331 research outputs found
Trace and rare earth elements contents of a Sardinian sedimentary Mn-rich deposit: preliminary results.
Mn oxides are important scavengers of trace elements from waters. They often form deposits with high metals concentrations that sometimes have economic significance. Within a thick sedimentary deposits of northern Sardinia, Mn oxide mineralization was found as both matrix and coatings on clasts of a conglomeratic deposit, and subrounded nodules in residual clays. Lithiophorite and birnessite are the sole Mn phases that are also accompanied by variable amounts of Fe oxides and hydroxides, clay minerals, and phyllosilicates. Chemical analysis of the studied samples revealed high concentrations of most of trace metals (Co, Ni, Zn, Cu, Ba, Y, U and Pb) and all rare earth elements (REE). The latter were used to provide the first hypothesis regarding environmental conditions and chemical processes determining the precipitation of Mn oxides
Homozygous mutation in the prokineticin-receptor2 gene (Val274Asp) presenting as reversible Kallmann syndrome and persistent oligozoospermia: case report.
Prokineticin 2 (Prok2) or prokineticin-receptor2 (Prok-R2) gene mutations are associated with Kallmann syndrome
(KS). We describe a new homozygous mutation of Prok-R2 gene in a man displaying KS with an apparent reversal of
hypogonadism. The proband, offspring of consanguineous parents, presented at age 19 years with absent puberty, no
sense of smell, low testosterone and gonadotrophin levels. Magnetic resonance imaging showed olfactory bulb absence.
The patient achieved virilization and spermatogenesis with gonadotrophin administration. Two years after discontinuing
hormonal therapy, he maintained moderate oligozoospermia and normal testosterone levels. Prok2 and Prok-
R2 gene sequence analyses were performed. The proband had a homozygous mutation in Prok-R2 exon 2 that harbours
the c.T820>A base substitution, causing the introduction of an aspartic acid in place of valine at position 274
(Val274Asp). His mother had the same mutation in heterozygous state. This report describes a novel homozygous
mutation of Prok-R2 gene in a man with variant KS, underlying the role of Prok-R2 gene in the olfactory and reproductive
system development in humans. Present findings indicate that markedly delayed activation of gonadotrophin
secretion may occur in some KS cases with definite gene defects, and that oligozoospermia might result from a variant
form of reversible hypogonadotrophic hypogonadism
Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in Na-Cl brackish waters of north-western Sardinia, Italy
Abstract. Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and waterârock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples) of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr), in addition to isotopic data including ÎŽ18O, ÎŽD in water, and ÎŽ34S and ÎŽ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg Lâ1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The ÎŽ18O and ÎŽD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the conclusion that they are meteoric in origin. A significant consequence of the meteoric origin of the Na-Cl-type water studied here is that the Br / Cl ratio, extensively used to assess the origin of salinity in fresh water, should be used with care in carbonate aquifers that are near the coast. Overall, ÎŽ34S and ÎŽ18O levels in dissolved SO4 suggest that waterârock interaction is responsible for the Na-Cl brackish composition of the water hosted by the Jurassic and Triassic aquifers of the Nurra, and this is consistent with the geology and lithological features of the study area. Evaporite dissolution may also explain the high Cl content, as halite was detected within the gypsum deposits. Finally, these Na-Cl brackish waters are undersaturated with respect to the more soluble salts, implying that in a climate evolving toward semi-arid conditions, the salinization process could intensify dramatically in the near future
Going Conservative or Conventional? Investigating Farm Management Strategies in between Economic and Environmental Sustainability in Southern Italy
The European âGreen Dealâ strategy is aimed at making Europe the first climate-neutral continent by 2050 through integrated actions relying on healthier agricultural systems grounded in (environmental and economic) sustainable practices, including soil carbon management and biodiversity enhancement. In this vein, the present study contrasts the economic-environmental performances of conventional (deep tillage) and conservative (no-tillage and soil ripping) practices for two varieties of durum wheat (Triticum turgidum spp. durum), namely a modern (Anco Marzio) and an ancient landrace (Saragolla Lucana) variety in the Basilicata region (Southern Italy). Field and laboratory analysis (granulometry, mineralogy, and geochemistry) as well as satellite data (RapidEye) were used to characterize the soil and vegetation patterns. The empirical results indicate a higher biomass production and vegetative potential together with higher grain yields in soils managed with conventional deep tillage compared with soil managed with conservative practices. Similarly, the modern wheat variety exhibited better performance with respect to the old landrace. The soils managed with conventional practices had a distribution of exchangeable macro-nutrients characterized by a reduction in Ca+ and an increase in Mg2+ and K+ between pre-sowing and post-harvesting. Such a distribution was also genotype-dependent, with a higher variability for Saragolla Lucana than Anco Marzio, showing a diverging adsorption of macro-elements between the modern and ancient landrace varieties
Robotic Therapy for Phantom Limb Pain in Upper Limb Amputees
The system described in this paper combines virtual reality with haptic feedback to increase the level of immersion and invoke the sense of agency in patients with phantom limb pain with the aim of reducing perceived pain. This paper presents three case studies of an on-going clinical study. The initial results suggest an increased sense of embodiment of the virtual limb promotes a decrease in perceived levels of pain. The results strengthen the view that the cortical map does not fully âdisappearâ yet lays dormant
Compact solid-state CMOS single-photon detector array for in vivo NIR fluorescence lifetime oncology measurements
In near infrared fluorescence-guided surgical oncology, it is challenging to distinguish healthy from cancerous tissue. One promising research avenue consists in the analysis of the exogenous fluorophoresâ lifetime, which are however in the (sub-)nanosecond range. We have integrated a single-photon pixel array, based on standard CMOS SPADs (single-photon avalanche diodes), in a compact, time-gated measurement system, named FluoCam. In vivo measurements were carried out with indocyanine green (ICG)-modified derivatives targeting the avb3 integrin, initially on a genetically engineered mouse model of melanoma injected with ICG conjugated with tetrameric cyclic pentapeptide (ICG􀀀E[c(RGDfK)4]), then on mice carrying tumour xenografts of U87-MG (a human primary glioblastoma cell line) injected with monomeric ICG􀀀c(RGDfK). Measurements on tumor, muscle and tail locations allowed us to demonstrate the feasibility of in vivo lifetime measurements with the FluoCam, to determine the characteristic lifetimes (around 500 ps) and subtle lifetime differences between bound and unbound ICG-modified fluorophores (10% level), as well as to estimate the available photon fluxes under realistic conditions
Identification of Isoform 2 Acid-Sensing Ion Channel Inhibitors as Tool Compounds for Target Validation Studies in CNS
Acid-sensing ion channels (ASICs) are a family of ion channels permeable to cations and largely responsible for the onset of acid-evoked ion currents both in neurons and in different types of cancer cells, thus representing a potential target for drug discovery. Owing to the limited attention ASIC2 has received so far, an exploratory program was initiated to identify ASIC2 inhibitors using diminazene, a known pan-ASIC inhibitor, as a chemical starting point for structural elaboration. The performed exploration enabled the identification of a novel series of ASIC2 inhibitors. In particular, compound 2u is a brain penetrant ASIC2 inhibitor endowed with an optimal pharmacokinetic profile. This compound may represent a useful tool to validate in animal models in vivo the role of ASIC2 in different neurodegenerative central nervous system pathologies
Plasmodium transmission blocking activities of Vernonia amygdalina extracts and isolated compounds
BACKGROUND: Medicinal plants are a validated source for discovery of new leads and standardized herbal medicines. The aim of this study was to assess the activity of Vernonia amygdalina leaf extracts and isolated compounds against gametocytes and sporogonic stages of Plasmodium berghei and to validate the findings on field isolates of Plasmodium falciparum.
METHODS:
Aqueous (Ver-H2O) and ethanolic (Ver-EtOH) leaf extracts were tested in vivo for activity against sexual and asexual blood stage P. berghei parasites. In vivo transmission blocking effects of Ver-EtOH and Ver-H2O were estimated by assessing P. berghei oocyst prevalence and density in Anopheles stephensi mosquitoes. Activity targeting early sporogonic stages (ESS), namely gametes, zygotes and ookinetes was assessed in vitro using P. berghei CTRPp.GFP strain. Bioassay guided fractionation was performed to characterize V. amygdalina fractions and molecules for anti-ESS activity. Fractions active against ESS of the murine parasite were tested for ex vivo transmission blocking activity on P. falciparum field isolates. Cytotoxic effects of extracts and isolated compounds vernolide and vernodalol were evaluated on the human cell lines HCT116 and EA.hy926.
RESULTS:
Ver-H2O reduced the P. berghei macrogametocyte density in mice by about 50% and Ver-EtOH reduced P. berghei oocyst prevalence and density by 27 and 90%, respectively, in An. stephensi mosquitoes. Ver-EtOH inhibited almost completely (>90%) ESS development in vitro at 50 ÎŒg/mL. At this concentration, four fractions obtained from the ethylacetate phase of the methanol extract displayed inhibitory activity >90% against ESS. Three tested fractions were also found active against field isolates of the human parasite P. falciparum, reducing oocyst prevalence in Anopheles coluzzii mosquitoes to one-half and oocyst density to one-fourth of controls. The molecules and fractions displayed considerable cytotoxicity on the two tested cell-lines.
CONCLUSIONS:
Vernonia amygdalina leaves contain molecules affecting multiple stages of Plasmodium, evidencing its potential for drug discovery. Chemical modification of the identified hit molecules, in particular vernodalol, could generate a library of druggable sesquiterpene lactones. The development of a multistage phytomedicine designed as preventive treatment to complement existing malaria control tools appears a challenging but feasible goal
Pre-clinical Evaluation of a Cyanine-Based SPECT Probe for Multimodal Tumor Necrosis Imaging
Purpose: Recently we showed that a number of carboxylated near-infrared fluorescent (NIRF) cyanine dyes possess strong necrosis avid properties in vitro as well as in different mouse models of spontaneous and therapy-induced tumor necrosis, indicating their potential use for cancer diagnostic- and prognostic purposes. In the previous study, the detection of the cyanines was achieved by whole body optical imaging, a technique that, due to the limited penetration of near-infrared light, is not suitable for investigations deeper than 1 cm within the human body. Therefore, in order to facilitate clinical translation, the purpose of the present study was to generate a necrosis avid cyanine-based NIRF probe that could also be used for single photon emission computed tomography (SPECT). For this, the necrosis avid NIRF cyanine HQ4 was radiolabeled with 111indium, via the chelate diethylene triamine pentaacetic acid (DTPA). Procedures: The necrosis avid properties of the radiotracer [111In]DTPA-HQ4 were examined in vitro and in vivo in different breast tumor models in mice using SPECT and optical imaging. Moreover, biodistribution studies were performed to examine the pharmacokinetics of the probe in vivo. Results: Using optical imaging and radioactivity measurements, in vitro, we showed selective accumulation of [111In]DTPA-HQ4 in dead cells. Using SPECT and in biodistribution studies, the necrosis avidity of the radiotracer was confirmed in a 4T1 mouse breast cancer model of spontaneous tumor necrosis and in a MCF-7 human breast cancer model of chemotherapy-induced tumor necrosis. Conclusions: The radiotracer [111In]DTPA-HQ4 possessed strong and selective necrosis avidity in vitro and in various mouse models of tumor necrosis in vivo, indicating its potential to be clinically applied for diagnostic purposes and to monitor anti-cancer treatment efficacy
New understandings of the genetic basis of isolated idiopathic central hypogonadism
Idiopathic hypogonadotropic hypogonadism is a rare disease that is characterized by delayed/absent puberty and/or infertility due to an insufficient stimulation of an otherwise normal pituitary-gonadal axis by gonadotrophin-releasing hormone (GnRH) action. Because reduced or normal luteinizing hormone (LH)/follicle-stimulating hormone (FSH) levels may be observed in the affected patients, the term idiopathic central hypogonadism (ICH) appears to be more appropriate. This disease should be distinguished from central hypogonadism that is combined with other pituitary deficiencies. Isolated ICH has a complex pathogenesis and is fivefold more prevalent in males. ICH frequently appears in a sporadic form, but several familial cases have also been reported. This finding, in conjunction with the description of numerous pathogenetic gene variants and the generation of several knockout models, supports the existence of a strong genetic component. ICH may be associated with several morphogenetic abnormalities, which include osmic defects that, with ICH, constitute the cardinal manifestations of Kallmann syndrome (KS). KS accounts for approximately 40% of the total ICH cases and has been generally considered to be a distinct subgroup. However, the description of several pedigrees, which include relatives who are affected either with isolated osmic defects, KS, or normo-osmic ICH (nICH), justifies the emerging idea that ICH is a complex genetic disease that is characterized by variable expressivity and penetrance. In this context, either multiple gene variants or environmental factors and epigenetic modifications may contribute to the variable disease manifestations. We review the genetic mechanisms that are presently known to be involved in ICH pathogenesis and provide a clinical overview of the 227 cases that have been collected by the collaborating centres of the Italian ICH Network
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