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1.
J Appl Toxicol ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862408

ABSTRACT

Parabens (PBs) are widely used in the cosmetic, pharmaceutical, and food industries as preservatives of products. Because of its great use, humans and other organisms are highly exposed daily. However, little is known about the effect of PBs on male infertility. Therefore, the aim of the present study was to evaluate the effect of methylparaben (MePB) and propylparaben (PrPB), alone or in combination, on the physiological characteristics of pig in vitro exposed sperm to different concentrations (0, 200, 500, and 700 µM) for viability, motility, and acrosome integrity evaluation and (0, 200, 500, 700, 1000, and 2000 µM) for DNA fragmentation index evaluation, after 4 h of exposure. The results showed that sperm viability decreased after exposure to MePB from the concentration of 500 µM. In the PrPB and mixture groups, viability decreased at all concentrations except for the control. The decrease in viability of sperm exposed to PrPB was greater than that of the mixture and MePB groups. Sperm motility decreased in all the experimental groups exposed to PBs, at all concentrations, except for the control group. Acrosome integrity was not decreased in the MePB group; however, in the PrPB group, it decreased at a concentration of 200 µM and in the mixture at 500 µM. All groups exhibited DNA damage at different concentrations, except for the control group. Additionally, the effect of PBs on sperm quality was concentration-dependent. The results demonstrated that MePB and PrPB alone or in combination can have adverse effects on sperm quality parameters. MePB had lower toxicity than did both PrPB and the mixture. The mixture did not have an additive effect on any of the parameters evaluated. This could partially explain the link between PB exposure and infertility.

2.
Prensa méd. argent ; 109(2): 48-52, 20230000.
Article in Spanish | LILACS, BINACIS | ID: biblio-1437017

ABSTRACT

Acinetobacter baumannii (AB) es un bacilo gram negativo, no fermentador,con frecuencia oportunista, ubicuo en el medio ambiente, con capacidad para sobrevivir en condiciones medioambientales adversas promoviendo su persistencia y diseminación en diferentes áreas de un hospital. Ha sido relacionado con múltiples brotes de infecciones asociadas al cuidado de la salud como neumonía, bacteriemias, contaminación de heridas quirúrgicas o infecciones del tracto urinario, especialmente entre pacientes con comorbilidades graves, como aquellos que motivan el ingreso a unidades de cuidados intensivos (UCI). Las cepas más problemáticas son aquellas resistentes a los carbapenémicos, resistencia causada por enzimas de la clase de las oxacilinasas (bla OXA) cromosómicas o plasmídicas y más recientemente bla NDM-1. La aparición de estas cepas deja escasos antimicrobianos activos (colistin, minociclina, tigeciclina; amikacina) que son limitados en su eficacia y su uso se asocia con toxicidad. A esto se agrega, como en la paciente que se describe, que desarrolló una meningitis posquirúrgica, la limitada capacidad de difusión en el sistema nervioso central (SNC) de estas últimas opciones. Una de las alternativas terapéuticas, es buscar asociaciones como sulbactam/avibactam que mostraron una adecuada actividad sinérgica y bactericida en asilamientos resistentes a ampicilina/sulbactam en base a una significativa reducción de la CIM que permite administrar dosis habituales, con mejor tolerancia y lograr concentraciones terapéuticas en SNC. Se presenta una paciente que desarrolló una meningitis posquirúrgica debida a una cepa de AB multirresistente.


Acinetobacter baumannii (AB) is a non-fermenting gram-negative bacillus, largely opportunistic, ubiquitous in the environment, with the ability to survive in adverse environmental conditions, promoting its persistence and dissemination in different areas of the hospital. It has been implicated in many outbreaks of healthcare-associated infections such as pneumonia, bacteremia, surgical wounds contamination, or urinary tract infections, especially among patients with previous severe illnesses such as those requiring admission to intensive care units (ICU). The most problematic strains are those resistant to carbapenems, resistance caused by chromosomal or plasmid oxacillinase class (bla OXA), and more recently bla NDM-1. The appearance of these strains leaves few active antimicrobials (Colistin, Minocycline, Tigecycline; Amikacin) that are limited in their efficacy and toxic. To this we must add, as is the case of our patient who presented post-surgical meningitis, the limited diffusion capacity in the central nervous system (CNS) of these last options. One of the therapeutic alternatives is to search for synergistic associations such as sulbactam/avibactam that showed rapid synergistic and bactericidal activity in isolates resistant to ampicillin/sulbactam due to a significant reduction in its MIC, which allows us to administer usual, better tolerated doses that reach therapeutic concentrations in CNS. Here, we present a patient who developed a post-surgical meningitis due to multiresistant AB


Subject(s)
Humans , Female , Adult , Sulbactam/therapeutic use , Acinetobacter baumannii , Drug Synergism , Meningitis/therapy
3.
Pharmacol Biochem Behav ; 225: 173558, 2023 04.
Article in English | MEDLINE | ID: mdl-37088449

ABSTRACT

There are a few studies suggesting that the hippocampus is involved in the regulation of impulsivity, and which attempt to explain drug seeking behavior in addiction. In addition, cannabinoid receptor 1 (CB1R) is highly expressed in the hippocampus (HPP). To further understand the potential role of the hippocampal CB1R in impulsive and drug seeking behaviors, we characterized impulsivity in adolescent and adult male rats, by means of a delay discounting task (DDT) by evaluating preference and seeking motivation for alcohol (10 % v/v) consumption, and analyzing CB1R expression in CA1, CA3 and the dentate gyrus (DG) of the HPP as well as in the medial prefrontal cortex (mPFC). Our results show that adolescent rats display more impulsive choices than adult rats in the DDT. The k value is statistically higher in adolescents, further supporting that they are more impulsive. Besides, adolescent rats have higher forced and voluntary alcohol consumption and display a higher alcohol conditioned place preference (CPP) vs. adult rats. In addition, CB1R expression in CA3 and the DG is higher in adolescent vs. adult rats. Our data further support the role of the hippocampus in impulsivity with the potential involvement of the endocannabinoid system, considering that CB1R in CA3 and DG is higher in adolescents, who display impulsivity and alcohol seeking and consumption.


Subject(s)
Alcohol Drinking , Hippocampus , Impulsive Behavior , Animals , Male , Rats , Ethanol/metabolism , Hippocampus/metabolism , Motivation
4.
Nat Prod Res ; 37(16): 2782-2786, 2023.
Article in English | MEDLINE | ID: mdl-36239484

ABSTRACT

Herpes simplex virus 1 is one of the most prevalent pathogens worldwide. Resistant strains to current anti-viral treatment have been reported, requiring the search for novel anti-virals. Using a qPCR method to assess anti-herpetic activity from natural products, we analyzed 72 plant extracts from El Salvador and identified eighteen methanolic extracts with anti-viral activity of ≥ 75%. Anti-herpetic activity has not been previously reported in fourteen of the plants (Euphorbia lancifolia, Piper tuberculatum, Cordia alliodora, Tecoma stans, Taraxacum officinale, Hamelia patens, Witheringia solanacea, Emilia fosbergii, Gnaphalium viscosum, Citrus aurantium, Ambrosia peruviana, Carica papaya, Solanum hazenii and Melothria pendula). Four extracts were from species with previously reported anti-herpetic activity (Plantago major, Psidium guajava, Sida acuta and Bursera simaruba). These extracts effective anti-viral concentrations (EC50) were between 203 and 6.31 µg/mL, while the selectivity indexes (SI) were between 55.91 and 2.57. Euphorbia lancifolia showed the most effective anti-viral activity (EC50 = 6.31 µg/mL, SI = 51.82).

5.
Public Health ; 213: 189-197, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36446150

ABSTRACT

OBJECTIVES: This study aimed at evaluating territorial inequalities in avoidable mortality in children under 5 years of age in Colombia between 2000 and 2019. STUDY DESIGN: This was an ecological study. METHODS: An ecological, longitudinal, multigroup study was conducted using secondary sources. Because of the hierarchical structure of the data, the effect of territorial characteristics on the count of avoidable under-five deaths was estimated using a three-level negative binomial regression model with random intercepts for municipality and fixed intercepts for time and departments. RESULTS: Between 2000 and 2019, there were 216,809 avoidable under-five deaths in Colombia (91.3% of all registered deaths of children under 5 years of age). A total of 1117 municipalities located in 33 departments were analyzed over five 4-year periods. Ecological relationships were found between avoidable under-five mortality and the percentage of adolescent births, female illiteracy, and multidimensional poverty at the municipal level (standardized mortality ratio: 1.43 95% confidence interval: 1.33-1.54 for the group with the highest level vs the group with the lowest level of poverty). Furthermore, multidimensional poverty was a confounding factor for the association between the percentage of the population living in rural areas and avoidable child mortality. CONCLUSIONS: Systematic and avoidable gaps were observed in mortality in children aged under 5 years in Colombia, where the territory constitutes an axis of inequality. Implementing strategies and programs that contribute to improving the conditions of women and socio-economic conditions in the territories should be a priority.


Subject(s)
Poverty , Child , Female , Humans , Child, Preschool , Adolescent , Colombia/epidemiology
6.
Cell Tissue Bank ; 2022 Jan 20.
Article in English | MEDLINE | ID: mdl-35059955

ABSTRACT

Deep second and third degree burns treatment requires fibroblasts, keratinocytes and other skin cells in order to grow new dermis and epidermis. Cells can proliferate, secrete growth factors and extracellular matrix required to repair the damaged tissue. Radiosterilized human amnion and radiosterilized pig skin have been used as natural origin skin dressings for burned patients. Adipose-derived mesenchymal stem cells can differentiate into fibroblasts and keratinocytes and improve wound-healing progress. These cells can stimulate vascular tissue formation, release growth factors, synthetize new extracellular matrix and immunoregulate other cells. In this study, we developed mesenchymal stem cells-cellularized skin substitutes based from radiosterilized human amnion or pig skin. Third-degree burns were induced in mice animal models to evaluate the effect of cellularized skin substitutes on burn wound healing. Mesenchymal phenotype was immunophenotypically confirmed by flow cytometry and cell viability was close to 100%. Skin recovery was evaluated in burned mice after seven and fourteen days post-coverage with cellularized and non-cellularized sustitutes. Histological techniques and immunofluorescence were used to evaluate re-epithelization and type I collagen deposition. We determined that cellularized-human amnion or cellularized-pig skin in combination with mesenchymal stem cells improve extracellular matrix deposition. Both cellularized constructs increase detection of type I collagen in newly formed mouse skin and can be potentially used as skin coverage for further clinical treatment of burned patients.

7.
Pathogens ; 10(11)2021 Oct 26.
Article in English | MEDLINE | ID: mdl-34832538

ABSTRACT

We study the kinetics of eosinophils during the development of the cellular infiltrate surrounding the nurse cell of Trichinella spiralis (T. spiralis) in experimentally infected mice. Male CD1 mice were experimentally infected with 50 viable muscle larvae of the MSUS/MEX/91/CM-91 T. spiralis strain. Tongues and diaphragms were obtained daily from days 13 to 39 post infection. Diaphragms were compressed and subjected to Giemsa stain. Tongues were histologically sectioned and stained with erythrosine B or hematoxylin and eosin. The cellular infiltrate and the nurse cell-larva complex were detected by optical microscopy since day 16 post infection. The size of the larva increased exponentially during the course of the infection. The kinetics of eosinophils showed a multimodal trend, with a bimodal predominance. The maximum peaks were reached on days 21 and 27 post infection. The results of this study demonstrate that eosinophils occur abundantly in two transcendent moments of the T. spiralis life cycle: first, when the stage 1 larva invades the myocyte and second when the nurse cell-larva complex has been fully developed. These results help one to understand the immunobiology of T. spiralis, highlighting the importance of eosinophils in the survival of the larva in skeletal muscle. Further studies are needed to characterize the cell populations that comprise the cellular infiltrate during the development of the mother cell.

8.
Sens Actuators B Chem ; 345: 130394, 2021 Oct 15.
Article in English | MEDLINE | ID: mdl-34248283

ABSTRACT

The standard rapid approach for the diagnosis of coronavirus disease 2019 (COVID-19) is the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. The detection of specific anti-SARS-CoV-2 immunoglobulins is crucial for screening people who have been exposed to the virus, whether or not they presented symptoms. Recent publications report different methods for the detection of specific IgGs, IgMs, and IgAs against SARS-CoV-2; these methods mainly detect immunoglobulins in the serum using conventional techniques such as rapid lateral flow tests or enzyme-linked immunosorbent assay (ELISA). In this article, we report the production of recombinant SARS-CoV-2 spike protein and the development of a rapid, reliable, cost-effective test, capable of detecting immunoglobulins in serum and saliva samples. This method is based on interferometric optical detection. The results obtained using this method and those obtained using ELISA were compared. Owing to its low cost and simplicity, this test can be used periodically for the early detection, surveillance, detection of immunity, and control of the spread of COVID-19.

9.
Mater Adv ; 2(10): 3282-3293, 2021 Mar 27.
Article in English | MEDLINE | ID: mdl-34124683

ABSTRACT

The synthesis of four well-defined conjugated polymers TStTT1-4 containing unusual heterocycle units in the main chain, namely stannole units as building blocks, is reported. The stannole-thiophenyl copolymers were generated by tin-selective Stille coupling reactions in nearly quantitative yields of 94% to 98%. NMR data show that the tin atoms in the rings remain unaffected. Weight-average molecular weights (M w) were high (4900-10 900 Da and 9600-21 900 Da); and molecular weight distributions (M w/M n) were between 1.9 and 2.3. The new materials are strongly absorbing and appear blue-black to purple-black. All iodothiophenyl-stannole monomers St1-4 and the resulting bisthiophenyl-stannole copolymers TStTT1-4 were investigated with respect to their optoelectronic properties. The absorption maxima of the polymers are strongly bathochromically shifted compared to their monomers by about 76 nm to 126 nm in chloroform. Density functional theory calculations support our experimental results of the single stannoles St1-4 showing small HOMO-LUMO energy gaps of 3.17-3.24 eV. The optical band gaps of the polymers are much more decreased and were determined to be only 1.61-1.79 eV. Furthermore, both the molecular structures of stannoles St2 and St3 from single crystal X-ray analyses and the results of the geometry optimisation by DFT confirm the high planarity of the molecules backbone leading to efficient conjugation within the molecule.

10.
Dalton Trans ; 50(18): 6213-6221, 2021 May 11.
Article in English | MEDLINE | ID: mdl-33871519

ABSTRACT

Polystannoles with thienyl co-monomers are in many ways similar to polythiophenes, but they display much reduced band gaps. However, their polymerization processes are not well researched. Thiophene can be oxidatively electropolymerized, but as stannoles are organometallic, the fundamental question arises whether their inclusion in a conjugated backbone can protect them sufficiently to be able to perform an oxidative electropolymerization. As well-defined oligothiophenes can be used as models to understand the optical and electronic properties of polythiophenes, we transposed this concept on stannole containing polymers; therefore we synthesized a monomeric 1 and dimeric thiophene-flanked stannole 2 and investigated their optoelectronic properties comparatively including polystannoles and the corresponding oligothiophenes in our analysis. With respect to monomer 1, a significantly redshifted absorption (λmax = 510 nm, Δ = 93 nm) and a small optical band gap (Eg,opt(2) = 2.13 eV), close to the bandgap of polymeric stannoles, was observed. In comparison to oligothiophenes, these thienyl-flanked stannoles exhibited a redshift in absorption and emission as well as a lower oxidation potential. Despite these differences, they showed an oligothiophene-like electrochemical behavior. Stannole 1 and the dimer 2 were subjected to an electropolymerization process. This process was investigated in detail by spectroelectrochemical methods which showed that radical cation species were formed in situ but readily decomposed. Nevertheless, under the milder multiscan cyclovoltammetric conditions, electropolymerization occurred as shown by cyclovoltammetry.

11.
Molecules ; 25(21)2020 Oct 28.
Article in English | MEDLINE | ID: mdl-33126599

ABSTRACT

A new spirostannole, 1,1',3,3'-tetrakis(5-methylthiophen-2-yl)-4,4',5,5',6,6',7,7'-octahydro-2,2'-spirobi[benzo[c]stannole] (4), is synthesised and the molecular structure is compared with the optimised geometry from DFT calculations. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are twice degenerated and show a small HOMO-LUMO energy gap of 3.2 eV. In addition, cyclic voltammetry measurements are conducted and three redox processes are observed. Absorption and emission spectra show maxima at λabs,max 436 nm and λem,max 533 nm, respectively. Spirostannole 4 is a strongly absorbing material, but an extremely weak emitter in solution at 295.15 K. However, when the solution is cooled from 280 to 80 K, the emission becomes visible. The reaction of spirostannole 4 with methyllithium is monitored by NMR spectroscopy at 238.15 K. The 119Sn{1H} NMR signal shifts from -36.0 (4) to -211.0 ppm, which is indicative of the formation of the lithium pentaorganostannate 5. The complex is thermally instable at 295.15 K, but insights into the molecular structure and electronic behaviour are obtained by DFT and TD-DFT calculations.


Subject(s)
Density Functional Theory , Models, Molecular , Organometallic Compounds/chemistry , Spiro Compounds/chemistry , Molecular Conformation
12.
Chem Commun (Camb) ; 56(68): 9775-9778, 2020 Aug 25.
Article in English | MEDLINE | ID: mdl-32748898

ABSTRACT

The optoelectronic and structural properties of six stannoles are reported. All revealed extremely weak emission in solution at 295 K, but intensive fluorescence in the solid state with quantum yields (ΦF) of up to 11.1% in the crystal, and of up to 24.4% (ΦF) in the thin film.

13.
Rev. argent. endocrinol. metab ; 56(4): 21-30, dic. 2019. graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1125840

ABSTRACT

RESUMEN La deficiencia de vitamina D en la población general se considera un importante problema en salud pública. Esta vitamina tiene un papel central en el metabolismo cálcico, por lo que el aporte adecuado, a través de la dieta o por síntesis cutánea, es esencial para la salud. Nos propusimos analizar el comportamiento de la vitamina D en mujeres adultas que concurren a la Clínica Tajy de Encamación, Paraguay. Además, determinar la prevalencia de hipovitaminosis, su relación con el metabolismo fosfocálcico y su asociación con factores de riesgo cardiovascular. Se estudiaron 120 mujeres, 61 pre-menopaúsicas y 59 pos-menopaúsicas, que asistieron al Laboratorio Tajy de Encarnación Paraguay desde enero del 2.015 hasta marzo del 2.016. Se tomaron muestras de sangre y datos de peso, talla, circunferencia de cintura y presión arterial. Fueron excluidas mujeres embarazadas, con diabetes, hipertensión, nefropatías, neoplasias, patologías tiroideas, procesos inflamatorios o infecciosos, que se encontraban bajo tratamiento o suplemento de cualquier tipo. El 72% de estas mujeres presentaron hipovitaminosis D (< 30 ng/ml), un 38% eran pre menopáusicas, destacando que dentro de esta población se halló el mayor porcentaje de mujeres con deficiencia severa, y un 39% eran pos-menopáusicas. Se encontró diferencia significativa (p<0,001) entre pre y post menopáusicas en edad, presión arterial sistólica, circunferencia de cintura, glucemia, colesterol-HDL, triglicéridos e índice TG/col-HDL, y concentración de calcio y fosforo (p< 0,001). La concentración de vitamina se correlacionó significativamente con circunferencia de cintura, concentración de calcio y fósforo (p<0.001). 67 mujeres con obesidad abdominal tuvieron hipovitaminosis D, presentando 15 veces más riesgo que aquellas con circunferencia <88 cm. El 72% de las mujeres estudiadas presentaron hipovitaminosis D, un 38% eran mujeres pre menopáusicas y 39% pos-menopáusicas. Esta hipovitaminosis D presentó correlación significativa con las concentraciones de calcio y fosforo, edad, presión arterial sistólica, glucemia y col-HDL y asociación significativa con obesidad abdominal.


ABSTRACT in adult women who attend the Tajy Clinic in Encarnación, Republic of Paraguay. To determine the prevalence of hypovitaminosis and the relationship that exists with phosphocalcic metabolism, as well as to evaluate the association of cardiovascular risk factors to hypovitaminosis D in this population of women. 120 women were studied, 61 pre-menopausal and 59 in post-menopause. With median and 25 and 75 percentiles for age 48 (35-62), who attended the Tajy Laboratory in Encamación Paraguay from January 2015 to March 2016. Blood samples were taken and a survey was carried out in order to collect information on those covariates that may influence the variables of interest and where all have signed a consent. Pregnant women, women with diabetes, with hypertension, nephropathies, neoplastic diseases, thyroid diseases, inflammatory or infectious processes, who are under treatment or supplement of any kind were excluded. We obtained data on weight, height, waist circumference and blood pressure. A blood extraction with fasting of 12 hours was performed for biochemical determinations. All samples were processed with internal and external quality control. It was found that 72% of these women had hypovitaminosis D (< 30 ng/ml) , where 38% were pre-menopausal, highlighting that within this population the highest percentage of women with severe vitamin D deficiency was found and 39% were post-menopausal. A statistically significant difference was found (p <0.001) with age, systolic blood pressure, waist circumference, glycemia, HDL-cholesterol concentration, triglyceride concentration and TG / HDL-col index, as well as calcium and phosphorus (p <0.001). It was found that the concentration of vitamin D had a significant correlation with the measurement of waist circumference, calcium and phosphorus concentration (p <0.001). It was found that 67 women with abdominal obesity had low vitamin D levels (<20 ng / ml), those with abdominal obesity had 15 times more risk of hypovitaminosis D than those with a waist circumference of <88 cm. Through this research, and analyzing the behavior of vitamin D concentration in pre and post menopausal women, we found that 72% of them presented hypovitaminosis D, in which 38% were pre-menopausal women and 39% were menopausal This hypovitaminosis D has a significant correlation with calcium and phosphorus concentrations, as well as with other variables such as age, systolic blood pressure, glycemia and HDL cholesterol concentration. Vitamin D deficiency has a significant association with abdominal obesity in this population of women.

14.
Chemistry ; 25(58): 13318-13328, 2019 Oct 17.
Article in English | MEDLINE | ID: mdl-31347203

ABSTRACT

Zirconacyclopentadienes are versatile precursors for a large number of heteroles, which are accessible by Zr-element exchange reactions. The vast majority of reports describe their preparation by the use of Negishi's reagent, which is a species that is formed in situ. The zirconacyclopentadiene is then formed by the addition of one equivalent of a diyne or two equivalents of a monoyne moiety to this Negishi species. Another route involves Rosenthal's reagent (Cp2 Zr(py)Me3 SiC≡CSiMe3 ), which then reacts with a diyne or monoyne moiety. In this work, the efficiency of both routes was compared in terms of reaction time, stability of the product in the reaction mixture, and yield. The synthetic implications of using both routes are evaluated. Novel zirconacyclopentadienes were synthesized, characterized directly from the reaction mixture, and crystal structures could be obtained in most cases.

15.
Inorg Chem ; 57(20): 12562-12575, 2018 Oct 15.
Article in English | MEDLINE | ID: mdl-30284825

ABSTRACT

Stannoles are organometallic rings in which the heteroatom is involved in a form of conjugation that is called σ*-π* conjugation. Only very little is known about how the substituents on the Sn atom or substituents on the stannole ring determine the optoelectronic properties of these heterocycles. In this work, this question has been studied experimentally and theoretically. Calculations of optimized equilibrium geometries, energy gaps between the highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs), and of the absorption spectra of a wide range of compounds were performed. The computational data showed that the substituents on the Sn atom influence the optoelectronic properties to a lower extent than the substituents in the 2 and 5 positions of the ring. These substituents in the 2 and 5 positions of the stannole ring can also have a strong influence on the overall planarity of the structure, in which mesomeric effects can play a substantial role only if the structure is planar. Thus, only structures with a planar backbone are of interest in the context of tuning the optoelectronic properties. These were selected for the experimental studies. On the basis of this information, a series of six novel stannoles was synthesized by the formation of a zirconium intermediate and subsequent transmetalation to obtain the tin compound. The calculated electronic HOMO-LUMO energy gaps varied between 2.94 and 2.68 eV. The measured absorption maxima were located between 415 and 448 nm compared to theoretically calculated values ranging from 447 nm (2.77 eV) to 482 nm (2.57 eV). In addition to these optical measurements, cyclic voltammetry data could be obtained, which show two reversible oxidation processes for three of the six stannoles. With this study, it could be demonstrated how the judicious choice of the substituents can lead to large and predictable bathochromic shifts in the absorption spectra.

17.
Chemistry ; 24(22): 5680-5696, 2018 Apr 17.
Article in English | MEDLINE | ID: mdl-28913884

ABSTRACT

Heterocycles that contain tin atoms can be aromatic in a similar sense to well-known aromatic compounds such as benzene or thiophene, but such examples are rare. However, due to the low-lying σ*-orbitals of the tin-substituent bond in stannoles, they are capable of σ*-π* conjugation in a way that is exclusive to heavier element containing heterocycles. This makes stannoles very interesting alternatives for purely organic heterocycles in material applications, in which optoelectronic properties are of interest. This Concept article will highlight the synthesis, reactivity and physical properties of stannoles and related fluorenostannoles. At first, a brief introduction to different types of tin-containing heterocycles is presented, followed by a discussion on different approaches to prepare stannoles, their reactivity and their physical properties. In addition, the first stannole-containing polymer will be reviewed.

18.
Oxid Med Cell Longev ; 2017: 8510761, 2017.
Article in English | MEDLINE | ID: mdl-29163756

ABSTRACT

The increase in the elderly population has generated concern to meet health demands. The research efforts to elucidate the mechanisms of damage associated with aging have also been significantly increased, especially in order to avoid the reduction of the cognitive abilities in geriatric patients, resulting from the damage generated mainly at the level of the hippocampus during old age. At present, many studies describe resveratrol as an antiaging component. There are reports that it can activate the Sirt1 gene related to antiaging, emulating the effects obtained by caloric restriction in rodents. The aim of the study was to evaluate the effect of chronic administration of resveratrol (10 mg/kg) on cognitive performance in behavioral tests after 8 months of treatment and on the preservation of cerebral integrity in the cytoarchitecture of regions CA1 and CA2. Results showed that the cytoarchitecture of the CA1 and CA2 regions in the hippocampus retained their integrity over time in rats treated with resveratrol, and the behavioral test performed revealed that chronic resveratrol administration for 8 months showed improvements in cognitive performance. The results indicate that resveratrol may exhibit therapeutic potential for age-related conditions.


Subject(s)
Cognition/drug effects , Stilbenes/therapeutic use , Aging , Animals , Drug Administration Routes , Male , Rats , Rats, Wistar , Resveratrol , Stilbenes/pharmacology
19.
Cell Tissue Bank ; 17(3): 481-9, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27566509

ABSTRACT

The external ear is composed of elastic cartilage. Microtia is a congenital malformation of the external ear that involves a small reduction in size or a complete absence. The aim of tissue engineering is to regenerate tissues and organs clinically implantable based on the utilization of cells and biomaterials. Remnants from microtia represent a source of cells for auricular reconstruction using tissue engineering. To examine the macromolecular architecture of microtia cartilage and behavior of chondrocytes, in order to enrich the knowledge of this type of cartilage as a cell reservoir. Auricular cartilage remnants were obtained from pediatric patients with microtia undergoing reconstructive procedures. Extracellular matrix composition was characterized using immunofluorescence and histological staining methods. Chondrocytes were isolated and expanded in vitro using a mechanical-enzymatic protocol. Chondrocyte phenotype was analyzed using qualitative PCR. Microtia cartilage preserves structural organization similar to healthy elastic cartilage. Extracellular matrix is composed of typical cartilage proteins such as type II collagen, elastin and proteoglycans. Chondrocytes displayed morphological features similar to chondrocytes derived from healthy cartilage, expressing SOX9, COL2 and ELN, thus preserving chondral phenotype. Cell viability was 94.6 % during in vitro expansion. Elastic cartilage from microtia has similar characteristics, both architectural and biochemical to healthy cartilage. We confirmed the suitability of microtia remnant as a reservoir of chondrocytes with potential to be expanded in vitro, maintaining phenotypical features and viability. Microtia remnants are an accessible source of autologous cells for auricular reconstruction using tissue engineering strategies.


Subject(s)
Chondrocytes/pathology , Congenital Microtia/pathology , Ear Cartilage/pathology , Plastic Surgery Procedures/methods , Tissue Engineering/methods , Cell Proliferation , Cell Separation , Cell Shape , Child , Child, Preschool , Collagen Type II/metabolism , Elastin/metabolism , Extracellular Matrix/metabolism , Humans , Phenotype
20.
Histol Histopathol ; 30(12): 1477-85, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26119536

ABSTRACT

Tissue engineering with the use of biodegradable and biocompatible scaffolds is an interesting option for ear repair. Chitosan-Polyvinyl alcohol-Epichlorohydrine hydrogel (CS-PVA-ECH) is biocompatible and displays appropriate mechanical properties to be used as a scaffold. The present work, studies the potential of CS-PVA-ECH scaffolds seeded with chondrocytes to develop elastic cartilage engineered-neotissues. Chondrocytes isolated from rabbit and swine elastic cartilage were independently cultured onto CS-PVA-ECH scaffolds for 20 days to form the appropriate constructs. Then, in vitro cell viability and morphology were evaluated by calcein AM and EthD-1 assays and Scanning Electron Microscopy (SEM) respectively, and the constructs were implanted in nu/nu mice for four months, in order to evaluate the neotissue formation. Histological analysis of the formed neotissues was performed by Safranin O, Toluidine blue (GAG's), Verhoeff-Van Gieson (elastic fibers), Masson's trichrome (collagen) and Von Kossa (Calcium salts) stains and SEM. Results indicate appropriate cell viability, seeded with rabbit or swine chondrocyte constructs; nevertheless, upon implantation the constructs developed neotissues with different characteristics depending on the animal species from which the seeded chondrocytes came from. Neotissues developed from swine chondrocytes were similar to auricular cartilage, while neotissues from rabbit chondrocytes were similar to hyaline cartilage and eventually they differentiate to bone. This result suggests that neotissue characteristics may be influenced by the animal species source of the chondrocytes isolated.


Subject(s)
Biocompatible Materials , Cell Differentiation/physiology , Chitosan , Chondrocytes/physiology , Ear Cartilage/cytology , Ear Cartilage/growth & development , Hydrogels , Tissue Scaffolds , Animals , Ethidium/analogs & derivatives , Hyaline Cartilage/cytology , Hyaline Cartilage/growth & development , Mice , Osteogenesis/physiology , Polyvinyl Alcohol , Rabbits , Sus scrofa , Swine
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