Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 39
Filter
2.
Matrix Biol ; 90: 40-60, 2020 08.
Article in English | MEDLINE | ID: mdl-32173581

ABSTRACT

Prolyl 3-hydroxylation is a rare collagen type I post translational modification in fibrillar collagens. The primary 3Hyp substrate sites in type I collagen are targeted by an endoplasmic reticulum (ER) complex composed by cartilage associated protein (CRTAP), prolyl 3-hydroxylase 1 (P3H1) and prolyl cis/trans isomerase B, whose mutations cause recessive forms of osteogenesis imperfecta with impaired levels of α1(I)3Hyp986. The absence of collagen type I 3Hyp in wild type zebrafish provides the unique opportunity to clarify the role of the complex in vertebrate. Zebrafish knock outs for crtap and p3h1 were generated by CRISPR/Cas9. Mutant fish have the typical OI patients' reduced size, body disproportion and altered mineralization. Vertebral body fusions, deformities and fractures are accompanied to reduced size, thickness and bone volume. Intracellularly, collagen type I is overmodified, and partially retained causing enlarged ER cisternae. In the extracellular matrix the abnormal collagen type I assembles in disorganized fibers characterized by altered diameter. The data support the defective chaperone role of the 3-hydroxylation complex as the primary cause of the skeletal phenotype.


Subject(s)
Collagen Type II/metabolism , Collagen Type I/metabolism , Extracellular Matrix Proteins/genetics , Osteogenesis Imperfecta/genetics , Prolyl Hydroxylases/genetics , Animals , CRISPR-Cas Systems , Cyclophilins/genetics , Disease Models, Animal , Gene Knockout Techniques , Hydroxylation , Osteogenesis Imperfecta/metabolism , Phenotype , Prolyl Hydroxylases/chemistry , Zebrafish , Zebrafish Proteins/chemistry , Zebrafish Proteins/genetics
3.
Eur Rev Med Pharmacol Sci ; 22(20): 7058-7068, 2018 10.
Article in English | MEDLINE | ID: mdl-30402874

ABSTRACT

OBJECTIVE: Neutrophils play a key role in immunity and are known to respond to exogenous threats by releasing neutrophil extracellular traps (NETs) through NETosis, a process involving the release of neutrophils nuclear DNA decorated with proteins into the extracellular space. In this study, attention has been focused on the ability of differently charged molecular systems polyhedral oligomeric silsesquioxanes (POSS) to induce NETosis. MATERIALS AND METHODS: NETs formation was induced by phorbol myristate acetate (PMA) (positive control) and POSS treatment and visualized by confocal microscopy. Moreover, NETs production was quantified by Sytox green staining. Oxidative stress, autophagy as well as endocytosis involvement in the observed phenomena was evaluated by a specific inhibitory approach. RESULTS: Results obtained in this study demonstrate a POSS time and dose-dependent ability in inducing NETs release irrespectively to their charge. POSS induced NETosis is a consequence of their internalization, as demonstrated by the strong reduction in NETs formation after endocytosis inhibition. Moreover, POSS induced NETosis involves both an increase in superoxide anion generation and autophagy pathway activation as demonstrated by the protective effect displayed by sodium azide and wortmannin. CONCLUSIONS: Data presented in this study indicate that nanomaterials and molecular systems could have a role in the onset of inflammatory phenomena.


Subject(s)
Extracellular Traps/immunology , Neutrophils/immunology , Oxidative Stress/drug effects , Silicon Dioxide/administration & dosage , Autophagy/drug effects , DNA/metabolism , Humans , Microscopy, Confocal , Neutrophils/metabolism , Oxidation-Reduction , Tetradecanoylphorbol Acetate/pharmacology
4.
Dalton Trans ; 47(9): 2939-2948, 2018 Feb 27.
Article in English | MEDLINE | ID: mdl-29441378

ABSTRACT

A class of heterogeneous catalysts based on commercial bentonite from natural origin, containing at least 80 wt% of montmorillonite clay, was designed to transform selectively and under mild conditions toxic organosulfur and organophosphorus chemical warfare agents into non-noxious products with a reduced impact on health and environment. The bentonite from the natural origin was modified by introducing iron species and acid sites in the interlayer space, aiming to obtain a sorbent with strong catalytic oxidising and hydrolytic properties. The catalytic performance of these materials was evaluated in the oxidative abatement of (2-chloroethyl)ethyl sulfide (CEES), a simulant of sulfur mustard, in the presence of aqueous hydrogen peroxide as an oxidant. A new decontamination formulation was, moreover, proposed and obtained by mixing sodium perborate, as a solid oxidant, to iron-bentonite catalysts. Solid-phase decontamination tests, performed on a cotton textile support contaminated with organosulfide and organophosphonate simulant agents revealed the good activity of the solid formulation, especially in the in situ detoxification of blistering agents. Tests carried out on the real blistering warfare agent, sulfur mustard (HD agent), showed that, thanks to the co-presence of the iron-based clay together with the solid oxidant component, a good decontamination of the test surface from the real warfare agent could be achieved (80% contaminant degradation, under ambient conditions, in 24 h).

5.
Phys Chem Chem Phys ; 19(43): 29449-29460, 2017 Nov 08.
Article in English | MEDLINE | ID: mdl-29077117

ABSTRACT

The CO2 adsorption properties of hybrid organic-inorganic MCM-41 silicas with different particle sizes are described here. Micrometric to nanometric MCM-41 silicas are functionalized by introducing amino groups via grafting of 3-[2-(2-aminoethyl)aminoethyl]aminopropyltrimethoxysilane (PAPTS). A combination of FTIR and SS-NMR spectroscopies is adopted to distinguish between physisorbed and chemisorbed CO2. A higher amount of CO2 is physisorbed in the nanometric sample because of a higher pore volume, whereas chemisorbed (carbamate and acid carbamic) species are more abundant in the micrometric sample. The adsorption process is also quantitatively studied using three different techniques (i.e. volumetric measurements, Thermo-Gravimetric Analysis (TGA) and Zero Length Column (ZLC) analysis), especially focusing on the reversibility of the reactions between CO2 and amino groups. The three techniques show a higher CO2 adsorption capacity for MCM-41 with nanometric size compared to the micrometric one. Finally, the process is studied at different temperatures (i.e. from 35 to 90 °C) in order to find the best operating conditions.

6.
Phys Chem Chem Phys ; 19(21): 14114-14128, 2017 May 31.
Article in English | MEDLINE | ID: mdl-28524206

ABSTRACT

Hybrid organic-inorganic SBA-15 silicas functionalized with increasing amounts of amino groups were studied in this work aiming to evaluate the effects of their physico-chemical properties on CO2 capture ability. Three different amino-silane species were used: 3-aminopropyltriethoxysilane (APTS), 3-(2-aminoethyl)aminopropyltrimethoxysilane (EAPTS) and 3-[2-(2-aminoethyl)aminoethyl] aminopropyltrimethoxysilane (PAPTS). More specifically, samples were prepared by using two methods, following a post-synthesis grafting procedure and a one-pot preparation method. Experimental and computational techniques were used to study the structural and textural properties of the obtained samples and their surface species in relation to the adopted preparation method. For the most reactive samples, additional hints on the interactions of organosilane species with the silica surface were obtained by a combination of IR and SS-NMR spectroscopy, with particular emphasis on the effects of the silane chain length on the mobility of the organic species. Advanced complementary solid-state NMR techniques provided deeper information on the interactions of organosilane species with the silica surface. Finally, the amount of CO2 adsorbed was estimated by comparing the classical microcalorimetric analysis method with a new type of screening test, the Zero Length Column analysis, which is able to evaluate small amounts of samples in a very short time and the adsorption properties of the adsorbents. The reactivity of the amino-modified silica samples is deeply influenced by both the preparation route and by the type of organosilane used for the functionalization of the materials. In particular, samples prepared by the post-synthesis grafting procedure and containing higher amount of amino groups in the chain are more reactive, following the order PAPTS > EAPTS > APTS.

7.
Phys Chem Chem Phys ; 18(13): 9042-52, 2016 Apr 07.
Article in English | MEDLINE | ID: mdl-26967375

ABSTRACT

A highly efficient bifunctional mesoporous silica nanodevice coupling optical imaging with photodynamic therapy (PDT) was successfully prepared by using Rhodamine B as a contrast agent and verteporfin as a photosensitizer. The precise localization and high dispersion of the contrast agent in the nanoparticles is the key point to get higher fluorescence quantum yields with respect to the fluorophore in solution. To obtain this information photoluminescence spectroscopy coupled with fluorescence lifetime measurements was used, due to its high sensitivity. The bifunctional nanodevice showed good performances both in terms of quantum yield of the anchored Rhodamine B (Φ(RhB) = 0.55) and the singlet oxygen delivery efficiency for PDT applications.


Subject(s)
Nanoparticles , Photochemotherapy , Photosensitizing Agents/administration & dosage , Porphyrins/administration & dosage , Rhodamines/chemistry , Silicon Dioxide/chemistry , Theranostic Nanomedicine , Fluorescence , Photosensitizing Agents/chemistry , Verteporfin
8.
Sci Rep ; 6: 21540, 2016 Feb 15.
Article in English | MEDLINE | ID: mdl-26876635

ABSTRACT

Over the last years the zebrafish imposed itself as a powerful model to study skeletal diseases, but a limit to its use is the poor characterization of collagen type I, the most abundant protein in bone and skin. In tetrapods collagen type I is a trimer mainly composed of two α1 chains and one α2 chain, encoded by COL1A1 and COL1A2 genes, respectively. In contrast, in zebrafish three type I collagen genes exist, col1a1a, col1a1b and col1a2 coding for α1(I), α3(I) and α2(I) chains. During embryonic and larval development the three collagen type I genes showed a similar spatio-temporal expression pattern, indicating their co-regulation and interdependence at these stages. In both embryonic and adult tissues, the presence of the three α(I) chains was demonstrated, although in embryos α1(I) was present in two distinct glycosylated states, suggesting a developmental-specific collagen composition. Even though in adult bone, skin and scales equal amounts of α1(I), α3(I) and α2(I) chains are present, the presented data suggest a tissue-specific stoichiometry and/or post-translational modification status for collagen type I. In conclusion, this data will be useful to properly interpret results and insights gained from zebrafish models of skeletal diseases.


Subject(s)
Bone Development/genetics , Collagen Type I/genetics , Collagen/genetics , Zebrafish Proteins/genetics , Zebrafish/genetics , Amino Acid Sequence , Animals , Collagen/biosynthesis , Collagen Type I/biosynthesis , Gene Expression Regulation, Developmental , Protein Processing, Post-Translational , Skin/growth & development , Skin/metabolism , Zebrafish/growth & development , Zebrafish Proteins/biosynthesis
9.
Phys Chem Chem Phys ; 17(40): 26804-12, 2015 Oct 28.
Article in English | MEDLINE | ID: mdl-26396040

ABSTRACT

Rose Bengal (RB), a xanthene dye, incorporated into mesostructured silica nanoparticles (MSNs) exhibits efficient singlet oxygen ((1)O2) generation when illuminated with 540 nm green light which is particularly promising for PDT applications. Several systems with different RB loadings were synthesized and fully characterized by means of spectroscopic techniques in combination with a computational study, to optimize the amount of RB in order to avoid the formation of aggregates that is detrimental for a high (1)O2 delivery.


Subject(s)
Nanoparticles/chemistry , Rose Bengal/chemistry , Silicon Dioxide/chemistry , Singlet Oxygen/chemistry , Models, Molecular , Molecular Structure , Particle Size , Porosity , Surface Properties
10.
Phys Chem Chem Phys ; 15(32): 13275-87, 2013 Aug 28.
Article in English | MEDLINE | ID: mdl-23860729

ABSTRACT

In this work, the interactions of methyl tert-butyl ether (MTBE) on different dealuminated high silica zeolites were studied by means of both experimental and computational approaches. Zeolites with different textural and surface features were selected as adsorbents and the effect of their physico-chemical properties (i.e. pore size architecture and type and amount of surface OH sites) on sorption capacity were studied. High silica mordenite (MOR) and Y zeolites (both with a SiO2/Al2O3 ratio of 200) and ZSM-5 solid (SiO2/Al2O3 ratio of 500) were selected as model sorbents. By combining FTIR and SS-NMR (both (1)H and (13)C CPMAS NMR) spectroscopy it was possible to follow accurately the MTBE adsorption process on highly defective MOR characterized by a high concentration of surface SiOH groups. The adsorption process is found to occur in different steps and to involve isolated silanol sites, weakly interacting silanols, and the siloxane network of the zeolite, respectively. H-bonding and van der Waals interactions occurring between the mordenite surface and MTBE molecules were modeled by DFT calculations using a large cluster of the MOR structure where two adjacent side-pockets were fused in a large micropore to simulate a dealumination process leading to silanol groups. This is the locus where MTBE molecules are more strongly bound and stabilized. FTIR spectroscopy and gravimetric measurements allowed determination of the interaction strength and sorption capacities of all three zeolites. In the case of both Y and MOR zeolites, medium-weak H-bonding with isolated silanols (both on internal and external zeolite surfaces) and van der Waals interactions are responsible for MTBE adsorption, whereas ZSM-5, in which a negligible amount of surface silanol species is present, displays a much lower amount of adsorbed MTBE retained mainly through van der Waals interactions with zeolite siloxane network.


Subject(s)
Methyl Ethers/chemistry , Silicon Dioxide/chemistry , Zeolites/chemistry , Quantum Theory
12.
Br J Dermatol ; 167(3): 688-91, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22486251

ABSTRACT

BACKGROUND: Vitamin D deficiency plays a role in autoimmune diseases and risk of fractures. No data are available on vitamin D levels and vertebral fractures in autoimmune bullous skin diseases. OBJECTIVES: To assess serum vitamin D levels and the prevalence of vertebral fractures in patients with pemphigus vulgaris (PV) and bullous pemphigoid (BP), potentially fatal autoimmune bullous disorders. METHODS: We studied 13 consecutive inpatients with untreated active PV (six men and seven women, mean ± SD age 53·5 ± 14·3 years), 15 with BP (seven men and eight women, mean ± SD age 76·9 ± 12·4 years) and 28 age-, body mass index- and sex-matched controls. The 25-hydroxyvitamin D (25-OHD) levels and presence of vertebral fractures on spinal X-ray were assessed in all subjects. RESULTS: In patients with PV, 25-OHD levels were lower (mean ± SD 12 ± 4·4 ng mL(-1) ) and prevalence of severe hypovitaminosis D higher (62%) than in controls (mean ± SD 22·2 ± 11·7 ng mL(-1) , P = 0·012; 23%, P = 0·0047, respectively). The prevalence of fractures was 54% and 31% in patients with PV and controls, respectively. Patients with BP showed lower 25-OHD levels (mean ± SD 9·6 ± 7·2 ng mL(-1) ) and higher prevalence of severe hypovitaminosis D (73%) than controls (mean ± SD 22·6 ± 18·7 ng mL(-1) , P = 0·022; 27%, P = 0·01, respectively). The prevalence of fractures tended to be higher in patients with BP than in controls (67% vs. 33%, respectively, P = 0·068). CONCLUSIONS: The low 25-OHD levels found in PV and BP may suggest a role for this agent in their pathogenesis. The increased prevalence of fractures should be taken into consideration in patients who must be given corticosteroids.


Subject(s)
Pemphigoid, Bullous/complications , Spinal Fractures/etiology , Vitamin D Deficiency/complications , Absorptiometry, Photon , Adult , Aged , Aged, 80 and over , Bone Density/physiology , Case-Control Studies , Female , Humans , Male , Middle Aged , Pemphigoid, Bullous/physiopathology , Risk Factors , Spinal Fractures/physiopathology , Vitamin D/analogs & derivatives , Vitamin D/blood , Vitamin D Deficiency/physiopathology
13.
Langmuir ; 24(6): 2808-19, 2008 Mar 18.
Article in English | MEDLINE | ID: mdl-18251562

ABSTRACT

Acid clays were prepared by exchanging a synthetic saponite in HCl solutions of different concentration (0.01 and 1M, respectively). A combined experimental approach (XRD, HRTEM, N2 physisorption, solid-state MAS NMR, and TGA) was used to investigate on the structural, morphological, and textural features of the samples treated under mild and strong acid conditions. FTIR spectroscopy of adsorbed probe molecules with different basicity (e.g., CO and NH3) was used to monitor the surface acid properties and acid site distribution. XRD and SS-MAS NMR indicated that the activation under mild acid conditions does not alter the clay structure, while a deep modification of the saponite framework occurred after ion exchange in 1 M HCl solution. The presence of porous amorphous silica phase after treatment under strong acid conditions was confirmed by TEM inspection augmented by SS-MAS NMR and FTIR spectroscopy. N2 and Ar physisorption measurements suggested that cavitation phenomena occurred in saponite structure. N2 physisorption confirmed that the porosity and surface area of the samples are strongly modified upon strong acid treatment. FTIR spectroscopy of adsorbed NH3 pointed out that the H-exchange in mild conditions increased the number of surface Brønsted acid sites. Conversely, these sites are significantly depleted after treatment under strong acid conditions. The use of CO as a FTIR probe molecule, which is applied for the first time to study synthetic acid clays, allowed to monitor distribution and strength of Brønsted acid sites, whose acidity is similar to that of strong acid zeolites. The Al-OH sites with medium acidity are also found in acid-activated saponites. The distribution of strong and medium acid sites is strictly dependent on the acid conditions adopted.

15.
Rev. cir. infant ; 12(3): 176-180, sept. 2002. ilus, tab
Article in Spanish | LILACS | ID: lil-336975

ABSTRACT

Las lesiones traumáticas del diafragma son raras en niños e indican la presencia de un trauma severo con lesiones asociadas graves.EL diagnósticoo de la lesión siempre es difícil y en general es tardío.El objetivo de este estudio retrospectivo es presentar tres casos de hernia diafragmática traumática en niños,se analizó la evolución y se destaca la posibilidad de lesiones no identificadas con manifestaciones tardías.Dos pacientes fueron víctimas de atropellamiento con trauma abdominal cerrrado.EL otro fue víctima de herida penetrante en flanco izquierdo que fue saturado de urgencia y cinco años después presentó un cuadro de abdomen agudo que llevó al diagnóstico.Los pacientes fueron sometidos a laparotomía,con sutura primaria de diafragma y tratamiento de las lesiones asociadas.Las rupturas diafragmáticas traumaticas son raras,principalmente en niños y son de difícil diagnóstico.Las lesiones de diafragma deben ser sospechadas en politraumatismo y tambien en heridas penetrantes de la transición tóracoabdominal.La severidad del cuadro depende de las lesiones asociadas que muchas veces dificultan el diagnsotico inicial de la lesión retrasando el tratamiento precoz


Subject(s)
Child, Preschool , Infant , Child , Abdominal Injuries , Hernia, Diaphragmatic, Traumatic/surgery , Laparotomy , Wounds, Penetrating , General Surgery , Pediatrics
16.
Rev. cir. infant ; 12(3): 176-180, sept. 2002. ilus, tab
Article in Spanish | BINACIS | ID: bin-6281

ABSTRACT

Las lesiones traumáticas del diafragma son raras en niños e indican la presencia de un trauma severo con lesiones asociadas graves.EL diagnósticoo de la lesión siempre es difícil y en general es tardío.El objetivo de este estudio retrospectivo es presentar tres casos de hernia diafragmática traumática en niños,se analizó la evolución y se destaca la posibilidad de lesiones no identificadas con manifestaciones tardías.Dos pacientes fueron víctimas de atropellamiento con trauma abdominal cerrrado.EL otro fue víctima de herida penetrante en flanco izquierdo que fue saturado de urgencia y cinco años después presentó un cuadro de abdomen agudo que llevó al diagnóstico.Los pacientes fueron sometidos a laparotomía,con sutura primaria de diafragma y tratamiento de las lesiones asociadas.Las rupturas diafragmáticas traumaticas son raras,principalmente en niños y son de difícil diagnóstico.Las lesiones de diafragma deben ser sospechadas en politraumatismo y tambien en heridas penetrantes de la transición tóracoabdominal.La severidad del cuadro depende de las lesiones asociadas que muchas veces dificultan el diagnsotico inicial de la lesión retrasando el tratamiento precoz


Subject(s)
Child, Preschool , Infant , Child , Hernia, Diaphragmatic, Traumatic/surgery , Abdominal Injuries , Wounds, Penetrating , Laparotomy , Pediatrics , General Surgery
17.
Chemistry ; 7(7): 1437-43, 2001 Apr 01.
Article in English | MEDLINE | ID: mdl-11330897

ABSTRACT

A highly active, three-dimensional, mesoporous titanosilica, TiTUD-1, with comparable properties to Ti-grafted mesoporous silica MCM-41, has been prepared in a one-step synthesis. A non-surfactant chemical, triethanolamine, was used as a template molecule. Triethanolamine easily forms complexes with titanium alkoxides, yielding titanatrane complexes, which together with free triethanolamine form meso-sized aggregates that template mesopores upon increasing the temperature of the synthesis mixture. Triethanolamine served as both mesopore template and ligand for the titanium complexes, which represent the majority of the catalytic-site precursors. The formation of the silica network and the titanium insertion were followed by a combination of diffuse reflectance UV/ Vis/NIR and FTIR spectroscopy. A titanium-rich phase was obtained on the mesopore surfaces during calcination, allowing for easy accessibility of the reactants to the catalytic sites. TiTUD-1 is about six times more active than framework-substituted Ti-MCM-41 and has similar activity to Ti-grafted MCM-41.

19.
Acta Leprol ; 11(3): 99-104, 1999.
Article in English | MEDLINE | ID: mdl-10544722

ABSTRACT

The incidence of digestive symptoms in 100 patients with Hansen's disease was evaluated in this study, following a standardized questionnaire. A correlation between the frequency of symptoms, the form of the disease, and the length of treatment was investigated. Digestive symptoms were found in 31 patients (31%). No statistically significant difference was found between the presence of symptoms and the length of the disease or between the multibacillary and the paucibacillary form of the disease. However, a positive correlation between digestive symptoms and Hansen's disease was found in the multibacillary form of the disease only for patients treated for more than 12 months. Baseline and pentagastrin-stimulated gastric acid secretion was studied in 30 Hansen's disease patients and in 10 controls. A Iower basal acid output was observed in patients with Hansen's disease, but no statistical difference was found. Pentagastrin-stimulated gastric acid secretion was statistically different in Hansen's disease patients, as compared to controls. A Iower pentagastrin-stimulated acid secretion was found in Hansen's disease patients under treatment, as compared to untreated patients, but the difference was not statistically significant.


Subject(s)
Digestive System/physiopathology , Gastric Acid/metabolism , Leprosy/physiopathology , Adolescent , Adult , Aged , Case-Control Studies , Female , Humans , Leprostatic Agents/therapeutic use , Leprosy/drug therapy , Male , Middle Aged , Pentagastrin , Surveys and Questionnaires
20.
Rev. cir. infant ; 8(4): 214-7, dic. 1998. ilus
Article in Spanish | LILACS | ID: lil-238040

ABSTRACT

Los"stends" ureterales son más utilizados en los reimplantes ureterales con modelaje, en aquellos con dificultades técnicas, en reoperaciones y eventualmente en pieloplastías. De enero de 1995 a junio de 1998 utilizamos "stents"ureterales en 40 niños. 29 sometido a reimplantes vesicoureterales, 10 a pieloplastías y una ureteroplastía. Las extremidades de los stents en los reimplantes permanecieron en la vejiga y fueron fijados a la cistotomía o a la sonda uretral y en la pieloplastías o en la ureteroplastía fueron fijados a la sonda de nefrostomía. Los stents fueron retirados ambulatoriamente, juntamente con la sonda a la que estaban fijados, 7 a 12 días despues de la operación. No hubo complicaciones, el tiempo medio de internación disminuyó de 6 a 3 días. El procedimiento resultó eficaz, facilitó el trabajo médico, permitió mayor confort y movilidad a los pacientes


Subject(s)
Humans , Infant , Child, Preschool , Child , Stents , Vesico-Ureteral Reflux
SELECTION OF CITATIONS
SEARCH DETAIL
...