay and TUNEL assay, respectively. Luciferase activity assay was employed to validate the relationship between 3'UTR of PDCD4 mRNA and miR-141.

RESULTS

We observed that miR-141 expression was significantly up-regulated in cisplatin-resistant A549/DDP cells compared with the parental cell line A549; and PDCD4, an important apoptosis regulator, was found to be down-regulated. Luciferase activity assay and Western blot analysis confirmed that PDCD4 is a direct target of miR-141. Inhibition of miR-141 in A549/DDP cells markedly increased cisplatin sensitivity and apoptosis, which was partially abrogated by PDCD4 inhibition, indicating that PDCD4 is a functional target of miR-141 in of the regulation of cisplatin sensitivity.

CONCLUSIONS

Our data showed that miR-141 participates in regulating cisplatin sensitivity in non-small lung cancer cells via PDCD4 inhibition, and suppression of miR-141 might be a therapeutic method to overcome cisplatin resistance in clinical practice.

Stereoselectivity of tradinterol's inhibition on proliferation of airway smooth muscle cells induced by acetylcholine through suppressing Ca(2+) signalling

The objective of this study is to investigate whether the inhibition of tradinterol (SPFF) against acetylcholine (ACh)-induced proliferation is mediated by Ca(2+) signaling in airway smooth muscle cells (ASMCs), and whether stereoselectivity of the drug exists. Guinea pig ASMCs were primarily prepared with the method described and treated with ACh combined to SPFF isomers for 24 or 48 hours, respectively. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to determine the proliferation of the guinea pig ASMCs. Ca(2+) fluorescent intensity in the guinea pig ASMCs, expressed with percentage increase in fluorescence when the intensity was determined with varioskan flash or shown with percentage increase in Geo Mean (GM) measured with flow cytometry, was recorded. Images of the intensity were obtained with fluorescent microscope. 2-APB, an (inositol 1,4,5-trisphosphate receptor) IP3R blocker, and NiCl2, a store-operated channel (SOC) inhibitor, were used to investigate the mechanism of SPFF isomers regulating intracellular Ca(2+) via IP3R on sarcoplasmic reticulum (SR) and/or SOC on plasma membrane. (-)SPFF and (±)SPFF, treated for 48 hours, showed significant inhibition against ACh-induced proliferation. The Ca(2+) elevation induced by ACh was concentration-dependently suppressed by SPFF isomers. (-)SPFF is the most effective but the potency of (±)SPFF is less than that of the former and stronger than that of (+)SPFF based on the half maximal inhibitory concentration (IC50) value. No significant additive effect was observed when (-)SPFF/(±)SPFF was used alone and combined with NiCl2/2-APB. As far as (+)SPFF is concerned, no similar phenomenon was observed. (-)SPFF and (±)SPFF but (+)SPFF showed significant inhibition against the percentage increase in fluorescence induced by CaCl2. It is likely that the influence of IP2RSOC-mediated Ca(2+) signaling in ASMCs helps (-)SPFF and (±)SPFF contribute to the suppression of ASMCs proliferation. Stereoselectivity of SPFF isomers may lead to different levels of suppression of ACh-induced intracellular Ca(2+) and ASMCs proliferation. Moreover, cell cycle analysis with flow cytometry was applied to the evaluation of the action in human ASMCs in order to further confirm the anti-proliferative effect of the drugs. It was found that (-)SPFF, (±)SPFF but (+)SPFF suppressed the elevated rate of cell population in Phase S over all the cells stimulated with ACh, when SPFF and its isomers were individually exposed to the cells for 72 hours. These results that demonstrate the different stereoselective activities of SPFF are in consistent with those obtained from the guinea pig ASMCs.

Scatter to volume registration for model-free respiratory motion estimation from dynamic MRIs

Respiratory motion is one major complicating factor in many image acquisition applications and image-guided interventions. Existing respiratory motion estimation and compensation methods typically rely on breathing motion models learned from certain training data, and therefore may not be able to effectively handle intra-subject and/or inter-subject variations of respiratory motion. In this paper, we propose a respiratory motion compensation framework that directly recovers motion fields from sparsely spaced and efficiently acquired dynamic 2-D MRIs without using a learned respiratory motion model. We present a scatter-to-volume deformable registration algorithm to register dynamic 2-D MRIs with a static 3-D MRI to recover dense deformation fields. Practical considerations and approximations are provided to solve the scatter-to-volume registration problem efficiently. The performance of the proposed method was investigated on both synthetic and real MRI datasets, and the results showed significant improvements over the state-of-art respiratory motion modeling methods. We also demonstrated a potential application of the proposed method on MRI-based motion corrected PET imaging using hybrid PET/MRI.

Adipose-derived stem cells undergo spontaneous osteogenic differentiation in vitro when passaged serially or seeded at low density

Adipose-derived stem cells (ADSCs) are a convenient source of cells for regenerating tissue. Widespread application of ADSCs requires that they propagate efficiently and differentiate in vitro. We investigated the differentiation potential of ADSCs during long-term expansion in vitro and when the cells were seeded at low density. ADSCs were isolated from the inguinal fat pads of 3-week-old male rats, then cultured serially for 12 passages; some ADSCs at passage 3 were seeded at low density. The differentiation potential of ADSCs from passage 3 to passage 12 was assessed by their capacity for adipogenesis and osteogenesis while cultured in specific induction media. Spontaneous osteogenesis of ADSCs at passage 12 and of ADSCs that were seeded at low density was detected by western blotting, alizarin red S staining and measurement of alkaline phosphatase (ALP) activity. We found that with increasing passage number, the adipogenic potential of ADSCs decreased and osteogenic differentiation increased. Alizarin red S staining, bone morphogenetic protein-2 (BMP-2) and runt-related transcription factor 2 (Runx2) expressions, and ALP activity demonstrated that both ADSCs at passage 12 and those that were seeded at low density differentiated into osteoblasts without additional induction factors.

[Effects of artesunate on cigarette smoke-induced lung oxidative damage in mice and the expression of Nrf2 and the possible mechanism]

OBJECTIVE

To explore the effects of artesunate on cigarette smoke-induced lung oxidative damage in mice and the expression of Nuclear factor-E2-related factor 2 (Nrf2).

METHODS

In vivo: A total of 40 female specific pathogen free BALB/c mice were divided randomly into four groups: normal group, cigarette smoke group, vehicle group and artesunate group. The latter three groups were exposed on cigarette smoke for 40 days. Vehicle (5% NaHCO3 containing 5% dimethyl sulfoxide, 0.1 ml of each mice) or artesunate (30 mg/kg, dissolved in the 0.1 ml vehicle) was given by intraperitoneal injections before each passive smoking of the vehicle or artesunate group. Saline of 0.1ml was given to the normal and cigarette smoke groups as negative controls. Cells in bronchoalveolar lavage fluid (BALF) were collected and analyzed by absolute different cell counts. Interleukin (IL)-8 levels in BALF and 3-nitrotyrosine (NT) levels in lung tissue were tested by emzyme linked immunosorbent assay (ELISA). Malondialdehyde levels in serum, total superoxide dismutase (SOD) activity and total glutathione peroxidase (GPx) activity in lung tissue were detected. The pathological changes of lung tissues were observed by HE staining. And the expression levels of Nrf2 were measured by Westernblotting. In vitro: 16HBE cells were cultured and transfected with Nrf2 siRNA. Cigarette smoke extract (CSE) were used to stimulate the secretion of IL-8 in cells. Cells were divided into five groups: blank group, non-transfected non-artesunate group, non-transfected artesunate group, transfected non-artesunate group and transfected artesunate group. The latter four groups were incubated with CSE, and non-transfected artesunate and transfected artesunate groups were intervened with artesunate (30 μmol/L) before CSE incubation. The IL-8 levels of each group were measured using ELISA kit.

RESULTS

In vivo: The total cell counts of BALF in artesunate group were significantly lower than the vehicle group [21.00(2.50)×10(4)/ml vs 35.50(2.50)×10(4)/ml, P<0.001], especially neutrophil counts [6.00(5.12)×10(4)/ml vs 13.60(5.25)×10(4)/ml, P<0.001]. The IL-8 levels in BALF, malondialdehyde levels in serum, 3-NT levels and total SOD activity in lung tissue of artesunate group were all drastically lower than those in the vehicle group [(508±55) vs (912±68) ng/L, (38.2±8.8) vs (48.7±10.6) μmol/L, (28.5±5.8) vs (50.0±9.7) μg/L and (11.8±1.8) vs (18.0±5.3) U/mg protein, respectively, all P<0.05]. No significant difference of total GPx activity existed in these four groups. And the expression level of Nrf2 in artesunate group significantly increased than that in vehicle group (P=0.008). In vitro: The IL-8 level of the non-transfected artesunate group was significantly lower than the non-transfected non-artesunate group [(352±26) vs (765±22) ng/L, P<0.001], while the IL-8 levels between the transfected artesunate and transfected non-artesunate groups had no significant difference.

CONCLUSION

Arteunate attenuates cigarette smoke-induced lung oxidative damage in mice and increases the expression level of Nrf2, and its effects might be mediated by the actions of nuclear Nrf2.

Effects of Coated Compound Proteases on Apparent Total Tract Digestibility of Nutrients and Apparent Ileal Digestibility of Amino Acids for Pigs

Two experiments were conducted to evaluate effects of coated compound proteases (CC protease) on apparent total tract digestibility (ATTD) of nitrogen (N) and energy, and apparent ileal digestibility (AID) of amino acids (AA) and nutrients in diets for pigs. In Exp. 1, 12 crossbred barrows (initial body weight: 20.14±1.71 kg) were housed in individual metabolism crates and allotted into 2 treatments with 6 piglets per treatment according to weight in a randomized complete block design. The 2 diets were corn-soybean meal basal diets with (0.2 g/kg) or without CC protease supplementation. The CC protease supplementation increased (p<0.05) the digestible and metabolizable N and energy values and the digestibility and retention rate of N in the diet. The ATTD of energy and nutrients had been improved (p<0.05) in the diet supplemented with CC protease. In Exp. 2, 12 crossbred barrows (initial body weight: 20.79±1.94 kg), fitted with T-cannulas at the distal ileum, were blocked by body weight into 2 groups with 6 pigs each. The diets were the same as those in Exp. 1. The CC protease increased (p<0.05) the AID of crude protein and some essential AA including arginine, isoleucine and leucine. The AID and ATTD of energy and nutrients had been improved (p<0.05) by supplemental CC protease, but the hindgut digestibility of nutrients was unaffected. Overall, the CC protease improved the ATTD of N and energy and AID of some indispensible AA and nutrients in the corn-soybean meal diet for pigs. Therefore, the CC protease supplement could improve the utilization of protein in the corn-soybean meal diet and thus contribute to lower N excretion to the environment.

Microphthalmia-associated transcription factor/T-box factor-2 axis acts through Cyclin D1 to regulate melanocyte proliferation

OBJECTIVES

Control of cell proliferation is critical for accurate cell differentiation and tissue formation, during development and regeneration. Here, we have analysed the role of microphthalmia-associated transcription factor MITF and its direct target, T-box factor TBX2, in regulating proliferation of mammalian neural crest-derived melanocytes.

MATERIALS AND METHODS

Immunohistochemistry was used to examine spatial and temporal expression of TBX2 in melanocytes in vivo. RNAi and cell proliferation analysis were used to investigate functional roles of TBX2. Furthermore, quantitative RT-PCR, western blot analysis and flow cytometry were used to further scrutinize molecular mechanisms underlying TBX2-dependent cell proliferation.

RESULTS

TBX2 was found to be co-expressed with MITF in melanocytes of mouse hair follicles. Specific Tbx2 knockdown in primary neural crest cells led to inhibition MITF-positive melanoblast proliferation. Tbx2 knockdown in melan-a cells led to reduction in Cyclin D1 expression and G1-phase cell cycle arrest. TBX2 directly activated Ccnd1 transcription by binding to a specific sequence in the Ccnd1 promoter, and the defect in cell proliferation could be rescued partially by overexpression of Cyclin D1 in Tbx2 knockdown melanocytes.

CONCLUSIONS

Results suggest that the Mitf-Tbx2-Cyclin D1 pathway played an important role in regulation of melanocyte proliferation, and provided novel insights into the complex physiology of melanocytes.

Research on rat models of hypobaric hypoxia-induced pulmonary hypertension

OBJECTIVE

Rat models of hypobaric hypoxia-induced pulmonary hypertension are commonly used in studies of chronic mountain sickness, while there are few researches specially focusing on these rats model. This study aims to exploring possible pathogenesis of hypobaric hypoxia-induced pulmonary hypertension by experimenting on hypobaric hypoxia-induced PH rat models at different simulate- altitudes.

MATERIALS AND METHODS

32 healthy male SD rats were randomly divided into six groups of different degree and time period of hypobaric hypoxia. The mean pulmonary arterial pressure (m PAP), right ventricular pressure (RVSP), the right ventricle (RV), left ventricular (LV), ventricular septal (S), the right ventricular hypertrophy index (RVHI) [calculated under the formula of RV / (LV + S)], hematoxylin-eosin staining, elastic fibers staining, the ratio of the thickness of vascular wall to its outer diameter (MT%), the ratio of the cross-sectional area of the middle vascular wall to the total vascular cross-sectional area (MA%); the α-SMA, and the Ki6 expressions were detected to evaluated the pulmonary hypertension.

RESULTS

There were significant differences of the mPAP, RVSP and RVHI value between the hypobaric hypoxia groups and the control group (p < 0.05). The mPAP, RVSP, RVHI, MT%, MA%, α-SMA, and Ki6 of rats in model groups at an altitude of 3KM were higher than those of the control group, which raised gradually with the number of weeks increasing. The mPAP, RVSP, RV / (LV + S) value, MT%, MA%, α-SMA, and Ki67 of the 5KM-4W group were significantly higher than those of the control group (p < 0.05).

CONCLUSIONS

Rat models with pulmonary hypertension at different altitudes have been successfully established by automatic adjusting hypobaric hypoxia chamber. Exposure to a low oxygen environment at a simulate-altitude of 3 km for 8 weeks have caused the pathological remodeling of pulmonary vascular walls and pulmonary hypertension, and further led to a series of pathological changes, including right ventricular hypertrophy. This model is easy to be replicated with good reproducibility and provides evidence for clinical trial of drugs.

Reciprocal positive regulation between Cx26 and PI3K/Akt pathway confers acquired gefitinib resistance in NSCLC cells via GJIC-independent induction of EMT

Gefitinib efficiency in non-small-cell lung cancer (NSCLC) therapy is limited due to development of drug resistance. The molecular mechanisms of gefitinib resistance remain still unclear. In this study, we first found that connexin 26 (Cx26) is the predominant Cx isoform expressed in various NSCLC cell lines. Then, two gefitinib-resistant (GR) NSCLC cell lines, HCC827 GR and PC9 GR, from their parental cells were established. In these GR cells, the results showed that gefitinib resistance correlated with changes in cellular EMT phenotypes and upregulation of Cx26. Cx26 was detected to be accumulated in the cytoplasm and failed to establish functional gap-junctional intercellular communication (GJIC) either in GR cells or their parental cells. Ectopic expression of GJIC-deficient chimeric Cx26 was sufficient to induce EMT and gefitinib insensitivity in HCC827 and PC9 cells, while knockdown of Cx26 reversed EMT and gefitinib resistance in their GR cells both in vitro and in vivo. Furthermore, Cx26 overexpression could activate PI3K/Akt signaling in these cells. Cx26-mediated EMT and gefitinib resistance were significantly blocked by inhibition of PI3K/Akt pathway. Specifically, inhibition of the constitutive activation of PI3K/Akt pathway substantially suppressed Cx26 expression, and Cx26 was confirmed to functionally interplay with PI3K/Akt signaling to promote EMT and gefitinib resistance in NSCLC cells. In conclusion, the reciprocal positive regulation between Cx26 and PI3K/Akt signaling contributes to acquired gefitinib resistance in NSCLC cells by promoting EMT via a GJIC-independent manner.

Oncolytic reovirus induces intracellular redistribution of Ras to promote apoptosis and progeny virus release

Reovirus is a naturally oncolytic virus that preferentially replicates in Ras-transformed cells and is currently undergoing clinical trials as a cancer therapeutic. Ras transformation promotes reovirus oncolysis by enhancing virion disassembly during entry, viral progeny production, and virus release through apoptosis; however, the mechanism behind the latter is not well understood. Here, we show that reovirus alters the intracellular location of oncogenic Ras to induce apoptosis of H-RasV12-transformed fibroblasts. Reovirus infection decreases Ras palmitoylation levels and causes accumulation of Ras in the Golgi through Golgi fragmentation. With the Golgi being the site of Ras palmitoylation, treatment of target cells with the palmitoylation inhibitor, 2-bromopalmitate (2BP), prompts a greater accumulation of H-RasV12 in the Golgi, and a dose-dependent increase in progeny virus release and subsequent spread. Conversely, tethering H-RasV12 to the plasma membrane (thereby preventing its movement to the Golgi) allows for efficient virus production, but results in basal levels of reovirus-induced cell death. Analysis of Ras downstream signaling reveals that cells expressing cycling H-RasV12 have elevated levels of phosphorylated JNK (c-Jun N-terminal kinase), and that Ras retained at the Golgi body by 2BP increases activation of the MEKK1/MKK4/JNK signaling pathway to promote cell death. Collectively, our data suggest that reovirus induces Golgi fragmentation of target cells, and the subsequent accumulation of oncogenic Ras in the Golgi body initiates apoptotic signaling events required for virus release and spread.

Correlation between down-expression of miR-431 and clinicopathological significance in HCC tissues

BACKGROUND AND AIMS

Researches have shown that miRNAs have been proposed as novel diagnostic biomarkers for classification and prognostic stratification of HCC. However, whether or not miR-431 contributes to the progression of HCC remains unknown. Therefore, we aimed to investigate the clinicopathological significance of miR-431 in HCC.

METHODS

MiR-431 expression in 95 HCC cases and corresponding adjacent non-cancerous tissues was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, statistical analysis was performed to identify the correlations between expression of miR-431 and a variety of clinicopathological parameters and patient recurrence. The area under the receiver operating characteristic curve (AUC) was used to evaluate the accuracy of miR-431 as a biomarker for HCC diagnosis and prediction of disease deterioration.

RESULTS

MiR-431 was markedly down-regulated in the HCC samples (1.1885 ± 0.75867) compared with corresponding adjacent tumor tissues (1.7957 ± 0.89333, P < 0.001). The AUC of low miR-431 expression to diagnose HCC was 0.668 (95 % CI 0.592-0.744, P < 0.001). MiR-431 down-expression was correlated with multiple malignant characteristics, including lymph node metastasis (r = -0.455, P < 0.001), clinical TNM stage (r = -0.223, P = 0.030), MTDH (r = -0.292, P = 0.006), vaso-invasion (r = -0.204, P = 0.047), MVD (r = -0.281, P = 0.006) and HCV (r = 0.215, P = 0.037). Additionally, the recurrent time of lower miR-431 expression group was 56.602 ± 3.914 months, much longer than that in the high expression group (50.009 ± 2.731 months), however, no significant difference was noted (χ (2) = 0.005, P = 0.943).

CONCLUSIONS

The down-expression of miR-431 is partially responsible for a series of clinicopathological features which may be tightly correlated with the progression of HCC. Thus, expression of miR-431 may be proposed as a new factor in association with the progression of HCC.

Intrinsic and interfacial effect of electrode metals on the resistive switching behaviors of zinc oxide films

Exploring the role of electrode metals on the resistive switching properties of metal electrode/oxide/metal electrode sandwiched structures provides not only essential information to understand the underlying switching mechanism of the devices, but also useful guidelines for the optimization of the switching performance. A systematic study has been performed to investigate the influence of electrodes on the resistive switching characteristics of zinc oxide (ZnO) films in this contribution, in terms of both the intrinsic and interfacial effects. It has been found that the low-resistance state resistances (Ω(LRS)) of all the investigated devices are below 50 Ω, which can be attributed to the formation of highly conductive channels throughout the ZnO films. On the other hand, the high-resistance state resistances (Ω(HRS)) depend on the electronegativity and ionic size of the employed electrode metals. Devices with electrode metals of high electronegativity and large ionic size possess high Ω(HRS) values, while those with electrode metals of low electronegativity and small ionic size carry low Ω(HRS) values. A similar trend of the set voltages has also been observed, while the reset voltages are all distributed in a narrow range close to ±0.5 V. Moreover, the forming voltages of the switching devices strongly depend on the roughness of the metal/ZnO and/or ZnO/metal interface. The present work provides essential information for better understanding the switching mechanism of zinc oxide based devices, and benefits the rational selection of proper electrode metals for the device performance optimization.