Local order in aqueous solutions of rare gases and the role of the solute concentration: a computer simulation study with a polarizable potential

Aqueous solutions of rare gases are studied by computer simulation employing a polarizable potential for both water and solutes. The use of a polarizable potential allows to study the systems from ambient to supercritical conditions for water. In particular the effects of increasing the concentration and the size of the apolar solutes are considered in an extended range of temperatures. By comparing the results at increasing temperature it appears clearly the change of behaviour from the tendency to demix at ambient conditions to a regime of complete solubility in the supercritical region. In this respect the role of the hydrogen bond network of water is evidenced.Comment: Accepted for publication in Molecular Physics 2004. 19 pages, 10 figure

Phagocytosis of haemozoin (malarial pigment) enhances metalloproteinase-9 activity in human adherent monocytes: Role of IL-1beta and 15-HETE

<p>Abstract</p> <p>Background</p> <p>It has been shown previously that human monocytes fed with haemozoin (HZ) or trophozoite-parasitized RBCs displayed increased matrix metalloproteinase-9 (MMP-9) enzyme activity and protein/mRNA expression and increased TNF production, and showed higher matrix invasion ability. The present study utilized the same experimental model to analyse the effect of phagocytosis of: HZ, delipidized HZ, beta-haematin (lipid-free synthetic HZ) and trophozoites on production of IL-1beta and MMP-9 activity and expression. The second aim was to find out which component of HZ was responsible for the effects.</p> <p>Methods</p> <p>Native HZ freshly isolated from <it>Plasmodium falciparum </it>(Palo Alto strain, Mycoplasma-free), delipidized HZ, beta-haematin (lipid-free synthetic HZ), trophozoites and control meals such as opsonized non-parasitized RBCs and inert latex particles, were fed to human monocytes. The production of IL-1beta by differently fed monocytes, in presence or absence of specific MMP-9 inhibitor or anti-hIL-1beta antibodies, was quantified in supernatants by ELISA. Expression of IL-1beta was analysed by quantitative real-time RT-PCR. MMP-9 activity and protein expression were quantified by gelatin zymography and Western blotting.</p> <p>Results</p> <p>Monocytes fed with HZ or trophozoite-parasitized RBCs generated increased amounts of IL-1beta and enhanced enzyme activity (in cell supernatants) and protein/mRNA expression (in cell lysates) of monocyte MMP-9. The latter appears to be causally related to enhanced IL-1beta production, as enhancement of both expression and enzyme activity were abrogated by anti-hIL-1beta Abs. Upregulation of IL-1beta and MMP-9 were absent in monocytes fed with beta-haematin or delipidized HZ, indicating a role for HZ-attached or HZ-generated lipid components. 15-HETE (15(S,R)-hydroxy-6,8,11,13-eicosatetraenoic acid) a potent lipoperoxidation derivative generated by HZ from arachidonic acid via haem-catalysis was identified as one mediator possibly responsible for increase of both IL-1beta production and MMP-9 activity.</p> <p>Conclusion</p> <p>Results indicate that specific lipoperoxide derivatives generated by HZ may play a role in modulating production of IL-1beta and MMP-9 expression and activity in HZ/trophozoite-fed human monocytes. Results may clarify aspects of cerebral malaria pathogenesis, since MMP-9, a metalloproteinase able to disrupt the basal lamina is possibly involved in generation of hallmarks of cerebral malaria, such as blood-brain barrier endothelium dysfunction, localized haemorrhages and extravasation of phagocytic cells and parasitized RBCs into brain tissues.</p

Suspension of mandatory vaccination and public health preserving: Rovigo Local Health Unit experience after appliance of Veneto regional law 7/2007

The burden of infectious diseases preventable by vaccination decreased considerably over last decades in all countries pro- vided with effective immunization schedules. Implementation of these programs with new vaccines has started discussion on dual- ity between mandatory and recommended vaccinations. Regional autonomy has allowed the Veneto Region, with introduction of Law 7/2007, to experience suspension of all mandatory childhood vaccinations, replaced by an active and free offer of all vaccines recognized as safe and effective. Coverage?s trends and accept- ance of invitation are carefully monitored to avoid loss of com- pliance and reduction of immunized children. The evaluation, performed on population of Rovigo ULSS18 for 2002-2008 birth cohorts (2008 is the first concerned by the change), revealed no fall for previously mandatory vaccinations, but rather a slight increase. Percentage of non-vaccinated children was negligible. The leading cause of non-vaccination to polio was inability to deliver the letter of invitation due to wrong address. An informed dissent was expressed only by a minority (0.9% in 2008 birth cohort). Compliance to immunization offer was elevated both for previ- ously compulsory and recommended vaccinations. Experience of Rovigo ULSS 18 showed that, in a context of already high levels of coverage for recommended vaccinations with optimal organization of immunization services, coverage rates for ex- mandatory vaccines remain unchanged. Further research and reports are required to carefully assess the effect on coverage rates in next birth cohorts, but available data are encourag- ing. Similar legislative measures can be successfully adopted by other Regions with starting conditions comparable to Veneto Region

Anticatabolic activity of alpha-ketoglutaric acid in growing rats

This study evaluated the anti-catabolic effect of α-ketoglutaric acid (AKG) in rats. Thirty Sprague Dowley male rats were divided into 3 groups of 10 animals each and fed ad libitum with protein-free diet (PFD) supplemented with 0, 3, and 6 g/kg feed of AKG for 14 consecutive days. The AKG administration had no effect on the growth performance of rats in the global trial period (0-14 d). After 7 d of excreta collection, the losses of endogenous nitrogen (N), both urinary and total, linearly reduced (P<0.05) following the administration of AKG, ranging from 35.00 mg/d to 28.00 mg/d, and from 45.28 mg/d to 36.36 mg/d, respectively. The villi and microvilli heights were lower when animals received 3 g/kg of AKG respecting to other tested AKG levels. Indeed, enterocytes length linearly increased (P<0.05) as the level of AKG increased in the diet by 25.0% (3 g/kg) and 49.0% (6 g/kg). The AKG levels quadratically influenced (P<0.05) the essential amino acids (EAA) concentrations in the blood, being EAA lower for animals treated with 6 g/kg of AKG (-21.6%) compared to the animals fed the control PFD and the PFD with 3 g/kg of AKG. In conclusion, AKG was effective in reducing catabolism and EAA depletion

Malarial pigment enhances heat shock protein-27 in THP-1 cells: New perspectives for in vitro studies on monocyte apoptosis prevention

Abstract Objective To investigate the effect of malarial pigment (hemozoin, HZ) on expression of heat shock proteins (HSPs) and cell viability in human monocytes by using a stable cell line (THP-1 cells). Methods THP-1 cells were fed with native HZ or treated with pro-apoptotic molecule gliotoxin for 9 h. Thereafter, the protein expression of HSP-27 and HSP-70 was evaluated by western blotting. Alternatively, HZ-fed cells were cultured up to 72 h and cell viability parameters (survival, apoptosis and necrosis rates) were measured by flow cytometric analysis. Results HZ increased basal protein levels of HSP-27 without altering those of HSP-70 in THP-1 cells, and promoted long-term cell survival without inducing apoptosis. As expected, gliotoxin inhibited HSP-27 protein expression and promoted long-term cell apoptosis. Conclusions Present data show that HZ prevents cell apoptosis and enhances the expression of anti-apoptotic HSP-27 in THP-1 cells, confirming the previous evidences obtained from HZ-fed immunopurified monocytes. Since the use of a stable cell line is pivotal to perform HSP-27 silencing experiments, monocytic THP-1 cells could be a good candidate line for such an approach, which is heavily required to clarify the role of HSP-27 in survival of impaired HZ-fed monocytes during falciparum malaria

A mesostructured hybrid CTA–silica carrier for curcumin delivery

Curcumin is a natural active principle with antioxidant, antibacterial and anti-inflammatory properties. Its use is limited by a low water solubility and fast degradation rate, which hinder its bioavailability. To overcome this problem, curcumin can be delivered through a carrier, which protects the drug molecule and enhances its pharmacological effects. The present work proposes a simple one-pot sol–gel synthesis to obtain a hybrid carrier for curcumin delivery. The hybrid consists of a mesostructured matrix of amorphous silica, which stabilizes the carrier, and hexadecyltrimethylammonium (CTA), a surfactant where curcumin is dissolved to increase its water solubility. The carrier was characterized in terms of morphology (FESEM), physicochemical properties (XRD, FTIR, UV spectroscopy) and release capability in pseudo-physiological solutions. Results show that curcumin molecules were entrapped, for the first time, in a silica-surfactant mesostructured hybrid carrier. The hybrid carrier successfully released curcumin in artificial sweat and in a phosphate buffer saline solution, so confirming its efficacy in increasing curcumin water solubility. The proposed drug release mechanism relies on the degradation of the carrier, which involves the concurrent release of silicon. This suggests strong potentialities for topical administration applications, since curcumin is effective against many dermal diseases while silicon is beneficial to the skin

Evolution of Surgical Management of Hemorrhoidal Disease: An Historical Overview

Enfermedad hemorroidal; Terapias quirúrgicasMalaltia hemorroidal; Teràpies quirúrgiquesHemorrhoidal disease; Surgical therapiesHemorrhoidal disease (HD) is the symptomatic enlargement and/or distal displacement of the normal hemorrhoidal cushions and is one of the most frequent diseases in colorectal surgery. Several surgical or office-based therapies are currently available, with the aim of being a more tailored approach. This article aimed to elucidate the historical evolution of surgical therapy for HD from ancient times, highlighting the crucial steps, controversies, and pioneers in the field. In contrast with the previous literature on the topic that is often updated to the 1990s, with the introduction of stapled hemorrhoidopexy and transanal hemorrhoidal dearterialization, this article describes all new surgical and office-based treatments introduced in the first 20 years of the 2000s

Design of high gradient, high repetition rate damped C-band rf structures

The gamma beam system of the European Extreme Light Infrastructure–Nuclear Physics project foresees the use of a multibunch train colliding with a high intensity recirculated laser pulse. The linac energy booster is composed of 12 traveling wave C-band structures, 1.8 m long with a field phase advance per cell of 2π=3 and a repetition rate of 100 Hz. Because of the multibunch operation, the structures have been designed with a dipole higher order mode (HOM) damping system to avoid beam breakup (BBU). They are quasiconstant gradient structures with symmetric input couplers and a very effective damping of the HOMs in each cell based on silicon carbide (SiC) rf absorbers coupled to each cell through waveguides. An optimization of the electromagnetic and mechanical design has been done to simplify the fabrication and to reduce the cost of the structures. In the paper, after a review of the beam dynamics issues related to the BBU effects, we discuss the electromagnetic and thermomechanic design criteria of the structures. We also illustrate the criteria to compensate the beam loading and the rf measurements that show the effectiveness of the HOM damping

Third harmonic cavity design and RF measurements for the Frascati DAΦNE collider

Third harmonic passive RF cavities have been proposed for installation in both rings of the DAΦNE factory collider to improve the Touschek lifetime and to increase the Landau damping. This paper illustrates the design of the harmonic cavities. The main requirements were to obtain a relatively low R/Q factor and a quality factor Q as high as possible to satisfy beam dynamics requirements and to damp all the higher order mode (HOM) to a harmless level in order to avoid multibunch instabilities. A spherical shape of the cavity central body has been chosen as an optimum compromise between a high Q resonator and a low R/Q factor. HOM suppression has been provided by a ferrite ring damper designed for the superconducting cavities of the high energy ring of the KEK-B factory. The design and electromagnetic properties of the resonant modes have been studied with MAFIA and HFSS codes. Cavities have been made of aluminum and the RF measurements have been performed to characterize them. The measurements are in a good agreement with numerical simulations results, demonstrating a satisfactory HOM damping