Sofía Ballesta

Uptake and Intracellular Activity of Moxifloxacin in Human Neutrophils and Tissue-Cultured Epithelial Cells

ABSTRACT The penetration by moxifloxacin of human neutrophils (polymorphonuclear leukocytes [PMN]) and tissue-cultured epithelial cells (McCoy cells) was evaluated by a fluorometric assay. At extracellular concentrations of 5 mg/liter, the cellular-to-extracellular concentration ratios (C/E) of moxifloxacin in PMN and McCoy cells were 10.9 ± 1.0 and 8.7 ± 1.0, respectively (20 min; 37°C). The uptake of moxifloxacin by PMN was rapid, reversible, nonsaturable (at extracellular concentrations ranging from 1 to 50 μg/ml), and not affected by cell viability. The uptake of moxifloxacin was affected by external pH and the environmental temperature. The incubation of PMN in the presence of sodium fluoride, sodium cyanide, and carbonyl cyanidem-chlorophenylhydrazone significantly decreased the C/E of this agent. Neither PMN stimulation nor phagocytosis of opsonizedStaphylococcus aureus significantly affected the uptake of moxifloxacin by human PMN. This agent, at concentrations of 0.5, 1, and 5 mg/liter, induced a significant reduction in the survival of intracellular S. aureus in human PMN. In summary, moxifloxacin reaches much higher intracellular concentrations within phagocytic and nonphagocytic cells than extracellular ones, remaining active inside the neutrophils.

Assessment of periodontal and opportunistic flora in patients with peri-implantitis

AIM To assess the presence of periodontal and opportunistic organisms in patients with peri-implantitis. MATERIAL AND METHODS Thirty-three partially edentulous subjects (22 women, 11 men), aged 32-90 years, who had one or more implants with peri-implantitis were included. Peri-implantitis was defined as: (i) the presence of bleeding on probing and/or suppuration and (ii) radiographic images showed marginal bone loss >1.8 mm after 1 year in function. Criteria for inclusion were: (i) partially edentulous patients having at least one implant diagnosed with peri-implantitis; (ii) no antibiotic therapy for 6 months prior to clinical examination. Following this definition, a total of 48 implants were diagnosed with peri-implantitis. Subgingival bacterial samples were obtained with sterile paper points from infected implants and selected teeth of each individual. Periodontopathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola) were detected by multiplex PCR targeting 16S rDNA. Samples were placed in reduced transport medium and cultured for opportunistic pathogens (Staphylococcus aureus, enteric bacteria, Pseudomonas and yeasts). RESULTS Twenty-two patients yielded positive results for P. gingivalis, 25 for T. forsythia, eight for P. intermedia and 13 for T. denticola. None of the patients yielded a positive result for A. actinomycetemcomitans. Non-periodontal species were found in five patients (15% of total). P. aeruginosa was found in four (12%) patients, and C. albicans (3%) and S. aureus in one patient (3%) each. In two cases of peri-implantitis, none of the periodontal or opportunistic microorganisms studied were detected in either implant or tooth samples. When results of the periodontopathic bacteria from the implant and tooth samples of the same patient were compared, 18 patients (54%) showed the same results for both samples and 15 (45%) patients different results. CONCLUSIONS The implant surface may be colonized with pathogens different from periodontal bacteria. Opportunistic pathogens such as P. aeruginosa, S. aureus and C. albicans may be associated with implant failure.

Postorthodontic External Root Resorption in Root-filled Teeth Is Influenced by Interleukin-1β Polymorphism

INTRODUCTION External apical root resorption (EARR) is a frequent iatrogenic effect of orthodontic treatment. The way root-filled teeth respond to orthodontic forces with respect to EARR has been reported as varying widely between individuals. Genetic variants in the interleukin-1 gene have been associated with an increased risk of experiencing postorthodontic EARR on vital teeth. The objective of this study is to determine whether variants in the interleukin-1 gene have a positive or negative influence on EARR on teeth that have been endodontically treated. METHODS Ninety-three orthodontic patients underwent genetic screening for 2 single nucleotide polymorphisms (rs1800587, rs1143634) in the IL1 gene cluster. Subjects were divided into 2 groups depending on the presence (affected group) or absence (control group) of more than 2 mm of EARR on root-filled teeth after orthodontic treatment as shown by radiography. Logistic regression analysis was used to obtain adjusted estimates of EARR and IL1 polymorphisms. Allele frequencies, genotype distributions, and adjusted odds ratios were also calculated (95% confidence interval). RESULTS No positive or negative statistical association was found between postorthodontic treatment EARR in root-filled teeth and genetic variations in IL1A (P > .05). A direct relationship was found for the IL1B gene in the comparative analysis of homozygous subjects (2/2[TT]) and (1/1[CC]), which led to an increased risk of experiencing postorthodontic treatment EARR in root-filled teeth (odds ratio = 11.59; P = .006; confidence interval, 95%) and (odds ratio = 2.54; P = .035; confidence interval, 95%), respectively. CONCLUSIONS The development of EARR in subjects with root-filled teeth who undergo orthodontic treatment might be attributable to genetic variations in the interleukin-1β gene (rs1143634).

Uptake and intracellular activity of ofloxacin isomers in human phagocytic and non-phagocytic cells

The penetration and intracellular activity of ofloxacin and its isomers (levofloxacin and D-ofloxacin) into human polymorphonuclear leucocytes (PMN), human peritoneal macrophages (PMphi) and tissue cultured epithelial cells (McCoy) were evaluated. The cellular to extracellular concentration (C/E) values of the three fluoroquinolones were higher than 3.6 and 2.6 in PMN and PMphi, respectively. The C/E ratios in McCoy cells were lower than those in PMN, but still higher than 2.0. The uptake of ofloxacin and its isomers was rapid, non-saturable and reversible. All quinolones (extracellular concentrations: 2, 5 and 10 mg/l) produced a significant reduction of viable intraphagocytic Staphylococcus aureus in phagocytic cells. We concluded that ofloxacin and its isomers reach high intracellular concentrations in phagocytic and non phagocytic cells while remaining active in the former.

Uptake and Intracellular Activity of Linezolid in Human Phagocytes and Nonphagocytic Cells

ABSTRACT The intracellular penetration and activity of linezolid in human polymorphonuclear leukocytes and tissue-cultured cells (McCoy) were evaluated. Linezolid reached intracellular concentrations slightly greater than extracellular ones in both types of cell. The uptake was rapid and not saturable and was affected by environmental temperature and cell viability. Linezolid showed slight intracellular activity against Staphylococcus epidermidis at high extracellular concentrations.

Intracellular penetration and activity of DX-619 in human polymorphonuclear leukocytes

ABSTRACT The intracellular penetration and activity of DX-619 in human polymorphonuclear leukocytes have been evaluated. DX-619 reached intracellular concentrations 10 times higher than the extracellular concentrations reached. Uptake was rapid, reversible, nonsaturable, and affected by environmental temperature, some metabolic inhibitors, and a soluble membrane activator. DX-619 showed intracellular activity against Staphylococcus aureus.

Interleukin 1 gene cluster SNPs (rs1800587, rs1143634) influences post‐orthodontic root resorption in endodontic and their contralateral vital control teeth differently

AIM To investigate whether the genetic variants of the interleukin-1 gene cluster (IL1) are associated with a possible genetically induced variability in post-orthodontic external apical root resorption (EARR) in root filled teeth and their control counterparts with vital pulps. METHODOLOGY One hundred and forty-six maxillary premolars were evaluated radiographically following orthodontic treatment. Genetic screening was performed on orthodontic patients for two single-nucleotide polymorphisms (SNPs: rs1800587 and rs1143634) in the IL1 gene cluster. Subjects were divided into two groups according to the presence or absence of radiographic post-orthodontic EARR (>2 mm) in root filled teeth and their controls with vital pulps. Logistic regression analysis was performed to obtain an adjusted estimation between EARR and IL1 polymorphisms. Allelic frequencies, genotype distributions, and adjusted odds ratio (OR), at 95% confidence interval, were also calculated. RESULTS Whilst no clear statistical association was found for gene variations in IL1A, a sound association was found in the comparative analysis of subjects homozygous [2/2(TT)] for the IL1B gene, which resulted in a two times increased risk of suffering post-orthodontic EARR in root filled teeth [OR, 2.032 (P = 0.031); CI,1.99-14.77] when compared with their controls with vital pulps. There was, however, a shared predisposition to EARR in controls with vital pulps and root filled teeth of subjects homozygous for allele 1 [OR, 5.05 (P = 0.002)] and [OR, 2.77 (P = 0.037)], respectively. CONCLUSIONS Genetic variations in the interleukin-1β gene (rs1143634) predispose root filled teeth to EARR for matched pairs secondary to orthodontic treatment in a different way from their control teeth with vital pulps in subjects homozygous for allele 2 [2/2(TT)].

Actividad y permeabilidad de linezolid y vancomicina en biocapas de Staphylococcus epidermidis

Introduccion Se ha evaluado la actividad y capacidad de penetracion de linezolid y vancomicina en biocapas de Staphylococcus epidermidis. Metodos La actividad de linezolid en comparacion con vancomicina se midio frente a biocapas bacterianas de S. epidermidis formadas sobre segmentos de silicona. La penetracion de estos antimicrobianos se midio en las biocapas formadas sobre membranas microporosas de policarbonato. Ambos ensayos se realizaron comparativamente con una cepa de S. epidermidis productora de slime y otra no productora. Resultados La actividad de linezolid frente a biocapas de S. epidermidis fue significativamente mayor que la de vancomicina tanto en la cepa productora de slime como en la no productora. Ninguno de los antimicrobianos erradico las biocapas de 24 h. La penetracion de linezolid en biocapas de S. epidermidis fue mayor que la de vancomicina en todos los tiempos estudiados para ambas cepas. Conclusiones Linezolid ha mostrado mayor actividad in vitro que vancomicina en biocapas de S. epidermidis formadas sobre cateteres de silicona y este efecto podria ser debido a su capacidad para atravesar la biocapa bacteriana.

Intracellular penetration and activity of gemifloxacin in human polymorphonuclear leukocytes.

ABSTRACT The intracellular penetration and activity of gemifloxacin in human polymorphonuclear leukocytes (PMN) were evaluated. Gemifloxacin reached intracellular concentrations eight times higher than extracellular concentrations. The uptake was rapid, reversible, and nonsaturable and was affected by environmental temperature, cell viability, and membrane stimuli. At therapeutic extracellular concentrations, gemifloxacin showed intracellular activity against Staphylococcus aureus.

Yogures frescos frente a pasteurizados: estudio comparativo de sus efectos sobre los parámetros microbiológicos, inmunológicos y el bienestar gastrointestinal

Objetivo Determinar si los efectos beneficiosos del yogur dependen de la viabilidad de las bacterias lacticas y son exclusivos de los yogures frescos, en comparacion con los obtenidos de los yogures pasteurizados tras la fermentacion. Material y metodo Mediante un ensayo enmascarado en una poblacion adulta sana y durante 75 dias, comparamos los efectos de la ingestion de yogures frescos y pasteurizados sobre los parametros microbiologicos (presencia de bacterias vivas del yogur y deteccion de AND en heces) e inmunologicos (mediante nefelometria, hematimetria y citometria de flujo). Con un cuestionario se evaluo el bienestar gastrointestinal y se utilizo una prueba de aliento para medir las diferencias en un ensayo de sobrecarga de lactosa tras el consumo de yogures. Resultados No hubo diferencias significativas entre los resultados obtenidos para los parametros inmunologicos, bienestar gastrointestinal y sobrecarga de lactosa de los voluntarios tras el consumo de yogures, con independencia del tipo de yogur ingerido. Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) solo se aislo en el 0,7% de las muestras de heces analizadas. Streptococcus thermophilus no se aislo en ninguna de las muestras. EL ADN de las bacterias lacticas del yogur solo fue detectado en el 12,5% de las muestras analizadas. Conclusion El transito gastrico afecto a la supervivencia de L. bulgaricus y S. thermophylus. No se encontraron diferencias respecto a los efectos que la ingestion de yogures frescos o pasteurizados pudieran tener sobre los parametros inmunologicos, los valores de las pruebas de sobrecarga de lactosa, ni sobre el bienestar gastrointestinal.