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1.
Nat Commun ; 14(1): 4954, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37587123

RESUMEN

Submolecular charge distribution significantly affects the physical-chemical properties of molecules and their mutual interaction. One example is the presence of a π-electron-deficient cavity in halogen-substituted polyaromatic hydrocarbon compounds, the so-called π-holes, the existence of which was predicted theoretically, but the direct experimental observation is still missing. Here we present the resolution of the π-hole on a single molecule using the Kelvin probe force microscopy, which supports the theoretical prediction of its existence. In addition, experimental measurements supported by theoretical calculations show the importance of π-holes in the process of adsorption of molecules on solid-state surfaces. This study expands our understanding of the π-hole systems and, at the same time, opens up possibilities for studying the influence of submolecular charge distribution on the chemical properties of molecules and their mutual interaction.

2.
Science ; 374(6569): 863-867, 2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34762455

RESUMEN

An anisotropic charge distribution on individual atoms, such as σ-holes, may strongly affect the material and structural properties of systems. However, the spatial resolution of such anisotropic charge distributions on an atom represents a long-standing experimental challenge. In particular, the existence of the σ-hole on halogen atoms has been demonstrated only indirectly through the determination of the crystal structures of organic molecules containing halogens or with theoretical calculations, consequently calling for its direct experimental visualization. We show that Kelvin probe force microscopy with a properly functionalized probe can image the anisotropic charge of the σ-hole and the quadrupolar charge of a carbon monoxide molecule. This opens a new way to characterize biological and chemical systems in which anisotropic atomic charges play a decisive role.

3.
Artículo en Inglés, Español | MEDLINE | ID: mdl-30611707

RESUMEN

OBJECTIVES: To evaluate the in vivo behaviour of a new bone cement loaded with antibiotics, in a rabbit bone infection model. MATERIAL AND METHODS: Sixteen New Zealand rabbits divided into 4 groups were used, depending on the cement (commercial or experimental) and the antibiotic (vancomycin or linezolid) used to control a bone infection caused by Staphylococcus aureus. The commercial cement is Palacos® R and the experimental cement has been achieved by adding PLGA to the solid phase of Palacos® R cement. A novel histological staging method based on bone histoarchitecture has been used. This staging allows us a global vision of bone repair capacity, in the presence of modified cement, and also allows us to correlate the damage generated with the functionality of the tissue. RESULTS: The degree of bone destructuration found depended on the type of cement and antibiotic, and was higher in the groups with commercial cement than in the experimental group (P<.01) and in the groups with linezolid with respect to vancomycin (P=.04) The percentage of macrophages varied exclusively depending on the antibiotic used, and was higher in the vancomycin groups (P=.04). DISCUSSION: The development of new formulations of bone cement that release more, and more prolonged, new generation antibiotics such as linezolid, present an in vivo behaviour superior to commercial cement, respecting the bone structure. This behaviour would have a clinical implication in fighting infections by increasingly resistant germs in the treatment of prosthetic infection.


Asunto(s)
Antibacterianos/administración & dosificación , Cementos para Huesos , Linezolid/administración & dosificación , Osteomielitis/tratamiento farmacológico , Osteomielitis/microbiología , Infecciones Estafilocócicas/tratamiento farmacológico , Vancomicina/administración & dosificación , Animales , Modelos Animales de Enfermedad , Conejos
4.
Int J Pharm ; 522(1-2): 11-20, 2017 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-28257884

RESUMEN

The incidence increase of infections in patients with hip or knee implants with resistant pathogens (mainly some S. coagulase-negative and gram positive bacteria) demands advanced antibiotic loaded formulations. In this paper, we report the design of new biantibiotic acrylic bone cements for in situ delivery. They include a last generation antibiotic (daptomycin or linezolid) in combination with vancomycin and are performed based on a novel modification of the Palacos R® acrylic bone cement, which is based on two components, a liquid (methyl methacrylate) and a solid (polymeric phase). Hence, the solid component of the experimental formulations include 45wt% of microparticles of poly(D,L-lactic-co-glycolic) acid, 55wt% of poly(methyl methacrylate) beads and supplements (10wt-% each) of antibiotics. These formulations provide a selective and excellent control of the local release of antibiotics during a long time period (up to 2 months), avoiding systemic dissemination. The antimicrobial activity of the advanced spacers tested against S. aureus shows that single doses would be enough for the control of the infection. In vitro biocompatibility of cements on human osteoblasts is ensured. This paper is mainly focused on the preparation and characterization of cements and the studies of elution kinetics and bactericidal effects. Developed formulations are proposed as spacers for the treatment of infected arthroplasties, but also, they could be applied in other antibiotic devices to treat relevant bone-related infection diseases.


Asunto(s)
Antibacterianos/administración & dosificación , Artroplastia/efectos adversos , Cementos para Huesos , Infecciones Relacionadas con Prótesis/prevención & control , Antibacterianos/farmacología , Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Daptomicina/administración & dosificación , Daptomicina/farmacología , Combinación de Medicamentos , Composición de Medicamentos , Humanos , Linezolid/administración & dosificación , Linezolid/farmacología , Ensayo de Materiales , Pruebas de Sensibilidad Microbiana , Microesferas , Staphylococcus aureus/efectos de los fármacos , Vancomicina/administración & dosificación , Vancomicina/farmacología
5.
Phys Rev Lett ; 116(24): 245502, 2016 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-27367394

RESUMEN

We show that noncontact atomic force microscopy (AFM) is sensitive to the local stiffness in the atomic-scale limit on weakly coupled 2D materials, as graphene on metals. Our large amplitude AFM topography and dissipation images under ultrahigh vacuum and low temperature resolve the atomic and moiré patterns in graphene on Pt(111), despite its extremely low geometric corrugation. The imaging mechanisms are identified with a multiscale model based on density-functional theory calculations, where the energy cost of global and local deformations of graphene competes with short-range chemical and long-range van der Waals interactions. Atomic contrast is related with short-range tip-sample interactions, while the dissipation can be understood in terms of global deformations in the weakly coupled graphene layer. Remarkably, the observed moiré modulation is linked with the subtle variations of the local interplanar graphene-substrate interaction, opening a new route to explore the local mechanical properties of 2D materials at the atomic scale.

6.
Amino Acids ; 46(11): 2561-71, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25100358

RESUMEN

Cathelicidins are phylogenetically ancient, pleiotropic host defense peptides-also called antimicrobial peptides (AMPs)-expressed in numerous life forms for innate immunity. Since even the jawless hagfish expresses cathelicidins, these genetically encoded host defense peptides are at least 400 million years old. More recently, cathelicidins with varying antipathogenic activities and cytotoxicities were discovered in the venoms of poisonous snakes; for these creatures, cathelicidins may also serve as weapons against prey and predators, as well as for innate immunity. We report herein the expression of orthologous cathelicidin genes in the venoms of four different South American pit vipers (Bothrops atrox, Bothrops lutzi, Crotalus durissus terrificus, and Lachesis muta rhombeata)-distant relatives of Asian cobras and kraits, previously shown to express cathelicidins-and an elapid, Pseudonaja textilis. We identified six novel, genetically encoded peptides: four from pit vipers, collectively named vipericidins, and two from the elapid. These new venom-derived cathelicidins exhibited potent killing activity against a number of bacterial strains (S. pyogenes, A. baumannii, E. faecalis, S. aureus, E. coli, K. pneumoniae, and P. aeruginosa), mostly with relatively less potent hemolysis, indicating their possible usefulness as lead structures for the development of new anti-infective agents. It is worth noting that these South American snake venom peptides are comparable in cytotoxicity (e.g., hemolysis) to human cathelicidin LL-37, and much lower than other membrane-active peptides such as mastoparan 7 and melittin from bee venom. Overall, the excellent bactericidal profile of vipericidins suggests they are a promising template for the development of broad-spectrum peptide antibiotics.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/química , Bothrops/metabolismo , Péptidos/química , Ponzoñas/química , Animales , Antiinfecciosos/química , Bacterias/efectos de los fármacos , Hemólisis , Humanos , Inmunidad Innata , Péptidos y Proteínas de Señalización Intercelular , Meliteno/química , Especificidad de la Especie , Venenos de Avispas/química , Catelicidinas
7.
Bioconjug Chem ; 24(4): 578-85, 2013 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-23458489

RESUMEN

Multimeric presentation, a well-proven way of enhancing peptide immunogenicity, has found substantial application in synthetic vaccine design. We have reported that a combination of four copies of a B-cell epitope with one of a T-cell epitope in a single branched construct results in a peptide vaccine conferring total protection against foot-and-mouth disease virus in swine, a natural host (Cubillos et al. (2008) J. Virol. 82, 7223-7230). More recently, a downsized version of this prototype with only two copies of the B epitope has proven as effective as the tetravalent one in mice. Here we evaluate three approaches to bivalent platforms of this latter type, involving different chemistries for the conjugation of two B epitope peptides to a branching T epitope. Comparison of classical thioether, "reverse" thioether (Monsó et al. (2012) Org. Biomol. Chem. 10, 3116-3121) and thiol-ene conjugation chemistries in terms of synthetic efficiency clearly singles out the latter, maleimide-based strategy as most advantageous. We also examine how minor structural differences among the conjugates--including the N- or C-terminal attachment of the B epitope to the branching T epitope--bear on the immunogenicity of these vaccine candidates, with the maleimide-based conjugate again emerging as the most successful.


Asunto(s)
Epítopos de Linfocito B/química , Epítopos de Linfocito B/inmunología , Péptidos/química , Péptidos/inmunología , Animales , Reacciones Antígeno-Anticuerpo/inmunología , Antígenos Virales/química , Antígenos Virales/inmunología , Epítopos de Linfocito T/química , Epítopos de Linfocito T/inmunología , Femenino , Ratones , Estructura Molecular , Péptidos/síntesis química , Vacunas Sintéticas/química , Vacunas Sintéticas/inmunología
8.
Eur J Clin Microbiol Infect Dis ; 30(11): 1391-8, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21479973

RESUMEN

Pan-resistant Acinetobacter baumannii have prompted the search for therapeutic alternatives. We evaluate the efficacy of four cecropin A-melittin hybrid peptides (CA-M) in vivo. Toxicity was determined in mouse erythrocytes and in mice (lethal dose parameters were LD(0), LD(50), LD(100)). Protective dose 50 (PD(50)) was determined by inoculating groups of ten mice with the minimal lethal dose of A. baumannii (BMLD) and treating with doses of each CA-M from 0.5 mg/kg to LD(0). The activity of CA-Ms against A. baumannii was assessed in a peritoneal sepsis model. Mice were sacrificed at 0 and 1, 3, 5, and 7-h post-treatment. Spleen and peritoneal fluid bacterial concentrations were measured. CA(1-8)M(1-18) was the less haemolytic on mouse erythrocytes. LD(0) (mg/kg) was 32 for CA(1-8)M(1-18), CA(1-7)M(2-9), and Oct-CA(1-7)M(2-9), and 16 for CA(1-7)M(5-9). PD(50) was not achieved with non-toxic doses (≤ LD(0)). In the sepsis model, all CA-Ms were bacteriostatic in spleen, and decreased bacterial concentration (p < 0.05) in peritoneal fluid, at 1-h post-treatment; at later times, bacterial regrowth was observed in peritoneal fluid. CA-Ms showed local short-term efficacy in the peritoneal sepsis model caused by pan-resistant Acinetobacter baumannii.


Asunto(s)
Infecciones por Acinetobacter/tratamiento farmacológico , Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Meliteno/farmacología , Sepsis/diagnóstico , Infecciones por Acinetobacter/microbiología , Infecciones por Acinetobacter/mortalidad , Acinetobacter baumannii/crecimiento & desarrollo , Animales , Antibacterianos/uso terapéutico , Péptidos Catiónicos Antimicrobianos/uso terapéutico , Líquido Ascítico/microbiología , Farmacorresistencia Bacteriana , Eritrocitos/efectos de los fármacos , Femenino , Humanos , Inyecciones Intraperitoneales , Dosificación Letal Mediana , Meliteno/uso terapéutico , Ratones , Ratones Endogámicos C57BL , Pruebas de Sensibilidad Microbiana , Modelos Animales , Proteínas Recombinantes de Fusión , Sepsis/microbiología , Sepsis/mortalidad , Bazo/microbiología , Factores de Tiempo
9.
Nefrologia ; 30(3): 342-8, 2010.
Artículo en Español | MEDLINE | ID: mdl-20514101

RESUMEN

AIM: To evaluate the prevalence of cardiovascular disease (CVD) and its association with cardiovascular risk factors, as well as their control in end-stage renal disease (ESRD) patients under maintenance hemodialysis (HD). PATIENTS AND METHODS: A total of 265 patients with ESRD on maintenance HD from a University Hospital and 4 dialysis units were included in this multicenter and cross-sectional study that analyzed the prevalence of CVD and the possible association with classic and new cardiovascular risk factors. Usual biochemical and haemathological parameters were analyzed, as well as plasma levels of homocysteine, troponin-I, BNP, lipoprotein(a), C reactive protein, IL-6, fibrinogen, asymmetrical dimethylarginine (ADMA), advanced oxidation protein products (AOPP), malondialdehyde, adiponectin, osteoprotegerin, and fetuin. In a subset of patients an echocardiography and carotid artery Doppler echography were also performed. RESULTS: The prevalence of CVD was 52.8%. Factors positively associated with prevalent CVD were age, BMI, left ventricular hypertrophy, hypertension, dyslipidemia and diabetes mellitus, dialysis vintage, Charlson s comorbility index, levels of fibrinogen, osteoprotegerin, BNP and CRP, as well as carotid intima-media thickness, left ventricular mass and pulse pressure. Factors negatively associated with prevalent CVD were: previous renal transplant, ejection fraction or levels of LDL-c and phosphorous. In the multivariate analysis dyslipidemia, left ventricular hypertrophy, age and LDL-c (negatively) were associated with CVD. CONCLUSIONS: In HD patients the prevalence of CVD is high and is associated with the presence of cardiovascular risk factors and subclinical CVD.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Uremia/epidemiología , Anciano , Anciano de 80 o más Años , Arginina/análogos & derivados , Arginina/sangre , Biomarcadores , Proteínas Sanguíneas/análisis , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/diagnóstico por imagen , Comorbilidad , Estudios Transversales , Complicaciones de la Diabetes/epidemiología , Femenino , Humanos , Hiperhomocisteinemia/epidemiología , Hiperlipidemias/epidemiología , Trasplante de Riñón , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Prevalencia , Factores de Riesgo , Fumar/epidemiología , Volumen Sistólico , Ultrasonografía , Uremia/sangre
10.
Ther Drug Monit ; 29(5): 612-8, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17898652

RESUMEN

Gene therapy is anticipated as being an important medical development. Essential to its effectiveness is the appropriate activity (protein expression) in the expected target cells. A noninvasive diagnostic procedure of successful gene expression will be of paramount importance to validate its use or its misuse (eg, sports gene doping). Externally detectable labeled oligonucleotide hybridizing with the messenger RNA generated by the transferred gene has been proposed as a possibility to monitor successful gene therapy. The authors selected the erythropoietin gene (Epo) for a pilot study on erythropoietin protein expression in mouse muscle. Oligonucleotides of peptide nucleic acid (PNA) type capable of antisense binding to unique murine Epo-mRNA sequences were synthesized by solid phase methods, and elongated at the N-terminus with the HIV Tat (48-60) cell penetrating peptide. They were labeled with fluorescence and radioactive tags to verify penetration and longer half-life properties in Epo gene transfected C2C12 mouse muscle cells as compared with corresponding wild-type cells. Downregulation of newly expressed erythropoietin protein in such cells additionally confirmed the penetration and hybridizing properties of the selected labeled oligonucleotide. I-labeled Tat-PNAs were intravenously injected into mice that had previously received the Epo gene into the right tibialis muscle by DNA electrotransfer. Preferential accumulation of radioactivity in the transferred limb as compared with the contralateral limb was ascertained, especially for I-Tat-CTA CGT AGA CCA CT (labeled Tat-PNA 1). This study provides experimental data to support the potential use of external noninvasive image detection to monitor gene therapy. The extension of the approach to more sensitive methods for whole-body external detection such as positron emission tomography appears feasible.


Asunto(s)
Eritropoyetina/genética , Músculo Esquelético/química , Animales , ADN sin Sentido , Monitoreo de Drogas/métodos , Terapia Genética , Ratones , Ácidos Nucleicos de Péptidos , Proyectos Piloto , ARN Mensajero/análisis
11.
Anal Bioanal Chem ; 388(7): 1531-8, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17534608

RESUMEN

Erythropoietin (EPO) is a hormone that regulates red blood cell production. Recombinant human EPO (rHuEPO) and NESP (novel erythropoiesis stimulating protein) have been produced for therapeutic purposes and also to improve sports performance. The primary sequences of rHuEPO and NESP differ by just five amino acids. Due to the high homology, no antibodies that are able to discriminate between both molecules have been obtained until now. The aim of the present work was to design synthetic peptides corresponding to the sequence that differs between EPO and NESP (87-90aa), that can then be used as immunogens to develop specific rabbit polyclonal antibodies for selectively detecting EPO and NESP. Three peptides were synthesized: EPO (81-95), NESP (81-95), and NESP (86-104), and these were coupled to KLH and OVA for immunization and screening purposes, respectively. The sera obtained were tested by ELISA on synthetic peptide-OVA conjugates and purified by immunoaffinity chromatography against the corresponding synthetic peptide. The specific purified antibodies were characterized by ELISA, SDS-PAGE, and isoelectric focusing, followed by western blot. Antisera raised against EPO (81-95) recognized rHuEPO but not NESP. In contrast, anti-NESP (84-106) sera gave a specific anti-NESP response only after immunoaffinity purification on a NESP (86-91) column. An efficient strategy for generating specific antibodies against EPO and NESP can be achieved by selecting suitable synthetic peptides. The antibodies obtained are able to differentiate between rHuEPO and NESP, and may be particularly useful for screening purposes in both therapeutic and antidoping contexts.


Asunto(s)
Anticuerpos Monoclonales , Eritropoyetina/inmunología , Fragmentos de Péptidos/inmunología , Secuencia de Aminoácidos , Anticuerpos Monoclonales/biosíntesis , Darbepoetina alfa , Epítopos , Eritropoyetina/análogos & derivados , Eritropoyetina/análisis , Humanos , Inmunoensayo , Fragmentos de Péptidos/síntesis química , Proteínas Recombinantes
12.
J Mater Sci Mater Med ; 18(5): 933-41, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17216581

RESUMEN

The biological response to an acrylic bone cement cured with 4,4'-bis-dimethylamino benzydrol (BZN) as activator of reduced cytotoxicity and antiseptic properties, has been carried out and compared with that obtained for CMW 3 cement. Histomorphometrical data (undecalcified trichromic Goldner staining) were obtained by measuring the most significant variables at the bone-cement interface. Quantitative results of tissue response revealed that newly formed bone and connective tissue were maximum at 4 weeks whereas bone marrow increased with time of implantation for both cements. Statistical analysis (p < 0.05) showed no significant differences in newly formed bone and bone marrow with time and between both groups, however, connective tissue significantly decreased between 4 weeks and 12 weeks for BZN cement, and between 12 weeks and 24 weeks for CMW3. By comparing both cements at each time, lower significant percentage of connective tissue at the bone-cement interface of the BZN cement, was obtained at 12 and 24 weeks, however, a very low amount of connective tissue was found for both cements. All the results indicate that the new activated system could be applied clinically in a relatively short time, after the corresponding preclinical study.


Asunto(s)
Antiinfecciosos Locales/química , Antiinfecciosos Locales/farmacología , Cementos para Huesos/química , Cementos para Huesos/farmacología , Animales , Compuestos de Bencidrilo , Médula Ósea/anatomía & histología , Tejido Conectivo/anatomía & histología , Femenino , Fémur/anatomía & histología , Fémur/efectos de los fármacos , Fémur/cirugía , Ensayo de Materiales , Metilmetacrilatos/química , Metilmetacrilatos/farmacología , Polimetil Metacrilato/química , Polimetil Metacrilato/farmacología , Conejos , Factores de Tiempo
13.
Hip Int ; 17(2): 91-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-19197852

RESUMEN

Femoroacetabular regularization in hip impingement is currently performed by means of trochanter osteotomy and hip dislocation or more recently by means of hip arthroscopy. We present a novel alternative through a unique mini-invasive anterior approach. Our first series consisted of 35 hips (32 patients) with a mean follow-up of 29.2 months. Range of motion (ROM) and clinical scores were evaluated preoperatively at six weeks, three months, six months and one-year follow-up (FU). Impingement test was negative in 33 out of 35 cases six weeks after surgery. Mean hospitalisation time was 2.6 days (2-5 days). Mean improvement in internal rotation was 23 degrees (p=0.006) and 21 degrees in flexion (p=0.011). There was a significant improvement in hip score according to the Merle d'Aubign evaluation (13.8 points preoperative vs. 16.9 at one-year visit) (p=0.017). No Trendelenburg, heterotopic calcifications or osteonecrosis were observed. Complications related to the femorocutaneous nerve appeared in six cases (17.1%) although all but one were neuroapraxia and disappeared before one year. Mean rehabilitation time was 4.4 weeks. We conclude that the anterior surgical approach for the treatment of femoroacetabular impingement enables early resumption of sport while accuracy in bone resection is maintained.

16.
Rev. peru. med. exp. salud publica ; 21(2): 71-75, abr.-jun. 2004. tab
Artículo en Español | LILACS, LIPECS, INS-PERU | ID: lil-498590

RESUMEN

Objetivo: Determinar la presencia de L. monocytogenes en quesos frescos de producción artesanal expendidos en los mercados de Ica durante el periodo enero - marzo de 2003. Material y Métodos: De la totalidad de los puestos que expenden queso fresco artesanal en los mercados Santo Domingo, Alejandro Toledo, San Antonio y Modelo, se evaluaron 74 muestras teniendo como unidad muestral 200 g según la Norma Técnica Peruana ISO 28329-1. El procesamiento, aislamiento e identificación se realizó de acuerdo con la metodología recomendada por el manual de bacteriología analítica de la Food and Drug Administration (FDA). Resultados: De las 74 muestras, 3 (4,05 por ciento)presentaban L. monocytogenes, y de ellas, una muestra correspondió al mercado Alejandro Toledo y 2 muestras al mercado Modelo. Se logró aislar 28 cepas de las cuales 6 (21,4 por ciento)correspondieron a L. monocytogenes, y 22 (78,6 por ciento) a otros microorganismos como Lactococcus lactis ss lactis, Enterococcus spp. y Bacillus spp. No se logró aislar L. monocytogenes en los mercados Santo Domingo y San Antonio; sin embargo, en el mercado Alejandro Toledo se aisló una cepa y en el mercado Modelo, se aislaron 5 cepas, lo cual demuestra la presencia significativa de L. monocytogenes sólo en el mercado Modelo. Conclusiones: Existe L. monocytogenes en quesos frescos de producción artesanal, representando un riesgo potencial para la población consumidora.


Objective: To determine the presence of L. monocytogenes in home made non-pasteurized cheese sold in Ica district markets during the period from January to March, 2003. Material and Methods: 74 samples were assessed from all the vendor places in Santo Domingo, Alejandro Toledo, San Antonio, and Modelo markets, and the sampling unit was 200 g, according to the Peruvian technical Specification ISO 28329-1. Processing, isolation, and identification were performed according the methodology recommended by analytical bacteriology manual edited by the US Food and Drug Administration (FDA). Results: Of the 74 samples, 3 (4.05 percent) had L. monocytogenes, one of them from Alejandro Toledo market and the other two were from Modelo market. Overall, 28 bacterial strains were isolated, 6 (21.4 percent) of them were identified as L. monocytogenes, and 22 (78.6 percent) had other microorganisms, such as Lactococcus ss lactis, Enterococcus spp., and Bacillus spp. No L. monocytogenes strains were isolated from Santo Domingo and San Antonio markets; however, in Alejandro Toledo market one strain was found, and in Modelo market 5 strains were isolated, which proves the significant presence of L. monocytogenes only in Modelo market. Conclusions: There is presence of L. monocytogenes in home made non pasteurized cheese, which represents a potential risk for the consumer population.


Asunto(s)
Enfermedades Transmitidas por los Alimentos , Listeriosis , Queso , Epidemiología Descriptiva , Estudios Transversales , Estudios Observacionales como Asunto
17.
Artículo en Inglés | MEDLINE | ID: mdl-14565244

RESUMEN

The synthesis of parallel hairpins carrying 8-aminopurines is described. These hairpins have a high affinity for specific polypyrimidine sequences resulting in the formation of very stable triplexes.


Asunto(s)
Oligodesoxirribonucleótidos/química , Purinas/química , Secuencia de Bases , Modelos Moleculares , Conformación de Ácido Nucleico , Desnaturalización de Ácido Nucleico , Oligodesoxirribonucleótidos/síntesis química , Termodinámica
18.
J Biomed Mater Res B Appl Biomater ; 66(2): 502-13, 2003 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-12861600

RESUMEN

Acrylic bone cements prepared with activators of reduced toxicity have been formulated with the aim of improving the biocompatibility of the final material. The activators used were N,N-dimethylaminobenzyl alcohol (DMOH) and 4,4'-dimethylamino benzydrol (BZN). The toxicity, cytotoxicity, and antiseptic action of these activators were first studied. DMOH and BZN presented LD50 values 3-4 times higher than DMT, were less cytotoxic against polymorphonuclear leucocytes, and possessed an antimicrobial character, with a high activity against the most representative microorganisms involved in postoperative infections. The properties of the acrylic bone cements formulated with DMOH and BZN were evaluated to determine the influence of these activators on the curing process and the physicochemical characteristics of the cements. A decrease of the peak temperature was observed for the curing with DMOH or BZN with respect to that of one commercially available formulation (CMW 3). However, residual monomer content and mechanical properties in tension and compression were comparable to those of CMW 3. The biocompatibility of acrylic bone cements containing DMOH or BZN was studied and compared with CMW 3. To that end, intramuscular and intraosseous implantation procedures were carried out and the results were obtained from the histological analysis of the surrounding tissues at different periods of time. Implantation of rods of cement into the dorsal muscle of rats showed the presence of a membrane of connective tissue, which increased in collagen fibers with time of implantation, for all formulations. The intraosseous implantation of the cements in the dough state in the femur of rabbits, revealed a higher and early osseous neoformation, with the presence of osteoid material surrounding the rest of the cured material, for the cement prepared with the activator BZN in comparison with that obtained following the implantation of the cement cured with DMOH or DMT (CMW 3).


Asunto(s)
Alcoholes/toxicidad , Aminas/toxicidad , Antiinfecciosos Locales/toxicidad , Materiales Biocompatibles/metabolismo , Polimetil Metacrilato/metabolismo , Alcoholes/química , Alcoholes/metabolismo , Aminas/química , Aminas/metabolismo , Animales , Antiinfecciosos Locales/química , Antiinfecciosos Locales/metabolismo , Huesos/citología , Huesos/metabolismo , Femenino , Masculino , Ensayo de Materiales , Ratones , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Prótesis e Implantes , Conejos , Ratas , Ratas Wistar
19.
An Esp Pediatr ; 55(3): 213-8, 2001 Sep.
Artículo en Español | MEDLINE | ID: mdl-11676895

RESUMEN

BACKGROUND: Because of the lack of data from our province, we performed the present study to determine the current situation and future evolution in our region of the most frequent chronic disease in childhood. OBJECTIVE: To evaluate the incidence of diabetes mellitus and the prevalence of type 1A diabetes mellitus in children younger than 16 years old from the province of Ciudad Real. MATERIAL AND METHODS: We performed an epidemiological, cross-sectional, observational study. The mark-release-recapture method was used to calculate exhaustivity. The patients were selected through surveys to primary care centers, hospital registries and diabetics associations in our province. All type 1A diabetics were included in the calculation of prevalence. Only diabetics with onset of symptoms in 1999 were included in the calculation of incidence. RESULTS: The incidence of diabetes mellitus in children younger than 16 years old was 26 per 100,000. Twenty-three children were diagnosed with the disease, with an exhaustivity rate of 88.5 %. The prevalence of type 1A diabetes mellitus in children younger than 16 years old was 2.1 per 1,000 and 0.42 per 1,000 inhabitants. The prevalence in the general population was 0.88 per 1,000 inhabitants. CONCLUSIONS: The incidence of diabetes mellitus in children younger than 16 years old and the prevalence of type 1A diabetes mellitus in the province of Ciudad Real are higher than expected and are the highest of currently known rates in Spain.


Asunto(s)
Diabetes Mellitus Tipo 1/epidemiología , Adolescente , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Masculino , Prevalencia , Estudios Retrospectivos , España/epidemiología
20.
An. esp. pediatr. (Ed. impr) ; 55(3): 213-218, sept. 2001.
Artículo en Es | IBECS | ID: ibc-1871

RESUMEN

Antecedentes: Al carecer de estudios previos en nuestra provincia sobre diabetes mellitus tipo 1A se realizó el presente trabajo para conocer el estado actual en nuestro medio, y valorar en el futuro, la evolución de la enfermedad crónica más frecuente en la infancia. Objetivos: Determinar la prevalencia de la diabetes mellitus tipo 1 (DM1A) y la incidencia en menores de 16 años en la provincia de Ciudad Real. Material y métodos: Se trata de un estudio epidemiológico, observacional de tipo transversal. Se utilizó el método captura-marcaje-recaptura para el cálculo de la exhaustividad. Los pacientes se recogieron mediante encuesta en centros de salud, registros hospitalarios y asociaciones de diabéticos de la provincia. Para el cálculo de la prevalencia se incluyeron todos los diabéticos tipo 1A y para el cálculo de la incidencia se incluyen aquellos diabéticos en los que la enfermedad se inició en 1999. Resultados: La incidencia de diabetes mellitus en menores de 16 años ha sido de 26,0/100.000; se detectaron 23 niños, con una tasa de exhaustividad del 88,5%. La prevalencia de la DM1 en menores de 16 años es de 2,1/1.000 y de 0,42/1.000 habitantes de la provincia. En la población general la prevalencia es de 0,88/1.000 habitantes. Conclusiones: La incidencia de la diabetes mellitus en menores de 16 años y la prevalencia de la DM1A en la provincia de Ciudad Real es mayor de la esperada, siendo la mayor de las conocidas en España en la actualidad (AU)


Asunto(s)
Niño , Preescolar , Adolescente , Masculino , Lactante , Femenino , Humanos , Perfil de Impacto de Enfermedad , Asma , Sensibilidad y Especificidad , España , Incidencia , Prevalencia , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Calidad de Vida , Estudios Retrospectivos , Diabetes Mellitus Tipo 1
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