Aldosterone deficiency prevents high-fat-feeding-induced hyperglycaemia and adipocyte dysfunction in mice

AIMS/HYPOTHESIS

Obesity is associated with aldosterone excess, hypertension and the metabolic syndrome, but the relative contribution of aldosterone to obesity-related complications is debated. We previously demonstrated that aldosterone impairs insulin secretion, and that genetic aldosterone deficiency increases glucose-stimulated insulin secretion in vivo. We hypothesised that elimination of endogenous aldosterone would prevent obesity-induced insulin resistance and hyperglycaemia.

METHODS

Wild-type and aldosterone synthase-deficient (As (-/-)) mice were fed a high-fat (HF) or normal chow diet for 12 weeks. We assessed insulin sensitivity and insulin secretion using clamp methodology and circulating plasma adipokines, and examined adipose tissue via histology.

RESULTS

HF diet induced weight gain similarly in the two groups, but As (-/-) mice were protected from blood glucose elevation. HF diet impaired insulin sensitivity similarly in As (-/-) and wild-type mice, assessed by hyperinsulinaemic-euglycaemic clamps. Fasting and glucose-stimulated insulin were higher in HF-fed As (-/-) mice than in wild-type controls. Although there was no difference in insulin sensitivity during HF feeding in As (-/-) mice compared with wild-type controls, fat mass, adipocyte size and adiponectin increased, while adipose macrophage infiltration decreased. HF feeding significantly increased hepatic steatosis and triacylglycerol content in wild-type mice, which was attenuated in aldosterone-deficient mice.

CONCLUSIONS/INTERPRETATION

These studies demonstrate that obesity induces insulin resistance independently of aldosterone and adipose tissue inflammation, and suggest a novel role for aldosterone in promoting obesity-induced beta cell dysfunction, hepatic steatosis and adipose tissue inflammation.

Identification of combining ability loci for five yield-related traits in maize using a set of testcrosses with introgression lines

Combining ability is essential for hybrid breeding in crops. However, the genetic basis of combining ability remains unclear and has been seldom investigated. Identifying molecular markers associated with this complex trait would help to understand its genetic basis and provide useful information for hybrid breeding in maize. In this study, we identified genetic loci of general combining ability (GCA) and specific combining ability (SCA) for five yield-related traits under three environments using a set of testcrosses with introgression lines (ILs). GCA or SCA of the five yield-related traits of the ILs was estimated by the performance of testcrosses with four testers from different heterotic groups. Genetic correlations between GCA of the traits and the corresponding traits per se were not significant or not strong, suggesting that the genetic basis between them is different. A total of 56 significant loci for GCA and 21 loci for SCA were commonly identified in at least two environments, and only 5 loci were simultaneously controlling GCA and SCA, indicating that the genetic basis of GCA and SCA is different. For all of the traits investigated, positive and significant correlations between the number of GCA loci in the ILs and the performance of the corresponding GCA of the ILs were detected, implying that pyramiding GCA loci would have positive effect on the performance of GCA. Results in this study would be useful for maize hybrid breeding.

In vitro ovicidal and larvicidal activity of the essential oil of Artemisia lancea against Haemonchus contortus (Strongylida)

Prolonged use of chemical anthelmintics has been found to result in anthelmintic resistance and environmental issues, thereby limiting the application of these drugs in domestic animals and prompting interest in the study of plant extracts as alternative sources thereof. The aim of this study was to evaluate the in vitro effect of the essential oil (EO) of Artemisia lancea against the parasitic nematode Haemonchus contortus using egg hatch assay, larval development assay, and larval migration inhibition assay. The EO yield of extraction was 0.63% (w/w), and the major constituents were 1,8-cineole (34.56%) and camphor (16.65%). In the egg hatch assay, an inhibition greater than 99% was observed with the EO at 10 mg mL(-1) and the LC50 was 1.82 mg mL(-1). 1,8-Cineole demonstrated moderate ovicidal activity with a LC50 of 4.64 mg mL(-1), whereas camphor did not show enough activity to have its LC50 determined. In the larval development assay, the EO, 1,8-cineole, and camphor inhibited 93.6%, 65.2%, and 57% of larval development at 10 mg mL(-1) and exhibited dose-dependent responses with LC50 values of 1.66, 5.07, and 7.80 mg mL(-1), respectively. In the migration inhibition assay, the EO and 1,8-cineole at best inhibited 77% and 60.3% of larval migration at 10 mg mL(-1), respectively. Camphor showed low inhibition capacity, and its efficacy was not dose dependent. The results indicate that the in vitro anthelmintic activity of the EO of A. lancea may be associated with the additive action of the two major constituents, as well as other more minor terpenoid components.

A simple QSPR model for the prediction of the adsorbability of organic compounds onto activated carbon cloth

A quantitative structure-property relationship (QSPR) model was proposed between the molecular descriptors representing the molecular structure and the Freundlich adsorbability parameter (K) for a set of 55 organic compounds onto activated carbon cloth. The best linear model was composed of three descriptors, which were selected by stepwise multiple linear regression (MLR) analysis. The statistical parameters provided by the linear model were r² = 0.7744, r²(adj) = 0.7551, s = 0.169 for the training set; and r² = 0.6725, r²(adj) = 0.6316, s = 0.196 for the external test set, respectively. The stability and predictive power of the proposed model were further verified using Y-randomization tests, five-fold cross-validation and leave-many-out cross-validation. The model may give some insight into the main structural features that affect the adsorption of the investigated compounds onto activated carbon cloth.

Carcass and meat quality traits of four commercial pig crossbreeds in China

We evaluated carcass and meat quality traits of two Chinese native crossbreeds Landrace x Meishan (LM) and Duroc x (Landrace x Meishan) (DLM) and two foreign crossbreeds Duroc x (Landrace x Yorkshire) (DLY) and PIC (an imported five-way crossbreed). One hundred and twenty weaned pigs (half castrated males and half females) were reared and slaughtered at a predestinated slaughter age. The general carcass and meat quality traits were measured and analyzed. The DLY and PIC crosses had significantly heavier live weights (93.39 and 96.33 kg, P < 0.01), significantly higher dressing percentages (80.65 and 79.39%, P < 0.05), significantly bigger loin areas (42.69 and 43.91 cm(2), P < 0.001), and significantly more lean carcasses (65.78 and 66.40%, P < 0.001) than LM and DLM. On the other hand, LM had a significantly lower live weight (70.29 kg, P < 0.01), significantly thicker back fat (3.54 cm, P < 0.001), significantly less lean carcasses (46.82%, P < 0.001), and significantly less ham and breech (26.53%, P < 0.05) than the other crossbreeds. Among meat quality parameters, LM had the highest intramuscular fat content (5.02%, P < 0.001) and the smallest fiber area (3126.45 μm(2), P < 0.01). However, PIC showed the lowest pH(1) (5.82, P < 0.01) and pH(2) (5.63, P < 0.01), the highest drip loss (2.89%, P < 0.01), and the lowest intramuscular fat (1.35%, P < 0.001). We concluded that LM and DLM had good meat quality traits but poorer carcass traits than DLY and PIC; DLY had good carcass and meat quality traits; PIC had good carcass traits, but it had less intramuscular fat, lower pH and higher drip loss.

Abstract P1-01-09: Which nomograms may be the best for predicting nonsentinel lymph node metastasis in breast cancer patients: a meta-analysis

Background: Axillary lymph node dissection (ALND) is the standard treatment for breast cancer patients with positive sentinel lymph nodes (SLNs). Several nomograms were developed to identify SLN-positive patients with low risk of nonsentinel lymph nodes (NSLNs) metastasis. These nomograms were validated in different populations and it is still unknown which is the best. This study is to present a systemic review and perform a meta-analysis to obtained the pooled AUC (Area Under the receiver-operator Curve) value of each models.

Methods: This review focused on six models: Cambridge, MSKCC, Mayo, MDA, Tenon and Stanford models. A “Pubmed” search and “Web of science” search were conducted and 35 literatures were ultimately included. AUC and the number of patients with positive NSLNs were extracted. Publication bias and heterogeneity were analyzed. AUCs were converted to odds ratios (ORs) for combination. The combined ORs were converted back to AUCs to represent the integrated discriminative capabilities of each models.

Findings: In total, the Cambridge, Mayo, MDA, MSKCC, Stanford and Tenon models were validated in 8, 6, 4, 39, 14 and 15 studies, with 2156, 2431, 843, 8143, 3700 and 3648 patients included, respectively. There were no publication bias or heterogeneity observed in the Cambridge, Mayo, MDA and Tenon models (Table 1). The combined ORs and the corresponding AUCs of each models were listed as follow: Cambridge (OR = 3.86, AUC = 0.71), Mayo (OR = 3.71, AUC = 0.71), MSKCC (OR = 3.47, AUC = 0.70), MDA(OR = 3.44, AUC = 0.70), Tenon (OR = 3.46, AUC = 0.70) and Stanford (OR = 2.92, AUC = 0.67). For each of the predictive models, both fixed and random effect models were used to calculate the combined OR. The presence of larger difference between the fixed and random effect analysis suggests small study effects, rendering the meta-analysis relatively less reliable. The combined ORs were identical when fixed and random effect models were used in the Cambridge and MDA models, suggesting that there was no small study effects in these two models.

Optic atrophy differentially diagnosed as spinocerebellar ataxia from Leber hereditary optic neuropathy by gene mutation analysis

Optic atrophy describes a group of diseases of retinal ganglion cells and axons that eventually lead to loss of vision. Optic atrophy has both congenital and acquired causes, and its diagnosis (or differential diagnosis) is complicated. This case report describes a 20-year-old man who presented with a 1-year history of progressive vision loss in both eyes and no obvious systemic symptoms. Fundus examination revealed bilateral optic atrophy. Based on clinical characteristics, visual field analysis and pattern visual evoked potential examination, the presumptive diagnosis was Leber hereditary optic neuropathy (LHON). Analysis of mitochondrial DNA indicated the absence of all of three common mutations associated with LHON (m.3460G>A, m.11778G>A, m.14484T>C). Detailed questioning of the patient revealed a history of prolonged language development and poor balance. Neurological examination indicated abnormal co-ordination, suggesting the presence of inherited spinocerebellar ataxia (SCA). Analysis of the SCA7 gene revealed a high number of trinucleotide repeats [(CAG)(n), n > 64], confirming the diagnosis of SCA. The aetiology of optic atrophies is complicated and the molecular genetic detection approach provides the best information for diagnosing these diseases.

Comparative analysis of the distribution of segmented filamentous bacteria in humans, mice and chickens

Segmented filamentous bacteria (SFB) are indigenous gut commensal bacteria. They are commonly detected in the gastrointestinal tracts of both vertebrates and invertebrates. Despite the significant role they have in the modulation of the development of host immune systems, little information exists regarding the presence of SFB in humans. The aim of this study was to investigate the distribution and diversity of SFB in humans and to determine their phylogenetic relationships with their hosts. Gut contents from 251 humans, 92 mice and 72 chickens were collected for bacterial genomic DNA extraction and subjected to SFB 16S rRNA-specific PCR detection. The results showed SFB colonization to be age-dependent in humans, with the majority of individuals colonized within the first 2 years of life, but this colonization disappeared by the age of 3 years. Results of 16S rRNA sequencing showed that multiple operational taxonomic units of SFB could exist in the same individuals. Cross-species comparison among human, mouse and chicken samples demonstrated that each host possessed an exclusive predominant SFB sequence. In summary, our results showed that SFB display host specificity, and SFB colonization, which occurs early in human life, declines in an age-dependent manner.

Association of hypomagnesemia with inferior survival in a phase III, randomized study of cetuximab plus best supportive care versus best supportive care alone: NCIC CTG/AGITG CO.17

BACKGROUND

Cetuximab-induced hypomagnesemia has been associated with improved clinical outcomes in advanced colorectal cancer (CRC). We explored this relationship from a randomized clinical trial of cetuximab plus best supportive care (BSC) versus BSC alone in patients with pretreated advanced CRC.

PATIENTS AND METHODS

Day 28 hypomagnesemia grade (0 versus ≥1) and percent reduction (<20% versus ≥20%) of Mg from baseline was correlated with outcome.

RESULTS

The median percentage Mg reduction at day 28 was 10% (-42.4% to 63.0%) for cetuximab (N = 260) versus 0% (-21.1% to 25%) for BSC (N = 251) [P < 0.0001]. Grade ≥1 hypomagnesemia and ≥20% reduction from baseline at day 28 were associated with worse overall survival (OS) [hazard ratio, HR 1.61 (95% CI 1.12-2.33), P = 0.01 and 2.08 (95% CI 1.32-3.29), P = 0.002, respectively] in multivariate analysis including grade of rash (0-1 versus 2+). Dyspnea (grade ≥3) was more common in patients with ≥20% versus < 20% Mg reduction (68% versus 45%; P = 0.02) and grade 3/4 anorexia were higher in patients with grade ≥1 hypomagnesemia (81% versus 63%; P = 0.02).

CONCLUSIONS

In contrast to prior reports, cetuximab-induced hypomagnesemia was associated with poor OS, even after adjustment for grade of rash.

TNF-α-induced CXCL8 production by A549 cells: involvement of the non-neuronal cholinergic system

It was recently suggested that the non-neuronal cholinergic system has a regulatory role in pulmonary inflammation. We investigated this system's involvement in the control of cytokine production by the A549 human alveolar epithelial cell line. CXCL8 and acetylcholine (ACh) concentrations were measured using ELISA and LC-MS/MS, respectively. The mRNA expression of muscarinic receptor (MR) subtypes was determined using RT-PCR. In A549 cells, TNF-α increased the release of CXCL8 and ACh and the expression of the subtype 3 MR (M3R). Furthermore, TNF-α-induced CXCL8 secretion was (i) inhibited by the MR antagonist tiotropium and the M3R antagonist 4-DAMP and (ii) enhanced by the M1/M3R agonist pilocarpine and the cholinesterase inhibitor physostigmine. Taken as a whole, these results suggest that ACh release by A549 cells enhances TNF-α-induced CXCL8 secretion through activation of the M3R. Western blot analysis revealed that pilocarpine and physostigmine enhanced the TNF-α-induced phosphorylation of ERK1/2 and p38 MAPK and the degradation of IκBα. Inhibition of these pathways with specific inhibitors abrogated the pilocarpine-induced CXCL8 release. Our results suggest that the TNF-α-induced secretion of CXCL8 in A549 cells is regulated by the release of ACh, the latter's binding to the M3R and the downstream activation of NF-κB and the ERK1/2 and p38 MAPK signaling pathways. Our findings suggest that MR antagonists may have anti-inflammatory effects by preventing pro-inflammatory events driven by endogenous, non-neuronal ACh.

Uranium and thorium leached from uranium mill tailing of Guangdong Province, China and its implication for radiological risk

The paper focused on the leaching behaviour of uranium (U) and thorium (Th) from uranium mill tailing collected from the Uranium Mill Plant in Northern Guangdong Province, China. Distilled water (pH 6) and sulphuric acid solution (pH 4 and 3) were used as solvent for the leaching over 22 weeks. It was found that the cumulative leach fraction from the mill tailing was 0.1, 0.1 and 0.7 % for U release, and overall 0.01 % for Th release, using distilled water, sulphuric acid solution of pH 4 and pH 3 as leaching agents, respectively. The results indicate that (1) the release of U and Th in uranium mill tailing is a slow and long-term process; (2) surface dissolution is the main mechanism for the release of U and Th when sulphuric acid solution of pH 3 is employed as the leaching agent; (3) both U and Th are released by diffusion when using sulphuric acid solution of pH 4 as the leaching agent and (4) U is released by surface dissolution, while Th is released by diffusion when using distilled water as the leaching agent. The implication for radiological risk in the real environment was also discussed.

SIRT1 induces EMT by cooperating with EMT transcription factors and enhances prostate cancer cell migration and metastasis

The epithelial-to-mesenchymal transition (EMT) is a crucial program for the invasion and metastasis of epithelial tumors that involves loss of cell-cell adhesion and increased cell mobility; however, mechanisms underlying this transition are not fully elucidated. Here, we propose a novel mechanism through which the nicotinamide adenine dinucleotide-dependent histone deacetylase SIRT1 regulates EMT in prostate cancer cells through cooperation with the EMT inducing transcription factor ZEB1. We found that forced expression of SIRT1 in non-transformed PZ-HPV-7 prostate epithelial cells disrupts the epithelial morphology concomitant with decreased expression of the epithelial marker, E-cadherin, and increased expression of mesenchymal markers. In contrast, silencing SIRT1 in metastatic prostate tumor cells restores cell-cell adhesion and induces a shift toward an epithelial morphology concomitant with increased expression of E-cadherin and decreased expression of mesenchymal markers. We also found that SIRT1 has a physiologically relevant role in endogenous EMT induced by EGF signaling in prostate cancer cells. We propose that the regulation of EMT by SIRT1 involves modulation of, and cooperation with, the EMT inducing transcription factor ZEB1. Specifically, we show that SIRT1 silencing reduces expression of ZEB1 and that SIRT1 is recruited to the E-cadherin proximal promoter by ZEB1 to deacetylate histone H3 and to reduce binding of RNA polymerase II, ultimately suppressing E-cadherin transcription. We thus identify a necessary role for ZEB1 in SIRT1-mediated EMT. Finally, we show that reduction of SIRT1 decreases prostate cancer cell migration in vitro and metastasis in vivo in immunodeficient mice, which is largely independent of any general effects of SIRT1 on prostate cancer growth and survival. We therefore identify SIRT1 as a positive regulator of EMT and metastatic growth of prostate cancer cells and our findings implicate overexpressed SIRT1 as a potential therapeutic target to reverse EMT and to prevent prostate cancer progression.

Resonance Raman Structural Evidence that the Cis-to-Trans Isomerization in Rhodopsin Occurs in Femtoseconds

Picosecond time-resolved resonance Raman spectroscopy is used to probe the structural changes of rhodopsin's retinal chromophore as the cis-to-trans isomerization reaction occurs that initiates vision. Room-temperature resonance Raman spectra of rhodopsin's photoproduct with time delays from -0.7 to 20.8 ps are measured using 2.2 ps, 480 nm pump and 1.5 ps, 600 nm probe pulses. Hydrogen-out-of-plane (HOOP) modes at 852, 871, and 919 cm(-1), fingerprint peaks at 1272, 1236, 1211, and 1166 cm(-1), and a broad red-shifted ethylenic band at 1530 cm(-1) are present at the earliest positive pump-probe time delay of 0.8 ps, indicating that the chromophore is already in a strained, all-trans configuration. Kinetic analyses of both the HOOP and ethylenic regions of the photoproduct spectra reveal that these features grow in with fast ( approximately 200 fs) and slow ( approximately 2-3 ps) components. These data provide the first structural evidence that photorhodopsin has a thermally unrelaxed, torsionally strained all-trans chromophore within approximately 1 ps, and possibly within 200 fs, of photon absorption. Following this ultrafast product formation, the all-trans chromophore cools and conformationally relaxes within a few picoseconds to form bathorhodopsin. This cooling process is revealed as an ethylenic frequency blue-shift of 6 cm(-1) (tau approximately 3.5 ps) as well as an ethylenic width narrowing (tau approximately 2 ps). The ultrafast production of photorhodopsin is likely accompanied by an impulsively driven, localized protein response. More delocalized protein modes are unable to relax on this ultrafast time scale enabling the chromophore-protein complex to store the large amounts of photon energy (30-35 kcal/mol) that are subsequently used to drive activating protein conformational changes.

Controlling DNA Fragmentation in MALDI-MS by Chemical Modification

Fragmentation has proven to be a major factor limiting accessible mass range, sensitivity, and mass resolution in the analysis of DNA by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Previous work has shown that this DNA fragmentation is strongly dependent on both the MALDI matrix and the nucleic acid sequence employed. Fragmentation is initiated by nucleobase protonation, leading to cleavage of the N-glycosidic bond with base loss, followed by cleavage of the phosphodiester backbone. In this study, asymmetric oligonucleotides incorporating cytidine and cytidine analogs such as 5-methyl-2'-deoxycytidine, 5-bromo-2'-deoxycytidine, aracytidine, and 2'-fluorodeoxycytidine nucleosides were used to systematically investigate the influence of the structural changes on the stability of the N-glycosidic bond. Modifications of the deoxyribose sugar ring by replacing the 2'-hydrogen with more electron-withdrawing groups such as the hydroxyl or fluoro group stabilize the N-glycosidic bond to a greater extent than the C5 nucleobase modifications. 2'-Hydroxyl and 2'-fluoro groups respectively are shown to partially or completely block fragmentation at the modified nucleosides. Mixtures of oligonucleotides incorporating such modifications demonstrate remarkably extended accessible mass range, as well as increased sensitivity and mass resolution. The stabilization provided by these chemical modifications also expands the range of matrices useful for nucleic acid analysis, yielding in some cases greatly improved performance.

RFLP analysis of the progeny from Oryza alta Swallen x Oryza sativa L

RFLP analyses were carried out in the progeny from a cross of two phylogenetically distant rice species, wild rice Oryza alta Swallen (CCDD, 2n = 48) and cultivated rice O. sativa L. (AA, 2n = 24). The sterile plants gave heterozygous RFLP patterns at most of the loci detected. They looked more like their wild rice parent, with 36 chromosomes in their root-tip cells and pollen mother cells. In two partially fertile plants, however, most of the markers that were used showed RFLP patterns similar to the cultivated parent, O. sativa. By cytological study, it was found that nearly one-third of the chromosomes had been eliminated in the partially fertile plants. Their seeds have short awns, which is a characteristic of their wild parent, O. alta. An introgression occurred in one of the partially fertile plants, which led to the discussion about a nonconventional mechanism in wide hybridization for transference of wild rice chromosome segments to cultivated rice chromosomes.

MicroCT Imaging and In Vivo Temperature Elevations in Implanted Prostatic Tumors in Laser Photothermal Therapy Using Gold Nanorods

In this study, in vivo animal experiments are performed on implanted xenograph prostatic tumors in nude mice to investigate enhanced laser energy absorption in the tumors by an intratumoral injection of gold nanorod solutions. In vivo temperature mapping of the tumors during laser photothermal therapy has shown the feasibility of elevating tumor temperatures higher than 50 °C using only 0.1 ml nanorod solution and a low laser irradiance of 1.6 W/cm2 incident on the tumor surface. The temperature profile suggests that normal tumor tissue still absorbs some amount of the laser energy without nanorod presence; however, the injected nanorods ensure that almost all the laser energy is absorbed and confined to the targeted tumors. The inverse relationship between the temperature elevations and the tumor size implies a relatively uniform spreading of the nanorods to the entire tumor, which is also shown by microcomputed tomography (microCT) imaging analyses. The feasibility of detecting 250 OD gold nanorod solution injected to the tumors is demonstrated via a high resolution microCT imaging system. Compared to other nanostructures, the gold nanorods used in this study do not accumulate surrounding the injection site. The relatively uniform deposition of the nanorods in the tumors observed by the microCT scans can be helpful in future study in simplifying theoretical simulation of temperature elevations in tumors during laser photothermal therapy.

Characterization of the phenotype of high collagen-producing fibroblast clones in systemic sclerosis, using a new modified limiting-dilution method

BACKGROUND

Overproduction of type I collagen in fibroblasts of systemic sclerosis (SSc) is the hallmark of fibrosis. Establishment and characterization of the phenotype of SSc fibroblasts has been hindered by the heterogeneity between fibroblasts and the lack of adequate cloning methods.

AIM

To establish and investigate the characteristics of the SSc high collagen-producing fibroblast phenotype.

METHODS

Primary cultured fibroblasts from skin biopsies of patients with SSc and normal controls were cloned by a new modified limiting-dilution method. All clones were divided into different subpopulations based on their α1(I) procollagen (COL1A1) mRNA level detected by real-time reverse transcriptase PCR assay. In the different subpopulations, cell growth and cycle distribution were analysed by MTT and flow cytometry, COL1A1 promoter activity was examined by transient transfection, and the binding activity of Sp1 to the COL1A1 proximal promoter was investigated by quantitative chromatin immunoprecipitation.

RESULTS

The clonogenicities of SSc and normal control fibroblasts were similar, but the mean COL1A1 mRNA level of clones and the percentage of the subpopulation with a high COL1A1 mRNA level were significantly higher in SSc fibroblasts than in controls. There was no significant difference on cell growth and cycle between different subpopulations of SSc and control fibroblasts. The COL1A1 proximal promoter activity and its binding activity to Sp1 in the clones were strongly correlated with their COL1A1 mRNA level.

CONCLUSION

Overproduction of collagen in an SSc fibroblast subpopulation seems to result mainly from the abnormally activated transcription of COL1A1 rather than from overproliferation of fibroblasts. The new modified limiting-dilution method provides a useful means for characterizing cells with heterogeneous phenotypes.