17beta-Estradiol modulates local cardiac renin-angiotensin system to prevent cardiac remodeling in the DOCA-salt model of hypertension in rats

Ventricular remodeling can play a detrimental role in the progression of cardiovascular diseases, leading to heart failure. The current study was designed to investigate the effects of 17beta-estradiol (E2) on cardiac remodeling. Cardiac fibrosis and hypertrophy were examined in deoxycorticosterone acetate (DOCA)-salt treated rats with chronic, six-week administration of two different doses of E2. Bilaterally ovariectomized (Ovex) female Sprague-Dawley rats were randomly assigned to one of the following groups: Ovex-control; Ovex-DOCA; Ovex-DOCA+low-dose E2 (1.66 microg/day); or Ovex-DOCA+high-dose E2 (2.38 microg/day). All DOCA-treated rats were uninephrectomized and drinking water was replaced by 0.15M NaCl solution for the remainder of the study period. DOCA-salt treatment resulted in a significant increase in blood pressure, which was not altered by estrogen replacement. Histological examinations revealed marked cardiac remodeling (both ventricular hypertrophy and interstitial fibrosis) with DOCA treatment, which was attenuated in animals receiving estrogen therapy. Western blot analysis demonstrated increased cardiac levels of angiotensin converting enzyme (ACE) with DOCA treatment, which was attenuated by E2 replacement. Furthermore, increased levels of cardiac angiotensin converting enzyme 2 (ACE2) protein were observed in animals receiving high-dose E2 replacement. These findings suggest that physiologically relevant estrogen replacement therapy has blood pressure-independent cardioprotective effects, which are possibly mediated through modulation of the cardiac renin-angiotensin system.

Evaluation of proposed oral disposition index measures in relation to the actual disposition index

Aims While the disposition index provides a useful measure of B-cell function, its calculation requires the performance of a frequently sampled intravenous glucose tolerance test (FSIVGTT). Recently, the demonstration of a hyperbolic relationship between indices of insulin secretion and insulin sensitivity derived from the oral glucose tolerance test (OGTT) has led to the introduction of two novel OGTT-based measures of B-cell function analogous to the disposition index: (i) the insulin secretion-sensitivity index-2 (ISSI-2) (defined as the ratio of the area-under-the-insulin-curve to the area-under-the-glucose curve, multiplied by the Matsuda index) and (ii) insulinogenic index (IGI)/fasting insulin. However, neither of these two measures has been directly compared with the disposition index. Methods Two hundred and thirteen non-diabetic children (122 boys, 91 girls) underwent both OGTT and FSIVGTT, allowing for the calculation of ISSI-2, IGI/fasting insulin and the disposition index. Results ISS1-2 and IGI/fasting insulin were strongly correlated with each other (r = 0.82, P < 0.0001). Both measures correlated with the disposition index, with ISSI-2 showing a modestly stronger association (ISSI-2: r = 0.24, P = 0.0003; IGI/fasting insulin: r = 0.21, P = 0.0022). Standardized linear regression analyses confirmed that the relationship between log ISSI-2 and the disposition index (standardized regression coefficient = 0.224, P = 0.001) was stronger than that between log IGI/fasting insulin and the disposition index (standardized regression coefficient = 0.166, P = 0.015). Conclusions The OGTT-derived measures ISSI-2 and IGI/fasting insulin exhibit modest correlations with the disposition index. These relationships require further assessment in other patient populations.

Projections of RFamide-related peptide-3 neurones in the ovine hypothalamus, with special reference to regions regulating energy balance and reproduction

RFamide-related peptide-3 (RFRP-3) is a neuropeptide produced in cells of the paraventricular nucleus and dorsomedial nucleus of the ovine hypothalamus. In the present study, we show that these cells project to cells in regions of the hypothalamus involved in energy balance and reproduction. A retrograde tracer (FluoroGold) was injected into either the arcuate nucleus, the lateral hypothalamic area or the ventromedial nucleus. The distribution and number of retrogradely-labelled RFRP-3 neurones was determined. RFRP-3 neurones projected to the lateral hypothalamic area and, to a lesser degree, to the ventromedial nucleus and the arcuate nucleus. Double-label immunohistochemistry was employed to identify cells receiving putative RFRP-3 input to cells in these target regions. RFRP-3 cells were seen to project to neuropeptide Y and pro-opiomelanocortin neurones in the arcuate nucleus, orexin and melanin-concentrating hormone neurones in the lateral hypothalamic area, as well as orexin cells in the dorsomedial nucleus and corticotrophin-releasing hormone and oxytocin cells in the paraventricular nucleus. Neurones expressing gonadotrophin-releasing hormone in the preoptic area were also seen to receive input from RFRP-3 projections. We conclude that RFRP-3 neurones project to hypothalamic regions and cells involved in regulation of energy balance and reproduction in the ovine brain.

Evidence that RF-amide related peptides are inhibitors of reproduction in mammals

Gonadotropin releasing hormone (GnRH) secretion represents the final common pathway in the control of the reproductive axis. Dogma has been that GnRH is solely responsible for the control of gonadotropin secretion, but emerging data presents a strong case for the existence of a gonadotropin inhibitory hormone in mammals. This evidence arose from initial work in avian species to isolate and identify a factor that inhibited gonadotropin release, which is known as gonadotropin inhibitory hormone (GnIH). The mammalian ortholog of avian GnIH is named RF-amide related peptide (RFRP). There are two forms of RFRP in mammals, RFRP-1 and RFRP-3 encoded by a single gene, but there has been skepticism and controversy as to whether these peptides play a significant role in the regulation of gonadotropin secretion. There is now a significant body of evidence that one or more RFRP exists in mammals and acts as an inhibitor of GnRH and/or gonadotropin secretion. Moreover, RFRP-producing neurons have been shown to transmit information to GnRH cells and/or gonadotropes in relation to seasonal status and to coordinate events around the preovulatory luteinizing hormone surge. This review will focus on the significant advances in RFRP research in mammalian species.

Discovery of a tumor-specific biomarker for gastric cancer using proteomic analysis in tissue and serum

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Background: Gastric cancer is curable at an early stage. However, most cases are diagnosed at an advanced stage because of the lack of screening programs. Therefore, for early detection, there is a need for serum biomarkers to be identified. Methods: We explored surface-enhanced laser desorption/ionization time-of-flight mass spectrometry to elucidate potential protein biomarkers of gastric cancer. Twenty-one resected gastric cancer samples were compared with matched adjacent normal mucosa samples. Serum from patients with gastric cancer (n=51) was compared with patients with benign gastric diseases (n=29). Samples were analyzed on Cu2+-loaded IMAC protein chips via surface-enhanced laser desorption /ionization time-of-flight mass spectrometry. Results: Comparisons of surface-enhanced laser desorption /ionization time-of-flight mass spectrometry spectra of 21 gastric cancer tissue extracts with paired adjacent normal mucosa showed a total of 56 differentially expressed protein peaks (p<0.05; Wilcoxon test). Twenty-two were up-regulated in gastric cancer tissue, whereas 34 were down-regulated. The surface- enhanced laser desorption /ionization time-of-flight mass spectrometry spectra of serum contained 130 peaks, of which 67 were significantly associated with gastric cancer (p<0.05; Wilcoxon test). We found five proteomic features (mass charge values of 2273, 3143, 3372, 3444, 3485) that were significantly up-regulated in both gastric cancer tissue and serum from gastric cancer patients. The peak intensities of tumor-specific proteomic features were used to develop a linear regression model for calculating a diagnostic index. The area under the receiver operating characteristic curve of the corresponding diagnostic index was 0.87. Conclusions: Serum biomarker panels associated with tumor tissue are capable of distinguishing gastric cancer patients from non-cancer ones.

No significant financial relationships to disclose.

Comparison of progression-free survival (PFS) and tumor response as endpoints for predicting overall survival (OS) in untreated extensive-stage small cell lung cancer (ED-SCLC): Findings based on North Central Cancer Treatment Group (NCCTG) trials

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Background: Historically, tumor response has been the primary endpoint in phase II (P2) trials in ED-SCLC. We investigated the suitability of alternate PFS based endpoints to predict OS as early evidence of efficacy in the P2 setting. Methods: Individual patient (pt) data from 942 pts from 11 previously untreated ED-SCLC P2 and phase III (P3) platinum- or paclitaxel-based treatment trials were pooled. Best response (BR), response confirmed (RC), objective status at 16 weeks (RR16), and PFS rate at 5 and 6 months were considered. Percent agreement (PA) and kappa (k) for PFS5, PFS6, BR, RC, and RR16 with OS at 12 months (OS12) was calculated on a per-pt basis and predictive utility was assessed using the area under the receiver operating characteristic (A- ROC) curve in logistic models. Cox models were used to assess the prognostic impact of the endpoints on subsequent survival, using landmark analysis. Results: The median OS and PFS were 9.6 m and 5.5 m, respectively. PFS5 and PFS6 had the highest PA, k, and A-ROC values, and were predictive of subsequent survival in the landmark analysis (p <0.0001; c-statistics ≥ 0.60). While RR16 and BR were significantly associated with subsequent survival (p<0.0001, c-statistics of 0.61 and 0.57, respectively) the PA, k, and A-ROC values were lower. Conclusions: PFS rate at 5 and 6 months is more predictive of 12-month OS and subsequent survival than tumor response in untreated ED-SCLC. PFS based endpoints should be routinely used as primary endpoints in P2 trials within ED-SCLC.

[Table: see text]

No significant financial relationships to disclose.

Impact of surface chemistry on grain boundary induced intrinsic stress evolution during polycrystalline thin film growth

First principles calculations were integrated with cohesive zone and growth chemistry models to demonstrate that adsorbed species can significantly alter stresses associated with grain boundary formation during polycrystalline film growth. Using diamond growth as an example, the results show that lower substrate temperatures increase the hydrogen content at the surface, which reduces tensile stress, widens the grain boundary separations, and permits additional atom insertions that can induce compressive stress. More generally, this work demonstrates that surface heteroatoms can lead to behavior which is not readily described by existing models of intrinsic stress evolution.

Lignite aided dewatering of digested sewage sludge

Mechanical dewatering is commonly used to increase the solids content of municipal sludge prior to its disposal. However, if the rate of filtration is slow, mechanical dewatering can be expensive. In this study, the use of lignite to improve the sludge dewatering is investigated. The effectiveness of lignite conditioning of polyelectrolyte-flocculated sludge is examined using mechanical compression tests. Results show that lignite conditioning in conjunction with polyelectrolyte flocculation gives much better dewatering than the polyelectrolyte flocculation alone. Using Darcy's filtration theory, the specific cake resistance and permeability of the compressed cakes are obtained. Both of these parameters are significantly improved after lignite conditioning. Mercury porosimetry tests on compressed cakes show that the porosity of the lignite-conditioned sludge cake is much higher than that of the polyelectrolyte-flocculated sludge and it increases with increasing doses of lignite. The mercury porosimetry results show that the lignite pore volume of pores greater than 0.5 microm are reduced with increasing sludge ratio indicating that sludge is trapped within these pores, whereas smaller pores are unaffected. The yield stress curves for sludge, lignite and sludge-lignite mixtures show that the sludge filter cake is very compressible, but the lignite-conditioned cake has a range of compressibility which although more than lignite indicate that the cake is relatively incompressible at low pressures. Thus, lignite conditioning acts to maintain the permeability of the filter cake during compression dewatering by resisting cake compression. This leads to a trade-off between the rate of dewatering and the solids content of the compressed cake. With lignite conditioning, the dewatering rate can be increased by a factor of five for the same degree of water removal.

Using FBRM to investigate the sewage sludge flocculation efficiency of cationic polyelectrolytes

Polyelectrolyte flocculation is a commonly used method for sewage sludge conditioning. The rate and extent of water removal from the flocculated sludge depends on the properties of the polyelectrolytes. This study investigates the flocculation performance of four different cationic polyelectrolytes using an in-situ laser probe which uses focused beam reflectance measurements (FBRM). It is used to characterise the floc number and size distribution of the flocculated sludge at various polyelectrolyte doses. Results show that the FBRM technique is very successful in tracking the change in particle population and chord lengths during the sludge flocculation process. The FBRM offers an alternative method for optimising the flocculation system in both selecting the flocculant and determining its optimum dose. Both the reduction in particle count for particles of less than 10 mum and the flocculation efficiency defined from the amount of the original sludge distribution remaining after flocculation correlate well with dewatering performance.

Enhancement of apoptosis of human hepatocellular carcinoma SMMC-7721 cells through synergy of berberine and evodiamine

Berberine and evodiamine, two kinds of alkaloids, have been reported to show many activities. In the present paper, inhibitory activities of the two compounds and their mixtures on human hepatocellular carcinoma SMMC-7721 cells were investigated, and the inhibitory rates, apoptosis, cell cycle distribution and tumor necrosis factor-alpha (TNF-alpha) were all tested and described. The results indicate that the mixtures of the two compounds showed the highest inhibition effect (50.00%) as compared with berberine and evodiamine used individually (20.24% and 16.33%, respectively) over 48 h. Through fluorescence microscope and flow cytometry (FCM) analysis, the cell apoptosis and cell cycle distribution of SMMC-7721 induced by the synergy of the two compounds was made evident. Furthermore, the TNF-alpha value in the mixture treated group was much higher (p<0.05) than in the other two groups. Thus, the combined use of berberine and evodiamine could significantly enhance the apoptosis of SMMC-7721 cells, which will be useful to further anti-cancer therapy and research.

Characterization of antibody responses against a neutralizing epitope on the glycoprotein E2 of classical swine fever virus

The sequence TAVSPTTLR is a conserved and linear neutralizing epitope on the glycoprotein E2 of classical swine fever virus. In this study, TAVSPTTLR-directed antibodies, induced either by virions or by an epitope-focused immunogen, were characterized. The results revealed that despite the same epitope specificity, the antibodies induced by different immunogens varied significantly both in the neutralizing test and in binding inhibition assays. This suggests that the protective immunity induced by this epitope is due to more than simply the epitope specificity and that this epitope might need essential contributions from its flanking context to induce functional epitope-specific antibodies.

Salacia oblonga root decreases cardiac hypertrophy in Zucker diabetic fatty rats: inhibition of cardiac expression of angiotensin II type 1 receptor

AIMS

We investigated the effect of the water extract of Salacia oblonga (SOE), an ayurvedic antidiabetic and antiobesity medicine, on obesity and diabetes-associated cardiac hypertrophy and discuss the role of modulation of cardiac angiotensin II type 1 receptor (AT(1)) expression in the effect.

METHODS

SOE (100 mg/kg) was given orally to male Zucker diabetic fatty (ZDF) rats for 7 weeks. At the end-point of the treatment, the hearts and left ventricles were weighed, cardiomyocyte cross-sectional areas were measured, and cardiac gene profiles were analysed. On the other hand, angiotensin II-stimulated embryonic rat heart-derived H9c2 cells and neonatal rat cardiac fibroblasts were pretreated with SOE and one of its prominent components mangiferin (MA), respectively. Atrial natriuretic peptide (ANP) mRNA expression and protein synthesis and [(3)H]thymidine incorporation were determined.

RESULTS

SOE-treated ZDF rats showed less cardiac hypertrophy (decrease in weights of the hearts and left ventricles and reduced cardiomyocyte cross-sectional areas). SOE treatment suppressed cardiac overexpression of ANP, brain natriuretic peptide (BNP) and AT(1) mRNAs and AT(1) protein in ZDF rats. SOE (50-100 microg/ml) and MA (25 micromol) suppressed angiotensin II-induced ANP mRNA overexpression and protein synthesis in H9c2 cells. They also inhibited angiotensin II-stimulated [(3)H]thymidine incorporation by cardiac fibroblasts.

CONCLUSIONS

Our findings demonstrate that SOE decreases cardiac hypertrophy in ZDF rats, at least in part by inhibiting cardiac AT(1) overexpression. These studies provide insights into a potential cardioprotective role of a traditional herb, which supports further clinical evaluation in obesity and diabetes-associated cardiac hypertrophy.

Neural connectivity in the mediobasal hypothalamus of the sheep brain

The ventromedial nucleus of the hypothalamus (VMN) and the arcuate nucleus (ARC) are two centres regulating energy balance and food intake, but inter-connectivity of these nuclei is not well defined in non-rodent species. In this study, we performed retrograde tracing and immunohistochemistry in the ovine brain with ewes receiving FluoroGold (FG) injections into either ARC or VMN for the mapping of retrogradely labelled cells. Strong reciprocal connections were found between the two regions. The distribution of the FG labelled neurons in other regions of the hypothalamus and brain stem was also mapped. Some of the cells projecting from ARC to VMN were immunopositive for neuropeptide Y, galanin, adrenocorticotropin (marker of pro-opiomelanocortin cells) or tyrosine hydroxylase (marker of dopaminergic cells). Melanin-concentrating hormone and orexin neurons in the lateral hypothalamic area were also found to provide input to the VMN and ARC. This observed interconnectivity between regions important for metabolic regulation and other neuroendocrine functions presumably allows coordinated functions. Input to both the ARC and VMN from other brain regions, such as brain stem cell groups, provides a further level of regulation. These data provide a substrate upon which further understanding of appetite regulation and neuroendocrine function can be derived in this species.

Improving the assessment of risk from pathogens in biosolids: fecal coliform regrowth, survival, enumeration, and assessment

Reactivation or regrowth of fecal coliform bacteria in biosolids has recently become a concern due to knowledge that Class B materials may fail to meet this criterion after storage or even after land application. In this paper, data show the two types of fecal coliform increases that have been characterized: immediate reappearance of large concentrations directly after dewatering; and the rapid, but less immediate, increases that follow dewatering with some biosolids after dewatering. The latter phenomenon is shown to extend over a time period of days prior to gradual decrease in fecal coliform numbers. Modeling shows that anaerobic or fermentative growth cannot simulate the observed growth, but that a straightforward biokinetic model can duplicate the observed conditions if a doubling time of one hour is assumed, which is supported by literature. Thus regrowth cannot be ruled out as the underlying phenomenon.

Correlation between angiotensinogen gene polymorphisms and essential hypertension in Chinese population

Essential hypertension (EHT) has a genetic basis. Considering the pathological, physiological and biological mechanisms implicated in blood pressure regulation, many candidates have been listed as hypertension genes, of which the angiotensinogen gene (AGT) is weighed as the most promising one.

Host filamentous actin is associated with Heliothis armigera single nucleopolyhedrosis virus (HaSNPV) nucleocapsid transport to the host nucleus

VP39 is the major capsid protein of Heliothis armigera nucleopolyhedrovirus (HaSNPV), and it might have induced the aggregation of host cellular actin in vitro in our previous study. We demonstrated here that VP39 could interact with host actin in vivo in Helicoverpazea (Hz-AM1 cells) through coimmunoprecipitation assay. With confocal immunofluorescence microscopy, it was confirmed further that the released HaSNPV nucleocapsids/VP39s in the host cytoplasm (0.5 hours after infection) colocalized where the actin aggregated and that the nucleocapsids/VP39s were transported from the host cytoplasm to the nucleus (2 hours after infection). Because cytochalasin D (CD) was used to prevent host global actin from forming filamentous structures, the infection efficiency of the recombinant virus HaSNPV/gfpdeltap74, with the gfp gene inserted into HaSNPV p74 gene loci, was decreased to 7.34%, whereas it was 34.7% in normal host cells and 55.7% in the cells whose microtubules had been destroyed by colchicin. Ultramicroscopy assay revealed that HaSNPV nucleocapsids could enter the cytoplasm of CD-treated cells but could not be transported to the nucleus, which resulted in the lower infection efficiency of HaSNPV/gfpdeltap74 in CD-treated cells. However, transportation of the nucleocapsids was not inhibited in colchicin-treated cells, demonstrating that the transportation of HaSNPV nucleocapsid from the cytoplasm to the nucleus was associated with actin filaments but not with microtubules, a conclusion that is also strongly supported by evidence from the RNAi interference of host actin during HaSNPV infection.

Whole genome amplification of buccal cytobrush DNA collected for molecular epidemiology studies

When cytobrush buccal cell samples have been collected as a genomic DNA (gDNA) source for an epidemiological study, whole genome amplification (WGA) can be critical to maintain sufficient DNA for genotyping. We evaluated REPLI-g WGA using gDNA from two paired cytobrushes (cytobush 'A' kept in a cell lysis buffer, and 'B' dried and kept at room temperature for 3 days, and frozen until DNA extraction) in a pilot study (n=21), and from 144 samples collected by mail in a breast cancer study. WGA success was assessed as the per cent completion/concordance of STR/SNP genotypes. Locus amplification bias was assessed using quantitative PCR of 23 human loci. The pilot study showed > 98% completion but low genotype concordance between cytobrush wgaDNA and paired blood gDNA (82% and 84% for cytobrushes A and B, respectively). Substantial amplification bias was observed with significantly lower human gDNA amplification from cytobrush B than A. Using cytobrush gDNA samples from the breast cancer study (n =20), an independent laboratory demonstrated that increasing template gDNA to the REPLI-g reaction improved genotype performance for 49 SNPs; however, average completion and concordance remained below 90%. To reduce genotype misclassification when cytobrush wgaDNA is used, inclusion of paired gDNA/wgaDNA and/or duplicate wgaDNA samples is critical to monitor data quality.