227 research outputs found

    Capacity for increasing soil organic carbon stocks in dryland agricultural systems

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    Assessment of the potential for soil carbon sequestration based on soil type, land use, and climate scenarios is crucial for determining which agricultural regions can be used to help mitigate increasing atmospheric CO2 concentrations. In semi-arid and Mediterranean-type environments, soil organic carbon (SOC) storage capacity is rarely achieved under dryland agricultural systems. We aimed to assess both actual (measured) and attainable (modelled) SOC stock values for the dryland agricultural production zone of Western Australia. We measured actual SOC storage (0–0.3 m) and known constraints to plant growth for a range of soils types (3–27% clay) and land uses (continuous cropping, mixed cropping, annual and perennial pastures) on the Albany sand plain in Western Australia (n = 261 sites), spanning a rainfall gradient of 421–747 mm. Average actual SOC stocks for land use–soil type combinations ranged from 33 to 128 t C/ha (0–0.3 m). Up to 89% of the variability in actual SOC stock was explained by soil depth, rainfall, land use, and soil type. The scenarios modelled with Roth-C predicted that attainable SOC values of 59–140 t C/ha (0–0.3 m) could be achieved within 100 years. This indicated an additional storage capacity of 5–45% (7–27 t C/ha) depending on the specific land use–soil type combination. However, actual SOC in the surface 0–0.1 m was 95 to >100% of modelled attainable SOC values, suggesting this soil depth was ‘saturated’. Our findings highlight that additional SOC storage capacity in this region is limited to the subsoil below 0.1 m. This has implications for management strategies to increase SOC sequestration in dryland agricultural systems, as current practices tend to concentrate organic matter near the soil surface

    Diminished presynaptic GABA(B) receptor function in the neocortex of a genetic model of absence epilepsy

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    Changes in GABA(B) receptor subunit expression have been recently reported in the neocortexof epileptic WAG/Rij rats that are genetically prone to experience absence seizures.These alterations may lead to hyperexcitability by downregulating the function of presynapticGABA(B) receptors in neocortical networks as suggested by a reduction in paired-pulsedepression. Here, we tested further this hypothesis by analyzing the effects induced by theGABA(B) receptor agonist baclofen (0.1-10 ÎŒM) on the inhibitory events recorded in vitro fromneocortical slices obtained from epileptic (>180 day-old) WAG/Rij and age-matched, nonepilepticcontrol (NEC) rats. We found that higher doses of baclofen were required todepress pharmacologically isolated, stimulus-induced IPSPs generated by WAG/Rij neuronsas compared to NEC. We also obtained similar evidence by comparing the effects ofbaclofen on the rate of occurrence of synchronous GABAergic events recorded by WAG/Rijand NEC neocortical slices treated with 4-aminopyridine+glutamatergic receptor antagonists.In conclusion, these data highlight a decreased function of presynaptic GABA(B) receptorsin the WAG/Rij rat neocortex. We propose that this alteration may contribute toneocortical hyperexcitability and thus to absence seizures

    Mosaic structure of the penA gene in the oropharynx of men who have sex with men negative for gonorrhoea

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    The oropharynx represents a crucial site for the emergence of multi-drug resistance in Neisseria gonorrhoeae. The mosaic penA alleles, associated with decreased susceptibility to cephalosporins, have emerged by DNA recombination with partial penA genes, particularly those from commensal pharyngeal Neisseria species. Here, we investigated the prevalence of the mosaic structure of the penA gene in the oropharynx of men who have sex with men testing negative for pharyngeal gonorrhoea. From January 2016 to June 2018, 351 gonorrhoea-negative men who have sex with men attending a sexually transmitted infection clinic in Italy were enrolled. Pharyngeal swabs underwent a real-time polymerase chain reaction (PCR) for the detection of the mosaic penA gene. In case of positivity, PCR products were sequenced and searched against several sequences of Neisseria strains. Overall, 31 patients (8.8%) were found positive for the presence of the mosaic penA gene. The positivity was significantly associated with previous cases of pharyngeal gonorrhoea (relative risk [RR]: 3.56, 95% confidence interval 1.44\u20138.80) and with recent exposure to beta-lactams (RR: 4.29, 95% confidence interval 2.20\u20138.38). All penA-positive samples showed a high relatedness (90\u201399%) with mosaic-positive Neisseria strains. Our data underline that commensal Neisseria species of the oropharynx may be a significant reservoir for genetic material conferring antimicrobial resistance in N. gonorrhoeae

    Faba bean (Vicia faba L.) seeds darken rapidly and phenolic content falls when stored at higher temperature, moisture and light intensity

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    Faba beans cv. Fiesta with seed moisture content (SMC) modified to 8, 10, 12 and 14% were packed in polyethylene lined aluminium foil bags and stored at 5, 15, 20, 25, 30, 37, 45, 50 or 60 C ( 2 C) for one year. Samples were analysed for moisture content and seed coat (testa) colour over the storage period using a chroma meter. A continuous increase in L* and b* values was found in all samples with the passage of time whereas a *values first increased and then decreased in samples stored at relatively high temperatures (= 37 C). The initial beige testa colour changed to light brown, dark reddish brown or almost black depending on storage conditions. The higher the temperature and SMC the faster the rate of change in colour (E ab* values). Seeds with 8% SMC had more stable testa colour compared to seeds with higher SMC. Exposure to artificial light (350 mol m -2 s -1) substantially accelerated the colour darkening. Cotyledon stored at 37+2 C also darkened with the storage time. A loss in total free phenolics, total tannins and proanthocyanidins was found with increased darkness of testa and cotyledons during storage

    Comparison between two treatment protocols with recombinant Human Erythropoietin (rHuEpo) in the treatment of late anemia in neonates with Rh-Isoimmunization

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    Objectve. The Rh-hemolytic disease can lead to a late anemia by hemolytic and hyporigenerative mechanism. We compared the effectiveness of rHuEPO in two care protocols that differ for doses of rHuEPO administrated and for timing of administration. Methods. A cohort of 14 neonates was investigated. The neonates were treated with two different protocols. Protocol A: a dose of 200 U/kg/day of rHuEpo administered subcutaneously starting from the end of the second week of life; Protocol B: a dose of 400 U/kg/day of rHuEpo administered subcutaneously starting from the end of the first week of life. Results. The hematocrit values in the protocol A group decreased during treatment (32,5% vs 25,2%), whereas the hematocrit value in protocol B group remained almost stable (38,7% vs 42,8%). The mean numbers of platelets remained stable in both groups while neutrophils increased in protocol A group and decreased in protocol B (p<0,05). Reticulocyte count increased during treatment in both groups, although only in protocol B group it was statistically significative (p<0,05). Conclusions. Our results suggest a similar efficacy between the two treatment protocols. Increasing doses of rHuEPO do not seem enhancing their effectiveness and the incidence of side effects

    Reduced GABA(B) receptor subunit expression and paired-pulse depression in a genetic model of absence seizures

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    Neocortical networks play a major role in the genesis of generalized spike-and-wave (SW) discharges associated with absence seizures in humans and in animal models, including genetically predisposed WAG/Rij rats. Here, we tested the hypothesis that alterations in GABAB receptors contribute to neocortical hyperexcitability in these animals. By using Real-Time PCR we found that mRNA levels for most GABAB(1) subunits are diminished in epileptic WAG/Rij neocortex as compared with age-matched non-epileptic controls (NEC), whereas GABAB(2) mRNA is unchanged. Next, we investigated the cellular distribution of GABAB(1) and GABAB(2) subunits by confocal microscopy and discovered that GABAB(1) subunits fail to localize in the distal dendrites of WAG/Rij neocortical pyramidal cells. Intracellular recordings from neocortical cells in an in vitro slice preparation demonstrated reduced paired-pulse depression of pharmacologically isolated excitatory and inhibitory responses in epileptic WAG/Rij rats as compared with NECs; moreover, paired-pulse depression in NEC slices was diminished by a GABAB receptor antagonist to a greater extent than in WAG/Rij rats further suggesting GABAB receptor dysfunction. In conclusion, our data identify changes in GABAB receptor subunit expression and distribution along with decreased paired-pulse depression in epileptic WAG/Rij rat neocortex. We propose that these alterations may contribute to neocorticalhyperexcitability and thus to SW generation in absence epilepsy

    Diversity of vaginal microbiome and metabolome during genital infections

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    We characterized the vaginal ecosystem during common infections of the female genital tract, as vulvovaginal candidiasis (VVC, n\u2009=\u200918) and Chlamydia trachomatis infection (CT, n\u2009=\u200920), recruiting healthy (HC, n\u2009=\u200921) and bacterial vaginosis-affected (BV, n\u2009=\u200920) women as references of eubiosis and dysbiosis. The profiles of the vaginal microbiome and metabolome were studied in 79 reproductive-aged women, by means of next generation sequencing and proton based-nuclear magnetic resonance spectroscopy. Lactobacillus genus was profoundly depleted in all the genital infections herein considered, and species-level analysis revealed that healthy vaginal microbiome was dominated by L. crispatus. In the shift from HC to CT, VVC, and BV, L. crispatus was progressively replaced by L. iners. CT infection and VVC, as well as BV condition, were mainly characterised by anaerobe genera, e.g. Gardnerella, Prevotella, Megasphaera, Roseburia and Atopobium. The changes in the bacterial communities occurring during the genital infections resulted in significant alterations in the vaginal metabolites composition, being the decrease of lactate a common marker of all the pathological conditions. In conclusion, according to the taxonomic and metabolomics analysis, we found that each of the four conditions is characterized by a peculiar vaginal microbiome/metabolome fingerprint

    Mitochondrial dysfunction induced by a SH2 domain-Targeting STAT3 inhibitor leads to metabolic synthetic lethality in cancer cells

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    In addition to its canonical role in nuclear transcription, signal transducer and activator of transcription 3 (STAT3) is emerging as an important regulator of mitochondrial function. Here, we demonstrate that a novel inhibitor that binds with high affinity to the STAT3 SH2 domain triggers a complex cascade of events initiated by interference with mitochondrial STAT3 (mSTAT3). The mSTAT3\u2013drug interaction leads to mitochondrial dysfunction, accumulation of proteotoxic STAT3 aggregates, and cell death. The cytotoxic effects depend directly on the drug\u2019s ability to interfere with mSTAT3 and mitochondrial function, as demonstrated by site-directed mutagenesis and use of STAT3 knockout and mitochondria-depleted cells. Importantly, the lethal consequences of mSTAT3 inhibition are enhanced by glucose starvation and by increased reliance of cancer cells and tumor-initiating cells on mitochondria, resulting in potent activity in cell cultures and tumor xenografts in mice. These findings can be exploited for eliciting synthetic lethality in metabolically stressed cancer cells using highaffinity STAT3 inhibitors. Thus, this study provides insights on the role of mSTAT3 in cancer cells and a conceptual framework for developing more effective cancer therapies

    Inhibition of Notch pathway arrests PTEN-deficient advanced prostate cancer by triggering p27-driven cellular senescence.

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    Activation of NOTCH signalling is associated with advanced prostate cancer and treatment resistance in prostate cancer patients. However, the mechanism that drives NOTCH activation in prostate cancer remains still elusive. Moreover, preclinical evidence of the therapeutic efficacy of NOTCH inhibitors in prostate cancer is lacking. Here, we provide evidence that PTEN loss in prostate tumours upregulates the expression of ADAM17, thereby activating NOTCH signalling. Using prostate conditional inactivation of both Pten and Notch1 along with preclinical trials carried out in Pten-null prostate conditional mouse models, we demonstrate that Pten-deficient prostate tumours are addicted to the NOTCH signalling. Importantly, we find that pharmacological inhibition of Îł-secretase promotes growth arrest in both Pten-null and Pten/Trp53-null prostate tumours by triggering cellular senescence. Altogether, our findings describe a novel pro-tumorigenic network that links PTEN loss to ADAM17 and NOTCH signalling, thus providing the rational for the use of Îł-secretase inhibitors in advanced prostate cancer patients

    Re-education of Tumor-Associated Macrophages by CXCR2 Blockade Drives Senescence and Tumor Inhibition in Advanced Prostate Cancer

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    Tumor-associated macrophages (TAMs) represent a major component of the tumor microenvironment supporting tumorigenesis. TAMs re-education has been proposed as a strategy to promote tumor inhibition. However, whether this approach may work in prostate cancer is unknown. Here we find that Pten-null prostate tumors are strongly infiltrated by TAMs expressing C-X-C chemokine receptor type 2 (CXCR2), and activation of this receptor through CXCL2 polarizes macrophages toward an anti-inflammatory phenotype. Notably, pharmacological blockade of CXCR2 receptor by a selective antagonist promoted the re-education of TAMs toward a pro-inflammatory phenotype. Strikingly, CXCR2 knockout monocytes infused in Ptenpc−/−; Trp53pc−/− mice differentiated in tumor necrosis factor alpha (TNF-α)-releasing pro-inflammatory macrophages, leading to senescence and tumor inhibition. Mechanistically, PTEN-deficient tumor cells are vulnerable to TNF-α-induced senescence, because of an increase of TNFR1. Our results identify TAMs as targets in prostate cancer and describe a therapeutic strategy based on CXCR2 blockade to harness anti-tumorigenic potential of macrophages against this disease. © 2019 The Author(s) Di Mitri et al. show that CXCR2 blockade in prostate cancer triggers TAMs re-education, leading to tumor inhibition. CXCR2-KO monocytes infused in Ptenpc−/−; Trp53pc−/− tumor-bearing mice differentiate into TNFα-releasing pro-inflammatory macrophages that induce senescence in tumor cells. PTEN-null tumors display higher sensitivity to TNF-α-induced senescence because of TNFR1 upregulation
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