P2Y12 deficiency in mouse impairs noradrenergic system in brain, and alters anxiety-like neurobehavior and memory

Purinergic receptor P2Y₁₂ (P2Y₁₂ ), a G protein-coupled purinergic receptor, is widely distributed in nervous system and involved in the progression of neurological diseases such as multiple sclerosis and neuropathic pain. The central noradrenergic system actively participates in a number of neurophysiological processes. Nevertheless, whether there is any direct relevance between P2Y₁₂ and noradrenergic signal transduction remains unknown. In the present study, we tested the hypothesis that lack of P2Y₁₂ impaired noradrenergic signal transduction in mouse brain. Our results showed that P2Y₁₂ knockout (KO) mice exhibited increased anxiety-like behavior in the open-field test (OFT) and elevated plus maze test and displayed deficits in memory in the radial-arm maze test (RAMT) and Morris water maze test (MWMT). They also exhibited reduced locomotion in the OFT and MWMT. Moreover, loss of P2Y₁₂ decreased the level of noradrenaline and the expression of noradrenergic α receptors, subtypes α2 (ARα2b) in mouse cerebellum and hippocampus. Meanwhile, it hampered the protein kinase A (PKA)/cAMP response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling pathway in these brain regions. Taken together, our results showed for the first time that P2Y₁₂ KO altered the anxiety, memory and locomotion of mice, which was closely associated with abnormal state of noradrenergic system in the brain. The findings implicate that P2Y₁₂ plays an indispensable role in noradrenergic signal transduction; its deficit is insufficient to limit anxiety responses or supports cognitive performance and activity.

Role of TIM-3 in ovarian cancer

Evidences have suggested that immunotherapy for ovarian cancer is effective. Immune checkpoints have emerged in the field of cancer immunotherapy. Multiple studies have shown negative regulation of TIM-3 expression on CD4⁺ and CD8⁺ T cells and other immunocytes. Overexpression of TIM-3 in innate immune cells has been found in certain types of tumor. The blockade of TIM-3 leads to sustained anti-tumor reactions. TIM-3 plays an inhibitive role for immunity in ovarian cancer. TIM-3 is involved in the development of various subtypes of ovarian cancer and thus has the potential to be a therapeutic target for treatment of ovarian cancer.

Embelin attenuates adipogenesis and lipogenesis through activating canonical Wnt signaling and inhibits high-fat diet-induced obesity

BACKGROUND

Recent studies suggest that Embelin, a natural plant extract might have the potential to prevent body weight gain in rats. However, the mechanisms involved remain to be elucidated.

METHODS

Effects of Embelin on adipocyte differentiation and lipogenesis were studied in murine ST2 stromal cells and C3H10T1/2 mesenchymal cells. The mechanisms through which Embelin regulates adipogenic differentiation and lipogenesis were explored. The in vivo anti-obesity effects of Embelin in high-fat diet (HFD)-induced obesity mice and possible transcriptional impact were investigated.

RESULTS

Embelin treatment suppressed ST2 and C3H10T1/2 cells to proliferate, and differentiate into mature adipocytes, along with the inhibition of adipogenic factors peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein-α, adipocyte protein 2 and adipsin. Embelin treatment also decreased the expression levels of lipogenic factors sterol regulatory element-binding protein 1, fatty acid synthase, acetyl-CoA carboxylase 1 and stearoyl-Coenzyme A desaturase 1. Embelin promoted the translocation of β-catenin from the cytoplasm into the nucleus in C3H10T1/2. The nuclear protein levels of β-catenin and TCF-4 were increased following Embelin treatment. Furthermore, Dickkopf-1 (Dkk1) expression was downregulated by Embelin, and overexpression of Dkk1 in C3H10T1/2 reversed the inhibition of adipogenesis and lipogenesis by Embelin. In vivo studies showed that Embelin treatment reduced the gain of body weight and fat, decreased the serum level of triglycerides, free fatty acid and total cholesterol, and improved glucose tolerance and insulin resistance in HFD-fed mice. Moreover, Embelin blocked induction of adipogenic and lipogenic factors and Dkk1 in adipose tissue in HFD-fed mice.

CONCLUSIONS

The present work provides evidences that Embelin is effective in inhibiting adipogenesis and lipogenesis in vitro and the mechanisms may involve canonical Wnt signaling. Embelin has the potential to prevent body weight gain and fat accumulation, and to improve obesity-related glucose tolerance impairment and insulin resistance in the HFD-fed mice.

The segregation resistance of the Pt2ML/Os/Pd3Al sandwich catalyst for oxygen reduction reaction: a density functional theory study

Pt_1ML/Pd₃Al, which comprises a Pd₃Al core protected by a Pt monolayer, may experience Al dealloying because of the strong affinity of Al toward O. To circumvent this issue, the Pt_2ML/Os/Pd₃Al catalyst has been designed to suppress the migration of Al by inserting an Os monolayer at the interface between the Pd₃Al core and two Pt monolayers. On the basis of segregation energies, Al leaching from the core to the 1st layer is determined to be endothermic even under O coverage, indicating an energetic preference for Al to reside in the core structure. The Pt_2ML/Os/Pd₃Al catalyst benefits from the energetic disadvantage of the inward movement of Os and the presence of the 2 ML Pt layer. As an ORR electrocatalyst, the relatively weak adsorption ability of Pt_2ML/Os/Pd₃Al suggests improved ORR activity. Finally, a representative OOH association mechanism with low reaction barriers of 0.46, 0.31, 0.38 and 0.41 eV for the OOH formation, OOH dissociation, OH formation and H₂O formation steps suggests that the catalyst can effectively activate the O-O bond and eliminate OH, which can act as a catalytic poison. These findings suggest the design of stable sandwich catalysts as potential candidates for ORR electrocatalysis.

A phase II trial to evaluate the efficacy of fostamatinib in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL)

PURPOSE

To assess the safety and efficacy of fostamatinib in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL).

EXPERIMENTAL DESIGN

Relapsed or refractory DLBCL patients originally received the oral spleen tyrosine kinase inhibitor, fostamatinib in a two-arm, randomised, double-blinded manner at either 100 mg twice a day (BID) or 200 mg BID until disease progression or unacceptable toxicity. The primary objective was to assess the overall response rate (ORR). Preliminary analysis showed limited efficacy and all subsequent patients were treated at 200 mg BID. Previously randomised patients were unblinded and given the opportunity to receive 200 mg BID.

RESULTS

Sixty-eight patients were treated (47 at 200 mg BID, 21 at 100 mg BID). Cell of origin analysis showed 58% germinal B-cell (GCB) origin, 30% activated B-cell (ABC) origin and 12% with an intermediate cell of origin signature. The most common treatment-related adverse events of all patients were diarrhoea (21% total, 6% grade 3/4), nausea (19% total, 3% grade 3/4), and, fatigue (18% total, 9% grade 3/4). The ORR rate was 3% across both arms and clinical benefit (≥ stable disease) was achieved for 13% of all patients. The cell of origin for patients with clinical benefit was GCB (4 patients), intermediate (4 patients) or unknown (1 patient). None of the patients with clinical benefit had ABC genotype.

CONCLUSIONS

While fostamatinib was generally well tolerated in this patient population, efficacy at these doses and schedule was poor. Unlike data with other B-cell antigen receptor pathway inhibitors, responses were not observed in the ABC genotype.

Efficacy of bisphosphonates against osteoporosis in adult men: a meta-analysis of randomized controlled trials

This meta-analysis of published randomized controlled trials (RCTs) aimed to analyze the efficacy of administration of bisphosphonates in men with osteoporosis. Compared with placebo, bisphosphonates could reduce the risk of vertebral and non-vertebral fractures, reduce bone-specific alkaline phosphatase (BSAP) and C-terminal telopeptide of type I collagen (CTX), and increase bone mineral density (BMD).

INTRODUCTION

Bisphosphonates are well-investigated antiresorptive medications, approved as first-line drugs for osteoporosis in postmenopausal women. However, there is a paucity of high-quality evidence regarding the efficacy of bisphosphonates administered for osteoporosis in adult men. The aim of this meta-analysis was to analyse the efficacy of administration of bisphosphonates in men based on published RCTs.

METHODS

PubMed, Embase, MEDLINE, and the Cochrane library were searched, and mean differences were calculated to evaluate the efficacy of bisphosphonates on reducing the risk of vertebral and non-vertebral fracture, reducing bone-turnover biomarkers, and increasing BMD.

RESULTS

Nine RCTs were included and the total number of participants was 2464. Compared with placebo, the efficacy of bisphosphonates on vertebral and non-vertebral fracture risk reduction was confirmed [for vertebral fracture, RR (95 % CI) 0.36 (0.24, 0.56), P < 0.01; for non-vertebral fracture, RR (95 % CI) 0.52 (0.32, 0.84), P < 0.01)] and heterogeneity was insignificant. The efficacy of bisphosphonates on reducing BSAP [MD (95 % CI) -24.41 (-26.19, -22.62), P < 0.01) and CTX [MD (95 % CI) -34.51 (-41.03, -27.98), P < 0.01)] was significant. A sensitivity analysis was applied to explain the origination of heterogeneity in analysis of decreasing of BSAP. BMD was increased in the bisphosphonates group compared with the control group at lumbar spine, femoral neck, and total hip (P < 0.01), and the heterogeneity of all comparisons was significant.

CONCLUSION

Compared with placebo, bisphosphonates could decrease the risk of vertebral and non-vertebral fractures, reduce BSAP and CTX, and increase BMD in men with osteoporosis.

Blockade of Extracellular HMGB1 Suppresses Xenoreactive B Cell Responses and Delays Acute Vascular Xenogeneic Rejection

Blockade of extracellular high mobility group box 1 (HMGB1) can significantly prolong murine cardiac allograft survival. Here, we determined the role of HMGB1 in xenotransplantation. Sprague-Dawley rat hearts were transplanted heterotopically into BALB/c mice. Xenografts without any treatment developed predominant acute vascular rejection within 6 days. Both passively released HMGB1 from xenografts and actively secreted HMGB1 from infiltrated immune cells were significantly increased after xenotransplantation. HMGB1-neutralizing antibody treatment significantly prolonged xenograft survival and attenuated pathologic damage, immune cell infiltration, and HMGB1 expression and release in the xenografts. Compared to control IgG treatment evaluated at study endpoint, treatment with HMGB1-neutralizing antibody markedly suppressed xenoreactive B cell responses, as evidenced by the significant inhibition of anti-rat antibody production and deposition in xenografts at Day 6 posttransplant. Furthermore, treatment with anti-HMGB1 antibody suppressed B cell activation and reduced IFN-γ and IL-17A production after xenotransplantation. These results demonstrate for the first time that HMGB1 plays an important role in mediating acute xenograft rejection. Thus, we have shown that neutralization of extracellular HMGB1 can significantly inhibit xenoreactive B cell responses and delay xenograft rejection in a rat-to-mouse model of xenotransplantation, uncovering new insights in the role of HMGB1 in transplantation.

Increased expression of macrophage migration inhibitory factor in aorta of patients with coronary atherosclerosis

AIM

The aim of the present study was to investigate the changes of macrophage migration inhibitory factor (MIF) in the aorta of patients with coronary atherosclerosis and to evaluate the relationship between aortic expression levels of MIF and atherosclerotic risk factors.

METHODS

We collected discarded aortic specimens from patients (N.=36) undergoing coronary artery bypass graft surgery (CABG), and studied the presence and distribution of MIF by immunohistochemistry. The arterial tissues from 10 subjects without known atherosclerosis through the kidney donation program were taken as control group. The preoperative serum triglycerides, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, lipoprotein(a), apolipoprotein A, apolipoprotein B, total bilirubin, direct bilirubin, and indirect bilirubin levels of patients were examined and the coronary angiography was performed in order to assess the severity of atherosclerotic lesions.

RESULTS

MIF was detectable in aorta from CABG patients. The aortic MIF expression was elevated in smokers, and patients with hypertension or diabetes. In addition, the aortic MIF expression was associated with the levels of triglycerides, total cholesterol, low density lipoprotein cholesterol, lipoprotein (a), apolipoprotein B, total bilirubin, direct bilirubin, indirect bilirubin and coronary severity scores in simple regression analysis. However, the expression of MIF was only correlated to coronary severity scores in multiple regression analysis.

CONCLUSION

MIF is overexpressed in aorta from patients with coronary atherosclerosis and the aortic MIF expression is correlated with the severity of coronary artery disease.

Propofol suppresses proliferation and invasion of gastric cancer cells via downregulation of microRNA-221 expression

Propofol is one of the extensively and commonly used intravenous anesthetic agents. The current study aimed to evaluate the effects of propofol on the behavior of human gastric cancer cells and the molecular mechanisms of this activity. The effects of propofol on SGC7901 and AGS cell proliferation, apoptosis, and invasion were detected by MTT assay, flow cytometric analysis, and matrigel invasion assay. Real-time polymerase chain reaction (PCR) was used to assess microRNA (miR)-221 expression. miR-221 mimics were transfected into SGC7901 and AGS cells to assess the role of miR- 221 in propofol-induced anti-tumor activity. Propofol significantly inhibited cell proliferation and invasion and promoted apoptosis of SGC7901 and AGS cells. Propofol also efficiently reduced miR-221 expression. Moreover, transfection of miR-221 mimics reversed the effects of propofol on the biological behavior of gastric cancer cells. Propofol can effectively inhibit proliferation and invasion and induce apoptosis of gastric cancer cells through, at least partly, downregulation of miR-221 expression.

Reverse-dipper pattern of blood pressure may predict lacunar infarction in patients with essential hypertension

BACKGROUND AND PURPOSE

The fluctuation of circadian blood pressure (BP) is of great diversity in patients with essential hypertension and may provide significant prognostic value for stroke. However, it remains uncertain whether reverse-dipper pattern of BP influences the incidence of lacunar infarction in hypertensive patients.

METHODS

In the current study, 362 hypertensive patients (195 males, 167 females) were enrolled. BP patterns were evaluated with 24-h ambulatory BP monitoring (ABPM). Multinomial logistic regression was applied to analyse the possible relationships between lacunar infarction and various clinical risk factors such as ABPM.

RESULTS

A total of 93 patients (25.7%) had reverse-dipper BP pattern. Non-dipper pattern of BP was observed in 179 hypertensive patients (49.4%) and dipper pattern in 90 patients (24.9%). The percentage of lacunar infarction was the highest in the patients with reverse-dipper pattern compared with pure hypertension or atherothrombotic cerebral infarction (P < 0.05). After multinomial logistic regression analysis, reverse-dipper pattern of BP (odds ratio 2.492; 95% confidence interval 1.133-5.479; P < 0.05) and age (odds ratio 1.084; 95% confidence interval 1.047-1.123; P < 0.01) were found to be directly associated with lacunar infarction.

CONCLUSIONS

Reverse-dipper BP pattern may serve as an independent risk factor for lacunar infarction and more personalized BP management should be offered to the patients who have elevated nocturnal BP.

Calreticulin promotes angiogenesis via activating nitric oxide signalling pathway in rheumatoid arthritis

Calreticulin (CRT) is a multi-functional endoplasmic reticulum protein implicated in the pathogenesis of rheumatoid arthritis (RA). The present study was undertaken to determine whether CRT was involved in angiogenesis via the activating nitric oxide (NO) signalling pathway. We explored the profile of CRT expression in RA (including serum, synovial fluid and synovial tissue). In order to investigate the role of CRT on angiogenesis, human umbilical vein endothelial cells (HUVECs) were isolated and cultured in this study for in-vitro experiments. Our results showed a significantly higher concentration of CRT in serum (5·4 ± 2·2 ng/ml) of RA patients compared to that of osteoarthritis (OA, 3·6 ± 0·9 ng/ml, P < 0·05) and healthy controls (HC, 3·7 ± 0·6 ng/ml, P < 0·05); and significantly higher CRT in synovial fluid (5·8 ± 1·2 ng/ml) of RA versus OA (3·7 ± 0·3 ng/ml, P < 0·05). High levels of CRT are expressed in synovial membrane localized predominantly to inflammatory cells and synovial perivascular areas in both the lining and sublining layers of RA synovial tissue (RAST). Increased nitric oxide (NO) production and phosphorylation level of endothelial nitric oxide synthase (eNOS) were measured in HUVECs following CRT stimulation, while the total eNOS expression was not significantly changed. Furthermore, CRT promoted the proliferation, migration and tube formation of HUVECs, which were significantly inhibited by a specific eNOS inhibitor. These findings suggested that CRT may be involved in angiogenesis events in RA through NO signalling pathways, which may provide a potential therapeutic target in the treatment of RA.

HMGB1 is involved in chronic rejection of cardiac allograft via promoting inflammatory-like mDCs

Chronic rejection that leads to diffuse narrowing and occlusion of graft vessels is the most important cause of morbidity and mortality following cardiac transplantation. The role and underlying mechanism of high-mobility group box 1 (HMGB1), as an established inflammatory mediator in acute rejection, remains poorly understood in chronic rejection. Here, we assessed the effects and mechanisms of HMGB1 on the chronic rejection using single MHC Class II-mismatched mouse cardiac transplantation model. It was found that HMGB1 was increased accompanying with the development of chronic rejection, while blockade of HMGB1 with specific neutralizing mAb substantially ameliorated chronic rejection-mediated vasculopathy and fibrosis of allograft, as well as markedly decreased T cell infiltration and production of IL-17A and interferon-gamma in allograft and recipient's spleen. Further, anti-HMGB1 antibody treatment significantly declined the number and frequency of mature dendritic cells (DCs) in allograft and recipient's spleen, especially CD11b(+) Ly6C(high) matured DCs that share the phenotypes with inflammatory-DCs. These findings indicate that HMGB1 contributes to chronic rejection, and HMGB1 blockade may be a novel mean to disrupt the proinflammatory loop after heart transplantation.

Effect of MPO/H2O2/NO(-) system on nitric oxide-mediated modification of TTR amyloid and serum TTR in FAP ATTR Val30Met patients

Amyloid deposits consist of protein fibrils and amorphous material, and this deposition is related to oxidative stress. Previously, we demonstrated the presence of high-density lipoproteins and/or lipids in amyloid deposits of familial amyloid polyneuropathy patients. In this study, the presence of myeloperoxidase (MPO) in amyloid deposits was demonstrated using immunohistochemical staining. In contrast, normal surrounding tissues were consistently negative for MPO. Nitrotyrosine was present in amyloid deposits after being exposed to the MPO/H2O2/NO(-) system by immunohistochemical staining, and the oxide mediated modification of serum transthyretin (TTR) was observed upon exposure to the MPO/H2O2 system using two-dimensional gel electrophoresis and TTR Western blotting. This observation revealed that the TTR amyloid deposits and serum TTR were oxidized by the MPO/H2O2/NO(-) system. Nitric oxide-mediated modification of TTR may play a role in amyloidogenesis in vivo.

Longikaurin A, a natural ent-kaurane, induces G2/M phase arrest via downregulation of Skp2 and apoptosis induction through ROS/JNK/c-Jun pathway in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, and is also highly resistant to conventional chemotherapy treatments. In this study, we report that Longikaurin A (LK-A), an ent-kaurane diterpenoid isolated from the plant Isodon ternifolius, induced cell cycle arrest and apoptosis in human HCC cell lines. LK-A also suppressed tumor growth in SMMC-7721 xenograft models, without inducing any notable major organ-related toxicity. LK-A treatment led to reduced expression of the proto-oncogene S phase kinase-associated protein 2 (Skp2) in SMMC-7721 cells. Lower Skp2 levels correlated with increased expression of p21 and p-cdc2 (Try15), and a corresponding decrease in protein levels of Cyclin B1 and cdc2. Overexpression of Skp2 significantly inhibited LK-A-induced cell cycle arrest in SMMC-7721 cells, suggesting that LK-A may target Skp2 to arrest cells at the G2/M phase. LK-A also induced reactive oxygen species (ROS) production and apoptosis in SMMC-7721 cells. LK-A induced phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase and P38 MAP kinase. Treatment with, the JNK inhibitor SP600125 prevented LK-A-induced apoptosis in SMMC-7721 cells. Moreover, the antioxidant N-acetylcysteine prevented phosphorylation of both JNK and c-Jun. Taken together, these data indicate that LK-A induces cell cycle arrest and apoptosis in cancer cells by dampening Skp2 expression, and thereby activating the ROS/JNK/c-Jun signaling pathways. LK-A is therefore a potential lead compound for development of antitumor drugs targeting HCC.

S-phase kinase-associated protein 2 knockdown blocks colorectal cancer growth via regulation of both p27 and p16 expression

The objective of this study was to determine the role and mechanism of S-phase kinase-associated protein 2 (Skp2) in colorectal cancer cell proliferation and survival both in vitro and in vivo. Adenoviral vector expressing Skp2 short hairpin RNA was transduced into SW480 cells. The effects of Skp2 on cell cycle and survival were assessed by Flow Cytometry. Cell proliferation was analyzed by MTT assay. The expression of cell cycle regulators p16 and p27 were measured by western blot. In vivo, human colorectal cancer was produced by xenograft of cancer cells in nude mouse. Tumor growth inhibitory rate was calculated to generate growth curve. Tumor growth was monitored by examining proliferating cell nuclear antigen expression, whereas tumor cell apoptosis was detected by TdT-mediated dUTP nick-end labeling (TUNEL) staining. Knockdown of Skp2 blocked SW480 tumor cell growth and induced cell apoptosis. Skp2 appeared to be very important for the progression of cell cycle at G1/S phase. In vivo, blockade of Skp2 expression inhibited tumor growth and induced tumor apoptosis. Mechanistically, Skp2 regulated the expression of both p27 and p16 both in vitro and in vivo. The conclusion that we derive from this study is that Skp2 regulates colorectal cancer cell growth by inhibiting the expression of cell cycle regulator p27 and p16.

Expression and purification of GST-FHL2 fusion protein

Escherichia coli is the most widely used host for the production of recombinant proteins. However, most eukaryotic proteins are typically obtained as insoluble, misfolded inclusion bodies that need solubilization and refolding. The interactions between human FHL2 protein and many types of proteins, including structural proteins, kinases, and several classes of transcription factor, have been found to have important roles in a variety of fundamental processes, including arrhythmia, hypertrophy, atherosclerosis, and angiogenesis. To achieve high-level expression of soluble recombinant human FHL2 protein in E. coli, we have constructed a recombinant expression plasmid, pGEX-4T-1-FHL2, in which we merged FHL2 cDNA with the glutathione S-transferase (GST) coding sequence downstream of the tac inducible promoter. Using this plasmid, we have achieved high expression of soluble FHL2 as a GST fusion protein in E. coli BL21. We have used the engineered plasmid (pGEX-4T-1-FHL2) and the modified E. coli strain to overcome the problem of removing the GST moiety while expressing soluble FHL2. Our results show that: 1) the recombinant plasmid was successfully constructed. Sequencing results showed that FHL2 and GST are in the same reading frame; 2) at 23°C, soluble GST-FHL2 fusion protein was highly expressed after induction with 0.1 mM IPTG; and 3) GST-FHL2 can be detected by Western blotting using mouse monoclonal anti-GST antibody. Our data are the first to show that high yields of soluble FHL2 tagged with GST can be achieved in E.coli.

Inhibitory effect of components from Streptomyces species on alpha-glucosidase and alpha-amilase of different origin

The search for the effective and safe a-glucosidase and alpha-amylase inhibitors from Actinomycetaceae being antidiabetic agents is actual problem. Twenty one Streptomyces spp. of soil samples collected from different places of China were screened for the ability to produce this kind of inhibitory activities. Fermentation broth of isolated strains had absorbance between 350-190 nm. The Streptomyces strains PW003, ZG636, and ZG731 were characterized by special absorption at 280, 275, and 400 nm, respectively. Ten of the collected actinomycete strains had the ability to inhibit alpha-glucosidase or/and alpha-amylase and the fermentation broth of the same strain had inhibitory activity varied greatly depending on the enzyme source. In the process to screen the leading compounds used as antidiabetic agents, human alpha-glucosidase and alpha-amylase were revealed as the best used in trail compared with the same enzymes from other sources. Active alpha-glucosidase inhibitor was isolated from Streptomyces strain PW638 fermentation broth and identified as acarviostatin 103 by MS and N MR spectrometry. Its IC50 value was 1.25 and 12.23 microg/mL against human intestinal N-terminal maltase-glucoamylase and human pancreatic alpha-amylase, respectively.

Biphasic airway-lung response to anaphylactic shock in Brown Norway rats

Bronchospasm may be part of the response to systemic anaphylaxis in humans. The anaphylactic shock has been characterized in allergic rats, but little data are available on the concurrent changes in airway-lung mechanics. The aim was to describe the respiratory resistance (Rrs) and reactance (Xrs) response to ovalbumin (OVA) induced systemic anaphylaxis in allergic rats. Thirty five anesthetized and mechanically ventilated Brown Norway rats were randomly allocated to OVA (n=20) or vehicle (n=15) sensitization and provocation. Rrs and Xrs were obtained by the forced oscillation technique at 20 Hz. Allergic rats showed dramatic and reproducible concurrent Rrs peak and Xrs through within 4 min of OVA injection (p<0.0001). Thereafter, Rrs returned to baseline while Xrs remained significantly more negative (p<0.0001). It is concluded that systemic anaphylaxis in allergic rats is associated with severe early acute inhomogeneous bronchoconstriction followed by pulmonary interstitial/small airspace edema. The model may be of interest to assess treatments targeting the associated bronchoconstriction and/or airway vascular leakage.

Improved post-prandial ghrelin response by nateglinide or acarbose therapy contributes to glucose stability in Type 2 diabetic patients

BACKGROUND

Recent studies highlight an important role of ghrelin in glucose homeostasis, while the association between ghrelin regulation and glucose fluctuation is unclear.

AIM

We compared the effects of two postprandial hypoglycemic agents on ghrelin response and determined the contribution of ghrelin response to glucose stability in Type 2 diabetic (T2DM) patients.

SUBJECTS AND METHODS

Forty newly- diagnosed T2DM patients were randomly allocated to receive nateglinide or acarbose for 4 weeks, with twenty body mass index (BMI)-matched normoglycemic subjects as controls. Mean glucose values and daily average glucose excursion were assessed using continuous glucose monitoring system. Serum ghrelin levels were determined by enzyme-linked immunosorbent assay.

RESULTS

T2DM patients had similar fasting ghrelin levels (p=0.546), while their postprandial ghrelin suppressions at 30 min and 120 min were reduced as compared to BMI-matched normoglycemic controls (p<0.01). Both nateglinide and acarbose increased post-prandial ghrelin suppression at 120 min and reduced ghrelin area under the curve (AUCGHRL) (p<0.05), while only nateglinide increased postprandial ghrelin suppression at 30 min (p<0.01), which was positively correlated with the increased early-phase insulin secretion by 4 weeks of nateglinide therapy (r=0.48, p=0.05). The decrease in AUCGHRL was positively correlated with the decrease in daily average glucose excursion and mean glucose values either by 4 weeks of nateglinide or acarbose therapy (p<0.05).

CONCLUSIONS

Both nateglinide and acarbose increase post-prandial ghrelin suppression. Improved ghrelin regulation is most likely to play a role in glucose stability in T2DM patients with nateglinide or acarbose therapy.

Cathepsin B may be a potential biomarker in cervical cancer

Cathepsin B is a protease which is able to digest extracellular matrix. It is currently unknown whether cathepsin B plays a role in cervical cancer development and progression. With Q-PCR and Western blotting, we observed cathepsin B expression in cervical cancer cell line Hela cells. After the gene was silenced in HeLa cells with SiRNA, we confirmed that cathepsin B expressions at both mRNA and protein levels were significantly reduced. At the same time, cell proliferation, migration and invasion of the HeLa cells were significantly decreased compared to control cells. In addition, a significant regression of tumor growth in nude mice which received the siRNA targeted cathepsin B HeLa cells was observed. We further studied the expression of cathepsin B in a series of 169 clinical samples, including 56 invasive cervical squamous carcinoma, 85 CINs and 28 normal cervical tissues. It was found that cathepsin B expression in invasive carcinomas was significantly higher than that in the CINs and normal tissues (P<0.01). In addition, cathepsin B expression in the invasive carcinomas was positively correlated to tumor invasion depth and lymphatic metastasis. Our results indicate that cathepsin B may be a potential biomarker for further strategical clinical studies in cervical cancer.

Gene mapping and mutation screening in candidate genes in a Chinese family of autosomal dominant retinitis pigmentosa

We wanted to find the gene defect in a Chinese pedigree with autosomal dominant form of retinitis pigmentosa (ADRP). A small Chinese family with retinitis pigmentosa was collected. The genetic analysis of the family suggested an autosomal dominant pattern. Microsatellite (STR) markers tightly linked to candidate genes for ADRP were selected for linkage analysis. We got a maximum LOD score of 0.87 between markers D19S210 and D19S418. Precursor mRNA-processing factor (PRPF) 31, 3, 8, rhodopsin (RHO), peripherin 2 (PRPH2 or RDS), rod outer segment protein 1 (ROM1), neural retina leucine zipper (NRL), cone-rod homeobox-containing (CRX), inosine-5-prime-monophosphate dehydrogenase, type I (IMPDH1) and retinitis pigmentosa 1 (RPI) were amplified by polymerase chain reaction (PCR) and screened by direct sequencing. One new sequence variation was found. It was the missence mutation c.148G > C (D50H) occurred in exon 1 of RDS gene which existed in all the effected individuals and one unaffected family member. The DNA sequence variation didn't cosegregate with the RP disease. We considered this transition was one new polymorphism which we speculate involved in the pathogenesis of ADRP and increased the risk of ADRP. Further study should be conducted to confirm the causative gene of this family.

Laser Synthesis of Iron Nitride Nanoparticles from Pyrolysis of Fe(CO)5-NH3 System

By vapor-phase pyrolysis of Fe(CO) 5 and NH3 induced by CW CO2 laser, γ'-Fe4N and ε- Fe3N nanoparticles(≤35nm) were prepared in Ar and N2 atmospheres. In Ar, γ'-Fe4N accompanied by a little α-Fe was formed at low temperatures below 650°C, while higher temperatures favored the formation of γ-Fe. In N2 atmospheres, a mixture of Fe4N and Fe3N nanoparticles were obtained at high temperatures. In addition, the influences of synthesis parameters on the structure, morphology and magnetic properties of the nanoparticles were discussed.

Silicate Formation at the Interface of high-k dielectrics and Si(001) Surfaces

The composition and chemical bonding of the first atoms across the interface between Si(001) and the dielectric determine the quality of dielectric gate stacks. An analysis of that hidden interface is a challenge as it requires both, high sensitivity and elemental and chemical state information. We used SR based photoelectron spectroscopies and, in particular, X-ray absorption spectroscopy in total electron yield and total fluorescence yield at the Si2p and the O1s edges to address that issue. We report on results of Hf-oxide prepared by ALD and compare to Pr2O3 / Si(001), and compare the two to the SiO2 / Si(001) system as a reference. For both, Hf-oxide and Pr-oxide thin films we find evidence for the silicate formation at the interface as derived from the characteristic features at the Si2p and the O1s edges.

Linking river, floodplain, and vadose zone hydrology to improve restoration of a coastal river affected by saltwater intrusion

Floodplain forests provide unique ecological structure and function, which are often degraded or lost when watershed hydrology is modified. Restoration of damaged ecosystems requires an understanding of surface water, groundwater, and vadose (unsaturated) zone hydrology in the floodplain. Soil moisture and porewater salinity are of particular importance for seed germination and seedling survival in systems affected by saltwater intrusion but are difficult to monitor and often overlooked. This study contributes to the understanding of floodplain hydrology in one of the last bald cypress [Taxodium distichum (L.) Rich.] floodplain swamps in southeast Florida. We investigated soil moisture and porewater salinity dynamics in the floodplain of the Loxahatchee River, where reduced freshwater flow has led to saltwater intrusion and a transition to salt-tolerant, mangrove-dominated communities. Twenty-four dielectric probes measuring soil moisture and porewater salinity every 30 min were installed along two transects-one in an upstream, freshwater location and one in a downstream tidal area. Complemented by surface water, groundwater, and meteorological data, these unique 4-yr datasets quantified the spatial variability and temporal dynamics of vadose zone hydrology. Results showed that soil moisture can be closely predicted based on river stage and topographic elevation (overall Nash-Sutcliffe coefficient of efficiency = 0.83). Porewater salinity rarely exceeded tolerance thresholds (0.3125 S m(-1)) for bald cypress upstream but did so in some downstream areas. This provided an explanation for observed vegetation changes that both surface water and groundwater salinity failed to explain. The results offer a methodological and analytical framework for floodplain monitoring in locations where restoration success depends on vadose zone hydrology and provide relationships for evaluating proposed restoration and management scenarios for the Loxahatchee River.

A new cell culture system for infection with hepatitis B virus that fuses HepG2 cells with primary human hepatocytes

Hepatitis B virus (HBV) infection exhibits a very narrow host range and shows a strong tropism for liver parenchymal cells, however none of the previously established experimental models can reproduce the natural process of HBV infection. In the present study, primary human hepatocytes were fused with HepG2 cells to establish the hybrid HepCHLine-4 cell line with high susceptibility to HBV. The HepCHLine-4 cells expressed HBV-specific antigen when co-incubated with HBV-positive serum from a hepatitis B patient. Post-infection, HBV relaxed circular DNA and covalently closed circular DNA were detected in HepCHLine-4 cells using a nested polymerase chain reaction, and HBV-specific particles were visualized by electron microscopy of the culture media of HepCHLine-4 cells. HepG2 cells were not susceptible to HBV infection under the same conditions. The HepCHLine-4 cells can be sub-cultured for > 12 months while maintaining susceptibility to HBV and may, therefore, be useful for studying HBV infection and the viral life cycle in human hepatocytes.

Activin tunes GABAergic neurotransmission and modulates anxiety-like behavior

Activin, a member of the transforming growth factor-beta superfamily, affords neuroprotection in acute brain injury, but its physiological functions in normal adult brain are largely unknown. Using transgenic (tg) mice expressing a dominant-negative activin receptor mutant under the control of the CaMKIIalpha promoter in forebrain neurons, we identified activin as a key regulator of gamma-aminobutyric acid (GABA)ergic synapses and anxiety-like behavior. In the open field, wild-type (wt) and tg mice did not differ in spontaneous locomotion and exploration behavior. However, tg mice visited inner fields significantly more often than wt mice. In the light-dark exploration test, tg mice made more exits, spent significantly more time on a well-lit elevated bar and went farther away from the dark box as compared to wt mice. In addition, the anxiolytic effect of diazepam was abrogated in tg mice. Thus the disruption of activin receptor signaling produced a low-anxiety phenotype that failed to respond to benzodiazepines. In whole-cell recordings from hippocampal pyramidal cells, enhanced spontaneous GABA release, increased GABA tonus, reduced benzodiazepine sensitivity and augmented GABA(B) receptor function emerged as likely substrates of the low-anxiety phenotype. These data provide strong evidence that activin influences pre- and postsynaptic components of GABAergic synapses in a highly synergistic fashion. Given the crucial role of GABAergic neurotransmission in emotional states, anxiety and depression, dysfunctions of activin receptor signaling could be involved in affective disorders: and drugs affecting this pathway might show promise for psychopharmacological treatment.

Comparison of the synthesis of Ge nanocrystals in hafnium aluminum oxide and silicon oxide matrices

Growth of germanium (Ge) nanocrystals in silicon (Si) oxide and hafnium aluminum oxide (HfAlO) is examined. In Si oxide, nanocrystals were able to form at annealing temperatures of 800 degrees C to 1000 degrees C. Nanocrystals formed at 800 degrees C were round and approximately 8 nm in diameter, at 900 degrees C they become facetted and at 1000 degrees C they become spherical again. In HfAlO, at 800 degrees C nanocrystals formed are relatively smaller (approximately 3 nm in diameter) and lower in density. While at 900 degrees C and 1000 degrees C, nanocrystals did not form due to out-diffusion of Ge. Different nanocrystal formation characteristics in the matrices are attributed to differences in their crystallization temperatures.

Intra-hippocampal tonic inhibition influences formalin pain-induced pyramidal cell suppression, but not excitation in dorsal field CA1 of rat

It has been hypothesized that intra-hippocampal GABAergic inhibitory interneurons mediate formalin pain-induced suppression of dorsal hippocampal CA1 pyramidal cell discharge. The present study performed on anaesthetized rats tested the hypothesis by disrupting GABAergic mechanisms with intra-hippocampal administration of the GABA(A) receptor antagonist bicuculline methiodide, applied either dorsally into the pyramidal cell layer and stratum oriens (dorsal-bicuculline) or ventrally into the region of apical dendrites (ventral-bicuculline). It was found that ventral-, but not dorsal-bicuculline attenuated formalin-induced suppression of pyramidal cell extracellular discharge. The antagonism was selective in such a way that the excitation of pyramidal cell was unaffected. Interestingly, ventral-bicuculline strongly disinhibited CA1 pyramidal cells and shifted the distribution of their spontaneous discharge to values higher than the control group. However, dorsal-bicuculline disinhibited the local CA1 interneurons that were strongly excited on injection of formalin. Overall, the findings favour the notion that tonic GABA(A) receptor mechanisms located in the region of apical dendrites facilitate formalin-induced pyramidal cell suppression by masking the background excitatory drive impinging on the pyramidal cells. Interestingly, both the attenuation of formalin-induced inhibition and facilitation of basal discharge of CA1 pyramidal cells by ventral-bicuculline are similar to the effects seen previously with the destruction of medial septal cholinergic neurons. This convergence of effects strengthens the proposal that the network of medial septal cholinergic neurons and hippocampal GABAergic interneurons influence formalin pain-induced CA1 pyramidal cell suppression. In addition, the data point to a non-overlapping excitatory drive whose strength is unaffected by the inhibitory drive that underpins formalin suppression.

Influence of strain on the conduction band structure of strained silicon nanomembranes

The influence of in-plane biaxial strain on the conduction bands of Si is explored using elastically strained Si(001) nanomembranes and high-resolution x-ray absorption measurements with electron yield detection. The strain-induced splitting of the conduction band minimum and the energy shifts of two higher conduction bands near L1 and L3 are clearly resolved. The linear increase of the splitting of the conduction band minimum with increasing strain and the nonlinear shift of the L1 point toward the conduction band minimum agree quantitatively with current theories.